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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
47static int shost_eh_deadline = -1;
48
49module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
50MODULE_PARM_DESC(eh_deadline,
51 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
52
53static DEFINE_IDA(host_index_ida);
54
55
56static void scsi_host_cls_release(struct device *dev)
57{
58 put_device(&class_to_shost(dev)->shost_gendev);
59}
60
61static 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 **/
75int 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 **/
165void 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
185 /*
186 * New SCSI devices cannot be attached anymore because of the SCSI host
187 * state so drop the tag set refcnt. Wait until the tag set refcnt drops
188 * to zero because .exit_cmd_priv implementations may need the host
189 * pointer.
190 */
191 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
192 wait_for_completion(&shost->tagset_freed);
193
194 spin_lock_irqsave(shost->host_lock, flags);
195 if (scsi_host_set_state(shost, SHOST_DEL))
196 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
197 spin_unlock_irqrestore(shost->host_lock, flags);
198
199 transport_unregister_device(&shost->shost_gendev);
200 device_unregister(&shost->shost_dev);
201 device_del(&shost->shost_gendev);
202}
203EXPORT_SYMBOL(scsi_remove_host);
204
205/**
206 * scsi_add_host_with_dma - add a scsi host with dma device
207 * @shost: scsi host pointer to add
208 * @dev: a struct device of type scsi class
209 * @dma_dev: dma device for the host
210 *
211 * Note: You rarely need to worry about this unless you're in a
212 * virtualised host environments, so use the simpler scsi_add_host()
213 * function instead.
214 *
215 * Return value:
216 * 0 on success / != 0 for error
217 **/
218int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
219 struct device *dma_dev)
220{
221 struct scsi_host_template *sht = shost->hostt;
222 int error = -EINVAL;
223
224 shost_printk(KERN_INFO, shost, "%s\n",
225 sht->info ? sht->info(shost) : sht->name);
226
227 if (!shost->can_queue) {
228 shost_printk(KERN_ERR, shost,
229 "can_queue = 0 no longer supported\n");
230 goto fail;
231 }
232
233 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
234 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
235 shost->can_queue);
236
237 error = scsi_init_sense_cache(shost);
238 if (error)
239 goto fail;
240
241 if (!shost->shost_gendev.parent)
242 shost->shost_gendev.parent = dev ? dev : &platform_bus;
243 if (!dma_dev)
244 dma_dev = shost->shost_gendev.parent;
245
246 shost->dma_dev = dma_dev;
247
248 if (dma_dev->dma_mask) {
249 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
250 dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
251 }
252
253 error = scsi_mq_setup_tags(shost);
254 if (error)
255 goto fail;
256
257 kref_init(&shost->tagset_refcnt);
258 init_completion(&shost->tagset_freed);
259
260 /*
261 * Increase usage count temporarily here so that calling
262 * scsi_autopm_put_host() will trigger runtime idle if there is
263 * nothing else preventing suspending the device.
264 */
265 pm_runtime_get_noresume(&shost->shost_gendev);
266 pm_runtime_set_active(&shost->shost_gendev);
267 pm_runtime_enable(&shost->shost_gendev);
268 device_enable_async_suspend(&shost->shost_gendev);
269
270 error = device_add(&shost->shost_gendev);
271 if (error)
272 goto out_disable_runtime_pm;
273
274 scsi_host_set_state(shost, SHOST_RUNNING);
275 get_device(shost->shost_gendev.parent);
276
277 device_enable_async_suspend(&shost->shost_dev);
278
279 get_device(&shost->shost_gendev);
280 error = device_add(&shost->shost_dev);
281 if (error)
282 goto out_del_gendev;
283
284 if (shost->transportt->host_size) {
285 shost->shost_data = kzalloc(shost->transportt->host_size,
286 GFP_KERNEL);
287 if (shost->shost_data == NULL) {
288 error = -ENOMEM;
289 goto out_del_dev;
290 }
291 }
292
293 if (shost->transportt->create_work_queue) {
294 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
295 "scsi_wq_%d", shost->host_no);
296 shost->work_q = alloc_workqueue("%s",
297 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
298 1, shost->work_q_name);
299
300 if (!shost->work_q) {
301 error = -EINVAL;
302 goto out_del_dev;
303 }
304 }
305
306 error = scsi_sysfs_add_host(shost);
307 if (error)
308 goto out_del_dev;
309
310 scsi_proc_host_add(shost);
311 scsi_autopm_put_host(shost);
312 return error;
313
314 /*
315 * Any host allocation in this function will be freed in
316 * scsi_host_dev_release().
