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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
42#include "scsi_priv.h"
43#include "scsi_logging.h"
44
45
46static int shost_eh_deadline = -1;
47
48module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
49MODULE_PARM_DESC(eh_deadline,
50 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
51
52static DEFINE_IDA(host_index_ida);
53
54
55static void scsi_host_cls_release(struct device *dev)
56{
57 put_device(&class_to_shost(dev)->shost_gendev);
58}
59
60static struct class shost_class = {
61 .name = "scsi_host",
62 .dev_release = scsi_host_cls_release,
63};
64
65/**
66 * scsi_host_set_state - Take the given host through the host state model.
67 * @shost: scsi host to change the state of.
68 * @state: state to change to.
69 *
70 * Returns zero if unsuccessful or an error if the requested
71 * transition is illegal.
72 **/
73int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
74{
75 enum scsi_host_state oldstate = shost->shost_state;
76
77 if (state == oldstate)
78 return 0;
79
80 switch (state) {
81 case SHOST_CREATED:
82 /* There are no legal states that come back to
83 * created. This is the manually initialised start
84 * state */
85 goto illegal;
86
87 case SHOST_RUNNING:
88 switch (oldstate) {
89 case SHOST_CREATED:
90 case SHOST_RECOVERY:
91 break;
92 default:
93 goto illegal;
94 }
95 break;
96
97 case SHOST_RECOVERY:
98 switch (oldstate) {
99 case SHOST_RUNNING:
100 break;
101 default:
102 goto illegal;
103 }
104 break;
105
106 case SHOST_CANCEL:
107 switch (oldstate) {
108 case SHOST_CREATED:
109 case SHOST_RUNNING:
110 case SHOST_CANCEL_RECOVERY:
111 break;
112 default:
113 goto illegal;
114 }
115 break;
116
117 case SHOST_DEL:
118 switch (oldstate) {
119 case SHOST_CANCEL:
120 case SHOST_DEL_RECOVERY:
121 break;
122 default:
123 goto illegal;
124 }
125 break;
126
127 case SHOST_CANCEL_RECOVERY:
128 switch (oldstate) {
129 case SHOST_CANCEL:
130 case SHOST_RECOVERY:
131 break;
132 default:
133 goto illegal;
134 }
135 break;
136
137 case SHOST_DEL_RECOVERY:
138 switch (oldstate) {
139 case SHOST_CANCEL_RECOVERY:
140 break;
141 default:
142 goto illegal;
143 }
144 break;
145 }
146 shost->shost_state = state;
147 return 0;
148
149 illegal:
150 SCSI_LOG_ERROR_RECOVERY(1,
151 shost_printk(KERN_ERR, shost,
152 "Illegal host state transition"
153 "%s->%s\n",
154 scsi_host_state_name(oldstate),
155 scsi_host_state_name(state)));
156 return -EINVAL;
157}
158
159/**
160 * scsi_remove_host - remove a scsi host
161 * @shost: a pointer to a scsi host to remove
162 **/
163void scsi_remove_host(struct Scsi_Host *shost)
164{
165 unsigned long flags;
166
167 mutex_lock(&shost->scan_mutex);
168 spin_lock_irqsave(shost->host_lock, flags);
169 if (scsi_host_set_state(shost, SHOST_CANCEL))
170 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
171 spin_unlock_irqrestore(shost->host_lock, flags);
172 mutex_unlock(&shost->scan_mutex);
173 return;
174 }
175 spin_unlock_irqrestore(shost->host_lock, flags);
176
177 scsi_autopm_get_host(shost);
178 flush_workqueue(shost->tmf_work_q);
179 scsi_forget_host(shost);
180 mutex_unlock(&shost->scan_mutex);
181 scsi_proc_host_rm(shost);
182
183 spin_lock_irqsave(shost->host_lock, flags);
184 if (scsi_host_set_state(shost, SHOST_DEL))
185 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
186 spin_unlock_irqrestore(shost->host_lock, flags);
187
188 transport_unregister_device(&shost->shost_gendev);
189 device_unregister(&shost->shost_dev);
190 device_del(&shost->shost_gendev);
191}
192EXPORT_SYMBOL(scsi_remove_host);
193
194/**
195 * scsi_add_host_with_dma - add a scsi host with dma device
196 * @shost: scsi host pointer to add
197 * @dev: a struct device of type scsi class
198 * @dma_dev: dma device for the host
199 *
200 * Note: You rarely need to worry about this unless you're in a
201 * virtualised host environments, so use the simpler scsi_add_host()
202 * function instead.
