xref: /linux/drivers/ata/libata-sff.c (revision f7be345515ab6d5c3a0973bb2b32510fcb7c0481)
1 /*
2  *  libata-sff.c - helper library for PCI IDE BMDMA
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2003-2006 Red Hat, Inc.  All rights reserved.
9  *  Copyright 2003-2006 Jeff Garzik
10  *
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2, or (at your option)
15  *  any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; see the file COPYING.  If not, write to
24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/gfp.h>
37 #include <linux/pci.h>
38 #include <linux/libata.h>
39 #include <linux/highmem.h>
40 
41 #include "libata.h"
42 
43 static struct workqueue_struct *ata_sff_wq;
44 
45 const struct ata_port_operations ata_sff_port_ops = {
46 	.inherits		= &ata_base_port_ops,
47 
48 	.qc_prep		= ata_noop_qc_prep,
49 	.qc_issue		= ata_sff_qc_issue,
50 	.qc_fill_rtf		= ata_sff_qc_fill_rtf,
51 
52 	.freeze			= ata_sff_freeze,
53 	.thaw			= ata_sff_thaw,
54 	.prereset		= ata_sff_prereset,
55 	.softreset		= ata_sff_softreset,
56 	.hardreset		= sata_sff_hardreset,
57 	.postreset		= ata_sff_postreset,
58 	.error_handler		= ata_sff_error_handler,
59 
60 	.sff_dev_select		= ata_sff_dev_select,
61 	.sff_check_status	= ata_sff_check_status,
62 	.sff_tf_load		= ata_sff_tf_load,
63 	.sff_tf_read		= ata_sff_tf_read,
64 	.sff_exec_command	= ata_sff_exec_command,
65 	.sff_data_xfer		= ata_sff_data_xfer,
66 	.sff_drain_fifo		= ata_sff_drain_fifo,
67 
68 	.lost_interrupt		= ata_sff_lost_interrupt,
69 };
70 EXPORT_SYMBOL_GPL(ata_sff_port_ops);
71 
72 /**
73  *	ata_sff_check_status - Read device status reg & clear interrupt
74  *	@ap: port where the device is
75  *
76  *	Reads ATA taskfile status register for currently-selected device
77  *	and return its value. This also clears pending interrupts
78  *      from this device
79  *
80  *	LOCKING:
81  *	Inherited from caller.
82  */
83 u8 ata_sff_check_status(struct ata_port *ap)
84 {
85 	return ioread8(ap->ioaddr.status_addr);
86 }
87 EXPORT_SYMBOL_GPL(ata_sff_check_status);
88 
89 /**
90  *	ata_sff_altstatus - Read device alternate status reg
91  *	@ap: port where the device is
92  *
93  *	Reads ATA taskfile alternate status register for
94  *	currently-selected device and return its value.
95  *
96  *	Note: may NOT be used as the check_altstatus() entry in
97  *	ata_port_operations.
98  *
99  *	LOCKING:
100  *	Inherited from caller.
101  */
102 static u8 ata_sff_altstatus(struct ata_port *ap)
103 {
104 	if (ap->ops->sff_check_altstatus)
105 		return ap->ops->sff_check_altstatus(ap);
106 
107 	return ioread8(ap->ioaddr.altstatus_addr);
108 }
109 
110 /**
111  *	ata_sff_irq_status - Check if the device is busy
112  *	@ap: port where the device is
113  *
114  *	Determine if the port is currently busy. Uses altstatus
115  *	if available in order to avoid clearing shared IRQ status
116  *	when finding an IRQ source. Non ctl capable devices don't
117  *	share interrupt lines fortunately for us.
118  *
119  *	LOCKING:
120  *	Inherited from caller.
121  */
122 static u8 ata_sff_irq_status(struct ata_port *ap)
123 {
124 	u8 status;
125 
126 	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
127 		status = ata_sff_altstatus(ap);
128 		/* Not us: We are busy */
129 		if (status & ATA_BUSY)
130 			return status;
131 	}
132 	/* Clear INTRQ latch */
133 	status = ap->ops->sff_check_status(ap);
134 	return status;
135 }
136 
137 /**
138  *	ata_sff_sync - Flush writes
139  *	@ap: Port to wait for.
140  *
141  *	CAUTION:
142  *	If we have an mmio device with no ctl and no altstatus
143  *	method this will fail. No such devices are known to exist.
144  *
145  *	LOCKING:
146  *	Inherited from caller.
147  */
148 
149 static void ata_sff_sync(struct ata_port *ap)
150 {
151 	if (ap->ops->sff_check_altstatus)
152 		ap->ops->sff_check_altstatus(ap);
153 	else if (ap->ioaddr.altstatus_addr)
154 		ioread8(ap->ioaddr.altstatus_addr);
155 }
156 
157 /**
158  *	ata_sff_pause		-	Flush writes and wait 400nS
159  *	@ap: Port to pause for.
160  *
161  *	CAUTION:
162  *	If we have an mmio device with no ctl and no altstatus
163  *	method this will fail. No such devices are known to exist.
164  *
165  *	LOCKING:
166  *	Inherited from caller.
167  */
168 
169 void ata_sff_pause(struct ata_port *ap)
170 {
171 	ata_sff_sync(ap);
172 	ndelay(400);
173 }
174 EXPORT_SYMBOL_GPL(ata_sff_pause);
175 
176 /**
177  *	ata_sff_dma_pause	-	Pause before commencing DMA
178  *	@ap: Port to pause for.
179  *
180  *	Perform I/O fencing and ensure sufficient cycle delays occur
181  *	for the HDMA1:0 transition
182  */
183 
184 void ata_sff_dma_pause(struct ata_port *ap)
185 {
186 	if (ap->ops->sff_check_altstatus || ap->ioaddr.altstatus_addr) {
187 		/* An altstatus read will cause the needed delay without
188 		   messing up the IRQ status */
189 		ata_sff_altstatus(ap);
190 		return;
191 	}
192 	/* There are no DMA controllers without ctl. BUG here to ensure
193 	   we never violate the HDMA1:0 transition timing and risk
194 	   corruption. */
195 	BUG();
196 }
197 EXPORT_SYMBOL_GPL(ata_sff_dma_pause);
198 
199 /**
200  *	ata_sff_busy_sleep - sleep until BSY clears, or timeout
201  *	@ap: port containing status register to be polled
202  *	@tmout_pat: impatience timeout in msecs
203  *	@tmout: overall timeout in msecs
204  *
205  *	Sleep until ATA Status register bit BSY clears,
206  *	or a timeout occurs.
207  *
208  *	LOCKING:
209  *	Kernel thread context (may sleep).
210  *
211  *	RETURNS:
212  *	0 on success, -errno otherwise.
213  */
214 int ata_sff_busy_sleep(struct ata_port *ap,
215 		       unsigned long tmout_pat, unsigned long tmout)
216 {
217 	unsigned long timer_start, timeout;
218 	u8 status;
219 
220 	status = ata_sff_busy_wait(ap, ATA_BUSY, 300);
221 	timer_start = jiffies;
222 	timeout = ata_deadline(timer_start, tmout_pat);
223 	while (status != 0xff && (status & ATA_BUSY) &&
224 	       time_before(jiffies, timeout)) {
225 		ata_msleep(ap, 50);
226 		status = ata_sff_busy_wait(ap, ATA_BUSY, 3);
227 	}
228 
229 	if (status != 0xff && (status & ATA_BUSY))
230 		ata_port_warn(ap,
231 			      "port is slow to respond, please be patient (Status 0x%x)\n",
232 			      status);
233 
234 	timeout = ata_deadline(timer_start, tmout);
235 	while (status != 0xff && (status & ATA_BUSY) &&
236 	       time_before(jiffies, timeout)) {
237 		ata_msleep(ap, 50);
238 		status = ap->ops->sff_check_status(ap);
239 	}
240 
241 	if (status == 0xff)
242 		return -ENODEV;
243 
244 	if (status & ATA_BUSY) {
245 		ata_port_err(ap,
246 			     "port failed to respond (%lu secs, Status 0x%x)\n",
247 			     DIV_ROUND_UP(tmout, 1000), status);
248 		return -EBUSY;
249 	}
250 
251 	return 0;
252 }
253 EXPORT_SYMBOL_GPL(ata_sff_busy_sleep);
254 
255 static int ata_sff_check_ready(struct ata_link *link)
256 {
257 	u8 status = link->ap->ops->sff_check_status(link->ap);
258 
259 	return ata_check_ready(status);
260 }
261 
262 /**
263  *	ata_sff_wait_ready - sleep until BSY clears, or timeout
264  *	@link: SFF link to wait ready status for
265  *	@deadline: deadline jiffies for the operation
266  *
267  *	Sleep until ATA Status register bit BSY clears, or timeout
268  *	occurs.
269  *
270  *	LOCKING:
271  *	Kernel thread context (may sleep).
272  *
273  *	RETURNS:
274  *	0 on success, -errno otherwise.
275  */
276 int ata_sff_wait_ready(struct ata_link *link, unsigned long deadline)
277 {
278 	return ata_wait_ready(link, deadline, ata_sff_check_ready);
279 }
280 EXPORT_SYMBOL_GPL(ata_sff_wait_ready);
281 
282 /**
283  *	ata_sff_set_devctl - Write device control reg
284  *	@ap: port where the device is
285  *	@ctl: value to write
286  *
287  *	Writes ATA taskfile device control register.
288  *
289  *	Note: may NOT be used as the sff_set_devctl() entry in
290  *	ata_port_operations.
291  *
292  *	LOCKING:
293  *	Inherited from caller.
294  */
295 static void ata_sff_set_devctl(struct ata_port *ap, u8 ctl)
296 {
297 	if (ap->ops->sff_set_devctl)
298 		ap->ops->sff_set_devctl(ap, ctl);
299 	else
300 		iowrite8(ctl, ap->ioaddr.ctl_addr);
301 }
302 
303 /**
304  *	ata_sff_dev_select - Select device 0/1 on ATA bus
305  *	@ap: ATA channel to manipulate
306  *	@device: ATA device (numbered from zero) to select
307  *
308  *	Use the method defined in the ATA specification to
309  *	make either device 0, or device 1, active on the
310  *	ATA channel.  Works with both PIO and MMIO.
311  *
312  *	May be used as the dev_select() entry in ata_port_operations.
313  *
314  *	LOCKING:
315  *	caller.
316  */
317 void ata_sff_dev_select(struct ata_port *ap, unsigned int device)
318 {
319 	u8 tmp;
320 
321 	if (device == 0)
322 		tmp = ATA_DEVICE_OBS;
323 	else
324 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
325 
326 	iowrite8(tmp, ap->ioaddr.device_addr);
327 	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
328 }
329 EXPORT_SYMBOL_GPL(ata_sff_dev_select);
330 
331 /**
332  *	ata_dev_select - Select device 0/1 on ATA bus
333  *	@ap: ATA channel to manipulate
334  *	@device: ATA device (numbered from zero) to select
335  *	@wait: non-zero to wait for Status register BSY bit to clear
336  *	@can_sleep: non-zero if context allows sleeping
337  *
338  *	Use the method defined in the ATA specification to
339  *	make either device 0, or device 1, active on the
340  *	ATA channel.
341  *
342  *	This is a high-level version of ata_sff_dev_select(), which
343  *	additionally provides the services of inserting the proper
344  *	pauses and status polling, where needed.
345  *
346  *	LOCKING:
347  *	caller.
348  */
349 static void ata_dev_select(struct ata_port *ap, unsigned int device,
350 			   unsigned int wait, unsigned int can_sleep)
351 {
352 	if (ata_msg_probe(ap))
353 		ata_port_info(ap, "ata_dev_select: ENTER, device %u, wait %u\n",
354 			      device, wait);
355 
356 	if (wait)
357 		ata_wait_idle(ap);
358 
359 	ap->ops->sff_dev_select(ap, device);
360 
361 	if (wait) {
362 		if (can_sleep && ap->link.device[device].class == ATA_DEV_ATAPI)
363 			ata_msleep(ap, 150);
364 		ata_wait_idle(ap);
365 	}
366 }
367 
368 /**
369  *	ata_sff_irq_on - Enable interrupts on a port.
370  *	@ap: Port on which interrupts are enabled.
371  *
372  *	Enable interrupts on a legacy IDE device using MMIO or PIO,
373  *	wait for idle, clear any pending interrupts.
374  *
375  *	Note: may NOT be used as the sff_irq_on() entry in
376  *	ata_port_operations.
377  *
378  *	LOCKING:
379  *	Inherited from caller.
380  */
381 void ata_sff_irq_on(struct ata_port *ap)
382 {
383 	struct ata_ioports *ioaddr = &ap->ioaddr;
384 
385 	if (ap->ops->sff_irq_on) {
386 		ap->ops->sff_irq_on(ap);
387 		return;
388 	}
389 
390 	ap->ctl &= ~ATA_NIEN;
391 	ap->last_ctl = ap->ctl;
392 
393 	if (ap->ops->sff_set_devctl || ioaddr->ctl_addr)
394 		ata_sff_set_devctl(ap, ap->ctl);
395 	ata_wait_idle(ap);
396 
397 	if (ap->ops->sff_irq_clear)
398 		ap->ops->sff_irq_clear(ap);
399 }
400 EXPORT_SYMBOL_GPL(ata_sff_irq_on);
401 
402 /**
403  *	ata_sff_tf_load - send taskfile registers to host controller
404  *	@ap: Port to which output is sent
405  *	@tf: ATA taskfile register set
406  *
407  *	Outputs ATA taskfile to standard ATA host controller.
408  *
409  *	LOCKING:
410  *	Inherited from caller.
411  */
412 void ata_sff_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
413 {
414 	struct ata_ioports *ioaddr = &ap->ioaddr;
415 	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
416 
417 	if (tf->ctl != ap->last_ctl) {
418 		if (ioaddr->ctl_addr)
419 			iowrite8(tf->ctl, ioaddr->ctl_addr);
420 		ap->last_ctl = tf->ctl;
421 		ata_wait_idle(ap);
422 	}
423 
424 	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
425 		WARN_ON_ONCE(!ioaddr->ctl_addr);
426 		iowrite8(tf->hob_feature, ioaddr->feature_addr);
427 		iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
428 		iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
429 		iowrite8(tf->hob_lbam, ioaddr->lbam_addr);
430 		iowrite8(tf->hob_lbah, ioaddr->lbah_addr);
431 		VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
432 			tf->hob_feature,
433 			tf->hob_nsect,
434 			tf->hob_lbal,
435 			tf->hob_lbam,
436 			tf->hob_lbah);
437 	}
438 
439 	if (is_addr) {
440 		iowrite8(tf->feature, ioaddr->feature_addr);
441 		iowrite8(tf->nsect, ioaddr->nsect_addr);
442 		iowrite8(tf->lbal, ioaddr->lbal_addr);
443 		iowrite8(tf->lbam, ioaddr->lbam_addr);
444 		iowrite8(tf->lbah, ioaddr->lbah_addr);
445 		VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
446 			tf->feature,
447 			tf->nsect,
448 			tf->lbal,
449 			tf->lbam,
450 			tf->lbah);
451 	}
452 
453 	if (tf->flags & ATA_TFLAG_DEVICE) {
454 		iowrite8(tf->device, ioaddr->device_addr);
455 		VPRINTK("device 0x%X\n", tf->device);
456 	}
457 
458 	ata_wait_idle(ap);
459 }
460 EXPORT_SYMBOL_GPL(ata_sff_tf_load);
461 
462 /**
463  *	ata_sff_tf_read - input device's ATA taskfile shadow registers
464  *	@ap: Port from which input is read
465  *	@tf: ATA taskfile register set for storing input
466  *
467  *	Reads ATA taskfile registers for currently-selected device
468  *	into @tf. Assumes the device has a fully SFF compliant task file
469  *	layout and behaviour. If you device does not (eg has a different
470  *	status method) then you will need to provide a replacement tf_read
471  *
472  *	LOCKING:
473  *	Inherited from caller.