317 */
318 out_del_dev:
319 device_del(&shost->shost_dev);
320 out_del_gendev:
321 /*
322 * Host state is SHOST_RUNNING so we have to explicitly release
323 * ->shost_dev.
324 */
325 put_device(&shost->shost_dev);
326 device_del(&shost->shost_gendev);
327 out_disable_runtime_pm:
328 device_disable_async_suspend(&shost->shost_gendev);
329 pm_runtime_disable(&shost->shost_gendev);
330 pm_runtime_set_suspended(&shost->shost_gendev);
331 pm_runtime_put_noidle(&shost->shost_gendev);
332 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
333 fail:
334 return error;
335}
336EXPORT_SYMBOL(scsi_add_host_with_dma);
337
338static void scsi_host_dev_release(struct device *dev)
339{
340 struct Scsi_Host *shost = dev_to_shost(dev);
341 struct device *parent = dev->parent;
342
343 scsi_proc_hostdir_rm(shost->hostt);
344
345 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
346 rcu_barrier();
347
348 if (shost->tmf_work_q)
349 destroy_workqueue(shost->tmf_work_q);
350 if (shost->ehandler)
351 kthread_stop(shost->ehandler);
352 if (shost->work_q)
353 destroy_workqueue(shost->work_q);
354
355 if (shost->shost_state == SHOST_CREATED) {
356 /*
357 * Free the shost_dev device name here if scsi_host_alloc()
358 * and scsi_host_put() have been called but neither
359 * scsi_host_add() nor scsi_host_remove() has been called.
360 * This avoids that the memory allocated for the shost_dev
361 * name is leaked.
362 */
363 kfree(dev_name(&shost->shost_dev));
364 }
365
366 kfree(shost->shost_data);
367
368 ida_free(&host_index_ida, shost->host_no);
369
370 if (shost->shost_state != SHOST_CREATED)
371 put_device(parent);
372 kfree(shost);
373}
374
375static struct device_type scsi_host_type = {
376 .name = "scsi_host",
377 .release = scsi_host_dev_release,
378};
379
380/**
381 * scsi_host_alloc - register a scsi host adapter instance.
382 * @sht: pointer to scsi host template
383 * @privsize: extra bytes to allocate for driver
384 *
385 * Note:
386 * Allocate a new Scsi_Host and perform basic initialization.
387 * The host is not published to the scsi midlayer until scsi_add_host
388 * is called.
389 *
390 * Return value:
391 * Pointer to a new Scsi_Host
392 **/
393struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
394{
395 struct Scsi_Host *shost;
396 int index;
397
398 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
399 if (!shost)
400 return NULL;
401
402 shost->host_lock = &shost->default_lock;
403 spin_lock_init(shost->host_lock);
404 shost->shost_state = SHOST_CREATED;
405 INIT_LIST_HEAD(&shost->__devices);
406 INIT_LIST_HEAD(&shost->__targets);
407 INIT_LIST_HEAD(&shost->eh_abort_list);
408 INIT_LIST_HEAD(&shost->eh_cmd_q);
409 INIT_LIST_HEAD(&shost->starved_list);
410 init_waitqueue_head(&shost->host_wait);
411 mutex_init(&shost->scan_mutex);
412
413 index = ida_alloc(&host_index_ida, GFP_KERNEL);
414 if (index < 0) {
415 kfree(shost);
416 return NULL;
417 }
418 shost->host_no = index;
419
420 shost->dma_channel = 0xff;
421
422 /* These three are default values which can be overridden */
423 shost->max_channel = 0;
424 shost->max_id = 8;
425 shost->max_lun = 8;
426
427 /* Give each shost a default transportt */
428 shost->transportt = &blank_transport_template;
429
430 /*
431 * All drivers right now should be able to handle 12 byte
432 * commands. Every so often there are requests for 16 byte
433 * commands, but individual low-level drivers need to certify that
434 * they actually do something sensible with such commands.
