drivers/scsi/libsas/sas_discover.c

   1 /*
   2  * Serial Attached SCSI (SAS) Discover process
   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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  22  *
  23  */
  24
  25 #include <linux/scatterlist.h>
  26 #include <linux/slab.h>
  27 #include <linux/async.h>
  28 #include <scsi/scsi_host.h>
  29 #include <scsi/scsi_eh.h>
  30 #include "sas_internal.h"
  31
  32 #include <scsi/scsi_transport.h>
  33 #include <scsi/scsi_transport_sas.h>
  34 #include <scsi/sas_ata.h>
  35 #include "../scsi_sas_internal.h"
  36
  37 /* ---------- Basic task processing for discovery purposes ---------- */
  38
  39 void sas_init_dev(struct domain_device *dev)
  40 {
  41         switch (dev->dev_type) {
  42         case SAS_END_DEVICE:
  43                 INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
  44                 break;
  45         case SAS_EDGE_EXPANDER_DEVICE:
  46         case SAS_FANOUT_EXPANDER_DEVICE:
  47                 INIT_LIST_HEAD(&dev->ex_dev.children);
  48                 mutex_init(&dev->ex_dev.cmd_mutex);
  49                 break;
  50         default:
  51                 break;
  52         }
  53 }
  54
  55 /* ---------- Domain device discovery ---------- */
  56
  57 /**
  58  * sas_get_port_device - Discover devices which caused port creation
  59  * @port: pointer to struct sas_port of interest
  60  *
  61  * Devices directly attached to a HA port, have no parent.  This is
  62  * how we know they are (domain) "root" devices.  All other devices
  63  * do, and should have their "parent" pointer set appropriately as
  64  * soon as a child device is discovered.
  65  */
  66 static int sas_get_port_device(struct asd_sas_port *port)
  67 {
  68         struct asd_sas_phy *phy;
  69         struct sas_rphy *rphy;
  70         struct domain_device *dev;
  71         int rc = -ENODEV;
  72
  73         dev = sas_alloc_device();
  74         if (!dev)
  75                 return -ENOMEM;
  76
  77         spin_lock_irq(&port->phy_list_lock);
  78         if (list_empty(&port->phy_list)) {
  79                 spin_unlock_irq(&port->phy_list_lock);
  80                 sas_put_device(dev);
  81                 return -ENODEV;
  82         }
  83         phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
  84         spin_lock(&phy->frame_rcvd_lock);
  85         memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
  86                                              (size_t)phy->frame_rcvd_size));
  87         spin_unlock(&phy->frame_rcvd_lock);
  88         spin_unlock_irq(&port->phy_list_lock);
  89
  90         if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
  91                 struct dev_to_host_fis *fis =
  92                         (struct dev_to_host_fis *) dev->frame_rcvd;
  93                 if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
  94                     fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
  95                     && (fis->device & ~0x10) == 0)
  96                         dev->dev_type = SAS_SATA_PM;
  97                 else
  98                         dev->dev_type = SAS_SATA_DEV;
  99                 dev->tproto = SAS_PROTOCOL_SATA;
 100         } else {
 101                 struct sas_identify_frame *id =
 102                         (struct sas_identify_frame *) dev->frame_rcvd;
 103                 dev->dev_type = id->dev_type;
 104                 dev->iproto = id->initiator_bits;
 105                 dev->tproto = id->target_bits;
 106         }
 107
 108         sas_init_dev(dev);
 109
 110         dev->port = port;
 111         switch (dev->dev_type) {
 112         case SAS_SATA_DEV:
 113                 rc = sas_ata_init(dev);
 114                 if (rc) {
 115                         rphy = NULL;
 116                         break;
 117                 }
 118                 /* fall through */
 119         case SAS_END_DEVICE:
 120                 rphy = sas_end_device_alloc(port->port);
 121                 break;
 122         case SAS_EDGE_EXPANDER_DEVICE:
 123                 rphy = sas_expander_alloc(port->port,
 124                                           SAS_EDGE_EXPANDER_DEVICE);
 125                 break;
 126         case SAS_FANOUT_EXPANDER_DEVICE:
 127                 rphy = sas_expander_alloc(port->port,
 128                                           SAS_FANOUT_EXPANDER_DEVICE);
 129                 break;
 130         default:
 131                 pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
 132                 rphy = NULL;
 133                 break;
 134         }
 135
 136         if (!rphy) {
 137                 sas_put_device(dev);
 138                 return rc;
 139         }
 140
 141         rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
 142         memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
 143         sas_fill_in_rphy(dev, rphy);
 144         sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 145         port->port_dev = dev;
 146         dev->linkrate = port->linkrate;
 147         dev->min_linkrate = port->linkrate;
