xref: /openbmc/linux/drivers/ata/libata-sff.c (revision 7a010c3c)
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 static void ata_pio_xfer(struct ata_queued_cmd *qc, struct page *page,
641 		unsigned int offset, size_t xfer_size)
642 {
643 	bool do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
644 	unsigned char *buf;
645 
646 	buf = kmap_atomic(page);
647 	qc->ap->ops->sff_data_xfer(qc, buf + offset, xfer_size, do_write);
648 	kunmap_atomic(buf);
649 
650 	if (!do_write && !PageSlab(page))
651 		flush_dcache_page(page);
652 }
653 
654 /**
655  *	ata_pio_sector - Transfer a sector of data.
656  *	@qc: Command on going
657  *
658  *	Transfer qc->sect_size bytes of data from/to the ATA device.
659  *
660  *	LOCKING:
661  *	Inherited from caller.
662  */
663 static void ata_pio_sector(struct ata_queued_cmd *qc)
664 {
665 	struct ata_port *ap = qc->ap;
666 	struct page *page;
667 	unsigned int offset;
668 
669 	if (!qc->cursg) {
670 		qc->curbytes = qc->nbytes;
671 		return;
672 	}
673 	if (qc->curbytes == qc->nbytes - qc->sect_size)
674 		ap->hsm_task_state = HSM_ST_LAST;
675 
676 	page = sg_page(qc->cursg);
677 	offset = qc->cursg->offset + qc->cursg_ofs;
678 
679 	/* get the current page and offset */
680 	page = nth_page(page, (offset >> PAGE_SHIFT));
681 	offset %= PAGE_SIZE;
682 
683 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
684 
685 	/*
686 	 * Split the transfer when it splits a page boundary.  Note that the
687 	 * split still has to be dword aligned like all ATA data transfers.
688 	 */
689 	WARN_ON_ONCE(offset % 4);
690 	if (offset + qc->sect_size > PAGE_SIZE) {
691 		unsigned int split_len = PAGE_SIZE - offset;
692 
693 		ata_pio_xfer(qc, page, offset, split_len);
694 		ata_pio_xfer(qc, nth_page(page, 1), 0,
695 			     qc->sect_size - split_len);
696 	} else {
697 		ata_pio_xfer(qc, page, offset, qc->sect_size);
698 	}
699 
700 	qc->curbytes += qc->sect_size;
701 	qc->cursg_ofs += qc->sect_size;
702 
703 	if (qc->cursg_ofs == qc->cursg->length) {
704 		qc->cursg = sg_next(qc->cursg);
705 		if (!qc->cursg)
706 			ap->hsm_task_state = HSM_ST_LAST;
707 		qc->cursg_ofs = 0;
708 	}
709 }
710 
711 /**
712  *	ata_pio_sectors - Transfer one or many sectors.
713  *	@qc: Command on going
714  *
715  *	Transfer one or many sectors of data from/to the
716  *	ATA device for the DRQ request.
717  *
718  *	LOCKING:
719  *	Inherited from caller.
720  */
721 static void ata_pio_sectors(struct ata_queued_cmd *qc)
722 {
723 	if (is_multi_taskfile(&qc->tf)) {
724 		/* READ/WRITE MULTIPLE */
725 		unsigned int nsect;
726 
727 		WARN_ON_ONCE(qc->dev->multi_count == 0);
728 
729 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
730 			    qc->dev->multi_count);
731 		while (nsect--)
732 			ata_pio_sector(qc);
733 	} else
734 		ata_pio_sector(qc);
735 
736 	ata_sff_sync(qc->ap); /* flush */
737 }
738 
739 /**
740  *	atapi_send_cdb - Write CDB bytes to hardware
741  *	@ap: Port to which ATAPI device is attached.
742  *	@qc: Taskfile currently active
743  *
744  *	When device has indicated its readiness to accept
745  *	a CDB, this function is called.  Send the CDB.
746  *
747  *	LOCKING:
748  *	caller.
749  */
750 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
751 {
752 	/* send SCSI cdb */
753 	DPRINTK("send cdb\n");
754 	WARN_ON_ONCE(qc->dev->cdb_len < 12);
755 
756 	ap->ops->sff_data_xfer(qc, qc->cdb, qc->dev->cdb_len, 1);
757 	ata_sff_sync(ap);
758 	/* FIXME: If the CDB is for DMA do we need to do the transition delay
759 	   or is bmdma_start guaranteed to do it ? */
760 	switch (qc->tf.protocol) {
761 	case ATAPI_PROT_PIO:
762 		ap->hsm_task_state = HSM_ST;
763 		break;
764 	case ATAPI_PROT_NODATA:
765 		ap->hsm_task_state = HSM_ST_LAST;
766 		break;
767 #ifdef CONFIG_ATA_BMDMA
768 	case ATAPI_PROT_DMA:
769 		ap->hsm_task_state = HSM_ST_LAST;
770 		/* initiate bmdma */
771 		ap->ops->bmdma_start(qc);
772 		break;
773 #endif /* CONFIG_ATA_BMDMA */
774 	default:
775 		BUG();
776 	}
777 }
778 
779 /**
780  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
781  *	@qc: Command on going
782  *	@bytes: number of bytes
783  *
784  *	Transfer Transfer data from/to the ATAPI device.
785  *
786  *	LOCKING:
787  *	Inherited from caller.
788  *
789  */
790 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
791 {
792 	int rw = (qc->tf.flags & ATA_TFLAG_WRITE) ? WRITE : READ;
793 	struct ata_port *ap = qc->ap;
794 	struct ata_device *dev = qc->dev;
795 	struct ata_eh_info *ehi = &dev->link->eh_info;
796 	struct scatterlist *sg;
797 	struct page *page;
798 	unsigned char *buf;
799 	unsigned int offset, count, consumed;
800 
801 next_sg:
802 	sg = qc->cursg;
803 	if (unlikely(!sg)) {
804 		ata_ehi_push_desc(ehi, "unexpected or too much trailing data "
805 				  "buf=%u cur=%u bytes=%u",
806 				  qc->nbytes, qc->curbytes, bytes);
807 		return -1;
808 	}
809 
810 	page = sg_page(sg);
811 	offset = sg->offset + qc->cursg_ofs;
812 
813 	/* get the current page and offset */
814 	page = nth_page(page, (offset >> PAGE_SHIFT));
815 	offset %= PAGE_SIZE;
816 
817 	/* don't overrun current sg */
818 	count = min(sg->length - qc->cursg_ofs, bytes);
819 
820 	/* don't cross page boundaries */
821 	count = min(count, (unsigned int)PAGE_SIZE - offset);
822 
823 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
824 
825 	/* do the actual data transfer */
826 	buf = kmap_atomic(page);
827 	consumed = ap->ops->sff_data_xfer(qc, buf + offset, count, rw);
828 	kunmap_atomic(buf);
829 
830 	bytes -= min(bytes, consumed);
831 	qc->curbytes += count;
832 	qc->cursg_ofs += count;
833 
834 	if (qc->cursg_ofs == sg->length) {
835 		qc->cursg = sg_next(qc->cursg);
836 		qc->cursg_ofs = 0;
837 	}
838 
839 	/*
840 	 * There used to be a  WARN_ON_ONCE(qc->cursg && count != consumed);
841 	 * Unfortunately __atapi_pio_bytes doesn't know enough to do the WARN
842 	 * check correctly as it doesn't know if it is the last request being
843 	 * made. Somebody should implement a proper sanity check.
844 	 */
845 	if (bytes)
846 		goto next_sg;
847 	return 0;
848 }
849 
850 /**
851  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
852  *	@qc: Command on going
853  *
854  *	Transfer Transfer data from/to the ATAPI device.
855  *
856  *	LOCKING:
857  *	Inherited from caller.
858  */
859 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
860 {
861 	struct ata_port *ap = qc->ap;
862 	struct ata_device *dev = qc->dev;
863 	struct ata_eh_info *ehi = &dev->link->eh_info;
864 	unsigned int ireason, bc_lo, bc_hi, bytes;
865 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
866 
867 	/* Abuse qc->result_tf for temp storage of intermediate TF
868 	 * here to save some kernel stack usage.
869 	 * For normal completion, qc->result_tf is not relevant. For
870 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
871 	 * So, the correctness of qc->result_tf is not affected.
872 	 */
873 	ap->ops->sff_tf_read(ap, &qc->result_tf);
874 	ireason = qc->result_tf.nsect;
875 	bc_lo = qc->result_tf.lbam;
876 	bc_hi = qc->result_tf.lbah;
877 	bytes = (bc_hi << 8) | bc_lo;
878 
879 	/* shall be cleared to zero, indicating xfer of data */
880 	if (unlikely(ireason & ATAPI_COD))
881 		goto atapi_check;
882 
883 	/* make sure transfer direction matches expected */
884 	i_write = ((ireason & ATAPI_IO) == 0) ? 1 : 0;
885 	if (unlikely(do_write != i_write))
886 		goto atapi_check;
887 
888 	if (unlikely(!bytes))
889 		goto atapi_check;
890 
891 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
892 
893 	if (unlikely(__atapi_pio_bytes(qc, bytes)))
894 		goto err_out;
895 	ata_sff_sync(ap); /* flush */
896 
897 	return;
898 
899  atapi_check:
900 	ata_ehi_push_desc(ehi, "ATAPI check failed (ireason=0x%x bytes=%u)",
901 			  ireason, bytes);
902  err_out:
903 	qc->err_mask |= AC_ERR_HSM;
904 	ap->hsm_task_state = HSM_ST_ERR;
905 }
906 
907 /**
908  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
909  *	@ap: the target ata_port
910  *	@qc: qc on going
911  *
912  *	RETURNS:
913  *	1 if ok in workqueue, 0 otherwise.
914  */
915 static inline int ata_hsm_ok_in_wq(struct ata_port *ap,
916 						struct ata_queued_cmd *qc)
917 {
918 	if (qc->tf.flags & ATA_TFLAG_POLLING)
919 		return 1;
920 
921 	if (ap->hsm_task_state == HSM_ST_FIRST) {
922 		if (qc->tf.protocol == ATA_PROT_PIO &&
923 		   (qc->tf.flags & ATA_TFLAG_WRITE))
924 		    return 1;
925 
926 		if (ata_is_atapi(qc->tf.protocol) &&
927 		   !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
928 			return 1;
929 	}
930 
931 	return 0;
932 }
933 
934 /**
935  *	ata_hsm_qc_complete - finish a qc running on standard HSM
936  *	@qc: Command to complete
937  *	@in_wq: 1 if called from workqueue, 0 otherwise
938  *
939  *	Finish @qc which is running on standard HSM.
940  *
941  *	LOCKING:
942  *	If @in_wq is zero, spin_lock_irqsave(host lock).
943  *	Otherwise, none on entry and grabs host lock.
944  */
945 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
946 {
947 	struct ata_port *ap = qc->ap;
948 
949 	if (ap->ops->error_handler) {
950 		if (in_wq) {
951 			/* EH might have kicked in while host lock is
952 			 * released.
953 			 */
954 			qc = ata_qc_from_tag(ap, qc->tag);
955 			if (qc) {
956 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
957 					ata_sff_irq_on(ap);
958 					ata_qc_complete(qc);
959 				} else
960 					ata_port_freeze(ap);
961 			}
962 		} else {
963 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
964 				ata_qc_complete(qc);
965 			else
966 				ata_port_freeze(ap);
967 		}
968 	} else {
969 		if (in_wq) {
970 			ata_sff_irq_on(ap);
971 			ata_qc_complete(qc);
972 		} else
973 			ata_qc_complete(qc);
974 	}
975 }
976 
977 /**
978  *	ata_sff_hsm_move - move the HSM to the next state.
979  *	@ap: the target ata_port
980  *	@qc: qc on going
981  *	@status: current device status
982  *	@in_wq: 1 if called from workqueue, 0 otherwise
983  *
984  *	RETURNS:
985  *	1 when poll next status needed, 0 otherwise.
