xref: /openbmc/linux/drivers/scsi/libsas/sas_init.c (revision 7e043a80) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Serial Attached SCSI (SAS) Transport Layer initialization
4  *
5  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
6  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/init.h>
12 #include <linux/device.h>
13 #include <linux/spinlock.h>
14 #include <scsi/sas_ata.h>
15 #include <scsi/scsi_host.h>
16 #include <scsi/scsi_device.h>
17 #include <scsi/scsi_transport.h>
18 #include <scsi/scsi_transport_sas.h>
19 
20 #include "sas_internal.h"
21 
22 #include "scsi_sas_internal.h"
23 
24 static struct kmem_cache *sas_task_cache;
25 static struct kmem_cache *sas_event_cache;
26 
27 struct sas_task *sas_alloc_task(gfp_t flags)
28 {
29 	struct sas_task *task = kmem_cache_zalloc(sas_task_cache, flags);
30 
31 	if (task) {
32 		spin_lock_init(&task->task_state_lock);
33 		task->task_state_flags = SAS_TASK_STATE_PENDING;
34 	}
35 
36 	return task;
37 }
38 EXPORT_SYMBOL_GPL(sas_alloc_task);
39 
40 struct sas_task *sas_alloc_slow_task(gfp_t flags)
41 {
42 	struct sas_task *task = sas_alloc_task(flags);
43 	struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);
44 
45 	if (!task || !slow) {
46 		if (task)
47 			kmem_cache_free(sas_task_cache, task);
48 		kfree(slow);
49 		return NULL;
50 	}
51 
52 	task->slow_task = slow;
53 	slow->task = task;
54 	timer_setup(&slow->timer, NULL, 0);
55 	init_completion(&slow->completion);
56 
57 	return task;
58 }
59 EXPORT_SYMBOL_GPL(sas_alloc_slow_task);
60 
61 void sas_free_task(struct sas_task *task)
62 {
63 	if (task) {
64 		kfree(task->slow_task);
65 		kmem_cache_free(sas_task_cache, task);
66 	}
67 }
68 EXPORT_SYMBOL_GPL(sas_free_task);
69 
70 /*------------ SAS addr hash -----------*/
71 void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
72 {
73 	const u32 poly = 0x00DB2777;
74 	u32 r = 0;
75 	int i;
76 
77 	for (i = 0; i < SAS_ADDR_SIZE; i++) {
78 		int b;
79 
80 		for (b = (SAS_ADDR_SIZE - 1); b >= 0; b--) {
81 			r <<= 1;
82 			if ((1 << b) & sas_addr[i]) {
83 				if (!(r & 0x01000000))
84 					r ^= poly;
85 			} else if (r & 0x01000000) {
86 				r ^= poly;
87 			}
88 		}
89 	}
90 
91 	hashed[0] = (r >> 16) & 0xFF;
92 	hashed[1] = (r >> 8) & 0xFF;
93 	hashed[2] = r & 0xFF;
94 }
95 
96 int sas_register_ha(struct sas_ha_struct *sas_ha)
97 {
98 	char name[64];
99 	int error = 0;
100 
101 	mutex_init(&sas_ha->disco_mutex);
102 	spin_lock_init(&sas_ha->phy_port_lock);
103 	sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);
104 
105 	set_bit(SAS_HA_REGISTERED, &sas_ha->state);
106 	spin_lock_init(&sas_ha->lock);
107 	mutex_init(&sas_ha->drain_mutex);
108 	init_waitqueue_head(&sas_ha->eh_wait_q);
109 	INIT_LIST_HEAD(&sas_ha->defer_q);
110 	INIT_LIST_HEAD(&sas_ha->eh_dev_q);
111 
112 	sas_ha->event_thres = SAS_PHY_SHUTDOWN_THRES;
113 
114 	error = sas_register_phys(sas_ha);
115 	if (error) {
116 		pr_notice("couldn't register sas phys:%d\n", error);
117 		return error;
118 	}
119 
120 	error = sas_register_ports(sas_ha);
121 	if (error) {
122 		pr_notice("couldn't register sas ports:%d\n", error);
123 		goto Undo_phys;
124 	}
125 
126 	error = -ENOMEM;
127 	snprintf(name, sizeof(name), "%s_event_q", dev_name(sas_ha->dev));
128 	sas_ha->event_q = create_singlethread_workqueue(name);
129 	if (!sas_ha->event_q)
130 		goto Undo_ports;
131 
