xref: /openbmc/linux/drivers/ata/libata-core.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  *  libata-core.c - helper library for ATA
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
9  *  Copyright 2003-2004 Jeff Garzik
10  *
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2, or (at your option)
15  *  any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; see the file COPYING.  If not, write to
24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/pci.h>
38 #include <linux/init.h>
39 #include <linux/list.h>
40 #include <linux/mm.h>
41 #include <linux/highmem.h>
42 #include <linux/spinlock.h>
43 #include <linux/blkdev.h>
44 #include <linux/delay.h>
45 #include <linux/timer.h>
46 #include <linux/interrupt.h>
47 #include <linux/completion.h>
48 #include <linux/suspend.h>
49 #include <linux/workqueue.h>
50 #include <linux/jiffies.h>
51 #include <linux/scatterlist.h>
52 #include <scsi/scsi.h>
53 #include <scsi/scsi_cmnd.h>
54 #include <scsi/scsi_host.h>
55 #include <linux/libata.h>
56 #include <asm/io.h>
57 #include <asm/semaphore.h>
58 #include <asm/byteorder.h>
59 
60 #include "libata.h"
61 
62 
63 /* debounce timing parameters in msecs { interval, duration, timeout } */
64 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
65 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
66 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
67 
68 static unsigned int ata_dev_init_params(struct ata_device *dev,
69 					u16 heads, u16 sectors);
70 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
71 static unsigned int ata_dev_set_AN(struct ata_device *dev, u8 enable);
72 static void ata_dev_xfermask(struct ata_device *dev);
73 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
74 
75 unsigned int ata_print_id = 1;
76 static struct workqueue_struct *ata_wq;
77 
78 struct workqueue_struct *ata_aux_wq;
79 
80 int atapi_enabled = 1;
81 module_param(atapi_enabled, int, 0444);
82 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
83 
84 int atapi_dmadir = 0;
85 module_param(atapi_dmadir, int, 0444);
86 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
87 
88 int atapi_passthru16 = 1;
89 module_param(atapi_passthru16, int, 0444);
90 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices; on by default (0=off, 1=on)");
91 
92 int libata_fua = 0;
93 module_param_named(fua, libata_fua, int, 0444);
94 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
95 
96 static int ata_ignore_hpa = 0;
97 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
98 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
99 
100 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
101 module_param_named(dma, libata_dma_mask, int, 0444);
102 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
103 
104 static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
105 module_param(ata_probe_timeout, int, 0444);
106 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
107 
108 int libata_noacpi = 0;
109 module_param_named(noacpi, libata_noacpi, int, 0444);
110 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
111 
112 MODULE_AUTHOR("Jeff Garzik");
113 MODULE_DESCRIPTION("Library module for ATA devices");
114 MODULE_LICENSE("GPL");
115 MODULE_VERSION(DRV_VERSION);
116 
117 
118 /**
119  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
120  *	@tf: Taskfile to convert
121  *	@pmp: Port multiplier port
122  *	@is_cmd: This FIS is for command
123  *	@fis: Buffer into which data will output
124  *
125  *	Converts a standard ATA taskfile to a Serial ATA
126  *	FIS structure (Register - Host to Device).
127  *
128  *	LOCKING:
129  *	Inherited from caller.
130  */
131 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
132 {
133 	fis[0] = 0x27;			/* Register - Host to Device FIS */
134 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
135 	if (is_cmd)
136 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
137 
138 	fis[2] = tf->command;
139 	fis[3] = tf->feature;
140 
141 	fis[4] = tf->lbal;
142 	fis[5] = tf->lbam;
143 	fis[6] = tf->lbah;
144 	fis[7] = tf->device;
145 
146 	fis[8] = tf->hob_lbal;
147 	fis[9] = tf->hob_lbam;
148 	fis[10] = tf->hob_lbah;
149 	fis[11] = tf->hob_feature;
150 
151 	fis[12] = tf->nsect;
152 	fis[13] = tf->hob_nsect;
153 	fis[14] = 0;
154 	fis[15] = tf->ctl;
155 
156 	fis[16] = 0;
157 	fis[17] = 0;
158 	fis[18] = 0;
159 	fis[19] = 0;
160 }
161 
162 /**
163  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
164  *	@fis: Buffer from which data will be input
165  *	@tf: Taskfile to output
166  *
167  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
168  *
169  *	LOCKING:
170  *	Inherited from caller.
171  */
172 
173 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
174 {
175 	tf->command	= fis[2];	/* status */
176 	tf->feature	= fis[3];	/* error */
177 
178 	tf->lbal	= fis[4];
179 	tf->lbam	= fis[5];
180 	tf->lbah	= fis[6];
181 	tf->device	= fis[7];
182 
183 	tf->hob_lbal	= fis[8];
184 	tf->hob_lbam	= fis[9];
185 	tf->hob_lbah	= fis[10];
186 
187 	tf->nsect	= fis[12];
188 	tf->hob_nsect	= fis[13];
189 }
190 
191 static const u8 ata_rw_cmds[] = {
192 	/* pio multi */
193 	ATA_CMD_READ_MULTI,
194 	ATA_CMD_WRITE_MULTI,
195 	ATA_CMD_READ_MULTI_EXT,
196 	ATA_CMD_WRITE_MULTI_EXT,
197 	0,
198 	0,
199 	0,
200 	ATA_CMD_WRITE_MULTI_FUA_EXT,
201 	/* pio */
202 	ATA_CMD_PIO_READ,
203 	ATA_CMD_PIO_WRITE,
204 	ATA_CMD_PIO_READ_EXT,
205 	ATA_CMD_PIO_WRITE_EXT,
206 	0,
207 	0,
208 	0,
209 	0,
210 	/* dma */
211 	ATA_CMD_READ,
212 	ATA_CMD_WRITE,
213 	ATA_CMD_READ_EXT,
214 	ATA_CMD_WRITE_EXT,
215 	0,
216 	0,
217 	0,
218 	ATA_CMD_WRITE_FUA_EXT
219 };
220 
221 /**
222  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
223  *	@tf: command to examine and configure
224  *	@dev: device tf belongs to
225  *
226  *	Examine the device configuration and tf->flags to calculate
227  *	the proper read/write commands and protocol to use.
228  *
229  *	LOCKING:
230  *	caller.
231  */
232 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
233 {
234 	u8 cmd;
235 
236 	int index, fua, lba48, write;
237 
238 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
239 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
240 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
241 
242 	if (dev->flags & ATA_DFLAG_PIO) {
243 		tf->protocol = ATA_PROT_PIO;
244 		index = dev->multi_count ? 0 : 8;
245 	} else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
246 		/* Unable to use DMA due to host limitation */
247 		tf->protocol = ATA_PROT_PIO;
248 		index = dev->multi_count ? 0 : 8;
249 	} else {
250 		tf->protocol = ATA_PROT_DMA;
251 		index = 16;
252 	}
253 
254 	cmd = ata_rw_cmds[index + fua + lba48 + write];
255 	if (cmd) {
256 		tf->command = cmd;
257 		return 0;
258 	}
259 	return -1;
260 }
261 
262 /**
263  *	ata_tf_read_block - Read block address from ATA taskfile
264  *	@tf: ATA taskfile of interest
265  *	@dev: ATA device @tf belongs to
266  *
267  *	LOCKING:
268  *	None.
269  *
270  *	Read block address from @tf.  This function can handle all
271  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
272  *	flags select the address format to use.
273  *
274  *	RETURNS:
275  *	Block address read from @tf.
276  */
277 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
278 {
279 	u64 block = 0;
280 
281 	if (tf->flags & ATA_TFLAG_LBA) {
282 		if (tf->flags & ATA_TFLAG_LBA48) {
283 			block |= (u64)tf->hob_lbah << 40;
284 			block |= (u64)tf->hob_lbam << 32;
285 			block |= tf->hob_lbal << 24;
286 		} else
287 			block |= (tf->device & 0xf) << 24;
288 
289 		block |= tf->lbah << 16;
290 		block |= tf->lbam << 8;
291 		block |= tf->lbal;
292 	} else {
293 		u32 cyl, head, sect;
294 
295 		cyl = tf->lbam | (tf->lbah << 8);
296 		head = tf->device & 0xf;
297 		sect = tf->lbal;
298 
299 		block = (cyl * dev->heads + head) * dev->sectors + sect;
300 	}
301 
302 	return block;
303 }
304 
305 /**
306  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
307  *	@tf: Target ATA taskfile
308  *	@dev: ATA device @tf belongs to
309  *	@block: Block address
310  *	@n_block: Number of blocks
311  *	@tf_flags: RW/FUA etc...
312  *	@tag: tag
313  *
314  *	LOCKING:
315  *	None.
316  *
317  *	Build ATA taskfile @tf for read/write request described by
318  *	@block, @n_block, @tf_flags and @tag on @dev.
319  *
320  *	RETURNS:
321  *
322  *	0 on success, -ERANGE if the request is too large for @dev,
323  *	-EINVAL if the request is invalid.
324  */
325 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
326 		    u64 block, u32 n_block, unsigned int tf_flags,
327 		    unsigned int tag)
328 {
329 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
330 	tf->flags |= tf_flags;
331 
332 	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
333 		/* yay, NCQ */
334 		if (!lba_48_ok(block, n_block))
335 			return -ERANGE;
336 
337 		tf->protocol = ATA_PROT_NCQ;
338 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
339 
340 		if (tf->flags & ATA_TFLAG_WRITE)
341 			tf->command = ATA_CMD_FPDMA_WRITE;
342 		else
343 			tf->command = ATA_CMD_FPDMA_READ;
344 
345 		tf->nsect = tag << 3;
346 		tf->hob_feature = (n_block >> 8) & 0xff;
347 		tf->feature = n_block & 0xff;
348 
349 		tf->hob_lbah = (block >> 40) & 0xff;
350 		tf->hob_lbam = (block >> 32) & 0xff;
351 		tf->hob_lbal = (block >> 24) & 0xff;
352 		tf->lbah = (block >> 16) & 0xff;
353 		tf->lbam = (block >> 8) & 0xff;
354 		tf->lbal = block & 0xff;
355 
356 		tf->device = 1 << 6;
357 		if (tf->flags & ATA_TFLAG_FUA)
358 			tf->device |= 1 << 7;
359 	} else if (dev->flags & ATA_DFLAG_LBA) {
360 		tf->flags |= ATA_TFLAG_LBA;
361 
362 		if (lba_28_ok(block, n_block)) {
363 			/* use LBA28 */
364 			tf->device |= (block >> 24) & 0xf;
365 		} else if (lba_48_ok(block, n_block)) {
366 			if (!(dev->flags & ATA_DFLAG_LBA48))
367 				return -ERANGE;
368 
369 			/* use LBA48 */
370 			tf->flags |= ATA_TFLAG_LBA48;
371 
372 			tf->hob_nsect = (n_block >> 8) & 0xff;
373 
374 			tf->hob_lbah = (block >> 40) & 0xff;
375 			tf->hob_lbam = (block >> 32) & 0xff;
376 			tf->hob_lbal = (block >> 24) & 0xff;
377 		} else
378 			/* request too large even for LBA48 */
379 			return -ERANGE;
380 
381 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
382 			return -EINVAL;
383 
384 		tf->nsect = n_block & 0xff;
385 
386 		tf->lbah = (block >> 16) & 0xff;
387 		tf->lbam = (block >> 8) & 0xff;
388 		tf->lbal = block & 0xff;
389 
390 		tf->device |= ATA_LBA;
391 	} else {
392 		/* CHS */
393 		u32 sect, head, cyl, track;
394 
395 		/* The request -may- be too large for CHS addressing. */
396 		if (!lba_28_ok(block, n_block))
397 			return -ERANGE;
398 
399 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
400 			return -EINVAL;
401 
402 		/* Convert LBA to CHS */
403 		track = (u32)block / dev->sectors;
404 		cyl   = track / dev->heads;
405 		head  = track % dev->heads;
406 		sect  = (u32)block % dev->sectors + 1;
407 
408 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
409 			(u32)block, track, cyl, head, sect);
410 
411 		/* Check whether the converted CHS can fit.
412 		   Cylinder: 0-65535
413 		   Head: 0-15
414 		   Sector: 1-255*/
415 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
416 			return -ERANGE;
417 
418 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
419 		tf->lbal = sect;
420 		tf->lbam = cyl;
421 		tf->lbah = cyl >> 8;
422 		tf->device |= head;
423 	}
424 
425 	return 0;
426 }
427 
428 /**
429  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
430  *	@pio_mask: pio_mask
431  *	@mwdma_mask: mwdma_mask
432  *	@udma_mask: udma_mask
433  *
434  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
435  *	unsigned int xfer_mask.
436  *
437  *	LOCKING:
438  *	None.
439  *
440  *	RETURNS:
441  *	Packed xfer_mask.
442  */
443 static unsigned int ata_pack_xfermask(unsigned int pio_mask,
444 				      unsigned int mwdma_mask,
445 				      unsigned int udma_mask)
446 {
447 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
448 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
449 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
450 }
451 
452 /**
453  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
454  *	@xfer_mask: xfer_mask to unpack
455  *	@pio_mask: resulting pio_mask
456  *	@mwdma_mask: resulting mwdma_mask
457  *	@udma_mask: resulting udma_mask
458  *
459  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
460  *	Any NULL distination masks will be ignored.
461  */
462 static void ata_unpack_xfermask(unsigned int xfer_mask,
463 				unsigned int *pio_mask,
464 				unsigned int *mwdma_mask,
465 				unsigned int *udma_mask)
466 {
467 	if (pio_mask)
468 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
469 	if (mwdma_mask)
470 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
471 	if (udma_mask)
472 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
473 }
474 
475 static const struct ata_xfer_ent {
476 	int shift, bits;
477 	u8 base;
478 } ata_xfer_tbl[] = {
479 	{ ATA_SHIFT_PIO, ATA_BITS_PIO, XFER_PIO_0 },
480 	{ ATA_SHIFT_MWDMA, ATA_BITS_MWDMA, XFER_MW_DMA_0 },
481 	{ ATA_SHIFT_UDMA, ATA_BITS_UDMA, XFER_UDMA_0 },
482 	{ -1, },
483 };
484 
485 /**
486  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
487  *	@xfer_mask: xfer_mask of interest
488  *
489  *	Return matching XFER_* value for @xfer_mask.  Only the highest
490  *	bit of @xfer_mask is considered.
491  *
492  *	LOCKING:
493  *	None.
494  *
495  *	RETURNS:
496  *	Matching XFER_* value, 0 if no match found.
497  */
498 static u8 ata_xfer_mask2mode(unsigned int xfer_mask)
499 {
500 	int highbit = fls(xfer_mask) - 1;
501 	const struct ata_xfer_ent *ent;
502 
503 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
504 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
505 			return ent->base + highbit - ent->shift;
506 	return 0;
507 }
508 
509 /**
510  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
511  *	@xfer_mode: XFER_* of interest
512  *
513  *	Return matching xfer_mask for @xfer_mode.
514  *
515  *	LOCKING:
516  *	None.
517  *
518  *	RETURNS:
519  *	Matching xfer_mask, 0 if no match found.
520  */
521 static unsigned int ata_xfer_mode2mask(u8 xfer_mode)
522 {
523 	const struct ata_xfer_ent *ent;
524 
525 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
526 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
527 			return 1 << (ent->shift + xfer_mode - ent->base);
528 	return 0;
529 }
530 
531 /**
532  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
533  *	@xfer_mode: XFER_* of interest
534  *
535  *	Return matching xfer_shift for @xfer_mode.
536  *
537  *	LOCKING:
538  *	None.
539  *
540  *	RETURNS:
541  *	Matching xfer_shift, -1 if no match found.
542  */
543 static int ata_xfer_mode2shift(unsigned int xfer_mode)
544 {
545 	const struct ata_xfer_ent *ent;
546 
547 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
548 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
549 			return ent->shift;
550 	return -1;
551 }
552 
553 /**
554  *	ata_mode_string - convert xfer_mask to string
555  *	@xfer_mask: mask of bits supported; only highest bit counts.
556  *
557  *	Determine string which represents the highest speed
558  *	(highest bit in @modemask).
559  *
560  *	LOCKING:
561  *	None.
562  *
563  *	RETURNS:
564  *	Constant C string representing highest speed listed in
565  *	@mode_mask, or the constant C string "<n/a>".
566  */
567 static const char *ata_mode_string(unsigned int xfer_mask)
568 {
569 	static const char * const xfer_mode_str[] = {
570 		"PIO0",
571 		"PIO1",
572 		"PIO2",
573 		"PIO3",
574 		"PIO4",
575 		"PIO5",
576 		"PIO6",
577 		"MWDMA0",
578 		"MWDMA1",
579 		"MWDMA2",
580 		"MWDMA3",
581 		"MWDMA4",
582 		"UDMA/16",
583 		"UDMA/25",
584 		"UDMA/33",
585 		"UDMA/44",
586 		"UDMA/66",
587 		"UDMA/100",
588 		"UDMA/133",
589 		"UDMA7",
590 	};
591 	int highbit;
592 
593 	highbit = fls(xfer_mask) - 1;
594 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
595 		return xfer_mode_str[highbit];
596 	return "<n/a>";
597 }
598 
599 static const char *sata_spd_string(unsigned int spd)
600 {
601 	static const char * const spd_str[] = {
602 		"1.5 Gbps",
603 		"3.0 Gbps",
604 	};
605 
606 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
607 		return "<unknown>";
608 	return spd_str[spd - 1];
609 }
610 
611 void ata_dev_disable(struct ata_device *dev)
612 {
613 	if (ata_dev_enabled(dev)) {
614 		if (ata_msg_drv(dev->link->ap))
615 			ata_dev_printk(dev, KERN_WARNING, "disabled\n");
616 		ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
617 					     ATA_DNXFER_QUIET);
618 		dev->class++;
619 	}
620 }
621 
622 /**
623  *	ata_devchk - PATA device presence detection
624  *	@ap: ATA channel to examine
625  *	@device: Device to examine (starting at zero)
626  *
627  *	This technique was originally described in
628  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
629  *	later found its way into the ATA/ATAPI spec.
630  *
631  *	Write a pattern to the ATA shadow registers,
632  *	and if a device is present, it will respond by
633  *	correctly storing and echoing back the
634  *	ATA shadow register contents.
635  *
636  *	LOCKING:
637  *	caller.
638  */
639 
640 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
641 {
642 	struct ata_ioports *ioaddr = &ap->ioaddr;
643 	u8 nsect, lbal;
644 
645 	ap->ops->dev_select(ap, device);
646 
647 	iowrite8(0x55, ioaddr->nsect_addr);
648 	iowrite8(0xaa, ioaddr->lbal_addr);
649 
650 	iowrite8(0xaa, ioaddr->nsect_addr);
651 	iowrite8(0x55, ioaddr->lbal_addr);
652 
653 	iowrite8(0x55, ioaddr->nsect_addr);
654 	iowrite8(0xaa, ioaddr->lbal_addr);
655 
656 	nsect = ioread8(ioaddr->nsect_addr);
657 	lbal = ioread8(ioaddr->lbal_addr);
658 
659 	if ((nsect == 0x55) && (lbal == 0xaa))
660 		return 1;	/* we found a device */
661 
662 	return 0;		/* nothing found */
663 }
664 
665 /**
666  *	ata_dev_classify - determine device type based on ATA-spec signature
667  *	@tf: ATA taskfile register set for device to be identified
668  *
669  *	Determine from taskfile register contents whether a device is
670  *	ATA or ATAPI, as per "Signature and persistence" section
671  *	of ATA/PI spec (volume 1, sect 5.14).
672  *
673  *	LOCKING:
674  *	None.
675  *
676  *	RETURNS:
677  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP or
678  *	%ATA_DEV_UNKNOWN the event of failure.
679  */
680 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
681 {
682 	/* Apple's open source Darwin code hints that some devices only
683 	 * put a proper signature into the LBA mid/high registers,
684 	 * So, we only check those.  It's sufficient for uniqueness.
685 	 *
686 	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
687 	 * signatures for ATA and ATAPI devices attached on SerialATA,
688 	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
689 	 * spec has never mentioned about using different signatures
690 	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
691 	 * Multiplier specification began to use 0x69/0x96 to identify
692 	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
693 	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
694 	 * 0x69/0x96 shortly and described them as reserved for
695 	 * SerialATA.
696 	 *
697 	 * We follow the current spec and consider that 0x69/0x96
698 	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
699 	 */
700 	if ((tf->lbam == 0) && (tf->lbah == 0)) {
701 		DPRINTK("found ATA device by sig\n");
702 		return ATA_DEV_ATA;
703 	}
704 
705 	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
706 		DPRINTK("found ATAPI device by sig\n");
707 		return ATA_DEV_ATAPI;
708 	}
709 
710 	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
711 		DPRINTK("found PMP device by sig\n");
712 		return ATA_DEV_PMP;
713 	}
714 
715 	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
716 		printk("ata: SEMB device ignored\n");
717 		return ATA_DEV_SEMB_UNSUP; /* not yet */
718 	}
719 
720 	DPRINTK("unknown device\n");
721 	return ATA_DEV_UNKNOWN;
722 }
723 
724 /**
725  *	ata_dev_try_classify - Parse returned ATA device signature
726  *	@dev: ATA device to classify (starting at zero)
727  *	@present: device seems present
728  *	@r_err: Value of error register on completion
729  *
730  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
731  *	an ATA/ATAPI-defined set of values is placed in the ATA
732  *	shadow registers, indicating the results of device detection
733  *	and diagnostics.
734  *
735  *	Select the ATA device, and read the values from the ATA shadow
736  *	registers.  Then parse according to the Error register value,
737  *	and the spec-defined values examined by ata_dev_classify().
738  *
739  *	LOCKING:
740  *	caller.
741  *
742  *	RETURNS:
743  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
744  */
745 unsigned int ata_dev_try_classify(struct ata_device *dev, int present,
746 				  u8 *r_err)
747 {
748 	struct ata_port *ap = dev->link->ap;
749 	struct ata_taskfile tf;
750 	unsigned int class;
751 	u8 err;
752 
753 	ap->ops->dev_select(ap, dev->devno);
754 
755 	memset(&tf, 0, sizeof(tf));
756 
757 	ap->ops->tf_read(ap, &tf);
758 	err = tf.feature;
759 	if (r_err)
760 		*r_err = err;
761 
762 	/* see if device passed diags: if master then continue and warn later */
763 	if (err == 0 && dev->devno == 0)
764 		/* diagnostic fail : do nothing _YET_ */
765 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
766 	else if (err == 1)
767 		/* do nothing */ ;
768 	else if ((dev->devno == 0) && (err == 0x81))
769 		/* do nothing */ ;
770 	else
771 		return ATA_DEV_NONE;
772 
773 	/* determine if device is ATA or ATAPI */
774 	class = ata_dev_classify(&tf);
775 
776 	if (class == ATA_DEV_UNKNOWN) {
777 		/* If the device failed diagnostic, it's likely to
778 		 * have reported incorrect device signature too.
779 		 * Assume ATA device if the device seems present but
780 		 * device signature is invalid with diagnostic
781 		 * failure.
782 		 */
783 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
784 			class = ATA_DEV_ATA;
785 		else
786 			class = ATA_DEV_NONE;
787 	} else if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
788 		class = ATA_DEV_NONE;
789 
790 	return class;
791 }
792 
793 /**
794  *	ata_id_string - Convert IDENTIFY DEVICE page into string
795  *	@id: IDENTIFY DEVICE results we will examine
796  *	@s: string into which data is output
797  *	@ofs: offset into identify device page
798  *	@len: length of string to return. must be an even number.
799  *
800  *	The strings in the IDENTIFY DEVICE page are broken up into
801  *	16-bit chunks.  Run through the string, and output each
802  *	8-bit chunk linearly, regardless of platform.
803  *
804  *	LOCKING:
805  *	caller.
806  */
807 
808 void ata_id_string(const u16 *id, unsigned char *s,
809 		   unsigned int ofs, unsigned int len)
810 {
811 	unsigned int c;
812 
813 	while (len > 0) {
814 		c = id[ofs] >> 8;
815 		*s = c;
816 		s++;
817 
818 		c = id[ofs] & 0xff;
819 		*s = c;
820 		s++;
821 
822 		ofs++;
823 		len -= 2;
824 	}
825 }
826 
827 /**
828  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
829  *	@id: IDENTIFY DEVICE results we will examine
830  *	@s: string into which data is output
831  *	@ofs: offset into identify device page
832  *	@len: length of string to return. must be an odd number.
833  *
834  *	This function is identical to ata_id_string except that it
835  *	trims trailing spaces and terminates the resulting string with
836  *	null.  @len must be actual maximum length (even number) + 1.
837  *
838  *	LOCKING:
839  *	caller.
840  */
841 void ata_id_c_string(const u16 *id, unsigned char *s,
842 		     unsigned int ofs, unsigned int len)
843 {
844 	unsigned char *p;
845 
846 	WARN_ON(!(len & 1));
847 
848 	ata_id_string(id, s, ofs, len - 1);
849 
850 	p = s + strnlen(s, len - 1);
851 	while (p > s && p[-1] == ' ')
852 		p--;
853 	*p = '\0';
854 }
855 
856 static u64 ata_id_n_sectors(const u16 *id)
857 {
858 	if (ata_id_has_lba(id)) {
859 		if (ata_id_has_lba48(id))
860 			return ata_id_u64(id, 100);
861 		else
862 			return ata_id_u32(id, 60);
863 	} else {
864 		if (ata_id_current_chs_valid(id))
865 			return ata_id_u32(id, 57);
866 		else
867 			return id[1] * id[3] * id[6];
868 	}
869 }
870 
871 static u64 ata_tf_to_lba48(struct ata_taskfile *tf)
872 {
873 	u64 sectors = 0;
874 
875 	sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
876 	sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
877 	sectors |= (tf->hob_lbal & 0xff) << 24;
878 	sectors |= (tf->lbah & 0xff) << 16;
879 	sectors |= (tf->lbam & 0xff) << 8;
880 	sectors |= (tf->lbal & 0xff);
881 
882 	return ++sectors;
883 }
884 
885 static u64 ata_tf_to_lba(struct ata_taskfile *tf)
886 {
887 	u64 sectors = 0;
888 
889 	sectors |= (tf->device & 0x0f) << 24;
890 	sectors |= (tf->lbah & 0xff) << 16;
891 	sectors |= (tf->lbam & 0xff) << 8;
892 	sectors |= (tf->lbal & 0xff);
893 
894 	return ++sectors;
895 }
896 
897 /**
898  *	ata_read_native_max_address - Read native max address
899  *	@dev: target device
900  *	@max_sectors: out parameter for the result native max address
901  *
902  *	Perform an LBA48 or LBA28 native size query upon the device in
903  *	question.
904  *
905  *	RETURNS:
906  *	0 on success, -EACCES if command is aborted by the drive.
907  *	-EIO on other errors.
908  */
909 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
910 {
911 	unsigned int err_mask;
912 	struct ata_taskfile tf;
913 	int lba48 = ata_id_has_lba48(dev->id);
914 
915 	ata_tf_init(dev, &tf);
916 
917 	/* always clear all address registers */
918 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
919 
920 	if (lba48) {
921 		tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
922 		tf.flags |= ATA_TFLAG_LBA48;
923 	} else
924 		tf.command = ATA_CMD_READ_NATIVE_MAX;
925 
926 	tf.protocol |= ATA_PROT_NODATA;
927 	tf.device |= ATA_LBA;
928 
929 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
930 	if (err_mask) {
931 		ata_dev_printk(dev, KERN_WARNING, "failed to read native "
932 			       "max address (err_mask=0x%x)\n", err_mask);
933 		if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
934 			return -EACCES;
935 		return -EIO;
936 	}
937 
938 	if (lba48)
939 		*max_sectors = ata_tf_to_lba48(&tf);
940 	else
941 		*max_sectors = ata_tf_to_lba(&tf);
942         if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
943 		(*max_sectors)--;
944 	return 0;
945 }
946 
947 /**
948  *	ata_set_max_sectors - Set max sectors
949  *	@dev: target device
950  *	@new_sectors: new max sectors value to set for the device
951  *
952  *	Set max sectors of @dev to @new_sectors.
953  *
954  *	RETURNS:
955  *	0 on success, -EACCES if command is aborted or denied (due to
956  *	previous non-volatile SET_MAX) by the drive.  -EIO on other
957  *	errors.
958  */
959 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
960 {
961 	unsigned int err_mask;
962 	struct ata_taskfile tf;
963 	int lba48 = ata_id_has_lba48(dev->id);
964 
965 	new_sectors--;
966 
967 	ata_tf_init(dev, &tf);
968 
969 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
970 
971 	if (lba48) {
972 		tf.command = ATA_CMD_SET_MAX_EXT;
973 		tf.flags |= ATA_TFLAG_LBA48;
974 
975 		tf.hob_lbal = (new_sectors >> 24) & 0xff;
976 		tf.hob_lbam = (new_sectors >> 32) & 0xff;
977 		tf.hob_lbah = (new_sectors >> 40) & 0xff;
978 	} else {
979 		tf.command = ATA_CMD_SET_MAX;
980 
981 		tf.device |= (new_sectors >> 24) & 0xf;
982 	}
983 
984 	tf.protocol |= ATA_PROT_NODATA;
985 	tf.device |= ATA_LBA;
986 
987 	tf.lbal = (new_sectors >> 0) & 0xff;
988 	tf.lbam = (new_sectors >> 8) & 0xff;
989 	tf.lbah = (new_sectors >> 16) & 0xff;
990 
991 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
992 	if (err_mask) {
993 		ata_dev_printk(dev, KERN_WARNING, "failed to set "
994 			       "max address (err_mask=0x%x)\n", err_mask);
995 		if (err_mask == AC_ERR_DEV &&
996 		    (tf.feature & (ATA_ABORTED | ATA_IDNF)))
997 			return -EACCES;
998 		return -EIO;
999 	}
1000 
1001 	return 0;
1002 }
1003 
1004 /**
1005  *	ata_hpa_resize		-	Resize a device with an HPA set
1006  *	@dev: Device to resize
1007  *
1008  *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
1009  *	it if required to the full size of the media. The caller must check
1010  *	the drive has the HPA feature set enabled.
1011  *
1012  *	RETURNS:
1013  *	0 on success, -errno on failure.
1014  */
1015 static int ata_hpa_resize(struct ata_device *dev)
1016 {
1017 	struct ata_eh_context *ehc = &dev->link->eh_context;
1018 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1019 	u64 sectors = ata_id_n_sectors(dev->id);
1020 	u64 native_sectors;
1021 	int rc;
1022 
1023 	/* do we need to do it? */
1024 	if (dev->class != ATA_DEV_ATA ||
1025 	    !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
1026 	    (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
1027 		return 0;
1028 
1029 	/* read native max address */
1030 	rc = ata_read_native_max_address(dev, &native_sectors);
1031 	if (rc) {
1032 		/* If HPA isn't going to be unlocked, skip HPA
1033 		 * resizing from the next try.