986  */
987 int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
988 		     u8 status, int in_wq)
989 {
990 	struct ata_link *link = qc->dev->link;
991 	struct ata_eh_info *ehi = &link->eh_info;
992 	int poll_next;
993 
994 	lockdep_assert_held(ap->lock);
995 
996 	WARN_ON_ONCE((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
997 
998 	/* Make sure ata_sff_qc_issue() does not throw things
999 	 * like DMA polling into the workqueue. Notice that
1000 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
1001 	 */
1002 	WARN_ON_ONCE(in_wq != ata_hsm_ok_in_wq(ap, qc));
1003 
1004 fsm_start:
1005 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
1006 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
1007 
1008 	switch (ap->hsm_task_state) {
1009 	case HSM_ST_FIRST:
1010 		/* Send first data block or PACKET CDB */
1011 
1012 		/* If polling, we will stay in the work queue after
1013 		 * sending the data. Otherwise, interrupt handler
1014 		 * takes over after sending the data.
1015 		 */
1016 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
1017 
1018 		/* check device status */
1019 		if (unlikely((status & ATA_DRQ) == 0)) {
1020 			/* handle BSY=0, DRQ=0 as error */
1021 			if (likely(status & (ATA_ERR | ATA_DF)))
1022 				/* device stops HSM for abort/error */
1023 				qc->err_mask |= AC_ERR_DEV;
1024 			else {
1025 				/* HSM violation. Let EH handle this */
1026 				ata_ehi_push_desc(ehi,
1027 					"ST_FIRST: !(DRQ|ERR|DF)");
1028 				qc->err_mask |= AC_ERR_HSM;
1029 			}
1030 
1031 			ap->hsm_task_state = HSM_ST_ERR;
1032 			goto fsm_start;
1033 		}
1034 
1035 		/* Device should not ask for data transfer (DRQ=1)
1036 		 * when it finds something wrong.
1037 		 * We ignore DRQ here and stop the HSM by
1038 		 * changing hsm_task_state to HSM_ST_ERR and
1039 		 * let the EH abort the command or reset the device.
1040 		 */
1041 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
1042 			/* Some ATAPI tape drives forget to clear the ERR bit
1043 			 * when doing the next command (mostly request sense).
1044 			 * We ignore ERR here to workaround and proceed sending
1045 			 * the CDB.
1046 			 */
1047 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
1048 				ata_ehi_push_desc(ehi, "ST_FIRST: "
1049 					"DRQ=1 with device error, "
1050 					"dev_stat 0x%X", status);
1051 				qc->err_mask |= AC_ERR_HSM;
1052 				ap->hsm_task_state = HSM_ST_ERR;
1053 				goto fsm_start;
1054 			}
1055 		}
1056 
1057 		if (qc->tf.protocol == ATA_PROT_PIO) {
1058 			/* PIO data out protocol.
1059 			 * send first data block.
1060 			 */
1061 
1062 			/* ata_pio_sectors() might change the state
1063 			 * to HSM_ST_LAST. so, the state is changed here
1064 			 * before ata_pio_sectors().
1065 			 */
1066 			ap->hsm_task_state = HSM_ST;
1067 			ata_pio_sectors(qc);
1068 		} else
1069 			/* send CDB */
1070 			atapi_send_cdb(ap, qc);
1071 
1072 		/* if polling, ata_sff_pio_task() handles the rest.
1073 		 * otherwise, interrupt handler takes over from here.
1074 		 */
1075 		break;
1076 
1077 	case HSM_ST:
1078 		/* complete command or read/write the data register */
1079 		if (qc->tf.protocol == ATAPI_PROT_PIO) {
1080 			/* ATAPI PIO protocol */
1081 			if ((status & ATA_DRQ) == 0) {
1082 				/* No more data to transfer or device error.
1083 				 * Device error will be tagged in HSM_ST_LAST.
1084 				 */
1085 				ap->hsm_task_state = HSM_ST_LAST;
1086 				goto fsm_start;
1087 			}
1088 
1089 			/* Device should not ask for data transfer (DRQ=1)
1090 			 * when it finds something wrong.
1091 			 * We ignore DRQ here and stop the HSM by
1092 			 * changing hsm_task_state to HSM_ST_ERR and
1093 			 * let the EH abort the command or reset the device.
1094 			 */
1095 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1096 				ata_ehi_push_desc(ehi, "ST-ATAPI: "
1097 					"DRQ=1 with device error, "
1098 					"dev_stat 0x%X", status);
1099 				qc->err_mask |= AC_ERR_HSM;
1100 				ap->hsm_task_state = HSM_ST_ERR;
1101 				goto fsm_start;
1102 			}
1103 
1104 			atapi_pio_bytes(qc);
1105 
1106 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
1107 				/* bad ireason reported by device */
1108 				goto fsm_start;
1109 
1110 		} else {
1111 			/* ATA PIO protocol */
1112 			if (unlikely((status & ATA_DRQ) == 0)) {
1113 				/* handle BSY=0, DRQ=0 as error */
1114 				if (likely(status & (ATA_ERR | ATA_DF))) {
1115 					/* device stops HSM for abort/error */
1116 					qc->err_mask |= AC_ERR_DEV;
1117 
1118 					/* If diagnostic failed and this is
1119 					 * IDENTIFY, it's likely a phantom
1120 					 * device.  Mark hint.
1121 					 */
1122 					if (qc->dev->horkage &
1123 					    ATA_HORKAGE_DIAGNOSTIC)
1124 						qc->err_mask |=
1125 							AC_ERR_NODEV_HINT;
1126 				} else {
1127 					/* HSM violation. Let EH handle this.
1128 					 * Phantom devices also trigger this
1129 					 * condition.  Mark hint.
1130 					 */
1131 					ata_ehi_push_desc(ehi, "ST-ATA: "
1132 						"DRQ=0 without device error, "
1133 						"dev_stat 0x%X", status);
1134 					qc->err_mask |= AC_ERR_HSM |
1135 							AC_ERR_NODEV_HINT;
1136 				}
1137 
1138 				ap->hsm_task_state = HSM_ST_ERR;
1139 				goto fsm_start;
1140 			}
1141 
1142 			/* For PIO reads, some devices may ask for
1143 			 * data transfer (DRQ=1) alone with ERR=1.
1144 			 * We respect DRQ here and transfer one
1145 			 * block of junk data before changing the
1146 			 * hsm_task_state to HSM_ST_ERR.
1147 			 *
1148 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
1149 			 * sense since the data block has been
1150 			 * transferred to the device.
1151 			 */
1152 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1153 				/* data might be corrputed */
1154 				qc->err_mask |= AC_ERR_DEV;
1155 
1156 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
1157 					ata_pio_sectors(qc);
1158 					status = ata_wait_idle(ap);
1159 				}
1160 
1161 				if (status & (ATA_BUSY | ATA_DRQ)) {
1162 					ata_ehi_push_desc(ehi, "ST-ATA: "
1163 						"BUSY|DRQ persists on ERR|DF, "
1164 						"dev_stat 0x%X", status);
1165 					qc->err_mask |= AC_ERR_HSM;
1166 				}
1167 
1168 				/* There are oddball controllers with
1169 				 * status register stuck at 0x7f and
1170 				 * lbal/m/h at zero which makes it
1171 				 * pass all other presence detection
1172 				 * mechanisms we have.  Set NODEV_HINT
1173 				 * for it.  Kernel bz#7241.
1174 				 */
1175 				if (status == 0x7f)
1176 					qc->err_mask |= AC_ERR_NODEV_HINT;
1177 
1178 				/* ata_pio_sectors() might change the
1179 				 * state to HSM_ST_LAST. so, the state
1180 				 * is changed after ata_pio_sectors().
1181 				 */
1182 				ap->hsm_task_state = HSM_ST_ERR;
1183 				goto fsm_start;
1184 			}
1185 
1186 			ata_pio_sectors(qc);
1187 
1188 			if (ap->hsm_task_state == HSM_ST_LAST &&
1189 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
1190 				/* all data read */
1191 				status = ata_wait_idle(ap);
1192 				goto fsm_start;
1193 			}
1194 		}
1195 
1196 		poll_next = 1;
1197 		break;
1198 
1199 	case HSM_ST_LAST:
1200 		if (unlikely(!ata_ok(status))) {
1201 			qc->err_mask |= __ac_err_mask(status);
1202 			ap->hsm_task_state = HSM_ST_ERR;
1203 			goto fsm_start;
1204 		}
1205 
1206 		/* no more data to transfer */
1207 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
1208 			ap->print_id, qc->dev->devno, status);
1209 
1210 		WARN_ON_ONCE(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
1211 
1212 		ap->hsm_task_state = HSM_ST_IDLE;
1213 
1214 		/* complete taskfile transaction */
1215 		ata_hsm_qc_complete(qc, in_wq);
1216 
1217 		poll_next = 0;
1218 		break;
1219 
1220 	case HSM_ST_ERR:
1221 		ap->hsm_task_state = HSM_ST_IDLE;
1222 
1223 		/* complete taskfile transaction */
1224 		ata_hsm_qc_complete(qc, in_wq);
1225 
1226 		poll_next = 0;
1227 		break;
1228 	default:
1229 		poll_next = 0;
1230 		WARN(true, "ata%d: SFF host state machine in invalid state %d",
1231 		     ap->print_id, ap->hsm_task_state);
1232 	}
1233 
1234 	return poll_next;
1235 }
1236 EXPORT_SYMBOL_GPL(ata_sff_hsm_move);
1237 
1238 void ata_sff_queue_work(struct work_struct *work)
1239 {
1240 	queue_work(ata_sff_wq, work);
1241 }
1242 EXPORT_SYMBOL_GPL(ata_sff_queue_work);
1243 
1244 void ata_sff_queue_delayed_work(struct delayed_work *dwork, unsigned long delay)
1245 {
1246 	queue_delayed_work(ata_sff_wq, dwork, delay);
1247 }
1248 EXPORT_SYMBOL_GPL(ata_sff_queue_delayed_work);
1249 
1250 void ata_sff_queue_pio_task(struct ata_link *link, unsigned long delay)
1251 {
1252 	struct ata_port *ap = link->ap;
1253 
1254 	WARN_ON((ap->sff_pio_task_link != NULL) &&
1255 		(ap->sff_pio_task_link != link));
1256 	ap->sff_pio_task_link = link;
1257 
1258 	/* may fail if ata_sff_flush_pio_task() in progress */
1259 	ata_sff_queue_delayed_work(&ap->sff_pio_task, msecs_to_jiffies(delay));
1260 }
1261 EXPORT_SYMBOL_GPL(ata_sff_queue_pio_task);
1262 
1263 void ata_sff_flush_pio_task(struct ata_port *ap)
1264 {
1265 	DPRINTK("ENTER\n");
1266 
1267 	cancel_delayed_work_sync(&ap->sff_pio_task);
1268 
1269 	/*
1270 	 * We wanna reset the HSM state to IDLE.  If we do so without
1271 	 * grabbing the port lock, critical sections protected by it which
1272 	 * expect the HSM state to stay stable may get surprised.  For
1273 	 * example, we may set IDLE in between the time
1274 	 * __ata_sff_port_intr() checks for HSM_ST_IDLE and before it calls
1275 	 * ata_sff_hsm_move() causing ata_sff_hsm_move() to BUG().
1276 	 */
1277 	spin_lock_irq(ap->lock);
1278 	ap->hsm_task_state = HSM_ST_IDLE;
1279 	spin_unlock_irq(ap->lock);
1280 
1281 	ap->sff_pio_task_link = NULL;
1282 
1283 	if (ata_msg_ctl(ap))
1284 		ata_port_dbg(ap, "%s: EXIT\n", __func__);
1285 }
1286 
1287 static void ata_sff_pio_task(struct work_struct *work)
1288 {
1289 	struct ata_port *ap =
1290 		container_of(work, struct ata_port, sff_pio_task.work);
1291 	struct ata_link *link = ap->sff_pio_task_link;
1292 	struct ata_queued_cmd *qc;
1293 	u8 status;
1294 	int poll_next;
1295 
1296 	spin_lock_irq(ap->lock);
1297 
1298 	BUG_ON(ap->sff_pio_task_link == NULL);
1299 	/* qc can be NULL if timeout occurred */
1300 	qc = ata_qc_from_tag(ap, link->active_tag);
1301 	if (!qc) {
1302 		ap->sff_pio_task_link = NULL;
1303 		goto out_unlock;
1304 	}
1305 
1306 fsm_start:
1307 	WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
1308 
1309 	/*
1310 	 * This is purely heuristic.  This is a fast path.
