drivers/scsi/libsas/sas_init.c

   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(sizeof(*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
 145         return error;
 146 }
 147 EXPORT_SYMBOL_GPL(sas_register_ha);
 148
 149 static void sas_disable_events(struct sas_ha_struct *sas_ha)
 150 {
 151         /* Set the state to unregistered to avoid further unchained
 152          * events to be queued, and flush any in-progress drainers
 153          */
 154         mutex_lock(&sas_ha->drain_mutex);
 155         spin_lock_irq(&sas_ha->lock);
 156         clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
 157         spin_unlock_irq(&sas_ha->lock);
 158         __sas_drain_work(sas_ha);
 159         mutex_unlock(&sas_ha->drain_mutex);
 160 }
 161
 162 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
 163 {
 164         sas_disable_events(sas_ha);
 165         sas_unregister_ports(sas_ha);
 166
 167         /* flush unregistration work */
 168         mutex_lock(&sas_ha->drain_mutex);
 169         __sas_drain_work(sas_ha);
 170         mutex_unlock(&sas_ha->drain_mutex);
 171
 172         destroy_workqueue(sas_ha->disco_q);
 173         destroy_workqueue(sas_ha->event_q);
 174
 175         return 0;
 176 }
 177 EXPORT_SYMBOL_GPL(sas_unregister_ha);
 178
 179 static int sas_get_linkerrors(struct sas_phy *phy)
 180 {
 181         if (scsi_is_sas_phy_local(phy)) {
 182                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
 183                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 184                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 185                 struct sas_internal *i =
 186                         to_sas_internal(sas_ha->shost->transportt);
 187
 188                 return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
 189         }
 190
 191         return sas_smp_get_phy_events(phy);
 192 }
 193
 194 int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
 195 {
 196         struct domain_device *dev = NULL;
 197
 198         /* try to route user requested link resets through libata */
 199         if (asd_phy->port)
 200                 dev = asd_phy->port->port_dev;
 201
 202         /* validate that dev has been probed */
 203         if (dev)
 204                 dev = sas_find_dev_by_rphy(dev->rphy);
 205
 206         if (dev && dev_is_sata(dev)) {
 207                 sas_ata_schedule_reset(dev);
 208                 sas_ata_wait_eh(dev);
 209                 return 0;
 210         }
 211
 212         return -ENODEV;
 213 }
 214
 215 /*
 216  * transport_sas_phy_reset - reset a phy and permit libata to manage the link
 217  *
 218  * phy reset request via sysfs in host workqueue context so we know we
 219  * can block on eh and safely traverse the domain_device topology
 220  */
 221 static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
 222 {
 223         enum phy_func reset_type;
 224
 225         if (hard_reset)
 226                 reset_type = PHY_FUNC_HARD_RESET;
 227         else
 228                 reset_type = PHY_FUNC_LINK_RESET;
 229
 230         if (scsi_is_sas_phy_local(phy)) {
 231                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
 232                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 233                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 234                 struct sas_internal *i =
 235                         to_sas_internal(sas_ha->shost->transportt);
 236
 237                 if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
 238                         return 0;
 239                 return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
 240         } else {
 241                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
 242                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
 243                 struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);
 244
 245                 if (ata_dev && !hard_reset) {
 246                         sas_ata_schedule_reset(ata_dev);
 247                         sas_ata_wait_eh(ata_dev);
 248                         return 0;
 249                 } else
 250                         return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
 251         }
 252 }
 253
 254 int sas_phy_enable(struct sas_phy *phy, int enable)
 255 {
 256         int ret;
 257         enum phy_func cmd;
 258
 259         if (enable)
 260                 cmd = PHY_FUNC_LINK_RESET;
 261         else
 262                 cmd = PHY_FUNC_DISABLE;
 263
 264         if (scsi_is_sas_phy_local(phy)) {
 265                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
 266                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 267                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 268                 struct sas_internal *i =
 269                         to_sas_internal(sas_ha->shost->transportt);
 270
 271                 if (enable)
 272                         ret = transport_sas_phy_reset(phy, 0);
 273                 else
 274                         ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
 275         } else {
 276                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
 277                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
 278
 279                 if (enable)
 280                         ret = transport_sas_phy_reset(phy, 0);
 281                 else
 282                         ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
 283         }
 284         return ret;
 285 }
 286 EXPORT_SYMBOL_GPL(sas_phy_enable);
 287
 288 int sas_phy_reset(struct sas_phy *phy, int hard_reset)
 289 {
 290         int ret;
 291         enum phy_func reset_type;
 292
 293         if (!phy->enabled)
 294                 return -ENODEV;
 295
 296         if (hard_reset)
 297                 reset_type = PHY_FUNC_HARD_RESET;
 298         else
 299                 reset_type = PHY_FUNC_LINK_RESET;
 300
 301         if (scsi_is_sas_phy_local(phy)) {
 302                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
 303                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 304                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 305                 struct sas_internal *i =
 306                         to_sas_internal(sas_ha->shost->transportt);
