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1 /*
2  * Serial Attached SCSI (SAS) Transport Layer initialization
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of the
12  * License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
22  * USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/device.h>
30 #include <linux/spinlock.h>
31 #include <scsi/sas_ata.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_transport.h>
35 #include <scsi/scsi_transport_sas.h>
36 
37 #include "sas_internal.h"
38 
39 #include "../scsi_sas_internal.h"
40 
41 static struct kmem_cache *sas_task_cache;
42 
sas_alloc_task(gfp_t flags)43 struct sas_task *sas_alloc_task(gfp_t flags)
44 {
45 	struct sas_task *task = kmem_cache_zalloc(sas_task_cache, flags);
46 
47 	if (task) {
48 		spin_lock_init(&task->task_state_lock);
49 		task->task_state_flags = SAS_TASK_STATE_PENDING;
50 	}
51 
52 	return task;
53 }
54 EXPORT_SYMBOL_GPL(sas_alloc_task);
55 
sas_alloc_slow_task(gfp_t flags)56 struct sas_task *sas_alloc_slow_task(gfp_t flags)
57 {
58 	struct sas_task *task = sas_alloc_task(flags);
59 	struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);
60 
61 	if (!task || !slow) {
62 		if (task)
63 			kmem_cache_free(sas_task_cache, task);
64 		kfree(slow);
65 		return NULL;
66 	}
67 
68 	task->slow_task = slow;
69 	init_timer(&slow->timer);
70 	init_completion(&slow->completion);
71 
72 	return task;
73 }
74 EXPORT_SYMBOL_GPL(sas_alloc_slow_task);
75 
sas_free_task(struct sas_task * task)76 void sas_free_task(struct sas_task *task)
77 {
78 	if (task) {
79 		kfree(task->slow_task);
80 		kmem_cache_free(sas_task_cache, task);
81 	}
82 }
83 EXPORT_SYMBOL_GPL(sas_free_task);
84 
85 /*------------ SAS addr hash -----------*/
sas_hash_addr(u8 * hashed,const u8 * sas_addr)86 void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
87 {
88         const u32 poly = 0x00DB2777;
89         u32     r = 0;
90         int     i;
91 
92         for (i = 0; i < 8; i++) {
93                 int b;
94                 for (b = 7; b >= 0; b--) {
95                         r <<= 1;
96                         if ((1 << b) & sas_addr[i]) {
97                                 if (!(r & 0x01000000))
98                                         r ^= poly;
99                         } else if (r & 0x01000000)
100                                 r ^= poly;
101                 }
102         }
103 
104         hashed[0] = (r >> 16) & 0xFF;
105         hashed[1] = (r >> 8) & 0xFF ;
106         hashed[2] = r & 0xFF;
107 }
108 
109 
110 /* ---------- HA events ---------- */
111 
sas_hae_reset(struct work_struct * work)112 void sas_hae_reset(struct work_struct *work)
113 {
114 	struct sas_ha_event *ev = to_sas_ha_event(work);
115 	struct sas_ha_struct *ha = ev->ha;
116 
117 	clear_bit(HAE_RESET, &ha->pending);
118 }
119 
sas_register_ha(struct sas_ha_struct * sas_ha)120 int sas_register_ha(struct sas_ha_struct *sas_ha)
121 {
122 	int error = 0;
123 
124 	mutex_init(&sas_ha->disco_mutex);
125 	spin_lock_init(&sas_ha->phy_port_lock);
126 	sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);
127 
128 	set_bit(SAS_HA_REGISTERED, &sas_ha->state);
129 	spin_lock_init(&sas_ha->lock);
130 	mutex_init(&sas_ha->drain_mutex);
131 	init_waitqueue_head(&sas_ha->eh_wait_q);
132 	INIT_LIST_HEAD(&sas_ha->defer_q);
133 	INIT_LIST_HEAD(&sas_ha->eh_dev_q);
134 
135 	error = sas_register_phys(sas_ha);
136 	if (error) {
137 		printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
138 		return error;
139 	}
140 
141 	error = sas_register_ports(sas_ha);
142 	if (error) {
143 		printk(KERN_NOTICE "couldn't register sas ports:%d\n", error);
144 		goto Undo_phys;
145 	}
146 
147 	error = sas_init_events(sas_ha);
148 	if (error) {
149 		printk(KERN_NOTICE "couldn't start event thread:%d\n", error);
150 		goto Undo_ports;
151 	}
152 
153 	INIT_LIST_HEAD(&sas_ha->eh_done_q);
154 	INIT_LIST_HEAD(&sas_ha->eh_ata_q);
155 
156 	return 0;
157 
158 Undo_ports:
159 	sas_unregister_ports(sas_ha);
160 Undo_phys:
