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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 DEFINE_IDA(host_index_ida);
46
47
48static void scsi_host_cls_release(struct device *dev)
49{
50 put_device(&class_to_shost(dev)->shost_gendev);
51}
52
53static struct class shost_class = {
54 .name = "scsi_host",
55 .dev_release = scsi_host_cls_release,
56};
57
58/**
59 * scsi_host_set_state - Take the given host through the host state model.
60 * @shost: scsi host to change the state of.
61 * @state: state to change to.
62 *
63 * Returns zero if unsuccessful or an error if the requested
64 * transition is illegal.
65 **/
66int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
67{
68 enum scsi_host_state oldstate = shost->shost_state;
69
70 if (state == oldstate)
71 return 0;
72
73 switch (state) {
74 case SHOST_CREATED:
75 /* There are no legal states that come back to
76 * created. This is the manually initialised start
77 * state */
78 goto illegal;
79
80 case SHOST_RUNNING:
81 switch (oldstate) {
82 case SHOST_CREATED:
83 case SHOST_RECOVERY:
84 break;
85 default:
86 goto illegal;
87 }
88 break;
89
90 case SHOST_RECOVERY:
91 switch (oldstate) {
92 case SHOST_RUNNING:
93 break;
94 default:
95 goto illegal;
96 }
97 break;
98
99 case SHOST_CANCEL:
100 switch (oldstate) {
101 case SHOST_CREATED:
102 case SHOST_RUNNING:
103 case SHOST_CANCEL_RECOVERY:
104 break;
105 default:
106 goto illegal;
107 }
108 break;
109
110 case SHOST_DEL:
111 switch (oldstate) {
112 case SHOST_CANCEL:
113 case SHOST_DEL_RECOVERY:
114 break;
115 default:
116 goto illegal;
117 }
118 break;
119
120 case SHOST_CANCEL_RECOVERY:
121 switch (oldstate) {
122 case SHOST_CANCEL:
123 case SHOST_RECOVERY:
124 break;
125 default:
126 goto illegal;
127 }
128 break;
129
130 case SHOST_DEL_RECOVERY:
131 switch (oldstate) {
132 case SHOST_CANCEL_RECOVERY:
133 break;
134 default:
135 goto illegal;
136 }
137 break;
138 }
139 shost->shost_state = state;
140 return 0;
141
142 illegal:
143 SCSI_LOG_ERROR_RECOVERY(1,
144 shost_printk(KERN_ERR, shost,
145 "Illegal host state transition"
146 "%s->%s\n",
147 scsi_host_state_name(oldstate),
148 scsi_host_state_name(state)));
149 return -EINVAL;
150}
151EXPORT_SYMBOL(scsi_host_set_state);
152
153/**
154 * scsi_remove_host - remove a scsi host
155 * @shost: a pointer to a scsi host to remove
156 **/
157void scsi_remove_host(struct Scsi_Host *shost)
158{
159 unsigned long flags;
160
161 mutex_lock(&shost->scan_mutex);
162 spin_lock_irqsave(shost->host_lock, flags);
163 if (scsi_host_set_state(shost, SHOST_CANCEL))
164 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
165 spin_unlock_irqrestore(shost->host_lock, flags);
166 mutex_unlock(&shost->scan_mutex);
167 return;
168 }
169 spin_unlock_irqrestore(shost->host_lock, flags);
170
171 scsi_autopm_get_host(shost);
172 flush_workqueue(shost->tmf_work_q);
173 scsi_forget_host(shost);
174 mutex_unlock(&shost->scan_mutex);
175 scsi_proc_host_rm(shost);
176
177 spin_lock_irqsave(shost->host_lock, flags);
178 if (scsi_host_set_state(shost, SHOST_DEL))
179 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
180 spin_unlock_irqrestore(shost->host_lock, flags);
181
182 transport_unregister_device(&shost->shost_gendev);
183 device_unregister(&shost->shost_dev);
184 device_del(&shost->shost_gendev);
185}
186EXPORT_SYMBOL(scsi_remove_host);
187
188/**
189 * scsi_add_host_with_dma - add a scsi host with dma device
190 * @shost: scsi host pointer to add
191 * @dev: a struct device of type scsi class
192 * @dma_dev: dma device for the host
193 *
194 * Note: You rarely need to worry about this unless you're in a
195 * virtualised host environments, so use the simpler scsi_add_host()
196 * function instead.
