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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 .dev_groups = scsi_shost_groups,
65};
66
67
68
69
70
71
72
73
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
85
86
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
163
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
185 spin_lock_irqsave(shost->host_lock, flags);
186 if (scsi_host_set_state(shost, SHOST_DEL))
187 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
188 spin_unlock_irqrestore(shost->host_lock, flags);
189
190 transport_unregister_device(&shost->shost_gendev);
191 device_unregister(&shost->shost_dev);
192 device_del(&shost->shost_gendev);
193}
194EXPORT_SYMBOL(scsi_remove_host);
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
210 struct device *dma_dev)
211{
212 struct scsi_host_template *sht = shost->hostt;
213 int error = -EINVAL;
214
215 shost_printk(KERN_INFO, shost, "%s\n",
216 sht->info ? sht->info(shost) : sht->name);
217
218 if (!shost->can_queue) {
219 shost_printk(KERN_ERR, shost,
220 "can_queue = 0 no longer supported\n");
221 goto fail;
222 }
223
224
225 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
226 shost->can_queue);
227
228 error = scsi_init_sense_cache(shost);
229 if (error)
230 goto fail;
231
232 error = scsi_mq_setup_tags(shost);
233 if (error)
234 goto fail;
235
236 if (!shost->shost_gendev.parent)
237 shost->shost_gendev.parent = dev ? dev : &platform_bus;
238 if (!dma_dev)
239 dma_dev = shost->shost_gendev.parent;
240
241 shost->dma_dev = dma_dev;
242
243
244
245
246
247
248 pm_runtime_get_noresume(&shost->shost_gendev);
249 pm_runtime_set_active(&shost->shost_gendev);
250 pm_runtime_enable(&shost->shost_gendev);
251 device_enable_async_suspend(&shost->shost_gendev);
252
253 error = device_add(&shost->shost_gendev);
254 if (error)
255 goto out_disable_runtime_pm;
256
257 scsi_host_set_state(shost, SHOST_RUNNING);
258 get_device(shost->shost_gendev.parent);
259
260 device_enable_async_suspend(&shost->shost_dev);
261
262 get_device(&shost->shost_gendev);
263 error = device_add(&shost->shost_dev);
264 if (error)
265 goto out_del_gendev;
266
267 if (shost->transportt->host_size) {
268 shost->shost_data = kzalloc(shost->transportt->host_size,
269 GFP_KERNEL);
270 if (shost->shost_data == NULL) {
271 error = -ENOMEM;
272 goto out_del_dev;
273 }
274 }
275
276 if (shost->transportt->create_work_queue) {
277 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
278 "scsi_wq_%d", shost->host_no);
279 shost->work_q = alloc_workqueue("%s",
280 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
281 1, shost->work_q_name);
282
283 if (!shost->work_q) {
284 error = -EINVAL;
285 goto out_del_dev;
286 }
287 }
288
289 error = scsi_sysfs_add_host(shost);
290 if (error)
291 goto out_del_dev;
292
293 scsi_proc_host_add(shost);
294 scsi_autopm_put_host(shost);
295 return error;
296
297
298
299
300
301 out_del_dev:
302 device_del(&shost->shost_dev);
303 out_del_gendev:
304
305
306
307
308 put_device(&shost->shost_dev);
309 device_del(&shost->shost_gendev);
310 out_disable_runtime_pm:
311 device_disable_async_suspend(&shost->shost_gendev);
312 pm_runtime_disable(&shost->shost_gendev);
313 pm_runtime_set_suspended(&shost->shost_gendev);
314 pm_runtime_put_noidle(&shost->shost_gendev);
315 fail:
316 return error;
317}
318EXPORT_SYMBOL(scsi_add_host_with_dma);
319
320static void scsi_host_dev_release(struct device *dev)
321{
322 struct Scsi_Host *shost = dev_to_shost(dev);
323 struct device *parent = dev->parent;
324
325 scsi_proc_hostdir_rm(shost->hostt);
326
327
328 rcu_barrier();
329
330 if (shost->tmf_work_q)
331 destroy_workqueue(shost->tmf_work_q);
332 if (shost->ehandler)
333 kthread_stop(shost->ehandler);
334 if (shost->work_q)
335 destroy_workqueue(shost->work_q);
336
337 if (shost->shost_state == SHOST_CREATED) {
338
339
340
341
342
343
344
345 kfree(dev_name(&shost->shost_dev));
346 }
347
348 if (shost->tag_set.tags)
349 scsi_mq_destroy_tags(shost);
350
351 kfree(shost->shost_data);
