drivers/scsi/hosts.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  hosts.c Copyright (C) 1992 Drew Eckhardt
   4  *          Copyright (C) 1993, 1994, 1995 Eric Youngdale
   5  *          Copyright (C) 2002-2003 Christoph Hellwig
   6  *
   7  *  mid to lowlevel SCSI driver interface
   8  *      Initial versions: Drew Eckhardt
   9  *      Subsequent revisions: Eric Youngdale
  10  *
  11  *  <drew@colorado.edu>
  12  *
  13  *  Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
  14  *  Added QLOGIC QLA1280 SCSI controller kernel host support.
  15  *     August 4, 1999 Fred Lewis, Intel DuPont
  16  *
  17  *  Updated to reflect the new initialization scheme for the higher
  18  *  level of scsi drivers (sd/sr/st)
  19  *  September 17, 2000 Torben Mathiasen <tmm@image.dk>
  20  *
  21  *  Restructured scsi_host lists and associated functions.
  22  *  September 04, 2002 Mike Anderson (andmike@us.ibm.com)
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/blkdev.h>
  27 #include <linux/kernel.h>
  28 #include <linux/slab.h>
  29 #include <linux/kthread.h>
  30 #include <linux/string.h>
  31 #include <linux/mm.h>
  32 #include <linux/init.h>
  33 #include <linux/completion.h>
  34 #include <linux/transport_class.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/pm_runtime.h>
  37 #include <linux/idr.h>
  38 #include <scsi/scsi_device.h>
  39 #include <scsi/scsi_host.h>
  40 #include <scsi/scsi_transport.h>
  41 #include <scsi/scsi_cmnd.h>
  42
  43 #include "scsi_priv.h"
  44 #include "scsi_logging.h"
  45
  46
  47 static int shost_eh_deadline = -1;
  48
  49 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
  50 MODULE_PARM_DESC(eh_deadline,
  51                  "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
  52
  53 static DEFINE_IDA(host_index_ida);
  54
  55
  56 static void scsi_host_cls_release(struct device *dev)
  57 {
  58         put_device(&class_to_shost(dev)->shost_gendev);
  59 }
  60
  61 static struct class shost_class = {
  62         .name           = "scsi_host",
  63         .dev_release    = scsi_host_cls_release,
  64 };
  65
  66 /**
  67  *      scsi_host_set_state - Take the given host through the host state model.
  68  *      @shost: scsi host to change the state of.
  69  *      @state: state to change to.
  70  *
  71  *      Returns zero if unsuccessful or an error if the requested
  72  *      transition is illegal.
  73  **/
  74 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
  75 {
  76         enum scsi_host_state oldstate = shost->shost_state;
  77
  78         if (state == oldstate)
  79                 return 0;
  80
  81         switch (state) {
  82         case SHOST_CREATED:
  83                 /* There are no legal states that come back to
  84                  * created.  This is the manually initialised start
  85                  * state */
  86                 goto illegal;
  87
  88         case SHOST_RUNNING:
  89                 switch (oldstate) {
  90                 case SHOST_CREATED:
  91                 case SHOST_RECOVERY:
  92                         break;
  93                 default:
  94                         goto illegal;
  95                 }
  96                 break;
  97
  98         case SHOST_RECOVERY:
  99                 switch (oldstate) {
 100                 case SHOST_RUNNING:
 101                         break;
 102                 default:
 103                         goto illegal;
 104                 }
 105                 break;
 106
 107         case SHOST_CANCEL:
 108                 switch (oldstate) {
 109                 case SHOST_CREATED:
 110                 case SHOST_RUNNING:
 111                 case SHOST_CANCEL_RECOVERY:
 112                         break;
 113                 default:
 114                         goto illegal;
 115                 }
 116                 break;
 117
 118         case SHOST_DEL:
 119                 switch (oldstate) {
 120                 case SHOST_CANCEL:
 121                 case SHOST_DEL_RECOVERY:
 122                         break;
 123                 default:
 124                         goto illegal;
 125                 }
 126                 break;
 127
 128         case SHOST_CANCEL_RECOVERY:
 129                 switch (oldstate) {
 130                 case SHOST_CANCEL:
 131                 case SHOST_RECOVERY:
 132                         break;
