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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
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 atomic_t scsi_host_next_hn = ATOMIC_INIT(0);
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
60
61
62
63
64
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
76
77
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
155
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
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191
192
193
194
195
196
197
198
199
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 }
221
222
223
224
225
226
227
228
229
230 error = scsi_setup_command_freelist(shost);
231 if (error)
232 goto out_destroy_tags;
233
234
235 if (!shost->shost_gendev.parent)
236 shost->shost_gendev.parent = dev ? dev : &platform_bus;
237 if (!dma_dev)
238 dma_dev = shost->shost_gendev.parent;
239
240 shost->dma_dev = dma_dev;
241
242 error = device_add(&shost->shost_gendev);
243 if (error)
244 goto out_destroy_freelist;
245
246 pm_runtime_set_active(&shost->shost_gendev);
247 pm_runtime_enable(&shost->shost_gendev);
248 device_enable_async_suspend(&shost->shost_gendev);
249
250 scsi_host_set_state(shost, SHOST_RUNNING);
251 get_device(shost->shost_gendev.parent);
252
253 device_enable_async_suspend(&shost->shost_dev);
254
255 error = device_add(&shost->shost_dev);
256 if (error)
257 goto out_del_gendev;
258
259 get_device(&shost->shost_gendev);
260
261 if (shost->transportt->host_size) {
262 shost->shost_data = kzalloc(shost->transportt->host_size,
263 GFP_KERNEL);
264 if (shost->shost_data == NULL) {
265 error = -ENOMEM;
266 goto out_del_dev;
267 }
268 }
269
270 if (shost->transportt->create_work_queue) {
271 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
272 "scsi_wq_%d", shost->host_no);
273 shost->work_q = create_singlethread_workqueue(
274 shost->work_q_name);
275 if (!shost->work_q) {
276 error = -EINVAL;
277 goto out_free_shost_data;
278 }
279 }
280
281 error = scsi_sysfs_add_host(shost);
282 if (error)
283 goto out_destroy_host;
284
285 scsi_proc_host_add(shost);
286 return error;
287
288 out_destroy_host:
289 if (shost->work_q)
290 destroy_workqueue(shost->work_q);
291 out_free_shost_data:
292 kfree(shost->shost_data);
293 out_del_dev:
294 device_del(&shost->shost_dev);
295 out_del_gendev:
296 device_del(&shost->shost_gendev);
297 out_destroy_freelist:
298 scsi_destroy_command_freelist(shost);
299 out_destroy_tags:
300 if (shost_use_blk_mq(shost))
301 scsi_mq_destroy_tags(shost);
302 fail:
303 return error;
304}
305EXPORT_SYMBOL(scsi_add_host_with_dma);
306
307static void scsi_host_dev_release(struct device *dev)
308{
309 struct Scsi_Host *shost = dev_to_shost(dev);
310 struct device *parent = dev->parent;
311 struct request_queue *q;
312 void *queuedata;
313
314 scsi_proc_hostdir_rm(shost->hostt);
315
316 if (shost->tmf_work_q)
317 destroy_workqueue(shost->tmf_work_q);
318 if (shost->ehandler)
319 kthread_stop(shost->ehandler);
320 if (shost->work_q)
321 destroy_workqueue(shost->work_q);
322 q = shost->uspace_req_q;
323 if (q) {
324 queuedata = q->queuedata;
325 blk_cleanup_queue(q);
326 kfree(queuedata);
327 }
328
329 scsi_destroy_command_freelist(shost);
330 if (shost_use_blk_mq(shost)) {
331 if (shost->tag_set.tags)
332 scsi_mq_destroy_tags(shost);
333 } else {
334 if (shost->bqt)
335 blk_free_tags(shost->bqt);
336 }
337
338 kfree(shost->shost_data);
339
340 if (parent)
341 put_device(parent);
342 kfree(shost);
343}
344
345static int shost_eh_deadline = -1;
346
347module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
348MODULE_PARM_DESC(eh_deadline,
349 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
350
351static struct device_type scsi_host_type = {
352 .name = "scsi_host",
353 .release = scsi_host_dev_release,
354};
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
370{
371 struct Scsi_Host *shost;
372 gfp_t gfp_mask = GFP_KERNEL;
373
374 if (sht->unchecked_isa_dma && privsize)
375 gfp_mask |= __GFP_DMA;
376
377 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
378 if (!shost)
379 return NULL;
380
381 shost->host_lock = &shost->default_lock;
382 spin_lock_init(shost->host_lock);
383 shost->shost_state = SHOST_CREATED;
384 INIT_LIST_HEAD(&shost->__devices);
385 INIT_LIST_HEAD(&shost->__targets);
386 INIT_LIST_HEAD(&shost->eh_cmd_q);
387 INIT_LIST_HEAD(&shost->starved_list);
388 init_waitqueue_head(&shost->host_wait);
389 mutex_init(&shost->scan_mutex);
390
391
392
393
394
395 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
396 shost->dma_channel = 0xff;
397
398
399 shost->max_channel = 0;
400 shost->max_id = 8;
401 shost->max_lun = 8;
402
403
404 shost->transportt = &blank_transport_template;
405
406
407
408
409
410
411
412 shost->max_cmd_len = 12;
413 shost->hostt = sht;
414 shost->this_id = sht->this_id;
415 shost->can_queue = sht->can_queue;
416 shost->sg_tablesize = sht->sg_tablesize;
417 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
418 shost->cmd_per_lun = sht->cmd_per_lun;
419 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