161 
162 	return error;
163 }
164 
sas_disable_events(struct sas_ha_struct * sas_ha)165 static void sas_disable_events(struct sas_ha_struct *sas_ha)
166 {
167 	/* Set the state to unregistered to avoid further unchained
168 	 * events to be queued, and flush any in-progress drainers
169 	 */
170 	mutex_lock(&sas_ha->drain_mutex);
171 	spin_lock_irq(&sas_ha->lock);
172 	clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
173 	spin_unlock_irq(&sas_ha->lock);
174 	__sas_drain_work(sas_ha);
175 	mutex_unlock(&sas_ha->drain_mutex);
176 }
177 
sas_unregister_ha(struct sas_ha_struct * sas_ha)178 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
179 {
180 	sas_disable_events(sas_ha);
181 	sas_unregister_ports(sas_ha);
182 
183 	/* flush unregistration work */
184 	mutex_lock(&sas_ha->drain_mutex);
185 	__sas_drain_work(sas_ha);
186 	mutex_unlock(&sas_ha->drain_mutex);
187 
188 	return 0;
189 }
190 
sas_get_linkerrors(struct sas_phy * phy)191 static int sas_get_linkerrors(struct sas_phy *phy)
192 {
193 	if (scsi_is_sas_phy_local(phy)) {
194 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
195 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
196 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
197 		struct sas_internal *i =
198 			to_sas_internal(sas_ha->core.shost->transportt);
199 
200 		return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
201 	}
202 
203 	return sas_smp_get_phy_events(phy);
204 }
205 
sas_try_ata_reset(struct asd_sas_phy * asd_phy)206 int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
207 {
208 	struct domain_device *dev = NULL;
209 
210 	/* try to route user requested link resets through libata */
211 	if (asd_phy->port)
212 		dev = asd_phy->port->port_dev;
213 
214 	/* validate that dev has been probed */
215 	if (dev)
216 		dev = sas_find_dev_by_rphy(dev->rphy);
217 
218 	if (dev && dev_is_sata(dev)) {
219 		sas_ata_schedule_reset(dev);
220 		sas_ata_wait_eh(dev);
221 		return 0;
222 	}
223 
224 	return -ENODEV;
225 }
226 
227 /**
228  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
229  *
230  * phy reset request via sysfs in host workqueue context so we know we
231  * can block on eh and safely traverse the domain_device topology
232  */
transport_sas_phy_reset(struct sas_phy * phy,int hard_reset)233 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
234 {
235 	enum phy_func reset_type;
236 
237 	if (hard_reset)
238 		reset_type = PHY_FUNC_HARD_RESET;
239 	else
240 		reset_type = PHY_FUNC_LINK_RESET;
241 
242 	if (scsi_is_sas_phy_local(phy)) {
243 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
244 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
245 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
246 		struct sas_internal *i =
247 			to_sas_internal(sas_ha->core.shost->transportt);
248 
249 		if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
250 			return 0;
251 		return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
252 	} else {
253 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
254 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
255 		struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);
256 
257 		if (ata_dev && !hard_reset) {
258 			sas_ata_schedule_reset(ata_dev);
259 			sas_ata_wait_eh(ata_dev);
260 			return 0;
261 		} else
262 			return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
263 	}
264 }
265 
sas_phy_enable(struct sas_phy * phy,int enable)266 static int sas_phy_enable(struct sas_phy *phy, int enable)
267 {
268 	int ret;
269 	enum phy_func cmd;
270 
271 	if (enable)
272 		cmd = PHY_FUNC_LINK_RESET;
273 	else
274 		cmd = PHY_FUNC_DISABLE;
275 
276 	if (scsi_is_sas_phy_local(phy)) {
277 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
278 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
279 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
280 		struct sas_internal *i =
281 			to_sas_internal(sas_ha->core.shost->transportt);
282 
283 		if (enable)
284 			ret = transport_sas_phy_reset(phy, 0);
