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 };
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 **/
scsi_host_set_state(struct Scsi_Host * shost,enum scsi_host_state state)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 **/
scsi_remove_host(struct Scsi_Host * shost)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
184 spin_lock_irqsave(shost->host_lock, flags);
185 if (scsi_host_set_state(shost, SHOST_DEL))
186 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
187 spin_unlock_irqrestore(shost->host_lock, flags);
188
189 transport_unregister_device(&shost->shost_gendev);
190 device_unregister(&shost->shost_dev);
191 device_del(&shost->shost_gendev);
192 }
193 EXPORT_SYMBOL(scsi_remove_host);
194
195 /**
196 * scsi_add_host_with_dma - add a scsi host with dma device
197 * @shost: scsi host pointer to add
198 * @dev: a struct device of type scsi class
199 * @dma_dev: dma device for the host
200 *
201 * Note: You rarely need to worry about this unless you're in a
202 * virtualised host environments, so use the simpler scsi_add_host()
203 * function instead.
204 *
205 * Return value:
206 * 0 on success / != 0 for error
207 **/
scsi_add_host_with_dma(struct Scsi_Host * shost,struct device * dev,struct device * dma_dev)208 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
209 struct device *dma_dev)
210 {
211 struct scsi_host_template *sht = shost->hostt;
212 int error = -EINVAL;
213
214 shost_printk(KERN_INFO, shost, "%s\n",
215 sht->info ? sht->info(shost) : sht->name);
216
217 if (!shost->can_queue) {
218 shost_printk(KERN_ERR, shost,
219 "can_queue = 0 no longer supported\n");
220 goto fail;
221 }
222
223 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
224 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
225 shost->can_queue);
226
227 error = scsi_init_sense_cache(shost);
228 if (error)
229 goto fail;
230
231 error = scsi_mq_setup_tags(shost);
232 if (error)
233 goto fail;
234
235 if (!shost->shost_gendev.parent)
236 shost->shost_gendev.parent = dev ? dev : &platform_bus;
237 if (!dma_dev)
238 dma_dev = shost->shost_gendev.parent;
239
240 shost->dma_dev = dma_dev;
241
242 /*
243 * Increase usage count temporarily here so that calling
244 * scsi_autopm_put_host() will trigger runtime idle if there is
245 * nothing else preventing suspending the device.
246 */
247 pm_runtime_get_noresume(&shost->shost_gendev);
248 pm_runtime_set_active(&shost->shost_gendev);
249 pm_runtime_enable(&shost->shost_gendev);
250 device_enable_async_suspend(&shost->shost_gendev);
251
252 error = device_add(&shost->shost_gendev);
253 if (error)
254 goto out_disable_runtime_pm;
255
256 scsi_host_set_state(shost, SHOST_RUNNING);
257 get_device(shost->shost_gendev.parent);
258
259 device_enable_async_suspend(&shost->shost_dev);
260
261 get_device(&shost->shost_gendev);
262 error = device_add(&shost->shost_dev);
263 if (error)
264 goto out_del_gendev;
265
266 if (shost->transportt->host_size) {
267 shost->shost_data = kzalloc(shost->transportt->host_size,
268 GFP_KERNEL);
269 if (shost->shost_data == NULL) {
270 error = -ENOMEM;
271 goto out_del_dev;
272 }
273 }
274
275 if (shost->transportt->create_work_queue) {
276 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
277 "scsi_wq_%d", shost->host_no);
278 shost->work_q = alloc_workqueue("%s",
279 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
280 1, shost->work_q_name);
281
282 if (!shost->work_q) {
283 error = -EINVAL;
284 goto out_del_dev;
285 }
286 }
287
288 error = scsi_sysfs_add_host(shost);
289 if (error)
290 goto out_del_dev;
291
292 scsi_proc_host_add(shost);
293 scsi_autopm_put_host(shost);
294 return error;
295
296 /*
297 * Any host allocation in this function will be freed in
298 * scsi_host_dev_release().
299 */
300 out_del_dev:
301 device_del(&shost->shost_dev);
302 out_del_gendev:
303 /*
304 * Host state is SHOST_RUNNING so we have to explicitly release
305 * ->shost_dev.
