[SCSI] libsas: execute transport link resets with libata-eh via host workqueue
[linux-2.6.git] / drivers / scsi / libsas / sas_init.c
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
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                 INIT_LIST_HEAD(&task->list);
49                 spin_lock_init(&task->task_state_lock);
50                 task->task_state_flags = SAS_TASK_STATE_PENDING;
51                 init_timer(&task->timer);
52                 init_completion(&task->completion);
53         }
54
55         return task;
56 }
57 EXPORT_SYMBOL_GPL(sas_alloc_task);
58
59 void sas_free_task(struct sas_task *task)
60 {
61         if (task) {
62                 BUG_ON(!list_empty(&task->list));
63                 kmem_cache_free(sas_task_cache, task);
64         }
65 }
66 EXPORT_SYMBOL_GPL(sas_free_task);
67
68 /*------------ SAS addr hash -----------*/
69 void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
70 {
71         const u32 poly = 0x00DB2777;
72         u32     r = 0;
73         int     i;
74
75         for (i = 0; i < 8; i++) {
76                 int b;
77                 for (b = 7; 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         hashed[0] = (r >> 16) & 0xFF;
88         hashed[1] = (r >> 8) & 0xFF ;
89         hashed[2] = r & 0xFF;
90 }
91
92
93 /* ---------- HA events ---------- */
94
95 void sas_hae_reset(struct work_struct *work)
96 {
97         struct sas_ha_event *ev =
98                 container_of(work, struct sas_ha_event, work);
99         struct sas_ha_struct *ha = ev->ha;
100
101         clear_bit(HAE_RESET, &ha->pending);
102 }
103
104 int sas_register_ha(struct sas_ha_struct *sas_ha)
105 {
106         int error = 0;
107
108         mutex_init(&sas_ha->disco_mutex);
109         spin_lock_init(&sas_ha->phy_port_lock);
110         sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);
111
112         if (sas_ha->lldd_queue_size == 0)
113                 sas_ha->lldd_queue_size = 1;
114         else if (sas_ha->lldd_queue_size == -1)
115                 sas_ha->lldd_queue_size = 128; /* Sanity */
116
117         set_bit(SAS_HA_REGISTERED, &sas_ha->state);
118         spin_lock_init(&sas_ha->state_lock);
119         mutex_init(&sas_ha->drain_mutex);
120         INIT_LIST_HEAD(&sas_ha->defer_q);
121
122         error = sas_register_phys(sas_ha);
123         if (error) {
124                 printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
125                 return error;
126         }
127
128         error = sas_register_ports(sas_ha);
129         if (error) {
130                 printk(KERN_NOTICE "couldn't register sas ports:%d\n", error);
131                 goto Undo_phys;
132         }
133
134         error = sas_init_events(sas_ha);
135         if (error) {
136                 printk(KERN_NOTICE "couldn't start event thread:%d\n", error);
137                 goto Undo_ports;
138         }
139
140         if (sas_ha->lldd_max_execute_num > 1) {
141                 error = sas_init_queue(sas_ha);
142                 if (error) {
143                         printk(KERN_NOTICE "couldn't start queue thread:%d, "
144                                "running in direct mode\n", error);
145                         sas_ha->lldd_max_execute_num = 1;
146                 }
147         }
148
149         INIT_LIST_HEAD(&sas_ha->eh_done_q);
150         INIT_LIST_HEAD(&sas_ha->eh_ata_q);
151
152         return 0;
153
154 Undo_ports:
155         sas_unregister_ports(sas_ha);
156 Undo_phys:
157
158         return error;
159 }
160
161 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
162 {
163         unsigned long flags;
164
165         /* Set the state to unregistered to avoid further unchained
166          * events to be queued
167          */
168         spin_lock_irqsave(&sas_ha->state_lock, flags);
169         clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
170         spin_unlock_irqrestore(&sas_ha->state_lock, flags);
171         sas_drain_work(sas_ha);
172
173         sas_unregister_ports(sas_ha);
174         sas_drain_work(sas_ha);
175
176         if (sas_ha->lldd_max_execute_num > 1) {
177                 sas_shutdown_queue(sas_ha);
178                 sas_ha->lldd_max_execute_num = 1;
179         }
180
181         return 0;
182 }
183
184 static int sas_get_linkerrors(struct sas_phy *phy)
185 {
186         if (scsi_is_sas_phy_local(phy)) {
187                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
188                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
189                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
190                 struct sas_internal *i =
191                         to_sas_internal(sas_ha->core.shost->transportt);
192
193                 return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