 133                 default:
 134                         goto illegal;
 135                 }
 136                 break;
 137
 138         case SHOST_DEL_RECOVERY:
 139                 switch (oldstate) {
 140                 case SHOST_CANCEL_RECOVERY:
 141                         break;
 142                 default:
 143                         goto illegal;
 144                 }
 145                 break;
 146         }
 147         shost->shost_state = state;
 148         return 0;
 149
 150  illegal:
 151         SCSI_LOG_ERROR_RECOVERY(1,
 152                                 shost_printk(KERN_ERR, shost,
 153                                              "Illegal host state transition"
 154                                              "%s->%s\n",
 155                                              scsi_host_state_name(oldstate),
 156                                              scsi_host_state_name(state)));
 157         return -EINVAL;
 158 }
 159
 160 /**
 161  * scsi_remove_host - remove a scsi host
 162  * @shost:      a pointer to a scsi host to remove
 163  **/
 164 void scsi_remove_host(struct Scsi_Host *shost)
 165 {
 166         unsigned long flags;
 167
 168         mutex_lock(&shost->scan_mutex);
 169         spin_lock_irqsave(shost->host_lock, flags);
 170         if (scsi_host_set_state(shost, SHOST_CANCEL))
 171                 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
 172                         spin_unlock_irqrestore(shost->host_lock, flags);
 173                         mutex_unlock(&shost->scan_mutex);
 174                         return;
 175                 }
 176         spin_unlock_irqrestore(shost->host_lock, flags);
 177
 178         scsi_autopm_get_host(shost);
 179         flush_workqueue(shost->tmf_work_q);
 180         scsi_forget_host(shost);
 181         mutex_unlock(&shost->scan_mutex);
 182         scsi_proc_host_rm(shost);
 183         scsi_proc_hostdir_rm(shost->hostt);
 184
 185         spin_lock_irqsave(shost->host_lock, flags);
 186         if (scsi_host_set_state(shost, SHOST_DEL))
 187                 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
 188         spin_unlock_irqrestore(shost->host_lock, flags);
 189
 190         transport_unregister_device(&shost->shost_gendev);
 191         device_unregister(&shost->shost_dev);
 192         device_del(&shost->shost_gendev);
 193 }
 194 EXPORT_SYMBOL(scsi_remove_host);
 195
 196 /**
 197  * scsi_add_host_with_dma - add a scsi host with dma device
 198  * @shost:      scsi host pointer to add
 199  * @dev:        a struct device of type scsi class
 200  * @dma_dev:    dma device for the host
 201  *
 202  * Note: You rarely need to worry about this unless you're in a
 203  * virtualised host environments, so use the simpler scsi_add_host()
 204  * function instead.
 205  *
 206  * Return value:
 207  *      0 on success / != 0 for error
 208  **/
 209 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 210                            struct device *dma_dev)
 211 {
 212         struct scsi_host_template *sht = shost->hostt;
 213         int error = -EINVAL;
 214
 215         shost_printk(KERN_INFO, shost, "%s\n",
 216                         sht->info ? sht->info(shost) : sht->name);
 217
 218         if (!shost->can_queue) {
 219                 shost_printk(KERN_ERR, shost,
 220                              "can_queue = 0 no longer supported\n");
 221                 goto fail;
 222         }
 223
 224         /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
 225         shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
 226                                    shost->can_queue);
 227
 228         error = scsi_init_sense_cache(shost);
 229         if (error)
 230                 goto fail;
 231
 232         error = scsi_mq_setup_tags(shost);
 233         if (error)
 234                 goto fail;
 235
 236         if (!shost->shost_gendev.parent)
 237                 shost->shost_gendev.parent = dev ? dev : &platform_bus;
 238         if (!dma_dev)
 239                 dma_dev = shost->shost_gendev.parent;
 240
 241         shost->dma_dev = dma_dev;
 242
 243         /*
 244          * Increase usage count temporarily here so that calling
 245          * scsi_autopm_put_host() will trigger runtime idle if there is
 246          * nothing else preventing suspending the device.
