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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; /* 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 scsi_forget_host(shost);
173 mutex_unlock(&shost->scan_mutex);
174 scsi_proc_host_rm(shost);
175
176 spin_lock_irqsave(shost->host_lock, flags);
177 if (scsi_host_set_state(shost, SHOST_DEL))
178 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
179 spin_unlock_irqrestore(shost->host_lock, flags);
180
181 transport_unregister_device(&shost->shost_gendev);
182 device_unregister(&shost->shost_dev);
183 device_del(&shost->shost_gendev);
184}
185EXPORT_SYMBOL(scsi_remove_host);
186
187/**
188 * scsi_add_host_with_dma - add a scsi host with dma device
189 * @shost: scsi host pointer to add
190 * @dev: a struct device of type scsi class
191 * @dma_dev: dma device for the host
192 *
193 * Note: You rarely need to worry about this unless you're in a
194 * virtualised host environments, so use the simpler scsi_add_host()
195 * function instead.
196 *
197 * Return value:
198 * 0 on success / != 0 for error
199 **/
200int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
201 struct device *dma_dev)
202{
203 struct scsi_host_template *sht = shost->hostt;
204 int error = -EINVAL;
205
206 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
207 sht->info ? sht->info(shost) : sht->name);
208
209 if (!shost->can_queue) {
210 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
211 sht->name);
212 goto fail;
213 }
214
215 error = scsi_setup_command_freelist(shost);
216 if (error)
217 goto fail;
218
219 if (!shost->shost_gendev.parent)
220 shost->shost_gendev.parent = dev ? dev : &platform_bus;
221 shost->dma_dev = dma_dev;
222
223 error = device_add(&shost->shost_gendev);
224 if (error)
225 goto out;
226
227 pm_runtime_set_active(&shost->shost_gendev);
228 pm_runtime_enable(&shost->shost_gendev);
229 device_enable_async_suspend(&shost->shost_gendev);
230
231 scsi_host_set_state(shost, SHOST_RUNNING);
232 get_device(shost->shost_gendev.parent);
233
234 device_enable_async_suspend(&shost->shost_dev);
235
236 error = device_add(&shost->shost_dev);
237 if (error)
238 goto out_del_gendev;
239
240 get_device(&shost->shost_gendev);
241
242 if (shost->transportt->host_size) {
243 shost->shost_data = kzalloc(shost->transportt->host_size,
244 GFP_KERNEL);
245 if (shost->shost_data == NULL) {
246 error = -ENOMEM;
247 goto out_del_dev;
248 }
249 }
250
251 if (shost->transportt->create_work_queue) {
252 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
253 "scsi_wq_%d", shost->host_no);
254 shost->work_q = create_singlethread_workqueue(
255 shost->work_q_name);
256 if (!shost->work_q) {
257 error = -EINVAL;
258 goto out_free_shost_data;
259 }
260 }
261
262 error = scsi_sysfs_add_host(shost);
263 if (error)
264 goto out_destroy_host;
265
266 scsi_proc_host_add(shost);
267 return error;
268
269 out_destroy_host:
270 if (shost->work_q)
271 destroy_workqueue(shost->work_q);
272 out_free_shost_data:
273 kfree(shost->shost_data);
274 out_del_dev:
275 device_del(&shost->shost_dev);
276 out_del_gendev:
277 device_del(&shost->shost_gendev);
278 out:
279 scsi_destroy_command_freelist(shost);
280 fail:
281 return error;
282}
283EXPORT_SYMBOL(scsi_add_host_with_dma);
284
285static void scsi_host_dev_release(struct device *dev)
286{
287 struct Scsi_Host *shost = dev_to_shost(dev);
288 struct device *parent = dev->parent;
289
290 scsi_proc_hostdir_rm(shost->hostt);
291
292 if (shost->ehandler)
293 kthread_stop(shost->ehandler);
294 if (shost->work_q)
295 destroy_workqueue(shost->work_q);
296 if (shost->uspace_req_q) {
297 kfree(shost->uspace_req_q->queuedata);
298 scsi_free_queue(shost->uspace_req_q);
299 }
300
301 scsi_destroy_command_freelist(shost);
302 if (shost->bqt)
303 blk_free_tags(shost->bqt);
304
305 kfree(shost->shost_data);
306
307 if (parent)
308 put_device(parent);
309 kfree(shost);
310}
311
312static struct device_type scsi_host_type = {
313 .name = "scsi_host",
314 .release = scsi_host_dev_release,
315};
316
317/**
318 * scsi_host_alloc - register a scsi host adapter instance.