435 */
436 shost->max_cmd_len = 12;
437 shost->hostt = sht;
438 shost->this_id = sht->this_id;
439 shost->can_queue = sht->can_queue;
440 shost->sg_tablesize = sht->sg_tablesize;
441 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
442 shost->cmd_per_lun = sht->cmd_per_lun;
443 shost->no_write_same = sht->no_write_same;
444 shost->host_tagset = sht->host_tagset;
445
446 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
447 shost->eh_deadline = -1;
448 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
449 shost_printk(KERN_WARNING, shost,
450 "eh_deadline %u too large, setting to %u\n",
451 shost_eh_deadline, INT_MAX / HZ);
452 shost->eh_deadline = INT_MAX;
453 } else
454 shost->eh_deadline = shost_eh_deadline * HZ;
455
456 if (sht->supported_mode == MODE_UNKNOWN)
457 /* means we didn't set it ... default to INITIATOR */
458 shost->active_mode = MODE_INITIATOR;
459 else
460 shost->active_mode = sht->supported_mode;
461
462 if (sht->max_host_blocked)
463 shost->max_host_blocked = sht->max_host_blocked;
464 else
465 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
466
467 /*
468 * If the driver imposes no hard sector transfer limit, start at
469 * machine infinity initially.
470 */
471 if (sht->max_sectors)
472 shost->max_sectors = sht->max_sectors;
473 else
474 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
475
476 if (sht->max_segment_size)
477 shost->max_segment_size = sht->max_segment_size;
478 else
479 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
480
481 /*
482 * assume a 4GB boundary, if not set
483 */
484 if (sht->dma_boundary)
485 shost->dma_boundary = sht->dma_boundary;
486 else
487 shost->dma_boundary = 0xffffffff;
488
489 if (sht->virt_boundary_mask)
490 shost->virt_boundary_mask = sht->virt_boundary_mask;
491
492 device_initialize(&shost->shost_gendev);
493 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
494 shost->shost_gendev.bus = &scsi_bus_type;
495 shost->shost_gendev.type = &scsi_host_type;
496 scsi_enable_async_suspend(&shost->shost_gendev);
497
498 device_initialize(&shost->shost_dev);
499 shost->shost_dev.parent = &shost->shost_gendev;
500 shost->shost_dev.class = &shost_class;
501 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
502 shost->shost_dev.groups = sht->shost_groups;
503
504 shost->ehandler = kthread_run(scsi_error_handler, shost,
505 "scsi_eh_%d", shost->host_no);
506 if (IS_ERR(shost->ehandler)) {
507 shost_printk(KERN_WARNING, shost,
508 "error handler thread failed to spawn, error = %ld\n",
509 PTR_ERR(shost->ehandler));
510 shost->ehandler = NULL;
511 goto fail;
512 }
513
514 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
515 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
516 1, shost->host_no);
517 if (!shost->tmf_work_q) {
518 shost_printk(KERN_WARNING, shost,
519 "failed to create tmf workq\n");
520 goto fail;
521 }
522 if (scsi_proc_hostdir_add(shost->hostt) < 0)
523 goto fail;
524 return shost;
525 fail:
526 /*
527 * Host state is still SHOST_CREATED and that is enough to release
528 * ->shost_gendev. scsi_host_dev_release() will free
529 * dev_name(&shost->shost_dev).
530 */
531 put_device(&shost->shost_gendev);
532
533 return NULL;
534}
535EXPORT_SYMBOL(scsi_host_alloc);
536
537static int __scsi_host_match(struct device *dev, const void *data)
538{
539 struct Scsi_Host *p;
540 const unsigned short *hostnum = data;
541
542 p = class_to_shost(dev);
543 return p->host_no == *hostnum;
544}
545
546/**
547 * scsi_host_lookup - get a reference to a Scsi_Host by host no
548 * @hostnum: host number to locate
549 *
550 * Return value:
551 * A pointer to located Scsi_Host or NULL.
552 *
553 * The caller must do a scsi_host_put() to drop the reference
554 * that scsi_host_get() took. The put_device() below dropped
555 * the reference from class_find_device().