420 shost->use_clustering = sht->use_clustering;
421 shost->no_write_same = sht->no_write_same;
422
423 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
424 shost->eh_deadline = -1;
425 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
426 shost_printk(KERN_WARNING, shost,
427 "eh_deadline %u too large, setting to %u\n",
428 shost_eh_deadline, INT_MAX / HZ);
429 shost->eh_deadline = INT_MAX;
430 } else
431 shost->eh_deadline = shost_eh_deadline * HZ;
432
433 if (sht->supported_mode == MODE_UNKNOWN)
434
435 shost->active_mode = MODE_INITIATOR;
436 else
437 shost->active_mode = sht->supported_mode;
438
439 if (sht->max_host_blocked)
440 shost->max_host_blocked = sht->max_host_blocked;
441 else
442 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
443
444
445
446
447
448 if (sht->max_sectors)
449 shost->max_sectors = sht->max_sectors;
450 else
451 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
452
453
454
455
456 if (sht->dma_boundary)
457 shost->dma_boundary = sht->dma_boundary;
458 else
459 shost->dma_boundary = 0xffffffff;
460
461 shost->use_blk_mq = scsi_use_blk_mq && !shost->hostt->disable_blk_mq;
462
463 device_initialize(&shost->shost_gendev);
464 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
465 shost->shost_gendev.bus = &scsi_bus_type;
466 shost->shost_gendev.type = &scsi_host_type;
467
468 device_initialize(&shost->shost_dev);
469 shost->shost_dev.parent = &shost->shost_gendev;
470 shost->shost_dev.class = &shost_class;
471 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
472 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
473
474 shost->ehandler = kthread_run(scsi_error_handler, shost,
475 "scsi_eh_%d", shost->host_no);
476 if (IS_ERR(shost->ehandler)) {
477 shost_printk(KERN_WARNING, shost,
478 "error handler thread failed to spawn, error = %ld\n",
479 PTR_ERR(shost->ehandler));
480 goto fail_kfree;
481 }
482
483 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
484 WQ_UNBOUND | WQ_MEM_RECLAIM,
485 1, shost->host_no);
486 if (!shost->tmf_work_q) {
487 shost_printk(KERN_WARNING, shost,
488 "failed to create tmf workq\n");
489 goto fail_kthread;
490 }
491 scsi_proc_hostdir_add(shost->hostt);
492 return shost;
493
494 fail_kthread:
495 kthread_stop(shost->ehandler);
496 fail_kfree:
497 kfree(shost);
498 return NULL;
499}
500EXPORT_SYMBOL(scsi_host_alloc);
501
502struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
503{
504 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
505
506 if (!sht->detect) {
507 printk(KERN_WARNING "scsi_register() called on new-style "
508 "template for driver %s\n", sht->name);
509 dump_stack();
510 }
511
512 if (shost)
513 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
514 return shost;
515}
516EXPORT_SYMBOL(scsi_register);
517
518void scsi_unregister(struct Scsi_Host *shost)
519{
520 list_del(&shost->sht_legacy_list);
521 scsi_host_put(shost);
522}
523EXPORT_SYMBOL(scsi_unregister);
524
525static int __scsi_host_match(struct device *dev, const void *data)
526{
527 struct Scsi_Host *p;
528 const unsigned short *hostnum = data;
529
530 p = class_to_shost(dev);
531 return p->host_no == *hostnum;
532}
533
534
535
536
537
538
539
540
541
542
543
544
545struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
546{
547 struct device *cdev;
548 struct Scsi_Host *shost = NULL;
549
550 cdev = class_find_device(&shost_class, NULL, &hostnum,
551 __scsi_host_match);
552 if (cdev) {
553 shost = scsi_host_get(class_to_shost(cdev));
554 put_device(cdev);
555 }
556 return shost;
557}
558EXPORT_SYMBOL(scsi_host_lookup);
559
560
561
562
563
564struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
565{
566 if ((shost->shost_state == SHOST_DEL) ||
567 !get_device(&shost->shost_gendev))
568 return NULL;
569 return shost;
570}
571EXPORT_SYMBOL(scsi_host_get);
572
573
574
575
576
577void scsi_host_put(struct Scsi_Host *shost)
578{
579 put_device(&shost->shost_gendev);
580}
581EXPORT_SYMBOL(scsi_host_put);
582
583int scsi_init_hosts(void)
584{
585 return class_register(&shost_class);
586}
587
588void scsi_exit_hosts(void)
589{
590 class_unregister(&shost_class);
591}
592
593int scsi_is_host_device(const struct device *dev)
594{
595 return dev->type == &scsi_host_type;
596}
597EXPORT_SYMBOL(scsi_is_host_device);
598
599
600
601
602
603
604
605
606
607
608
609int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
610{
611 if (unlikely(!shost->work_q)) {
612 shost_printk(KERN_ERR, shost,
613 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
614 "when no workqueue created.\n", shost->hostt->name);
615 dump_stack();
616
617 return -EINVAL;
618 }
619
620 return queue_work(shost->work_q, work);
621}
622EXPORT_SYMBOL_GPL(scsi_queue_work);
623
624
625
626
627
628void scsi_flush_work(struct Scsi_Host *shost)
629{
630 if (!shost->work_q) {
631 shost_printk(KERN_ERR, shost,
632 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
633 "when no workqueue created.\n", shost->hostt->name);
634 dump_stack();
635 return;
636 }
637
638 flush_workqueue(shost->work_q);
639}
640EXPORT_SYMBOL_GPL(scsi_flush_work);
641