1034 		 */
1035 		if (!ata_ignore_hpa) {
1036 			ata_dev_printk(dev, KERN_WARNING, "HPA support seems "
1037 				       "broken, will skip HPA handling\n");
1038 			dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1039 
1040 			/* we can continue if device aborted the command */
1041 			if (rc == -EACCES)
1042 				rc = 0;
1043 		}
1044 
1045 		return rc;
1046 	}
1047 
1048 	/* nothing to do? */
1049 	if (native_sectors <= sectors || !ata_ignore_hpa) {
1050 		if (!print_info || native_sectors == sectors)
1051 			return 0;
1052 
1053 		if (native_sectors > sectors)
1054 			ata_dev_printk(dev, KERN_INFO,
1055 				"HPA detected: current %llu, native %llu\n",
1056 				(unsigned long long)sectors,
1057 				(unsigned long long)native_sectors);
1058 		else if (native_sectors < sectors)
1059 			ata_dev_printk(dev, KERN_WARNING,
1060 				"native sectors (%llu) is smaller than "
1061 				"sectors (%llu)\n",
1062 				(unsigned long long)native_sectors,
1063 				(unsigned long long)sectors);
1064 		return 0;
1065 	}
1066 
1067 	/* let's unlock HPA */
1068 	rc = ata_set_max_sectors(dev, native_sectors);
1069 	if (rc == -EACCES) {
1070 		/* if device aborted the command, skip HPA resizing */
1071 		ata_dev_printk(dev, KERN_WARNING, "device aborted resize "
1072 			       "(%llu -> %llu), skipping HPA handling\n",
1073 			       (unsigned long long)sectors,
1074 			       (unsigned long long)native_sectors);
1075 		dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1076 		return 0;
1077 	} else if (rc)
1078 		return rc;
1079 
1080 	/* re-read IDENTIFY data */
1081 	rc = ata_dev_reread_id(dev, 0);
1082 	if (rc) {
1083 		ata_dev_printk(dev, KERN_ERR, "failed to re-read IDENTIFY "
1084 			       "data after HPA resizing\n");
1085 		return rc;
1086 	}
1087 
1088 	if (print_info) {
1089 		u64 new_sectors = ata_id_n_sectors(dev->id);
1090 		ata_dev_printk(dev, KERN_INFO,
1091 			"HPA unlocked: %llu -> %llu, native %llu\n",
1092 			(unsigned long long)sectors,
1093 			(unsigned long long)new_sectors,
1094 			(unsigned long long)native_sectors);
1095 	}
1096 
1097 	return 0;
1098 }
1099 
1100 /**
1101  *	ata_id_to_dma_mode	-	Identify DMA mode from id block
1102  *	@dev: device to identify
1103  *	@unknown: mode to assume if we cannot tell
1104  *
1105  *	Set up the timing values for the device based upon the identify
1106  *	reported values for the DMA mode. This function is used by drivers
1107  *	which rely upon firmware configured modes, but wish to report the
1108  *	mode correctly when possible.
1109  *
1110  *	In addition we emit similarly formatted messages to the default
1111  *	ata_dev_set_mode handler, in order to provide consistency of
1112  *	presentation.
1113  */
1114 
1115 void ata_id_to_dma_mode(struct ata_device *dev, u8 unknown)
1116 {
1117 	unsigned int mask;
1118 	u8 mode;
1119 
1120 	/* Pack the DMA modes */
1121 	mask = ((dev->id[63] >> 8) << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA;
1122 	if (dev->id[53] & 0x04)
1123 		mask |= ((dev->id[88] >> 8) << ATA_SHIFT_UDMA) & ATA_MASK_UDMA;
1124 
1125 	/* Select the mode in use */
1126 	mode = ata_xfer_mask2mode(mask);
1127 
1128 	if (mode != 0) {
1129 		ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
1130 		       ata_mode_string(mask));
1131 	} else {
1132 		/* SWDMA perhaps ? */
1133 		mode = unknown;
1134 		ata_dev_printk(dev, KERN_INFO, "configured for DMA\n");
1135 	}
1136 
1137 	/* Configure the device reporting */
1138 	dev->xfer_mode = mode;
1139 	dev->xfer_shift = ata_xfer_mode2shift(mode);
1140 }
1141 
1142 /**
1143  *	ata_noop_dev_select - Select device 0/1 on ATA bus
1144  *	@ap: ATA channel to manipulate
1145  *	@device: ATA device (numbered from zero) to select
1146  *
1147  *	This function performs no actual function.
1148  *
1149  *	May be used as the dev_select() entry in ata_port_operations.
1150  *
1151  *	LOCKING:
1152  *	caller.
1153  */
1154 void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
1155 {
1156 }
1157 
1158 
1159 /**
1160  *	ata_std_dev_select - Select device 0/1 on ATA bus
1161  *	@ap: ATA channel to manipulate
1162  *	@device: ATA device (numbered from zero) to select
1163  *
1164  *	Use the method defined in the ATA specification to
1165  *	make either device 0, or device 1, active on the
1166  *	ATA channel.  Works with both PIO and MMIO.
1167  *
1168  *	May be used as the dev_select() entry in ata_port_operations.
1169  *
1170  *	LOCKING:
1171  *	caller.
1172  */
1173 
1174 void ata_std_dev_select (struct ata_port *ap, unsigned int device)
1175 {
1176 	u8 tmp;
1177 
1178 	if (device == 0)
1179 		tmp = ATA_DEVICE_OBS;
1180 	else
1181 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
1182 
1183 	iowrite8(tmp, ap->ioaddr.device_addr);
1184 	ata_pause(ap);		/* needed; also flushes, for mmio */
1185 }
1186 
1187 /**
1188  *	ata_dev_select - Select device 0/1 on ATA bus
1189  *	@ap: ATA channel to manipulate
1190  *	@device: ATA device (numbered from zero) to select
1191  *	@wait: non-zero to wait for Status register BSY bit to clear
1192  *	@can_sleep: non-zero if context allows sleeping
1193  *
1194  *	Use the method defined in the ATA specification to
1195  *	make either device 0, or device 1, active on the
1196  *	ATA channel.
1197  *
1198  *	This is a high-level version of ata_std_dev_select(),
1199  *	which additionally provides the services of inserting
1200  *	the proper pauses and status polling, where needed.
1201  *
1202  *	LOCKING:
1203  *	caller.
1204  */
1205 
1206 void ata_dev_select(struct ata_port *ap, unsigned int device,
1207 			   unsigned int wait, unsigned int can_sleep)
1208 {
1209 	if (ata_msg_probe(ap))
1210 		ata_port_printk(ap, KERN_INFO, "ata_dev_select: ENTER, "
1211 				"device %u, wait %u\n", device, wait);
1212 
1213 	if (wait)
1214 		ata_wait_idle(ap);
1215 
1216 	ap->ops->dev_select(ap, device);
1217 
1218 	if (wait) {
1219 		if (can_sleep && ap->link.device[device].class == ATA_DEV_ATAPI)
1220 			msleep(150);
1221 		ata_wait_idle(ap);
1222 	}
1223 }
1224 
1225 /**
1226  *	ata_dump_id - IDENTIFY DEVICE info debugging output
1227  *	@id: IDENTIFY DEVICE page to dump
1228  *
1229  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
1230  *	page.
1231  *
1232  *	LOCKING:
1233  *	caller.
1234  */
1235 
1236 static inline void ata_dump_id(const u16 *id)
1237 {
1238 	DPRINTK("49==0x%04x  "
1239 		"53==0x%04x  "
1240 		"63==0x%04x  "
1241 		"64==0x%04x  "
1242 		"75==0x%04x  \n",
1243 		id[49],
1244 		id[53],
1245 		id[63],
1246 		id[64],
1247 		id[75]);
1248 	DPRINTK("80==0x%04x  "
1249 		"81==0x%04x  "
1250 		"82==0x%04x  "
1251 		"83==0x%04x  "
1252 		"84==0x%04x  \n",
1253 		id[80],
1254 		id[81],
1255 		id[82],
1256 		id[83],
1257 		id[84]);
1258 	DPRINTK("88==0x%04x  "
1259 		"93==0x%04x\n",
1260 		id[88],
1261 		id[93]);
1262 }
1263 
1264 /**
1265  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1266  *	@id: IDENTIFY data to compute xfer mask from
1267  *
1268  *	Compute the xfermask for this device. This is not as trivial
1269  *	as it seems if we must consider early devices correctly.
1270  *
1271  *	FIXME: pre IDE drive timing (do we care ?).
1272  *
1273  *	LOCKING:
1274  *	None.
1275  *
1276  *	RETURNS:
1277  *	Computed xfermask
1278  */
1279 static unsigned int ata_id_xfermask(const u16 *id)
1280 {
1281 	unsigned int pio_mask, mwdma_mask, udma_mask;
1282 
1283 	/* Usual case. Word 53 indicates word 64 is valid */
1284 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1285 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1286 		pio_mask <<= 3;
1287 		pio_mask |= 0x7;
1288 	} else {
1289 		/* If word 64 isn't valid then Word 51 high byte holds
1290 		 * the PIO timing number for the maximum. Turn it into
1291 		 * a mask.
1292 		 */
1293 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1294 		if (mode < 5)	/* Valid PIO range */
1295                 	pio_mask = (2 << mode) - 1;
1296 		else
1297 			pio_mask = 1;
1298 
1299 		/* But wait.. there's more. Design your standards by
1300 		 * committee and you too can get a free iordy field to
1301 		 * process. However its the speeds not the modes that
1302 		 * are supported... Note drivers using the timing API
1303 		 * will get this right anyway
1304 		 */
1305 	}
1306 
1307 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1308 
1309 	if (ata_id_is_cfa(id)) {
1310 		/*
1311 		 *	Process compact flash extended modes
1312 		 */
1313 		int pio = id[163] & 0x7;
1314 		int dma = (id[163] >> 3) & 7;
1315 
1316 		if (pio)
1317 			pio_mask |= (1 << 5);
1318 		if (pio > 1)
1319 			pio_mask |= (1 << 6);
1320 		if (dma)
1321 			mwdma_mask |= (1 << 3);
1322 		if (dma > 1)
1323 			mwdma_mask |= (1 << 4);
1324 	}
1325 
1326 	udma_mask = 0;
1327 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1328 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1329 
1330 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1331 }
1332 
1333 /**
1334  *	ata_port_queue_task - Queue port_task
1335  *	@ap: The ata_port to queue port_task for
1336  *	@fn: workqueue function to be scheduled
1337  *	@data: data for @fn to use
1338  *	@delay: delay time for workqueue function
1339  *
1340  *	Schedule @fn(@data) for execution after @delay jiffies using
1341  *	port_task.  There is one port_task per port and it's the
1342  *	user(low level driver)'s responsibility to make sure that only
1343  *	one task is active at any given time.
1344  *
1345  *	libata core layer takes care of synchronization between
1346  *	port_task and EH.  ata_port_queue_task() may be ignored for EH
1347  *	synchronization.
1348  *
1349  *	LOCKING:
1350  *	Inherited from caller.
1351  */
1352 void ata_port_queue_task(struct ata_port *ap, work_func_t fn, void *data,
1353 			 unsigned long delay)
1354 {
1355 	PREPARE_DELAYED_WORK(&ap->port_task, fn);
1356 	ap->port_task_data = data;
1357 
1358 	/* may fail if ata_port_flush_task() in progress */
1359 	queue_delayed_work(ata_wq, &ap->port_task, delay);
1360 }
1361 
1362 /**
1363  *	ata_port_flush_task - Flush port_task
1364  *	@ap: The ata_port to flush port_task for
1365  *
1366  *	After this function completes, port_task is guranteed not to
1367  *	be running or scheduled.
1368  *
1369  *	LOCKING:
1370  *	Kernel thread context (may sleep)
1371  */
1372 void ata_port_flush_task(struct ata_port *ap)
1373 {
1374 	DPRINTK("ENTER\n");
1375 
1376 	cancel_rearming_delayed_work(&ap->port_task);
1377 
1378 	if (ata_msg_ctl(ap))
1379 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __FUNCTION__);
1380 }
1381 
1382 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1383 {
1384 	struct completion *waiting = qc->private_data;
1385 
1386 	complete(waiting);
1387 }
1388 
1389 /**
1390  *	ata_exec_internal_sg - execute libata internal command
1391  *	@dev: Device to which the command is sent
1392  *	@tf: Taskfile registers for the command and the result
1393  *	@cdb: CDB for packet command
1394  *	@dma_dir: Data tranfer direction of the command
1395  *	@sg: sg list for the data buffer of the command
1396  *	@n_elem: Number of sg entries
1397  *	@timeout: Timeout in msecs (0 for default)
1398  *
1399  *	Executes libata internal command with timeout.  @tf contains
1400  *	command on entry and result on return.  Timeout and error
1401  *	conditions are reported via return value.  No recovery action
1402  *	is taken after a command times out.  It's caller's duty to
1403  *	clean up after timeout.
1404  *
1405  *	LOCKING:
1406  *	None.  Should be called with kernel context, might sleep.
1407  *
1408  *	RETURNS:
1409  *	Zero on success, AC_ERR_* mask on failure
1410  */
1411 unsigned ata_exec_internal_sg(struct ata_device *dev,
1412 			      struct ata_taskfile *tf, const u8 *cdb,
1413 			      int dma_dir, struct scatterlist *sgl,
1414 			      unsigned int n_elem, unsigned long timeout)
1415 {
1416 	struct ata_link *link = dev->link;
1417 	struct ata_port *ap = link->ap;
1418 	u8 command = tf->command;
1419 	struct ata_queued_cmd *qc;
1420 	unsigned int tag, preempted_tag;
1421 	u32 preempted_sactive, preempted_qc_active;
1422 	int preempted_nr_active_links;
1423 	DECLARE_COMPLETION_ONSTACK(wait);
1424 	unsigned long flags;
1425 	unsigned int err_mask;
1426 	int rc;
1427 
1428 	spin_lock_irqsave(ap->lock, flags);
1429 
1430 	/* no internal command while frozen */
1431 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1432 		spin_unlock_irqrestore(ap->lock, flags);
1433 		return AC_ERR_SYSTEM;
1434 	}
1435 
1436 	/* initialize internal qc */
1437 
1438 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1439 	 * drivers choke if any other tag is given.  This breaks
1440 	 * ata_tag_internal() test for those drivers.  Don't use new
1441 	 * EH stuff without converting to it.
1442 	 */
1443 	if (ap->ops->error_handler)
1444 		tag = ATA_TAG_INTERNAL;
1445 	else
1446 		tag = 0;
1447 
1448 	if (test_and_set_bit(tag, &ap->qc_allocated))
1449 		BUG();
1450 	qc = __ata_qc_from_tag(ap, tag);
1451 
1452 	qc->tag = tag;
1453 	qc->scsicmd = NULL;
1454 	qc->ap = ap;
1455 	qc->dev = dev;
1456 	ata_qc_reinit(qc);
1457 
1458 	preempted_tag = link->active_tag;
1459 	preempted_sactive = link->sactive;
1460 	preempted_qc_active = ap->qc_active;
1461 	preempted_nr_active_links = ap->nr_active_links;
1462 	link->active_tag = ATA_TAG_POISON;
1463 	link->sactive = 0;
1464 	ap->qc_active = 0;
1465 	ap->nr_active_links = 0;
1466 
1467 	/* prepare & issue qc */
1468 	qc->tf = *tf;
1469 	if (cdb)
1470 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1471 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1472 	qc->dma_dir = dma_dir;
1473 	if (dma_dir != DMA_NONE) {
1474 		unsigned int i, buflen = 0;
1475 		struct scatterlist *sg;
1476 
1477 		for_each_sg(sgl, sg, n_elem, i)
1478 			buflen += sg->length;
1479 
1480 		ata_sg_init(qc, sgl, n_elem);
1481 		qc->nbytes = buflen;
1482 	}
1483 
1484 	qc->private_data = &wait;
1485 	qc->complete_fn = ata_qc_complete_internal;
1486 
1487 	ata_qc_issue(qc);
1488 
1489 	spin_unlock_irqrestore(ap->lock, flags);
1490 
1491 	if (!timeout)
1492 		timeout = ata_probe_timeout * 1000 / HZ;
1493 
1494 	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
1495 
1496 	ata_port_flush_task(ap);
1497 
1498 	if (!rc) {
1499 		spin_lock_irqsave(ap->lock, flags);
1500 
1501 		/* We're racing with irq here.  If we lose, the
1502 		 * following test prevents us from completing the qc
1503 		 * twice.  If we win, the port is frozen and will be
1504 		 * cleaned up by ->post_internal_cmd().
1505 		 */
1506 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1507 			qc->err_mask |= AC_ERR_TIMEOUT;
1508 
1509 			if (ap->ops->error_handler)
1510 				ata_port_freeze(ap);
1511 			else
1512 				ata_qc_complete(qc);
1513 
1514 			if (ata_msg_warn(ap))
1515 				ata_dev_printk(dev, KERN_WARNING,
1516 					"qc timeout (cmd 0x%x)\n", command);
1517 		}
1518 
1519 		spin_unlock_irqrestore(ap->lock, flags);
1520 	}
1521 
1522 	/* do post_internal_cmd */
1523 	if (ap->ops->post_internal_cmd)
1524 		ap->ops->post_internal_cmd(qc);
1525 
1526 	/* perform minimal error analysis */
1527 	if (qc->flags & ATA_QCFLAG_FAILED) {
1528 		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
1529 			qc->err_mask |= AC_ERR_DEV;
1530 
1531 		if (!qc->err_mask)
1532 			qc->err_mask |= AC_ERR_OTHER;
1533 
1534 		if (qc->err_mask & ~AC_ERR_OTHER)
1535 			qc->err_mask &= ~AC_ERR_OTHER;
1536 	}
1537 
1538 	/* finish up */
1539 	spin_lock_irqsave(ap->lock, flags);
1540 
1541 	*tf = qc->result_tf;
1542 	err_mask = qc->err_mask;
1543 
1544 	ata_qc_free(qc);
1545 	link->active_tag = preempted_tag;
1546 	link->sactive = preempted_sactive;
1547 	ap->qc_active = preempted_qc_active;
1548 	ap->nr_active_links = preempted_nr_active_links;
1549 
1550 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1551 	 * Until those drivers are fixed, we detect the condition
1552 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1553 	 * port.
1554 	 *
1555 	 * Note that this doesn't change any behavior as internal
1556 	 * command failure results in disabling the device in the
1557 	 * higher layer for LLDDs without new reset/EH callbacks.
1558 	 *
1559 	 * Kill the following code as soon as those drivers are fixed.
1560 	 */
1561 	if (ap->flags & ATA_FLAG_DISABLED) {
1562 		err_mask |= AC_ERR_SYSTEM;
1563 		ata_port_probe(ap);
1564 	}
1565 
1566 	spin_unlock_irqrestore(ap->lock, flags);
1567 
1568 	return err_mask;
1569 }
1570 
1571 /**
1572  *	ata_exec_internal - execute libata internal command
1573  *	@dev: Device to which the command is sent
1574  *	@tf: Taskfile registers for the command and the result
1575  *	@cdb: CDB for packet command
1576  *	@dma_dir: Data tranfer direction of the command
1577  *	@buf: Data buffer of the command
1578  *	@buflen: Length of data buffer
1579  *	@timeout: Timeout in msecs (0 for default)
1580  *
1581  *	Wrapper around ata_exec_internal_sg() which takes simple
1582  *	buffer instead of sg list.
1583  *
1584  *	LOCKING:
1585  *	None.  Should be called with kernel context, might sleep.
1586  *
1587  *	RETURNS:
1588  *	Zero on success, AC_ERR_* mask on failure
1589  */
1590 unsigned ata_exec_internal(struct ata_device *dev,
1591 			   struct ata_taskfile *tf, const u8 *cdb,
1592 			   int dma_dir, void *buf, unsigned int buflen,
1593 			   unsigned long timeout)
1594 {
1595 	struct scatterlist *psg = NULL, sg;
1596 	unsigned int n_elem = 0;
1597 
1598 	if (dma_dir != DMA_NONE) {
1599 		WARN_ON(!buf);
1600 		sg_init_one(&sg, buf, buflen);
1601 		psg = &sg;
1602 		n_elem++;
1603 	}
1604 
1605 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
1606 				    timeout);
1607 }
1608 
1609 /**
1610  *	ata_do_simple_cmd - execute simple internal command
1611  *	@dev: Device to which the command is sent
1612  *	@cmd: Opcode to execute
1613  *
1614  *	Execute a 'simple' command, that only consists of the opcode
1615  *	'cmd' itself, without filling any other registers
1616  *
1617  *	LOCKING:
1618  *	Kernel thread context (may sleep).
1619  *
1620  *	RETURNS:
1621  *	Zero on success, AC_ERR_* mask on failure
1622  */
1623 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
1624 {
1625 	struct ata_taskfile tf;
1626 
1627 	ata_tf_init(dev, &tf);
1628 
1629 	tf.command = cmd;
1630 	tf.flags |= ATA_TFLAG_DEVICE;
1631 	tf.protocol = ATA_PROT_NODATA;
1632 
1633 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1634 }
1635 
1636 /**
1637  *	ata_pio_need_iordy	-	check if iordy needed
1638  *	@adev: ATA device
1639  *
1640  *	Check if the current speed of the device requires IORDY. Used
1641  *	by various controllers for chip configuration.
1642  */
1643 
1644 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1645 {
1646 	/* Controller doesn't support  IORDY. Probably a pointless check
1647 	   as the caller should know this */
1648 	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
1649 		return 0;
1650 	/* PIO3 and higher it is mandatory */
1651 	if (adev->pio_mode > XFER_PIO_2)
1652 		return 1;
1653 	/* We turn it on when possible */
1654 	if (ata_id_has_iordy(adev->id))
1655 		return 1;
1656 	return 0;
1657 }
1658 
1659 /**
1660  *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
1661  *	@adev: ATA device
1662  *
1663  *	Compute the highest mode possible if we are not using iordy. Return
1664  *	-1 if no iordy mode is available.
1665  */
1666 
1667 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
1668 {
1669 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1670 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1671 		u16 pio = adev->id[ATA_ID_EIDE_PIO];
1672 		/* Is the speed faster than the drive allows non IORDY ? */
1673 		if (pio) {
1674 			/* This is cycle times not frequency - watch the logic! */
1675 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1676 				return 3 << ATA_SHIFT_PIO;
1677 			return 7 << ATA_SHIFT_PIO;
1678 		}
1679 	}
1680 	return 3 << ATA_SHIFT_PIO;
1681 }
1682 
1683 /**
1684  *	ata_dev_read_id - Read ID data from the specified device
1685  *	@dev: target device
1686  *	@p_class: pointer to class of the target device (may be changed)
1687  *	@flags: ATA_READID_* flags
1688  *	@id: buffer to read IDENTIFY data into
1689  *
1690  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1691  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1692  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1693  *	for pre-ATA4 drives.
1694  *
1695  *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
1696  *	now we abort if we hit that case.
1697  *
1698  *	LOCKING:
1699  *	Kernel thread context (may sleep)
1700  *
1701  *	RETURNS:
1702  *	0 on success, -errno otherwise.
1703  */
1704 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1705 		    unsigned int flags, u16 *id)
1706 {
1707 	struct ata_port *ap = dev->link->ap;
1708 	unsigned int class = *p_class;
1709 	struct ata_taskfile tf;
1710 	unsigned int err_mask = 0;
1711 	const char *reason;
1712 	int may_fallback = 1, tried_spinup = 0;
1713 	int rc;
1714 
1715 	if (ata_msg_ctl(ap))
1716 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __FUNCTION__);
1717 
1718 	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
1719  retry:
1720 	ata_tf_init(dev, &tf);
1721 
1722 	switch (class) {
1723 	case ATA_DEV_ATA:
1724 		tf.command = ATA_CMD_ID_ATA;
1725 		break;
1726 	case ATA_DEV_ATAPI:
1727 		tf.command = ATA_CMD_ID_ATAPI;
1728 		break;
1729 	default:
1730 		rc = -ENODEV;
1731 		reason = "unsupported class";
1732 		goto err_out;
1733 	}
1734 
1735 	tf.protocol = ATA_PROT_PIO;
1736 
1737 	/* Some devices choke if TF registers contain garbage.  Make
1738 	 * sure those are properly initialized.
1739 	 */
1740 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1741 
1742 	/* Device presence detection is unreliable on some
1743 	 * controllers.  Always poll IDENTIFY if available.
1744 	 */
1745 	tf.flags |= ATA_TFLAG_POLLING;
1746 
1747 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1748 				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
1749 	if (err_mask) {
1750 		if (err_mask & AC_ERR_NODEV_HINT) {
1751 			DPRINTK("ata%u.%d: NODEV after polling detection\n",
1752 				ap->print_id, dev->devno);
1753 			return -ENOENT;
1754 		}
1755 
1756 		/* Device or controller might have reported the wrong
1757 		 * device class.  Give a shot at the other IDENTIFY if
1758 		 * the current one is aborted by the device.
1759 		 */
1760 		if (may_fallback &&
1761 		    (err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
1762 			may_fallback = 0;
1763 
1764 			if (class == ATA_DEV_ATA)
1765 				class = ATA_DEV_ATAPI;
1766 			else
1767 				class = ATA_DEV_ATA;
1768 			goto retry;
1769 		}
1770 
1771 		rc = -EIO;
1772 		reason = "I/O error";
1773 		goto err_out;
1774 	}
1775 
1776 	/* Falling back doesn't make sense if ID data was read
1777 	 * successfully at least once.
1778 	 */
1779 	may_fallback = 0;
1780 
1781 	swap_buf_le16(id, ATA_ID_WORDS);
1782 
1783 	/* sanity check */
1784 	rc = -EINVAL;
1785 	reason = "device reports invalid type";
1786 
1787 	if (class == ATA_DEV_ATA) {
1788 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
1789 			goto err_out;
1790 	} else {
1791 		if (ata_id_is_ata(id))
1792 			goto err_out;
1793 	}
1794 
1795 	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
1796 		tried_spinup = 1;
1797 		/*
1798 		 * Drive powered-up in standby mode, and requires a specific
1799 		 * SET_FEATURES spin-up subcommand before it will accept
1800 		 * anything other than the original IDENTIFY command.
1801 		 */
1802 		ata_tf_init(dev, &tf);
1803 		tf.command = ATA_CMD_SET_FEATURES;
1804 		tf.feature = SETFEATURES_SPINUP;
1805 		tf.protocol = ATA_PROT_NODATA;
1806 		tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1807 		err_mask = ata_exec_internal(dev, &tf, NULL,
1808 					     DMA_NONE, NULL, 0, 0);
1809 		if (err_mask && id[2] != 0x738c) {
1810 			rc = -EIO;
1811 			reason = "SPINUP failed";
1812 			goto err_out;
1813 		}
1814 		/*
1815 		 * If the drive initially returned incomplete IDENTIFY info,
1816 		 * we now must reissue the IDENTIFY command.
1817 		 */
1818 		if (id[2] == 0x37c8)
1819 			goto retry;
1820 	}
1821 
1822 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
1823 		/*
1824 		 * The exact sequence expected by certain pre-ATA4 drives is:
1825 		 * SRST RESET
1826 		 * IDENTIFY (optional in early ATA)
1827 		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
1828 		 * anything else..
1829 		 * Some drives were very specific about that exact sequence.
1830 		 *
1831 		 * Note that ATA4 says lba is mandatory so the second check
1832 		 * shoud never trigger.
1833 		 */
1834 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
1835 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
1836 			if (err_mask) {
1837 				rc = -EIO;
1838 				reason = "INIT_DEV_PARAMS failed";
1839 				goto err_out;
1840 			}
1841 
1842 			/* current CHS translation info (id[53-58]) might be
1843 			 * changed. reread the identify device info.
1844 			 */
1845 			flags &= ~ATA_READID_POSTRESET;
1846 			goto retry;
1847 		}
1848 	}
1849 
1850 	*p_class = class;
1851 
1852 	return 0;
1853 
1854  err_out:
1855 	if (ata_msg_warn(ap))
1856 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
1857 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
1858 	return rc;
1859 }
1860 
1861 static inline u8 ata_dev_knobble(struct ata_device *dev)
1862 {
1863 	struct ata_port *ap = dev->link->ap;
1864 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
1865 }
1866 
1867 static void ata_dev_config_ncq(struct ata_device *dev,
1868 			       char *desc, size_t desc_sz)
1869 {
1870 	struct ata_port *ap = dev->link->ap;
1871 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
1872 
1873 	if (!ata_id_has_ncq(dev->id)) {
1874 		desc[0] = '\0';
1875 		return;
1876 	}
1877 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
1878 		snprintf(desc, desc_sz, "NCQ (not used)");
1879 		return;
1880 	}
1881 	if (ap->flags & ATA_FLAG_NCQ) {
1882 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
1883 		dev->flags |= ATA_DFLAG_NCQ;
1884 	}
1885 
1886 	if (hdepth >= ddepth)
1887 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
1888 	else
1889 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
1890 }
1891 
1892 /**
1893  *	ata_dev_configure - Configure the specified ATA/ATAPI device
1894  *	@dev: Target device to configure
1895  *
1896  *	Configure @dev according to @dev->id.  Generic and low-level
1897  *	driver specific fixups are also applied.