 148         dev->max_linkrate = port->linkrate;
 149         dev->pathways = port->num_phys;
 150         memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
 151         memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 152         memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 153         port->disc.max_level = 0;
 154         sas_device_set_phy(dev, port->port);
 155
 156         dev->rphy = rphy;
 157         get_device(&dev->rphy->dev);
 158
 159         if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
 160                 list_add_tail(&dev->disco_list_node, &port->disco_list);
 161         else {
 162                 spin_lock_irq(&port->dev_list_lock);
 163                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 164                 spin_unlock_irq(&port->dev_list_lock);
 165         }
 166
 167         spin_lock_irq(&port->phy_list_lock);
 168         list_for_each_entry(phy, &port->phy_list, port_phy_el)
 169                 sas_phy_set_target(phy, dev);
 170         spin_unlock_irq(&port->phy_list_lock);
 171
 172         return 0;
 173 }
 174
 175 /* ---------- Discover and Revalidate ---------- */
 176
 177 int sas_notify_lldd_dev_found(struct domain_device *dev)
 178 {
 179         int res = 0;
 180         struct sas_ha_struct *sas_ha = dev->port->ha;
 181         struct Scsi_Host *shost = sas_ha->core.shost;
 182         struct sas_internal *i = to_sas_internal(shost->transportt);
 183
 184         if (!i->dft->lldd_dev_found)
 185                 return 0;
 186
 187         res = i->dft->lldd_dev_found(dev);
 188         if (res) {
 189                 pr_warn("driver on host %s cannot handle device %llx, error:%d\n",
 190                         dev_name(sas_ha->dev),
 191                         SAS_ADDR(dev->sas_addr), res);
 192         }
 193         set_bit(SAS_DEV_FOUND, &dev->state);
 194         kref_get(&dev->kref);
 195         return res;
 196 }
 197
 198
 199 void sas_notify_lldd_dev_gone(struct domain_device *dev)
 200 {
 201         struct sas_ha_struct *sas_ha = dev->port->ha;
 202         struct Scsi_Host *shost = sas_ha->core.shost;
 203         struct sas_internal *i = to_sas_internal(shost->transportt);
 204
 205         if (!i->dft->lldd_dev_gone)
 206                 return;
 207
 208         if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
 209                 i->dft->lldd_dev_gone(dev);
 210                 sas_put_device(dev);
 211         }
 212 }
 213
 214 static void sas_probe_devices(struct asd_sas_port *port)
 215 {
 216         struct domain_device *dev, *n;
 217
 218         /* devices must be domain members before link recovery and probe */
 219         list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 220                 spin_lock_irq(&port->dev_list_lock);
 221                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 222                 spin_unlock_irq(&port->dev_list_lock);
 223         }
 224
 225         sas_probe_sata(port);
 226
 227         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
 228                 int err;
 229
 230                 err = sas_rphy_add(dev->rphy);
 231                 if (err)
 232                         sas_fail_probe(dev, __func__, err);
 233                 else
 234                         list_del_init(&dev->disco_list_node);
 235         }
 236 }
 237
 238 static void sas_suspend_devices(struct work_struct *work)
 239 {
 240         struct asd_sas_phy *phy;
 241         struct domain_device *dev;
 242         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 243         struct asd_sas_port *port = ev->port;
 244         struct Scsi_Host *shost = port->ha->core.shost;
 245         struct sas_internal *si = to_sas_internal(shost->transportt);
 246
 247         clear_bit(DISCE_SUSPEND, &port->disc.pending);
 248
 249         sas_suspend_sata(port);
 250
 251         /* lldd is free to forget the domain_device across the
 252          * suspension, we force the issue here to keep the reference
 253          * counts aligned
 254          */
 255         list_for_each_entry(dev, &port->dev_list, dev_list_node)
 256                 sas_notify_lldd_dev_gone(dev);
 257
 258         /* we are suspending, so we know events are disabled and
 259          * phy_list is not being mutated
 260          */
 261         list_for_each_entry(phy, &port->phy_list, port_phy_el) {
 262                 if (si->dft->lldd_port_deformed)
 263                         si->dft->lldd_port_deformed(phy);
 264                 phy->suspended = 1;
 265                 port->suspended = 1;
 266         }
 267 }
 268
 269 static void sas_resume_devices(struct work_struct *work)
 270 {
 271         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 272         struct asd_sas_port *port = ev->port;
 273
 274         clear_bit(DISCE_RESUME, &port->disc.pending);
 275
 276         sas_resume_sata(port);
 277 }
 278
 279 /**
 280  * sas_discover_end_dev - discover an end device (SSP, etc)
 281  * @dev: pointer to domain device of interest
 282  *
 283  * See comment in sas_discover_sata().
