xref: /openbmc/linux/drivers/ata/libata-sff.c (revision 95298d63)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  libata-sff.c - helper library for PCI IDE BMDMA
4  *
5  *  Copyright 2003-2006 Red Hat, Inc.  All rights reserved.
6  *  Copyright 2003-2006 Jeff Garzik
7  *
8  *  libata documentation is available via 'make {ps|pdf}docs',
9  *  as Documentation/driver-api/libata.rst
10  *
11  *  Hardware documentation available from http://www.t13.org/ and
12  *  http://www.sata-io.org/
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/gfp.h>
17 #include <linux/pci.h>
18 #include <linux/module.h>
19 #include <linux/libata.h>
20 #include <linux/highmem.h>
21 
22 #include "libata.h"
23 
24 static struct workqueue_struct *ata_sff_wq;
25 
26 const struct ata_port_operations ata_sff_port_ops = {
27 	.inherits		= &ata_base_port_ops,
28 
29 	.qc_prep		= ata_noop_qc_prep,
30 	.qc_issue		= ata_sff_qc_issue,
31 	.qc_fill_rtf		= ata_sff_qc_fill_rtf,
32 
33 	.freeze			= ata_sff_freeze,
34 	.thaw			= ata_sff_thaw,
35 	.prereset		= ata_sff_prereset,
36 	.softreset		= ata_sff_softreset,
37 	.hardreset		= sata_sff_hardreset,
38 	.postreset		= ata_sff_postreset,
39 	.error_handler		= ata_sff_error_handler,
40 
41 	.sff_dev_select		= ata_sff_dev_select,
42 	.sff_check_status	= ata_sff_check_status,
43 	.sff_tf_load		= ata_sff_tf_load,
44 	.sff_tf_read		= ata_sff_tf_read,
45 	.sff_exec_command	= ata_sff_exec_command,
46 	.sff_data_xfer		= ata_sff_data_xfer,
47 	.sff_drain_fifo		= ata_sff_drain_fifo,
48 
49 	.lost_interrupt		= ata_sff_lost_interrupt,
50 };
51 EXPORT_SYMBOL_GPL(ata_sff_port_ops);
52 
53 /**
54  *	ata_sff_check_status - Read device status reg & clear interrupt
55  *	@ap: port where the device is
56  *
57  *	Reads ATA taskfile status register for currently-selected device
58  *	and return its value. This also clears pending interrupts
59  *      from this device
60  *
61  *	LOCKING:
62  *	Inherited from caller.
63  */
64 u8 ata_sff_check_status(struct ata_port *ap)
65 {
66 	return ioread8(ap->ioaddr.status_addr);
67 }
68 EXPORT_SYMBOL_GPL(ata_sff_check_status);
69 
70 /**
71  *	ata_sff_altstatus - Read device alternate status reg
72  *	@ap: port where the device is
73  *
74  *	Reads ATA taskfile alternate status register for
75  *	currently-selected device and return its value.
76  *
77  *	Note: may NOT be used as the check_altstatus() entry in
78  *	ata_port_operations.
79  *
80  *	LOCKING:
81  *	Inherited from caller.
82  */
83 static u8 ata_sff_altstatus(struct ata_port *ap)
84 {
85 	if (ap->ops->sff_check_altstatus)
86 		return ap->ops->sff_check_altstatus(ap);
87 
88 	return ioread8(ap->ioaddr.altstatus_addr);
89 }
90 
91 /**
92  *	ata_sff_irq_status - Check if the device is busy
93  *	@ap: port where the device is
94  *
95  *	Determine if the port is currently busy. Uses altstatus
96  *	if available in order to avoid clearing shared IRQ status
97  *	when finding an IRQ source. Non ctl capable devices don't
98  *	share interrupt lines fortunately for us.
99  *
100  *	LOCKING:
101  *	Inherited from caller.
102  */
103 static u8 ata_sff_irq_status(struct ata_port *ap)
104 {
105 	u8 status;
106 
107 	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
108 		status = ata_sff_altstatus(ap);
109 		/* Not us: We are busy */
110 		if (status & ATA_BUSY)
111 			return status;
112 	}
113 	/* Clear INTRQ latch */
114 	status = ap->ops->sff_check_status(ap);
115 	return status;
116 }
117 
118 /**
119  *	ata_sff_sync - Flush writes
120  *	@ap: Port to wait for.
121  *
122  *	CAUTION:
123  *	If we have an mmio device with no ctl and no altstatus
124  *	method this will fail. No such devices are known to exist.
125  *
126  *	LOCKING:
127  *	Inherited from caller.
128  */
129 
130 static void ata_sff_sync(struct ata_port *ap)
131 {
132 	if (ap->ops->sff_check_altstatus)
133 		ap->ops->sff_check_altstatus(ap);
134 	else if (ap->ioaddr.altstatus_addr)
135 		ioread8(ap->ioaddr.altstatus_addr);
136 }
137 
138 /**
139  *	ata_sff_pause		-	Flush writes and wait 400nS
140  *	@ap: Port to pause for.
141  *
142  *	CAUTION:
143  *	If we have an mmio device with no ctl and no altstatus
144  *	method this will fail. No such devices are known to exist.
145  *
146  *	LOCKING:
147  *	Inherited from caller.
148  */
149 
150 void ata_sff_pause(struct ata_port *ap)
151 {
152 	ata_sff_sync(ap);
153 	ndelay(400);
154 }
155 EXPORT_SYMBOL_GPL(ata_sff_pause);
156 
157 /**
158  *	ata_sff_dma_pause	-	Pause before commencing DMA
159  *	@ap: Port to pause for.
160  *
161  *	Perform I/O fencing and ensure sufficient cycle delays occur
162  *	for the HDMA1:0 transition
163  */
164 
165 void ata_sff_dma_pause(struct ata_port *ap)
166 {
167 	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
168 		/* An altstatus read will cause the needed delay without
169 		   messing up the IRQ status */
170 		ata_sff_altstatus(ap);
171 		return;
172 	}
173 	/* There are no DMA controllers without ctl. BUG here to ensure
174 	   we never violate the HDMA1:0 transition timing and risk
175 	   corruption. */
176 	BUG();
177 }
178 EXPORT_SYMBOL_GPL(ata_sff_dma_pause);
179 
180 /**
181  *	ata_sff_busy_sleep - sleep until BSY clears, or timeout
182  *	@ap: port containing status register to be polled
183  *	@tmout_pat: impatience timeout in msecs
184  *	@tmout: overall timeout in msecs
185  *
186  *	Sleep until ATA Status register bit BSY clears,
187  *	or a timeout occurs.
188  *
189  *	LOCKING:
190  *	Kernel thread context (may sleep).
191  *
192  *	RETURNS:
193  *	0 on success, -errno otherwise.
194  */
195 int ata_sff_busy_sleep(struct ata_port *ap,
196 		       unsigned long tmout_pat, unsigned long tmout)
197 {
198 	unsigned long timer_start, timeout;
199 	u8 status;
200 
201 	status = ata_sff_busy_wait(ap, ATA_BUSY, 300);
202 	timer_start = jiffies;
203 	timeout = ata_deadline(timer_start, tmout_pat);
204 	while (status != 0xff && (status & ATA_BUSY) &&
205 	       time_before(jiffies, timeout)) {
206 		ata_msleep(ap, 50);
207 		status = ata_sff_busy_wait(ap, ATA_BUSY, 3);
208 	}
209 
210 	if (status != 0xff && (status & ATA_BUSY))
211 		ata_port_warn(ap,
212 			      "port is slow to respond, please be patient (Status 0x%x)\n",
213 			      status);
214 
215 	timeout = ata_deadline(timer_start, tmout);
216 	while (status != 0xff && (status & ATA_BUSY) &&
217 	       time_before(jiffies, timeout)) {
218 		ata_msleep(ap, 50);
219 		status = ap->ops->sff_check_status(ap);
220 	}
221 
222 	if (status == 0xff)
223 		return -ENODEV;
224 
225 	if (status & ATA_BUSY) {
226 		ata_port_err(ap,
227 			     "port failed to respond (%lu secs, Status 0x%x)\n",
228 			     DIV_ROUND_UP(tmout, 1000), status);
229 		return -EBUSY;
230 	}
231 
232 	return 0;
233 }
234 EXPORT_SYMBOL_GPL(ata_sff_busy_sleep);
235 
236 static int ata_sff_check_ready(struct ata_link *link)
237 {
238 	u8 status = link->ap->ops->sff_check_status(link->ap);
239 
240 	return ata_check_ready(status);
241 }
242 
243 /**
244  *	ata_sff_wait_ready - sleep until BSY clears, or timeout
245  *	@link: SFF link to wait ready status for
246  *	@deadline: deadline jiffies for the operation
247  *
248  *	Sleep until ATA Status register bit BSY clears, or timeout
249  *	occurs.
250  *
251  *	LOCKING:
252  *	Kernel thread context (may sleep).
253  *
254  *	RETURNS:
255  *	0 on success, -errno otherwise.
256  */
257 int ata_sff_wait_ready(struct ata_link *link, unsigned long deadline)
258 {
259 	return ata_wait_ready(link, deadline, ata_sff_check_ready);
260 }
261 EXPORT_SYMBOL_GPL(ata_sff_wait_ready);
262 
263 /**
264  *	ata_sff_set_devctl - Write device control reg
265  *	@ap: port where the device is
266  *	@ctl: value to write
267  *
268  *	Writes ATA taskfile device control register.
269  *
270  *	Note: may NOT be used as the sff_set_devctl() entry in
271  *	ata_port_operations.
272  *
273  *	LOCKING:
274  *	Inherited from caller.
275  */
276 static void ata_sff_set_devctl(struct ata_port *ap, u8 ctl)
277 {
278 	if (ap->ops->sff_set_devctl)
279 		ap->ops->sff_set_devctl(ap, ctl);
280 	else
281 		iowrite8(ctl, ap->ioaddr.ctl_addr);
282 }
283 
284 /**
285  *	ata_sff_dev_select - Select device 0/1 on ATA bus
286  *	@ap: ATA channel to manipulate
287  *	@device: ATA device (numbered from zero) to select
288  *
289  *	Use the method defined in the ATA specification to
290  *	make either device 0, or device 1, active on the
291  *	ATA channel.  Works with both PIO and MMIO.
292  *
293  *	May be used as the dev_select() entry in ata_port_operations.
294  *
295  *	LOCKING:
296  *	caller.
297  */
298 void ata_sff_dev_select(struct ata_port *ap, unsigned int device)
299 {
300 	u8 tmp;
301 
302 	if (device == 0)
303 		tmp = ATA_DEVICE_OBS;
304 	else
305 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
306 
307 	iowrite8(tmp, ap->ioaddr.device_addr);
308 	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
309 }
310 EXPORT_SYMBOL_GPL(ata_sff_dev_select);
311 
312 /**
313  *	ata_dev_select - Select device 0/1 on ATA bus
314  *	@ap: ATA channel to manipulate
315  *	@device: ATA device (numbered from zero) to select
316  *	@wait: non-zero to wait for Status register BSY bit to clear
317  *	@can_sleep: non-zero if context allows sleeping
318  *
319  *	Use the method defined in the ATA specification to
320  *	make either device 0, or device 1, active on the
321  *	ATA channel.
322  *
323  *	This is a high-level version of ata_sff_dev_select(), which
324  *	additionally provides the services of inserting the proper
325  *	pauses and status polling, where needed.
326  *
327  *	LOCKING:
328  *	caller.
329  */
330 static void ata_dev_select(struct ata_port *ap, unsigned int device,
331 			   unsigned int wait, unsigned int can_sleep)
332 {
333 	if (ata_msg_probe(ap))
334 		ata_port_info(ap, "ata_dev_select: ENTER, device %u, wait %u\n",
335 			      device, wait);
336 
337 	if (wait)
338 		ata_wait_idle(ap);
339 
340 	ap->ops->sff_dev_select(ap, device);
341 
342 	if (wait) {
343 		if (can_sleep && ap->link.device[device].class == ATA_DEV_ATAPI)
344 			ata_msleep(ap, 150);
345 		ata_wait_idle(ap);
346 	}
347 }
348 
349 /**
350  *	ata_sff_irq_on - Enable interrupts on a port.
351  *	@ap: Port on which interrupts are enabled.
352  *
353  *	Enable interrupts on a legacy IDE device using MMIO or PIO,
354  *	wait for idle, clear any pending interrupts.
355  *
356  *	Note: may NOT be used as the sff_irq_on() entry in
357  *	ata_port_operations.
358  *
359  *	LOCKING:
360  *	Inherited from caller.
361  */
362 void ata_sff_irq_on(struct ata_port *ap)
363 {
364 	struct ata_ioports *ioaddr = &ap->ioaddr;
365 
366 	if (ap->ops->sff_irq_on) {
367 		ap->ops->sff_irq_on(ap);
368 		return;
369 	}
370 
371 	ap->ctl &= ~ATA_NIEN;
372 	ap->last_ctl = ap->ctl;
373 
374 	if (ap->ops->sff_set_devctl || ioaddr->ctl_addr)
375 		ata_sff_set_devctl(ap, ap->ctl);
376 	ata_wait_idle(ap);
377 
378 	if (ap->ops->sff_irq_clear)
379 		ap->ops->sff_irq_clear(ap);
380 }
381 EXPORT_SYMBOL_GPL(ata_sff_irq_on);
382 
383 /**
384  *	ata_sff_tf_load - send taskfile registers to host controller
385  *	@ap: Port to which output is sent
386  *	@tf: ATA taskfile register set
387  *
388  *	Outputs ATA taskfile to standard ATA host controller.
389  *
390  *	LOCKING:
391  *	Inherited from caller.
392  */
393 void ata_sff_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
394 {
395 	struct ata_ioports *ioaddr = &ap->ioaddr;
396 	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
397 
398 	if (tf->ctl != ap->last_ctl) {
399 		if (ioaddr->ctl_addr)
400 			iowrite8(tf->ctl, ioaddr->ctl_addr);
401 		ap->last_ctl = tf->ctl;
402 		ata_wait_idle(ap);
403 	}
404 
405 	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
406 		WARN_ON_ONCE(!ioaddr->ctl_addr);
407 		iowrite8(tf->hob_feature, ioaddr->feature_addr);
408 		iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
409 		iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
410 		iowrite8(tf->hob_lbam, ioaddr->lbam_addr);
411 		iowrite8(tf->hob_lbah, ioaddr->lbah_addr);
412 		VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
413 			tf->hob_feature,
414 			tf->hob_nsect,
415 			tf->hob_lbal,
416 			tf->hob_lbam,
417 			tf->hob_lbah);
418 	}
419 
420 	if (is_addr) {
421 		iowrite8(tf->feature, ioaddr->feature_addr);
422 		iowrite8(tf->nsect, ioaddr->nsect_addr);
423 		iowrite8(tf->lbal, ioaddr->lbal_addr);
424 		iowrite8(tf->lbam, ioaddr->lbam_addr);
425 		iowrite8(tf->lbah, ioaddr->lbah_addr);
426 		VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
427 			tf->feature,
428 			tf->nsect,
429 			tf->lbal,
430 			tf->lbam,
431 			tf->lbah);
432 	}
433 
434 	if (tf->flags & ATA_TFLAG_DEVICE) {
435 		iowrite8(tf->device, ioaddr->device_addr);
436 		VPRINTK("device 0x%X\n", tf->device);
437 	}
438 
439 	ata_wait_idle(ap);
440 }
441 EXPORT_SYMBOL_GPL(ata_sff_tf_load);
442 
443 /**
444  *	ata_sff_tf_read - input device's ATA taskfile shadow registers
445  *	@ap: Port from which input is read
446  *	@tf: ATA taskfile register set for storing input
447  *
448  *	Reads ATA taskfile registers for currently-selected device
449  *	into @tf. Assumes the device has a fully SFF compliant task file
450  *	layout and behaviour. If you device does not (eg has a different
451  *	status method) then you will need to provide a replacement tf_read
452  *
453  *	LOCKING:
454  *	Inherited from caller.
