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
scsi_host_cls_release(struct device * dev)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 .dev_groups = scsi_shost_groups,
65 };
66
67 /**
68 * scsi_host_set_state - Take the given host through the host state model.
69 * @shost: scsi host to change the state of.
70 * @state: state to change to.
71 *
72 * Returns zero if unsuccessful or an error if the requested
73 * transition is illegal.
74 **/
scsi_host_set_state(struct Scsi_Host * shost,enum scsi_host_state state)75 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
76 {
77 enum scsi_host_state oldstate = shost->shost_state;
78
79 if (state == oldstate)
80 return 0;
81
82 switch (state) {
83 case SHOST_CREATED:
84 /* There are no legal states that come back to
85 * created. This is the manually initialised start
86 * state */
87 goto illegal;
88
89 case SHOST_RUNNING:
90 switch (oldstate) {
91 case SHOST_CREATED:
92 case SHOST_RECOVERY:
93 break;
94 default:
95 goto illegal;
96 }
97 break;
98
99 case SHOST_RECOVERY:
100 switch (oldstate) {
101 case SHOST_RUNNING:
102 break;
103 default:
104 goto illegal;
105 }
106 break;
107
108 case SHOST_CANCEL:
109 switch (oldstate) {
110 case SHOST_CREATED:
111 case SHOST_RUNNING:
112 case SHOST_CANCEL_RECOVERY:
113 break;
114 default:
115 goto illegal;
116 }
117 break;
118
119 case SHOST_DEL:
120 switch (oldstate) {
121 case SHOST_CANCEL:
122 case SHOST_DEL_RECOVERY:
123 break;
124 default:
125 goto illegal;
126 }
127 break;
128
129 case SHOST_CANCEL_RECOVERY:
130 switch (oldstate) {
131 case SHOST_CANCEL:
132 case SHOST_RECOVERY:
133 break;
134 default:
135 goto illegal;
136 }
137 break;
138
139 case SHOST_DEL_RECOVERY:
140 switch (oldstate) {
141 case SHOST_CANCEL_RECOVERY:
142 break;
143 default:
144 goto illegal;
145 }
146 break;
147 }
148 shost->shost_state = state;
149 return 0;
150
151 illegal:
152 SCSI_LOG_ERROR_RECOVERY(1,
153 shost_printk(KERN_ERR, shost,
154 "Illegal host state transition"
155 "%s->%s\n",
156 scsi_host_state_name(oldstate),
157 scsi_host_state_name(state)));
158 return -EINVAL;
159 }
160
161 /**
162 * scsi_remove_host - remove a scsi host
163 * @shost: a pointer to a scsi host to remove
164 **/
scsi_remove_host(struct Scsi_Host * shost)165 void scsi_remove_host(struct Scsi_Host *shost)
166 {
167 unsigned long flags;
168
169 mutex_lock(&shost->scan_mutex);
170 spin_lock_irqsave(shost->host_lock, flags);
171 if (scsi_host_set_state(shost, SHOST_CANCEL))
172 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
173 spin_unlock_irqrestore(shost->host_lock, flags);
174 mutex_unlock(&shost->scan_mutex);
175 return;
176 }
177 spin_unlock_irqrestore(shost->host_lock, flags);
178
179 scsi_autopm_get_host(shost);
180 flush_workqueue(shost->tmf_work_q);
181 scsi_forget_host(shost);
182 mutex_unlock(&shost->scan_mutex);
183 scsi_proc_host_rm(shost);
184 scsi_proc_hostdir_rm(shost->hostt);
185
186 /*
187 * New SCSI devices cannot be attached anymore because of the SCSI host
188 * state so drop the tag set refcnt. Wait until the tag set refcnt drops
189 * to zero because .exit_cmd_priv implementations may need the host
190 * pointer.