556 **/
557struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
558{
559 struct device *cdev;
560 struct Scsi_Host *shost = NULL;
561
562 cdev = class_find_device(&shost_class, NULL, &hostnum,
563 __scsi_host_match);
564 if (cdev) {
565 shost = scsi_host_get(class_to_shost(cdev));
566 put_device(cdev);
567 }
568 return shost;
569}
570EXPORT_SYMBOL(scsi_host_lookup);
571
572/**
573 * scsi_host_get - inc a Scsi_Host ref count
574 * @shost: Pointer to Scsi_Host to inc.
575 **/
576struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
577{
578 if ((shost->shost_state == SHOST_DEL) ||
579 !get_device(&shost->shost_gendev))
580 return NULL;
581 return shost;
582}
583EXPORT_SYMBOL(scsi_host_get);
584
585static bool scsi_host_check_in_flight(struct request *rq, void *data)
586{
587 int *count = data;
588 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
589
590 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
591 (*count)++;
592
593 return true;
594}
595
596/**
597 * scsi_host_busy - Return the host busy counter
598 * @shost: Pointer to Scsi_Host to inc.
599 **/
600int scsi_host_busy(struct Scsi_Host *shost)
601{
602 int cnt = 0;
603
604 blk_mq_tagset_busy_iter(&shost->tag_set,
605 scsi_host_check_in_flight, &cnt);
606 return cnt;
607}
608EXPORT_SYMBOL(scsi_host_busy);
609
610/**
611 * scsi_host_put - dec a Scsi_Host ref count
612 * @shost: Pointer to Scsi_Host to dec.
613 **/
614void scsi_host_put(struct Scsi_Host *shost)
615{
616 put_device(&shost->shost_gendev);
617}
618EXPORT_SYMBOL(scsi_host_put);
619
620int scsi_init_hosts(void)
621{
622 return class_register(&shost_class);
623}
624
625void scsi_exit_hosts(void)
626{
627 class_unregister(&shost_class);
628 ida_destroy(&host_index_ida);
629}
630
631int scsi_is_host_device(const struct device *dev)
632{
633 return dev->type == &scsi_host_type;
634}
635EXPORT_SYMBOL(scsi_is_host_device);
636
637/**
638 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
639 * @shost: Pointer to Scsi_Host.
640 * @work: Work to queue for execution.
641 *
642 * Return value:
643 * 1 - work queued for execution
644 * 0 - work is already queued
645 * -EINVAL - work queue doesn't exist
646 **/
647int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
648{
649 if (unlikely(!shost->work_q)) {
650 shost_printk(KERN_ERR, shost,
651 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
652 "when no workqueue created.\n", shost->hostt->name);
653 dump_stack();
654
655 return -EINVAL;
656 }
657
658 return queue_work(shost->work_q, work);
659}
660EXPORT_SYMBOL_GPL(scsi_queue_work);
661
662/**
663 * scsi_flush_work - Flush a Scsi_Host's workqueue.
664 * @shost: Pointer to Scsi_Host.
665 **/
666void scsi_flush_work(struct Scsi_Host *shost)
667{
668 if (!shost->work_q) {
669 shost_printk(KERN_ERR, shost,
670 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
671 "when no workqueue created.\n", shost->hostt->name);
672 dump_stack();
673 return;
674 }
675
676 flush_workqueue(shost->work_q);
677}
678EXPORT_SYMBOL_GPL(scsi_flush_work);
679
680static bool complete_all_cmds_iter(struct request *rq, void *data)
681{
682 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
683 enum scsi_host_status status = *(enum scsi_host_status *)data;
684
685 scsi_dma_unmap(scmd);
686 scmd->result = 0;
687 set_host_byte(scmd, status);
688 scsi_done(scmd);
689 return true;
690}
691
692/**
693 * scsi_host_complete_all_commands - Terminate all running commands
694 * @shost: Scsi Host on which commands should be terminated
695 * @status: Status to be set for the terminated commands
696 *
697 * There is no protection against modification of the number
698 * of outstanding commands. It is the responsibility of the
699 * caller to ensure that concurrent I/O submission and/or
700 * completion is stopped when calling this function.
701 */
702void scsi_host_complete_all_commands(struct Scsi_Host *shost,
703 enum scsi_host_status status)
704{
705 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
706 &status);
707}
708EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
709
710struct scsi_host_busy_iter_data {
711 bool (*fn)(struct scsi_cmnd *, void *);
712 void *priv;
713};
714
715static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
716{
717 struct scsi_host_busy_iter_data *iter_data = priv;
718 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
719
720 return iter_data->fn(sc, iter_data->priv);
721}
722
723/**
724 * scsi_host_busy_iter - Iterate over all busy commands
725 * @shost: Pointer to Scsi_Host.
