drivers/scsi/libsas/sas_discover.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Serial Attached SCSI (SAS) Discover process
   4  *
   5  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
   6  * Copyright (C) 2005 Luben Tuikov <[email protected]>
   7  */
   8
   9 #include <linux/scatterlist.h>
  10 #include <linux/slab.h>
  11 #include <scsi/scsi_host.h>
  12 #include <scsi/scsi_eh.h>
  13 #include "sas_internal.h"
  14
  15 #include <scsi/scsi_transport.h>
  16 #include <scsi/scsi_transport_sas.h>
  17 #include <scsi/sas_ata.h>
  18 #include "scsi_sas_internal.h"
  19
  20 /* ---------- Basic task processing for discovery purposes ---------- */
  21
  22 void sas_init_dev(struct domain_device *dev)
  23 {
  24         switch (dev->dev_type) {
  25         case SAS_END_DEVICE:
  26                 INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
  27                 break;
  28         case SAS_EDGE_EXPANDER_DEVICE:
  29         case SAS_FANOUT_EXPANDER_DEVICE:
  30                 INIT_LIST_HEAD(&dev->ex_dev.children);
  31                 mutex_init(&dev->ex_dev.cmd_mutex);
  32                 break;
  33         default:
  34                 break;
  35         }
  36 }
  37
  38 /* ---------- Domain device discovery ---------- */
  39
  40 /**
  41  * sas_get_port_device - Discover devices which caused port creation
  42  * @port: pointer to struct sas_port of interest
  43  *
  44  * Devices directly attached to a HA port, have no parent.  This is
  45  * how we know they are (domain) "root" devices.  All other devices
  46  * do, and should have their "parent" pointer set appropriately as
  47  * soon as a child device is discovered.
  48  */
  49 static int sas_get_port_device(struct asd_sas_port *port)
  50 {
  51         struct asd_sas_phy *phy;
  52         struct sas_rphy *rphy;
  53         struct domain_device *dev;
  54         int rc = -ENODEV;
  55
  56         dev = sas_alloc_device();
  57         if (!dev)
  58                 return -ENOMEM;
  59
  60         spin_lock_irq(&port->phy_list_lock);
  61         if (list_empty(&port->phy_list)) {
  62                 spin_unlock_irq(&port->phy_list_lock);
  63                 sas_put_device(dev);
  64                 return -ENODEV;
  65         }
  66         phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
  67         spin_lock(&phy->frame_rcvd_lock);
  68         memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
  69                                              (size_t)phy->frame_rcvd_size));
  70         spin_unlock(&phy->frame_rcvd_lock);
  71         spin_unlock_irq(&port->phy_list_lock);
  72
  73         if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
  74                 struct dev_to_host_fis *fis =
  75                         (struct dev_to_host_fis *) dev->frame_rcvd;
  76                 if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
  77                     fis->byte_count_low == 0x69 && fis->byte_count_high == 0x96
  78                     && (fis->device & ~0x10) == 0)
  79                         dev->dev_type = SAS_SATA_PM;
  80                 else
  81                         dev->dev_type = SAS_SATA_DEV;
  82                 dev->tproto = SAS_PROTOCOL_SATA;
  83         } else if (port->oob_mode == SAS_OOB_MODE) {
  84                 struct sas_identify_frame *id =
  85                         (struct sas_identify_frame *) dev->frame_rcvd;
  86                 dev->dev_type = id->dev_type;
  87                 dev->iproto = id->initiator_bits;
  88                 dev->tproto = id->target_bits;
  89         } else {
  90                 /* If the oob mode is OOB_NOT_CONNECTED, the port is
  91                  * disconnected due to race with PHY down. We cannot
  92                  * continue to discover this port
  93                  */
  94                 sas_put_device(dev);
  95                 pr_warn("Port %016llx is disconnected when discovering\n",