1311 	 * Sometimes when we enter, BSY will be cleared in
1312 	 * a chk-status or two.  If not, the drive is probably seeking
1313 	 * or something.  Snooze for a couple msecs, then
1314 	 * chk-status again.  If still busy, queue delayed work.
1315 	 */
1316 	status = ata_sff_busy_wait(ap, ATA_BUSY, 5);
1317 	if (status & ATA_BUSY) {
1318 		spin_unlock_irq(ap->lock);
1319 		ata_msleep(ap, 2);
1320 		spin_lock_irq(ap->lock);
1321 
1322 		status = ata_sff_busy_wait(ap, ATA_BUSY, 10);
1323 		if (status & ATA_BUSY) {
1324 			ata_sff_queue_pio_task(link, ATA_SHORT_PAUSE);
1325 			goto out_unlock;
1326 		}
1327 	}
1328 
1329 	/*
1330 	 * hsm_move() may trigger another command to be processed.
1331 	 * clean the link beforehand.
1332 	 */
1333 	ap->sff_pio_task_link = NULL;
1334 	/* move the HSM */
1335 	poll_next = ata_sff_hsm_move(ap, qc, status, 1);
1336 
1337 	/* another command or interrupt handler
1338 	 * may be running at this point.
1339 	 */
1340 	if (poll_next)
1341 		goto fsm_start;
1342 out_unlock:
1343 	spin_unlock_irq(ap->lock);
1344 }
1345 
1346 /**
1347  *	ata_sff_qc_issue - issue taskfile to a SFF controller
1348  *	@qc: command to issue to device
1349  *
1350  *	This function issues a PIO or NODATA command to a SFF
1351  *	controller.
1352  *
1353  *	LOCKING:
1354  *	spin_lock_irqsave(host lock)
1355  *
1356  *	RETURNS:
1357  *	Zero on success, AC_ERR_* mask on failure
1358  */
1359 unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
1360 {
1361 	struct ata_port *ap = qc->ap;
1362 	struct ata_link *link = qc->dev->link;
1363 
1364 	/* Use polling pio if the LLD doesn't handle
1365 	 * interrupt driven pio and atapi CDB interrupt.
1366 	 */
1367 	if (ap->flags & ATA_FLAG_PIO_POLLING)
1368 		qc->tf.flags |= ATA_TFLAG_POLLING;
1369 
1370 	/* select the device */
1371 	ata_dev_select(ap, qc->dev->devno, 1, 0);
1372 
1373 	/* start the command */
1374 	switch (qc->tf.protocol) {
1375 	case ATA_PROT_NODATA:
1376 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1377 			ata_qc_set_polling(qc);
1378 
1379 		ata_tf_to_host(ap, &qc->tf);
1380 		ap->hsm_task_state = HSM_ST_LAST;
1381 
1382 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1383 			ata_sff_queue_pio_task(link, 0);
1384 
1385 		break;
1386 
1387 	case ATA_PROT_PIO:
1388 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1389 			ata_qc_set_polling(qc);
1390 
1391 		ata_tf_to_host(ap, &qc->tf);
1392 
1393 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
1394 			/* PIO data out protocol */
1395 			ap->hsm_task_state = HSM_ST_FIRST;
1396 			ata_sff_queue_pio_task(link, 0);
1397 
1398 			/* always send first data block using the
1399 			 * ata_sff_pio_task() codepath.
1400 			 */
1401 		} else {
1402 			/* PIO data in protocol */
1403 			ap->hsm_task_state = HSM_ST;
1404 
1405 			if (qc->tf.flags & ATA_TFLAG_POLLING)
1406 				ata_sff_queue_pio_task(link, 0);
1407 
1408 			/* if polling, ata_sff_pio_task() handles the
1409 			 * rest.  otherwise, interrupt handler takes
1410 			 * over from here.
1411 			 */
1412 		}
1413 
1414 		break;
1415 
1416 	case ATAPI_PROT_PIO:
1417 	case ATAPI_PROT_NODATA:
1418 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1419 			ata_qc_set_polling(qc);
1420 
1421 		ata_tf_to_host(ap, &qc->tf);
1422 
1423 		ap->hsm_task_state = HSM_ST_FIRST;
1424 
1425 		/* send cdb by polling if no cdb interrupt */
1426 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
1427 		    (qc->tf.flags & ATA_TFLAG_POLLING))
1428 			ata_sff_queue_pio_task(link, 0);
1429 		break;
1430 
1431 	default:
1432 		return AC_ERR_SYSTEM;
1433 	}
1434 
1435 	return 0;
1436 }
1437 EXPORT_SYMBOL_GPL(ata_sff_qc_issue);
1438 
1439 /**
1440  *	ata_sff_qc_fill_rtf - fill result TF using ->sff_tf_read
1441  *	@qc: qc to fill result TF for
1442  *
1443  *	@qc is finished and result TF needs to be filled.  Fill it
1444  *	using ->sff_tf_read.
1445  *
1446  *	LOCKING:
1447  *	spin_lock_irqsave(host lock)
1448  *
1449  *	RETURNS:
1450  *	true indicating that result TF is successfully filled.
1451  */
1452 bool ata_sff_qc_fill_rtf(struct ata_queued_cmd *qc)
1453 {
1454 	qc->ap->ops->sff_tf_read(qc->ap, &qc->result_tf);
1455 	return true;
1456 }
1457 EXPORT_SYMBOL_GPL(ata_sff_qc_fill_rtf);
1458 
1459 static unsigned int ata_sff_idle_irq(struct ata_port *ap)
1460 {
1461 	ap->stats.idle_irq++;
1462 
1463 #ifdef ATA_IRQ_TRAP
1464 	if ((ap->stats.idle_irq % 1000) == 0) {
1465 		ap->ops->sff_check_status(ap);
1466 		if (ap->ops->sff_irq_clear)
1467 			ap->ops->sff_irq_clear(ap);
1468 		ata_port_warn(ap, "irq trap\n");
1469 		return 1;
1470 	}
1471 #endif
1472 	return 0;	/* irq not handled */
1473 }
1474 
1475 static unsigned int __ata_sff_port_intr(struct ata_port *ap,
1476 					struct ata_queued_cmd *qc,
1477 					bool hsmv_on_idle)
1478 {
1479 	u8 status;
1480 
1481 	VPRINTK("ata%u: protocol %d task_state %d\n",
1482 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
1483 
1484 	/* Check whether we are expecting interrupt in this state */
1485 	switch (ap->hsm_task_state) {
1486 	case HSM_ST_FIRST:
1487 		/* Some pre-ATAPI-4 devices assert INTRQ
1488 		 * at this state when ready to receive CDB.
1489 		 */
1490 
1491 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
1492 		 * The flag was turned on only for atapi devices.  No
1493 		 * need to check ata_is_atapi(qc->tf.protocol) again.
1494 		 */
1495 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
1496 			return ata_sff_idle_irq(ap);
1497 		break;
1498 	case HSM_ST_IDLE:
1499 		return ata_sff_idle_irq(ap);
1500 	default:
1501 		break;
1502 	}
1503 
1504 	/* check main status, clearing INTRQ if needed */
1505 	status = ata_sff_irq_status(ap);
1506 	if (status & ATA_BUSY) {
1507 		if (hsmv_on_idle) {
1508 			/* BMDMA engine is already stopped, we're screwed */
1509 			qc->err_mask |= AC_ERR_HSM;
1510 			ap->hsm_task_state = HSM_ST_ERR;
1511 		} else
1512 			return ata_sff_idle_irq(ap);
1513 	}
1514 
1515 	/* clear irq events */
1516 	if (ap->ops->sff_irq_clear)
1517 		ap->ops->sff_irq_clear(ap);
1518 
1519 	ata_sff_hsm_move(ap, qc, status, 0);
1520 
1521 	return 1;	/* irq handled */
1522 }
1523 
1524 /**
1525  *	ata_sff_port_intr - Handle SFF port interrupt
1526  *	@ap: Port on which interrupt arrived (possibly...)
1527  *	@qc: Taskfile currently active in engine
1528  *
1529  *	Handle port interrupt for given queued command.
1530  *
1531  *	LOCKING:
1532  *	spin_lock_irqsave(host lock)
1533  *
1534  *	RETURNS:
1535  *	One if interrupt was handled, zero if not (shared irq).
1536  */
1537 unsigned int ata_sff_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
1538 {
1539 	return __ata_sff_port_intr(ap, qc, false);
1540 }
1541 EXPORT_SYMBOL_GPL(ata_sff_port_intr);
1542 
1543 static inline irqreturn_t __ata_sff_interrupt(int irq, void *dev_instance,
1544 	unsigned int (*port_intr)(struct ata_port *, struct ata_queued_cmd *))
1545 {
1546 	struct ata_host *host = dev_instance;
1547 	bool retried = false;
1548 	unsigned int i;
1549 	unsigned int handled, idle, polling;
1550 	unsigned long flags;
1551 
1552 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
1553 	spin_lock_irqsave(&host->lock, flags);
1554 
1555 retry:
1556 	handled = idle = polling = 0;
1557 	for (i = 0; i < host->n_ports; i++) {
1558 		struct ata_port *ap = host->ports[i];
1559 		struct ata_queued_cmd *qc;
1560 
1561 		qc = ata_qc_from_tag(ap, ap->link.active_tag);
1562 		if (qc) {
1563 			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
1564 				handled |= port_intr(ap, qc);
1565 			else
1566 				polling |= 1 << i;
1567 		} else
1568 			idle |= 1 << i;
1569 	}
1570 
1571 	/*
1572 	 * If no port was expecting IRQ but the controller is actually
1573 	 * asserting IRQ line, nobody cared will ensue.  Check IRQ
1574 	 * pending status if available and clear spurious IRQ.
1575 	 */
1576 	if (!handled && !retried) {
1577 		bool retry = false;
1578 
1579 		for (i = 0; i < host->n_ports; i++) {
1580 			struct ata_port *ap = host->ports[i];
1581 
1582 			if (polling & (1 << i))
1583 				continue;
1584 
1585 			if (!ap->ops->sff_irq_check ||
1586 			    !ap->ops->sff_irq_check(ap))
1587 				continue;
1588 
1589 			if (idle & (1 << i)) {
1590 				ap->ops->sff_check_status(ap);
1591 				if (ap->ops->sff_irq_clear)
1592 					ap->ops->sff_irq_clear(ap);
1593 			} else {
1594 				/* clear INTRQ and check if BUSY cleared */
1595 				if (!(ap->ops->sff_check_status(ap) & ATA_BUSY))
1596 					retry |= true;
1597 				/*
1598 				 * With command in flight, we can't do
1599 				 * sff_irq_clear() w/o racing with completion.
1600 				 */
1601 			}
1602 		}
1603 
1604 		if (retry) {
1605 			retried = true;
1606 			goto retry;
1607 		}
1608 	}
1609 
1610 	spin_unlock_irqrestore(&host->lock, flags);
1611 
1612 	return IRQ_RETVAL(handled);
1613 }
1614 
1615 /**
1616  *	ata_sff_interrupt - Default SFF ATA host interrupt handler
1617  *	@irq: irq line (unused)
1618  *	@dev_instance: pointer to our ata_host information structure
1619  *
1620  *	Default interrupt handler for PCI IDE devices.  Calls
1621  *	ata_sff_port_intr() for each port that is not disabled.
1622  *
1623  *	LOCKING:
1624  *	Obtains host lock during operation.
1625  *
1626  *	RETURNS:
1627  *	IRQ_NONE or IRQ_HANDLED.
1628  */
1629 irqreturn_t ata_sff_interrupt(int irq, void *dev_instance)
1630 {
1631 	return __ata_sff_interrupt(irq, dev_instance, ata_sff_port_intr);
1632 }
1633 EXPORT_SYMBOL_GPL(ata_sff_interrupt);
1634 
1635 /**
1636  *	ata_sff_lost_interrupt	-	Check for an apparent lost interrupt
1637  *	@ap: port that appears to have timed out
1638  *
1639  *	Called from the libata error handlers when the core code suspects
1640  *	an interrupt has been lost. If it has complete anything we can and
1641  *	then return. Interface must support altstatus for this faster
1642  *	recovery to occur.
