xref: /openbmc/linux/drivers/ata/libata-core.c (revision 384740dc)
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  *  Standards documents from:
34  *	http://www.t13.org (ATA standards, PCI DMA IDE spec)
35  *	http://www.t10.org (SCSI MMC - for ATAPI MMC)
36  *	http://www.sata-io.org (SATA)
37  *	http://www.compactflash.org (CF)
38  *	http://www.qic.org (QIC157 - Tape and DSC)
39  *	http://www.ce-ata.org (CE-ATA: not supported)
40  *
41  */
42 
43 #include <linux/kernel.h>
44 #include <linux/module.h>
45 #include <linux/pci.h>
46 #include <linux/init.h>
47 #include <linux/list.h>
48 #include <linux/mm.h>
49 #include <linux/spinlock.h>
50 #include <linux/blkdev.h>
51 #include <linux/delay.h>
52 #include <linux/timer.h>
53 #include <linux/interrupt.h>
54 #include <linux/completion.h>
55 #include <linux/suspend.h>
56 #include <linux/workqueue.h>
57 #include <linux/scatterlist.h>
58 #include <linux/io.h>
59 #include <scsi/scsi.h>
60 #include <scsi/scsi_cmnd.h>
61 #include <scsi/scsi_host.h>
62 #include <linux/libata.h>
63 #include <asm/byteorder.h>
64 #include <linux/cdrom.h>
65 
66 #include "libata.h"
67 
68 
69 /* debounce timing parameters in msecs { interval, duration, timeout } */
70 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
71 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
72 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
73 
74 const struct ata_port_operations ata_base_port_ops = {
75 	.prereset		= ata_std_prereset,
76 	.postreset		= ata_std_postreset,
77 	.error_handler		= ata_std_error_handler,
78 };
79 
80 const struct ata_port_operations sata_port_ops = {
81 	.inherits		= &ata_base_port_ops,
82 
83 	.qc_defer		= ata_std_qc_defer,
84 	.hardreset		= sata_std_hardreset,
85 };
86 
87 static unsigned int ata_dev_init_params(struct ata_device *dev,
88 					u16 heads, u16 sectors);
89 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
90 static unsigned int ata_dev_set_feature(struct ata_device *dev,
91 					u8 enable, u8 feature);
92 static void ata_dev_xfermask(struct ata_device *dev);
93 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
94 
95 unsigned int ata_print_id = 1;
96 static struct workqueue_struct *ata_wq;
97 
98 struct workqueue_struct *ata_aux_wq;
99 
100 struct ata_force_param {
101 	const char	*name;
102 	unsigned int	cbl;
103 	int		spd_limit;
104 	unsigned long	xfer_mask;
105 	unsigned int	horkage_on;
106 	unsigned int	horkage_off;
107 	unsigned int	lflags;
108 };
109 
110 struct ata_force_ent {
111 	int			port;
112 	int			device;
113 	struct ata_force_param	param;
114 };
115 
116 static struct ata_force_ent *ata_force_tbl;
117 static int ata_force_tbl_size;
118 
119 static char ata_force_param_buf[PAGE_SIZE] __initdata;
120 /* param_buf is thrown away after initialization, disallow read */
121 module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0);
122 MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/kernel-parameters.txt for details)");
123 
124 static int atapi_enabled = 1;
125 module_param(atapi_enabled, int, 0444);
126 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
127 
128 static int atapi_dmadir = 0;
129 module_param(atapi_dmadir, int, 0444);
130 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
131 
132 int atapi_passthru16 = 1;
133 module_param(atapi_passthru16, int, 0444);
134 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices; on by default (0=off, 1=on)");
135 
136 int libata_fua = 0;
137 module_param_named(fua, libata_fua, int, 0444);
138 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
139 
140 static int ata_ignore_hpa;
141 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
142 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
143 
144 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
145 module_param_named(dma, libata_dma_mask, int, 0444);
146 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
147 
148 static int ata_probe_timeout;
149 module_param(ata_probe_timeout, int, 0444);
150 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
151 
152 int libata_noacpi = 0;
153 module_param_named(noacpi, libata_noacpi, int, 0444);
154 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
155 
156 int libata_allow_tpm = 0;
157 module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
158 MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands");
159 
160 MODULE_AUTHOR("Jeff Garzik");
161 MODULE_DESCRIPTION("Library module for ATA devices");
162 MODULE_LICENSE("GPL");
163 MODULE_VERSION(DRV_VERSION);
164 
165 
166 /*
167  * Iterator helpers.  Don't use directly.
168  *
169  * LOCKING:
170  * Host lock or EH context.
171  */
172 struct ata_link *__ata_port_next_link(struct ata_port *ap,
173 				      struct ata_link *link, bool dev_only)
174 {
175 	/* NULL link indicates start of iteration */
176 	if (!link) {
177 		if (dev_only && sata_pmp_attached(ap))
178 			return ap->pmp_link;
179 		return &ap->link;
180 	}
181 
182 	/* we just iterated over the host master link, what's next? */
183 	if (link == &ap->link) {
184 		if (!sata_pmp_attached(ap)) {
185 			if (unlikely(ap->slave_link) && !dev_only)
186 				return ap->slave_link;
187 			return NULL;
188 		}
189 		return ap->pmp_link;
190 	}
191 
192 	/* slave_link excludes PMP */
193 	if (unlikely(link == ap->slave_link))
194 		return NULL;
195 
196 	/* iterate to the next PMP link */
197 	if (++link < ap->pmp_link + ap->nr_pmp_links)
198 		return link;
199 	return NULL;
200 }
201 
202 /**
203  *	ata_dev_phys_link - find physical link for a device
204  *	@dev: ATA device to look up physical link for
205  *
206  *	Look up physical link which @dev is attached to.  Note that
207  *	this is different from @dev->link only when @dev is on slave
208  *	link.  For all other cases, it's the same as @dev->link.
209  *
210  *	LOCKING:
211  *	Don't care.
212  *
213  *	RETURNS:
214  *	Pointer to the found physical link.
215  */
216 struct ata_link *ata_dev_phys_link(struct ata_device *dev)
217 {
218 	struct ata_port *ap = dev->link->ap;
219 
220 	if (!ap->slave_link)
221 		return dev->link;
222 	if (!dev->devno)
223 		return &ap->link;
224 	return ap->slave_link;
225 }
226 
227 /**
228  *	ata_force_cbl - force cable type according to libata.force
229  *	@ap: ATA port of interest
230  *
231  *	Force cable type according to libata.force and whine about it.
232  *	The last entry which has matching port number is used, so it
233  *	can be specified as part of device force parameters.  For
234  *	example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
235  *	same effect.
236  *
237  *	LOCKING:
238  *	EH context.
239  */
240 void ata_force_cbl(struct ata_port *ap)
241 {
242 	int i;
243 
244 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
245 		const struct ata_force_ent *fe = &ata_force_tbl[i];
246 
247 		if (fe->port != -1 && fe->port != ap->print_id)
248 			continue;
249 
250 		if (fe->param.cbl == ATA_CBL_NONE)
251 			continue;
252 
253 		ap->cbl = fe->param.cbl;
254 		ata_port_printk(ap, KERN_NOTICE,
255 				"FORCE: cable set to %s\n", fe->param.name);
256 		return;
257 	}
258 }
259 
260 /**
261  *	ata_force_link_limits - force link limits according to libata.force
262  *	@link: ATA link of interest
263  *
264  *	Force link flags and SATA spd limit according to libata.force
265  *	and whine about it.  When only the port part is specified
266  *	(e.g. 1:), the limit applies to all links connected to both
267  *	the host link and all fan-out ports connected via PMP.  If the
268  *	device part is specified as 0 (e.g. 1.00:), it specifies the
269  *	first fan-out link not the host link.  Device number 15 always
270  *	points to the host link whether PMP is attached or not.  If the
271  *	controller has slave link, device number 16 points to it.
272  *
273  *	LOCKING:
274  *	EH context.
275  */
276 static void ata_force_link_limits(struct ata_link *link)
277 {
278 	bool did_spd = false;
279 	int linkno = link->pmp;
280 	int i;
281 
282 	if (ata_is_host_link(link))
283 		linkno += 15;
284 
285 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
286 		const struct ata_force_ent *fe = &ata_force_tbl[i];
287 
288 		if (fe->port != -1 && fe->port != link->ap->print_id)
289 			continue;
290 
291 		if (fe->device != -1 && fe->device != linkno)
292 			continue;
293 
294 		/* only honor the first spd limit */
295 		if (!did_spd && fe->param.spd_limit) {
296 			link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
297 			ata_link_printk(link, KERN_NOTICE,
298 					"FORCE: PHY spd limit set to %s\n",
299 					fe->param.name);
300 			did_spd = true;
301 		}
302 
303 		/* let lflags stack */
304 		if (fe->param.lflags) {
305 			link->flags |= fe->param.lflags;
306 			ata_link_printk(link, KERN_NOTICE,
307 					"FORCE: link flag 0x%x forced -> 0x%x\n",
308 					fe->param.lflags, link->flags);
309 		}
310 	}
311 }
312 
313 /**
314  *	ata_force_xfermask - force xfermask according to libata.force
315  *	@dev: ATA device of interest
316  *
317  *	Force xfer_mask according to libata.force and whine about it.
318  *	For consistency with link selection, device number 15 selects
319  *	the first device connected to the host link.
320  *
321  *	LOCKING:
322  *	EH context.
323  */
324 static void ata_force_xfermask(struct ata_device *dev)
325 {
326 	int devno = dev->link->pmp + dev->devno;
327 	int alt_devno = devno;
328 	int i;
329 
330 	/* allow n.15/16 for devices attached to host port */
331 	if (ata_is_host_link(dev->link))
332 		alt_devno += 15;
333 
334 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
335 		const struct ata_force_ent *fe = &ata_force_tbl[i];
336 		unsigned long pio_mask, mwdma_mask, udma_mask;
337 
338 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
339 			continue;
340 
341 		if (fe->device != -1 && fe->device != devno &&
342 		    fe->device != alt_devno)
343 			continue;
344 
345 		if (!fe->param.xfer_mask)
346 			continue;
347 
348 		ata_unpack_xfermask(fe->param.xfer_mask,
349 				    &pio_mask, &mwdma_mask, &udma_mask);
350 		if (udma_mask)
351 			dev->udma_mask = udma_mask;
352 		else if (mwdma_mask) {
353 			dev->udma_mask = 0;
354 			dev->mwdma_mask = mwdma_mask;
355 		} else {
356 			dev->udma_mask = 0;
357 			dev->mwdma_mask = 0;
358 			dev->pio_mask = pio_mask;
359 		}
360 
361 		ata_dev_printk(dev, KERN_NOTICE,
362 			"FORCE: xfer_mask set to %s\n", fe->param.name);
363 		return;
364 	}
365 }
366 
367 /**
368  *	ata_force_horkage - force horkage according to libata.force
369  *	@dev: ATA device of interest
370  *
371  *	Force horkage according to libata.force and whine about it.
372  *	For consistency with link selection, device number 15 selects
373  *	the first device connected to the host link.
374  *
375  *	LOCKING:
376  *	EH context.
377  */
378 static void ata_force_horkage(struct ata_device *dev)
379 {
380 	int devno = dev->link->pmp + dev->devno;
381 	int alt_devno = devno;
382 	int i;
383 
384 	/* allow n.15/16 for devices attached to host port */
385 	if (ata_is_host_link(dev->link))
386 		alt_devno += 15;
387 
388 	for (i = 0; i < ata_force_tbl_size; i++) {
389 		const struct ata_force_ent *fe = &ata_force_tbl[i];
390 
391 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
392 			continue;
393 
394 		if (fe->device != -1 && fe->device != devno &&
395 		    fe->device != alt_devno)
396 			continue;
397 
398 		if (!(~dev->horkage & fe->param.horkage_on) &&
399 		    !(dev->horkage & fe->param.horkage_off))
400 			continue;
401 
402 		dev->horkage |= fe->param.horkage_on;
403 		dev->horkage &= ~fe->param.horkage_off;
404 
405 		ata_dev_printk(dev, KERN_NOTICE,
406 			"FORCE: horkage modified (%s)\n", fe->param.name);
407 	}
408 }
409 
410 /**
411  *	atapi_cmd_type - Determine ATAPI command type from SCSI opcode
412  *	@opcode: SCSI opcode
413  *
414  *	Determine ATAPI command type from @opcode.
415  *
416  *	LOCKING:
417  *	None.
418  *
419  *	RETURNS:
420  *	ATAPI_{READ|WRITE|READ_CD|PASS_THRU|MISC}
421  */
422 int atapi_cmd_type(u8 opcode)
423 {
424 	switch (opcode) {
425 	case GPCMD_READ_10:
426 	case GPCMD_READ_12:
427 		return ATAPI_READ;
428 
429 	case GPCMD_WRITE_10:
430 	case GPCMD_WRITE_12:
431 	case GPCMD_WRITE_AND_VERIFY_10:
432 		return ATAPI_WRITE;
433 
434 	case GPCMD_READ_CD:
435 	case GPCMD_READ_CD_MSF:
436 		return ATAPI_READ_CD;
437 
438 	case ATA_16:
439 	case ATA_12:
440 		if (atapi_passthru16)
441 			return ATAPI_PASS_THRU;
442 		/* fall thru */
443 	default:
444 		return ATAPI_MISC;
445 	}
446 }
447 
448 /**
449  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
450  *	@tf: Taskfile to convert
451  *	@pmp: Port multiplier port
452  *	@is_cmd: This FIS is for command
453  *	@fis: Buffer into which data will output
454  *
455  *	Converts a standard ATA taskfile to a Serial ATA
456  *	FIS structure (Register - Host to Device).
457  *
458  *	LOCKING:
459  *	Inherited from caller.
460  */
461 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
462 {
463 	fis[0] = 0x27;			/* Register - Host to Device FIS */
464 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
465 	if (is_cmd)
466 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
467 
468 	fis[2] = tf->command;
469 	fis[3] = tf->feature;
470 
471 	fis[4] = tf->lbal;
472 	fis[5] = tf->lbam;
473 	fis[6] = tf->lbah;
474 	fis[7] = tf->device;
475 
476 	fis[8] = tf->hob_lbal;
477 	fis[9] = tf->hob_lbam;
478 	fis[10] = tf->hob_lbah;
479 	fis[11] = tf->hob_feature;
480 
481 	fis[12] = tf->nsect;
482 	fis[13] = tf->hob_nsect;
483 	fis[14] = 0;
484 	fis[15] = tf->ctl;
485 
486 	fis[16] = 0;
487 	fis[17] = 0;
488 	fis[18] = 0;
489 	fis[19] = 0;
490 }
491 
492 /**
493  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
494  *	@fis: Buffer from which data will be input
495  *	@tf: Taskfile to output
496  *
497  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
498  *
499  *	LOCKING:
500  *	Inherited from caller.
501  */
502 
503 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
504 {
505 	tf->command	= fis[2];	/* status */
506 	tf->feature	= fis[3];	/* error */
507 
508 	tf->lbal	= fis[4];
509 	tf->lbam	= fis[5];
510 	tf->lbah	= fis[6];
511 	tf->device	= fis[7];
512 
513 	tf->hob_lbal	= fis[8];
514 	tf->hob_lbam	= fis[9];
515 	tf->hob_lbah	= fis[10];
516 
517 	tf->nsect	= fis[12];
518 	tf->hob_nsect	= fis[13];
519 }
520 
521 static const u8 ata_rw_cmds[] = {
522 	/* pio multi */
523 	ATA_CMD_READ_MULTI,
524 	ATA_CMD_WRITE_MULTI,
525 	ATA_CMD_READ_MULTI_EXT,
526 	ATA_CMD_WRITE_MULTI_EXT,
527 	0,
528 	0,
529 	0,
530 	ATA_CMD_WRITE_MULTI_FUA_EXT,
531 	/* pio */
532 	ATA_CMD_PIO_READ,
533 	ATA_CMD_PIO_WRITE,
534 	ATA_CMD_PIO_READ_EXT,
535 	ATA_CMD_PIO_WRITE_EXT,
536 	0,
537 	0,
538 	0,
539 	0,
540 	/* dma */
541 	ATA_CMD_READ,
542 	ATA_CMD_WRITE,
543 	ATA_CMD_READ_EXT,
544 	ATA_CMD_WRITE_EXT,
545 	0,
546 	0,
547 	0,
548 	ATA_CMD_WRITE_FUA_EXT
549 };
550 
551 /**
552  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
553  *	@tf: command to examine and configure
554  *	@dev: device tf belongs to
555  *
556  *	Examine the device configuration and tf->flags to calculate
557  *	the proper read/write commands and protocol to use.
558  *
559  *	LOCKING:
560  *	caller.
561  */
562 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
563 {
564 	u8 cmd;
565 
566 	int index, fua, lba48, write;
567 
568 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
569 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
570 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
571 
572 	if (dev->flags & ATA_DFLAG_PIO) {
573 		tf->protocol = ATA_PROT_PIO;
574 		index = dev->multi_count ? 0 : 8;
575 	} else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
576 		/* Unable to use DMA due to host limitation */
577 		tf->protocol = ATA_PROT_PIO;
578 		index = dev->multi_count ? 0 : 8;
579 	} else {
580 		tf->protocol = ATA_PROT_DMA;
581 		index = 16;
582 	}
583 
584 	cmd = ata_rw_cmds[index + fua + lba48 + write];
585 	if (cmd) {
586 		tf->command = cmd;
587 		return 0;
588 	}
589 	return -1;
590 }
591 
592 /**
593  *	ata_tf_read_block - Read block address from ATA taskfile
594  *	@tf: ATA taskfile of interest
595  *	@dev: ATA device @tf belongs to
596  *
597  *	LOCKING:
598  *	None.
599  *
600  *	Read block address from @tf.  This function can handle all
601  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
602  *	flags select the address format to use.
603  *
604  *	RETURNS:
605  *	Block address read from @tf.
606  */
607 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
608 {
609 	u64 block = 0;
610 
611 	if (tf->flags & ATA_TFLAG_LBA) {
612 		if (tf->flags & ATA_TFLAG_LBA48) {
613 			block |= (u64)tf->hob_lbah << 40;
614 			block |= (u64)tf->hob_lbam << 32;
615 			block |= tf->hob_lbal << 24;
616 		} else
617 			block |= (tf->device & 0xf) << 24;
618 
619 		block |= tf->lbah << 16;
620 		block |= tf->lbam << 8;
621 		block |= tf->lbal;
622 	} else {
623 		u32 cyl, head, sect;
624 
625 		cyl = tf->lbam | (tf->lbah << 8);
626 		head = tf->device & 0xf;
627 		sect = tf->lbal;
628 
629 		block = (cyl * dev->heads + head) * dev->sectors + sect;
630 	}
631 
632 	return block;
633 }
634 
635 /**
636  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
637  *	@tf: Target ATA taskfile
638  *	@dev: ATA device @tf belongs to
639  *	@block: Block address
640  *	@n_block: Number of blocks
641  *	@tf_flags: RW/FUA etc...
642  *	@tag: tag
643  *
644  *	LOCKING:
645  *	None.
646  *
647  *	Build ATA taskfile @tf for read/write request described by
648  *	@block, @n_block, @tf_flags and @tag on @dev.
649  *
650  *	RETURNS:
651  *
652  *	0 on success, -ERANGE if the request is too large for @dev,
653  *	-EINVAL if the request is invalid.
654  */
655 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
656 		    u64 block, u32 n_block, unsigned int tf_flags,
657 		    unsigned int tag)
658 {
659 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
660 	tf->flags |= tf_flags;
661 
662 	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
663 		/* yay, NCQ */
664 		if (!lba_48_ok(block, n_block))
665 			return -ERANGE;
666 
667 		tf->protocol = ATA_PROT_NCQ;
668 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
669 
670 		if (tf->flags & ATA_TFLAG_WRITE)
671 			tf->command = ATA_CMD_FPDMA_WRITE;
672 		else
673 			tf->command = ATA_CMD_FPDMA_READ;
674 
675 		tf->nsect = tag << 3;
676 		tf->hob_feature = (n_block >> 8) & 0xff;
677 		tf->feature = n_block & 0xff;
678 
679 		tf->hob_lbah = (block >> 40) & 0xff;
680 		tf->hob_lbam = (block >> 32) & 0xff;
681 		tf->hob_lbal = (block >> 24) & 0xff;
682 		tf->lbah = (block >> 16) & 0xff;
683 		tf->lbam = (block >> 8) & 0xff;
684 		tf->lbal = block & 0xff;
685 
686 		tf->device = 1 << 6;
687 		if (tf->flags & ATA_TFLAG_FUA)
688 			tf->device |= 1 << 7;
689 	} else if (dev->flags & ATA_DFLAG_LBA) {
690 		tf->flags |= ATA_TFLAG_LBA;
691 
692 		if (lba_28_ok(block, n_block)) {
693 			/* use LBA28 */
694 			tf->device |= (block >> 24) & 0xf;
695 		} else if (lba_48_ok(block, n_block)) {
696 			if (!(dev->flags & ATA_DFLAG_LBA48))
697 				return -ERANGE;
698 
699 			/* use LBA48 */
700 			tf->flags |= ATA_TFLAG_LBA48;
701 
702 			tf->hob_nsect = (n_block >> 8) & 0xff;
703 
704 			tf->hob_lbah = (block >> 40) & 0xff;
705 			tf->hob_lbam = (block >> 32) & 0xff;
706 			tf->hob_lbal = (block >> 24) & 0xff;
707 		} else
708 			/* request too large even for LBA48 */
709 			return -ERANGE;
710 
711 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
712 			return -EINVAL;
713 
714 		tf->nsect = n_block & 0xff;
715 
716 		tf->lbah = (block >> 16) & 0xff;
717 		tf->lbam = (block >> 8) & 0xff;
718 		tf->lbal = block & 0xff;
719 
720 		tf->device |= ATA_LBA;
721 	} else {
722 		/* CHS */
723 		u32 sect, head, cyl, track;
724 
725 		/* The request -may- be too large for CHS addressing. */
726 		if (!lba_28_ok(block, n_block))
727 			return -ERANGE;
728 
729 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
730 			return -EINVAL;
731 
732 		/* Convert LBA to CHS */
733 		track = (u32)block / dev->sectors;
734 		cyl   = track / dev->heads;
735 		head  = track % dev->heads;
736 		sect  = (u32)block % dev->sectors + 1;
737 
738 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
739 			(u32)block, track, cyl, head, sect);
740 
741 		/* Check whether the converted CHS can fit.
742 		   Cylinder: 0-65535
743 		   Head: 0-15
744 		   Sector: 1-255*/
745 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
746 			return -ERANGE;
747 
748 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
749 		tf->lbal = sect;
750 		tf->lbam = cyl;
751 		tf->lbah = cyl >> 8;
752 		tf->device |= head;
753 	}
754 
755 	return 0;
756 }
757 
758 /**
759  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
760  *	@pio_mask: pio_mask
761  *	@mwdma_mask: mwdma_mask
762  *	@udma_mask: udma_mask
763  *
764  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
765  *	unsigned int xfer_mask.
766  *
767  *	LOCKING:
768  *	None.
769  *
770  *	RETURNS:
771  *	Packed xfer_mask.
772  */
773 unsigned long ata_pack_xfermask(unsigned long pio_mask,
774 				unsigned long mwdma_mask,
775 				unsigned long udma_mask)
776 {
777 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
778 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
779 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
780 }
781 
782 /**
783  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
784  *	@xfer_mask: xfer_mask to unpack
785  *	@pio_mask: resulting pio_mask
786  *	@mwdma_mask: resulting mwdma_mask
787  *	@udma_mask: resulting udma_mask
788  *
789  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
790  *	Any NULL distination masks will be ignored.
791  */
792 void ata_unpack_xfermask(unsigned long xfer_mask, unsigned long *pio_mask,
793 			 unsigned long *mwdma_mask, unsigned long *udma_mask)
794 {
795 	if (pio_mask)
796 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
797 	if (mwdma_mask)
798 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
799 	if (udma_mask)
800 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
801 }
802 
803 static const struct ata_xfer_ent {
804 	int shift, bits;
805 	u8 base;
806 } ata_xfer_tbl[] = {
807 	{ ATA_SHIFT_PIO, ATA_NR_PIO_MODES, XFER_PIO_0 },
808 	{ ATA_SHIFT_MWDMA, ATA_NR_MWDMA_MODES, XFER_MW_DMA_0 },
809 	{ ATA_SHIFT_UDMA, ATA_NR_UDMA_MODES, XFER_UDMA_0 },
810 	{ -1, },
811 };
812 
813 /**
814  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
815  *	@xfer_mask: xfer_mask of interest
816  *
817  *	Return matching XFER_* value for @xfer_mask.  Only the highest
818  *	bit of @xfer_mask is considered.
819  *
820  *	LOCKING:
821  *	None.
822  *
823  *	RETURNS:
824  *	Matching XFER_* value, 0xff if no match found.
825  */
826 u8 ata_xfer_mask2mode(unsigned long xfer_mask)
827 {
828 	int highbit = fls(xfer_mask) - 1;
829 	const struct ata_xfer_ent *ent;
830 
831 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
832 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
833 			return ent->base + highbit - ent->shift;
834 	return 0xff;
835 }
836 
837 /**
838  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
839  *	@xfer_mode: XFER_* of interest
840  *
841  *	Return matching xfer_mask for @xfer_mode.
842  *
843  *	LOCKING:
844  *	None.
845  *
846  *	RETURNS:
847  *	Matching xfer_mask, 0 if no match found.
848  */
849 unsigned long ata_xfer_mode2mask(u8 xfer_mode)
850 {
851 	const struct ata_xfer_ent *ent;
852 
853 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
854 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
855 			return ((2 << (ent->shift + xfer_mode - ent->base)) - 1)
856 				& ~((1 << ent->shift) - 1);
857 	return 0;
858 }
859 
860 /**
861  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
862  *	@xfer_mode: XFER_* of interest
863  *
864  *	Return matching xfer_shift for @xfer_mode.
865  *
866  *	LOCKING:
867  *	None.
868  *
869  *	RETURNS:
870  *	Matching xfer_shift, -1 if no match found.
871  */
872 int ata_xfer_mode2shift(unsigned long xfer_mode)
873 {
874 	const struct ata_xfer_ent *ent;
875 
876 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
877 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
878 			return ent->shift;
879 	return -1;
880 }
881 
882 /**
883  *	ata_mode_string - convert xfer_mask to string
884  *	@xfer_mask: mask of bits supported; only highest bit counts.
885  *
886  *	Determine string which represents the highest speed
887  *	(highest bit in @modemask).
888  *
889  *	LOCKING:
890  *	None.
891  *
892  *	RETURNS:
893  *	Constant C string representing highest speed listed in
894  *	@mode_mask, or the constant C string "<n/a>".
