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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
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); /* host_no for next new host */
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 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
208 sht->info ? sht->info(shost) : sht->name);
209
210 if (!shost->can_queue) {
211 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
212 sht->name);
213 goto fail;
214 }
215
216 error = scsi_setup_command_freelist(shost);
217 if (error)
218 goto fail;
219
220 if (!shost->shost_gendev.parent)
221 shost->shost_gendev.parent = dev ? dev : &platform_bus;
222 if (!dma_dev)
223 dma_dev = shost->shost_gendev.parent;
224
225 shost->dma_dev = dma_dev;
226
227 error = device_add(&shost->shost_gendev);
228 if (error)
229 goto out;
230
231 pm_runtime_set_active(&shost->shost_gendev);
232 pm_runtime_enable(&shost->shost_gendev);
233 device_enable_async_suspend(&shost->shost_gendev);
234
235 scsi_host_set_state(shost, SHOST_RUNNING);
236 get_device(shost->shost_gendev.parent);
237
238 device_enable_async_suspend(&shost->shost_dev);
239
240 error = device_add(&shost->shost_dev);
241 if (error)
242 goto out_del_gendev;
243
244 get_device(&shost->shost_gendev);
245
246 if (shost->transportt->host_size) {
247 shost->shost_data = kzalloc(shost->transportt->host_size,
248 GFP_KERNEL);
249 if (shost->shost_data == NULL) {
250 error = -ENOMEM;
251 goto out_del_dev;
252 }
253 }
254
255 if (shost->transportt->create_work_queue) {
256 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
257 "scsi_wq_%d", shost->host_no);
258 shost->work_q = create_singlethread_workqueue(
259 shost->work_q_name);
260 if (!shost->work_q) {
261 error = -EINVAL;
262 goto out_free_shost_data;
263 }
264 }
265
266 error = scsi_sysfs_add_host(shost);
267 if (error)
268 goto out_destroy_host;
269
270 scsi_proc_host_add(shost);
271 return error;
272
273 out_destroy_host:
274 if (shost->work_q)
275 destroy_workqueue(shost->work_q);
276 out_free_shost_data:
277 kfree(shost->shost_data);
278 out_del_dev:
279 device_del(&shost->shost_dev);
280 out_del_gendev:
281 device_del(&shost->shost_gendev);
282 out:
283 scsi_destroy_command_freelist(shost);
284 fail:
285 return error;
286}
287EXPORT_SYMBOL(scsi_add_host_with_dma);
288
289static void scsi_host_dev_release(struct device *dev)
290{
291 struct Scsi_Host *shost = dev_to_shost(dev);
292 struct device *parent = dev->parent;
293 struct request_queue *q;
294 void *queuedata;
295
296 scsi_proc_hostdir_rm(shost->hostt);
297
298 if (shost->tmf_work_q)
299 destroy_workqueue(shost->tmf_work_q);
300 if (shost->ehandler)
301 kthread_stop(shost->ehandler);
302 if (shost->work_q)
303 destroy_workqueue(shost->work_q);
304 q = shost->uspace_req_q;
305 if (q) {
306 queuedata = q->queuedata;
307 blk_cleanup_queue(q);
308 kfree(queuedata);
309 }
310
311 scsi_destroy_command_freelist(shost);
312 if (shost->bqt)
313 blk_free_tags(shost->bqt);
314
315 kfree(shost->shost_data);
316
317 if (parent)
318 put_device(parent);
319 kfree(shost);
320}
321
322static int shost_eh_deadline = -1;
323
324module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
325MODULE_PARM_DESC(eh_deadline,
326 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
327
328static struct device_type scsi_host_type = {
329 .name = "scsi_host",
330 .release = scsi_host_dev_release,
331};
332
333/**
334 * scsi_host_alloc - register a scsi host adapter instance.
335 * @sht: pointer to scsi host template
336 * @privsize: extra bytes to allocate for driver
337 *
338 * Note:
339 * Allocate a new Scsi_Host and perform basic initialization.
340 * The host is not published to the scsi midlayer until scsi_add_host
341 * is called.
