xref: /linux/drivers/scsi/libsas/sas_init.c (revision 9d19ca5d0e8b4a3f4b2eaa14e86a25f1c93ff35b) 
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 
39 struct sas_task *sas_alloc_slow_task(gfp_t flags)
40 {
41 	struct sas_task *task = sas_alloc_task(flags);
42 	struct sas_task_slow *slow = kmalloc_obj(*slow, flags);
43 
44 	if (!task || !slow) {
45 		if (task)
46 			kmem_cache_free(sas_task_cache, task);
47 		kfree(slow);
48 		return NULL;
49 	}
50 
51 	task->slow_task = slow;
52 	slow->task = task;
53 	timer_setup(&slow->timer, NULL, 0);
54 	init_completion(&slow->completion);
55 
56 	return task;
57 }
58 
59 void sas_free_task(struct sas_task *task)
60 {
61 	if (task) {
62 		kfree(task->slow_task);
63 		kmem_cache_free(sas_task_cache, task);
64 	}
65 }
66 
67 /*------------ SAS addr hash -----------*/
68 void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
69 {
70 	const u32 poly = 0x00DB2777;
71 	u32 r = 0;
72 	int i;
73 
74 	for (i = 0; i < SAS_ADDR_SIZE; i++) {
75 		int b;
76 
77 		for (b = (SAS_ADDR_SIZE - 1); b >= 0; b--) {
78 			r <<= 1;
79 			if ((1 << b) & sas_addr[i]) {
80 				if (!(r & 0x01000000))
81 					r ^= poly;
82 			} else if (r & 0x01000000) {
83 				r ^= poly;
84 			}
85 		}
86 	}
87 
88 	hashed[0] = (r >> 16) & 0xFF;
89 	hashed[1] = (r >> 8) & 0xFF;
90 	hashed[2] = r & 0xFF;
91 }
92 
93 int sas_register_ha(struct sas_ha_struct *sas_ha)
94 {
95 	char name[64];
96 	int error = 0;
97 
98 	mutex_init(&sas_ha->disco_mutex);
99 	spin_lock_init(&sas_ha->phy_port_lock);
100 	sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);
101 
102 	set_bit(SAS_HA_REGISTERED, &sas_ha->state);
103 	spin_lock_init(&sas_ha->lock);
104 	mutex_init(&sas_ha->drain_mutex);
105 	init_waitqueue_head(&sas_ha->eh_wait_q);
106 	INIT_LIST_HEAD(&sas_ha->defer_q);
107 	INIT_LIST_HEAD(&sas_ha->eh_dev_q);
108 
109 	sas_ha->event_thres = SAS_PHY_SHUTDOWN_THRES;
110 
111 	error = sas_register_phys(sas_ha);
112 	if (error) {
113 		pr_notice("couldn't register sas phys:%d\n", error);
114 		return error;
115 	}
116 
117 	error = sas_register_ports(sas_ha);
118 	if (error) {
119 		pr_notice("couldn't register sas ports:%d\n", error);
120 		goto Undo_phys;
121 	}
122 
123 	error = -ENOMEM;
124 	snprintf(name, sizeof(name), "%s_event_q", dev_name(sas_ha->dev));
125 	sas_ha->event_q = alloc_ordered_workqueue("%s", WQ_MEM_RECLAIM, name);
126 	if (!sas_ha->event_q)
127 		goto Undo_ports;
128 
129 	snprintf(name, sizeof(name), "%s_disco_q", dev_name(sas_ha->dev));
130 	sas_ha->disco_q = alloc_ordered_workqueue("%s", WQ_MEM_RECLAIM, name);
131 	if (!sas_ha->disco_q)
132 		goto Undo_event_q;
133 
134 	INIT_LIST_HEAD(&sas_ha->eh_done_q);
135 	INIT_LIST_HEAD(&sas_ha->eh_ata_q);
136 
137 	return 0;
138 
139 Undo_event_q:
140 	destroy_workqueue(sas_ha->event_q);
141 Undo_ports:
142 	sas_unregister_ports(sas_ha);
143 Undo_phys:
144 	sas_unregister_phys(sas_ha);
145 
146 	return error;
147 }
148 EXPORT_SYMBOL_GPL(sas_register_ha);
149 
150 static void sas_disable_events(struct sas_ha_struct *sas_ha)
151 {
152 	/* Set the state to unregistered to avoid further unchained
153 	 * events to be queued, and flush any in-progress drainers
154 	 */
155 	mutex_lock(&sas_ha->drain_mutex);
156 	spin_lock_irq(&sas_ha->lock);
157 	clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
158 	spin_unlock_irq(&sas_ha->lock);
159 	__sas_drain_work(sas_ha);
160 	mutex_unlock(&sas_ha->drain_mutex);
161 }
162 
163 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
164 {
165 	sas_disable_events(sas_ha);
166 	sas_unregister_ports(sas_ha);
167 
168 	/* flush unregistration work */
169 	mutex_lock(&sas_ha->drain_mutex);
170 	__sas_drain_work(sas_ha);
171 	mutex_unlock(&sas_ha->drain_mutex);
172 
173 	destroy_workqueue(sas_ha->disco_q);
174 	destroy_workqueue(sas_ha->event_q);
175 
176 	return 0;
177 }
178 EXPORT_SYMBOL_GPL(sas_unregister_ha);
179 
180 static int sas_get_linkerrors(struct sas_phy *phy)
181 {
182 	if (scsi_is_sas_phy_local(phy)) {
183 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