197 *
198 * Return value:
199 * 0 on success / != 0 for error
200 **/
201int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
202 struct device *dma_dev)
203{
204 struct scsi_host_template *sht = shost->hostt;
205 int error = -EINVAL;
206
207 shost_printk(KERN_INFO, shost, "%s\n",
208 sht->info ? sht->info(shost) : sht->name);
209
210 if (!shost->can_queue) {
211 shost_printk(KERN_ERR, shost,
212 "can_queue = 0 no longer supported\n");
213 goto fail;
214 }
215
216 if (shost_use_blk_mq(shost)) {
217 error = scsi_mq_setup_tags(shost);
218 if (error)
219 goto fail;
220 } else {
221 shost->bqt = blk_init_tags(shost->can_queue,
222 shost->hostt->tag_alloc_policy);
223 if (!shost->bqt) {
224 error = -ENOMEM;
225 goto fail;
226 }
227 }
228
229 /*
230 * Note that we allocate the freelist even for the MQ case for now,
231 * as we need a command set aside for scsi_reset_provider. Having
232 * the full host freelist and one command available for that is a
233 * little heavy-handed, but avoids introducing a special allocator
234 * just for this. Eventually the structure of scsi_reset_provider
235 * will need a major overhaul.
236 */
237 error = scsi_setup_command_freelist(shost);
238 if (error)
239 goto out_destroy_tags;
240
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 /*
250 * Increase usage count temporarily here so that calling
251 * scsi_autopm_put_host() will trigger runtime idle if there is
252 * nothing else preventing suspending the device.
253 */
254 pm_runtime_get_noresume(&shost->shost_gendev);
255 pm_runtime_set_active(&shost->shost_gendev);
256 pm_runtime_enable(&shost->shost_gendev);
257 device_enable_async_suspend(&shost->shost_gendev);
258
259 error = device_add(&shost->shost_gendev);
260 if (error)
261 goto out_destroy_freelist;
262
263 scsi_host_set_state(shost, SHOST_RUNNING);
264 get_device(shost->shost_gendev.parent);
265
266 device_enable_async_suspend(&shost->shost_dev);
267
268 error = device_add(&shost->shost_dev);
269 if (error)
270 goto out_del_gendev;
271
272 get_device(&shost->shost_gendev);
273
274 if (shost->transportt->host_size) {
275 shost->shost_data = kzalloc(shost->transportt->host_size,
276 GFP_KERNEL);
277 if (shost->shost_data == NULL) {
278 error = -ENOMEM;
279 goto out_del_dev;
280 }
281 }
282
283 if (shost->transportt->create_work_queue) {
284 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
285 "scsi_wq_%d", shost->host_no);
286 shost->work_q = create_singlethread_workqueue(
287 shost->work_q_name);
288 if (!shost->work_q) {
289 error = -EINVAL;
290 goto out_free_shost_data;
291 }
292 }
293
294 error = scsi_sysfs_add_host(shost);
295 if (error)
296 goto out_destroy_host;
297
298 scsi_proc_host_add(shost);
299 scsi_autopm_put_host(shost);
300 return error;
301
302 out_destroy_host:
303 if (shost->work_q)
304 destroy_workqueue(shost->work_q);
305 out_free_shost_data:
306 kfree(shost->shost_data);
307 out_del_dev:
308 device_del(&shost->shost_dev);
309 out_del_gendev:
310 device_del(&shost->shost_gendev);
311 out_destroy_freelist:
312 device_disable_async_suspend(&shost->shost_gendev);
313 pm_runtime_disable(&shost->shost_gendev);
314 pm_runtime_set_suspended(&shost->shost_gendev);
315 pm_runtime_put_noidle(&shost->shost_gendev);
316 scsi_destroy_command_freelist(shost);
317 out_destroy_tags:
318 if (shost_use_blk_mq(shost))
319 scsi_mq_destroy_tags(shost);
320 fail:
321 return error;
322}
323EXPORT_SYMBOL(scsi_add_host_with_dma);