191 */
192 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
193 wait_for_completion(&shost->tagset_freed);
194
195 spin_lock_irqsave(shost->host_lock, flags);
196 if (scsi_host_set_state(shost, SHOST_DEL))
197 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
198 spin_unlock_irqrestore(shost->host_lock, flags);
199
200 transport_unregister_device(&shost->shost_gendev);
201 device_unregister(&shost->shost_dev);
202 device_del(&shost->shost_gendev);
203 }
204 EXPORT_SYMBOL(scsi_remove_host);
205
206 /**
207 * scsi_add_host_with_dma - add a scsi host with dma device
208 * @shost: scsi host pointer to add
209 * @dev: a struct device of type scsi class
210 * @dma_dev: dma device for the host
211 *
212 * Note: You rarely need to worry about this unless you're in a
213 * virtualised host environments, so use the simpler scsi_add_host()
214 * function instead.
215 *
216 * Return value:
217 * 0 on success / != 0 for error
218 **/
scsi_add_host_with_dma(struct Scsi_Host * shost,struct device * dev,struct device * dma_dev)219 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
220 struct device *dma_dev)
221 {
222 const struct scsi_host_template *sht = shost->hostt;
223 int error = -EINVAL;
224
225 shost_printk(KERN_INFO, shost, "%s\n",
226 sht->info ? sht->info(shost) : sht->name);
227
228 if (!shost->can_queue) {
229 shost_printk(KERN_ERR, shost,
230 "can_queue = 0 no longer supported\n");
231 goto fail;
232 }
233
234 if (shost->nr_reserved_cmds && !sht->queue_reserved_command) {
235 shost_printk(KERN_ERR, shost,
236 "nr_reserved_cmds set but no method to queue\n");
237 goto fail;
238 }
239
240 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
241 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
242 shost->can_queue);
243
244 error = scsi_init_sense_cache(shost);
245 if (error)
246 goto fail;
247
248 if (!shost->shost_gendev.parent)
249 shost->shost_gendev.parent = dev ? dev : &platform_bus;
250 if (!dma_dev)
251 dma_dev = shost->shost_gendev.parent;
252
253 shost->dma_dev = dma_dev;
254
255 if (dma_dev->dma_mask) {
256 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
257 dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
258 }
259
260 error = scsi_mq_setup_tags(shost);
261 if (error)
262 goto fail;
263
264 kref_init(&shost->tagset_refcnt);
265 init_completion(&shost->tagset_freed);
266
267 /*
268 * Increase usage count temporarily here so that calling
269 * scsi_autopm_put_host() will trigger runtime idle if there is
270 * nothing else preventing suspending the device.
271 */
272 pm_runtime_get_noresume(&shost->shost_gendev);
273 pm_runtime_set_active(&shost->shost_gendev);
274 pm_runtime_enable(&shost->shost_gendev);
275 device_enable_async_suspend(&shost->shost_gendev);
276
277 error = device_add(&shost->shost_gendev);
278 if (error)
279 goto out_disable_runtime_pm;
280
281 scsi_host_set_state(shost, SHOST_RUNNING);
282 get_device(shost->shost_gendev.parent);
283
284 device_enable_async_suspend(&shost->shost_dev);
285
286 get_device(&shost->shost_gendev);
287 error = device_add(&shost->shost_dev);
288 if (error)
289 goto out_del_gendev;
290
291 if (shost->transportt->host_size) {
292 shost->shost_data = kzalloc(shost->transportt->host_size,
293 GFP_KERNEL);
294 if (shost->shost_data == NULL) {
295 error = -ENOMEM;
296 goto out_del_dev;
297 }
298 }
299
300 if (shost->transportt->create_work_queue) {
301 shost->work_q = alloc_workqueue(
302 "scsi_wq_%d",
303 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND, 1,
304 shost->host_no);
305
306 if (!shost->work_q) {
307 error = -EINVAL;
308 goto out_del_dev;
309 }
310 }
311
312 error = scsi_sysfs_add_host(shost);
313 if (error)
314 goto out_del_dev;
315
316 if (shost->nr_reserved_cmds) {
317 shost->pseudo_sdev = scsi_get_pseudo_sdev(shost);
318 if (!shost->pseudo_sdev) {
319 error = -ENOMEM;
320 goto out_del_dev;
321 }
322 }
323
324 scsi_proc_host_add(shost);
325 scsi_autopm_put_host(shost);
326 return error;
327
328 /*
329 * Any host allocation in this function will be freed in
330 * scsi_host_dev_release().