1898  *
1899  *	LOCKING:
1900  *	Kernel thread context (may sleep)
1901  *
1902  *	RETURNS:
1903  *	0 on success, -errno otherwise
1904  */
1905 int ata_dev_configure(struct ata_device *dev)
1906 {
1907 	struct ata_port *ap = dev->link->ap;
1908 	struct ata_eh_context *ehc = &dev->link->eh_context;
1909 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1910 	const u16 *id = dev->id;
1911 	unsigned int xfer_mask;
1912 	char revbuf[7];		/* XYZ-99\0 */
1913 	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
1914 	char modelbuf[ATA_ID_PROD_LEN+1];
1915 	int rc;
1916 
1917 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
1918 		ata_dev_printk(dev, KERN_INFO, "%s: ENTER/EXIT -- nodev\n",
1919 			       __FUNCTION__);
1920 		return 0;
1921 	}
1922 
1923 	if (ata_msg_probe(ap))
1924 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __FUNCTION__);
1925 
1926 	/* set horkage */
1927 	dev->horkage |= ata_dev_blacklisted(dev);
1928 
1929 	/* let ACPI work its magic */
1930 	rc = ata_acpi_on_devcfg(dev);
1931 	if (rc)
1932 		return rc;
1933 
1934 	/* massage HPA, do it early as it might change IDENTIFY data */
1935 	rc = ata_hpa_resize(dev);
1936 	if (rc)
1937 		return rc;
1938 
1939 	/* print device capabilities */
1940 	if (ata_msg_probe(ap))
1941 		ata_dev_printk(dev, KERN_DEBUG,
1942 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
1943 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
1944 			       __FUNCTION__,
1945 			       id[49], id[82], id[83], id[84],
1946 			       id[85], id[86], id[87], id[88]);
1947 
1948 	/* initialize to-be-configured parameters */
1949 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
1950 	dev->max_sectors = 0;
1951 	dev->cdb_len = 0;
1952 	dev->n_sectors = 0;
1953 	dev->cylinders = 0;
1954 	dev->heads = 0;
1955 	dev->sectors = 0;
1956 
1957 	/*
1958 	 * common ATA, ATAPI feature tests
1959 	 */
1960 
1961 	/* find max transfer mode; for printk only */
1962 	xfer_mask = ata_id_xfermask(id);
1963 
1964 	if (ata_msg_probe(ap))
1965 		ata_dump_id(id);
1966 
1967 	/* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
1968 	ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
1969 			sizeof(fwrevbuf));
1970 
1971 	ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
1972 			sizeof(modelbuf));
1973 
1974 	/* ATA-specific feature tests */
1975 	if (dev->class == ATA_DEV_ATA) {
1976 		if (ata_id_is_cfa(id)) {
1977 			if (id[162] & 1) /* CPRM may make this media unusable */
1978 				ata_dev_printk(dev, KERN_WARNING,
1979 					       "supports DRM functions and may "
1980 					       "not be fully accessable.\n");
1981 			snprintf(revbuf, 7, "CFA");
1982 		}
1983 		else
1984 			snprintf(revbuf, 7, "ATA-%d",  ata_id_major_version(id));
1985 
1986 		dev->n_sectors = ata_id_n_sectors(id);
1987 
1988 		if (dev->id[59] & 0x100)
1989 			dev->multi_count = dev->id[59] & 0xff;
1990 
1991 		if (ata_id_has_lba(id)) {
1992 			const char *lba_desc;
1993 			char ncq_desc[20];
1994 
1995 			lba_desc = "LBA";
1996 			dev->flags |= ATA_DFLAG_LBA;
1997 			if (ata_id_has_lba48(id)) {
1998 				dev->flags |= ATA_DFLAG_LBA48;
1999 				lba_desc = "LBA48";
2000 
2001 				if (dev->n_sectors >= (1UL << 28) &&
2002 				    ata_id_has_flush_ext(id))
2003 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
2004 			}
2005 
2006 			/* config NCQ */
2007 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
2008 
2009 			/* print device info to dmesg */
2010 			if (ata_msg_drv(ap) && print_info) {
2011 				ata_dev_printk(dev, KERN_INFO,
2012 					"%s: %s, %s, max %s\n",
2013 					revbuf, modelbuf, fwrevbuf,
2014 					ata_mode_string(xfer_mask));
2015 				ata_dev_printk(dev, KERN_INFO,
2016 					"%Lu sectors, multi %u: %s %s\n",
2017 					(unsigned long long)dev->n_sectors,
2018 					dev->multi_count, lba_desc, ncq_desc);
2019 			}
2020 		} else {
2021 			/* CHS */
2022 
2023 			/* Default translation */
2024 			dev->cylinders	= id[1];
2025 			dev->heads	= id[3];
2026 			dev->sectors	= id[6];
2027 
2028 			if (ata_id_current_chs_valid(id)) {
2029 				/* Current CHS translation is valid. */
2030 				dev->cylinders = id[54];
2031 				dev->heads     = id[55];
2032 				dev->sectors   = id[56];
2033 			}
2034 
2035 			/* print device info to dmesg */
2036 			if (ata_msg_drv(ap) && print_info) {
2037 				ata_dev_printk(dev, KERN_INFO,
2038 					"%s: %s, %s, max %s\n",
2039 					revbuf,	modelbuf, fwrevbuf,
2040 					ata_mode_string(xfer_mask));
2041 				ata_dev_printk(dev, KERN_INFO,
2042 					"%Lu sectors, multi %u, CHS %u/%u/%u\n",
2043 					(unsigned long long)dev->n_sectors,
2044 					dev->multi_count, dev->cylinders,
2045 					dev->heads, dev->sectors);
2046 			}
2047 		}
2048 
2049 		dev->cdb_len = 16;
2050 	}
2051 
2052 	/* ATAPI-specific feature tests */
2053 	else if (dev->class == ATA_DEV_ATAPI) {
2054 		const char *cdb_intr_string = "";
2055 		const char *atapi_an_string = "";
2056 		u32 sntf;
2057 
2058 		rc = atapi_cdb_len(id);
2059 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
2060 			if (ata_msg_warn(ap))
2061 				ata_dev_printk(dev, KERN_WARNING,
2062 					       "unsupported CDB len\n");
2063 			rc = -EINVAL;
2064 			goto err_out_nosup;
2065 		}
2066 		dev->cdb_len = (unsigned int) rc;
2067 
2068 		/* Enable ATAPI AN if both the host and device have
2069 		 * the support.  If PMP is attached, SNTF is required
2070 		 * to enable ATAPI AN to discern between PHY status
2071 		 * changed notifications and ATAPI ANs.
2072 		 */
2073 		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
2074 		    (!ap->nr_pmp_links ||
2075 		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
2076 			unsigned int err_mask;
2077 
2078 			/* issue SET feature command to turn this on */
2079 			err_mask = ata_dev_set_AN(dev, SETFEATURES_SATA_ENABLE);
2080 			if (err_mask)
2081 				ata_dev_printk(dev, KERN_ERR,
2082 					"failed to enable ATAPI AN "
2083 					"(err_mask=0x%x)\n", err_mask);
2084 			else {
2085 				dev->flags |= ATA_DFLAG_AN;
2086 				atapi_an_string = ", ATAPI AN";
2087 			}
2088 		}
2089 
2090 		if (ata_id_cdb_intr(dev->id)) {
2091 			dev->flags |= ATA_DFLAG_CDB_INTR;
2092 			cdb_intr_string = ", CDB intr";
2093 		}
2094 
2095 		/* print device info to dmesg */
2096 		if (ata_msg_drv(ap) && print_info)
2097 			ata_dev_printk(dev, KERN_INFO,
2098 				       "ATAPI: %s, %s, max %s%s%s\n",
2099 				       modelbuf, fwrevbuf,
2100 				       ata_mode_string(xfer_mask),
2101 				       cdb_intr_string, atapi_an_string);
2102 	}
2103 
2104 	/* determine max_sectors */
2105 	dev->max_sectors = ATA_MAX_SECTORS;
2106 	if (dev->flags & ATA_DFLAG_LBA48)
2107 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2108 
2109 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
2110 		/* Let the user know. We don't want to disallow opens for
2111 		   rescue purposes, or in case the vendor is just a blithering
2112 		   idiot */
2113                 if (print_info) {
2114 			ata_dev_printk(dev, KERN_WARNING,
2115 "Drive reports diagnostics failure. This may indicate a drive\n");
2116 			ata_dev_printk(dev, KERN_WARNING,
2117 "fault or invalid emulation. Contact drive vendor for information.\n");
2118 		}
2119 	}
2120 
2121 	/* limit bridge transfers to udma5, 200 sectors */
2122 	if (ata_dev_knobble(dev)) {
2123 		if (ata_msg_drv(ap) && print_info)
2124 			ata_dev_printk(dev, KERN_INFO,
2125 				       "applying bridge limits\n");
2126 		dev->udma_mask &= ATA_UDMA5;
2127 		dev->max_sectors = ATA_MAX_SECTORS;
2128 	}
2129 
2130 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
2131 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
2132 					 dev->max_sectors);
2133 
2134 	if (ap->ops->dev_config)
2135 		ap->ops->dev_config(dev);
2136 
2137 	if (ata_msg_probe(ap))
2138 		ata_dev_printk(dev, KERN_DEBUG, "%s: EXIT, drv_stat = 0x%x\n",
2139 			__FUNCTION__, ata_chk_status(ap));
2140 	return 0;
2141 
2142 err_out_nosup:
2143 	if (ata_msg_probe(ap))
2144 		ata_dev_printk(dev, KERN_DEBUG,
2145 			       "%s: EXIT, err\n", __FUNCTION__);
2146 	return rc;
2147 }
2148 
2149 /**
2150  *	ata_cable_40wire	-	return 40 wire cable type
2151  *	@ap: port
2152  *
2153  *	Helper method for drivers which want to hardwire 40 wire cable
2154  *	detection.
2155  */
2156 
2157 int ata_cable_40wire(struct ata_port *ap)
2158 {
2159 	return ATA_CBL_PATA40;
2160 }
2161 
2162 /**
2163  *	ata_cable_80wire	-	return 80 wire cable type
2164  *	@ap: port
2165  *
2166  *	Helper method for drivers which want to hardwire 80 wire cable
2167  *	detection.
2168  */
2169 
2170 int ata_cable_80wire(struct ata_port *ap)
2171 {
2172 	return ATA_CBL_PATA80;
2173 }
2174 
2175 /**
2176  *	ata_cable_unknown	-	return unknown PATA cable.
2177  *	@ap: port
2178  *
2179  *	Helper method for drivers which have no PATA cable detection.
2180  */
2181 
2182 int ata_cable_unknown(struct ata_port *ap)
2183 {
2184 	return ATA_CBL_PATA_UNK;
2185 }
2186 
2187 /**
2188  *	ata_cable_sata	-	return SATA cable type
2189  *	@ap: port
2190  *
2191  *	Helper method for drivers which have SATA cables
2192  */
2193 
2194 int ata_cable_sata(struct ata_port *ap)
2195 {
2196 	return ATA_CBL_SATA;
2197 }
2198 
2199 /**
2200  *	ata_bus_probe - Reset and probe ATA bus
2201  *	@ap: Bus to probe
2202  *
2203  *	Master ATA bus probing function.  Initiates a hardware-dependent
2204  *	bus reset, then attempts to identify any devices found on
2205  *	the bus.
2206  *
2207  *	LOCKING:
2208  *	PCI/etc. bus probe sem.
2209  *
2210  *	RETURNS:
2211  *	Zero on success, negative errno otherwise.
2212  */
2213 
2214 int ata_bus_probe(struct ata_port *ap)
2215 {
2216 	unsigned int classes[ATA_MAX_DEVICES];
2217 	int tries[ATA_MAX_DEVICES];
2218 	int rc;
2219 	struct ata_device *dev;
2220 
2221 	ata_port_probe(ap);
2222 
2223 	ata_link_for_each_dev(dev, &ap->link)
2224 		tries[dev->devno] = ATA_PROBE_MAX_TRIES;
2225 
2226  retry:
2227 	/* reset and determine device classes */
2228 	ap->ops->phy_reset(ap);
2229 
2230 	ata_link_for_each_dev(dev, &ap->link) {
2231 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
2232 		    dev->class != ATA_DEV_UNKNOWN)
2233 			classes[dev->devno] = dev->class;
2234 		else
2235 			classes[dev->devno] = ATA_DEV_NONE;
2236 
2237 		dev->class = ATA_DEV_UNKNOWN;
2238 	}
2239 
2240 	ata_port_probe(ap);
2241 
2242 	/* after the reset the device state is PIO 0 and the controller
2243 	   state is undefined. Record the mode */
2244 
2245 	ata_link_for_each_dev(dev, &ap->link)
2246 		dev->pio_mode = XFER_PIO_0;
2247 
2248 	/* read IDENTIFY page and configure devices. We have to do the identify
2249 	   specific sequence bass-ackwards so that PDIAG- is released by
2250 	   the slave device */
2251 
2252 	ata_link_for_each_dev(dev, &ap->link) {
2253 		if (tries[dev->devno])
2254 			dev->class = classes[dev->devno];
2255 
2256 		if (!ata_dev_enabled(dev))
2257 			continue;
2258 
2259 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
2260 				     dev->id);
2261 		if (rc)
2262 			goto fail;
2263 	}
2264 
2265 	/* Now ask for the cable type as PDIAG- should have been released */
2266 	if (ap->ops->cable_detect)
2267 		ap->cbl = ap->ops->cable_detect(ap);
2268 
2269 	/* We may have SATA bridge glue hiding here irrespective of the
2270 	   reported cable types and sensed types */
2271 	ata_link_for_each_dev(dev, &ap->link) {
2272 		if (!ata_dev_enabled(dev))
2273 			continue;
2274 		/* SATA drives indicate we have a bridge. We don't know which
2275 		   end of the link the bridge is which is a problem */
2276 		if (ata_id_is_sata(dev->id))
2277 			ap->cbl = ATA_CBL_SATA;
2278 	}
2279 
2280 	/* After the identify sequence we can now set up the devices. We do
2281 	   this in the normal order so that the user doesn't get confused */
2282 
2283 	ata_link_for_each_dev(dev, &ap->link) {
2284 		if (!ata_dev_enabled(dev))
2285 			continue;
2286 
2287 		ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
2288 		rc = ata_dev_configure(dev);
2289 		ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
2290 		if (rc)
2291 			goto fail;
2292 	}
2293 
2294 	/* configure transfer mode */
2295 	rc = ata_set_mode(&ap->link, &dev);
2296 	if (rc)
2297 		goto fail;
2298 
2299 	ata_link_for_each_dev(dev, &ap->link)
2300 		if (ata_dev_enabled(dev))
2301 			return 0;
2302 
2303 	/* no device present, disable port */
2304 	ata_port_disable(ap);
2305 	return -ENODEV;
2306 
2307  fail:
2308 	tries[dev->devno]--;
2309 
2310 	switch (rc) {
2311 	case -EINVAL:
2312 		/* eeek, something went very wrong, give up */
2313 		tries[dev->devno] = 0;
2314 		break;
2315 
2316 	case -ENODEV:
2317 		/* give it just one more chance */
2318 		tries[dev->devno] = min(tries[dev->devno], 1);
2319 	case -EIO:
2320 		if (tries[dev->devno] == 1) {
2321 			/* This is the last chance, better to slow
2322 			 * down than lose it.
2323 			 */
2324 			sata_down_spd_limit(&ap->link);
2325 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2326 		}
2327 	}
2328 
2329 	if (!tries[dev->devno])
2330 		ata_dev_disable(dev);
2331 
2332 	goto retry;
2333 }
2334 
2335 /**
2336  *	ata_port_probe - Mark port as enabled
2337  *	@ap: Port for which we indicate enablement
2338  *
2339  *	Modify @ap data structure such that the system
2340  *	thinks that the entire port is enabled.
2341  *
2342  *	LOCKING: host lock, or some other form of
2343  *	serialization.
2344  */
2345 
2346 void ata_port_probe(struct ata_port *ap)
2347 {
2348 	ap->flags &= ~ATA_FLAG_DISABLED;
2349 }
2350 
2351 /**
2352  *	sata_print_link_status - Print SATA link status
2353  *	@link: SATA link to printk link status about
2354  *
2355  *	This function prints link speed and status of a SATA link.
2356  *
2357  *	LOCKING:
2358  *	None.
2359  */
2360 void sata_print_link_status(struct ata_link *link)
2361 {
2362 	u32 sstatus, scontrol, tmp;
2363 
2364 	if (sata_scr_read(link, SCR_STATUS, &sstatus))
2365 		return;
2366 	sata_scr_read(link, SCR_CONTROL, &scontrol);
2367 
2368 	if (ata_link_online(link)) {
2369 		tmp = (sstatus >> 4) & 0xf;
2370 		ata_link_printk(link, KERN_INFO,
2371 				"SATA link up %s (SStatus %X SControl %X)\n",
2372 				sata_spd_string(tmp), sstatus, scontrol);
2373 	} else {
2374 		ata_link_printk(link, KERN_INFO,
2375 				"SATA link down (SStatus %X SControl %X)\n",
2376 				sstatus, scontrol);
2377 	}
2378 }
2379 
2380 /**
2381  *	__sata_phy_reset - Wake/reset a low-level SATA PHY
2382  *	@ap: SATA port associated with target SATA PHY.
2383  *
2384  *	This function issues commands to standard SATA Sxxx
2385  *	PHY registers, to wake up the phy (and device), and
2386  *	clear any reset condition.
2387  *
2388  *	LOCKING:
2389  *	PCI/etc. bus probe sem.
2390  *
2391  */
2392 void __sata_phy_reset(struct ata_port *ap)
2393 {
2394 	struct ata_link *link = &ap->link;
2395 	unsigned long timeout = jiffies + (HZ * 5);
2396 	u32 sstatus;
2397 
2398 	if (ap->flags & ATA_FLAG_SATA_RESET) {
2399 		/* issue phy wake/reset */
2400 		sata_scr_write_flush(link, SCR_CONTROL, 0x301);
2401 		/* Couldn't find anything in SATA I/II specs, but
2402 		 * AHCI-1.1 10.4.2 says at least 1 ms. */
2403 		mdelay(1);
2404 	}
2405 	/* phy wake/clear reset */
2406 	sata_scr_write_flush(link, SCR_CONTROL, 0x300);
2407 
2408 	/* wait for phy to become ready, if necessary */
2409 	do {
2410 		msleep(200);
2411 		sata_scr_read(link, SCR_STATUS, &sstatus);
2412 		if ((sstatus & 0xf) != 1)
2413 			break;
2414 	} while (time_before(jiffies, timeout));
2415 
2416 	/* print link status */
2417 	sata_print_link_status(link);
2418 
2419 	/* TODO: phy layer with polling, timeouts, etc. */
2420 	if (!ata_link_offline(link))
2421 		ata_port_probe(ap);
2422 	else
2423 		ata_port_disable(ap);
2424 
2425 	if (ap->flags & ATA_FLAG_DISABLED)
2426 		return;
2427 
2428 	if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
2429 		ata_port_disable(ap);
2430 		return;
2431 	}
2432 
2433 	ap->cbl = ATA_CBL_SATA;
2434 }
2435 
2436 /**
2437  *	sata_phy_reset - Reset SATA bus.
2438  *	@ap: SATA port associated with target SATA PHY.
2439  *
2440  *	This function resets the SATA bus, and then probes
2441  *	the bus for devices.
2442  *
2443  *	LOCKING:
2444  *	PCI/etc. bus probe sem.
2445  *
2446  */
2447 void sata_phy_reset(struct ata_port *ap)
2448 {
2449 	__sata_phy_reset(ap);
2450 	if (ap->flags & ATA_FLAG_DISABLED)
2451 		return;
2452 	ata_bus_reset(ap);
2453 }
2454 
2455 /**
2456  *	ata_dev_pair		-	return other device on cable
2457  *	@adev: device
2458  *
2459  *	Obtain the other device on the same cable, or if none is
2460  *	present NULL is returned
2461  */
2462 
2463 struct ata_device *ata_dev_pair(struct ata_device *adev)
2464 {
2465 	struct ata_link *link = adev->link;
2466 	struct ata_device *pair = &link->device[1 - adev->devno];
2467 	if (!ata_dev_enabled(pair))
2468 		return NULL;
2469 	return pair;
2470 }
2471 
2472 /**
2473  *	ata_port_disable - Disable port.
2474  *	@ap: Port to be disabled.
2475  *
2476  *	Modify @ap data structure such that the system
2477  *	thinks that the entire port is disabled, and should
2478  *	never attempt to probe or communicate with devices
2479  *	on this port.
2480  *
2481  *	LOCKING: host lock, or some other form of
2482  *	serialization.
2483  */
2484 
2485 void ata_port_disable(struct ata_port *ap)
2486 {
2487 	ap->link.device[0].class = ATA_DEV_NONE;
2488 	ap->link.device[1].class = ATA_DEV_NONE;
2489 	ap->flags |= ATA_FLAG_DISABLED;
2490 }
2491 
2492 /**
2493  *	sata_down_spd_limit - adjust SATA spd limit downward
2494  *	@link: Link to adjust SATA spd limit for
2495  *
2496  *	Adjust SATA spd limit of @link downward.  Note that this
2497  *	function only adjusts the limit.  The change must be applied
2498  *	using sata_set_spd().
2499  *
2500  *	LOCKING:
2501  *	Inherited from caller.
2502  *
2503  *	RETURNS:
2504  *	0 on success, negative errno on failure
2505  */
2506 int sata_down_spd_limit(struct ata_link *link)
2507 {
2508 	u32 sstatus, spd, mask;
2509 	int rc, highbit;
2510 
2511 	if (!sata_scr_valid(link))
2512 		return -EOPNOTSUPP;
2513 
2514 	/* If SCR can be read, use it to determine the current SPD.
2515 	 * If not, use cached value in link->sata_spd.
2516 	 */
2517 	rc = sata_scr_read(link, SCR_STATUS, &sstatus);
2518 	if (rc == 0)
2519 		spd = (sstatus >> 4) & 0xf;
2520 	else
2521 		spd = link->sata_spd;
2522 
2523 	mask = link->sata_spd_limit;
2524 	if (mask <= 1)
2525 		return -EINVAL;
2526 
2527 	/* unconditionally mask off the highest bit */
2528 	highbit = fls(mask) - 1;
2529 	mask &= ~(1 << highbit);
2530 
2531 	/* Mask off all speeds higher than or equal to the current
2532 	 * one.  Force 1.5Gbps if current SPD is not available.
2533 	 */
2534 	if (spd > 1)
2535 		mask &= (1 << (spd - 1)) - 1;
2536 	else
2537 		mask &= 1;
2538 
2539 	/* were we already at the bottom? */
2540 	if (!mask)
2541 		return -EINVAL;
2542 
2543 	link->sata_spd_limit = mask;
2544 
2545 	ata_link_printk(link, KERN_WARNING, "limiting SATA link speed to %s\n",
2546 			sata_spd_string(fls(mask)));
2547 
2548 	return 0;
2549 }
2550 
2551 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
2552 {
2553 	u32 spd, limit;
2554 
2555 	if (link->sata_spd_limit == UINT_MAX)
2556 		limit = 0;
2557 	else
2558 		limit = fls(link->sata_spd_limit);
2559 
2560 	spd = (*scontrol >> 4) & 0xf;
2561 	*scontrol = (*scontrol & ~0xf0) | ((limit & 0xf) << 4);
2562 
2563 	return spd != limit;
2564 }
2565 
2566 /**
2567  *	sata_set_spd_needed - is SATA spd configuration needed
2568  *	@link: Link in question
2569  *
2570  *	Test whether the spd limit in SControl matches
2571  *	@link->sata_spd_limit.  This function is used to determine
2572  *	whether hardreset is necessary to apply SATA spd
2573  *	configuration.
2574  *
2575  *	LOCKING:
2576  *	Inherited from caller.
2577  *
2578  *	RETURNS:
2579  *	1 if SATA spd configuration is needed, 0 otherwise.
2580  */
2581 int sata_set_spd_needed(struct ata_link *link)
2582 {
2583 	u32 scontrol;
2584 
2585 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
2586 		return 0;
2587 
2588 	return __sata_set_spd_needed(link, &scontrol);
2589 }
2590 
2591 /**
2592  *	sata_set_spd - set SATA spd according to spd limit
2593  *	@link: Link to set SATA spd for
2594  *
2595  *	Set SATA spd of @link according to sata_spd_limit.
2596  *
2597  *	LOCKING:
2598  *	Inherited from caller.
2599  *
2600  *	RETURNS:
2601  *	0 if spd doesn't need to be changed, 1 if spd has been
2602  *	changed.  Negative errno if SCR registers are inaccessible.
2603  */
2604 int sata_set_spd(struct ata_link *link)
2605 {
2606 	u32 scontrol;
2607 	int rc;
2608 
2609 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
2610 		return rc;
2611 
2612 	if (!__sata_set_spd_needed(link, &scontrol))
2613 		return 0;
2614 
2615 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
2616 		return rc;
2617 
2618 	return 1;
2619 }
2620 
2621 /*
2622  * This mode timing computation functionality is ported over from
2623  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2624  */
2625 /*
2626  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2627  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2628  * for UDMA6, which is currently supported only by Maxtor drives.
2629  *
2630  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2631  */
2632 
2633 static const struct ata_timing ata_timing[] = {
2634 
2635 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
2636 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
2637 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
2638 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
2639 
2640 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
2641 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
2642 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
2643 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
2644 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
2645 
2646 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
2647 
2648 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
2649 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
2650 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
2651 
2652 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
2653 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
2654 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
2655 
2656 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
2657 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
2658 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
2659 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
2660 
2661 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
2662 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
2663 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
2664 
2665 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
2666 
2667 	{ 0xFF }
2668 };
2669 
2670 #define ENOUGH(v,unit)		(((v)-1)/(unit)+1)
2671 #define EZ(v,unit)		((v)?ENOUGH(v,unit):0)
2672 
2673 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2674 {
2675 	q->setup   = EZ(t->setup   * 1000,  T);
2676 	q->act8b   = EZ(t->act8b   * 1000,  T);
2677 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
2678 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
2679 	q->active  = EZ(t->active  * 1000,  T);
2680 	q->recover = EZ(t->recover * 1000,  T);
2681 	q->cycle   = EZ(t->cycle   * 1000,  T);
2682 	q->udma    = EZ(t->udma    * 1000, UT);
2683 }
2684 
2685 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2686 		      struct ata_timing *m, unsigned int what)
2687 {
2688 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2689 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2690 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2691 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2692 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
2693 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
2694 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
2695 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
2696 }
2697 
2698 static const struct ata_timing* ata_timing_find_mode(unsigned short speed)
2699 {
2700 	const struct ata_timing *t;
2701 
2702 	for (t = ata_timing; t->mode != speed; t++)
2703 		if (t->mode == 0xFF)
2704 			return NULL;
2705 	return t;
2706 }
2707 
2708 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
2709 		       struct ata_timing *t, int T, int UT)
2710 {
2711 	const struct ata_timing *s;
2712 	struct ata_timing p;
2713 
2714 	/*
2715 	 * Find the mode.
2716 	 */
2717 
2718 	if (!(s = ata_timing_find_mode(speed)))
2719 		return -EINVAL;
2720 
2721 	memcpy(t, s, sizeof(*s));
2722 
2723 	/*
2724 	 * If the drive is an EIDE drive, it can tell us it needs extended
2725 	 * PIO/MW_DMA cycle timing.
2726 	 */
2727 
2728 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
2729 		memset(&p, 0, sizeof(p));
2730 		if(speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
2731 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
2732 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
2733 		} else if(speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
2734 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
2735 		}
2736 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
2737 	}
2738 
2739 	/*
2740 	 * Convert the timing to bus clock counts.
2741 	 */
2742 
2743 	ata_timing_quantize(t, t, T, UT);
2744 
2745 	/*
2746 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
2747 	 * S.M.A.R.T * and some other commands. We have to ensure that the
2748 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
2749 	 */
2750 
2751 	if (speed > XFER_PIO_6) {
2752 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
2753 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
2754 	}
2755 
2756 	/*
2757 	 * Lengthen active & recovery time so that cycle time is correct.
2758 	 */
2759 
2760 	if (t->act8b + t->rec8b < t->cyc8b) {
2761 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
2762 		t->rec8b = t->cyc8b - t->act8b;
2763 	}
2764 
2765 	if (t->active + t->recover < t->cycle) {
2766 		t->active += (t->cycle - (t->active + t->recover)) / 2;
2767 		t->recover = t->cycle - t->active;
2768 	}
2769 
2770 	/* In a few cases quantisation may produce enough errors to
2771 	   leave t->cycle too low for the sum of active and recovery
2772 	   if so we must correct this */
2773 	if (t->active + t->recover > t->cycle)
2774 		t->cycle = t->active + t->recover;
2775 
2776 	return 0;
2777 }
2778 
2779 /**
2780  *	ata_down_xfermask_limit - adjust dev xfer masks downward
2781  *	@dev: Device to adjust xfer masks
2782  *	@sel: ATA_DNXFER_* selector
2783  *
2784  *	Adjust xfer masks of @dev downward.  Note that this function
2785  *	does not apply the change.  Invoking ata_set_mode() afterwards
2786  *	will apply the limit.
2787  *
2788  *	LOCKING:
2789  *	Inherited from caller.
2790  *
2791  *	RETURNS:
2792  *	0 on success, negative errno on failure
2793  */
2794 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
2795 {
2796 	char buf[32];
2797 	unsigned int orig_mask, xfer_mask;
2798 	unsigned int pio_mask, mwdma_mask, udma_mask;
2799 	int quiet, highbit;
2800 
2801 	quiet = !!(sel & ATA_DNXFER_QUIET);
2802 	sel &= ~ATA_DNXFER_QUIET;
2803 
2804 	xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
2805 						  dev->mwdma_mask,
2806 						  dev->udma_mask);
2807 	ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
2808 
2809 	switch (sel) {
2810 	case ATA_DNXFER_PIO:
2811 		highbit = fls(pio_mask) - 1;
2812 		pio_mask &= ~(1 << highbit);
2813 		break;
2814 
2815 	case ATA_DNXFER_DMA:
2816 		if (udma_mask) {
2817 			highbit = fls(udma_mask) - 1;
2818 			udma_mask &= ~(1 << highbit);
2819 			if (!udma_mask)
2820 				return -ENOENT;
2821 		} else if (mwdma_mask) {
2822 			highbit = fls(mwdma_mask) - 1;
2823 			mwdma_mask &= ~(1 << highbit);
2824 			if (!mwdma_mask)
2825 				return -ENOENT;
2826 		}
2827 		break;
2828 
2829 	case ATA_DNXFER_40C:
2830 		udma_mask &= ATA_UDMA_MASK_40C;
2831 		break;
2832 
2833 	case ATA_DNXFER_FORCE_PIO0:
2834 		pio_mask &= 1;
2835 	case ATA_DNXFER_FORCE_PIO:
2836 		mwdma_mask = 0;
2837 		udma_mask = 0;
2838 		break;
2839 
2840 	default:
2841 		BUG();
2842 	}
2843 
2844 	xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
2845 
2846 	if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
2847 		return -ENOENT;
2848 
2849 	if (!quiet) {
2850 		if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
2851 			snprintf(buf, sizeof(buf), "%s:%s",
2852 				 ata_mode_string(xfer_mask),
2853 				 ata_mode_string(xfer_mask & ATA_MASK_PIO));
2854 		else
2855 			snprintf(buf, sizeof(buf), "%s",
2856 				 ata_mode_string(xfer_mask));
2857 
2858 		ata_dev_printk(dev, KERN_WARNING,
2859 			       "limiting speed to %s\n", buf);
2860 	}
2861 
2862 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
2863 			    &dev->udma_mask);
2864 
2865 	return 0;
2866 }
2867 
2868 static int ata_dev_set_mode(struct ata_device *dev)
2869 {
2870 	struct ata_eh_context *ehc = &dev->link->eh_context;
2871 	unsigned int err_mask;
2872 	int rc;
2873 
2874 	dev->flags &= ~ATA_DFLAG_PIO;
2875 	if (dev->xfer_shift == ATA_SHIFT_PIO)
2876 		dev->flags |= ATA_DFLAG_PIO;
2877 
2878 	err_mask = ata_dev_set_xfermode(dev);
2879 	/* Old CFA may refuse this command, which is just fine */
2880 	if (dev->xfer_shift == ATA_SHIFT_PIO && ata_id_is_cfa(dev->id))
2881         	err_mask &= ~AC_ERR_DEV;
2882 	/* Some very old devices and some bad newer ones fail any kind of
2883 	   SET_XFERMODE request but support PIO0-2 timings and no IORDY */
2884 	if (dev->xfer_shift == ATA_SHIFT_PIO && !ata_id_has_iordy(dev->id) &&
2885 			dev->pio_mode <= XFER_PIO_2)
2886 		err_mask &= ~AC_ERR_DEV;
2887 	if (err_mask) {
2888 		ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
2889 			       "(err_mask=0x%x)\n", err_mask);
2890 		return -EIO;
2891 	}
2892 
2893 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
2894 	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
2895 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
2896 	if (rc)
2897 		return rc;
2898 
2899 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
2900 		dev->xfer_shift, (int)dev->xfer_mode);
2901 
2902 	ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
2903 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)));
2904 	return 0;
2905 }
2906 
2907 /**
2908  *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
2909  *	@link: link on which timings will be programmed
2910  *	@r_failed_dev: out paramter for failed device
2911  *
2912  *	Standard implementation of the function used to tune and set
2913  *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
2914  *	ata_dev_set_mode() fails, pointer to the failing device is
2915  *	returned in @r_failed_dev.