 247          */
 248         pm_runtime_get_noresume(&shost->shost_gendev);
 249         pm_runtime_set_active(&shost->shost_gendev);
 250         pm_runtime_enable(&shost->shost_gendev);
 251         device_enable_async_suspend(&shost->shost_gendev);
 252
 253         error = device_add(&shost->shost_gendev);
 254         if (error)
 255                 goto out_disable_runtime_pm;
 256
 257         scsi_host_set_state(shost, SHOST_RUNNING);
 258         get_device(shost->shost_gendev.parent);
 259
 260         device_enable_async_suspend(&shost->shost_dev);
 261
 262         get_device(&shost->shost_gendev);
 263         error = device_add(&shost->shost_dev);
 264         if (error)
 265                 goto out_del_gendev;
 266
 267         if (shost->transportt->host_size) {
 268                 shost->shost_data = kzalloc(shost->transportt->host_size,
 269                                          GFP_KERNEL);
 270                 if (shost->shost_data == NULL) {
 271                         error = -ENOMEM;
 272                         goto out_del_dev;
 273                 }
 274         }
 275
 276         if (shost->transportt->create_work_queue) {
 277                 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
 278                          "scsi_wq_%d", shost->host_no);
 279                 shost->work_q = alloc_workqueue("%s",
 280                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
 281                         1, shost->work_q_name);
 282
 283                 if (!shost->work_q) {
 284                         error = -EINVAL;
 285                         goto out_del_dev;
 286                 }
 287         }
 288
 289         error = scsi_sysfs_add_host(shost);
 290         if (error)
 291                 goto out_del_dev;
 292
 293         scsi_proc_host_add(shost);
 294         scsi_autopm_put_host(shost);
 295         return error;
 296
 297         /*
 298          * Any host allocation in this function will be freed in
 299          * scsi_host_dev_release().
 300          */
 301  out_del_dev:
 302         device_del(&shost->shost_dev);
 303  out_del_gendev:
 304         /*
 305          * Host state is SHOST_RUNNING so we have to explicitly release
 306          * ->shost_dev.
 307          */
 308         put_device(&shost->shost_dev);
 309         device_del(&shost->shost_gendev);
 310  out_disable_runtime_pm:
 311         device_disable_async_suspend(&shost->shost_gendev);
 312         pm_runtime_disable(&shost->shost_gendev);
 313         pm_runtime_set_suspended(&shost->shost_gendev);
 314         pm_runtime_put_noidle(&shost->shost_gendev);
 315  fail:
 316         return error;
 317 }
 318 EXPORT_SYMBOL(scsi_add_host_with_dma);
 319
 320 static void scsi_host_dev_release(struct device *dev)
 321 {
 322         struct Scsi_Host *shost = dev_to_shost(dev);
 323         struct device *parent = dev->parent;
 324
 325         /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
 326         rcu_barrier();
 327
 328         if (shost->tmf_work_q)
 329                 destroy_workqueue(shost->tmf_work_q);
 330         if (shost->ehandler)
 331                 kthread_stop(shost->ehandler);
 332         if (shost->work_q)
 333                 destroy_workqueue(shost->work_q);
 334
 335         if (shost->shost_state == SHOST_CREATED) {
 336                 /*
 337                  * Free the shost_dev device name and remove the proc host dir
 338                  * here if scsi_host_{alloc,put}() have been called but neither
 339                  * scsi_host_add() nor scsi_host_remove() has been called.
 340                  * This avoids that the memory allocated for the shost_dev
 341                  * name as well as the proc dir structure are leaked.
 342                  */
 343                 scsi_proc_hostdir_rm(shost->hostt);
 344                 kfree(dev_name(&shost->shost_dev));
 345         }
 346
 347         if (shost->tag_set.tags)
 348                 scsi_mq_destroy_tags(shost);
 349
 350         kfree(shost->shost_data);
 351
 352         ida_simple_remove(&host_index_ida, shost->host_no);
 353
 354         if (shost->shost_state != SHOST_CREATED)
 355                 put_device(parent);
 356         kfree(shost);
 357 }
 358
 359 static struct device_type scsi_host_type = {
 360         .name =         "scsi_host",
 361         .release =      scsi_host_dev_release,
 362 };
 363
 364 /**
 365  * scsi_host_alloc - register a scsi host adapter instance.
