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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
68
69
70
71
72
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
84
85
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
162
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
197
198
199
200
201
202
203
204
205
206
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
224 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
225 shost->can_queue);
226
227 error = scsi_init_sense_cache(shost);
228 if (error)
229 goto fail;
230
231 error = scsi_mq_setup_tags(shost);
232 if (error)
233 goto fail;
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
243
244
245
246
247 pm_runtime_get_noresume(&shost->shost_gendev);
248 pm_runtime_set_active(&shost->shost_gendev);
249 pm_runtime_enable(&shost->shost_gendev);
250 device_enable_async_suspend(&shost->shost_gendev);
251
252 error = device_add(&shost->shost_gendev);
253 if (error)
254 goto out_disable_runtime_pm;
255
256 scsi_host_set_state(shost, SHOST_RUNNING);
257 get_device(shost->shost_gendev.parent);
258
259 device_enable_async_suspend(&shost->shost_dev);
260
261 get_device(&shost->shost_gendev);
262 error = device_add(&shost->shost_dev);
263 if (error)
264 goto out_del_gendev;
265
266 if (shost->transportt->host_size) {
267 shost->shost_data = kzalloc(shost->transportt->host_size,
268 GFP_KERNEL);
269 if (shost->shost_data == NULL) {
270 error = -ENOMEM;
271 goto out_del_dev;
272 }
273 }
274
275 if (shost->transportt->create_work_queue) {
276 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
277 "scsi_wq_%d", shost->host_no);
278 shost->work_q = alloc_workqueue("%s",
279 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
280 1, shost->work_q_name);
281
282 if (!shost->work_q) {
283 error = -EINVAL;
284 goto out_del_dev;
285 }
286 }
287
288 error = scsi_sysfs_add_host(shost);
289 if (error)
290 goto out_del_dev;
291
292 scsi_proc_host_add(shost);
293 scsi_autopm_put_host(shost);
294 return error;
295
296
297
298
299
300 out_del_dev:
301 device_del(&shost->shost_dev);
302 out_del_gendev:
303
304
305
306
307 put_device(&shost->shost_dev);
308 device_del(&shost->shost_gendev);
309 out_disable_runtime_pm:
310 device_disable_async_suspend(&shost->shost_gendev);
311 pm_runtime_disable(&shost->shost_gendev);
312 pm_runtime_set_suspended(&shost->shost_gendev);
313 pm_runtime_put_noidle(&shost->shost_gendev);
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
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
339
340
341
342
343
344 kfree(dev_name(&shost->shost_dev));
345 }
346
347 if (shost->tag_set.tags)
348 scsi_mq_destroy_tags(shost);
349
350 kfree(shost->shost_data);
351
352 ida_simple_remove(&host_index_ida, shost->host_no);
353
354 if (shost->shost_state != SHOST_CREATED)
355 put_device(parent);
356 kfree(shost);
357}
358
359static struct device_type scsi_host_type = {
360 .name = "scsi_host",
361 .release = scsi_host_dev_release,
362};
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
378{
379 struct Scsi_Host *shost;
380 int index;
381
382 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
383 if (!shost)
384 return NULL;
385
386 shost->host_lock = &shost->default_lock;
387 spin_lock_init(shost->host_lock);
388 shost->shost_state = SHOST_CREATED;
389 INIT_LIST_HEAD(&shost->__devices);
390 INIT_LIST_HEAD(&shost->__targets);
391 INIT_LIST_HEAD(&shost->eh_cmd_q);
392 INIT_LIST_HEAD(&shost->starved_list);
393 init_waitqueue_head(&shost->host_wait);
394 mutex_init(&shost->scan_mutex);
395
396 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
397 if (index < 0) {
398 kfree(shost);
399 return NULL;
400 }
401 shost->host_no = index;
402
403 shost->dma_channel = 0xff;
404
405
406 shost->max_channel = 0;
407 shost->max_id = 8;
408 shost->max_lun = 8;
409
410
411 shost->transportt = &blank_transport_template;
412
413
414
415
416
417
418
419 shost->max_cmd_len = 12;
420 shost->hostt = sht;
421 shost->this_id = sht->this_id;
422 shost->can_queue = sht->can_queue;
423 shost->sg_tablesize = sht->sg_tablesize;
424 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
425 shost->cmd_per_lun = sht->cmd_per_lun;
426 shost->no_write_same = sht->no_write_same;
427 shost->host_tagset = sht->host_tagset;
428
429 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
430 shost->eh_deadline = -1;
431 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
432 shost_printk(KERN_WARNING, shost,
433 "eh_deadline %u too large, setting to %u\n",
434 shost_eh_deadline, INT_MAX / HZ);
435 shost->eh_deadline = INT_MAX;
436 } else
437 shost->eh_deadline = shost_eh_deadline * HZ;
438
439 if (sht->supported_mode == MODE_UNKNOWN)
440
441 shost->active_mode = MODE_INITIATOR;
442 else
443 shost->active_mode = sht->supported_mode;
444
445 if (sht->max_host_blocked)
446 shost->max_host_blocked = sht->max_host_blocked;
447 else
448 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
449
450
451
452
453
454 if (sht->max_sectors)
455 shost->max_sectors = sht->max_sectors;
456 else