342 *
343 * Return value:
344 * Pointer to a new Scsi_Host
345 **/
346struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
347{
348 struct Scsi_Host *shost;
349 gfp_t gfp_mask = GFP_KERNEL;
350
351 if (sht->unchecked_isa_dma && privsize)
352 gfp_mask |= __GFP_DMA;
353
354 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
355 if (!shost)
356 return NULL;
357
358 shost->host_lock = &shost->default_lock;
359 spin_lock_init(shost->host_lock);
360 shost->shost_state = SHOST_CREATED;
361 INIT_LIST_HEAD(&shost->__devices);
362 INIT_LIST_HEAD(&shost->__targets);
363 INIT_LIST_HEAD(&shost->eh_cmd_q);
364 INIT_LIST_HEAD(&shost->starved_list);
365 init_waitqueue_head(&shost->host_wait);
366 mutex_init(&shost->scan_mutex);
367
368 /*
369 * subtract one because we increment first then return, but we need to
370 * know what the next host number was before increment
371 */
372 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
373 shost->dma_channel = 0xff;
374
375 /* These three are default values which can be overridden */
376 shost->max_channel = 0;
377 shost->max_id = 8;
378 shost->max_lun = 8;
379
380 /* Give each shost a default transportt */
381 shost->transportt = &blank_transport_template;
382
383 /*
384 * All drivers right now should be able to handle 12 byte
385 * commands. Every so often there are requests for 16 byte
386 * commands, but individual low-level drivers need to certify that
387 * they actually do something sensible with such commands.
388 */
389 shost->max_cmd_len = 12;
390 shost->hostt = sht;
391 shost->this_id = sht->this_id;
392 shost->can_queue = sht->can_queue;
393 shost->sg_tablesize = sht->sg_tablesize;
394 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
395 shost->cmd_per_lun = sht->cmd_per_lun;
396 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
397 shost->use_clustering = sht->use_clustering;
398 shost->ordered_tag = sht->ordered_tag;
399 shost->no_write_same = sht->no_write_same;
400
401 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
402 shost->eh_deadline = -1;
403 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
404 shost_printk(KERN_WARNING, shost,
405 "eh_deadline %u too large, setting to %u\n",
406 shost_eh_deadline, INT_MAX / HZ);
407 shost->eh_deadline = INT_MAX;
408 } else
409 shost->eh_deadline = shost_eh_deadline * HZ;
410
411 if (sht->supported_mode == MODE_UNKNOWN)
412 /* means we didn't set it ... default to INITIATOR */
413 shost->active_mode = MODE_INITIATOR;
414 else
415 shost->active_mode = sht->supported_mode;
416
417 if (sht->max_host_blocked)
418 shost->max_host_blocked = sht->max_host_blocked;
419 else
420 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
421
422 /*
423 * If the driver imposes no hard sector transfer limit, start at
424 * machine infinity initially.
425 */
426 if (sht->max_sectors)
427 shost->max_sectors = sht->max_sectors;
428 else
429 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
430
431 /*
432 * assume a 4GB boundary, if not set
433 */
434 if (sht->dma_boundary)
435 shost->dma_boundary = sht->dma_boundary;
436 else
437 shost->dma_boundary = 0xffffffff;
438
439 device_initialize(&shost->shost_gendev);
440 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
441 shost->shost_gendev.bus = &scsi_bus_type;
442 shost->shost_gendev.type = &scsi_host_type;
443
444 device_initialize(&shost->shost_dev);
445 shost->shost_dev.parent = &shost->shost_gendev;
446 shost->shost_dev.class = &shost_class;
447 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
448 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
449
450 shost->ehandler = kthread_run(scsi_error_handler, shost,
451 "scsi_eh_%d", shost->host_no);
452 if (IS_ERR(shost->ehandler)) {
453 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
454 shost->host_no, PTR_ERR(shost->ehandler));
455 goto fail_kfree;
456 }
457
458 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
459 WQ_UNBOUND | WQ_MEM_RECLAIM,
460 1, shost->host_no);
461 if (!shost->tmf_work_q) {
462 printk(KERN_WARNING "scsi%d: failed to create tmf workq\n",
463 shost->host_no);
464 goto fail_kthread;
465 }
466 scsi_proc_hostdir_add(shost->hostt);
467 return shost;
468
469 fail_kthread:
470 kthread_stop(shost->ehandler);
471 fail_kfree:
472 kfree(shost);
473 return NULL;
474}
475EXPORT_SYMBOL(scsi_host_alloc);
476
477struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
478{
479 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
480
481 if (!sht->detect) {
482 printk(KERN_WARNING "scsi_register() called on new-style "
483 "template for driver %s\n", sht->name);
484 dump_stack();
485 }
486
487 if (shost)
488 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
489 return shost;
490}
491EXPORT_SYMBOL(scsi_register);
492
493void scsi_unregister(struct Scsi_Host *shost)
494{
495 list_del(&shost->sht_legacy_list);
496 scsi_host_put(shost);
497}
498EXPORT_SYMBOL(scsi_unregister);
499
500static int __scsi_host_match(struct device *dev, const void *data)
501{
502 struct Scsi_Host *p;
503 const unsigned short *hostnum = data;
504
505 p = class_to_shost(dev);
506 return p->host_no == *hostnum;
507}
508
509/**
510 * scsi_host_lookup - get a reference to a Scsi_Host by host no
511 * @hostnum: host number to locate
512 *
513 * Return value:
514 * A pointer to located Scsi_Host or NULL.