895  */
896 const char *ata_mode_string(unsigned long xfer_mask)
897 {
898 	static const char * const xfer_mode_str[] = {
899 		"PIO0",
900 		"PIO1",
901 		"PIO2",
902 		"PIO3",
903 		"PIO4",
904 		"PIO5",
905 		"PIO6",
906 		"MWDMA0",
907 		"MWDMA1",
908 		"MWDMA2",
909 		"MWDMA3",
910 		"MWDMA4",
911 		"UDMA/16",
912 		"UDMA/25",
913 		"UDMA/33",
914 		"UDMA/44",
915 		"UDMA/66",
916 		"UDMA/100",
917 		"UDMA/133",
918 		"UDMA7",
919 	};
920 	int highbit;
921 
922 	highbit = fls(xfer_mask) - 1;
923 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
924 		return xfer_mode_str[highbit];
925 	return "<n/a>";
926 }
927 
928 static const char *sata_spd_string(unsigned int spd)
929 {
930 	static const char * const spd_str[] = {
931 		"1.5 Gbps",
932 		"3.0 Gbps",
933 	};
934 
935 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
936 		return "<unknown>";
937 	return spd_str[spd - 1];
938 }
939 
940 void ata_dev_disable(struct ata_device *dev)
941 {
942 	if (ata_dev_enabled(dev)) {
943 		if (ata_msg_drv(dev->link->ap))
944 			ata_dev_printk(dev, KERN_WARNING, "disabled\n");
945 		ata_acpi_on_disable(dev);
946 		ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
947 					     ATA_DNXFER_QUIET);
948 		dev->class++;
949 	}
950 }
951 
952 static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
953 {
954 	struct ata_link *link = dev->link;
955 	struct ata_port *ap = link->ap;
956 	u32 scontrol;
957 	unsigned int err_mask;
958 	int rc;
959 
960 	/*
961 	 * disallow DIPM for drivers which haven't set
962 	 * ATA_FLAG_IPM.  This is because when DIPM is enabled,
963 	 * phy ready will be set in the interrupt status on
964 	 * state changes, which will cause some drivers to
965 	 * think there are errors - additionally drivers will
966 	 * need to disable hot plug.
967 	 */
968 	if (!(ap->flags & ATA_FLAG_IPM) || !ata_dev_enabled(dev)) {
969 		ap->pm_policy = NOT_AVAILABLE;
970 		return -EINVAL;
971 	}
972 
973 	/*
974 	 * For DIPM, we will only enable it for the
975 	 * min_power setting.
976 	 *
977 	 * Why?  Because Disks are too stupid to know that
978 	 * If the host rejects a request to go to SLUMBER
979 	 * they should retry at PARTIAL, and instead it
980 	 * just would give up.  So, for medium_power to
981 	 * work at all, we need to only allow HIPM.
982 	 */
983 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
984 	if (rc)
985 		return rc;
986 
987 	switch (policy) {
988 	case MIN_POWER:
989 		/* no restrictions on IPM transitions */
990 		scontrol &= ~(0x3 << 8);
991 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
992 		if (rc)
993 			return rc;
994 
995 		/* enable DIPM */
996 		if (dev->flags & ATA_DFLAG_DIPM)
997 			err_mask = ata_dev_set_feature(dev,
998 					SETFEATURES_SATA_ENABLE, SATA_DIPM);
999 		break;
1000 	case MEDIUM_POWER:
1001 		/* allow IPM to PARTIAL */
1002 		scontrol &= ~(0x1 << 8);
1003 		scontrol |= (0x2 << 8);
1004 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
1005 		if (rc)
1006 			return rc;
1007 
1008 		/*
1009 		 * we don't have to disable DIPM since IPM flags
1010 		 * disallow transitions to SLUMBER, which effectively
1011 		 * disable DIPM if it does not support PARTIAL
1012 		 */
1013 		break;
1014 	case NOT_AVAILABLE:
1015 	case MAX_PERFORMANCE:
1016 		/* disable all IPM transitions */
1017 		scontrol |= (0x3 << 8);
1018 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
1019 		if (rc)
1020 			return rc;
1021 
1022 		/*
1023 		 * we don't have to disable DIPM since IPM flags
1024 		 * disallow all transitions which effectively
1025 		 * disable DIPM anyway.
1026 		 */
1027 		break;
1028 	}
1029 
1030 	/* FIXME: handle SET FEATURES failure */
1031 	(void) err_mask;
1032 
1033 	return 0;
1034 }
1035 
1036 /**
1037  *	ata_dev_enable_pm - enable SATA interface power management
1038  *	@dev:  device to enable power management
1039  *	@policy: the link power management policy
1040  *
1041  *	Enable SATA Interface power management.  This will enable
1042  *	Device Interface Power Management (DIPM) for min_power
1043  * 	policy, and then call driver specific callbacks for
1044  *	enabling Host Initiated Power management.
1045  *
1046  *	Locking: Caller.
1047  *	Returns: -EINVAL if IPM is not supported, 0 otherwise.
1048  */
1049 void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy)
1050 {
1051 	int rc = 0;
1052 	struct ata_port *ap = dev->link->ap;
1053 
1054 	/* set HIPM first, then DIPM */
1055 	if (ap->ops->enable_pm)
1056 		rc = ap->ops->enable_pm(ap, policy);
1057 	if (rc)
1058 		goto enable_pm_out;
1059 	rc = ata_dev_set_dipm(dev, policy);
1060 
1061 enable_pm_out:
1062 	if (rc)
1063 		ap->pm_policy = MAX_PERFORMANCE;
1064 	else
1065 		ap->pm_policy = policy;
1066 	return /* rc */;	/* hopefully we can use 'rc' eventually */
1067 }
1068 
1069 #ifdef CONFIG_PM
1070 /**
1071  *	ata_dev_disable_pm - disable SATA interface power management
1072  *	@dev: device to disable power management
1073  *
1074  *	Disable SATA Interface power management.  This will disable
1075  *	Device Interface Power Management (DIPM) without changing
1076  * 	policy,  call driver specific callbacks for disabling Host
1077  * 	Initiated Power management.
1078  *
1079  *	Locking: Caller.
1080  *	Returns: void
1081  */
1082 static void ata_dev_disable_pm(struct ata_device *dev)
1083 {
1084 	struct ata_port *ap = dev->link->ap;
1085 
1086 	ata_dev_set_dipm(dev, MAX_PERFORMANCE);
1087 	if (ap->ops->disable_pm)
1088 		ap->ops->disable_pm(ap);
1089 }
1090 #endif	/* CONFIG_PM */
1091 
1092 void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
1093 {
1094 	ap->pm_policy = policy;
1095 	ap->link.eh_info.action |= ATA_EH_LPM;
1096 	ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
1097 	ata_port_schedule_eh(ap);
1098 }
1099 
1100 #ifdef CONFIG_PM
1101 static void ata_lpm_enable(struct ata_host *host)
1102 {
1103 	struct ata_link *link;
1104 	struct ata_port *ap;
1105 	struct ata_device *dev;
1106 	int i;
1107 
1108 	for (i = 0; i < host->n_ports; i++) {
1109 		ap = host->ports[i];
1110 		ata_port_for_each_link(link, ap) {
1111 			ata_link_for_each_dev(dev, link)
1112 				ata_dev_disable_pm(dev);
1113 		}
1114 	}
1115 }
1116 
1117 static void ata_lpm_disable(struct ata_host *host)
1118 {
1119 	int i;
1120 
1121 	for (i = 0; i < host->n_ports; i++) {
1122 		struct ata_port *ap = host->ports[i];
1123 		ata_lpm_schedule(ap, ap->pm_policy);
1124 	}
1125 }
1126 #endif	/* CONFIG_PM */
1127 
1128 /**
1129  *	ata_dev_classify - determine device type based on ATA-spec signature
1130  *	@tf: ATA taskfile register set for device to be identified
1131  *
1132  *	Determine from taskfile register contents whether a device is
1133  *	ATA or ATAPI, as per "Signature and persistence" section
1134  *	of ATA/PI spec (volume 1, sect 5.14).
1135  *
1136  *	LOCKING:
1137  *	None.
1138  *
1139  *	RETURNS:
1140  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP or
1141  *	%ATA_DEV_UNKNOWN the event of failure.
1142  */
1143 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
1144 {
1145 	/* Apple's open source Darwin code hints that some devices only
1146 	 * put a proper signature into the LBA mid/high registers,
1147 	 * So, we only check those.  It's sufficient for uniqueness.
1148 	 *
1149 	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
1150 	 * signatures for ATA and ATAPI devices attached on SerialATA,
1151 	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
1152 	 * spec has never mentioned about using different signatures
1153 	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
1154 	 * Multiplier specification began to use 0x69/0x96 to identify
1155 	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
1156 	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
1157 	 * 0x69/0x96 shortly and described them as reserved for
1158 	 * SerialATA.
1159 	 *
1160 	 * We follow the current spec and consider that 0x69/0x96
1161 	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
1162 	 */
1163 	if ((tf->lbam == 0) && (tf->lbah == 0)) {
1164 		DPRINTK("found ATA device by sig\n");
1165 		return ATA_DEV_ATA;
1166 	}
1167 
1168 	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
1169 		DPRINTK("found ATAPI device by sig\n");
1170 		return ATA_DEV_ATAPI;
1171 	}
1172 
1173 	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
1174 		DPRINTK("found PMP device by sig\n");
1175 		return ATA_DEV_PMP;
1176 	}
1177 
1178 	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
1179 		printk(KERN_INFO "ata: SEMB device ignored\n");
1180 		return ATA_DEV_SEMB_UNSUP; /* not yet */
1181 	}
1182 
1183 	DPRINTK("unknown device\n");
1184 	return ATA_DEV_UNKNOWN;
1185 }
1186 
1187 /**
1188  *	ata_id_string - Convert IDENTIFY DEVICE page into string
1189  *	@id: IDENTIFY DEVICE results we will examine
1190  *	@s: string into which data is output
1191  *	@ofs: offset into identify device page
1192  *	@len: length of string to return. must be an even number.
1193  *
1194  *	The strings in the IDENTIFY DEVICE page are broken up into
1195  *	16-bit chunks.  Run through the string, and output each
1196  *	8-bit chunk linearly, regardless of platform.
1197  *
1198  *	LOCKING:
1199  *	caller.
1200  */
1201 
1202 void ata_id_string(const u16 *id, unsigned char *s,
1203 		   unsigned int ofs, unsigned int len)
1204 {
1205 	unsigned int c;
1206 
1207 	BUG_ON(len & 1);
1208 
1209 	while (len > 0) {
1210 		c = id[ofs] >> 8;
1211 		*s = c;
1212 		s++;
1213 
1214 		c = id[ofs] & 0xff;
1215 		*s = c;
1216 		s++;
1217 
1218 		ofs++;
1219 		len -= 2;
1220 	}
1221 }
1222 
1223 /**
1224  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
1225  *	@id: IDENTIFY DEVICE results we will examine
1226  *	@s: string into which data is output
1227  *	@ofs: offset into identify device page
1228  *	@len: length of string to return. must be an odd number.
1229  *
1230  *	This function is identical to ata_id_string except that it
1231  *	trims trailing spaces and terminates the resulting string with
1232  *	null.  @len must be actual maximum length (even number) + 1.
1233  *
1234  *	LOCKING:
1235  *	caller.
1236  */
1237 void ata_id_c_string(const u16 *id, unsigned char *s,
1238 		     unsigned int ofs, unsigned int len)
1239 {
1240 	unsigned char *p;
1241 
1242 	ata_id_string(id, s, ofs, len - 1);
1243 
1244 	p = s + strnlen(s, len - 1);
1245 	while (p > s && p[-1] == ' ')
1246 		p--;
1247 	*p = '\0';
1248 }
1249 
1250 static u64 ata_id_n_sectors(const u16 *id)
1251 {
1252 	if (ata_id_has_lba(id)) {
1253 		if (ata_id_has_lba48(id))
1254 			return ata_id_u64(id, 100);
1255 		else
1256 			return ata_id_u32(id, 60);
1257 	} else {
1258 		if (ata_id_current_chs_valid(id))
1259 			return ata_id_u32(id, 57);
1260 		else
1261 			return id[1] * id[3] * id[6];
1262 	}
1263 }
1264 
1265 u64 ata_tf_to_lba48(const struct ata_taskfile *tf)
1266 {
1267 	u64 sectors = 0;
1268 
1269 	sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
1270 	sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
1271 	sectors |= (tf->hob_lbal & 0xff) << 24;
1272 	sectors |= (tf->lbah & 0xff) << 16;
1273 	sectors |= (tf->lbam & 0xff) << 8;
1274 	sectors |= (tf->lbal & 0xff);
1275 
1276 	return sectors;
1277 }
1278 
1279 u64 ata_tf_to_lba(const struct ata_taskfile *tf)
1280 {
1281 	u64 sectors = 0;
1282 
1283 	sectors |= (tf->device & 0x0f) << 24;
1284 	sectors |= (tf->lbah & 0xff) << 16;
1285 	sectors |= (tf->lbam & 0xff) << 8;
1286 	sectors |= (tf->lbal & 0xff);
1287 
1288 	return sectors;
1289 }
1290 
1291 /**
1292  *	ata_read_native_max_address - Read native max address
1293  *	@dev: target device
1294  *	@max_sectors: out parameter for the result native max address
1295  *
1296  *	Perform an LBA48 or LBA28 native size query upon the device in
1297  *	question.
1298  *
1299  *	RETURNS:
1300  *	0 on success, -EACCES if command is aborted by the drive.
1301  *	-EIO on other errors.
1302  */
1303 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
1304 {
1305 	unsigned int err_mask;
1306 	struct ata_taskfile tf;
1307 	int lba48 = ata_id_has_lba48(dev->id);
1308 
1309 	ata_tf_init(dev, &tf);
1310 
1311 	/* always clear all address registers */
1312 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1313 
1314 	if (lba48) {
1315 		tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
1316 		tf.flags |= ATA_TFLAG_LBA48;
1317 	} else
1318 		tf.command = ATA_CMD_READ_NATIVE_MAX;
1319 
1320 	tf.protocol |= ATA_PROT_NODATA;
1321 	tf.device |= ATA_LBA;
1322 
1323 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1324 	if (err_mask) {
1325 		ata_dev_printk(dev, KERN_WARNING, "failed to read native "
1326 			       "max address (err_mask=0x%x)\n", err_mask);
1327 		if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
1328 			return -EACCES;
1329 		return -EIO;
1330 	}
1331 
1332 	if (lba48)
1333 		*max_sectors = ata_tf_to_lba48(&tf) + 1;
1334 	else
1335 		*max_sectors = ata_tf_to_lba(&tf) + 1;
1336 	if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
1337 		(*max_sectors)--;
1338 	return 0;
1339 }
1340 
1341 /**
1342  *	ata_set_max_sectors - Set max sectors
1343  *	@dev: target device
1344  *	@new_sectors: new max sectors value to set for the device
1345  *
1346  *	Set max sectors of @dev to @new_sectors.
1347  *
1348  *	RETURNS:
1349  *	0 on success, -EACCES if command is aborted or denied (due to
1350  *	previous non-volatile SET_MAX) by the drive.  -EIO on other
1351  *	errors.
1352  */
1353 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
1354 {
1355 	unsigned int err_mask;
1356 	struct ata_taskfile tf;
1357 	int lba48 = ata_id_has_lba48(dev->id);
1358 
1359 	new_sectors--;
1360 
1361 	ata_tf_init(dev, &tf);
1362 
1363 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1364 
1365 	if (lba48) {
1366 		tf.command = ATA_CMD_SET_MAX_EXT;
1367 		tf.flags |= ATA_TFLAG_LBA48;
1368 
1369 		tf.hob_lbal = (new_sectors >> 24) & 0xff;
1370 		tf.hob_lbam = (new_sectors >> 32) & 0xff;
1371 		tf.hob_lbah = (new_sectors >> 40) & 0xff;
1372 	} else {
1373 		tf.command = ATA_CMD_SET_MAX;
1374 
1375 		tf.device |= (new_sectors >> 24) & 0xf;
1376 	}
1377 
1378 	tf.protocol |= ATA_PROT_NODATA;
1379 	tf.device |= ATA_LBA;
1380 
1381 	tf.lbal = (new_sectors >> 0) & 0xff;
1382 	tf.lbam = (new_sectors >> 8) & 0xff;
1383 	tf.lbah = (new_sectors >> 16) & 0xff;
1384 
1385 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1386 	if (err_mask) {
1387 		ata_dev_printk(dev, KERN_WARNING, "failed to set "
1388 			       "max address (err_mask=0x%x)\n", err_mask);
1389 		if (err_mask == AC_ERR_DEV &&
1390 		    (tf.feature & (ATA_ABORTED | ATA_IDNF)))
1391 			return -EACCES;
1392 		return -EIO;
1393 	}
1394 
1395 	return 0;
1396 }
1397 
1398 /**
1399  *	ata_hpa_resize		-	Resize a device with an HPA set
1400  *	@dev: Device to resize
1401  *
1402  *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
1403  *	it if required to the full size of the media. The caller must check
1404  *	the drive has the HPA feature set enabled.
1405  *
1406  *	RETURNS:
1407  *	0 on success, -errno on failure.
1408  */
1409 static int ata_hpa_resize(struct ata_device *dev)
1410 {
1411 	struct ata_eh_context *ehc = &dev->link->eh_context;
1412 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1413 	u64 sectors = ata_id_n_sectors(dev->id);
1414 	u64 native_sectors;
1415 	int rc;
1416 
1417 	/* do we need to do it? */
1418 	if (dev->class != ATA_DEV_ATA ||
1419 	    !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
1420 	    (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
1421 		return 0;
1422 
1423 	/* read native max address */
1424 	rc = ata_read_native_max_address(dev, &native_sectors);
1425 	if (rc) {
1426 		/* If device aborted the command or HPA isn't going to
1427 		 * be unlocked, skip HPA resizing.
1428 		 */
1429 		if (rc == -EACCES || !ata_ignore_hpa) {
1430 			ata_dev_printk(dev, KERN_WARNING, "HPA support seems "
1431 				       "broken, skipping HPA handling\n");
1432 			dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1433 
1434 			/* we can continue if device aborted the command */
1435 			if (rc == -EACCES)
1436 				rc = 0;
1437 		}
1438 
1439 		return rc;
1440 	}
1441 
1442 	/* nothing to do? */
1443 	if (native_sectors <= sectors || !ata_ignore_hpa) {
1444 		if (!print_info || native_sectors == sectors)
1445 			return 0;
1446 
1447 		if (native_sectors > sectors)
1448 			ata_dev_printk(dev, KERN_INFO,
1449 				"HPA detected: current %llu, native %llu\n",
1450 				(unsigned long long)sectors,
1451 				(unsigned long long)native_sectors);
1452 		else if (native_sectors < sectors)
1453 			ata_dev_printk(dev, KERN_WARNING,
1454 				"native sectors (%llu) is smaller than "
1455 				"sectors (%llu)\n",
1456 				(unsigned long long)native_sectors,
1457 				(unsigned long long)sectors);
1458 		return 0;
1459 	}
1460 
1461 	/* let's unlock HPA */
1462 	rc = ata_set_max_sectors(dev, native_sectors);
1463 	if (rc == -EACCES) {
1464 		/* if device aborted the command, skip HPA resizing */
1465 		ata_dev_printk(dev, KERN_WARNING, "device aborted resize "
1466 			       "(%llu -> %llu), skipping HPA handling\n",
1467 			       (unsigned long long)sectors,
1468 			       (unsigned long long)native_sectors);
1469 		dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1470 		return 0;
1471 	} else if (rc)
1472 		return rc;
1473 
1474 	/* re-read IDENTIFY data */
1475 	rc = ata_dev_reread_id(dev, 0);
1476 	if (rc) {
1477 		ata_dev_printk(dev, KERN_ERR, "failed to re-read IDENTIFY "
1478 			       "data after HPA resizing\n");
1479 		return rc;
1480 	}
1481 
1482 	if (print_info) {
1483 		u64 new_sectors = ata_id_n_sectors(dev->id);
1484 		ata_dev_printk(dev, KERN_INFO,
1485 			"HPA unlocked: %llu -> %llu, native %llu\n",
1486 			(unsigned long long)sectors,
1487 			(unsigned long long)new_sectors,
1488 			(unsigned long long)native_sectors);
1489 	}
1490 
1491 	return 0;
1492 }
1493 
1494 /**
1495  *	ata_dump_id - IDENTIFY DEVICE info debugging output
1496  *	@id: IDENTIFY DEVICE page to dump
1497  *
1498  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
1499  *	page.
1500  *
1501  *	LOCKING:
1502  *	caller.
1503  */
1504 
1505 static inline void ata_dump_id(const u16 *id)
1506 {
1507 	DPRINTK("49==0x%04x  "
1508 		"53==0x%04x  "
1509 		"63==0x%04x  "
1510 		"64==0x%04x  "
1511 		"75==0x%04x  \n",
1512 		id[49],
1513 		id[53],
1514 		id[63],
1515 		id[64],
1516 		id[75]);
1517 	DPRINTK("80==0x%04x  "
1518 		"81==0x%04x  "
1519 		"82==0x%04x  "
1520 		"83==0x%04x  "
1521 		"84==0x%04x  \n",
1522 		id[80],
1523 		id[81],
1524 		id[82],
1525 		id[83],
1526 		id[84]);
1527 	DPRINTK("88==0x%04x  "
1528 		"93==0x%04x\n",
1529 		id[88],
1530 		id[93]);
1531 }
1532 
1533 /**
1534  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1535  *	@id: IDENTIFY data to compute xfer mask from
1536  *
1537  *	Compute the xfermask for this device. This is not as trivial
1538  *	as it seems if we must consider early devices correctly.
1539  *
1540  *	FIXME: pre IDE drive timing (do we care ?).
1541  *
1542  *	LOCKING:
1543  *	None.
1544  *
1545  *	RETURNS:
1546  *	Computed xfermask
1547  */
1548 unsigned long ata_id_xfermask(const u16 *id)
1549 {
1550 	unsigned long pio_mask, mwdma_mask, udma_mask;
1551 
1552 	/* Usual case. Word 53 indicates word 64 is valid */
1553 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1554 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1555 		pio_mask <<= 3;
1556 		pio_mask |= 0x7;
1557 	} else {
1558 		/* If word 64 isn't valid then Word 51 high byte holds
1559 		 * the PIO timing number for the maximum. Turn it into
1560 		 * a mask.
1561 		 */
1562 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1563 		if (mode < 5)	/* Valid PIO range */
1564 			pio_mask = (2 << mode) - 1;
1565 		else
1566 			pio_mask = 1;
1567 
1568 		/* But wait.. there's more. Design your standards by
1569 		 * committee and you too can get a free iordy field to
1570 		 * process. However its the speeds not the modes that
1571 		 * are supported... Note drivers using the timing API
1572 		 * will get this right anyway
1573 		 */
1574 	}
1575 
1576 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1577 
1578 	if (ata_id_is_cfa(id)) {
1579 		/*
1580 		 *	Process compact flash extended modes
1581 		 */
1582 		int pio = id[163] & 0x7;
1583 		int dma = (id[163] >> 3) & 7;
1584 
1585 		if (pio)
1586 			pio_mask |= (1 << 5);
1587 		if (pio > 1)
1588 			pio_mask |= (1 << 6);
1589 		if (dma)
1590 			mwdma_mask |= (1 << 3);
1591 		if (dma > 1)
1592 			mwdma_mask |= (1 << 4);
1593 	}
1594 
1595 	udma_mask = 0;
1596 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1597 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1598 
1599 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1600 }
1601 
1602 /**
1603  *	ata_pio_queue_task - Queue port_task
1604  *	@ap: The ata_port to queue port_task for
1605  *	@fn: workqueue function to be scheduled
1606  *	@data: data for @fn to use
1607  *	@delay: delay time in msecs for workqueue function
1608  *
1609  *	Schedule @fn(@data) for execution after @delay jiffies using
1610  *	port_task.  There is one port_task per port and it's the
1611  *	user(low level driver)'s responsibility to make sure that only
1612  *	one task is active at any given time.
1613  *
1614  *	libata core layer takes care of synchronization between
1615  *	port_task and EH.  ata_pio_queue_task() may be ignored for EH
1616  *	synchronization.
1617  *
1618  *	LOCKING:
1619  *	Inherited from caller.
1620  */
1621 void ata_pio_queue_task(struct ata_port *ap, void *data, unsigned long delay)
1622 {
1623 	ap->port_task_data = data;
1624 
1625 	/* may fail if ata_port_flush_task() in progress */
1626 	queue_delayed_work(ata_wq, &ap->port_task, msecs_to_jiffies(delay));
1627 }
1628 
1629 /**
1630  *	ata_port_flush_task - Flush port_task
1631  *	@ap: The ata_port to flush port_task for
1632  *
1633  *	After this function completes, port_task is guranteed not to
1634  *	be running or scheduled.
1635  *
1636  *	LOCKING:
1637  *	Kernel thread context (may sleep)
1638  */
1639 void ata_port_flush_task(struct ata_port *ap)
1640 {
1641 	DPRINTK("ENTER\n");
1642 
1643 	cancel_rearming_delayed_work(&ap->port_task);
1644 
1645 	if (ata_msg_ctl(ap))
1646 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __func__);
1647 }
1648 
1649 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1650 {
1651 	struct completion *waiting = qc->private_data;
1652 
1653 	complete(waiting);
1654 }
1655 
1656 /**
1657  *	ata_exec_internal_sg - execute libata internal command
1658  *	@dev: Device to which the command is sent
1659  *	@tf: Taskfile registers for the command and the result
1660  *	@cdb: CDB for packet command
1661  *	@dma_dir: Data tranfer direction of the command
1662  *	@sgl: sg list for the data buffer of the command
1663  *	@n_elem: Number of sg entries
1664  *	@timeout: Timeout in msecs (0 for default)
1665  *
1666  *	Executes libata internal command with timeout.  @tf contains
1667  *	command on entry and result on return.  Timeout and error
1668  *	conditions are reported via return value.  No recovery action
1669  *	is taken after a command times out.  It's caller's duty to
1670  *	clean up after timeout.
1671  *
1672  *	LOCKING:
1673  *	None.  Should be called with kernel context, might sleep.
1674  *
1675  *	RETURNS:
1676  *	Zero on success, AC_ERR_* mask on failure
1677  */
1678 unsigned ata_exec_internal_sg(struct ata_device *dev,
1679 			      struct ata_taskfile *tf, const u8 *cdb,
1680 			      int dma_dir, struct scatterlist *sgl,
1681 			      unsigned int n_elem, unsigned long timeout)
1682 {
1683 	struct ata_link *link = dev->link;
1684 	struct ata_port *ap = link->ap;
1685 	u8 command = tf->command;
1686 	int auto_timeout = 0;
1687 	struct ata_queued_cmd *qc;
1688 	unsigned int tag, preempted_tag;
1689 	u32 preempted_sactive, preempted_qc_active;
1690 	int preempted_nr_active_links;
1691 	DECLARE_COMPLETION_ONSTACK(wait);
1692 	unsigned long flags;
1693 	unsigned int err_mask;
1694 	int rc;
1695 
1696 	spin_lock_irqsave(ap->lock, flags);
1697 
1698 	/* no internal command while frozen */
1699 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1700 		spin_unlock_irqrestore(ap->lock, flags);
1701 		return AC_ERR_SYSTEM;
1702 	}
1703 
1704 	/* initialize internal qc */
1705 
1706 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1707 	 * drivers choke if any other tag is given.  This breaks
1708 	 * ata_tag_internal() test for those drivers.  Don't use new
1709 	 * EH stuff without converting to it.