  96                         SAS_ADDR(port->attached_sas_addr));
  97                 return -ENODEV;
  98         }
  99
 100         sas_init_dev(dev);
 101
 102         dev->port = port;
 103         switch (dev->dev_type) {
 104         case SAS_SATA_DEV:
 105                 rc = sas_ata_init(dev);
 106                 if (rc) {
 107                         rphy = NULL;
 108                         break;
 109                 }
 110                 fallthrough;
 111         case SAS_END_DEVICE:
 112                 rphy = sas_end_device_alloc(port->port);
 113                 break;
 114         case SAS_EDGE_EXPANDER_DEVICE:
 115                 rphy = sas_expander_alloc(port->port,
 116                                           SAS_EDGE_EXPANDER_DEVICE);
 117                 break;
 118         case SAS_FANOUT_EXPANDER_DEVICE:
 119                 rphy = sas_expander_alloc(port->port,
 120                                           SAS_FANOUT_EXPANDER_DEVICE);
 121                 break;
 122         default:
 123                 pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
 124                 rphy = NULL;
 125                 break;
 126         }
 127
 128         if (!rphy) {
 129                 sas_put_device(dev);
 130                 return rc;
 131         }
 132
 133         rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
 134         memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
 135         sas_fill_in_rphy(dev, rphy);
 136         sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 137         port->port_dev = dev;
 138         dev->linkrate = port->linkrate;
 139         dev->min_linkrate = port->linkrate;
 140         dev->max_linkrate = port->linkrate;
 141         dev->pathways = port->num_phys;
 142         memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
 143         memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 144         memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 145         port->disc.max_level = 0;
 146         sas_device_set_phy(dev, port->port);
 147
 148         dev->rphy = rphy;
 149         get_device(&dev->rphy->dev);
 150
 151         if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
 152                 list_add_tail(&dev->disco_list_node, &port->disco_list);
 153         else {
 154                 spin_lock_irq(&port->dev_list_lock);
 155                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 156                 spin_unlock_irq(&port->dev_list_lock);
 157         }
 158
 159         spin_lock_irq(&port->phy_list_lock);
 160         list_for_each_entry(phy, &port->phy_list, port_phy_el)
 161                 sas_phy_set_target(phy, dev);
 162         spin_unlock_irq(&port->phy_list_lock);
 163
 164         return 0;
 165 }
 166
 167 /* ---------- Discover and Revalidate ---------- */
 168
 169 int sas_notify_lldd_dev_found(struct domain_device *dev)
 170 {
 171         int res = 0;
 172         struct sas_ha_struct *sas_ha = dev->port->ha;
 173         struct Scsi_Host *shost = sas_ha->core.shost;
 174         struct sas_internal *i = to_sas_internal(shost->transportt);
 175
 176         if (!i->dft->lldd_dev_found)
 177                 return 0;
 178
 179         res = i->dft->lldd_dev_found(dev);
 180         if (res) {
 181                 pr_warn("driver on host %s cannot handle device %016llx, error:%d\n",
 182                         dev_name(sas_ha->dev),
 183                         SAS_ADDR(dev->sas_addr), res);
 184                 return res;
 185         }
 186         set_bit(SAS_DEV_FOUND, &dev->state);
 187         kref_get(&dev->kref);
 188         return 0;
 189 }
 190
 191
 192 void sas_notify_lldd_dev_gone(struct domain_device *dev)
 193 {
 194         struct sas_ha_struct *sas_ha = dev->port->ha;
 195         struct Scsi_Host *shost = sas_ha->core.shost;
 196         struct sas_internal *i = to_sas_internal(shost->transportt);
 197
 198         if (!i->dft->lldd_dev_gone)