352
353 ida_simple_remove(&host_index_ida, shost->host_no);
354
355 if (shost->shost_state != SHOST_CREATED)
356 put_device(parent);
357 kfree(shost);
358}
359
360static struct device_type scsi_host_type = {
361 .name = "scsi_host",
362 .release = scsi_host_dev_release,
363};
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
379{
380 struct Scsi_Host *shost;
381 int index;
382
383 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
384 if (!shost)
385 return NULL;
386
387 shost->host_lock = &shost->default_lock;
388 spin_lock_init(shost->host_lock);
389 shost->shost_state = SHOST_CREATED;
390 INIT_LIST_HEAD(&shost->__devices);
391 INIT_LIST_HEAD(&shost->__targets);
392 INIT_LIST_HEAD(&shost->eh_abort_list);
393 INIT_LIST_HEAD(&shost->eh_cmd_q);
394 INIT_LIST_HEAD(&shost->starved_list);
395 init_waitqueue_head(&shost->host_wait);
396 mutex_init(&shost->scan_mutex);
397
398 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
399 if (index < 0) {
400 kfree(shost);
401 return NULL;
402 }
403 shost->host_no = index;
404
405 shost->dma_channel = 0xff;
406
407
408 shost->max_channel = 0;
409 shost->max_id = 8;
410 shost->max_lun = 8;
411
412
413 shost->transportt = &blank_transport_template;
414
415
416
417
418
419
420
421 shost->max_cmd_len = 12;
422 shost->hostt = sht;
423 shost->this_id = sht->this_id;
424 shost->can_queue = sht->can_queue;
425 shost->sg_tablesize = sht->sg_tablesize;
426 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
427 shost->cmd_per_lun = sht->cmd_per_lun;
428 shost->no_write_same = sht->no_write_same;
429 shost->host_tagset = sht->host_tagset;
430
431 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
432 shost->eh_deadline = -1;
433 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
434 shost_printk(KERN_WARNING, shost,
435 "eh_deadline %u too large, setting to %u\n",
436 shost_eh_deadline, INT_MAX / HZ);
437 shost->eh_deadline = INT_MAX;
438 } else
439 shost->eh_deadline = shost_eh_deadline * HZ;
440
441 if (sht->supported_mode == MODE_UNKNOWN)
442
443 shost->active_mode = MODE_INITIATOR;
444 else
445 shost->active_mode = sht->supported_mode;
446
447 if (sht->max_host_blocked)
448 shost->max_host_blocked = sht->max_host_blocked;
449 else
450 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
451
452
453
454
455
456 if (sht->max_sectors)
457 shost->max_sectors = sht->max_sectors;
458 else
459 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
460
461 if (sht->max_segment_size)
462 shost->max_segment_size = sht->max_segment_size;
463 else
464 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
465
466
467
468
469 if (sht->dma_boundary)
470 shost->dma_boundary = sht->dma_boundary;
471 else
472 shost->dma_boundary = 0xffffffff;
473
474 if (sht->virt_boundary_mask)
475 shost->virt_boundary_mask = sht->virt_boundary_mask;
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 scsi_enable_async_suspend(&shost->shost_gendev);
482
483 device_initialize(&shost->shost_dev);
484 shost->shost_dev.parent = &shost->shost_gendev;
485 shost->shost_dev.class = &shost_class;
486 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
487 shost->shost_dev.groups = sht->shost_groups;
488
489 shost->ehandler = kthread_run(scsi_error_handler, shost,
490 "scsi_eh_%d", shost->host_no);
491 if (IS_ERR(shost->ehandler)) {
492 shost_printk(KERN_WARNING, shost,
493 "error handler thread failed to spawn, error = %ld\n",
494 PTR_ERR(shost->ehandler));
495 shost->ehandler = NULL;
496 goto fail;
497 }
498
499 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
500 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
501 1, shost->host_no);
502 if (!shost->tmf_work_q) {
503 shost_printk(KERN_WARNING, shost,
504 "failed to create tmf workq\n");
505 goto fail;
506 }
507 scsi_proc_hostdir_add(shost->hostt);
508 return shost;
509 fail:
510
511
512
513
514
515 put_device(&shost->shost_gendev);
516
517 return NULL;
518}
519EXPORT_SYMBOL(scsi_host_alloc);
520
521static int __scsi_host_match(struct device *dev, const void *data)
522{