132 	snprintf(name, sizeof(name), "%s_disco_q", dev_name(sas_ha->dev));
133 	sas_ha->disco_q = create_singlethread_workqueue(name);
134 	if (!sas_ha->disco_q)
135 		goto Undo_event_q;
136 
137 	INIT_LIST_HEAD(&sas_ha->eh_done_q);
138 	INIT_LIST_HEAD(&sas_ha->eh_ata_q);
139 
140 	return 0;
141 
142 Undo_event_q:
143 	destroy_workqueue(sas_ha->event_q);
144 Undo_ports:
145 	sas_unregister_ports(sas_ha);
146 Undo_phys:
147 
148 	return error;
149 }
150 EXPORT_SYMBOL_GPL(sas_register_ha);
151 
152 static void sas_disable_events(struct sas_ha_struct *sas_ha)
153 {
154 	/* Set the state to unregistered to avoid further unchained
155 	 * events to be queued, and flush any in-progress drainers
156 	 */
157 	mutex_lock(&sas_ha->drain_mutex);
158 	spin_lock_irq(&sas_ha->lock);
159 	clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
160 	spin_unlock_irq(&sas_ha->lock);
161 	__sas_drain_work(sas_ha);
162 	mutex_unlock(&sas_ha->drain_mutex);
163 }
164 
165 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
166 {
167 	sas_disable_events(sas_ha);
168 	sas_unregister_ports(sas_ha);
169 
170 	/* flush unregistration work */
171 	mutex_lock(&sas_ha->drain_mutex);
172 	__sas_drain_work(sas_ha);
173 	mutex_unlock(&sas_ha->drain_mutex);
174 
175 	destroy_workqueue(sas_ha->disco_q);
176 	destroy_workqueue(sas_ha->event_q);
177 
178 	return 0;
179 }
180 EXPORT_SYMBOL_GPL(sas_unregister_ha);
181 
182 static int sas_get_linkerrors(struct sas_phy *phy)
183 {
184 	if (scsi_is_sas_phy_local(phy)) {
185 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
186 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
187 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
188 		struct sas_internal *i =
189 			to_sas_internal(sas_ha->core.shost->transportt);
190 
191 		return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
192 	}
193 
194 	return sas_smp_get_phy_events(phy);
195 }
196 
197 int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
198 {
199 	struct domain_device *dev = NULL;
200 
201 	/* try to route user requested link resets through libata */
202 	if (asd_phy->port)
203 		dev = asd_phy->port->port_dev;
204 
205 	/* validate that dev has been probed */
206 	if (dev)
207 		dev = sas_find_dev_by_rphy(dev->rphy);
208 
209 	if (dev && dev_is_sata(dev)) {
210 		sas_ata_schedule_reset(dev);
211 		sas_ata_wait_eh(dev);
212 		return 0;
213 	}
214 
215 	return -ENODEV;
216 }
217 
218 /*
219  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
220  *
221  * phy reset request via sysfs in host workqueue context so we know we
222  * can block on eh and safely traverse the domain_device topology
223  */
224 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
225 {
226 	enum phy_func reset_type;
227 
228 	if (hard_reset)
229 		reset_type = PHY_FUNC_HARD_RESET;
230 	else
231 		reset_type = PHY_FUNC_LINK_RESET;
232 
233 	if (scsi_is_sas_phy_local(phy)) {
234 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
235 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
236 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
237 		struct sas_internal *i =
238 			to_sas_internal(sas_ha->core.shost->transportt);
239 
240 		if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
241 			return 0;
242 		return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
243 	} else {
244 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