474  */
475 void ata_sff_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
476 {
477 	struct ata_ioports *ioaddr = &ap->ioaddr;
478 
479 	tf->command = ata_sff_check_status(ap);
480 	tf->feature = ioread8(ioaddr->error_addr);
481 	tf->nsect = ioread8(ioaddr->nsect_addr);
482 	tf->lbal = ioread8(ioaddr->lbal_addr);
483 	tf->lbam = ioread8(ioaddr->lbam_addr);
484 	tf->lbah = ioread8(ioaddr->lbah_addr);
485 	tf->device = ioread8(ioaddr->device_addr);
486 
487 	if (tf->flags & ATA_TFLAG_LBA48) {
488 		if (likely(ioaddr->ctl_addr)) {
489 			iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
490 			tf->hob_feature = ioread8(ioaddr->error_addr);
491 			tf->hob_nsect = ioread8(ioaddr->nsect_addr);
492 			tf->hob_lbal = ioread8(ioaddr->lbal_addr);
493 			tf->hob_lbam = ioread8(ioaddr->lbam_addr);
494 			tf->hob_lbah = ioread8(ioaddr->lbah_addr);
495 			iowrite8(tf->ctl, ioaddr->ctl_addr);
496 			ap->last_ctl = tf->ctl;
497 		} else
498 			WARN_ON_ONCE(1);
499 	}
500 }
501 EXPORT_SYMBOL_GPL(ata_sff_tf_read);
502 
503 /**
504  *	ata_sff_exec_command - issue ATA command to host controller
505  *	@ap: port to which command is being issued
506  *	@tf: ATA taskfile register set
507  *
508  *	Issues ATA command, with proper synchronization with interrupt
509  *	handler / other threads.
510  *
511  *	LOCKING:
512  *	spin_lock_irqsave(host lock)
513  */
514 void ata_sff_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
515 {
516 	DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
517 
518 	iowrite8(tf->command, ap->ioaddr.command_addr);
519 	ata_sff_pause(ap);
520 }
521 EXPORT_SYMBOL_GPL(ata_sff_exec_command);
522 
523 /**
524  *	ata_tf_to_host - issue ATA taskfile to host controller
525  *	@ap: port to which command is being issued
526  *	@tf: ATA taskfile register set
527  *
528  *	Issues ATA taskfile register set to ATA host controller,
529  *	with proper synchronization with interrupt handler and
530  *	other threads.
531  *
532  *	LOCKING:
533  *	spin_lock_irqsave(host lock)
534  */
535 static inline void ata_tf_to_host(struct ata_port *ap,
536 				  const struct ata_taskfile *tf)
537 {
538 	ap->ops->sff_tf_load(ap, tf);
539 	ap->ops->sff_exec_command(ap, tf);
540 }
541 
542 /**
543  *	ata_sff_data_xfer - Transfer data by PIO
544  *	@dev: device to target
545  *	@buf: data buffer
546  *	@buflen: buffer length
547  *	@rw: read/write
548  *
549  *	Transfer data from/to the device data register by PIO.
550  *
551  *	LOCKING:
552  *	Inherited from caller.
553  *
554  *	RETURNS:
555  *	Bytes consumed.
556  */
557 unsigned int ata_sff_data_xfer(struct ata_device *dev, unsigned char *buf,
558 			       unsigned int buflen, int rw)
559 {
560 	struct ata_port *ap = dev->link->ap;
561 	void __iomem *data_addr = ap->ioaddr.data_addr;
562 	unsigned int words = buflen >> 1;
563 
564 	/* Transfer multiple of 2 bytes */
565 	if (rw == READ)
566 		ioread16_rep(data_addr, buf, words);
567 	else
568 		iowrite16_rep(data_addr, buf, words);
569 
570 	/* Transfer trailing byte, if any. */
571 	if (unlikely(buflen & 0x01)) {
572 		unsigned char pad[2] = { };
573 
574 		/* Point buf to the tail of buffer */
575 		buf += buflen - 1;
576 
577 		/*
578 		 * Use io*16_rep() accessors here as well to avoid pointlessly
579 		 * swapping bytes to and from on the big endian machines...
580 		 */
581 		if (rw == READ) {
582 			ioread16_rep(data_addr, pad, 1);
583 			*buf = pad[0];
584 		} else {
585 			pad[0] = *buf;
586 			iowrite16_rep(data_addr, pad, 1);
587 		}
588 		words++;
589 	}
590 
591 	return words << 1;
592 }
593 EXPORT_SYMBOL_GPL(ata_sff_data_xfer);
594 
595 /**
596  *	ata_sff_data_xfer32 - Transfer data by PIO
597  *	@dev: device to target
598  *	@buf: data buffer
599  *	@buflen: buffer length
600  *	@rw: read/write
601  *
602  *	Transfer data from/to the device data register by PIO using 32bit
603  *	I/O operations.
604  *
605  *	LOCKING:
606  *	Inherited from caller.
607  *
608  *	RETURNS:
609  *	Bytes consumed.
610  */
611 
612 unsigned int ata_sff_data_xfer32(struct ata_device *dev, unsigned char *buf,
613 			       unsigned int buflen, int rw)
614 {
615 	struct ata_port *ap = dev->link->ap;
616 	void __iomem *data_addr = ap->ioaddr.data_addr;
617 	unsigned int words = buflen >> 2;
618 	int slop = buflen & 3;
619 
620 	if (!(ap->pflags & ATA_PFLAG_PIO32))
621 		return ata_sff_data_xfer(dev, buf, buflen, rw);
622 
623 	/* Transfer multiple of 4 bytes */
624 	if (rw == READ)
625 		ioread32_rep(data_addr, buf, words);
626 	else
627 		iowrite32_rep(data_addr, buf, words);
628 
629 	/* Transfer trailing bytes, if any */
630 	if (unlikely(slop)) {
631 		unsigned char pad[4] = { };
632 
633 		/* Point buf to the tail of buffer */
634 		buf += buflen - slop;
635 
636 		/*
637 		 * Use io*_rep() accessors here as well to avoid pointlessly
638 		 * swapping bytes to and from on the big endian machines...
639 		 */
640 		if (rw == READ) {
641 			if (slop < 3)
642 				ioread16_rep(data_addr, pad, 1);
643 			else
644 				ioread32_rep(data_addr, pad, 1);
645 			memcpy(buf, pad, slop);
646 		} else {
647 			memcpy(pad, buf, slop);
648 			if (slop < 3)
649 				iowrite16_rep(data_addr, pad, 1);
650 			else
651 				iowrite32_rep(data_addr, pad, 1);
652 		}
653 	}
654 	return (buflen + 1) & ~1;
655 }
656 EXPORT_SYMBOL_GPL(ata_sff_data_xfer32);
657 
658 /**
659  *	ata_sff_data_xfer_noirq - Transfer data by PIO
660  *	@dev: device to target
661  *	@buf: data buffer
662  *	@buflen: buffer length
663  *	@rw: read/write
664  *
665  *	Transfer data from/to the device data register by PIO. Do the
666  *	transfer with interrupts disabled.
667  *
668  *	LOCKING:
669  *	Inherited from caller.
670  *
671  *	RETURNS:
672  *	Bytes consumed.
673  */
674 unsigned int ata_sff_data_xfer_noirq(struct ata_device *dev, unsigned char *buf,
675 				     unsigned int buflen, int rw)
676 {
677 	unsigned long flags;
678 	unsigned int consumed;
679 
680 	local_irq_save(flags);
681 	consumed = ata_sff_data_xfer32(dev, buf, buflen, rw);
682 	local_irq_restore(flags);
683 
684 	return consumed;
685 }
686 EXPORT_SYMBOL_GPL(ata_sff_data_xfer_noirq);
687 
688 /**
689  *	ata_pio_sector - Transfer a sector of data.
690  *	@qc: Command on going
691  *
692  *	Transfer qc->sect_size bytes of data from/to the ATA device.
693  *
694  *	LOCKING:
695  *	Inherited from caller.
696  */
697 static void ata_pio_sector(struct ata_queued_cmd *qc)
698 {
699 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
700 	struct ata_port *ap = qc->ap;
701 	struct page *page;
702 	unsigned int offset;
703 	unsigned char *buf;
704 
705 	if (qc->curbytes == qc->nbytes - qc->sect_size)
706 		ap->hsm_task_state = HSM_ST_LAST;
707 
708 	page = sg_page(qc->cursg);
709 	offset = qc->cursg->offset + qc->cursg_ofs;
710 
711 	/* get the current page and offset */
712 	page = nth_page(page, (offset >> PAGE_SHIFT));
713 	offset %= PAGE_SIZE;
714 
715 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
716 
717 	if (PageHighMem(page)) {
718 		unsigned long flags;
719 
720 		/* FIXME: use a bounce buffer */
721 		local_irq_save(flags);
722 		buf = kmap_atomic(page, KM_IRQ0);
723 
724 		/* do the actual data transfer */
725 		ap->ops->sff_data_xfer(qc->dev, buf + offset, qc->sect_size,
726 				       do_write);
727 
728 		kunmap_atomic(buf, KM_IRQ0);
729 		local_irq_restore(flags);
730 	} else {
731 		buf = page_address(page);
732 		ap->ops->sff_data_xfer(qc->dev, buf + offset, qc->sect_size,
733 				       do_write);
734 	}
735 
736 	if (!do_write && !PageSlab(page))
737 		flush_dcache_page(page);
738 
739 	qc->curbytes += qc->sect_size;
740 	qc->cursg_ofs += qc->sect_size;
741 
742 	if (qc->cursg_ofs == qc->cursg->length) {
743 		qc->cursg = sg_next(qc->cursg);
744 		qc->cursg_ofs = 0;
745 	}
746 }
747 
748 /**
749  *	ata_pio_sectors - Transfer one or many sectors.
750  *	@qc: Command on going
751  *
752  *	Transfer one or many sectors of data from/to the
753  *	ATA device for the DRQ request.
754  *
755  *	LOCKING:
756  *	Inherited from caller.
757  */
758 static void ata_pio_sectors(struct ata_queued_cmd *qc)
759 {
760 	if (is_multi_taskfile(&qc->tf)) {
761 		/* READ/WRITE MULTIPLE */
762 		unsigned int nsect;
763 
764 		WARN_ON_ONCE(qc->dev->multi_count == 0);
765 
766 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
767 			    qc->dev->multi_count);
768 		while (nsect--)
769 			ata_pio_sector(qc);
770 	} else
771 		ata_pio_sector(qc);
772 
773 	ata_sff_sync(qc->ap); /* flush */
774 }
775 
776 /**
777  *	atapi_send_cdb - Write CDB bytes to hardware
778  *	@ap: Port to which ATAPI device is attached.
779  *	@qc: Taskfile currently active
780  *
781  *	When device has indicated its readiness to accept
782  *	a CDB, this function is called.  Send the CDB.
783  *
784  *	LOCKING:
785  *	caller.
786  */
787 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
788 {
789 	/* send SCSI cdb */
790 	DPRINTK("send cdb\n");
791 	WARN_ON_ONCE(qc->dev->cdb_len < 12);
792 
793 	ap->ops->sff_data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
794 	ata_sff_sync(ap);
795 	/* FIXME: If the CDB is for DMA do we need to do the transition delay
796 	   or is bmdma_start guaranteed to do it ? */
797 	switch (qc->tf.protocol) {
798 	case ATAPI_PROT_PIO:
799 		ap->hsm_task_state = HSM_ST;
800 		break;
801 	case ATAPI_PROT_NODATA:
802 		ap->hsm_task_state = HSM_ST_LAST;
803 		break;
804 #ifdef CONFIG_ATA_BMDMA
805 	case ATAPI_PROT_DMA:
806 		ap->hsm_task_state = HSM_ST_LAST;
807 		/* initiate bmdma */
808 		ap->ops->bmdma_start(qc);
809 		break;
810 #endif /* CONFIG_ATA_BMDMA */
811 	default:
812 		BUG();
813 	}
814 }
815 
816 /**
817  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
818  *	@qc: Command on going
819  *	@bytes: number of bytes
820  *
821  *	Transfer Transfer data from/to the ATAPI device.
822  *
823  *	LOCKING:
824  *	Inherited from caller.
825  *
826  */
827 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
828 {
829 	int rw = (qc->tf.flags & ATA_TFLAG_WRITE) ? WRITE : READ;
830 	struct ata_port *ap = qc->ap;
831 	struct ata_device *dev = qc->dev;
832 	struct ata_eh_info *ehi = &dev->link->eh_info;
833 	struct scatterlist *sg;
834 	struct page *page;
835 	unsigned char *buf;
836 	unsigned int offset, count, consumed;
837 
838 next_sg:
839 	sg = qc->cursg;
840 	if (unlikely(!sg)) {
841 		ata_ehi_push_desc(ehi, "unexpected or too much trailing data "
842 				  "buf=%u cur=%u bytes=%u",
843 				  qc->nbytes, qc->curbytes, bytes);
844 		return -1;
845 	}
846 
847 	page = sg_page(sg);
848 	offset = sg->offset + qc->cursg_ofs;
849 
850 	/* get the current page and offset */
851 	page = nth_page(page, (offset >> PAGE_SHIFT));
852 	offset %= PAGE_SIZE;
853 
854 	/* don't overrun current sg */
855 	count = min(sg->length - qc->cursg_ofs, bytes);
856 
857 	/* don't cross page boundaries */
858 	count = min(count, (unsigned int)PAGE_SIZE - offset);
859 
860 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
861 
862 	if (PageHighMem(page)) {
863 		unsigned long flags;
864 
865 		/* FIXME: use bounce buffer */
866 		local_irq_save(flags);
867 		buf = kmap_atomic(page, KM_IRQ0);
868 
869 		/* do the actual data transfer */
870 		consumed = ap->ops->sff_data_xfer(dev,  buf + offset,
871 								count, rw);
872 
873 		kunmap_atomic(buf, KM_IRQ0);
874 		local_irq_restore(flags);
875 	} else {
876 		buf = page_address(page);
877 		consumed = ap->ops->sff_data_xfer(dev,  buf + offset,
878 								count, rw);
879 	}
880 
881 	bytes -= min(bytes, consumed);
882 	qc->curbytes += count;
883 	qc->cursg_ofs += count;
884 
885 	if (qc->cursg_ofs == sg->length) {
886 		qc->cursg = sg_next(qc->cursg);
887 		qc->cursg_ofs = 0;
888 	}
889 
890 	/*
891 	 * There used to be a  WARN_ON_ONCE(qc->cursg && count != consumed);
892 	 * Unfortunately __atapi_pio_bytes doesn't know enough to do the WARN
893 	 * check correctly as it doesn't know if it is the last request being
894 	 * made. Somebody should implement a proper sanity check.