 307
 308                 ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
 309         } else {
 310                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
 311                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
 312                 ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
 313         }
 314         return ret;
 315 }
 316 EXPORT_SYMBOL_GPL(sas_phy_reset);
 317
 318 static int sas_set_phy_speed(struct sas_phy *phy,
 319                              struct sas_phy_linkrates *rates)
 320 {
 321         int ret;
 322
 323         if ((rates->minimum_linkrate &&
 324              rates->minimum_linkrate > phy->maximum_linkrate) ||
 325             (rates->maximum_linkrate &&
 326              rates->maximum_linkrate < phy->minimum_linkrate))
 327                 return -EINVAL;
 328
 329         if (rates->minimum_linkrate &&
 330             rates->minimum_linkrate < phy->minimum_linkrate_hw)
 331                 rates->minimum_linkrate = phy->minimum_linkrate_hw;
 332
 333         if (rates->maximum_linkrate &&
 334             rates->maximum_linkrate > phy->maximum_linkrate_hw)
 335                 rates->maximum_linkrate = phy->maximum_linkrate_hw;
 336
 337         if (scsi_is_sas_phy_local(phy)) {
 338                 struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
 339                 struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
 340                 struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
 341                 struct sas_internal *i =
 342                         to_sas_internal(sas_ha->shost->transportt);
 343
 344                 ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
 345                                                rates);
 346         } else {
 347                 struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
 348                 struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
 349                 ret = sas_smp_phy_control(ddev, phy->number,
 350                                           PHY_FUNC_LINK_RESET, rates);
 351
 352         }
 353
 354         return ret;
 355 }
 356
 357 void sas_prep_resume_ha(struct sas_ha_struct *ha)
 358 {
 359         int i;
 360
 361         set_bit(SAS_HA_REGISTERED, &ha->state);
 362         set_bit(SAS_HA_RESUMING, &ha->state);
 363
 364         /* clear out any stale link events/data from the suspension path */
 365         for (i = 0; i < ha->num_phys; i++) {
 366                 struct asd_sas_phy *phy = ha->sas_phy[i];
 367
 368                 memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
 369                 phy->frame_rcvd_size = 0;
 370         }
 371 }
 372 EXPORT_SYMBOL(sas_prep_resume_ha);
 373
 374 static int phys_suspended(struct sas_ha_struct *ha)
 375 {
 376         int i, rc = 0;
 377
 378         for (i = 0; i < ha->num_phys; i++) {
 379                 struct asd_sas_phy *phy = ha->sas_phy[i];
 380
 381                 if (phy->suspended)
 382                         rc++;
 383         }
 384
 385         return rc;
 386 }
 387
 388 static void sas_resume_insert_broadcast_ha(struct sas_ha_struct *ha)
 389 {
 390         int i;
 391
 392         for (i = 0; i < ha->num_phys; i++) {
 393                 struct asd_sas_port *port = ha->sas_port[i];
 394                 struct domain_device *dev = port->port_dev;
 395
 396                 if (dev && dev_is_expander(dev->dev_type)) {
 397                         struct asd_sas_phy *first_phy;
 398
 399                         spin_lock(&port->phy_list_lock);
 400                         first_phy = list_first_entry_or_null(
 401                                 &port->phy_list, struct asd_sas_phy,
 402                                 port_phy_el);
 403                         spin_unlock(&port->phy_list_lock);
 404
 405                         if (first_phy)
 406                                 sas_notify_port_event(first_phy,
 407                                         PORTE_BROADCAST_RCVD, GFP_KERNEL);
 408                 }
 409         }
 410 }
 411
 412 static void _sas_resume_ha(struct sas_ha_struct *ha, bool drain)
 413 {
 414         const unsigned long tmo = msecs_to_jiffies(25000);
 415         int i;
 416
 417         /* deform ports on phys that did not resume
 418          * at this point we may be racing the phy coming back (as posted
 419          * by the lldd).  So we post the event and once we are in the
 420          * libsas context check that the phy remains suspended before
 421          * tearing it down.
 422          */
 423         i = phys_suspended(ha);
 424         if (i)
 425                 dev_info(ha->dev, "waiting up to 25 seconds for %d phy%s to resume\n",
 426                          i, i > 1 ? "s" : "");
 427         wait_event_timeout(ha->eh_wait_q, phys_suspended(ha) == 0, tmo);
 428         for (i = 0; i < ha->num_phys; i++) {
 429                 struct asd_sas_phy *phy = ha->sas_phy[i];
 430
 431                 if (phy->suspended) {
 432                         dev_warn(&phy->phy->dev, "resume timeout\n");
 433                         sas_notify_phy_event(phy, PHYE_RESUME_TIMEOUT,
 434                                              GFP_KERNEL);
 435                 }
 436         }
 437
 438         /* all phys are back up or timed out, turn on i/o so we can
 439          * flush out disks that did not return
 440          */
 441         scsi_unblock_requests(ha->shost);
 442         if (drain)
 443                 sas_drain_work(ha);
 444         clear_bit(SAS_HA_RESUMING, &ha->state);
 445
 446         sas_queue_deferred_work(ha);
 447         /* send event PORTE_BROADCAST_RCVD to identify some new inserted
 448          * disks for expander
 449          */
 450         sas_resume_insert_broadcast_ha(ha);
 451 }
 452
 453 void sas_resume_ha(struct sas_ha_struct *ha)
 454 {
 455         _sas_resume_ha(ha, true);
 456 }
 457 EXPORT_SYMBOL(sas_resume_ha);
 458
 459 /* A no-sync variant, which does not call sas_drain_ha(). */
 460 void sas_resume_ha_no_sync(struct sas_ha_struct *ha)
 461 {
 462         _sas_resume_ha(ha, false);
 463 }
 464 EXPORT_SYMBOL(sas_resume_ha_no_sync);
 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(sizeof(*d), GFP_KERNEL);
 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