726 * @fn: Function to call on each busy command
727 * @priv: Data pointer passed to @fn
728 *
729 * If locking against concurrent command completions is required
730 * ithas to be provided by the caller
731 **/
732void scsi_host_busy_iter(struct Scsi_Host *shost,
733 bool (*fn)(struct scsi_cmnd *, void *),
734 void *priv)
735{
736 struct scsi_host_busy_iter_data iter_data = {
737 .fn = fn,
738 .priv = priv,
739 };
740
741 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
742 &iter_data);
743}
744EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
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
47static int shost_eh_deadline = -1;
48
49module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
50MODULE_PARM_DESC(eh_deadline,
51 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
52
53static DEFINE_IDA(host_index_ida);
54
55
56static void scsi_host_cls_release(struct device *dev)
57{
58 put_device(&class_to_shost(dev)->shost_gendev);
59}
60
61static 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 **/
75int 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 **/
165void 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}
204EXPORT_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 **/
219int 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 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
235 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
236 shost->can_queue);
237
238 error = scsi_init_sense_cache(shost);
239 if (error)
240 goto fail;
241
242 if (!shost->shost_gendev.parent)
243 shost->shost_gendev.parent = dev ? dev : &platform_bus;
244 if (!dma_dev)
245 dma_dev = shost->shost_gendev.parent;
246
247 shost->dma_dev = dma_dev;
248
249 if (dma_dev->dma_mask) {
250 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
251 dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
252 }
253
254 error = scsi_mq_setup_tags(shost);
255 if (error)
256 goto fail;
257
258 kref_init(&shost->tagset_refcnt);
259 init_completion(&shost->tagset_freed);
260
261 /*
262 * Increase usage count temporarily here so that calling
263 * scsi_autopm_put_host() will trigger runtime idle if there is
264 * nothing else preventing suspending the device.
265 */
266 pm_runtime_get_noresume(&shost->shost_gendev);
267 pm_runtime_set_active(&shost->shost_gendev);
268 pm_runtime_enable(&shost->shost_gendev);
269 device_enable_async_suspend(&shost->shost_gendev);
270
271 error = device_add(&shost->shost_gendev);
272 if (error)
273 goto out_disable_runtime_pm;
274
275 scsi_host_set_state(shost, SHOST_RUNNING);
276 get_device(shost->shost_gendev.parent);
277
278 device_enable_async_suspend(&shost->shost_dev);
279
280 get_device(&shost->shost_gendev);
281 error = device_add(&shost->shost_dev);
282 if (error)
283 goto out_del_gendev;
284
285 if (shost->transportt->host_size) {
286 shost->shost_data = kzalloc(shost->transportt->host_size,
287 GFP_KERNEL);
288 if (shost->shost_data == NULL) {
289 error = -ENOMEM;
290 goto out_del_dev;
291 }
292 }
293
294 if (shost->transportt->create_work_queue) {
295 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
296 "scsi_wq_%d", shost->host_no);
297 shost->work_q = alloc_workqueue("%s",
298 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
299 1, shost->work_q_name);
300
301 if (!shost->work_q) {
302 error = -EINVAL;
303 goto out_del_dev;
304 }
305 }
306
307 error = scsi_sysfs_add_host(shost);
308 if (error)
309 goto out_del_dev;
310
311 scsi_proc_host_add(shost);
312 scsi_autopm_put_host(shost);
313 return error;
314
315 /*
316 * Any host allocation in this function will be freed in
317 * scsi_host_dev_release().
318 */
319 out_del_dev:
320 device_del(&shost->shost_dev);
321 out_del_gendev:
322 /*
323 * Host state is SHOST_RUNNING so we have to explicitly release
324 * ->shost_dev.
