xref: /openbmc/linux/drivers/scsi/libsas/sas_ata.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Support for SATA devices on Serial Attached SCSI (SAS) controllers
4  *
5  * Copyright (C) 2006 IBM Corporation
6  *
7  * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
8  */
9 
10 #include <linux/scatterlist.h>
11 #include <linux/slab.h>
12 #include <linux/async.h>
13 #include <linux/export.h>
14 
15 #include <scsi/sas_ata.h>
16 #include "sas_internal.h"
17 #include <scsi/scsi_host.h>
18 #include <scsi/scsi_device.h>
19 #include <scsi/scsi_tcq.h>
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_transport.h>
22 #include <scsi/scsi_transport_sas.h>
23 #include "scsi_sas_internal.h"
24 #include "scsi_transport_api.h"
25 #include <scsi/scsi_eh.h>
26 
27 static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
28 {
29 	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */
30 
31 	/* transport error */
32 	if (ts->resp == SAS_TASK_UNDELIVERED)
33 		return AC_ERR_ATA_BUS;
34 
35 	/* ts->resp == SAS_TASK_COMPLETE */
36 	/* task delivered, what happened afterwards? */
37 	switch (ts->stat) {
38 	case SAS_DEV_NO_RESPONSE:
39 		return AC_ERR_TIMEOUT;
40 	case SAS_INTERRUPTED:
41 	case SAS_PHY_DOWN:
42 	case SAS_NAK_R_ERR:
43 		return AC_ERR_ATA_BUS;
44 	case SAS_DATA_UNDERRUN:
45 		/*
46 		 * Some programs that use the taskfile interface
47 		 * (smartctl in particular) can cause underrun
48 		 * problems.  Ignore these errors, perhaps at our
49 		 * peril.
50 		 */
51 		return 0;
52 	case SAS_DATA_OVERRUN:
53 	case SAS_QUEUE_FULL:
54 	case SAS_DEVICE_UNKNOWN:
55 	case SAS_SG_ERR:
56 		return AC_ERR_INVALID;
57 	case SAS_OPEN_TO:
58 	case SAS_OPEN_REJECT:
59 		pr_warn("%s: Saw error %d.  What to do?\n",
60 			__func__, ts->stat);
61 		return AC_ERR_OTHER;
62 	case SAM_STAT_CHECK_CONDITION:
63 	case SAS_ABORTED_TASK:
64 		return AC_ERR_DEV;
65 	case SAS_PROTO_RESPONSE:
66 		/* This means the ending_fis has the error
67 		 * value; return 0 here to collect it
68 		 */
69 		return 0;
70 	default:
71 		return 0;
72 	}
73 }
74 
75 static void sas_ata_task_done(struct sas_task *task)
76 {
77 	struct ata_queued_cmd *qc = task->uldd_task;
78 	struct domain_device *dev = task->dev;
79 	struct task_status_struct *stat = &task->task_status;
80 	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
81 	struct sas_ha_struct *sas_ha = dev->port->ha;
82 	enum ata_completion_errors ac;
83 	unsigned long flags;
84 	struct ata_link *link;
85 	struct ata_port *ap;
86 
87 	spin_lock_irqsave(&dev->done_lock, flags);
88 	if (test_bit(SAS_HA_FROZEN, &sas_ha->state))
89 		task = NULL;
90 	else if (qc && qc->scsicmd)
91 		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
92 	spin_unlock_irqrestore(&dev->done_lock, flags);
93 
94 	/* check if libsas-eh got to the task before us */
95 	if (unlikely(!task))
96 		return;
97 
98 	if (!qc)
99 		goto qc_already_gone;
100 
101 	ap = qc->ap;
102 	link = &ap->link;
103 