 366  * @sht:        pointer to scsi host template
 367  * @privsize:   extra bytes to allocate for driver
 368  *
 369  * Note:
 370  *      Allocate a new Scsi_Host and perform basic initialization.
 371  *      The host is not published to the scsi midlayer until scsi_add_host
 372  *      is called.
 373  *
 374  * Return value:
 375  *      Pointer to a new Scsi_Host
 376  **/
 377 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
 378 {
 379         struct Scsi_Host *shost;
 380         gfp_t gfp_mask = GFP_KERNEL;
 381         int index;
 382
 383         if (sht->unchecked_isa_dma && privsize)
 384                 gfp_mask |= __GFP_DMA;
 385
 386         shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
 387         if (!shost)
 388                 return NULL;
 389
 390         shost->host_lock = &shost->default_lock;
 391         spin_lock_init(shost->host_lock);
 392         shost->shost_state = SHOST_CREATED;
 393         INIT_LIST_HEAD(&shost->__devices);
 394         INIT_LIST_HEAD(&shost->__targets);
 395         INIT_LIST_HEAD(&shost->eh_cmd_q);
 396         INIT_LIST_HEAD(&shost->starved_list);
 397         init_waitqueue_head(&shost->host_wait);
 398         mutex_init(&shost->scan_mutex);
 399
 400         index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
 401         if (index < 0) {
 402                 kfree(shost);
 403                 return NULL;
 404         }
 405         shost->host_no = index;
 406
 407         shost->dma_channel = 0xff;
 408
 409         /* These three are default values which can be overridden */
 410         shost->max_channel = 0;
 411         shost->max_id = 8;
 412         shost->max_lun = 8;
 413
 414         /* Give each shost a default transportt */
 415         shost->transportt = &blank_transport_template;
 416
 417         /*
 418          * All drivers right now should be able to handle 12 byte
 419          * commands.  Every so often there are requests for 16 byte
 420          * commands, but individual low-level drivers need to certify that
 421          * they actually do something sensible with such commands.
 422          */
 423         shost->max_cmd_len = 12;
 424         shost->hostt = sht;
 425         shost->this_id = sht->this_id;
 426         shost->can_queue = sht->can_queue;
 427         shost->sg_tablesize = sht->sg_tablesize;
 428         shost->sg_prot_tablesize = sht->sg_prot_tablesize;
 429         shost->cmd_per_lun = sht->cmd_per_lun;
 430         shost->unchecked_isa_dma = sht->unchecked_isa_dma;
 431         shost->no_write_same = sht->no_write_same;
 432         shost->host_tagset = sht->host_tagset;
 433
 434         if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
 435                 shost->eh_deadline = -1;
 436         else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
 437                 shost_printk(KERN_WARNING, shost,
 438                              "eh_deadline %u too large, setting to %u\n",
 439                              shost_eh_deadline, INT_MAX / HZ);
 440                 shost->eh_deadline = INT_MAX;
 441         } else
 442                 shost->eh_deadline = shost_eh_deadline * HZ;
 443
 444         if (sht->supported_mode == MODE_UNKNOWN)
 445                 /* means we didn't set it ... default to INITIATOR */
 446                 shost->active_mode = MODE_INITIATOR;
 447         else
 448                 shost->active_mode = sht->supported_mode;
 449
 450         if (sht->max_host_blocked)
 451                 shost->max_host_blocked = sht->max_host_blocked;
 452         else
 453                 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
 454
 455         /*
 456          * If the driver imposes no hard sector transfer limit, start at
 457          * machine infinity initially.