194         }
195
196         return sas_smp_get_phy_events(phy);
197 }
198
199 /**
200  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
201  *
202  * phy reset request via sysfs in host workqueue context so we know we
203  * can block on eh and safely traverse the domain_device topology
204  */
205 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
206 {
207         int ret;
208         enum phy_func reset_type;
209
210         if (hard_reset)
211                 reset_type = PHY_FUNC_HARD_RESET;
212         else
213                 reset_type = PHY_FUNC_LINK_RESET;
214
215         if (scsi_is_sas_phy_local(phy)) {
216                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
217                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
218                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
219                 struct sas_internal *i =
220                         to_sas_internal(sas_ha->core.shost->transportt);
221                 struct domain_device *dev = NULL;
222
223                 if (asd_phy->port)
224                         dev = asd_phy->port->port_dev;
225
226                 /* validate that dev has been probed */
227                 if (dev)
228                         dev = sas_find_dev_by_rphy(dev->rphy);
229
230                 if (dev && dev_is_sata(dev) && !hard_reset) {
231                         sas_ata_schedule_reset(dev);
232                         sas_ata_wait_eh(dev);
233                         ret = 0;
234                 } else
235                         ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
236         } else {
237                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
238                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
239                 struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);
240
241                 if (ata_dev && !hard_reset) {
242                         sas_ata_schedule_reset(ata_dev);
243                         sas_ata_wait_eh(ata_dev);
244                         ret = 0;
245                 } else
246                         ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
247         }
248
249         return ret;
250 }
251
252 int sas_phy_enable(struct sas_phy *phy, int enable)
253 {
254         int ret;
255         enum phy_func command;
256
257         if (enable)
258                 command = PHY_FUNC_LINK_RESET;
259         else
260                 command = PHY_FUNC_DISABLE;
261
262         if (scsi_is_sas_phy_local(phy)) {
263                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
264                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
265                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
266                 struct sas_internal *i =
267                         to_sas_internal(sas_ha->core.shost->transportt);
268
269                 if (!enable) {
270                         sas_phy_disconnected(asd_phy);
271                         sas_ha->notify_phy_event(asd_phy, PHYE_LOSS_OF_SIGNAL);
272                 }
273                 ret = i->dft->lldd_control_phy(asd_phy, command, NULL);
274         } else {
275                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
276                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
277                 ret = sas_smp_phy_control(ddev, phy->number, command, NULL);
278         }
279         return ret;
280 }
281
282 int sas_phy_reset(struct sas_phy *phy, int hard_reset)
283 {
284         int ret;
285         enum phy_func reset_type;
286
287         if (hard_reset)
288                 reset_type = PHY_FUNC_HARD_RESET;
289         else
290                 reset_type = PHY_FUNC_LINK_RESET;
291
292         if (scsi_is_sas_phy_local(phy)) {
293                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
294                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
295                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
296                 struct sas_internal *i =
297                         to_sas_internal(sas_ha->core.shost->transportt);
298
299                 ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
300         } else {
301                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
302                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
303                 ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
304         }
305         return ret;
306 }
307
308 int sas_set_phy_speed(struct sas_phy *phy,
309                       struct sas_phy_linkrates *rates)
310 {
311         int ret;
312
313         if ((rates->minimum_linkrate &&
314              rates->minimum_linkrate > phy->maximum_linkrate) ||
315             (rates->maximum_linkrate &&