515 *
516 * The caller must do a scsi_host_put() to drop the reference
517 * that scsi_host_get() took. The put_device() below dropped
518 * the reference from class_find_device().
519 **/
520struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
521{
522 struct device *cdev;
523 struct Scsi_Host *shost = NULL;
524
525 cdev = class_find_device(&shost_class, NULL, &hostnum,
526 __scsi_host_match);
527 if (cdev) {
528 shost = scsi_host_get(class_to_shost(cdev));
529 put_device(cdev);
530 }
531 return shost;
532}
533EXPORT_SYMBOL(scsi_host_lookup);
534
535/**
536 * scsi_host_get - inc a Scsi_Host ref count
537 * @shost: Pointer to Scsi_Host to inc.
538 **/
539struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
540{
541 if ((shost->shost_state == SHOST_DEL) ||
542 !get_device(&shost->shost_gendev))
543 return NULL;
544 return shost;
545}
546EXPORT_SYMBOL(scsi_host_get);
547
548/**
549 * scsi_host_put - dec a Scsi_Host ref count
550 * @shost: Pointer to Scsi_Host to dec.
551 **/
552void scsi_host_put(struct Scsi_Host *shost)
553{
554 put_device(&shost->shost_gendev);
555}
556EXPORT_SYMBOL(scsi_host_put);
557
558int scsi_init_hosts(void)
559{
560 return class_register(&shost_class);
561}
562
563void scsi_exit_hosts(void)
564{
565 class_unregister(&shost_class);
566}
567
568int scsi_is_host_device(const struct device *dev)
569{
570 return dev->type == &scsi_host_type;
571}
572EXPORT_SYMBOL(scsi_is_host_device);
573
574/**
575 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
576 * @shost: Pointer to Scsi_Host.
577 * @work: Work to queue for execution.
578 *
579 * Return value:
580 * 1 - work queued for execution
581 * 0 - work is already queued
582 * -EINVAL - work queue doesn't exist
583 **/
584int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
585{
586 if (unlikely(!shost->work_q)) {
587 printk(KERN_ERR
588 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
589 "when no workqueue created.\n", shost->hostt->name);
590 dump_stack();
591
592 return -EINVAL;
593 }
594
595 return queue_work(shost->work_q, work);
596}
597EXPORT_SYMBOL_GPL(scsi_queue_work);
598
599/**
600 * scsi_flush_work - Flush a Scsi_Host's workqueue.
601 * @shost: Pointer to Scsi_Host.
602 **/
603void scsi_flush_work(struct Scsi_Host *shost)
604{
605 if (!shost->work_q) {
606 printk(KERN_ERR
607 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
608 "when no workqueue created.\n", shost->hostt->name);
609 dump_stack();
610 return;
611 }
612
613 flush_workqueue(shost->work_q);
614}
615EXPORT_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 .dev_groups = scsi_shost_groups,
65};
66
67/**
68 * scsi_host_set_state - Take the given host through the host state model.
69 * @shost: scsi host to change the state of.
70 * @state: state to change to.
71 *
72 * Returns zero if unsuccessful or an error if the requested
73 * transition is illegal.
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 /* There are no legal states that come back to
85 * created. This is the manually initialised start
86 * state */
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 * scsi_remove_host - remove a scsi host
163 * @shost: a pointer to a scsi host to remove
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 scsi_proc_hostdir_rm(shost->hostt);
185
186 /*
187 * New SCSI devices cannot be attached anymore because of the SCSI host
188 * state so drop the tag set refcnt. Wait until the tag set refcnt drops
189 * to zero because .exit_cmd_priv implementations may need the host
190 * pointer.