1710 	 */
1711 	if (ap->ops->error_handler)
1712 		tag = ATA_TAG_INTERNAL;
1713 	else
1714 		tag = 0;
1715 
1716 	if (test_and_set_bit(tag, &ap->qc_allocated))
1717 		BUG();
1718 	qc = __ata_qc_from_tag(ap, tag);
1719 
1720 	qc->tag = tag;
1721 	qc->scsicmd = NULL;
1722 	qc->ap = ap;
1723 	qc->dev = dev;
1724 	ata_qc_reinit(qc);
1725 
1726 	preempted_tag = link->active_tag;
1727 	preempted_sactive = link->sactive;
1728 	preempted_qc_active = ap->qc_active;
1729 	preempted_nr_active_links = ap->nr_active_links;
1730 	link->active_tag = ATA_TAG_POISON;
1731 	link->sactive = 0;
1732 	ap->qc_active = 0;
1733 	ap->nr_active_links = 0;
1734 
1735 	/* prepare & issue qc */
1736 	qc->tf = *tf;
1737 	if (cdb)
1738 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1739 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1740 	qc->dma_dir = dma_dir;
1741 	if (dma_dir != DMA_NONE) {
1742 		unsigned int i, buflen = 0;
1743 		struct scatterlist *sg;
1744 
1745 		for_each_sg(sgl, sg, n_elem, i)
1746 			buflen += sg->length;
1747 
1748 		ata_sg_init(qc, sgl, n_elem);
1749 		qc->nbytes = buflen;
1750 	}
1751 
1752 	qc->private_data = &wait;
1753 	qc->complete_fn = ata_qc_complete_internal;
1754 
1755 	ata_qc_issue(qc);
1756 
1757 	spin_unlock_irqrestore(ap->lock, flags);
1758 
1759 	if (!timeout) {
1760 		if (ata_probe_timeout)
1761 			timeout = ata_probe_timeout * 1000;
1762 		else {
1763 			timeout = ata_internal_cmd_timeout(dev, command);
1764 			auto_timeout = 1;
1765 		}
1766 	}
1767 
1768 	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
1769 
1770 	ata_port_flush_task(ap);
1771 
1772 	if (!rc) {
1773 		spin_lock_irqsave(ap->lock, flags);
1774 
1775 		/* We're racing with irq here.  If we lose, the
1776 		 * following test prevents us from completing the qc
1777 		 * twice.  If we win, the port is frozen and will be
1778 		 * cleaned up by ->post_internal_cmd().
1779 		 */
1780 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1781 			qc->err_mask |= AC_ERR_TIMEOUT;
1782 
1783 			if (ap->ops->error_handler)
1784 				ata_port_freeze(ap);
1785 			else
1786 				ata_qc_complete(qc);
1787 
1788 			if (ata_msg_warn(ap))
1789 				ata_dev_printk(dev, KERN_WARNING,
1790 					"qc timeout (cmd 0x%x)\n", command);
1791 		}
1792 
1793 		spin_unlock_irqrestore(ap->lock, flags);
1794 	}
1795 
1796 	/* do post_internal_cmd */
1797 	if (ap->ops->post_internal_cmd)
1798 		ap->ops->post_internal_cmd(qc);
1799 
1800 	/* perform minimal error analysis */
1801 	if (qc->flags & ATA_QCFLAG_FAILED) {
1802 		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
1803 			qc->err_mask |= AC_ERR_DEV;
1804 
1805 		if (!qc->err_mask)
1806 			qc->err_mask |= AC_ERR_OTHER;
1807 
1808 		if (qc->err_mask & ~AC_ERR_OTHER)
1809 			qc->err_mask &= ~AC_ERR_OTHER;
1810 	}
1811 
1812 	/* finish up */
1813 	spin_lock_irqsave(ap->lock, flags);
1814 
1815 	*tf = qc->result_tf;
1816 	err_mask = qc->err_mask;
1817 
1818 	ata_qc_free(qc);
1819 	link->active_tag = preempted_tag;
1820 	link->sactive = preempted_sactive;
1821 	ap->qc_active = preempted_qc_active;
1822 	ap->nr_active_links = preempted_nr_active_links;
1823 
1824 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1825 	 * Until those drivers are fixed, we detect the condition
1826 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1827 	 * port.
1828 	 *
1829 	 * Note that this doesn't change any behavior as internal
1830 	 * command failure results in disabling the device in the
1831 	 * higher layer for LLDDs without new reset/EH callbacks.
1832 	 *
1833 	 * Kill the following code as soon as those drivers are fixed.
1834 	 */
1835 	if (ap->flags & ATA_FLAG_DISABLED) {
1836 		err_mask |= AC_ERR_SYSTEM;
1837 		ata_port_probe(ap);
1838 	}
1839 
1840 	spin_unlock_irqrestore(ap->lock, flags);
1841 
1842 	if ((err_mask & AC_ERR_TIMEOUT) && auto_timeout)
1843 		ata_internal_cmd_timed_out(dev, command);
1844 
1845 	return err_mask;
1846 }
1847 
1848 /**
1849  *	ata_exec_internal - execute libata internal command
1850  *	@dev: Device to which the command is sent
1851  *	@tf: Taskfile registers for the command and the result
1852  *	@cdb: CDB for packet command
1853  *	@dma_dir: Data tranfer direction of the command
1854  *	@buf: Data buffer of the command
1855  *	@buflen: Length of data buffer
1856  *	@timeout: Timeout in msecs (0 for default)
1857  *
1858  *	Wrapper around ata_exec_internal_sg() which takes simple
1859  *	buffer instead of sg list.
1860  *
1861  *	LOCKING:
1862  *	None.  Should be called with kernel context, might sleep.
1863  *
1864  *	RETURNS:
1865  *	Zero on success, AC_ERR_* mask on failure
1866  */
1867 unsigned ata_exec_internal(struct ata_device *dev,
1868 			   struct ata_taskfile *tf, const u8 *cdb,
1869 			   int dma_dir, void *buf, unsigned int buflen,
1870 			   unsigned long timeout)
1871 {
1872 	struct scatterlist *psg = NULL, sg;
1873 	unsigned int n_elem = 0;
1874 
1875 	if (dma_dir != DMA_NONE) {
1876 		WARN_ON(!buf);
1877 		sg_init_one(&sg, buf, buflen);
1878 		psg = &sg;
1879 		n_elem++;
1880 	}
1881 
1882 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
1883 				    timeout);
1884 }
1885 
1886 /**
1887  *	ata_do_simple_cmd - execute simple internal command
1888  *	@dev: Device to which the command is sent
1889  *	@cmd: Opcode to execute
1890  *
1891  *	Execute a 'simple' command, that only consists of the opcode
1892  *	'cmd' itself, without filling any other registers
1893  *
1894  *	LOCKING:
1895  *	Kernel thread context (may sleep).
1896  *
1897  *	RETURNS:
1898  *	Zero on success, AC_ERR_* mask on failure
1899  */
1900 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
1901 {
1902 	struct ata_taskfile tf;
1903 
1904 	ata_tf_init(dev, &tf);
1905 
1906 	tf.command = cmd;
1907 	tf.flags |= ATA_TFLAG_DEVICE;
1908 	tf.protocol = ATA_PROT_NODATA;
1909 
1910 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1911 }
1912 
1913 /**
1914  *	ata_pio_need_iordy	-	check if iordy needed
1915  *	@adev: ATA device
1916  *
1917  *	Check if the current speed of the device requires IORDY. Used
1918  *	by various controllers for chip configuration.
1919  */
1920 
1921 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1922 {
1923 	/* Controller doesn't support  IORDY. Probably a pointless check
1924 	   as the caller should know this */
1925 	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
1926 		return 0;
1927 	/* PIO3 and higher it is mandatory */
1928 	if (adev->pio_mode > XFER_PIO_2)
1929 		return 1;
1930 	/* We turn it on when possible */
1931 	if (ata_id_has_iordy(adev->id))
1932 		return 1;
1933 	return 0;
1934 }
1935 
1936 /**
1937  *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
1938  *	@adev: ATA device
1939  *
1940  *	Compute the highest mode possible if we are not using iordy. Return
1941  *	-1 if no iordy mode is available.
1942  */
1943 
1944 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
1945 {
1946 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1947 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1948 		u16 pio = adev->id[ATA_ID_EIDE_PIO];
1949 		/* Is the speed faster than the drive allows non IORDY ? */
1950 		if (pio) {
1951 			/* This is cycle times not frequency - watch the logic! */
1952 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1953 				return 3 << ATA_SHIFT_PIO;
1954 			return 7 << ATA_SHIFT_PIO;
1955 		}
1956 	}
1957 	return 3 << ATA_SHIFT_PIO;
1958 }
1959 
1960 /**
1961  *	ata_do_dev_read_id		-	default ID read method
1962  *	@dev: device
1963  *	@tf: proposed taskfile
1964  *	@id: data buffer
1965  *
1966  *	Issue the identify taskfile and hand back the buffer containing
1967  *	identify data. For some RAID controllers and for pre ATA devices
1968  *	this function is wrapped or replaced by the driver
1969  */
1970 unsigned int ata_do_dev_read_id(struct ata_device *dev,
1971 					struct ata_taskfile *tf, u16 *id)
1972 {
1973 	return ata_exec_internal(dev, tf, NULL, DMA_FROM_DEVICE,
1974 				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
1975 }
1976 
1977 /**
1978  *	ata_dev_read_id - Read ID data from the specified device
1979  *	@dev: target device
1980  *	@p_class: pointer to class of the target device (may be changed)
1981  *	@flags: ATA_READID_* flags
1982  *	@id: buffer to read IDENTIFY data into
1983  *
1984  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1985  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1986  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1987  *	for pre-ATA4 drives.
1988  *
1989  *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
1990  *	now we abort if we hit that case.
1991  *
1992  *	LOCKING:
1993  *	Kernel thread context (may sleep)
1994  *
1995  *	RETURNS:
1996  *	0 on success, -errno otherwise.
1997  */
1998 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1999 		    unsigned int flags, u16 *id)
2000 {
2001 	struct ata_port *ap = dev->link->ap;
2002 	unsigned int class = *p_class;
2003 	struct ata_taskfile tf;
2004 	unsigned int err_mask = 0;
2005 	const char *reason;
2006 	int may_fallback = 1, tried_spinup = 0;
2007 	int rc;
2008 
2009 	if (ata_msg_ctl(ap))
2010 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __func__);
2011 
2012 retry:
2013 	ata_tf_init(dev, &tf);
2014 
2015 	switch (class) {
2016 	case ATA_DEV_ATA:
2017 		tf.command = ATA_CMD_ID_ATA;
2018 		break;
2019 	case ATA_DEV_ATAPI:
2020 		tf.command = ATA_CMD_ID_ATAPI;
2021 		break;
2022 	default:
2023 		rc = -ENODEV;
2024 		reason = "unsupported class";
2025 		goto err_out;
2026 	}
2027 
2028 	tf.protocol = ATA_PROT_PIO;
2029 
2030 	/* Some devices choke if TF registers contain garbage.  Make
2031 	 * sure those are properly initialized.
2032 	 */
2033 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
2034 
2035 	/* Device presence detection is unreliable on some
2036 	 * controllers.  Always poll IDENTIFY if available.
2037 	 */
2038 	tf.flags |= ATA_TFLAG_POLLING;
2039 
2040 	if (ap->ops->read_id)
2041 		err_mask = ap->ops->read_id(dev, &tf, id);
2042 	else
2043 		err_mask = ata_do_dev_read_id(dev, &tf, id);
2044 
2045 	if (err_mask) {
2046 		if (err_mask & AC_ERR_NODEV_HINT) {
2047 			ata_dev_printk(dev, KERN_DEBUG,
2048 				       "NODEV after polling detection\n");
2049 			return -ENOENT;
2050 		}
2051 
2052 		if ((err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
2053 			/* Device or controller might have reported
2054 			 * the wrong device class.  Give a shot at the
2055 			 * other IDENTIFY if the current one is
2056 			 * aborted by the device.
2057 			 */
2058 			if (may_fallback) {
2059 				may_fallback = 0;
2060 
2061 				if (class == ATA_DEV_ATA)
2062 					class = ATA_DEV_ATAPI;
2063 				else
2064 					class = ATA_DEV_ATA;
2065 				goto retry;
2066 			}
2067 
2068 			/* Control reaches here iff the device aborted
2069 			 * both flavors of IDENTIFYs which happens
2070 			 * sometimes with phantom devices.
2071 			 */
2072 			ata_dev_printk(dev, KERN_DEBUG,
2073 				       "both IDENTIFYs aborted, assuming NODEV\n");
2074 			return -ENOENT;
2075 		}
2076 
2077 		rc = -EIO;
2078 		reason = "I/O error";
2079 		goto err_out;
2080 	}
2081 
2082 	/* Falling back doesn't make sense if ID data was read
2083 	 * successfully at least once.
2084 	 */
2085 	may_fallback = 0;
2086 
2087 	swap_buf_le16(id, ATA_ID_WORDS);
2088 
2089 	/* sanity check */
2090 	rc = -EINVAL;
2091 	reason = "device reports invalid type";
2092 
2093 	if (class == ATA_DEV_ATA) {
2094 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
2095 			goto err_out;
2096 	} else {
2097 		if (ata_id_is_ata(id))
2098 			goto err_out;
2099 	}
2100 
2101 	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
2102 		tried_spinup = 1;
2103 		/*
2104 		 * Drive powered-up in standby mode, and requires a specific
2105 		 * SET_FEATURES spin-up subcommand before it will accept
2106 		 * anything other than the original IDENTIFY command.
2107 		 */
2108 		err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
2109 		if (err_mask && id[2] != 0x738c) {
2110 			rc = -EIO;
2111 			reason = "SPINUP failed";
2112 			goto err_out;
2113 		}
2114 		/*
2115 		 * If the drive initially returned incomplete IDENTIFY info,
2116 		 * we now must reissue the IDENTIFY command.
2117 		 */
2118 		if (id[2] == 0x37c8)
2119 			goto retry;
2120 	}
2121 
2122 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
2123 		/*
2124 		 * The exact sequence expected by certain pre-ATA4 drives is:
2125 		 * SRST RESET
2126 		 * IDENTIFY (optional in early ATA)
2127 		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
2128 		 * anything else..
2129 		 * Some drives were very specific about that exact sequence.
2130 		 *
2131 		 * Note that ATA4 says lba is mandatory so the second check
2132 		 * shoud never trigger.
2133 		 */
2134 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
2135 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
2136 			if (err_mask) {
2137 				rc = -EIO;
2138 				reason = "INIT_DEV_PARAMS failed";
2139 				goto err_out;
2140 			}
2141 
2142 			/* current CHS translation info (id[53-58]) might be
2143 			 * changed. reread the identify device info.
2144 			 */
2145 			flags &= ~ATA_READID_POSTRESET;
2146 			goto retry;
2147 		}
2148 	}
2149 
2150 	*p_class = class;
2151 
2152 	return 0;
2153 
2154  err_out:
2155 	if (ata_msg_warn(ap))
2156 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
2157 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
2158 	return rc;
2159 }
2160 
2161 static inline u8 ata_dev_knobble(struct ata_device *dev)
2162 {
2163 	struct ata_port *ap = dev->link->ap;
2164 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
2165 }
2166 
2167 static void ata_dev_config_ncq(struct ata_device *dev,
2168 			       char *desc, size_t desc_sz)
2169 {
2170 	struct ata_port *ap = dev->link->ap;
2171 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
2172 
2173 	if (!ata_id_has_ncq(dev->id)) {
2174 		desc[0] = '\0';
2175 		return;
2176 	}
2177 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
2178 		snprintf(desc, desc_sz, "NCQ (not used)");
2179 		return;
2180 	}
2181 	if (ap->flags & ATA_FLAG_NCQ) {
2182 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
2183 		dev->flags |= ATA_DFLAG_NCQ;
2184 	}
2185 
2186 	if (hdepth >= ddepth)
2187 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
2188 	else
2189 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
2190 }
2191 
2192 /**
2193  *	ata_dev_configure - Configure the specified ATA/ATAPI device
2194  *	@dev: Target device to configure
2195  *
2196  *	Configure @dev according to @dev->id.  Generic and low-level
2197  *	driver specific fixups are also applied.
2198  *
2199  *	LOCKING:
2200  *	Kernel thread context (may sleep)
2201  *
2202  *	RETURNS:
2203  *	0 on success, -errno otherwise
2204  */
2205 int ata_dev_configure(struct ata_device *dev)
2206 {
2207 	struct ata_port *ap = dev->link->ap;
2208 	struct ata_eh_context *ehc = &dev->link->eh_context;
2209 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
2210 	const u16 *id = dev->id;
2211 	unsigned long xfer_mask;
2212 	char revbuf[7];		/* XYZ-99\0 */
2213 	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
2214 	char modelbuf[ATA_ID_PROD_LEN+1];
2215 	int rc;
2216 
2217 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
2218 		ata_dev_printk(dev, KERN_INFO, "%s: ENTER/EXIT -- nodev\n",
2219 			       __func__);
2220 		return 0;
2221 	}
2222 
2223 	if (ata_msg_probe(ap))
2224 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __func__);
2225 
2226 	/* set horkage */
2227 	dev->horkage |= ata_dev_blacklisted(dev);
2228 	ata_force_horkage(dev);
2229 
2230 	if (dev->horkage & ATA_HORKAGE_DISABLE) {
2231 		ata_dev_printk(dev, KERN_INFO,
2232 			       "unsupported device, disabling\n");
2233 		ata_dev_disable(dev);
2234 		return 0;
2235 	}
2236 
2237 	if ((!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) &&
2238 	    dev->class == ATA_DEV_ATAPI) {
2239 		ata_dev_printk(dev, KERN_WARNING,
2240 			"WARNING: ATAPI is %s, device ignored.\n",
2241 			atapi_enabled ? "not supported with this driver"
2242 				      : "disabled");
2243 		ata_dev_disable(dev);
2244 		return 0;
2245 	}
2246 
2247 	/* let ACPI work its magic */
2248 	rc = ata_acpi_on_devcfg(dev);
2249 	if (rc)
2250 		return rc;
2251 
2252 	/* massage HPA, do it early as it might change IDENTIFY data */
2253 	rc = ata_hpa_resize(dev);
2254 	if (rc)
2255 		return rc;
2256 
2257 	/* print device capabilities */
2258 	if (ata_msg_probe(ap))
2259 		ata_dev_printk(dev, KERN_DEBUG,
2260 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
2261 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
2262 			       __func__,
2263 			       id[49], id[82], id[83], id[84],
2264 			       id[85], id[86], id[87], id[88]);
2265 
2266 	/* initialize to-be-configured parameters */
2267 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
2268 	dev->max_sectors = 0;
2269 	dev->cdb_len = 0;
2270 	dev->n_sectors = 0;
2271 	dev->cylinders = 0;
2272 	dev->heads = 0;
2273 	dev->sectors = 0;
2274 
2275 	/*
2276 	 * common ATA, ATAPI feature tests
2277 	 */
2278 
2279 	/* find max transfer mode; for printk only */
2280 	xfer_mask = ata_id_xfermask(id);
2281 
2282 	if (ata_msg_probe(ap))
2283 		ata_dump_id(id);
2284 
2285 	/* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
2286 	ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
2287 			sizeof(fwrevbuf));
2288 
2289 	ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
2290 			sizeof(modelbuf));
2291 
2292 	/* ATA-specific feature tests */
2293 	if (dev->class == ATA_DEV_ATA) {
2294 		if (ata_id_is_cfa(id)) {
2295 			if (id[162] & 1) /* CPRM may make this media unusable */
2296 				ata_dev_printk(dev, KERN_WARNING,
2297 					       "supports DRM functions and may "
2298 					       "not be fully accessable.\n");
2299 			snprintf(revbuf, 7, "CFA");
2300 		} else {
2301 			snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
2302 			/* Warn the user if the device has TPM extensions */
2303 			if (ata_id_has_tpm(id))
2304 				ata_dev_printk(dev, KERN_WARNING,
2305 					       "supports DRM functions and may "
2306 					       "not be fully accessable.\n");
2307 		}
2308 
2309 		dev->n_sectors = ata_id_n_sectors(id);
2310 
2311 		if (dev->id[59] & 0x100)
2312 			dev->multi_count = dev->id[59] & 0xff;
2313 
2314 		if (ata_id_has_lba(id)) {
2315 			const char *lba_desc;
2316 			char ncq_desc[20];
2317 
2318 			lba_desc = "LBA";
2319 			dev->flags |= ATA_DFLAG_LBA;
2320 			if (ata_id_has_lba48(id)) {
2321 				dev->flags |= ATA_DFLAG_LBA48;
2322 				lba_desc = "LBA48";
2323 
2324 				if (dev->n_sectors >= (1UL << 28) &&
2325 				    ata_id_has_flush_ext(id))
2326 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
2327 			}
2328 
2329 			/* config NCQ */
2330 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
2331 
2332 			/* print device info to dmesg */
2333 			if (ata_msg_drv(ap) && print_info) {
2334 				ata_dev_printk(dev, KERN_INFO,
2335 					"%s: %s, %s, max %s\n",
2336 					revbuf, modelbuf, fwrevbuf,
2337 					ata_mode_string(xfer_mask));
2338 				ata_dev_printk(dev, KERN_INFO,
2339 					"%Lu sectors, multi %u: %s %s\n",
2340 					(unsigned long long)dev->n_sectors,
2341 					dev->multi_count, lba_desc, ncq_desc);
2342 			}
2343 		} else {
2344 			/* CHS */
2345 
2346 			/* Default translation */
2347 			dev->cylinders	= id[1];
2348 			dev->heads	= id[3];
2349 			dev->sectors	= id[6];
2350 
2351 			if (ata_id_current_chs_valid(id)) {
2352 				/* Current CHS translation is valid. */
2353 				dev->cylinders = id[54];
2354 				dev->heads     = id[55];
2355 				dev->sectors   = id[56];
2356 			}
2357 
2358 			/* print device info to dmesg */
2359 			if (ata_msg_drv(ap) && print_info) {
2360 				ata_dev_printk(dev, KERN_INFO,
2361 					"%s: %s, %s, max %s\n",
2362 					revbuf,	modelbuf, fwrevbuf,
2363 					ata_mode_string(xfer_mask));
2364 				ata_dev_printk(dev, KERN_INFO,
2365 					"%Lu sectors, multi %u, CHS %u/%u/%u\n",
2366 					(unsigned long long)dev->n_sectors,
2367 					dev->multi_count, dev->cylinders,
2368 					dev->heads, dev->sectors);
2369 			}
2370 		}
2371 
2372 		dev->cdb_len = 16;
2373 	}
2374 
2375 	/* ATAPI-specific feature tests */
2376 	else if (dev->class == ATA_DEV_ATAPI) {
2377 		const char *cdb_intr_string = "";
2378 		const char *atapi_an_string = "";
2379 		const char *dma_dir_string = "";
2380 		u32 sntf;
2381 
2382 		rc = atapi_cdb_len(id);
2383 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
2384 			if (ata_msg_warn(ap))
2385 				ata_dev_printk(dev, KERN_WARNING,
2386 					       "unsupported CDB len\n");
2387 			rc = -EINVAL;
2388 			goto err_out_nosup;
2389 		}
2390 		dev->cdb_len = (unsigned int) rc;
2391 
2392 		/* Enable ATAPI AN if both the host and device have
2393 		 * the support.  If PMP is attached, SNTF is required
2394 		 * to enable ATAPI AN to discern between PHY status
2395 		 * changed notifications and ATAPI ANs.
2396 		 */
2397 		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
2398 		    (!sata_pmp_attached(ap) ||
2399 		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
2400 			unsigned int err_mask;
2401 
2402 			/* issue SET feature command to turn this on */
2403 			err_mask = ata_dev_set_feature(dev,
2404 					SETFEATURES_SATA_ENABLE, SATA_AN);
2405 			if (err_mask)
2406 				ata_dev_printk(dev, KERN_ERR,
2407 					"failed to enable ATAPI AN "
2408 					"(err_mask=0x%x)\n", err_mask);
2409 			else {
2410 				dev->flags |= ATA_DFLAG_AN;
2411 				atapi_an_string = ", ATAPI AN";
2412 			}
2413 		}
2414 
2415 		if (ata_id_cdb_intr(dev->id)) {
2416 			dev->flags |= ATA_DFLAG_CDB_INTR;
2417 			cdb_intr_string = ", CDB intr";
2418 		}
2419 
2420 		if (atapi_dmadir || atapi_id_dmadir(dev->id)) {
2421 			dev->flags |= ATA_DFLAG_DMADIR;
2422 			dma_dir_string = ", DMADIR";
2423 		}
2424 
2425 		/* print device info to dmesg */
2426 		if (ata_msg_drv(ap) && print_info)
2427 			ata_dev_printk(dev, KERN_INFO,
2428 				       "ATAPI: %s, %s, max %s%s%s%s\n",
2429 				       modelbuf, fwrevbuf,
2430 				       ata_mode_string(xfer_mask),
2431 				       cdb_intr_string, atapi_an_string,
2432 				       dma_dir_string);
2433 	}
2434 
2435 	/* determine max_sectors */
2436 	dev->max_sectors = ATA_MAX_SECTORS;
2437 	if (dev->flags & ATA_DFLAG_LBA48)
2438 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2439 
2440 	if (!(dev->horkage & ATA_HORKAGE_IPM)) {
2441 		if (ata_id_has_hipm(dev->id))
2442 			dev->flags |= ATA_DFLAG_HIPM;
2443 		if (ata_id_has_dipm(dev->id))
2444 			dev->flags |= ATA_DFLAG_DIPM;
2445 	}
2446 
2447 	/* Limit PATA drive on SATA cable bridge transfers to udma5,
2448 	   200 sectors */
2449 	if (ata_dev_knobble(dev)) {
2450 		if (ata_msg_drv(ap) && print_info)
2451 			ata_dev_printk(dev, KERN_INFO,
2452 				       "applying bridge limits\n");
2453 		dev->udma_mask &= ATA_UDMA5;
2454 		dev->max_sectors = ATA_MAX_SECTORS;
2455 	}
2456 
2457 	if ((dev->class == ATA_DEV_ATAPI) &&
2458 	    (atapi_command_packet_set(id) == TYPE_TAPE)) {
2459 		dev->max_sectors = ATA_MAX_SECTORS_TAPE;
2460 		dev->horkage |= ATA_HORKAGE_STUCK_ERR;
2461 	}
2462 
2463 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
2464 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
2465 					 dev->max_sectors);
2466 
2467 	if (ata_dev_blacklisted(dev) & ATA_HORKAGE_IPM) {
2468 		dev->horkage |= ATA_HORKAGE_IPM;
2469 
2470 		/* reset link pm_policy for this port to no pm */
2471 		ap->pm_policy = MAX_PERFORMANCE;
2472 	}
2473 
2474 	if (ap->ops->dev_config)
2475 		ap->ops->dev_config(dev);
2476 
2477 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
2478 		/* Let the user know. We don't want to disallow opens for
2479 		   rescue purposes, or in case the vendor is just a blithering
2480 		   idiot. Do this after the dev_config call as some controllers
2481 		   with buggy firmware may want to avoid reporting false device
2482 		   bugs */
2483 
2484 		if (print_info) {
2485 			ata_dev_printk(dev, KERN_WARNING,
2486 "Drive reports diagnostics failure. This may indicate a drive\n");
2487 			ata_dev_printk(dev, KERN_WARNING,
2488 "fault or invalid emulation. Contact drive vendor for information.\n");
2489 		}
2490 	}
2491 
2492 	return 0;
2493 
2494 err_out_nosup:
2495 	if (ata_msg_probe(ap))
2496 		ata_dev_printk(dev, KERN_DEBUG,
2497 			       "%s: EXIT, err\n", __func__);
2498 	return rc;
2499 }
2500 
2501 /**
2502  *	ata_cable_40wire	-	return 40 wire cable type
2503  *	@ap: port
2504  *
2505  *	Helper method for drivers which want to hardwire 40 wire cable
2506  *	detection.