331 */
332 out_del_dev:
333 device_del(&shost->shost_dev);
334 out_del_gendev:
335 /*
336 * Host state is SHOST_RUNNING so we have to explicitly release
337 * ->shost_dev.
338 */
339 put_device(&shost->shost_dev);
340 device_del(&shost->shost_gendev);
341 out_disable_runtime_pm:
342 device_disable_async_suspend(&shost->shost_gendev);
343 pm_runtime_disable(&shost->shost_gendev);
344 pm_runtime_set_suspended(&shost->shost_gendev);
345 pm_runtime_put_noidle(&shost->shost_gendev);
346 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
347 fail:
348 return error;
349 }
350 EXPORT_SYMBOL(scsi_add_host_with_dma);
351
scsi_host_dev_release(struct device * dev)352 static void scsi_host_dev_release(struct device *dev)
353 {
354 struct Scsi_Host *shost = dev_to_shost(dev);
355 struct device *parent = dev->parent;
356
357 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
358 rcu_barrier();
359
360 if (shost->tmf_work_q)
361 destroy_workqueue(shost->tmf_work_q);
362 if (shost->ehandler)
363 kthread_stop(shost->ehandler);
364 if (shost->work_q)
365 destroy_workqueue(shost->work_q);
366
367 if (shost->shost_state == SHOST_CREATED) {
368 /*
369 * Free the shost_dev device name and remove the proc host dir
370 * here if scsi_host_{alloc,put}() have been called but neither
371 * scsi_host_add() nor scsi_remove_host() has been called.
372 * This avoids that the memory allocated for the shost_dev
373 * name as well as the proc dir structure are leaked.
374 */
375 scsi_proc_hostdir_rm(shost->hostt);
376 kfree(dev_name(&shost->shost_dev));
377 }
378
379 kfree(shost->shost_data);
380
381 ida_free(&host_index_ida, shost->host_no);
382
383 if (shost->shost_state != SHOST_CREATED)
384 put_device(parent);
385 kfree(shost);
386 }
387
388 static const struct device_type scsi_host_type = {
389 .name = "scsi_host",
390 .release = scsi_host_dev_release,
391 };
392
393 /**
394 * scsi_host_alloc - register a scsi host adapter instance.
395 * @sht: pointer to scsi host template
396 * @privsize: extra bytes to allocate for driver
397 *
398 * Note:
399 * Allocate a new Scsi_Host and perform basic initialization.
400 * The host is not published to the scsi midlayer until scsi_add_host
401 * is called.
402 *
403 * Return value:
404 * Pointer to a new Scsi_Host
405 **/
scsi_host_alloc(const struct scsi_host_template * sht,int privsize)406 struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int privsize)
407 {
408 struct Scsi_Host *shost;
409 int index;
410
411 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
412 if (!shost)
413 return NULL;
414
415 shost->host_lock = &shost->default_lock;
416 spin_lock_init(shost->host_lock);
417 shost->shost_state = SHOST_CREATED;
418 INIT_LIST_HEAD(&shost->__devices);
419 INIT_LIST_HEAD(&shost->__targets);
420 INIT_LIST_HEAD(&shost->eh_abort_list);
421 INIT_LIST_HEAD(&shost->eh_cmd_q);
422 INIT_LIST_HEAD(&shost->starved_list);
423 init_waitqueue_head(&shost->host_wait);
424 mutex_init(&shost->scan_mutex);
425
426 index = ida_alloc(&host_index_ida, GFP_KERNEL);
427 if (index < 0) {
428 kfree(shost);
429 return NULL;
430 }
431 shost->host_no = index;
432
433 shost->dma_channel = 0xff;
434
435 /* These three are default values which can be overridden */
436 shost->max_channel = 0;
437 shost->max_id = 8;
438 shost->max_lun = 8;
439
440 /* Give each shost a default transportt */
441 shost->transportt = &blank_transport_template;
442
443 /*
444 * All drivers right now should be able to handle 12 byte
445 * commands. Every so often there are requests for 16 byte
446 * commands, but individual low-level drivers need to certify that
447 * they actually do something sensible with such commands.