2916  *
2917  *	LOCKING:
2918  *	PCI/etc. bus probe sem.
2919  *
2920  *	RETURNS:
2921  *	0 on success, negative errno otherwise
2922  */
2923 
2924 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
2925 {
2926 	struct ata_port *ap = link->ap;
2927 	struct ata_device *dev;
2928 	int rc = 0, used_dma = 0, found = 0;
2929 
2930 	/* step 1: calculate xfer_mask */
2931 	ata_link_for_each_dev(dev, link) {
2932 		unsigned int pio_mask, dma_mask;
2933 		unsigned int mode_mask;
2934 
2935 		if (!ata_dev_enabled(dev))
2936 			continue;
2937 
2938 		mode_mask = ATA_DMA_MASK_ATA;
2939 		if (dev->class == ATA_DEV_ATAPI)
2940 			mode_mask = ATA_DMA_MASK_ATAPI;
2941 		else if (ata_id_is_cfa(dev->id))
2942 			mode_mask = ATA_DMA_MASK_CFA;
2943 
2944 		ata_dev_xfermask(dev);
2945 
2946 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
2947 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
2948 
2949 		if (libata_dma_mask & mode_mask)
2950 			dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
2951 		else
2952 			dma_mask = 0;
2953 
2954 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
2955 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
2956 
2957 		found = 1;
2958 		if (dev->dma_mode)
2959 			used_dma = 1;
2960 	}
2961 	if (!found)
2962 		goto out;
2963 
2964 	/* step 2: always set host PIO timings */
2965 	ata_link_for_each_dev(dev, link) {
2966 		if (!ata_dev_enabled(dev))
2967 			continue;
2968 
2969 		if (!dev->pio_mode) {
2970 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
2971 			rc = -EINVAL;
2972 			goto out;
2973 		}
2974 
2975 		dev->xfer_mode = dev->pio_mode;
2976 		dev->xfer_shift = ATA_SHIFT_PIO;
2977 		if (ap->ops->set_piomode)
2978 			ap->ops->set_piomode(ap, dev);
2979 	}
2980 
2981 	/* step 3: set host DMA timings */
2982 	ata_link_for_each_dev(dev, link) {
2983 		if (!ata_dev_enabled(dev) || !dev->dma_mode)
2984 			continue;
2985 
2986 		dev->xfer_mode = dev->dma_mode;
2987 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
2988 		if (ap->ops->set_dmamode)
2989 			ap->ops->set_dmamode(ap, dev);
2990 	}
2991 
2992 	/* step 4: update devices' xfer mode */
2993 	ata_link_for_each_dev(dev, link) {
2994 		/* don't update suspended devices' xfer mode */
2995 		if (!ata_dev_enabled(dev))
2996 			continue;
2997 
2998 		rc = ata_dev_set_mode(dev);
2999 		if (rc)
3000 			goto out;
3001 	}
3002 
3003 	/* Record simplex status. If we selected DMA then the other
3004 	 * host channels are not permitted to do so.
3005 	 */
3006 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
3007 		ap->host->simplex_claimed = ap;
3008 
3009  out:
3010 	if (rc)
3011 		*r_failed_dev = dev;
3012 	return rc;
3013 }
3014 
3015 /**
3016  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
3017  *	@link: link on which timings will be programmed
3018  *	@r_failed_dev: out paramter for failed device
3019  *
3020  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3021  *	ata_set_mode() fails, pointer to the failing device is
3022  *	returned in @r_failed_dev.
3023  *
3024  *	LOCKING:
3025  *	PCI/etc. bus probe sem.
3026  *
3027  *	RETURNS:
3028  *	0 on success, negative errno otherwise
3029  */
3030 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3031 {
3032 	struct ata_port *ap = link->ap;
3033 
3034 	/* has private set_mode? */
3035 	if (ap->ops->set_mode)
3036 		return ap->ops->set_mode(link, r_failed_dev);
3037 	return ata_do_set_mode(link, r_failed_dev);
3038 }
3039 
3040 /**
3041  *	ata_tf_to_host - issue ATA taskfile to host controller
3042  *	@ap: port to which command is being issued
3043  *	@tf: ATA taskfile register set
3044  *
3045  *	Issues ATA taskfile register set to ATA host controller,
3046  *	with proper synchronization with interrupt handler and
3047  *	other threads.
3048  *
3049  *	LOCKING:
3050  *	spin_lock_irqsave(host lock)
3051  */
3052 
3053 static inline void ata_tf_to_host(struct ata_port *ap,
3054 				  const struct ata_taskfile *tf)
3055 {
3056 	ap->ops->tf_load(ap, tf);
3057 	ap->ops->exec_command(ap, tf);
3058 }
3059 
3060 /**
3061  *	ata_busy_sleep - sleep until BSY clears, or timeout
3062  *	@ap: port containing status register to be polled
3063  *	@tmout_pat: impatience timeout
3064  *	@tmout: overall timeout
3065  *
3066  *	Sleep until ATA Status register bit BSY clears,
3067  *	or a timeout occurs.
3068  *
3069  *	LOCKING:
3070  *	Kernel thread context (may sleep).
3071  *
3072  *	RETURNS:
3073  *	0 on success, -errno otherwise.
3074  */
3075 int ata_busy_sleep(struct ata_port *ap,
3076 		   unsigned long tmout_pat, unsigned long tmout)
3077 {
3078 	unsigned long timer_start, timeout;
3079 	u8 status;
3080 
3081 	status = ata_busy_wait(ap, ATA_BUSY, 300);
3082 	timer_start = jiffies;
3083 	timeout = timer_start + tmout_pat;
3084 	while (status != 0xff && (status & ATA_BUSY) &&
3085 	       time_before(jiffies, timeout)) {
3086 		msleep(50);
3087 		status = ata_busy_wait(ap, ATA_BUSY, 3);
3088 	}
3089 
3090 	if (status != 0xff && (status & ATA_BUSY))
3091 		ata_port_printk(ap, KERN_WARNING,
3092 				"port is slow to respond, please be patient "
3093 				"(Status 0x%x)\n", status);
3094 
3095 	timeout = timer_start + tmout;
3096 	while (status != 0xff && (status & ATA_BUSY) &&
3097 	       time_before(jiffies, timeout)) {
3098 		msleep(50);
3099 		status = ata_chk_status(ap);
3100 	}
3101 
3102 	if (status == 0xff)
3103 		return -ENODEV;
3104 
3105 	if (status & ATA_BUSY) {
3106 		ata_port_printk(ap, KERN_ERR, "port failed to respond "
3107 				"(%lu secs, Status 0x%x)\n",
3108 				tmout / HZ, status);
3109 		return -EBUSY;
3110 	}
3111 
3112 	return 0;
3113 }
3114 
3115 /**
3116  *	ata_wait_ready - sleep until BSY clears, or timeout
3117  *	@ap: port containing status register to be polled
3118  *	@deadline: deadline jiffies for the operation
3119  *
3120  *	Sleep until ATA Status register bit BSY clears, or timeout
3121  *	occurs.
3122  *
3123  *	LOCKING:
3124  *	Kernel thread context (may sleep).
3125  *
3126  *	RETURNS:
3127  *	0 on success, -errno otherwise.
3128  */
3129 int ata_wait_ready(struct ata_port *ap, unsigned long deadline)
3130 {
3131 	unsigned long start = jiffies;
3132 	int warned = 0;
3133 
3134 	while (1) {
3135 		u8 status = ata_chk_status(ap);
3136 		unsigned long now = jiffies;
3137 
3138 		if (!(status & ATA_BUSY))
3139 			return 0;
3140 		if (!ata_link_online(&ap->link) && status == 0xff)
3141 			return -ENODEV;
3142 		if (time_after(now, deadline))
3143 			return -EBUSY;
3144 
3145 		if (!warned && time_after(now, start + 5 * HZ) &&
3146 		    (deadline - now > 3 * HZ)) {
3147 			ata_port_printk(ap, KERN_WARNING,
3148 				"port is slow to respond, please be patient "
3149 				"(Status 0x%x)\n", status);
3150 			warned = 1;
3151 		}
3152 
3153 		msleep(50);
3154 	}
3155 }
3156 
3157 static int ata_bus_post_reset(struct ata_port *ap, unsigned int devmask,
3158 			      unsigned long deadline)
3159 {
3160 	struct ata_ioports *ioaddr = &ap->ioaddr;
3161 	unsigned int dev0 = devmask & (1 << 0);
3162 	unsigned int dev1 = devmask & (1 << 1);
3163 	int rc, ret = 0;
3164 
3165 	/* if device 0 was found in ata_devchk, wait for its
3166 	 * BSY bit to clear
3167 	 */
3168 	if (dev0) {
3169 		rc = ata_wait_ready(ap, deadline);
3170 		if (rc) {
3171 			if (rc != -ENODEV)
3172 				return rc;
3173 			ret = rc;
3174 		}
3175 	}
3176 
3177 	/* if device 1 was found in ata_devchk, wait for register
3178 	 * access briefly, then wait for BSY to clear.
3179 	 */
3180 	if (dev1) {
3181 		int i;
3182 
3183 		ap->ops->dev_select(ap, 1);
3184 
3185 		/* Wait for register access.  Some ATAPI devices fail
3186 		 * to set nsect/lbal after reset, so don't waste too
3187 		 * much time on it.  We're gonna wait for !BSY anyway.
3188 		 */
3189 		for (i = 0; i < 2; i++) {
3190 			u8 nsect, lbal;
3191 
3192 			nsect = ioread8(ioaddr->nsect_addr);
3193 			lbal = ioread8(ioaddr->lbal_addr);
3194 			if ((nsect == 1) && (lbal == 1))
3195 				break;
3196 			msleep(50);	/* give drive a breather */
3197 		}
3198 
3199 		rc = ata_wait_ready(ap, deadline);
3200 		if (rc) {
3201 			if (rc != -ENODEV)
3202 				return rc;
3203 			ret = rc;
3204 		}
3205 	}
3206 
3207 	/* is all this really necessary? */
3208 	ap->ops->dev_select(ap, 0);
3209 	if (dev1)
3210 		ap->ops->dev_select(ap, 1);
3211 	if (dev0)
3212 		ap->ops->dev_select(ap, 0);
3213 
3214 	return ret;
3215 }
3216 
3217 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
3218 			     unsigned long deadline)
3219 {
3220 	struct ata_ioports *ioaddr = &ap->ioaddr;
3221 	struct ata_device *dev;
3222 	int i = 0;
3223 
3224 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
3225 
3226 	/* software reset.  causes dev0 to be selected */
3227 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3228 	udelay(20);	/* FIXME: flush */
3229 	iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
3230 	udelay(20);	/* FIXME: flush */
3231 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3232 
3233 	/* If we issued an SRST then an ATA drive (not ATAPI)
3234 	 * may have changed configuration and be in PIO0 timing. If
3235 	 * we did a hard reset (or are coming from power on) this is
3236 	 * true for ATA or ATAPI. Until we've set a suitable controller
3237 	 * mode we should not touch the bus as we may be talking too fast.
3238 	 */
3239 
3240 	ata_link_for_each_dev(dev, &ap->link)
3241 		dev->pio_mode = XFER_PIO_0;
3242 
3243 	/* If the controller has a pio mode setup function then use
3244 	   it to set the chipset to rights. Don't touch the DMA setup
3245 	   as that will be dealt with when revalidating */
3246 	if (ap->ops->set_piomode) {
3247 		ata_link_for_each_dev(dev, &ap->link)
3248 			if (devmask & (1 << i++))
3249 				ap->ops->set_piomode(ap, dev);
3250 	}
3251 
3252 	/* spec mandates ">= 2ms" before checking status.
3253 	 * We wait 150ms, because that was the magic delay used for
3254 	 * ATAPI devices in Hale Landis's ATADRVR, for the period of time
3255 	 * between when the ATA command register is written, and then
3256 	 * status is checked.  Because waiting for "a while" before
3257 	 * checking status is fine, post SRST, we perform this magic
3258 	 * delay here as well.
3259 	 *
3260 	 * Old drivers/ide uses the 2mS rule and then waits for ready
3261 	 */
3262 	msleep(150);
3263 
3264 	/* Before we perform post reset processing we want to see if
3265 	 * the bus shows 0xFF because the odd clown forgets the D7
3266 	 * pulldown resistor.
3267 	 */
3268 	if (ata_check_status(ap) == 0xFF)
3269 		return -ENODEV;
3270 
3271 	return ata_bus_post_reset(ap, devmask, deadline);
3272 }
3273 
3274 /**
3275  *	ata_bus_reset - reset host port and associated ATA channel
3276  *	@ap: port to reset
3277  *
3278  *	This is typically the first time we actually start issuing
3279  *	commands to the ATA channel.  We wait for BSY to clear, then
3280  *	issue EXECUTE DEVICE DIAGNOSTIC command, polling for its
3281  *	result.  Determine what devices, if any, are on the channel
3282  *	by looking at the device 0/1 error register.  Look at the signature
3283  *	stored in each device's taskfile registers, to determine if
3284  *	the device is ATA or ATAPI.
3285  *
3286  *	LOCKING:
3287  *	PCI/etc. bus probe sem.
3288  *	Obtains host lock.
3289  *
3290  *	SIDE EFFECTS:
3291  *	Sets ATA_FLAG_DISABLED if bus reset fails.
3292  */
3293 
3294 void ata_bus_reset(struct ata_port *ap)
3295 {
3296 	struct ata_device *device = ap->link.device;
3297 	struct ata_ioports *ioaddr = &ap->ioaddr;
3298 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
3299 	u8 err;
3300 	unsigned int dev0, dev1 = 0, devmask = 0;
3301 	int rc;
3302 
3303 	DPRINTK("ENTER, host %u, port %u\n", ap->print_id, ap->port_no);
3304 
3305 	/* determine if device 0/1 are present */
3306 	if (ap->flags & ATA_FLAG_SATA_RESET)
3307 		dev0 = 1;
3308 	else {
3309 		dev0 = ata_devchk(ap, 0);
3310 		if (slave_possible)
3311 			dev1 = ata_devchk(ap, 1);
3312 	}
3313 
3314 	if (dev0)
3315 		devmask |= (1 << 0);
3316 	if (dev1)
3317 		devmask |= (1 << 1);
3318 
3319 	/* select device 0 again */
3320 	ap->ops->dev_select(ap, 0);
3321 
3322 	/* issue bus reset */
3323 	if (ap->flags & ATA_FLAG_SRST) {
3324 		rc = ata_bus_softreset(ap, devmask, jiffies + 40 * HZ);
3325 		if (rc && rc != -ENODEV)
3326 			goto err_out;
3327 	}
3328 
3329 	/*
3330 	 * determine by signature whether we have ATA or ATAPI devices
3331 	 */
3332 	device[0].class = ata_dev_try_classify(&device[0], dev0, &err);
3333 	if ((slave_possible) && (err != 0x81))
3334 		device[1].class = ata_dev_try_classify(&device[1], dev1, &err);
3335 
3336 	/* is double-select really necessary? */
3337 	if (device[1].class != ATA_DEV_NONE)
3338 		ap->ops->dev_select(ap, 1);
3339 	if (device[0].class != ATA_DEV_NONE)
3340 		ap->ops->dev_select(ap, 0);
3341 
3342 	/* if no devices were detected, disable this port */
3343 	if ((device[0].class == ATA_DEV_NONE) &&
3344 	    (device[1].class == ATA_DEV_NONE))
3345 		goto err_out;
3346 
3347 	if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
3348 		/* set up device control for ATA_FLAG_SATA_RESET */
3349 		iowrite8(ap->ctl, ioaddr->ctl_addr);
3350 	}
3351 
3352 	DPRINTK("EXIT\n");
3353 	return;
3354 
3355 err_out:
3356 	ata_port_printk(ap, KERN_ERR, "disabling port\n");
3357 	ata_port_disable(ap);
3358 
3359 	DPRINTK("EXIT\n");
3360 }
3361 
3362 /**
3363  *	sata_link_debounce - debounce SATA phy status
3364  *	@link: ATA link to debounce SATA phy status for
3365  *	@params: timing parameters { interval, duratinon, timeout } in msec
3366  *	@deadline: deadline jiffies for the operation
3367  *
3368 *	Make sure SStatus of @link reaches stable state, determined by
3369  *	holding the same value where DET is not 1 for @duration polled
3370  *	every @interval, before @timeout.  Timeout constraints the
3371  *	beginning of the stable state.  Because DET gets stuck at 1 on
3372  *	some controllers after hot unplugging, this functions waits
3373  *	until timeout then returns 0 if DET is stable at 1.
3374  *
3375  *	@timeout is further limited by @deadline.  The sooner of the
3376  *	two is used.
3377  *
3378  *	LOCKING:
3379  *	Kernel thread context (may sleep)
3380  *
3381  *	RETURNS:
3382  *	0 on success, -errno on failure.
3383  */
3384 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
3385 		       unsigned long deadline)
3386 {
3387 	unsigned long interval_msec = params[0];
3388 	unsigned long duration = msecs_to_jiffies(params[1]);
3389 	unsigned long last_jiffies, t;
3390 	u32 last, cur;
3391 	int rc;
3392 
3393 	t = jiffies + msecs_to_jiffies(params[2]);
3394 	if (time_before(t, deadline))
3395 		deadline = t;
3396 
3397 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3398 		return rc;
3399 	cur &= 0xf;
3400 
3401 	last = cur;
3402 	last_jiffies = jiffies;
3403 
3404 	while (1) {
3405 		msleep(interval_msec);
3406 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3407 			return rc;
3408 		cur &= 0xf;
3409 
3410 		/* DET stable? */
3411 		if (cur == last) {
3412 			if (cur == 1 && time_before(jiffies, deadline))
3413 				continue;
3414 			if (time_after(jiffies, last_jiffies + duration))
3415 				return 0;
3416 			continue;
3417 		}
3418 
3419 		/* unstable, start over */
3420 		last = cur;
3421 		last_jiffies = jiffies;
3422 
3423 		/* Check deadline.  If debouncing failed, return
3424 		 * -EPIPE to tell upper layer to lower link speed.
3425 		 */
3426 		if (time_after(jiffies, deadline))
3427 			return -EPIPE;
3428 	}
3429 }
3430 
3431 /**
3432  *	sata_link_resume - resume SATA link
3433  *	@link: ATA link to resume SATA
3434  *	@params: timing parameters { interval, duratinon, timeout } in msec
3435  *	@deadline: deadline jiffies for the operation
3436  *
3437  *	Resume SATA phy @link and debounce it.
3438  *
3439  *	LOCKING:
3440  *	Kernel thread context (may sleep)
3441  *
3442  *	RETURNS:
3443  *	0 on success, -errno on failure.
3444  */
3445 int sata_link_resume(struct ata_link *link, const unsigned long *params,
3446 		     unsigned long deadline)
3447 {
3448 	u32 scontrol;
3449 	int rc;
3450 
3451 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3452 		return rc;
3453 
3454 	scontrol = (scontrol & 0x0f0) | 0x300;
3455 
3456 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3457 		return rc;
3458 
3459 	/* Some PHYs react badly if SStatus is pounded immediately
3460 	 * after resuming.  Delay 200ms before debouncing.
3461 	 */
3462 	msleep(200);
3463 
3464 	return sata_link_debounce(link, params, deadline);
3465 }
3466 
3467 /**
3468  *	ata_std_prereset - prepare for reset
3469  *	@link: ATA link to be reset
3470  *	@deadline: deadline jiffies for the operation
3471  *
3472  *	@link is about to be reset.  Initialize it.  Failure from
3473  *	prereset makes libata abort whole reset sequence and give up
3474  *	that port, so prereset should be best-effort.  It does its
3475  *	best to prepare for reset sequence but if things go wrong, it
3476  *	should just whine, not fail.
3477  *
3478  *	LOCKING:
3479  *	Kernel thread context (may sleep)
3480  *
3481  *	RETURNS:
3482  *	0 on success, -errno otherwise.
3483  */
3484 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
3485 {
3486 	struct ata_port *ap = link->ap;
3487 	struct ata_eh_context *ehc = &link->eh_context;
3488 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
3489 	int rc;
3490 
3491 	/* handle link resume */
3492 	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
3493 	    (link->flags & ATA_LFLAG_HRST_TO_RESUME))
3494 		ehc->i.action |= ATA_EH_HARDRESET;
3495 
3496 	/* Some PMPs don't work with only SRST, force hardreset if PMP
3497 	 * is supported.
3498 	 */
3499 	if (ap->flags & ATA_FLAG_PMP)
3500 		ehc->i.action |= ATA_EH_HARDRESET;
3501 
3502 	/* if we're about to do hardreset, nothing more to do */
3503 	if (ehc->i.action & ATA_EH_HARDRESET)
3504 		return 0;
3505 
3506 	/* if SATA, resume link */
3507 	if (ap->flags & ATA_FLAG_SATA) {
3508 		rc = sata_link_resume(link, timing, deadline);
3509 		/* whine about phy resume failure but proceed */
3510 		if (rc && rc != -EOPNOTSUPP)
3511 			ata_link_printk(link, KERN_WARNING, "failed to resume "
3512 					"link for reset (errno=%d)\n", rc);
3513 	}
3514 
3515 	/* Wait for !BSY if the controller can wait for the first D2H
3516 	 * Reg FIS and we don't know that no device is attached.
3517 	 */
3518 	if (!(link->flags & ATA_LFLAG_SKIP_D2H_BSY) && !ata_link_offline(link)) {
3519 		rc = ata_wait_ready(ap, deadline);
3520 		if (rc && rc != -ENODEV) {
3521 			ata_link_printk(link, KERN_WARNING, "device not ready "
3522 					"(errno=%d), forcing hardreset\n", rc);
3523 			ehc->i.action |= ATA_EH_HARDRESET;
3524 		}
3525 	}
3526 
3527 	return 0;
3528 }
3529 
3530 /**
3531  *	ata_std_softreset - reset host port via ATA SRST
3532  *	@link: ATA link to reset
3533  *	@classes: resulting classes of attached devices
3534  *	@deadline: deadline jiffies for the operation
3535  *
3536  *	Reset host port using ATA SRST.
3537  *
3538  *	LOCKING:
3539  *	Kernel thread context (may sleep)
3540  *
3541  *	RETURNS:
3542  *	0 on success, -errno otherwise.
3543  */
3544 int ata_std_softreset(struct ata_link *link, unsigned int *classes,
3545 		      unsigned long deadline)
3546 {
3547 	struct ata_port *ap = link->ap;
3548 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
3549 	unsigned int devmask = 0;
3550 	int rc;
3551 	u8 err;
3552 
3553 	DPRINTK("ENTER\n");
3554 
3555 	if (ata_link_offline(link)) {
3556 		classes[0] = ATA_DEV_NONE;
3557 		goto out;
3558 	}
3559 
3560 	/* determine if device 0/1 are present */
3561 	if (ata_devchk(ap, 0))
3562 		devmask |= (1 << 0);
3563 	if (slave_possible && ata_devchk(ap, 1))
3564 		devmask |= (1 << 1);
3565 
3566 	/* select device 0 again */
3567 	ap->ops->dev_select(ap, 0);
3568 
3569 	/* issue bus reset */
3570 	DPRINTK("about to softreset, devmask=%x\n", devmask);
3571 	rc = ata_bus_softreset(ap, devmask, deadline);
3572 	/* if link is occupied, -ENODEV too is an error */
3573 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
3574 		ata_link_printk(link, KERN_ERR, "SRST failed (errno=%d)\n", rc);
3575 		return rc;
3576 	}
3577 
3578 	/* determine by signature whether we have ATA or ATAPI devices */
3579 	classes[0] = ata_dev_try_classify(&link->device[0],
3580 					  devmask & (1 << 0), &err);
3581 	if (slave_possible && err != 0x81)
3582 		classes[1] = ata_dev_try_classify(&link->device[1],
3583 						  devmask & (1 << 1), &err);
3584 
3585  out:
3586 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
3587 	return 0;
3588 }
3589 
3590 /**
3591  *	sata_link_hardreset - reset link via SATA phy reset
3592  *	@link: link to reset
3593  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3594  *	@deadline: deadline jiffies for the operation
3595  *
3596  *	SATA phy-reset @link using DET bits of SControl register.
3597  *
3598  *	LOCKING:
3599  *	Kernel thread context (may sleep)
3600  *
3601  *	RETURNS:
3602  *	0 on success, -errno otherwise.
3603  */
3604 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
3605 			unsigned long deadline)
3606 {
3607 	u32 scontrol;
3608 	int rc;
3609 
3610 	DPRINTK("ENTER\n");
3611 
3612 	if (sata_set_spd_needed(link)) {
3613 		/* SATA spec says nothing about how to reconfigure
3614 		 * spd.  To be on the safe side, turn off phy during
3615 		 * reconfiguration.  This works for at least ICH7 AHCI
3616 		 * and Sil3124.
3617 		 */
3618 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3619 			goto out;
3620 
3621 		scontrol = (scontrol & 0x0f0) | 0x304;
3622 
3623 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3624 			goto out;
3625 
3626 		sata_set_spd(link);
3627 	}
3628 
3629 	/* issue phy wake/reset */
3630 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3631 		goto out;
3632 
3633 	scontrol = (scontrol & 0x0f0) | 0x301;
3634 
3635 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
3636 		goto out;
3637 
3638 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3639 	 * 10.4.2 says at least 1 ms.
3640 	 */
3641 	msleep(1);
3642 
3643 	/* bring link back */
3644 	rc = sata_link_resume(link, timing, deadline);
3645  out:
3646 	DPRINTK("EXIT, rc=%d\n", rc);
3647 	return rc;
3648 }
3649 
3650 /**
3651  *	sata_std_hardreset - reset host port via SATA phy reset
3652  *	@link: link to reset
3653  *	@class: resulting class of attached device
3654  *	@deadline: deadline jiffies for the operation
3655  *
3656  *	SATA phy-reset host port using DET bits of SControl register,
3657  *	wait for !BSY and classify the attached device.
3658  *
3659  *	LOCKING:
3660  *	Kernel thread context (may sleep)
3661  *
3662  *	RETURNS:
3663  *	0 on success, -errno otherwise.
3664  */
3665 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
3666 		       unsigned long deadline)
3667 {
3668 	struct ata_port *ap = link->ap;
3669 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
3670 	int rc;
3671 
3672 	DPRINTK("ENTER\n");
3673 
3674 	/* do hardreset */
3675 	rc = sata_link_hardreset(link, timing, deadline);
3676 	if (rc) {
3677 		ata_link_printk(link, KERN_ERR,
3678 				"COMRESET failed (errno=%d)\n", rc);
3679 		return rc;
3680 	}
3681 
3682 	/* TODO: phy layer with polling, timeouts, etc. */
3683 	if (ata_link_offline(link)) {
3684 		*class = ATA_DEV_NONE;
3685 		DPRINTK("EXIT, link offline\n");
3686 		return 0;
3687 	}
3688 
3689 	/* wait a while before checking status, see SRST for more info */
3690 	msleep(150);
3691 
3692 	/* If PMP is supported, we have to do follow-up SRST.  Note
3693 	 * that some PMPs don't send D2H Reg FIS after hardreset at
3694 	 * all if the first port is empty.  Wait for it just for a
3695 	 * second and request follow-up SRST.
3696 	 */
3697 	if (ap->flags & ATA_FLAG_PMP) {
3698 		ata_wait_ready(ap, jiffies + HZ);
3699 		return -EAGAIN;
3700 	}
3701 
3702 	rc = ata_wait_ready(ap, deadline);
3703 	/* link occupied, -ENODEV too is an error */
3704 	if (rc) {
3705 		ata_link_printk(link, KERN_ERR,
3706 				"COMRESET failed (errno=%d)\n", rc);
3707 		return rc;
3708 	}
3709 
3710 	ap->ops->dev_select(ap, 0);	/* probably unnecessary */
3711 
3712 	*class = ata_dev_try_classify(link->device, 1, NULL);
3713 
3714 	DPRINTK("EXIT, class=%u\n", *class);
3715 	return 0;
3716 }
3717 
3718 /**
3719  *	ata_std_postreset - standard postreset callback
3720  *	@link: the target ata_link
3721  *	@classes: classes of attached devices
3722  *
3723  *	This function is invoked after a successful reset.  Note that
3724  *	the device might have been reset more than once using
3725  *	different reset methods before postreset is invoked.
3726  *
3727  *	LOCKING:
3728  *	Kernel thread context (may sleep)
3729  */
3730 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
3731 {
3732 	struct ata_port *ap = link->ap;
3733 	u32 serror;
3734 
3735 	DPRINTK("ENTER\n");
3736 
3737 	/* print link status */
3738 	sata_print_link_status(link);
3739 
3740 	/* clear SError */
3741 	if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
3742 		sata_scr_write(link, SCR_ERROR, serror);
3743 
3744 	/* is double-select really necessary? */
3745 	if (classes[0] != ATA_DEV_NONE)
3746 		ap->ops->dev_select(ap, 1);
3747 	if (classes[1] != ATA_DEV_NONE)
3748 		ap->ops->dev_select(ap, 0);
3749 
3750 	/* bail out if no device is present */
3751 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
3752 		DPRINTK("EXIT, no device\n");
3753 		return;
3754 	}
3755 
3756 	/* set up device control */
3757 	if (ap->ioaddr.ctl_addr)
3758 		iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
3759 
3760 	DPRINTK("EXIT\n");
3761 }
3762 
3763 /**
3764  *	ata_dev_same_device - Determine whether new ID matches configured device
3765  *	@dev: device to compare against
3766  *	@new_class: class of the new device
3767  *	@new_id: IDENTIFY page of the new device
3768  *
3769  *	Compare @new_class and @new_id against @dev and determine
3770  *	whether @dev is the device indicated by @new_class and
3771  *	@new_id.
