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