895 	 */
896 	if (bytes)
897 		goto next_sg;
898 	return 0;
899 }
900 
901 /**
902  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
903  *	@qc: Command on going
904  *
905  *	Transfer Transfer data from/to the ATAPI device.
906  *
907  *	LOCKING:
908  *	Inherited from caller.
909  */
910 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
911 {
912 	struct ata_port *ap = qc->ap;
913 	struct ata_device *dev = qc->dev;
914 	struct ata_eh_info *ehi = &dev->link->eh_info;
915 	unsigned int ireason, bc_lo, bc_hi, bytes;
916 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
917 
918 	/* Abuse qc->result_tf for temp storage of intermediate TF
919 	 * here to save some kernel stack usage.
920 	 * For normal completion, qc->result_tf is not relevant. For
921 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
922 	 * So, the correctness of qc->result_tf is not affected.
923 	 */
924 	ap->ops->sff_tf_read(ap, &qc->result_tf);
925 	ireason = qc->result_tf.nsect;
926 	bc_lo = qc->result_tf.lbam;
927 	bc_hi = qc->result_tf.lbah;
928 	bytes = (bc_hi << 8) | bc_lo;
929 
930 	/* shall be cleared to zero, indicating xfer of data */
931 	if (unlikely(ireason & (1 << 0)))
932 		goto atapi_check;
933 
934 	/* make sure transfer direction matches expected */
935 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
936 	if (unlikely(do_write != i_write))
937 		goto atapi_check;
938 
939 	if (unlikely(!bytes))
940 		goto atapi_check;
941 
942 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
943 
944 	if (unlikely(__atapi_pio_bytes(qc, bytes)))
945 		goto err_out;
946 	ata_sff_sync(ap); /* flush */
947 
948 	return;
949 
950  atapi_check:
951 	ata_ehi_push_desc(ehi, "ATAPI check failed (ireason=0x%x bytes=%u)",
952 			  ireason, bytes);
953  err_out:
954 	qc->err_mask |= AC_ERR_HSM;
955 	ap->hsm_task_state = HSM_ST_ERR;
956 }
957 
958 /**
959  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
960  *	@ap: the target ata_port
961  *	@qc: qc on going
962  *
963  *	RETURNS:
964  *	1 if ok in workqueue, 0 otherwise.
965  */
966 static inline int ata_hsm_ok_in_wq(struct ata_port *ap,
967 						struct ata_queued_cmd *qc)
968 {
969 	if (qc->tf.flags & ATA_TFLAG_POLLING)
970 		return 1;
971 
972 	if (ap->hsm_task_state == HSM_ST_FIRST) {
973 		if (qc->tf.protocol == ATA_PROT_PIO &&
974 		   (qc->tf.flags & ATA_TFLAG_WRITE))
975 		    return 1;
976 
977 		if (ata_is_atapi(qc->tf.protocol) &&
978 		   !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
979 			return 1;
980 	}
981 
982 	return 0;
983 }
984 
985 /**
986  *	ata_hsm_qc_complete - finish a qc running on standard HSM
987  *	@qc: Command to complete
988  *	@in_wq: 1 if called from workqueue, 0 otherwise
989  *
990  *	Finish @qc which is running on standard HSM.
991  *
992  *	LOCKING:
993  *	If @in_wq is zero, spin_lock_irqsave(host lock).
994  *	Otherwise, none on entry and grabs host lock.
995  */
996 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
997 {
998 	struct ata_port *ap = qc->ap;
999 	unsigned long flags;
1000 
1001 	if (ap->ops->error_handler) {
1002 		if (in_wq) {
1003 			spin_lock_irqsave(ap->lock, flags);
1004 
1005 			/* EH might have kicked in while host lock is
1006 			 * released.
1007 			 */
1008 			qc = ata_qc_from_tag(ap, qc->tag);
1009 			if (qc) {
1010 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
1011 					ata_sff_irq_on(ap);
1012 					ata_qc_complete(qc);
1013 				} else
1014 					ata_port_freeze(ap);
1015 			}
1016 
1017 			spin_unlock_irqrestore(ap->lock, flags);
1018 		} else {
1019 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
1020 				ata_qc_complete(qc);
1021 			else
1022 				ata_port_freeze(ap);
1023 		}
1024 	} else {
1025 		if (in_wq) {
1026 			spin_lock_irqsave(ap->lock, flags);
1027 			ata_sff_irq_on(ap);
1028 			ata_qc_complete(qc);
1029 			spin_unlock_irqrestore(ap->lock, flags);
1030 		} else
1031 			ata_qc_complete(qc);
1032 	}
1033 }
1034 
1035 /**
1036  *	ata_sff_hsm_move - move the HSM to the next state.
1037  *	@ap: the target ata_port
1038  *	@qc: qc on going
1039  *	@status: current device status
1040  *	@in_wq: 1 if called from workqueue, 0 otherwise
1041  *
1042  *	RETURNS:
1043  *	1 when poll next status needed, 0 otherwise.
1044  */
1045 int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
1046 		     u8 status, int in_wq)
1047 {
1048 	struct ata_link *link = qc->dev->link;
1049 	struct ata_eh_info *ehi = &link->eh_info;
1050 	unsigned long flags = 0;
1051 	int poll_next;
1052 
1053 	WARN_ON_ONCE((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
1054 
1055 	/* Make sure ata_sff_qc_issue() does not throw things
1056 	 * like DMA polling into the workqueue. Notice that
1057 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
1058 	 */
1059 	WARN_ON_ONCE(in_wq != ata_hsm_ok_in_wq(ap, qc));
1060 
1061 fsm_start:
1062 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
1063 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
1064 
1065 	switch (ap->hsm_task_state) {
1066 	case HSM_ST_FIRST:
1067 		/* Send first data block or PACKET CDB */
1068 
1069 		/* If polling, we will stay in the work queue after
1070 		 * sending the data. Otherwise, interrupt handler
1071 		 * takes over after sending the data.
1072 		 */
1073 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
1074 
1075 		/* check device status */
1076 		if (unlikely((status & ATA_DRQ) == 0)) {
1077 			/* handle BSY=0, DRQ=0 as error */
1078 			if (likely(status & (ATA_ERR | ATA_DF)))
1079 				/* device stops HSM for abort/error */
1080 				qc->err_mask |= AC_ERR_DEV;
1081 			else {
1082 				/* HSM violation. Let EH handle this */
1083 				ata_ehi_push_desc(ehi,
1084 					"ST_FIRST: !(DRQ|ERR|DF)");
1085 				qc->err_mask |= AC_ERR_HSM;
1086 			}
1087 
1088 			ap->hsm_task_state = HSM_ST_ERR;
1089 			goto fsm_start;
1090 		}
1091 
1092 		/* Device should not ask for data transfer (DRQ=1)
1093 		 * when it finds something wrong.
1094 		 * We ignore DRQ here and stop the HSM by
1095 		 * changing hsm_task_state to HSM_ST_ERR and
1096 		 * let the EH abort the command or reset the device.
1097 		 */
1098 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
1099 			/* Some ATAPI tape drives forget to clear the ERR bit
1100 			 * when doing the next command (mostly request sense).
1101 			 * We ignore ERR here to workaround and proceed sending
1102 			 * the CDB.
1103 			 */
1104 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
1105 				ata_ehi_push_desc(ehi, "ST_FIRST: "
1106 					"DRQ=1 with device error, "
1107 					"dev_stat 0x%X", status);
1108 				qc->err_mask |= AC_ERR_HSM;
1109 				ap->hsm_task_state = HSM_ST_ERR;
1110 				goto fsm_start;
1111 			}
1112 		}
1113 
1114 		/* Send the CDB (atapi) or the first data block (ata pio out).
1115 		 * During the state transition, interrupt handler shouldn't
1116 		 * be invoked before the data transfer is complete and
1117 		 * hsm_task_state is changed. Hence, the following locking.
1118 		 */
1119 		if (in_wq)
1120 			spin_lock_irqsave(ap->lock, flags);
1121 
1122 		if (qc->tf.protocol == ATA_PROT_PIO) {
1123 			/* PIO data out protocol.
1124 			 * send first data block.
1125 			 */
1126 
1127 			/* ata_pio_sectors() might change the state
1128 			 * to HSM_ST_LAST. so, the state is changed here
1129 			 * before ata_pio_sectors().
1130 			 */
1131 			ap->hsm_task_state = HSM_ST;
1132 			ata_pio_sectors(qc);
1133 		} else
1134 			/* send CDB */
1135 			atapi_send_cdb(ap, qc);
1136 
1137 		if (in_wq)
1138 			spin_unlock_irqrestore(ap->lock, flags);
1139 
1140 		/* if polling, ata_sff_pio_task() handles the rest.
1141 		 * otherwise, interrupt handler takes over from here.
1142 		 */
1143 		break;
1144 
1145 	case HSM_ST:
1146 		/* complete command or read/write the data register */
1147 		if (qc->tf.protocol == ATAPI_PROT_PIO) {
1148 			/* ATAPI PIO protocol */
1149 			if ((status & ATA_DRQ) == 0) {
1150 				/* No more data to transfer or device error.
1151 				 * Device error will be tagged in HSM_ST_LAST.
1152 				 */
1153 				ap->hsm_task_state = HSM_ST_LAST;
1154 				goto fsm_start;
1155 			}
1156 
1157 			/* Device should not ask for data transfer (DRQ=1)
1158 			 * when it finds something wrong.
1159 			 * We ignore DRQ here and stop the HSM by
1160 			 * changing hsm_task_state to HSM_ST_ERR and
1161 			 * let the EH abort the command or reset the device.
1162 			 */
1163 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1164 				ata_ehi_push_desc(ehi, "ST-ATAPI: "
1165 					"DRQ=1 with device error, "
1166 					"dev_stat 0x%X", status);
1167 				qc->err_mask |= AC_ERR_HSM;
1168 				ap->hsm_task_state = HSM_ST_ERR;
1169 				goto fsm_start;
1170 			}
1171 
1172 			atapi_pio_bytes(qc);
1173 
1174 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
1175 				/* bad ireason reported by device */
1176 				goto fsm_start;
1177 
1178 		} else {
1179 			/* ATA PIO protocol */
1180 			if (unlikely((status & ATA_DRQ) == 0)) {
1181 				/* handle BSY=0, DRQ=0 as error */
1182 				if (likely(status & (ATA_ERR | ATA_DF))) {
1183 					/* device stops HSM for abort/error */
1184 					qc->err_mask |= AC_ERR_DEV;
1185 
1186 					/* If diagnostic failed and this is
1187 					 * IDENTIFY, it's likely a phantom
1188 					 * device.  Mark hint.
1189 					 */
1190 					if (qc->dev->horkage &
1191 					    ATA_HORKAGE_DIAGNOSTIC)
1192 						qc->err_mask |=
1193 							AC_ERR_NODEV_HINT;
1194 				} else {
1195 					/* HSM violation. Let EH handle this.
1196 					 * Phantom devices also trigger this
1197 					 * condition.  Mark hint.
1198 					 */
1199 					ata_ehi_push_desc(ehi, "ST-ATA: "
1200 						"DRQ=0 without device error, "
1201 						"dev_stat 0x%X", status);
1202 					qc->err_mask |= AC_ERR_HSM |
1203 							AC_ERR_NODEV_HINT;
1204 				}
1205 
1206 				ap->hsm_task_state = HSM_ST_ERR;
1207 				goto fsm_start;
1208 			}
1209 
1210 			/* For PIO reads, some devices may ask for
1211 			 * data transfer (DRQ=1) alone with ERR=1.
1212 			 * We respect DRQ here and transfer one
1213 			 * block of junk data before changing the
1214 			 * hsm_task_state to HSM_ST_ERR.
1215 			 *
1216 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
1217 			 * sense since the data block has been
1218 			 * transferred to the device.
1219 			 */
1220 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
1221 				/* data might be corrputed */
1222 				qc->err_mask |= AC_ERR_DEV;
1223 
1224 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
1225 					ata_pio_sectors(qc);
1226 					status = ata_wait_idle(ap);
1227 				}
1228 
1229 				if (status & (ATA_BUSY | ATA_DRQ)) {
1230 					ata_ehi_push_desc(ehi, "ST-ATA: "
1231 						"BUSY|DRQ persists on ERR|DF, "
1232 						"dev_stat 0x%X", status);
1233 					qc->err_mask |= AC_ERR_HSM;
1234 				}
1235 
1236 				/* There are oddball controllers with
1237 				 * status register stuck at 0x7f and
1238 				 * lbal/m/h at zero which makes it
1239 				 * pass all other presence detection
1240 				 * mechanisms we have.  Set NODEV_HINT
1241 				 * for it.  Kernel bz#7241.
1242 				 */
1243 				if (status == 0x7f)
1244 					qc->err_mask |= AC_ERR_NODEV_HINT;
1245 
1246 				/* ata_pio_sectors() might change the
1247 				 * state to HSM_ST_LAST. so, the state
1248 				 * is changed after ata_pio_sectors().