455  */
456 void ata_sff_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
457 {
458 	struct ata_ioports *ioaddr = &ap->ioaddr;
459 
460 	tf->command = ata_sff_check_status(ap);
461 	tf->feature = ioread8(ioaddr->error_addr);
462 	tf->nsect = ioread8(ioaddr->nsect_addr);
463 	tf->lbal = ioread8(ioaddr->lbal_addr);
464 	tf->lbam = ioread8(ioaddr->lbam_addr);
465 	tf->lbah = ioread8(ioaddr->lbah_addr);
466 	tf->device = ioread8(ioaddr->device_addr);
467 
468 	if (tf->flags & ATA_TFLAG_LBA48) {
469 		if (likely(ioaddr->ctl_addr)) {
470 			iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
471 			tf->hob_feature = ioread8(ioaddr->error_addr);
472 			tf->hob_nsect = ioread8(ioaddr->nsect_addr);
473 			tf->hob_lbal = ioread8(ioaddr->lbal_addr);
474 			tf->hob_lbam = ioread8(ioaddr->lbam_addr);
475 			tf->hob_lbah = ioread8(ioaddr->lbah_addr);
476 			iowrite8(tf->ctl, ioaddr->ctl_addr);
477 			ap->last_ctl = tf->ctl;
478 		} else
479 			WARN_ON_ONCE(1);
480 	}
481 }
482 EXPORT_SYMBOL_GPL(ata_sff_tf_read);
483 
484 /**
485  *	ata_sff_exec_command - issue ATA command to host controller
486  *	@ap: port to which command is being issued
487  *	@tf: ATA taskfile register set
488  *
489  *	Issues ATA command, with proper synchronization with interrupt
490  *	handler / other threads.
491  *
492  *	LOCKING:
493  *	spin_lock_irqsave(host lock)
494  */
495 void ata_sff_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
496 {
497 	DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
498 
499 	iowrite8(tf->command, ap->ioaddr.command_addr);
500 	ata_sff_pause(ap);
501 }
502 EXPORT_SYMBOL_GPL(ata_sff_exec_command);
503 
504 /**
505  *	ata_tf_to_host - issue ATA taskfile to host controller
506  *	@ap: port to which command is being issued
507  *	@tf: ATA taskfile register set
508  *
509  *	Issues ATA taskfile register set to ATA host controller,
510  *	with proper synchronization with interrupt handler and
511  *	other threads.
512  *
513  *	LOCKING:
514  *	spin_lock_irqsave(host lock)
515  */
516 static inline void ata_tf_to_host(struct ata_port *ap,
517 				  const struct ata_taskfile *tf)
518 {
519 	ap->ops->sff_tf_load(ap, tf);
520 	ap->ops->sff_exec_command(ap, tf);
521 }
522 
523 /**
524  *	ata_sff_data_xfer - Transfer data by PIO
525  *	@qc: queued command
526  *	@buf: data buffer
527  *	@buflen: buffer length
528  *	@rw: read/write
529  *
530  *	Transfer data from/to the device data register by PIO.
531  *
532  *	LOCKING:
533  *	Inherited from caller.
534  *
535  *	RETURNS:
536  *	Bytes consumed.
537  */
538 unsigned int ata_sff_data_xfer(struct ata_queued_cmd *qc, unsigned char *buf,
539 			       unsigned int buflen, int rw)
540 {
541 	struct ata_port *ap = qc->dev->link->ap;
542 	void __iomem *data_addr = ap->ioaddr.data_addr;
543 	unsigned int words = buflen >> 1;
544 
545 	/* Transfer multiple of 2 bytes */
546 	if (rw == READ)
547 		ioread16_rep(data_addr, buf, words);
548 	else
549 		iowrite16_rep(data_addr, buf, words);
550 
551 	/* Transfer trailing byte, if any. */
552 	if (unlikely(buflen & 0x01)) {
553 		unsigned char pad[2] = { };
554 
555 		/* Point buf to the tail of buffer */
556 		buf += buflen - 1;
557 
558 		/*
559 		 * Use io*16_rep() accessors here as well to avoid pointlessly
560 		 * swapping bytes to and from on the big endian machines...
561 		 */
562 		if (rw == READ) {
563 			ioread16_rep(data_addr, pad, 1);
564 			*buf = pad[0];
565 		} else {
566 			pad[0] = *buf;
567 			iowrite16_rep(data_addr, pad, 1);
568 		}
569 		words++;
570 	}
571 
572 	return words << 1;
573 }
574 EXPORT_SYMBOL_GPL(ata_sff_data_xfer);
575 
576 /**
577  *	ata_sff_data_xfer32 - Transfer data by PIO
578  *	@qc: queued command
579  *	@buf: data buffer
580  *	@buflen: buffer length
581  *	@rw: read/write
582  *
583  *	Transfer data from/to the device data register by PIO using 32bit
584  *	I/O operations.
585  *
586  *	LOCKING:
587  *	Inherited from caller.
588  *
589  *	RETURNS:
590  *	Bytes consumed.
591  */
592 
593 unsigned int ata_sff_data_xfer32(struct ata_queued_cmd *qc, unsigned char *buf,
594 			       unsigned int buflen, int rw)
595 {
596 	struct ata_device *dev = qc->dev;
597 	struct ata_port *ap = dev->link->ap;
598 	void __iomem *data_addr = ap->ioaddr.data_addr;
599 	unsigned int words = buflen >> 2;
600 	int slop = buflen & 3;
601 
602 	if (!(ap->pflags & ATA_PFLAG_PIO32))
603 		return ata_sff_data_xfer(qc, buf, buflen, rw);
604 
605 	/* Transfer multiple of 4 bytes */
606 	if (rw == READ)
607 		ioread32_rep(data_addr, buf, words);
608 	else
609 		iowrite32_rep(data_addr, buf, words);
610 
611 	/* Transfer trailing bytes, if any */
612 	if (unlikely(slop)) {
613 		unsigned char pad[4] = { };
614 
615 		/* Point buf to the tail of buffer */
616 		buf += buflen - slop;
617 
618 		/*
619 		 * Use io*_rep() accessors here as well to avoid pointlessly
620 		 * swapping bytes to and from on the big endian machines...
621 		 */
622 		if (rw == READ) {
623 			if (slop < 3)
624 				ioread16_rep(data_addr, pad, 1);
625 			else
626 				ioread32_rep(data_addr, pad, 1);
627 			memcpy(buf, pad, slop);
628 		} else {
629 			memcpy(pad, buf, slop);
630 			if (slop < 3)
631 				iowrite16_rep(data_addr, pad, 1);
632 			else
633 				iowrite32_rep(data_addr, pad, 1);
634 		}
635 	}
636 	return (buflen + 1) & ~1;
637 }
638 EXPORT_SYMBOL_GPL(ata_sff_data_xfer32);
639 
640 /**
641  *	ata_pio_sector - Transfer a sector of data.
642  *	@qc: Command on going
643  *
644  *	Transfer qc->sect_size bytes of data from/to the ATA device.
645  *
646  *	LOCKING:
647  *	Inherited from caller.
648  */
649 static void ata_pio_sector(struct ata_queued_cmd *qc)
650 {
651 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
652 	struct ata_port *ap = qc->ap;
653 	struct page *page;
654 	unsigned int offset;
655 	unsigned char *buf;
656 
657 	if (!qc->cursg) {
658 		qc->curbytes = qc->nbytes;
659 		return;
660 	}
661 	if (qc->curbytes == qc->nbytes - qc->sect_size)
662 		ap->hsm_task_state = HSM_ST_LAST;
663 
664 	page = sg_page(qc->cursg);
665 	offset = qc->cursg->offset + qc->cursg_ofs;
666 
667 	/* get the current page and offset */
668 	page = nth_page(page, (offset >> PAGE_SHIFT));
669 	offset %= PAGE_SIZE;
670 
671 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
672 
673 	/* do the actual data transfer */
674 	buf = kmap_atomic(page);
675 	ap->ops->sff_data_xfer(qc, buf + offset, qc->sect_size, do_write);
676 	kunmap_atomic(buf);
677 
678 	if (!do_write && !PageSlab(page))
679 		flush_dcache_page(page);
680 
681 	qc->curbytes += qc->sect_size;
682 	qc->cursg_ofs += qc->sect_size;
683 
684 	if (qc->cursg_ofs == qc->cursg->length) {
685 		qc->cursg = sg_next(qc->cursg);
686 		if (!qc->cursg)
687 			ap->hsm_task_state = HSM_ST_LAST;
688 		qc->cursg_ofs = 0;
689 	}
690 }
691 
692 /**
693  *	ata_pio_sectors - Transfer one or many sectors.
694  *	@qc: Command on going
695  *
696  *	Transfer one or many sectors of data from/to the
697  *	ATA device for the DRQ request.
698  *
699  *	LOCKING:
700  *	Inherited from caller.
701  */
702 static void ata_pio_sectors(struct ata_queued_cmd *qc)
703 {
704 	if (is_multi_taskfile(&qc->tf)) {
705 		/* READ/WRITE MULTIPLE */
706 		unsigned int nsect;
707 
708 		WARN_ON_ONCE(qc->dev->multi_count == 0);
709 
710 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
711 			    qc->dev->multi_count);
712 		while (nsect--)
713 			ata_pio_sector(qc);
714 	} else
715 		ata_pio_sector(qc);
716 
717 	ata_sff_sync(qc->ap); /* flush */
718 }
719 
720 /**
721  *	atapi_send_cdb - Write CDB bytes to hardware
722  *	@ap: Port to which ATAPI device is attached.
723  *	@qc: Taskfile currently active
724  *
725  *	When device has indicated its readiness to accept
726  *	a CDB, this function is called.  Send the CDB.
727  *
728  *	LOCKING:
729  *	caller.
730  */
731 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
732 {
733 	/* send SCSI cdb */
734 	DPRINTK("send cdb\n");
735 	WARN_ON_ONCE(qc->dev->cdb_len < 12);
736 
737 	ap->ops->sff_data_xfer(qc, qc->cdb, qc->dev->cdb_len, 1);
738 	ata_sff_sync(ap);
739 	/* FIXME: If the CDB is for DMA do we need to do the transition delay
740 	   or is bmdma_start guaranteed to do it ? */
741 	switch (qc->tf.protocol) {
742 	case ATAPI_PROT_PIO:
743 		ap->hsm_task_state = HSM_ST;
744 		break;
745 	case ATAPI_PROT_NODATA:
746 		ap->hsm_task_state = HSM_ST_LAST;
747 		break;
748 #ifdef CONFIG_ATA_BMDMA
749 	case ATAPI_PROT_DMA:
750 		ap->hsm_task_state = HSM_ST_LAST;
751 		/* initiate bmdma */
752 		ap->ops->bmdma_start(qc);
753 		break;
754 #endif /* CONFIG_ATA_BMDMA */
755 	default:
756 		BUG();
757 	}
758 }
759 
760 /**
761  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
762  *	@qc: Command on going
763  *	@bytes: number of bytes
764  *
765  *	Transfer Transfer data from/to the ATAPI device.
766  *
767  *	LOCKING:
768  *	Inherited from caller.
769  *
770  */
771 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
772 {
773 	int rw = (qc->tf.flags & ATA_TFLAG_WRITE) ? WRITE : READ;
774 	struct ata_port *ap = qc->ap;
775 	struct ata_device *dev = qc->dev;
776 	struct ata_eh_info *ehi = &dev->link->eh_info;
777 	struct scatterlist *sg;
778 	struct page *page;
779 	unsigned char *buf;
780 	unsigned int offset, count, consumed;
781 
782 next_sg:
783 	sg = qc->cursg;
784 	if (unlikely(!sg)) {
785 		ata_ehi_push_desc(ehi, "unexpected or too much trailing data "
786 				  "buf=%u cur=%u bytes=%u",
787 				  qc->nbytes, qc->curbytes, bytes);
788 		return -1;
789 	}
790 
791 	page = sg_page(sg);
792 	offset = sg->offset + qc->cursg_ofs;
793 
794 	/* get the current page and offset */
795 	page = nth_page(page, (offset >> PAGE_SHIFT));
796 	offset %= PAGE_SIZE;
797 
798 	/* don't overrun current sg */
799 	count = min(sg->length - qc->cursg_ofs, bytes);
800 
801 	/* don't cross page boundaries */
802 	count = min(count, (unsigned int)PAGE_SIZE - offset);
803 
804 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
805 
806 	/* do the actual data transfer */
807 	buf = kmap_atomic(page);
808 	consumed = ap->ops->sff_data_xfer(qc, buf + offset, count, rw);
809 	kunmap_atomic(buf);
810 
811 	bytes -= min(bytes, consumed);
812 	qc->curbytes += count;
813 	qc->cursg_ofs += count;
814 
815 	if (qc->cursg_ofs == sg->length) {
816 		qc->cursg = sg_next(qc->cursg);
817 		qc->cursg_ofs = 0;
818 	}
819 
820 	/*
821 	 * There used to be a  WARN_ON_ONCE(qc->cursg && count != consumed);
822 	 * Unfortunately __atapi_pio_bytes doesn't know enough to do the WARN
823 	 * check correctly as it doesn't know if it is the last request being
824 	 * made. Somebody should implement a proper sanity check.
825 	 */
826 	if (bytes)
827 		goto next_sg;
828 	return 0;
829 }
830 
831 /**
832  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
833  *	@qc: Command on going
834  *
835  *	Transfer Transfer data from/to the ATAPI device.
836  *
837  *	LOCKING:
838  *	Inherited from caller.