319 * @sht: pointer to scsi host template
320 * @privsize: extra bytes to allocate for driver
321 *
322 * Note:
323 * Allocate a new Scsi_Host and perform basic initialization.
324 * The host is not published to the scsi midlayer until scsi_add_host
325 * is called.
326 *
327 * Return value:
328 * Pointer to a new Scsi_Host
329 **/
330struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
331{
332 struct Scsi_Host *shost;
333 gfp_t gfp_mask = GFP_KERNEL;
334
335 if (sht->unchecked_isa_dma && privsize)
336 gfp_mask |= __GFP_DMA;
337
338 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
339 if (!shost)
340 return NULL;
341
342 shost->host_lock = &shost->default_lock;
343 spin_lock_init(shost->host_lock);
344 shost->shost_state = SHOST_CREATED;
345 INIT_LIST_HEAD(&shost->__devices);
346 INIT_LIST_HEAD(&shost->__targets);
347 INIT_LIST_HEAD(&shost->eh_cmd_q);
348 INIT_LIST_HEAD(&shost->starved_list);
349 init_waitqueue_head(&shost->host_wait);
350
351 mutex_init(&shost->scan_mutex);
352
353 /*
354 * subtract one because we increment first then return, but we need to
355 * know what the next host number was before increment
356 */
357 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
358 shost->dma_channel = 0xff;
359
360 /* These three are default values which can be overridden */
361 shost->max_channel = 0;
362 shost->max_id = 8;
363 shost->max_lun = 8;
364
365 /* Give each shost a default transportt */
366 shost->transportt = &blank_transport_template;
367
368 /*
369 * All drivers right now should be able to handle 12 byte
370 * commands. Every so often there are requests for 16 byte
371 * commands, but individual low-level drivers need to certify that
372 * they actually do something sensible with such commands.
373 */
374 shost->max_cmd_len = 12;
375 shost->hostt = sht;
376 shost->this_id = sht->this_id;
377 shost->can_queue = sht->can_queue;
378 shost->sg_tablesize = sht->sg_tablesize;
379 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
380 shost->cmd_per_lun = sht->cmd_per_lun;
381 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
382 shost->use_clustering = sht->use_clustering;
383 shost->ordered_tag = sht->ordered_tag;
384
385 if (sht->supported_mode == MODE_UNKNOWN)
386 /* means we didn't set it ... default to INITIATOR */
387 shost->active_mode = MODE_INITIATOR;
388 else
389 shost->active_mode = sht->supported_mode;
390
391 if (sht->max_host_blocked)
392 shost->max_host_blocked = sht->max_host_blocked;
393 else
394 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
395
396 /*
397 * If the driver imposes no hard sector transfer limit, start at
398 * machine infinity initially.