184 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
185 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
186 		struct sas_internal *i =
187 			to_sas_internal(sas_ha->shost->transportt);
188 
189 		return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
190 	}
191 
192 	return sas_smp_get_phy_events(phy);
193 }
194 
195 int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
196 {
197 	struct domain_device *dev = NULL;
198 
199 	/* try to route user requested link resets through libata */
200 	if (asd_phy->port)
201 		dev = asd_phy->port->port_dev;
202 
203 	/* validate that dev has been probed */
204 	if (dev)
205 		dev = sas_find_dev_by_rphy(dev->rphy);
206 
207 	if (dev && dev_is_sata(dev)) {
208 		sas_ata_schedule_reset(dev);
209 		sas_ata_wait_eh(dev);
210 		return 0;
211 	}
212 
213 	return -ENODEV;
214 }
215 
216 /*
217  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
218  *
219  * phy reset request via sysfs in host workqueue context so we know we
220  * can block on eh and safely traverse the domain_device topology
221  */
222 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
223 {
224 	enum phy_func reset_type;
225 
226 	if (hard_reset)
227 		reset_type = PHY_FUNC_HARD_RESET;
228 	else
229 		reset_type = PHY_FUNC_LINK_RESET;
230 
231 	if (scsi_is_sas_phy_local(phy)) {
232 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
233 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
234 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
235 		struct sas_internal *i =
236 			to_sas_internal(sas_ha->shost->transportt);
237 
238 		if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
239 			return 0;
240 		return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
241 	} else {
242 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
243 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
244 		struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);
245 
246 		if (ata_dev && !hard_reset) {
247 			sas_ata_schedule_reset(ata_dev);
248 			sas_ata_wait_eh(ata_dev);
249 			return 0;
250 		} else
251 			return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
252 	}
253 }
254 
255 int sas_phy_enable(struct sas_phy *phy, int enable)
256 {
257 	int ret;
258 	enum phy_func cmd;
259 
260 	if (enable)
261 		cmd = PHY_FUNC_LINK_RESET;
262 	else
263 		cmd = PHY_FUNC_DISABLE;
264 
265 	if (scsi_is_sas_phy_local(phy)) {
266 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
267 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
268 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
269 		struct sas_internal *i =
270 			to_sas_internal(sas_ha->shost->transportt);
271 
272 		if (enable)
273 			ret = transport_sas_phy_reset(phy, 0);
274 		else
275 			ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
276 	} else {
277 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
278 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
279 
280 		if (enable)
281 			ret = transport_sas_phy_reset(phy, 0);
282 		else
283 			ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
284 	}
285 	return ret;
286 }
287 EXPORT_SYMBOL_GPL(sas_phy_enable);
288 
289 int sas_phy_reset(struct sas_phy *phy, int hard_reset)
290 {
291 	int ret;
292 	enum phy_func reset_type;
293 
294 	if (!phy->enabled)
295 		return -ENODEV;
296 
297 	if (hard_reset)
298 		reset_type = PHY_FUNC_HARD_RESET;
299 	else
300 		reset_type = PHY_FUNC_LINK_RESET;
301 
302 	if (scsi_is_sas_phy_local(phy)) {
303 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
304 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
305 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
306 		struct sas_internal *i =
307 			to_sas_internal(sas_ha->shost->transportt);
308 
309 		ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
310 	} else {
311 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
312 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
313 		ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
314 	}
315 	return ret;
316 }