3772  *
3773  *	LOCKING:
3774  *	None.
3775  *
3776  *	RETURNS:
3777  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3778  */
3779 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3780 			       const u16 *new_id)
3781 {
3782 	const u16 *old_id = dev->id;
3783 	unsigned char model[2][ATA_ID_PROD_LEN + 1];
3784 	unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
3785 
3786 	if (dev->class != new_class) {
3787 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
3788 			       dev->class, new_class);
3789 		return 0;
3790 	}
3791 
3792 	ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
3793 	ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
3794 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
3795 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
3796 
3797 	if (strcmp(model[0], model[1])) {
3798 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
3799 			       "'%s' != '%s'\n", model[0], model[1]);
3800 		return 0;
3801 	}
3802 
3803 	if (strcmp(serial[0], serial[1])) {
3804 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
3805 			       "'%s' != '%s'\n", serial[0], serial[1]);
3806 		return 0;
3807 	}
3808 
3809 	return 1;
3810 }
3811 
3812 /**
3813  *	ata_dev_reread_id - Re-read IDENTIFY data
3814  *	@dev: target ATA device
3815  *	@readid_flags: read ID flags
3816  *
3817  *	Re-read IDENTIFY page and make sure @dev is still attached to
3818  *	the port.
3819  *
3820  *	LOCKING:
3821  *	Kernel thread context (may sleep)
3822  *
3823  *	RETURNS:
3824  *	0 on success, negative errno otherwise
3825  */
3826 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
3827 {
3828 	unsigned int class = dev->class;
3829 	u16 *id = (void *)dev->link->ap->sector_buf;
3830 	int rc;
3831 
3832 	/* read ID data */
3833 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
3834 	if (rc)
3835 		return rc;
3836 
3837 	/* is the device still there? */
3838 	if (!ata_dev_same_device(dev, class, id))
3839 		return -ENODEV;
3840 
3841 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
3842 	return 0;
3843 }
3844 
3845 /**
3846  *	ata_dev_revalidate - Revalidate ATA device
3847  *	@dev: device to revalidate
3848  *	@new_class: new class code
3849  *	@readid_flags: read ID flags
3850  *
3851  *	Re-read IDENTIFY page, make sure @dev is still attached to the
3852  *	port and reconfigure it according to the new IDENTIFY page.
3853  *
3854  *	LOCKING:
3855  *	Kernel thread context (may sleep)
3856  *
3857  *	RETURNS:
3858  *	0 on success, negative errno otherwise
3859  */
3860 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
3861 		       unsigned int readid_flags)
3862 {
3863 	u64 n_sectors = dev->n_sectors;
3864 	int rc;
3865 
3866 	if (!ata_dev_enabled(dev))
3867 		return -ENODEV;
3868 
3869 	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
3870 	if (ata_class_enabled(new_class) &&
3871 	    new_class != ATA_DEV_ATA && new_class != ATA_DEV_ATAPI) {
3872 		ata_dev_printk(dev, KERN_INFO, "class mismatch %u != %u\n",
3873 			       dev->class, new_class);
3874 		rc = -ENODEV;
3875 		goto fail;
3876 	}
3877 
3878 	/* re-read ID */
3879 	rc = ata_dev_reread_id(dev, readid_flags);
3880 	if (rc)
3881 		goto fail;
3882 
3883 	/* configure device according to the new ID */
3884 	rc = ata_dev_configure(dev);
3885 	if (rc)
3886 		goto fail;
3887 
3888 	/* verify n_sectors hasn't changed */
3889 	if (dev->class == ATA_DEV_ATA && n_sectors &&
3890 	    dev->n_sectors != n_sectors) {
3891 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
3892 			       "%llu != %llu\n",
3893 			       (unsigned long long)n_sectors,
3894 			       (unsigned long long)dev->n_sectors);
3895 
3896 		/* restore original n_sectors */
3897 		dev->n_sectors = n_sectors;
3898 
3899 		rc = -ENODEV;
3900 		goto fail;
3901 	}
3902 
3903 	return 0;
3904 
3905  fail:
3906 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
3907 	return rc;
3908 }
3909 
3910 struct ata_blacklist_entry {
3911 	const char *model_num;
3912 	const char *model_rev;
3913 	unsigned long horkage;
3914 };
3915 
3916 static const struct ata_blacklist_entry ata_device_blacklist [] = {
3917 	/* Devices with DMA related problems under Linux */
3918 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
3919 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
3920 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
3921 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
3922 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
3923 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
3924 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
3925 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
3926 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
3927 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
3928 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
3929 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
3930 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
3931 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
3932 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
3933 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
3934 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
3935 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
3936 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
3937 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
3938 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
3939 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
3940 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
3941 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
3942 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
3943 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
3944 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
3945 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
3946 	{ "SAMSUNG CD-ROM SN-124","N001",	ATA_HORKAGE_NODMA },
3947 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
3948 	{ "IOMEGA  ZIP 250       ATAPI", NULL,	ATA_HORKAGE_NODMA }, /* temporary fix */
3949 	{ "IOMEGA  ZIP 250       ATAPI       Floppy",
3950 				NULL,		ATA_HORKAGE_NODMA },
3951 	/* Odd clown on sil3726/4726 PMPs */
3952 	{ "Config  Disk",	NULL,		ATA_HORKAGE_NODMA |
3953 						ATA_HORKAGE_SKIP_PM },
3954 
3955 	/* Weird ATAPI devices */
3956 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
3957 
3958 	/* Devices we expect to fail diagnostics */
3959 
3960 	/* Devices where NCQ should be avoided */
3961 	/* NCQ is slow */
3962         { "WDC WD740ADFD-00",   NULL,		ATA_HORKAGE_NONCQ },
3963 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
3964 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
3965 	/* NCQ is broken */
3966 	{ "Maxtor *",		"BANC*",	ATA_HORKAGE_NONCQ },
3967 	{ "Maxtor 7V300F0",	"VA111630",	ATA_HORKAGE_NONCQ },
3968 	{ "HITACHI HDS7250SASUN500G*", NULL,    ATA_HORKAGE_NONCQ },
3969 	{ "HITACHI HDS7225SBSUN250G*", NULL,    ATA_HORKAGE_NONCQ },
3970 	{ "ST380817AS",		"3.42",		ATA_HORKAGE_NONCQ },
3971 
3972 	/* Blacklist entries taken from Silicon Image 3124/3132
3973 	   Windows driver .inf file - also several Linux problem reports */
3974 	{ "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
3975 	{ "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
3976 	{ "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },
3977 	/* Drives which do spurious command completion */
3978 	{ "HTS541680J9SA00",	"SB2IC7EP",	ATA_HORKAGE_NONCQ, },
3979 	{ "HTS541612J9SA00",	"SBDIC7JP",	ATA_HORKAGE_NONCQ, },
3980 	{ "HDT722516DLA380",	"V43OA96A",	ATA_HORKAGE_NONCQ, },
3981 	{ "Hitachi HTS541616J9SA00", "SB4OC70P", ATA_HORKAGE_NONCQ, },
3982 	{ "WDC WD740ADFD-00NLR1", NULL,		ATA_HORKAGE_NONCQ, },
3983 	{ "WDC WD3200AAJS-00RYA0", "12.01B01",	ATA_HORKAGE_NONCQ, },
3984 	{ "FUJITSU MHV2080BH",	"00840028",	ATA_HORKAGE_NONCQ, },
3985 	{ "ST9120822AS",	"3.CLF",	ATA_HORKAGE_NONCQ, },
3986 	{ "ST9160821AS",	"3.CLF",	ATA_HORKAGE_NONCQ, },
3987 	{ "ST9160821AS",	"3.ALD",	ATA_HORKAGE_NONCQ, },
3988 	{ "ST9160821AS",	"3.CCD",	ATA_HORKAGE_NONCQ, },
3989 	{ "ST3160812AS",	"3.ADJ",	ATA_HORKAGE_NONCQ, },
3990 	{ "ST980813AS",		"3.ADB",	ATA_HORKAGE_NONCQ, },
3991 	{ "SAMSUNG HD401LJ",	"ZZ100-15",	ATA_HORKAGE_NONCQ, },
3992 
3993 	/* devices which puke on READ_NATIVE_MAX */
3994 	{ "HDS724040KLSA80",	"KFAOA20N",	ATA_HORKAGE_BROKEN_HPA, },
3995 	{ "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
3996 	{ "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
3997 	{ "MAXTOR 6L080L4",	"A93.0500",	ATA_HORKAGE_BROKEN_HPA },
3998 
3999 	/* Devices which report 1 sector over size HPA */
4000 	{ "ST340823A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4001 	{ "ST320413A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4002 
4003 	/* End Marker */
4004 	{ }
4005 };
4006 
4007 int strn_pattern_cmp(const char *patt, const char *name, int wildchar)
4008 {
4009 	const char *p;
4010 	int len;
4011 
4012 	/*
4013 	 * check for trailing wildcard: *\0
4014 	 */
4015 	p = strchr(patt, wildchar);
4016 	if (p && ((*(p + 1)) == 0))
4017 		len = p - patt;
4018 	else {
4019 		len = strlen(name);
4020 		if (!len) {
4021 			if (!*patt)
4022 				return 0;
4023 			return -1;
4024 		}
4025 	}
4026 
4027 	return strncmp(patt, name, len);
4028 }
4029 
4030 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
4031 {
4032 	unsigned char model_num[ATA_ID_PROD_LEN + 1];
4033 	unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
4034 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
4035 
4036 	ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
4037 	ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
4038 
4039 	while (ad->model_num) {
4040 		if (!strn_pattern_cmp(ad->model_num, model_num, '*')) {
4041 			if (ad->model_rev == NULL)
4042 				return ad->horkage;
4043 			if (!strn_pattern_cmp(ad->model_rev, model_rev, '*'))
4044 				return ad->horkage;
4045 		}
4046 		ad++;
4047 	}
4048 	return 0;
4049 }
4050 
4051 static int ata_dma_blacklisted(const struct ata_device *dev)
4052 {
4053 	/* We don't support polling DMA.
4054 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
4055 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
4056 	 */
4057 	if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
4058 	    (dev->flags & ATA_DFLAG_CDB_INTR))
4059 		return 1;
4060 	return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
4061 }
4062 
4063 /**
4064  *	ata_dev_xfermask - Compute supported xfermask of the given device
4065  *	@dev: Device to compute xfermask for
4066  *
4067  *	Compute supported xfermask of @dev and store it in
4068  *	dev->*_mask.  This function is responsible for applying all
4069  *	known limits including host controller limits, device
4070  *	blacklist, etc...
4071  *
4072  *	LOCKING:
4073  *	None.
4074  */
4075 static void ata_dev_xfermask(struct ata_device *dev)
4076 {
4077 	struct ata_link *link = dev->link;
4078 	struct ata_port *ap = link->ap;
4079 	struct ata_host *host = ap->host;
4080 	unsigned long xfer_mask;
4081 
4082 	/* controller modes available */
4083 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
4084 				      ap->mwdma_mask, ap->udma_mask);
4085 
4086 	/* drive modes available */
4087 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
4088 				       dev->mwdma_mask, dev->udma_mask);
4089 	xfer_mask &= ata_id_xfermask(dev->id);
4090 
4091 	/*
4092 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
4093 	 *	cable
4094 	 */
4095 	if (ata_dev_pair(dev)) {
4096 		/* No PIO5 or PIO6 */
4097 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
4098 		/* No MWDMA3 or MWDMA 4 */
4099 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
4100 	}
4101 
4102 	if (ata_dma_blacklisted(dev)) {
4103 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4104 		ata_dev_printk(dev, KERN_WARNING,
4105 			       "device is on DMA blacklist, disabling DMA\n");
4106 	}
4107 
4108 	if ((host->flags & ATA_HOST_SIMPLEX) &&
4109             host->simplex_claimed && host->simplex_claimed != ap) {
4110 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4111 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
4112 			       "other device, disabling DMA\n");
4113 	}
4114 
4115 	if (ap->flags & ATA_FLAG_NO_IORDY)
4116 		xfer_mask &= ata_pio_mask_no_iordy(dev);
4117 
4118 	if (ap->ops->mode_filter)
4119 		xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
4120 
4121 	/* Apply cable rule here.  Don't apply it early because when
4122 	 * we handle hot plug the cable type can itself change.
4123 	 * Check this last so that we know if the transfer rate was
4124 	 * solely limited by the cable.
4125 	 * Unknown or 80 wire cables reported host side are checked
4126 	 * drive side as well. Cases where we know a 40wire cable
4127 	 * is used safely for 80 are not checked here.
4128 	 */
4129 	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
4130 		/* UDMA/44 or higher would be available */
4131 		if((ap->cbl == ATA_CBL_PATA40) ||
4132    		    (ata_drive_40wire(dev->id) &&
4133 		     (ap->cbl == ATA_CBL_PATA_UNK ||
4134                      ap->cbl == ATA_CBL_PATA80))) {
4135 		      	ata_dev_printk(dev, KERN_WARNING,
4136 				 "limited to UDMA/33 due to 40-wire cable\n");
4137 			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
4138 		}
4139 
4140 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
4141 			    &dev->mwdma_mask, &dev->udma_mask);
4142 }
4143 
4144 /**
4145  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
4146  *	@dev: Device to which command will be sent
4147  *
4148  *	Issue SET FEATURES - XFER MODE command to device @dev
4149  *	on port @ap.
4150  *
4151  *	LOCKING:
4152  *	PCI/etc. bus probe sem.
4153  *
4154  *	RETURNS:
4155  *	0 on success, AC_ERR_* mask otherwise.
4156  */
4157 
4158 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
4159 {
4160 	struct ata_taskfile tf;
4161 	unsigned int err_mask;
4162 
4163 	/* set up set-features taskfile */
4164 	DPRINTK("set features - xfer mode\n");
4165 
4166 	/* Some controllers and ATAPI devices show flaky interrupt
4167 	 * behavior after setting xfer mode.  Use polling instead.
4168 	 */
4169 	ata_tf_init(dev, &tf);
4170 	tf.command = ATA_CMD_SET_FEATURES;
4171 	tf.feature = SETFEATURES_XFER;
4172 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
4173 	tf.protocol = ATA_PROT_NODATA;
4174 	tf.nsect = dev->xfer_mode;
4175 
4176 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4177 
4178 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4179 	return err_mask;
4180 }
4181 
4182 /**
4183  *	ata_dev_set_AN - Issue SET FEATURES - SATA FEATURES
4184  *	@dev: Device to which command will be sent
4185  *	@enable: Whether to enable or disable the feature
4186  *
4187  *	Issue SET FEATURES - SATA FEATURES command to device @dev
4188  *	on port @ap with sector count set to indicate Asynchronous
4189  *	Notification feature
4190  *
4191  *	LOCKING:
4192  *	PCI/etc. bus probe sem.
4193  *
4194  *	RETURNS:
4195  *	0 on success, AC_ERR_* mask otherwise.
4196  */
4197 static unsigned int ata_dev_set_AN(struct ata_device *dev, u8 enable)
4198 {
4199 	struct ata_taskfile tf;
4200 	unsigned int err_mask;
4201 
4202 	/* set up set-features taskfile */
4203 	DPRINTK("set features - SATA features\n");
4204 
4205 	ata_tf_init(dev, &tf);
4206 	tf.command = ATA_CMD_SET_FEATURES;
4207 	tf.feature = enable;
4208 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4209 	tf.protocol = ATA_PROT_NODATA;
4210 	tf.nsect = SATA_AN;
4211 
4212 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4213 
4214 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4215 	return err_mask;
4216 }
4217 
4218 /**
4219  *	ata_dev_init_params - Issue INIT DEV PARAMS command
4220  *	@dev: Device to which command will be sent
4221  *	@heads: Number of heads (taskfile parameter)
4222  *	@sectors: Number of sectors (taskfile parameter)
4223  *
4224  *	LOCKING:
4225  *	Kernel thread context (may sleep)
4226  *
4227  *	RETURNS:
4228  *	0 on success, AC_ERR_* mask otherwise.
4229  */
4230 static unsigned int ata_dev_init_params(struct ata_device *dev,
4231 					u16 heads, u16 sectors)
4232 {
4233 	struct ata_taskfile tf;
4234 	unsigned int err_mask;
4235 
4236 	/* Number of sectors per track 1-255. Number of heads 1-16 */
4237 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
4238 		return AC_ERR_INVALID;
4239 
4240 	/* set up init dev params taskfile */
4241 	DPRINTK("init dev params \n");
4242 
4243 	ata_tf_init(dev, &tf);
4244 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
4245 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4246 	tf.protocol = ATA_PROT_NODATA;
4247 	tf.nsect = sectors;
4248 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
4249 
4250 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4251 	/* A clean abort indicates an original or just out of spec drive
4252 	   and we should continue as we issue the setup based on the
4253 	   drive reported working geometry */
4254 	if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
4255 		err_mask = 0;
4256 
4257 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4258 	return err_mask;
4259 }
4260 
4261 /**
4262  *	ata_sg_clean - Unmap DMA memory associated with command
4263  *	@qc: Command containing DMA memory to be released
4264  *
4265  *	Unmap all mapped DMA memory associated with this command.
4266  *
4267  *	LOCKING:
4268  *	spin_lock_irqsave(host lock)
4269  */
4270 void ata_sg_clean(struct ata_queued_cmd *qc)
4271 {
4272 	struct ata_port *ap = qc->ap;
4273 	struct scatterlist *sg = qc->__sg;
4274 	int dir = qc->dma_dir;
4275 	void *pad_buf = NULL;
4276 
4277 	WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
4278 	WARN_ON(sg == NULL);
4279 
4280 	if (qc->flags & ATA_QCFLAG_SINGLE)
4281 		WARN_ON(qc->n_elem > 1);
4282 
4283 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
4284 
4285 	/* if we padded the buffer out to 32-bit bound, and data
4286 	 * xfer direction is from-device, we must copy from the
4287 	 * pad buffer back into the supplied buffer
4288 	 */
4289 	if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
4290 		pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4291 
4292 	if (qc->flags & ATA_QCFLAG_SG) {
4293 		if (qc->n_elem)
4294 			dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
4295 		/* restore last sg */
4296 		sg_last(sg, qc->orig_n_elem)->length += qc->pad_len;
4297 		if (pad_buf) {
4298 			struct scatterlist *psg = &qc->pad_sgent;
4299 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
4300 			memcpy(addr + psg->offset, pad_buf, qc->pad_len);
4301 			kunmap_atomic(addr, KM_IRQ0);
4302 		}
4303 	} else {
4304 		if (qc->n_elem)
4305 			dma_unmap_single(ap->dev,
4306 				sg_dma_address(&sg[0]), sg_dma_len(&sg[0]),
4307 				dir);
4308 		/* restore sg */
4309 		sg->length += qc->pad_len;
4310 		if (pad_buf)
4311 			memcpy(qc->buf_virt + sg->length - qc->pad_len,
4312 			       pad_buf, qc->pad_len);
4313 	}
4314 
4315 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4316 	qc->__sg = NULL;
4317 }
4318 
4319 /**
4320  *	ata_fill_sg - Fill PCI IDE PRD table
4321  *	@qc: Metadata associated with taskfile to be transferred
4322  *
4323  *	Fill PCI IDE PRD (scatter-gather) table with segments
4324  *	associated with the current disk command.
4325  *
4326  *	LOCKING:
4327  *	spin_lock_irqsave(host lock)
4328  *
4329  */
4330 static void ata_fill_sg(struct ata_queued_cmd *qc)
4331 {
4332 	struct ata_port *ap = qc->ap;
4333 	struct scatterlist *sg;
4334 	unsigned int idx;
4335 
4336 	WARN_ON(qc->__sg == NULL);
4337 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
4338 
4339 	idx = 0;
4340 	ata_for_each_sg(sg, qc) {
4341 		u32 addr, offset;
4342 		u32 sg_len, len;
4343 
4344 		/* determine if physical DMA addr spans 64K boundary.
4345 		 * Note h/w doesn't support 64-bit, so we unconditionally
4346 		 * truncate dma_addr_t to u32.
4347 		 */
4348 		addr = (u32) sg_dma_address(sg);
4349 		sg_len = sg_dma_len(sg);
4350 
4351 		while (sg_len) {
4352 			offset = addr & 0xffff;
4353 			len = sg_len;
4354 			if ((offset + sg_len) > 0x10000)
4355 				len = 0x10000 - offset;
4356 
4357 			ap->prd[idx].addr = cpu_to_le32(addr);
4358 			ap->prd[idx].flags_len = cpu_to_le32(len & 0xffff);
4359 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
4360 
4361 			idx++;
4362 			sg_len -= len;
4363 			addr += len;
4364 		}
4365 	}
4366 
4367 	if (idx)
4368 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4369 }
4370 
4371 /**
4372  *	ata_fill_sg_dumb - Fill PCI IDE PRD table
4373  *	@qc: Metadata associated with taskfile to be transferred
4374  *
4375  *	Fill PCI IDE PRD (scatter-gather) table with segments
4376  *	associated with the current disk command. Perform the fill
4377  *	so that we avoid writing any length 64K records for
4378  *	controllers that don't follow the spec.
4379  *
4380  *	LOCKING:
4381  *	spin_lock_irqsave(host lock)
4382  *
4383  */
4384 static void ata_fill_sg_dumb(struct ata_queued_cmd *qc)
4385 {
4386 	struct ata_port *ap = qc->ap;
4387 	struct scatterlist *sg;
4388 	unsigned int idx;
4389 
4390 	WARN_ON(qc->__sg == NULL);
4391 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
4392 
4393 	idx = 0;
4394 	ata_for_each_sg(sg, qc) {
4395 		u32 addr, offset;
4396 		u32 sg_len, len, blen;
4397 
4398  		/* determine if physical DMA addr spans 64K boundary.
4399 		 * Note h/w doesn't support 64-bit, so we unconditionally
4400 		 * truncate dma_addr_t to u32.
4401 		 */
4402 		addr = (u32) sg_dma_address(sg);
4403 		sg_len = sg_dma_len(sg);
4404 
4405 		while (sg_len) {
4406 			offset = addr & 0xffff;
4407 			len = sg_len;
4408 			if ((offset + sg_len) > 0x10000)
4409 				len = 0x10000 - offset;
4410 
4411 			blen = len & 0xffff;
4412 			ap->prd[idx].addr = cpu_to_le32(addr);
4413 			if (blen == 0) {
4414 			   /* Some PATA chipsets like the CS5530 can't
4415 			      cope with 0x0000 meaning 64K as the spec says */
4416 				ap->prd[idx].flags_len = cpu_to_le32(0x8000);
4417 				blen = 0x8000;
4418 				ap->prd[++idx].addr = cpu_to_le32(addr + 0x8000);
4419 			}
4420 			ap->prd[idx].flags_len = cpu_to_le32(blen);
4421 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
4422 
4423 			idx++;
4424 			sg_len -= len;
4425 			addr += len;
4426 		}
4427 	}
4428 
4429 	if (idx)
4430 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4431 }
4432 
4433 /**
4434  *	ata_check_atapi_dma - Check whether ATAPI DMA can be supported
4435  *	@qc: Metadata associated with taskfile to check
4436  *
4437  *	Allow low-level driver to filter ATA PACKET commands, returning
4438  *	a status indicating whether or not it is OK to use DMA for the
4439  *	supplied PACKET command.
4440  *
4441  *	LOCKING:
4442  *	spin_lock_irqsave(host lock)
4443  *
4444  *	RETURNS: 0 when ATAPI DMA can be used
4445  *               nonzero otherwise
4446  */
4447 int ata_check_atapi_dma(struct ata_queued_cmd *qc)
4448 {
4449 	struct ata_port *ap = qc->ap;
4450 
4451 	/* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
4452 	 * few ATAPI devices choke on such DMA requests.
4453 	 */
4454 	if (unlikely(qc->nbytes & 15))
4455 		return 1;
4456 
4457 	if (ap->ops->check_atapi_dma)
4458 		return ap->ops->check_atapi_dma(qc);
4459 
4460 	return 0;
4461 }
4462 
4463 /**
4464  *	ata_std_qc_defer - Check whether a qc needs to be deferred
4465  *	@qc: ATA command in question
4466  *
4467  *	Non-NCQ commands cannot run with any other command, NCQ or
4468  *	not.  As upper layer only knows the queue depth, we are
4469  *	responsible for maintaining exclusion.  This function checks
4470  *	whether a new command @qc can be issued.
4471  *
4472  *	LOCKING:
4473  *	spin_lock_irqsave(host lock)
4474  *
4475  *	RETURNS:
4476  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
4477  */
4478 int ata_std_qc_defer(struct ata_queued_cmd *qc)
4479 {
4480 	struct ata_link *link = qc->dev->link;
4481 
4482 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4483 		if (!ata_tag_valid(link->active_tag))
4484 			return 0;
4485 	} else {
4486 		if (!ata_tag_valid(link->active_tag) && !link->sactive)
4487 			return 0;
4488 	}
4489 
4490 	return ATA_DEFER_LINK;
4491 }
4492 
4493 /**
4494  *	ata_qc_prep - Prepare taskfile for submission
4495  *	@qc: Metadata associated with taskfile to be prepared
4496  *
4497  *	Prepare ATA taskfile for submission.
4498  *
4499  *	LOCKING:
4500  *	spin_lock_irqsave(host lock)
4501  */
4502 void ata_qc_prep(struct ata_queued_cmd *qc)
4503 {
4504 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4505 		return;
4506 
4507 	ata_fill_sg(qc);
4508 }
4509 
4510 /**
4511  *	ata_dumb_qc_prep - Prepare taskfile for submission
4512  *	@qc: Metadata associated with taskfile to be prepared
4513  *
4514  *	Prepare ATA taskfile for submission.
4515  *
4516  *	LOCKING:
4517  *	spin_lock_irqsave(host lock)
4518  */
4519 void ata_dumb_qc_prep(struct ata_queued_cmd *qc)
4520 {
4521 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4522 		return;
4523 
4524 	ata_fill_sg_dumb(qc);
4525 }
4526 
4527 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
4528 
4529 /**
4530  *	ata_sg_init_one - Associate command with memory buffer
4531  *	@qc: Command to be associated
4532  *	@buf: Memory buffer
4533  *	@buflen: Length of memory buffer, in bytes.
4534  *
4535  *	Initialize the data-related elements of queued_cmd @qc
4536  *	to point to a single memory buffer, @buf of byte length @buflen.
4537  *
4538  *	LOCKING:
4539  *	spin_lock_irqsave(host lock)
4540  */
4541 
4542 void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
4543 {
4544 	qc->flags |= ATA_QCFLAG_SINGLE;
4545 
4546 	qc->__sg = &qc->sgent;
4547 	qc->n_elem = 1;
4548 	qc->orig_n_elem = 1;
4549 	qc->buf_virt = buf;
4550 	qc->nbytes = buflen;
4551 	qc->cursg = qc->__sg;
4552 
4553 	sg_init_one(&qc->sgent, buf, buflen);
4554 }
4555 
4556 /**
4557  *	ata_sg_init - Associate command with scatter-gather table.
4558  *	@qc: Command to be associated
4559  *	@sg: Scatter-gather table.
4560  *	@n_elem: Number of elements in s/g table.
4561  *
4562  *	Initialize the data-related elements of queued_cmd @qc
4563  *	to point to a scatter-gather table @sg, containing @n_elem
4564  *	elements.
4565  *
4566  *	LOCKING:
4567  *	spin_lock_irqsave(host lock)
4568  */
4569 
4570 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
4571 		 unsigned int n_elem)
4572 {
4573 	qc->flags |= ATA_QCFLAG_SG;
4574 	qc->__sg = sg;
4575 	qc->n_elem = n_elem;
4576 	qc->orig_n_elem = n_elem;
4577 	qc->cursg = qc->__sg;
4578 }
4579 
4580 /**
4581  *	ata_sg_setup_one - DMA-map the memory buffer associated with a command.
4582  *	@qc: Command with memory buffer to be mapped.
4583  *
4584  *	DMA-map the memory buffer associated with queued_cmd @qc.
4585  *
4586  *	LOCKING:
4587  *	spin_lock_irqsave(host lock)
4588  *
4589  *	RETURNS:
4590  *	Zero on success, negative on error.
4591  */
4592 
4593 static int ata_sg_setup_one(struct ata_queued_cmd *qc)
4594 {
4595 	struct ata_port *ap = qc->ap;
4596 	int dir = qc->dma_dir;
4597 	struct scatterlist *sg = qc->__sg;
4598 	dma_addr_t dma_address;
4599 	int trim_sg = 0;
4600 
4601 	/* we must lengthen transfers to end on a 32-bit boundary */
4602 	qc->pad_len = sg->length & 3;
4603 	if (qc->pad_len) {
4604 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4605 		struct scatterlist *psg = &qc->pad_sgent;
4606 
4607 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
4608 
4609 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
4610 
4611 		if (qc->tf.flags & ATA_TFLAG_WRITE)
4612 			memcpy(pad_buf, qc->buf_virt + sg->length - qc->pad_len,
4613 			       qc->pad_len);
4614 
4615 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
4616 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
4617 		/* trim sg */
4618 		sg->length -= qc->pad_len;
4619 		if (sg->length == 0)
4620 			trim_sg = 1;
4621 
4622 		DPRINTK("padding done, sg->length=%u pad_len=%u\n",
4623 			sg->length, qc->pad_len);
4624 	}
4625 
4626 	if (trim_sg) {
4627 		qc->n_elem--;
4628 		goto skip_map;
4629 	}
4630 
4631 	dma_address = dma_map_single(ap->dev, qc->buf_virt,
4632 				     sg->length, dir);
4633 	if (dma_mapping_error(dma_address)) {
4634 		/* restore sg */
4635 		sg->length += qc->pad_len;
4636 		return -1;
4637 	}
4638 
4639 	sg_dma_address(sg) = dma_address;
4640 	sg_dma_len(sg) = sg->length;
4641 
4642 skip_map:
4643 	DPRINTK("mapped buffer of %d bytes for %s\n", sg_dma_len(sg),
4644 		qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4645 
4646 	return 0;
4647 }
4648 
4649 /**
4650  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
4651  *	@qc: Command with scatter-gather table to be mapped.
4652  *
4653  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
4654  *
4655  *	LOCKING:
4656  *	spin_lock_irqsave(host lock)
4657  *
4658  *	RETURNS:
4659  *	Zero on success, negative on error.