324
325static void scsi_host_dev_release(struct device *dev)
326{
327 struct Scsi_Host *shost = dev_to_shost(dev);
328 struct device *parent = dev->parent;
329 struct request_queue *q;
330 void *queuedata;
331
332 scsi_proc_hostdir_rm(shost->hostt);
333
334 if (shost->tmf_work_q)
335 destroy_workqueue(shost->tmf_work_q);
336 if (shost->ehandler)
337 kthread_stop(shost->ehandler);
338 if (shost->work_q)
339 destroy_workqueue(shost->work_q);
340 q = shost->uspace_req_q;
341 if (q) {
342 queuedata = q->queuedata;
343 blk_cleanup_queue(q);
344 kfree(queuedata);
345 }
346
347 if (shost->shost_state == SHOST_CREATED) {
348 /*
349 * Free the shost_dev device name here if scsi_host_alloc()
350 * and scsi_host_put() have been called but neither
351 * scsi_host_add() nor scsi_host_remove() has been called.
352 * This avoids that the memory allocated for the shost_dev
353 * name is leaked.
354 */
355 kfree(dev_name(&shost->shost_dev));
356 }
357
358 scsi_destroy_command_freelist(shost);
359 if (shost_use_blk_mq(shost)) {
360 if (shost->tag_set.tags)
361 scsi_mq_destroy_tags(shost);
362 } else {
363 if (shost->bqt)
364 blk_free_tags(shost->bqt);
365 }
366
367 kfree(shost->shost_data);
368
369 ida_simple_remove(&host_index_ida, shost->host_no);
370
371 if (parent)
372 put_device(parent);
373 kfree(shost);
374}
375
376static int shost_eh_deadline = -1;
377
378module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
379MODULE_PARM_DESC(eh_deadline,
380 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
381
382static struct device_type scsi_host_type = {
383 .name = "scsi_host",
384 .release = scsi_host_dev_release,
385};
386
387/**
388 * scsi_host_alloc - register a scsi host adapter instance.
389 * @sht: pointer to scsi host template
390 * @privsize: extra bytes to allocate for driver
391 *
392 * Note:
393 * Allocate a new Scsi_Host and perform basic initialization.
394 * The host is not published to the scsi midlayer until scsi_add_host
395 * is called.
396 *
397 * Return value:
398 * Pointer to a new Scsi_Host
399 **/
400struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
401{
402 struct Scsi_Host *shost;
403 gfp_t gfp_mask = GFP_KERNEL;
404 int index;
405
406 if (sht->unchecked_isa_dma && privsize)
407 gfp_mask |= __GFP_DMA;
408
409 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
410 if (!shost)
411 return NULL;
412
413 shost->host_lock = &shost->default_lock;
414 spin_lock_init(shost->host_lock);
415 shost->shost_state = SHOST_CREATED;
416 INIT_LIST_HEAD(&shost->__devices);
417 INIT_LIST_HEAD(&shost->__targets);
418 INIT_LIST_HEAD(&shost->eh_cmd_q);
419 INIT_LIST_HEAD(&shost->starved_list);
420 init_waitqueue_head(&shost->host_wait);
421 mutex_init(&shost->scan_mutex);
422
423 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
424 if (index < 0)
425 goto fail_kfree;
426 shost->host_no = index;
427
428 shost->dma_channel = 0xff;
429
430 /* These three are default values which can be overridden */
431 shost->max_channel = 0;
432 shost->max_id = 8;
433 shost->max_lun = 8;
434
435 /* Give each shost a default transportt */
436 shost->transportt = &blank_transport_template;
437
438 /*
439 * All drivers right now should be able to handle 12 byte
440 * commands. Every so often there are requests for 16 byte
441 * commands, but individual low-level drivers need to certify that
442 * they actually do something sensible with such commands.