317 EXPORT_SYMBOL_GPL(sas_phy_reset);
318 
319 static int sas_set_phy_speed(struct sas_phy *phy,
320 			     struct sas_phy_linkrates *rates)
321 {
322 	int ret;
323 
324 	if ((rates->minimum_linkrate &&
325 	     rates->minimum_linkrate > phy->maximum_linkrate) ||
326 	    (rates->maximum_linkrate &&
327 	     rates->maximum_linkrate < phy->minimum_linkrate))
328 		return -EINVAL;
329 
330 	if (rates->minimum_linkrate &&
331 	    rates->minimum_linkrate < phy->minimum_linkrate_hw)
332 		rates->minimum_linkrate = phy->minimum_linkrate_hw;
333 
334 	if (rates->maximum_linkrate &&
335 	    rates->maximum_linkrate > phy->maximum_linkrate_hw)
336 		rates->maximum_linkrate = phy->maximum_linkrate_hw;
337 
338 	if (scsi_is_sas_phy_local(phy)) {
339 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
340 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
341 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
342 		struct sas_internal *i =
343 			to_sas_internal(sas_ha->shost->transportt);
344 
345 		ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
346 					       rates);
347 	} else {
348 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
349 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
350 		ret = sas_smp_phy_control(ddev, phy->number,
351 					  PHY_FUNC_LINK_RESET, rates);
352 
353 	}
354 
355 	return ret;
356 }
357 
358 void sas_prep_resume_ha(struct sas_ha_struct *ha)
359 {
360 	int i;
361 
362 	set_bit(SAS_HA_REGISTERED, &ha->state);
363 	set_bit(SAS_HA_RESUMING, &ha->state);
364 
365 	/* clear out any stale link events/data from the suspension path */
366 	for (i = 0; i < ha->num_phys; i++) {
367 		struct asd_sas_phy *phy = ha->sas_phy[i];
368 
369 		memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
370 		phy->frame_rcvd_size = 0;
371 	}
372 }
373 EXPORT_SYMBOL(sas_prep_resume_ha);
374 
375 static int phys_suspended(struct sas_ha_struct *ha)
376 {
377 	int i, rc = 0;
378 
379 	for (i = 0; i < ha->num_phys; i++) {
380 		struct asd_sas_phy *phy = ha->sas_phy[i];
381 
382 		if (phy->suspended)
383 			rc++;
384 	}
385 
386 	return rc;
387 }
388 
389 static void sas_resume_insert_broadcast_ha(struct sas_ha_struct *ha)
390 {
391 	int i;
392 
393 	for (i = 0; i < ha->num_phys; i++) {
394 		struct asd_sas_port *port = ha->sas_port[i];
395 		struct domain_device *dev = port->port_dev;
396 
397 		if (dev && dev_is_expander(dev->dev_type)) {
398 			struct asd_sas_phy *first_phy;
399 
400 			spin_lock(&port->phy_list_lock);
401 			first_phy = list_first_entry_or_null(
402 				&port->phy_list, struct asd_sas_phy,
403 				port_phy_el);
404 			spin_unlock(&port->phy_list_lock);
405 
406 			if (first_phy)
407 				sas_notify_port_event(first_phy,
408 					PORTE_BROADCAST_RCVD, GFP_KERNEL);
409 		}
410 	}
411 }
412 
413 void sas_resume_ha(struct sas_ha_struct *ha)
414 {
415 	const unsigned long tmo = msecs_to_jiffies(25000);
416 	int i;
417 
418 	/* deform ports on phys that did not resume
419 	 * at this point we may be racing the phy coming back (as posted
420 	 * by the lldd).  So we post the event and once we are in the
421 	 * libsas context check that the phy remains suspended before
422 	 * tearing it down.
423 	 */
424 	i = phys_suspended(ha);
425 	if (i)
426 		dev_info(ha->dev, "waiting up to 25 seconds for %d phy%s to resume\n",
427 			 i, i > 1 ? "s" : "");
428 	wait_event_timeout(ha->eh_wait_q, phys_suspended(ha) == 0, tmo);
429 
430 	/*
431 	 * All phys are back up or timed out. Turn on I/O and drain
432 	 * pending work.
433 	 */
434 	scsi_unblock_requests(ha->shost);
435 	sas_drain_work(ha);
436 
437 	/*
438 	 * Send PHYE_RESUME_TIMEOUT after sas_drain_work(). The handler
439 	 * calls sas_deform_port() -> sas_destruct_devices(), which removes
440 	 * SCSI devices and, for LLDDs using device_link() PM sync, waits
441 	 * for the host to be runtime-active. Sending it before the drain
442 	 * would deadlock: the drain waits for the handler, the handler
443 	 * waits for host resume, and host resume waits for the drain to
444 	 * finish.