2507  */
2508 
2509 int ata_cable_40wire(struct ata_port *ap)
2510 {
2511 	return ATA_CBL_PATA40;
2512 }
2513 
2514 /**
2515  *	ata_cable_80wire	-	return 80 wire cable type
2516  *	@ap: port
2517  *
2518  *	Helper method for drivers which want to hardwire 80 wire cable
2519  *	detection.
2520  */
2521 
2522 int ata_cable_80wire(struct ata_port *ap)
2523 {
2524 	return ATA_CBL_PATA80;
2525 }
2526 
2527 /**
2528  *	ata_cable_unknown	-	return unknown PATA cable.
2529  *	@ap: port
2530  *
2531  *	Helper method for drivers which have no PATA cable detection.
2532  */
2533 
2534 int ata_cable_unknown(struct ata_port *ap)
2535 {
2536 	return ATA_CBL_PATA_UNK;
2537 }
2538 
2539 /**
2540  *	ata_cable_ignore	-	return ignored PATA cable.
2541  *	@ap: port
2542  *
2543  *	Helper method for drivers which don't use cable type to limit
2544  *	transfer mode.
2545  */
2546 int ata_cable_ignore(struct ata_port *ap)
2547 {
2548 	return ATA_CBL_PATA_IGN;
2549 }
2550 
2551 /**
2552  *	ata_cable_sata	-	return SATA cable type
2553  *	@ap: port
2554  *
2555  *	Helper method for drivers which have SATA cables
2556  */
2557 
2558 int ata_cable_sata(struct ata_port *ap)
2559 {
2560 	return ATA_CBL_SATA;
2561 }
2562 
2563 /**
2564  *	ata_bus_probe - Reset and probe ATA bus
2565  *	@ap: Bus to probe
2566  *
2567  *	Master ATA bus probing function.  Initiates a hardware-dependent
2568  *	bus reset, then attempts to identify any devices found on
2569  *	the bus.
2570  *
2571  *	LOCKING:
2572  *	PCI/etc. bus probe sem.
2573  *
2574  *	RETURNS:
2575  *	Zero on success, negative errno otherwise.
2576  */
2577 
2578 int ata_bus_probe(struct ata_port *ap)
2579 {
2580 	unsigned int classes[ATA_MAX_DEVICES];
2581 	int tries[ATA_MAX_DEVICES];
2582 	int rc;
2583 	struct ata_device *dev;
2584 
2585 	ata_port_probe(ap);
2586 
2587 	ata_link_for_each_dev(dev, &ap->link)
2588 		tries[dev->devno] = ATA_PROBE_MAX_TRIES;
2589 
2590  retry:
2591 	ata_link_for_each_dev(dev, &ap->link) {
2592 		/* If we issue an SRST then an ATA drive (not ATAPI)
2593 		 * may change configuration and be in PIO0 timing. If
2594 		 * we do a hard reset (or are coming from power on)
2595 		 * this is true for ATA or ATAPI. Until we've set a
2596 		 * suitable controller mode we should not touch the
2597 		 * bus as we may be talking too fast.
2598 		 */
2599 		dev->pio_mode = XFER_PIO_0;
2600 
2601 		/* If the controller has a pio mode setup function
2602 		 * then use it to set the chipset to rights. Don't
2603 		 * touch the DMA setup as that will be dealt with when
2604 		 * configuring devices.
2605 		 */
2606 		if (ap->ops->set_piomode)
2607 			ap->ops->set_piomode(ap, dev);
2608 	}
2609 
2610 	/* reset and determine device classes */
2611 	ap->ops->phy_reset(ap);
2612 
2613 	ata_link_for_each_dev(dev, &ap->link) {
2614 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
2615 		    dev->class != ATA_DEV_UNKNOWN)
2616 			classes[dev->devno] = dev->class;
2617 		else
2618 			classes[dev->devno] = ATA_DEV_NONE;
2619 
2620 		dev->class = ATA_DEV_UNKNOWN;
2621 	}
2622 
2623 	ata_port_probe(ap);
2624 
2625 	/* read IDENTIFY page and configure devices. We have to do the identify
2626 	   specific sequence bass-ackwards so that PDIAG- is released by
2627 	   the slave device */
2628 
2629 	ata_link_for_each_dev_reverse(dev, &ap->link) {
2630 		if (tries[dev->devno])
2631 			dev->class = classes[dev->devno];
2632 
2633 		if (!ata_dev_enabled(dev))
2634 			continue;
2635 
2636 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
2637 				     dev->id);
2638 		if (rc)
2639 			goto fail;
2640 	}
2641 
2642 	/* Now ask for the cable type as PDIAG- should have been released */
2643 	if (ap->ops->cable_detect)
2644 		ap->cbl = ap->ops->cable_detect(ap);
2645 
2646 	/* We may have SATA bridge glue hiding here irrespective of the
2647 	   reported cable types and sensed types */
2648 	ata_link_for_each_dev(dev, &ap->link) {
2649 		if (!ata_dev_enabled(dev))
2650 			continue;
2651 		/* SATA drives indicate we have a bridge. We don't know which
2652 		   end of the link the bridge is which is a problem */
2653 		if (ata_id_is_sata(dev->id))
2654 			ap->cbl = ATA_CBL_SATA;
2655 	}
2656 
2657 	/* After the identify sequence we can now set up the devices. We do
2658 	   this in the normal order so that the user doesn't get confused */
2659 
2660 	ata_link_for_each_dev(dev, &ap->link) {
2661 		if (!ata_dev_enabled(dev))
2662 			continue;
2663 
2664 		ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
2665 		rc = ata_dev_configure(dev);
2666 		ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
2667 		if (rc)
2668 			goto fail;
2669 	}
2670 
2671 	/* configure transfer mode */
2672 	rc = ata_set_mode(&ap->link, &dev);
2673 	if (rc)
2674 		goto fail;
2675 
2676 	ata_link_for_each_dev(dev, &ap->link)
2677 		if (ata_dev_enabled(dev))
2678 			return 0;
2679 
2680 	/* no device present, disable port */
2681 	ata_port_disable(ap);
2682 	return -ENODEV;
2683 
2684  fail:
2685 	tries[dev->devno]--;
2686 
2687 	switch (rc) {
2688 	case -EINVAL:
2689 		/* eeek, something went very wrong, give up */
2690 		tries[dev->devno] = 0;
2691 		break;
2692 
2693 	case -ENODEV:
2694 		/* give it just one more chance */
2695 		tries[dev->devno] = min(tries[dev->devno], 1);
2696 	case -EIO:
2697 		if (tries[dev->devno] == 1) {
2698 			/* This is the last chance, better to slow
2699 			 * down than lose it.
2700 			 */
2701 			sata_down_spd_limit(&ap->link);
2702 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2703 		}
2704 	}
2705 
2706 	if (!tries[dev->devno])
2707 		ata_dev_disable(dev);
2708 
2709 	goto retry;
2710 }
2711 
2712 /**
2713  *	ata_port_probe - Mark port as enabled
2714  *	@ap: Port for which we indicate enablement
2715  *
2716  *	Modify @ap data structure such that the system
2717  *	thinks that the entire port is enabled.
2718  *
2719  *	LOCKING: host lock, or some other form of
2720  *	serialization.
2721  */
2722 
2723 void ata_port_probe(struct ata_port *ap)
2724 {
2725 	ap->flags &= ~ATA_FLAG_DISABLED;
2726 }
2727 
2728 /**
2729  *	sata_print_link_status - Print SATA link status
2730  *	@link: SATA link to printk link status about
2731  *
2732  *	This function prints link speed and status of a SATA link.
2733  *
2734  *	LOCKING:
2735  *	None.
2736  */
2737 static void sata_print_link_status(struct ata_link *link)
2738 {
2739 	u32 sstatus, scontrol, tmp;
2740 
2741 	if (sata_scr_read(link, SCR_STATUS, &sstatus))
2742 		return;
2743 	sata_scr_read(link, SCR_CONTROL, &scontrol);
2744 
2745 	if (ata_phys_link_online(link)) {
2746 		tmp = (sstatus >> 4) & 0xf;
2747 		ata_link_printk(link, KERN_INFO,
2748 				"SATA link up %s (SStatus %X SControl %X)\n",
2749 				sata_spd_string(tmp), sstatus, scontrol);
2750 	} else {
2751 		ata_link_printk(link, KERN_INFO,
2752 				"SATA link down (SStatus %X SControl %X)\n",
2753 				sstatus, scontrol);
2754 	}
2755 }
2756 
2757 /**
2758  *	ata_dev_pair		-	return other device on cable
2759  *	@adev: device
2760  *
2761  *	Obtain the other device on the same cable, or if none is
2762  *	present NULL is returned
2763  */
2764 
2765 struct ata_device *ata_dev_pair(struct ata_device *adev)
2766 {
2767 	struct ata_link *link = adev->link;
2768 	struct ata_device *pair = &link->device[1 - adev->devno];
2769 	if (!ata_dev_enabled(pair))
2770 		return NULL;
2771 	return pair;
2772 }
2773 
2774 /**
2775  *	ata_port_disable - Disable port.
2776  *	@ap: Port to be disabled.
2777  *
2778  *	Modify @ap data structure such that the system
2779  *	thinks that the entire port is disabled, and should
2780  *	never attempt to probe or communicate with devices
2781  *	on this port.
2782  *
2783  *	LOCKING: host lock, or some other form of
2784  *	serialization.
2785  */
2786 
2787 void ata_port_disable(struct ata_port *ap)
2788 {
2789 	ap->link.device[0].class = ATA_DEV_NONE;
2790 	ap->link.device[1].class = ATA_DEV_NONE;
2791 	ap->flags |= ATA_FLAG_DISABLED;
2792 }
2793 
2794 /**
2795  *	sata_down_spd_limit - adjust SATA spd limit downward
2796  *	@link: Link to adjust SATA spd limit for
2797  *
2798  *	Adjust SATA spd limit of @link downward.  Note that this
2799  *	function only adjusts the limit.  The change must be applied
2800  *	using sata_set_spd().
2801  *
2802  *	LOCKING:
2803  *	Inherited from caller.
2804  *
2805  *	RETURNS:
2806  *	0 on success, negative errno on failure
2807  */
2808 int sata_down_spd_limit(struct ata_link *link)
2809 {
2810 	u32 sstatus, spd, mask;
2811 	int rc, highbit;
2812 
2813 	if (!sata_scr_valid(link))
2814 		return -EOPNOTSUPP;
2815 
2816 	/* If SCR can be read, use it to determine the current SPD.
2817 	 * If not, use cached value in link->sata_spd.
2818 	 */
2819 	rc = sata_scr_read(link, SCR_STATUS, &sstatus);
2820 	if (rc == 0)
2821 		spd = (sstatus >> 4) & 0xf;
2822 	else
2823 		spd = link->sata_spd;
2824 
2825 	mask = link->sata_spd_limit;
2826 	if (mask <= 1)
2827 		return -EINVAL;
2828 
2829 	/* unconditionally mask off the highest bit */
2830 	highbit = fls(mask) - 1;
2831 	mask &= ~(1 << highbit);
2832 
2833 	/* Mask off all speeds higher than or equal to the current
2834 	 * one.  Force 1.5Gbps if current SPD is not available.
2835 	 */
2836 	if (spd > 1)
2837 		mask &= (1 << (spd - 1)) - 1;
2838 	else
2839 		mask &= 1;
2840 
2841 	/* were we already at the bottom? */
2842 	if (!mask)
2843 		return -EINVAL;
2844 
2845 	link->sata_spd_limit = mask;
2846 
2847 	ata_link_printk(link, KERN_WARNING, "limiting SATA link speed to %s\n",
2848 			sata_spd_string(fls(mask)));
2849 
2850 	return 0;
2851 }
2852 
2853 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
2854 {
2855 	struct ata_link *host_link = &link->ap->link;
2856 	u32 limit, target, spd;
2857 
2858 	limit = link->sata_spd_limit;
2859 
2860 	/* Don't configure downstream link faster than upstream link.
2861 	 * It doesn't speed up anything and some PMPs choke on such
2862 	 * configuration.
2863 	 */
2864 	if (!ata_is_host_link(link) && host_link->sata_spd)
2865 		limit &= (1 << host_link->sata_spd) - 1;
2866 
2867 	if (limit == UINT_MAX)
2868 		target = 0;
2869 	else
2870 		target = fls(limit);
2871 
2872 	spd = (*scontrol >> 4) & 0xf;
2873 	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
2874 
2875 	return spd != target;
2876 }
2877 
2878 /**
2879  *	sata_set_spd_needed - is SATA spd configuration needed
2880  *	@link: Link in question
2881  *
2882  *	Test whether the spd limit in SControl matches
2883  *	@link->sata_spd_limit.  This function is used to determine
2884  *	whether hardreset is necessary to apply SATA spd
2885  *	configuration.
2886  *
2887  *	LOCKING:
2888  *	Inherited from caller.
2889  *
2890  *	RETURNS:
2891  *	1 if SATA spd configuration is needed, 0 otherwise.
2892  */
2893 static int sata_set_spd_needed(struct ata_link *link)
2894 {
2895 	u32 scontrol;
2896 
2897 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
2898 		return 1;
2899 
2900 	return __sata_set_spd_needed(link, &scontrol);
2901 }
2902 
2903 /**
2904  *	sata_set_spd - set SATA spd according to spd limit
2905  *	@link: Link to set SATA spd for
2906  *
2907  *	Set SATA spd of @link according to sata_spd_limit.
2908  *
2909  *	LOCKING:
2910  *	Inherited from caller.
2911  *
2912  *	RETURNS:
2913  *	0 if spd doesn't need to be changed, 1 if spd has been
2914  *	changed.  Negative errno if SCR registers are inaccessible.
2915  */
2916 int sata_set_spd(struct ata_link *link)
2917 {
2918 	u32 scontrol;
2919 	int rc;
2920 
2921 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
2922 		return rc;
2923 
2924 	if (!__sata_set_spd_needed(link, &scontrol))
2925 		return 0;
2926 
2927 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
2928 		return rc;
2929 
2930 	return 1;
2931 }
2932 
2933 /*
2934  * This mode timing computation functionality is ported over from
2935  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2936  */
2937 /*
2938  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2939  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2940  * for UDMA6, which is currently supported only by Maxtor drives.
2941  *
2942  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2943  */
2944 
2945 static const struct ata_timing ata_timing[] = {
2946 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
2947 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
2948 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
2949 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
2950 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
2951 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
2952 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
2953 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
2954 
2955 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
2956 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
2957 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
2958 
2959 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
2960 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
2961 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
2962 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
2963 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
2964 
2965 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
2966 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
2967 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
2968 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
2969 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
2970 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
2971 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
2972 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
2973 
2974 	{ 0xFF }
2975 };
2976 
2977 #define ENOUGH(v, unit)		(((v)-1)/(unit)+1)
2978 #define EZ(v, unit)		((v)?ENOUGH(v, unit):0)
2979 
2980 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2981 {
2982 	q->setup   = EZ(t->setup   * 1000,  T);
2983 	q->act8b   = EZ(t->act8b   * 1000,  T);
2984 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
2985 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
2986 	q->active  = EZ(t->active  * 1000,  T);
2987 	q->recover = EZ(t->recover * 1000,  T);
2988 	q->cycle   = EZ(t->cycle   * 1000,  T);
2989 	q->udma    = EZ(t->udma    * 1000, UT);
2990 }
2991 
2992 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2993 		      struct ata_timing *m, unsigned int what)
2994 {
2995 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2996 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2997 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2998 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2999 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
3000 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
3001 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
3002 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
3003 }
3004 
3005 const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
3006 {
3007 	const struct ata_timing *t = ata_timing;
3008 
3009 	while (xfer_mode > t->mode)
3010 		t++;
3011 
3012 	if (xfer_mode == t->mode)
3013 		return t;
3014 	return NULL;
3015 }
3016 
3017 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
3018 		       struct ata_timing *t, int T, int UT)
3019 {
3020 	const struct ata_timing *s;
3021 	struct ata_timing p;
3022 
3023 	/*
3024 	 * Find the mode.
3025 	 */
3026 
3027 	if (!(s = ata_timing_find_mode(speed)))
3028 		return -EINVAL;
3029 
3030 	memcpy(t, s, sizeof(*s));
3031 
3032 	/*
3033 	 * If the drive is an EIDE drive, it can tell us it needs extended
3034 	 * PIO/MW_DMA cycle timing.
3035 	 */
3036 
3037 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
3038 		memset(&p, 0, sizeof(p));
3039 		if (speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
3040 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
3041 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
3042 		} else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
3043 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
3044 		}
3045 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
3046 	}
3047 
3048 	/*
3049 	 * Convert the timing to bus clock counts.
3050 	 */
3051 
3052 	ata_timing_quantize(t, t, T, UT);
3053 
3054 	/*
3055 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
3056 	 * S.M.A.R.T * and some other commands. We have to ensure that the
3057 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
3058 	 */
3059 
3060 	if (speed > XFER_PIO_6) {
3061 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
3062 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
3063 	}
3064 
3065 	/*
3066 	 * Lengthen active & recovery time so that cycle time is correct.
3067 	 */
3068 
3069 	if (t->act8b + t->rec8b < t->cyc8b) {
3070 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
3071 		t->rec8b = t->cyc8b - t->act8b;
3072 	}
3073 
3074 	if (t->active + t->recover < t->cycle) {
3075 		t->active += (t->cycle - (t->active + t->recover)) / 2;
3076 		t->recover = t->cycle - t->active;
3077 	}
3078 
3079 	/* In a few cases quantisation may produce enough errors to
3080 	   leave t->cycle too low for the sum of active and recovery
3081 	   if so we must correct this */
3082 	if (t->active + t->recover > t->cycle)
3083 		t->cycle = t->active + t->recover;
3084 
3085 	return 0;
3086 }
3087 
3088 /**
3089  *	ata_timing_cycle2mode - find xfer mode for the specified cycle duration
3090  *	@xfer_shift: ATA_SHIFT_* value for transfer type to examine.
3091  *	@cycle: cycle duration in ns
3092  *
3093  *	Return matching xfer mode for @cycle.  The returned mode is of
3094  *	the transfer type specified by @xfer_shift.  If @cycle is too
3095  *	slow for @xfer_shift, 0xff is returned.  If @cycle is faster
3096  *	than the fastest known mode, the fasted mode is returned.
3097  *
3098  *	LOCKING:
3099  *	None.
3100  *
3101  *	RETURNS:
3102  *	Matching xfer_mode, 0xff if no match found.
3103  */
3104 u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
3105 {
3106 	u8 base_mode = 0xff, last_mode = 0xff;
3107 	const struct ata_xfer_ent *ent;
3108 	const struct ata_timing *t;
3109 
3110 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
3111 		if (ent->shift == xfer_shift)
3112 			base_mode = ent->base;
3113 
3114 	for (t = ata_timing_find_mode(base_mode);
3115 	     t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
3116 		unsigned short this_cycle;
3117 
3118 		switch (xfer_shift) {
3119 		case ATA_SHIFT_PIO:
3120 		case ATA_SHIFT_MWDMA:
3121 			this_cycle = t->cycle;
3122 			break;
3123 		case ATA_SHIFT_UDMA:
3124 			this_cycle = t->udma;
3125 			break;
3126 		default:
3127 			return 0xff;
3128 		}
3129 
3130 		if (cycle > this_cycle)
3131 			break;
3132 
3133 		last_mode = t->mode;
3134 	}
3135 
3136 	return last_mode;
3137 }
3138 
3139 /**
3140  *	ata_down_xfermask_limit - adjust dev xfer masks downward
3141  *	@dev: Device to adjust xfer masks
3142  *	@sel: ATA_DNXFER_* selector
3143  *
3144  *	Adjust xfer masks of @dev downward.  Note that this function
3145  *	does not apply the change.  Invoking ata_set_mode() afterwards
3146  *	will apply the limit.
3147  *
3148  *	LOCKING:
3149  *	Inherited from caller.
3150  *
3151  *	RETURNS:
3152  *	0 on success, negative errno on failure
3153  */
3154 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
3155 {
3156 	char buf[32];
3157 	unsigned long orig_mask, xfer_mask;
3158 	unsigned long pio_mask, mwdma_mask, udma_mask;
3159 	int quiet, highbit;
3160 
3161 	quiet = !!(sel & ATA_DNXFER_QUIET);
3162 	sel &= ~ATA_DNXFER_QUIET;
3163 
3164 	xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
3165 						  dev->mwdma_mask,
3166 						  dev->udma_mask);
3167 	ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
3168 
3169 	switch (sel) {
3170 	case ATA_DNXFER_PIO:
3171 		highbit = fls(pio_mask) - 1;
3172 		pio_mask &= ~(1 << highbit);
3173 		break;
3174 
3175 	case ATA_DNXFER_DMA:
3176 		if (udma_mask) {
3177 			highbit = fls(udma_mask) - 1;
3178 			udma_mask &= ~(1 << highbit);
3179 			if (!udma_mask)
3180 				return -ENOENT;
3181 		} else if (mwdma_mask) {
3182 			highbit = fls(mwdma_mask) - 1;
3183 			mwdma_mask &= ~(1 << highbit);
3184 			if (!mwdma_mask)
3185 				return -ENOENT;
3186 		}
3187 		break;
3188 
3189 	case ATA_DNXFER_40C:
3190 		udma_mask &= ATA_UDMA_MASK_40C;
3191 		break;
3192 
3193 	case ATA_DNXFER_FORCE_PIO0:
3194 		pio_mask &= 1;
3195 	case ATA_DNXFER_FORCE_PIO:
3196 		mwdma_mask = 0;
3197 		udma_mask = 0;
3198 		break;
3199 
3200 	default:
3201 		BUG();
3202 	}
3203 
3204 	xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
3205 
3206 	if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
3207 		return -ENOENT;
3208 
3209 	if (!quiet) {
3210 		if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
3211 			snprintf(buf, sizeof(buf), "%s:%s",
3212 				 ata_mode_string(xfer_mask),
3213 				 ata_mode_string(xfer_mask & ATA_MASK_PIO));
3214 		else
3215 			snprintf(buf, sizeof(buf), "%s",
3216 				 ata_mode_string(xfer_mask));
3217 
3218 		ata_dev_printk(dev, KERN_WARNING,
3219 			       "limiting speed to %s\n", buf);
3220 	}
3221 
3222 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
3223 			    &dev->udma_mask);
3224 
3225 	return 0;
3226 }
3227 
3228 static int ata_dev_set_mode(struct ata_device *dev)
3229 {
3230 	struct ata_eh_context *ehc = &dev->link->eh_context;
3231 	const char *dev_err_whine = "";
3232 	int ign_dev_err = 0;
3233 	unsigned int err_mask;
3234 	int rc;
3235 
3236 	dev->flags &= ~ATA_DFLAG_PIO;
3237 	if (dev->xfer_shift == ATA_SHIFT_PIO)
3238 		dev->flags |= ATA_DFLAG_PIO;
3239 
3240 	err_mask = ata_dev_set_xfermode(dev);
3241 
3242 	if (err_mask & ~AC_ERR_DEV)
3243 		goto fail;
3244 
3245 	/* revalidate */
3246 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
3247 	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
3248 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
3249 	if (rc)
3250 		return rc;
3251 
3252 	if (dev->xfer_shift == ATA_SHIFT_PIO) {
3253 		/* Old CFA may refuse this command, which is just fine */
3254 		if (ata_id_is_cfa(dev->id))
3255 			ign_dev_err = 1;
3256 		/* Catch several broken garbage emulations plus some pre
3257 		   ATA devices */
3258 		if (ata_id_major_version(dev->id) == 0 &&
3259 					dev->pio_mode <= XFER_PIO_2)
3260 			ign_dev_err = 1;
3261 		/* Some very old devices and some bad newer ones fail
3262 		   any kind of SET_XFERMODE request but support PIO0-2
3263 		   timings and no IORDY */
3264 		if (!ata_id_has_iordy(dev->id) && dev->pio_mode <= XFER_PIO_2)
3265 			ign_dev_err = 1;
3266 	}
3267 	/* Early MWDMA devices do DMA but don't allow DMA mode setting.
3268 	   Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
3269 	if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
3270 	    dev->dma_mode == XFER_MW_DMA_0 &&
3271 	    (dev->id[63] >> 8) & 1)
3272 		ign_dev_err = 1;
3273 
3274 	/* if the device is actually configured correctly, ignore dev err */
3275 	if (dev->xfer_mode == ata_xfer_mask2mode(ata_id_xfermask(dev->id)))
3276 		ign_dev_err = 1;
3277 
3278 	if (err_mask & AC_ERR_DEV) {
3279 		if (!ign_dev_err)
3280 			goto fail;
3281 		else
3282 			dev_err_whine = " (device error ignored)";
3283 	}
3284 
3285 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
3286 		dev->xfer_shift, (int)dev->xfer_mode);
3287 
3288 	ata_dev_printk(dev, KERN_INFO, "configured for %s%s\n",
3289 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)),
3290 		       dev_err_whine);
3291 
3292 	return 0;
3293 
3294  fail:
3295 	ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
3296 		       "(err_mask=0x%x)\n", err_mask);
3297 	return -EIO;
3298 }
3299 
3300 /**
3301  *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
3302  *	@link: link on which timings will be programmed
3303  *	@r_failed_dev: out parameter for failed device
3304  *
3305  *	Standard implementation of the function used to tune and set
3306  *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3307  *	ata_dev_set_mode() fails, pointer to the failing device is
3308  *	returned in @r_failed_dev.
3309  *
3310  *	LOCKING:
3311  *	PCI/etc. bus probe sem.