399 */
400 if (sht->max_sectors)
401 shost->max_sectors = sht->max_sectors;
402 else
403 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
404
405 /*
406 * assume a 4GB boundary, if not set
407 */
408 if (sht->dma_boundary)
409 shost->dma_boundary = sht->dma_boundary;
410 else
411 shost->dma_boundary = 0xffffffff;
412
413 device_initialize(&shost->shost_gendev);
414 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
415 shost->shost_gendev.bus = &scsi_bus_type;
416 shost->shost_gendev.type = &scsi_host_type;
417
418 device_initialize(&shost->shost_dev);
419 shost->shost_dev.parent = &shost->shost_gendev;
420 shost->shost_dev.class = &shost_class;
421 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
422 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
423
424 shost->ehandler = kthread_run(scsi_error_handler, shost,
425 "scsi_eh_%d", shost->host_no);
426 if (IS_ERR(shost->ehandler)) {
427 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
428 shost->host_no, PTR_ERR(shost->ehandler));
429 goto fail_kfree;
430 }
431
432 scsi_proc_hostdir_add(shost->hostt);
433 return shost;
434
435 fail_kfree:
436 kfree(shost);
437 return NULL;
438}
439EXPORT_SYMBOL(scsi_host_alloc);
440
441struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
442{
443 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
444
445 if (!sht->detect) {
446 printk(KERN_WARNING "scsi_register() called on new-style "
447 "template for driver %s\n", sht->name);
448 dump_stack();
449 }
450
451 if (shost)
452 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
453 return shost;
454}
455EXPORT_SYMBOL(scsi_register);
456
457void scsi_unregister(struct Scsi_Host *shost)
458{
459 list_del(&shost->sht_legacy_list);
460 scsi_host_put(shost);
461}
462EXPORT_SYMBOL(scsi_unregister);
463
464static int __scsi_host_match(struct device *dev, void *data)
465{
466 struct Scsi_Host *p;
467 unsigned short *hostnum = (unsigned short *)data;
468
469 p = class_to_shost(dev);
470 return p->host_no == *hostnum;
471}
472
473/**
474 * scsi_host_lookup - get a reference to a Scsi_Host by host no
475 * @hostnum: host number to locate
476 *
477 * Return value:
478 * A pointer to located Scsi_Host or NULL.
479 *
480 * The caller must do a scsi_host_put() to drop the reference
481 * that scsi_host_get() took. The put_device() below dropped
482 * the reference from class_find_device().
483 **/
484struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
485{
486 struct device *cdev;
487 struct Scsi_Host *shost = NULL;
488
489 cdev = class_find_device(&shost_class, NULL, &hostnum,
490 __scsi_host_match);
491 if (cdev) {
492 shost = scsi_host_get(class_to_shost(cdev));
493 put_device(cdev);
494 }
495 return shost;
496}
497EXPORT_SYMBOL(scsi_host_lookup);
498
499/**
500 * scsi_host_get - inc a Scsi_Host ref count
501 * @shost: Pointer to Scsi_Host to inc.
502 **/
503struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
504{
505 if ((shost->shost_state == SHOST_DEL) ||
506 !get_device(&shost->shost_gendev))
507 return NULL;
508 return shost;
509}
510EXPORT_SYMBOL(scsi_host_get);
511
512/**
513 * scsi_host_put - dec a Scsi_Host ref count
514 * @shost: Pointer to Scsi_Host to dec.
515 **/
516void scsi_host_put(struct Scsi_Host *shost)
517{
518 put_device(&shost->shost_gendev);
519}
520EXPORT_SYMBOL(scsi_host_put);
521
522int scsi_init_hosts(void)
523{
524 return class_register(&shost_class);
525}
526
527void scsi_exit_hosts(void)
528{
529 class_unregister(&shost_class);
530}
531
532int scsi_is_host_device(const struct device *dev)
533{
534 return dev->type == &scsi_host_type;
535}
536EXPORT_SYMBOL(scsi_is_host_device);
537
538/**
539 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
540 * @shost: Pointer to Scsi_Host.
541 * @work: Work to queue for execution.
542 *
543 * Return value:
544 * 1 - work queued for execution
545 * 0 - work is already queued
546 * -EINVAL - work queue doesn't exist
547 **/
548int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
549{
550 if (unlikely(!shost->work_q)) {
551 printk(KERN_ERR
552 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
553 "when no workqueue created.\n", shost->hostt->name);
554 dump_stack();
555
556 return -EINVAL;
557 }
558
559 return queue_work(shost->work_q, work);
560}
561EXPORT_SYMBOL_GPL(scsi_queue_work);
562
563/**
564 * scsi_flush_work - Flush a Scsi_Host's workqueue.