1249 				 */
1250 				ap->hsm_task_state = HSM_ST_ERR;
1251 				goto fsm_start;
1252 			}
1253 
1254 			ata_pio_sectors(qc);
1255 
1256 			if (ap->hsm_task_state == HSM_ST_LAST &&
1257 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
1258 				/* all data read */
1259 				status = ata_wait_idle(ap);
1260 				goto fsm_start;
1261 			}
1262 		}
1263 
1264 		poll_next = 1;
1265 		break;
1266 
1267 	case HSM_ST_LAST:
1268 		if (unlikely(!ata_ok(status))) {
1269 			qc->err_mask |= __ac_err_mask(status);
1270 			ap->hsm_task_state = HSM_ST_ERR;
1271 			goto fsm_start;
1272 		}
1273 
1274 		/* no more data to transfer */
1275 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
1276 			ap->print_id, qc->dev->devno, status);
1277 
1278 		WARN_ON_ONCE(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
1279 
1280 		ap->hsm_task_state = HSM_ST_IDLE;
1281 
1282 		/* complete taskfile transaction */
1283 		ata_hsm_qc_complete(qc, in_wq);
1284 
1285 		poll_next = 0;
1286 		break;
1287 
1288 	case HSM_ST_ERR:
1289 		ap->hsm_task_state = HSM_ST_IDLE;
1290 
1291 		/* complete taskfile transaction */
1292 		ata_hsm_qc_complete(qc, in_wq);
1293 
1294 		poll_next = 0;
1295 		break;
1296 	default:
1297 		poll_next = 0;
1298 		BUG();
1299 	}
1300 
1301 	return poll_next;
1302 }
1303 EXPORT_SYMBOL_GPL(ata_sff_hsm_move);
1304 
1305 void ata_sff_queue_work(struct work_struct *work)
1306 {
1307 	queue_work(ata_sff_wq, work);
1308 }
1309 EXPORT_SYMBOL_GPL(ata_sff_queue_work);
1310 
1311 void ata_sff_queue_delayed_work(struct delayed_work *dwork, unsigned long delay)
1312 {
1313 	queue_delayed_work(ata_sff_wq, dwork, delay);
1314 }
1315 EXPORT_SYMBOL_GPL(ata_sff_queue_delayed_work);
1316 
1317 void ata_sff_queue_pio_task(struct ata_link *link, unsigned long delay)
1318 {
1319 	struct ata_port *ap = link->ap;
1320 
1321 	WARN_ON((ap->sff_pio_task_link != NULL) &&
1322 		(ap->sff_pio_task_link != link));
1323 	ap->sff_pio_task_link = link;
1324 
1325 	/* may fail if ata_sff_flush_pio_task() in progress */
1326 	ata_sff_queue_delayed_work(&ap->sff_pio_task, msecs_to_jiffies(delay));
1327 }
1328 EXPORT_SYMBOL_GPL(ata_sff_queue_pio_task);
1329 
1330 void ata_sff_flush_pio_task(struct ata_port *ap)
1331 {
1332 	DPRINTK("ENTER\n");
1333 
1334 	cancel_delayed_work_sync(&ap->sff_pio_task);
1335 	ap->hsm_task_state = HSM_ST_IDLE;
1336 	ap->sff_pio_task_link = NULL;
1337 
1338 	if (ata_msg_ctl(ap))
1339 		ata_port_dbg(ap, "%s: EXIT\n", __func__);
1340 }
1341 
1342 static void ata_sff_pio_task(struct work_struct *work)
1343 {
1344 	struct ata_port *ap =
1345 		container_of(work, struct ata_port, sff_pio_task.work);
1346 	struct ata_link *link = ap->sff_pio_task_link;
1347 	struct ata_queued_cmd *qc;
1348 	u8 status;
1349 	int poll_next;
1350 
1351 	BUG_ON(ap->sff_pio_task_link == NULL);
1352 	/* qc can be NULL if timeout occurred */
1353 	qc = ata_qc_from_tag(ap, link->active_tag);
1354 	if (!qc) {
1355 		ap->sff_pio_task_link = NULL;
1356 		return;
1357 	}
1358 
1359 fsm_start:
1360 	WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
1361 
1362 	/*
1363 	 * This is purely heuristic.  This is a fast path.
1364 	 * Sometimes when we enter, BSY will be cleared in
1365 	 * a chk-status or two.  If not, the drive is probably seeking
1366 	 * or something.  Snooze for a couple msecs, then
1367 	 * chk-status again.  If still busy, queue delayed work.
1368 	 */
1369 	status = ata_sff_busy_wait(ap, ATA_BUSY, 5);
1370 	if (status & ATA_BUSY) {
1371 		ata_msleep(ap, 2);
1372 		status = ata_sff_busy_wait(ap, ATA_BUSY, 10);
1373 		if (status & ATA_BUSY) {
1374 			ata_sff_queue_pio_task(link, ATA_SHORT_PAUSE);
1375 			return;
1376 		}
1377 	}
1378 
1379 	/*
1380 	 * hsm_move() may trigger another command to be processed.
1381 	 * clean the link beforehand.
1382 	 */
1383 	ap->sff_pio_task_link = NULL;
1384 	/* move the HSM */
1385 	poll_next = ata_sff_hsm_move(ap, qc, status, 1);
1386 
1387 	/* another command or interrupt handler
1388 	 * may be running at this point.
1389 	 */
1390 	if (poll_next)
1391 		goto fsm_start;
1392 }
1393 
1394 /**
1395  *	ata_sff_qc_issue - issue taskfile to a SFF controller
1396  *	@qc: command to issue to device
1397  *
1398  *	This function issues a PIO or NODATA command to a SFF
1399  *	controller.
1400  *
1401  *	LOCKING:
1402  *	spin_lock_irqsave(host lock)
1403  *
1404  *	RETURNS:
1405  *	Zero on success, AC_ERR_* mask on failure
1406  */
1407 unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
1408 {
1409 	struct ata_port *ap = qc->ap;
1410 	struct ata_link *link = qc->dev->link;
1411 
1412 	/* Use polling pio if the LLD doesn't handle
1413 	 * interrupt driven pio and atapi CDB interrupt.
1414 	 */
1415 	if (ap->flags & ATA_FLAG_PIO_POLLING)
1416 		qc->tf.flags |= ATA_TFLAG_POLLING;
1417 
1418 	/* select the device */
1419 	ata_dev_select(ap, qc->dev->devno, 1, 0);
1420 
1421 	/* start the command */
1422 	switch (qc->tf.protocol) {
1423 	case ATA_PROT_NODATA:
1424 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1425 			ata_qc_set_polling(qc);
1426 
1427 		ata_tf_to_host(ap, &qc->tf);
1428 		ap->hsm_task_state = HSM_ST_LAST;
1429 
1430 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1431 			ata_sff_queue_pio_task(link, 0);
1432 
1433 		break;
1434 
1435 	case ATA_PROT_PIO:
1436 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1437 			ata_qc_set_polling(qc);
1438 
1439 		ata_tf_to_host(ap, &qc->tf);
1440 
1441 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
1442 			/* PIO data out protocol */
1443 			ap->hsm_task_state = HSM_ST_FIRST;
1444 			ata_sff_queue_pio_task(link, 0);
1445 
1446 			/* always send first data block using the
1447 			 * ata_sff_pio_task() codepath.
1448 			 */
1449 		} else {
1450 			/* PIO data in protocol */
1451 			ap->hsm_task_state = HSM_ST;
1452 
1453 			if (qc->tf.flags & ATA_TFLAG_POLLING)
1454 				ata_sff_queue_pio_task(link, 0);
1455 
1456 			/* if polling, ata_sff_pio_task() handles the
1457 			 * rest.  otherwise, interrupt handler takes
1458 			 * over from here.
1459 			 */
1460 		}
1461 
1462 		break;
1463 
1464 	case ATAPI_PROT_PIO:
1465 	case ATAPI_PROT_NODATA:
1466 		if (qc->tf.flags & ATA_TFLAG_POLLING)
1467 			ata_qc_set_polling(qc);
1468 
1469 		ata_tf_to_host(ap, &qc->tf);
1470 
1471 		ap->hsm_task_state = HSM_ST_FIRST;
1472 
1473 		/* send cdb by polling if no cdb interrupt */
1474 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
1475 		    (qc->tf.flags & ATA_TFLAG_POLLING))
1476 			ata_sff_queue_pio_task(link, 0);
1477 		break;
1478 
1479 	default:
1480 		WARN_ON_ONCE(1);
1481 		return AC_ERR_SYSTEM;
1482 	}
1483 
1484 	return 0;
1485 }
1486 EXPORT_SYMBOL_GPL(ata_sff_qc_issue);
1487 
1488 /**
1489  *	ata_sff_qc_fill_rtf - fill result TF using ->sff_tf_read
1490  *	@qc: qc to fill result TF for
1491  *
1492  *	@qc is finished and result TF needs to be filled.  Fill it
1493  *	using ->sff_tf_read.
1494  *
1495  *	LOCKING:
1496  *	spin_lock_irqsave(host lock)
1497  *
1498  *	RETURNS:
1499  *	true indicating that result TF is successfully filled.
1500  */
1501 bool ata_sff_qc_fill_rtf(struct ata_queued_cmd *qc)
1502 {
1503 	qc->ap->ops->sff_tf_read(qc->ap, &qc->result_tf);
1504 	return true;
1505 }
1506 EXPORT_SYMBOL_GPL(ata_sff_qc_fill_rtf);
1507 
1508 static unsigned int ata_sff_idle_irq(struct ata_port *ap)
1509 {
1510 	ap->stats.idle_irq++;
1511 
1512 #ifdef ATA_IRQ_TRAP
1513 	if ((ap->stats.idle_irq % 1000) == 0) {
1514 		ap->ops->sff_check_status(ap);
1515 		if (ap->ops->sff_irq_clear)
1516 			ap->ops->sff_irq_clear(ap);
1517 		ata_port_warn(ap, "irq trap\n");
1518 		return 1;
1519 	}
1520 #endif
1521 	return 0;	/* irq not handled */
1522 }
1523 
1524 static unsigned int __ata_sff_port_intr(struct ata_port *ap,
1525 					struct ata_queued_cmd *qc,
1526 					bool hsmv_on_idle)
1527 {
1528 	u8 status;
1529 
1530 	VPRINTK("ata%u: protocol %d task_state %d\n",
1531 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
1532 
1533 	/* Check whether we are expecting interrupt in this state */
1534 	switch (ap->hsm_task_state) {
1535 	case HSM_ST_FIRST:
1536 		/* Some pre-ATAPI-4 devices assert INTRQ
1537 		 * at this state when ready to receive CDB.
1538 		 */
1539 
1540 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
1541 		 * The flag was turned on only for atapi devices.  No
1542 		 * need to check ata_is_atapi(qc->tf.protocol) again.
1543 		 */
1544 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
1545 			return ata_sff_idle_irq(ap);
1546 		break;
1547 	case HSM_ST_IDLE:
1548 		return ata_sff_idle_irq(ap);
1549 	default:
1550 		break;
1551 	}
1552 
1553 	/* check main status, clearing INTRQ if needed */
1554 	status = ata_sff_irq_status(ap);
1555 	if (status & ATA_BUSY) {
1556 		if (hsmv_on_idle) {
1557 			/* BMDMA engine is already stopped, we're screwed */
1558 			qc->err_mask |= AC_ERR_HSM;
1559 			ap->hsm_task_state = HSM_ST_ERR;
1560 		} else
1561 			return ata_sff_idle_irq(ap);
1562 	}
1563 
1564 	/* clear irq events */
1565 	if (ap->ops->sff_irq_clear)
1566 		ap->ops->sff_irq_clear(ap);
1567 
1568 	ata_sff_hsm_move(ap, qc, status, 0);
1569 
1570 	return 1;	/* irq handled */
1571 }
1572 
1573 /**
1574  *	ata_sff_port_intr - Handle SFF port interrupt
1575  *	@ap: Port on which interrupt arrived (possibly...)
1576  *	@qc: Taskfile currently active in engine
1577  *
1578  *	Handle port interrupt for given queued command.
1579  *
1580  *	LOCKING:
1581  *	spin_lock_irqsave(host lock)
1582  *
1583  *	RETURNS:
1584  *	One if interrupt was handled, zero if not (shared irq).
1585  */
1586 unsigned int ata_sff_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
1587 {
1588 	return __ata_sff_port_intr(ap, qc, false);
1589 }
1590 EXPORT_SYMBOL_GPL(ata_sff_port_intr);
1591 
1592 static inline irqreturn_t __ata_sff_interrupt(int irq, void *dev_instance,
1593 	unsigned int (*port_intr)(struct ata_port *, struct ata_queued_cmd *))
1594 {
1595 	struct ata_host *host = dev_instance;
1596 	bool retried = false;
1597 	unsigned int i;
1598 	unsigned int handled, idle, polling;
1599 	unsigned long flags;
1600 
1601 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
1602 	spin_lock_irqsave(&host->lock, flags);
1603 
1604 retry:
1605 	handled = idle = polling = 0;
1606 	for (i = 0; i < host->n_ports; i++) {
1607 		struct ata_port *ap = host->ports[i];
1608 		struct ata_queued_cmd *qc;
1609 
1610 		qc = ata_qc_from_tag(ap, ap->link.active_tag);
1611 		if (qc) {
1612 			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
1613 				handled |= port_intr(ap, qc);
1614 			else
1615 				polling |= 1 << i;
1616 		} else
1617 			idle |= 1 << i;
1618 	}
1619 
1620 	/*
1621 	 * If no port was expecting IRQ but the controller is actually
1622 	 * asserting IRQ line, nobody cared will ensue.  Check IRQ
1623 	 * pending status if available and clear spurious IRQ.
1624 	 */
1625 	if (!handled && !retried) {
1626 		bool retry = false;
1627 
1628 		for (i = 0; i < host->n_ports; i++) {
1629 			struct ata_port *ap = host->ports[i];
1630 
1631 			if (polling & (1 << i))
1632 				continue;
1633 
1634 			if (!ap->ops->sff_irq_check ||
1635 			    !ap->ops->sff_irq_check(ap))
1636 				continue;
1637 
1638 			if (idle & (1 << i)) {
1639 				ap->ops->sff_check_status(ap);
1640 				if (ap->ops->sff_irq_clear)
1641 					ap->ops->sff_irq_clear(ap);
1642 			} else {
1643 				/* clear INTRQ and check if BUSY cleared */
1644 				if (!(ap->ops->sff_check_status(ap) & ATA_BUSY))
1645 					retry |= true;
1646 				/*
1647 				 * With command in flight, we can't do
1648 				 * sff_irq_clear() w/o racing with completion.
1649 				 */
1650 			}
1651 		}
1652 
1653 		if (retry) {
1654 			retried = true;
1655 			goto retry;
1656 		}
1657 	}
1658 
1659 	spin_unlock_irqrestore(&host->lock, flags);
1660 
1661 	return IRQ_RETVAL(handled);
1662 }
1663 
1664 /**
1665  *	ata_sff_interrupt - Default SFF ATA host interrupt handler
1666  *	@irq: irq line (unused)
1667  *	@dev_instance: pointer to our ata_host information structure
1668  *
1669  *	Default interrupt handler for PCI IDE devices.  Calls
1670  *	ata_sff_port_intr() for each port that is not disabled.
1671  *
1672  *	LOCKING:
1673  *	Obtains host lock during operation.
1674  *
1675  *	RETURNS:
1676  *	IRQ_NONE or IRQ_HANDLED.
1677  */
1678 irqreturn_t ata_sff_interrupt(int irq, void *dev_instance)
1679 {
1680 	return __ata_sff_interrupt(irq, dev_instance, ata_sff_port_intr);
1681 }
1682 EXPORT_SYMBOL_GPL(ata_sff_interrupt);
1683 
1684 /**
1685  *	ata_sff_lost_interrupt	-	Check for an apparent lost interrupt
1686  *	@ap: port that appears to have timed out
1687  *
1688  *	Called from the libata error handlers when the core code suspects
1689  *	an interrupt has been lost. If it has complete anything we can and
1690  *	then return. Interface must support altstatus for this faster
1691  *	recovery to occur.