1643  *
1644  *	Locking:
1645  *	Caller holds host lock
1646  */
1647 
1648 void ata_sff_lost_interrupt(struct ata_port *ap)
1649 {
1650 	u8 status;
1651 	struct ata_queued_cmd *qc;
1652 
1653 	/* Only one outstanding command per SFF channel */
1654 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
1655 	/* We cannot lose an interrupt on a non-existent or polled command */
1656 	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
1657 		return;
1658 	/* See if the controller thinks it is still busy - if so the command
1659 	   isn't a lost IRQ but is still in progress */
1660 	status = ata_sff_altstatus(ap);
1661 	if (status & ATA_BUSY)
1662 		return;
1663 
1664 	/* There was a command running, we are no longer busy and we have
1665 	   no interrupt. */
1666 	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
1667 								status);
1668 	/* Run the host interrupt logic as if the interrupt had not been
1669 	   lost */
1670 	ata_sff_port_intr(ap, qc);
1671 }
1672 EXPORT_SYMBOL_GPL(ata_sff_lost_interrupt);
1673 
1674 /**
1675  *	ata_sff_freeze - Freeze SFF controller port
1676  *	@ap: port to freeze
1677  *
1678  *	Freeze SFF controller port.
1679  *
1680  *	LOCKING:
1681  *	Inherited from caller.
1682  */
1683 void ata_sff_freeze(struct ata_port *ap)
1684 {
1685 	ap->ctl |= ATA_NIEN;
1686 	ap->last_ctl = ap->ctl;
1687 
1688 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr)
1689 		ata_sff_set_devctl(ap, ap->ctl);
1690 
1691 	/* Under certain circumstances, some controllers raise IRQ on
1692 	 * ATA_NIEN manipulation.  Also, many controllers fail to mask
1693 	 * previously pending IRQ on ATA_NIEN assertion.  Clear it.
1694 	 */
1695 	ap->ops->sff_check_status(ap);
1696 
1697 	if (ap->ops->sff_irq_clear)
1698 		ap->ops->sff_irq_clear(ap);
1699 }
1700 EXPORT_SYMBOL_GPL(ata_sff_freeze);
1701 
1702 /**
1703  *	ata_sff_thaw - Thaw SFF controller port
1704  *	@ap: port to thaw
1705  *
1706  *	Thaw SFF controller port.
1707  *
1708  *	LOCKING:
1709  *	Inherited from caller.
1710  */
1711 void ata_sff_thaw(struct ata_port *ap)
1712 {
1713 	/* clear & re-enable interrupts */
1714 	ap->ops->sff_check_status(ap);
1715 	if (ap->ops->sff_irq_clear)
1716 		ap->ops->sff_irq_clear(ap);
1717 	ata_sff_irq_on(ap);
1718 }
1719 EXPORT_SYMBOL_GPL(ata_sff_thaw);
1720 
1721 /**
1722  *	ata_sff_prereset - prepare SFF link for reset
1723  *	@link: SFF link to be reset
1724  *	@deadline: deadline jiffies for the operation
1725  *
1726  *	SFF link @link is about to be reset.  Initialize it.  It first
1727  *	calls ata_std_prereset() and wait for !BSY if the port is
1728  *	being softreset.
1729  *
1730  *	LOCKING:
1731  *	Kernel thread context (may sleep)
1732  *
1733  *	RETURNS:
1734  *	0 on success, -errno otherwise.
1735  */
1736 int ata_sff_prereset(struct ata_link *link, unsigned long deadline)
1737 {
1738 	struct ata_eh_context *ehc = &link->eh_context;
1739 	int rc;
1740 
1741 	rc = ata_std_prereset(link, deadline);
1742 	if (rc)
1743 		return rc;
1744 
1745 	/* if we're about to do hardreset, nothing more to do */
1746 	if (ehc->i.action & ATA_EH_HARDRESET)
1747 		return 0;
1748 
1749 	/* wait for !BSY if we don't know that no device is attached */
1750 	if (!ata_link_offline(link)) {
1751 		rc = ata_sff_wait_ready(link, deadline);
1752 		if (rc && rc != -ENODEV) {
1753 			ata_link_warn(link,
1754 				      "device not ready (errno=%d), forcing hardreset\n",
1755 				      rc);
1756 			ehc->i.action |= ATA_EH_HARDRESET;
1757 		}
1758 	}
1759 
1760 	return 0;
1761 }
1762 EXPORT_SYMBOL_GPL(ata_sff_prereset);
1763 
1764 /**
1765  *	ata_devchk - PATA device presence detection
1766  *	@ap: ATA channel to examine
1767  *	@device: Device to examine (starting at zero)
1768  *
1769  *	This technique was originally described in
1770  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
1771  *	later found its way into the ATA/ATAPI spec.
1772  *
1773  *	Write a pattern to the ATA shadow registers,
1774  *	and if a device is present, it will respond by
1775  *	correctly storing and echoing back the
1776  *	ATA shadow register contents.
1777  *
1778  *	LOCKING:
1779  *	caller.
1780  */
1781 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
1782 {
1783 	struct ata_ioports *ioaddr = &ap->ioaddr;
1784 	u8 nsect, lbal;
1785 
1786 	ap->ops->sff_dev_select(ap, device);
1787 
1788 	iowrite8(0x55, ioaddr->nsect_addr);
1789 	iowrite8(0xaa, ioaddr->lbal_addr);
1790 
1791 	iowrite8(0xaa, ioaddr->nsect_addr);
1792 	iowrite8(0x55, ioaddr->lbal_addr);
1793 
1794 	iowrite8(0x55, ioaddr->nsect_addr);
1795 	iowrite8(0xaa, ioaddr->lbal_addr);
1796 
1797 	nsect = ioread8(ioaddr->nsect_addr);
1798 	lbal = ioread8(ioaddr->lbal_addr);
1799 
1800 	if ((nsect == 0x55) && (lbal == 0xaa))
1801 		return 1;	/* we found a device */
1802 
1803 	return 0;		/* nothing found */
1804 }
1805 
1806 /**
1807  *	ata_sff_dev_classify - Parse returned ATA device signature
1808  *	@dev: ATA device to classify (starting at zero)
1809  *	@present: device seems present
1810  *	@r_err: Value of error register on completion
1811  *
1812  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
1813  *	an ATA/ATAPI-defined set of values is placed in the ATA
1814  *	shadow registers, indicating the results of device detection
1815  *	and diagnostics.
1816  *
1817  *	Select the ATA device, and read the values from the ATA shadow
1818  *	registers.  Then parse according to the Error register value,
1819  *	and the spec-defined values examined by ata_dev_classify().
1820  *
1821  *	LOCKING:
1822  *	caller.
1823  *
1824  *	RETURNS:
1825  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
1826  */
1827 unsigned int ata_sff_dev_classify(struct ata_device *dev, int present,
1828 				  u8 *r_err)
1829 {
1830 	struct ata_port *ap = dev->link->ap;
1831 	struct ata_taskfile tf;
1832 	unsigned int class;
1833 	u8 err;
1834 
1835 	ap->ops->sff_dev_select(ap, dev->devno);
1836 
1837 	memset(&tf, 0, sizeof(tf));
1838 
1839 	ap->ops->sff_tf_read(ap, &tf);
1840 	err = tf.feature;
1841 	if (r_err)
1842 		*r_err = err;
1843 
1844 	/* see if device passed diags: continue and warn later */
1845 	if (err == 0)
1846 		/* diagnostic fail : do nothing _YET_ */
1847 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
1848 	else if (err == 1)
1849 		/* do nothing */ ;
1850 	else if ((dev->devno == 0) && (err == 0x81))
1851 		/* do nothing */ ;
1852 	else
1853 		return ATA_DEV_NONE;
1854 
1855 	/* determine if device is ATA or ATAPI */
1856 	class = ata_dev_classify(&tf);
1857 
1858 	if (class == ATA_DEV_UNKNOWN) {
1859 		/* If the device failed diagnostic, it's likely to
1860 		 * have reported incorrect device signature too.
1861 		 * Assume ATA device if the device seems present but
1862 		 * device signature is invalid with diagnostic
1863 		 * failure.
1864 		 */
1865 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
1866 			class = ATA_DEV_ATA;
1867 		else
1868 			class = ATA_DEV_NONE;
1869 	} else if ((class == ATA_DEV_ATA) &&
1870 		   (ap->ops->sff_check_status(ap) == 0))
1871 		class = ATA_DEV_NONE;
1872 
1873 	return class;
1874 }
1875 EXPORT_SYMBOL_GPL(ata_sff_dev_classify);
1876 
1877 /**
1878  *	ata_sff_wait_after_reset - wait for devices to become ready after reset
1879  *	@link: SFF link which is just reset
1880  *	@devmask: mask of present devices
1881  *	@deadline: deadline jiffies for the operation
1882  *
1883  *	Wait devices attached to SFF @link to become ready after
1884  *	reset.  It contains preceding 150ms wait to avoid accessing TF
1885  *	status register too early.
1886  *
1887  *	LOCKING:
1888  *	Kernel thread context (may sleep).
1889  *
1890  *	RETURNS:
1891  *	0 on success, -ENODEV if some or all of devices in @devmask
1892  *	don't seem to exist.  -errno on other errors.
1893  */
1894 int ata_sff_wait_after_reset(struct ata_link *link, unsigned int devmask,
1895 			     unsigned long deadline)
1896 {
1897 	struct ata_port *ap = link->ap;
1898 	struct ata_ioports *ioaddr = &ap->ioaddr;
1899 	unsigned int dev0 = devmask & (1 << 0);
1900 	unsigned int dev1 = devmask & (1 << 1);
1901 	int rc, ret = 0;
1902 
1903 	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
1904 
1905 	/* always check readiness of the master device */
1906 	rc = ata_sff_wait_ready(link, deadline);
1907 	/* -ENODEV means the odd clown forgot the D7 pulldown resistor
1908 	 * and TF status is 0xff, bail out on it too.
1909 	 */
1910 	if (rc)
1911 		return rc;
1912 
1913 	/* if device 1 was found in ata_devchk, wait for register
1914 	 * access briefly, then wait for BSY to clear.
1915 	 */
1916 	if (dev1) {
1917 		int i;
1918 
1919 		ap->ops->sff_dev_select(ap, 1);
1920 
1921 		/* Wait for register access.  Some ATAPI devices fail
1922 		 * to set nsect/lbal after reset, so don't waste too
1923 		 * much time on it.  We're gonna wait for !BSY anyway.
1924 		 */
1925 		for (i = 0; i < 2; i++) {
1926 			u8 nsect, lbal;
1927 
1928 			nsect = ioread8(ioaddr->nsect_addr);
1929 			lbal = ioread8(ioaddr->lbal_addr);
1930 			if ((nsect == 1) && (lbal == 1))
1931 				break;
1932 			ata_msleep(ap, 50);	/* give drive a breather */
1933 		}
1934 
1935 		rc = ata_sff_wait_ready(link, deadline);
1936 		if (rc) {
1937 			if (rc != -ENODEV)
1938 				return rc;
1939 			ret = rc;
1940 		}
1941 	}
1942 
1943 	/* is all this really necessary? */
1944 	ap->ops->sff_dev_select(ap, 0);
1945 	if (dev1)
1946 		ap->ops->sff_dev_select(ap, 1);
1947 	if (dev0)
1948 		ap->ops->sff_dev_select(ap, 0);
1949 
1950 	return ret;
1951 }
1952 EXPORT_SYMBOL_GPL(ata_sff_wait_after_reset);
1953 
1954 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
1955 			     unsigned long deadline)
1956 {
1957 	struct ata_ioports *ioaddr = &ap->ioaddr;
1958 
1959 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
1960 
1961 	if (ap->ioaddr.ctl_addr) {
1962 		/* software reset.  causes dev0 to be selected */
1963 		iowrite8(ap->ctl, ioaddr->ctl_addr);
1964 		udelay(20);	/* FIXME: flush */
1965 		iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
1966 		udelay(20);	/* FIXME: flush */
1967 		iowrite8(ap->ctl, ioaddr->ctl_addr);
1968 		ap->last_ctl = ap->ctl;
1969 	}
1970 
1971 	/* wait the port to become ready */
1972 	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
1973 }
1974 
1975 /**
1976  *	ata_sff_softreset - reset host port via ATA SRST
1977  *	@link: ATA link to reset
1978  *	@classes: resulting classes of attached devices
1979  *	@deadline: deadline jiffies for the operation
1980  *
1981  *	Reset host port using ATA SRST.