191 */
192 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
193 wait_for_completion(&shost->tagset_freed);
194
195 spin_lock_irqsave(shost->host_lock, flags);
196 if (scsi_host_set_state(shost, SHOST_DEL))
197 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
198 spin_unlock_irqrestore(shost->host_lock, flags);
199
200 transport_unregister_device(&shost->shost_gendev);
201 device_unregister(&shost->shost_dev);
202 device_del(&shost->shost_gendev);
203}
204EXPORT_SYMBOL(scsi_remove_host);
205
206/**
207 * scsi_add_host_with_dma - add a scsi host with dma device
208 * @shost: scsi host pointer to add
209 * @dev: a struct device of type scsi class
210 * @dma_dev: dma device for the host
211 *
212 * Note: You rarely need to worry about this unless you're in a
213 * virtualised host environments, so use the simpler scsi_add_host()
214 * function instead.
215 *
216 * Return value:
217 * 0 on success / != 0 for error
218 **/
219int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
220 struct device *dma_dev)
221{
222 const struct scsi_host_template *sht = shost->hostt;
223 int error = -EINVAL;
224
225 shost_printk(KERN_INFO, shost, "%s\n",
226 sht->info ? sht->info(shost) : sht->name);
227
228 if (!shost->can_queue) {
229 shost_printk(KERN_ERR, shost,
230 "can_queue = 0 no longer supported\n");
231 goto fail;
232 }
233
234 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
235 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
236 shost->can_queue);
237
238 error = scsi_init_sense_cache(shost);
239 if (error)
240 goto fail;
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 if (dma_dev->dma_mask) {
250 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
251 dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
252 }
253
254 error = scsi_mq_setup_tags(shost);
255 if (error)
256 goto fail;
257
258 kref_init(&shost->tagset_refcnt);
259 init_completion(&shost->tagset_freed);
260
261 /*
262 * Increase usage count temporarily here so that calling
263 * scsi_autopm_put_host() will trigger runtime idle if there is
264 * nothing else preventing suspending the device.
265 */
266 pm_runtime_get_noresume(&shost->shost_gendev);
267 pm_runtime_set_active(&shost->shost_gendev);
268 pm_runtime_enable(&shost->shost_gendev);
269 device_enable_async_suspend(&shost->shost_gendev);
270
271 error = device_add(&shost->shost_gendev);
272 if (error)
273 goto out_disable_runtime_pm;
274
275 scsi_host_set_state(shost, SHOST_RUNNING);
276 get_device(shost->shost_gendev.parent);
277
278 device_enable_async_suspend(&shost->shost_dev);
279
280 get_device(&shost->shost_gendev);
281 error = device_add(&shost->shost_dev);
282 if (error)
283 goto out_del_gendev;
284
285 if (shost->transportt->host_size) {
286 shost->shost_data = kzalloc(shost->transportt->host_size,
287 GFP_KERNEL);
288 if (shost->shost_data == NULL) {
289 error = -ENOMEM;
290 goto out_del_dev;
291 }
292 }
293
294 if (shost->transportt->create_work_queue) {
295 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
296 "scsi_wq_%d", shost->host_no);
297 shost->work_q = alloc_workqueue("%s",
298 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
299 1, shost->work_q_name);
300
301 if (!shost->work_q) {
302 error = -EINVAL;
303 goto out_del_dev;
304 }
305 }
306
307 error = scsi_sysfs_add_host(shost);
308 if (error)
309 goto out_del_dev;
310
311 scsi_proc_host_add(shost);
312 scsi_autopm_put_host(shost);
313 return error;
314
315 /*
316 * Any host allocation in this function will be freed in
317 * scsi_host_dev_release().
318 */
319 out_del_dev:
320 device_del(&shost->shost_dev);
321 out_del_gendev:
322 /*
323 * Host state is SHOST_RUNNING so we have to explicitly release
324 * ->shost_dev.
