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 if (port->oob_mode == SAS_OOB_MODE) {
 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         } else {
 107                 /* If the oob mode is OOB_NOT_CONNECTED, the port is
 108                  * disconnected due to race with PHY down. We cannot
 109                  * continue to discover this port
 110                  */
 111                 sas_put_device(dev);
 112                 pr_warn("Port %016llx is disconnected when discovering\n",
 113                         SAS_ADDR(port->attached_sas_addr));
 114                 return -ENODEV;
 115         }
 116
 117         sas_init_dev(dev);
 118
 119         dev->port = port;
 120         switch (dev->dev_type) {
 121         case SAS_SATA_DEV:
 122                 rc = sas_ata_init(dev);
 123                 if (rc) {
 124                         rphy = NULL;
 125                         break;
 126                 }
 127                 /* fall through */
 128         case SAS_END_DEVICE:
 129                 rphy = sas_end_device_alloc(port->port);
 130                 break;
 131         case SAS_EDGE_EXPANDER_DEVICE:
 132                 rphy = sas_expander_alloc(port->port,
 133                                           SAS_EDGE_EXPANDER_DEVICE);
 134                 break;
 135         case SAS_FANOUT_EXPANDER_DEVICE:
 136                 rphy = sas_expander_alloc(port->port,
 137                                           SAS_FANOUT_EXPANDER_DEVICE);
 138                 break;
 139         default:
 140                 printk("ERROR: Unidentified device type %d\n", dev->dev_type);
 141                 rphy = NULL;
 142                 break;
 143         }
 144
 145         if (!rphy) {
 146                 sas_put_device(dev);
 147                 return rc;
 148         }
 149
 150         rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
 151         memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
 152         sas_fill_in_rphy(dev, rphy);
 153         sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 154         port->port_dev = dev;
 155         dev->linkrate = port->linkrate;
 156         dev->min_linkrate = port->linkrate;
 157         dev->max_linkrate = port->linkrate;
 158         dev->pathways = port->num_phys;
 159         memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
 160         memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 161         memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 162         port->disc.max_level = 0;
 163         sas_device_set_phy(dev, port->port);
 164
 165         dev->rphy = rphy;
 166         get_device(&dev->rphy->dev);
 167
 168         if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEVICE)
 169                 list_add_tail(&dev->disco_list_node, &port->disco_list);
 170         else {
 171                 spin_lock_irq(&port->dev_list_lock);
 172                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 173                 spin_unlock_irq(&port->dev_list_lock);
 174         }
 175
 176         spin_lock_irq(&port->phy_list_lock);
 177         list_for_each_entry(phy, &port->phy_list, port_phy_el)
 178                 sas_phy_set_target(phy, dev);
 179         spin_unlock_irq(&port->phy_list_lock);
 180
 181         return 0;
 182 }
 183
 184 /* ---------- Discover and Revalidate ---------- */
 185
 186 int sas_notify_lldd_dev_found(struct domain_device *dev)
 187 {
 188         int res = 0;
 189         struct sas_ha_struct *sas_ha = dev->port->ha;
 190         struct Scsi_Host *shost = sas_ha->core.shost;
 191         struct sas_internal *i = to_sas_internal(shost->transportt);
 192
 193         if (!i->dft->lldd_dev_found)
 194                 return 0;
 195
 196         res = i->dft->lldd_dev_found(dev);
 197         if (res) {
 198                 printk("sas: driver on pcidev %s cannot handle "
 199                        "device %llx, error:%d\n",
 200                        dev_name(sas_ha->dev),
 201                        SAS_ADDR(dev->sas_addr), res);
 202         }
 203         set_bit(SAS_DEV_FOUND, &dev->state);
 204         kref_get(&dev->kref);
 205         return res;
 206 }
 207
 208