 458          */
 459         if (sht->max_sectors)
 460                 shost->max_sectors = sht->max_sectors;
 461         else
 462                 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
 463
 464         if (sht->max_segment_size)
 465                 shost->max_segment_size = sht->max_segment_size;
 466         else
 467                 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
 468
 469         /*
 470          * assume a 4GB boundary, if not set
 471          */
 472         if (sht->dma_boundary)
 473                 shost->dma_boundary = sht->dma_boundary;
 474         else
 475                 shost->dma_boundary = 0xffffffff;
 476
 477         if (sht->virt_boundary_mask)
 478                 shost->virt_boundary_mask = sht->virt_boundary_mask;
 479
 480         device_initialize(&shost->shost_gendev);
 481         dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
 482         shost->shost_gendev.bus = &scsi_bus_type;
 483         shost->shost_gendev.type = &scsi_host_type;
 484
 485         device_initialize(&shost->shost_dev);
 486         shost->shost_dev.parent = &shost->shost_gendev;
 487         shost->shost_dev.class = &shost_class;
 488         dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
 489         shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
 490
 491         shost->ehandler = kthread_run(scsi_error_handler, shost,
 492                         "scsi_eh_%d", shost->host_no);
 493         if (IS_ERR(shost->ehandler)) {
 494                 shost_printk(KERN_WARNING, shost,
 495                         "error handler thread failed to spawn, error = %ld\n",
 496                         PTR_ERR(shost->ehandler));
 497                 shost->ehandler = NULL;
 498                 goto fail;
 499         }
 500
 501         shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
 502                                         WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
 503                                            1, shost->host_no);
 504         if (!shost->tmf_work_q) {
 505                 shost_printk(KERN_WARNING, shost,
 506                              "failed to create tmf workq\n");
 507                 goto fail;
 508         }
 509         scsi_proc_hostdir_add(shost->hostt);
 510         return shost;
 511  fail:
 512         /*
 513          * Host state is still SHOST_CREATED and that is enough to release
 514          * ->shost_gendev. scsi_host_dev_release() will free
 515          * dev_name(&shost->shost_dev).
 516          */
 517         put_device(&shost->shost_gendev);
 518
 519         return NULL;
 520 }
 521 EXPORT_SYMBOL(scsi_host_alloc);
 522
 523 static int __scsi_host_match(struct device *dev, const void *data)
 524 {
 525         struct Scsi_Host *p;
 526         const unsigned int *hostnum = data;
 527
 528         p = class_to_shost(dev);
 529         return p->host_no == *hostnum;
 530 }
 531
 532 /**
 533  * scsi_host_lookup - get a reference to a Scsi_Host by host no
 534  * @hostnum:    host number to locate
 535  *
 536  * Return value:
 537  *      A pointer to located Scsi_Host or NULL.
 538  *
 539  *      The caller must do a scsi_host_put() to drop the reference
 540  *      that scsi_host_get() took. The put_device() below dropped
 541  *      the reference from class_find_device().
 542  **/
 543 struct Scsi_Host *scsi_host_lookup(unsigned int hostnum)
 544 {
 545         struct device *cdev;
 546         struct Scsi_Host *shost = NULL;
 547
 548         cdev = class_find_device(&shost_class, NULL, &hostnum,
 549                                  __scsi_host_match);
 550         if (cdev) {
 551                 shost = scsi_host_get(class_to_shost(cdev));
 552                 put_device(cdev);
 553         }
 554         return shost;
 555 }
 556 EXPORT_SYMBOL(scsi_host_lookup);
 557
 558 /**
 559  * scsi_host_get - inc a Scsi_Host ref count
 560  * @shost:      Pointer to Scsi_Host to inc.
 561  **/
 562 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
 563 {
 564         if ((shost->shost_state == SHOST_DEL) ||
 565                 !get_device(&shost->shost_gendev))
 566                 return NULL;
 567         return shost;
 568 }
 569 EXPORT_SYMBOL(scsi_host_get);
 570
 571 static bool scsi_host_check_in_flight(struct request *rq, void *data,
 572                                       bool reserved)
 573 {
 574         int *count = data;
 575         struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
 576
 577         if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
 578                 (*count)++;
 579
 580         return true;
 581 }
 582
 583 /**
 584  * scsi_host_busy - Return the host busy counter
 585  * @shost:      Pointer to Scsi_Host to inc.
 586  **/
 587 int scsi_host_busy(struct Scsi_Host *shost)
 588 {
 589         int cnt = 0;
 590
 591         blk_mq_tagset_busy_iter(&shost->tag_set,
 592                                 scsi_host_check_in_flight, &cnt);
 593         return cnt;
 594 }
 595 EXPORT_SYMBOL(scsi_host_busy);
 596
 597 /**
 598  * scsi_host_put - dec a Scsi_Host ref count
 599  * @shost:      Pointer to Scsi_Host to dec.