 199                 return;
 200
 201         if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
 202                 i->dft->lldd_dev_gone(dev);
 203                 sas_put_device(dev);
 204         }
 205 }
 206
 207 static void sas_probe_devices(struct asd_sas_port *port)
 208 {
 209         struct domain_device *dev, *n;
 210
 211         /* devices must be domain members before link recovery and probe */
 212         list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 213                 spin_lock_irq(&port->dev_list_lock);
 214                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 215                 spin_unlock_irq(&port->dev_list_lock);
 216         }
 217
 218         sas_probe_sata(port);
 219
 220         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
 221                 int err;
 222
 223                 err = sas_rphy_add(dev->rphy);
 224                 if (err)
 225                         sas_fail_probe(dev, __func__, err);
 226                 else
 227                         list_del_init(&dev->disco_list_node);
 228         }
 229 }
 230
 231 static void sas_suspend_devices(struct work_struct *work)
 232 {
 233         struct asd_sas_phy *phy;
 234         struct domain_device *dev;
 235         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 236         struct asd_sas_port *port = ev->port;
 237         struct Scsi_Host *shost = port->ha->core.shost;
 238         struct sas_internal *si = to_sas_internal(shost->transportt);
 239
 240         clear_bit(DISCE_SUSPEND, &port->disc.pending);
 241
 242         sas_suspend_sata(port);
 243
 244         /* lldd is free to forget the domain_device across the
 245          * suspension, we force the issue here to keep the reference
 246          * counts aligned
 247          */
 248         list_for_each_entry(dev, &port->dev_list, dev_list_node)
 249                 sas_notify_lldd_dev_gone(dev);
 250
 251         /* we are suspending, so we know events are disabled and
 252          * phy_list is not being mutated
 253          */
 254         list_for_each_entry(phy, &port->phy_list, port_phy_el) {
 255                 if (si->dft->lldd_port_deformed)
 256                         si->dft->lldd_port_deformed(phy);
 257                 phy->suspended = 1;
 258                 port->suspended = 1;
 259         }
 260 }
 261
 262 static void sas_resume_devices(struct work_struct *work)
 263 {
 264         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 265         struct asd_sas_port *port = ev->port;
 266
 267         clear_bit(DISCE_RESUME, &port->disc.pending);
 268
 269         sas_resume_sata(port);
 270 }
 271
 272 /**
 273  * sas_discover_end_dev - discover an end device (SSP, etc)
 274  * @dev: pointer to domain device of interest
 275  *
 276  * See comment in sas_discover_sata().
 277  */
 278 int sas_discover_end_dev(struct domain_device *dev)
 279 {
 280         return sas_notify_lldd_dev_found(dev);
 281 }
 282
 283 /* ---------- Device registration and unregistration ---------- */
 284
 285 void sas_free_device(struct kref *kref)
 286 {
 287         struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 288
 289         put_device(&dev->rphy->dev);
 290         dev->rphy = NULL;
 291
 292         if (dev->parent)
 293                 sas_put_device(dev->parent);
 294
 295         sas_port_put_phy(dev->phy);
 296         dev->phy = NULL;
 297
 298         /* remove the phys and ports, everything else should be gone */
 299         if (dev_is_expander(dev->dev_type))
 300                 kfree(dev->ex_dev.ex_phy);
 301
 302         if (dev_is_sata(dev) && dev->sata_dev.ap) {
 303                 ata_sas_tport_delete(dev->sata_dev.ap);
 304                 ata_sas_port_destroy(dev->sata_dev.ap);
 305                 ata_host_put(dev->sata_dev.ata_host);
 306                 dev->sata_dev.ata_host = NULL;
 307                 dev->sata_dev.ap = NULL;