839  */
840 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
841 {
842 	struct ata_port *ap = qc->ap;
843 	struct ata_device *dev = qc->dev;
844 	struct ata_eh_info *ehi = &dev->link->eh_info;
845 	unsigned int ireason, bc_lo, bc_hi, bytes;
846 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
847 
848 	/* Abuse qc->result_tf for temp storage of intermediate TF
849 	 * here to save some kernel stack usage.
850 	 * For normal completion, qc->result_tf is not relevant. For
851 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
852 	 * So, the correctness of qc->result_tf is not affected.
853 	 */
854 	ap->ops->sff_tf_read(ap, &qc->result_tf);
855 	ireason = qc->result_tf.nsect;
856 	bc_lo = qc->result_tf.lbam;
857 	bc_hi = qc->result_tf.lbah;
858 	bytes = (bc_hi << 8) | bc_lo;
859 
860 	/* shall be cleared to zero, indicating xfer of data */
861 	if (unlikely(ireason & ATAPI_COD))
862 		goto atapi_check;
863 
864 	/* make sure transfer direction matches expected */
865 	i_write = ((ireason & ATAPI_IO) == 0) ? 1 : 0;
866 	if (unlikely(do_write != i_write))
867 		goto atapi_check;
868 
869 	if (unlikely(!bytes))
870 		goto atapi_check;
871 
872 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
873 
874 	if (unlikely(__atapi_pio_bytes(qc, bytes)))
875 		goto err_out;
876 	ata_sff_sync(ap); /* flush */
877 
878 	return;
879 
880  atapi_check:
881 	ata_ehi_push_desc(ehi, "ATAPI check failed (ireason=0x%x bytes=%u)",
882 			  ireason, bytes);
883  err_out:
884 	qc->err_mask |= AC_ERR_HSM;
885 	ap->hsm_task_state = HSM_ST_ERR;
886 }
887 
888 /**
889  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
890  *	@ap: the target ata_port
891  *	@qc: qc on going
892  *
893  *	RETURNS:
894  *	1 if ok in workqueue, 0 otherwise.
895  */
896 static inline int ata_hsm_ok_in_wq(struct ata_port *ap,
897 						struct ata_queued_cmd *qc)
898 {
899 	if (qc->tf.flags & ATA_TFLAG_POLLING)
900 		return 1;
901 
902 	if (ap->hsm_task_state == HSM_ST_FIRST) {
903 		if (qc->tf.protocol == ATA_PROT_PIO &&
904 		   (qc->tf.flags & ATA_TFLAG_WRITE))
905 		    return 1;
906 
907 		if (ata_is_atapi(qc->tf.protocol) &&
908 		   !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
909 			return 1;
910 	}
911 
912 	return 0;
913 }
914 
915 /**
916  *	ata_hsm_qc_complete - finish a qc running on standard HSM
917  *	@qc: Command to complete
918  *	@in_wq: 1 if called from workqueue, 0 otherwise
919  *
920  *	Finish @qc which is running on standard HSM.
921  *
922  *	LOCKING:
923  *	If @in_wq is zero, spin_lock_irqsave(host lock).
924  *	Otherwise, none on entry and grabs host lock.
925  */
926 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
927 {
928 	struct ata_port *ap = qc->ap;
929 
930 	if (ap->ops->error_handler) {
931 		if (in_wq) {
932 			/* EH might have kicked in while host lock is
933 			 * released.
934 			 */
935 			qc = ata_qc_from_tag(ap, qc->tag);
936 			if (qc) {
937 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
938 					ata_sff_irq_on(ap);
939 					ata_qc_complete(qc);
940 				} else
941 					ata_port_freeze(ap);
942 			}
943 		} else {
944 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
945 				ata_qc_complete(qc);
946 			else
947 				ata_port_freeze(ap);
948 		}
949 	} else {
950 		if (in_wq) {
951 			ata_sff_irq_on(ap);
952 			ata_qc_complete(qc);
953 		} else
954 			ata_qc_complete(qc);
955 	}
956 }
957 
958 /**
959  *	ata_sff_hsm_move - move the HSM to the next state.
960  *	@ap: the target ata_port
961  *	@qc: qc on going
962  *	@status: current device status
963  *	@in_wq: 1 if called from workqueue, 0 otherwise
964  *
965  *	RETURNS:
966  *	1 when poll next status needed, 0 otherwise.
967  */
968 int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
969 		     u8 status, int in_wq)
970 {
971 	struct ata_link *link = qc->dev->link;
972 	struct ata_eh_info *ehi = &link->eh_info;
973 	int poll_next;
974 
975 	lockdep_assert_held(ap->lock);
976 
977 	WARN_ON_ONCE((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
978 
979 	/* Make sure ata_sff_qc_issue() does not throw things
980 	 * like DMA polling into the workqueue. Notice that
981 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
982 	 */
983 	WARN_ON_ONCE(in_wq != ata_hsm_ok_in_wq(ap, qc));
984 
985 fsm_start:
986 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
987 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
988 
989 	switch (ap->hsm_task_state) {
990 	case HSM_ST_FIRST:
991 		/* Send first data block or PACKET CDB */
992 
993 		/* If polling, we will stay in the work queue after
994 		 * sending the data. Otherwise, interrupt handler
995 		 * takes over after sending the data.
996 		 */
997 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
998 
999 		/* check device status */
1000 		if (unlikely((status & ATA_DRQ) == 0)) {
1001 			/* handle BSY=0, DRQ=0 as error */
1002 			if (likely(status & (ATA_ERR | ATA_DF)))
1003 				/* device stops HSM for abort/error */
1004 				qc->err_mask |= AC_ERR_DEV;
1005 			else {
1006 				/* HSM violation. Let EH handle this */
1007 				ata_ehi_push_desc(ehi,
1008 					"ST_FIRST: !(DRQ|ERR|DF)");
1009 				qc->err_mask |= AC_ERR_HSM;
1010 			}
1011 
1012 			ap->hsm_task_state = HSM_ST_ERR;
1013 			goto fsm_start;
1014 		}
1015 
1016 		/* Device should not ask for data transfer (DRQ=1)
1017 		 * when it finds something wrong.
1018 		 * We ignore DRQ here and stop the HSM by
1019 		 * changing hsm_task_state to HSM_ST_ERR and
1020 		 * let the EH abort the command or reset the device.
1021 		 */
1022 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
1023 			/* Some ATAPI tape drives forget to clear the ERR bit
1024 			 * when doing the next command (mostly request sense).
1025 			 * We ignore ERR here to workaround and proceed sending
1026 			 * the CDB.
1027 			 */
1028 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
1029 				ata_ehi_push_desc(ehi, "ST_FIRST: "
1030 					"DRQ=1 with device error, "
1031 					"dev_stat 0x%X", status);
1032 				qc->err_mask |= AC_ERR_HSM;
1033 				ap->hsm_task_state = HSM_ST_ERR;
1034 				goto fsm_start;
1035 			}
1036 		}
1037 
1038 		if (qc->tf.protocol == ATA_PROT_PIO) {
1039 			/* PIO data out protocol.
1040 			 * send first data block.
1041 			 */
1042 
1043 			/* ata_pio_sectors() might change the state
1044 			 * to HSM_ST_LAST. so, the state is changed here
1045 			 * before ata_pio_sectors().
1046 			 */
1047 			ap->hsm_task_state = HSM_ST;
1048 			ata_pio_sectors(qc);
1049 		} else
1050 			/* send CDB */
1051 			atapi_send_cdb(ap, qc);
1052 
1053 		/* if polling, ata_sff_pio_task() handles the rest.
1054 		 * otherwise, interrupt handler takes over from here.
1055 		 */
1056 		break;
1057 
1058 	case HSM_ST:
1059 		/* complete command or read/write the data register */
1060 		if (qc->tf.protocol == ATAPI_PROT_PIO) {
1061 			/* ATAPI PIO protocol */
1062 			if ((status & ATA_DRQ) == 0) {
1063 				/* No more data to transfer or device error.
1064 				 * Device error will be tagged in HSM_ST_LAST.
1065 				 */
1066 				ap->hsm_task_state = HSM_ST_LAST;
1067 				goto fsm_start;
1068 			}
1069 
1070 			/* Device should not ask for data transfer (DRQ=1)
1071 			 * when it finds something wrong.
1072 			 * We ignore DRQ here and stop the HSM by
1073 			 * changing hsm_task_state to HSM_ST_ERR and
1074 			 * let the EH abort the command or reset the device.
1075 			 */
1076 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1077 				ata_ehi_push_desc(ehi, "ST-ATAPI: "
1078 					"DRQ=1 with device error, "
1079 					"dev_stat 0x%X", status);
1080 				qc->err_mask |= AC_ERR_HSM;
1081 				ap->hsm_task_state = HSM_ST_ERR;
1082 				goto fsm_start;
1083 			}
1084 
1085 			atapi_pio_bytes(qc);
1086 
1087 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
1088 				/* bad ireason reported by device */
1089 				goto fsm_start;
1090 
1091 		} else {
1092 			/* ATA PIO protocol */
1093 			if (unlikely((status & ATA_DRQ) == 0)) {
1094 				/* handle BSY=0, DRQ=0 as error */
1095 				if (likely(status & (ATA_ERR | ATA_DF))) {
1096 					/* device stops HSM for abort/error */
1097 					qc->err_mask |= AC_ERR_DEV;
1098 
1099 					/* If diagnostic failed and this is
1100 					 * IDENTIFY, it's likely a phantom
1101 					 * device.  Mark hint.
1102 					 */
1103 					if (qc->dev->horkage &
1104 					    ATA_HORKAGE_DIAGNOSTIC)
1105 						qc->err_mask |=
1106 							AC_ERR_NODEV_HINT;
1107 				} else {
1108 					/* HSM violation. Let EH handle this.
1109 					 * Phantom devices also trigger this
1110 					 * condition.  Mark hint.
1111 					 */
1112 					ata_ehi_push_desc(ehi, "ST-ATA: "
1113 						"DRQ=0 without device error, "
1114 						"dev_stat 0x%X", status);
1115 					qc->err_mask |= AC_ERR_HSM |
1116 							AC_ERR_NODEV_HINT;
1117 				}
1118 
1119 				ap->hsm_task_state = HSM_ST_ERR;
1120 				goto fsm_start;
1121 			}
1122 
1123 			/* For PIO reads, some devices may ask for
1124 			 * data transfer (DRQ=1) alone with ERR=1.
1125 			 * We respect DRQ here and transfer one
1126 			 * block of junk data before changing the
1127 			 * hsm_task_state to HSM_ST_ERR.
1128 			 *
1129 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
1130 			 * sense since the data block has been
1131 			 * transferred to the device.
1132 			 */
1133 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1134 				/* data might be corrputed */
1135 				qc->err_mask |= AC_ERR_DEV;
1136 
1137 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
1138 					ata_pio_sectors(qc);
1139 					status = ata_wait_idle(ap);
1140 				}
1141 
1142 				if (status & (ATA_BUSY | ATA_DRQ)) {
1143 					ata_ehi_push_desc(ehi, "ST-ATA: "
1144 						"BUSY|DRQ persists on ERR|DF, "
1145 						"dev_stat 0x%X", status);
1146 					qc->err_mask |= AC_ERR_HSM;
1147 				}
1148 
1149 				/* There are oddball controllers with
1150 				 * status register stuck at 0x7f and
1151 				 * lbal/m/h at zero which makes it
1152 				 * pass all other presence detection
1153 				 * mechanisms we have.  Set NODEV_HINT
1154 				 * for it.  Kernel bz#7241.
1155 				 */
1156 				if (status == 0x7f)
1157 					qc->err_mask |= AC_ERR_NODEV_HINT;
1158 
1159 				/* ata_pio_sectors() might change the
1160 				 * state to HSM_ST_LAST. so, the state
1161 				 * is changed after ata_pio_sectors().
1162 				 */
1163 				ap->hsm_task_state = HSM_ST_ERR;
1164 				goto fsm_start;
1165 			}
1166 
1167 			ata_pio_sectors(qc);
1168 
1169 			if (ap->hsm_task_state == HSM_ST_LAST &&
1170 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
1171 				/* all data read */
1172 				status = ata_wait_idle(ap);
1173 				goto fsm_start;
1174 			}
1175 		}
1176 
1177 		poll_next = 1;
1178 		break;
1179 
1180 	case HSM_ST_LAST:
1181 		if (unlikely(!ata_ok(status))) {
1182 			qc->err_mask |= __ac_err_mask(status);
1183 			ap->hsm_task_state = HSM_ST_ERR;
1184 			goto fsm_start;
1185 		}
1186 
1187 		/* no more data to transfer */
1188 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
1189 			ap->print_id, qc->dev->devno, status);
1190 
1191 		WARN_ON_ONCE(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
1192 
1193 		ap->hsm_task_state = HSM_ST_IDLE;
1194 
1195 		/* complete taskfile transaction */
1196 		ata_hsm_qc_complete(qc, in_wq);
1197 
1198 		poll_next = 0;
1199 		break;
1200 
1201 	case HSM_ST_ERR:
1202 		ap->hsm_task_state = HSM_ST_IDLE;
1203 
1204 		/* complete taskfile transaction */
1205 		ata_hsm_qc_complete(qc, in_wq);
1206 
1207 		poll_next = 0;
1208 		break;
1209 	default:
1210 		poll_next = 0;
1211 		WARN(true, "ata%d: SFF host state machine in invalid state %d",
1212 		     ap->print_id, ap->hsm_task_state);
1213 	}
1214 
1215 	return poll_next;
1216 }
1217 EXPORT_SYMBOL_GPL(ata_sff_hsm_move);
1218 
1219 void ata_sff_queue_work(struct work_struct *work)
1220 {
1221 	queue_work(ata_sff_wq, work);
1222 }
1223 EXPORT_SYMBOL_GPL(ata_sff_queue_work);
1224 
1225 void ata_sff_queue_delayed_work(struct delayed_work *dwork, unsigned long delay)
1226 {
1227 	queue_delayed_work(ata_sff_wq, dwork, delay);
1228 }
1229 EXPORT_SYMBOL_GPL(ata_sff_queue_delayed_work);
1230 
1231 void ata_sff_queue_pio_task(struct ata_link *link, unsigned long delay)
1232 {
1233 	struct ata_port *ap = link->ap;
1234 
1235 	WARN_ON((ap->sff_pio_task_link != NULL) &&
1236 		(ap->sff_pio_task_link != link));
1237 	ap->sff_pio_task_link = link;
1238 
1239 	/* may fail if ata_sff_flush_pio_task() in progress */
1240 	ata_sff_queue_delayed_work(&ap->sff_pio_task, msecs_to_jiffies(delay));
1241 }
1242 EXPORT_SYMBOL_GPL(ata_sff_queue_pio_task);
1243 
1244 void ata_sff_flush_pio_task(struct ata_port *ap)
1245 {
1246 	DPRINTK("ENTER\n");
1247 
1248 	cancel_delayed_work_sync(&ap->sff_pio_task);
1249 
1250 	/*
1251 	 * We wanna reset the HSM state to IDLE.  If we do so without
1252 	 * grabbing the port lock, critical sections protected by it which
1253 	 * expect the HSM state to stay stable may get surprised.  For
1254 	 * example, we may set IDLE in between the time
1255 	 * __ata_sff_port_intr() checks for HSM_ST_IDLE and before it calls
1256 	 * ata_sff_hsm_move() causing ata_sff_hsm_move() to BUG().