 209 void sas_notify_lldd_dev_gone(struct domain_device *dev)
 210 {
 211         struct sas_ha_struct *sas_ha = dev->port->ha;
 212         struct Scsi_Host *shost = sas_ha->core.shost;
 213         struct sas_internal *i = to_sas_internal(shost->transportt);
 214
 215         if (!i->dft->lldd_dev_gone)
 216                 return;
 217
 218         if (test_and_clear_bit(SAS_DEV_FOUND, &dev->state)) {
 219                 i->dft->lldd_dev_gone(dev);
 220                 sas_put_device(dev);
 221         }
 222 }
 223
 224 static void sas_probe_devices(struct asd_sas_port *port)
 225 {
 226         struct domain_device *dev, *n;
 227
 228         /* devices must be domain members before link recovery and probe */
 229         list_for_each_entry(dev, &port->disco_list, disco_list_node) {
 230                 spin_lock_irq(&port->dev_list_lock);
 231                 list_add_tail(&dev->dev_list_node, &port->dev_list);
 232                 spin_unlock_irq(&port->dev_list_lock);
 233         }
 234
 235         sas_probe_sata(port);
 236
 237         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
 238                 int err;
 239
 240                 err = sas_rphy_add(dev->rphy);
 241                 if (err)
 242                         sas_fail_probe(dev, __func__, err);
 243                 else
 244                         list_del_init(&dev->disco_list_node);
 245         }
 246 }
 247
 248 static void sas_suspend_devices(struct work_struct *work)
 249 {
 250         struct asd_sas_phy *phy;
 251         struct domain_device *dev;
 252         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 253         struct asd_sas_port *port = ev->port;
 254         struct Scsi_Host *shost = port->ha->core.shost;
 255         struct sas_internal *si = to_sas_internal(shost->transportt);
 256
 257         clear_bit(DISCE_SUSPEND, &port->disc.pending);
 258
 259         sas_suspend_sata(port);
 260
 261         /* lldd is free to forget the domain_device across the
 262          * suspension, we force the issue here to keep the reference
 263          * counts aligned
 264          */
 265         list_for_each_entry(dev, &port->dev_list, dev_list_node)
 266                 sas_notify_lldd_dev_gone(dev);
 267
 268         /* we are suspending, so we know events are disabled and
 269          * phy_list is not being mutated
 270          */
 271         list_for_each_entry(phy, &port->phy_list, port_phy_el) {
 272                 if (si->dft->lldd_port_formed)
 273                         si->dft->lldd_port_deformed(phy);
 274                 phy->suspended = 1;
 275                 port->suspended = 1;
 276         }
 277 }
 278
 279 static void sas_resume_devices(struct work_struct *work)
 280 {
 281         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 282         struct asd_sas_port *port = ev->port;
 283
 284         clear_bit(DISCE_RESUME, &port->disc.pending);
 285
 286         sas_resume_sata(port);
 287 }
 288
 289 /**
 290  * sas_discover_end_dev - discover an end device (SSP, etc)
 291  * @dev: pointer to domain device of interest
 292  *
 293  * See comment in sas_discover_sata().
 294  */
 295 int sas_discover_end_dev(struct domain_device *dev)
 296 {
 297         int res;
 298
 299         res = sas_notify_lldd_dev_found(dev);
 300         if (res)
 301                 return res;
 302
 303         return 0;
 304 }
 305
 306 /* ---------- Device registration and unregistration ---------- */
 307
 308 void sas_free_device(struct kref *kref)
 309 {
 310         struct domain_device *dev = container_of(kref, typeof(*dev), kref);
 311
 312         put_device(&dev->rphy->dev);
 313         dev->rphy = NULL;
 314
 315         if (dev->parent)
 316                 sas_put_device(dev->parent);
 317
 318         sas_port_put_phy(dev->phy);
 319         dev->phy = NULL;
 320
 321         /* remove the phys and ports, everything else should be gone */
 322         if (dev->dev_type == SAS_EDGE_EXPANDER_DEVICE || dev->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
 323                 kfree(dev->ex_dev.ex_phy);
 324
 325         if (dev_is_sata(dev) && dev->sata_dev.ap) {
 326                 ata_sas_tport_delete(dev->sata_dev.ap);