245 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
246 		struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);
247 
248 		if (ata_dev && !hard_reset) {
249 			sas_ata_schedule_reset(ata_dev);
250 			sas_ata_wait_eh(ata_dev);
251 			return 0;
252 		} else
253 			return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
254 	}
255 }
256 
257 int sas_phy_enable(struct sas_phy *phy, int enable)
258 {
259 	int ret;
260 	enum phy_func cmd;
261 
262 	if (enable)
263 		cmd = PHY_FUNC_LINK_RESET;
264 	else
265 		cmd = PHY_FUNC_DISABLE;
266 
267 	if (scsi_is_sas_phy_local(phy)) {
268 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
269 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
270 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
271 		struct sas_internal *i =
272 			to_sas_internal(sas_ha->core.shost->transportt);
273 
274 		if (enable)
275 			ret = transport_sas_phy_reset(phy, 0);
276 		else
277 			ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
278 	} else {
279 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
280 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
281 
282 		if (enable)
283 			ret = transport_sas_phy_reset(phy, 0);
284 		else
285 			ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
286 	}
287 	return ret;
288 }
289 EXPORT_SYMBOL_GPL(sas_phy_enable);
290 
291 int sas_phy_reset(struct sas_phy *phy, int hard_reset)
292 {
293 	int ret;
294 	enum phy_func reset_type;
295 
296 	if (!phy->enabled)
297 		return -ENODEV;
298 
299 	if (hard_reset)
300 		reset_type = PHY_FUNC_HARD_RESET;
301 	else
302 		reset_type = PHY_FUNC_LINK_RESET;
303 
304 	if (scsi_is_sas_phy_local(phy)) {
305 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
306 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
307 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
308 		struct sas_internal *i =
309 			to_sas_internal(sas_ha->core.shost->transportt);
310 
311 		ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
312 	} else {
313 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
314 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
315 		ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
316 	}
317 	return ret;
318 }
319 EXPORT_SYMBOL_GPL(sas_phy_reset);
320 
321 int sas_set_phy_speed(struct sas_phy *phy,
322 		      struct sas_phy_linkrates *rates)
323 {
324 	int ret;
325 
326 	if ((rates->minimum_linkrate &&
327 	     rates->minimum_linkrate > phy->maximum_linkrate) ||
328 	    (rates->maximum_linkrate &&
329 	     rates->maximum_linkrate < phy->minimum_linkrate))
330 		return -EINVAL;
331 
332 	if (rates->minimum_linkrate &&
333 	    rates->minimum_linkrate < phy->minimum_linkrate_hw)
334 		rates->minimum_linkrate = phy->minimum_linkrate_hw;
335 
336 	if (rates->maximum_linkrate &&
337 	    rates->maximum_linkrate > phy->maximum_linkrate_hw)
338 		rates->maximum_linkrate = phy->maximum_linkrate_hw;
339 
340 	if (scsi_is_sas_phy_local(phy)) {
341 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
342 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
343 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
344 		struct sas_internal *i =
345 			to_sas_internal(sas_ha->core.shost->transportt);
346 
347 		ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
348 					       rates);
349 	} else {
350 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