1692  *
1693  *	Locking:
1694  *	Caller holds host lock
1695  */
1696 
1697 void ata_sff_lost_interrupt(struct ata_port *ap)
1698 {
1699 	u8 status;
1700 	struct ata_queued_cmd *qc;
1701 
1702 	/* Only one outstanding command per SFF channel */
1703 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
1704 	/* We cannot lose an interrupt on a non-existent or polled command */
1705 	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
1706 		return;
1707 	/* See if the controller thinks it is still busy - if so the command
1708 	   isn't a lost IRQ but is still in progress */
1709 	status = ata_sff_altstatus(ap);
1710 	if (status & ATA_BUSY)
1711 		return;
1712 
1713 	/* There was a command running, we are no longer busy and we have
1714 	   no interrupt. */
1715 	ata_port_warn(ap, "lost interrupt (Status 0x%x)\n",
1716 								status);
1717 	/* Run the host interrupt logic as if the interrupt had not been
1718 	   lost */
1719 	ata_sff_port_intr(ap, qc);
1720 }
1721 EXPORT_SYMBOL_GPL(ata_sff_lost_interrupt);
1722 
1723 /**
1724  *	ata_sff_freeze - Freeze SFF controller port
1725  *	@ap: port to freeze
1726  *
1727  *	Freeze SFF controller port.
1728  *
1729  *	LOCKING:
1730  *	Inherited from caller.
1731  */
1732 void ata_sff_freeze(struct ata_port *ap)
1733 {
1734 	ap->ctl |= ATA_NIEN;
1735 	ap->last_ctl = ap->ctl;
1736 
1737 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr)
1738 		ata_sff_set_devctl(ap, ap->ctl);
1739 
1740 	/* Under certain circumstances, some controllers raise IRQ on
1741 	 * ATA_NIEN manipulation.  Also, many controllers fail to mask
1742 	 * previously pending IRQ on ATA_NIEN assertion.  Clear it.
1743 	 */
1744 	ap->ops->sff_check_status(ap);
1745 
1746 	if (ap->ops->sff_irq_clear)
1747 		ap->ops->sff_irq_clear(ap);
1748 }
1749 EXPORT_SYMBOL_GPL(ata_sff_freeze);
1750 
1751 /**
1752  *	ata_sff_thaw - Thaw SFF controller port
1753  *	@ap: port to thaw
1754  *
1755  *	Thaw SFF controller port.
1756  *
1757  *	LOCKING:
1758  *	Inherited from caller.
1759  */
1760 void ata_sff_thaw(struct ata_port *ap)
1761 {
1762 	/* clear & re-enable interrupts */
1763 	ap->ops->sff_check_status(ap);
1764 	if (ap->ops->sff_irq_clear)
1765 		ap->ops->sff_irq_clear(ap);
1766 	ata_sff_irq_on(ap);
1767 }
1768 EXPORT_SYMBOL_GPL(ata_sff_thaw);
1769 
1770 /**
1771  *	ata_sff_prereset - prepare SFF link for reset
1772  *	@link: SFF link to be reset
1773  *	@deadline: deadline jiffies for the operation
1774  *
1775  *	SFF link @link is about to be reset.  Initialize it.  It first
1776  *	calls ata_std_prereset() and wait for !BSY if the port is
1777  *	being softreset.
1778  *
1779  *	LOCKING:
1780  *	Kernel thread context (may sleep)
1781  *
1782  *	RETURNS:
1783  *	0 on success, -errno otherwise.
1784  */
1785 int ata_sff_prereset(struct ata_link *link, unsigned long deadline)
1786 {
1787 	struct ata_eh_context *ehc = &link->eh_context;
1788 	int rc;
1789 
1790 	rc = ata_std_prereset(link, deadline);
1791 	if (rc)
1792 		return rc;
1793 
1794 	/* if we're about to do hardreset, nothing more to do */
1795 	if (ehc->i.action & ATA_EH_HARDRESET)
1796 		return 0;
1797 
1798 	/* wait for !BSY if we don't know that no device is attached */
1799 	if (!ata_link_offline(link)) {
1800 		rc = ata_sff_wait_ready(link, deadline);
1801 		if (rc && rc != -ENODEV) {
1802 			ata_link_warn(link,
1803 				      "device not ready (errno=%d), forcing hardreset\n",
1804 				      rc);
1805 			ehc->i.action |= ATA_EH_HARDRESET;
1806 		}
1807 	}
1808 
1809 	return 0;
1810 }
1811 EXPORT_SYMBOL_GPL(ata_sff_prereset);
1812 
1813 /**
1814  *	ata_devchk - PATA device presence detection
1815  *	@ap: ATA channel to examine
1816  *	@device: Device to examine (starting at zero)
1817  *
1818  *	This technique was originally described in
1819  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
1820  *	later found its way into the ATA/ATAPI spec.
1821  *
1822  *	Write a pattern to the ATA shadow registers,
1823  *	and if a device is present, it will respond by
1824  *	correctly storing and echoing back the
1825  *	ATA shadow register contents.
1826  *
1827  *	LOCKING:
1828  *	caller.
1829  */
1830 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
1831 {
1832 	struct ata_ioports *ioaddr = &ap->ioaddr;
1833 	u8 nsect, lbal;
1834 
1835 	ap->ops->sff_dev_select(ap, device);
1836 
1837 	iowrite8(0x55, ioaddr->nsect_addr);
1838 	iowrite8(0xaa, ioaddr->lbal_addr);
1839 
1840 	iowrite8(0xaa, ioaddr->nsect_addr);
1841 	iowrite8(0x55, ioaddr->lbal_addr);
1842 
1843 	iowrite8(0x55, ioaddr->nsect_addr);
1844 	iowrite8(0xaa, ioaddr->lbal_addr);
1845 
1846 	nsect = ioread8(ioaddr->nsect_addr);
1847 	lbal = ioread8(ioaddr->lbal_addr);
1848 
1849 	if ((nsect == 0x55) && (lbal == 0xaa))
1850 		return 1;	/* we found a device */
1851 
1852 	return 0;		/* nothing found */
1853 }
1854 
1855 /**
1856  *	ata_sff_dev_classify - Parse returned ATA device signature
1857  *	@dev: ATA device to classify (starting at zero)
1858  *	@present: device seems present
1859  *	@r_err: Value of error register on completion
1860  *
1861  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
1862  *	an ATA/ATAPI-defined set of values is placed in the ATA
1863  *	shadow registers, indicating the results of device detection
1864  *	and diagnostics.
1865  *
1866  *	Select the ATA device, and read the values from the ATA shadow
1867  *	registers.  Then parse according to the Error register value,
1868  *	and the spec-defined values examined by ata_dev_classify().
1869  *
1870  *	LOCKING:
1871  *	caller.
1872  *
1873  *	RETURNS:
1874  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
1875  */
1876 unsigned int ata_sff_dev_classify(struct ata_device *dev, int present,
1877 				  u8 *r_err)
1878 {
1879 	struct ata_port *ap = dev->link->ap;
1880 	struct ata_taskfile tf;
1881 	unsigned int class;
1882 	u8 err;
1883 
1884 	ap->ops->sff_dev_select(ap, dev->devno);
1885 
1886 	memset(&tf, 0, sizeof(tf));
1887 
1888 	ap->ops->sff_tf_read(ap, &tf);
1889 	err = tf.feature;
1890 	if (r_err)
1891 		*r_err = err;
1892 
1893 	/* see if device passed diags: continue and warn later */
1894 	if (err == 0)
1895 		/* diagnostic fail : do nothing _YET_ */
1896 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
1897 	else if (err == 1)
1898 		/* do nothing */ ;
1899 	else if ((dev->devno == 0) && (err == 0x81))
1900 		/* do nothing */ ;
1901 	else
1902 		return ATA_DEV_NONE;
1903 
1904 	/* determine if device is ATA or ATAPI */
1905 	class = ata_dev_classify(&tf);
1906 
1907 	if (class == ATA_DEV_UNKNOWN) {
1908 		/* If the device failed diagnostic, it's likely to
1909 		 * have reported incorrect device signature too.
1910 		 * Assume ATA device if the device seems present but
1911 		 * device signature is invalid with diagnostic
1912 		 * failure.
1913 		 */
1914 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
1915 			class = ATA_DEV_ATA;
1916 		else
1917 			class = ATA_DEV_NONE;
1918 	} else if ((class == ATA_DEV_ATA) &&
1919 		   (ap->ops->sff_check_status(ap) == 0))
1920 		class = ATA_DEV_NONE;
1921 
1922 	return class;
1923 }
1924 EXPORT_SYMBOL_GPL(ata_sff_dev_classify);
1925 
1926 /**
1927  *	ata_sff_wait_after_reset - wait for devices to become ready after reset
1928  *	@link: SFF link which is just reset
1929  *	@devmask: mask of present devices
1930  *	@deadline: deadline jiffies for the operation
1931  *
1932  *	Wait devices attached to SFF @link to become ready after
1933  *	reset.  It contains preceding 150ms wait to avoid accessing TF
1934  *	status register too early.
1935  *
1936  *	LOCKING:
1937  *	Kernel thread context (may sleep).
1938  *
1939  *	RETURNS:
1940  *	0 on success, -ENODEV if some or all of devices in @devmask
1941  *	don't seem to exist.  -errno on other errors.
1942  */
1943 int ata_sff_wait_after_reset(struct ata_link *link, unsigned int devmask,
1944 			     unsigned long deadline)
1945 {
1946 	struct ata_port *ap = link->ap;
1947 	struct ata_ioports *ioaddr = &ap->ioaddr;
1948 	unsigned int dev0 = devmask & (1 << 0);
1949 	unsigned int dev1 = devmask & (1 << 1);
1950 	int rc, ret = 0;
1951 
1952 	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
1953 
1954 	/* always check readiness of the master device */
1955 	rc = ata_sff_wait_ready(link, deadline);
1956 	/* -ENODEV means the odd clown forgot the D7 pulldown resistor
1957 	 * and TF status is 0xff, bail out on it too.
1958 	 */
1959 	if (rc)
1960 		return rc;
1961 
1962 	/* if device 1 was found in ata_devchk, wait for register
1963 	 * access briefly, then wait for BSY to clear.
1964 	 */
1965 	if (dev1) {
1966 		int i;
1967 
1968 		ap->ops->sff_dev_select(ap, 1);
1969 
1970 		/* Wait for register access.  Some ATAPI devices fail
1971 		 * to set nsect/lbal after reset, so don't waste too
1972 		 * much time on it.  We're gonna wait for !BSY anyway.
1973 		 */
1974 		for (i = 0; i < 2; i++) {
1975 			u8 nsect, lbal;
1976 
1977 			nsect = ioread8(ioaddr->nsect_addr);
1978 			lbal = ioread8(ioaddr->lbal_addr);
1979 			if ((nsect == 1) && (lbal == 1))
1980 				break;
1981 			ata_msleep(ap, 50);	/* give drive a breather */
1982 		}
1983 
1984 		rc = ata_sff_wait_ready(link, deadline);
1985 		if (rc) {
1986 			if (rc != -ENODEV)
1987 				return rc;
1988 			ret = rc;
1989 		}
1990 	}
1991 
1992 	/* is all this really necessary? */
1993 	ap->ops->sff_dev_select(ap, 0);
1994 	if (dev1)
1995 		ap->ops->sff_dev_select(ap, 1);
1996 	if (dev0)
1997 		ap->ops->sff_dev_select(ap, 0);
1998 
1999 	return ret;
2000 }
2001 EXPORT_SYMBOL_GPL(ata_sff_wait_after_reset);
2002 
2003 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
2004 			     unsigned long deadline)
2005 {
2006 	struct ata_ioports *ioaddr = &ap->ioaddr;
2007 
2008 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
2009 
2010 	/* software reset.  causes dev0 to be selected */
2011 	iowrite8(ap->ctl, ioaddr->ctl_addr);
2012 	udelay(20);	/* FIXME: flush */
2013 	iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
2014 	udelay(20);	/* FIXME: flush */
2015 	iowrite8(ap->ctl, ioaddr->ctl_addr);
2016 	ap->last_ctl = ap->ctl;
2017 
2018 	/* wait the port to become ready */
2019 	return ata_sff_wait_after_reset(&ap->link, devmask, deadline);
2020 }
2021 
2022 /**
2023  *	ata_sff_softreset - reset host port via ATA SRST
2024  *	@link: ATA link to reset
2025  *	@classes: resulting classes of attached devices
2026  *	@deadline: deadline jiffies for the operation
2027  *
2028  *	Reset host port using ATA SRST.
2029  *
2030  *	LOCKING:
2031  *	Kernel thread context (may sleep)
2032  *
2033  *	RETURNS:
2034  *	0 on success, -errno otherwise.
2035  */
2036 int ata_sff_softreset(struct ata_link *link, unsigned int *classes,
2037 		      unsigned long deadline)
2038 {
2039 	struct ata_port *ap = link->ap;
2040 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
2041 	unsigned int devmask = 0;
2042 	int rc;
2043 	u8 err;
2044 
2045 	DPRINTK("ENTER\n");
2046 
2047 	/* determine if device 0/1 are present */
2048 	if (ata_devchk(ap, 0))
2049 		devmask |= (1 << 0);
2050 	if (slave_possible && ata_devchk(ap, 1))
2051 		devmask |= (1 << 1);
2052 
2053 	/* select device 0 again */
2054 	ap->ops->sff_dev_select(ap, 0);
2055 
2056 	/* issue bus reset */
2057 	DPRINTK("about to softreset, devmask=%x\n", devmask);
2058 	rc = ata_bus_softreset(ap, devmask, deadline);
2059 	/* if link is occupied, -ENODEV too is an error */
2060 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
2061 		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
2062 		return rc;
2063 	}
2064 
2065 	/* determine by signature whether we have ATA or ATAPI devices */
2066 	classes[0] = ata_sff_dev_classify(&link->device[0],
2067 					  devmask & (1 << 0), &err);
2068 	if (slave_possible && err != 0x81)
2069 		classes[1] = ata_sff_dev_classify(&link->device[1],
2070 						  devmask & (1 << 1), &err);
2071 
2072 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
2073 	return 0;
2074 }
2075 EXPORT_SYMBOL_GPL(ata_sff_softreset);
2076 
2077 /**
2078  *	sata_sff_hardreset - reset host port via SATA phy reset
2079  *	@link: link to reset
2080  *	@class: resulting class of attached device
2081  *	@deadline: deadline jiffies for the operation
2082  *
2083  *	SATA phy-reset host port using DET bits of SControl register,
2084  *	wait for !BSY and classify the attached device.
2085  *
2086  *	LOCKING:
2087  *	Kernel thread context (may sleep)
2088  *
2089  *	RETURNS:
2090  *	0 on success, -errno otherwise.
2091  */
2092 int sata_sff_hardreset(struct ata_link *link, unsigned int *class,
2093 		       unsigned long deadline)
2094 {
2095 	struct ata_eh_context *ehc = &link->eh_context;
2096 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
2097 	bool online;
2098 	int rc;
2099 
2100 	rc = sata_link_hardreset(link, timing, deadline, &online,
2101 				 ata_sff_check_ready);
2102 	if (online)
2103 		*class = ata_sff_dev_classify(link->device, 1, NULL);
2104 
2105 	DPRINTK("EXIT, class=%u\n", *class);
2106 	return rc;
2107 }
2108 EXPORT_SYMBOL_GPL(sata_sff_hardreset);
2109 
2110 /**
2111  *	ata_sff_postreset - SFF postreset callback
2112  *	@link: the target SFF ata_link
2113  *	@classes: classes of attached devices
2114  *
2115  *	This function is invoked after a successful reset.  It first
2116  *	calls ata_std_postreset() and performs SFF specific postreset
2117  *	processing.