325 */
326 put_device(&shost->shost_dev);
327 device_del(&shost->shost_gendev);
328 out_disable_runtime_pm:
329 device_disable_async_suspend(&shost->shost_gendev);
330 pm_runtime_disable(&shost->shost_gendev);
331 pm_runtime_set_suspended(&shost->shost_gendev);
332 pm_runtime_put_noidle(&shost->shost_gendev);
333 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
334 fail:
335 return error;
336}
337EXPORT_SYMBOL(scsi_add_host_with_dma);
338
339static void scsi_host_dev_release(struct device *dev)
340{
341 struct Scsi_Host *shost = dev_to_shost(dev);
342 struct device *parent = dev->parent;
343
344 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
345 rcu_barrier();
346
347 if (shost->tmf_work_q)
348 destroy_workqueue(shost->tmf_work_q);
349 if (shost->ehandler)
350 kthread_stop(shost->ehandler);
351 if (shost->work_q)
352 destroy_workqueue(shost->work_q);
353
354 if (shost->shost_state == SHOST_CREATED) {
355 /*
356 * Free the shost_dev device name here if scsi_host_alloc()
357 * and scsi_host_put() have been called but neither
358 * scsi_host_add() nor scsi_remove_host() has been called.
359 * This avoids that the memory allocated for the shost_dev
360 * name is leaked.
361 */
362 kfree(dev_name(&shost->shost_dev));
363 }
364
365 kfree(shost->shost_data);
366
367 ida_free(&host_index_ida, shost->host_no);
368
369 if (shost->shost_state != SHOST_CREATED)
370 put_device(parent);
371 kfree(shost);
372}
373
374static struct device_type scsi_host_type = {
375 .name = "scsi_host",
376 .release = scsi_host_dev_release,
377};
378
379/**
380 * scsi_host_alloc - register a scsi host adapter instance.
381 * @sht: pointer to scsi host template
382 * @privsize: extra bytes to allocate for driver
383 *
384 * Note:
385 * Allocate a new Scsi_Host and perform basic initialization.
386 * The host is not published to the scsi midlayer until scsi_add_host
387 * is called.
388 *
389 * Return value:
390 * Pointer to a new Scsi_Host
391 **/
392struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int privsize)
393{
394 struct Scsi_Host *shost;
395 int index;
396
397 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
398 if (!shost)
399 return NULL;
400
401 shost->host_lock = &shost->default_lock;
402 spin_lock_init(shost->host_lock);
403 shost->shost_state = SHOST_CREATED;
404 INIT_LIST_HEAD(&shost->__devices);
405 INIT_LIST_HEAD(&shost->__targets);
406 INIT_LIST_HEAD(&shost->eh_abort_list);
407 INIT_LIST_HEAD(&shost->eh_cmd_q);
408 INIT_LIST_HEAD(&shost->starved_list);
409 init_waitqueue_head(&shost->host_wait);
410 mutex_init(&shost->scan_mutex);
411
412 index = ida_alloc(&host_index_ida, GFP_KERNEL);
413 if (index < 0) {
414 kfree(shost);
415 return NULL;
416 }
417 shost->host_no = index;
418
419 shost->dma_channel = 0xff;
420
421 /* These three are default values which can be overridden */
422 shost->max_channel = 0;
423 shost->max_id = 8;
424 shost->max_lun = 8;
425
426 /* Give each shost a default transportt */
427 shost->transportt = &blank_transport_template;
428
429 /*
430 * All drivers right now should be able to handle 12 byte
431 * commands. Every so often there are requests for 16 byte
432 * commands, but individual low-level drivers need to certify that
433 * they actually do something sensible with such commands.
434 */
435 shost->max_cmd_len = 12;
436 shost->hostt = sht;
437 shost->this_id = sht->this_id;
438 shost->can_queue = sht->can_queue;
439 shost->sg_tablesize = sht->sg_tablesize;
440 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
441 shost->cmd_per_lun = sht->cmd_per_lun;
442 shost->no_write_same = sht->no_write_same;
443 shost->host_tagset = sht->host_tagset;
444 shost->queuecommand_may_block = sht->queuecommand_may_block;
445
446 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
447 shost->eh_deadline = -1;
448 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
449 shost_printk(KERN_WARNING, shost,
450 "eh_deadline %u too large, setting to %u\n",
451 shost_eh_deadline, INT_MAX / HZ);
452 shost->eh_deadline = INT_MAX;
453 } else
454 shost->eh_deadline = shost_eh_deadline * HZ;
455
456 if (sht->supported_mode == MODE_UNKNOWN)
457 /* means we didn't set it ... default to INITIATOR */
458 shost->active_mode = MODE_INITIATOR;
459 else
460 shost->active_mode = sht->supported_mode;
461
462 if (sht->max_host_blocked)
463 shost->max_host_blocked = sht->max_host_blocked;
464 else
465 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
466
467 /*
468 * If the driver imposes no hard sector transfer limit, start at
469 * machine infinity initially.