1257 	 */
1258 	spin_lock_irq(ap->lock);
1259 	ap->hsm_task_state = HSM_ST_IDLE;
1260 	spin_unlock_irq(ap->lock);
1261 
1262 	ap->sff_pio_task_link = NULL;
1263 
1264 	if (ata_msg_ctl(ap))
1265 		ata_port_dbg(ap, "%s: EXIT\n", __func__);
1266 }
1267 
1268 static void ata_sff_pio_task(struct work_struct *work)
1269 {
1270 	struct ata_port *ap =
1271 		container_of(work, struct ata_port, sff_pio_task.work);
1272 	struct ata_link *link = ap->sff_pio_task_link;
1273 	struct ata_queued_cmd *qc;
1274 	u8 status;
1275 	int poll_next;
1276 
1277 	spin_lock_irq(ap->lock);
1278 
1279 	BUG_ON(ap->sff_pio_task_link == NULL);
1280 	/* qc can be NULL if timeout occurred */
1281 	qc = ata_qc_from_tag(ap, link->active_tag);
1282 	if (!qc) {
1283 		ap->sff_pio_task_link = NULL;
1284 		goto out_unlock;
1285 	}
1286 
1287 fsm_start:
1288 	WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
1289 
1290 	/*
1291 	 * This is purely heuristic.  This is a fast path.
1292 	 * Sometimes when we enter, BSY will be cleared in
1293 	 * a chk-status or two.  If not, the drive is probably seeking
1294 	 * or something.  Snooze for a couple msecs, then
1295 	 * chk-status again.  If still busy, queue delayed work.
1296 	 */
1297 	status = ata_sff_busy_wait(ap, ATA_BUSY, 5);
1298 	if (status & ATA_BUSY) {
1299 		spin_unlock_irq(ap->lock);
1300 		ata_msleep(ap, 2);
1301 		spin_lock_irq(ap->lock);
1302 
1303 		status = ata_sff_busy_wait(ap, ATA_BUSY, 10);
1304 		if (status & ATA_BUSY) {
1305 			ata_sff_queue_pio_task(link, ATA_SHORT_PAUSE);
1306 			goto out_unlock;
1307 		}
1308 	}
1309 
1310 	/*
1311 	 * hsm_move() may trigger another command to be processed.
1312 	 * clean the link beforehand.
1313 	 */
1314 	ap->sff_pio_task_link = NULL;
1315 	/* move the HSM */
1316 	poll_next = ata_sff_hsm_move(ap, qc, status, 1);
1317 
1318 	/* another command or interrupt handler
1319 	 * may be running at this point.
1320 	 */
1321 	if (poll_next)
1322 		goto fsm_start;
1323 out_unlock:
1324 	spin_unlock_irq(ap->lock);
1325 }
1326 
1327 /**
1328  *	ata_sff_qc_issue - issue taskfile to a SFF controller
1329  *	@qc: command to issue to device
1330  *
1331  *	This function issues a PIO or NODATA command to a SFF
1332  *	controller.
1333  *
1334  *	LOCKING:
1335  *	spin_lock_irqsave(host lock)
1336  *
1337  *	RETURNS:
1338  *	Zero on success, AC_ERR_* mask on failure
1339  */
1340 unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
1341 {
1342 	struct ata_port *ap = qc->ap;
1343 	struct ata_link *link = qc->dev->link;
1344 
1345 	/* Use polling pio if the LLD doesn't handle
1346 	 * interrupt driven pio and atapi CDB interrupt.
1347 	 */
1348 	if (ap->flags & ATA_FLAG_PIO_POLLING)
1349 		qc->tf.flags |= ATA_TFLAG_POLLING;
1350 
1351 	/* select the device */
1352 	ata_dev_select(ap, qc->dev->devno, 1, 0);
1353 
1354 	/* start the command */
1355 	switch (qc->tf.protocol) {
1356 	case ATA_PROT_NODATA:
1357 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1358 			ata_qc_set_polling(qc);
1359 
1360 		ata_tf_to_host(ap, &qc->tf);
1361 		ap->hsm_task_state = HSM_ST_LAST;
1362 
1363 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1364 			ata_sff_queue_pio_task(link, 0);
1365 
1366 		break;
1367 
1368 	case ATA_PROT_PIO:
1369 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1370 			ata_qc_set_polling(qc);
1371 
1372 		ata_tf_to_host(ap, &qc->tf);
1373 
1374 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
1375 			/* PIO data out protocol */
1376 			ap->hsm_task_state = HSM_ST_FIRST;
1377 			ata_sff_queue_pio_task(link, 0);
1378 
1379 			/* always send first data block using the
1380 			 * ata_sff_pio_task() codepath.
1381 			 */
1382 		} else {
1383 			/* PIO data in protocol */
1384 			ap->hsm_task_state = HSM_ST;
1385 
1386 			if (qc->tf.flags & ATA_TFLAG_POLLING)
1387 				ata_sff_queue_pio_task(link, 0);
1388 
1389 			/* if polling, ata_sff_pio_task() handles the
1390 			 * rest.  otherwise, interrupt handler takes
1391 			 * over from here.
1392 			 */
1393 		}
1394 
1395 		break;
1396 
1397 	case ATAPI_PROT_PIO:
1398 	case ATAPI_PROT_NODATA:
1399 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1400 			ata_qc_set_polling(qc);
1401 
1402 		ata_tf_to_host(ap, &qc->tf);
1403 
1404 		ap->hsm_task_state = HSM_ST_FIRST;
1405 
1406 		/* send cdb by polling if no cdb interrupt */
1407 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
1408 		    (qc->tf.flags & ATA_TFLAG_POLLING))
1409 			ata_sff_queue_pio_task(link, 0);
1410 		break;
1411 
1412 	default:
1413 		return AC_ERR_SYSTEM;
1414 	}
1415 
1416 	return 0;
1417 }
1418 EXPORT_SYMBOL_GPL(ata_sff_qc_issue);
1419 
1420 /**
1421  *	ata_sff_qc_fill_rtf - fill result TF using ->sff_tf_read
1422  *	@qc: qc to fill result TF for
1423  *
1424  *	@qc is finished and result TF needs to be filled.  Fill it
1425  *	using ->sff_tf_read.
1426  *
1427  *	LOCKING:
1428  *	spin_lock_irqsave(host lock)
1429  *
1430  *	RETURNS:
1431  *	true indicating that result TF is successfully filled.
1432  */
1433 bool ata_sff_qc_fill_rtf(struct ata_queued_cmd *qc)
1434 {
1435 	qc->ap->ops->sff_tf_read(qc->ap, &qc->result_tf);
1436 	return true;
1437 }
1438 EXPORT_SYMBOL_GPL(ata_sff_qc_fill_rtf);
1439 
1440 static unsigned int ata_sff_idle_irq(struct ata_port *ap)
1441 {
1442 	ap->stats.idle_irq++;
1443 
1444 #ifdef ATA_IRQ_TRAP
1445 	if ((ap->stats.idle_irq % 1000) == 0) {
1446 		ap->ops->sff_check_status(ap);
1447 		if (ap->ops->sff_irq_clear)
1448 			ap->ops->sff_irq_clear(ap);
1449 		ata_port_warn(ap, "irq trap\n");
1450 		return 1;
1451 	}
1452 #endif
1453 	return 0;	/* irq not handled */
1454 }
1455 
1456 static unsigned int __ata_sff_port_intr(struct ata_port *ap,
1457 					struct ata_queued_cmd *qc,
1458 					bool hsmv_on_idle)
1459 {
1460 	u8 status;
1461 
1462 	VPRINTK("ata%u: protocol %d task_state %d\n",
1463 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
1464 
1465 	/* Check whether we are expecting interrupt in this state */
1466 	switch (ap->hsm_task_state) {
1467 	case HSM_ST_FIRST:
1468 		/* Some pre-ATAPI-4 devices assert INTRQ
1469 		 * at this state when ready to receive CDB.
1470 		 */
1471 
1472 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
1473 		 * The flag was turned on only for atapi devices.  No
1474 		 * need to check ata_is_atapi(qc->tf.protocol) again.
1475 		 */
1476 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
1477 			return ata_sff_idle_irq(ap);
1478 		break;
1479 	case HSM_ST_IDLE:
1480 		return ata_sff_idle_irq(ap);
1481 	default:
1482 		break;
1483 	}
1484 
1485 	/* check main status, clearing INTRQ if needed */
1486 	status = ata_sff_irq_status(ap);
1487 	if (status & ATA_BUSY) {
1488 		if (hsmv_on_idle) {
1489 			/* BMDMA engine is already stopped, we're screwed */
1490 			qc->err_mask |= AC_ERR_HSM;
1491 			ap->hsm_task_state = HSM_ST_ERR;
1492 		} else
1493 			return ata_sff_idle_irq(ap);
1494 	}
1495 
1496 	/* clear irq events */
1497 	if (ap->ops->sff_irq_clear)
1498 		ap->ops->sff_irq_clear(ap);
1499 
1500 	ata_sff_hsm_move(ap, qc, status, 0);
1501 
1502 	return 1;	/* irq handled */
1503 }
1504 
1505 /**
1506  *	ata_sff_port_intr - Handle SFF port interrupt
1507  *	@ap: Port on which interrupt arrived (possibly...)
1508  *	@qc: Taskfile currently active in engine
1509  *
1510  *	Handle port interrupt for given queued command.
1511  *
1512  *	LOCKING:
1513  *	spin_lock_irqsave(host lock)
1514  *
1515  *	RETURNS:
1516  *	One if interrupt was handled, zero if not (shared irq).
1517  */
1518 unsigned int ata_sff_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
1519 {
1520 	return __ata_sff_port_intr(ap, qc, false);
1521 }
1522 EXPORT_SYMBOL_GPL(ata_sff_port_intr);
1523 
1524 static inline irqreturn_t __ata_sff_interrupt(int irq, void *dev_instance,
1525 	unsigned int (*port_intr)(struct ata_port *, struct ata_queued_cmd *))
1526 {
1527 	struct ata_host *host = dev_instance;
1528 	bool retried = false;
1529 	unsigned int i;
1530 	unsigned int handled, idle, polling;
1531 	unsigned long flags;
1532 
1533 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
1534 	spin_lock_irqsave(&host->lock, flags);
1535 
1536 retry:
1537 	handled = idle = polling = 0;
1538 	for (i = 0; i < host->n_ports; i++) {
1539 		struct ata_port *ap = host->ports[i];
1540 		struct ata_queued_cmd *qc;
1541 
1542 		qc = ata_qc_from_tag(ap, ap->link.active_tag);
1543 		if (qc) {
1544 			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
1545 				handled |= port_intr(ap, qc);
1546 			else
1547 				polling |= 1 << i;
1548 		} else
1549 			idle |= 1 << i;
1550 	}
1551 
1552 	/*
1553 	 * If no port was expecting IRQ but the controller is actually
1554 	 * asserting IRQ line, nobody cared will ensue.  Check IRQ
1555 	 * pending status if available and clear spurious IRQ.
1556 	 */
1557 	if (!handled && !retried) {
1558 		bool retry = false;
1559 
1560 		for (i = 0; i < host->n_ports; i++) {
1561 			struct ata_port *ap = host->ports[i];
1562 
1563 			if (polling & (1 << i))
1564 				continue;
1565 
1566 			if (!ap->ops->sff_irq_check ||
1567 			    !ap->ops->sff_irq_check(ap))
1568 				continue;
1569 
1570 			if (idle & (1 << i)) {
1571 				ap->ops->sff_check_status(ap);
1572 				if (ap->ops->sff_irq_clear)
1573 					ap->ops->sff_irq_clear(ap);
1574 			} else {
1575 				/* clear INTRQ and check if BUSY cleared */
1576 				if (!(ap->ops->sff_check_status(ap) & ATA_BUSY))
1577 					retry |= true;
1578 				/*
1579 				 * With command in flight, we can't do
1580 				 * sff_irq_clear() w/o racing with completion.
1581 				 */
1582 			}
1583 		}
1584 
1585 		if (retry) {
1586 			retried = true;
1587 			goto retry;
1588 		}
1589 	}
1590 
1591 	spin_unlock_irqrestore(&host->lock, flags);
1592 
1593 	return IRQ_RETVAL(handled);
1594 }
1595 
1596 /**
1597  *	ata_sff_interrupt - Default SFF ATA host interrupt handler
1598  *	@irq: irq line (unused)
1599  *	@dev_instance: pointer to our ata_host information structure
1600  *
1601  *	Default interrupt handler for PCI IDE devices.  Calls
1602  *	ata_sff_port_intr() for each port that is not disabled.
1603  *
1604  *	LOCKING:
1605  *	Obtains host lock during operation.
1606  *
1607  *	RETURNS:
1608  *	IRQ_NONE or IRQ_HANDLED.
1609  */
1610 irqreturn_t ata_sff_interrupt(int irq, void *dev_instance)
1611 {
1612 	return __ata_sff_interrupt(irq, dev_instance, ata_sff_port_intr);
1613 }
1614 EXPORT_SYMBOL_GPL(ata_sff_interrupt);
1615 
1616 /**
1617  *	ata_sff_lost_interrupt	-	Check for an apparent lost interrupt
1618  *	@ap: port that appears to have timed out
1619  *
1620  *	Called from the libata error handlers when the core code suspects
1621  *	an interrupt has been lost. If it has complete anything we can and
1622  *	then return. Interface must support altstatus for this faster
1623  *	recovery to occur.
1624  *
1625  *	Locking:
1626  *	Caller holds host lock
1627  */
1628 
1629 void ata_sff_lost_interrupt(struct ata_port *ap)
1630 {
1631 	u8 status;
1632 	struct ata_queued_cmd *qc;
1633 
1634 	/* Only one outstanding command per SFF channel */
1635 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
1636 	/* We cannot lose an interrupt on a non-existent or polled command */
1637 	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
1638 		return;
1639 	/* See if the controller thinks it is still busy - if so the command
1640 	   isn't a lost IRQ but is still in progress */
1641 	status = ata_sff_altstatus(ap);
1642 	if (status & ATA_BUSY)
1643 		return;
1644 
1645 	/* There was a command running, we are no longer busy and we have
1646 	   no interrupt. */
1647 	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
1648 								status);
1649 	/* Run the host interrupt logic as if the interrupt had not been
1650 	   lost */
1651 	ata_sff_port_intr(ap, qc);
1652 }
1653 EXPORT_SYMBOL_GPL(ata_sff_lost_interrupt);
1654 
1655 /**
1656  *	ata_sff_freeze - Freeze SFF controller port
1657  *	@ap: port to freeze
1658  *
1659  *	Freeze SFF controller port.
