root/drivers/scsi/libsas/sas_discover.c

DEFINITIONS

1. sas_init_dev
2. sas_get_port_device
3. sas_notify_lldd_dev_found
4. sas_notify_lldd_dev_gone
5. sas_probe_devices
6. sas_suspend_devices
7. sas_resume_devices
8. sas_discover_end_dev
9. sas_free_device
10. sas_unregister_common_dev
11. sas_destruct_devices
12. sas_destruct_ports
13. sas_unregister_dev
14. sas_unregister_domain_devices
15. sas_device_set_phy
16. sas_discover_domain
17. sas_revalidate_domain
18. sas_chain_work
19. sas_chain_event
20. sas_discover_event
21. sas_init_disc

   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 <luben_tuikov@adaptec.com>
   7  */
   8 
   9 #include <linux/scatterlist.h>
  10 #include <linux/slab.h>
  11 #include <linux/async.h>
  12 #include <scsi/scsi_host.h>
  13 #include <scsi/scsi_eh.h>
  14 #include "sas_internal.h"
  15 
  16 #include <scsi/scsi_transport.h>
  17 #include <scsi/scsi_transport_sas.h>
  18 #include <scsi/sas_ata.h>
  19 #include "../scsi_sas_internal.h"
  20 
  21 /* ---------- Basic task processing for discovery purposes ---------- */
  22 
  23 void sas_init_dev(struct domain_device *dev)
  24 {
  25         switch (dev->dev_type) {
  26         case SAS_END_DEVICE:
  27                 INIT_LIST_HEAD(&dev->ssp_dev.eh_list_node);
  28                 break;
  29         case SAS_EDGE_EXPANDER_DEVICE:
  30         case SAS_FANOUT_EXPANDER_DEVICE:
  31                 INIT_LIST_HEAD(&dev->ex_dev.children);
  32                 mutex_init(&dev->ex_dev.cmd_mutex);
  33                 break;
  34         default:
  35                 break;
  36         }
  37 }
  38 
  39 /* ---------- Domain device discovery ---------- */
  40 
  41 /**
  42  * sas_get_port_device - Discover devices which caused port creation
  43  * @port: pointer to struct sas_port of interest
  44  *
  45  * Devices directly attached to a HA port, have no parent.  This is
  46  * how we know they are (domain) "root" devices.  All other devices
  47  * do, and should have their "parent" pointer set appropriately as
  48  * soon as a child device is discovered.
  49  */
  50 static int sas_get_port_device(struct asd_sas_port *port)
  51 {
  52         struct asd_sas_phy *phy;
  53         struct sas_rphy *rphy;
  54         struct domain_device *dev;
  55         int rc = -ENODEV;
  56 
  57         dev = sas_alloc_device();
  58         if (!dev)
  59                 return -ENOMEM;
  60 
  61         spin_lock_irq(&port->phy_list_lock);
  62         if (list_empty(&port->phy_list)) {
  63                 spin_unlock_irq(&port->phy_list_lock);
  64                 sas_put_device(dev);
  65                 return -ENODEV;
  66         }
  67         phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
  68         spin_lock(&phy->frame_rcvd_lock);
  69         memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
  70                                              (size_t)phy->frame_rcvd_size));
  71         spin_unlock(&phy->frame_rcvd_lock);
  72         spin_unlock_irq(&port->phy_list_lock);
  73 
  74         if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
  75                 struct dev_to_host_fis *fis =
  76                         (struct dev_to_host_fis *) dev->frame_rcvd;
  77                 if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
  78                     fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
  79                     && (fis->device & ~0x10) == 0)
  80                         dev->dev_type = SAS_SATA_PM;
  81                 else
  82                         dev->dev_type = SAS_SATA_DEV;
  83                 dev->tproto = SAS_PROTOCOL_SATA;
  84         } else if (port->oob_mode == SAS_OOB_MODE) {
  85                 struct sas_identify_frame *id =
  86                         (struct sas_identify_frame *) dev->frame_rcvd;
  87                 dev->dev_type = id->dev_type;
  88                 dev->iproto = id->initiator_bits;
  89                 dev->tproto = id->target_bits;
  90         } else {
  91                 /* If the oob mode is OOB_NOT_CONNECTED, the port is
  92                  * disconnected due to race with PHY down. We cannot
  93                  * continue to discover this port
  94                  */
  95                 sas_put_device(dev);
  96                 pr_warn("Port %016llx is disconnected when discovering\n",
  97                         SAS_ADDR(port->attached_sas_addr));