306 */
307 put_device(&shost->shost_dev);
308 device_del(&shost->shost_gendev);
309 out_disable_runtime_pm:
310 device_disable_async_suspend(&shost->shost_gendev);
311 pm_runtime_disable(&shost->shost_gendev);
312 pm_runtime_set_suspended(&shost->shost_gendev);
313 pm_runtime_put_noidle(&shost->shost_gendev);
314 fail:
315 return error;
316 }
317 EXPORT_SYMBOL(scsi_add_host_with_dma);
318
scsi_host_dev_release(struct device * dev)319 static void scsi_host_dev_release(struct device *dev)
320 {
321 struct Scsi_Host *shost = dev_to_shost(dev);
322 struct device *parent = dev->parent;
323
324 scsi_proc_hostdir_rm(shost->hostt);
325
326 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
327 rcu_barrier();
328
329 if (shost->tmf_work_q)
330 destroy_workqueue(shost->tmf_work_q);
331 if (shost->ehandler)
332 kthread_stop(shost->ehandler);
333 if (shost->work_q)
334 destroy_workqueue(shost->work_q);
335
336 if (shost->shost_state == SHOST_CREATED) {
337 /*
338 * Free the shost_dev device name here if scsi_host_alloc()
339 * and scsi_host_put() have been called but neither
340 * scsi_host_add() nor scsi_host_remove() has been called.
341 * This avoids that the memory allocated for the shost_dev
342 * name is leaked.
343 */
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 **/
scsi_host_alloc(struct scsi_host_template * sht,int privsize)377 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
378 {
379 struct Scsi_Host *shost;
380 int index, i, j = 0;
381
382 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
383 if (!shost)
384 return NULL;
385
386 shost->host_lock = &shost->default_lock;
387 spin_lock_init(shost->host_lock);
388 shost->shost_state = SHOST_CREATED;
389 INIT_LIST_HEAD(&shost->__devices);
390 INIT_LIST_HEAD(&shost->__targets);
391 INIT_LIST_HEAD(&shost->eh_abort_list);
392 INIT_LIST_HEAD(&shost->eh_cmd_q);
393 INIT_LIST_HEAD(&shost->starved_list);
394 init_waitqueue_head(&shost->host_wait);
395 mutex_init(&shost->scan_mutex);
396
397 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
398 if (index < 0) {
399 kfree(shost);
400 return NULL;
401 }
402 shost->host_no = index;
403
404 shost->dma_channel = 0xff;
405
406 /* These three are default values which can be overridden */
407 shost->max_channel = 0;
408 shost->max_id = 8;
409 shost->max_lun = 8;
410
411 /* Give each shost a default transportt */
412 shost->transportt = &blank_transport_template;
413
414 /*
415 * All drivers right now should be able to handle 12 byte
416 * commands. Every so often there are requests for 16 byte
417 * commands, but individual low-level drivers need to certify that
418 * they actually do something sensible with such commands.
419 */
420 shost->max_cmd_len = 12;
421 shost->hostt = sht;
422 shost->this_id = sht->this_id;
423 shost->can_queue = sht->can_queue;
424 shost->sg_tablesize = sht->sg_tablesize;
425 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
426 shost->cmd_per_lun = sht->cmd_per_lun;
427 shost->no_write_same = sht->no_write_same;
428 shost->host_tagset = sht->host_tagset;
429
430 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
431 shost->eh_deadline = -1;
432 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
433 shost_printk(KERN_WARNING, shost,
434 "eh_deadline %u too large, setting to %u\n",
435 shost_eh_deadline, INT_MAX / HZ);
436 shost->eh_deadline = INT_MAX;
437 } else
438 shost->eh_deadline = shost_eh_deadline * HZ;
439
440 if (sht->supported_mode == MODE_UNKNOWN)
441 /* means we didn't set it ... default to INITIATOR */
442 shost->active_mode = MODE_INITIATOR;
443 else
444 shost->active_mode = sht->supported_mode;
445
446 if (sht->max_host_blocked)
447 shost->max_host_blocked = sht->max_host_blocked;
448 else
449 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
450
451 /*
452 * If the driver imposes no hard sector transfer limit, start at
453 * machine infinity initially.