1982  *
1983  *	LOCKING:
1984  *	Kernel thread context (may sleep)
1985  *
1986  *	RETURNS:
1987  *	0 on success, -errno otherwise.
1988  */
1989 int ata_sff_softreset(struct ata_link *link, unsigned int *classes,
1990 		      unsigned long deadline)
1991 {
1992 	struct ata_port *ap = link->ap;
1993 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
1994 	unsigned int devmask = 0;
1995 	int rc;
1996 	u8 err;
1997 
1998 	DPRINTK("ENTER\n");
1999 
2000 	/* determine if device 0/1 are present */
2001 	if (ata_devchk(ap, 0))
2002 		devmask |= (1 << 0);
2003 	if (slave_possible && ata_devchk(ap, 1))
2004 		devmask |= (1 << 1);
2005 
2006 	/* select device 0 again */
2007 	ap->ops->sff_dev_select(ap, 0);
2008 
2009 	/* issue bus reset */
2010 	DPRINTK("about to softreset, devmask=%x\n", devmask);
2011 	rc = ata_bus_softreset(ap, devmask, deadline);
2012 	/* if link is occupied, -ENODEV too is an error */
2013 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
2014 		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
2015 		return rc;
2016 	}
2017 
2018 	/* determine by signature whether we have ATA or ATAPI devices */
2019 	classes[0] = ata_sff_dev_classify(&link->device[0],
2020 					  devmask & (1 << 0), &err);
2021 	if (slave_possible && err != 0x81)
2022 		classes[1] = ata_sff_dev_classify(&link->device[1],
2023 						  devmask & (1 << 1), &err);
2024 
2025 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
2026 	return 0;
2027 }
2028 EXPORT_SYMBOL_GPL(ata_sff_softreset);
2029 
2030 /**
2031  *	sata_sff_hardreset - reset host port via SATA phy reset
2032  *	@link: link to reset
2033  *	@class: resulting class of attached device
2034  *	@deadline: deadline jiffies for the operation
2035  *
2036  *	SATA phy-reset host port using DET bits of SControl register,
2037  *	wait for !BSY and classify the attached device.
2038  *
2039  *	LOCKING:
2040  *	Kernel thread context (may sleep)
2041  *
2042  *	RETURNS:
2043  *	0 on success, -errno otherwise.
2044  */
2045 int sata_sff_hardreset(struct ata_link *link, unsigned int *class,
2046 		       unsigned long deadline)
2047 {
2048 	struct ata_eh_context *ehc = &link->eh_context;
2049 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
2050 	bool online;
2051 	int rc;
2052 
2053 	rc = sata_link_hardreset(link, timing, deadline, &online,
2054 				 ata_sff_check_ready);
2055 	if (online)
2056 		*class = ata_sff_dev_classify(link->device, 1, NULL);
2057 
2058 	DPRINTK("EXIT, class=%u\n", *class);
2059 	return rc;
2060 }
2061 EXPORT_SYMBOL_GPL(sata_sff_hardreset);
2062 
2063 /**
2064  *	ata_sff_postreset - SFF postreset callback
2065  *	@link: the target SFF ata_link
2066  *	@classes: classes of attached devices
2067  *
2068  *	This function is invoked after a successful reset.  It first
2069  *	calls ata_std_postreset() and performs SFF specific postreset
2070  *	processing.
2071  *
2072  *	LOCKING:
2073  *	Kernel thread context (may sleep)
2074  */
2075 void ata_sff_postreset(struct ata_link *link, unsigned int *classes)
2076 {
2077 	struct ata_port *ap = link->ap;
2078 
2079 	ata_std_postreset(link, classes);
2080 
2081 	/* is double-select really necessary? */
2082 	if (classes[0] != ATA_DEV_NONE)
2083 		ap->ops->sff_dev_select(ap, 1);
2084 	if (classes[1] != ATA_DEV_NONE)
2085 		ap->ops->sff_dev_select(ap, 0);
2086 
2087 	/* bail out if no device is present */
2088 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
2089 		DPRINTK("EXIT, no device\n");
2090 		return;
2091 	}
2092 
2093 	/* set up device control */
2094 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr) {
2095 		ata_sff_set_devctl(ap, ap->ctl);
2096 		ap->last_ctl = ap->ctl;
2097 	}
2098 }
2099 EXPORT_SYMBOL_GPL(ata_sff_postreset);
2100 
2101 /**
2102  *	ata_sff_drain_fifo - Stock FIFO drain logic for SFF controllers
2103  *	@qc: command
2104  *
2105  *	Drain the FIFO and device of any stuck data following a command
2106  *	failing to complete. In some cases this is necessary before a
2107  *	reset will recover the device.
2108  *
2109  */
2110 
2111 void ata_sff_drain_fifo(struct ata_queued_cmd *qc)
2112 {
2113 	int count;
2114 	struct ata_port *ap;
2115 
2116 	/* We only need to flush incoming data when a command was running */
2117 	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
2118 		return;
2119 
2120 	ap = qc->ap;
2121 	/* Drain up to 64K of data before we give up this recovery method */
2122 	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
2123 						&& count < 65536; count += 2)
2124 		ioread16(ap->ioaddr.data_addr);
2125 
2126 	/* Can become DEBUG later */
2127 	if (count)
2128 		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
2129 
2130 }
2131 EXPORT_SYMBOL_GPL(ata_sff_drain_fifo);
2132 
2133 /**
2134  *	ata_sff_error_handler - Stock error handler for SFF controller
2135  *	@ap: port to handle error for
2136  *
2137  *	Stock error handler for SFF controller.  It can handle both
2138  *	PATA and SATA controllers.  Many controllers should be able to
2139  *	use this EH as-is or with some added handling before and
2140  *	after.
2141  *
2142  *	LOCKING:
2143  *	Kernel thread context (may sleep)
2144  */
2145 void ata_sff_error_handler(struct ata_port *ap)
2146 {
2147 	ata_reset_fn_t softreset = ap->ops->softreset;
2148 	ata_reset_fn_t hardreset = ap->ops->hardreset;
2149 	struct ata_queued_cmd *qc;
2150 	unsigned long flags;
2151 
2152 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2153 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2154 		qc = NULL;
2155 
2156 	spin_lock_irqsave(ap->lock, flags);
2157 
2158 	/*
2159 	 * We *MUST* do FIFO draining before we issue a reset as
2160 	 * several devices helpfully clear their internal state and
2161 	 * will lock solid if we touch the data port post reset. Pass
2162 	 * qc in case anyone wants to do different PIO/DMA recovery or
2163 	 * has per command fixups
2164 	 */
2165 	if (ap->ops->sff_drain_fifo)
2166 		ap->ops->sff_drain_fifo(qc);
2167 
2168 	spin_unlock_irqrestore(ap->lock, flags);
2169 
2170 	/* ignore built-in hardresets if SCR access is not available */
2171 	if ((hardreset == sata_std_hardreset ||
2172 	     hardreset == sata_sff_hardreset) && !sata_scr_valid(&ap->link))
2173 		hardreset = NULL;
2174 
2175 	ata_do_eh(ap, ap->ops->prereset, softreset, hardreset,
2176 		  ap->ops->postreset);
2177 }
2178 EXPORT_SYMBOL_GPL(ata_sff_error_handler);
2179 
2180 /**
2181  *	ata_sff_std_ports - initialize ioaddr with standard port offsets.
2182  *	@ioaddr: IO address structure to be initialized
2183  *
2184  *	Utility function which initializes data_addr, error_addr,
2185  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
2186  *	device_addr, status_addr, and command_addr to standard offsets
2187  *	relative to cmd_addr.
2188  *
2189  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
2190  */
2191 void ata_sff_std_ports(struct ata_ioports *ioaddr)
2192 {
2193 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
2194 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
2195 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
2196 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
2197 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
2198 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
2199 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
2200 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
2201 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
2202 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
2203 }
2204 EXPORT_SYMBOL_GPL(ata_sff_std_ports);
2205 
2206 #ifdef CONFIG_PCI
2207 
2208 static int ata_resources_present(struct pci_dev *pdev, int port)
2209 {
2210 	int i;
2211 
2212 	/* Check the PCI resources for this channel are enabled */
2213 	port = port * 2;
2214 	for (i = 0; i < 2; i++) {
2215 		if (pci_resource_start(pdev, port + i) == 0 ||
2216 		    pci_resource_len(pdev, port + i) == 0)
2217 			return 0;
2218 	}
2219 	return 1;
2220 }
2221 
2222 /**
2223  *	ata_pci_sff_init_host - acquire native PCI ATA resources and init host
2224  *	@host: target ATA host
2225  *
2226  *	Acquire native PCI ATA resources for @host and initialize the
2227  *	first two ports of @host accordingly.  Ports marked dummy are
2228  *	skipped and allocation failure makes the port dummy.
2229  *
2230  *	Note that native PCI resources are valid even for legacy hosts
2231  *	as we fix up pdev resources array early in boot, so this
2232  *	function can be used for both native and legacy SFF hosts.
2233  *
2234  *	LOCKING:
2235  *	Inherited from calling layer (may sleep).
2236  *
2237  *	RETURNS:
2238  *	0 if at least one port is initialized, -ENODEV if no port is
2239  *	available.
2240  */
2241 int ata_pci_sff_init_host(struct ata_host *host)
2242 {
2243 	struct device *gdev = host->dev;
2244 	struct pci_dev *pdev = to_pci_dev(gdev);
2245 	unsigned int mask = 0;
2246 	int i, rc;
2247 
2248 	/* request, iomap BARs and init port addresses accordingly */
2249 	for (i = 0; i < 2; i++) {
2250 		struct ata_port *ap = host->ports[i];
2251 		int base = i * 2;
2252 		void __iomem * const *iomap;
2253 
2254 		if (ata_port_is_dummy(ap))
2255 			continue;
2256 
2257 		/* Discard disabled ports.  Some controllers show
2258 		 * their unused channels this way.  Disabled ports are
2259 		 * made dummy.
2260 		 */
2261 		if (!ata_resources_present(pdev, i)) {
2262 			ap->ops = &ata_dummy_port_ops;
2263 			continue;
2264 		}
2265 
2266 		rc = pcim_iomap_regions(pdev, 0x3 << base,
2267 					dev_driver_string(gdev));
2268 		if (rc) {
2269 			dev_warn(gdev,
2270 				 "failed to request/iomap BARs for port %d (errno=%d)\n",
2271 				 i, rc);
2272 			if (rc == -EBUSY)
2273 				pcim_pin_device(pdev);
2274 			ap->ops = &ata_dummy_port_ops;
2275 			continue;
2276 		}
2277 		host->iomap = iomap = pcim_iomap_table(pdev);
2278 
2279 		ap->ioaddr.cmd_addr = iomap[base];
2280 		ap->ioaddr.altstatus_addr =
2281 		ap->ioaddr.ctl_addr = (void __iomem *)
2282 			((unsigned long)iomap[base + 1] | ATA_PCI_CTL_OFS);
2283 		ata_sff_std_ports(&ap->ioaddr);
2284 
2285 		ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
2286 			(unsigned long long)pci_resource_start(pdev, base),
2287 			(unsigned long long)pci_resource_start(pdev, base + 1));
2288 
2289 		mask |= 1 << i;
2290 	}
2291 
2292 	if (!mask) {
2293 		dev_err(gdev, "no available native port\n");
2294 		return -ENODEV;
2295 	}
2296 
2297 	return 0;
2298 }
2299 EXPORT_SYMBOL_GPL(ata_pci_sff_init_host);
2300 
2301 /**
2302  *	ata_pci_sff_prepare_host - helper to prepare PCI PIO-only SFF ATA host
2303  *	@pdev: target PCI device
2304  *	@ppi: array of port_info, must be enough for two ports
2305  *	@r_host: out argument for the initialized ATA host
2306  *
2307  *	Helper to allocate PIO-only SFF ATA host for @pdev, acquire
2308  *	all PCI resources and initialize it accordingly in one go.