285 		else
286 			ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
287 	} else {
288 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
289 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
290 
291 		if (enable)
292 			ret = transport_sas_phy_reset(phy, 0);
293 		else
294 			ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
295 	}
296 	return ret;
297 }
298 
sas_phy_reset(struct sas_phy * phy,int hard_reset)299 int sas_phy_reset(struct sas_phy *phy, int hard_reset)
300 {
301 	int ret;
302 	enum phy_func reset_type;
303 
304 	if (!phy->enabled)
305 		return -ENODEV;
306 
307 	if (hard_reset)
308 		reset_type = PHY_FUNC_HARD_RESET;
309 	else
310 		reset_type = PHY_FUNC_LINK_RESET;
311 
312 	if (scsi_is_sas_phy_local(phy)) {
313 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
314 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
315 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
316 		struct sas_internal *i =
317 			to_sas_internal(sas_ha->core.shost->transportt);
318 
319 		ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
320 	} else {
321 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
322 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
323 		ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
324 	}
325 	return ret;
326 }
327 
sas_set_phy_speed(struct sas_phy * phy,struct sas_phy_linkrates * rates)328 int sas_set_phy_speed(struct sas_phy *phy,
329 		      struct sas_phy_linkrates *rates)
330 {
331 	int ret;
332 
333 	if ((rates->minimum_linkrate &&
334 	     rates->minimum_linkrate > phy->maximum_linkrate) ||
335 	    (rates->maximum_linkrate &&
336 	     rates->maximum_linkrate < phy->minimum_linkrate))
337 		return -EINVAL;
338 
339 	if (rates->minimum_linkrate &&
340 	    rates->minimum_linkrate < phy->minimum_linkrate_hw)
341 		rates->minimum_linkrate = phy->minimum_linkrate_hw;
342 
343 	if (rates->maximum_linkrate &&
344 	    rates->maximum_linkrate > phy->maximum_linkrate_hw)
345 		rates->maximum_linkrate = phy->maximum_linkrate_hw;
346 
347 	if (scsi_is_sas_phy_local(phy)) {
348 		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
349 		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
350 		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
351 		struct sas_internal *i =
352 			to_sas_internal(sas_ha->core.shost->transportt);
353 
354 		ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
355 					       rates);
356 	} else {
357 		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
358 		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
359 		ret = sas_smp_phy_control(ddev, phy->number,
360 					  PHY_FUNC_LINK_RESET, rates);
361 
362 	}
363 
364 	return ret;
365 }
366 
sas_prep_resume_ha(struct sas_ha_struct * ha)367 void sas_prep_resume_ha(struct sas_ha_struct *ha)
368 {
369 	int i;
370 
371 	set_bit(SAS_HA_REGISTERED, &ha->state);
372 
373 	/* clear out any stale link events/data from the suspension path */
374 	for (i = 0; i < ha->num_phys; i++) {
375 		struct asd_sas_phy *phy = ha->sas_phy[i];
376 
377 		memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
378 		phy->port_events_pending = 0;
379 		phy->phy_events_pending = 0;
380 		phy->frame_rcvd_size = 0;
381 	}
382 }
383 EXPORT_SYMBOL(sas_prep_resume_ha);
384 
phys_suspended(struct sas_ha_struct * ha)385 static int phys_suspended(struct sas_ha_struct *ha)
386 {
387 	int i, rc = 0;
388 
389 	for (i = 0; i < ha->num_phys; i++) {
390 		struct asd_sas_phy *phy = ha->sas_phy[i];
391 
392 		if (phy->suspended)
393 			rc++;
394 	}
395 
396 	return rc;
397 }
398 
sas_resume_ha(struct sas_ha_struct * ha)399 void sas_resume_ha(struct sas_ha_struct *ha)
400 {
401 	const unsigned long tmo = msecs_to_jiffies(25000);
402 	int i;
403 
404 	/* deform ports on phys that did not resume
405 	 * at this point we may be racing the phy coming back (as posted
406 	 * by the lldd).  So we post the event and once we are in the
407 	 * libsas context check that the phy remains suspended before
408 	 * tearing it down.