2118  *
2119  *	LOCKING:
2120  *	Kernel thread context (may sleep)
2121  */
2122 void ata_sff_postreset(struct ata_link *link, unsigned int *classes)
2123 {
2124 	struct ata_port *ap = link->ap;
2125 
2126 	ata_std_postreset(link, classes);
2127 
2128 	/* is double-select really necessary? */
2129 	if (classes[0] != ATA_DEV_NONE)
2130 		ap->ops->sff_dev_select(ap, 1);
2131 	if (classes[1] != ATA_DEV_NONE)
2132 		ap->ops->sff_dev_select(ap, 0);
2133 
2134 	/* bail out if no device is present */
2135 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
2136 		DPRINTK("EXIT, no device\n");
2137 		return;
2138 	}
2139 
2140 	/* set up device control */
2141 	if (ap->ops->sff_set_devctl || ap->ioaddr.ctl_addr) {
2142 		ata_sff_set_devctl(ap, ap->ctl);
2143 		ap->last_ctl = ap->ctl;
2144 	}
2145 }
2146 EXPORT_SYMBOL_GPL(ata_sff_postreset);
2147 
2148 /**
2149  *	ata_sff_drain_fifo - Stock FIFO drain logic for SFF controllers
2150  *	@qc: command
2151  *
2152  *	Drain the FIFO and device of any stuck data following a command
2153  *	failing to complete. In some cases this is necessary before a
2154  *	reset will recover the device.
2155  *
2156  */
2157 
2158 void ata_sff_drain_fifo(struct ata_queued_cmd *qc)
2159 {
2160 	int count;
2161 	struct ata_port *ap;
2162 
2163 	/* We only need to flush incoming data when a command was running */
2164 	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
2165 		return;
2166 
2167 	ap = qc->ap;
2168 	/* Drain up to 64K of data before we give up this recovery method */
2169 	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ)
2170 						&& count < 65536; count += 2)
2171 		ioread16(ap->ioaddr.data_addr);
2172 
2173 	/* Can become DEBUG later */
2174 	if (count)
2175 		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
2176 
2177 }
2178 EXPORT_SYMBOL_GPL(ata_sff_drain_fifo);
2179 
2180 /**
2181  *	ata_sff_error_handler - Stock error handler for SFF controller
2182  *	@ap: port to handle error for
2183  *
2184  *	Stock error handler for SFF controller.  It can handle both
2185  *	PATA and SATA controllers.  Many controllers should be able to
2186  *	use this EH as-is or with some added handling before and
2187  *	after.
2188  *
2189  *	LOCKING:
2190  *	Kernel thread context (may sleep)
2191  */
2192 void ata_sff_error_handler(struct ata_port *ap)
2193 {
2194 	ata_reset_fn_t softreset = ap->ops->softreset;
2195 	ata_reset_fn_t hardreset = ap->ops->hardreset;
2196 	struct ata_queued_cmd *qc;
2197 	unsigned long flags;
2198 
2199 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2200 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2201 		qc = NULL;
2202 
2203 	spin_lock_irqsave(ap->lock, flags);
2204 
2205 	/*
2206 	 * We *MUST* do FIFO draining before we issue a reset as
2207 	 * several devices helpfully clear their internal state and
2208 	 * will lock solid if we touch the data port post reset. Pass
2209 	 * qc in case anyone wants to do different PIO/DMA recovery or
2210 	 * has per command fixups
2211 	 */
2212 	if (ap->ops->sff_drain_fifo)
2213 		ap->ops->sff_drain_fifo(qc);
2214 
2215 	spin_unlock_irqrestore(ap->lock, flags);
2216 
2217 	/* ignore ata_sff_softreset if ctl isn't accessible */
2218 	if (softreset == ata_sff_softreset && !ap->ioaddr.ctl_addr)
2219 		softreset = NULL;
2220 
2221 	/* ignore built-in hardresets if SCR access is not available */
2222 	if ((hardreset == sata_std_hardreset ||
2223 	     hardreset == sata_sff_hardreset) && !sata_scr_valid(&ap->link))
2224 		hardreset = NULL;
2225 
2226 	ata_do_eh(ap, ap->ops->prereset, softreset, hardreset,
2227 		  ap->ops->postreset);
2228 }
2229 EXPORT_SYMBOL_GPL(ata_sff_error_handler);
2230 
2231 /**
2232  *	ata_sff_std_ports - initialize ioaddr with standard port offsets.
2233  *	@ioaddr: IO address structure to be initialized
2234  *
2235  *	Utility function which initializes data_addr, error_addr,
2236  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
2237  *	device_addr, status_addr, and command_addr to standard offsets
2238  *	relative to cmd_addr.
2239  *
2240  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
2241  */
2242 void ata_sff_std_ports(struct ata_ioports *ioaddr)
2243 {
2244 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
2245 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
2246 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
2247 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
2248 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
2249 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
2250 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
2251 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
2252 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
2253 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
2254 }
2255 EXPORT_SYMBOL_GPL(ata_sff_std_ports);
2256 
2257 #ifdef CONFIG_PCI
2258 
2259 static int ata_resources_present(struct pci_dev *pdev, int port)
2260 {
2261 	int i;
2262 
2263 	/* Check the PCI resources for this channel are enabled */
2264 	port = port * 2;
2265 	for (i = 0; i < 2; i++) {
2266 		if (pci_resource_start(pdev, port + i) == 0 ||
2267 		    pci_resource_len(pdev, port + i) == 0)
2268 			return 0;
2269 	}
2270 	return 1;
2271 }
2272 
2273 /**
2274  *	ata_pci_sff_init_host - acquire native PCI ATA resources and init host
2275  *	@host: target ATA host
2276  *
2277  *	Acquire native PCI ATA resources for @host and initialize the
2278  *	first two ports of @host accordingly.  Ports marked dummy are
2279  *	skipped and allocation failure makes the port dummy.
2280  *
2281  *	Note that native PCI resources are valid even for legacy hosts
2282  *	as we fix up pdev resources array early in boot, so this
2283  *	function can be used for both native and legacy SFF hosts.
2284  *
2285  *	LOCKING:
2286  *	Inherited from calling layer (may sleep).
2287  *
2288  *	RETURNS:
2289  *	0 if at least one port is initialized, -ENODEV if no port is
2290  *	available.
2291  */
2292 int ata_pci_sff_init_host(struct ata_host *host)
2293 {
2294 	struct device *gdev = host->dev;
2295 	struct pci_dev *pdev = to_pci_dev(gdev);
2296 	unsigned int mask = 0;
2297 	int i, rc;
2298 
2299 	/* request, iomap BARs and init port addresses accordingly */
2300 	for (i = 0; i < 2; i++) {
2301 		struct ata_port *ap = host->ports[i];
2302 		int base = i * 2;
2303 		void __iomem * const *iomap;
2304 
2305 		if (ata_port_is_dummy(ap))
2306 			continue;
2307 
2308 		/* Discard disabled ports.  Some controllers show
2309 		 * their unused channels this way.  Disabled ports are
2310 		 * made dummy.
2311 		 */
2312 		if (!ata_resources_present(pdev, i)) {
2313 			ap->ops = &ata_dummy_port_ops;
2314 			continue;
2315 		}
2316 
2317 		rc = pcim_iomap_regions(pdev, 0x3 << base,
2318 					dev_driver_string(gdev));
2319 		if (rc) {
2320 			dev_warn(gdev,
2321 				 "failed to request/iomap BARs for port %d (errno=%d)\n",
2322 				 i, rc);
2323 			if (rc == -EBUSY)
2324 				pcim_pin_device(pdev);
2325 			ap->ops = &ata_dummy_port_ops;
2326 			continue;
2327 		}
2328 		host->iomap = iomap = pcim_iomap_table(pdev);
2329 
2330 		ap->ioaddr.cmd_addr = iomap[base];
2331 		ap->ioaddr.altstatus_addr =
2332 		ap->ioaddr.ctl_addr = (void __iomem *)
2333 			((unsigned long)iomap[base + 1] | ATA_PCI_CTL_OFS);
2334 		ata_sff_std_ports(&ap->ioaddr);
2335 
2336 		ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
2337 			(unsigned long long)pci_resource_start(pdev, base),
2338 			(unsigned long long)pci_resource_start(pdev, base + 1));
2339 
2340 		mask |= 1 << i;
2341 	}
2342 
2343 	if (!mask) {
2344 		dev_err(gdev, "no available native port\n");
2345 		return -ENODEV;
2346 	}
2347 
2348 	return 0;
2349 }
2350 EXPORT_SYMBOL_GPL(ata_pci_sff_init_host);
2351 
2352 /**
2353  *	ata_pci_sff_prepare_host - helper to prepare PCI PIO-only SFF ATA host
2354  *	@pdev: target PCI device
2355  *	@ppi: array of port_info, must be enough for two ports
2356  *	@r_host: out argument for the initialized ATA host
2357  *
2358  *	Helper to allocate PIO-only SFF ATA host for @pdev, acquire
2359  *	all PCI resources and initialize it accordingly in one go.
2360  *
2361  *	LOCKING:
2362  *	Inherited from calling layer (may sleep).
2363  *
2364  *	RETURNS:
2365  *	0 on success, -errno otherwise.
2366  */
2367 int ata_pci_sff_prepare_host(struct pci_dev *pdev,
2368 			     const struct ata_port_info * const *ppi,
2369 			     struct ata_host **r_host)
2370 {
2371 	struct ata_host *host;
2372 	int rc;
2373 
2374 	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
2375 		return -ENOMEM;
2376 
2377 	host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
2378 	if (!host) {
2379 		dev_err(&pdev->dev, "failed to allocate ATA host\n");
2380 		rc = -ENOMEM;
2381 		goto err_out;
2382 	}
2383 
2384 	rc = ata_pci_sff_init_host(host);
2385 	if (rc)
2386 		goto err_out;
2387 
2388 	devres_remove_group(&pdev->dev, NULL);
2389 	*r_host = host;
2390 	return 0;
2391 
2392 err_out:
2393 	devres_release_group(&pdev->dev, NULL);
2394 	return rc;
2395 }
2396 EXPORT_SYMBOL_GPL(ata_pci_sff_prepare_host);
2397 
2398 /**
2399  *	ata_pci_sff_activate_host - start SFF host, request IRQ and register it
2400  *	@host: target SFF ATA host
2401  *	@irq_handler: irq_handler used when requesting IRQ(s)
2402  *	@sht: scsi_host_template to use when registering the host
2403  *
2404  *	This is the counterpart of ata_host_activate() for SFF ATA
2405  *	hosts.  This separate helper is necessary because SFF hosts
2406  *	use two separate interrupts in legacy mode.
2407  *
2408  *	LOCKING:
2409  *	Inherited from calling layer (may sleep).
2410  *
2411  *	RETURNS:
2412  *	0 on success, -errno otherwise.
2413  */
2414 int ata_pci_sff_activate_host(struct ata_host *host,
2415 			      irq_handler_t irq_handler,
2416 			      struct scsi_host_template *sht)
2417 {
2418 	struct device *dev = host->dev;
2419 	struct pci_dev *pdev = to_pci_dev(dev);
2420 	const char *drv_name = dev_driver_string(host->dev);
2421 	int legacy_mode = 0, rc;
2422 
2423 	rc = ata_host_start(host);
2424 	if (rc)
2425 		return rc;
2426 
2427 	if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
2428 		u8 tmp8, mask;
2429 
2430 		/* TODO: What if one channel is in native mode ... */
2431 		pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp8);
2432 		mask = (1 << 2) | (1 << 0);
2433 		if ((tmp8 & mask) != mask)
2434 			legacy_mode = 1;
2435 #if defined(CONFIG_NO_ATA_LEGACY)
2436 		/* Some platforms with PCI limits cannot address compat
2437 		   port space. In that case we punt if their firmware has
2438 		   left a device in compatibility mode */
2439 		if (legacy_mode) {
2440 			printk(KERN_ERR "ata: Compatibility mode ATA is not supported on this platform, skipping.\n");
2441 			return -EOPNOTSUPP;
2442 		}
2443 #endif
2444 	}
2445 
2446 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2447 		return -ENOMEM;
2448 
2449 	if (!legacy_mode && pdev->irq) {
2450 		int i;
2451 
2452 		rc = devm_request_irq(dev, pdev->irq, irq_handler,
2453 				      IRQF_SHARED, drv_name, host);
2454 		if (rc)
2455 			goto out;
2456 
2457 		for (i = 0; i < 2; i++) {
2458 			if (ata_port_is_dummy(host->ports[i]))
2459 				continue;
2460 			ata_port_desc(host->ports[i], "irq %d", pdev->irq);
2461 		}
2462 	} else if (legacy_mode) {
2463 		if (!ata_port_is_dummy(host->ports[0])) {
2464 			rc = devm_request_irq(dev, ATA_PRIMARY_IRQ(pdev),
2465 					      irq_handler, IRQF_SHARED,
2466 					      drv_name, host);
2467 			if (rc)
2468 				goto out;
2469 
2470 			ata_port_desc(host->ports[0], "irq %d",
2471 				      ATA_PRIMARY_IRQ(pdev));
2472 		}
2473 
2474 		if (!ata_port_is_dummy(host->ports[1])) {
2475 			rc = devm_request_irq(dev, ATA_SECONDARY_IRQ(pdev),
2476 					      irq_handler, IRQF_SHARED,
2477 					      drv_name, host);
2478 			if (rc)
2479 				goto out;
2480 
2481 			ata_port_desc(host->ports[1], "irq %d",
2482 				      ATA_SECONDARY_IRQ(pdev));
2483 		}
2484 	}
2485 
2486 	rc = ata_host_register(host, sht);
2487 out:
2488 	if (rc == 0)
2489 		devres_remove_group(dev, NULL);
2490 	else
2491 		devres_release_group(dev, NULL);
2492 
2493 	return rc;
2494 }
2495 EXPORT_SYMBOL_GPL(ata_pci_sff_activate_host);
2496 
2497 static const struct ata_port_info *ata_sff_find_valid_pi(
2498 					const struct ata_port_info * const *ppi)
2499 {
2500 	int i;
2501 
2502 	/* look up the first valid port_info */
2503 	for (i = 0; i < 2 && ppi[i]; i++)
2504 		if (ppi[i]->port_ops != &ata_dummy_port_ops)
2505 			return ppi[i];
2506 
2507 	return NULL;
2508 }
2509 
2510 static int ata_pci_init_one(struct pci_dev *pdev,
2511 		const struct ata_port_info * const *ppi,
2512 		struct scsi_host_template *sht, void *host_priv,
2513 		int hflags, bool bmdma)
2514 {
2515 	struct device *dev = &pdev->dev;
2516 	const struct ata_port_info *pi;
2517 	struct ata_host *host = NULL;
2518 	int rc;
2519 
2520 	DPRINTK("ENTER\n");
2521 
2522 	pi = ata_sff_find_valid_pi(ppi);
2523 	if (!pi) {
2524 		dev_err(&pdev->dev, "no valid port_info specified\n");
2525 		return -EINVAL;
2526 	}
2527 
2528 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
2529 		return -ENOMEM;
2530 
2531 	rc = pcim_enable_device(pdev);
2532 	if (rc)
2533 		goto out;
2534 
2535 	if (bmdma)
2536 		/* prepare and activate BMDMA host */
2537 		rc = ata_pci_bmdma_prepare_host(pdev, ppi, &host);
2538 	else
2539 		/* prepare and activate SFF host */
2540 		rc = ata_pci_sff_prepare_host(pdev, ppi, &host);
2541 	if (rc)
2542 		goto out;
2543 	host->private_data = host_priv;
2544 	host->flags |= hflags;
2545 
2546 	if (bmdma) {
2547 		pci_set_master(pdev);
2548 		rc = ata_pci_sff_activate_host(host, ata_bmdma_interrupt, sht);
2549 	} else
2550 		rc = ata_pci_sff_activate_host(host, ata_sff_interrupt, sht);
2551 out:
2552 	if (rc == 0)
2553 		devres_remove_group(&pdev->dev, NULL);
2554 	else
2555 		devres_release_group(&pdev->dev, NULL);
2556 
2557 	return rc;
2558 }
2559 
2560 /**
2561  *	ata_pci_sff_init_one - Initialize/register PIO-only PCI IDE controller
2562  *	@pdev: Controller to be initialized
2563  *	@ppi: array of port_info, must be enough for two ports
2564  *	@sht: scsi_host_template to use when registering the host
2565  *	@host_priv: host private_data
2566  *	@hflag: host flags
2567  *
2568  *	This is a helper function which can be called from a driver's
2569  *	xxx_init_one() probe function if the hardware uses traditional
2570  *	IDE taskfile registers and is PIO only.