104 	spin_lock_irqsave(ap->lock, flags);
105 	/* check if we lost the race with libata/sas_ata_post_internal() */
106 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) {
107 		spin_unlock_irqrestore(ap->lock, flags);
108 		if (qc->scsicmd)
109 			goto qc_already_gone;
110 		else {
111 			/* if eh is not involved and the port is frozen then the
112 			 * ata internal abort process has taken responsibility
113 			 * for this sas_task
114 			 */
115 			return;
116 		}
117 	}
118 
119 	if (stat->stat == SAS_PROTO_RESPONSE ||
120 	    stat->stat == SAS_SAM_STAT_GOOD ||
121 	    (stat->stat == SAS_SAM_STAT_CHECK_CONDITION &&
122 	      dev->sata_dev.class == ATA_DEV_ATAPI)) {
123 		memcpy(dev->sata_dev.fis, resp->ending_fis, ATA_RESP_FIS_SIZE);
124 
125 		if (!link->sactive) {
126 			qc->err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
127 		} else {
128 			link->eh_info.err_mask |= ac_err_mask(dev->sata_dev.fis[2]);
129 			if (unlikely(link->eh_info.err_mask))
130 				qc->flags |= ATA_QCFLAG_FAILED;
131 		}
132 	} else {
133 		ac = sas_to_ata_err(stat);
134 		if (ac) {
135 			pr_warn("%s: SAS error 0x%x\n", __func__, stat->stat);
136 			/* We saw a SAS error. Send a vague error. */
137 			if (!link->sactive) {
138 				qc->err_mask = ac;
139 			} else {
140 				link->eh_info.err_mask |= AC_ERR_DEV;
141 				qc->flags |= ATA_QCFLAG_FAILED;
142 			}
143 
144 			dev->sata_dev.fis[3] = 0x04; /* status err */
145 			dev->sata_dev.fis[2] = ATA_ERR;
146 		}
147 	}
148 
149 	qc->lldd_task = NULL;
150 	ata_qc_complete(qc);
151 	spin_unlock_irqrestore(ap->lock, flags);
152 
153 qc_already_gone:
154 	sas_free_task(task);
155 }
156 
157 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
158 	__must_hold(ap->lock)
159 {
160 	struct sas_task *task;
161 	struct scatterlist *sg;
162 	int ret = AC_ERR_SYSTEM;
163 	unsigned int si, xfer = 0;
164 	struct ata_port *ap = qc->ap;
165 	struct domain_device *dev = ap->private_data;
166 	struct sas_ha_struct *sas_ha = dev->port->ha;
167 	struct Scsi_Host *host = sas_ha->core.shost;
168 	struct sas_internal *i = to_sas_internal(host->transportt);
169 
170 	/* TODO: we should try to remove that unlock */
171 	spin_unlock(ap->lock);
172 
173 	/* If the device fell off, no sense in issuing commands */
174 	if (test_bit(SAS_DEV_GONE, &dev->state))
175 		goto out;
176 
177 	task = sas_alloc_task(GFP_ATOMIC);
178 	if (!task)
179 		goto out;
180 	task->dev = dev;
181 	task->task_proto = SAS_PROTOCOL_STP;
182 	task->task_done = sas_ata_task_done;
183 
184 	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
185 	    qc->tf.command == ATA_CMD_FPDMA_READ ||
186 	    qc->tf.command == ATA_CMD_FPDMA_RECV ||
187 	    qc->tf.command == ATA_CMD_FPDMA_SEND ||
188 	    qc->tf.command == ATA_CMD_NCQ_NON_DATA) {
189 		/* Need to zero out the tag libata assigned us */
190 		qc->tf.nsect = 0;
191 	}
192 
193 	ata_tf_to_fis(&qc->tf, qc->dev->link->pmp, 1, (u8 *)&task->ata_task.fis);