448 */
449 shost->max_cmd_len = 12;
450 shost->hostt = sht;
451 shost->this_id = sht->this_id;
452 shost->can_queue = sht->can_queue;
453 shost->nr_reserved_cmds = sht->nr_reserved_cmds;
454 shost->sg_tablesize = sht->sg_tablesize;
455 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
456 shost->cmd_per_lun = sht->cmd_per_lun;
457 shost->no_write_same = sht->no_write_same;
458 shost->host_tagset = sht->host_tagset;
459 shost->queuecommand_may_block = sht->queuecommand_may_block;
460
461 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
462 shost->eh_deadline = -1;
463 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
464 shost_printk(KERN_WARNING, shost,
465 "eh_deadline %u too large, setting to %u\n",
466 shost_eh_deadline, INT_MAX / HZ);
467 shost->eh_deadline = INT_MAX;
468 } else
469 shost->eh_deadline = shost_eh_deadline * HZ;
470
471 if (sht->supported_mode == MODE_UNKNOWN)
472 /* means we didn't set it ... default to INITIATOR */
473 shost->active_mode = MODE_INITIATOR;
474 else
475 shost->active_mode = sht->supported_mode;
476
477 if (sht->max_host_blocked)
478 shost->max_host_blocked = sht->max_host_blocked;
479 else
480 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
481
482 /*
483 * If the driver imposes no hard sector transfer limit, start at
484 * machine infinity initially.
485 */
486 if (sht->max_sectors)
487 shost->max_sectors = sht->max_sectors;
488 else
489 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
490
491 shost->virt_boundary_mask = sht->virt_boundary_mask;
492 if (shost->virt_boundary_mask) {
493 WARN_ON_ONCE(sht->max_segment_size &&
494 sht->max_segment_size != UINT_MAX);
495 shost->max_segment_size = UINT_MAX;
496 } else {
497 if (sht->max_segment_size)
498 shost->max_segment_size = sht->max_segment_size;
499 else
500 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
501 }
502
503 /* 32-byte (dword) is a common minimum for HBAs. */
504 if (sht->dma_alignment)
505 shost->dma_alignment = sht->dma_alignment;
506 else
507 shost->dma_alignment = 3;
508
509 /*
510 * assume a 4GB boundary, if not set
511 */
512 if (sht->dma_boundary)
513 shost->dma_boundary = sht->dma_boundary;
514 else
515 shost->dma_boundary = 0xffffffff;
516
517 device_initialize(&shost->shost_gendev);
518 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
519 shost->shost_gendev.bus = &scsi_bus_type;
520 shost->shost_gendev.type = &scsi_host_type;
521 scsi_enable_async_suspend(&shost->shost_gendev);
522
523 device_initialize(&shost->shost_dev);
524 shost->shost_dev.parent = &shost->shost_gendev;
525 shost->shost_dev.class = &shost_class;
526 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
527 shost->shost_dev.groups = sht->shost_groups;
528
529 shost->ehandler = kthread_run(scsi_error_handler, shost,
530 "scsi_eh_%d", shost->host_no);
531 if (IS_ERR(shost->ehandler)) {
532 shost_printk(KERN_WARNING, shost,
533 "error handler thread failed to spawn, error = %ld\n",
534 PTR_ERR(shost->ehandler));
535 shost->ehandler = NULL;
536 goto fail;
537 }
538
539 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
540 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
541 1, shost->host_no);
542 if (!shost->tmf_work_q) {
543 shost_printk(KERN_WARNING, shost,
544 "failed to create tmf workq\n");
545 goto fail;
546 }
547 if (scsi_proc_hostdir_add(shost->hostt) < 0)
548 goto fail;
549 return shost;
550 fail:
551 /*
552 * Host state is still SHOST_CREATED and that is enough to release
553 * ->shost_gendev. scsi_host_dev_release() will free
554 * dev_name(&shost->shost_dev).