457 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
458
459 if (sht->max_segment_size)
460 shost->max_segment_size = sht->max_segment_size;
461 else
462 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
463
464
465
466
467 if (sht->dma_boundary)
468 shost->dma_boundary = sht->dma_boundary;
469 else
470 shost->dma_boundary = 0xffffffff;
471
472 if (sht->virt_boundary_mask)
473 shost->virt_boundary_mask = sht->virt_boundary_mask;
474
475 device_initialize(&shost->shost_gendev);
476 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
477 shost->shost_gendev.bus = &scsi_bus_type;
478 shost->shost_gendev.type = &scsi_host_type;
479
480 device_initialize(&shost->shost_dev);
481 shost->shost_dev.parent = &shost->shost_gendev;
482 shost->shost_dev.class = &shost_class;
483 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
484 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
485
486 shost->ehandler = kthread_run(scsi_error_handler, shost,
487 "scsi_eh_%d", shost->host_no);
488 if (IS_ERR(shost->ehandler)) {
489 shost_printk(KERN_WARNING, shost,
490 "error handler thread failed to spawn, error = %ld\n",
491 PTR_ERR(shost->ehandler));
492 shost->ehandler = NULL;
493 goto fail;
494 }
495
496 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
497 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
498 1, shost->host_no);
499 if (!shost->tmf_work_q) {
500 shost_printk(KERN_WARNING, shost,
501 "failed to create tmf workq\n");
502 goto fail;
503 }
504 scsi_proc_hostdir_add(shost->hostt);
505 return shost;
506 fail:
507
508
509
510
511
512 put_device(&shost->shost_gendev);
513
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
529
530
531
532
533
534
535
536
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
555
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
566static bool scsi_host_check_in_flight(struct request *rq, void *data,
567 bool reserved)
568{
569 int *count = data;
570 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
571
572 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
573 (*count)++;
574
575 return true;
576}
577
578
579
580
581
582int scsi_host_busy(struct Scsi_Host *shost)
583{
584 int cnt = 0;
585
586 blk_mq_tagset_busy_iter(&shost->tag_set,
587 scsi_host_check_in_flight, &cnt);
588 return cnt;
589}
590EXPORT_SYMBOL(scsi_host_busy);
591
592
593
594
595
596void scsi_host_put(struct Scsi_Host *shost)
597{
598 put_device(&shost->shost_gendev);
599}
600EXPORT_SYMBOL(scsi_host_put);
601
602int scsi_init_hosts(void)
603{
604 return class_register(&shost_class);
605}
606
607void scsi_exit_hosts(void)
608{
609 class_unregister(&shost_class);
610 ida_destroy(&host_index_ida);
611}
612
613int scsi_is_host_device(const struct device *dev)
614{
615 return dev->type == &scsi_host_type;
616}
617EXPORT_SYMBOL(scsi_is_host_device);
618
619
620
621
622
623
624
625
626
627
628
629int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
630{
631 if (unlikely(!shost->work_q)) {
632 shost_printk(KERN_ERR, shost,
633 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
634 "when no workqueue created.\n", shost->hostt->name);
635 dump_stack();
636
637 return -EINVAL;
638 }
639
640 return queue_work(shost->work_q, work);
641}
642EXPORT_SYMBOL_GPL(scsi_queue_work);
643
644
645
646
647
648void scsi_flush_work(struct Scsi_Host *shost)
649{
650 if (!shost->work_q) {
651 shost_printk(KERN_ERR, shost,
652 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
653 "when no workqueue created.\n", shost->hostt->name);
654 dump_stack();
655 return;
656 }
657
658 flush_workqueue(shost->work_q);
659}
660EXPORT_SYMBOL_GPL(scsi_flush_work);
661
662static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
663{
664 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
665 enum scsi_host_status status = *(enum scsi_host_status *)data;
666
667 scsi_dma_unmap(scmd);
668 scmd->result = 0;
669 set_host_byte(scmd, status);
670 scmd->scsi_done(scmd);
671 return true;
672}
673
674
675
676
677
678
679
680
681
682
683
684void scsi_host_complete_all_commands(struct Scsi_Host *shost,
685 enum scsi_host_status status)
686{
687 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
688 &status);
689}
690EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
691
692struct scsi_host_busy_iter_data {
693 bool (*fn)(struct scsi_cmnd *, void *, bool);
694 void *priv;
695};
696
697static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
698 bool reserved)
699{
700 struct scsi_host_busy_iter_data *iter_data = priv;
701 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
702
703 return iter_data->fn(sc, iter_data->priv, reserved);
704}
705
706
707
708
709
710
711
712
713
714
715void scsi_host_busy_iter(struct Scsi_Host *shost,
716 bool (*fn)(struct scsi_cmnd *, void *, bool),
717 void *priv)
718{
719 struct scsi_host_busy_iter_data iter_data = {
720 .fn = fn,
721 .priv = priv,
722 };
723
724 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
725 &iter_data);
726}
727EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
728