523 struct Scsi_Host *p;
524 const unsigned short *hostnum = data;
525
526 p = class_to_shost(dev);
527 return p->host_no == *hostnum;
528}
529
530
531
532
533
534
535
536
537
538
539
540
541struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
542{
543 struct device *cdev;
544 struct Scsi_Host *shost = NULL;
545
546 cdev = class_find_device(&shost_class, NULL, &hostnum,
547 __scsi_host_match);
548 if (cdev) {
549 shost = scsi_host_get(class_to_shost(cdev));
550 put_device(cdev);
551 }
552 return shost;
553}
554EXPORT_SYMBOL(scsi_host_lookup);
555
556
557
558
559
560struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
561{
562 if ((shost->shost_state == SHOST_DEL) ||
563 !get_device(&shost->shost_gendev))
564 return NULL;
565 return shost;
566}
567EXPORT_SYMBOL(scsi_host_get);
568
569static bool scsi_host_check_in_flight(struct request *rq, void *data,
570 bool reserved)
571{
572 int *count = data;
573 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
574
575 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
576 (*count)++;
577
578 return true;
579}
580
581
582
583
584
585int scsi_host_busy(struct Scsi_Host *shost)
586{
587 int cnt = 0;
588
589 blk_mq_tagset_busy_iter(&shost->tag_set,
590 scsi_host_check_in_flight, &cnt);
591 return cnt;
592}
593EXPORT_SYMBOL(scsi_host_busy);
594
595
596
597
598
599void scsi_host_put(struct Scsi_Host *shost)
600{
601 put_device(&shost->shost_gendev);
602}
603EXPORT_SYMBOL(scsi_host_put);
604
605int scsi_init_hosts(void)
606{
607 return class_register(&shost_class);
608}
609
610void scsi_exit_hosts(void)
611{
612 class_unregister(&shost_class);
613 ida_destroy(&host_index_ida);
614}
615
616int scsi_is_host_device(const struct device *dev)
617{
618 return dev->type == &scsi_host_type;
619}
620EXPORT_SYMBOL(scsi_is_host_device);
621
622
623
624
625
626
627
628
629
630
631
632int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
633{
634 if (unlikely(!shost->work_q)) {
635 shost_printk(KERN_ERR, shost,
636 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
637 "when no workqueue created.\n", shost->hostt->name);
638 dump_stack();
639
640 return -EINVAL;
641 }
642
643 return queue_work(shost->work_q, work);
644}
645EXPORT_SYMBOL_GPL(scsi_queue_work);
646
647
648
649
650
651void scsi_flush_work(struct Scsi_Host *shost)
652{
653 if (!shost->work_q) {
654 shost_printk(KERN_ERR, shost,
655 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
656 "when no workqueue created.\n", shost->hostt->name);
657 dump_stack();
658 return;
659 }
660
661 flush_workqueue(shost->work_q);
662}
663EXPORT_SYMBOL_GPL(scsi_flush_work);
664
665static bool complete_all_cmds_iter(struct request *rq, void *data, bool rsvd)
666{
667 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
668 enum scsi_host_status status = *(enum scsi_host_status *)data;
669
670 scsi_dma_unmap(scmd);
671 scmd->result = 0;
672 set_host_byte(scmd, status);
673 scsi_done(scmd);
674 return true;
675}
676
677
678
679
680
681
682
683
684
685
686
687void scsi_host_complete_all_commands(struct Scsi_Host *shost,
688 enum scsi_host_status status)
689{
690 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
691 &status);
692}
693EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
694
695struct scsi_host_busy_iter_data {
696 bool (*fn)(struct scsi_cmnd *, void *, bool);
697 void *priv;
698};
699
700static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
701 bool reserved)
702{
703 struct scsi_host_busy_iter_data *iter_data = priv;
704 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
705
706 return iter_data->fn(sc, iter_data->priv, reserved);
707}
708
709
710
711
712
713
714
715
716
717
718void scsi_host_busy_iter(struct Scsi_Host *shost,
719 bool (*fn)(struct scsi_cmnd *, void *, bool),
720 void *priv)
721{
722 struct scsi_host_busy_iter_data iter_data = {
723 .fn = fn,
724 .priv = priv,
725 };
726
727 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
728 &iter_data);
729}
730EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
731