  98                 return -ENODEV;
  99         }
 100 
 101         sas_init_dev(dev);
 102 
 103         dev->port = port;
 104         switch (dev->dev_type) {
 105         case SAS_SATA_DEV:
 106                 rc = sas_ata_init(dev);
 107                 if (rc) {
 108                         rphy = NULL;
 109                         break;
 110                 }
 111                 /* fall through */
 112         case SAS_END_DEVICE:
 113                 rphy = sas_end_device_alloc(port->port);
 114                 break;
 115         case SAS_EDGE_EXPANDER_DEVICE:
 116                 rphy = sas_expander_alloc(port->port,
 117                                           SAS_EDGE_EXPANDER_DEVICE);
 118                 break;
 119         case SAS_FANOUT_EXPANDER_DEVICE:
 120                 rphy = sas_expander_alloc(port->port,
 121                                           SAS_FANOUT_EXPANDER_DEVICE);
 122                 break;
 123         default:
 124                 pr_warn("ERROR: Unidentified device type %d\n", dev->dev_type);
 125                 rphy = NULL;
 126                 break;
 127         }
 128 
 129         if (!rphy) {
 130                 sas_put_device(dev);
 131                 return rc;
 132         }
 133 
 134         rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
 135         memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
 136         sas_fill_in_rphy(dev, rphy);
 137         sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 138         port->port_dev = dev;
 139         dev->linkrate = port->linkrate;
 140         dev->min_linkrate = port->linkrate;
 141         dev->max_linkrate = port->linkrate;
 142         dev->pathways = port->num_phys;
 143         memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
 144         memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 145         memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 146         port->disc.max_level = 0;
 147         sas_device_set_phy(dev, port->port);
 148 
 149         dev->rphy = rphy;
 150         get_device(&dev->rphy->dev);
 151 
 152         if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
 153                 list_add_tail(&dev->disco_list_node, &port->disco_list);
 154         else {
 155                 spin_lock_irq(&port->dev_list_lock);
 156                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 157                 spin_unlock_irq(&port->dev_list_lock);
 158         }
 159 
 160         spin_lock_irq(&port->phy_list_lock);
 161         list_for_each_entry(phy, &port->phy_list, port_phy_el)
 162                 sas_phy_set_target(phy, dev);
 163         spin_unlock_irq(&port->phy_list_lock);
 164 
 165         return 0;
 166 }
 167 
 168 /* ---------- Discover and Revalidate ---------- */
 169 
 170 int sas_notify_lldd_dev_found(struct domain_device *dev)
 171 {
 172         int res = 0;
 173         struct sas_ha_struct *sas_ha = dev->port->ha;
 174         struct Scsi_Host *shost = sas_ha->core.shost;
 175         struct sas_internal *i = to_sas_internal(shost->transportt);
 176 
 177         if (!i->dft->lldd_dev_found)
 178                 return 0;
 179 
 180         res = i->dft->lldd_dev_found(dev);
 181         if (res) {
 182                 pr_warn("driver on host %s cannot handle device %llx, error:%d\n",
 183                         dev_name(sas_ha->dev),
 184                         SAS_ADDR(dev->sas_addr), res);
 185         }
 186         set_bit(SAS_DEV_FOUND, &dev->state);
 187         kref_get(&dev->kref);
 188         return res;
 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         int res;
 281 
 282         res = sas_notify_lldd_dev_found(dev);
 283         if (res)
 284                 return res;
 285 
 286         return 0;
 287 }
 288 
 289 /* ---------- Device registration and unregistration ---------- */
 290 
 291 void sas_free_device(struct kref *kref)
 292 {
 293         struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 294 
 295         put_device(&dev->rphy->dev);
 296         dev->rphy = NULL;
 297 
 298         if (dev->parent)
 299                 sas_put_device(dev->parent);
 300 
 301         sas_port_put_phy(dev->phy);
 302         dev->phy = NULL;
 303 
 304         /* remove the phys and ports, everything else should be gone */
 305         if (dev_is_expander(dev->dev_type))