 327                 ata_sas_port_destroy(dev->sata_dev.ap);
 328                 ata_host_put(dev->sata_dev.ata_host);
 329                 dev->sata_dev.ata_host = NULL;
 330                 dev->sata_dev.ap = NULL;
 331         }
 332
 333         kfree(dev);
 334 }
 335
 336 static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
 337 {
 338         struct sas_ha_struct *ha = port->ha;
 339
 340         sas_notify_lldd_dev_gone(dev);
 341         if (!dev->parent)
 342                 dev->port->port_dev = NULL;
 343         else
 344                 list_del_init(&dev->siblings);
 345
 346         spin_lock_irq(&port->dev_list_lock);
 347         list_del_init(&dev->dev_list_node);
 348         if (dev_is_sata(dev))
 349                 sas_ata_end_eh(dev->sata_dev.ap);
 350         spin_unlock_irq(&port->dev_list_lock);
 351
 352         spin_lock_irq(&ha->lock);
 353         if (dev->dev_type == SAS_END_DEVICE &&
 354             !list_empty(&dev->ssp_dev.eh_list_node)) {
 355                 list_del_init(&dev->ssp_dev.eh_list_node);
 356                 ha->eh_active--;
 357         }
 358         spin_unlock_irq(&ha->lock);
 359
 360         sas_put_device(dev);
 361 }
 362
 363 void sas_destruct_devices(struct asd_sas_port *port)
 364 {
 365         struct domain_device *dev, *n;
 366
 367         list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
 368                 list_del_init(&dev->disco_list_node);
 369
 370                 sas_remove_children(&dev->rphy->dev);
 371                 sas_rphy_delete(dev->rphy);
 372                 sas_unregister_common_dev(port, dev);
 373         }
 374 }
 375
 376 static void sas_destruct_ports(struct asd_sas_port *port)
 377 {
 378         struct sas_port *sas_port, *p;
 379
 380         list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, del_list) {
 381                 list_del_init(&sas_port->del_list);
 382                 sas_port_delete(sas_port);
 383         }
 384 }
 385
 386 void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
 387 {
 388         if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
 389             !list_empty(&dev->disco_list_node)) {
 390                 /* this rphy never saw sas_rphy_add */
 391                 list_del_init(&dev->disco_list_node);
 392                 sas_rphy_free(dev->rphy);
 393                 sas_unregister_common_dev(port, dev);
 394                 return;
 395         }
 396
 397         if (!test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
 398                 sas_rphy_unlink(dev->rphy);
 399                 list_move_tail(&dev->disco_list_node, &port->destroy_list);
 400         }
 401 }
 402
 403 void sas_unregister_domain_devices(struct asd_sas_port *port, int gone)
 404 {
 405         struct domain_device *dev, *n;
 406
 407         list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node) {
 408                 if (gone)
 409                         set_bit(SAS_DEV_GONE, &dev->state);
 410                 sas_unregister_dev(port, dev);
 411         }
 412
 413         list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
 414                 sas_unregister_dev(port, dev);
 415
 416         port->port->rphy = NULL;
 417
 418 }
 419
 420 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
 421 {
 422         struct sas_ha_struct *ha;
 423         struct sas_phy *new_phy;
 424
 425         if (!dev)
 426                 return;
 427
 428         ha = dev->port->ha;
 429         new_phy = sas_port_get_phy(port);
 430
 431         /* pin and record last seen phy */
 432         spin_lock_irq(&ha->phy_port_lock);
 433         if (new_phy) {
 434                 sas_port_put_phy(dev->phy);
 435                 dev->phy = new_phy;
 436         }
 437         spin_unlock_irq(&ha->phy_port_lock);
 438 }
 439
 440 /* ---------- Discovery and Revalidation ---------- */
 441
 442 /**
 443  * sas_discover_domain - discover the domain
 444  * @work: work structure embedded in port domain device.
 445  *
 446  * NOTE: this process _must_ quit (return) as soon as any connection
 447  * errors are encountered.  Connection recovery is done elsewhere.
 448  * Discover process only interrogates devices in order to discover the
 449  * domain.