194 	task->uldd_task = qc;
195 	if (ata_is_atapi(qc->tf.protocol)) {
196 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
197 		task->total_xfer_len = qc->nbytes;
198 		task->num_scatter = qc->n_elem;
199 		task->data_dir = qc->dma_dir;
200 	} else if (qc->tf.protocol == ATA_PROT_NODATA) {
201 		task->data_dir = DMA_NONE;
202 	} else {
203 		for_each_sg(qc->sg, sg, qc->n_elem, si)
204 			xfer += sg_dma_len(sg);
205 
206 		task->total_xfer_len = xfer;
207 		task->num_scatter = si;
208 		task->data_dir = qc->dma_dir;
209 	}
210 	task->scatter = qc->sg;
211 	task->ata_task.retry_count = 1;
212 	task->task_state_flags = SAS_TASK_STATE_PENDING;
213 	qc->lldd_task = task;
214 
215 	task->ata_task.use_ncq = ata_is_ncq(qc->tf.protocol);
216 	task->ata_task.dma_xfer = ata_is_dma(qc->tf.protocol);
217 
218 	if (qc->scsicmd)
219 		ASSIGN_SAS_TASK(qc->scsicmd, task);
220 
221 	ret = i->dft->lldd_execute_task(task, GFP_ATOMIC);
222 	if (ret) {
223 		pr_debug("lldd_execute_task returned: %d\n", ret);
224 
225 		if (qc->scsicmd)
226 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
227 		sas_free_task(task);
228 		qc->lldd_task = NULL;
229 		ret = AC_ERR_SYSTEM;
230 	}
231 
232  out:
233 	spin_lock(ap->lock);
234 	return ret;
235 }
236 
237 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
238 {
239 	struct domain_device *dev = qc->ap->private_data;
240 
241 	ata_tf_from_fis(dev->sata_dev.fis, &qc->result_tf);
242 	return true;
243 }
244 
245 static struct sas_internal *dev_to_sas_internal(struct domain_device *dev)
246 {
247 	return to_sas_internal(dev->port->ha->core.shost->transportt);
248 }
249 
250 static int sas_get_ata_command_set(struct domain_device *dev);
251 
252 int sas_get_ata_info(struct domain_device *dev, struct ex_phy *phy)
253 {
254 	if (phy->attached_tproto & SAS_PROTOCOL_STP)
255 		dev->tproto = phy->attached_tproto;
256 	if (phy->attached_sata_dev)
257 		dev->tproto |= SAS_SATA_DEV;
258 
259 	if (phy->attached_dev_type == SAS_SATA_PENDING)
260 		dev->dev_type = SAS_SATA_PENDING;
261 	else {
262 		int res;
263 
264 		dev->dev_type = SAS_SATA_DEV;
265 		res = sas_get_report_phy_sata(dev->parent, phy->phy_id,
266 					      &dev->sata_dev.rps_resp);
267 		if (res) {
268 			pr_debug("report phy sata to %016llx:%02d returned 0x%x\n",
269 				 SAS_ADDR(dev->parent->sas_addr),
270 				 phy->phy_id, res);
271 			return res;
272 		}
273 		memcpy(dev->frame_rcvd, &dev->sata_dev.rps_resp.rps.fis,
274 		       sizeof(struct dev_to_host_fis));
275 		dev->sata_dev.class = sas_get_ata_command_set(dev);
276 	}
277 	return 0;
278 }
279 
280 static int sas_ata_clear_pending(struct domain_device *dev, struct ex_phy *phy)
281 {
282 	int res;
283 
284 	/* we weren't pending, so successfully end the reset sequence now */
285 	if (dev->dev_type != SAS_SATA_PENDING)
286 		return 1;
287 
288 	/* hmmm, if this succeeds do we need to repost the domain_device to the
289 	 * lldd so it can pick up new parameters?