443 */
444 shost->max_cmd_len = 12;
445 shost->hostt = sht;
446 shost->this_id = sht->this_id;
447 shost->can_queue = sht->can_queue;
448 shost->sg_tablesize = sht->sg_tablesize;
449 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
450 shost->cmd_per_lun = sht->cmd_per_lun;
451 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
452 shost->use_clustering = sht->use_clustering;
453 shost->no_write_same = sht->no_write_same;
454
455 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
456 shost->eh_deadline = -1;
457 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
458 shost_printk(KERN_WARNING, shost,
459 "eh_deadline %u too large, setting to %u\n",
460 shost_eh_deadline, INT_MAX / HZ);
461 shost->eh_deadline = INT_MAX;
462 } else
463 shost->eh_deadline = shost_eh_deadline * HZ;
464
465 if (sht->supported_mode == MODE_UNKNOWN)
466 /* means we didn't set it ... default to INITIATOR */
467 shost->active_mode = MODE_INITIATOR;
468 else
469 shost->active_mode = sht->supported_mode;
470
471 if (sht->max_host_blocked)
472 shost->max_host_blocked = sht->max_host_blocked;
473 else
474 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
475
476 /*
477 * If the driver imposes no hard sector transfer limit, start at
478 * machine infinity initially.
479 */
480 if (sht->max_sectors)
481 shost->max_sectors = sht->max_sectors;
482 else
483 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
484
485 /*
486 * assume a 4GB boundary, if not set
487 */
488 if (sht->dma_boundary)
489 shost->dma_boundary = sht->dma_boundary;
490 else
491 shost->dma_boundary = 0xffffffff;
492
493 shost->use_blk_mq = scsi_use_blk_mq;
494
495 device_initialize(&shost->shost_gendev);
496 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
497 shost->shost_gendev.bus = &scsi_bus_type;
498 shost->shost_gendev.type = &scsi_host_type;
499
500 device_initialize(&shost->shost_dev);
501 shost->shost_dev.parent = &shost->shost_gendev;
502 shost->shost_dev.class = &shost_class;
503 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
504 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
505
506 shost->ehandler = kthread_run(scsi_error_handler, shost,
507 "scsi_eh_%d", shost->host_no);
508 if (IS_ERR(shost->ehandler)) {
509 shost_printk(KERN_WARNING, shost,
510 "error handler thread failed to spawn, error = %ld\n",
511 PTR_ERR(shost->ehandler));
512 goto fail_index_remove;
513 }
514
515 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
516 WQ_UNBOUND | WQ_MEM_RECLAIM,
517 1, shost->host_no);
518 if (!shost->tmf_work_q) {
519 shost_printk(KERN_WARNING, shost,
520 "failed to create tmf workq\n");
521 goto fail_kthread;
522 }
523 scsi_proc_hostdir_add(shost->hostt);
524 return shost;
525
526 fail_kthread:
527 kthread_stop(shost->ehandler);
528 fail_index_remove:
529 ida_simple_remove(&host_index_ida, shost->host_no);
530 fail_kfree:
531 kfree(shost);
532 return NULL;
533}
534EXPORT_SYMBOL(scsi_host_alloc);
535
536struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
537{
538 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
539
540 if (!sht->detect) {
541 printk(KERN_WARNING "scsi_register() called on new-style "
542 "template for driver %s\n", sht->name);
543 dump_stack();
544 }
545
546 if (shost)
547 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
548 return shost;
549}
550EXPORT_SYMBOL(scsi_register);
551
552void scsi_unregister(struct Scsi_Host *shost)
553{
554 list_del(&shost->sht_legacy_list);
555 scsi_host_put(shost);
556}
557EXPORT_SYMBOL(scsi_unregister);
558
559static int __scsi_host_match(struct device *dev, const void *data)
560{
561 struct Scsi_Host *p;
562 const unsigned short *hostnum = data;
563
564 p = class_to_shost(dev);
565 return p->host_no == *hostnum;
566}
567
568/**
569 * scsi_host_lookup - get a reference to a Scsi_Host by host no
570 * @hostnum: host number to locate
571 *
572 * Return value:
573 * A pointer to located Scsi_Host or NULL.