1660  *
1661  *	LOCKING:
1662  *	Inherited from caller.
1663  */
1664 void ata_sff_freeze(struct ata_port *ap)
1665 {
1666 	ap->ctl |= ATA_NIEN;
1667 	ap->last_ctl = ap->ctl;
1668 
1669 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr)
1670 		ata_sff_set_devctl(ap, ap->ctl);
1671 
1672 	/* Under certain circumstances, some controllers raise IRQ on
1673 	 * ATA_NIEN manipulation.  Also, many controllers fail to mask
1674 	 * previously pending IRQ on ATA_NIEN assertion.  Clear it.
1675 	 */
1676 	ap->ops->sff_check_status(ap);
1677 
1678 	if (ap->ops->sff_irq_clear)
1679 		ap->ops->sff_irq_clear(ap);
1680 }
1681 EXPORT_SYMBOL_GPL(ata_sff_freeze);
1682 
1683 /**
1684  *	ata_sff_thaw - Thaw SFF controller port
1685  *	@ap: port to thaw
1686  *
1687  *	Thaw SFF controller port.
1688  *
1689  *	LOCKING:
1690  *	Inherited from caller.
1691  */
1692 void ata_sff_thaw(struct ata_port *ap)
1693 {
1694 	/* clear & re-enable interrupts */
1695 	ap->ops->sff_check_status(ap);
1696 	if (ap->ops->sff_irq_clear)
1697 		ap->ops->sff_irq_clear(ap);
1698 	ata_sff_irq_on(ap);
1699 }
1700 EXPORT_SYMBOL_GPL(ata_sff_thaw);
1701 
1702 /**
1703  *	ata_sff_prereset - prepare SFF link for reset
1704  *	@link: SFF link to be reset
1705  *	@deadline: deadline jiffies for the operation
1706  *
1707  *	SFF link @link is about to be reset.  Initialize it.  It first
1708  *	calls ata_std_prereset() and wait for !BSY if the port is
1709  *	being softreset.
1710  *
1711  *	LOCKING:
1712  *	Kernel thread context (may sleep)
1713  *
1714  *	RETURNS:
1715  *	0 on success, -errno otherwise.
1716  */
1717 int ata_sff_prereset(struct ata_link *link, unsigned long deadline)
1718 {
1719 	struct ata_eh_context *ehc = &link->eh_context;
1720 	int rc;
1721 
1722 	rc = ata_std_prereset(link, deadline);
1723 	if (rc)
1724 		return rc;
1725 
1726 	/* if we're about to do hardreset, nothing more to do */
1727 	if (ehc->i.action & ATA_EH_HARDRESET)
1728 		return 0;
1729 
1730 	/* wait for !BSY if we don't know that no device is attached */
1731 	if (!ata_link_offline(link)) {
1732 		rc = ata_sff_wait_ready(link, deadline);
1733 		if (rc && rc != -ENODEV) {
1734 			ata_link_warn(link,
1735 				      "device not ready (errno=%d), forcing hardreset\n",
1736 				      rc);
1737 			ehc->i.action |= ATA_EH_HARDRESET;
1738 		}
1739 	}
1740 
1741 	return 0;
1742 }
1743 EXPORT_SYMBOL_GPL(ata_sff_prereset);
1744 
1745 /**
1746  *	ata_devchk - PATA device presence detection
1747  *	@ap: ATA channel to examine
1748  *	@device: Device to examine (starting at zero)
1749  *
1750  *	This technique was originally described in
1751  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
1752  *	later found its way into the ATA/ATAPI spec.
1753  *
1754  *	Write a pattern to the ATA shadow registers,
1755  *	and if a device is present, it will respond by
1756  *	correctly storing and echoing back the
1757  *	ATA shadow register contents.
1758  *
1759  *	LOCKING:
1760  *	caller.
1761  */
1762 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
1763 {
1764 	struct ata_ioports *ioaddr = &ap->ioaddr;
1765 	u8 nsect, lbal;
1766 
1767 	ap->ops->sff_dev_select(ap, device);
1768 
1769 	iowrite8(0x55, ioaddr->nsect_addr);
1770 	iowrite8(0xaa, ioaddr->lbal_addr);
1771 
1772 	iowrite8(0xaa, ioaddr->nsect_addr);
1773 	iowrite8(0x55, ioaddr->lbal_addr);
1774 
1775 	iowrite8(0x55, ioaddr->nsect_addr);
1776 	iowrite8(0xaa, ioaddr->lbal_addr);
1777 
1778 	nsect = ioread8(ioaddr->nsect_addr);
1779 	lbal = ioread8(ioaddr->lbal_addr);
1780 
1781 	if ((nsect == 0x55) && (lbal == 0xaa))
1782 		return 1;	/* we found a device */
1783 
1784 	return 0;		/* nothing found */
1785 }
1786 
1787 /**
1788  *	ata_sff_dev_classify - Parse returned ATA device signature
1789  *	@dev: ATA device to classify (starting at zero)
1790  *	@present: device seems present
1791  *	@r_err: Value of error register on completion
1792  *
1793  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
1794  *	an ATA/ATAPI-defined set of values is placed in the ATA
1795  *	shadow registers, indicating the results of device detection
1796  *	and diagnostics.
1797  *
1798  *	Select the ATA device, and read the values from the ATA shadow
1799  *	registers.  Then parse according to the Error register value,
1800  *	and the spec-defined values examined by ata_dev_classify().
1801  *
1802  *	LOCKING:
1803  *	caller.
1804  *
1805  *	RETURNS:
1806  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
1807  */
1808 unsigned int ata_sff_dev_classify(struct ata_device *dev, int present,
1809 				  u8 *r_err)
1810 {
1811 	struct ata_port *ap = dev->link->ap;
1812 	struct ata_taskfile tf;
1813 	unsigned int class;
1814 	u8 err;
1815 
1816 	ap->ops->sff_dev_select(ap, dev->devno);
1817 
1818 	memset(&tf, 0, sizeof(tf));
1819 
1820 	ap->ops->sff_tf_read(ap, &tf);
1821 	err = tf.feature;
1822 	if (r_err)
1823 		*r_err = err;
1824 
1825 	/* see if device passed diags: continue and warn later */
1826 	if (err == 0)
1827 		/* diagnostic fail : do nothing _YET_ */
1828 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
1829 	else if (err == 1)
1830 		/* do nothing */ ;
1831 	else if ((dev->devno == 0) && (err == 0x81))
1832 		/* do nothing */ ;
1833 	else
1834 		return ATA_DEV_NONE;
1835 
1836 	/* determine if device is ATA or ATAPI */
1837 	class = ata_dev_classify(&tf);
1838 
1839 	if (class == ATA_DEV_UNKNOWN) {
1840 		/* If the device failed diagnostic, it's likely to
1841 		 * have reported incorrect device signature too.
1842 		 * Assume ATA device if the device seems present but
1843 		 * device signature is invalid with diagnostic
1844 		 * failure.
1845 		 */
1846 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
1847 			class = ATA_DEV_ATA;
1848 		else
1849 			class = ATA_DEV_NONE;
1850 	} else if ((class == ATA_DEV_ATA) &&
1851 		   (ap->ops->sff_check_status(ap) == 0))
1852 		class = ATA_DEV_NONE;
1853 
1854 	return class;
1855 }
1856 EXPORT_SYMBOL_GPL(ata_sff_dev_classify);
1857 
1858 /**
1859  *	ata_sff_wait_after_reset - wait for devices to become ready after reset
1860  *	@link: SFF link which is just reset
1861  *	@devmask: mask of present devices
1862  *	@deadline: deadline jiffies for the operation
1863  *
1864  *	Wait devices attached to SFF @link to become ready after
1865  *	reset.  It contains preceding 150ms wait to avoid accessing TF
1866  *	status register too early.
1867  *
1868  *	LOCKING:
1869  *	Kernel thread context (may sleep).
1870  *
1871  *	RETURNS:
1872  *	0 on success, -ENODEV if some or all of devices in @devmask
1873  *	don't seem to exist.  -errno on other errors.
1874  */
1875 int ata_sff_wait_after_reset(struct ata_link *link, unsigned int devmask,
1876 			     unsigned long deadline)
1877 {
1878 	struct ata_port *ap = link->ap;
1879 	struct ata_ioports *ioaddr = &ap->ioaddr;
1880 	unsigned int dev0 = devmask & (1 << 0);
1881 	unsigned int dev1 = devmask & (1 << 1);
1882 	int rc, ret = 0;
1883 
1884 	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
1885 
1886 	/* always check readiness of the master device */
1887 	rc = ata_sff_wait_ready(link, deadline);
1888 	/* -ENODEV means the odd clown forgot the D7 pulldown resistor
1889 	 * and TF status is 0xff, bail out on it too.
1890 	 */
1891 	if (rc)
1892 		return rc;
1893 
1894 	/* if device 1 was found in ata_devchk, wait for register
1895 	 * access briefly, then wait for BSY to clear.
1896 	 */
1897 	if (dev1) {
1898 		int i;
1899 
1900 		ap->ops->sff_dev_select(ap, 1);
1901 
1902 		/* Wait for register access.  Some ATAPI devices fail
1903 		 * to set nsect/lbal after reset, so don't waste too
1904 		 * much time on it.  We're gonna wait for !BSY anyway.
1905 		 */
1906 		for (i = 0; i < 2; i++) {
1907 			u8 nsect, lbal;
1908 
1909 			nsect = ioread8(ioaddr->nsect_addr);
1910 			lbal = ioread8(ioaddr->lbal_addr);
1911 			if ((nsect == 1) && (lbal == 1))
1912 				break;
1913 			ata_msleep(ap, 50);	/* give drive a breather */
1914 		}
1915 
1916 		rc = ata_sff_wait_ready(link, deadline);
1917 		if (rc) {
1918 			if (rc != -ENODEV)
1919 				return rc;
1920 			ret = rc;
1921 		}
1922 	}
1923 
1924 	/* is all this really necessary? */
1925 	ap->ops->sff_dev_select(ap, 0);
1926 	if (dev1)
1927 		ap->ops->sff_dev_select(ap, 1);
1928 	if (dev0)
1929 		ap->ops->sff_dev_select(ap, 0);
1930 
1931 	return ret;
1932 }
1933 EXPORT_SYMBOL_GPL(ata_sff_wait_after_reset);
1934 
1935 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
1936 			     unsigned long deadline)
1937 {
1938 	struct ata_ioports *ioaddr = &ap->ioaddr;
1939 
1940 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
1941 
1942 	if (ap->ioaddr.ctl_addr) {
1943 		/* software reset.  causes dev0 to be selected */
1944 		iowrite8(ap->ctl, ioaddr->ctl_addr);
1945 		udelay(20);	/* FIXME: flush */
1946 		iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
1947 		udelay(20);	/* FIXME: flush */
1948 		iowrite8(ap->ctl, ioaddr->ctl_addr);
1949 		ap->last_ctl = ap->ctl;
1950 	}
1951 
1952 	/* wait the port to become ready */
1953 	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
1954 }
1955 
1956 /**
1957  *	ata_sff_softreset - reset host port via ATA SRST
1958  *	@link: ATA link to reset
1959  *	@classes: resulting classes of attached devices
1960  *	@deadline: deadline jiffies for the operation
1961  *
1962  *	Reset host port using ATA SRST.
1963  *
1964  *	LOCKING:
1965  *	Kernel thread context (may sleep)
1966  *
1967  *	RETURNS:
1968  *	0 on success, -errno otherwise.
1969  */
1970 int ata_sff_softreset(struct ata_link *link, unsigned int *classes,
1971 		      unsigned long deadline)
1972 {
1973 	struct ata_port *ap = link->ap;
1974 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
1975 	unsigned int devmask = 0;
1976 	int rc;
1977 	u8 err;
1978 
1979 	DPRINTK("ENTER\n");
1980 
1981 	/* determine if device 0/1 are present */
1982 	if (ata_devchk(ap, 0))
1983 		devmask |= (1 << 0);
1984 	if (slave_possible && ata_devchk(ap, 1))
1985 		devmask |= (1 << 1);
1986 
1987 	/* select device 0 again */
1988 	ap->ops->sff_dev_select(ap, 0);
1989 
1990 	/* issue bus reset */
1991 	DPRINTK("about to softreset, devmask=%x\n", devmask);
1992 	rc = ata_bus_softreset(ap, devmask, deadline);
1993 	/* if link is occupied, -ENODEV too is an error */
1994 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
1995 		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
1996 		return rc;
1997 	}
1998 
1999 	/* determine by signature whether we have ATA or ATAPI devices */
2000 	classes[0] = ata_sff_dev_classify(&link->device[0],
2001 					  devmask & (1 << 0), &err);
2002 	if (slave_possible && err != 0x81)
2003 		classes[1] = ata_sff_dev_classify(&link->device[1],
2004 						  devmask & (1 << 1), &err);
2005 
2006 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
2007 	return 0;
2008 }
2009 EXPORT_SYMBOL_GPL(ata_sff_softreset);
2010 
2011 /**
2012  *	sata_sff_hardreset - reset host port via SATA phy reset
2013  *	@link: link to reset
2014  *	@class: resulting class of attached device
2015  *	@deadline: deadline jiffies for the operation
2016  *
2017  *	SATA phy-reset host port using DET bits of SControl register,
2018  *	wait for !BSY and classify the attached device.
2019  *
2020  *	LOCKING:
2021  *	Kernel thread context (may sleep)
2022  *
2023  *	RETURNS:
2024  *	0 on success, -errno otherwise.
2025  */
2026 int sata_sff_hardreset(struct ata_link *link, unsigned int *class,
2027 		       unsigned long deadline)
2028 {
2029 	struct ata_eh_context *ehc = &link->eh_context;
2030 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
2031 	bool online;
2032 	int rc;
2033 
2034 	rc = sata_link_hardreset(link, timing, deadline, &online,
2035 				 ata_sff_check_ready);
2036 	if (online)
2037 		*class = ata_sff_dev_classify(link->device, 1, NULL);
2038 
2039 	DPRINTK("EXIT, class=%u\n", *class);
2040 	return rc;
2041 }
2042 EXPORT_SYMBOL_GPL(sata_sff_hardreset);
2043 
2044 /**
2045  *	ata_sff_postreset - SFF postreset callback
2046  *	@link: the target SFF ata_link
2047  *	@classes: classes of attached devices
2048  *
2049  *	This function is invoked after a successful reset.  It first
2050  *	calls ata_std_postreset() and performs SFF specific postreset
2051  *	processing.