 306                 kfree(dev->ex_dev.ex_phy);
 307 
 308         if (dev_is_sata(dev) && dev->sata_dev.ap) {
 309                 ata_sas_tport_delete(dev->sata_dev.ap);
 310                 ata_sas_port_destroy(dev->sata_dev.ap);
 311                 ata_host_put(dev->sata_dev.ata_host);
 312                 dev->sata_dev.ata_host = NULL;
 313                 dev->sata_dev.ap = NULL;
 314         }
 315 
 316         kfree(dev);
 317 }
 318 
 319 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 320 {
 321         struct sas_ha_struct *ha = port->ha;
 322 
 323         sas_notify_lldd_dev_gone(dev);
 324         if (!dev->parent)
 325                 dev->port->port_dev = NULL;
 326         else
 327                 list_del_init(&dev->siblings);
 328 
 329         spin_lock_irq(&port->dev_list_lock);
 330         list_del_init(&dev->dev_list_node);
 331         if (dev_is_sata(dev))
 332                 sas_ata_end_eh(dev->sata_dev.ap);
 333         spin_unlock_irq(&port->dev_list_lock);
 334 
 335         spin_lock_irq(&ha->lock);
 336         if (dev->dev_type == SAS_END_DEVICE &&
 337             !list_empty(&dev->ssp_dev.eh_list_node)) {
 338                 list_del_init(&dev->ssp_dev.eh_list_node);
 339                 ha->eh_active--;
 340         }
 341         spin_unlock_irq(&ha->lock);
 342 
 343         sas_put_device(dev);
 344 }
 345 
 346 void sas_destruct_devices(struct asd_sas_port *port)
 347 {
 348         struct domain_device *dev, *n;
 349 
 350         list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 351                 list_del_init(&dev->disco_list_node);
 352 
 353                 sas_remove_children(&dev->rphy->dev);
 354                 sas_rphy_delete(dev->rphy);
 355                 sas_unregister_common_dev(port, dev);
 356         }
 357 }
 358 
 359 static void sas_destruct_ports(struct asd_sas_port *port)
 360 {
 361         struct sas_port *sas_port, *p;
 362 
 363         list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 364                 list_del_init(&sas_port->del_list);
 365                 sas_port_delete(sas_port);
 366         }
 367 }
 368 
 369 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 370 {
 371         if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 372             !list_empty(&dev->disco_list_node)) {
 373                 /* this rphy never saw sas_rphy_add */
 374                 list_del_init(&dev->disco_list_node);
 375                 sas_rphy_free(dev->rphy);
 376                 sas_unregister_common_dev(port, dev);
 377                 return;
 378         }
 379 
 380         if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 381                 sas_rphy_unlink(dev->rphy);
 382                 list_move_tail(&dev->disco_list_node, &port->destroy_list);
 383         }
 384 }
 385 
 386 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 387 {
 388         struct domain_device *dev, *n;
 389 
 390         list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 391                 if (gone)
 392                         set_bit(SAS_DEV_GONE, &dev->state);
 393                 sas_unregister_dev(port, dev);
 394         }
 395 
 396         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 397                 sas_unregister_dev(port, dev);
 398 
 399         port->port->rphy = NULL;
 400 
 401 }
 402 
 403 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 404 {
 405         struct sas_ha_struct *ha;
 406         struct sas_phy *new_phy;
 407 
 408         if (!dev)
 409                 return;
 410 
 411         ha = dev->port->ha;
 412         new_phy = sas_port_get_phy(port);
 413 
 414         /* pin and record last seen phy */
 415         spin_lock_irq(&ha->phy_port_lock);
 416         if (new_phy) {
 417                 sas_port_put_phy(dev->phy);
 418                 dev->phy = new_phy;
 419         }
 420         spin_unlock_irq(&ha->phy_port_lock);
 421 }
 422 
 423 /* ---------- Discovery and Revalidation ---------- */
 424 
 425 /**
 426  * sas_discover_domain - discover the domain
 427  * @work: work structure embedded in port domain device.
 428  *
 429  * NOTE: this process _must_ quit (return) as soon as any connection
 430  * errors are encountered.  Connection recovery is done elsewhere.
 431  * Discover process only interrogates devices in order to discover the
 432  * domain.