555 */
556 put_device(&shost->shost_gendev);
557
558 return NULL;
559 }
560 EXPORT_SYMBOL(scsi_host_alloc);
561
__scsi_host_match(struct device * dev,const void * data)562 static int __scsi_host_match(struct device *dev, const void *data)
563 {
564 struct Scsi_Host *p;
565 const unsigned int *hostnum = data;
566
567 p = class_to_shost(dev);
568 return p->host_no == *hostnum;
569 }
570
571 /**
572 * scsi_host_lookup - get a reference to a Scsi_Host by host no
573 * @hostnum: host number to locate
574 *
575 * Return value:
576 * A pointer to located Scsi_Host or NULL.
577 *
578 * The caller must do a scsi_host_put() to drop the reference
579 * that scsi_host_get() took. The put_device() below dropped
580 * the reference from class_find_device().
581 **/
scsi_host_lookup(unsigned int hostnum)582 struct Scsi_Host *scsi_host_lookup(unsigned int hostnum)
583 {
584 struct device *cdev;
585 struct Scsi_Host *shost = NULL;
586
587 cdev = class_find_device(&shost_class, NULL, &hostnum,
588 __scsi_host_match);
589 if (cdev) {
590 shost = scsi_host_get(class_to_shost(cdev));
591 put_device(cdev);
592 }
593 return shost;
594 }
595 EXPORT_SYMBOL(scsi_host_lookup);
596
597 /**
598 * scsi_host_get - inc a Scsi_Host ref count
599 * @shost: Pointer to Scsi_Host to inc.
600 **/
scsi_host_get(struct Scsi_Host * shost)601 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
602 {
603 if ((shost->shost_state == SHOST_DEL) ||
604 !get_device(&shost->shost_gendev))
605 return NULL;
606 return shost;
607 }
608 EXPORT_SYMBOL(scsi_host_get);
609
scsi_host_check_in_flight(struct request * rq,void * data)610 static bool scsi_host_check_in_flight(struct request *rq, void *data)
611 {
612 int *count = data;
613 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
614
615 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
616 (*count)++;
617
618 return true;
619 }
620
621 /**
622 * scsi_host_busy - Return the count of in-flight commands
623 * @shost: Pointer to Scsi_Host
624 **/
scsi_host_busy(struct Scsi_Host * shost)625 int scsi_host_busy(struct Scsi_Host *shost)
626 {
627 int cnt = 0;
628
629 if (shost->tag_set.ops)
630 blk_mq_tagset_busy_iter(&shost->tag_set,
631 scsi_host_check_in_flight, &cnt);
632 return cnt;
633 }
634 EXPORT_SYMBOL(scsi_host_busy);
635
636 /**
637 * scsi_host_put - dec a Scsi_Host ref count
638 * @shost: Pointer to Scsi_Host to dec.
639 **/
scsi_host_put(struct Scsi_Host * shost)640 void scsi_host_put(struct Scsi_Host *shost)
641 {
642 put_device(&shost->shost_gendev);
643 }
644 EXPORT_SYMBOL(scsi_host_put);
645
scsi_init_hosts(void)646 int scsi_init_hosts(void)
647 {
648 return class_register(&shost_class);
649 }
650
scsi_exit_hosts(void)651 void scsi_exit_hosts(void)
652 {
653 class_unregister(&shost_class);
654 ida_destroy(&host_index_ida);
655 }
656
scsi_is_host_device(const struct device * dev)657 int scsi_is_host_device(const struct device *dev)
658 {
659 return dev->type == &scsi_host_type;
660 }
661 EXPORT_SYMBOL(scsi_is_host_device);
662
663 /**
664 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
665 * @shost: Pointer to Scsi_Host.