 600  **/
 601 void scsi_host_put(struct Scsi_Host *shost)
 602 {
 603         put_device(&shost->shost_gendev);
 604 }
 605 EXPORT_SYMBOL(scsi_host_put);
 606
 607 int scsi_init_hosts(void)
 608 {
 609         return class_register(&shost_class);
 610 }
 611
 612 void scsi_exit_hosts(void)
 613 {
 614         class_unregister(&shost_class);
 615         ida_destroy(&host_index_ida);
 616 }
 617
 618 int scsi_is_host_device(const struct device *dev)
 619 {
 620         return dev->type == &scsi_host_type;
 621 }
 622 EXPORT_SYMBOL(scsi_is_host_device);
 623
 624 /**
 625  * scsi_queue_work - Queue work to the Scsi_Host workqueue.
 626  * @shost:      Pointer to Scsi_Host.
 627  * @work:       Work to queue for execution.
 628  *
 629  * Return value:
 630  *      1 - work queued for execution
 631  *      0 - work is already queued
 632  *      -EINVAL - work queue doesn't exist
 633  **/
 634 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
 635 {
 636         if (unlikely(!shost->work_q)) {
 637                 shost_printk(KERN_ERR, shost,
 638                         "ERROR: Scsi host '%s' attempted to queue scsi-work, "
 639                         "when no workqueue created.\n", shost->hostt->name);
 640                 dump_stack();
 641
 642                 return -EINVAL;
 643         }
 644
 645         return queue_work(shost->work_q, work);
 646 }
 647 EXPORT_SYMBOL_GPL(scsi_queue_work);
 648
 649 /**
 650  * scsi_flush_work - Flush a Scsi_Host's workqueue.
 651  * @shost:      Pointer to Scsi_Host.
 652  **/
 653 void scsi_flush_work(struct Scsi_Host *shost)
 654 {
 655         if (!shost->work_q) {
 656                 shost_printk(KERN_ERR, shost,
 657                         "ERROR: Scsi host '%s' attempted to flush scsi-work, "
 658                         "when no workqueue created.\n", shost->hostt->name);
 659                 dump_stack();
 660                 return;
 661         }
 662
 663         flush_workqueue(shost->work_q);
 664 }
 665 EXPORT_SYMBOL_GPL(scsi_flush_work);
 666
 667 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
 668 {
 669         struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
 670         int status = *(int *)data;
 671
 672         scsi_dma_unmap(scmd);
 673         scmd->result = status << 16;
 674         scmd->scsi_done(scmd);
 675         return true;
 676 }
 677
 678 /**
 679  * scsi_host_complete_all_commands - Terminate all running commands
 680  * @shost:      Scsi Host on which commands should be terminated
 681  * @status:     Status to be set for the terminated commands
 682  *
 683  * There is no protection against modification of the number
 684  * of outstanding commands. It is the responsibility of the
 685  * caller to ensure that concurrent I/O submission and/or
 686  * completion is stopped when calling this function.
 687  */
 688 void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
 689 {
 690         blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
 691                                 &status);
 692 }
 693 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
 694
 695 struct scsi_host_busy_iter_data {
 696         bool (*fn)(struct scsi_cmnd *, void *, bool);
 697         void *priv;
 698 };
 699
 700 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
 701                                    bool reserved)
 702 {
 703         struct scsi_host_busy_iter_data *iter_data = priv;
 704         struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
 705
 706         return iter_data->fn(sc, iter_data->priv, reserved);
 707 }
 708
 709 /**
 710  * scsi_host_busy_iter - Iterate over all busy commands
 711  * @shost:      Pointer to Scsi_Host.
 712  * @fn:         Function to call on each busy command
 713  * @priv:       Data pointer passed to @fn
 714  *
 715  * If locking against concurrent command completions is required
 716  * ithas to be provided by the caller
 717  **/
 718 void scsi_host_busy_iter(struct Scsi_Host *shost,
 719                          bool (*fn)(struct scsi_cmnd *, void *, bool),
 720                          void *priv)
 721 {
 722         struct scsi_host_busy_iter_data iter_data = {
 723                 .fn = fn,
 724                 .priv = priv,
 725         };
 726
 727         blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
 728                                 &iter_data);
 729 }
 730 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);