351 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
352 		ret = sas_smp_phy_control(ddev, phy->number,
353 					  PHY_FUNC_LINK_RESET, rates);
354 
355 	}
356 
357 	return ret;
358 }
359 
360 void sas_prep_resume_ha(struct sas_ha_struct *ha)
361 {
362 	int i;
363 
364 	set_bit(SAS_HA_REGISTERED, &ha->state);
365 	set_bit(SAS_HA_RESUMING, &ha->state);
366 
367 	/* clear out any stale link events/data from the suspension path */
368 	for (i = 0; i < ha->num_phys; i++) {
369 		struct asd_sas_phy *phy = ha->sas_phy[i];
370 
371 		memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
372 		phy->frame_rcvd_size = 0;
373 	}
374 }
375 EXPORT_SYMBOL(sas_prep_resume_ha);
376 
377 static int phys_suspended(struct sas_ha_struct *ha)
378 {
379 	int i, rc = 0;
380 
381 	for (i = 0; i < ha->num_phys; i++) {
382 		struct asd_sas_phy *phy = ha->sas_phy[i];
383 
384 		if (phy->suspended)
385 			rc++;
386 	}
387 
388 	return rc;
389 }
390 
391 static void sas_resume_insert_broadcast_ha(struct sas_ha_struct *ha)
392 {
393 	int i;
394 
395 	for (i = 0; i < ha->num_phys; i++) {
396 		struct asd_sas_port *port = ha->sas_port[i];
397 		struct domain_device *dev = port->port_dev;
398 
399 		if (dev && dev_is_expander(dev->dev_type)) {
400 			struct asd_sas_phy *first_phy;
401 
402 			spin_lock(&port->phy_list_lock);
403 			first_phy = list_first_entry_or_null(
404 				&port->phy_list, struct asd_sas_phy,
405 				port_phy_el);
406 			spin_unlock(&port->phy_list_lock);
407 
408 			if (first_phy)
409 				sas_notify_port_event(first_phy,
410 					PORTE_BROADCAST_RCVD, GFP_KERNEL);
411 		}
412 	}
413 }
414 
415 static void _sas_resume_ha(struct sas_ha_struct *ha, bool drain)
416 {
417 	const unsigned long tmo = msecs_to_jiffies(25000);
418 	int i;
419 
420 	/* deform ports on phys that did not resume
421 	 * at this point we may be racing the phy coming back (as posted
422 	 * by the lldd).  So we post the event and once we are in the
423 	 * libsas context check that the phy remains suspended before
424 	 * tearing it down.
425 	 */
426 	i = phys_suspended(ha);
427 	if (i)
428 		dev_info(ha->dev, "waiting up to 25 seconds for %d phy%s to resume\n",
429 			 i, i > 1 ? "s" : "");
430 	wait_event_timeout(ha->eh_wait_q, phys_suspended(ha) == 0, tmo);
431 	for (i = 0; i < ha->num_phys; i++) {
432 		struct asd_sas_phy *phy = ha->sas_phy[i];
433 
434 		if (phy->suspended) {
435 			dev_warn(&phy->phy->dev, "resume timeout\n");
436 			sas_notify_phy_event(phy, PHYE_RESUME_TIMEOUT,
437 					     GFP_KERNEL);
438 		}
439 	}
440 
441 	/* all phys are back up or timed out, turn on i/o so we can
442 	 * flush out disks that did not return
443 	 */
444 	scsi_unblock_requests(ha->core.shost);
445 	if (drain)
446 		sas_drain_work(ha);
447 	clear_bit(SAS_HA_RESUMING, &ha->state);
448 
449 	sas_queue_deferred_work(ha);
450 	/* send event PORTE_BROADCAST_RCVD to identify some new inserted
451 	 * disks for expander
452 	 */
453 	sas_resume_insert_broadcast_ha(ha);
454 }
455 
456 void sas_resume_ha(struct sas_ha_struct *ha)
457 {
458 	_sas_resume_ha(ha, true);
459 }
460 EXPORT_SYMBOL(sas_resume_ha);
461 
462 /* A no-sync variant, which does not call sas_drain_ha(). */
463 void sas_resume_ha_no_sync(struct sas_ha_struct *ha)
464 {
465 	_sas_resume_ha(ha, false);
466 }
467 EXPORT_SYMBOL(sas_resume_ha_no_sync);
468 
469 void sas_suspend_ha(struct sas_ha_struct *ha)
470 {