3312  *
3313  *	RETURNS:
3314  *	0 on success, negative errno otherwise
3315  */
3316 
3317 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3318 {
3319 	struct ata_port *ap = link->ap;
3320 	struct ata_device *dev;
3321 	int rc = 0, used_dma = 0, found = 0;
3322 
3323 	/* step 1: calculate xfer_mask */
3324 	ata_link_for_each_dev(dev, link) {
3325 		unsigned long pio_mask, dma_mask;
3326 		unsigned int mode_mask;
3327 
3328 		if (!ata_dev_enabled(dev))
3329 			continue;
3330 
3331 		mode_mask = ATA_DMA_MASK_ATA;
3332 		if (dev->class == ATA_DEV_ATAPI)
3333 			mode_mask = ATA_DMA_MASK_ATAPI;
3334 		else if (ata_id_is_cfa(dev->id))
3335 			mode_mask = ATA_DMA_MASK_CFA;
3336 
3337 		ata_dev_xfermask(dev);
3338 		ata_force_xfermask(dev);
3339 
3340 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
3341 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3342 
3343 		if (libata_dma_mask & mode_mask)
3344 			dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3345 		else
3346 			dma_mask = 0;
3347 
3348 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
3349 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
3350 
3351 		found = 1;
3352 		if (ata_dma_enabled(dev))
3353 			used_dma = 1;
3354 	}
3355 	if (!found)
3356 		goto out;
3357 
3358 	/* step 2: always set host PIO timings */
3359 	ata_link_for_each_dev(dev, link) {
3360 		if (!ata_dev_enabled(dev))
3361 			continue;
3362 
3363 		if (dev->pio_mode == 0xff) {
3364 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
3365 			rc = -EINVAL;
3366 			goto out;
3367 		}
3368 
3369 		dev->xfer_mode = dev->pio_mode;
3370 		dev->xfer_shift = ATA_SHIFT_PIO;
3371 		if (ap->ops->set_piomode)
3372 			ap->ops->set_piomode(ap, dev);
3373 	}
3374 
3375 	/* step 3: set host DMA timings */
3376 	ata_link_for_each_dev(dev, link) {
3377 		if (!ata_dev_enabled(dev) || !ata_dma_enabled(dev))
3378 			continue;
3379 
3380 		dev->xfer_mode = dev->dma_mode;
3381 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
3382 		if (ap->ops->set_dmamode)
3383 			ap->ops->set_dmamode(ap, dev);
3384 	}
3385 
3386 	/* step 4: update devices' xfer mode */
3387 	ata_link_for_each_dev(dev, link) {
3388 		/* don't update suspended devices' xfer mode */
3389 		if (!ata_dev_enabled(dev))
3390 			continue;
3391 
3392 		rc = ata_dev_set_mode(dev);
3393 		if (rc)
3394 			goto out;
3395 	}
3396 
3397 	/* Record simplex status. If we selected DMA then the other
3398 	 * host channels are not permitted to do so.
3399 	 */
3400 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
3401 		ap->host->simplex_claimed = ap;
3402 
3403  out:
3404 	if (rc)
3405 		*r_failed_dev = dev;
3406 	return rc;
3407 }
3408 
3409 /**
3410  *	ata_wait_ready - wait for link to become ready
3411  *	@link: link to be waited on
3412  *	@deadline: deadline jiffies for the operation
3413  *	@check_ready: callback to check link readiness
3414  *
3415  *	Wait for @link to become ready.  @check_ready should return
3416  *	positive number if @link is ready, 0 if it isn't, -ENODEV if
3417  *	link doesn't seem to be occupied, other errno for other error
3418  *	conditions.
3419  *
3420  *	Transient -ENODEV conditions are allowed for
3421  *	ATA_TMOUT_FF_WAIT.
3422  *
3423  *	LOCKING:
3424  *	EH context.
3425  *
3426  *	RETURNS:
3427  *	0 if @linke is ready before @deadline; otherwise, -errno.
3428  */
3429 int ata_wait_ready(struct ata_link *link, unsigned long deadline,
3430 		   int (*check_ready)(struct ata_link *link))
3431 {
3432 	unsigned long start = jiffies;
3433 	unsigned long nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);
3434 	int warned = 0;
3435 
3436 	/* Slave readiness can't be tested separately from master.  On
3437 	 * M/S emulation configuration, this function should be called
3438 	 * only on the master and it will handle both master and slave.
3439 	 */
3440 	WARN_ON(link == link->ap->slave_link);
3441 
3442 	if (time_after(nodev_deadline, deadline))
3443 		nodev_deadline = deadline;
3444 
3445 	while (1) {
3446 		unsigned long now = jiffies;
3447 		int ready, tmp;
3448 
3449 		ready = tmp = check_ready(link);
3450 		if (ready > 0)
3451 			return 0;
3452 
3453 		/* -ENODEV could be transient.  Ignore -ENODEV if link
3454 		 * is online.  Also, some SATA devices take a long
3455 		 * time to clear 0xff after reset.  For example,
3456 		 * HHD424020F7SV00 iVDR needs >= 800ms while Quantum
3457 		 * GoVault needs even more than that.  Wait for
3458 		 * ATA_TMOUT_FF_WAIT on -ENODEV if link isn't offline.
3459 		 *
3460 		 * Note that some PATA controllers (pata_ali) explode
3461 		 * if status register is read more than once when
3462 		 * there's no device attached.
3463 		 */
3464 		if (ready == -ENODEV) {
3465 			if (ata_link_online(link))
3466 				ready = 0;
3467 			else if ((link->ap->flags & ATA_FLAG_SATA) &&
3468 				 !ata_link_offline(link) &&
3469 				 time_before(now, nodev_deadline))
3470 				ready = 0;
3471 		}
3472 
3473 		if (ready)
3474 			return ready;
3475 		if (time_after(now, deadline))
3476 			return -EBUSY;
3477 
3478 		if (!warned && time_after(now, start + 5 * HZ) &&
3479 		    (deadline - now > 3 * HZ)) {
3480 			ata_link_printk(link, KERN_WARNING,
3481 				"link is slow to respond, please be patient "
3482 				"(ready=%d)\n", tmp);
3483 			warned = 1;
3484 		}
3485 
3486 		msleep(50);
3487 	}
3488 }
3489 
3490 /**
3491  *	ata_wait_after_reset - wait for link to become ready after reset
3492  *	@link: link to be waited on
3493  *	@deadline: deadline jiffies for the operation
3494  *	@check_ready: callback to check link readiness
3495  *
3496  *	Wait for @link to become ready after reset.
3497  *
3498  *	LOCKING:
3499  *	EH context.
3500  *
3501  *	RETURNS:
3502  *	0 if @linke is ready before @deadline; otherwise, -errno.
3503  */
3504 int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
3505 				int (*check_ready)(struct ata_link *link))
3506 {
3507 	msleep(ATA_WAIT_AFTER_RESET);
3508 
3509 	return ata_wait_ready(link, deadline, check_ready);
3510 }
3511 
3512 /**
3513  *	sata_link_debounce - debounce SATA phy status
3514  *	@link: ATA link to debounce SATA phy status for
3515  *	@params: timing parameters { interval, duratinon, timeout } in msec
3516  *	@deadline: deadline jiffies for the operation
3517  *
3518 *	Make sure SStatus of @link reaches stable state, determined by
3519  *	holding the same value where DET is not 1 for @duration polled
3520  *	every @interval, before @timeout.  Timeout constraints the
3521  *	beginning of the stable state.  Because DET gets stuck at 1 on
3522  *	some controllers after hot unplugging, this functions waits
3523  *	until timeout then returns 0 if DET is stable at 1.
3524  *
3525  *	@timeout is further limited by @deadline.  The sooner of the
3526  *	two is used.
3527  *
3528  *	LOCKING:
3529  *	Kernel thread context (may sleep)
3530  *
3531  *	RETURNS:
3532  *	0 on success, -errno on failure.
3533  */
3534 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
3535 		       unsigned long deadline)
3536 {
3537 	unsigned long interval = params[0];
3538 	unsigned long duration = params[1];
3539 	unsigned long last_jiffies, t;
3540 	u32 last, cur;
3541 	int rc;
3542 
3543 	t = ata_deadline(jiffies, params[2]);
3544 	if (time_before(t, deadline))
3545 		deadline = t;
3546 
3547 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3548 		return rc;
3549 	cur &= 0xf;
3550 
3551 	last = cur;
3552 	last_jiffies = jiffies;
3553 
3554 	while (1) {
3555 		msleep(interval);
3556 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3557 			return rc;
3558 		cur &= 0xf;
3559 
3560 		/* DET stable? */
3561 		if (cur == last) {
3562 			if (cur == 1 && time_before(jiffies, deadline))
3563 				continue;
3564 			if (time_after(jiffies,
3565 				       ata_deadline(last_jiffies, duration)))
3566 				return 0;
3567 			continue;
3568 		}
3569 
3570 		/* unstable, start over */
3571 		last = cur;
3572 		last_jiffies = jiffies;
3573 
3574 		/* Check deadline.  If debouncing failed, return
3575 		 * -EPIPE to tell upper layer to lower link speed.
3576 		 */
3577 		if (time_after(jiffies, deadline))
3578 			return -EPIPE;
3579 	}
3580 }
3581 
3582 /**
3583  *	sata_link_resume - resume SATA link
3584  *	@link: ATA link to resume SATA
3585  *	@params: timing parameters { interval, duratinon, timeout } in msec
3586  *	@deadline: deadline jiffies for the operation
3587  *
3588  *	Resume SATA phy @link and debounce it.
3589  *
3590  *	LOCKING:
3591  *	Kernel thread context (may sleep)
3592  *
3593  *	RETURNS:
3594  *	0 on success, -errno on failure.
3595  */
3596 int sata_link_resume(struct ata_link *link, const unsigned long *params,
3597 		     unsigned long deadline)
3598 {
3599 	u32 scontrol, serror;
3600 	int rc;
3601 
3602 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3603 		return rc;
3604 
3605 	scontrol = (scontrol & 0x0f0) | 0x300;
3606 
3607 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3608 		return rc;
3609 
3610 	/* Some PHYs react badly if SStatus is pounded immediately
3611 	 * after resuming.  Delay 200ms before debouncing.
3612 	 */
3613 	msleep(200);
3614 
3615 	if ((rc = sata_link_debounce(link, params, deadline)))
3616 		return rc;
3617 
3618 	/* clear SError, some PHYs require this even for SRST to work */
3619 	if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
3620 		rc = sata_scr_write(link, SCR_ERROR, serror);
3621 
3622 	return rc != -EINVAL ? rc : 0;
3623 }
3624 
3625 /**
3626  *	ata_std_prereset - prepare for reset
3627  *	@link: ATA link to be reset
3628  *	@deadline: deadline jiffies for the operation
3629  *
3630  *	@link is about to be reset.  Initialize it.  Failure from
3631  *	prereset makes libata abort whole reset sequence and give up
3632  *	that port, so prereset should be best-effort.  It does its
3633  *	best to prepare for reset sequence but if things go wrong, it
3634  *	should just whine, not fail.
3635  *
3636  *	LOCKING:
3637  *	Kernel thread context (may sleep)
3638  *
3639  *	RETURNS:
3640  *	0 on success, -errno otherwise.
3641  */
3642 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
3643 {
3644 	struct ata_port *ap = link->ap;
3645 	struct ata_eh_context *ehc = &link->eh_context;
3646 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
3647 	int rc;
3648 
3649 	/* if we're about to do hardreset, nothing more to do */
3650 	if (ehc->i.action & ATA_EH_HARDRESET)
3651 		return 0;
3652 
3653 	/* if SATA, resume link */
3654 	if (ap->flags & ATA_FLAG_SATA) {
3655 		rc = sata_link_resume(link, timing, deadline);
3656 		/* whine about phy resume failure but proceed */
3657 		if (rc && rc != -EOPNOTSUPP)
3658 			ata_link_printk(link, KERN_WARNING, "failed to resume "
3659 					"link for reset (errno=%d)\n", rc);
3660 	}
3661 
3662 	/* no point in trying softreset on offline link */
3663 	if (ata_phys_link_offline(link))
3664 		ehc->i.action &= ~ATA_EH_SOFTRESET;
3665 
3666 	return 0;
3667 }
3668 
3669 /**
3670  *	sata_link_hardreset - reset link via SATA phy reset
3671  *	@link: link to reset
3672  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3673  *	@deadline: deadline jiffies for the operation
3674  *	@online: optional out parameter indicating link onlineness
3675  *	@check_ready: optional callback to check link readiness
3676  *
3677  *	SATA phy-reset @link using DET bits of SControl register.
3678  *	After hardreset, link readiness is waited upon using
3679  *	ata_wait_ready() if @check_ready is specified.  LLDs are
3680  *	allowed to not specify @check_ready and wait itself after this
3681  *	function returns.  Device classification is LLD's
3682  *	responsibility.
3683  *
3684  *	*@online is set to one iff reset succeeded and @link is online
3685  *	after reset.
3686  *
3687  *	LOCKING:
3688  *	Kernel thread context (may sleep)
3689  *
3690  *	RETURNS:
3691  *	0 on success, -errno otherwise.
3692  */
3693 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
3694 			unsigned long deadline,
3695 			bool *online, int (*check_ready)(struct ata_link *))
3696 {
3697 	u32 scontrol;
3698 	int rc;
3699 
3700 	DPRINTK("ENTER\n");
3701 
3702 	if (online)
3703 		*online = false;
3704 
3705 	if (sata_set_spd_needed(link)) {
3706 		/* SATA spec says nothing about how to reconfigure
3707 		 * spd.  To be on the safe side, turn off phy during
3708 		 * reconfiguration.  This works for at least ICH7 AHCI
3709 		 * and Sil3124.
3710 		 */
3711 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3712 			goto out;
3713 
3714 		scontrol = (scontrol & 0x0f0) | 0x304;
3715 
3716 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3717 			goto out;
3718 
3719 		sata_set_spd(link);
3720 	}
3721 
3722 	/* issue phy wake/reset */
3723 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3724 		goto out;
3725 
3726 	scontrol = (scontrol & 0x0f0) | 0x301;
3727 
3728 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
3729 		goto out;
3730 
3731 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3732 	 * 10.4.2 says at least 1 ms.
3733 	 */
3734 	msleep(1);
3735 
3736 	/* bring link back */
3737 	rc = sata_link_resume(link, timing, deadline);
3738 	if (rc)
3739 		goto out;
3740 	/* if link is offline nothing more to do */
3741 	if (ata_phys_link_offline(link))
3742 		goto out;
3743 
3744 	/* Link is online.  From this point, -ENODEV too is an error. */
3745 	if (online)
3746 		*online = true;
3747 
3748 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
3749 		/* If PMP is supported, we have to do follow-up SRST.
3750 		 * Some PMPs don't send D2H Reg FIS after hardreset if
3751 		 * the first port is empty.  Wait only for
3752 		 * ATA_TMOUT_PMP_SRST_WAIT.
3753 		 */
3754 		if (check_ready) {
3755 			unsigned long pmp_deadline;
3756 
3757 			pmp_deadline = ata_deadline(jiffies,
3758 						    ATA_TMOUT_PMP_SRST_WAIT);
3759 			if (time_after(pmp_deadline, deadline))
3760 				pmp_deadline = deadline;
3761 			ata_wait_ready(link, pmp_deadline, check_ready);
3762 		}
3763 		rc = -EAGAIN;
3764 		goto out;
3765 	}
3766 
3767 	rc = 0;
3768 	if (check_ready)
3769 		rc = ata_wait_ready(link, deadline, check_ready);
3770  out:
3771 	if (rc && rc != -EAGAIN) {
3772 		/* online is set iff link is online && reset succeeded */
3773 		if (online)
3774 			*online = false;
3775 		ata_link_printk(link, KERN_ERR,
3776 				"COMRESET failed (errno=%d)\n", rc);
3777 	}
3778 	DPRINTK("EXIT, rc=%d\n", rc);
3779 	return rc;
3780 }
3781 
3782 /**
3783  *	sata_std_hardreset - COMRESET w/o waiting or classification
3784  *	@link: link to reset
3785  *	@class: resulting class of attached device
3786  *	@deadline: deadline jiffies for the operation
3787  *
3788  *	Standard SATA COMRESET w/o waiting or classification.
3789  *
3790  *	LOCKING:
3791  *	Kernel thread context (may sleep)
3792  *
3793  *	RETURNS:
3794  *	0 if link offline, -EAGAIN if link online, -errno on errors.
3795  */
3796 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
3797 		       unsigned long deadline)
3798 {
3799 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
3800 	bool online;
3801 	int rc;
3802 
3803 	/* do hardreset */
3804 	rc = sata_link_hardreset(link, timing, deadline, &online, NULL);
3805 	return online ? -EAGAIN : rc;
3806 }
3807 
3808 /**
3809  *	ata_std_postreset - standard postreset callback
3810  *	@link: the target ata_link
3811  *	@classes: classes of attached devices
3812  *
3813  *	This function is invoked after a successful reset.  Note that
3814  *	the device might have been reset more than once using
3815  *	different reset methods before postreset is invoked.
3816  *
3817  *	LOCKING:
3818  *	Kernel thread context (may sleep)
3819  */
3820 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
3821 {
3822 	u32 serror;
3823 
3824 	DPRINTK("ENTER\n");
3825 
3826 	/* reset complete, clear SError */
3827 	if (!sata_scr_read(link, SCR_ERROR, &serror))
3828 		sata_scr_write(link, SCR_ERROR, serror);
3829 
3830 	/* print link status */
3831 	sata_print_link_status(link);
3832 
3833 	DPRINTK("EXIT\n");
3834 }
3835 
3836 /**
3837  *	ata_dev_same_device - Determine whether new ID matches configured device
3838  *	@dev: device to compare against
3839  *	@new_class: class of the new device
3840  *	@new_id: IDENTIFY page of the new device
3841  *
3842  *	Compare @new_class and @new_id against @dev and determine
3843  *	whether @dev is the device indicated by @new_class and
3844  *	@new_id.
3845  *
3846  *	LOCKING:
3847  *	None.
3848  *
3849  *	RETURNS:
3850  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3851  */
3852 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3853 			       const u16 *new_id)
3854 {
3855 	const u16 *old_id = dev->id;
3856 	unsigned char model[2][ATA_ID_PROD_LEN + 1];
3857 	unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
3858 
3859 	if (dev->class != new_class) {
3860 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
3861 			       dev->class, new_class);
3862 		return 0;
3863 	}
3864 
3865 	ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
3866 	ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
3867 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
3868 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
3869 
3870 	if (strcmp(model[0], model[1])) {
3871 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
3872 			       "'%s' != '%s'\n", model[0], model[1]);
3873 		return 0;
3874 	}
3875 
3876 	if (strcmp(serial[0], serial[1])) {
3877 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
3878 			       "'%s' != '%s'\n", serial[0], serial[1]);
3879 		return 0;
3880 	}
3881 
3882 	return 1;
3883 }
3884 
3885 /**
3886  *	ata_dev_reread_id - Re-read IDENTIFY data
3887  *	@dev: target ATA device
3888  *	@readid_flags: read ID flags
3889  *
3890  *	Re-read IDENTIFY page and make sure @dev is still attached to
3891  *	the port.
3892  *
3893  *	LOCKING:
3894  *	Kernel thread context (may sleep)
3895  *
3896  *	RETURNS:
3897  *	0 on success, negative errno otherwise
3898  */
3899 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
3900 {
3901 	unsigned int class = dev->class;
3902 	u16 *id = (void *)dev->link->ap->sector_buf;
3903 	int rc;
3904 
3905 	/* read ID data */
3906 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
3907 	if (rc)
3908 		return rc;
3909 
3910 	/* is the device still there? */
3911 	if (!ata_dev_same_device(dev, class, id))
3912 		return -ENODEV;
3913 
3914 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
3915 	return 0;
3916 }
3917 
3918 /**
3919  *	ata_dev_revalidate - Revalidate ATA device
3920  *	@dev: device to revalidate
3921  *	@new_class: new class code
3922  *	@readid_flags: read ID flags
3923  *
3924  *	Re-read IDENTIFY page, make sure @dev is still attached to the
3925  *	port and reconfigure it according to the new IDENTIFY page.
3926  *
3927  *	LOCKING:
3928  *	Kernel thread context (may sleep)
3929  *
3930  *	RETURNS:
3931  *	0 on success, negative errno otherwise
3932  */
3933 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
3934 		       unsigned int readid_flags)
3935 {
3936 	u64 n_sectors = dev->n_sectors;
3937 	int rc;
3938 
3939 	if (!ata_dev_enabled(dev))
3940 		return -ENODEV;
3941 
3942 	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
3943 	if (ata_class_enabled(new_class) &&
3944 	    new_class != ATA_DEV_ATA && new_class != ATA_DEV_ATAPI) {
3945 		ata_dev_printk(dev, KERN_INFO, "class mismatch %u != %u\n",
3946 			       dev->class, new_class);
3947 		rc = -ENODEV;
3948 		goto fail;
3949 	}
3950 
3951 	/* re-read ID */
3952 	rc = ata_dev_reread_id(dev, readid_flags);
3953 	if (rc)
3954 		goto fail;
3955 
3956 	/* configure device according to the new ID */
3957 	rc = ata_dev_configure(dev);
3958 	if (rc)
3959 		goto fail;
3960 
3961 	/* verify n_sectors hasn't changed */
3962 	if (dev->class == ATA_DEV_ATA && n_sectors &&
3963 	    dev->n_sectors != n_sectors) {
3964 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
3965 			       "%llu != %llu\n",
3966 			       (unsigned long long)n_sectors,
3967 			       (unsigned long long)dev->n_sectors);
3968 
3969 		/* restore original n_sectors */
3970 		dev->n_sectors = n_sectors;
3971 
3972 		rc = -ENODEV;
3973 		goto fail;
3974 	}
3975 
3976 	return 0;
3977 
3978  fail:
3979 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
3980 	return rc;
3981 }
3982 
3983 struct ata_blacklist_entry {
3984 	const char *model_num;
3985 	const char *model_rev;
3986 	unsigned long horkage;
3987 };
3988 
3989 static const struct ata_blacklist_entry ata_device_blacklist [] = {
3990 	/* Devices with DMA related problems under Linux */
3991 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
3992 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
3993 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
3994 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
3995 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
3996 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
3997 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
3998 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
3999 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
4000 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
4001 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
4002 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
4003 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
4004 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
4005 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
4006 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
4007 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
4008 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
4009 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
4010 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
4011 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
4012 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
4013 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
4014 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
4015 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
4016 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
4017 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
4018 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
4019 	{ "SAMSUNG CD-ROM SN-124", "N001",	ATA_HORKAGE_NODMA },
4020 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
4021 	/* Odd clown on sil3726/4726 PMPs */
4022 	{ "Config  Disk",	NULL,		ATA_HORKAGE_DISABLE },
4023 
4024 	/* Weird ATAPI devices */
4025 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
4026 
4027 	/* Devices we expect to fail diagnostics */
4028 
4029 	/* Devices where NCQ should be avoided */
4030 	/* NCQ is slow */
4031 	{ "WDC WD740ADFD-00",	NULL,		ATA_HORKAGE_NONCQ },
4032 	{ "WDC WD740ADFD-00NLR1", NULL,		ATA_HORKAGE_NONCQ, },
4033 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
4034 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
4035 	/* NCQ is broken */
4036 	{ "Maxtor *",		"BANC*",	ATA_HORKAGE_NONCQ },
4037 	{ "Maxtor 7V300F0",	"VA111630",	ATA_HORKAGE_NONCQ },
4038 	{ "ST380817AS",		"3.42",		ATA_HORKAGE_NONCQ },
4039 	{ "ST3160023AS",	"3.42",		ATA_HORKAGE_NONCQ },
4040 
4041 	/* Blacklist entries taken from Silicon Image 3124/3132
4042 	   Windows driver .inf file - also several Linux problem reports */
4043 	{ "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
4044 	{ "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
4045 	{ "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },
4046 
4047 	/* devices which puke on READ_NATIVE_MAX */
4048 	{ "HDS724040KLSA80",	"KFAOA20N",	ATA_HORKAGE_BROKEN_HPA, },
4049 	{ "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
4050 	{ "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
4051 	{ "MAXTOR 6L080L4",	"A93.0500",	ATA_HORKAGE_BROKEN_HPA },
4052 
4053 	/* Devices which report 1 sector over size HPA */
4054 	{ "ST340823A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4055 	{ "ST320413A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4056 	{ "ST310211A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4057 
4058 	/* Devices which get the IVB wrong */
4059 	{ "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB, },
4060 	/* Maybe we should just blacklist TSSTcorp... */
4061 	{ "TSSTcorp CDDVDW SH-S202H", "SB00",	  ATA_HORKAGE_IVB, },
4062 	{ "TSSTcorp CDDVDW SH-S202H", "SB01",	  ATA_HORKAGE_IVB, },
4063 	{ "TSSTcorp CDDVDW SH-S202J", "SB00",	  ATA_HORKAGE_IVB, },
4064 	{ "TSSTcorp CDDVDW SH-S202J", "SB01",	  ATA_HORKAGE_IVB, },
4065 	{ "TSSTcorp CDDVDW SH-S202N", "SB00",	  ATA_HORKAGE_IVB, },
4066 	{ "TSSTcorp CDDVDW SH-S202N", "SB01",	  ATA_HORKAGE_IVB, },
4067 
4068 	/* End Marker */
4069 	{ }
4070 };
4071 
4072 static int strn_pattern_cmp(const char *patt, const char *name, int wildchar)
4073 {
4074 	const char *p;
4075 	int len;
4076 
4077 	/*
4078 	 * check for trailing wildcard: *\0
4079 	 */
4080 	p = strchr(patt, wildchar);
4081 	if (p && ((*(p + 1)) == 0))
4082 		len = p - patt;
4083 	else {
4084 		len = strlen(name);
4085 		if (!len) {
4086 			if (!*patt)
4087 				return 0;
4088 			return -1;
4089 		}
4090 	}
4091 
4092 	return strncmp(patt, name, len);
4093 }
4094 
4095 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
4096 {
4097 	unsigned char model_num[ATA_ID_PROD_LEN + 1];
4098 	unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
4099 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
4100 
4101 	ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
4102 	ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
4103 
4104 	while (ad->model_num) {
4105 		if (!strn_pattern_cmp(ad->model_num, model_num, '*')) {
4106 			if (ad->model_rev == NULL)
4107 				return ad->horkage;
4108 			if (!strn_pattern_cmp(ad->model_rev, model_rev, '*'))
4109 				return ad->horkage;
4110 		}
4111 		ad++;
4112 	}
4113 	return 0;
4114 }
4115 
4116 static int ata_dma_blacklisted(const struct ata_device *dev)
4117 {
4118 	/* We don't support polling DMA.
4119 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
4120 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
4121 	 */
4122 	if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
4123 	    (dev->flags & ATA_DFLAG_CDB_INTR))
4124 		return 1;
4125 	return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
4126 }
4127 
4128 /**
4129  *	ata_is_40wire		-	check drive side detection
4130  *	@dev: device
4131  *
4132  *	Perform drive side detection decoding, allowing for device vendors
4133  *	who can't follow the documentation.