290 	 */
291 	res = sas_get_ata_info(dev, phy);
292 	if (res)
293 		return 0; /* retry */
294 	else
295 		return 1;
296 }
297 
298 static int smp_ata_check_ready(struct ata_link *link)
299 {
300 	int res;
301 	struct ata_port *ap = link->ap;
302 	struct domain_device *dev = ap->private_data;
303 	struct domain_device *ex_dev = dev->parent;
304 	struct sas_phy *phy = sas_get_local_phy(dev);
305 	struct ex_phy *ex_phy = &ex_dev->ex_dev.ex_phy[phy->number];
306 
307 	res = sas_ex_phy_discover(ex_dev, phy->number);
308 	sas_put_local_phy(phy);
309 
310 	/* break the wait early if the expander is unreachable,
311 	 * otherwise keep polling
312 	 */
313 	if (res == -ECOMM)
314 		return res;
315 	if (res != SMP_RESP_FUNC_ACC)
316 		return 0;
317 
318 	switch (ex_phy->attached_dev_type) {
319 	case SAS_SATA_PENDING:
320 		return 0;
321 	case SAS_END_DEVICE:
322 		if (ex_phy->attached_sata_dev)
323 			return sas_ata_clear_pending(dev, ex_phy);
324 		fallthrough;
325 	default:
326 		return -ENODEV;
327 	}
328 }
329 
330 static int local_ata_check_ready(struct ata_link *link)
331 {
332 	struct ata_port *ap = link->ap;
333 	struct domain_device *dev = ap->private_data;
334 	struct sas_internal *i = dev_to_sas_internal(dev);
335 
336 	if (i->dft->lldd_ata_check_ready)
337 		return i->dft->lldd_ata_check_ready(dev);
338 	else {
339 		/* lldd's that don't implement 'ready' checking get the
340 		 * old default behavior of not coordinating reset
341 		 * recovery with libata
342 		 */
343 		return 1;
344 	}
345 }
346 
347 static int sas_ata_printk(const char *level, const struct domain_device *ddev,
348 			  const char *fmt, ...)
349 {
350 	struct ata_port *ap = ddev->sata_dev.ap;
351 	struct device *dev = &ddev->rphy->dev;
352 	struct va_format vaf;
353 	va_list args;
354 	int r;
355 
356 	va_start(args, fmt);
357 
358 	vaf.fmt = fmt;
359 	vaf.va = &args;
360 
361 	r = printk("%s" SAS_FMT "ata%u: %s: %pV",
362 		   level, ap->print_id, dev_name(dev), &vaf);
363 
364 	va_end(args);
365 
366 	return r;
367 }
368 
369 static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
370 			      unsigned long deadline)
371 {
372 	int ret = 0, res;
373 	struct sas_phy *phy;
374 	struct ata_port *ap = link->ap;
375 	int (*check_ready)(struct ata_link *link);
376 	struct domain_device *dev = ap->private_data;
377 	struct sas_internal *i = dev_to_sas_internal(dev);
378 
379 	res = i->dft->lldd_I_T_nexus_reset(dev);
380 	if (res == -ENODEV)
381 		return res;
382 
383 	if (res != TMF_RESP_FUNC_COMPLETE)
384 		sas_ata_printk(KERN_DEBUG, dev, "Unable to reset ata device?\n");
385 
386 	phy = sas_get_local_phy(dev);
387 	if (scsi_is_sas_phy_local(phy))
388 		check_ready = local_ata_check_ready;
389 	else
390 		check_ready = smp_ata_check_ready;
391 	sas_put_local_phy(phy);
392 
393 	ret = ata_wait_after_reset(link, deadline, check_ready);
394 	if (ret && ret != -EAGAIN)
395 		sas_ata_printk(KERN_ERR, dev, "reset failed (errno=%d)\n", ret);
396 
397 	*class = dev->sata_dev.class;
398 
399 	ap->cbl = ATA_CBL_SATA;
400 	return ret;
401 }
402 
403 /*
404  * notify the lldd to forget the sas_task for this internal ata command
405  * that bypasses scsi-eh
406  */
407 static void sas_ata_internal_abort(struct sas_task *task)
408 {
409 	struct sas_internal *si = dev_to_sas_internal(task->dev);
410 	unsigned long flags;
411 	int res;
412 