565 * @shost: Pointer to Scsi_Host.
566 **/
567void scsi_flush_work(struct Scsi_Host *shost)
568{
569 if (!shost->work_q) {
570 printk(KERN_ERR
571 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
572 "when no workqueue created.\n", shost->hostt->name);
573 dump_stack();
574 return;
575 }
576
577 flush_workqueue(shost->work_q);
578}
579EXPORT_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
185 /*
186 * New SCSI devices cannot be attached anymore because of the SCSI host
187 * state so drop the tag set refcnt. Wait until the tag set refcnt drops
188 * to zero because .exit_cmd_priv implementations may need the host
189 * pointer.
190 */
191 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
192 wait_for_completion(&shost->tagset_freed);
193
194 spin_lock_irqsave(shost->host_lock, flags);
195 if (scsi_host_set_state(shost, SHOST_DEL))
196 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
197 spin_unlock_irqrestore(shost->host_lock, flags);
198
199 transport_unregister_device(&shost->shost_gendev);
200 device_unregister(&shost->shost_dev);
201 device_del(&shost->shost_gendev);
202}
203EXPORT_SYMBOL(scsi_remove_host);
204
205/**
206 * scsi_add_host_with_dma - add a scsi host with dma device
207 * @shost: scsi host pointer to add
208 * @dev: a struct device of type scsi class
209 * @dma_dev: dma device for the host
210 *
211 * Note: You rarely need to worry about this unless you're in a
212 * virtualised host environments, so use the simpler scsi_add_host()
213 * function instead.
214 *
215 * Return value:
216 * 0 on success / != 0 for error
217 **/
218int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
219 struct device *dma_dev)
220{
221 struct scsi_host_template *sht = shost->hostt;
222 int error = -EINVAL;
223
224 shost_printk(KERN_INFO, shost, "%s\n",
225 sht->info ? sht->info(shost) : sht->name);
226
227 if (!shost->can_queue) {
228 shost_printk(KERN_ERR, shost,
229 "can_queue = 0 no longer supported\n");
230 goto fail;
231 }
232
233 /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */
234 shost->cmd_per_lun = min_t(int, shost->cmd_per_lun,
235 shost->can_queue);
236
237 error = scsi_init_sense_cache(shost);
238 if (error)
239 goto fail;
240
241 if (!shost->shost_gendev.parent)
242 shost->shost_gendev.parent = dev ? dev : &platform_bus;
243 if (!dma_dev)
244 dma_dev = shost->shost_gendev.parent;
245
246 shost->dma_dev = dma_dev;
247
248 if (dma_dev->dma_mask) {
249 shost->max_sectors = min_t(unsigned int, shost->max_sectors,
250 dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT);
251 }
252
253 error = scsi_mq_setup_tags(shost);
254 if (error)
255 goto fail;
256
257 kref_init(&shost->tagset_refcnt);
258 init_completion(&shost->tagset_freed);
259
260 /*
261 * Increase usage count temporarily here so that calling
262 * scsi_autopm_put_host() will trigger runtime idle if there is
263 * nothing else preventing suspending the device.