470 */
471 if (sht->max_sectors)
472 shost->max_sectors = sht->max_sectors;
473 else
474 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
475
476 if (sht->max_segment_size)
477 shost->max_segment_size = sht->max_segment_size;
478 else
479 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
480
481 /*
482 * assume a 4GB boundary, if not set
483 */
484 if (sht->dma_boundary)
485 shost->dma_boundary = sht->dma_boundary;
486 else
487 shost->dma_boundary = 0xffffffff;
488
489 if (sht->virt_boundary_mask)
490 shost->virt_boundary_mask = sht->virt_boundary_mask;
491
492 device_initialize(&shost->shost_gendev);
493 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
494 shost->shost_gendev.bus = &scsi_bus_type;
495 shost->shost_gendev.type = &scsi_host_type;
496 scsi_enable_async_suspend(&shost->shost_gendev);
497
498 device_initialize(&shost->shost_dev);
499 shost->shost_dev.parent = &shost->shost_gendev;
500 shost->shost_dev.class = &shost_class;
501 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
502 shost->shost_dev.groups = sht->shost_groups;
503
504 shost->ehandler = kthread_run(scsi_error_handler, shost,
505 "scsi_eh_%d", shost->host_no);
506 if (IS_ERR(shost->ehandler)) {
507 shost_printk(KERN_WARNING, shost,
508 "error handler thread failed to spawn, error = %ld\n",
509 PTR_ERR(shost->ehandler));
510 shost->ehandler = NULL;
511 goto fail;
512 }
513
514 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
515 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
516 1, shost->host_no);
517 if (!shost->tmf_work_q) {
518 shost_printk(KERN_WARNING, shost,
519 "failed to create tmf workq\n");
520 goto fail;
521 }
522 if (scsi_proc_hostdir_add(shost->hostt) < 0)
523 goto fail;
524 return shost;
525 fail:
526 /*
527 * Host state is still SHOST_CREATED and that is enough to release
528 * ->shost_gendev. scsi_host_dev_release() will free
529 * dev_name(&shost->shost_dev).
530 */
531 put_device(&shost->shost_gendev);
532
533 return NULL;
534}
535EXPORT_SYMBOL(scsi_host_alloc);
536
537static int __scsi_host_match(struct device *dev, const void *data)
538{
539 struct Scsi_Host *p;
540 const unsigned int *hostnum = data;
541
542 p = class_to_shost(dev);
543 return p->host_no == *hostnum;
544}
545
546/**
547 * scsi_host_lookup - get a reference to a Scsi_Host by host no
548 * @hostnum: host number to locate
549 *
550 * Return value:
551 * A pointer to located Scsi_Host or NULL.
552 *
553 * The caller must do a scsi_host_put() to drop the reference
554 * that scsi_host_get() took. The put_device() below dropped
555 * the reference from class_find_device().
556 **/
557struct Scsi_Host *scsi_host_lookup(unsigned int hostnum)
558{
559 struct device *cdev;
560 struct Scsi_Host *shost = NULL;
561
562 cdev = class_find_device(&shost_class, NULL, &hostnum,
563 __scsi_host_match);
564 if (cdev) {
565 shost = scsi_host_get(class_to_shost(cdev));
566 put_device(cdev);
567 }
568 return shost;
569}
570EXPORT_SYMBOL(scsi_host_lookup);
571
572/**
573 * scsi_host_get - inc a Scsi_Host ref count
574 * @shost: Pointer to Scsi_Host to inc.
575 **/
576struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
577{
578 if ((shost->shost_state == SHOST_DEL) ||
579 !get_device(&shost->shost_gendev))
580 return NULL;
581 return shost;
582}
583EXPORT_SYMBOL(scsi_host_get);
584
585static bool scsi_host_check_in_flight(struct request *rq, void *data)
586{
587 int *count = data;
588 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
589
590 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
591 (*count)++;
592
593 return true;
594}
595
596/**
597 * scsi_host_busy - Return the host busy counter
598 * @shost: Pointer to Scsi_Host to inc.