413 	spin_lock_irqsave(&task->task_state_lock, flags);
414 	if (task->task_state_flags & SAS_TASK_STATE_ABORTED ||
415 	    task->task_state_flags & SAS_TASK_STATE_DONE) {
416 		spin_unlock_irqrestore(&task->task_state_lock, flags);
417 		pr_debug("%s: Task %p already finished.\n", __func__, task);
418 		goto out;
419 	}
420 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
421 	spin_unlock_irqrestore(&task->task_state_lock, flags);
422 
423 	res = si->dft->lldd_abort_task(task);
424 
425 	spin_lock_irqsave(&task->task_state_lock, flags);
426 	if (task->task_state_flags & SAS_TASK_STATE_DONE ||
427 	    res == TMF_RESP_FUNC_COMPLETE) {
428 		spin_unlock_irqrestore(&task->task_state_lock, flags);
429 		goto out;
430 	}
431 
432 	/* XXX we are not prepared to deal with ->lldd_abort_task()
433 	 * failures.  TODO: lldds need to unconditionally forget about
434 	 * aborted ata tasks, otherwise we (likely) leak the sas task
435 	 * here
436 	 */
437 	pr_warn("%s: Task %p leaked.\n", __func__, task);
438 
439 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
440 		task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
441 	spin_unlock_irqrestore(&task->task_state_lock, flags);
442 
443 	return;
444  out:
445 	sas_free_task(task);
446 }
447 
448 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
449 {
450 	if (qc->flags & ATA_QCFLAG_FAILED)
451 		qc->err_mask |= AC_ERR_OTHER;
452 
453 	if (qc->err_mask) {
454 		/*
455 		 * Find the sas_task and kill it.  By this point, libata
456 		 * has decided to kill the qc and has frozen the port.
457 		 * In this state sas_ata_task_done() will no longer free
458 		 * the sas_task, so we need to notify the lldd (via
459 		 * ->lldd_abort_task) that the task is dead and free it
460 		 *  ourselves.
461 		 */
462 		struct sas_task *task = qc->lldd_task;
463 
464 		qc->lldd_task = NULL;
465 		if (!task)
466 			return;
467 		task->uldd_task = NULL;
468 		sas_ata_internal_abort(task);
469 	}
470 }
471 
472 
473 static void sas_ata_set_dmamode(struct ata_port *ap, struct ata_device *ata_dev)
474 {
475 	struct domain_device *dev = ap->private_data;
476 	struct sas_internal *i = dev_to_sas_internal(dev);
477 
478 	if (i->dft->lldd_ata_set_dmamode)
479 		i->dft->lldd_ata_set_dmamode(dev);
480 }
481 
482 static void sas_ata_sched_eh(struct ata_port *ap)
483 {
484 	struct domain_device *dev = ap->private_data;
485 	struct sas_ha_struct *ha = dev->port->ha;
486 	unsigned long flags;
487 
488 	spin_lock_irqsave(&ha->lock, flags);
489 	if (!test_and_set_bit(SAS_DEV_EH_PENDING, &dev->state))
490 		ha->eh_active++;
491 	ata_std_sched_eh(ap);
492 	spin_unlock_irqrestore(&ha->lock, flags);
493 }
494 
495 void sas_ata_end_eh(struct ata_port *ap)
496 {
497 	struct domain_device *dev = ap->private_data;
498 	struct sas_ha_struct *ha = dev->port->ha;
499 	unsigned long flags;
500 
501 	spin_lock_irqsave(&ha->lock, flags);
502 	if (test_and_clear_bit(SAS_DEV_EH_PENDING, &dev->state))
503 		ha->eh_active--;
504 	spin_unlock_irqrestore(&ha->lock, flags);
505 }
506 
507 static int sas_ata_prereset(struct ata_link *link, unsigned long deadline)
508 {
509 	struct ata_port *ap = link->ap;
510 	struct domain_device *dev = ap->private_data;
511 	struct sas_phy *local_phy = sas_get_local_phy(dev);
512 	int res = 0;
513 
514 	if (!local_phy->enabled || test_bit(SAS_DEV_GONE, &dev->state))
515 		res = -ENOENT;
516 	sas_put_local_phy(local_phy);