 308         }
 309
 310         kfree(dev);
 311 }
 312
 313 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 314 {
 315         struct sas_ha_struct *ha = port->ha;
 316
 317         sas_notify_lldd_dev_gone(dev);
 318         if (!dev->parent)
 319                 dev->port->port_dev = NULL;
 320         else
 321                 list_del_init(&dev->siblings);
 322
 323         spin_lock_irq(&port->dev_list_lock);
 324         list_del_init(&dev->dev_list_node);
 325         if (dev_is_sata(dev))
 326                 sas_ata_end_eh(dev->sata_dev.ap);
 327         spin_unlock_irq(&port->dev_list_lock);
 328
 329         spin_lock_irq(&ha->lock);
 330         if (dev->dev_type == SAS_END_DEVICE &&
 331             !list_empty(&dev->ssp_dev.eh_list_node)) {
 332                 list_del_init(&dev->ssp_dev.eh_list_node);
 333                 ha->eh_active--;
 334         }
 335         spin_unlock_irq(&ha->lock);
 336
 337         sas_put_device(dev);
 338 }
 339
 340 void sas_destruct_devices(struct asd_sas_port *port)
 341 {
 342         struct domain_device *dev, *n;
 343
 344         list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 345                 list_del_init(&dev->disco_list_node);
 346
 347                 sas_remove_children(&dev->rphy->dev);
 348                 sas_rphy_delete(dev->rphy);
 349                 sas_unregister_common_dev(port, dev);
 350         }
 351 }
 352
 353 static void sas_destruct_ports(struct asd_sas_port *port)
 354 {
 355         struct sas_port *sas_port, *p;
 356
 357         list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 358                 list_del_init(&sas_port->del_list);
 359                 sas_port_delete(sas_port);
 360         }
 361 }
 362
 363 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 364 {
 365         if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 366             !list_empty(&dev->disco_list_node)) {
 367                 /* this rphy never saw sas_rphy_add */
 368                 list_del_init(&dev->disco_list_node);
 369                 sas_rphy_free(dev->rphy);
 370                 sas_unregister_common_dev(port, dev);
 371                 return;
 372         }
 373
 374         if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 375                 sas_rphy_unlink(dev->rphy);
 376                 list_move_tail(&dev->disco_list_node, &port->destroy_list);
 377         }
 378 }
 379
 380 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 381 {
 382         struct domain_device *dev, *n;
 383
 384         list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 385                 if (gone)
 386                         set_bit(SAS_DEV_GONE, &dev->state);
 387                 sas_unregister_dev(port, dev);
 388         }
 389
 390         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 391                 sas_unregister_dev(port, dev);
 392
 393         port->port->rphy = NULL;
 394
 395 }
 396
 397 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 398 {
 399         struct sas_ha_struct *ha;
 400         struct sas_phy *new_phy;
 401
 402         if (!dev)
 403                 return;
 404
 405         ha = dev->port->ha;
 406         new_phy = sas_port_get_phy(port);
 407
 408         /* pin and record last seen phy */
 409         spin_lock_irq(&ha->phy_port_lock);
 410         if (new_phy) {
 411                 sas_port_put_phy(dev->phy);
 412                 dev->phy = new_phy;
 413         }
 414         spin_unlock_irq(&ha->phy_port_lock);
 415 }
 416
 417 /* ---------- Discovery and Revalidation ---------- */
 418
 419 /**
 420  * sas_discover_domain - discover the domain
 421  * @work: work structure embedded in port domain device.
 422  *
 423  * NOTE: this process _must_ quit (return) as soon as any connection
 424  * errors are encountered.  Connection recovery is done elsewhere.
 425  * Discover process only interrogates devices in order to discover the
 426  * domain.