471 	int i;
472 
473 	sas_disable_events(ha);
474 	scsi_block_requests(ha->core.shost);
475 	for (i = 0; i < ha->num_phys; i++) {
476 		struct asd_sas_port *port = ha->sas_port[i];
477 
478 		sas_discover_event(port, DISCE_SUSPEND);
479 	}
480 
481 	/* flush suspend events while unregistered */
482 	mutex_lock(&ha->drain_mutex);
483 	__sas_drain_work(ha);
484 	mutex_unlock(&ha->drain_mutex);
485 }
486 EXPORT_SYMBOL(sas_suspend_ha);
487 
488 static void sas_phy_release(struct sas_phy *phy)
489 {
490 	kfree(phy->hostdata);
491 	phy->hostdata = NULL;
492 }
493 
494 static void phy_reset_work(struct work_struct *work)
495 {
496 	struct sas_phy_data *d = container_of(work, typeof(*d), reset_work.work);
497 
498 	d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
499 }
500 
501 static void phy_enable_work(struct work_struct *work)
502 {
503 	struct sas_phy_data *d = container_of(work, typeof(*d), enable_work.work);
504 
505 	d->enable_result = sas_phy_enable(d->phy, d->enable);
506 }
507 
508 static int sas_phy_setup(struct sas_phy *phy)
509 {
510 	struct sas_phy_data *d = kzalloc(sizeof(*d), GFP_KERNEL);
511 
512 	if (!d)
513 		return -ENOMEM;
514 
515 	mutex_init(&d->event_lock);
516 	INIT_SAS_WORK(&d->reset_work, phy_reset_work);
517 	INIT_SAS_WORK(&d->enable_work, phy_enable_work);
518 	d->phy = phy;
519 	phy->hostdata = d;
520 
521 	return 0;
522 }
523 
524 static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
525 {
526 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
527 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
528 	struct sas_phy_data *d = phy->hostdata;
529 	int rc;
530 
531 	if (!d)
532 		return -ENOMEM;
533 
534 	pm_runtime_get_sync(ha->dev);
535 	/* libsas workqueue coordinates ata-eh reset with discovery */
536 	mutex_lock(&d->event_lock);
537 	d->reset_result = 0;
538 	d->hard_reset = hard_reset;
539 
540 	spin_lock_irq(&ha->lock);
541 	sas_queue_work(ha, &d->reset_work);
542 	spin_unlock_irq(&ha->lock);
543 
544 	rc = sas_drain_work(ha);
545 	if (rc == 0)
546 		rc = d->reset_result;
547 	mutex_unlock(&d->event_lock);
548 	pm_runtime_put_sync(ha->dev);
549 
550 	return rc;
551 }
552 
553 static int queue_phy_enable(struct sas_phy *phy, int enable)
554 {
555 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
556 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
557 	struct sas_phy_data *d = phy->hostdata;
558 	int rc;
559 
560 	if (!d)
561 		return -ENOMEM;
562 
563 	pm_runtime_get_sync(ha->dev);
564 	/* libsas workqueue coordinates ata-eh reset with discovery */
565 	mutex_lock(&d->event_lock);
566 	d->enable_result = 0;
567 	d->enable = enable;
568 
569 	spin_lock_irq(&ha->lock);
570 	sas_queue_work(ha, &d->enable_work);
571 	spin_unlock_irq(&ha->lock);
572 
573 	rc = sas_drain_work(ha);
574 	if (rc == 0)
575 		rc = d->enable_result;
576 	mutex_unlock(&d->event_lock);
577 	pm_runtime_put_sync(ha->dev);
578 
579 	return rc;
580 }
581 
582 static struct sas_function_template sft = {
583 	.phy_enable = queue_phy_enable,
584 	.phy_reset = queue_phy_reset,
585 	.phy_setup = sas_phy_setup,
586 	.phy_release = sas_phy_release,
587 	.set_phy_speed = sas_set_phy_speed,
588 	.get_linkerrors = sas_get_linkerrors,
589 	.smp_handler = sas_smp_handler,
590 };
591 
592 static inline ssize_t phy_event_threshold_show(struct device *dev,
593 			struct device_attribute *attr, char *buf)
594 {
