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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
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);