 450  */
 451 static void sas_discover_domain(struct work_struct *work)
 452 {
 453         struct domain_device *dev;
 454         int error = 0;
 455         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 456         struct asd_sas_port *port = ev->port;
 457
 458         clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 459
 460         if (port->port_dev)
 461                 return;
 462
 463         error = sas_get_port_device(port);
 464         if (error)
 465                 return;
 466         dev = port->port_dev;
 467
 468         SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
 469                     task_pid_nr(current));
 470
 471         switch (dev->dev_type) {
 472         case SAS_END_DEVICE:
 473                 error = sas_discover_end_dev(dev);
 474                 break;
 475         case SAS_EDGE_EXPANDER_DEVICE:
 476         case SAS_FANOUT_EXPANDER_DEVICE:
 477                 error = sas_discover_root_expander(dev);
 478                 break;
 479         case SAS_SATA_DEV:
 480         case SAS_SATA_PM:
 481 #ifdef CONFIG_SCSI_SAS_ATA
 482                 error = sas_discover_sata(dev);
 483                 break;
 484 #else
 485                 SAS_DPRINTK("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
 486                 /* Fall through */
 487 #endif
 488         default:
 489                 error = -ENXIO;
 490                 SAS_DPRINTK("unhandled device %d\n", dev->dev_type);
 491                 break;
 492         }
 493
 494         if (error) {
 495                 sas_rphy_free(dev->rphy);
 496                 list_del_init(&dev->disco_list_node);
 497                 spin_lock_irq(&port->dev_list_lock);
 498                 list_del_init(&dev->dev_list_node);
 499                 spin_unlock_irq(&port->dev_list_lock);
 500
 501                 sas_put_device(dev);
 502                 port->port_dev = NULL;
 503         }
 504
 505         sas_probe_devices(port);
 506
 507         SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
 508                     task_pid_nr(current), error);
 509 }
 510
 511 static void sas_revalidate_domain(struct work_struct *work)
 512 {
 513         int res = 0;
 514         struct sas_discovery_event *ev = to_sas_discovery_event(work);
 515         struct asd_sas_port *port = ev->port;
 516         struct sas_ha_struct *ha = port->ha;
 517         struct domain_device *ddev = port->port_dev;
 518
 519         /* prevent revalidation from finding sata links in recovery */
 520         mutex_lock(&ha->disco_mutex);
 521         if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 522                 SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
 523                             port->id, task_pid_nr(current));
 524                 goto out;
 525         }
 526
 527         clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 528
 529         SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
 530                     task_pid_nr(current));
 531
 532         if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
 533                      ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
 534                 res = sas_ex_revalidate_domain(ddev);
 535
 536         SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 537                     port->id, task_pid_nr(current), res);
 538  out:
 539         mutex_unlock(&ha->disco_mutex);
 540
 541         sas_destruct_devices(port);
 542         sas_destruct_ports(port);
 543         sas_probe_devices(port);
 544 }
 545
 546 /* ---------- Events ---------- */
 547
 548 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 549 {
 550         /* chained work is not subject to SA_HA_DRAINING or
 551          * SAS_HA_REGISTERED, because it is either submitted in the
 552          * workqueue, or known to be submitted from a context that is
 553          * not racing against draining
 554          */
 555         queue_work(ha->disco_q, &sw->work);
 556 }
 557
 558 static void sas_chain_event(int event, unsigned long *pending,
 559                             struct sas_work *sw,
 560                             struct sas_ha_struct *ha)
 561 {
 562         if (!test_and_set_bit(event, pending)) {
 563                 unsigned long flags;
 564
 565                 spin_lock_irqsave(&ha->lock, flags);
 566                 sas_chain_work(ha, sw);
 567                 spin_unlock_irqrestore(&ha->lock, flags);
 568         }
 569 }
 570
 571 int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 572 {
 573         struct sas_discovery *disc;
 574
 575         if (!port)
 576                 return 0;
 577         disc = &port->disc;
 578
 579         BUG_ON(ev >= DISC_NUM_EVENTS);
 580
 581         sas_chain_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 582
 583         return 0;
 584 }
 585
 586 /**
 587  * sas_init_disc - initialize the discovery struct in the port
 588  * @disc: port discovery structure
 589  * @port: pointer to struct port
 590  *
 591  * Called when the ports are being initialized.
 592  */
 593 void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 594 {
 595         int i;
 596
 597         static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 598                 [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 599                 [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
 600                 [DISCE_SUSPEND] = sas_suspend_devices,
 601                 [DISCE_RESUME] = sas_resume_devices,
 602         };
 603
 604         disc->pending = 0;
 605         for (i = 0; i < DISC_NUM_EVENTS; i++) {
 606                 INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
 607                 disc->disc_work[i].port = port;
 608         }
 609 }