203 *
204 * Return value:
205 * 0 on success / != 0 for error
206 **/
207int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
208 struct device *dma_dev)
209{
210 struct scsi_host_template *sht = shost->hostt;
211 int error = -EINVAL;
212
213 shost_printk(KERN_INFO, shost, "%s\n",
214 sht->info ? sht->info(shost) : sht->name);
215
216 if (!shost->can_queue) {
217 shost_printk(KERN_ERR, shost,
218 "can_queue = 0 no longer supported\n");
219 goto fail;
220 }
221
222 error = scsi_init_sense_cache(shost);
223 if (error)
224 goto fail;
225
226 error = scsi_mq_setup_tags(shost);
227 if (error)
228 goto fail;
229
230 if (!shost->shost_gendev.parent)
231 shost->shost_gendev.parent = dev ? dev : &platform_bus;
232 if (!dma_dev)
233 dma_dev = shost->shost_gendev.parent;
234
235 shost->dma_dev = dma_dev;
236
237 /*
238 * Increase usage count temporarily here so that calling
239 * scsi_autopm_put_host() will trigger runtime idle if there is
240 * nothing else preventing suspending the device.
241 */
242 pm_runtime_get_noresume(&shost->shost_gendev);
243 pm_runtime_set_active(&shost->shost_gendev);
244 pm_runtime_enable(&shost->shost_gendev);
245 device_enable_async_suspend(&shost->shost_gendev);
246
247 error = device_add(&shost->shost_gendev);
248 if (error)
249 goto out_disable_runtime_pm;
250
251 scsi_host_set_state(shost, SHOST_RUNNING);
252 get_device(shost->shost_gendev.parent);
253
254 device_enable_async_suspend(&shost->shost_dev);
255
256 error = device_add(&shost->shost_dev);
257 if (error)
258 goto out_del_gendev;
259
260 get_device(&shost->shost_gendev);
261
262 if (shost->transportt->host_size) {
263 shost->shost_data = kzalloc(shost->transportt->host_size,
264 GFP_KERNEL);
265 if (shost->shost_data == NULL) {
266 error = -ENOMEM;
267 goto out_del_dev;
268 }
269 }
270
271 if (shost->transportt->create_work_queue) {
272 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
273 "scsi_wq_%d", shost->host_no);
274 shost->work_q = create_singlethread_workqueue(
275 shost->work_q_name);
276 if (!shost->work_q) {
277 error = -EINVAL;
278 goto out_free_shost_data;
279 }
280 }
281
282 error = scsi_sysfs_add_host(shost);
283 if (error)
284 goto out_destroy_host;
285
286 scsi_proc_host_add(shost);
287 scsi_autopm_put_host(shost);
288 return error;
289
290 out_destroy_host:
291 if (shost->work_q)
292 destroy_workqueue(shost->work_q);
293 out_free_shost_data:
294 kfree(shost->shost_data);
295 out_del_dev:
296 device_del(&shost->shost_dev);
297 out_del_gendev:
298 device_del(&shost->shost_gendev);
299 out_disable_runtime_pm:
300 device_disable_async_suspend(&shost->shost_gendev);
301 pm_runtime_disable(&shost->shost_gendev);
302 pm_runtime_set_suspended(&shost->shost_gendev);
303 pm_runtime_put_noidle(&shost->shost_gendev);
304 scsi_mq_destroy_tags(shost);
305 fail:
306 return error;
307}
308EXPORT_SYMBOL(scsi_add_host_with_dma);
309
310static void scsi_host_dev_release(struct device *dev)
311{
312 struct Scsi_Host *shost = dev_to_shost(dev);
313 struct device *parent = dev->parent;
314
315 scsi_proc_hostdir_rm(shost->hostt);
316
317 /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */
318 rcu_barrier();
319
320 if (shost->tmf_work_q)
321 destroy_workqueue(shost->tmf_work_q);
322 if (shost->ehandler)
323 kthread_stop(shost->ehandler);
324 if (shost->work_q)
325 destroy_workqueue(shost->work_q);
326
327 if (shost->shost_state == SHOST_CREATED) {
328 /*
329 * Free the shost_dev device name here if scsi_host_alloc()
330 * and scsi_host_put() have been called but neither
331 * scsi_host_add() nor scsi_host_remove() has been called.
