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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/*
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 if (!dma_dev)
222 dma_dev = shost->shost_gendev.parent;
223
224 shost->dma_dev = dma_dev;
225
226 error = device_add(&shost->shost_gendev);
227 if (error)
228 goto out;
229
230 pm_runtime_set_active(&shost->shost_gendev);
231 pm_runtime_enable(&shost->shost_gendev);
232 device_enable_async_suspend(&shost->shost_gendev);
233
234 scsi_host_set_state(shost, SHOST_RUNNING);
235 get_device(shost->shost_gendev.parent);
236
237 device_enable_async_suspend(&shost->shost_dev);
238
239 error = device_add(&shost->shost_dev);
240 if (error)
241 goto out_del_gendev;
242
243 get_device(&shost->shost_gendev);
244
245 if (shost->transportt->host_size) {
246 shost->shost_data = kzalloc(shost->transportt->host_size,
247 GFP_KERNEL);
248 if (shost->shost_data == NULL) {
249 error = -ENOMEM;
250 goto out_del_dev;
251 }
252 }
253
254 if (shost->transportt->create_work_queue) {
255 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
256 "scsi_wq_%d", shost->host_no);
257 shost->work_q = create_singlethread_workqueue(
258 shost->work_q_name);
259 if (!shost->work_q) {
260 error = -EINVAL;
261 goto out_free_shost_data;
262 }
263 }
264
265 error = scsi_sysfs_add_host(shost);
266 if (error)
267 goto out_destroy_host;
268
269 scsi_proc_host_add(shost);
270 return error;
271
272 out_destroy_host:
273 if (shost->work_q)
274 destroy_workqueue(shost->work_q);
275 out_free_shost_data:
276 kfree(shost->shost_data);
277 out_del_dev:
278 device_del(&shost->shost_dev);
279 out_del_gendev:
280 device_del(&shost->shost_gendev);
281 out:
282 scsi_destroy_command_freelist(shost);
283 fail:
284 return error;
285}
286EXPORT_SYMBOL(scsi_add_host_with_dma);
287
288static void scsi_host_dev_release(struct device *dev)
289{
290 struct Scsi_Host *shost = dev_to_shost(dev);
291 struct device *parent = dev->parent;
292 struct request_queue *q;
293 void *queuedata;
294
295 scsi_proc_hostdir_rm(shost->hostt);
296
297 if (shost->ehandler)
298 kthread_stop(shost->ehandler);
299 if (shost->work_q)
300 destroy_workqueue(shost->work_q);
301 q = shost->uspace_req_q;
302 if (q) {
303 queuedata = q->queuedata;
304 blk_cleanup_queue(q);
305 kfree(queuedata);
306 }
307
308 scsi_destroy_command_freelist(shost);
309 if (shost->bqt)
310 blk_free_tags(shost->bqt);
311
312 kfree(shost->shost_data);
313
314 if (parent)
315 put_device(parent);
316 kfree(shost);
317}
318
319static struct device_type scsi_host_type = {
320 .name = "scsi_host",
321 .release = scsi_host_dev_release,
322};
323
324/**
325 * scsi_host_alloc - register a scsi host adapter instance.
326 * @sht: pointer to scsi host template
327 * @privsize: extra bytes to allocate for driver
328 *
329 * Note:
330 * Allocate a new Scsi_Host and perform basic initialization.
331 * The host is not published to the scsi midlayer until scsi_add_host
332 * is called.
333 *
334 * Return value:
335 * Pointer to a new Scsi_Host
336 **/
337struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
338{
339 struct Scsi_Host *shost;
340 gfp_t gfp_mask = GFP_KERNEL;
341
342 if (sht->unchecked_isa_dma && privsize)
343 gfp_mask |= __GFP_DMA;
344
345 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
346 if (!shost)
347 return NULL;
348
349 shost->host_lock = &shost->default_lock;
350 spin_lock_init(shost->host_lock);
351 shost->shost_state = SHOST_CREATED;
352 INIT_LIST_HEAD(&shost->__devices);
353 INIT_LIST_HEAD(&shost->__targets);
354 INIT_LIST_HEAD(&shost->eh_cmd_q);
355 INIT_LIST_HEAD(&shost->starved_list);
356 init_waitqueue_head(&shost->host_wait);
357
358 mutex_init(&shost->scan_mutex);
359
360 /*
361 * subtract one because we increment first then return, but we need to
362 * know what the next host number was before increment
363 */
364 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
365 shost->dma_channel = 0xff;
366
367 /* These three are default values which can be overridden */
368 shost->max_channel = 0;
369 shost->max_id = 8;
370 shost->max_lun = 8;
371
372 /* Give each shost a default transportt */
373 shost->transportt = &blank_transport_template;
374
375 /*
376 * All drivers right now should be able to handle 12 byte
377 * commands. Every so often there are requests for 16 byte
378 * commands, but individual low-level drivers need to certify that
379 * they actually do something sensible with such commands.
380 */
381 shost->max_cmd_len = 12;
382 shost->hostt = sht;
383 shost->this_id = sht->this_id;
384 shost->can_queue = sht->can_queue;
385 shost->sg_tablesize = sht->sg_tablesize;
386 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
387 shost->cmd_per_lun = sht->cmd_per_lun;
388 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
389 shost->use_clustering = sht->use_clustering;
390 shost->ordered_tag = sht->ordered_tag;
391
392 if (sht->supported_mode == MODE_UNKNOWN)
393 /* means we didn't set it ... default to INITIATOR */
394 shost->active_mode = MODE_INITIATOR;
395 else
396 shost->active_mode = sht->supported_mode;
397
398 if (sht->max_host_blocked)
399 shost->max_host_blocked = sht->max_host_blocked;
400 else
401 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
402
403 /*
404 * If the driver imposes no hard sector transfer limit, start at
405 * machine infinity initially.