517 
518 	return res;
519 }
520 
521 static struct ata_port_operations sas_sata_ops = {
522 	.prereset		= sas_ata_prereset,
523 	.hardreset		= sas_ata_hard_reset,
524 	.error_handler		= ata_std_error_handler,
525 	.post_internal_cmd	= sas_ata_post_internal,
526 	.qc_defer               = ata_std_qc_defer,
527 	.qc_prep		= ata_noop_qc_prep,
528 	.qc_issue		= sas_ata_qc_issue,
529 	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
530 	.port_start		= ata_sas_port_start,
531 	.port_stop		= ata_sas_port_stop,
532 	.set_dmamode		= sas_ata_set_dmamode,
533 	.sched_eh		= sas_ata_sched_eh,
534 	.end_eh			= sas_ata_end_eh,
535 };
536 
537 static struct ata_port_info sata_port_info = {
538 	.flags = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ |
539 		 ATA_FLAG_SAS_HOST | ATA_FLAG_FPDMA_AUX,
540 	.pio_mask = ATA_PIO4,
541 	.mwdma_mask = ATA_MWDMA2,
542 	.udma_mask = ATA_UDMA6,
543 	.port_ops = &sas_sata_ops
544 };
545 
546 int sas_ata_init(struct domain_device *found_dev)
547 {
548 	struct sas_ha_struct *ha = found_dev->port->ha;
549 	struct Scsi_Host *shost = ha->core.shost;
550 	struct ata_host *ata_host;
551 	struct ata_port *ap;
552 	int rc;
553 
554 	ata_host = kzalloc(sizeof(*ata_host), GFP_KERNEL);
555 	if (!ata_host)	{
556 		pr_err("ata host alloc failed.\n");
557 		return -ENOMEM;
558 	}
559 
560 	ata_host_init(ata_host, ha->dev, &sas_sata_ops);
561 
562 	ap = ata_sas_port_alloc(ata_host, &sata_port_info, shost);
563 	if (!ap) {
564 		pr_err("ata_sas_port_alloc failed.\n");
565 		rc = -ENODEV;
566 		goto free_host;
567 	}
568 
569 	ap->private_data = found_dev;
570 	ap->cbl = ATA_CBL_SATA;
571 	ap->scsi_host = shost;
572 	rc = ata_sas_port_init(ap);
573 	if (rc)
574 		goto destroy_port;
575 
576 	rc = ata_sas_tport_add(ata_host->dev, ap);
577 	if (rc)
578 		goto destroy_port;
579 
580 	found_dev->sata_dev.ata_host = ata_host;
581 	found_dev->sata_dev.ap = ap;
582 
583 	return 0;
584 
585 destroy_port:
586 	ata_sas_port_destroy(ap);
587 free_host:
588 	ata_host_put(ata_host);
589 	return rc;
590 }
591 
592 void sas_ata_task_abort(struct sas_task *task)
593 {
594 	struct ata_queued_cmd *qc = task->uldd_task;
595 	struct completion *waiting;
596 
597 	/* Bounce SCSI-initiated commands to the SCSI EH */
598 	if (qc->scsicmd) {
599 		blk_abort_request(scsi_cmd_to_rq(qc->scsicmd));
600 		return;
601 	}
602 
603 	/* Internal command, fake a timeout and complete. */
604 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
605 	qc->flags |= ATA_QCFLAG_FAILED;
606 	qc->err_mask |= AC_ERR_TIMEOUT;
607 	waiting = qc->private_data;
608 	complete(waiting);
609 }
610 
611 static int sas_get_ata_command_set(struct domain_device *dev)
612 {
613 	struct dev_to_host_fis *fis =
614 		(struct dev_to_host_fis *) dev->frame_rcvd;
615 	struct ata_taskfile tf;
616 
617 	if (dev->dev_type == SAS_SATA_PENDING)
618 		return ATA_DEV_UNKNOWN;
619 
620 	ata_tf_from_fis((const u8 *)fis, &tf);
621 
622 	return ata_dev_classify(&tf);
623 }
624 
625 void sas_probe_sata(struct asd_sas_port *port)
626 {
627 	struct domain_device *dev, *n;
628 
629 	mutex_lock(&port->ha->disco_mutex);
630 	list_for_each_entry(dev, &port->disco_list, disco_list_node) {
631 		if (!dev_is_sata(dev))
632 			continue;
633 
634 		ata_sas_async_probe(dev->sata_dev.ap);
635 	}
636 	mutex_unlock(&port->ha->disco_mutex);
637 