 433  */
 434 static void sas_discover_domain(struct work_struct *work)
 435 {
 436         struct domain_device *dev;
 437         int error = 0;
 438         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 439         struct asd_sas_port *port = ev->port;
 440 
 441         clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 442 
 443         if (port->port_dev)
 444                 return;
 445 
 446         error = sas_get_port_device(port);
 447         if (error)
 448                 return;
 449         dev = port->port_dev;
 450 
 451         pr_debug("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 452                  task_pid_nr(current));
 453 
 454         switch (dev->dev_type) {
 455         case SAS_END_DEVICE:
 456                 error = sas_discover_end_dev(dev);
 457                 break;
 458         case SAS_EDGE_EXPANDER_DEVICE:
 459         case SAS_FANOUT_EXPANDER_DEVICE:
 460                 error = sas_discover_root_expander(dev);
 461                 break;
 462         case SAS_SATA_DEV:
 463         case SAS_SATA_PM:
 464 #ifdef CONFIG_SCSI_SAS_ATA
 465                 error = sas_discover_sata(dev);
 466                 break;
 467 #else
 468                 pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 469                 /* Fall through */
 470 #endif
 471                 /* Fall through - only for the #else condition above. */
 472         default:
 473                 error = -ENXIO;
 474                 pr_err("unhandled device %d\n", dev->dev_type);
 475                 break;
 476         }
 477 
 478         if (error) {
 479                 sas_rphy_free(dev->rphy);
 480                 list_del_init(&dev->disco_list_node);
 481                 spin_lock_irq(&port->dev_list_lock);
 482                 list_del_init(&dev->dev_list_node);
 483                 spin_unlock_irq(&port->dev_list_lock);
 484 
 485                 sas_put_device(dev);
 486                 port->port_dev = NULL;
 487         }
 488 
 489         sas_probe_devices(port);
 490 
 491         pr_debug("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 492                  task_pid_nr(current), error);
 493 }
 494 
 495 static void sas_revalidate_domain(struct work_struct *work)
 496 {
 497         int res = 0;
 498         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 499         struct asd_sas_port *port = ev->port;
 500         struct sas_ha_struct *ha = port->ha;
 501         struct domain_device *ddev = port->port_dev;
 502 
 503         /* prevent revalidation from finding sata links in recovery */
 504         mutex_lock(&ha->disco_mutex);
 505         if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 506                 pr_debug("REVALIDATION DEFERRED on port %d, pid:%d\n",
 507                          port->id, task_pid_nr(current));
 508                 goto out;
 509         }
 510 
 511         clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 512 
 513         pr_debug("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 514                  task_pid_nr(current));
 515 
 516         if (ddev && dev_is_expander(ddev->dev_type))
 517                 res = sas_ex_revalidate_domain(ddev);
 518 
 519         pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 520                  port->id, task_pid_nr(current), res);
 521  out:
 522         mutex_unlock(&ha->disco_mutex);
 523 
 524         sas_destruct_devices(port);
 525         sas_destruct_ports(port);
 526         sas_probe_devices(port);
 527 }
 528 
 529 /* ---------- Events ---------- */
 530 
 531 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 532 {
 533         /* chained work is not subject to SA_HA_DRAINING or
 534          * SAS_HA_REGISTERED, because it is either submitted in the
 535          * workqueue, or known to be submitted from a context that is
 536          * not racing against draining
 537          */
 538         queue_work(ha->disco_q, &sw->work);
 539 }
 540 
 541 static void sas_chain_event(int event, unsigned long *pending,
 542                             struct sas_work *sw,
 543                             struct sas_ha_struct *ha)
 544 {
 545         if (!test_and_set_bit(event, pending)) {
 546                 unsigned long flags;
 547 
 548                 spin_lock_irqsave(&ha->lock, flags);
 549                 sas_chain_work(ha, sw);
 550                 spin_unlock_irqrestore(&ha->lock, flags);
 551         }
 552 }
 553 
 554 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 555 {
 556         struct sas_discovery *disc;
 557 
 558         if (!port)
 559                 return 0;
 560         disc = &port->disc;
 561 
 562         BUG_ON(ev >= DISC_NUM_EVENTS);
 563 
 564         sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 565 
 566         return 0;
 567 }
 568 
 569 /**
 570  * sas_init_disc - initialize the discovery struct in the port
 571  * @disc: port discovery structure
 572  * @port: pointer to struct port
 573  *
 574  * Called when the ports are being initialized.
 575  */
 576 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 577 {
 578         int i;
 579 
 580         static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 581                 [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 582                 [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 583                 [DISCE_SUSPEND] = sas_suspend_devices,
 584                 [DISCE_RESUME] = sas_resume_devices,
 585         };
 586 
 587         disc->pending = 0;
 588         for (i = 0; i < DISC_NUM_EVENTS; i++) {
 589                 INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 590                 disc->disc_work[i].port = port;
 591         }
 592 }