4134  */
4135 
4136 static int ata_is_40wire(struct ata_device *dev)
4137 {
4138 	if (dev->horkage & ATA_HORKAGE_IVB)
4139 		return ata_drive_40wire_relaxed(dev->id);
4140 	return ata_drive_40wire(dev->id);
4141 }
4142 
4143 /**
4144  *	cable_is_40wire		-	40/80/SATA decider
4145  *	@ap: port to consider
4146  *
4147  *	This function encapsulates the policy for speed management
4148  *	in one place. At the moment we don't cache the result but
4149  *	there is a good case for setting ap->cbl to the result when
4150  *	we are called with unknown cables (and figuring out if it
4151  *	impacts hotplug at all).
4152  *
4153  *	Return 1 if the cable appears to be 40 wire.
4154  */
4155 
4156 static int cable_is_40wire(struct ata_port *ap)
4157 {
4158 	struct ata_link *link;
4159 	struct ata_device *dev;
4160 
4161 	/* If the controller thinks we are 40 wire, we are */
4162 	if (ap->cbl == ATA_CBL_PATA40)
4163 		return 1;
4164 	/* If the controller thinks we are 80 wire, we are */
4165 	if (ap->cbl == ATA_CBL_PATA80 || ap->cbl == ATA_CBL_SATA)
4166 		return 0;
4167 	/* If the system is known to be 40 wire short cable (eg laptop),
4168 	   then we allow 80 wire modes even if the drive isn't sure */
4169 	if (ap->cbl == ATA_CBL_PATA40_SHORT)
4170 		return 0;
4171 	/* If the controller doesn't know we scan
4172 
4173 	   - Note: We look for all 40 wire detects at this point.
4174 	     Any 80 wire detect is taken to be 80 wire cable
4175 	     because
4176 	     - In many setups only the one drive (slave if present)
4177                will give a valid detect
4178              - If you have a non detect capable drive you don't
4179                want it to colour the choice
4180         */
4181 	ata_port_for_each_link(link, ap) {
4182 		ata_link_for_each_dev(dev, link) {
4183 			if (!ata_is_40wire(dev))
4184 				return 0;
4185 		}
4186 	}
4187 	return 1;
4188 }
4189 
4190 /**
4191  *	ata_dev_xfermask - Compute supported xfermask of the given device
4192  *	@dev: Device to compute xfermask for
4193  *
4194  *	Compute supported xfermask of @dev and store it in
4195  *	dev->*_mask.  This function is responsible for applying all
4196  *	known limits including host controller limits, device
4197  *	blacklist, etc...
4198  *
4199  *	LOCKING:
4200  *	None.
4201  */
4202 static void ata_dev_xfermask(struct ata_device *dev)
4203 {
4204 	struct ata_link *link = dev->link;
4205 	struct ata_port *ap = link->ap;
4206 	struct ata_host *host = ap->host;
4207 	unsigned long xfer_mask;
4208 
4209 	/* controller modes available */
4210 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
4211 				      ap->mwdma_mask, ap->udma_mask);
4212 
4213 	/* drive modes available */
4214 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
4215 				       dev->mwdma_mask, dev->udma_mask);
4216 	xfer_mask &= ata_id_xfermask(dev->id);
4217 
4218 	/*
4219 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
4220 	 *	cable
4221 	 */
4222 	if (ata_dev_pair(dev)) {
4223 		/* No PIO5 or PIO6 */
4224 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
4225 		/* No MWDMA3 or MWDMA 4 */
4226 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
4227 	}
4228 
4229 	if (ata_dma_blacklisted(dev)) {
4230 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4231 		ata_dev_printk(dev, KERN_WARNING,
4232 			       "device is on DMA blacklist, disabling DMA\n");
4233 	}
4234 
4235 	if ((host->flags & ATA_HOST_SIMPLEX) &&
4236 	    host->simplex_claimed && host->simplex_claimed != ap) {
4237 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4238 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
4239 			       "other device, disabling DMA\n");
4240 	}
4241 
4242 	if (ap->flags & ATA_FLAG_NO_IORDY)
4243 		xfer_mask &= ata_pio_mask_no_iordy(dev);
4244 
4245 	if (ap->ops->mode_filter)
4246 		xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
4247 
4248 	/* Apply cable rule here.  Don't apply it early because when
4249 	 * we handle hot plug the cable type can itself change.
4250 	 * Check this last so that we know if the transfer rate was
4251 	 * solely limited by the cable.
4252 	 * Unknown or 80 wire cables reported host side are checked
4253 	 * drive side as well. Cases where we know a 40wire cable
4254 	 * is used safely for 80 are not checked here.
4255 	 */
4256 	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
4257 		/* UDMA/44 or higher would be available */
4258 		if (cable_is_40wire(ap)) {
4259 			ata_dev_printk(dev, KERN_WARNING,
4260 				 "limited to UDMA/33 due to 40-wire cable\n");
4261 			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
4262 		}
4263 
4264 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
4265 			    &dev->mwdma_mask, &dev->udma_mask);
4266 }
4267 
4268 /**
4269  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
4270  *	@dev: Device to which command will be sent
4271  *
4272  *	Issue SET FEATURES - XFER MODE command to device @dev
4273  *	on port @ap.
4274  *
4275  *	LOCKING:
4276  *	PCI/etc. bus probe sem.
4277  *
4278  *	RETURNS:
4279  *	0 on success, AC_ERR_* mask otherwise.
4280  */
4281 
4282 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
4283 {
4284 	struct ata_taskfile tf;
4285 	unsigned int err_mask;
4286 
4287 	/* set up set-features taskfile */
4288 	DPRINTK("set features - xfer mode\n");
4289 
4290 	/* Some controllers and ATAPI devices show flaky interrupt
4291 	 * behavior after setting xfer mode.  Use polling instead.
4292 	 */
4293 	ata_tf_init(dev, &tf);
4294 	tf.command = ATA_CMD_SET_FEATURES;
4295 	tf.feature = SETFEATURES_XFER;
4296 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
4297 	tf.protocol = ATA_PROT_NODATA;
4298 	/* If we are using IORDY we must send the mode setting command */
4299 	if (ata_pio_need_iordy(dev))
4300 		tf.nsect = dev->xfer_mode;
4301 	/* If the device has IORDY and the controller does not - turn it off */
4302  	else if (ata_id_has_iordy(dev->id))
4303 		tf.nsect = 0x01;
4304 	else /* In the ancient relic department - skip all of this */
4305 		return 0;
4306 
4307 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4308 
4309 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4310 	return err_mask;
4311 }
4312 /**
4313  *	ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
4314  *	@dev: Device to which command will be sent
4315  *	@enable: Whether to enable or disable the feature
4316  *	@feature: The sector count represents the feature to set
4317  *
4318  *	Issue SET FEATURES - SATA FEATURES command to device @dev
4319  *	on port @ap with sector count
4320  *
4321  *	LOCKING:
4322  *	PCI/etc. bus probe sem.
4323  *
4324  *	RETURNS:
4325  *	0 on success, AC_ERR_* mask otherwise.
4326  */
4327 static unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable,
4328 					u8 feature)
4329 {
4330 	struct ata_taskfile tf;
4331 	unsigned int err_mask;
4332 
4333 	/* set up set-features taskfile */
4334 	DPRINTK("set features - SATA features\n");
4335 
4336 	ata_tf_init(dev, &tf);
4337 	tf.command = ATA_CMD_SET_FEATURES;
4338 	tf.feature = enable;
4339 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4340 	tf.protocol = ATA_PROT_NODATA;
4341 	tf.nsect = feature;
4342 
4343 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4344 
4345 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4346 	return err_mask;
4347 }
4348 
4349 /**
4350  *	ata_dev_init_params - Issue INIT DEV PARAMS command
4351  *	@dev: Device to which command will be sent
4352  *	@heads: Number of heads (taskfile parameter)
4353  *	@sectors: Number of sectors (taskfile parameter)
4354  *
4355  *	LOCKING:
4356  *	Kernel thread context (may sleep)
4357  *
4358  *	RETURNS:
4359  *	0 on success, AC_ERR_* mask otherwise.
4360  */
4361 static unsigned int ata_dev_init_params(struct ata_device *dev,
4362 					u16 heads, u16 sectors)
4363 {
4364 	struct ata_taskfile tf;
4365 	unsigned int err_mask;
4366 
4367 	/* Number of sectors per track 1-255. Number of heads 1-16 */
4368 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
4369 		return AC_ERR_INVALID;
4370 
4371 	/* set up init dev params taskfile */
4372 	DPRINTK("init dev params \n");
4373 
4374 	ata_tf_init(dev, &tf);
4375 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
4376 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4377 	tf.protocol = ATA_PROT_NODATA;
4378 	tf.nsect = sectors;
4379 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
4380 
4381 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4382 	/* A clean abort indicates an original or just out of spec drive
4383 	   and we should continue as we issue the setup based on the
4384 	   drive reported working geometry */
4385 	if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
4386 		err_mask = 0;
4387 
4388 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4389 	return err_mask;
4390 }
4391 
4392 /**
4393  *	ata_sg_clean - Unmap DMA memory associated with command
4394  *	@qc: Command containing DMA memory to be released
4395  *
4396  *	Unmap all mapped DMA memory associated with this command.
4397  *
4398  *	LOCKING:
4399  *	spin_lock_irqsave(host lock)
4400  */
4401 void ata_sg_clean(struct ata_queued_cmd *qc)
4402 {
4403 	struct ata_port *ap = qc->ap;
4404 	struct scatterlist *sg = qc->sg;
4405 	int dir = qc->dma_dir;
4406 
4407 	WARN_ON(sg == NULL);
4408 
4409 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
4410 
4411 	if (qc->n_elem)
4412 		dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
4413 
4414 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4415 	qc->sg = NULL;
4416 }
4417 
4418 /**
4419  *	atapi_check_dma - Check whether ATAPI DMA can be supported
4420  *	@qc: Metadata associated with taskfile to check
4421  *
4422  *	Allow low-level driver to filter ATA PACKET commands, returning
4423  *	a status indicating whether or not it is OK to use DMA for the
4424  *	supplied PACKET command.
4425  *
4426  *	LOCKING:
4427  *	spin_lock_irqsave(host lock)
4428  *
4429  *	RETURNS: 0 when ATAPI DMA can be used
4430  *               nonzero otherwise
4431  */
4432 int atapi_check_dma(struct ata_queued_cmd *qc)
4433 {
4434 	struct ata_port *ap = qc->ap;
4435 
4436 	/* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
4437 	 * few ATAPI devices choke on such DMA requests.
4438 	 */
4439 	if (unlikely(qc->nbytes & 15))
4440 		return 1;
4441 
4442 	if (ap->ops->check_atapi_dma)
4443 		return ap->ops->check_atapi_dma(qc);
4444 
4445 	return 0;
4446 }
4447 
4448 /**
4449  *	ata_std_qc_defer - Check whether a qc needs to be deferred
4450  *	@qc: ATA command in question
4451  *
4452  *	Non-NCQ commands cannot run with any other command, NCQ or
4453  *	not.  As upper layer only knows the queue depth, we are
4454  *	responsible for maintaining exclusion.  This function checks
4455  *	whether a new command @qc can be issued.
4456  *
4457  *	LOCKING:
4458  *	spin_lock_irqsave(host lock)
4459  *
4460  *	RETURNS:
4461  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
4462  */
4463 int ata_std_qc_defer(struct ata_queued_cmd *qc)
4464 {
4465 	struct ata_link *link = qc->dev->link;
4466 
4467 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4468 		if (!ata_tag_valid(link->active_tag))
4469 			return 0;
4470 	} else {
4471 		if (!ata_tag_valid(link->active_tag) && !link->sactive)
4472 			return 0;
4473 	}
4474 
4475 	return ATA_DEFER_LINK;
4476 }
4477 
4478 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
4479 
4480 /**
4481  *	ata_sg_init - Associate command with scatter-gather table.
4482  *	@qc: Command to be associated
4483  *	@sg: Scatter-gather table.
4484  *	@n_elem: Number of elements in s/g table.
4485  *
4486  *	Initialize the data-related elements of queued_cmd @qc
4487  *	to point to a scatter-gather table @sg, containing @n_elem
4488  *	elements.
4489  *
4490  *	LOCKING:
4491  *	spin_lock_irqsave(host lock)
4492  */
4493 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
4494 		 unsigned int n_elem)
4495 {
4496 	qc->sg = sg;
4497 	qc->n_elem = n_elem;
4498 	qc->cursg = qc->sg;
4499 }
4500 
4501 /**
4502  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
4503  *	@qc: Command with scatter-gather table to be mapped.
4504  *
4505  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
4506  *
4507  *	LOCKING:
4508  *	spin_lock_irqsave(host lock)
4509  *
4510  *	RETURNS:
4511  *	Zero on success, negative on error.
4512  *
4513  */
4514 static int ata_sg_setup(struct ata_queued_cmd *qc)
4515 {
4516 	struct ata_port *ap = qc->ap;
4517 	unsigned int n_elem;
4518 
4519 	VPRINTK("ENTER, ata%u\n", ap->print_id);
4520 
4521 	n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
4522 	if (n_elem < 1)
4523 		return -1;
4524 
4525 	DPRINTK("%d sg elements mapped\n", n_elem);
4526 
4527 	qc->n_elem = n_elem;
4528 	qc->flags |= ATA_QCFLAG_DMAMAP;
4529 
4530 	return 0;
4531 }
4532 
4533 /**
4534  *	swap_buf_le16 - swap halves of 16-bit words in place
4535  *	@buf:  Buffer to swap
4536  *	@buf_words:  Number of 16-bit words in buffer.
4537  *
4538  *	Swap halves of 16-bit words if needed to convert from
4539  *	little-endian byte order to native cpu byte order, or
4540  *	vice-versa.
4541  *
4542  *	LOCKING:
4543  *	Inherited from caller.
4544  */
4545 void swap_buf_le16(u16 *buf, unsigned int buf_words)
4546 {
4547 #ifdef __BIG_ENDIAN
4548 	unsigned int i;
4549 
4550 	for (i = 0; i < buf_words; i++)
4551 		buf[i] = le16_to_cpu(buf[i]);
4552 #endif /* __BIG_ENDIAN */
4553 }
4554 
4555 /**
4556  *	ata_qc_new - Request an available ATA command, for queueing
4557  *	@ap: Port associated with device @dev
4558  *	@dev: Device from whom we request an available command structure
4559  *
4560  *	LOCKING:
4561  *	None.
4562  */
4563 
4564 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
4565 {
4566 	struct ata_queued_cmd *qc = NULL;
4567 	unsigned int i;
4568 
4569 	/* no command while frozen */
4570 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
4571 		return NULL;
4572 
4573 	/* the last tag is reserved for internal command. */
4574 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
4575 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
4576 			qc = __ata_qc_from_tag(ap, i);
4577 			break;
4578 		}
4579 
4580 	if (qc)
4581 		qc->tag = i;
4582 
4583 	return qc;
4584 }
4585 
4586 /**
4587  *	ata_qc_new_init - Request an available ATA command, and initialize it
4588  *	@dev: Device from whom we request an available command structure
4589  *
4590  *	LOCKING:
4591  *	None.
4592  */
4593 
4594 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
4595 {
4596 	struct ata_port *ap = dev->link->ap;
4597 	struct ata_queued_cmd *qc;
4598 
4599 	qc = ata_qc_new(ap);
4600 	if (qc) {
4601 		qc->scsicmd = NULL;
4602 		qc->ap = ap;
4603 		qc->dev = dev;
4604 
4605 		ata_qc_reinit(qc);
4606 	}
4607 
4608 	return qc;
4609 }
4610 
4611 /**
4612  *	ata_qc_free - free unused ata_queued_cmd
4613  *	@qc: Command to complete
4614  *
4615  *	Designed to free unused ata_queued_cmd object
4616  *	in case something prevents using it.
4617  *
4618  *	LOCKING:
4619  *	spin_lock_irqsave(host lock)
4620  */
4621 void ata_qc_free(struct ata_queued_cmd *qc)
4622 {
4623 	struct ata_port *ap = qc->ap;
4624 	unsigned int tag;
4625 
4626 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4627 
4628 	qc->flags = 0;
4629 	tag = qc->tag;
4630 	if (likely(ata_tag_valid(tag))) {
4631 		qc->tag = ATA_TAG_POISON;
4632 		clear_bit(tag, &ap->qc_allocated);
4633 	}
4634 }
4635 
4636 void __ata_qc_complete(struct ata_queued_cmd *qc)
4637 {
4638 	struct ata_port *ap = qc->ap;
4639 	struct ata_link *link = qc->dev->link;
4640 
4641 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4642 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
4643 
4644 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
4645 		ata_sg_clean(qc);
4646 
4647 	/* command should be marked inactive atomically with qc completion */
4648 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4649 		link->sactive &= ~(1 << qc->tag);
4650 		if (!link->sactive)
4651 			ap->nr_active_links--;
4652 	} else {
4653 		link->active_tag = ATA_TAG_POISON;
4654 		ap->nr_active_links--;
4655 	}
4656 
4657 	/* clear exclusive status */
4658 	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
4659 		     ap->excl_link == link))
4660 		ap->excl_link = NULL;
4661 
4662 	/* atapi: mark qc as inactive to prevent the interrupt handler
4663 	 * from completing the command twice later, before the error handler
4664 	 * is called. (when rc != 0 and atapi request sense is needed)
4665 	 */
4666 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
4667 	ap->qc_active &= ~(1 << qc->tag);
4668 
4669 	/* call completion callback */
4670 	qc->complete_fn(qc);
4671 }
4672 
4673 static void fill_result_tf(struct ata_queued_cmd *qc)
4674 {
4675 	struct ata_port *ap = qc->ap;
4676 
4677 	qc->result_tf.flags = qc->tf.flags;
4678 	ap->ops->qc_fill_rtf(qc);
4679 }
4680 
4681 static void ata_verify_xfer(struct ata_queued_cmd *qc)
4682 {
4683 	struct ata_device *dev = qc->dev;
4684 
4685 	if (ata_tag_internal(qc->tag))
4686 		return;
4687 
4688 	if (ata_is_nodata(qc->tf.protocol))
4689 		return;
4690 
4691 	if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
4692 		return;
4693 
4694 	dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
4695 }
4696 
4697 /**
4698  *	ata_qc_complete - Complete an active ATA command
4699  *	@qc: Command to complete
4700  *	@err_mask: ATA Status register contents
4701  *
4702  *	Indicate to the mid and upper layers that an ATA
4703  *	command has completed, with either an ok or not-ok status.
4704  *
4705  *	LOCKING:
4706  *	spin_lock_irqsave(host lock)
4707  */
4708 void ata_qc_complete(struct ata_queued_cmd *qc)
4709 {
4710 	struct ata_port *ap = qc->ap;
4711 
4712 	/* XXX: New EH and old EH use different mechanisms to
4713 	 * synchronize EH with regular execution path.
4714 	 *
4715 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
4716 	 * Normal execution path is responsible for not accessing a
4717 	 * failed qc.  libata core enforces the rule by returning NULL
4718 	 * from ata_qc_from_tag() for failed qcs.
4719 	 *
4720 	 * Old EH depends on ata_qc_complete() nullifying completion
4721 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
4722 	 * not synchronize with interrupt handler.  Only PIO task is
4723 	 * taken care of.
4724 	 */
4725 	if (ap->ops->error_handler) {
4726 		struct ata_device *dev = qc->dev;
4727 		struct ata_eh_info *ehi = &dev->link->eh_info;
4728 
4729 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
4730 
4731 		if (unlikely(qc->err_mask))
4732 			qc->flags |= ATA_QCFLAG_FAILED;
4733 
4734 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
4735 			if (!ata_tag_internal(qc->tag)) {
4736 				/* always fill result TF for failed qc */
4737 				fill_result_tf(qc);
4738 				ata_qc_schedule_eh(qc);
4739 				return;
4740 			}
4741 		}
4742 
4743 		/* read result TF if requested */
4744 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
4745 			fill_result_tf(qc);
4746 
4747 		/* Some commands need post-processing after successful
4748 		 * completion.
4749 		 */
4750 		switch (qc->tf.command) {
4751 		case ATA_CMD_SET_FEATURES:
4752 			if (qc->tf.feature != SETFEATURES_WC_ON &&
4753 			    qc->tf.feature != SETFEATURES_WC_OFF)
4754 				break;
4755 			/* fall through */
4756 		case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
4757 		case ATA_CMD_SET_MULTI: /* multi_count changed */
4758 			/* revalidate device */
4759 			ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
4760 			ata_port_schedule_eh(ap);
4761 			break;
4762 
4763 		case ATA_CMD_SLEEP:
4764 			dev->flags |= ATA_DFLAG_SLEEPING;
4765 			break;
4766 		}
4767 
4768 		if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
4769 			ata_verify_xfer(qc);
4770 
4771 		__ata_qc_complete(qc);
4772 	} else {
4773 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
4774 			return;
4775 
4776 		/* read result TF if failed or requested */
4777 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
4778 			fill_result_tf(qc);
4779 
4780 		__ata_qc_complete(qc);
4781 	}
4782 }
4783 
4784 /**
4785  *	ata_qc_complete_multiple - Complete multiple qcs successfully
4786  *	@ap: port in question
4787  *	@qc_active: new qc_active mask
4788  *
4789  *	Complete in-flight commands.  This functions is meant to be
4790  *	called from low-level driver's interrupt routine to complete
4791  *	requests normally.  ap->qc_active and @qc_active is compared
4792  *	and commands are completed accordingly.
4793  *
4794  *	LOCKING:
4795  *	spin_lock_irqsave(host lock)
4796  *
4797  *	RETURNS:
4798  *	Number of completed commands on success, -errno otherwise.
4799  */
4800 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active)
4801 {
4802 	int nr_done = 0;
4803 	u32 done_mask;
4804 	int i;
4805 
4806 	done_mask = ap->qc_active ^ qc_active;
4807 
4808 	if (unlikely(done_mask & qc_active)) {
4809 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
4810 				"(%08x->%08x)\n", ap->qc_active, qc_active);
4811 		return -EINVAL;
4812 	}
4813 
4814 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
4815 		struct ata_queued_cmd *qc;
4816 
4817 		if (!(done_mask & (1 << i)))
4818 			continue;
4819 
4820 		if ((qc = ata_qc_from_tag(ap, i))) {
4821 			ata_qc_complete(qc);
4822 			nr_done++;
4823 		}
4824 	}
4825 
4826 	return nr_done;
4827 }
4828 
4829 /**
4830  *	ata_qc_issue - issue taskfile to device
4831  *	@qc: command to issue to device
4832  *
4833  *	Prepare an ATA command to submission to device.
4834  *	This includes mapping the data into a DMA-able
4835  *	area, filling in the S/G table, and finally
4836  *	writing the taskfile to hardware, starting the command.
4837  *
4838  *	LOCKING:
4839  *	spin_lock_irqsave(host lock)
4840  */
4841 void ata_qc_issue(struct ata_queued_cmd *qc)
4842 {
4843 	struct ata_port *ap = qc->ap;
4844 	struct ata_link *link = qc->dev->link;
4845 	u8 prot = qc->tf.protocol;
4846 
4847 	/* Make sure only one non-NCQ command is outstanding.  The
4848 	 * check is skipped for old EH because it reuses active qc to
4849 	 * request ATAPI sense.
4850 	 */
4851 	WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
4852 
4853 	if (ata_is_ncq(prot)) {
4854 		WARN_ON(link->sactive & (1 << qc->tag));
4855 
4856 		if (!link->sactive)
4857 			ap->nr_active_links++;
4858 		link->sactive |= 1 << qc->tag;
4859 	} else {
4860 		WARN_ON(link->sactive);
4861 
4862 		ap->nr_active_links++;
4863 		link->active_tag = qc->tag;
4864 	}
4865 
4866 	qc->flags |= ATA_QCFLAG_ACTIVE;
4867 	ap->qc_active |= 1 << qc->tag;
4868 
4869 	/* We guarantee to LLDs that they will have at least one
4870 	 * non-zero sg if the command is a data command.
4871 	 */
4872 	BUG_ON(ata_is_data(prot) && (!qc->sg || !qc->n_elem || !qc->nbytes));
4873 
4874 	if (ata_is_dma(prot) || (ata_is_pio(prot) &&
4875 				 (ap->flags & ATA_FLAG_PIO_DMA)))
4876 		if (ata_sg_setup(qc))
4877 			goto sg_err;
4878 
4879 	/* if device is sleeping, schedule reset and abort the link */
4880 	if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
4881 		link->eh_info.action |= ATA_EH_RESET;
4882 		ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
4883 		ata_link_abort(link);
4884 		return;
4885 	}
4886 
4887 	ap->ops->qc_prep(qc);
4888 
4889 	qc->err_mask |= ap->ops->qc_issue(qc);
4890 	if (unlikely(qc->err_mask))
4891 		goto err;
4892 	return;
4893 
4894 sg_err:
4895 	qc->err_mask |= AC_ERR_SYSTEM;
4896 err:
4897 	ata_qc_complete(qc);
4898 }
4899 
4900 /**
4901  *	sata_scr_valid - test whether SCRs are accessible
4902  *	@link: ATA link to test SCR accessibility for
4903  *
4904  *	Test whether SCRs are accessible for @link.
4905  *
4906  *	LOCKING:
4907  *	None.
4908  *
4909  *	RETURNS:
4910  *	1 if SCRs are accessible, 0 otherwise.
4911  */
4912 int sata_scr_valid(struct ata_link *link)
4913 {
4914 	struct ata_port *ap = link->ap;
4915 
4916 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
4917 }
4918 
4919 /**
4920  *	sata_scr_read - read SCR register of the specified port
4921  *	@link: ATA link to read SCR for
4922  *	@reg: SCR to read
4923  *	@val: Place to store read value
4924  *
4925  *	Read SCR register @reg of @link into *@val.  This function is
4926  *	guaranteed to succeed if @link is ap->link, the cable type of
4927  *	the port is SATA and the port implements ->scr_read.
4928  *
4929  *	LOCKING:
4930  *	None if @link is ap->link.  Kernel thread context otherwise.
4931  *
4932  *	RETURNS:
4933  *	0 on success, negative errno on failure.
4934  */
4935 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
4936 {
4937 	if (ata_is_host_link(link)) {
4938 		if (sata_scr_valid(link))
4939 			return link->ap->ops->scr_read(link, reg, val);
4940 		return -EOPNOTSUPP;
4941 	}
4942 
4943 	return sata_pmp_scr_read(link, reg, val);
4944 }
4945 
4946 /**
4947  *	sata_scr_write - write SCR register of the specified port
4948  *	@link: ATA link to write SCR for
4949  *	@reg: SCR to write
4950  *	@val: value to write
4951  *
4952  *	Write @val to SCR register @reg of @link.  This function is
4953  *	guaranteed to succeed if @link is ap->link, the cable type of
4954  *	the port is SATA and the port implements ->scr_read.
4955  *
4956  *	LOCKING:
4957  *	None if @link is ap->link.  Kernel thread context otherwise.
4958  *
4959  *	RETURNS:
4960  *	0 on success, negative errno on failure.