638 	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
639 		if (!dev_is_sata(dev))
640 			continue;
641 
642 		sas_ata_wait_eh(dev);
643 
644 		/* if libata could not bring the link up, don't surface
645 		 * the device
646 		 */
647 		if (!ata_dev_enabled(sas_to_ata_dev(dev)))
648 			sas_fail_probe(dev, __func__, -ENODEV);
649 	}
650 
651 }
652 
653 static void sas_ata_flush_pm_eh(struct asd_sas_port *port, const char *func)
654 {
655 	struct domain_device *dev, *n;
656 
657 	list_for_each_entry_safe(dev, n, &port->dev_list, dev_list_node) {
658 		if (!dev_is_sata(dev))
659 			continue;
660 
661 		sas_ata_wait_eh(dev);
662 
663 		/* if libata failed to power manage the device, tear it down */
664 		if (ata_dev_disabled(sas_to_ata_dev(dev)))
665 			sas_fail_probe(dev, func, -ENODEV);
666 	}
667 }
668 
669 void sas_suspend_sata(struct asd_sas_port *port)
670 {
671 	struct domain_device *dev;
672 
673 	mutex_lock(&port->ha->disco_mutex);
674 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
675 		struct sata_device *sata;
676 
677 		if (!dev_is_sata(dev))
678 			continue;
679 
680 		sata = &dev->sata_dev;
681 		if (sata->ap->pm_mesg.event == PM_EVENT_SUSPEND)
682 			continue;
683 
684 		ata_sas_port_suspend(sata->ap);
685 	}
686 	mutex_unlock(&port->ha->disco_mutex);
687 
688 	sas_ata_flush_pm_eh(port, __func__);
689 }
690 
691 void sas_resume_sata(struct asd_sas_port *port)
692 {
693 	struct domain_device *dev;
694 
695 	mutex_lock(&port->ha->disco_mutex);
696 	list_for_each_entry(dev, &port->dev_list, dev_list_node) {
697 		struct sata_device *sata;
698 
699 		if (!dev_is_sata(dev))
700 			continue;
701 
702 		sata = &dev->sata_dev;
703 		if (sata->ap->pm_mesg.event == PM_EVENT_ON)
704 			continue;
705 
706 		ata_sas_port_resume(sata->ap);
707 	}
708 	mutex_unlock(&port->ha->disco_mutex);
709 
710 	sas_ata_flush_pm_eh(port, __func__);
711 }
712 
713 /**
714  * sas_discover_sata - discover an STP/SATA domain device
715  * @dev: pointer to struct domain_device of interest
716  *
717  * Devices directly attached to a HA port, have no parents.  All other
718  * devices do, and should have their "parent" pointer set appropriately
719  * before calling this function.
720  */
721 int sas_discover_sata(struct domain_device *dev)
722 {
723 	if (dev->dev_type == SAS_SATA_PM)
724 		return -ENODEV;
725 
726 	dev->sata_dev.class = sas_get_ata_command_set(dev);
727 	sas_fill_in_rphy(dev, dev->rphy);
728 
729 	return sas_notify_lldd_dev_found(dev);
730 }
731 
732 static void async_sas_ata_eh(void *data, async_cookie_t cookie)
733 {
734 	struct domain_device *dev = data;
735 	struct ata_port *ap = dev->sata_dev.ap;
736 	struct sas_ha_struct *ha = dev->port->ha;
737 
738 	sas_ata_printk(KERN_DEBUG, dev, "dev error handler\n");
739 	ata_scsi_port_error_handler(ha->core.shost, ap);
740 	sas_put_device(dev);
741 }
742 
743 void sas_ata_strategy_handler(struct Scsi_Host *shost)
744 {
745 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
746 	ASYNC_DOMAIN_EXCLUSIVE(async);
747 	int i;
748 
749 	/* it's ok to defer revalidation events during ata eh, these
750 	 * disks are in one of three states:
751 	 * 1/ present for initial domain discovery, and these
752 	 *    resets will cause bcn flutters
753 	 * 2/ hot removed, we'll discover that after eh fails
754 	 * 3/ hot added after initial discovery, lost the race, and need
755 	 *    to catch the next train.
