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