2052  *
2053  *	LOCKING:
2054  *	Kernel thread context (may sleep)
2055  */
2056 void ata_sff_postreset(struct ata_link *link, unsigned int *classes)
2057 {
2058 	struct ata_port *ap = link->ap;
2059 
2060 	ata_std_postreset(link, classes);
2061 
2062 	/* is double-select really necessary? */
2063 	if (classes[0] != ATA_DEV_NONE)
2064 		ap->ops->sff_dev_select(ap, 1);
2065 	if (classes[1] != ATA_DEV_NONE)
2066 		ap->ops->sff_dev_select(ap, 0);
2067 
2068 	/* bail out if no device is present */
2069 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
2070 		DPRINTK("EXIT, no device\n");
2071 		return;
2072 	}
2073 
2074 	/* set up device control */
2075 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr) {
2076 		ata_sff_set_devctl(ap, ap->ctl);
2077 		ap->last_ctl = ap->ctl;
2078 	}
2079 }
2080 EXPORT_SYMBOL_GPL(ata_sff_postreset);
2081 
2082 /**
2083  *	ata_sff_drain_fifo - Stock FIFO drain logic for SFF controllers
2084  *	@qc: command
2085  *
2086  *	Drain the FIFO and device of any stuck data following a command
2087  *	failing to complete. In some cases this is necessary before a
2088  *	reset will recover the device.
2089  *
2090  */
2091 
2092 void ata_sff_drain_fifo(struct ata_queued_cmd *qc)
2093 {
2094 	int count;
2095 	struct ata_port *ap;
2096 
2097 	/* We only need to flush incoming data when a command was running */
2098 	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
2099 		return;
2100 
2101 	ap = qc->ap;
2102 	/* Drain up to 64K of data before we give up this recovery method */
2103 	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
2104 						&& count < 65536; count += 2)
2105 		ioread16(ap->ioaddr.data_addr);
2106 
2107 	/* Can become DEBUG later */
2108 	if (count)
2109 		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
2110 
2111 }
2112 EXPORT_SYMBOL_GPL(ata_sff_drain_fifo);
2113 
2114 /**
2115  *	ata_sff_error_handler - Stock error handler for SFF controller
2116  *	@ap: port to handle error for
2117  *
2118  *	Stock error handler for SFF controller.  It can handle both
2119  *	PATA and SATA controllers.  Many controllers should be able to
2120  *	use this EH as-is or with some added handling before and
2121  *	after.
2122  *
2123  *	LOCKING:
2124  *	Kernel thread context (may sleep)
2125  */
2126 void ata_sff_error_handler(struct ata_port *ap)
2127 {
2128 	ata_reset_fn_t softreset = ap->ops->softreset;
2129 	ata_reset_fn_t hardreset = ap->ops->hardreset;
2130 	struct ata_queued_cmd *qc;
2131 	unsigned long flags;
2132 
2133 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2134 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2135 		qc = NULL;
2136 
2137 	spin_lock_irqsave(ap->lock, flags);
2138 
2139 	/*
2140 	 * We *MUST* do FIFO draining before we issue a reset as
2141 	 * several devices helpfully clear their internal state and
2142 	 * will lock solid if we touch the data port post reset. Pass
2143 	 * qc in case anyone wants to do different PIO/DMA recovery or
2144 	 * has per command fixups
2145 	 */
2146 	if (ap->ops->sff_drain_fifo)
2147 		ap->ops->sff_drain_fifo(qc);
2148 
2149 	spin_unlock_irqrestore(ap->lock, flags);
2150 
2151 	/* ignore built-in hardresets if SCR access is not available */
2152 	if ((hardreset == sata_std_hardreset ||
2153 	     hardreset == sata_sff_hardreset) && !sata_scr_valid(&ap->link))
2154 		hardreset = NULL;
2155 
2156 	ata_do_eh(ap, ap->ops->prereset, softreset, hardreset,
2157 		  ap->ops->postreset);
2158 }
2159 EXPORT_SYMBOL_GPL(ata_sff_error_handler);
2160 
2161 /**
2162  *	ata_sff_std_ports - initialize ioaddr with standard port offsets.
2163  *	@ioaddr: IO address structure to be initialized
2164  *
2165  *	Utility function which initializes data_addr, error_addr,
2166  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
2167  *	device_addr, status_addr, and command_addr to standard offsets
2168  *	relative to cmd_addr.
2169  *
2170  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
2171  */
2172 void ata_sff_std_ports(struct ata_ioports *ioaddr)
2173 {
2174 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
2175 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
2176 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
2177 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
2178 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
2179 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
2180 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
2181 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
2182 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
2183 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
2184 }
2185 EXPORT_SYMBOL_GPL(ata_sff_std_ports);
2186 
2187 #ifdef CONFIG_PCI
2188 
2189 static int ata_resources_present(struct pci_dev *pdev, int port)
2190 {
2191 	int i;
2192 
2193 	/* Check the PCI resources for this channel are enabled */
2194 	port = port * 2;
2195 	for (i = 0; i < 2; i++) {
2196 		if (pci_resource_start(pdev, port + i) == 0 ||
2197 		    pci_resource_len(pdev, port + i) == 0)
2198 			return 0;
2199 	}
2200 	return 1;
2201 }
2202 
2203 /**
2204  *	ata_pci_sff_init_host - acquire native PCI ATA resources and init host
2205  *	@host: target ATA host
2206  *
2207  *	Acquire native PCI ATA resources for @host and initialize the
2208  *	first two ports of @host accordingly.  Ports marked dummy are
2209  *	skipped and allocation failure makes the port dummy.
2210  *
2211  *	Note that native PCI resources are valid even for legacy hosts
2212  *	as we fix up pdev resources array early in boot, so this
2213  *	function can be used for both native and legacy SFF hosts.
2214  *
2215  *	LOCKING:
2216  *	Inherited from calling layer (may sleep).
2217  *
2218  *	RETURNS:
2219  *	0 if at least one port is initialized, -ENODEV if no port is
2220  *	available.
2221  */
2222 int ata_pci_sff_init_host(struct ata_host *host)
2223 {
2224 	struct device *gdev = host->dev;
2225 	struct pci_dev *pdev = to_pci_dev(gdev);
2226 	unsigned int mask = 0;
2227 	int i, rc;
2228 
2229 	/* request, iomap BARs and init port addresses accordingly */
2230 	for (i = 0; i < 2; i++) {
2231 		struct ata_port *ap = host->ports[i];
2232 		int base = i * 2;
2233 		void __iomem * const *iomap;
2234 
2235 		if (ata_port_is_dummy(ap))
2236 			continue;
2237 
2238 		/* Discard disabled ports.  Some controllers show
2239 		 * their unused channels this way.  Disabled ports are
2240 		 * made dummy.
2241 		 */
2242 		if (!ata_resources_present(pdev, i)) {
2243 			ap->ops = &ata_dummy_port_ops;
2244 			continue;
2245 		}
2246 
2247 		rc = pcim_iomap_regions(pdev, 0x3 << base,
2248 					dev_driver_string(gdev));
2249 		if (rc) {
2250 			dev_warn(gdev,
2251 				 "failed to request/iomap BARs for port %d (errno=%d)\n",
2252 				 i, rc);
2253 			if (rc == -EBUSY)
2254 				pcim_pin_device(pdev);
2255 			ap->ops = &ata_dummy_port_ops;
2256 			continue;
2257 		}
2258 		host->iomap = iomap = pcim_iomap_table(pdev);
2259 
2260 		ap->ioaddr.cmd_addr = iomap[base];
2261 		ap->ioaddr.altstatus_addr =
2262 		ap->ioaddr.ctl_addr = (void __iomem *)
2263 			((unsigned long)iomap[base + 1] | ATA_PCI_CTL_OFS);
2264 		ata_sff_std_ports(&ap->ioaddr);
2265 
2266 		ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
2267 			(unsigned long long)pci_resource_start(pdev, base),
2268 			(unsigned long long)pci_resource_start(pdev, base + 1));
2269 
2270 		mask |= 1 << i;
2271 	}
2272 
2273 	if (!mask) {
2274 		dev_err(gdev, "no available native port\n");
2275 		return -ENODEV;
2276 	}
2277 
2278 	return 0;
2279 }
2280 EXPORT_SYMBOL_GPL(ata_pci_sff_init_host);
2281 
2282 /**
2283  *	ata_pci_sff_prepare_host - helper to prepare PCI PIO-only SFF ATA host
2284  *	@pdev: target PCI device
2285  *	@ppi: array of port_info, must be enough for two ports
2286  *	@r_host: out argument for the initialized ATA host
2287  *
2288  *	Helper to allocate PIO-only SFF ATA host for @pdev, acquire
2289  *	all PCI resources and initialize it accordingly in one go.
2290  *
2291  *	LOCKING:
2292  *	Inherited from calling layer (may sleep).
2293  *
2294  *	RETURNS:
2295  *	0 on success, -errno otherwise.
2296  */
2297 int ata_pci_sff_prepare_host(struct pci_dev *pdev,
2298 			     const struct ata_port_info * const *ppi,
2299 			     struct ata_host **r_host)
2300 {
2301 	struct ata_host *host;
2302 	int rc;
2303 
2304 	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
2305 		return -ENOMEM;
2306 
2307 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
2308 	if (!host) {
2309 		dev_err(&pdev->dev, "failed to allocate ATA host\n");
2310 		rc = -ENOMEM;
2311 		goto err_out;
2312 	}
2313 
2314 	rc = ata_pci_sff_init_host(host);
2315 	if (rc)
2316 		goto err_out;
2317 
2318 	devres_remove_group(&pdev->dev, NULL);
2319 	*r_host = host;
2320 	return 0;
2321 
2322 err_out:
2323 	devres_release_group(&pdev->dev, NULL);
2324 	return rc;
2325 }
2326 EXPORT_SYMBOL_GPL(ata_pci_sff_prepare_host);
2327 
2328 /**
2329  *	ata_pci_sff_activate_host - start SFF host, request IRQ and register it
2330  *	@host: target SFF ATA host
2331  *	@irq_handler: irq_handler used when requesting IRQ(s)
2332  *	@sht: scsi_host_template to use when registering the host
2333  *
2334  *	This is the counterpart of ata_host_activate() for SFF ATA
2335  *	hosts.  This separate helper is necessary because SFF hosts
2336  *	use two separate interrupts in legacy mode.
2337  *
2338  *	LOCKING:
2339  *	Inherited from calling layer (may sleep).
2340  *
2341  *	RETURNS:
2342  *	0 on success, -errno otherwise.
2343  */
2344 int ata_pci_sff_activate_host(struct ata_host *host,
2345 			      irq_handler_t irq_handler,
2346 			      struct scsi_host_template *sht)
2347 {
2348 	struct device *dev = host->dev;
2349 	struct pci_dev *pdev = to_pci_dev(dev);
2350 	const char *drv_name = dev_driver_string(host->dev);
2351 	int legacy_mode = 0, rc;
2352 
2353 	rc = ata_host_start(host);
2354 	if (rc)
2355 		return rc;
2356 
2357 	if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
2358 		u8 tmp8, mask = 0;
2359 
2360 		/*
2361 		 * ATA spec says we should use legacy mode when one
2362 		 * port is in legacy mode, but disabled ports on some
2363 		 * PCI hosts appear as fixed legacy ports, e.g SB600/700
2364 		 * on which the secondary port is not wired, so
2365 		 * ignore ports that are marked as 'dummy' during
2366 		 * this check
2367 		 */
2368 		pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp8);
2369 		if (!ata_port_is_dummy(host->ports[0]))
2370 			mask |= (1 << 0);
2371 		if (!ata_port_is_dummy(host->ports[1]))
2372 			mask |= (1 << 2);
2373 		if ((tmp8 & mask) != mask)
2374 			legacy_mode = 1;
2375 	}
2376 
2377 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2378 		return -ENOMEM;
2379 
2380 	if (!legacy_mode && pdev->irq) {
2381 		int i;
2382 
2383 		rc = devm_request_irq(dev, pdev->irq, irq_handler,
2384 				      IRQF_SHARED, drv_name, host);
2385 		if (rc)
2386 			goto out;
2387 
2388 		for (i = 0; i < 2; i++) {
2389 			if (ata_port_is_dummy(host->ports[i]))
2390 				continue;
2391 			ata_port_desc(host->ports[i], "irq %d", pdev->irq);
2392 		}
2393 	} else if (legacy_mode) {
2394 		if (!ata_port_is_dummy(host->ports[0])) {
2395 			rc = devm_request_irq(dev, ATA_PRIMARY_IRQ(pdev),
2396 					      irq_handler, IRQF_SHARED,
2397 					      drv_name, host);
2398 			if (rc)
2399 				goto out;
2400 
2401 			ata_port_desc(host->ports[0], "irq %d",
2402 				      ATA_PRIMARY_IRQ(pdev));
2403 		}
2404 
2405 		if (!ata_port_is_dummy(host->ports[1])) {
2406 			rc = devm_request_irq(dev, ATA_SECONDARY_IRQ(pdev),
2407 					      irq_handler, IRQF_SHARED,
2408 					      drv_name, host);
2409 			if (rc)
2410 				goto out;
2411 
2412 			ata_port_desc(host->ports[1], "irq %d",
2413 				      ATA_SECONDARY_IRQ(pdev));
2414 		}
2415 	}
2416 
2417 	rc = ata_host_register(host, sht);
2418 out:
2419 	if (rc == 0)
2420 		devres_remove_group(dev, NULL);
2421 	else
2422 		devres_release_group(dev, NULL);
2423 
2424 	return rc;
2425 }
2426 EXPORT_SYMBOL_GPL(ata_pci_sff_activate_host);
2427 
2428 static const struct ata_port_info *ata_sff_find_valid_pi(
2429 					const struct ata_port_info * const *ppi)
2430 {
2431 	int i;
2432 
2433 	/* look up the first valid port_info */
2434 	for (i = 0; i < 2 && ppi[i]; i++)
2435 		if (ppi[i]->port_ops != &ata_dummy_port_ops)
2436 			return ppi[i];
2437 
2438 	return NULL;
2439 }
2440 
2441 static int ata_pci_init_one(struct pci_dev *pdev,
2442 		const struct ata_port_info * const *ppi,
2443 		struct scsi_host_template *sht, void *host_priv,
2444 		int hflags, bool bmdma)
2445 {
2446 	struct device *dev = &pdev->dev;
2447 	const struct ata_port_info *pi;
2448 	struct ata_host *host = NULL;
2449 	int rc;
2450 
2451 	DPRINTK("ENTER\n");
2452 
2453 	pi = ata_sff_find_valid_pi(ppi);
2454 	if (!pi) {
2455 		dev_err(&pdev->dev, "no valid port_info specified\n");
2456 		return -EINVAL;
2457 	}
2458 
2459 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2460 		return -ENOMEM;
2461 
2462 	rc = pcim_enable_device(pdev);
2463 	if (rc)
2464 		goto out;
2465 
2466 #ifdef CONFIG_ATA_BMDMA
2467 	if (bmdma)
2468 		/* prepare and activate BMDMA host */
2469 		rc = ata_pci_bmdma_prepare_host(pdev, ppi, &host);
2470 	else
2471 #endif
2472 		/* prepare and activate SFF host */
2473 		rc = ata_pci_sff_prepare_host(pdev, ppi, &host);
2474 	if (rc)
2475 		goto out;
2476 	host->private_data = host_priv;
2477 	host->flags |= hflags;
2478 
2479 #ifdef CONFIG_ATA_BMDMA
2480 	if (bmdma) {
2481 		pci_set_master(pdev);
2482 		rc = ata_pci_sff_activate_host(host, ata_bmdma_interrupt, sht);
2483 	} else
2484 #endif
2485 		rc = ata_pci_sff_activate_host(host, ata_sff_interrupt, sht);
2486 out:
2487 	if (rc == 0)
2488 		devres_remove_group(&pdev->dev, NULL);
2489 	else
2490 		devres_release_group(&pdev->dev, NULL);
2491 
2492 	return rc;
2493 }
2494 
2495 /**
2496  *	ata_pci_sff_init_one - Initialize/register PIO-only PCI IDE controller
2497  *	@pdev: Controller to be initialized
2498  *	@ppi: array of port_info, must be enough for two ports
2499  *	@sht: scsi_host_template to use when registering the host
2500  *	@host_priv: host private_data
2501  *	@hflag: host flags
2502  *
2503  *	This is a helper function which can be called from a driver's
2504  *	xxx_init_one() probe function if the hardware uses traditional
2505  *	IDE taskfile registers and is PIO only.