4961  */
4962 int sata_scr_write(struct ata_link *link, int reg, u32 val)
4963 {
4964 	if (ata_is_host_link(link)) {
4965 		if (sata_scr_valid(link))
4966 			return link->ap->ops->scr_write(link, reg, val);
4967 		return -EOPNOTSUPP;
4968 	}
4969 
4970 	return sata_pmp_scr_write(link, reg, val);
4971 }
4972 
4973 /**
4974  *	sata_scr_write_flush - write SCR register of the specified port and flush
4975  *	@link: ATA link to write SCR for
4976  *	@reg: SCR to write
4977  *	@val: value to write
4978  *
4979  *	This function is identical to sata_scr_write() except that this
4980  *	function performs flush after writing to the register.
4981  *
4982  *	LOCKING:
4983  *	None if @link is ap->link.  Kernel thread context otherwise.
4984  *
4985  *	RETURNS:
4986  *	0 on success, negative errno on failure.
4987  */
4988 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
4989 {
4990 	if (ata_is_host_link(link)) {
4991 		int rc;
4992 
4993 		if (sata_scr_valid(link)) {
4994 			rc = link->ap->ops->scr_write(link, reg, val);
4995 			if (rc == 0)
4996 				rc = link->ap->ops->scr_read(link, reg, &val);
4997 			return rc;
4998 		}
4999 		return -EOPNOTSUPP;
5000 	}
5001 
5002 	return sata_pmp_scr_write(link, reg, val);
5003 }
5004 
5005 /**
5006  *	ata_phys_link_online - test whether the given link is online
5007  *	@link: ATA link to test
5008  *
5009  *	Test whether @link is online.  Note that this function returns
5010  *	0 if online status of @link cannot be obtained, so
5011  *	ata_link_online(link) != !ata_link_offline(link).
5012  *
5013  *	LOCKING:
5014  *	None.
5015  *
5016  *	RETURNS:
5017  *	True if the port online status is available and online.
5018  */
5019 bool ata_phys_link_online(struct ata_link *link)
5020 {
5021 	u32 sstatus;
5022 
5023 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
5024 	    (sstatus & 0xf) == 0x3)
5025 		return true;
5026 	return false;
5027 }
5028 
5029 /**
5030  *	ata_phys_link_offline - test whether the given link is offline
5031  *	@link: ATA link to test
5032  *
5033  *	Test whether @link is offline.  Note that this function
5034  *	returns 0 if offline status of @link cannot be obtained, so
5035  *	ata_link_online(link) != !ata_link_offline(link).
5036  *
5037  *	LOCKING:
5038  *	None.
5039  *
5040  *	RETURNS:
5041  *	True if the port offline status is available and offline.
5042  */
5043 bool ata_phys_link_offline(struct ata_link *link)
5044 {
5045 	u32 sstatus;
5046 
5047 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
5048 	    (sstatus & 0xf) != 0x3)
5049 		return true;
5050 	return false;
5051 }
5052 
5053 /**
5054  *	ata_link_online - test whether the given link is online
5055  *	@link: ATA link to test
5056  *
5057  *	Test whether @link is online.  This is identical to
5058  *	ata_phys_link_online() when there's no slave link.  When
5059  *	there's a slave link, this function should only be called on
5060  *	the master link and will return true if any of M/S links is
5061  *	online.
5062  *
5063  *	LOCKING:
5064  *	None.
5065  *
5066  *	RETURNS:
5067  *	True if the port online status is available and online.
5068  */
5069 bool ata_link_online(struct ata_link *link)
5070 {
5071 	struct ata_link *slave = link->ap->slave_link;
5072 
5073 	WARN_ON(link == slave);	/* shouldn't be called on slave link */
5074 
5075 	return ata_phys_link_online(link) ||
5076 		(slave && ata_phys_link_online(slave));
5077 }
5078 
5079 /**
5080  *	ata_link_offline - test whether the given link is offline
5081  *	@link: ATA link to test
5082  *
5083  *	Test whether @link is offline.  This is identical to
5084  *	ata_phys_link_offline() when there's no slave link.  When
5085  *	there's a slave link, this function should only be called on
5086  *	the master link and will return true if both M/S links are
5087  *	offline.
5088  *
5089  *	LOCKING:
5090  *	None.
5091  *
5092  *	RETURNS:
5093  *	True if the port offline status is available and offline.
5094  */
5095 bool ata_link_offline(struct ata_link *link)
5096 {
5097 	struct ata_link *slave = link->ap->slave_link;
5098 
5099 	WARN_ON(link == slave);	/* shouldn't be called on slave link */
5100 
5101 	return ata_phys_link_offline(link) &&
5102 		(!slave || ata_phys_link_offline(slave));
5103 }
5104 
5105 #ifdef CONFIG_PM
5106 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
5107 			       unsigned int action, unsigned int ehi_flags,
5108 			       int wait)
5109 {
5110 	unsigned long flags;
5111 	int i, rc;
5112 
5113 	for (i = 0; i < host->n_ports; i++) {
5114 		struct ata_port *ap = host->ports[i];
5115 		struct ata_link *link;
5116 
5117 		/* Previous resume operation might still be in
5118 		 * progress.  Wait for PM_PENDING to clear.
5119 		 */
5120 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
5121 			ata_port_wait_eh(ap);
5122 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5123 		}
5124 
5125 		/* request PM ops to EH */
5126 		spin_lock_irqsave(ap->lock, flags);
5127 
5128 		ap->pm_mesg = mesg;
5129 		if (wait) {
5130 			rc = 0;
5131 			ap->pm_result = &rc;
5132 		}
5133 
5134 		ap->pflags |= ATA_PFLAG_PM_PENDING;
5135 		__ata_port_for_each_link(link, ap) {
5136 			link->eh_info.action |= action;
5137 			link->eh_info.flags |= ehi_flags;
5138 		}
5139 
5140 		ata_port_schedule_eh(ap);
5141 
5142 		spin_unlock_irqrestore(ap->lock, flags);
5143 
5144 		/* wait and check result */
5145 		if (wait) {
5146 			ata_port_wait_eh(ap);
5147 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5148 			if (rc)
5149 				return rc;
5150 		}
5151 	}
5152 
5153 	return 0;
5154 }
5155 
5156 /**
5157  *	ata_host_suspend - suspend host
5158  *	@host: host to suspend
5159  *	@mesg: PM message
5160  *
5161  *	Suspend @host.  Actual operation is performed by EH.  This
5162  *	function requests EH to perform PM operations and waits for EH
5163  *	to finish.
5164  *
5165  *	LOCKING:
5166  *	Kernel thread context (may sleep).
5167  *
5168  *	RETURNS:
5169  *	0 on success, -errno on failure.
5170  */
5171 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
5172 {
5173 	int rc;
5174 
5175 	/*
5176 	 * disable link pm on all ports before requesting
5177 	 * any pm activity
5178 	 */
5179 	ata_lpm_enable(host);
5180 
5181 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
5182 	if (rc == 0)
5183 		host->dev->power.power_state = mesg;
5184 	return rc;
5185 }
5186 
5187 /**
5188  *	ata_host_resume - resume host
5189  *	@host: host to resume
5190  *
5191  *	Resume @host.  Actual operation is performed by EH.  This
5192  *	function requests EH to perform PM operations and returns.
5193  *	Note that all resume operations are performed parallely.
5194  *
5195  *	LOCKING:
5196  *	Kernel thread context (may sleep).
5197  */
5198 void ata_host_resume(struct ata_host *host)
5199 {
5200 	ata_host_request_pm(host, PMSG_ON, ATA_EH_RESET,
5201 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
5202 	host->dev->power.power_state = PMSG_ON;
5203 
5204 	/* reenable link pm */
5205 	ata_lpm_disable(host);
5206 }
5207 #endif
5208 
5209 /**
5210  *	ata_port_start - Set port up for dma.
5211  *	@ap: Port to initialize
5212  *
5213  *	Called just after data structures for each port are
5214  *	initialized.  Allocates space for PRD table.
5215  *
5216  *	May be used as the port_start() entry in ata_port_operations.
5217  *
5218  *	LOCKING:
5219  *	Inherited from caller.
5220  */
5221 int ata_port_start(struct ata_port *ap)
5222 {
5223 	struct device *dev = ap->dev;
5224 
5225 	ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma,
5226 				      GFP_KERNEL);
5227 	if (!ap->prd)
5228 		return -ENOMEM;
5229 
5230 	return 0;
5231 }
5232 
5233 /**
5234  *	ata_dev_init - Initialize an ata_device structure
5235  *	@dev: Device structure to initialize
5236  *
5237  *	Initialize @dev in preparation for probing.
5238  *
5239  *	LOCKING:
5240  *	Inherited from caller.
5241  */
5242 void ata_dev_init(struct ata_device *dev)
5243 {
5244 	struct ata_link *link = ata_dev_phys_link(dev);
5245 	struct ata_port *ap = link->ap;
5246 	unsigned long flags;
5247 
5248 	/* SATA spd limit is bound to the attached device, reset together */
5249 	link->sata_spd_limit = link->hw_sata_spd_limit;
5250 	link->sata_spd = 0;
5251 
5252 	/* High bits of dev->flags are used to record warm plug
5253 	 * requests which occur asynchronously.  Synchronize using
5254 	 * host lock.
5255 	 */
5256 	spin_lock_irqsave(ap->lock, flags);
5257 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
5258 	dev->horkage = 0;
5259 	spin_unlock_irqrestore(ap->lock, flags);
5260 
5261 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
5262 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
5263 	dev->pio_mask = UINT_MAX;
5264 	dev->mwdma_mask = UINT_MAX;
5265 	dev->udma_mask = UINT_MAX;
5266 }
5267 
5268 /**
5269  *	ata_link_init - Initialize an ata_link structure
5270  *	@ap: ATA port link is attached to
5271  *	@link: Link structure to initialize
5272  *	@pmp: Port multiplier port number
5273  *
5274  *	Initialize @link.
5275  *
5276  *	LOCKING:
5277  *	Kernel thread context (may sleep)
5278  */
5279 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
5280 {
5281 	int i;
5282 
5283 	/* clear everything except for devices */
5284 	memset(link, 0, offsetof(struct ata_link, device[0]));
5285 
5286 	link->ap = ap;
5287 	link->pmp = pmp;
5288 	link->active_tag = ATA_TAG_POISON;
5289 	link->hw_sata_spd_limit = UINT_MAX;
5290 
5291 	/* can't use iterator, ap isn't initialized yet */
5292 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
5293 		struct ata_device *dev = &link->device[i];
5294 
5295 		dev->link = link;
5296 		dev->devno = dev - link->device;
5297 		ata_dev_init(dev);
5298 	}
5299 }
5300 
5301 /**
5302  *	sata_link_init_spd - Initialize link->sata_spd_limit
5303  *	@link: Link to configure sata_spd_limit for
5304  *
5305  *	Initialize @link->[hw_]sata_spd_limit to the currently
5306  *	configured value.
5307  *
5308  *	LOCKING:
5309  *	Kernel thread context (may sleep).
5310  *
5311  *	RETURNS:
5312  *	0 on success, -errno on failure.
5313  */
5314 int sata_link_init_spd(struct ata_link *link)
5315 {
5316 	u8 spd;
5317 	int rc;
5318 
5319 	rc = sata_scr_read(link, SCR_CONTROL, &link->saved_scontrol);
5320 	if (rc)
5321 		return rc;
5322 
5323 	spd = (link->saved_scontrol >> 4) & 0xf;
5324 	if (spd)
5325 		link->hw_sata_spd_limit &= (1 << spd) - 1;
5326 
5327 	ata_force_link_limits(link);
5328 
5329 	link->sata_spd_limit = link->hw_sata_spd_limit;
5330 
5331 	return 0;
5332 }
5333 
5334 /**
5335  *	ata_port_alloc - allocate and initialize basic ATA port resources
5336  *	@host: ATA host this allocated port belongs to
5337  *
5338  *	Allocate and initialize basic ATA port resources.
5339  *
5340  *	RETURNS:
5341  *	Allocate ATA port on success, NULL on failure.
5342  *
5343  *	LOCKING:
5344  *	Inherited from calling layer (may sleep).
5345  */
5346 struct ata_port *ata_port_alloc(struct ata_host *host)
5347 {
5348 	struct ata_port *ap;
5349 
5350 	DPRINTK("ENTER\n");
5351 
5352 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
5353 	if (!ap)
5354 		return NULL;
5355 
5356 	ap->pflags |= ATA_PFLAG_INITIALIZING;
5357 	ap->lock = &host->lock;
5358 	ap->flags = ATA_FLAG_DISABLED;
5359 	ap->print_id = -1;
5360 	ap->ctl = ATA_DEVCTL_OBS;
5361 	ap->host = host;
5362 	ap->dev = host->dev;
5363 	ap->last_ctl = 0xFF;
5364 
5365 #if defined(ATA_VERBOSE_DEBUG)
5366 	/* turn on all debugging levels */
5367 	ap->msg_enable = 0x00FF;
5368 #elif defined(ATA_DEBUG)
5369 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
5370 #else
5371 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
5372 #endif
5373 
5374 #ifdef CONFIG_ATA_SFF
5375 	INIT_DELAYED_WORK(&ap->port_task, ata_pio_task);
5376 #endif
5377 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
5378 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
5379 	INIT_LIST_HEAD(&ap->eh_done_q);
5380 	init_waitqueue_head(&ap->eh_wait_q);
5381 	init_completion(&ap->park_req_pending);
5382 	init_timer_deferrable(&ap->fastdrain_timer);
5383 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
5384 	ap->fastdrain_timer.data = (unsigned long)ap;
5385 
5386 	ap->cbl = ATA_CBL_NONE;
5387 
5388 	ata_link_init(ap, &ap->link, 0);
5389 
5390 #ifdef ATA_IRQ_TRAP
5391 	ap->stats.unhandled_irq = 1;
5392 	ap->stats.idle_irq = 1;
5393 #endif
5394 	return ap;
5395 }
5396 
5397 static void ata_host_release(struct device *gendev, void *res)
5398 {
5399 	struct ata_host *host = dev_get_drvdata(gendev);
5400 	int i;
5401 
5402 	for (i = 0; i < host->n_ports; i++) {
5403 		struct ata_port *ap = host->ports[i];
5404 
5405 		if (!ap)
5406 			continue;
5407 
5408 		if (ap->scsi_host)
5409 			scsi_host_put(ap->scsi_host);
5410 
5411 		kfree(ap->pmp_link);
5412 		kfree(ap->slave_link);
5413 		kfree(ap);
5414 		host->ports[i] = NULL;
5415 	}
5416 
5417 	dev_set_drvdata(gendev, NULL);
5418 }
5419 
5420 /**
5421  *	ata_host_alloc - allocate and init basic ATA host resources
5422  *	@dev: generic device this host is associated with
5423  *	@max_ports: maximum number of ATA ports associated with this host
5424  *
5425  *	Allocate and initialize basic ATA host resources.  LLD calls
5426  *	this function to allocate a host, initializes it fully and
5427  *	attaches it using ata_host_register().
5428  *
5429  *	@max_ports ports are allocated and host->n_ports is
5430  *	initialized to @max_ports.  The caller is allowed to decrease
5431  *	host->n_ports before calling ata_host_register().  The unused
5432  *	ports will be automatically freed on registration.
5433  *
5434  *	RETURNS:
5435  *	Allocate ATA host on success, NULL on failure.
5436  *
5437  *	LOCKING:
5438  *	Inherited from calling layer (may sleep).
5439  */
5440 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
5441 {
5442 	struct ata_host *host;
5443 	size_t sz;
5444 	int i;
5445 
5446 	DPRINTK("ENTER\n");
5447 
5448 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
5449 		return NULL;
5450 
5451 	/* alloc a container for our list of ATA ports (buses) */
5452 	sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
5453 	/* alloc a container for our list of ATA ports (buses) */
5454 	host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
5455 	if (!host)
5456 		goto err_out;
5457 
5458 	devres_add(dev, host);
5459 	dev_set_drvdata(dev, host);
5460 
5461 	spin_lock_init(&host->lock);
5462 	host->dev = dev;
5463 	host->n_ports = max_ports;
5464 
5465 	/* allocate ports bound to this host */
5466 	for (i = 0; i < max_ports; i++) {
5467 		struct ata_port *ap;
5468 
5469 		ap = ata_port_alloc(host);
5470 		if (!ap)
5471 			goto err_out;
5472 
5473 		ap->port_no = i;
5474 		host->ports[i] = ap;
5475 	}
5476 
5477 	devres_remove_group(dev, NULL);
5478 	return host;
5479 
5480  err_out:
5481 	devres_release_group(dev, NULL);
5482 	return NULL;
5483 }
5484 
5485 /**
5486  *	ata_host_alloc_pinfo - alloc host and init with port_info array
5487  *	@dev: generic device this host is associated with
5488  *	@ppi: array of ATA port_info to initialize host with
5489  *	@n_ports: number of ATA ports attached to this host
5490  *
5491  *	Allocate ATA host and initialize with info from @ppi.  If NULL
5492  *	terminated, @ppi may contain fewer entries than @n_ports.  The
5493  *	last entry will be used for the remaining ports.
5494  *
5495  *	RETURNS:
5496  *	Allocate ATA host on success, NULL on failure.
5497  *
5498  *	LOCKING:
5499  *	Inherited from calling layer (may sleep).
5500  */
5501 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
5502 				      const struct ata_port_info * const * ppi,
5503 				      int n_ports)
5504 {
5505 	const struct ata_port_info *pi;
5506 	struct ata_host *host;
5507 	int i, j;
5508 
5509 	host = ata_host_alloc(dev, n_ports);
5510 	if (!host)
5511 		return NULL;
5512 
5513 	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
5514 		struct ata_port *ap = host->ports[i];
5515 
5516 		if (ppi[j])
5517 			pi = ppi[j++];
5518 
5519 		ap->pio_mask = pi->pio_mask;
5520 		ap->mwdma_mask = pi->mwdma_mask;
5521 		ap->udma_mask = pi->udma_mask;
5522 		ap->flags |= pi->flags;
5523 		ap->link.flags |= pi->link_flags;
5524 		ap->ops = pi->port_ops;
5525 
5526 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
5527 			host->ops = pi->port_ops;
5528 	}
5529 
5530 	return host;
5531 }
5532 
5533 /**
5534  *	ata_slave_link_init - initialize slave link
5535  *	@ap: port to initialize slave link for
5536  *
5537  *	Create and initialize slave link for @ap.  This enables slave
5538  *	link handling on the port.
5539  *
5540  *	In libata, a port contains links and a link contains devices.
5541  *	There is single host link but if a PMP is attached to it,
5542  *	there can be multiple fan-out links.  On SATA, there's usually
5543  *	a single device connected to a link but PATA and SATA
5544  *	controllers emulating TF based interface can have two - master
5545  *	and slave.
5546  *
5547  *	However, there are a few controllers which don't fit into this
5548  *	abstraction too well - SATA controllers which emulate TF
5549  *	interface with both master and slave devices but also have
5550  *	separate SCR register sets for each device.  These controllers
5551  *	need separate links for physical link handling
5552  *	(e.g. onlineness, link speed) but should be treated like a
5553  *	traditional M/S controller for everything else (e.g. command
5554  *	issue, softreset).
5555  *
5556  *	slave_link is libata's way of handling this class of
5557  *	controllers without impacting core layer too much.  For
5558  *	anything other than physical link handling, the default host
5559  *	link is used for both master and slave.  For physical link
5560  *	handling, separate @ap->slave_link is used.  All dirty details
5561  *	are implemented inside libata core layer.  From LLD's POV, the
5562  *	only difference is that prereset, hardreset and postreset are
5563  *	called once more for the slave link, so the reset sequence
5564  *	looks like the following.
5565  *
5566  *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
5567  *	softreset(M) -> postreset(M) -> postreset(S)
5568  *
5569  *	Note that softreset is called only for the master.  Softreset
5570  *	resets both M/S by definition, so SRST on master should handle
5571  *	both (the standard method will work just fine).
5572  *
5573  *	LOCKING:
5574  *	Should be called before host is registered.
5575  *
5576  *	RETURNS:
5577  *	0 on success, -errno on failure.
5578  */
5579 int ata_slave_link_init(struct ata_port *ap)
5580 {
5581 	struct ata_link *link;
5582 
5583 	WARN_ON(ap->slave_link);
5584 	WARN_ON(ap->flags & ATA_FLAG_PMP);
5585 
5586 	link = kzalloc(sizeof(*link), GFP_KERNEL);
5587 	if (!link)
5588 		return -ENOMEM;
5589 
5590 	ata_link_init(ap, link, 1);
5591 	ap->slave_link = link;
5592 	return 0;
5593 }
5594 
5595 static void ata_host_stop(struct device *gendev, void *res)
5596 {
5597 	struct ata_host *host = dev_get_drvdata(gendev);
5598 	int i;
5599 
5600 	WARN_ON(!(host->flags & ATA_HOST_STARTED));
5601 
5602 	for (i = 0; i < host->n_ports; i++) {
5603 		struct ata_port *ap = host->ports[i];
5604 
5605 		if (ap->ops->port_stop)
5606 			ap->ops->port_stop(ap);
5607 	}
5608 
5609 	if (host->ops->host_stop)
5610 		host->ops->host_stop(host);
5611 }
5612 
5613 /**
5614  *	ata_finalize_port_ops - finalize ata_port_operations
5615  *	@ops: ata_port_operations to finalize
5616  *
5617  *	An ata_port_operations can inherit from another ops and that
5618  *	ops can again inherit from another.  This can go on as many
5619  *	times as necessary as long as there is no loop in the
5620  *	inheritance chain.
5621  *
5622  *	Ops tables are finalized when the host is started.  NULL or
5623  *	unspecified entries are inherited from the closet ancestor
5624  *	which has the method and the entry is populated with it.
5625  *	After finalization, the ops table directly points to all the
5626  *	methods and ->inherits is no longer necessary and cleared.
5627  *
5628  *	Using ATA_OP_NULL, inheriting ops can force a method to NULL.
5629  *
5630  *	LOCKING:
5631  *	None.
5632  */
5633 static void ata_finalize_port_ops(struct ata_port_operations *ops)
5634 {
5635 	static DEFINE_SPINLOCK(lock);
5636 	const struct ata_port_operations *cur;
5637 	void **begin = (void **)ops;
5638 	void **end = (void **)&ops->inherits;
5639 	void **pp;
5640 
5641 	if (!ops || !ops->inherits)
5642 		return;
5643 
5644 	spin_lock(&lock);
5645 
5646 	for (cur = ops->inherits; cur; cur = cur->inherits) {
5647 		void **inherit = (void **)cur;
5648 
5649 		for (pp = begin; pp < end; pp++, inherit++)
5650 			if (!*pp)
5651 				*pp = *inherit;
5652 	}
5653 
5654 	for (pp = begin; pp < end; pp++)
5655 		if (IS_ERR(*pp))
5656 			*pp = NULL;
5657 
5658 	ops->inherits = NULL;
5659 
5660 	spin_unlock(&lock);
5661 }
5662 
5663 /**
5664  *	ata_host_start - start and freeze ports of an ATA host
5665  *	@host: ATA host to start ports for
5666  *
5667  *	Start and then freeze ports of @host.  Started status is
5668  *	recorded in host->flags, so this function can be called
5669  *	multiple times.  Ports are guaranteed to get started only
5670  *	once.  If host->ops isn't initialized yet, its set to the
5671  *	first non-dummy port ops.
5672  *
5673  *	LOCKING:
5674  *	Inherited from calling layer (may sleep).
5675  *
5676  *	RETURNS:
5677  *	0 if all ports are started successfully, -errno otherwise.
5678  */
5679 int ata_host_start(struct ata_host *host)
5680 {
5681 	int have_stop = 0;
5682 	void *start_dr = NULL;
5683 	int i, rc;
5684 
5685 	if (host->flags & ATA_HOST_STARTED)
5686 		return 0;
5687 
5688 	ata_finalize_port_ops(host->ops);
5689 
5690 	for (i = 0; i < host->n_ports; i++) {
5691 		struct ata_port *ap = host->ports[i];
5692 
5693 		ata_finalize_port_ops(ap->ops);
5694 
5695 		if (!host->ops && !ata_port_is_dummy(ap))
5696 			host->ops = ap->ops;
5697 
5698 		if (ap->ops->port_stop)
5699 			have_stop = 1;
5700 	}
5701 
5702 	if (host->ops->host_stop)
5703 		have_stop = 1;
5704 
5705 	if (have_stop) {
5706 		start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
5707 		if (!start_dr)
5708 			return -ENOMEM;
5709 	}
5710 
5711 	for (i = 0; i < host->n_ports; i++) {
5712 		struct ata_port *ap = host->ports[i];
5713 
5714 		if (ap->ops->port_start) {
5715 			rc = ap->ops->port_start(ap);
5716 			if (rc) {
5717 				if (rc != -ENODEV)
5718 					dev_printk(KERN_ERR, host->dev,
5719 						"failed to start port %d "
5720 						"(errno=%d)\n", i, rc);
5721 				goto err_out;
5722 			}
5723 		}
5724 		ata_eh_freeze_port(ap);
5725 	}
5726 
5727 	if (start_dr)
5728 		devres_add(host->dev, start_dr);
5729 	host->flags |= ATA_HOST_STARTED;
5730 	return 0;
5731 
5732  err_out:
5733 	while (--i >= 0) {
5734 		struct ata_port *ap = host->ports[i];
5735 
5736 		if (ap->ops->port_stop)
5737 			ap->ops->port_stop(ap);
5738 	}
5739 	devres_free(start_dr);
5740 	return rc;
5741 }
5742 
5743 /**
5744  *	ata_sas_host_init - Initialize a host struct
5745  *	@host:	host to initialize
5746  *	@dev:	device host is attached to
5747  *	@flags:	host flags
5748  *	@ops:	port_ops
5749  *
5750  *	LOCKING:
5751  *	PCI/etc. bus probe sem.
5752  *
5753  */
5754 /* KILLME - the only user left is ipr */
5755 void ata_host_init(struct ata_host *host, struct device *dev,
5756 		   unsigned long flags, struct ata_port_operations *ops)
5757 {
5758 	spin_lock_init(&host->lock);
5759 	host->dev = dev;
5760 	host->flags = flags;
5761 	host->ops = ops;
5762 }
5763 
5764 /**
5765  *	ata_host_register - register initialized ATA host
5766  *	@host: ATA host to register
5767  *	@sht: template for SCSI host
5768  *
5769  *	Register initialized ATA host.  @host is allocated using
5770  *	ata_host_alloc() and fully initialized by LLD.  This function
5771  *	starts ports, registers @host with ATA and SCSI layers and
5772  *	probe registered devices.
5773  *
5774  *	LOCKING:
5775  *	Inherited from calling layer (may sleep).
5776  *
5777  *	RETURNS:
5778  *	0 on success, -errno otherwise.