406 */
407 if (sht->max_sectors)
408 shost->max_sectors = sht->max_sectors;
409 else
410 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
411
412 /*
413 * assume a 4GB boundary, if not set
414 */
415 if (sht->dma_boundary)
416 shost->dma_boundary = sht->dma_boundary;
417 else
418 shost->dma_boundary = 0xffffffff;
419
420 device_initialize(&shost->shost_gendev);
421 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
422 shost->shost_gendev.bus = &scsi_bus_type;
423 shost->shost_gendev.type = &scsi_host_type;
424
425 device_initialize(&shost->shost_dev);
426 shost->shost_dev.parent = &shost->shost_gendev;
427 shost->shost_dev.class = &shost_class;
428 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
429 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
430
431 shost->ehandler = kthread_run(scsi_error_handler, shost,
432 "scsi_eh_%d", shost->host_no);
433 if (IS_ERR(shost->ehandler)) {
434 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
435 shost->host_no, PTR_ERR(shost->ehandler));
436 goto fail_kfree;
437 }
438
439 scsi_proc_hostdir_add(shost->hostt);
440 return shost;
441
442 fail_kfree:
443 kfree(shost);
444 return NULL;
445}
446EXPORT_SYMBOL(scsi_host_alloc);
447
448struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
449{
450 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
451
452 if (!sht->detect) {
453 printk(KERN_WARNING "scsi_register() called on new-style "
454 "template for driver %s\n", sht->name);
455 dump_stack();
456 }
457
458 if (shost)
459 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
460 return shost;
461}
462EXPORT_SYMBOL(scsi_register);
463
464void scsi_unregister(struct Scsi_Host *shost)
465{
466 list_del(&shost->sht_legacy_list);
467 scsi_host_put(shost);
468}
469EXPORT_SYMBOL(scsi_unregister);
470
471static int __scsi_host_match(struct device *dev, void *data)
472{
473 struct Scsi_Host *p;
474 unsigned short *hostnum = (unsigned short *)data;
475
476 p = class_to_shost(dev);
477 return p->host_no == *hostnum;
478}
479
480/**
481 * scsi_host_lookup - get a reference to a Scsi_Host by host no
482 * @hostnum: host number to locate
483 *
484 * Return value:
485 * A pointer to located Scsi_Host or NULL.
486 *
487 * The caller must do a scsi_host_put() to drop the reference
488 * that scsi_host_get() took. The put_device() below dropped
489 * the reference from class_find_device().
490 **/
491struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
492{
493 struct device *cdev;
494 struct Scsi_Host *shost = NULL;
495
496 cdev = class_find_device(&shost_class, NULL, &hostnum,
497 __scsi_host_match);
498 if (cdev) {
499 shost = scsi_host_get(class_to_shost(cdev));
500 put_device(cdev);
501 }
502 return shost;
503}
504EXPORT_SYMBOL(scsi_host_lookup);
505
506/**
507 * scsi_host_get - inc a Scsi_Host ref count
508 * @shost: Pointer to Scsi_Host to inc.
509 **/
510struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
511{
512 if ((shost->shost_state == SHOST_DEL) ||
513 !get_device(&shost->shost_gendev))
514 return NULL;
515 return shost;
516}
517EXPORT_SYMBOL(scsi_host_get);
518
519/**
520 * scsi_host_put - dec a Scsi_Host ref count
521 * @shost: Pointer to Scsi_Host to dec.
522 **/
523void scsi_host_put(struct Scsi_Host *shost)
524{
525 put_device(&shost->shost_gendev);
526}
527EXPORT_SYMBOL(scsi_host_put);
528
529int scsi_init_hosts(void)
530{
531 return class_register(&shost_class);
532}
533
534void scsi_exit_hosts(void)
535{
536 class_unregister(&shost_class);
537}
538
539int scsi_is_host_device(const struct device *dev)
540{
541 return dev->type == &scsi_host_type;
542}
543EXPORT_SYMBOL(scsi_is_host_device);
544
545/**
546 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
547 * @shost: Pointer to Scsi_Host.
548 * @work: Work to queue for execution.
549 *
550 * Return value:
551 * 1 - work queued for execution
552 * 0 - work is already queued
553 * -EINVAL - work queue doesn't exist
554 **/
555int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
556{
557 if (unlikely(!shost->work_q)) {
558 printk(KERN_ERR
559 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
560 "when no workqueue created.\n", shost->hostt->name);
561 dump_stack();
562
563 return -EINVAL;
564 }
565
566 return queue_work(shost->work_q, work);
567}
568EXPORT_SYMBOL_GPL(scsi_queue_work);
569
570/**
571 * scsi_flush_work - Flush a Scsi_Host's workqueue.
572 * @shost: Pointer to Scsi_Host.
573 **/
574void scsi_flush_work(struct Scsi_Host *shost)
575{
576 if (!shost->work_q) {
577 printk(KERN_ERR
578 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
579 "when no workqueue created.\n", shost->hostt->name);
580 dump_stack();
581 return;
582 }
583
584 flush_workqueue(shost->work_q);
585}
586EXPORT_SYMBOL_GPL(scsi_flush_work);