2506  *
2507  *	ASSUMPTION:
2508  *	Nobody makes a single channel controller that appears solely as
2509  *	the secondary legacy port on PCI.
2510  *
2511  *	LOCKING:
2512  *	Inherited from PCI layer (may sleep).
2513  *
2514  *	RETURNS:
2515  *	Zero on success, negative on errno-based value on error.
2516  */
2517 int ata_pci_sff_init_one(struct pci_dev *pdev,
2518 		 const struct ata_port_info * const *ppi,
2519 		 struct scsi_host_template *sht, void *host_priv, int hflag)
2520 {
2521 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflag, 0);
2522 }
2523 EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
2524 
2525 #endif /* CONFIG_PCI */
2526 
2527 /*
2528  *	BMDMA support
2529  */
2530 
2531 #ifdef CONFIG_ATA_BMDMA
2532 
2533 const struct ata_port_operations ata_bmdma_port_ops = {
2534 	.inherits		= &ata_sff_port_ops,
2535 
2536 	.error_handler		= ata_bmdma_error_handler,
2537 	.post_internal_cmd	= ata_bmdma_post_internal_cmd,
2538 
2539 	.qc_prep		= ata_bmdma_qc_prep,
2540 	.qc_issue		= ata_bmdma_qc_issue,
2541 
2542 	.sff_irq_clear		= ata_bmdma_irq_clear,
2543 	.bmdma_setup		= ata_bmdma_setup,
2544 	.bmdma_start		= ata_bmdma_start,
2545 	.bmdma_stop		= ata_bmdma_stop,
2546 	.bmdma_status		= ata_bmdma_status,
2547 
2548 	.port_start		= ata_bmdma_port_start,
2549 };
2550 EXPORT_SYMBOL_GPL(ata_bmdma_port_ops);
2551 
2552 const struct ata_port_operations ata_bmdma32_port_ops = {
2553 	.inherits		= &ata_bmdma_port_ops,
2554 
2555 	.sff_data_xfer		= ata_sff_data_xfer32,
2556 	.port_start		= ata_bmdma_port_start32,
2557 };
2558 EXPORT_SYMBOL_GPL(ata_bmdma32_port_ops);
2559 
2560 /**
2561  *	ata_bmdma_fill_sg - Fill PCI IDE PRD table
2562  *	@qc: Metadata associated with taskfile to be transferred
2563  *
2564  *	Fill PCI IDE PRD (scatter-gather) table with segments
2565  *	associated with the current disk command.
2566  *
2567  *	LOCKING:
2568  *	spin_lock_irqsave(host lock)
2569  *
2570  */
2571 static void ata_bmdma_fill_sg(struct ata_queued_cmd *qc)
2572 {
2573 	struct ata_port *ap = qc->ap;
2574 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2575 	struct scatterlist *sg;
2576 	unsigned int si, pi;
2577 
2578 	pi = 0;
2579 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2580 		u32 addr, offset;
2581 		u32 sg_len, len;
2582 
2583 		/* determine if physical DMA addr spans 64K boundary.
2584 		 * Note h/w doesn't support 64-bit, so we unconditionally
2585 		 * truncate dma_addr_t to u32.
2586 		 */
2587 		addr = (u32) sg_dma_address(sg);
2588 		sg_len = sg_dma_len(sg);
2589 
2590 		while (sg_len) {
2591 			offset = addr & 0xffff;
2592 			len = sg_len;
2593 			if ((offset + sg_len) > 0x10000)
2594 				len = 0x10000 - offset;
2595 
2596 			prd[pi].addr = cpu_to_le32(addr);
2597 			prd[pi].flags_len = cpu_to_le32(len & 0xffff);
2598 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2599 
2600 			pi++;
2601 			sg_len -= len;
2602 			addr += len;
2603 		}
2604 	}
2605 
2606 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2607 }
2608 
2609 /**
2610  *	ata_bmdma_fill_sg_dumb - Fill PCI IDE PRD table
2611  *	@qc: Metadata associated with taskfile to be transferred
2612  *
2613  *	Fill PCI IDE PRD (scatter-gather) table with segments
2614  *	associated with the current disk command. Perform the fill
2615  *	so that we avoid writing any length 64K records for
2616  *	controllers that don't follow the spec.
2617  *
2618  *	LOCKING:
2619  *	spin_lock_irqsave(host lock)
2620  *
2621  */
2622 static void ata_bmdma_fill_sg_dumb(struct ata_queued_cmd *qc)
2623 {
2624 	struct ata_port *ap = qc->ap;
2625 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2626 	struct scatterlist *sg;
2627 	unsigned int si, pi;
2628 
2629 	pi = 0;
2630 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2631 		u32 addr, offset;
2632 		u32 sg_len, len, blen;
2633 
2634 		/* determine if physical DMA addr spans 64K boundary.
2635 		 * Note h/w doesn't support 64-bit, so we unconditionally
2636 		 * truncate dma_addr_t to u32.
2637 		 */
2638 		addr = (u32) sg_dma_address(sg);
2639 		sg_len = sg_dma_len(sg);
2640 
2641 		while (sg_len) {
2642 			offset = addr & 0xffff;
2643 			len = sg_len;
2644 			if ((offset + sg_len) > 0x10000)
2645 				len = 0x10000 - offset;
2646 
2647 			blen = len & 0xffff;
2648 			prd[pi].addr = cpu_to_le32(addr);
2649 			if (blen == 0) {
2650 				/* Some PATA chipsets like the CS5530 can't
2651 				   cope with 0x0000 meaning 64K as the spec
2652 				   says */
2653 				prd[pi].flags_len = cpu_to_le32(0x8000);
2654 				blen = 0x8000;
2655 				prd[++pi].addr = cpu_to_le32(addr + 0x8000);
2656 			}
2657 			prd[pi].flags_len = cpu_to_le32(blen);
2658 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2659 
2660 			pi++;
2661 			sg_len -= len;
2662 			addr += len;
2663 		}
2664 	}
2665 
2666 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2667 }
2668 
2669 /**
2670  *	ata_bmdma_qc_prep - Prepare taskfile for submission
2671  *	@qc: Metadata associated with taskfile to be prepared
2672  *
2673  *	Prepare ATA taskfile for submission.
2674  *
2675  *	LOCKING:
2676  *	spin_lock_irqsave(host lock)
2677  */
2678 enum ata_completion_errors ata_bmdma_qc_prep(struct ata_queued_cmd *qc)
2679 {
2680 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2681 		return AC_ERR_OK;
2682 
2683 	ata_bmdma_fill_sg(qc);
2684 
2685 	return AC_ERR_OK;
2686 }
2687 EXPORT_SYMBOL_GPL(ata_bmdma_qc_prep);
2688 
2689 /**
2690  *	ata_bmdma_dumb_qc_prep - Prepare taskfile for submission
2691  *	@qc: Metadata associated with taskfile to be prepared
2692  *
2693  *	Prepare ATA taskfile for submission.
2694  *
2695  *	LOCKING:
2696  *	spin_lock_irqsave(host lock)
2697  */
2698 enum ata_completion_errors ata_bmdma_dumb_qc_prep(struct ata_queued_cmd *qc)
2699 {
2700 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2701 		return AC_ERR_OK;
2702 
2703 	ata_bmdma_fill_sg_dumb(qc);
2704 
2705 	return AC_ERR_OK;
2706 }
2707 EXPORT_SYMBOL_GPL(ata_bmdma_dumb_qc_prep);
2708 
2709 /**
2710  *	ata_bmdma_qc_issue - issue taskfile to a BMDMA controller
2711  *	@qc: command to issue to device
2712  *
2713  *	This function issues a PIO, NODATA or DMA command to a
2714  *	SFF/BMDMA controller.  PIO and NODATA are handled by
2715  *	ata_sff_qc_issue().
2716  *
2717  *	LOCKING:
2718  *	spin_lock_irqsave(host lock)
2719  *
2720  *	RETURNS:
2721  *	Zero on success, AC_ERR_* mask on failure
2722  */
2723 unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc)
2724 {
2725 	struct ata_port *ap = qc->ap;
2726 	struct ata_link *link = qc->dev->link;
2727 
2728 	/* defer PIO handling to sff_qc_issue */
2729 	if (!ata_is_dma(qc->tf.protocol))
2730 		return ata_sff_qc_issue(qc);
2731 
2732 	/* select the device */
2733 	ata_dev_select(ap, qc->dev->devno, 1, 0);
2734 
2735 	/* start the command */
2736 	switch (qc->tf.protocol) {
2737 	case ATA_PROT_DMA:
2738 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2739 
2740 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2741 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2742 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
2743 		ap->hsm_task_state = HSM_ST_LAST;
2744 		break;
2745 
2746 	case ATAPI_PROT_DMA:
2747 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2748 
2749 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2750 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2751 		ap->hsm_task_state = HSM_ST_FIRST;
2752 
2753 		/* send cdb by polling if no cdb interrupt */
2754 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
2755 			ata_sff_queue_pio_task(link, 0);
2756 		break;
2757 
2758 	default:
2759 		WARN_ON(1);
2760 		return AC_ERR_SYSTEM;
2761 	}
2762 
2763 	return 0;
2764 }
2765 EXPORT_SYMBOL_GPL(ata_bmdma_qc_issue);
2766 
2767 /**
2768  *	ata_bmdma_port_intr - Handle BMDMA port interrupt
2769  *	@ap: Port on which interrupt arrived (possibly...)
2770  *	@qc: Taskfile currently active in engine
2771  *
2772  *	Handle port interrupt for given queued command.
2773  *
2774  *	LOCKING:
2775  *	spin_lock_irqsave(host lock)
2776  *
2777  *	RETURNS:
2778  *	One if interrupt was handled, zero if not (shared irq).
2779  */
2780 unsigned int ata_bmdma_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
2781 {
2782 	struct ata_eh_info *ehi = &ap->link.eh_info;
2783 	u8 host_stat = 0;
2784 	bool bmdma_stopped = false;
2785 	unsigned int handled;
2786 
2787 	if (ap->hsm_task_state == HSM_ST_LAST && ata_is_dma(qc->tf.protocol)) {
2788 		/* check status of DMA engine */
2789 		host_stat = ap->ops->bmdma_status(ap);
2790 		VPRINTK("ata%u: host_stat 0x%X\n", ap->print_id, host_stat);
2791 
2792 		/* if it's not our irq... */
2793 		if (!(host_stat & ATA_DMA_INTR))
2794 			return ata_sff_idle_irq(ap);
2795 
2796 		/* before we do anything else, clear DMA-Start bit */
2797 		ap->ops->bmdma_stop(qc);
2798 		bmdma_stopped = true;
2799 
2800 		if (unlikely(host_stat & ATA_DMA_ERR)) {
2801 			/* error when transferring data to/from memory */
2802 			qc->err_mask |= AC_ERR_HOST_BUS;
2803 			ap->hsm_task_state = HSM_ST_ERR;
2804 		}
2805 	}
2806 
2807 	handled = __ata_sff_port_intr(ap, qc, bmdma_stopped);
2808 
2809 	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
2810 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
2811 
2812 	return handled;
2813 }
2814 EXPORT_SYMBOL_GPL(ata_bmdma_port_intr);
2815 
2816 /**
2817  *	ata_bmdma_interrupt - Default BMDMA ATA host interrupt handler
2818  *	@irq: irq line (unused)
2819  *	@dev_instance: pointer to our ata_host information structure
2820  *
2821  *	Default interrupt handler for PCI IDE devices.  Calls
2822  *	ata_bmdma_port_intr() for each port that is not disabled.
2823  *
2824  *	LOCKING:
2825  *	Obtains host lock during operation.
2826  *
2827  *	RETURNS:
2828  *	IRQ_NONE or IRQ_HANDLED.
2829  */
2830 irqreturn_t ata_bmdma_interrupt(int irq, void *dev_instance)
2831 {
2832 	return __ata_sff_interrupt(irq, dev_instance, ata_bmdma_port_intr);
2833 }
2834 EXPORT_SYMBOL_GPL(ata_bmdma_interrupt);
2835 
2836 /**
2837  *	ata_bmdma_error_handler - Stock error handler for BMDMA controller
2838  *	@ap: port to handle error for
2839  *
2840  *	Stock error handler for BMDMA controller.  It can handle both
2841  *	PATA and SATA controllers.  Most BMDMA controllers should be
2842  *	able to use this EH as-is or with some added handling before
2843  *	and after.
2844  *
2845  *	LOCKING:
2846  *	Kernel thread context (may sleep)
2847  */
2848 void ata_bmdma_error_handler(struct ata_port *ap)
2849 {
2850 	struct ata_queued_cmd *qc;
2851 	unsigned long flags;
2852 	bool thaw = false;
2853 
2854 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2855 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2856 		qc = NULL;
2857 
2858 	/* reset PIO HSM and stop DMA engine */
2859 	spin_lock_irqsave(ap->lock, flags);
2860 
2861 	if (qc && ata_is_dma(qc->tf.protocol)) {
2862 		u8 host_stat;
2863 
2864 		host_stat = ap->ops->bmdma_status(ap);
2865 
2866 		/* BMDMA controllers indicate host bus error by
2867 		 * setting DMA_ERR bit and timing out.  As it wasn't
2868 		 * really a timeout event, adjust error mask and
2869 		 * cancel frozen state.