454 */
455 if (sht->max_sectors)
456 shost->max_sectors = sht->max_sectors;
457 else
458 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
459
460 if (sht->max_segment_size)
461 shost->max_segment_size = sht->max_segment_size;
462 else
463 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
464
465 /*
466 * assume a 4GB boundary, if not set
467 */
468 if (sht->dma_boundary)
469 shost->dma_boundary = sht->dma_boundary;
470 else
471 shost->dma_boundary = 0xffffffff;
472
473 if (sht->virt_boundary_mask)
474 shost->virt_boundary_mask = sht->virt_boundary_mask;
475
476 device_initialize(&shost->shost_gendev);
477 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
478 shost->shost_gendev.bus = &scsi_bus_type;
479 shost->shost_gendev.type = &scsi_host_type;
480 scsi_enable_async_suspend(&shost->shost_gendev);
481
482 device_initialize(&shost->shost_dev);
483 shost->shost_dev.parent = &shost->shost_gendev;
484 shost->shost_dev.class = &shost_class;
485 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
486 shost->shost_dev.groups = shost->shost_dev_attr_groups;
487 shost->shost_dev_attr_groups[j++] = &scsi_shost_attr_group;
488 if (sht->shost_groups) {
489 for (i = 0; sht->shost_groups[i] &&
490 j < ARRAY_SIZE(shost->shost_dev_attr_groups);
491 i++, j++) {
492 shost->shost_dev_attr_groups[j] =
493 sht->shost_groups[i];
494 }
495 }
496 WARN_ON_ONCE(j >= ARRAY_SIZE(shost->shost_dev_attr_groups));
497
498 shost->ehandler = kthread_run(scsi_error_handler, shost,
499 "scsi_eh_%d", shost->host_no);
500 if (IS_ERR(shost->ehandler)) {
501 shost_printk(KERN_WARNING, shost,
502 "error handler thread failed to spawn, error = %ld\n",
503 PTR_ERR(shost->ehandler));
504 shost->ehandler = NULL;
505 goto fail;
506 }
507
508 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
509 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
510 1, shost->host_no);
511 if (!shost->tmf_work_q) {
512 shost_printk(KERN_WARNING, shost,
513 "failed to create tmf workq\n");
514 goto fail;
515 }
516 scsi_proc_hostdir_add(shost->hostt);
517 return shost;
518 fail:
519 /*
520 * Host state is still SHOST_CREATED and that is enough to release
521 * ->shost_gendev. scsi_host_dev_release() will free
522 * dev_name(&shost->shost_dev).
523 */
524 put_device(&shost->shost_gendev);
525
526 return NULL;
527 }
528 EXPORT_SYMBOL(scsi_host_alloc);
529
__scsi_host_match(struct device * dev,const void * data)530 static int __scsi_host_match(struct device *dev, const void *data)
531 {
532 struct Scsi_Host *p;
533 const unsigned short *hostnum = data;
534
535 p = class_to_shost(dev);
536 return p->host_no == *hostnum;
537 }
538
539 /**
540 * scsi_host_lookup - get a reference to a Scsi_Host by host no
541 * @hostnum: host number to locate
542 *
543 * Return value:
544 * A pointer to located Scsi_Host or NULL.
545 *
546 * The caller must do a scsi_host_put() to drop the reference
547 * that scsi_host_get() took. The put_device() below dropped
548 * the reference from class_find_device().
549 **/
scsi_host_lookup(unsigned short hostnum)550 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
551 {
552 struct device *cdev;
553 struct Scsi_Host *shost = NULL;
554
555 cdev = class_find_device(&shost_class, NULL, &hostnum,
556 __scsi_host_match);
557 if (cdev) {
558 shost = scsi_host_get(class_to_shost(cdev));
559 put_device(cdev);
560 }
561 return shost;
562 }
563 EXPORT_SYMBOL(scsi_host_lookup);
564
565 /**
566 * scsi_host_get - inc a Scsi_Host ref count
567 * @shost: Pointer to Scsi_Host to inc.
568 **/
scsi_host_get(struct Scsi_Host * shost)569 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
570 {
571 if ((shost->shost_state == SHOST_DEL) ||
572 !get_device(&shost->shost_gendev))
573 return NULL;
574 return shost;
575 }
576 EXPORT_SYMBOL(scsi_host_get);
577
scsi_host_check_in_flight(struct request * rq,void * data,bool reserved)578 static bool scsi_host_check_in_flight(struct request *rq, void *data,
579 bool reserved)
580 {
581 int *count = data;
582 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
583
584 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
585 (*count)++;
586
587 return true;
588 }
589
590 /**
591 * scsi_host_busy - Return the host busy counter
592 * @shost: Pointer to Scsi_Host to inc.
593 **/
scsi_host_busy(struct Scsi_Host * shost)594 int scsi_host_busy(struct Scsi_Host *shost)
595 {
596 int cnt = 0;
597
598 blk_mq_tagset_busy_iter(&shost->tag_set,
599 scsi_host_check_in_flight, &cnt);
600 return cnt;
601 }
602 EXPORT_SYMBOL(scsi_host_busy);
603
604 /**
605 * scsi_host_put - dec a Scsi_Host ref count
606 * @shost: Pointer to Scsi_Host to dec.