325 */
326 put_device(&shost->shost_dev);
327 device_del(&shost->shost_gendev);
328 out_disable_runtime_pm:
329 device_disable_async_suspend(&shost->shost_gendev);
330 pm_runtime_disable(&shost->shost_gendev);
331 pm_runtime_set_suspended(&shost->shost_gendev);
332 pm_runtime_put_noidle(&shost->shost_gendev);
333 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
334 fail:
335 return error;
336}
337EXPORT_SYMBOL(scsi_add_host_with_dma);
338
339static void scsi_host_dev_release(struct device *dev)
340{
341 struct Scsi_Host *shost = dev_to_shost(dev);
342 struct device *parent = dev->parent;
343
344 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
345 rcu_barrier();
346
347 if (shost->tmf_work_q)
348 destroy_workqueue(shost->tmf_work_q);
349 if (shost->ehandler)
350 kthread_stop(shost->ehandler);
351 if (shost->work_q)
352 destroy_workqueue(shost->work_q);
353
354 if (shost->shost_state == SHOST_CREATED) {
355 /*
356 * Free the shost_dev device name and remove the proc host dir
357 * here if scsi_host_{alloc,put}() have been called but neither
358 * scsi_host_add() nor scsi_remove_host() has been called.
359 * This avoids that the memory allocated for the shost_dev
360 * name as well as the proc dir structure are leaked.
361 */
362 scsi_proc_hostdir_rm(shost->hostt);
363 kfree(dev_name(&shost->shost_dev));
364 }
365
366 kfree(shost->shost_data);
367
368 ida_free(&host_index_ida, shost->host_no);
369
370 if (shost->shost_state != SHOST_CREATED)
371 put_device(parent);
372 kfree(shost);
373}
374
375static const struct device_type scsi_host_type = {
376 .name = "scsi_host",
377 .release = scsi_host_dev_release,
378};
379
380/**
381 * scsi_host_alloc - register a scsi host adapter instance.
382 * @sht: pointer to scsi host template
383 * @privsize: extra bytes to allocate for driver
384 *
385 * Note:
386 * Allocate a new Scsi_Host and perform basic initialization.
387 * The host is not published to the scsi midlayer until scsi_add_host
388 * is called.
389 *
390 * Return value:
391 * Pointer to a new Scsi_Host
392 **/
393struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int privsize)
394{
395 struct Scsi_Host *shost;
396 int index;
397
398 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
399 if (!shost)
400 return NULL;
401
402 shost->host_lock = &shost->default_lock;
403 spin_lock_init(shost->host_lock);
404 shost->shost_state = SHOST_CREATED;
405 INIT_LIST_HEAD(&shost->__devices);
406 INIT_LIST_HEAD(&shost->__targets);
407 INIT_LIST_HEAD(&shost->eh_abort_list);
408 INIT_LIST_HEAD(&shost->eh_cmd_q);
409 INIT_LIST_HEAD(&shost->starved_list);
410 init_waitqueue_head(&shost->host_wait);
411 mutex_init(&shost->scan_mutex);
412
413 index = ida_alloc(&host_index_ida, GFP_KERNEL);
414 if (index < 0) {
415 kfree(shost);
416 return NULL;
417 }
418 shost->host_no = index;
419
420 shost->dma_channel = 0xff;
421
422 /* These three are default values which can be overridden */
423 shost->max_channel = 0;
424 shost->max_id = 8;
425 shost->max_lun = 8;
426
427 /* Give each shost a default transportt */
428 shost->transportt = &blank_transport_template;
429
430 /*
431 * All drivers right now should be able to handle 12 byte
432 * commands. Every so often there are requests for 16 byte
433 * commands, but individual low-level drivers need to certify that
434 * they actually do something sensible with such commands.
435 */
436 shost->max_cmd_len = 12;
437 shost->hostt = sht;
438 shost->this_id = sht->this_id;
439 shost->can_queue = sht->can_queue;
440 shost->sg_tablesize = sht->sg_tablesize;
441 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
442 shost->cmd_per_lun = sht->cmd_per_lun;
443 shost->no_write_same = sht->no_write_same;
444 shost->host_tagset = sht->host_tagset;
445 shost->queuecommand_may_block = sht->queuecommand_may_block;
446
447 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
448 shost->eh_deadline = -1;
449 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
450 shost_printk(KERN_WARNING, shost,
451 "eh_deadline %u too large, setting to %u\n",
452 shost_eh_deadline, INT_MAX / HZ);
453 shost->eh_deadline = INT_MAX;
454 } else
455 shost->eh_deadline = shost_eh_deadline * HZ;
456
457 if (sht->supported_mode == MODE_UNKNOWN)
458 /* means we didn't set it ... default to INITIATOR */
459 shost->active_mode = MODE_INITIATOR;
460 else
461 shost->active_mode = sht->supported_mode;
462
463 if (sht->max_host_blocked)
464 shost->max_host_blocked = sht->max_host_blocked;
465 else
466 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
467
468 /*
469 * If the driver imposes no hard sector transfer limit, start at
470 * machine infinity initially.