2309  *
2310  *	LOCKING:
2311  *	Inherited from calling layer (may sleep).
2312  *
2313  *	RETURNS:
2314  *	0 on success, -errno otherwise.
2315  */
2316 int ata_pci_sff_prepare_host(struct pci_dev *pdev,
2317 			     const struct ata_port_info * const *ppi,
2318 			     struct ata_host **r_host)
2319 {
2320 	struct ata_host *host;
2321 	int rc;
2322 
2323 	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
2324 		return -ENOMEM;
2325 
2326 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
2327 	if (!host) {
2328 		dev_err(&pdev->dev, "failed to allocate ATA host\n");
2329 		rc = -ENOMEM;
2330 		goto err_out;
2331 	}
2332 
2333 	rc = ata_pci_sff_init_host(host);
2334 	if (rc)
2335 		goto err_out;
2336 
2337 	devres_remove_group(&pdev->dev, NULL);
2338 	*r_host = host;
2339 	return 0;
2340 
2341 err_out:
2342 	devres_release_group(&pdev->dev, NULL);
2343 	return rc;
2344 }
2345 EXPORT_SYMBOL_GPL(ata_pci_sff_prepare_host);
2346 
2347 /**
2348  *	ata_pci_sff_activate_host - start SFF host, request IRQ and register it
2349  *	@host: target SFF ATA host
2350  *	@irq_handler: irq_handler used when requesting IRQ(s)
2351  *	@sht: scsi_host_template to use when registering the host
2352  *
2353  *	This is the counterpart of ata_host_activate() for SFF ATA
2354  *	hosts.  This separate helper is necessary because SFF hosts
2355  *	use two separate interrupts in legacy mode.
2356  *
2357  *	LOCKING:
2358  *	Inherited from calling layer (may sleep).
2359  *
2360  *	RETURNS:
2361  *	0 on success, -errno otherwise.
2362  */
2363 int ata_pci_sff_activate_host(struct ata_host *host,
2364 			      irq_handler_t irq_handler,
2365 			      struct scsi_host_template *sht)
2366 {
2367 	struct device *dev = host->dev;
2368 	struct pci_dev *pdev = to_pci_dev(dev);
2369 	const char *drv_name = dev_driver_string(host->dev);
2370 	int legacy_mode = 0, rc;
2371 
2372 	rc = ata_host_start(host);
2373 	if (rc)
2374 		return rc;
2375 
2376 	if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
2377 		u8 tmp8, mask = 0;
2378 
2379 		/*
2380 		 * ATA spec says we should use legacy mode when one
2381 		 * port is in legacy mode, but disabled ports on some
2382 		 * PCI hosts appear as fixed legacy ports, e.g SB600/700
2383 		 * on which the secondary port is not wired, so
2384 		 * ignore ports that are marked as 'dummy' during
2385 		 * this check
2386 		 */
2387 		pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp8);
2388 		if (!ata_port_is_dummy(host->ports[0]))
2389 			mask |= (1 << 0);
2390 		if (!ata_port_is_dummy(host->ports[1]))
2391 			mask |= (1 << 2);
2392 		if ((tmp8 & mask) != mask)
2393 			legacy_mode = 1;
2394 	}
2395 
2396 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2397 		return -ENOMEM;
2398 
2399 	if (!legacy_mode && pdev->irq) {
2400 		int i;
2401 
2402 		rc = devm_request_irq(dev, pdev->irq, irq_handler,
2403 				      IRQF_SHARED, drv_name, host);
2404 		if (rc)
2405 			goto out;
2406 
2407 		for (i = 0; i < 2; i++) {
2408 			if (ata_port_is_dummy(host->ports[i]))
2409 				continue;
2410 			ata_port_desc(host->ports[i], "irq %d", pdev->irq);
2411 		}
2412 	} else if (legacy_mode) {
2413 		if (!ata_port_is_dummy(host->ports[0])) {
2414 			rc = devm_request_irq(dev, ATA_PRIMARY_IRQ(pdev),
2415 					      irq_handler, IRQF_SHARED,
2416 					      drv_name, host);
2417 			if (rc)
2418 				goto out;
2419 
2420 			ata_port_desc(host->ports[0], "irq %d",
2421 				      ATA_PRIMARY_IRQ(pdev));
2422 		}
2423 
2424 		if (!ata_port_is_dummy(host->ports[1])) {
2425 			rc = devm_request_irq(dev, ATA_SECONDARY_IRQ(pdev),
2426 					      irq_handler, IRQF_SHARED,
2427 					      drv_name, host);
2428 			if (rc)
2429 				goto out;
2430 
2431 			ata_port_desc(host->ports[1], "irq %d",
2432 				      ATA_SECONDARY_IRQ(pdev));
2433 		}
2434 	}
2435 
2436 	rc = ata_host_register(host, sht);
2437 out:
2438 	if (rc == 0)
2439 		devres_remove_group(dev, NULL);
2440 	else
2441 		devres_release_group(dev, NULL);
2442 
2443 	return rc;
2444 }
2445 EXPORT_SYMBOL_GPL(ata_pci_sff_activate_host);
2446 
2447 static const struct ata_port_info *ata_sff_find_valid_pi(
2448 					const struct ata_port_info * const *ppi)
2449 {
2450 	int i;
2451 
2452 	/* look up the first valid port_info */
2453 	for (i = 0; i < 2 && ppi[i]; i++)
2454 		if (ppi[i]->port_ops != &ata_dummy_port_ops)
2455 			return ppi[i];
2456 
2457 	return NULL;
2458 }
2459 
2460 static int ata_pci_init_one(struct pci_dev *pdev,
2461 		const struct ata_port_info * const *ppi,
2462 		struct scsi_host_template *sht, void *host_priv,
2463 		int hflags, bool bmdma)
2464 {
2465 	struct device *dev = &pdev->dev;
2466 	const struct ata_port_info *pi;
2467 	struct ata_host *host = NULL;
2468 	int rc;
2469 
2470 	DPRINTK("ENTER\n");
2471 
2472 	pi = ata_sff_find_valid_pi(ppi);
2473 	if (!pi) {
2474 		dev_err(&pdev->dev, "no valid port_info specified\n");
2475 		return -EINVAL;
2476 	}
2477 
2478 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2479 		return -ENOMEM;
2480 
2481 	rc = pcim_enable_device(pdev);
2482 	if (rc)
2483 		goto out;
2484 
2485 #ifdef CONFIG_ATA_BMDMA
2486 	if (bmdma)
2487 		/* prepare and activate BMDMA host */
2488 		rc = ata_pci_bmdma_prepare_host(pdev, ppi, &host);
2489 	else
2490 #endif
2491 		/* prepare and activate SFF host */
2492 		rc = ata_pci_sff_prepare_host(pdev, ppi, &host);
2493 	if (rc)
2494 		goto out;
2495 	host->private_data = host_priv;
2496 	host->flags |= hflags;
2497 
2498 #ifdef CONFIG_ATA_BMDMA
2499 	if (bmdma) {
2500 		pci_set_master(pdev);
2501 		rc = ata_pci_sff_activate_host(host, ata_bmdma_interrupt, sht);
2502 	} else
2503 #endif
2504 		rc = ata_pci_sff_activate_host(host, ata_sff_interrupt, sht);
2505 out:
2506 	if (rc == 0)
2507 		devres_remove_group(&pdev->dev, NULL);
2508 	else
2509 		devres_release_group(&pdev->dev, NULL);
2510 
2511 	return rc;
2512 }
2513 
2514 /**
2515  *	ata_pci_sff_init_one - Initialize/register PIO-only PCI IDE controller
2516  *	@pdev: Controller to be initialized
2517  *	@ppi: array of port_info, must be enough for two ports
2518  *	@sht: scsi_host_template to use when registering the host
2519  *	@host_priv: host private_data
2520  *	@hflag: host flags
2521  *
2522  *	This is a helper function which can be called from a driver's
2523  *	xxx_init_one() probe function if the hardware uses traditional
2524  *	IDE taskfile registers and is PIO only.
2525  *
2526  *	ASSUMPTION:
2527  *	Nobody makes a single channel controller that appears solely as
2528  *	the secondary legacy port on PCI.
2529  *
2530  *	LOCKING:
2531  *	Inherited from PCI layer (may sleep).
2532  *
2533  *	RETURNS:
2534  *	Zero on success, negative on errno-based value on error.
2535  */
2536 int ata_pci_sff_init_one(struct pci_dev *pdev,
2537 		 const struct ata_port_info * const *ppi,
2538 		 struct scsi_host_template *sht, void *host_priv, int hflag)
2539 {
2540 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflag, 0);
2541 }
2542 EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
2543 
2544 #endif /* CONFIG_PCI */
2545 
2546 /*
2547  *	BMDMA support
2548  */
2549 
2550 #ifdef CONFIG_ATA_BMDMA
2551 
2552 const struct ata_port_operations ata_bmdma_port_ops = {
2553 	.inherits		= &ata_sff_port_ops,
2554 
2555 	.error_handler		= ata_bmdma_error_handler,
2556 	.post_internal_cmd	= ata_bmdma_post_internal_cmd,
2557 
2558 	.qc_prep		= ata_bmdma_qc_prep,
2559 	.qc_issue		= ata_bmdma_qc_issue,
2560 
2561 	.sff_irq_clear		= ata_bmdma_irq_clear,
2562 	.bmdma_setup		= ata_bmdma_setup,
2563 	.bmdma_start		= ata_bmdma_start,
2564 	.bmdma_stop		= ata_bmdma_stop,
2565 	.bmdma_status		= ata_bmdma_status,
2566 
2567 	.port_start		= ata_bmdma_port_start,
2568 };
2569 EXPORT_SYMBOL_GPL(ata_bmdma_port_ops);
2570 
2571 const struct ata_port_operations ata_bmdma32_port_ops = {
2572 	.inherits		= &ata_bmdma_port_ops,
2573 
2574 	.sff_data_xfer		= ata_sff_data_xfer32,
2575 	.port_start		= ata_bmdma_port_start32,
2576 };
2577 EXPORT_SYMBOL_GPL(ata_bmdma32_port_ops);
2578 
2579 /**
2580  *	ata_bmdma_fill_sg - Fill PCI IDE PRD table
2581  *	@qc: Metadata associated with taskfile to be transferred
2582  *
2583  *	Fill PCI IDE PRD (scatter-gather) table with segments
2584  *	associated with the current disk command.
2585  *
2586  *	LOCKING:
2587  *	spin_lock_irqsave(host lock)
2588  *
2589  */
2590 static void ata_bmdma_fill_sg(struct ata_queued_cmd *qc)
2591 {
2592 	struct ata_port *ap = qc->ap;
2593 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2594 	struct scatterlist *sg;
2595 	unsigned int si, pi;
2596 
2597 	pi = 0;
2598 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2599 		u32 addr, offset;
2600 		u32 sg_len, len;
2601 
2602 		/* determine if physical DMA addr spans 64K boundary.
2603 		 * Note h/w doesn't support 64-bit, so we unconditionally
2604 		 * truncate dma_addr_t to u32.
2605 		 */
2606 		addr = (u32) sg_dma_address(sg);
2607 		sg_len = sg_dma_len(sg);
2608 
2609 		while (sg_len) {
2610 			offset = addr & 0xffff;
2611 			len = sg_len;
2612 			if ((offset + sg_len) > 0x10000)
2613 				len = 0x10000 - offset;
2614 
2615 			prd[pi].addr = cpu_to_le32(addr);
2616 			prd[pi].flags_len = cpu_to_le32(len & 0xffff);
2617 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2618 
2619 			pi++;
2620 			sg_len -= len;
2621 			addr += len;
2622 		}
2623 	}
2624 
2625 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2626 }
2627 
2628 /**
2629  *	ata_bmdma_fill_sg_dumb - Fill PCI IDE PRD table
2630  *	@qc: Metadata associated with taskfile to be transferred
2631  *
2632  *	Fill PCI IDE PRD (scatter-gather) table with segments
2633  *	associated with the current disk command. Perform the fill
2634  *	so that we avoid writing any length 64K records for
2635  *	controllers that don't follow the spec.