 427  */
 428 static void sas_discover_domain(struct work_struct *work)
 429 {
 430         struct domain_device *dev;
 431         int error = 0;
 432         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 433         struct asd_sas_port *port = ev->port;
 434
 435         clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 436
 437         if (port->port_dev)
 438                 return;
 439
 440         error = sas_get_port_device(port);
 441         if (error)
 442                 return;
 443         dev = port->port_dev;
 444
 445         pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 446                  task_pid_nr(current));
 447
 448         switch (dev->dev_type) {
 449         case SAS_END_DEVICE:
 450                 error = sas_discover_end_dev(dev);
 451                 break;
 452         case SAS_EDGE_EXPANDER_DEVICE:
 453         case SAS_FANOUT_EXPANDER_DEVICE:
 454                 error = sas_discover_root_expander(dev);
 455                 break;
 456         case SAS_SATA_DEV:
 457         case SAS_SATA_PM:
 458 #ifdef CONFIG_SCSI_SAS_ATA
 459                 error = sas_discover_sata(dev);
 460                 break;
 461 #else
 462                 pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 463                 fallthrough;
 464 #endif
 465                 /* Fall through - only for the #else condition above. */
 466         default:
 467                 error = -ENXIO;
 468                 pr_err("unhandled device %d\n", dev->dev_type);
 469                 break;
 470         }
 471
 472         if (error) {
 473                 sas_rphy_free(dev->rphy);
 474                 list_del_init(&dev->disco_list_node);
 475                 spin_lock_irq(&port->dev_list_lock);
 476                 list_del_init(&dev->dev_list_node);
 477                 spin_unlock_irq(&port->dev_list_lock);
 478
 479                 sas_put_device(dev);
 480                 port->port_dev = NULL;
 481         }
 482
 483         sas_probe_devices(port);
 484
 485         pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 486                  task_pid_nr(current), error);
 487 }
 488
 489 static void sas_revalidate_domain(struct work_struct *work)
 490 {
 491         int res = 0;
 492         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 493         struct asd_sas_port *port = ev->port;
 494         struct sas_ha_struct *ha = port->ha;
 495         struct domain_device *ddev = port->port_dev;
 496
 497         /* prevent revalidation from finding sata links in recovery */
 498         mutex_lock(&ha->disco_mutex);
 499         if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 500                 pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
 501                          port->id, task_pid_nr(current));
 502                 goto out;
 503         }
 504
 505         clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 506
 507         pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 508                  task_pid_nr(current));
 509
 510         if (ddev && dev_is_expander(ddev->dev_type))
 511                 res = sas_ex_revalidate_domain(ddev);
 512
 513         pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 514                  port->id, task_pid_nr(current), res);
 515  out:
 516         mutex_unlock(&ha->disco_mutex);
 517
 518         sas_destruct_devices(port);
 519         sas_destruct_ports(port);
 520         sas_probe_devices(port);
 521 }
 522
 523 /* ---------- Events ---------- */
 524
 525 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 526 {
 527         /* chained work is not subject to SA_HA_DRAINING or
 528          * SAS_HA_REGISTERED, because it is either submitted in the
 529          * workqueue, or known to be submitted from a context that is
 530          * not racing against draining
 531          */
 532         queue_work(ha->disco_q, &sw->work);
 533 }
 534
 535 static void sas_chain_event(int event, unsigned long *pending,
 536                             struct sas_work *sw,
 537                             struct sas_ha_struct *ha)
 538 {
 539         if (!test_and_set_bit(event, pending)) {
 540                 unsigned long flags;
 541
 542                 spin_lock_irqsave(&ha->lock, flags);
 543                 sas_chain_work(ha, sw);
 544                 spin_unlock_irqrestore(&ha->lock, flags);
 545         }
 546 }
 547
 548 void sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 549 {
 550         struct sas_discovery *disc;
 551
 552         if (!port)
 553                 return;
 554         disc = &port->disc;
 555
 556         BUG_ON(ev >= DISC_NUM_EVENTS);
 557
 558         sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 559 }
 560
 561 /**
 562  * sas_init_disc - initialize the discovery struct in the port
 563  * @disc: port discovery structure
 564  * @port: pointer to struct port
 565  *
 566  * Called when the ports are being initialized.
 567  */
 568 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 569 {
 570         int i;
 571
 572         static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 573                 [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 574                 [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 575                 [DISCE_SUSPEND] = sas_suspend_devices,
 576                 [DISCE_RESUME] = sas_resume_devices,
 577         };
 578
 579         disc->pending = 0;
 580         for (i = 0; i < DISC_NUM_EVENTS; i++) {
 581                 INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 582                 disc->disc_work[i].port = port;
 583         }
 584 }