316              rates->maximum_linkrate < phy->minimum_linkrate))
317                 return -EINVAL;
318
319         if (rates->minimum_linkrate &&
320             rates->minimum_linkrate < phy->minimum_linkrate_hw)
321                 rates->minimum_linkrate = phy->minimum_linkrate_hw;
322
323         if (rates->maximum_linkrate &&
324             rates->maximum_linkrate > phy->maximum_linkrate_hw)
325                 rates->maximum_linkrate = phy->maximum_linkrate_hw;
326
327         if (scsi_is_sas_phy_local(phy)) {
328                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
329                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
330                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
331                 struct sas_internal *i =
332                         to_sas_internal(sas_ha->core.shost->transportt);
333
334                 ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
335                                                rates);
336         } else {
337                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
338                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
339                 ret = sas_smp_phy_control(ddev, phy->number,
340                                           PHY_FUNC_LINK_RESET, rates);
341
342         }
343
344         return ret;
345 }
346
347 static void sas_phy_release(struct sas_phy *phy)
348 {
349         kfree(phy->hostdata);
350         phy->hostdata = NULL;
351 }
352
353 static void phy_reset_work(struct work_struct *work)
354 {
355         struct sas_phy_data *d = container_of(work, typeof(*d), reset_work);
356
357         d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
358 }
359
360 static int sas_phy_setup(struct sas_phy *phy)
361 {
362         struct sas_phy_data *d = kzalloc(sizeof(*d), GFP_KERNEL);
363
364         if (!d)
365                 return -ENOMEM;
366
367         mutex_init(&d->event_lock);
368         INIT_WORK(&d->reset_work, phy_reset_work);
369         d->phy = phy;
370         phy->hostdata = d;
371
372         return 0;
373 }
374
375 static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
376 {
377         struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
378         struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
379         struct sas_phy_data *d = phy->hostdata;
380         int rc;
381
382         if (!d)
383                 return -ENOMEM;
384
385         /* libsas workqueue coordinates ata-eh reset with discovery */
386         mutex_lock(&d->event_lock);
387         d->reset_result = 0;
388         d->hard_reset = hard_reset;
389
390         spin_lock_irq(&ha->state_lock);
391         sas_queue_work(ha, &d->reset_work);
392         spin_unlock_irq(&ha->state_lock);
393
394         rc = sas_drain_work(ha);
395         if (rc == 0)
396                 rc = d->reset_result;
397         mutex_unlock(&d->event_lock);
398
399         return rc;
400 }
401
402 static struct sas_function_template sft = {
403         .phy_enable = sas_phy_enable,
404         .phy_reset = queue_phy_reset,
405         .phy_setup = sas_phy_setup,
406         .phy_release = sas_phy_release,
407         .set_phy_speed = sas_set_phy_speed,
408         .get_linkerrors = sas_get_linkerrors,
409         .smp_handler = sas_smp_handler,
410 };
411
412 struct scsi_transport_template *
413 sas_domain_attach_transport(struct sas_domain_function_template *dft)
414 {
415         struct scsi_transport_template *stt = sas_attach_transport(&sft);
416         struct sas_internal *i;
417
418         if (!stt)
419                 return stt;
420
421         i = to_sas_internal(stt);
422         i->dft = dft;
423         stt->create_work_queue = 1;
424         stt->eh_timed_out = sas_scsi_timed_out;
425         stt->eh_strategy_handler = sas_scsi_recover_host;
426
427         return stt;
428 }
429 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
430
431
432 void sas_domain_release_transport(struct scsi_transport_template *stt)
433 {
434         sas_release_transport(stt);
435 }
436 EXPORT_SYMBOL_GPL(sas_domain_release_transport);
437
438 /* ---------- SAS Class register/unregister ---------- */
439
440 static int __init sas_class_init(void)
441 {
442         sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
443         if (!sas_task_cache)
444                 return -ENOMEM;
445
446         return 0;
447 }
448
449 static void __exit sas_class_exit(void)
450 {
451         kmem_cache_destroy(sas_task_cache);
452 }
453
454 MODULE_AUTHOR("Luben Tuikov <luben_tuikov@adaptec.com>");
455 MODULE_DESCRIPTION("SAS Transport Layer");
456 MODULE_LICENSE("GPL v2");
457
458 module_init(sas_class_init);
459 module_exit(sas_class_exit);
460
461 EXPORT_SYMBOL_GPL(sas_register_ha);
462 EXPORT_SYMBOL_GPL(sas_unregister_ha);