574 *
575 * The caller must do a scsi_host_put() to drop the reference
576 * that scsi_host_get() took. The put_device() below dropped
577 * the reference from class_find_device().
578 **/
579struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
580{
581 struct device *cdev;
582 struct Scsi_Host *shost = NULL;
583
584 cdev = class_find_device(&shost_class, NULL, &hostnum,
585 __scsi_host_match);
586 if (cdev) {
587 shost = scsi_host_get(class_to_shost(cdev));
588 put_device(cdev);
589 }
590 return shost;
591}
592EXPORT_SYMBOL(scsi_host_lookup);
593
594/**
595 * scsi_host_get - inc a Scsi_Host ref count
596 * @shost: Pointer to Scsi_Host to inc.
597 **/
598struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
599{
600 if ((shost->shost_state == SHOST_DEL) ||
601 !get_device(&shost->shost_gendev))
602 return NULL;
603 return shost;
604}
605EXPORT_SYMBOL(scsi_host_get);
606
607/**
608 * scsi_host_put - dec a Scsi_Host ref count
609 * @shost: Pointer to Scsi_Host to dec.
610 **/
611void scsi_host_put(struct Scsi_Host *shost)
612{
613 put_device(&shost->shost_gendev);
614}
615EXPORT_SYMBOL(scsi_host_put);
616
617int scsi_init_hosts(void)
618{
619 return class_register(&shost_class);
620}
621
622void scsi_exit_hosts(void)
623{
624 class_unregister(&shost_class);
625 ida_destroy(&host_index_ida);
626}
627
628int scsi_is_host_device(const struct device *dev)
629{
630 return dev->type == &scsi_host_type;
631}
632EXPORT_SYMBOL(scsi_is_host_device);
633
634/**
635 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
636 * @shost: Pointer to Scsi_Host.
637 * @work: Work to queue for execution.
638 *
639 * Return value:
640 * 1 - work queued for execution
641 * 0 - work is already queued
642 * -EINVAL - work queue doesn't exist
643 **/
644int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
645{
646 if (unlikely(!shost->work_q)) {
647 shost_printk(KERN_ERR, shost,
648 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
649 "when no workqueue created.\n", shost->hostt->name);
650 dump_stack();
651
652 return -EINVAL;
653 }
654
655 return queue_work(shost->work_q, work);
656}
657EXPORT_SYMBOL_GPL(scsi_queue_work);
658
659/**
660 * scsi_flush_work - Flush a Scsi_Host's workqueue.
661 * @shost: Pointer to Scsi_Host.
662 **/
663void scsi_flush_work(struct Scsi_Host *shost)
664{
665 if (!shost->work_q) {
666 shost_printk(KERN_ERR, shost,
667 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
668 "when no workqueue created.\n", shost->hostt->name);
669 dump_stack();
670 return;
671 }
672
673 flush_workqueue(shost->work_q);
674}
675EXPORT_SYMBOL_GPL(scsi_flush_work);
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 shost->work_q = alloc_workqueue(
296 "scsi_wq_%d",
297 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND, 1,
298 shost->host_no);
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 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
344 rcu_barrier();
345
346 if (shost->tmf_work_q)
347 destroy_workqueue(shost->tmf_work_q);
348 if (shost->ehandler)
349 kthread_stop(shost->ehandler);
350 if (shost->work_q)
351 destroy_workqueue(shost->work_q);
352
353 if (shost->shost_state == SHOST_CREATED) {
354 /*
355 * Free the shost_dev device name and remove the proc host dir
356 * here if scsi_host_{alloc,put}() have been called but neither
357 * scsi_host_add() nor scsi_remove_host() has been called.
358 * This avoids that the memory allocated for the shost_dev
359 * name as well as the proc dir structure are leaked.