2870 		 */
2871 		if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
2872 			qc->err_mask = AC_ERR_HOST_BUS;
2873 			thaw = true;
2874 		}
2875 
2876 		ap->ops->bmdma_stop(qc);
2877 
2878 		/* if we're gonna thaw, make sure IRQ is clear */
2879 		if (thaw) {
2880 			ap->ops->sff_check_status(ap);
2881 			if (ap->ops->sff_irq_clear)
2882 				ap->ops->sff_irq_clear(ap);
2883 		}
2884 	}
2885 
2886 	spin_unlock_irqrestore(ap->lock, flags);
2887 
2888 	if (thaw)
2889 		ata_eh_thaw_port(ap);
2890 
2891 	ata_sff_error_handler(ap);
2892 }
2893 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
2894 
2895 /**
2896  *	ata_bmdma_post_internal_cmd - Stock post_internal_cmd for BMDMA
2897  *	@qc: internal command to clean up
2898  *
2899  *	LOCKING:
2900  *	Kernel thread context (may sleep)
2901  */
2902 void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
2903 {
2904 	struct ata_port *ap = qc->ap;
2905 	unsigned long flags;
2906 
2907 	if (ata_is_dma(qc->tf.protocol)) {
2908 		spin_lock_irqsave(ap->lock, flags);
2909 		ap->ops->bmdma_stop(qc);
2910 		spin_unlock_irqrestore(ap->lock, flags);
2911 	}
2912 }
2913 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
2914 
2915 /**
2916  *	ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
2917  *	@ap: Port associated with this ATA transaction.
2918  *
2919  *	Clear interrupt and error flags in DMA status register.
2920  *
2921  *	May be used as the irq_clear() entry in ata_port_operations.
2922  *
2923  *	LOCKING:
2924  *	spin_lock_irqsave(host lock)
2925  */
2926 void ata_bmdma_irq_clear(struct ata_port *ap)
2927 {
2928 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
2929 
2930 	if (!mmio)
2931 		return;
2932 
2933 	iowrite8(ioread8(mmio + ATA_DMA_STATUS), mmio + ATA_DMA_STATUS);
2934 }
2935 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
2936 
2937 /**
2938  *	ata_bmdma_setup - Set up PCI IDE BMDMA transaction
2939  *	@qc: Info associated with this ATA transaction.
2940  *
2941  *	LOCKING:
2942  *	spin_lock_irqsave(host lock)
2943  */
2944 void ata_bmdma_setup(struct ata_queued_cmd *qc)
2945 {
2946 	struct ata_port *ap = qc->ap;
2947 	unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
2948 	u8 dmactl;
2949 
2950 	/* load PRD table addr. */
2951 	mb();	/* make sure PRD table writes are visible to controller */
2952 	iowrite32(ap->bmdma_prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
2953 
2954 	/* specify data direction, triple-check start bit is clear */
2955 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2956 	dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
2957 	if (!rw)
2958 		dmactl |= ATA_DMA_WR;
2959 	iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2960 
2961 	/* issue r/w command */
2962 	ap->ops->sff_exec_command(ap, &qc->tf);
2963 }
2964 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
2965 
2966 /**
2967  *	ata_bmdma_start - Start a PCI IDE BMDMA transaction
2968  *	@qc: Info associated with this ATA transaction.
2969  *
2970  *	LOCKING:
2971  *	spin_lock_irqsave(host lock)
2972  */
2973 void ata_bmdma_start(struct ata_queued_cmd *qc)
2974 {
2975 	struct ata_port *ap = qc->ap;
2976 	u8 dmactl;
2977 
2978 	/* start host DMA transaction */
2979 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2980 	iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2981 
2982 	/* Strictly, one may wish to issue an ioread8() here, to
2983 	 * flush the mmio write.  However, control also passes
2984 	 * to the hardware at this point, and it will interrupt
2985 	 * us when we are to resume control.  So, in effect,
2986 	 * we don't care when the mmio write flushes.
2987 	 * Further, a read of the DMA status register _immediately_
2988 	 * following the write may not be what certain flaky hardware
2989 	 * is expected, so I think it is best to not add a readb()
2990 	 * without first all the MMIO ATA cards/mobos.
2991 	 * Or maybe I'm just being paranoid.
2992 	 *
2993 	 * FIXME: The posting of this write means I/O starts are
2994 	 * unnecessarily delayed for MMIO
2995 	 */
2996 }
2997 EXPORT_SYMBOL_GPL(ata_bmdma_start);
2998 
2999 /**
3000  *	ata_bmdma_stop - Stop PCI IDE BMDMA transfer
3001  *	@qc: Command we are ending DMA for
3002  *
3003  *	Clears the ATA_DMA_START flag in the dma control register
3004  *
3005  *	May be used as the bmdma_stop() entry in ata_port_operations.
3006  *
3007  *	LOCKING:
3008  *	spin_lock_irqsave(host lock)
3009  */
3010 void ata_bmdma_stop(struct ata_queued_cmd *qc)
3011 {
3012 	struct ata_port *ap = qc->ap;
3013 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
3014 
3015 	/* clear start/stop bit */
3016 	iowrite8(ioread8(mmio + ATA_DMA_CMD) & ~ATA_DMA_START,
3017 		 mmio + ATA_DMA_CMD);
3018 
3019 	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
3020 	ata_sff_dma_pause(ap);
3021 }
3022 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
3023 
3024 /**
3025  *	ata_bmdma_status - Read PCI IDE BMDMA status
3026  *	@ap: Port associated with this ATA transaction.
3027  *
3028  *	Read and return BMDMA status register.
3029  *
3030  *	May be used as the bmdma_status() entry in ata_port_operations.
3031  *
3032  *	LOCKING:
3033  *	spin_lock_irqsave(host lock)
3034  */
3035 u8 ata_bmdma_status(struct ata_port *ap)
3036 {
3037 	return ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
3038 }
3039 EXPORT_SYMBOL_GPL(ata_bmdma_status);
3040 
3041 
3042 /**
3043  *	ata_bmdma_port_start - Set port up for bmdma.
3044  *	@ap: Port to initialize
3045  *
3046  *	Called just after data structures for each port are
3047  *	initialized.  Allocates space for PRD table.
3048  *
3049  *	May be used as the port_start() entry in ata_port_operations.
3050  *
3051  *	LOCKING:
3052  *	Inherited from caller.
3053  */
3054 int ata_bmdma_port_start(struct ata_port *ap)
3055 {
3056 	if (ap->mwdma_mask || ap->udma_mask) {
3057 		ap->bmdma_prd =
3058 			dmam_alloc_coherent(ap->host->dev, ATA_PRD_TBL_SZ,
3059 					    &ap->bmdma_prd_dma, GFP_KERNEL);
3060 		if (!ap->bmdma_prd)
3061 			return -ENOMEM;
3062 	}
3063 
3064 	return 0;
3065 }
3066 EXPORT_SYMBOL_GPL(ata_bmdma_port_start);
3067 
3068 /**
3069  *	ata_bmdma_port_start32 - Set port up for dma.
3070  *	@ap: Port to initialize
3071  *
3072  *	Called just after data structures for each port are
3073  *	initialized.  Enables 32bit PIO and allocates space for PRD
3074  *	table.
3075  *
3076  *	May be used as the port_start() entry in ata_port_operations for
3077  *	devices that are capable of 32bit PIO.
3078  *
3079  *	LOCKING:
3080  *	Inherited from caller.
3081  */
3082 int ata_bmdma_port_start32(struct ata_port *ap)
3083 {
3084 	ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
3085 	return ata_bmdma_port_start(ap);
3086 }
3087 EXPORT_SYMBOL_GPL(ata_bmdma_port_start32);
3088 
3089 #ifdef CONFIG_PCI
3090 
3091 /**
3092  *	ata_pci_bmdma_clear_simplex -	attempt to kick device out of simplex
3093  *	@pdev: PCI device
3094  *
3095  *	Some PCI ATA devices report simplex mode but in fact can be told to
3096  *	enter non simplex mode. This implements the necessary logic to
3097  *	perform the task on such devices. Calling it on other devices will
3098  *	have -undefined- behaviour.
3099  */
3100 int ata_pci_bmdma_clear_simplex(struct pci_dev *pdev)
3101 {
3102 	unsigned long bmdma = pci_resource_start(pdev, 4);
3103 	u8 simplex;
3104 
3105 	if (bmdma == 0)
3106 		return -ENOENT;
3107 
3108 	simplex = inb(bmdma + 0x02);
3109 	outb(simplex & 0x60, bmdma + 0x02);
3110 	simplex = inb(bmdma + 0x02);
3111 	if (simplex & 0x80)
3112 		return -EOPNOTSUPP;
3113 	return 0;
3114 }
3115 EXPORT_SYMBOL_GPL(ata_pci_bmdma_clear_simplex);
3116 
3117 static void ata_bmdma_nodma(struct ata_host *host, const char *reason)
3118 {
3119 	int i;
3120 
3121 	dev_err(host->dev, "BMDMA: %s, falling back to PIO\n", reason);
3122 
3123 	for (i = 0; i < 2; i++) {
3124 		host->ports[i]->mwdma_mask = 0;
3125 		host->ports[i]->udma_mask = 0;
3126 	}
3127 }
3128 
3129 /**
3130  *	ata_pci_bmdma_init - acquire PCI BMDMA resources and init ATA host
3131  *	@host: target ATA host
3132  *
3133  *	Acquire PCI BMDMA resources and initialize @host accordingly.
3134  *
3135  *	LOCKING:
3136  *	Inherited from calling layer (may sleep).
3137  */
3138 void ata_pci_bmdma_init(struct ata_host *host)
3139 {
3140 	struct device *gdev = host->dev;
3141 	struct pci_dev *pdev = to_pci_dev(gdev);
3142 	int i, rc;
3143 
3144 	/* No BAR4 allocation: No DMA */
3145 	if (pci_resource_start(pdev, 4) == 0) {
3146 		ata_bmdma_nodma(host, "BAR4 is zero");
3147 		return;
3148 	}
3149 
3150 	/*
3151 	 * Some controllers require BMDMA region to be initialized
3152 	 * even if DMA is not in use to clear IRQ status via
3153 	 * ->sff_irq_clear method.  Try to initialize bmdma_addr
3154 	 * regardless of dma masks.
3155 	 */
3156 	rc = dma_set_mask_and_coherent(&pdev->dev, ATA_DMA_MASK);
3157 	if (rc)
3158 		ata_bmdma_nodma(host, "failed to set dma mask");
3159 
3160 	/* request and iomap DMA region */
3161 	rc = pcim_iomap_regions(pdev, 1 << 4, dev_driver_string(gdev));
3162 	if (rc) {
3163 		ata_bmdma_nodma(host, "failed to request/iomap BAR4");
3164 		return;
3165 	}
3166 	host->iomap = pcim_iomap_table(pdev);
3167 
3168 	for (i = 0; i < 2; i++) {
3169 		struct ata_port *ap = host->ports[i];
3170 		void __iomem *bmdma = host->iomap[4] + 8 * i;
3171 
3172 		if (ata_port_is_dummy(ap))
3173 			continue;
3174 
3175 		ap->ioaddr.bmdma_addr = bmdma;
3176 		if ((!(ap->flags & ATA_FLAG_IGN_SIMPLEX)) &&
3177 		    (ioread8(bmdma + 2) & 0x80))
3178 			host->flags |= ATA_HOST_SIMPLEX;
3179 
3180 		ata_port_desc(ap, "bmdma 0x%llx",
3181 		    (unsigned long long)pci_resource_start(pdev, 4) + 8 * i);
3182 	}
3183 }
3184 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init);
3185 
3186 /**
3187  *	ata_pci_bmdma_prepare_host - helper to prepare PCI BMDMA ATA host
3188  *	@pdev: target PCI device
3189  *	@ppi: array of port_info, must be enough for two ports
3190  *	@r_host: out argument for the initialized ATA host
3191  *
3192  *	Helper to allocate BMDMA ATA host for @pdev, acquire all PCI
3193  *	resources and initialize it accordingly in one go.
3194  *
3195  *	LOCKING:
3196  *	Inherited from calling layer (may sleep).
3197  *
3198  *	RETURNS:
3199  *	0 on success, -errno otherwise.
3200  */
3201 int ata_pci_bmdma_prepare_host(struct pci_dev *pdev,
3202 			       const struct ata_port_info * const * ppi,
3203 			       struct ata_host **r_host)
3204 {
3205 	int rc;
3206 
3207 	rc = ata_pci_sff_prepare_host(pdev, ppi, r_host);
3208 	if (rc)
3209 		return rc;
3210 
3211 	ata_pci_bmdma_init(*r_host);
3212 	return 0;
3213 }
3214 EXPORT_SYMBOL_GPL(ata_pci_bmdma_prepare_host);
3215 
3216 /**
3217  *	ata_pci_bmdma_init_one - Initialize/register BMDMA PCI IDE controller
3218  *	@pdev: Controller to be initialized
3219  *	@ppi: array of port_info, must be enough for two ports
3220  *	@sht: scsi_host_template to use when registering the host
3221  *	@host_priv: host private_data
3222  *	@hflags: host flags
3223  *
3224  *	This function is similar to ata_pci_sff_init_one() but also
3225  *	takes care of BMDMA initialization.
3226  *
3227  *	LOCKING:
3228  *	Inherited from PCI layer (may sleep).
3229  *
3230  *	RETURNS:
3231  *	Zero on success, negative on errno-based value on error.
3232  */
3233 int ata_pci_bmdma_init_one(struct pci_dev *pdev,
3234 			   const struct ata_port_info * const * ppi,
3235 			   struct scsi_host_template *sht, void *host_priv,
3236 			   int hflags)
3237 {
3238 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflags, 1);
3239 }
3240 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init_one);
3241 
3242 #endif /* CONFIG_PCI */
3243 #endif /* CONFIG_ATA_BMDMA */
3244 
3245 /**
3246  *	ata_sff_port_init - Initialize SFF/BMDMA ATA port
3247  *	@ap: Port to initialize
3248  *
3249  *	Called on port allocation to initialize SFF/BMDMA specific
3250  *	fields.
3251  *
3252  *	LOCKING:
3253  *	None.
3254  */
3255 void ata_sff_port_init(struct ata_port *ap)
3256 {
3257 	INIT_DELAYED_WORK(&ap->sff_pio_task, ata_sff_pio_task);
3258 	ap->ctl = ATA_DEVCTL_OBS;
3259 	ap->last_ctl = 0xFF;
3260 }
3261 
3262 int __init ata_sff_init(void)
3263 {
3264 	ata_sff_wq = alloc_workqueue("ata_sff", WQ_MEM_RECLAIM, WQ_MAX_ACTIVE);
3265 	if (!ata_sff_wq)
3266 		return -ENOMEM;
3267 
3268 	return 0;
3269 }
3270 
3271 void ata_sff_exit(void)
3272 {
3273 	destroy_workqueue(ata_sff_wq);
3274 }
3275