5779  */
5780 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
5781 {
5782 	int i, rc;
5783 
5784 	/* host must have been started */
5785 	if (!(host->flags & ATA_HOST_STARTED)) {
5786 		dev_printk(KERN_ERR, host->dev,
5787 			   "BUG: trying to register unstarted host\n");
5788 		WARN_ON(1);
5789 		return -EINVAL;
5790 	}
5791 
5792 	/* Blow away unused ports.  This happens when LLD can't
5793 	 * determine the exact number of ports to allocate at
5794 	 * allocation time.
5795 	 */
5796 	for (i = host->n_ports; host->ports[i]; i++)
5797 		kfree(host->ports[i]);
5798 
5799 	/* give ports names and add SCSI hosts */
5800 	for (i = 0; i < host->n_ports; i++)
5801 		host->ports[i]->print_id = ata_print_id++;
5802 
5803 	rc = ata_scsi_add_hosts(host, sht);
5804 	if (rc)
5805 		return rc;
5806 
5807 	/* associate with ACPI nodes */
5808 	ata_acpi_associate(host);
5809 
5810 	/* set cable, sata_spd_limit and report */
5811 	for (i = 0; i < host->n_ports; i++) {
5812 		struct ata_port *ap = host->ports[i];
5813 		unsigned long xfer_mask;
5814 
5815 		/* set SATA cable type if still unset */
5816 		if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
5817 			ap->cbl = ATA_CBL_SATA;
5818 
5819 		/* init sata_spd_limit to the current value */
5820 		sata_link_init_spd(&ap->link);
5821 		if (ap->slave_link)
5822 			sata_link_init_spd(ap->slave_link);
5823 
5824 		/* print per-port info to dmesg */
5825 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
5826 					      ap->udma_mask);
5827 
5828 		if (!ata_port_is_dummy(ap)) {
5829 			ata_port_printk(ap, KERN_INFO,
5830 					"%cATA max %s %s\n",
5831 					(ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
5832 					ata_mode_string(xfer_mask),
5833 					ap->link.eh_info.desc);
5834 			ata_ehi_clear_desc(&ap->link.eh_info);
5835 		} else
5836 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
5837 	}
5838 
5839 	/* perform each probe synchronously */
5840 	DPRINTK("probe begin\n");
5841 	for (i = 0; i < host->n_ports; i++) {
5842 		struct ata_port *ap = host->ports[i];
5843 
5844 		/* probe */
5845 		if (ap->ops->error_handler) {
5846 			struct ata_eh_info *ehi = &ap->link.eh_info;
5847 			unsigned long flags;
5848 
5849 			ata_port_probe(ap);
5850 
5851 			/* kick EH for boot probing */
5852 			spin_lock_irqsave(ap->lock, flags);
5853 
5854 			ehi->probe_mask |= ATA_ALL_DEVICES;
5855 			ehi->action |= ATA_EH_RESET | ATA_EH_LPM;
5856 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
5857 
5858 			ap->pflags &= ~ATA_PFLAG_INITIALIZING;
5859 			ap->pflags |= ATA_PFLAG_LOADING;
5860 			ata_port_schedule_eh(ap);
5861 
5862 			spin_unlock_irqrestore(ap->lock, flags);
5863 
5864 			/* wait for EH to finish */
5865 			ata_port_wait_eh(ap);
5866 		} else {
5867 			DPRINTK("ata%u: bus probe begin\n", ap->print_id);
5868 			rc = ata_bus_probe(ap);
5869 			DPRINTK("ata%u: bus probe end\n", ap->print_id);
5870 
5871 			if (rc) {
5872 				/* FIXME: do something useful here?
5873 				 * Current libata behavior will
5874 				 * tear down everything when
5875 				 * the module is removed
5876 				 * or the h/w is unplugged.
5877 				 */
5878 			}
5879 		}
5880 	}
5881 
5882 	/* probes are done, now scan each port's disk(s) */
5883 	DPRINTK("host probe begin\n");
5884 	for (i = 0; i < host->n_ports; i++) {
5885 		struct ata_port *ap = host->ports[i];
5886 
5887 		ata_scsi_scan_host(ap, 1);
5888 	}
5889 
5890 	return 0;
5891 }
5892 
5893 /**
5894  *	ata_host_activate - start host, request IRQ and register it
5895  *	@host: target ATA host
5896  *	@irq: IRQ to request
5897  *	@irq_handler: irq_handler used when requesting IRQ
5898  *	@irq_flags: irq_flags used when requesting IRQ
5899  *	@sht: scsi_host_template to use when registering the host
5900  *
5901  *	After allocating an ATA host and initializing it, most libata
5902  *	LLDs perform three steps to activate the host - start host,
5903  *	request IRQ and register it.  This helper takes necessasry
5904  *	arguments and performs the three steps in one go.
5905  *
5906  *	An invalid IRQ skips the IRQ registration and expects the host to
5907  *	have set polling mode on the port. In this case, @irq_handler
5908  *	should be NULL.
5909  *
5910  *	LOCKING:
5911  *	Inherited from calling layer (may sleep).
5912  *
5913  *	RETURNS:
5914  *	0 on success, -errno otherwise.
5915  */
5916 int ata_host_activate(struct ata_host *host, int irq,
5917 		      irq_handler_t irq_handler, unsigned long irq_flags,
5918 		      struct scsi_host_template *sht)
5919 {
5920 	int i, rc;
5921 
5922 	rc = ata_host_start(host);
5923 	if (rc)
5924 		return rc;
5925 
5926 	/* Special case for polling mode */
5927 	if (!irq) {
5928 		WARN_ON(irq_handler);
5929 		return ata_host_register(host, sht);
5930 	}
5931 
5932 	rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
5933 			      dev_driver_string(host->dev), host);
5934 	if (rc)
5935 		return rc;
5936 
5937 	for (i = 0; i < host->n_ports; i++)
5938 		ata_port_desc(host->ports[i], "irq %d", irq);
5939 
5940 	rc = ata_host_register(host, sht);
5941 	/* if failed, just free the IRQ and leave ports alone */
5942 	if (rc)
5943 		devm_free_irq(host->dev, irq, host);
5944 
5945 	return rc;
5946 }
5947 
5948 /**
5949  *	ata_port_detach - Detach ATA port in prepration of device removal
5950  *	@ap: ATA port to be detached
5951  *
5952  *	Detach all ATA devices and the associated SCSI devices of @ap;
5953  *	then, remove the associated SCSI host.  @ap is guaranteed to
5954  *	be quiescent on return from this function.
5955  *
5956  *	LOCKING:
5957  *	Kernel thread context (may sleep).
5958  */
5959 static void ata_port_detach(struct ata_port *ap)
5960 {
5961 	unsigned long flags;
5962 	struct ata_link *link;
5963 	struct ata_device *dev;
5964 
5965 	if (!ap->ops->error_handler)
5966 		goto skip_eh;
5967 
5968 	/* tell EH we're leaving & flush EH */
5969 	spin_lock_irqsave(ap->lock, flags);
5970 	ap->pflags |= ATA_PFLAG_UNLOADING;
5971 	spin_unlock_irqrestore(ap->lock, flags);
5972 
5973 	ata_port_wait_eh(ap);
5974 
5975 	/* EH is now guaranteed to see UNLOADING - EH context belongs
5976 	 * to us.  Restore SControl and disable all existing devices.
5977 	 */
5978 	__ata_port_for_each_link(link, ap) {
5979 		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol);
5980 		ata_link_for_each_dev(dev, link)
5981 			ata_dev_disable(dev);
5982 	}
5983 
5984 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
5985 	 * will be skipped and retrials will be terminated with bad
5986 	 * target.
5987 	 */
5988 	spin_lock_irqsave(ap->lock, flags);
5989 	ata_port_freeze(ap);	/* won't be thawed */
5990 	spin_unlock_irqrestore(ap->lock, flags);
5991 
5992 	ata_port_wait_eh(ap);
5993 	cancel_rearming_delayed_work(&ap->hotplug_task);
5994 
5995  skip_eh:
5996 	/* remove the associated SCSI host */
5997 	scsi_remove_host(ap->scsi_host);
5998 }
5999 
6000 /**
6001  *	ata_host_detach - Detach all ports of an ATA host
6002  *	@host: Host to detach
6003  *
6004  *	Detach all ports of @host.
6005  *
6006  *	LOCKING:
6007  *	Kernel thread context (may sleep).
6008  */
6009 void ata_host_detach(struct ata_host *host)
6010 {
6011 	int i;
6012 
6013 	for (i = 0; i < host->n_ports; i++)
6014 		ata_port_detach(host->ports[i]);
6015 
6016 	/* the host is dead now, dissociate ACPI */
6017 	ata_acpi_dissociate(host);
6018 }
6019 
6020 #ifdef CONFIG_PCI
6021 
6022 /**
6023  *	ata_pci_remove_one - PCI layer callback for device removal
6024  *	@pdev: PCI device that was removed
6025  *
6026  *	PCI layer indicates to libata via this hook that hot-unplug or
6027  *	module unload event has occurred.  Detach all ports.  Resource
6028  *	release is handled via devres.
6029  *
6030  *	LOCKING:
6031  *	Inherited from PCI layer (may sleep).
6032  */
6033 void ata_pci_remove_one(struct pci_dev *pdev)
6034 {
6035 	struct device *dev = &pdev->dev;
6036 	struct ata_host *host = dev_get_drvdata(dev);
6037 
6038 	ata_host_detach(host);
6039 }
6040 
6041 /* move to PCI subsystem */
6042 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
6043 {
6044 	unsigned long tmp = 0;
6045 
6046 	switch (bits->width) {
6047 	case 1: {
6048 		u8 tmp8 = 0;
6049 		pci_read_config_byte(pdev, bits->reg, &tmp8);
6050 		tmp = tmp8;
6051 		break;
6052 	}
6053 	case 2: {
6054 		u16 tmp16 = 0;
6055 		pci_read_config_word(pdev, bits->reg, &tmp16);
6056 		tmp = tmp16;
6057 		break;
6058 	}
6059 	case 4: {
6060 		u32 tmp32 = 0;
6061 		pci_read_config_dword(pdev, bits->reg, &tmp32);
6062 		tmp = tmp32;
6063 		break;
6064 	}
6065 
6066 	default:
6067 		return -EINVAL;
6068 	}
6069 
6070 	tmp &= bits->mask;
6071 
6072 	return (tmp == bits->val) ? 1 : 0;
6073 }
6074 
6075 #ifdef CONFIG_PM
6076 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
6077 {
6078 	pci_save_state(pdev);
6079 	pci_disable_device(pdev);
6080 
6081 	if (mesg.event & PM_EVENT_SLEEP)
6082 		pci_set_power_state(pdev, PCI_D3hot);
6083 }
6084 
6085 int ata_pci_device_do_resume(struct pci_dev *pdev)
6086 {
6087 	int rc;
6088 
6089 	pci_set_power_state(pdev, PCI_D0);
6090 	pci_restore_state(pdev);
6091 
6092 	rc = pcim_enable_device(pdev);
6093 	if (rc) {
6094 		dev_printk(KERN_ERR, &pdev->dev,
6095 			   "failed to enable device after resume (%d)\n", rc);
6096 		return rc;
6097 	}
6098 
6099 	pci_set_master(pdev);
6100 	return 0;
6101 }
6102 
6103 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
6104 {
6105 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6106 	int rc = 0;
6107 
6108 	rc = ata_host_suspend(host, mesg);
6109 	if (rc)
6110 		return rc;
6111 
6112 	ata_pci_device_do_suspend(pdev, mesg);
6113 
6114 	return 0;
6115 }
6116 
6117 int ata_pci_device_resume(struct pci_dev *pdev)
6118 {
6119 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6120 	int rc;
6121 
6122 	rc = ata_pci_device_do_resume(pdev);
6123 	if (rc == 0)
6124 		ata_host_resume(host);
6125 	return rc;
6126 }
6127 #endif /* CONFIG_PM */
6128 
6129 #endif /* CONFIG_PCI */
6130 
6131 static int __init ata_parse_force_one(char **cur,
6132 				      struct ata_force_ent *force_ent,
6133 				      const char **reason)
6134 {
6135 	/* FIXME: Currently, there's no way to tag init const data and
6136 	 * using __initdata causes build failure on some versions of
6137 	 * gcc.  Once __initdataconst is implemented, add const to the
6138 	 * following structure.
6139 	 */
6140 	static struct ata_force_param force_tbl[] __initdata = {
6141 		{ "40c",	.cbl		= ATA_CBL_PATA40 },
6142 		{ "80c",	.cbl		= ATA_CBL_PATA80 },
6143 		{ "short40c",	.cbl		= ATA_CBL_PATA40_SHORT },
6144 		{ "unk",	.cbl		= ATA_CBL_PATA_UNK },
6145 		{ "ign",	.cbl		= ATA_CBL_PATA_IGN },
6146 		{ "sata",	.cbl		= ATA_CBL_SATA },
6147 		{ "1.5Gbps",	.spd_limit	= 1 },
6148 		{ "3.0Gbps",	.spd_limit	= 2 },
6149 		{ "noncq",	.horkage_on	= ATA_HORKAGE_NONCQ },
6150 		{ "ncq",	.horkage_off	= ATA_HORKAGE_NONCQ },
6151 		{ "pio0",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 0) },
6152 		{ "pio1",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 1) },
6153 		{ "pio2",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 2) },
6154 		{ "pio3",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 3) },
6155 		{ "pio4",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 4) },
6156 		{ "pio5",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 5) },
6157 		{ "pio6",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 6) },
6158 		{ "mwdma0",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 0) },
6159 		{ "mwdma1",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 1) },
6160 		{ "mwdma2",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 2) },
6161 		{ "mwdma3",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 3) },
6162 		{ "mwdma4",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 4) },
6163 		{ "udma0",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6164 		{ "udma16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6165 		{ "udma/16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6166 		{ "udma1",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6167 		{ "udma25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6168 		{ "udma/25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6169 		{ "udma2",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6170 		{ "udma33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6171 		{ "udma/33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6172 		{ "udma3",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6173 		{ "udma44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6174 		{ "udma/44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6175 		{ "udma4",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6176 		{ "udma66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6177 		{ "udma/66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6178 		{ "udma5",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6179 		{ "udma100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6180 		{ "udma/100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6181 		{ "udma6",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6182 		{ "udma133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6183 		{ "udma/133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6184 		{ "udma7",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 7) },
6185 		{ "nohrst",	.lflags		= ATA_LFLAG_NO_HRST },
6186 		{ "nosrst",	.lflags		= ATA_LFLAG_NO_SRST },
6187 		{ "norst",	.lflags		= ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST },
6188 	};
6189 	char *start = *cur, *p = *cur;
6190 	char *id, *val, *endp;
6191 	const struct ata_force_param *match_fp = NULL;
6192 	int nr_matches = 0, i;
6193 
6194 	/* find where this param ends and update *cur */
6195 	while (*p != '\0' && *p != ',')
6196 		p++;
6197 
6198 	if (*p == '\0')
6199 		*cur = p;
6200 	else
6201 		*cur = p + 1;
6202 
6203 	*p = '\0';
6204 
6205 	/* parse */
6206 	p = strchr(start, ':');
6207 	if (!p) {
6208 		val = strstrip(start);
6209 		goto parse_val;
6210 	}
6211 	*p = '\0';
6212 
6213 	id = strstrip(start);
6214 	val = strstrip(p + 1);
6215 
6216 	/* parse id */
6217 	p = strchr(id, '.');
6218 	if (p) {
6219 		*p++ = '\0';
6220 		force_ent->device = simple_strtoul(p, &endp, 10);
6221 		if (p == endp || *endp != '\0') {
6222 			*reason = "invalid device";
6223 			return -EINVAL;
6224 		}
6225 	}
6226 
6227 	force_ent->port = simple_strtoul(id, &endp, 10);
6228 	if (p == endp || *endp != '\0') {
6229 		*reason = "invalid port/link";
6230 		return -EINVAL;
6231 	}
6232 
6233  parse_val:
6234 	/* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
6235 	for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
6236 		const struct ata_force_param *fp = &force_tbl[i];
6237 
6238 		if (strncasecmp(val, fp->name, strlen(val)))
6239 			continue;
6240 
6241 		nr_matches++;
6242 		match_fp = fp;
6243 
6244 		if (strcasecmp(val, fp->name) == 0) {
6245 			nr_matches = 1;
6246 			break;
6247 		}
6248 	}
6249 
6250 	if (!nr_matches) {
6251 		*reason = "unknown value";
6252 		return -EINVAL;
6253 	}
6254 	if (nr_matches > 1) {
6255 		*reason = "ambigious value";
6256 		return -EINVAL;
6257 	}
6258 
6259 	force_ent->param = *match_fp;
6260 
6261 	return 0;
6262 }
6263 
6264 static void __init ata_parse_force_param(void)
6265 {
6266 	int idx = 0, size = 1;
6267 	int last_port = -1, last_device = -1;
6268 	char *p, *cur, *next;
6269 
6270 	/* calculate maximum number of params and allocate force_tbl */
6271 	for (p = ata_force_param_buf; *p; p++)
6272 		if (*p == ',')
6273 			size++;
6274 
6275 	ata_force_tbl = kzalloc(sizeof(ata_force_tbl[0]) * size, GFP_KERNEL);
6276 	if (!ata_force_tbl) {
6277 		printk(KERN_WARNING "ata: failed to extend force table, "
6278 		       "libata.force ignored\n");
6279 		return;
6280 	}
6281 
6282 	/* parse and populate the table */
6283 	for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
6284 		const char *reason = "";
6285 		struct ata_force_ent te = { .port = -1, .device = -1 };
6286 
6287 		next = cur;
6288 		if (ata_parse_force_one(&next, &te, &reason)) {
6289 			printk(KERN_WARNING "ata: failed to parse force "
6290 			       "parameter \"%s\" (%s)\n",
6291 			       cur, reason);
6292 			continue;
6293 		}
6294 
6295 		if (te.port == -1) {
6296 			te.port = last_port;
6297 			te.device = last_device;
6298 		}
6299 
6300 		ata_force_tbl[idx++] = te;
6301 
6302 		last_port = te.port;
6303 		last_device = te.device;
6304 	}
6305 
6306 	ata_force_tbl_size = idx;
6307 }
6308 
6309 static int __init ata_init(void)
6310 {
6311 	ata_parse_force_param();
6312 
6313 	ata_wq = create_workqueue("ata");
6314 	if (!ata_wq)
6315 		goto free_force_tbl;
6316 
6317 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
6318 	if (!ata_aux_wq)
6319 		goto free_wq;
6320 
6321 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
6322 	return 0;
6323 
6324 free_wq:
6325 	destroy_workqueue(ata_wq);
6326 free_force_tbl:
6327 	kfree(ata_force_tbl);
6328 	return -ENOMEM;
6329 }
6330 
6331 static void __exit ata_exit(void)
6332 {
6333 	kfree(ata_force_tbl);
6334 	destroy_workqueue(ata_wq);
6335 	destroy_workqueue(ata_aux_wq);
6336 }
6337 
6338 subsys_initcall(ata_init);
6339 module_exit(ata_exit);
6340 
6341 static unsigned long ratelimit_time;
6342 static DEFINE_SPINLOCK(ata_ratelimit_lock);
6343 
6344 int ata_ratelimit(void)
6345 {
6346 	int rc;
6347 	unsigned long flags;
6348 
6349 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
6350 
6351 	if (time_after(jiffies, ratelimit_time)) {
6352 		rc = 1;
6353 		ratelimit_time = jiffies + (HZ/5);
6354 	} else
6355 		rc = 0;
6356 
6357 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
6358 
6359 	return rc;
6360 }
6361 
6362 /**
6363  *	ata_wait_register - wait until register value changes
6364  *	@reg: IO-mapped register
6365  *	@mask: Mask to apply to read register value
6366  *	@val: Wait condition
6367  *	@interval: polling interval in milliseconds
6368  *	@timeout: timeout in milliseconds
6369  *
6370  *	Waiting for some bits of register to change is a common
6371  *	operation for ATA controllers.  This function reads 32bit LE
6372  *	IO-mapped register @reg and tests for the following condition.
6373  *
6374  *	(*@reg & mask) != val
6375  *
6376  *	If the condition is met, it returns; otherwise, the process is
6377  *	repeated after @interval_msec until timeout.
6378  *
6379  *	LOCKING:
6380  *	Kernel thread context (may sleep)
6381  *
6382  *	RETURNS:
6383  *	The final register value.
6384  */
6385 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
6386 		      unsigned long interval, unsigned long timeout)
6387 {
6388 	unsigned long deadline;
6389 	u32 tmp;
6390 
6391 	tmp = ioread32(reg);
6392 
6393 	/* Calculate timeout _after_ the first read to make sure
6394 	 * preceding writes reach the controller before starting to
6395 	 * eat away the timeout.
6396 	 */
6397 	deadline = ata_deadline(jiffies, timeout);
6398 
6399 	while ((tmp & mask) == val && time_before(jiffies, deadline)) {
6400 		msleep(interval);
6401 		tmp = ioread32(reg);
6402 	}
6403 
6404 	return tmp;
6405 }
6406 
6407 /*
6408  * Dummy port_ops
6409  */
6410 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
6411 {
6412 	return AC_ERR_SYSTEM;
6413 }
6414 
6415 static void ata_dummy_error_handler(struct ata_port *ap)
6416 {
6417 	/* truly dummy */
6418 }
6419 
6420 struct ata_port_operations ata_dummy_port_ops = {
6421 	.qc_prep		= ata_noop_qc_prep,
6422 	.qc_issue		= ata_dummy_qc_issue,
6423 	.error_handler		= ata_dummy_error_handler,
6424 };
6425 
6426 const struct ata_port_info ata_dummy_port_info = {
6427 	.port_ops		= &ata_dummy_port_ops,
6428 };
6429 
6430 /*
6431  * libata is essentially a library of internal helper functions for
6432  * low-level ATA host controller drivers.  As such, the API/ABI is
6433  * likely to change as new drivers are added and updated.
6434  * Do not depend on ABI/API stability.
6435  */
6436 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
6437 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
6438 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
6439 EXPORT_SYMBOL_GPL(ata_base_port_ops);
6440 EXPORT_SYMBOL_GPL(sata_port_ops);
6441 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
6442 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
6443 EXPORT_SYMBOL_GPL(__ata_port_next_link);
6444 EXPORT_SYMBOL_GPL(ata_std_bios_param);
6445 EXPORT_SYMBOL_GPL(ata_host_init);
6446 EXPORT_SYMBOL_GPL(ata_host_alloc);
6447 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
6448 EXPORT_SYMBOL_GPL(ata_slave_link_init);
6449 EXPORT_SYMBOL_GPL(ata_host_start);
6450 EXPORT_SYMBOL_GPL(ata_host_register);
6451 EXPORT_SYMBOL_GPL(ata_host_activate);
6452 EXPORT_SYMBOL_GPL(ata_host_detach);
6453 EXPORT_SYMBOL_GPL(ata_sg_init);
6454 EXPORT_SYMBOL_GPL(ata_qc_complete);
6455 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
6456 EXPORT_SYMBOL_GPL(atapi_cmd_type);
6457 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
6458 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
6459 EXPORT_SYMBOL_GPL(ata_pack_xfermask);
6460 EXPORT_SYMBOL_GPL(ata_unpack_xfermask);
6461 EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
6462 EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
6463 EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
6464 EXPORT_SYMBOL_GPL(ata_mode_string);
6465 EXPORT_SYMBOL_GPL(ata_id_xfermask);
6466 EXPORT_SYMBOL_GPL(ata_port_start);
6467 EXPORT_SYMBOL_GPL(ata_do_set_mode);
6468 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
6469 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
6470 EXPORT_SYMBOL_GPL(ata_port_probe);
6471 EXPORT_SYMBOL_GPL(ata_dev_disable);
6472 EXPORT_SYMBOL_GPL(sata_set_spd);
6473 EXPORT_SYMBOL_GPL(ata_wait_after_reset);
6474 EXPORT_SYMBOL_GPL(sata_link_debounce);
6475 EXPORT_SYMBOL_GPL(sata_link_resume);
6476 EXPORT_SYMBOL_GPL(ata_std_prereset);
6477 EXPORT_SYMBOL_GPL(sata_link_hardreset);
6478 EXPORT_SYMBOL_GPL(sata_std_hardreset);
6479 EXPORT_SYMBOL_GPL(ata_std_postreset);
6480 EXPORT_SYMBOL_GPL(ata_dev_classify);
6481 EXPORT_SYMBOL_GPL(ata_dev_pair);
6482 EXPORT_SYMBOL_GPL(ata_port_disable);
6483 EXPORT_SYMBOL_GPL(ata_ratelimit);
6484 EXPORT_SYMBOL_GPL(ata_wait_register);
6485 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
6486 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
6487 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
6488 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
6489 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
6490 EXPORT_SYMBOL_GPL(sata_scr_valid);
6491 EXPORT_SYMBOL_GPL(sata_scr_read);
6492 EXPORT_SYMBOL_GPL(sata_scr_write);
6493 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
6494 EXPORT_SYMBOL_GPL(ata_link_online);
6495 EXPORT_SYMBOL_GPL(ata_link_offline);
6496 #ifdef CONFIG_PM
6497 EXPORT_SYMBOL_GPL(ata_host_suspend);
6498 EXPORT_SYMBOL_GPL(ata_host_resume);
6499 #endif /* CONFIG_PM */
6500 EXPORT_SYMBOL_GPL(ata_id_string);
6501 EXPORT_SYMBOL_GPL(ata_id_c_string);
6502 EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
6503 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
6504 
6505 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
6506 EXPORT_SYMBOL_GPL(ata_timing_find_mode);
6507 EXPORT_SYMBOL_GPL(ata_timing_compute);
6508 EXPORT_SYMBOL_GPL(ata_timing_merge);
6509 EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);
6510 
6511 #ifdef CONFIG_PCI
6512 EXPORT_SYMBOL_GPL(pci_test_config_bits);
6513 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
6514 #ifdef CONFIG_PM
6515 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
6516 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
6517 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
6518 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
6519 #endif /* CONFIG_PM */
6520 #endif /* CONFIG_PCI */
6521 
6522 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
6523 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
6524 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
6525 EXPORT_SYMBOL_GPL(ata_port_desc);
6526 #ifdef CONFIG_PCI
6527 EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
6528 #endif /* CONFIG_PCI */
6529 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
6530 EXPORT_SYMBOL_GPL(ata_link_abort);
6531 EXPORT_SYMBOL_GPL(ata_port_abort);
6532 EXPORT_SYMBOL_GPL(ata_port_freeze);
6533 EXPORT_SYMBOL_GPL(sata_async_notification);
6534 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
6535 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
6536 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
6537 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
6538 EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);
6539 EXPORT_SYMBOL_GPL(ata_do_eh);
6540 EXPORT_SYMBOL_GPL(ata_std_error_handler);
6541 
6542 EXPORT_SYMBOL_GPL(ata_cable_40wire);
6543 EXPORT_SYMBOL_GPL(ata_cable_80wire);
6544 EXPORT_SYMBOL_GPL(ata_cable_unknown);
6545 EXPORT_SYMBOL_GPL(ata_cable_ignore);
6546 EXPORT_SYMBOL_GPL(ata_cable_sata);
6547