360 */
361 scsi_proc_hostdir_rm(shost->hostt);
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 const 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 /* 32-byte (dword) is a common minimum for HBAs. */
482 if (sht->dma_alignment)
483 shost->dma_alignment = sht->dma_alignment;
484 else
485 shost->dma_alignment = 3;
486
487 /*
488 * assume a 4GB boundary, if not set
489 */
490 if (sht->dma_boundary)
491 shost->dma_boundary = sht->dma_boundary;
492 else
493 shost->dma_boundary = 0xffffffff;
494
495 if (sht->virt_boundary_mask)
496 shost->virt_boundary_mask = sht->virt_boundary_mask;
497
498 device_initialize(&shost->shost_gendev);
499 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
500 shost->shost_gendev.bus = &scsi_bus_type;
501 shost->shost_gendev.type = &scsi_host_type;
502 scsi_enable_async_suspend(&shost->shost_gendev);
503
504 device_initialize(&shost->shost_dev);
505 shost->shost_dev.parent = &shost->shost_gendev;
506 shost->shost_dev.class = &shost_class;
507 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
508 shost->shost_dev.groups = sht->shost_groups;
509
510 shost->ehandler = kthread_run(scsi_error_handler, shost,
511 "scsi_eh_%d", shost->host_no);
512 if (IS_ERR(shost->ehandler)) {
513 shost_printk(KERN_WARNING, shost,
514 "error handler thread failed to spawn, error = %ld\n",
515 PTR_ERR(shost->ehandler));
516 shost->ehandler = NULL;
517 goto fail;
518 }
519
520 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
521 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
522 1, shost->host_no);
523 if (!shost->tmf_work_q) {
524 shost_printk(KERN_WARNING, shost,
525 "failed to create tmf workq\n");
526 goto fail;
527 }
528 if (scsi_proc_hostdir_add(shost->hostt) < 0)
529 goto fail;
530 return shost;
531 fail:
532 /*
533 * Host state is still SHOST_CREATED and that is enough to release
534 * ->shost_gendev. scsi_host_dev_release() will free
535 * dev_name(&shost->shost_dev).
536 */
537 put_device(&shost->shost_gendev);
538
539 return NULL;
540}
541EXPORT_SYMBOL(scsi_host_alloc);
542
543static int __scsi_host_match(struct device *dev, const void *data)
544{
545 struct Scsi_Host *p;
546 const unsigned int *hostnum = data;
547
548 p = class_to_shost(dev);
549 return p->host_no == *hostnum;
550}
551
552/**
553 * scsi_host_lookup - get a reference to a Scsi_Host by host no
554 * @hostnum: host number to locate
555 *
556 * Return value:
557 * A pointer to located Scsi_Host or NULL.
558 *
559 * The caller must do a scsi_host_put() to drop the reference
560 * that scsi_host_get() took. The put_device() below dropped
561 * the reference from class_find_device().
562 **/
563struct Scsi_Host *scsi_host_lookup(unsigned int hostnum)
564{
565 struct device *cdev;
566 struct Scsi_Host *shost = NULL;
567
568 cdev = class_find_device(&shost_class, NULL, &hostnum,
569 __scsi_host_match);
570 if (cdev) {
571 shost = scsi_host_get(class_to_shost(cdev));
572 put_device(cdev);
573 }
574 return shost;
575}
576EXPORT_SYMBOL(scsi_host_lookup);
577
578/**
579 * scsi_host_get - inc a Scsi_Host ref count
580 * @shost: Pointer to Scsi_Host to inc.
581 **/
582struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
583{
584 if ((shost->shost_state == SHOST_DEL) ||
585 !get_device(&shost->shost_gendev))
586 return NULL;
587 return shost;
588}
589EXPORT_SYMBOL(scsi_host_get);
590
591static bool scsi_host_check_in_flight(struct request *rq, void *data)
592{
593 int *count = data;
594 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
595
596 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
597 (*count)++;
598
599 return true;
600}
601
602/**
603 * scsi_host_busy - Return the host busy counter
604 * @shost: Pointer to Scsi_Host to inc.