607 **/
scsi_host_put(struct Scsi_Host * shost)608 void scsi_host_put(struct Scsi_Host *shost)
609 {
610 put_device(&shost->shost_gendev);
611 }
612 EXPORT_SYMBOL(scsi_host_put);
613
scsi_init_hosts(void)614 int scsi_init_hosts(void)
615 {
616 return class_register(&shost_class);
617 }
618
scsi_exit_hosts(void)619 void scsi_exit_hosts(void)
620 {
621 class_unregister(&shost_class);
622 ida_destroy(&host_index_ida);
623 }
624
scsi_is_host_device(const struct device * dev)625 int scsi_is_host_device(const struct device *dev)
626 {
627 return dev->type == &scsi_host_type;
628 }
629 EXPORT_SYMBOL(scsi_is_host_device);
630
631 /**
632 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
633 * @shost: Pointer to Scsi_Host.
634 * @work: Work to queue for execution.
635 *
636 * Return value:
637 * 1 - work queued for execution
638 * 0 - work is already queued
639 * -EINVAL - work queue doesn't exist
640 **/
scsi_queue_work(struct Scsi_Host * shost,struct work_struct * work)641 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
642 {
643 if (unlikely(!shost->work_q)) {
644 shost_printk(KERN_ERR, shost,
645 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
646 "when no workqueue created.\n", shost->hostt->name);
647 dump_stack();
648
649 return -EINVAL;
650 }
651
652 return queue_work(shost->work_q, work);
653 }
654 EXPORT_SYMBOL_GPL(scsi_queue_work);
655
656 /**
657 * scsi_flush_work - Flush a Scsi_Host's workqueue.
658 * @shost: Pointer to Scsi_Host.
659 **/
scsi_flush_work(struct Scsi_Host * shost)660 void scsi_flush_work(struct Scsi_Host *shost)
661 {
662 if (!shost->work_q) {
663 shost_printk(KERN_ERR, shost,
664 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
665 "when no workqueue created.\n", shost->hostt->name);
666 dump_stack();
667 return;
668 }
669
670 flush_workqueue(shost->work_q);
671 }
672 EXPORT_SYMBOL_GPL(scsi_flush_work);
673
complete_all_cmds_iter(struct request * rq,void * data,bool rsvd)674 static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
675 {
676 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
677 enum scsi_host_status status = *(enum scsi_host_status *)data;
678
679 scsi_dma_unmap(scmd);
680 scmd->result = 0;
681 set_host_byte(scmd, status);
682 scsi_done(scmd);
683 return true;
684 }
685
686 /**
687 * scsi_host_complete_all_commands - Terminate all running commands
688 * @shost: Scsi Host on which commands should be terminated
689 * @status: Status to be set for the terminated commands
690 *
691 * There is no protection against modification of the number
692 * of outstanding commands. It is the responsibility of the
693 * caller to ensure that concurrent I/O submission and/or
694 * completion is stopped when calling this function.
695 */
scsi_host_complete_all_commands(struct Scsi_Host * shost,enum scsi_host_status status)696 void scsi_host_complete_all_commands(struct Scsi_Host *shost,
697 enum scsi_host_status status)
698 {
699 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
700 &status);
701 }
702 EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
703
704 struct scsi_host_busy_iter_data {
705 bool (*fn)(struct scsi_cmnd *, void *, bool);
706 void *priv;
707 };
708
__scsi_host_busy_iter_fn(struct request * req,void * priv,bool reserved)709 static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
710 bool reserved)
711 {
712 struct scsi_host_busy_iter_data *iter_data = priv;
713 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
714
715 return iter_data->fn(sc, iter_data->priv, reserved);
716 }
717
718 /**
719 * scsi_host_busy_iter - Iterate over all busy commands
720 * @shost: Pointer to Scsi_Host.
721 * @fn: Function to call on each busy command
722 * @priv: Data pointer passed to @fn
723 *
724 * If locking against concurrent command completions is required
725 * ithas to be provided by the caller
726 **/
scsi_host_busy_iter(struct Scsi_Host * shost,bool (* fn)(struct scsi_cmnd *,void *,bool),void * priv)727 void scsi_host_busy_iter(struct Scsi_Host *shost,
728 bool (*fn)(struct scsi_cmnd *, void *, bool),
729 void *priv)
730 {
731 struct scsi_host_busy_iter_data iter_data = {
732 .fn = fn,
733 .priv = priv,
734 };
735
736 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
737 &iter_data);
738 }
739 EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
740