666 * @work: Work to queue for execution.
667 *
668 * Return value:
669 * 1 - work queued for execution
670 * 0 - work is already queued
671 * -EINVAL - work queue doesn't exist
672 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)673 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
674 {
675 if (unlikely(!shost->work_q)) {
676 shost_printk(KERN_ERR, shost,
677 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
678 "when no workqueue created.\n", shost->hostt->name);
679 dump_stack();
680
681 return -EINVAL;
682 }
683
684 return queue_work(shost->work_q, work);
685 }
686 EXPORT_SYMBOL_GPL(scsi_queue_work);
687
688 /**
689 * scsi_flush_work - Flush a Scsi_Host's workqueue.
690 * @shost: Pointer to Scsi_Host.
691 **/
scsi_flush_work(struct Scsi_Host * shost)692 void scsi_flush_work(struct Scsi_Host *shost)
693 {
694 if (!shost->work_q) {
695 shost_printk(KERN_ERR, shost,
696 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
697 "when no workqueue created.\n", shost->hostt->name);
698 dump_stack();
699 return;
700 }
701
702 flush_workqueue(shost->work_q);
703 }
704 EXPORT_SYMBOL_GPL(scsi_flush_work);
705
complete_all_cmds_iter(struct request * rq,void * data)706 static bool complete_all_cmds_iter(struct request *rq, void *data)
707 {
708 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
709 enum scsi_host_status status = *(enum scsi_host_status *)data;
710
711 scsi_dma_unmap(scmd);
712 scmd->result = 0;
713 set_host_byte(scmd, status);
714 scsi_done(scmd);
715 return true;
716 }
717
718 /**
719 * scsi_host_complete_all_commands - Terminate all running commands
720 * @shost: Scsi Host on which commands should be terminated
721 * @status: Status to be set for the terminated commands
722 *
723 * There is no protection against modification of the number
724 * of outstanding commands. It is the responsibility of the
725 * caller to ensure that concurrent I/O submission and/or
726 * completion is stopped when calling this function.
727 */
scsi_host_complete_all_commands(struct Scsi_Host * shost,enum scsi_host_status status)728 void scsi_host_complete_all_commands(struct Scsi_Host *shost,
729 enum scsi_host_status status)
730 {
731 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
732 &status);
733 }
734 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
735
736 struct scsi_host_busy_iter_data {
737 bool (*fn)(struct scsi_cmnd *, void *);
738 void *priv;
739 };
740
__scsi_host_busy_iter_fn(struct request * req,void * priv)741 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
742 {
743 struct scsi_host_busy_iter_data *iter_data = priv;
744 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
745
746 return iter_data->fn(sc, iter_data->priv);
747 }
748
749 /**
750 * scsi_host_busy_iter - Iterate over all busy commands
751 * @shost: Pointer to Scsi_Host.
752 * @fn: Function to call on each busy command
753 * @priv: Data pointer passed to @fn
754 *
755 * If locking against concurrent command completions is required
756 * ithas to be provided by the caller
757 **/
scsi_host_busy_iter(struct Scsi_Host * shost,bool (* fn)(struct scsi_cmnd *,void *),void * priv)758 void scsi_host_busy_iter(struct Scsi_Host *shost,
759 bool (*fn)(struct scsi_cmnd *, void *),
760 void *priv)
761 {
762 struct scsi_host_busy_iter_data iter_data = {
763 .fn = fn,
764 .priv = priv,
765 };
766
767 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
768 &iter_data);
769 }
770 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
771