264 */
265 pm_runtime_get_noresume(&shost->shost_gendev);
266 pm_runtime_set_active(&shost->shost_gendev);
267 pm_runtime_enable(&shost->shost_gendev);
268 device_enable_async_suspend(&shost->shost_gendev);
269
270 error = device_add(&shost->shost_gendev);
271 if (error)
272 goto out_disable_runtime_pm;
273
274 scsi_host_set_state(shost, SHOST_RUNNING);
275 get_device(shost->shost_gendev.parent);
276
277 device_enable_async_suspend(&shost->shost_dev);
278
279 get_device(&shost->shost_gendev);
280 error = device_add(&shost->shost_dev);
281 if (error)
282 goto out_del_gendev;
283
284 if (shost->transportt->host_size) {
285 shost->shost_data = kzalloc(shost->transportt->host_size,
286 GFP_KERNEL);
287 if (shost->shost_data == NULL) {
288 error = -ENOMEM;
289 goto out_del_dev;
290 }
291 }
292
293 if (shost->transportt->create_work_queue) {
294 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
295 "scsi_wq_%d", shost->host_no);
296 shost->work_q = alloc_workqueue("%s",
297 WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
298 1, shost->work_q_name);
299
300 if (!shost->work_q) {
301 error = -EINVAL;
302 goto out_del_dev;
303 }
304 }
305
306 error = scsi_sysfs_add_host(shost);
307 if (error)
308 goto out_del_dev;
309
310 scsi_proc_host_add(shost);
311 scsi_autopm_put_host(shost);
312 return error;
313
314 /*
315 * Any host allocation in this function will be freed in
316 * scsi_host_dev_release().
317 */
318 out_del_dev:
319 device_del(&shost->shost_dev);
320 out_del_gendev:
321 /*
322 * Host state is SHOST_RUNNING so we have to explicitly release
323 * ->shost_dev.
324 */
325 put_device(&shost->shost_dev);
326 device_del(&shost->shost_gendev);
327 out_disable_runtime_pm:
328 device_disable_async_suspend(&shost->shost_gendev);
329 pm_runtime_disable(&shost->shost_gendev);
330 pm_runtime_set_suspended(&shost->shost_gendev);
331 pm_runtime_put_noidle(&shost->shost_gendev);
332 kref_put(&shost->tagset_refcnt, scsi_mq_free_tags);
333 fail:
334 return error;
335}
336EXPORT_SYMBOL(scsi_add_host_with_dma);
337
338static void scsi_host_dev_release(struct device *dev)
339{
340 struct Scsi_Host *shost = dev_to_shost(dev);
341 struct device *parent = dev->parent;
342
343 scsi_proc_hostdir_rm(shost->hostt);
344
345 /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */
346 rcu_barrier();
347
348 if (shost->tmf_work_q)
349 destroy_workqueue(shost->tmf_work_q);
350 if (shost->ehandler)
351 kthread_stop(shost->ehandler);
352 if (shost->work_q)
353 destroy_workqueue(shost->work_q);
354
355 if (shost->shost_state == SHOST_CREATED) {
356 /*
357 * Free the shost_dev device name here if scsi_host_alloc()
358 * and scsi_host_put() have been called but neither
359 * scsi_host_add() nor scsi_host_remove() has been called.
360 * This avoids that the memory allocated for the shost_dev
361 * name is leaked.
362 */
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 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(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
446 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
447 shost->eh_deadline = -1;
448 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
449 shost_printk(KERN_WARNING, shost,
450 "eh_deadline %u too large, setting to %u\n",
451 shost_eh_deadline, INT_MAX / HZ);
452 shost->eh_deadline = INT_MAX;
453 } else
454 shost->eh_deadline = shost_eh_deadline * HZ;
455
456 if (sht->supported_mode == MODE_UNKNOWN)
457 /* means we didn't set it ... default to INITIATOR */
458 shost->active_mode = MODE_INITIATOR;
459 else
460 shost->active_mode = sht->supported_mode;
461
462 if (sht->max_host_blocked)
463 shost->max_host_blocked = sht->max_host_blocked;
464 else
465 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
466
467 /*
468 * If the driver imposes no hard sector transfer limit, start at
469 * machine infinity initially.