2571  *
2572  *	ASSUMPTION:
2573  *	Nobody makes a single channel controller that appears solely as
2574  *	the secondary legacy port on PCI.
2575  *
2576  *	LOCKING:
2577  *	Inherited from PCI layer (may sleep).
2578  *
2579  *	RETURNS:
2580  *	Zero on success, negative on errno-based value on error.
2581  */
2582 int ata_pci_sff_init_one(struct pci_dev *pdev,
2583 		 const struct ata_port_info * const *ppi,
2584 		 struct scsi_host_template *sht, void *host_priv, int hflag)
2585 {
2586 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflag, 0);
2587 }
2588 EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
2589 
2590 #endif /* CONFIG_PCI */
2591 
2592 /*
2593  *	BMDMA support
2594  */
2595 
2596 #ifdef CONFIG_ATA_BMDMA
2597 
2598 const struct ata_port_operations ata_bmdma_port_ops = {
2599 	.inherits		= &ata_sff_port_ops,
2600 
2601 	.error_handler		= ata_bmdma_error_handler,
2602 	.post_internal_cmd	= ata_bmdma_post_internal_cmd,
2603 
2604 	.qc_prep		= ata_bmdma_qc_prep,
2605 	.qc_issue		= ata_bmdma_qc_issue,
2606 
2607 	.sff_irq_clear		= ata_bmdma_irq_clear,
2608 	.bmdma_setup		= ata_bmdma_setup,
2609 	.bmdma_start		= ata_bmdma_start,
2610 	.bmdma_stop		= ata_bmdma_stop,
2611 	.bmdma_status		= ata_bmdma_status,
2612 
2613 	.port_start		= ata_bmdma_port_start,
2614 };
2615 EXPORT_SYMBOL_GPL(ata_bmdma_port_ops);
2616 
2617 const struct ata_port_operations ata_bmdma32_port_ops = {
2618 	.inherits		= &ata_bmdma_port_ops,
2619 
2620 	.sff_data_xfer		= ata_sff_data_xfer32,
2621 	.port_start		= ata_bmdma_port_start32,
2622 };
2623 EXPORT_SYMBOL_GPL(ata_bmdma32_port_ops);
2624 
2625 /**
2626  *	ata_bmdma_fill_sg - Fill PCI IDE PRD table
2627  *	@qc: Metadata associated with taskfile to be transferred
2628  *
2629  *	Fill PCI IDE PRD (scatter-gather) table with segments
2630  *	associated with the current disk command.
2631  *
2632  *	LOCKING:
2633  *	spin_lock_irqsave(host lock)
2634  *
2635  */
2636 static void ata_bmdma_fill_sg(struct ata_queued_cmd *qc)
2637 {
2638 	struct ata_port *ap = qc->ap;
2639 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2640 	struct scatterlist *sg;
2641 	unsigned int si, pi;
2642 
2643 	pi = 0;
2644 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2645 		u32 addr, offset;
2646 		u32 sg_len, len;
2647 
2648 		/* determine if physical DMA addr spans 64K boundary.
2649 		 * Note h/w doesn't support 64-bit, so we unconditionally
2650 		 * truncate dma_addr_t to u32.
2651 		 */
2652 		addr = (u32) sg_dma_address(sg);
2653 		sg_len = sg_dma_len(sg);
2654 
2655 		while (sg_len) {
2656 			offset = addr & 0xffff;
2657 			len = sg_len;
2658 			if ((offset + sg_len) > 0x10000)
2659 				len = 0x10000 - offset;
2660 
2661 			prd[pi].addr = cpu_to_le32(addr);
2662 			prd[pi].flags_len = cpu_to_le32(len & 0xffff);
2663 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2664 
2665 			pi++;
2666 			sg_len -= len;
2667 			addr += len;
2668 		}
2669 	}
2670 
2671 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2672 }
2673 
2674 /**
2675  *	ata_bmdma_fill_sg_dumb - Fill PCI IDE PRD table
2676  *	@qc: Metadata associated with taskfile to be transferred
2677  *
2678  *	Fill PCI IDE PRD (scatter-gather) table with segments
2679  *	associated with the current disk command. Perform the fill
2680  *	so that we avoid writing any length 64K records for
2681  *	controllers that don't follow the spec.
2682  *
2683  *	LOCKING:
2684  *	spin_lock_irqsave(host lock)
2685  *
2686  */
2687 static void ata_bmdma_fill_sg_dumb(struct ata_queued_cmd *qc)
2688 {
2689 	struct ata_port *ap = qc->ap;
2690 	struct ata_bmdma_prd *prd = ap->bmdma_prd;
2691 	struct scatterlist *sg;
2692 	unsigned int si, pi;
2693 
2694 	pi = 0;
2695 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
2696 		u32 addr, offset;
2697 		u32 sg_len, len, blen;
2698 
2699 		/* determine if physical DMA addr spans 64K boundary.
2700 		 * Note h/w doesn't support 64-bit, so we unconditionally
2701 		 * truncate dma_addr_t to u32.
2702 		 */
2703 		addr = (u32) sg_dma_address(sg);
2704 		sg_len = sg_dma_len(sg);
2705 
2706 		while (sg_len) {
2707 			offset = addr & 0xffff;
2708 			len = sg_len;
2709 			if ((offset + sg_len) > 0x10000)
2710 				len = 0x10000 - offset;
2711 
2712 			blen = len & 0xffff;
2713 			prd[pi].addr = cpu_to_le32(addr);
2714 			if (blen == 0) {
2715 				/* Some PATA chipsets like the CS5530 can't
2716 				   cope with 0x0000 meaning 64K as the spec
2717 				   says */
2718 				prd[pi].flags_len = cpu_to_le32(0x8000);
2719 				blen = 0x8000;
2720 				prd[++pi].addr = cpu_to_le32(addr + 0x8000);
2721 			}
2722 			prd[pi].flags_len = cpu_to_le32(blen);
2723 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
2724 
2725 			pi++;
2726 			sg_len -= len;
2727 			addr += len;
2728 		}
2729 	}
2730 
2731 	prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
2732 }
2733 
2734 /**
2735  *	ata_bmdma_qc_prep - Prepare taskfile for submission
2736  *	@qc: Metadata associated with taskfile to be prepared
2737  *
2738  *	Prepare ATA taskfile for submission.
2739  *
2740  *	LOCKING:
2741  *	spin_lock_irqsave(host lock)
2742  */
2743 void ata_bmdma_qc_prep(struct ata_queued_cmd *qc)
2744 {
2745 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2746 		return;
2747 
2748 	ata_bmdma_fill_sg(qc);
2749 }
2750 EXPORT_SYMBOL_GPL(ata_bmdma_qc_prep);
2751 
2752 /**
2753  *	ata_bmdma_dumb_qc_prep - Prepare taskfile for submission
2754  *	@qc: Metadata associated with taskfile to be prepared
2755  *
2756  *	Prepare ATA taskfile for submission.
2757  *
2758  *	LOCKING:
2759  *	spin_lock_irqsave(host lock)
2760  */
2761 void ata_bmdma_dumb_qc_prep(struct ata_queued_cmd *qc)
2762 {
2763 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
2764 		return;
2765 
2766 	ata_bmdma_fill_sg_dumb(qc);
2767 }
2768 EXPORT_SYMBOL_GPL(ata_bmdma_dumb_qc_prep);
2769 
2770 /**
2771  *	ata_bmdma_qc_issue - issue taskfile to a BMDMA controller
2772  *	@qc: command to issue to device
2773  *
2774  *	This function issues a PIO, NODATA or DMA command to a
2775  *	SFF/BMDMA controller.  PIO and NODATA are handled by
2776  *	ata_sff_qc_issue().
2777  *
2778  *	LOCKING:
2779  *	spin_lock_irqsave(host lock)
2780  *
2781  *	RETURNS:
2782  *	Zero on success, AC_ERR_* mask on failure
2783  */
2784 unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc)
2785 {
2786 	struct ata_port *ap = qc->ap;
2787 	struct ata_link *link = qc->dev->link;
2788 
2789 	/* defer PIO handling to sff_qc_issue */
2790 	if (!ata_is_dma(qc->tf.protocol))
2791 		return ata_sff_qc_issue(qc);
2792 
2793 	/* select the device */
2794 	ata_dev_select(ap, qc->dev->devno, 1, 0);
2795 
2796 	/* start the command */
2797 	switch (qc->tf.protocol) {
2798 	case ATA_PROT_DMA:
2799 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2800 
2801 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2802 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2803 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
2804 		ap->hsm_task_state = HSM_ST_LAST;
2805 		break;
2806 
2807 	case ATAPI_PROT_DMA:
2808 		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
2809 
2810 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
2811 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
2812 		ap->hsm_task_state = HSM_ST_FIRST;
2813 
2814 		/* send cdb by polling if no cdb interrupt */
2815 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
2816 			ata_sff_queue_pio_task(link, 0);
2817 		break;
2818 
2819 	default:
2820 		WARN_ON(1);
2821 		return AC_ERR_SYSTEM;
2822 	}
2823 
2824 	return 0;
2825 }
2826 EXPORT_SYMBOL_GPL(ata_bmdma_qc_issue);
2827 
2828 /**
2829  *	ata_bmdma_port_intr - Handle BMDMA port interrupt
2830  *	@ap: Port on which interrupt arrived (possibly...)
2831  *	@qc: Taskfile currently active in engine
2832  *
2833  *	Handle port interrupt for given queued command.
2834  *
2835  *	LOCKING:
2836  *	spin_lock_irqsave(host lock)
2837  *
2838  *	RETURNS:
2839  *	One if interrupt was handled, zero if not (shared irq).
2840  */
2841 unsigned int ata_bmdma_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
2842 {
2843 	struct ata_eh_info *ehi = &ap->link.eh_info;
2844 	u8 host_stat = 0;
2845 	bool bmdma_stopped = false;
2846 	unsigned int handled;
2847 
2848 	if (ap->hsm_task_state == HSM_ST_LAST && ata_is_dma(qc->tf.protocol)) {
2849 		/* check status of DMA engine */
2850 		host_stat = ap->ops->bmdma_status(ap);
2851 		VPRINTK("ata%u: host_stat 0x%X\n", ap->print_id, host_stat);
2852 
2853 		/* if it's not our irq... */
2854 		if (!(host_stat & ATA_DMA_INTR))
2855 			return ata_sff_idle_irq(ap);
2856 
2857 		/* before we do anything else, clear DMA-Start bit */
2858 		ap->ops->bmdma_stop(qc);
2859 		bmdma_stopped = true;
2860 
2861 		if (unlikely(host_stat & ATA_DMA_ERR)) {
2862 			/* error when transferring data to/from memory */
2863 			qc->err_mask |= AC_ERR_HOST_BUS;
2864 			ap->hsm_task_state = HSM_ST_ERR;
2865 		}
2866 	}
2867 
2868 	handled = __ata_sff_port_intr(ap, qc, bmdma_stopped);
2869 
2870 	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
2871 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
2872 
2873 	return handled;
2874 }
2875 EXPORT_SYMBOL_GPL(ata_bmdma_port_intr);
2876 
2877 /**
2878  *	ata_bmdma_interrupt - Default BMDMA ATA host interrupt handler
2879  *	@irq: irq line (unused)
2880  *	@dev_instance: pointer to our ata_host information structure
2881  *
2882  *	Default interrupt handler for PCI IDE devices.  Calls
2883  *	ata_bmdma_port_intr() for each port that is not disabled.
2884  *
2885  *	LOCKING:
2886  *	Obtains host lock during operation.
2887  *
2888  *	RETURNS:
2889  *	IRQ_NONE or IRQ_HANDLED.
2890  */
2891 irqreturn_t ata_bmdma_interrupt(int irq, void *dev_instance)
2892 {
2893 	return __ata_sff_interrupt(irq, dev_instance, ata_bmdma_port_intr);
2894 }
2895 EXPORT_SYMBOL_GPL(ata_bmdma_interrupt);
2896 
2897 /**
2898  *	ata_bmdma_error_handler - Stock error handler for BMDMA controller
2899  *	@ap: port to handle error for
2900  *
2901  *	Stock error handler for BMDMA controller.  It can handle both
2902  *	PATA and SATA controllers.  Most BMDMA controllers should be
2903  *	able to use this EH as-is or with some added handling before
2904  *	and after.
2905  *
2906  *	LOCKING:
2907  *	Kernel thread context (may sleep)
2908  */
2909 void ata_bmdma_error_handler(struct ata_port *ap)
2910 {
2911 	struct ata_queued_cmd *qc;
2912 	unsigned long flags;
2913 	bool thaw = false;
2914 
2915 	qc = __ata_qc_from_tag(ap, ap->link.active_tag);
2916 	if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
2917 		qc = NULL;
2918 
2919 	/* reset PIO HSM and stop DMA engine */
2920 	spin_lock_irqsave(ap->lock, flags);
2921 
2922 	if (qc && ata_is_dma(qc->tf.protocol)) {
2923 		u8 host_stat;
2924 
2925 		host_stat = ap->ops->bmdma_status(ap);
2926 
2927 		/* BMDMA controllers indicate host bus error by
2928 		 * setting DMA_ERR bit and timing out.  As it wasn't
2929 		 * really a timeout event, adjust error mask and
2930 		 * cancel frozen state.