4660  *
4661  */
4662 
4663 static int ata_sg_setup(struct ata_queued_cmd *qc)
4664 {
4665 	struct ata_port *ap = qc->ap;
4666 	struct scatterlist *sg = qc->__sg;
4667 	struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
4668 	int n_elem, pre_n_elem, dir, trim_sg = 0;
4669 
4670 	VPRINTK("ENTER, ata%u\n", ap->print_id);
4671 	WARN_ON(!(qc->flags & ATA_QCFLAG_SG));
4672 
4673 	/* we must lengthen transfers to end on a 32-bit boundary */
4674 	qc->pad_len = lsg->length & 3;
4675 	if (qc->pad_len) {
4676 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4677 		struct scatterlist *psg = &qc->pad_sgent;
4678 		unsigned int offset;
4679 
4680 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
4681 
4682 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
4683 
4684 		/*
4685 		 * psg->page/offset are used to copy to-be-written
4686 		 * data in this function or read data in ata_sg_clean.
4687 		 */
4688 		offset = lsg->offset + lsg->length - qc->pad_len;
4689 		psg->page = nth_page(lsg->page, offset >> PAGE_SHIFT);
4690 		psg->offset = offset_in_page(offset);
4691 
4692 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
4693 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
4694 			memcpy(pad_buf, addr + psg->offset, qc->pad_len);
4695 			kunmap_atomic(addr, KM_IRQ0);
4696 		}
4697 
4698 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
4699 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
4700 		/* trim last sg */
4701 		lsg->length -= qc->pad_len;
4702 		if (lsg->length == 0)
4703 			trim_sg = 1;
4704 
4705 		DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
4706 			qc->n_elem - 1, lsg->length, qc->pad_len);
4707 	}
4708 
4709 	pre_n_elem = qc->n_elem;
4710 	if (trim_sg && pre_n_elem)
4711 		pre_n_elem--;
4712 
4713 	if (!pre_n_elem) {
4714 		n_elem = 0;
4715 		goto skip_map;
4716 	}
4717 
4718 	dir = qc->dma_dir;
4719 	n_elem = dma_map_sg(ap->dev, sg, pre_n_elem, dir);
4720 	if (n_elem < 1) {
4721 		/* restore last sg */
4722 		lsg->length += qc->pad_len;
4723 		return -1;
4724 	}
4725 
4726 	DPRINTK("%d sg elements mapped\n", n_elem);
4727 
4728 skip_map:
4729 	qc->n_elem = n_elem;
4730 
4731 	return 0;
4732 }
4733 
4734 /**
4735  *	swap_buf_le16 - swap halves of 16-bit words in place
4736  *	@buf:  Buffer to swap
4737  *	@buf_words:  Number of 16-bit words in buffer.
4738  *
4739  *	Swap halves of 16-bit words if needed to convert from
4740  *	little-endian byte order to native cpu byte order, or
4741  *	vice-versa.
4742  *
4743  *	LOCKING:
4744  *	Inherited from caller.
4745  */
4746 void swap_buf_le16(u16 *buf, unsigned int buf_words)
4747 {
4748 #ifdef __BIG_ENDIAN
4749 	unsigned int i;
4750 
4751 	for (i = 0; i < buf_words; i++)
4752 		buf[i] = le16_to_cpu(buf[i]);
4753 #endif /* __BIG_ENDIAN */
4754 }
4755 
4756 /**
4757  *	ata_data_xfer - Transfer data by PIO
4758  *	@adev: device to target
4759  *	@buf: data buffer
4760  *	@buflen: buffer length
4761  *	@write_data: read/write
4762  *
4763  *	Transfer data from/to the device data register by PIO.
4764  *
4765  *	LOCKING:
4766  *	Inherited from caller.
4767  */
4768 void ata_data_xfer(struct ata_device *adev, unsigned char *buf,
4769 		   unsigned int buflen, int write_data)
4770 {
4771 	struct ata_port *ap = adev->link->ap;
4772 	unsigned int words = buflen >> 1;
4773 
4774 	/* Transfer multiple of 2 bytes */
4775 	if (write_data)
4776 		iowrite16_rep(ap->ioaddr.data_addr, buf, words);
4777 	else
4778 		ioread16_rep(ap->ioaddr.data_addr, buf, words);
4779 
4780 	/* Transfer trailing 1 byte, if any. */
4781 	if (unlikely(buflen & 0x01)) {
4782 		u16 align_buf[1] = { 0 };
4783 		unsigned char *trailing_buf = buf + buflen - 1;
4784 
4785 		if (write_data) {
4786 			memcpy(align_buf, trailing_buf, 1);
4787 			iowrite16(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
4788 		} else {
4789 			align_buf[0] = cpu_to_le16(ioread16(ap->ioaddr.data_addr));
4790 			memcpy(trailing_buf, align_buf, 1);
4791 		}
4792 	}
4793 }
4794 
4795 /**
4796  *	ata_data_xfer_noirq - Transfer data by PIO
4797  *	@adev: device to target
4798  *	@buf: data buffer
4799  *	@buflen: buffer length
4800  *	@write_data: read/write
4801  *
4802  *	Transfer data from/to the device data register by PIO. Do the
4803  *	transfer with interrupts disabled.
4804  *
4805  *	LOCKING:
4806  *	Inherited from caller.
4807  */
4808 void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
4809 			 unsigned int buflen, int write_data)
4810 {
4811 	unsigned long flags;
4812 	local_irq_save(flags);
4813 	ata_data_xfer(adev, buf, buflen, write_data);
4814 	local_irq_restore(flags);
4815 }
4816 
4817 
4818 /**
4819  *	ata_pio_sector - Transfer a sector of data.
4820  *	@qc: Command on going
4821  *
4822  *	Transfer qc->sect_size bytes of data from/to the ATA device.
4823  *
4824  *	LOCKING:
4825  *	Inherited from caller.
4826  */
4827 
4828 static void ata_pio_sector(struct ata_queued_cmd *qc)
4829 {
4830 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4831 	struct ata_port *ap = qc->ap;
4832 	struct page *page;
4833 	unsigned int offset;
4834 	unsigned char *buf;
4835 
4836 	if (qc->curbytes == qc->nbytes - qc->sect_size)
4837 		ap->hsm_task_state = HSM_ST_LAST;
4838 
4839 	page = qc->cursg->page;
4840 	offset = qc->cursg->offset + qc->cursg_ofs;
4841 
4842 	/* get the current page and offset */
4843 	page = nth_page(page, (offset >> PAGE_SHIFT));
4844 	offset %= PAGE_SIZE;
4845 
4846 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4847 
4848 	if (PageHighMem(page)) {
4849 		unsigned long flags;
4850 
4851 		/* FIXME: use a bounce buffer */
4852 		local_irq_save(flags);
4853 		buf = kmap_atomic(page, KM_IRQ0);
4854 
4855 		/* do the actual data transfer */
4856 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
4857 
4858 		kunmap_atomic(buf, KM_IRQ0);
4859 		local_irq_restore(flags);
4860 	} else {
4861 		buf = page_address(page);
4862 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
4863 	}
4864 
4865 	qc->curbytes += qc->sect_size;
4866 	qc->cursg_ofs += qc->sect_size;
4867 
4868 	if (qc->cursg_ofs == qc->cursg->length) {
4869 		qc->cursg = sg_next(qc->cursg);
4870 		qc->cursg_ofs = 0;
4871 	}
4872 }
4873 
4874 /**
4875  *	ata_pio_sectors - Transfer one or many sectors.
4876  *	@qc: Command on going
4877  *
4878  *	Transfer one or many sectors of data from/to the
4879  *	ATA device for the DRQ request.
4880  *
4881  *	LOCKING:
4882  *	Inherited from caller.
4883  */
4884 
4885 static void ata_pio_sectors(struct ata_queued_cmd *qc)
4886 {
4887 	if (is_multi_taskfile(&qc->tf)) {
4888 		/* READ/WRITE MULTIPLE */
4889 		unsigned int nsect;
4890 
4891 		WARN_ON(qc->dev->multi_count == 0);
4892 
4893 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
4894 			    qc->dev->multi_count);
4895 		while (nsect--)
4896 			ata_pio_sector(qc);
4897 	} else
4898 		ata_pio_sector(qc);
4899 
4900 	ata_altstatus(qc->ap); /* flush */
4901 }
4902 
4903 /**
4904  *	atapi_send_cdb - Write CDB bytes to hardware
4905  *	@ap: Port to which ATAPI device is attached.
4906  *	@qc: Taskfile currently active
4907  *
4908  *	When device has indicated its readiness to accept
4909  *	a CDB, this function is called.  Send the CDB.
4910  *
4911  *	LOCKING:
4912  *	caller.
4913  */
4914 
4915 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
4916 {
4917 	/* send SCSI cdb */
4918 	DPRINTK("send cdb\n");
4919 	WARN_ON(qc->dev->cdb_len < 12);
4920 
4921 	ap->ops->data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
4922 	ata_altstatus(ap); /* flush */
4923 
4924 	switch (qc->tf.protocol) {
4925 	case ATA_PROT_ATAPI:
4926 		ap->hsm_task_state = HSM_ST;
4927 		break;
4928 	case ATA_PROT_ATAPI_NODATA:
4929 		ap->hsm_task_state = HSM_ST_LAST;
4930 		break;
4931 	case ATA_PROT_ATAPI_DMA:
4932 		ap->hsm_task_state = HSM_ST_LAST;
4933 		/* initiate bmdma */
4934 		ap->ops->bmdma_start(qc);
4935 		break;
4936 	}
4937 }
4938 
4939 /**
4940  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
4941  *	@qc: Command on going
4942  *	@bytes: number of bytes
4943  *
4944  *	Transfer Transfer data from/to the ATAPI device.
4945  *
4946  *	LOCKING:
4947  *	Inherited from caller.
4948  *
4949  */
4950 
4951 static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
4952 {
4953 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4954 	struct scatterlist *sg = qc->__sg;
4955 	struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
4956 	struct ata_port *ap = qc->ap;
4957 	struct page *page;
4958 	unsigned char *buf;
4959 	unsigned int offset, count;
4960 	int no_more_sg = 0;
4961 
4962 	if (qc->curbytes + bytes >= qc->nbytes)
4963 		ap->hsm_task_state = HSM_ST_LAST;
4964 
4965 next_sg:
4966 	if (unlikely(no_more_sg)) {
4967 		/*
4968 		 * The end of qc->sg is reached and the device expects
4969 		 * more data to transfer. In order not to overrun qc->sg
4970 		 * and fulfill length specified in the byte count register,
4971 		 *    - for read case, discard trailing data from the device
4972 		 *    - for write case, padding zero data to the device
4973 		 */
4974 		u16 pad_buf[1] = { 0 };
4975 		unsigned int words = bytes >> 1;
4976 		unsigned int i;
4977 
4978 		if (words) /* warning if bytes > 1 */
4979 			ata_dev_printk(qc->dev, KERN_WARNING,
4980 				       "%u bytes trailing data\n", bytes);
4981 
4982 		for (i = 0; i < words; i++)
4983 			ap->ops->data_xfer(qc->dev, (unsigned char*)pad_buf, 2, do_write);
4984 
4985 		ap->hsm_task_state = HSM_ST_LAST;
4986 		return;
4987 	}
4988 
4989 	sg = qc->cursg;
4990 
4991 	page = sg->page;
4992 	offset = sg->offset + qc->cursg_ofs;
4993 
4994 	/* get the current page and offset */
4995 	page = nth_page(page, (offset >> PAGE_SHIFT));
4996 	offset %= PAGE_SIZE;
4997 
4998 	/* don't overrun current sg */
4999 	count = min(sg->length - qc->cursg_ofs, bytes);
5000 
5001 	/* don't cross page boundaries */
5002 	count = min(count, (unsigned int)PAGE_SIZE - offset);
5003 
5004 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
5005 
5006 	if (PageHighMem(page)) {
5007 		unsigned long flags;
5008 
5009 		/* FIXME: use bounce buffer */
5010 		local_irq_save(flags);
5011 		buf = kmap_atomic(page, KM_IRQ0);
5012 
5013 		/* do the actual data transfer */
5014 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
5015 
5016 		kunmap_atomic(buf, KM_IRQ0);
5017 		local_irq_restore(flags);
5018 	} else {
5019 		buf = page_address(page);
5020 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
5021 	}
5022 
5023 	bytes -= count;
5024 	qc->curbytes += count;
5025 	qc->cursg_ofs += count;
5026 
5027 	if (qc->cursg_ofs == sg->length) {
5028 		if (qc->cursg == lsg)
5029 			no_more_sg = 1;
5030 
5031 		qc->cursg = sg_next(qc->cursg);
5032 		qc->cursg_ofs = 0;
5033 	}
5034 
5035 	if (bytes)
5036 		goto next_sg;
5037 }
5038 
5039 /**
5040  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
5041  *	@qc: Command on going
5042  *
5043  *	Transfer Transfer data from/to the ATAPI device.
5044  *
5045  *	LOCKING:
5046  *	Inherited from caller.
5047  */
5048 
5049 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
5050 {
5051 	struct ata_port *ap = qc->ap;
5052 	struct ata_device *dev = qc->dev;
5053 	unsigned int ireason, bc_lo, bc_hi, bytes;
5054 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
5055 
5056 	/* Abuse qc->result_tf for temp storage of intermediate TF
5057 	 * here to save some kernel stack usage.
5058 	 * For normal completion, qc->result_tf is not relevant. For
5059 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
5060 	 * So, the correctness of qc->result_tf is not affected.
5061 	 */
5062 	ap->ops->tf_read(ap, &qc->result_tf);
5063 	ireason = qc->result_tf.nsect;
5064 	bc_lo = qc->result_tf.lbam;
5065 	bc_hi = qc->result_tf.lbah;
5066 	bytes = (bc_hi << 8) | bc_lo;
5067 
5068 	/* shall be cleared to zero, indicating xfer of data */
5069 	if (ireason & (1 << 0))
5070 		goto err_out;
5071 
5072 	/* make sure transfer direction matches expected */
5073 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
5074 	if (do_write != i_write)
5075 		goto err_out;
5076 
5077 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
5078 
5079 	__atapi_pio_bytes(qc, bytes);
5080 	ata_altstatus(ap); /* flush */
5081 
5082 	return;
5083 
5084 err_out:
5085 	ata_dev_printk(dev, KERN_INFO, "ATAPI check failed\n");
5086 	qc->err_mask |= AC_ERR_HSM;
5087 	ap->hsm_task_state = HSM_ST_ERR;
5088 }
5089 
5090 /**
5091  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
5092  *	@ap: the target ata_port
5093  *	@qc: qc on going
5094  *
5095  *	RETURNS:
5096  *	1 if ok in workqueue, 0 otherwise.
5097  */
5098 
5099 static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
5100 {
5101 	if (qc->tf.flags & ATA_TFLAG_POLLING)
5102 		return 1;
5103 
5104 	if (ap->hsm_task_state == HSM_ST_FIRST) {
5105 		if (qc->tf.protocol == ATA_PROT_PIO &&
5106 		    (qc->tf.flags & ATA_TFLAG_WRITE))
5107 		    return 1;
5108 
5109 		if (is_atapi_taskfile(&qc->tf) &&
5110 		    !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5111 			return 1;
5112 	}
5113 
5114 	return 0;
5115 }
5116 
5117 /**
5118  *	ata_hsm_qc_complete - finish a qc running on standard HSM
5119  *	@qc: Command to complete
5120  *	@in_wq: 1 if called from workqueue, 0 otherwise
5121  *
5122  *	Finish @qc which is running on standard HSM.
5123  *
5124  *	LOCKING:
5125  *	If @in_wq is zero, spin_lock_irqsave(host lock).
5126  *	Otherwise, none on entry and grabs host lock.
5127  */
5128 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
5129 {
5130 	struct ata_port *ap = qc->ap;
5131 	unsigned long flags;
5132 
5133 	if (ap->ops->error_handler) {
5134 		if (in_wq) {
5135 			spin_lock_irqsave(ap->lock, flags);
5136 
5137 			/* EH might have kicked in while host lock is
5138 			 * released.
5139 			 */
5140 			qc = ata_qc_from_tag(ap, qc->tag);
5141 			if (qc) {
5142 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
5143 					ap->ops->irq_on(ap);
5144 					ata_qc_complete(qc);
5145 				} else
5146 					ata_port_freeze(ap);
5147 			}
5148 
5149 			spin_unlock_irqrestore(ap->lock, flags);
5150 		} else {
5151 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
5152 				ata_qc_complete(qc);
5153 			else
5154 				ata_port_freeze(ap);
5155 		}
5156 	} else {
5157 		if (in_wq) {
5158 			spin_lock_irqsave(ap->lock, flags);
5159 			ap->ops->irq_on(ap);
5160 			ata_qc_complete(qc);
5161 			spin_unlock_irqrestore(ap->lock, flags);
5162 		} else
5163 			ata_qc_complete(qc);
5164 	}
5165 }
5166 
5167 /**
5168  *	ata_hsm_move - move the HSM to the next state.
5169  *	@ap: the target ata_port
5170  *	@qc: qc on going
5171  *	@status: current device status
5172  *	@in_wq: 1 if called from workqueue, 0 otherwise
5173  *
5174  *	RETURNS:
5175  *	1 when poll next status needed, 0 otherwise.
5176  */
5177 int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
5178 		 u8 status, int in_wq)
5179 {
5180 	unsigned long flags = 0;
5181 	int poll_next;
5182 
5183 	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
5184 
5185 	/* Make sure ata_qc_issue_prot() does not throw things
5186 	 * like DMA polling into the workqueue. Notice that
5187 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
5188 	 */
5189 	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
5190 
5191 fsm_start:
5192 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
5193 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
5194 
5195 	switch (ap->hsm_task_state) {
5196 	case HSM_ST_FIRST:
5197 		/* Send first data block or PACKET CDB */
5198 
5199 		/* If polling, we will stay in the work queue after
5200 		 * sending the data. Otherwise, interrupt handler
5201 		 * takes over after sending the data.
5202 		 */
5203 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
5204 
5205 		/* check device status */
5206 		if (unlikely((status & ATA_DRQ) == 0)) {
5207 			/* handle BSY=0, DRQ=0 as error */
5208 			if (likely(status & (ATA_ERR | ATA_DF)))
5209 				/* device stops HSM for abort/error */
5210 				qc->err_mask |= AC_ERR_DEV;
5211 			else
5212 				/* HSM violation. Let EH handle this */
5213 				qc->err_mask |= AC_ERR_HSM;
5214 
5215 			ap->hsm_task_state = HSM_ST_ERR;
5216 			goto fsm_start;
5217 		}
5218 
5219 		/* Device should not ask for data transfer (DRQ=1)
5220 		 * when it finds something wrong.
5221 		 * We ignore DRQ here and stop the HSM by
5222 		 * changing hsm_task_state to HSM_ST_ERR and
5223 		 * let the EH abort the command or reset the device.
5224 		 */
5225 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
5226 			ata_port_printk(ap, KERN_WARNING, "DRQ=1 with device "
5227 					"error, dev_stat 0x%X\n", status);
5228 			qc->err_mask |= AC_ERR_HSM;
5229 			ap->hsm_task_state = HSM_ST_ERR;
5230 			goto fsm_start;
5231 		}
5232 
5233 		/* Send the CDB (atapi) or the first data block (ata pio out).
5234 		 * During the state transition, interrupt handler shouldn't
5235 		 * be invoked before the data transfer is complete and
5236 		 * hsm_task_state is changed. Hence, the following locking.
5237 		 */
5238 		if (in_wq)
5239 			spin_lock_irqsave(ap->lock, flags);
5240 
5241 		if (qc->tf.protocol == ATA_PROT_PIO) {
5242 			/* PIO data out protocol.
5243 			 * send first data block.
5244 			 */
5245 
5246 			/* ata_pio_sectors() might change the state
5247 			 * to HSM_ST_LAST. so, the state is changed here
5248 			 * before ata_pio_sectors().
5249 			 */
5250 			ap->hsm_task_state = HSM_ST;
5251 			ata_pio_sectors(qc);
5252 		} else
5253 			/* send CDB */
5254 			atapi_send_cdb(ap, qc);
5255 
5256 		if (in_wq)
5257 			spin_unlock_irqrestore(ap->lock, flags);
5258 
5259 		/* if polling, ata_pio_task() handles the rest.
5260 		 * otherwise, interrupt handler takes over from here.
5261 		 */
5262 		break;
5263 
5264 	case HSM_ST:
5265 		/* complete command or read/write the data register */
5266 		if (qc->tf.protocol == ATA_PROT_ATAPI) {
5267 			/* ATAPI PIO protocol */
5268 			if ((status & ATA_DRQ) == 0) {
5269 				/* No more data to transfer or device error.
5270 				 * Device error will be tagged in HSM_ST_LAST.
5271 				 */
5272 				ap->hsm_task_state = HSM_ST_LAST;
5273 				goto fsm_start;
5274 			}
5275 
5276 			/* Device should not ask for data transfer (DRQ=1)
5277 			 * when it finds something wrong.
5278 			 * We ignore DRQ here and stop the HSM by
5279 			 * changing hsm_task_state to HSM_ST_ERR and
5280 			 * let the EH abort the command or reset the device.
5281 			 */
5282 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5283 				ata_port_printk(ap, KERN_WARNING, "DRQ=1 with "
5284 						"device error, dev_stat 0x%X\n",
5285 						status);
5286 				qc->err_mask |= AC_ERR_HSM;
5287 				ap->hsm_task_state = HSM_ST_ERR;
5288 				goto fsm_start;
5289 			}
5290 
5291 			atapi_pio_bytes(qc);
5292 
5293 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
5294 				/* bad ireason reported by device */
5295 				goto fsm_start;
5296 
5297 		} else {
5298 			/* ATA PIO protocol */
5299 			if (unlikely((status & ATA_DRQ) == 0)) {
5300 				/* handle BSY=0, DRQ=0 as error */
5301 				if (likely(status & (ATA_ERR | ATA_DF)))
5302 					/* device stops HSM for abort/error */
5303 					qc->err_mask |= AC_ERR_DEV;
5304 				else
5305 					/* HSM violation. Let EH handle this.
5306 					 * Phantom devices also trigger this
5307 					 * condition.  Mark hint.
5308 					 */
5309 					qc->err_mask |= AC_ERR_HSM |
5310 							AC_ERR_NODEV_HINT;
5311 
5312 				ap->hsm_task_state = HSM_ST_ERR;
5313 				goto fsm_start;
5314 			}
5315 
5316 			/* For PIO reads, some devices may ask for
5317 			 * data transfer (DRQ=1) alone with ERR=1.
5318 			 * We respect DRQ here and transfer one
5319 			 * block of junk data before changing the
5320 			 * hsm_task_state to HSM_ST_ERR.
5321 			 *
5322 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
5323 			 * sense since the data block has been
5324 			 * transferred to the device.
5325 			 */
5326 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5327 				/* data might be corrputed */
5328 				qc->err_mask |= AC_ERR_DEV;
5329 
5330 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
5331 					ata_pio_sectors(qc);
5332 					status = ata_wait_idle(ap);
5333 				}
5334 
5335 				if (status & (ATA_BUSY | ATA_DRQ))
5336 					qc->err_mask |= AC_ERR_HSM;
5337 
5338 				/* ata_pio_sectors() might change the
5339 				 * state to HSM_ST_LAST. so, the state
5340 				 * is changed after ata_pio_sectors().
5341 				 */
5342 				ap->hsm_task_state = HSM_ST_ERR;
5343 				goto fsm_start;
5344 			}
5345 
5346 			ata_pio_sectors(qc);
5347 
5348 			if (ap->hsm_task_state == HSM_ST_LAST &&
5349 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
5350 				/* all data read */
5351 				status = ata_wait_idle(ap);
5352 				goto fsm_start;
5353 			}
5354 		}
5355 
5356 		poll_next = 1;
5357 		break;
5358 
5359 	case HSM_ST_LAST:
5360 		if (unlikely(!ata_ok(status))) {
5361 			qc->err_mask |= __ac_err_mask(status);
5362 			ap->hsm_task_state = HSM_ST_ERR;
5363 			goto fsm_start;
5364 		}
5365 
5366 		/* no more data to transfer */
5367 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
5368 			ap->print_id, qc->dev->devno, status);
5369 
5370 		WARN_ON(qc->err_mask);
5371 
5372 		ap->hsm_task_state = HSM_ST_IDLE;
5373 
5374 		/* complete taskfile transaction */
5375 		ata_hsm_qc_complete(qc, in_wq);
5376 
5377 		poll_next = 0;
5378 		break;
5379 
5380 	case HSM_ST_ERR:
5381 		/* make sure qc->err_mask is available to
5382 		 * know what's wrong and recover
5383 		 */
5384 		WARN_ON(qc->err_mask == 0);
5385 
5386 		ap->hsm_task_state = HSM_ST_IDLE;
5387 
5388 		/* complete taskfile transaction */
5389 		ata_hsm_qc_complete(qc, in_wq);
5390 
5391 		poll_next = 0;
5392 		break;
5393 	default:
5394 		poll_next = 0;
5395 		BUG();
5396 	}
5397 
5398 	return poll_next;
5399 }
5400 
5401 static void ata_pio_task(struct work_struct *work)
5402 {
5403 	struct ata_port *ap =
5404 		container_of(work, struct ata_port, port_task.work);
5405 	struct ata_queued_cmd *qc = ap->port_task_data;
5406 	u8 status;
5407 	int poll_next;
5408 
5409 fsm_start:
5410 	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
5411 
5412 	/*
5413 	 * This is purely heuristic.  This is a fast path.
5414 	 * Sometimes when we enter, BSY will be cleared in
5415 	 * a chk-status or two.  If not, the drive is probably seeking
5416 	 * or something.  Snooze for a couple msecs, then
5417 	 * chk-status again.  If still busy, queue delayed work.
5418 	 */
5419 	status = ata_busy_wait(ap, ATA_BUSY, 5);
5420 	if (status & ATA_BUSY) {
5421 		msleep(2);
5422 		status = ata_busy_wait(ap, ATA_BUSY, 10);
5423 		if (status & ATA_BUSY) {
5424 			ata_port_queue_task(ap, ata_pio_task, qc, ATA_SHORT_PAUSE);
5425 			return;
5426 		}
5427 	}
5428 
5429 	/* move the HSM */
5430 	poll_next = ata_hsm_move(ap, qc, status, 1);
5431 
5432 	/* another command or interrupt handler
5433 	 * may be running at this point.
5434 	 */
5435 	if (poll_next)
5436 		goto fsm_start;
5437 }
5438 
5439 /**
5440  *	ata_qc_new - Request an available ATA command, for queueing
5441  *	@ap: Port associated with device @dev
5442  *	@dev: Device from whom we request an available command structure
5443  *
5444  *	LOCKING:
5445  *	None.
5446  */
5447 
5448 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
5449 {
5450 	struct ata_queued_cmd *qc = NULL;
5451 	unsigned int i;
5452 
5453 	/* no command while frozen */
5454 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
5455 		return NULL;
5456 
5457 	/* the last tag is reserved for internal command. */
5458 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
5459 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
5460 			qc = __ata_qc_from_tag(ap, i);
5461 			break;
5462 		}
5463 
5464 	if (qc)
5465 		qc->tag = i;
5466 
5467 	return qc;
5468 }
5469 
5470 /**
5471  *	ata_qc_new_init - Request an available ATA command, and initialize it
5472  *	@dev: Device from whom we request an available command structure
5473  *
5474  *	LOCKING:
5475  *	None.
5476  */
5477 
5478 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
5479 {
5480 	struct ata_port *ap = dev->link->ap;
5481 	struct ata_queued_cmd *qc;
5482 
5483 	qc = ata_qc_new(ap);
5484 	if (qc) {
5485 		qc->scsicmd = NULL;
5486 		qc->ap = ap;
5487 		qc->dev = dev;
5488 
5489 		ata_qc_reinit(qc);
5490 	}
5491 
5492 	return qc;
5493 }
5494 
5495 /**
5496  *	ata_qc_free - free unused ata_queued_cmd
5497  *	@qc: Command to complete
5498  *
5499  *	Designed to free unused ata_queued_cmd object
5500  *	in case something prevents using it.
5501  *
5502  *	LOCKING:
5503  *	spin_lock_irqsave(host lock)
5504  */
5505 void ata_qc_free(struct ata_queued_cmd *qc)
5506 {
5507 	struct ata_port *ap = qc->ap;
5508 	unsigned int tag;
5509 
5510 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5511 
5512 	qc->flags = 0;
5513 	tag = qc->tag;
5514 	if (likely(ata_tag_valid(tag))) {
5515 		qc->tag = ATA_TAG_POISON;
5516 		clear_bit(tag, &ap->qc_allocated);
5517 	}
5518 }
5519 
5520 void __ata_qc_complete(struct ata_queued_cmd *qc)
5521 {
5522 	struct ata_port *ap = qc->ap;
5523 	struct ata_link *link = qc->dev->link;
5524 
5525 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5526 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
5527 
5528 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
5529 		ata_sg_clean(qc);
5530 
5531 	/* command should be marked inactive atomically with qc completion */
5532 	if (qc->tf.protocol == ATA_PROT_NCQ) {
5533 		link->sactive &= ~(1 << qc->tag);
5534 		if (!link->sactive)
5535 			ap->nr_active_links--;
5536 	} else {
5537 		link->active_tag = ATA_TAG_POISON;
5538 		ap->nr_active_links--;
5539 	}
5540 
5541 	/* clear exclusive status */
5542 	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
5543 		     ap->excl_link == link))
5544 		ap->excl_link = NULL;
5545 
5546 	/* atapi: mark qc as inactive to prevent the interrupt handler
5547 	 * from completing the command twice later, before the error handler
5548 	 * is called. (when rc != 0 and atapi request sense is needed)
5549 	 */
5550 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
5551 	ap->qc_active &= ~(1 << qc->tag);
5552 
5553 	/* call completion callback */
5554 	qc->complete_fn(qc);
5555 }
5556 
5557 static void fill_result_tf(struct ata_queued_cmd *qc)
5558 {
5559 	struct ata_port *ap = qc->ap;
5560 
5561 	qc->result_tf.flags = qc->tf.flags;
5562 	ap->ops->tf_read(ap, &qc->result_tf);
5563 }
5564 
5565 /**
5566  *	ata_qc_complete - Complete an active ATA command
5567  *	@qc: Command to complete
5568  *	@err_mask: ATA Status register contents
5569  *
5570  *	Indicate to the mid and upper layers that an ATA
5571  *	command has completed, with either an ok or not-ok status.
5572  *
5573  *	LOCKING:
5574  *	spin_lock_irqsave(host lock)
5575  */
5576 void ata_qc_complete(struct ata_queued_cmd *qc)
5577 {
5578 	struct ata_port *ap = qc->ap;
5579 
5580 	/* XXX: New EH and old EH use different mechanisms to
5581 	 * synchronize EH with regular execution path.