595 	struct Scsi_Host *shost = class_to_shost(dev);
596 	struct sas_ha_struct *sha = SHOST_TO_SAS_HA(shost);
597 
598 	return scnprintf(buf, PAGE_SIZE, "%u\n", sha->event_thres);
599 }
600 
601 static inline ssize_t phy_event_threshold_store(struct device *dev,
602 			struct device_attribute *attr,
603 			const char *buf, size_t count)
604 {
605 	struct Scsi_Host *shost = class_to_shost(dev);
606 	struct sas_ha_struct *sha = SHOST_TO_SAS_HA(shost);
607 
608 	sha->event_thres = simple_strtol(buf, NULL, 10);
609 
610 	/* threshold cannot be set too small */
611 	if (sha->event_thres < 32)
612 		sha->event_thres = 32;
613 
614 	return count;
615 }
616 
617 DEVICE_ATTR(phy_event_threshold,
618 	S_IRUGO|S_IWUSR,
619 	phy_event_threshold_show,
620 	phy_event_threshold_store);
621 EXPORT_SYMBOL_GPL(dev_attr_phy_event_threshold);
622 
623 struct scsi_transport_template *
624 sas_domain_attach_transport(struct sas_domain_function_template *dft)
625 {
626 	struct scsi_transport_template *stt = sas_attach_transport(&sft);
627 	struct sas_internal *i;
628 
629 	if (!stt)
630 		return stt;
631 
632 	i = to_sas_internal(stt);
633 	i->dft = dft;
634 	stt->create_work_queue = 1;
635 	stt->eh_strategy_handler = sas_scsi_recover_host;
636 
637 	return stt;
638 }
639 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
640 
641 struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy,
642 				      gfp_t gfp_flags)
643 {
644 	struct asd_sas_event *event;
645 	struct sas_ha_struct *sas_ha = phy->ha;
646 	struct sas_internal *i =
647 		to_sas_internal(sas_ha->core.shost->transportt);
648 
649 	event = kmem_cache_zalloc(sas_event_cache, gfp_flags);
650 	if (!event)
651 		return NULL;
652 
653 	atomic_inc(&phy->event_nr);
654 
655 	if (atomic_read(&phy->event_nr) > phy->ha->event_thres) {
656 		if (i->dft->lldd_control_phy) {
657 			if (cmpxchg(&phy->in_shutdown, 0, 1) == 0) {
658 				pr_notice("The phy%d bursting events, shut it down.\n",
659 					  phy->id);
660 				sas_notify_phy_event(phy, PHYE_SHUTDOWN,
661 						     gfp_flags);
662 			}
663 		} else {
664 			/* Do not support PHY control, stop allocating events */
665 			WARN_ONCE(1, "PHY control not supported.\n");
666 			kmem_cache_free(sas_event_cache, event);
667 			atomic_dec(&phy->event_nr);
668 			event = NULL;
669 		}
670 	}
671 
672 	return event;
673 }
674 
675 void sas_free_event(struct asd_sas_event *event)
676 {
677 	struct asd_sas_phy *phy = event->phy;
678 
679 	kmem_cache_free(sas_event_cache, event);
680 	atomic_dec(&phy->event_nr);
681 }
682 
683 /* ---------- SAS Class register/unregister ---------- */
684 
685 static int __init sas_class_init(void)
686 {
687 	sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
688 	if (!sas_task_cache)
689 		goto out;
690 
691 	sas_event_cache = KMEM_CACHE(asd_sas_event, SLAB_HWCACHE_ALIGN);
692 	if (!sas_event_cache)
693 		goto free_task_kmem;
694 
695 	return 0;
696 free_task_kmem:
697 	kmem_cache_destroy(sas_task_cache);
698 out:
699 	return -ENOMEM;
700 }
701 
702 static void __exit sas_class_exit(void)
703 {
704 	kmem_cache_destroy(sas_task_cache);
705 	kmem_cache_destroy(sas_event_cache);
706 }
707 
708 MODULE_AUTHOR("Luben Tuikov <luben_tuikov@adaptec.com>");
709 MODULE_DESCRIPTION("SAS Transport Layer");
710 MODULE_LICENSE("GPL v2");
711 
712 module_init(sas_class_init);
713 module_exit(sas_class_exit);
714 
715