599 **/
600int scsi_host_busy(struct Scsi_Host *shost)
601{
602 int cnt = 0;
603
604 blk_mq_tagset_busy_iter(&shost->tag_set,
605 scsi_host_check_in_flight, &cnt);
606 return cnt;
607}
608EXPORT_SYMBOL(scsi_host_busy);
609
610/**
611 * scsi_host_put - dec a Scsi_Host ref count
612 * @shost: Pointer to Scsi_Host to dec.
613 **/
614void scsi_host_put(struct Scsi_Host *shost)
615{
616 put_device(&shost->shost_gendev);
617}
618EXPORT_SYMBOL(scsi_host_put);
619
620int scsi_init_hosts(void)
621{
622 return class_register(&shost_class);
623}
624
625void scsi_exit_hosts(void)
626{
627 class_unregister(&shost_class);
628 ida_destroy(&host_index_ida);
629}
630
631int scsi_is_host_device(const struct device *dev)
632{
633 return dev->type == &scsi_host_type;
634}
635EXPORT_SYMBOL(scsi_is_host_device);
636
637/**
638 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
639 * @shost: Pointer to Scsi_Host.
640 * @work: Work to queue for execution.
641 *
642 * Return value:
643 * 1 - work queued for execution
644 * 0 - work is already queued
645 * -EINVAL - work queue doesn't exist
646 **/
647int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
648{
649 if (unlikely(!shost->work_q)) {
650 shost_printk(KERN_ERR, shost,
651 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
652 "when no workqueue created.\n", shost->hostt->name);
653 dump_stack();
654
655 return -EINVAL;
656 }
657
658 return queue_work(shost->work_q, work);
659}
660EXPORT_SYMBOL_GPL(scsi_queue_work);
661
662/**
663 * scsi_flush_work - Flush a Scsi_Host's workqueue.
664 * @shost: Pointer to Scsi_Host.
665 **/
666void scsi_flush_work(struct Scsi_Host *shost)
667{
668 if (!shost->work_q) {
669 shost_printk(KERN_ERR, shost,
670 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
671 "when no workqueue created.\n", shost->hostt->name);
672 dump_stack();
673 return;
674 }
675
676 flush_workqueue(shost->work_q);
677}
678EXPORT_SYMBOL_GPL(scsi_flush_work);
679
680static bool complete_all_cmds_iter(struct request *rq, void *data)
681{
682 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
683 enum scsi_host_status status = *(enum scsi_host_status *)data;
684
685 scsi_dma_unmap(scmd);
686 scmd->result = 0;
687 set_host_byte(scmd, status);
688 scsi_done(scmd);
689 return true;
690}
691
692/**
693 * scsi_host_complete_all_commands - Terminate all running commands
694 * @shost: Scsi Host on which commands should be terminated
695 * @status: Status to be set for the terminated commands
696 *
697 * There is no protection against modification of the number
698 * of outstanding commands. It is the responsibility of the
699 * caller to ensure that concurrent I/O submission and/or
700 * completion is stopped when calling this function.
701 */
702void scsi_host_complete_all_commands(struct Scsi_Host *shost,
703 enum scsi_host_status status)
704{
705 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
706 &status);
707}
708EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
709
710struct scsi_host_busy_iter_data {
711 bool (*fn)(struct scsi_cmnd *, void *);
712 void *priv;
713};
714
715static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
716{
717 struct scsi_host_busy_iter_data *iter_data = priv;
718 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
719
720 return iter_data->fn(sc, iter_data->priv);
721}
722
723/**
724 * scsi_host_busy_iter - Iterate over all busy commands
725 * @shost: Pointer to Scsi_Host.
726 * @fn: Function to call on each busy command
727 * @priv: Data pointer passed to @fn
728 *
729 * If locking against concurrent command completions is required
730 * ithas to be provided by the caller
731 **/
732void scsi_host_busy_iter(struct Scsi_Host *shost,
733 bool (*fn)(struct scsi_cmnd *, void *),
734 void *priv)
735{
736 struct scsi_host_busy_iter_data iter_data = {
737 .fn = fn,
738 .priv = priv,
739 };
740
741 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
742 &iter_data);
743}
744EXPORT_SYMBOL_GPL(scsi_host_busy_iter);