5582 	 *
5583 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
5584 	 * Normal execution path is responsible for not accessing a
5585 	 * failed qc.  libata core enforces the rule by returning NULL
5586 	 * from ata_qc_from_tag() for failed qcs.
5587 	 *
5588 	 * Old EH depends on ata_qc_complete() nullifying completion
5589 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
5590 	 * not synchronize with interrupt handler.  Only PIO task is
5591 	 * taken care of.
5592 	 */
5593 	if (ap->ops->error_handler) {
5594 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
5595 
5596 		if (unlikely(qc->err_mask))
5597 			qc->flags |= ATA_QCFLAG_FAILED;
5598 
5599 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
5600 			if (!ata_tag_internal(qc->tag)) {
5601 				/* always fill result TF for failed qc */
5602 				fill_result_tf(qc);
5603 				ata_qc_schedule_eh(qc);
5604 				return;
5605 			}
5606 		}
5607 
5608 		/* read result TF if requested */
5609 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
5610 			fill_result_tf(qc);
5611 
5612 		__ata_qc_complete(qc);
5613 	} else {
5614 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
5615 			return;
5616 
5617 		/* read result TF if failed or requested */
5618 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
5619 			fill_result_tf(qc);
5620 
5621 		__ata_qc_complete(qc);
5622 	}
5623 }
5624 
5625 /**
5626  *	ata_qc_complete_multiple - Complete multiple qcs successfully
5627  *	@ap: port in question
5628  *	@qc_active: new qc_active mask
5629  *	@finish_qc: LLDD callback invoked before completing a qc
5630  *
5631  *	Complete in-flight commands.  This functions is meant to be
5632  *	called from low-level driver's interrupt routine to complete
5633  *	requests normally.  ap->qc_active and @qc_active is compared
5634  *	and commands are completed accordingly.
5635  *
5636  *	LOCKING:
5637  *	spin_lock_irqsave(host lock)
5638  *
5639  *	RETURNS:
5640  *	Number of completed commands on success, -errno otherwise.
5641  */
5642 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
5643 			     void (*finish_qc)(struct ata_queued_cmd *))
5644 {
5645 	int nr_done = 0;
5646 	u32 done_mask;
5647 	int i;
5648 
5649 	done_mask = ap->qc_active ^ qc_active;
5650 
5651 	if (unlikely(done_mask & qc_active)) {
5652 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
5653 				"(%08x->%08x)\n", ap->qc_active, qc_active);
5654 		return -EINVAL;
5655 	}
5656 
5657 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
5658 		struct ata_queued_cmd *qc;
5659 
5660 		if (!(done_mask & (1 << i)))
5661 			continue;
5662 
5663 		if ((qc = ata_qc_from_tag(ap, i))) {
5664 			if (finish_qc)
5665 				finish_qc(qc);
5666 			ata_qc_complete(qc);
5667 			nr_done++;
5668 		}
5669 	}
5670 
5671 	return nr_done;
5672 }
5673 
5674 static inline int ata_should_dma_map(struct ata_queued_cmd *qc)
5675 {
5676 	struct ata_port *ap = qc->ap;
5677 
5678 	switch (qc->tf.protocol) {
5679 	case ATA_PROT_NCQ:
5680 	case ATA_PROT_DMA:
5681 	case ATA_PROT_ATAPI_DMA:
5682 		return 1;
5683 
5684 	case ATA_PROT_ATAPI:
5685 	case ATA_PROT_PIO:
5686 		if (ap->flags & ATA_FLAG_PIO_DMA)
5687 			return 1;
5688 
5689 		/* fall through */
5690 
5691 	default:
5692 		return 0;
5693 	}
5694 
5695 	/* never reached */
5696 }
5697 
5698 /**
5699  *	ata_qc_issue - issue taskfile to device
5700  *	@qc: command to issue to device
5701  *
5702  *	Prepare an ATA command to submission to device.
5703  *	This includes mapping the data into a DMA-able
5704  *	area, filling in the S/G table, and finally
5705  *	writing the taskfile to hardware, starting the command.
5706  *
5707  *	LOCKING:
5708  *	spin_lock_irqsave(host lock)
5709  */
5710 void ata_qc_issue(struct ata_queued_cmd *qc)
5711 {
5712 	struct ata_port *ap = qc->ap;
5713 	struct ata_link *link = qc->dev->link;
5714 
5715 	/* Make sure only one non-NCQ command is outstanding.  The
5716 	 * check is skipped for old EH because it reuses active qc to
5717 	 * request ATAPI sense.
5718 	 */
5719 	WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
5720 
5721 	if (qc->tf.protocol == ATA_PROT_NCQ) {
5722 		WARN_ON(link->sactive & (1 << qc->tag));
5723 
5724 		if (!link->sactive)
5725 			ap->nr_active_links++;
5726 		link->sactive |= 1 << qc->tag;
5727 	} else {
5728 		WARN_ON(link->sactive);
5729 
5730 		ap->nr_active_links++;
5731 		link->active_tag = qc->tag;
5732 	}
5733 
5734 	qc->flags |= ATA_QCFLAG_ACTIVE;
5735 	ap->qc_active |= 1 << qc->tag;
5736 
5737 	if (ata_should_dma_map(qc)) {
5738 		if (qc->flags & ATA_QCFLAG_SG) {
5739 			if (ata_sg_setup(qc))
5740 				goto sg_err;
5741 		} else if (qc->flags & ATA_QCFLAG_SINGLE) {
5742 			if (ata_sg_setup_one(qc))
5743 				goto sg_err;
5744 		}
5745 	} else {
5746 		qc->flags &= ~ATA_QCFLAG_DMAMAP;
5747 	}
5748 
5749 	ap->ops->qc_prep(qc);
5750 
5751 	qc->err_mask |= ap->ops->qc_issue(qc);
5752 	if (unlikely(qc->err_mask))
5753 		goto err;
5754 	return;
5755 
5756 sg_err:
5757 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
5758 	qc->err_mask |= AC_ERR_SYSTEM;
5759 err:
5760 	ata_qc_complete(qc);
5761 }
5762 
5763 /**
5764  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
5765  *	@qc: command to issue to device
5766  *
5767  *	Using various libata functions and hooks, this function
5768  *	starts an ATA command.  ATA commands are grouped into
5769  *	classes called "protocols", and issuing each type of protocol
5770  *	is slightly different.
5771  *
5772  *	May be used as the qc_issue() entry in ata_port_operations.
5773  *
5774  *	LOCKING:
5775  *	spin_lock_irqsave(host lock)
5776  *
5777  *	RETURNS:
5778  *	Zero on success, AC_ERR_* mask on failure
5779  */
5780 
5781 unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
5782 {
5783 	struct ata_port *ap = qc->ap;
5784 
5785 	/* Use polling pio if the LLD doesn't handle
5786 	 * interrupt driven pio and atapi CDB interrupt.
5787 	 */
5788 	if (ap->flags & ATA_FLAG_PIO_POLLING) {
5789 		switch (qc->tf.protocol) {
5790 		case ATA_PROT_PIO:
5791 		case ATA_PROT_NODATA:
5792 		case ATA_PROT_ATAPI:
5793 		case ATA_PROT_ATAPI_NODATA:
5794 			qc->tf.flags |= ATA_TFLAG_POLLING;
5795 			break;
5796 		case ATA_PROT_ATAPI_DMA:
5797 			if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
5798 				/* see ata_dma_blacklisted() */
5799 				BUG();
5800 			break;
5801 		default:
5802 			break;
5803 		}
5804 	}
5805 
5806 	/* select the device */
5807 	ata_dev_select(ap, qc->dev->devno, 1, 0);
5808 
5809 	/* start the command */
5810 	switch (qc->tf.protocol) {
5811 	case ATA_PROT_NODATA:
5812 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5813 			ata_qc_set_polling(qc);
5814 
5815 		ata_tf_to_host(ap, &qc->tf);
5816 		ap->hsm_task_state = HSM_ST_LAST;
5817 
5818 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5819 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5820 
5821 		break;
5822 
5823 	case ATA_PROT_DMA:
5824 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5825 
5826 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5827 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5828 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
5829 		ap->hsm_task_state = HSM_ST_LAST;
5830 		break;
5831 
5832 	case ATA_PROT_PIO:
5833 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5834 			ata_qc_set_polling(qc);
5835 
5836 		ata_tf_to_host(ap, &qc->tf);
5837 
5838 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
5839 			/* PIO data out protocol */
5840 			ap->hsm_task_state = HSM_ST_FIRST;
5841 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5842 
5843 			/* always send first data block using
5844 			 * the ata_pio_task() codepath.
5845 			 */
5846 		} else {
5847 			/* PIO data in protocol */
5848 			ap->hsm_task_state = HSM_ST;
5849 
5850 			if (qc->tf.flags & ATA_TFLAG_POLLING)
5851 				ata_port_queue_task(ap, ata_pio_task, qc, 0);
5852 
5853 			/* if polling, ata_pio_task() handles the rest.
5854 			 * otherwise, interrupt handler takes over from here.
5855 			 */
5856 		}
5857 
5858 		break;
5859 
5860 	case ATA_PROT_ATAPI:
5861 	case ATA_PROT_ATAPI_NODATA:
5862 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5863 			ata_qc_set_polling(qc);
5864 
5865 		ata_tf_to_host(ap, &qc->tf);
5866 
5867 		ap->hsm_task_state = HSM_ST_FIRST;
5868 
5869 		/* send cdb by polling if no cdb interrupt */
5870 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
5871 		    (qc->tf.flags & ATA_TFLAG_POLLING))
5872 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5873 		break;
5874 
5875 	case ATA_PROT_ATAPI_DMA:
5876 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5877 
5878 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5879 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5880 		ap->hsm_task_state = HSM_ST_FIRST;
5881 
5882 		/* send cdb by polling if no cdb interrupt */
5883 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5884 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5885 		break;
5886 
5887 	default:
5888 		WARN_ON(1);
5889 		return AC_ERR_SYSTEM;
5890 	}
5891 
5892 	return 0;
5893 }
5894 
5895 /**
5896  *	ata_host_intr - Handle host interrupt for given (port, task)
5897  *	@ap: Port on which interrupt arrived (possibly...)
5898  *	@qc: Taskfile currently active in engine
5899  *
5900  *	Handle host interrupt for given queued command.  Currently,
5901  *	only DMA interrupts are handled.  All other commands are
5902  *	handled via polling with interrupts disabled (nIEN bit).
5903  *
5904  *	LOCKING:
5905  *	spin_lock_irqsave(host lock)
5906  *
5907  *	RETURNS:
5908  *	One if interrupt was handled, zero if not (shared irq).
5909  */
5910 
5911 inline unsigned int ata_host_intr (struct ata_port *ap,
5912 				   struct ata_queued_cmd *qc)
5913 {
5914 	struct ata_eh_info *ehi = &ap->link.eh_info;
5915 	u8 status, host_stat = 0;
5916 
5917 	VPRINTK("ata%u: protocol %d task_state %d\n",
5918 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
5919 
5920 	/* Check whether we are expecting interrupt in this state */
5921 	switch (ap->hsm_task_state) {
5922 	case HSM_ST_FIRST:
5923 		/* Some pre-ATAPI-4 devices assert INTRQ
5924 		 * at this state when ready to receive CDB.
5925 		 */
5926 
5927 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
5928 		 * The flag was turned on only for atapi devices.
5929 		 * No need to check is_atapi_taskfile(&qc->tf) again.
5930 		 */
5931 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5932 			goto idle_irq;
5933 		break;
5934 	case HSM_ST_LAST:
5935 		if (qc->tf.protocol == ATA_PROT_DMA ||
5936 		    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
5937 			/* check status of DMA engine */
5938 			host_stat = ap->ops->bmdma_status(ap);
5939 			VPRINTK("ata%u: host_stat 0x%X\n",
5940 				ap->print_id, host_stat);
5941 
5942 			/* if it's not our irq... */
5943 			if (!(host_stat & ATA_DMA_INTR))
5944 				goto idle_irq;
5945 
5946 			/* before we do anything else, clear DMA-Start bit */
5947 			ap->ops->bmdma_stop(qc);
5948 
5949 			if (unlikely(host_stat & ATA_DMA_ERR)) {
5950 				/* error when transfering data to/from memory */
5951 				qc->err_mask |= AC_ERR_HOST_BUS;
5952 				ap->hsm_task_state = HSM_ST_ERR;
5953 			}
5954 		}
5955 		break;
5956 	case HSM_ST:
5957 		break;
5958 	default:
5959 		goto idle_irq;
5960 	}
5961 
5962 	/* check altstatus */
5963 	status = ata_altstatus(ap);
5964 	if (status & ATA_BUSY)
5965 		goto idle_irq;
5966 
5967 	/* check main status, clearing INTRQ */
5968 	status = ata_chk_status(ap);
5969 	if (unlikely(status & ATA_BUSY))
5970 		goto idle_irq;
5971 
5972 	/* ack bmdma irq events */
5973 	ap->ops->irq_clear(ap);
5974 
5975 	ata_hsm_move(ap, qc, status, 0);
5976 
5977 	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
5978 				       qc->tf.protocol == ATA_PROT_ATAPI_DMA))
5979 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
5980 
5981 	return 1;	/* irq handled */
5982 
5983 idle_irq:
5984 	ap->stats.idle_irq++;
5985 
5986 #ifdef ATA_IRQ_TRAP
5987 	if ((ap->stats.idle_irq % 1000) == 0) {
5988 		ata_chk_status(ap);
5989 		ap->ops->irq_clear(ap);
5990 		ata_port_printk(ap, KERN_WARNING, "irq trap\n");
5991 		return 1;
5992 	}
5993 #endif
5994 	return 0;	/* irq not handled */
5995 }
5996 
5997 /**
5998  *	ata_interrupt - Default ATA host interrupt handler
5999  *	@irq: irq line (unused)
6000  *	@dev_instance: pointer to our ata_host information structure
6001  *
6002  *	Default interrupt handler for PCI IDE devices.  Calls
6003  *	ata_host_intr() for each port that is not disabled.
6004  *
6005  *	LOCKING:
6006  *	Obtains host lock during operation.
6007  *
6008  *	RETURNS:
6009  *	IRQ_NONE or IRQ_HANDLED.
6010  */
6011 
6012 irqreturn_t ata_interrupt (int irq, void *dev_instance)
6013 {
6014 	struct ata_host *host = dev_instance;
6015 	unsigned int i;
6016 	unsigned int handled = 0;
6017 	unsigned long flags;
6018 
6019 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
6020 	spin_lock_irqsave(&host->lock, flags);
6021 
6022 	for (i = 0; i < host->n_ports; i++) {
6023 		struct ata_port *ap;
6024 
6025 		ap = host->ports[i];
6026 		if (ap &&
6027 		    !(ap->flags & ATA_FLAG_DISABLED)) {
6028 			struct ata_queued_cmd *qc;
6029 
6030 			qc = ata_qc_from_tag(ap, ap->link.active_tag);
6031 			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
6032 			    (qc->flags & ATA_QCFLAG_ACTIVE))
6033 				handled |= ata_host_intr(ap, qc);
6034 		}
6035 	}
6036 
6037 	spin_unlock_irqrestore(&host->lock, flags);
6038 
6039 	return IRQ_RETVAL(handled);
6040 }
6041 
6042 /**
6043  *	sata_scr_valid - test whether SCRs are accessible
6044  *	@link: ATA link to test SCR accessibility for
6045  *
6046  *	Test whether SCRs are accessible for @link.
6047  *
6048  *	LOCKING:
6049  *	None.
6050  *
6051  *	RETURNS:
6052  *	1 if SCRs are accessible, 0 otherwise.
6053  */
6054 int sata_scr_valid(struct ata_link *link)
6055 {
6056 	struct ata_port *ap = link->ap;
6057 
6058 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
6059 }
6060 
6061 /**
6062  *	sata_scr_read - read SCR register of the specified port
6063  *	@link: ATA link to read SCR for
6064  *	@reg: SCR to read
6065  *	@val: Place to store read value
6066  *
6067  *	Read SCR register @reg of @link into *@val.  This function is
6068  *	guaranteed to succeed if @link is ap->link, the cable type of
6069  *	the port is SATA and the port implements ->scr_read.
6070  *
6071  *	LOCKING:
6072  *	None if @link is ap->link.  Kernel thread context otherwise.
6073  *
6074  *	RETURNS:
6075  *	0 on success, negative errno on failure.
6076  */
6077 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
6078 {
6079 	if (ata_is_host_link(link)) {
6080 		struct ata_port *ap = link->ap;
6081 
6082 		if (sata_scr_valid(link))
6083 			return ap->ops->scr_read(ap, reg, val);
6084 		return -EOPNOTSUPP;
6085 	}
6086 
6087 	return sata_pmp_scr_read(link, reg, val);
6088 }
6089 
6090 /**
6091  *	sata_scr_write - write SCR register of the specified port
6092  *	@link: ATA link to write SCR for
6093  *	@reg: SCR to write
6094  *	@val: value to write
6095  *
6096  *	Write @val to SCR register @reg of @link.  This function is
6097  *	guaranteed to succeed if @link is ap->link, the cable type of
6098  *	the port is SATA and the port implements ->scr_read.
6099  *
6100  *	LOCKING:
6101  *	None if @link is ap->link.  Kernel thread context otherwise.
6102  *
6103  *	RETURNS:
6104  *	0 on success, negative errno on failure.
6105  */
6106 int sata_scr_write(struct ata_link *link, int reg, u32 val)
6107 {
6108 	if (ata_is_host_link(link)) {
6109 		struct ata_port *ap = link->ap;
6110 
6111 		if (sata_scr_valid(link))
6112 			return ap->ops->scr_write(ap, reg, val);
6113 		return -EOPNOTSUPP;
6114 	}
6115 
6116 	return sata_pmp_scr_write(link, reg, val);
6117 }
6118 
6119 /**
6120  *	sata_scr_write_flush - write SCR register of the specified port and flush
6121  *	@link: ATA link to write SCR for
6122  *	@reg: SCR to write
6123  *	@val: value to write
6124  *
6125  *	This function is identical to sata_scr_write() except that this
6126  *	function performs flush after writing to the register.
6127  *
6128  *	LOCKING:
6129  *	None if @link is ap->link.  Kernel thread context otherwise.
6130  *
6131  *	RETURNS:
6132  *	0 on success, negative errno on failure.
6133  */
6134 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
6135 {
6136 	if (ata_is_host_link(link)) {
6137 		struct ata_port *ap = link->ap;
6138 		int rc;
6139 
6140 		if (sata_scr_valid(link)) {
6141 			rc = ap->ops->scr_write(ap, reg, val);
6142 			if (rc == 0)
6143 				rc = ap->ops->scr_read(ap, reg, &val);
6144 			return rc;
6145 		}
6146 		return -EOPNOTSUPP;
6147 	}
6148 
6149 	return sata_pmp_scr_write(link, reg, val);
6150 }
6151 
6152 /**
6153  *	ata_link_online - test whether the given link is online
6154  *	@link: ATA link to test
6155  *
6156  *	Test whether @link is online.  Note that this function returns
6157  *	0 if online status of @link cannot be obtained, so
6158  *	ata_link_online(link) != !ata_link_offline(link).
6159  *
6160  *	LOCKING:
6161  *	None.
6162  *
6163  *	RETURNS:
6164  *	1 if the port online status is available and online.
6165  */
6166 int ata_link_online(struct ata_link *link)
6167 {
6168 	u32 sstatus;
6169 
6170 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6171 	    (sstatus & 0xf) == 0x3)
6172 		return 1;
6173 	return 0;
6174 }
6175 
6176 /**
6177  *	ata_link_offline - test whether the given link is offline
6178  *	@link: ATA link to test
6179  *
6180  *	Test whether @link is offline.  Note that this function
6181  *	returns 0 if offline status of @link cannot be obtained, so
6182  *	ata_link_online(link) != !ata_link_offline(link).
6183  *
6184  *	LOCKING:
6185  *	None.
6186  *
6187  *	RETURNS:
6188  *	1 if the port offline status is available and offline.
6189  */
6190 int ata_link_offline(struct ata_link *link)
6191 {
6192 	u32 sstatus;
6193 
6194 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6195 	    (sstatus & 0xf) != 0x3)
6196 		return 1;
6197 	return 0;
6198 }
6199 
6200 int ata_flush_cache(struct ata_device *dev)
6201 {
6202 	unsigned int err_mask;
6203 	u8 cmd;
6204 
6205 	if (!ata_try_flush_cache(dev))
6206 		return 0;
6207 
6208 	if (dev->flags & ATA_DFLAG_FLUSH_EXT)
6209 		cmd = ATA_CMD_FLUSH_EXT;
6210 	else
6211 		cmd = ATA_CMD_FLUSH;
6212 
6213 	/* This is wrong. On a failed flush we get back the LBA of the lost
6214 	   sector and we should (assuming it wasn't aborted as unknown) issue
6215 	   a further flush command to continue the writeback until it
6216 	   does not error */
6217 	err_mask = ata_do_simple_cmd(dev, cmd);
6218 	if (err_mask) {
6219 		ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
6220 		return -EIO;
6221 	}
6222 
6223 	return 0;
6224 }
6225 
6226 #ifdef CONFIG_PM
6227 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
6228 			       unsigned int action, unsigned int ehi_flags,
6229 			       int wait)
6230 {
6231 	unsigned long flags;
6232 	int i, rc;
6233 
6234 	for (i = 0; i < host->n_ports; i++) {
6235 		struct ata_port *ap = host->ports[i];
6236 		struct ata_link *link;
6237 
6238 		/* Previous resume operation might still be in
6239 		 * progress.  Wait for PM_PENDING to clear.
6240 		 */
6241 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
6242 			ata_port_wait_eh(ap);
6243 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6244 		}
6245 
6246 		/* request PM ops to EH */
6247 		spin_lock_irqsave(ap->lock, flags);
6248 
6249 		ap->pm_mesg = mesg;
6250 		if (wait) {
6251 			rc = 0;
6252 			ap->pm_result = &rc;
6253 		}
6254 
6255 		ap->pflags |= ATA_PFLAG_PM_PENDING;
6256 		__ata_port_for_each_link(link, ap) {
6257 			link->eh_info.action |= action;
6258 			link->eh_info.flags |= ehi_flags;
6259 		}
6260 
6261 		ata_port_schedule_eh(ap);
6262 
6263 		spin_unlock_irqrestore(ap->lock, flags);
6264 
6265 		/* wait and check result */
6266 		if (wait) {
6267 			ata_port_wait_eh(ap);
6268 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6269 			if (rc)
6270 				return rc;
6271 		}
6272 	}
6273 
6274 	return 0;
6275 }
6276 
6277 /**
6278  *	ata_host_suspend - suspend host
6279  *	@host: host to suspend
6280  *	@mesg: PM message
6281  *
6282  *	Suspend @host.  Actual operation is performed by EH.  This
6283  *	function requests EH to perform PM operations and waits for EH
6284  *	to finish.
6285  *
6286  *	LOCKING:
6287  *	Kernel thread context (may sleep).
6288  *
6289  *	RETURNS:
6290  *	0 on success, -errno on failure.
6291  */
6292 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
6293 {
6294 	int rc;
6295 
6296 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
6297 	if (rc == 0)
6298 		host->dev->power.power_state = mesg;
6299 	return rc;
6300 }
6301 
6302 /**
6303  *	ata_host_resume - resume host
6304  *	@host: host to resume
6305  *
6306  *	Resume @host.  Actual operation is performed by EH.  This
6307  *	function requests EH to perform PM operations and returns.
6308  *	Note that all resume operations are performed parallely.
6309  *
6310  *	LOCKING:
6311  *	Kernel thread context (may sleep).
6312  */
6313 void ata_host_resume(struct ata_host *host)
6314 {
6315 	ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
6316 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
6317 	host->dev->power.power_state = PMSG_ON;
6318 }
6319 #endif
6320 
6321 /**
6322  *	ata_port_start - Set port up for dma.
6323  *	@ap: Port to initialize
6324  *
6325  *	Called just after data structures for each port are
6326  *	initialized.  Allocates space for PRD table.
6327  *
6328  *	May be used as the port_start() entry in ata_port_operations.
6329  *
6330  *	LOCKING:
6331  *	Inherited from caller.
6332  */
6333 int ata_port_start(struct ata_port *ap)
6334 {
6335 	struct device *dev = ap->dev;
6336 	int rc;
6337 
6338 	ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma,
6339 				      GFP_KERNEL);
6340 	if (!ap->prd)
6341 		return -ENOMEM;
6342 
6343 	rc = ata_pad_alloc(ap, dev);
6344 	if (rc)
6345 		return rc;
6346 
6347 	DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd,
6348 		(unsigned long long)ap->prd_dma);
6349 	return 0;
6350 }
6351 
6352 /**
6353  *	ata_dev_init - Initialize an ata_device structure
6354  *	@dev: Device structure to initialize
6355  *
6356  *	Initialize @dev in preparation for probing.
6357  *
6358  *	LOCKING:
6359  *	Inherited from caller.
6360  */
6361 void ata_dev_init(struct ata_device *dev)
6362 {
6363 	struct ata_link *link = dev->link;
6364 	struct ata_port *ap = link->ap;
6365 	unsigned long flags;
6366 
6367 	/* SATA spd limit is bound to the first device */
6368 	link->sata_spd_limit = link->hw_sata_spd_limit;
6369 	link->sata_spd = 0;
6370 
6371 	/* High bits of dev->flags are used to record warm plug
6372 	 * requests which occur asynchronously.  Synchronize using
6373 	 * host lock.
6374 	 */
6375 	spin_lock_irqsave(ap->lock, flags);
6376 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
6377 	dev->horkage = 0;
6378 	spin_unlock_irqrestore(ap->lock, flags);
6379 
6380 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
6381 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
6382 	dev->pio_mask = UINT_MAX;
6383 	dev->mwdma_mask = UINT_MAX;
6384 	dev->udma_mask = UINT_MAX;
6385 }
6386 
6387 /**
6388  *	ata_link_init - Initialize an ata_link structure
6389  *	@ap: ATA port link is attached to
6390  *	@link: Link structure to initialize
6391  *	@pmp: Port multiplier port number
6392  *
6393  *	Initialize @link.
6394  *
6395  *	LOCKING:
6396  *	Kernel thread context (may sleep)
6397  */
6398 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
6399 {
6400 	int i;
6401 
6402 	/* clear everything except for devices */
6403 	memset(link, 0, offsetof(struct ata_link, device[0]));
6404 
6405 	link->ap = ap;
6406 	link->pmp = pmp;
6407 	link->active_tag = ATA_TAG_POISON;
6408 	link->hw_sata_spd_limit = UINT_MAX;
6409 
6410 	/* can't use iterator, ap isn't initialized yet */
6411 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
6412 		struct ata_device *dev = &link->device[i];
6413 
6414 		dev->link = link;
6415 		dev->devno = dev - link->device;
6416 		ata_dev_init(dev);
6417 	}
6418 }
6419 
6420 /**
6421  *	sata_link_init_spd - Initialize link->sata_spd_limit
6422  *	@link: Link to configure sata_spd_limit for
6423  *
6424  *	Initialize @link->[hw_]sata_spd_limit to the currently
6425  *	configured value.
6426  *
6427  *	LOCKING:
6428  *	Kernel thread context (may sleep).
6429  *
6430  *	RETURNS:
6431  *	0 on success, -errno on failure.
6432  */
6433 int sata_link_init_spd(struct ata_link *link)
6434 {
6435 	u32 scontrol, spd;
6436 	int rc;
6437 
6438 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
6439 	if (rc)
6440 		return rc;
6441 
6442 	spd = (scontrol >> 4) & 0xf;
6443 	if (spd)
6444 		link->hw_sata_spd_limit &= (1 << spd) - 1;
6445 
6446 	link->sata_spd_limit = link->hw_sata_spd_limit;
6447 
6448 	return 0;
6449 }
6450 
6451 /**
6452  *	ata_port_alloc - allocate and initialize basic ATA port resources
6453  *	@host: ATA host this allocated port belongs to
6454  *
6455  *	Allocate and initialize basic ATA port resources.
6456  *
6457  *	RETURNS:
6458  *	Allocate ATA port on success, NULL on failure.
6459  *
6460  *	LOCKING:
6461  *	Inherited from calling layer (may sleep).
6462  */
6463 struct ata_port *ata_port_alloc(struct ata_host *host)
6464 {
6465 	struct ata_port *ap;
6466 
6467 	DPRINTK("ENTER\n");
6468 
6469 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
6470 	if (!ap)
6471 		return NULL;
6472 
6473 	ap->pflags |= ATA_PFLAG_INITIALIZING;
6474 	ap->lock = &host->lock;
6475 	ap->flags = ATA_FLAG_DISABLED;
6476 	ap->print_id = -1;
6477 	ap->ctl = ATA_DEVCTL_OBS;
6478 	ap->host = host;
6479 	ap->dev = host->dev;
6480 	ap->last_ctl = 0xFF;
6481 
6482 #if defined(ATA_VERBOSE_DEBUG)
6483 	/* turn on all debugging levels */
6484 	ap->msg_enable = 0x00FF;
6485 #elif defined(ATA_DEBUG)
6486 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
6487 #else
6488 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
6489 #endif
6490 
6491 	INIT_DELAYED_WORK(&ap->port_task, NULL);
6492 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
6493 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
6494 	INIT_LIST_HEAD(&ap->eh_done_q);
6495 	init_waitqueue_head(&ap->eh_wait_q);
6496 	init_timer_deferrable(&ap->fastdrain_timer);
6497 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
6498 	ap->fastdrain_timer.data = (unsigned long)ap;
6499 
6500 	ap->cbl = ATA_CBL_NONE;
6501 
6502 	ata_link_init(ap, &ap->link, 0);
6503 
6504 #ifdef ATA_IRQ_TRAP
6505 	ap->stats.unhandled_irq = 1;
6506 	ap->stats.idle_irq = 1;
6507 #endif
6508 	return ap;
6509 }
6510 
6511 static void ata_host_release(struct device *gendev, void *res)
6512 {
6513 	struct ata_host *host = dev_get_drvdata(gendev);
6514 	int i;
6515 
6516 	for (i = 0; i < host->n_ports; i++) {
6517 		struct ata_port *ap = host->ports[i];
6518 
6519 		if (!ap)
6520 			continue;
6521 
6522 		if ((host->flags & ATA_HOST_STARTED) && ap->ops->port_stop)
6523 			ap->ops->port_stop(ap);
6524 	}
6525 
6526 	if ((host->flags & ATA_HOST_STARTED) && host->ops->host_stop)
6527 		host->ops->host_stop(host);
6528 
6529 	for (i = 0; i < host->n_ports; i++) {
6530 		struct ata_port *ap = host->ports[i];
6531 
6532 		if (!ap)
6533 			continue;
6534 
6535 		if (ap->scsi_host)
6536 			scsi_host_put(ap->scsi_host);
6537 
6538 		kfree(ap->pmp_link);
6539 		kfree(ap);
6540 		host->ports[i] = NULL;
6541 	}
6542 
6543 	dev_set_drvdata(gendev, NULL);
6544 }
6545 
6546 /**
6547  *	ata_host_alloc - allocate and init basic ATA host resources
6548  *	@dev: generic device this host is associated with
6549  *	@max_ports: maximum number of ATA ports associated with this host
6550  *
6551  *	Allocate and initialize basic ATA host resources.  LLD calls
6552  *	this function to allocate a host, initializes it fully and
6553  *	attaches it using ata_host_register().