471 */
472 if (sht->max_sectors)
473 shost->max_sectors = sht->max_sectors;
474 else
475 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
476
477 if (sht->max_segment_size)
478 shost->max_segment_size = sht->max_segment_size;
479 else
480 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
481
482 /*
483 * assume a 4GB boundary, if not set
484 */
485 if (sht->dma_boundary)
486 shost->dma_boundary = sht->dma_boundary;
487 else
488 shost->dma_boundary = 0xffffffff;
489
490 if (sht->virt_boundary_mask)
491 shost->virt_boundary_mask = sht->virt_boundary_mask;
492
493 device_initialize(&shost->shost_gendev);
494 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
495 shost->shost_gendev.bus = &scsi_bus_type;
496 shost->shost_gendev.type = &scsi_host_type;
497 scsi_enable_async_suspend(&shost->shost_gendev);
498
499 device_initialize(&shost->shost_dev);
500 shost->shost_dev.parent = &shost->shost_gendev;
501 shost->shost_dev.class = &shost_class;
502 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
503 shost->shost_dev.groups = sht->shost_groups;
504
505 shost->ehandler = kthread_run(scsi_error_handler, shost,
506 "scsi_eh_%d", shost->host_no);
507 if (IS_ERR(shost->ehandler)) {
508 shost_printk(KERN_WARNING, shost,
509 "error handler thread failed to spawn, error = %ld\n",
510 PTR_ERR(shost->ehandler));
511 shost->ehandler = NULL;
512 goto fail;
513 }
514
515 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
516 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
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;
522 }
523 if (scsi_proc_hostdir_add(shost->hostt) < 0)
524 goto fail;
525 return shost;
526 fail:
527 /*
528 * Host state is still SHOST_CREATED and that is enough to release
529 * ->shost_gendev. scsi_host_dev_release() will free
530 * dev_name(&shost->shost_dev).
531 */
532 put_device(&shost->shost_gendev);
533
534 return NULL;
535}
536EXPORT_SYMBOL(scsi_host_alloc);
537
538static int __scsi_host_match(struct device *dev, const void *data)
539{
540 struct Scsi_Host *p;
541 const unsigned int *hostnum = data;
542
543 p = class_to_shost(dev);
544 return p->host_no == *hostnum;
545}
546
547/**
548 * scsi_host_lookup - get a reference to a Scsi_Host by host no
549 * @hostnum: host number to locate
550 *
551 * Return value:
552 * A pointer to located Scsi_Host or NULL.
553 *
554 * The caller must do a scsi_host_put() to drop the reference
555 * that scsi_host_get() took. The put_device() below dropped
556 * the reference from class_find_device().
557 **/
558struct Scsi_Host *scsi_host_lookup(unsigned int hostnum)
559{
560 struct device *cdev;
561 struct Scsi_Host *shost = NULL;
562
563 cdev = class_find_device(&shost_class, NULL, &hostnum,
564 __scsi_host_match);
565 if (cdev) {
566 shost = scsi_host_get(class_to_shost(cdev));
567 put_device(cdev);
568 }
569 return shost;
570}
571EXPORT_SYMBOL(scsi_host_lookup);
572
573/**
574 * scsi_host_get - inc a Scsi_Host ref count
575 * @shost: Pointer to Scsi_Host to inc.
576 **/
577struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
578{
579 if ((shost->shost_state == SHOST_DEL) ||
580 !get_device(&shost->shost_gendev))
581 return NULL;
582 return shost;
583}
584EXPORT_SYMBOL(scsi_host_get);
585
586static bool scsi_host_check_in_flight(struct request *rq, void *data)
587{
588 int *count = data;
589 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
590
591 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
592 (*count)++;
593
594 return true;
595}
596
597/**
598 * scsi_host_busy - Return the host busy counter
599 * @shost: Pointer to Scsi_Host to inc.