409 	 */
410 	i = phys_suspended(ha);
411 	if (i)
412 		dev_info(ha->dev, "waiting up to 25 seconds for %d phy%s to resume\n",
413 			 i, i > 1 ? "s" : "");
414 	wait_event_timeout(ha->eh_wait_q, phys_suspended(ha) == 0, tmo);
415 	for (i = 0; i < ha->num_phys; i++) {
416 		struct asd_sas_phy *phy = ha->sas_phy[i];
417 
418 		if (phy->suspended) {
419 			dev_warn(&phy->phy->dev, "resume timeout\n");
420 			sas_notify_phy_event(phy, PHYE_RESUME_TIMEOUT);
421 		}
422 	}
423 
424 	/* all phys are back up or timed out, turn on i/o so we can
425 	 * flush out disks that did not return
426 	 */
427 	scsi_unblock_requests(ha->core.shost);
428 	sas_drain_work(ha);
429 }
430 EXPORT_SYMBOL(sas_resume_ha);
431 
sas_suspend_ha(struct sas_ha_struct * ha)432 void sas_suspend_ha(struct sas_ha_struct *ha)
433 {
434 	int i;
435 
436 	sas_disable_events(ha);
437 	scsi_block_requests(ha->core.shost);
438 	for (i = 0; i < ha->num_phys; i++) {
439 		struct asd_sas_port *port = ha->sas_port[i];
440 
441 		sas_discover_event(port, DISCE_SUSPEND);
442 	}
443 
444 	/* flush suspend events while unregistered */
445 	mutex_lock(&ha->drain_mutex);
446 	__sas_drain_work(ha);
447 	mutex_unlock(&ha->drain_mutex);
448 }
449 EXPORT_SYMBOL(sas_suspend_ha);
450 
sas_phy_release(struct sas_phy * phy)451 static void sas_phy_release(struct sas_phy *phy)
452 {
453 	kfree(phy->hostdata);
454 	phy->hostdata = NULL;
455 }
456 
phy_reset_work(struct work_struct * work)457 static void phy_reset_work(struct work_struct *work)
458 {
459 	struct sas_phy_data *d = container_of(work, typeof(*d), reset_work.work);
460 
461 	d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
462 }
463 
phy_enable_work(struct work_struct * work)464 static void phy_enable_work(struct work_struct *work)
465 {
466 	struct sas_phy_data *d = container_of(work, typeof(*d), enable_work.work);
467 
468 	d->enable_result = sas_phy_enable(d->phy, d->enable);
469 }
470 
sas_phy_setup(struct sas_phy * phy)471 static int sas_phy_setup(struct sas_phy *phy)
472 {
473 	struct sas_phy_data *d = kzalloc(sizeof(*d), GFP_KERNEL);
474 
475 	if (!d)
476 		return -ENOMEM;
477 
478 	mutex_init(&d->event_lock);
479 	INIT_SAS_WORK(&d->reset_work, phy_reset_work);
480 	INIT_SAS_WORK(&d->enable_work, phy_enable_work);
481 	d->phy = phy;
482 	phy->hostdata = d;
483 
484 	return 0;
485 }
486 
queue_phy_reset(struct sas_phy * phy,int hard_reset)487 static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
488 {
489 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
490 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
491 	struct sas_phy_data *d = phy->hostdata;
492 	int rc;
493 
494 	if (!d)
495 		return -ENOMEM;
496 
497 	/* libsas workqueue coordinates ata-eh reset with discovery */
498 	mutex_lock(&d->event_lock);
499 	d->reset_result = 0;
500 	d->hard_reset = hard_reset;
501 
502 	spin_lock_irq(&ha->lock);