445 	 */
446 	for (i = 0; i < ha->num_phys; i++) {
447 		struct asd_sas_phy *phy = ha->sas_phy[i];
448 
449 		if (phy->suspended) {
450 			dev_warn(&phy->phy->dev, "resume timeout\n");
451 			sas_notify_phy_event(phy, PHYE_RESUME_TIMEOUT,
452 					     GFP_KERNEL);
453 		}
454 	}
455 
456 	clear_bit(SAS_HA_RESUMING, &ha->state);
457 
458 	sas_queue_deferred_work(ha);
459 	/* send event PORTE_BROADCAST_RCVD to identify some new inserted
460 	 * disks for expander
461 	 */
462 	sas_resume_insert_broadcast_ha(ha);
463 }
464 EXPORT_SYMBOL(sas_resume_ha);
465 
466 void sas_suspend_ha(struct sas_ha_struct *ha)
467 {
468 	int i;
469 
470 	sas_disable_events(ha);
471 	scsi_block_requests(ha->shost);
472 	for (i = 0; i < ha->num_phys; i++) {
473 		struct asd_sas_port *port = ha->sas_port[i];
474 
475 		sas_discover_event(port, DISCE_SUSPEND);
476 	}
477 
478 	/* flush suspend events while unregistered */
479 	mutex_lock(&ha->drain_mutex);
480 	__sas_drain_work(ha);
481 	mutex_unlock(&ha->drain_mutex);
482 }
483 EXPORT_SYMBOL(sas_suspend_ha);
484 
485 static void sas_phy_release(struct sas_phy *phy)
486 {
487 	kfree(phy->hostdata);
488 	phy->hostdata = NULL;
489 }
490 
491 static void phy_reset_work(struct work_struct *work)
492 {
493 	struct sas_phy_data *d = container_of(work, typeof(*d), reset_work.work);
494 
495 	d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
496 }
497 
498 static void phy_enable_work(struct work_struct *work)
499 {
500 	struct sas_phy_data *d = container_of(work, typeof(*d), enable_work.work);
501 
502 	d->enable_result = sas_phy_enable(d->phy, d->enable);
503 }
504 
505 static int sas_phy_setup(struct sas_phy *phy)
506 {
507 	struct sas_phy_data *d = kzalloc_obj(*d);
508 
509 	if (!d)
510 		return -ENOMEM;
511 
512 	mutex_init(&d->event_lock);
513 	INIT_SAS_WORK(&d->reset_work, phy_reset_work);
514 	INIT_SAS_WORK(&d->enable_work, phy_enable_work);
515 	d->phy = phy;
516 	phy->hostdata = d;
517 
518 	return 0;
519 }
520 
521 static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
522 {
523 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
524 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
525 	struct sas_phy_data *d = phy->hostdata;
526 	int rc;
527 
528 	if (!d)
529 		return -ENOMEM;
530 
531 	pm_runtime_get_sync(ha->dev);
532 	/* libsas workqueue coordinates ata-eh reset with discovery */
533 	mutex_lock(&d->event_lock);
534 	d->reset_result = 0;
535 	d->hard_reset = hard_reset;
536 
537 	spin_lock_irq(&ha->lock);
538 	sas_queue_work(ha, &d->reset_work);
539 	spin_unlock_irq(&ha->lock);
540 
541 	rc = sas_drain_work(ha);
542 	if (rc == 0)
543 		rc = d->reset_result;
544 	mutex_unlock(&d->event_lock);
545 	pm_runtime_put_sync(ha->dev);
546 
547 	return rc;
548 }
549 
550 static int queue_phy_enable(struct sas_phy *phy, int enable)
551 {
552 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
553 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
554 	struct sas_phy_data *d = phy->hostdata;
555 	int rc;
556 
557 	if (!d)
558 		return -ENOMEM;
559 
560 	pm_runtime_get_sync(ha->dev);
561 	/* libsas workqueue coordinates ata-eh reset with discovery */
562 	mutex_lock(&d->event_lock);
563 	d->enable_result = 0;
564 	d->enable = enable;
565 
566 	spin_lock_irq(&ha->lock);
567 	sas_queue_work(ha, &d->enable_work);
568 	spin_unlock_irq(&ha->lock);
569 
570 	rc = sas_drain_work(ha);
571 	if (rc == 0)
572 		rc = d->enable_result;
573 	mutex_unlock(&d->event_lock);
574 	pm_runtime_put_sync(ha->dev);
575 
576 	return rc;
577 }
578 
579 static struct sas_function_template sft = {
580 	.phy_enable = queue_phy_enable,
581 	.phy_reset = queue_phy_reset,
582 	.phy_setup = sas_phy_setup,