600 **/
601int scsi_host_busy(struct Scsi_Host *shost)
602{
603 int cnt = 0;
604
605 blk_mq_tagset_busy_iter(&shost->tag_set,
606 scsi_host_check_in_flight, &cnt);
607 return cnt;
608}
609EXPORT_SYMBOL(scsi_host_busy);
610
611/**
612 * scsi_host_put - dec a Scsi_Host ref count
613 * @shost: Pointer to Scsi_Host to dec.
614 **/
615void scsi_host_put(struct Scsi_Host *shost)
616{
617 put_device(&shost->shost_gendev);
618}
619EXPORT_SYMBOL(scsi_host_put);
620
621int scsi_init_hosts(void)
622{
623 return class_register(&shost_class);
624}
625
626void scsi_exit_hosts(void)
627{
628 class_unregister(&shost_class);
629 ida_destroy(&host_index_ida);
630}
631
632int scsi_is_host_device(const struct device *dev)
633{
634 return dev->type == &scsi_host_type;
635}
636EXPORT_SYMBOL(scsi_is_host_device);
637
638/**
639 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
640 * @shost: Pointer to Scsi_Host.
641 * @work: Work to queue for execution.
642 *
643 * Return value:
644 * 1 - work queued for execution
645 * 0 - work is already queued
646 * -EINVAL - work queue doesn't exist
647 **/
648int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
649{
650 if (unlikely(!shost->work_q)) {
651 shost_printk(KERN_ERR, shost,
652 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
653 "when no workqueue created.\n", shost->hostt->name);
654 dump_stack();
655
656 return -EINVAL;
657 }
658
659 return queue_work(shost->work_q, work);
660}
661EXPORT_SYMBOL_GPL(scsi_queue_work);
662
663/**
664 * scsi_flush_work - Flush a Scsi_Host's workqueue.
665 * @shost: Pointer to Scsi_Host.
666 **/
667void scsi_flush_work(struct Scsi_Host *shost)
668{
669 if (!shost->work_q) {
670 shost_printk(KERN_ERR, shost,
671 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
672 "when no workqueue created.\n", shost->hostt->name);
673 dump_stack();
674 return;
675 }
676
677 flush_workqueue(shost->work_q);
678}
679EXPORT_SYMBOL_GPL(scsi_flush_work);
680
681static bool complete_all_cmds_iter(struct request *rq, void *data)
682{
683 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
684 enum scsi_host_status status = *(enum scsi_host_status *)data;
685
686 scsi_dma_unmap(scmd);
687 scmd->result = 0;
688 set_host_byte(scmd, status);
689 scsi_done(scmd);
690 return true;
691}
692
693/**
694 * scsi_host_complete_all_commands - Terminate all running commands
695 * @shost: Scsi Host on which commands should be terminated
696 * @status: Status to be set for the terminated commands
697 *
698 * There is no protection against modification of the number
699 * of outstanding commands. It is the responsibility of the
700 * caller to ensure that concurrent I/O submission and/or
701 * completion is stopped when calling this function.
702 */
703void scsi_host_complete_all_commands(struct Scsi_Host *shost,
704 enum scsi_host_status status)
705{
706 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
707 &status);
708}
709EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
710
711struct scsi_host_busy_iter_data {
712 bool (*fn)(struct scsi_cmnd *, void *);
713 void *priv;
714};
715
716static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
717{
718 struct scsi_host_busy_iter_data *iter_data = priv;
719 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
720
721 return iter_data->fn(sc, iter_data->priv);
722}
723
724/**
725 * scsi_host_busy_iter - Iterate over all busy commands
726 * @shost: Pointer to Scsi_Host.
727 * @fn: Function to call on each busy command
728 * @priv: Data pointer passed to @fn
729 *
730 * If locking against concurrent command completions is required
731 * ithas to be provided by the caller
732 **/
733void scsi_host_busy_iter(struct Scsi_Host *shost,
734 bool (*fn)(struct scsi_cmnd *, void *),
735 void *priv)
736{
737 struct scsi_host_busy_iter_data iter_data = {
738 .fn = fn,
739 .priv = priv,
740 };
741
742 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
743 &iter_data);
744}
745EXPORT_SYMBOL_GPL(scsi_host_busy_iter);