 284  */
 285 int sas_discover_end_dev(struct domain_device *dev)
 286 {
 287         int res;
 288
 289         res = sas_notify_lldd_dev_found(dev);
 290         if (res)
 291                 return res;
 292
 293         return 0;
 294 }
 295
 296 /* ---------- Device registration and unregistration ---------- */
 297
 298 void sas_free_device(struct kref *kref)
 299 {
 300         struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 301
 302         put_device(&dev->rphy->dev);
 303         dev->rphy = NULL;
 304
 305         if (dev->parent)
 306                 sas_put_device(dev->parent);
 307
 308         sas_port_put_phy(dev->phy);
 309         dev->phy = NULL;
 310
 311         /* remove the phys and ports, everything else should be gone */
 312         if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
 313                 kfree(dev->ex_dev.ex_phy);
 314
 315         if (dev_is_sata(dev) && dev->sata_dev.ap) {
 316                 ata_sas_tport_delete(dev->sata_dev.ap);
 317                 ata_sas_port_destroy(dev->sata_dev.ap);
 318                 ata_host_put(dev->sata_dev.ata_host);
 319                 dev->sata_dev.ata_host = NULL;
 320                 dev->sata_dev.ap = NULL;
 321         }
 322
 323         kfree(dev);
 324 }
 325
 326 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 327 {
 328         struct sas_ha_struct *ha = port->ha;
 329
 330         sas_notify_lldd_dev_gone(dev);
 331         if (!dev->parent)
 332                 dev->port->port_dev = NULL;
 333         else
 334                 list_del_init(&dev->siblings);
 335
 336         spin_lock_irq(&port->dev_list_lock);
 337         list_del_init(&dev->dev_list_node);
 338         if (dev_is_sata(dev))
 339                 sas_ata_end_eh(dev->sata_dev.ap);
 340         spin_unlock_irq(&port->dev_list_lock);
 341
 342         spin_lock_irq(&ha->lock);
 343         if (dev->dev_type == SAS_END_DEVICE &&
 344             !list_empty(&dev->ssp_dev.eh_list_node)) {
 345                 list_del_init(&dev->ssp_dev.eh_list_node);
 346                 ha->eh_active--;
 347         }
 348         spin_unlock_irq(&ha->lock);
 349
 350         sas_put_device(dev);
 351 }
 352
 353 void sas_destruct_devices(struct asd_sas_port *port)
 354 {
 355         struct domain_device *dev, *n;
 356
 357         list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 358                 list_del_init(&dev->disco_list_node);
 359
 360                 sas_remove_children(&dev->rphy->dev);
 361                 sas_rphy_delete(dev->rphy);
 362                 sas_unregister_common_dev(port, dev);
 363         }
 364 }
 365
 366 static void sas_destruct_ports(struct asd_sas_port *port)
 367 {
 368         struct sas_port *sas_port, *p;
 369
 370         list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 371                 list_del_init(&sas_port->del_list);
 372                 sas_port_delete(sas_port);
 373         }
 374 }
 375
 376 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 377 {
 378         if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 379             !list_empty(&dev->disco_list_node)) {
 380                 /* this rphy never saw sas_rphy_add */
 381                 list_del_init(&dev->disco_list_node);
 382                 sas_rphy_free(dev->rphy);
 383                 sas_unregister_common_dev(port, dev);
 384                 return;
 385         }
 386
 387         if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 388                 sas_rphy_unlink(dev->rphy);
 389                 list_move_tail(&dev->disco_list_node, &port->destroy_list);
 390         }
 391 }
 392
 393 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 394 {
 395         struct domain_device *dev, *n;
 396
 397         list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 398                 if (gone)
 399                         set_bit(SAS_DEV_GONE, &dev->state);
 400                 sas_unregister_dev(port, dev);
 401         }
 402
 403         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 404                 sas_unregister_dev(port, dev);
 405
 406         port->port->rphy = NULL;
 407
 408 }
 409
 410 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 411 {
 412         struct sas_ha_struct *ha;
 413         struct sas_phy *new_phy;
 414
 415         if (!dev)
 416                 return;
 417
 418         ha = dev->port->ha;
 419         new_phy = sas_port_get_phy(port);
 420
 421         /* pin and record last seen phy */
 422         spin_lock_irq(&ha->phy_port_lock);
 423         if (new_phy) {
 424                 sas_port_put_phy(dev->phy);
 425                 dev->phy = new_phy;
 426         }
 427         spin_unlock_irq(&ha->phy_port_lock);
 428 }
 429
 430 /* ---------- Discovery and Revalidation ---------- */
 431
 432 /**
 433  * sas_discover_domain - discover the domain
 434  * @work: work structure embedded in port domain device.
 435  *
 436  * NOTE: this process _must_ quit (return) as soon as any connection
 437  * errors are encountered.  Connection recovery is done elsewhere.