503 	sas_queue_work(ha, &d->reset_work);
504 	spin_unlock_irq(&ha->lock);
505 
506 	rc = sas_drain_work(ha);
507 	if (rc == 0)
508 		rc = d->reset_result;
509 	mutex_unlock(&d->event_lock);
510 
511 	return rc;
512 }
513 
queue_phy_enable(struct sas_phy * phy,int enable)514 static int queue_phy_enable(struct sas_phy *phy, int enable)
515 {
516 	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
517 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
518 	struct sas_phy_data *d = phy->hostdata;
519 	int rc;
520 
521 	if (!d)
522 		return -ENOMEM;
523 
524 	/* libsas workqueue coordinates ata-eh reset with discovery */
525 	mutex_lock(&d->event_lock);
526 	d->enable_result = 0;
527 	d->enable = enable;
528 
529 	spin_lock_irq(&ha->lock);
530 	sas_queue_work(ha, &d->enable_work);
531 	spin_unlock_irq(&ha->lock);
532 
533 	rc = sas_drain_work(ha);
534 	if (rc == 0)
535 		rc = d->enable_result;
536 	mutex_unlock(&d->event_lock);
537 
538 	return rc;
539 }
540 
541 static struct sas_function_template sft = {
542 	.phy_enable = queue_phy_enable,
543 	.phy_reset = queue_phy_reset,
544 	.phy_setup = sas_phy_setup,
545 	.phy_release = sas_phy_release,
546 	.set_phy_speed = sas_set_phy_speed,
547 	.get_linkerrors = sas_get_linkerrors,
548 	.smp_handler = sas_smp_handler,
549 };
550 
551 struct scsi_transport_template *
sas_domain_attach_transport(struct sas_domain_function_template * dft)552 sas_domain_attach_transport(struct sas_domain_function_template *dft)
553 {
554 	struct scsi_transport_template *stt = sas_attach_transport(&sft);
555 	struct sas_internal *i;
556 
557 	if (!stt)
558 		return stt;
559 
560 	i = to_sas_internal(stt);
561 	i->dft = dft;
562 	stt->create_work_queue = 1;
563 	stt->eh_timed_out = sas_scsi_timed_out;
564 	stt->eh_strategy_handler = sas_scsi_recover_host;
565 
566 	return stt;
567 }
568 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
569 
570 
sas_domain_release_transport(struct scsi_transport_template * stt)571 void sas_domain_release_transport(struct scsi_transport_template *stt)
572 {
573 	sas_release_transport(stt);
574 }
575 EXPORT_SYMBOL_GPL(sas_domain_release_transport);
576 
577 /* ---------- SAS Class register/unregister ---------- */
578 
sas_class_init(void)579 static int __init sas_class_init(void)
580 {
581 	sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
582 	if (!sas_task_cache)
583 		return -ENOMEM;
584 
585 	return 0;
586 }
587 
sas_class_exit(void)588 static void __exit sas_class_exit(void)
589 {
590 	kmem_cache_destroy(sas_task_cache);
591 }
592 
593 MODULE_AUTHOR("Luben Tuikov <luben_tuikov@adaptec.com>");
594 MODULE_DESCRIPTION("SAS Transport Layer");
595 MODULE_LICENSE("GPL v2");
596 
597 module_init(sas_class_init);
598 module_exit(sas_class_exit);
599 
600 EXPORT_SYMBOL_GPL(sas_register_ha);
601 EXPORT_SYMBOL_GPL(sas_unregister_ha);
602