756 	 */
757 	sas_disable_revalidation(sas_ha);
758 
759 	spin_lock_irq(&sas_ha->phy_port_lock);
760 	for (i = 0; i < sas_ha->num_phys; i++) {
761 		struct asd_sas_port *port = sas_ha->sas_port[i];
762 		struct domain_device *dev;
763 
764 		spin_lock(&port->dev_list_lock);
765 		list_for_each_entry(dev, &port->dev_list, dev_list_node) {
766 			if (!dev_is_sata(dev))
767 				continue;
768 
769 			/* hold a reference over eh since we may be
770 			 * racing with final remove once all commands
771 			 * are completed
772 			 */
773 			kref_get(&dev->kref);
774 
775 			async_schedule_domain(async_sas_ata_eh, dev, &async);
776 		}
777 		spin_unlock(&port->dev_list_lock);
778 	}
779 	spin_unlock_irq(&sas_ha->phy_port_lock);
780 
781 	async_synchronize_full_domain(&async);
782 
783 	sas_enable_revalidation(sas_ha);
784 }
785 
786 void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
787 		struct list_head *done_q)
788 {
789 	struct scsi_cmnd *cmd, *n;
790 	struct domain_device *eh_dev;
791 
792 	do {
793 		LIST_HEAD(sata_q);
794 		eh_dev = NULL;
795 
796 		list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
797 			struct domain_device *ddev = cmd_to_domain_dev(cmd);
798 
799 			if (!dev_is_sata(ddev) || TO_SAS_TASK(cmd))
800 				continue;
801 			if (eh_dev && eh_dev != ddev)
802 				continue;
803 			eh_dev = ddev;
804 			list_move(&cmd->eh_entry, &sata_q);
805 		}
806 
807 		if (!list_empty(&sata_q)) {
808 			struct ata_port *ap = eh_dev->sata_dev.ap;
809 
810 			sas_ata_printk(KERN_DEBUG, eh_dev, "cmd error handler\n");
811 			ata_scsi_cmd_error_handler(shost, ap, &sata_q);
812 			/*
813 			 * ata's error handler may leave the cmd on the list
814 			 * so make sure they don't remain on a stack list
815 			 * about to go out of scope.
816 			 *
817 			 * This looks strange, since the commands are
818 			 * now part of no list, but the next error
819 			 * action will be ata_port_error_handler()
820 			 * which takes no list and sweeps them up
821 			 * anyway from the ata tag array.
822 			 */
823 			while (!list_empty(&sata_q))
824 				list_del_init(sata_q.next);
825 		}
826 	} while (eh_dev);
827 }
828 
829 void sas_ata_schedule_reset(struct domain_device *dev)
830 {
831 	struct ata_eh_info *ehi;
832 	struct ata_port *ap;
833 	unsigned long flags;
834 
835 	if (!dev_is_sata(dev))
836 		return;
837 
838 	ap = dev->sata_dev.ap;
839 	ehi = &ap->link.eh_info;
840 
841 	spin_lock_irqsave(ap->lock, flags);
842 	ehi->err_mask |= AC_ERR_TIMEOUT;
843 	ehi->action |= ATA_EH_RESET;
844 	ata_port_schedule_eh(ap);
845 	spin_unlock_irqrestore(ap->lock, flags);
846 }
847 EXPORT_SYMBOL_GPL(sas_ata_schedule_reset);
848 
849 void sas_ata_wait_eh(struct domain_device *dev)
850 {
851 	struct ata_port *ap;
852 
853 	if (!dev_is_sata(dev))
854 		return;
855 
856 	ap = dev->sata_dev.ap;
857 	ata_port_wait_eh(ap);
858 }
859