2931 		 */
2932 		if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
2933 			qc->err_mask = AC_ERR_HOST_BUS;
2934 			thaw = true;
2935 		}
2936 
2937 		ap->ops->bmdma_stop(qc);
2938 
2939 		/* if we're gonna thaw, make sure IRQ is clear */
2940 		if (thaw) {
2941 			ap->ops->sff_check_status(ap);
2942 			if (ap->ops->sff_irq_clear)
2943 				ap->ops->sff_irq_clear(ap);
2944 		}
2945 	}
2946 
2947 	spin_unlock_irqrestore(ap->lock, flags);
2948 
2949 	if (thaw)
2950 		ata_eh_thaw_port(ap);
2951 
2952 	ata_sff_error_handler(ap);
2953 }
2954 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
2955 
2956 /**
2957  *	ata_bmdma_post_internal_cmd - Stock post_internal_cmd for BMDMA
2958  *	@qc: internal command to clean up
2959  *
2960  *	LOCKING:
2961  *	Kernel thread context (may sleep)
2962  */
2963 void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
2964 {
2965 	struct ata_port *ap = qc->ap;
2966 	unsigned long flags;
2967 
2968 	if (ata_is_dma(qc->tf.protocol)) {
2969 		spin_lock_irqsave(ap->lock, flags);
2970 		ap->ops->bmdma_stop(qc);
2971 		spin_unlock_irqrestore(ap->lock, flags);
2972 	}
2973 }
2974 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
2975 
2976 /**
2977  *	ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
2978  *	@ap: Port associated with this ATA transaction.
2979  *
2980  *	Clear interrupt and error flags in DMA status register.
2981  *
2982  *	May be used as the irq_clear() entry in ata_port_operations.
2983  *
2984  *	LOCKING:
2985  *	spin_lock_irqsave(host lock)
2986  */
2987 void ata_bmdma_irq_clear(struct ata_port *ap)
2988 {
2989 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
2990 
2991 	if (!mmio)
2992 		return;
2993 
2994 	iowrite8(ioread8(mmio + ATA_DMA_STATUS), mmio + ATA_DMA_STATUS);
2995 }
2996 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
2997 
2998 /**
2999  *	ata_bmdma_setup - Set up PCI IDE BMDMA transaction
3000  *	@qc: Info associated with this ATA transaction.
3001  *
3002  *	LOCKING:
3003  *	spin_lock_irqsave(host lock)
3004  */
3005 void ata_bmdma_setup(struct ata_queued_cmd *qc)
3006 {
3007 	struct ata_port *ap = qc->ap;
3008 	unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
3009 	u8 dmactl;
3010 
3011 	/* load PRD table addr. */
3012 	mb();	/* make sure PRD table writes are visible to controller */
3013 	iowrite32(ap->bmdma_prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
3014 
3015 	/* specify data direction, triple-check start bit is clear */
3016 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
3017 	dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
3018 	if (!rw)
3019 		dmactl |= ATA_DMA_WR;
3020 	iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
3021 
3022 	/* issue r/w command */
3023 	ap->ops->sff_exec_command(ap, &qc->tf);
3024 }
3025 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
3026 
3027 /**
3028  *	ata_bmdma_start - Start a PCI IDE BMDMA transaction
3029  *	@qc: Info associated with this ATA transaction.
3030  *
3031  *	LOCKING:
3032  *	spin_lock_irqsave(host lock)
3033  */
3034 void ata_bmdma_start(struct ata_queued_cmd *qc)
3035 {
3036 	struct ata_port *ap = qc->ap;
3037 	u8 dmactl;
3038 
3039 	/* start host DMA transaction */
3040 	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
3041 	iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
3042 
3043 	/* Strictly, one may wish to issue an ioread8() here, to
3044 	 * flush the mmio write.  However, control also passes
3045 	 * to the hardware at this point, and it will interrupt
3046 	 * us when we are to resume control.  So, in effect,
3047 	 * we don't care when the mmio write flushes.
3048 	 * Further, a read of the DMA status register _immediately_
3049 	 * following the write may not be what certain flaky hardware
3050 	 * is expected, so I think it is best to not add a readb()
3051 	 * without first all the MMIO ATA cards/mobos.
3052 	 * Or maybe I'm just being paranoid.
3053 	 *
3054 	 * FIXME: The posting of this write means I/O starts are
3055 	 * unnecessarily delayed for MMIO
3056 	 */
3057 }
3058 EXPORT_SYMBOL_GPL(ata_bmdma_start);
3059 
3060 /**
3061  *	ata_bmdma_stop - Stop PCI IDE BMDMA transfer
3062  *	@qc: Command we are ending DMA for
3063  *
3064  *	Clears the ATA_DMA_START flag in the dma control register
3065  *
3066  *	May be used as the bmdma_stop() entry in ata_port_operations.
3067  *
3068  *	LOCKING:
3069  *	spin_lock_irqsave(host lock)
3070  */
3071 void ata_bmdma_stop(struct ata_queued_cmd *qc)
3072 {
3073 	struct ata_port *ap = qc->ap;
3074 	void __iomem *mmio = ap->ioaddr.bmdma_addr;
3075 
3076 	/* clear start/stop bit */
3077 	iowrite8(ioread8(mmio + ATA_DMA_CMD) & ~ATA_DMA_START,
3078 		 mmio + ATA_DMA_CMD);
3079 
3080 	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
3081 	ata_sff_dma_pause(ap);
3082 }
3083 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
3084 
3085 /**
3086  *	ata_bmdma_status - Read PCI IDE BMDMA status
3087  *	@ap: Port associated with this ATA transaction.
3088  *
3089  *	Read and return BMDMA status register.
3090  *
3091  *	May be used as the bmdma_status() entry in ata_port_operations.
3092  *
3093  *	LOCKING:
3094  *	spin_lock_irqsave(host lock)
3095  */
3096 u8 ata_bmdma_status(struct ata_port *ap)
3097 {
3098 	return ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
3099 }
3100 EXPORT_SYMBOL_GPL(ata_bmdma_status);
3101 
3102 
3103 /**
3104  *	ata_bmdma_port_start - Set port up for bmdma.
3105  *	@ap: Port to initialize
3106  *
3107  *	Called just after data structures for each port are
3108  *	initialized.  Allocates space for PRD table.
3109  *
3110  *	May be used as the port_start() entry in ata_port_operations.
3111  *
3112  *	LOCKING:
3113  *	Inherited from caller.
3114  */
3115 int ata_bmdma_port_start(struct ata_port *ap)
3116 {
3117 	if (ap->mwdma_mask || ap->udma_mask) {
3118 		ap->bmdma_prd =
3119 			dmam_alloc_coherent(ap->host->dev, ATA_PRD_TBL_SZ,
3120 					    &ap->bmdma_prd_dma, GFP_KERNEL);
3121 		if (!ap->bmdma_prd)
3122 			return -ENOMEM;
3123 	}
3124 
3125 	return 0;
3126 }
3127 EXPORT_SYMBOL_GPL(ata_bmdma_port_start);
3128 
3129 /**
3130  *	ata_bmdma_port_start32 - Set port up for dma.
3131  *	@ap: Port to initialize
3132  *
3133  *	Called just after data structures for each port are
3134  *	initialized.  Enables 32bit PIO and allocates space for PRD
3135  *	table.
3136  *
3137  *	May be used as the port_start() entry in ata_port_operations for
3138  *	devices that are capable of 32bit PIO.
3139  *
3140  *	LOCKING:
3141  *	Inherited from caller.
3142  */
3143 int ata_bmdma_port_start32(struct ata_port *ap)
3144 {
3145 	ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
3146 	return ata_bmdma_port_start(ap);
3147 }
3148 EXPORT_SYMBOL_GPL(ata_bmdma_port_start32);
3149 
3150 #ifdef CONFIG_PCI
3151 
3152 /**
3153  *	ata_pci_bmdma_clear_simplex -	attempt to kick device out of simplex
3154  *	@pdev: PCI device
3155  *
3156  *	Some PCI ATA devices report simplex mode but in fact can be told to
3157  *	enter non simplex mode. This implements the necessary logic to
3158  *	perform the task on such devices. Calling it on other devices will
3159  *	have -undefined- behaviour.
3160  */
3161 int ata_pci_bmdma_clear_simplex(struct pci_dev *pdev)
3162 {
3163 	unsigned long bmdma = pci_resource_start(pdev, 4);
3164 	u8 simplex;
3165 
3166 	if (bmdma == 0)
3167 		return -ENOENT;
3168 
3169 	simplex = inb(bmdma + 0x02);
3170 	outb(simplex & 0x60, bmdma + 0x02);
3171 	simplex = inb(bmdma + 0x02);
3172 	if (simplex & 0x80)
3173 		return -EOPNOTSUPP;
3174 	return 0;
3175 }
3176 EXPORT_SYMBOL_GPL(ata_pci_bmdma_clear_simplex);
3177 
3178 static void ata_bmdma_nodma(struct ata_host *host, const char *reason)
3179 {
3180 	int i;
3181 
3182 	dev_err(host->dev, "BMDMA: %s, falling back to PIO\n", reason);
3183 
3184 	for (i = 0; i < 2; i++) {
3185 		host->ports[i]->mwdma_mask = 0;
3186 		host->ports[i]->udma_mask = 0;
3187 	}
3188 }
3189 
3190 /**
3191  *	ata_pci_bmdma_init - acquire PCI BMDMA resources and init ATA host
3192  *	@host: target ATA host
3193  *
3194  *	Acquire PCI BMDMA resources and initialize @host accordingly.
3195  *
3196  *	LOCKING:
3197  *	Inherited from calling layer (may sleep).
3198  */
3199 void ata_pci_bmdma_init(struct ata_host *host)
3200 {
3201 	struct device *gdev = host->dev;
3202 	struct pci_dev *pdev = to_pci_dev(gdev);
3203 	int i, rc;
3204 
3205 	/* No BAR4 allocation: No DMA */
3206 	if (pci_resource_start(pdev, 4) == 0) {
3207 		ata_bmdma_nodma(host, "BAR4 is zero");
3208 		return;
3209 	}
3210 
3211 	/*
3212 	 * Some controllers require BMDMA region to be initialized
3213 	 * even if DMA is not in use to clear IRQ status via
3214 	 * ->sff_irq_clear method.  Try to initialize bmdma_addr
3215 	 * regardless of dma masks.
3216 	 */
3217 	rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
3218 	if (rc)
3219 		ata_bmdma_nodma(host, "failed to set dma mask");
3220 	if (!rc) {
3221 		rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
3222 		if (rc)
3223 			ata_bmdma_nodma(host,
3224 					"failed to set consistent dma mask");
3225 	}
3226 
3227 	/* request and iomap DMA region */
3228 	rc = pcim_iomap_regions(pdev, 1 << 4, dev_driver_string(gdev));
3229 	if (rc) {
3230 		ata_bmdma_nodma(host, "failed to request/iomap BAR4");
3231 		return;
3232 	}
3233 	host->iomap = pcim_iomap_table(pdev);
3234 
3235 	for (i = 0; i < 2; i++) {
3236 		struct ata_port *ap = host->ports[i];
3237 		void __iomem *bmdma = host->iomap[4] + 8 * i;
3238 
3239 		if (ata_port_is_dummy(ap))
3240 			continue;
3241 
3242 		ap->ioaddr.bmdma_addr = bmdma;
3243 		if ((!(ap->flags & ATA_FLAG_IGN_SIMPLEX)) &&
3244 		    (ioread8(bmdma + 2) & 0x80))
3245 			host->flags |= ATA_HOST_SIMPLEX;
3246 
3247 		ata_port_desc(ap, "bmdma 0x%llx",
3248 		    (unsigned long long)pci_resource_start(pdev, 4) + 8 * i);
3249 	}
3250 }
3251 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init);
3252 
3253 /**
3254  *	ata_pci_bmdma_prepare_host - helper to prepare PCI BMDMA ATA host
3255  *	@pdev: target PCI device
3256  *	@ppi: array of port_info, must be enough for two ports
3257  *	@r_host: out argument for the initialized ATA host
3258  *
3259  *	Helper to allocate BMDMA ATA host for @pdev, acquire all PCI
3260  *	resources and initialize it accordingly in one go.
3261  *
3262  *	LOCKING:
3263  *	Inherited from calling layer (may sleep).
3264  *
3265  *	RETURNS:
3266  *	0 on success, -errno otherwise.
3267  */
3268 int ata_pci_bmdma_prepare_host(struct pci_dev *pdev,
3269 			       const struct ata_port_info * const * ppi,
3270 			       struct ata_host **r_host)
3271 {
3272 	int rc;
3273 
3274 	rc = ata_pci_sff_prepare_host(pdev, ppi, r_host);
3275 	if (rc)
3276 		return rc;
3277 
3278 	ata_pci_bmdma_init(*r_host);
3279 	return 0;
3280 }
3281 EXPORT_SYMBOL_GPL(ata_pci_bmdma_prepare_host);
3282 
3283 /**
3284  *	ata_pci_bmdma_init_one - Initialize/register BMDMA PCI IDE controller
3285  *	@pdev: Controller to be initialized
3286  *	@ppi: array of port_info, must be enough for two ports
3287  *	@sht: scsi_host_template to use when registering the host
3288  *	@host_priv: host private_data
3289  *	@hflags: host flags
3290  *
3291  *	This function is similar to ata_pci_sff_init_one() but also
3292  *	takes care of BMDMA initialization.
3293  *
3294  *	LOCKING:
3295  *	Inherited from PCI layer (may sleep).
3296  *
3297  *	RETURNS:
3298  *	Zero on success, negative on errno-based value on error.
3299  */
3300 int ata_pci_bmdma_init_one(struct pci_dev *pdev,
3301 			   const struct ata_port_info * const * ppi,
3302 			   struct scsi_host_template *sht, void *host_priv,
3303 			   int hflags)
3304 {
3305 	return ata_pci_init_one(pdev, ppi, sht, host_priv, hflags, 1);
3306 }
3307 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init_one);
3308 
3309 #endif /* CONFIG_PCI */
3310 #endif /* CONFIG_ATA_BMDMA */
3311 
3312 /**
3313  *	ata_sff_port_init - Initialize SFF/BMDMA ATA port
3314  *	@ap: Port to initialize
3315  *
3316  *	Called on port allocation to initialize SFF/BMDMA specific
3317  *	fields.
3318  *
3319  *	LOCKING:
3320  *	None.
3321  */
3322 void ata_sff_port_init(struct ata_port *ap)
3323 {
3324 	INIT_DELAYED_WORK(&ap->sff_pio_task, ata_sff_pio_task);
3325 	ap->ctl = ATA_DEVCTL_OBS;
3326 	ap->last_ctl = 0xFF;
3327 }
3328 
3329 int __init ata_sff_init(void)
3330 {
3331 	ata_sff_wq = alloc_workqueue("ata_sff", WQ_MEM_RECLAIM, WQ_MAX_ACTIVE);
3332 	if (!ata_sff_wq)
3333 		return -ENOMEM;
3334 
3335 	return 0;
3336 }
3337 
3338 void ata_sff_exit(void)
3339 {
3340 	destroy_workqueue(ata_sff_wq);
3341 }
3342