 438  * Discover process only interrogates devices in order to discover the
 439  * domain.
 440  */
 441 static void sas_discover_domain(struct work_struct *work)
 442 {
 443         struct domain_device *dev;
 444         int error = 0;
 445         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 446         struct asd_sas_port *port = ev->port;
 447
 448         clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 449
 450         if (port->port_dev)
 451                 return;
 452
 453         error = sas_get_port_device(port);
 454         if (error)
 455                 return;
 456         dev = port->port_dev;
 457
 458         pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 459                  task_pid_nr(current));
 460
 461         switch (dev->dev_type) {
 462         case SAS_END_DEVICE:
 463                 error = sas_discover_end_dev(dev);
 464                 break;
 465         case SAS_EDGE_EXPANDER_DEVICE:
 466         case SAS_FANOUT_EXPANDER_DEVICE:
 467                 error = sas_discover_root_expander(dev);
 468                 break;
 469         case SAS_SATA_DEV:
 470         case SAS_SATA_PM:
 471 #ifdef CONFIG_SCSI_SAS_ATA
 472                 error = sas_discover_sata(dev);
 473                 break;
 474 #else
 475                 pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 476                 /* Fall through */
 477 #endif
 478         default:
 479                 error = -ENXIO;
 480                 pr_err("unhandled device %d\n", dev->dev_type);
 481                 break;
 482         }
 483
 484         if (error) {
 485                 sas_rphy_free(dev->rphy);
 486                 list_del_init(&dev->disco_list_node);
 487                 spin_lock_irq(&port->dev_list_lock);
 488                 list_del_init(&dev->dev_list_node);
 489                 spin_unlock_irq(&port->dev_list_lock);
 490
 491                 sas_put_device(dev);
 492                 port->port_dev = NULL;
 493         }
 494
 495         sas_probe_devices(port);
 496
 497         pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 498                  task_pid_nr(current), error);
 499 }
 500
 501 static void sas_revalidate_domain(struct work_struct *work)
 502 {
 503         int res = 0;
 504         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 505         struct asd_sas_port *port = ev->port;
 506         struct sas_ha_struct *ha = port->ha;
 507         struct domain_device *ddev = port->port_dev;
 508
 509         /* prevent revalidation from finding sata links in recovery */
 510         mutex_lock(&ha->disco_mutex);
 511         if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 512                 pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
 513                          port->id, task_pid_nr(current));
 514                 goto out;
 515         }
 516
 517         clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 518
 519         pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 520                  task_pid_nr(current));
 521
 522         if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
 523                      ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
 524                 res = sas_ex_revalidate_domain(ddev);
 525
 526         pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 527                  port->id, task_pid_nr(current), res);
 528  out:
 529         mutex_unlock(&ha->disco_mutex);
 530
 531         sas_destruct_devices(port);
 532         sas_destruct_ports(port);
 533         sas_probe_devices(port);
 534 }
 535
 536 /* ---------- Events ---------- */
 537
 538 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 539 {
 540         /* chained work is not subject to SA_HA_DRAINING or
 541          * SAS_HA_REGISTERED, because it is either submitted in the
 542          * workqueue, or known to be submitted from a context that is
 543          * not racing against draining
 544          */
 545         queue_work(ha->disco_q, &sw->work);
 546 }
 547
 548 static void sas_chain_event(int event, unsigned long *pending,
 549                             struct sas_work *sw,
 550                             struct sas_ha_struct *ha)
 551 {
 552         if (!test_and_set_bit(event, pending)) {
 553                 unsigned long flags;
 554
 555                 spin_lock_irqsave(&ha->lock, flags);
 556                 sas_chain_work(ha, sw);
 557                 spin_unlock_irqrestore(&ha->lock, flags);
 558         }
 559 }
 560
 561 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 562 {
 563         struct sas_discovery *disc;
 564
 565         if (!port)
 566                 return 0;
 567         disc = &port->disc;
 568
 569         BUG_ON(ev >= DISC_NUM_EVENTS);
 570
 571         sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 572
 573         return 0;
 574 }
 575
 576 /**
 577  * sas_init_disc - initialize the discovery struct in the port
 578  * @disc: port discovery structure
 579  * @port: pointer to struct port
 580  *
 581  * Called when the ports are being initialized.
 582  */
 583 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 584 {
 585         int i;
 586
 587         static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 588                 [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 589                 [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 590                 [DISCE_SUSPEND] = sas_suspend_devices,
 591                 [DISCE_RESUME] = sas_resume_devices,
 592         };
 593
 594         disc->pending = 0;
 595         for (i = 0; i < DISC_NUM_EVENTS; i++) {
 596                 INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 597                 disc->disc_work[i].port = port;
 598         }
 599 }