332 * This avoids that the memory allocated for the shost_dev
333 * name is leaked.
334 */
335 kfree(dev_name(&shost->shost_dev));
336 }
337
338 if (shost->tag_set.tags)
339 scsi_mq_destroy_tags(shost);
340
341 kfree(shost->shost_data);
342
343 ida_simple_remove(&host_index_ida, shost->host_no);
344
345 if (parent)
346 put_device(parent);
347 kfree(shost);
348}
349
350static struct device_type scsi_host_type = {
351 .name = "scsi_host",
352 .release = scsi_host_dev_release,
353};
354
355/**
356 * scsi_host_alloc - register a scsi host adapter instance.
357 * @sht: pointer to scsi host template
358 * @privsize: extra bytes to allocate for driver
359 *
360 * Note:
361 * Allocate a new Scsi_Host and perform basic initialization.
362 * The host is not published to the scsi midlayer until scsi_add_host
363 * is called.
364 *
365 * Return value:
366 * Pointer to a new Scsi_Host
367 **/
368struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
369{
370 struct Scsi_Host *shost;
371 gfp_t gfp_mask = GFP_KERNEL;
372 int index;
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 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
392 if (index < 0)
393 goto fail_kfree;
394 shost->host_no = index;
395
396 shost->dma_channel = 0xff;
397
398 /* These three are default values which can be overridden */
399 shost->max_channel = 0;
400 shost->max_id = 8;
401 shost->max_lun = 8;
402
403 /* Give each shost a default transportt */
404 shost->transportt = &blank_transport_template;
405
406 /*
407 * All drivers right now should be able to handle 12 byte
408 * commands. Every so often there are requests for 16 byte
409 * commands, but individual low-level drivers need to certify that
410 * they actually do something sensible with such commands.
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->no_write_same = sht->no_write_same;
421
422 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
423 shost->eh_deadline = -1;
424 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
425 shost_printk(KERN_WARNING, shost,
426 "eh_deadline %u too large, setting to %u\n",
427 shost_eh_deadline, INT_MAX / HZ);
428 shost->eh_deadline = INT_MAX;
429 } else
430 shost->eh_deadline = shost_eh_deadline * HZ;
431
432 if (sht->supported_mode == MODE_UNKNOWN)
433 /* means we didn't set it ... default to INITIATOR */
434 shost->active_mode = MODE_INITIATOR;
435 else
436 shost->active_mode = sht->supported_mode;
437
438 if (sht->max_host_blocked)
439 shost->max_host_blocked = sht->max_host_blocked;
440 else
441 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
442
443 /*
444 * If the driver imposes no hard sector transfer limit, start at
445 * machine infinity initially.
446 */
447 if (sht->max_sectors)
448 shost->max_sectors = sht->max_sectors;
449 else
450 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
451
452 if (sht->max_segment_size)
453 shost->max_segment_size = sht->max_segment_size;
454 else
455 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
456
457 /*
458 * assume a 4GB boundary, if not set
459 */
460 if (sht->dma_boundary)
461 shost->dma_boundary = sht->dma_boundary;
462 else
463 shost->dma_boundary = 0xffffffff;
464
465 if (sht->virt_boundary_mask)
466 shost->virt_boundary_mask = sht->virt_boundary_mask;
467
468 device_initialize(&shost->shost_gendev);
469 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
470 shost->shost_gendev.bus = &scsi_bus_type;
471 shost->shost_gendev.type = &scsi_host_type;
472
473 device_initialize(&shost->shost_dev);
474 shost->shost_dev.parent = &shost->shost_gendev;
475 shost->shost_dev.class = &shost_class;
476 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
477 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
478
479 shost->ehandler = kthread_run(scsi_error_handler, shost,
480 "scsi_eh_%d", shost->host_no);
481 if (IS_ERR(shost->ehandler)) {
482 shost_printk(KERN_WARNING, shost,
483 "error handler thread failed to spawn, error = %ld\n",
484 PTR_ERR(shost->ehandler));
485 goto fail_index_remove;
486 }
487
488 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
489 WQ_UNBOUND | WQ_MEM_RECLAIM,
490 1, shost->host_no);
491 if (!shost->tmf_work_q) {
492 shost_printk(KERN_WARNING, shost,
493 "failed to create tmf workq\n");
494 goto fail_kthread;
495 }
496 scsi_proc_hostdir_add(shost->hostt);
497 return shost;
498
499 fail_kthread:
500 kthread_stop(shost->ehandler);
501 fail_index_remove:
502 ida_simple_remove(&host_index_ida, shost->host_no);
503 fail_kfree:
504 kfree(shost);
505 return NULL;
506}
507EXPORT_SYMBOL(scsi_host_alloc);
508
509static int __scsi_host_match(struct device *dev, const void *data)
510{
511 struct Scsi_Host *p;
512 const unsigned short *hostnum = data;
513
514 p = class_to_shost(dev);
515 return p->host_no == *hostnum;
516}
517
518/**
519 * scsi_host_lookup - get a reference to a Scsi_Host by host no
520 * @hostnum: host number to locate
521 *
522 * Return value:
523 * A pointer to located Scsi_Host or NULL.