605 **/
606int scsi_host_busy(struct Scsi_Host *shost)
607{
608 int cnt = 0;
609
610 blk_mq_tagset_busy_iter(&shost->tag_set,
611 scsi_host_check_in_flight, &cnt);
612 return cnt;
613}
614EXPORT_SYMBOL(scsi_host_busy);
615
616/**
617 * scsi_host_put - dec a Scsi_Host ref count
618 * @shost: Pointer to Scsi_Host to dec.
619 **/
620void scsi_host_put(struct Scsi_Host *shost)
621{
622 put_device(&shost->shost_gendev);
623}
624EXPORT_SYMBOL(scsi_host_put);
625
626int scsi_init_hosts(void)
627{
628 return class_register(&shost_class);
629}
630
631void scsi_exit_hosts(void)
632{
633 class_unregister(&shost_class);
634 ida_destroy(&host_index_ida);
635}
636
637int scsi_is_host_device(const struct device *dev)
638{
639 return dev->type == &scsi_host_type;
640}
641EXPORT_SYMBOL(scsi_is_host_device);
642
643/**
644 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
645 * @shost: Pointer to Scsi_Host.
646 * @work: Work to queue for execution.
647 *
648 * Return value:
649 * 1 - work queued for execution
650 * 0 - work is already queued
651 * -EINVAL - work queue doesn't exist
652 **/
653int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
654{
655 if (unlikely(!shost->work_q)) {
656 shost_printk(KERN_ERR, shost,
657 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
658 "when no workqueue created.\n", shost->hostt->name);
659 dump_stack();
660
661 return -EINVAL;
662 }
663
664 return queue_work(shost->work_q, work);
665}
666EXPORT_SYMBOL_GPL(scsi_queue_work);
667
668/**
669 * scsi_flush_work - Flush a Scsi_Host's workqueue.
670 * @shost: Pointer to Scsi_Host.
671 **/
672void scsi_flush_work(struct Scsi_Host *shost)
673{
674 if (!shost->work_q) {
675 shost_printk(KERN_ERR, shost,
676 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
677 "when no workqueue created.\n", shost->hostt->name);
678 dump_stack();
679 return;
680 }
681
682 flush_workqueue(shost->work_q);
683}
684EXPORT_SYMBOL_GPL(scsi_flush_work);
685
686static bool complete_all_cmds_iter(struct request *rq, void *data)
687{
688 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
689 enum scsi_host_status status = *(enum scsi_host_status *)data;
690
691 scsi_dma_unmap(scmd);
692 scmd->result = 0;
693 set_host_byte(scmd, status);
694 scsi_done(scmd);
695 return true;
696}
697
698/**
699 * scsi_host_complete_all_commands - Terminate all running commands
700 * @shost: Scsi Host on which commands should be terminated
701 * @status: Status to be set for the terminated commands
702 *
703 * There is no protection against modification of the number
704 * of outstanding commands. It is the responsibility of the
705 * caller to ensure that concurrent I/O submission and/or
706 * completion is stopped when calling this function.
707 */
708void scsi_host_complete_all_commands(struct Scsi_Host *shost,
709 enum scsi_host_status status)
710{
711 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
712 &status);
713}
714EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
715
716struct scsi_host_busy_iter_data {
717 bool (*fn)(struct scsi_cmnd *, void *);
718 void *priv;
719};
720
721static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
722{
723 struct scsi_host_busy_iter_data *iter_data = priv;
724 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
725
726 return iter_data->fn(sc, iter_data->priv);
727}
728
729/**
730 * scsi_host_busy_iter - Iterate over all busy commands
731 * @shost: Pointer to Scsi_Host.
732 * @fn: Function to call on each busy command
733 * @priv: Data pointer passed to @fn
734 *
735 * If locking against concurrent command completions is required
736 * ithas to be provided by the caller
737 **/
738void scsi_host_busy_iter(struct Scsi_Host *shost,
739 bool (*fn)(struct scsi_cmnd *, void *),
740 void *priv)
741{
742 struct scsi_host_busy_iter_data iter_data = {
743 .fn = fn,
744 .priv = priv,
745 };
746
747 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
748 &iter_data);
749}
750EXPORT_SYMBOL_GPL(scsi_host_busy_iter);