470 */
471 if (sht->max_sectors)
472 shost->max_sectors = sht->max_sectors;
473 else
474 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
475
476 if (sht->max_segment_size)
477 shost->max_segment_size = sht->max_segment_size;
478 else
479 shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;
480
481 /*
482 * assume a 4GB boundary, if not set
483 */
484 if (sht->dma_boundary)
485 shost->dma_boundary = sht->dma_boundary;
486 else
487 shost->dma_boundary = 0xffffffff;
488
489 if (sht->virt_boundary_mask)
490 shost->virt_boundary_mask = sht->virt_boundary_mask;
491
492 device_initialize(&shost->shost_gendev);
493 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
494 shost->shost_gendev.bus = &scsi_bus_type;
495 shost->shost_gendev.type = &scsi_host_type;
496 scsi_enable_async_suspend(&shost->shost_gendev);
497
498 device_initialize(&shost->shost_dev);
499 shost->shost_dev.parent = &shost->shost_gendev;
500 shost->shost_dev.class = &shost_class;
501 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
502 shost->shost_dev.groups = sht->shost_groups;
503
504 shost->ehandler = kthread_run(scsi_error_handler, shost,
505 "scsi_eh_%d", shost->host_no);
506 if (IS_ERR(shost->ehandler)) {
507 shost_printk(KERN_WARNING, shost,
508 "error handler thread failed to spawn, error = %ld\n",
509 PTR_ERR(shost->ehandler));
510 shost->ehandler = NULL;
511 goto fail;
512 }
513
514 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
515 WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS,
516 1, shost->host_no);
517 if (!shost->tmf_work_q) {
518 shost_printk(KERN_WARNING, shost,
519 "failed to create tmf workq\n");
520 goto fail;
521 }
522 if (scsi_proc_hostdir_add(shost->hostt) < 0)
523 goto fail;
524 return shost;
525 fail:
526 /*
527 * Host state is still SHOST_CREATED and that is enough to release
528 * ->shost_gendev. scsi_host_dev_release() will free
529 * dev_name(&shost->shost_dev).
530 */
531 put_device(&shost->shost_gendev);
532
533 return NULL;
534}
535EXPORT_SYMBOL(scsi_host_alloc);
536
537static int __scsi_host_match(struct device *dev, const void *data)
538{
539 struct Scsi_Host *p;
540 const unsigned short *hostnum = data;
541
542 p = class_to_shost(dev);
543 return p->host_no == *hostnum;
544}
545
546/**
547 * scsi_host_lookup - get a reference to a Scsi_Host by host no
548 * @hostnum: host number to locate
549 *
550 * Return value:
551 * A pointer to located Scsi_Host or NULL.
552 *
553 * The caller must do a scsi_host_put() to drop the reference
554 * that scsi_host_get() took. The put_device() below dropped
555 * the reference from class_find_device().
556 **/
557struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
558{
559 struct device *cdev;
560 struct Scsi_Host *shost = NULL;
561
562 cdev = class_find_device(&shost_class, NULL, &hostnum,
563 __scsi_host_match);
564 if (cdev) {
565 shost = scsi_host_get(class_to_shost(cdev));
566 put_device(cdev);
567 }
568 return shost;
569}
570EXPORT_SYMBOL(scsi_host_lookup);
571
572/**
573 * scsi_host_get - inc a Scsi_Host ref count
574 * @shost: Pointer to Scsi_Host to inc.
575 **/
576struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
577{
578 if ((shost->shost_state == SHOST_DEL) ||
579 !get_device(&shost->shost_gendev))
580 return NULL;
581 return shost;
582}
583EXPORT_SYMBOL(scsi_host_get);
584
585static bool scsi_host_check_in_flight(struct request *rq, void *data)
586{
587 int *count = data;
588 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
589
590 if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
591 (*count)++;
592
593 return true;
594}
595
596/**
597 * scsi_host_busy - Return the host busy counter
598 * @shost: Pointer to Scsi_Host to inc.
599 **/
600int scsi_host_busy(struct Scsi_Host *shost)
601{
602 int cnt = 0;
603
604 blk_mq_tagset_busy_iter(&shost->tag_set,
605 scsi_host_check_in_flight, &cnt);
606 return cnt;
607}
608EXPORT_SYMBOL(scsi_host_busy);
609
610/**
611 * scsi_host_put - dec a Scsi_Host ref count
612 * @shost: Pointer to Scsi_Host to dec.