524 *
525 * The caller must do a scsi_host_put() to drop the reference
526 * that scsi_host_get() took. The put_device() below dropped
527 * the reference from class_find_device().
528 **/
529struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
530{
531 struct device *cdev;
532 struct Scsi_Host *shost = NULL;
533
534 cdev = class_find_device(&shost_class, NULL, &hostnum,
535 __scsi_host_match);
536 if (cdev) {
537 shost = scsi_host_get(class_to_shost(cdev));
538 put_device(cdev);
539 }
540 return shost;
541}
542EXPORT_SYMBOL(scsi_host_lookup);
543
544/**
545 * scsi_host_get - inc a Scsi_Host ref count
546 * @shost: Pointer to Scsi_Host to inc.
547 **/
548struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
549{
550 if ((shost->shost_state == SHOST_DEL) ||
551 !get_device(&shost->shost_gendev))
552 return NULL;
553 return shost;
554}
555EXPORT_SYMBOL(scsi_host_get);
556
557/**
558 * scsi_host_busy - Return the host busy counter
559 * @shost: Pointer to Scsi_Host to inc.
560 **/
561int scsi_host_busy(struct Scsi_Host *shost)
562{
563 return atomic_read(&shost->host_busy);
564}
565EXPORT_SYMBOL(scsi_host_busy);
566
567/**
568 * scsi_host_put - dec a Scsi_Host ref count
569 * @shost: Pointer to Scsi_Host to dec.
570 **/
571void scsi_host_put(struct Scsi_Host *shost)
572{
573 put_device(&shost->shost_gendev);
574}
575EXPORT_SYMBOL(scsi_host_put);
576
577int scsi_init_hosts(void)
578{
579 return class_register(&shost_class);
580}
581
582void scsi_exit_hosts(void)
583{
584 class_unregister(&shost_class);
585 ida_destroy(&host_index_ida);
586}
587
588int scsi_is_host_device(const struct device *dev)
589{
590 return dev->type == &scsi_host_type;
591}
592EXPORT_SYMBOL(scsi_is_host_device);
593
594/**
595 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
596 * @shost: Pointer to Scsi_Host.
597 * @work: Work to queue for execution.
598 *
599 * Return value:
600 * 1 - work queued for execution
601 * 0 - work is already queued
602 * -EINVAL - work queue doesn't exist
603 **/
604int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
605{
606 if (unlikely(!shost->work_q)) {
607 shost_printk(KERN_ERR, shost,
608 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
609 "when no workqueue created.\n", shost->hostt->name);
610 dump_stack();
611
612 return -EINVAL;
613 }
614
615 return queue_work(shost->work_q, work);
616}
617EXPORT_SYMBOL_GPL(scsi_queue_work);
618
619/**
620 * scsi_flush_work - Flush a Scsi_Host's workqueue.
621 * @shost: Pointer to Scsi_Host.
622 **/
623void scsi_flush_work(struct Scsi_Host *shost)
624{
625 if (!shost->work_q) {
626 shost_printk(KERN_ERR, shost,
627 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
628 "when no workqueue created.\n", shost->hostt->name);
629 dump_stack();
630 return;
631 }
632
633 flush_workqueue(shost->work_q);
634}
635EXPORT_SYMBOL_GPL(scsi_flush_work);