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