613 **/
614void scsi_host_put(struct Scsi_Host *shost)
615{
616 put_device(&shost->shost_gendev);
617}
618EXPORT_SYMBOL(scsi_host_put);
619
620int scsi_init_hosts(void)
621{
622 return class_register(&shost_class);
623}
624
625void scsi_exit_hosts(void)
626{
627 class_unregister(&shost_class);
628 ida_destroy(&host_index_ida);
629}
630
631int scsi_is_host_device(const struct device *dev)
632{
633 return dev->type == &scsi_host_type;
634}
635EXPORT_SYMBOL(scsi_is_host_device);
636
637/**
638 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
639 * @shost: Pointer to Scsi_Host.
640 * @work: Work to queue for execution.
641 *
642 * Return value:
643 * 1 - work queued for execution
644 * 0 - work is already queued
645 * -EINVAL - work queue doesn't exist
646 **/
647int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
648{
649 if (unlikely(!shost->work_q)) {
650 shost_printk(KERN_ERR, shost,
651 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
652 "when no workqueue created.\n", shost->hostt->name);
653 dump_stack();
654
655 return -EINVAL;
656 }
657
658 return queue_work(shost->work_q, work);
659}
660EXPORT_SYMBOL_GPL(scsi_queue_work);
661
662/**
663 * scsi_flush_work - Flush a Scsi_Host's workqueue.
664 * @shost: Pointer to Scsi_Host.
665 **/
666void scsi_flush_work(struct Scsi_Host *shost)
667{
668 if (!shost->work_q) {
669 shost_printk(KERN_ERR, shost,
670 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
671 "when no workqueue created.\n", shost->hostt->name);
672 dump_stack();
673 return;
674 }
675
676 flush_workqueue(shost->work_q);
677}
678EXPORT_SYMBOL_GPL(scsi_flush_work);
679
680static bool complete_all_cmds_iter(struct request *rq, void *data)
681{
682 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
683 enum scsi_host_status status = *(enum scsi_host_status *)data;
684
685 scsi_dma_unmap(scmd);
686 scmd->result = 0;
687 set_host_byte(scmd, status);
688 scsi_done(scmd);
689 return true;
690}
691
692/**
693 * scsi_host_complete_all_commands - Terminate all running commands
694 * @shost: Scsi Host on which commands should be terminated
695 * @status: Status to be set for the terminated commands
696 *
697 * There is no protection against modification of the number
698 * of outstanding commands. It is the responsibility of the
699 * caller to ensure that concurrent I/O submission and/or
700 * completion is stopped when calling this function.
701 */
702void scsi_host_complete_all_commands(struct Scsi_Host *shost,
703 enum scsi_host_status status)
704{
705 blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter,
706 &status);
707}
708EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
709
710struct scsi_host_busy_iter_data {
711 bool (*fn)(struct scsi_cmnd *, void *);
712 void *priv;
713};
714
715static bool __scsi_host_busy_iter_fn(struct request *req, void *priv)
716{
717 struct scsi_host_busy_iter_data *iter_data = priv;
718 struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
719
720 return iter_data->fn(sc, iter_data->priv);
721}
722
723/**
724 * scsi_host_busy_iter - Iterate over all busy commands
725 * @shost: Pointer to Scsi_Host.
726 * @fn: Function to call on each busy command
727 * @priv: Data pointer passed to @fn
728 *
729 * If locking against concurrent command completions is required
730 * ithas to be provided by the caller
731 **/
732void scsi_host_busy_iter(struct Scsi_Host *shost,
733 bool (*fn)(struct scsi_cmnd *, void *),
734 void *priv)
735{
736 struct scsi_host_busy_iter_data iter_data = {
737 .fn = fn,
738 .priv = priv,
739 };
740
741 blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
742 &iter_data);
743}
744EXPORT_SYMBOL_GPL(scsi_host_busy_iter);