2636  *
2637  *	LOCKING:
2638  *	spin_lock_irqsave(host lock)
2639  *
2640  */
2641 static void ata_bmdma_fill_sg_dumb(struct ata_queued_cmd *qc)
2642 {
2643 	struct ata_port *ap = qc->ap;
2644 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2645 	struct scatterlist *sg;
2646 	unsigned int si, pi;
2647 
2648 	pi = 0;
2649 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2650 		u32 addr, offset;
2651 		u32 sg_len, len, blen;
2652 
2653 		/* determine if physical DMA addr spans 64K boundary.
2654 		 * Note h/w doesn't support 64-bit, so we unconditionally
2655 		 * truncate dma_addr_t to u32.
2656 		 */
2657 		addr = (u32) sg_dma_address(sg);
2658 		sg_len = sg_dma_len(sg);
2659 
2660 		while (sg_len) {
2661 			offset = addr & 0xffff;
2662 			len = sg_len;
2663 			if ((offset + sg_len) > 0x10000)
2664 				len = 0x10000 - offset;
2665 
2666 			blen = len & 0xffff;
2667 			prd[pi].addr = cpu_to_le32(addr);
2668 			if (blen == 0) {
2669 				/* Some PATA chipsets like the CS5530 can't
2670 				   cope with 0x0000 meaning 64K as the spec
2671 				   says */
2672 				prd[pi].flags_len = cpu_to_le32(0x8000);
2673 				blen = 0x8000;
2674 				prd[++pi].addr = cpu_to_le32(addr + 0x8000);
2675 			}
2676 			prd[pi].flags_len = cpu_to_le32(blen);
2677 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2678 
2679 			pi++;
2680 			sg_len -= len;
2681 			addr += len;
2682 		}
2683 	}
2684 
2685 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2686 }
2687 
2688 /**
2689  *	ata_bmdma_qc_prep - Prepare taskfile for submission
2690  *	@qc: Metadata associated with taskfile to be prepared
2691  *
2692  *	Prepare ATA taskfile for submission.
2693  *
2694  *	LOCKING:
2695  *	spin_lock_irqsave(host lock)
2696  */
2697 enum ata_completion_errors ata_bmdma_qc_prep(struct ata_queued_cmd *qc)
2698 {
2699 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2700 		return AC_ERR_OK;
2701 
2702 	ata_bmdma_fill_sg(qc);
2703 
2704 	return AC_ERR_OK;
2705 }
2706 EXPORT_SYMBOL_GPL(ata_bmdma_qc_prep);
2707 
2708 /**
2709  *	ata_bmdma_dumb_qc_prep - Prepare taskfile for submission
2710  *	@qc: Metadata associated with taskfile to be prepared
2711  *
2712  *	Prepare ATA taskfile for submission.
2713  *
2714  *	LOCKING:
2715  *	spin_lock_irqsave(host lock)
2716  */
2717 enum ata_completion_errors ata_bmdma_dumb_qc_prep(struct ata_queued_cmd *qc)
2718 {
2719 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2720 		return AC_ERR_OK;
2721 
2722 	ata_bmdma_fill_sg_dumb(qc);
2723 
2724 	return AC_ERR_OK;
2725 }
2726 EXPORT_SYMBOL_GPL(ata_bmdma_dumb_qc_prep);
2727 
2728 /**
2729  *	ata_bmdma_qc_issue - issue taskfile to a BMDMA controller
2730  *	@qc: command to issue to device
2731  *
2732  *	This function issues a PIO, NODATA or DMA command to a
2733  *	SFF/BMDMA controller.  PIO and NODATA are handled by
2734  *	ata_sff_qc_issue().
2735  *
2736  *	LOCKING:
2737  *	spin_lock_irqsave(host lock)
2738  *
2739  *	RETURNS:
2740  *	Zero on success, AC_ERR_* mask on failure
2741  */
2742 unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc)
2743 {
2744 	struct ata_port *ap = qc->ap;
2745 	struct ata_link *link = qc->dev->link;
2746 
2747 	/* defer PIO handling to sff_qc_issue */
2748 	if (!ata_is_dma(qc->tf.protocol))
2749 		return ata_sff_qc_issue(qc);
2750 
2751 	/* select the device */
2752 	ata_dev_select(ap, qc->dev->devno, 1, 0);
2753 
2754 	/* start the command */
2755 	switch (qc->tf.protocol) {
2756 	case ATA_PROT_DMA:
2757 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2758 
2759 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2760 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2761 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
2762 		ap->hsm_task_state = HSM_ST_LAST;
2763 		break;
2764 
2765 	case ATAPI_PROT_DMA:
2766 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2767 
2768 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2769 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2770 		ap->hsm_task_state = HSM_ST_FIRST;
2771 
2772 		/* send cdb by polling if no cdb interrupt */
2773 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
2774 			ata_sff_queue_pio_task(link, 0);
2775 		break;
2776 
2777 	default:
2778 		WARN_ON(1);
2779 		return AC_ERR_SYSTEM;
2780 	}
2781 
2782 	return 0;
2783 }
2784 EXPORT_SYMBOL_GPL(ata_bmdma_qc_issue);
2785 
2786 /**
2787  *	ata_bmdma_port_intr - Handle BMDMA port interrupt
2788  *	@ap: Port on which interrupt arrived (possibly...)
2789  *	@qc: Taskfile currently active in engine
2790  *
2791  *	Handle port interrupt for given queued command.
2792  *
2793  *	LOCKING:
2794  *	spin_lock_irqsave(host lock)
2795  *
2796  *	RETURNS:
2797  *	One if interrupt was handled, zero if not (shared irq).
2798  */
2799 unsigned int ata_bmdma_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
2800 {
2801 	struct ata_eh_info *ehi = &ap->link.eh_info;
2802 	u8 host_stat = 0;
2803 	bool bmdma_stopped = false;
2804 	unsigned int handled;
2805 
2806 	if (ap->hsm_task_state == HSM_ST_LAST && ata_is_dma(qc->tf.protocol)) {
2807 		/* check status of DMA engine */
2808 		host_stat = ap->ops->bmdma_status(ap);
2809 		VPRINTK("ata%u: host_stat 0x%X\n", ap->print_id, host_stat);
2810 
2811 		/* if it's not our irq... */
2812 		if (!(host_stat & ATA_DMA_INTR))
2813 			return ata_sff_idle_irq(ap);
2814 
2815 		/* before we do anything else, clear DMA-Start bit */
2816 		ap->ops->bmdma_stop(qc);
2817 		bmdma_stopped = true;
2818 
2819 		if (unlikely(host_stat & ATA_DMA_ERR)) {
2820 			/* error when transferring data to/from memory */
2821 			qc->err_mask |= AC_ERR_HOST_BUS;
2822 			ap->hsm_task_state = HSM_ST_ERR;
2823 		}
2824 	}
2825 
2826 	handled = __ata_sff_port_intr(ap, qc, bmdma_stopped);
2827 
2828 	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
2829 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
2830 
2831 	return handled;
2832 }
2833 EXPORT_SYMBOL_GPL(ata_bmdma_port_intr);
2834 
2835 /**
2836  *	ata_bmdma_interrupt - Default BMDMA ATA host interrupt handler
2837  *	@irq: irq line (unused)
2838  *	@dev_instance: pointer to our ata_host information structure
2839  *
2840  *	Default interrupt handler for PCI IDE devices.  Calls
2841  *	ata_bmdma_port_intr() for each port that is not disabled.
2842  *
2843  *	LOCKING:
2844  *	Obtains host lock during operation.
2845  *
2846  *	RETURNS:
2847  *	IRQ_NONE or IRQ_HANDLED.
2848  */
2849 irqreturn_t ata_bmdma_interrupt(int irq, void *dev_instance)
2850 {
2851 	return __ata_sff_interrupt(irq, dev_instance, ata_bmdma_port_intr);
2852 }
2853 EXPORT_SYMBOL_GPL(ata_bmdma_interrupt);
2854 
2855 /**
2856  *	ata_bmdma_error_handler - Stock error handler for BMDMA controller
2857  *	@ap: port to handle error for
2858  *
2859  *	Stock error handler for BMDMA controller.  It can handle both
2860  *	PATA and SATA controllers.  Most BMDMA controllers should be
2861  *	able to use this EH as-is or with some added handling before
2862  *	and after.
2863  *
2864  *	LOCKING:
2865  *	Kernel thread context (may sleep)
2866  */
2867 void ata_bmdma_error_handler(struct ata_port *ap)
2868 {
2869 	struct ata_queued_cmd *qc;
2870 	unsigned long flags;
2871 	bool thaw = false;
2872 
2873 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2874 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2875 		qc = NULL;
2876 
2877 	/* reset PIO HSM and stop DMA engine */
2878 	spin_lock_irqsave(ap->lock, flags);
2879 
2880 	if (qc && ata_is_dma(qc->tf.protocol)) {
2881 		u8 host_stat;
2882 
2883 		host_stat = ap->ops->bmdma_status(ap);
2884 
2885 		/* BMDMA controllers indicate host bus error by
2886 		 * setting DMA_ERR bit and timing out.  As it wasn't
2887 		 * really a timeout event, adjust error mask and
2888 		 * cancel frozen state.
2889 		 */
2890 		if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
2891 			qc->err_mask = AC_ERR_HOST_BUS;
2892 			thaw = true;
2893 		}
2894 
2895 		ap->ops->bmdma_stop(qc);
2896 
2897 		/* if we're gonna thaw, make sure IRQ is clear */
2898 		if (thaw) {
2899 			ap->ops->sff_check_status(ap);
2900 			if (ap->ops->sff_irq_clear)
2901 				ap->ops->sff_irq_clear(ap);
2902 		}
2903 	}
2904 
2905 	spin_unlock_irqrestore(ap->lock, flags);
2906 
2907 	if (thaw)
2908 		ata_eh_thaw_port(ap);
2909 
2910 	ata_sff_error_handler(ap);
2911 }
2912 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
2913 
2914 /**
2915  *	ata_bmdma_post_internal_cmd - Stock post_internal_cmd for BMDMA
2916  *	@qc: internal command to clean up
2917  *
2918  *	LOCKING:
2919  *	Kernel thread context (may sleep)
2920  */
2921 void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
2922 {
2923 	struct ata_port *ap = qc->ap;
2924 	unsigned long flags;
2925 
2926 	if (ata_is_dma(qc->tf.protocol)) {
2927 		spin_lock_irqsave(ap->lock, flags);
2928 		ap->ops->bmdma_stop(qc);
2929 		spin_unlock_irqrestore(ap->lock, flags);
2930 	}
2931 }
2932 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
2933 
2934 /**
2935  *	ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
2936  *	@ap: Port associated with this ATA transaction.
2937  *
2938  *	Clear interrupt and error flags in DMA status register.
2939  *
2940  *	May be used as the irq_clear() entry in ata_port_operations.
2941  *
2942  *	LOCKING:
2943  *	spin_lock_irqsave(host lock)
2944  */
2945 void ata_bmdma_irq_clear(struct ata_port *ap)
2946 {
2947 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
2948 
2949 	if (!mmio)
2950 		return;
2951 
2952 	iowrite8(ioread8(mmio + ATA_DMA_STATUS), mmio + ATA_DMA_STATUS);
2953 }
2954 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
2955 
2956 /**
2957  *	ata_bmdma_setup - Set up PCI IDE BMDMA transaction
2958  *	@qc: Info associated with this ATA transaction.
2959  *
2960  *	LOCKING:
2961  *	spin_lock_irqsave(host lock)
2962  */
2963 void ata_bmdma_setup(struct ata_queued_cmd *qc)
2964 {
2965 	struct ata_port *ap = qc->ap;
2966 	unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
2967 	u8 dmactl;
2968 
2969 	/* load PRD table addr. */
2970 	mb();	/* make sure PRD table writes are visible to controller */
2971 	iowrite32(ap->bmdma_prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
2972 
2973 	/* specify data direction, triple-check start bit is clear */
2974 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2975 	dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
2976 	if (!rw)
2977 		dmactl |= ATA_DMA_WR;
2978 	iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2979 
2980 	/* issue r/w command */
2981 	ap->ops->sff_exec_command(ap, &qc->tf);
2982 }
2983 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
2984 
2985 /**
2986  *	ata_bmdma_start - Start a PCI IDE BMDMA transaction
2987  *	@qc: Info associated with this ATA transaction.