583 	.phy_release = sas_phy_release,
584 	.set_phy_speed = sas_set_phy_speed,
585 	.get_linkerrors = sas_get_linkerrors,
586 	.smp_handler = sas_smp_handler,
587 };
588 
589 static inline ssize_t phy_event_threshold_show(struct device *dev,
590 			struct device_attribute *attr, char *buf)
591 {
592 	struct Scsi_Host *shost = class_to_shost(dev);
593 	struct sas_ha_struct *sha = SHOST_TO_SAS_HA(shost);
594 
595 	return scnprintf(buf, PAGE_SIZE, "%u\n", sha->event_thres);
596 }
597 
598 static inline ssize_t phy_event_threshold_store(struct device *dev,
599 			struct device_attribute *attr,
600 			const char *buf, size_t count)
601 {
602 	struct Scsi_Host *shost = class_to_shost(dev);
603 	struct sas_ha_struct *sha = SHOST_TO_SAS_HA(shost);
604 
605 	sha->event_thres = simple_strtol(buf, NULL, 10);
606 
607 	/* threshold cannot be set too small */
608 	if (sha->event_thres < 32)
609 		sha->event_thres = 32;
610 
611 	return count;
612 }
613 
614 DEVICE_ATTR(phy_event_threshold,
615 	S_IRUGO|S_IWUSR,
616 	phy_event_threshold_show,
617 	phy_event_threshold_store);
618 EXPORT_SYMBOL_GPL(dev_attr_phy_event_threshold);
619 
620 struct scsi_transport_template *
621 sas_domain_attach_transport(struct sas_domain_function_template *dft)
622 {
623 	struct scsi_transport_template *stt = sas_attach_transport(&sft);
624 	struct sas_internal *i;
625 
626 	if (!stt)
627 		return stt;
628 
629 	i = to_sas_internal(stt);
630 	i->dft = dft;
631 	stt->create_work_queue = 1;
632 	stt->eh_strategy_handler = sas_scsi_recover_host;
633 
634 	return stt;
635 }
636 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
637 
638 struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy,
639 				      gfp_t gfp_flags)
640 {
641 	struct asd_sas_event *event;
642 	struct sas_ha_struct *sas_ha = phy->ha;
643 	struct sas_internal *i =
644 		to_sas_internal(sas_ha->shost->transportt);
645 
646 	event = kmem_cache_zalloc(sas_event_cache, gfp_flags);
647 	if (!event)
648 		return NULL;
649 
650 	atomic_inc(&phy->event_nr);
651 
652 	if (atomic_read(&phy->event_nr) > phy->ha->event_thres) {
653 		if (i->dft->lldd_control_phy) {
654 			if (cmpxchg(&phy->in_shutdown, 0, 1) == 0) {
655 				pr_notice("The phy%d bursting events, shut it down.\n",
656 					  phy->id);
657 				sas_notify_phy_event(phy, PHYE_SHUTDOWN,
658 						     gfp_flags);
659 			}
660 		} else {
661 			/* Do not support PHY control, stop allocating events */
662 			WARN_ONCE(1, "PHY control not supported.\n");
663 			kmem_cache_free(sas_event_cache, event);
664 			atomic_dec(&phy->event_nr);
665 			event = NULL;
666 		}
667 	}
668 
669 	return event;
670 }
671 
672 void sas_free_event(struct asd_sas_event *event)
673 {
674 	struct asd_sas_phy *phy = event->phy;
675 
676 	kmem_cache_free(sas_event_cache, event);
677 	atomic_dec(&phy->event_nr);
678 }
679 
680 /* ---------- SAS Class register/unregister ---------- */
681 
682 static int __init sas_class_init(void)
683 {
684 	sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
685 	if (!sas_task_cache)
686 		goto out;
687 
688 	sas_event_cache = KMEM_CACHE(asd_sas_event, SLAB_HWCACHE_ALIGN);
689 	if (!sas_event_cache)
690 		goto free_task_kmem;
691 
692 	return 0;
693 free_task_kmem:
694 	kmem_cache_destroy(sas_task_cache);
695 out:
696 	return -ENOMEM;
697 }
698 
699 static void __exit sas_class_exit(void)
700 {
701 	kmem_cache_destroy(sas_task_cache);
702 	kmem_cache_destroy(sas_event_cache);
703 }
704 
705 MODULE_AUTHOR("Luben Tuikov <luben_tuikov@adaptec.com>");
706 MODULE_DESCRIPTION("SAS Transport Layer");
707 MODULE_LICENSE("GPL v2");
708 
709 module_init(sas_class_init);
710 module_exit(sas_class_exit);
711 
712