6554  *
6555  *	@max_ports ports are allocated and host->n_ports is
6556  *	initialized to @max_ports.  The caller is allowed to decrease
6557  *	host->n_ports before calling ata_host_register().  The unused
6558  *	ports will be automatically freed on registration.
6559  *
6560  *	RETURNS:
6561  *	Allocate ATA host on success, NULL on failure.
6562  *
6563  *	LOCKING:
6564  *	Inherited from calling layer (may sleep).
6565  */
6566 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
6567 {
6568 	struct ata_host *host;
6569 	size_t sz;
6570 	int i;
6571 
6572 	DPRINTK("ENTER\n");
6573 
6574 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
6575 		return NULL;
6576 
6577 	/* alloc a container for our list of ATA ports (buses) */
6578 	sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
6579 	/* alloc a container for our list of ATA ports (buses) */
6580 	host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
6581 	if (!host)
6582 		goto err_out;
6583 
6584 	devres_add(dev, host);
6585 	dev_set_drvdata(dev, host);
6586 
6587 	spin_lock_init(&host->lock);
6588 	host->dev = dev;
6589 	host->n_ports = max_ports;
6590 
6591 	/* allocate ports bound to this host */
6592 	for (i = 0; i < max_ports; i++) {
6593 		struct ata_port *ap;
6594 
6595 		ap = ata_port_alloc(host);
6596 		if (!ap)
6597 			goto err_out;
6598 
6599 		ap->port_no = i;
6600 		host->ports[i] = ap;
6601 	}
6602 
6603 	devres_remove_group(dev, NULL);
6604 	return host;
6605 
6606  err_out:
6607 	devres_release_group(dev, NULL);
6608 	return NULL;
6609 }
6610 
6611 /**
6612  *	ata_host_alloc_pinfo - alloc host and init with port_info array
6613  *	@dev: generic device this host is associated with
6614  *	@ppi: array of ATA port_info to initialize host with
6615  *	@n_ports: number of ATA ports attached to this host
6616  *
6617  *	Allocate ATA host and initialize with info from @ppi.  If NULL
6618  *	terminated, @ppi may contain fewer entries than @n_ports.  The
6619  *	last entry will be used for the remaining ports.
6620  *
6621  *	RETURNS:
6622  *	Allocate ATA host on success, NULL on failure.
6623  *
6624  *	LOCKING:
6625  *	Inherited from calling layer (may sleep).
6626  */
6627 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
6628 				      const struct ata_port_info * const * ppi,
6629 				      int n_ports)
6630 {
6631 	const struct ata_port_info *pi;
6632 	struct ata_host *host;
6633 	int i, j;
6634 
6635 	host = ata_host_alloc(dev, n_ports);
6636 	if (!host)
6637 		return NULL;
6638 
6639 	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
6640 		struct ata_port *ap = host->ports[i];
6641 
6642 		if (ppi[j])
6643 			pi = ppi[j++];
6644 
6645 		ap->pio_mask = pi->pio_mask;
6646 		ap->mwdma_mask = pi->mwdma_mask;
6647 		ap->udma_mask = pi->udma_mask;
6648 		ap->flags |= pi->flags;
6649 		ap->link.flags |= pi->link_flags;
6650 		ap->ops = pi->port_ops;
6651 
6652 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
6653 			host->ops = pi->port_ops;
6654 		if (!host->private_data && pi->private_data)
6655 			host->private_data = pi->private_data;
6656 	}
6657 
6658 	return host;
6659 }
6660 
6661 /**
6662  *	ata_host_start - start and freeze ports of an ATA host
6663  *	@host: ATA host to start ports for
6664  *
6665  *	Start and then freeze ports of @host.  Started status is
6666  *	recorded in host->flags, so this function can be called
6667  *	multiple times.  Ports are guaranteed to get started only
6668  *	once.  If host->ops isn't initialized yet, its set to the
6669  *	first non-dummy port ops.
6670  *
6671  *	LOCKING:
6672  *	Inherited from calling layer (may sleep).
6673  *
6674  *	RETURNS:
6675  *	0 if all ports are started successfully, -errno otherwise.
6676  */
6677 int ata_host_start(struct ata_host *host)
6678 {
6679 	int i, rc;
6680 
6681 	if (host->flags & ATA_HOST_STARTED)
6682 		return 0;
6683 
6684 	for (i = 0; i < host->n_ports; i++) {
6685 		struct ata_port *ap = host->ports[i];
6686 
6687 		if (!host->ops && !ata_port_is_dummy(ap))
6688 			host->ops = ap->ops;
6689 
6690 		if (ap->ops->port_start) {
6691 			rc = ap->ops->port_start(ap);
6692 			if (rc) {
6693 				ata_port_printk(ap, KERN_ERR, "failed to "
6694 						"start port (errno=%d)\n", rc);
6695 				goto err_out;
6696 			}
6697 		}
6698 
6699 		ata_eh_freeze_port(ap);
6700 	}
6701 
6702 	host->flags |= ATA_HOST_STARTED;
6703 	return 0;
6704 
6705  err_out:
6706 	while (--i >= 0) {
6707 		struct ata_port *ap = host->ports[i];
6708 
6709 		if (ap->ops->port_stop)
6710 			ap->ops->port_stop(ap);
6711 	}
6712 	return rc;
6713 }
6714 
6715 /**
6716  *	ata_sas_host_init - Initialize a host struct
6717  *	@host:	host to initialize
6718  *	@dev:	device host is attached to
6719  *	@flags:	host flags
6720  *	@ops:	port_ops
6721  *
6722  *	LOCKING:
6723  *	PCI/etc. bus probe sem.
6724  *
6725  */
6726 /* KILLME - the only user left is ipr */
6727 void ata_host_init(struct ata_host *host, struct device *dev,
6728 		   unsigned long flags, const struct ata_port_operations *ops)
6729 {
6730 	spin_lock_init(&host->lock);
6731 	host->dev = dev;
6732 	host->flags = flags;
6733 	host->ops = ops;
6734 }
6735 
6736 /**
6737  *	ata_host_register - register initialized ATA host
6738  *	@host: ATA host to register
6739  *	@sht: template for SCSI host
6740  *
6741  *	Register initialized ATA host.  @host is allocated using
6742  *	ata_host_alloc() and fully initialized by LLD.  This function
6743  *	starts ports, registers @host with ATA and SCSI layers and
6744  *	probe registered devices.
6745  *
6746  *	LOCKING:
6747  *	Inherited from calling layer (may sleep).
6748  *
6749  *	RETURNS:
6750  *	0 on success, -errno otherwise.
6751  */
6752 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
6753 {
6754 	int i, rc;
6755 
6756 	/* host must have been started */
6757 	if (!(host->flags & ATA_HOST_STARTED)) {
6758 		dev_printk(KERN_ERR, host->dev,
6759 			   "BUG: trying to register unstarted host\n");
6760 		WARN_ON(1);
6761 		return -EINVAL;
6762 	}
6763 
6764 	/* Blow away unused ports.  This happens when LLD can't
6765 	 * determine the exact number of ports to allocate at
6766 	 * allocation time.
6767 	 */
6768 	for (i = host->n_ports; host->ports[i]; i++)
6769 		kfree(host->ports[i]);
6770 
6771 	/* give ports names and add SCSI hosts */
6772 	for (i = 0; i < host->n_ports; i++)
6773 		host->ports[i]->print_id = ata_print_id++;
6774 
6775 	rc = ata_scsi_add_hosts(host, sht);
6776 	if (rc)
6777 		return rc;
6778 
6779 	/* associate with ACPI nodes */
6780 	ata_acpi_associate(host);
6781 
6782 	/* set cable, sata_spd_limit and report */
6783 	for (i = 0; i < host->n_ports; i++) {
6784 		struct ata_port *ap = host->ports[i];
6785 		unsigned long xfer_mask;
6786 
6787 		/* set SATA cable type if still unset */
6788 		if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
6789 			ap->cbl = ATA_CBL_SATA;
6790 
6791 		/* init sata_spd_limit to the current value */
6792 		sata_link_init_spd(&ap->link);
6793 
6794 		/* print per-port info to dmesg */
6795 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
6796 					      ap->udma_mask);
6797 
6798 		if (!ata_port_is_dummy(ap)) {
6799 			ata_port_printk(ap, KERN_INFO,
6800 					"%cATA max %s %s\n",
6801 					(ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
6802 					ata_mode_string(xfer_mask),
6803 					ap->link.eh_info.desc);
6804 			ata_ehi_clear_desc(&ap->link.eh_info);
6805 		} else
6806 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
6807 	}
6808 
6809 	/* perform each probe synchronously */
6810 	DPRINTK("probe begin\n");
6811 	for (i = 0; i < host->n_ports; i++) {
6812 		struct ata_port *ap = host->ports[i];
6813 		int rc;
6814 
6815 		/* probe */
6816 		if (ap->ops->error_handler) {
6817 			struct ata_eh_info *ehi = &ap->link.eh_info;
6818 			unsigned long flags;
6819 
6820 			ata_port_probe(ap);
6821 
6822 			/* kick EH for boot probing */
6823 			spin_lock_irqsave(ap->lock, flags);
6824 
6825 			ehi->probe_mask =
6826 				(1 << ata_link_max_devices(&ap->link)) - 1;
6827 			ehi->action |= ATA_EH_SOFTRESET;
6828 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
6829 
6830 			ap->pflags &= ~ATA_PFLAG_INITIALIZING;
6831 			ap->pflags |= ATA_PFLAG_LOADING;
6832 			ata_port_schedule_eh(ap);
6833 
6834 			spin_unlock_irqrestore(ap->lock, flags);
6835 
6836 			/* wait for EH to finish */
6837 			ata_port_wait_eh(ap);
6838 		} else {
6839 			DPRINTK("ata%u: bus probe begin\n", ap->print_id);
6840 			rc = ata_bus_probe(ap);
6841 			DPRINTK("ata%u: bus probe end\n", ap->print_id);
6842 
6843 			if (rc) {
6844 				/* FIXME: do something useful here?
6845 				 * Current libata behavior will
6846 				 * tear down everything when
6847 				 * the module is removed
6848 				 * or the h/w is unplugged.
6849 				 */
6850 			}
6851 		}
6852 	}
6853 
6854 	/* probes are done, now scan each port's disk(s) */
6855 	DPRINTK("host probe begin\n");
6856 	for (i = 0; i < host->n_ports; i++) {
6857 		struct ata_port *ap = host->ports[i];
6858 
6859 		ata_scsi_scan_host(ap, 1);
6860 	}
6861 
6862 	return 0;
6863 }
6864 
6865 /**
6866  *	ata_host_activate - start host, request IRQ and register it
6867  *	@host: target ATA host
6868  *	@irq: IRQ to request
6869  *	@irq_handler: irq_handler used when requesting IRQ
6870  *	@irq_flags: irq_flags used when requesting IRQ
6871  *	@sht: scsi_host_template to use when registering the host
6872  *
6873  *	After allocating an ATA host and initializing it, most libata
6874  *	LLDs perform three steps to activate the host - start host,
6875  *	request IRQ and register it.  This helper takes necessasry
6876  *	arguments and performs the three steps in one go.
6877  *
6878  *	LOCKING:
6879  *	Inherited from calling layer (may sleep).
6880  *
6881  *	RETURNS:
6882  *	0 on success, -errno otherwise.
6883  */
6884 int ata_host_activate(struct ata_host *host, int irq,
6885 		      irq_handler_t irq_handler, unsigned long irq_flags,
6886 		      struct scsi_host_template *sht)
6887 {
6888 	int i, rc;
6889 
6890 	rc = ata_host_start(host);
6891 	if (rc)
6892 		return rc;
6893 
6894 	rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
6895 			      dev_driver_string(host->dev), host);
6896 	if (rc)
6897 		return rc;
6898 
6899 	for (i = 0; i < host->n_ports; i++)
6900 		ata_port_desc(host->ports[i], "irq %d", irq);
6901 
6902 	rc = ata_host_register(host, sht);
6903 	/* if failed, just free the IRQ and leave ports alone */
6904 	if (rc)
6905 		devm_free_irq(host->dev, irq, host);
6906 
6907 	return rc;
6908 }
6909 
6910 /**
6911  *	ata_port_detach - Detach ATA port in prepration of device removal
6912  *	@ap: ATA port to be detached
6913  *
6914  *	Detach all ATA devices and the associated SCSI devices of @ap;
6915  *	then, remove the associated SCSI host.  @ap is guaranteed to
6916  *	be quiescent on return from this function.
6917  *
6918  *	LOCKING:
6919  *	Kernel thread context (may sleep).
6920  */
6921 void ata_port_detach(struct ata_port *ap)
6922 {
6923 	unsigned long flags;
6924 	struct ata_link *link;
6925 	struct ata_device *dev;
6926 
6927 	if (!ap->ops->error_handler)
6928 		goto skip_eh;
6929 
6930 	/* tell EH we're leaving & flush EH */
6931 	spin_lock_irqsave(ap->lock, flags);
6932 	ap->pflags |= ATA_PFLAG_UNLOADING;
6933 	spin_unlock_irqrestore(ap->lock, flags);
6934 
6935 	ata_port_wait_eh(ap);
6936 
6937 	/* EH is now guaranteed to see UNLOADING, so no new device
6938 	 * will be attached.  Disable all existing devices.
6939 	 */
6940 	spin_lock_irqsave(ap->lock, flags);
6941 
6942 	ata_port_for_each_link(link, ap) {
6943 		ata_link_for_each_dev(dev, link)
6944 			ata_dev_disable(dev);
6945 	}
6946 
6947 	spin_unlock_irqrestore(ap->lock, flags);
6948 
6949 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
6950 	 * will be skipped and retrials will be terminated with bad
6951 	 * target.
6952 	 */
6953 	spin_lock_irqsave(ap->lock, flags);
6954 	ata_port_freeze(ap);	/* won't be thawed */
6955 	spin_unlock_irqrestore(ap->lock, flags);
6956 
6957 	ata_port_wait_eh(ap);
6958 	cancel_rearming_delayed_work(&ap->hotplug_task);
6959 
6960  skip_eh:
6961 	/* remove the associated SCSI host */
6962 	scsi_remove_host(ap->scsi_host);
6963 }
6964 
6965 /**
6966  *	ata_host_detach - Detach all ports of an ATA host
6967  *	@host: Host to detach
6968  *
6969  *	Detach all ports of @host.
6970  *
6971  *	LOCKING:
6972  *	Kernel thread context (may sleep).
6973  */
6974 void ata_host_detach(struct ata_host *host)
6975 {
6976 	int i;
6977 
6978 	for (i = 0; i < host->n_ports; i++)
6979 		ata_port_detach(host->ports[i]);
6980 }
6981 
6982 /**
6983  *	ata_std_ports - initialize ioaddr with standard port offsets.
6984  *	@ioaddr: IO address structure to be initialized
6985  *
6986  *	Utility function which initializes data_addr, error_addr,
6987  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
6988  *	device_addr, status_addr, and command_addr to standard offsets
6989  *	relative to cmd_addr.
6990  *
6991  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
6992  */
6993 
6994 void ata_std_ports(struct ata_ioports *ioaddr)
6995 {
6996 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
6997 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
6998 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
6999 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
7000 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
7001 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
7002 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
7003 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
7004 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
7005 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
7006 }
7007 
7008 
7009 #ifdef CONFIG_PCI
7010 
7011 /**
7012  *	ata_pci_remove_one - PCI layer callback for device removal
7013  *	@pdev: PCI device that was removed
7014  *
7015  *	PCI layer indicates to libata via this hook that hot-unplug or
7016  *	module unload event has occurred.  Detach all ports.  Resource
7017  *	release is handled via devres.
7018  *
7019  *	LOCKING:
7020  *	Inherited from PCI layer (may sleep).
7021  */
7022 void ata_pci_remove_one(struct pci_dev *pdev)
7023 {
7024 	struct device *dev = &pdev->dev;
7025 	struct ata_host *host = dev_get_drvdata(dev);
7026 
7027 	ata_host_detach(host);
7028 }
7029 
7030 /* move to PCI subsystem */
7031 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
7032 {
7033 	unsigned long tmp = 0;
7034 
7035 	switch (bits->width) {
7036 	case 1: {
7037 		u8 tmp8 = 0;
7038 		pci_read_config_byte(pdev, bits->reg, &tmp8);
7039 		tmp = tmp8;
7040 		break;
7041 	}
7042 	case 2: {
7043 		u16 tmp16 = 0;
7044 		pci_read_config_word(pdev, bits->reg, &tmp16);
7045 		tmp = tmp16;
7046 		break;
7047 	}
7048 	case 4: {
7049 		u32 tmp32 = 0;
7050 		pci_read_config_dword(pdev, bits->reg, &tmp32);
7051 		tmp = tmp32;
7052 		break;
7053 	}
7054 
7055 	default:
7056 		return -EINVAL;
7057 	}
7058 
7059 	tmp &= bits->mask;
7060 
7061 	return (tmp == bits->val) ? 1 : 0;
7062 }
7063 
7064 #ifdef CONFIG_PM
7065 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
7066 {
7067 	pci_save_state(pdev);
7068 	pci_disable_device(pdev);
7069 
7070 	if (mesg.event == PM_EVENT_SUSPEND)
7071 		pci_set_power_state(pdev, PCI_D3hot);
7072 }
7073 
7074 int ata_pci_device_do_resume(struct pci_dev *pdev)
7075 {
7076 	int rc;
7077 
7078 	pci_set_power_state(pdev, PCI_D0);
7079 	pci_restore_state(pdev);
7080 
7081 	rc = pcim_enable_device(pdev);
7082 	if (rc) {
7083 		dev_printk(KERN_ERR, &pdev->dev,
7084 			   "failed to enable device after resume (%d)\n", rc);
7085 		return rc;
7086 	}
7087 
7088 	pci_set_master(pdev);
7089 	return 0;
7090 }
7091 
7092 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
7093 {
7094 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7095 	int rc = 0;
7096 
7097 	rc = ata_host_suspend(host, mesg);
7098 	if (rc)
7099 		return rc;
7100 
7101 	ata_pci_device_do_suspend(pdev, mesg);
7102 
7103 	return 0;
7104 }
7105 
7106 int ata_pci_device_resume(struct pci_dev *pdev)
7107 {
7108 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7109 	int rc;
7110 
7111 	rc = ata_pci_device_do_resume(pdev);
7112 	if (rc == 0)
7113 		ata_host_resume(host);
7114 	return rc;
7115 }
7116 #endif /* CONFIG_PM */
7117 
7118 #endif /* CONFIG_PCI */
7119 
7120 
7121 static int __init ata_init(void)
7122 {
7123 	ata_probe_timeout *= HZ;
7124 	ata_wq = create_workqueue("ata");
7125 	if (!ata_wq)
7126 		return -ENOMEM;
7127 
7128 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
7129 	if (!ata_aux_wq) {
7130 		destroy_workqueue(ata_wq);
7131 		return -ENOMEM;
7132 	}
7133 
7134 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
7135 	return 0;
7136 }
7137 
7138 static void __exit ata_exit(void)
7139 {
7140 	destroy_workqueue(ata_wq);
7141 	destroy_workqueue(ata_aux_wq);
7142 }
7143 
7144 subsys_initcall(ata_init);
7145 module_exit(ata_exit);
7146 
7147 static unsigned long ratelimit_time;
7148 static DEFINE_SPINLOCK(ata_ratelimit_lock);
7149 
7150 int ata_ratelimit(void)
7151 {
7152 	int rc;
7153 	unsigned long flags;
7154 
7155 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
7156 
7157 	if (time_after(jiffies, ratelimit_time)) {
7158 		rc = 1;
7159 		ratelimit_time = jiffies + (HZ/5);
7160 	} else
7161 		rc = 0;
7162 
7163 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
7164 
7165 	return rc;
7166 }
7167 
7168 /**
7169  *	ata_wait_register - wait until register value changes
7170  *	@reg: IO-mapped register
7171  *	@mask: Mask to apply to read register value
7172  *	@val: Wait condition
7173  *	@interval_msec: polling interval in milliseconds
7174  *	@timeout_msec: timeout in milliseconds
7175  *
7176  *	Waiting for some bits of register to change is a common
7177  *	operation for ATA controllers.  This function reads 32bit LE
7178  *	IO-mapped register @reg and tests for the following condition.
7179  *
7180  *	(*@reg & mask) != val
7181  *
7182  *	If the condition is met, it returns; otherwise, the process is
7183  *	repeated after @interval_msec until timeout.
7184  *
7185  *	LOCKING:
7186  *	Kernel thread context (may sleep)
7187  *
7188  *	RETURNS:
7189  *	The final register value.
7190  */
7191 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
7192 		      unsigned long interval_msec,
7193 		      unsigned long timeout_msec)
7194 {
7195 	unsigned long timeout;
7196 	u32 tmp;
7197 
7198 	tmp = ioread32(reg);
7199 
7200 	/* Calculate timeout _after_ the first read to make sure
7201 	 * preceding writes reach the controller before starting to
7202 	 * eat away the timeout.
7203 	 */
7204 	timeout = jiffies + (timeout_msec * HZ) / 1000;
7205 
7206 	while ((tmp & mask) == val && time_before(jiffies, timeout)) {
7207 		msleep(interval_msec);
7208 		tmp = ioread32(reg);
7209 	}
7210 
7211 	return tmp;
7212 }
7213 
7214 /*
7215  * Dummy port_ops
7216  */
7217 static void ata_dummy_noret(struct ata_port *ap)	{ }
7218 static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
7219 static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
7220 
7221 static u8 ata_dummy_check_status(struct ata_port *ap)
7222 {
7223 	return ATA_DRDY;
7224 }
7225 
7226 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
7227 {
7228 	return AC_ERR_SYSTEM;
7229 }
7230 
7231 const struct ata_port_operations ata_dummy_port_ops = {
7232 	.check_status		= ata_dummy_check_status,
7233 	.check_altstatus	= ata_dummy_check_status,
7234 	.dev_select		= ata_noop_dev_select,
7235 	.qc_prep		= ata_noop_qc_prep,
7236 	.qc_issue		= ata_dummy_qc_issue,
7237 	.freeze			= ata_dummy_noret,
7238 	.thaw			= ata_dummy_noret,
7239 	.error_handler		= ata_dummy_noret,
7240 	.post_internal_cmd	= ata_dummy_qc_noret,
7241 	.irq_clear		= ata_dummy_noret,
7242 	.port_start		= ata_dummy_ret0,
7243 	.port_stop		= ata_dummy_noret,
7244 };
7245 
7246 const struct ata_port_info ata_dummy_port_info = {
7247 	.port_ops		= &ata_dummy_port_ops,
7248 };
7249 
7250 /*
7251  * libata is essentially a library of internal helper functions for
7252  * low-level ATA host controller drivers.  As such, the API/ABI is
7253  * likely to change as new drivers are added and updated.
7254  * Do not depend on ABI/API stability.
7255  */
7256 
7257 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
7258 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
7259 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
7260 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
7261 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
7262 EXPORT_SYMBOL_GPL(ata_std_bios_param);
7263 EXPORT_SYMBOL_GPL(ata_std_ports);
7264 EXPORT_SYMBOL_GPL(ata_host_init);
7265 EXPORT_SYMBOL_GPL(ata_host_alloc);
7266 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
7267 EXPORT_SYMBOL_GPL(ata_host_start);
7268 EXPORT_SYMBOL_GPL(ata_host_register);
7269 EXPORT_SYMBOL_GPL(ata_host_activate);
7270 EXPORT_SYMBOL_GPL(ata_host_detach);
7271 EXPORT_SYMBOL_GPL(ata_sg_init);
7272 EXPORT_SYMBOL_GPL(ata_sg_init_one);
7273 EXPORT_SYMBOL_GPL(ata_hsm_move);
7274 EXPORT_SYMBOL_GPL(ata_qc_complete);
7275 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
7276 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
7277 EXPORT_SYMBOL_GPL(ata_tf_load);
7278 EXPORT_SYMBOL_GPL(ata_tf_read);
7279 EXPORT_SYMBOL_GPL(ata_noop_dev_select);
7280 EXPORT_SYMBOL_GPL(ata_std_dev_select);
7281 EXPORT_SYMBOL_GPL(sata_print_link_status);
7282 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
7283 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
7284 EXPORT_SYMBOL_GPL(ata_check_status);
7285 EXPORT_SYMBOL_GPL(ata_altstatus);
7286 EXPORT_SYMBOL_GPL(ata_exec_command);
7287 EXPORT_SYMBOL_GPL(ata_port_start);
7288 EXPORT_SYMBOL_GPL(ata_sff_port_start);
7289 EXPORT_SYMBOL_GPL(ata_interrupt);
7290 EXPORT_SYMBOL_GPL(ata_do_set_mode);
7291 EXPORT_SYMBOL_GPL(ata_data_xfer);
7292 EXPORT_SYMBOL_GPL(ata_data_xfer_noirq);
7293 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
7294 EXPORT_SYMBOL_GPL(ata_qc_prep);
7295 EXPORT_SYMBOL_GPL(ata_dumb_qc_prep);
7296 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
7297 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
7298 EXPORT_SYMBOL_GPL(ata_bmdma_start);
7299 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
7300 EXPORT_SYMBOL_GPL(ata_bmdma_status);
7301 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
7302 EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
7303 EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
7304 EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
7305 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
7306 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
7307 EXPORT_SYMBOL_GPL(ata_port_probe);
7308 EXPORT_SYMBOL_GPL(ata_dev_disable);
7309 EXPORT_SYMBOL_GPL(sata_set_spd);
7310 EXPORT_SYMBOL_GPL(sata_link_debounce);
7311 EXPORT_SYMBOL_GPL(sata_link_resume);
7312 EXPORT_SYMBOL_GPL(sata_phy_reset);
7313 EXPORT_SYMBOL_GPL(__sata_phy_reset);
7314 EXPORT_SYMBOL_GPL(ata_bus_reset);
7315 EXPORT_SYMBOL_GPL(ata_std_prereset);
7316 EXPORT_SYMBOL_GPL(ata_std_softreset);
7317 EXPORT_SYMBOL_GPL(sata_link_hardreset);
7318 EXPORT_SYMBOL_GPL(sata_std_hardreset);
7319 EXPORT_SYMBOL_GPL(ata_std_postreset);
7320 EXPORT_SYMBOL_GPL(ata_dev_classify);
7321 EXPORT_SYMBOL_GPL(ata_dev_pair);
7322 EXPORT_SYMBOL_GPL(ata_port_disable);
7323 EXPORT_SYMBOL_GPL(ata_ratelimit);
7324 EXPORT_SYMBOL_GPL(ata_wait_register);
7325 EXPORT_SYMBOL_GPL(ata_busy_sleep);
7326 EXPORT_SYMBOL_GPL(ata_wait_ready);
7327 EXPORT_SYMBOL_GPL(ata_port_queue_task);
7328 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
7329 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
7330 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
7331 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
7332 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
7333 EXPORT_SYMBOL_GPL(ata_host_intr);
7334 EXPORT_SYMBOL_GPL(sata_scr_valid);
7335 EXPORT_SYMBOL_GPL(sata_scr_read);
7336 EXPORT_SYMBOL_GPL(sata_scr_write);
7337 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
7338 EXPORT_SYMBOL_GPL(ata_link_online);
7339 EXPORT_SYMBOL_GPL(ata_link_offline);
7340 #ifdef CONFIG_PM
7341 EXPORT_SYMBOL_GPL(ata_host_suspend);
7342 EXPORT_SYMBOL_GPL(ata_host_resume);
7343 #endif /* CONFIG_PM */
7344 EXPORT_SYMBOL_GPL(ata_id_string);
7345 EXPORT_SYMBOL_GPL(ata_id_c_string);
7346 EXPORT_SYMBOL_GPL(ata_id_to_dma_mode);
7347 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
7348 
7349 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
7350 EXPORT_SYMBOL_GPL(ata_timing_compute);
7351 EXPORT_SYMBOL_GPL(ata_timing_merge);
7352 
7353 #ifdef CONFIG_PCI
7354 EXPORT_SYMBOL_GPL(pci_test_config_bits);
7355 EXPORT_SYMBOL_GPL(ata_pci_init_sff_host);
7356 EXPORT_SYMBOL_GPL(ata_pci_init_bmdma);
7357 EXPORT_SYMBOL_GPL(ata_pci_prepare_sff_host);
7358 EXPORT_SYMBOL_GPL(ata_pci_init_one);
7359 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
7360 #ifdef CONFIG_PM
7361 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
7362 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
7363 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
7364 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
7365 #endif /* CONFIG_PM */
7366 EXPORT_SYMBOL_GPL(ata_pci_default_filter);
7367 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
7368 #endif /* CONFIG_PCI */
7369 
7370 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
7371 EXPORT_SYMBOL_GPL(sata_pmp_std_prereset);
7372 EXPORT_SYMBOL_GPL(sata_pmp_std_hardreset);
7373 EXPORT_SYMBOL_GPL(sata_pmp_std_postreset);
7374 EXPORT_SYMBOL_GPL(sata_pmp_do_eh);
7375 
7376 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
7377 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
7378 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
7379 EXPORT_SYMBOL_GPL(ata_port_desc);
7380 #ifdef CONFIG_PCI
7381 EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
7382 #endif /* CONFIG_PCI */
7383 EXPORT_SYMBOL_GPL(ata_eng_timeout);
7384 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
7385 EXPORT_SYMBOL_GPL(ata_link_abort);
7386 EXPORT_SYMBOL_GPL(ata_port_abort);
7387 EXPORT_SYMBOL_GPL(ata_port_freeze);
7388 EXPORT_SYMBOL_GPL(sata_async_notification);
7389 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
7390 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
7391 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
7392 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
7393 EXPORT_SYMBOL_GPL(ata_do_eh);
7394 EXPORT_SYMBOL_GPL(ata_irq_on);
7395 EXPORT_SYMBOL_GPL(ata_dev_try_classify);
7396 
7397 EXPORT_SYMBOL_GPL(ata_cable_40wire);
7398 EXPORT_SYMBOL_GPL(ata_cable_80wire);
7399 EXPORT_SYMBOL_GPL(ata_cable_unknown);
7400 EXPORT_SYMBOL_GPL(ata_cable_sata);
7401