2988  *
2989  *	LOCKING:
2990  *	spin_lock_irqsave(host lock)
2991  */
2992 void ata_bmdma_start(struct ata_queued_cmd *qc)
2993 {
2994 	struct ata_port *ap = qc->ap;
2995 	u8 dmactl;
2996 
2997 	/* start host DMA transaction */
2998 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
2999 	iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
3000 
3001 	/* Strictly, one may wish to issue an ioread8() here, to
3002 	 * flush the mmio write.  However, control also passes
3003 	 * to the hardware at this point, and it will interrupt
3004 	 * us when we are to resume control.  So, in effect,
3005 	 * we don't care when the mmio write flushes.
3006 	 * Further, a read of the DMA status register _immediately_
3007 	 * following the write may not be what certain flaky hardware
3008 	 * is expected, so I think it is best to not add a readb()
3009 	 * without first all the MMIO ATA cards/mobos.
3010 	 * Or maybe I'm just being paranoid.
3011 	 *
3012 	 * FIXME: The posting of this write means I/O starts are
3013 	 * unnecessarily delayed for MMIO
3014 	 */
3015 }
3016 EXPORT_SYMBOL_GPL(ata_bmdma_start);
3017 
3018 /**
3019  *	ata_bmdma_stop - Stop PCI IDE BMDMA transfer
3020  *	@qc: Command we are ending DMA for
3021  *
3022  *	Clears the ATA_DMA_START flag in the dma control register
3023  *
3024  *	May be used as the bmdma_stop() entry in ata_port_operations.
3025  *
3026  *	LOCKING:
3027  *	spin_lock_irqsave(host lock)
3028  */
3029 void ata_bmdma_stop(struct ata_queued_cmd *qc)
3030 {
3031 	struct ata_port *ap = qc->ap;
3032 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
3033 
3034 	/* clear start/stop bit */
3035 	iowrite8(ioread8(mmio + ATA_DMA_CMD) & ~ATA_DMA_START,
3036 		 mmio + ATA_DMA_CMD);
3037 
3038 	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
3039 	ata_sff_dma_pause(ap);
3040 }
3041 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
3042 
3043 /**
3044  *	ata_bmdma_status - Read PCI IDE BMDMA status
3045  *	@ap: Port associated with this ATA transaction.
3046  *
3047  *	Read and return BMDMA status register.
3048  *
3049  *	May be used as the bmdma_status() entry in ata_port_operations.
3050  *
3051  *	LOCKING:
3052  *	spin_lock_irqsave(host lock)
3053  */
3054 u8 ata_bmdma_status(struct ata_port *ap)
3055 {
3056 	return ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
3057 }
3058 EXPORT_SYMBOL_GPL(ata_bmdma_status);
3059 
3060 
3061 /**
3062  *	ata_bmdma_port_start - Set port up for bmdma.
3063  *	@ap: Port to initialize
3064  *
3065  *	Called just after data structures for each port are
3066  *	initialized.  Allocates space for PRD table.
3067  *
3068  *	May be used as the port_start() entry in ata_port_operations.
3069  *
3070  *	LOCKING:
3071  *	Inherited from caller.
3072  */
3073 int ata_bmdma_port_start(struct ata_port *ap)
3074 {
3075 	if (ap->mwdma_mask || ap->udma_mask) {
3076 		ap->bmdma_prd =
3077 			dmam_alloc_coherent(ap->host->dev, ATA_PRD_TBL_SZ,
3078 					    &ap->bmdma_prd_dma, GFP_KERNEL);
3079 		if (!ap->bmdma_prd)
3080 			return -ENOMEM;
3081 	}
3082 
3083 	return 0;
3084 }
3085 EXPORT_SYMBOL_GPL(ata_bmdma_port_start);
3086 
3087 /**
3088  *	ata_bmdma_port_start32 - Set port up for dma.
3089  *	@ap: Port to initialize
3090  *
3091  *	Called just after data structures for each port are
3092  *	initialized.  Enables 32bit PIO and allocates space for PRD
3093  *	table.
3094  *
3095  *	May be used as the port_start() entry in ata_port_operations for
3096  *	devices that are capable of 32bit PIO.
3097  *
3098  *	LOCKING:
3099  *	Inherited from caller.
3100  */
3101 int ata_bmdma_port_start32(struct ata_port *ap)
3102 {
3103 	ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
3104 	return ata_bmdma_port_start(ap);
3105 }
3106 EXPORT_SYMBOL_GPL(ata_bmdma_port_start32);
3107 
3108 #ifdef CONFIG_PCI
3109 
3110 /**
3111  *	ata_pci_bmdma_clear_simplex -	attempt to kick device out of simplex
3112  *	@pdev: PCI device
3113  *
3114  *	Some PCI ATA devices report simplex mode but in fact can be told to
3115  *	enter non simplex mode. This implements the necessary logic to
3116  *	perform the task on such devices. Calling it on other devices will
3117  *	have -undefined- behaviour.
3118  */
3119 int ata_pci_bmdma_clear_simplex(struct pci_dev *pdev)
3120 {
3121 	unsigned long bmdma = pci_resource_start(pdev, 4);
3122 	u8 simplex;
3123 
3124 	if (bmdma == 0)
3125 		return -ENOENT;
3126 
3127 	simplex = inb(bmdma + 0x02);
3128 	outb(simplex & 0x60, bmdma + 0x02);
3129 	simplex = inb(bmdma + 0x02);
3130 	if (simplex & 0x80)
3131 		return -EOPNOTSUPP;
3132 	return 0;
3133 }
3134 EXPORT_SYMBOL_GPL(ata_pci_bmdma_clear_simplex);
3135 
3136 static void ata_bmdma_nodma(struct ata_host *host, const char *reason)
3137 {
3138 	int i;
3139 
3140 	dev_err(host->dev, "BMDMA: %s, falling back to PIO\n", reason);
3141 
3142 	for (i = 0; i < 2; i++) {
3143 		host->ports[i]->mwdma_mask = 0;
3144 		host->ports[i]->udma_mask = 0;
3145 	}
3146 }
3147 
3148 /**
3149  *	ata_pci_bmdma_init - acquire PCI BMDMA resources and init ATA host
3150  *	@host: target ATA host
3151  *
3152  *	Acquire PCI BMDMA resources and initialize @host accordingly.
3153  *
3154  *	LOCKING:
3155  *	Inherited from calling layer (may sleep).
3156  */
3157 void ata_pci_bmdma_init(struct ata_host *host)
3158 {
3159 	struct device *gdev = host->dev;
3160 	struct pci_dev *pdev = to_pci_dev(gdev);
3161 	int i, rc;
3162 
3163 	/* No BAR4 allocation: No DMA */
3164 	if (pci_resource_start(pdev, 4) == 0) {
3165 		ata_bmdma_nodma(host, "BAR4 is zero");
3166 		return;
3167 	}
3168 
3169 	/*
3170 	 * Some controllers require BMDMA region to be initialized
3171 	 * even if DMA is not in use to clear IRQ status via
3172 	 * ->sff_irq_clear method.  Try to initialize bmdma_addr
3173 	 * regardless of dma masks.
3174 	 */
3175 	rc = dma_set_mask_and_coherent(&pdev->dev, ATA_DMA_MASK);
3176 	if (rc)
3177 		ata_bmdma_nodma(host, "failed to set dma mask");
3178 
3179 	/* request and iomap DMA region */
3180 	rc = pcim_iomap_regions(pdev, 1 << 4, dev_driver_string(gdev));
3181 	if (rc) {
3182 		ata_bmdma_nodma(host, "failed to request/iomap BAR4");
3183 		return;
3184 	}
3185 	host->iomap = pcim_iomap_table(pdev);
3186 
3187 	for (i = 0; i < 2; i++) {
3188 		struct ata_port *ap = host->ports[i];
3189 		void __iomem *bmdma = host->iomap[4] + 8 * i;
3190 
3191 		if (ata_port_is_dummy(ap))
3192 			continue;
3193 
3194 		ap->ioaddr.bmdma_addr = bmdma;
3195 		if ((!(ap->flags & ATA_FLAG_IGN_SIMPLEX)) &&
3196 		    (ioread8(bmdma + 2) & 0x80))
3197 			host->flags |= ATA_HOST_SIMPLEX;
3198 
3199 		ata_port_desc(ap, "bmdma 0x%llx",
3200 		    (unsigned long long)pci_resource_start(pdev, 4) + 8 * i);
3201 	}
3202 }
3203 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init);
3204 
3205 /**
3206  *	ata_pci_bmdma_prepare_host - helper to prepare PCI BMDMA ATA host
3207  *	@pdev: target PCI device
3208  *	@ppi: array of port_info, must be enough for two ports
3209  *	@r_host: out argument for the initialized ATA host
3210  *
3211  *	Helper to allocate BMDMA ATA host for @pdev, acquire all PCI
3212  *	resources and initialize it accordingly in one go.
3213  *
3214  *	LOCKING:
3215  *	Inherited from calling layer (may sleep).
3216  *
3217  *	RETURNS:
3218  *	0 on success, -errno otherwise.
3219  */
3220 int ata_pci_bmdma_prepare_host(struct pci_dev *pdev,
3221 			       const struct ata_port_info * const * ppi,
3222 			       struct ata_host **r_host)
3223 {
3224 	int rc;
3225 
3226 	rc = ata_pci_sff_prepare_host(pdev, ppi, r_host);
3227 	if (rc)
3228 		return rc;
3229 
3230 	ata_pci_bmdma_init(*r_host);
3231 	return 0;
3232 }
3233 EXPORT_SYMBOL_GPL(ata_pci_bmdma_prepare_host);
3234 
3235 /**
3236  *	ata_pci_bmdma_init_one - Initialize/register BMDMA PCI IDE controller
3237  *	@pdev: Controller to be initialized
3238  *	@ppi: array of port_info, must be enough for two ports
3239  *	@sht: scsi_host_template to use when registering the host
3240  *	@host_priv: host private_data
3241  *	@hflags: host flags
3242  *
3243  *	This function is similar to ata_pci_sff_init_one() but also
3244  *	takes care of BMDMA initialization.
3245  *
3246  *	LOCKING:
3247  *	Inherited from PCI layer (may sleep).
3248  *
3249  *	RETURNS:
3250  *	Zero on success, negative on errno-based value on error.
3251  */
3252 int ata_pci_bmdma_init_one(struct pci_dev *pdev,
3253 			   const struct ata_port_info * const * ppi,
3254 			   struct scsi_host_template *sht, void *host_priv,
3255 			   int hflags)
3256 {
3257 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflags, 1);
3258 }
3259 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init_one);
3260 
3261 #endif /* CONFIG_PCI */
3262 #endif /* CONFIG_ATA_BMDMA */
3263 
3264 /**
3265  *	ata_sff_port_init - Initialize SFF/BMDMA ATA port
3266  *	@ap: Port to initialize
3267  *
3268  *	Called on port allocation to initialize SFF/BMDMA specific
3269  *	fields.
3270  *
3271  *	LOCKING:
3272  *	None.
3273  */
3274 void ata_sff_port_init(struct ata_port *ap)
3275 {
3276 	INIT_DELAYED_WORK(&ap->sff_pio_task, ata_sff_pio_task);
3277 	ap->ctl = ATA_DEVCTL_OBS;
3278 	ap->last_ctl = 0xFF;
3279 }
3280 
3281 int __init ata_sff_init(void)
3282 {
3283 	ata_sff_wq = alloc_workqueue("ata_sff", WQ_MEM_RECLAIM, WQ_MAX_ACTIVE);
3284 	if (!ata_sff_wq)
3285 		return -ENOMEM;
3286 
3287 	return 0;
3288 }
3289 
3290 void ata_sff_exit(void)
3291 {
3292 	destroy_workqueue(ata_sff_wq);
3293 }
3294