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1da177e4 LT |
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> | |
c5478def | 27 | #include <linux/kthread.h> |
1da177e4 LT |
28 | #include <linux/string.h> |
29 | #include <linux/mm.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/completion.h> | |
32 | #include <linux/transport_class.h> | |
d052d1be | 33 | #include <linux/platform_device.h> |
1da177e4 LT |
34 | |
35 | #include <scsi/scsi_device.h> | |
36 | #include <scsi/scsi_host.h> | |
37 | #include <scsi/scsi_transport.h> | |
38 | ||
39 | #include "scsi_priv.h" | |
40 | #include "scsi_logging.h" | |
41 | ||
42 | ||
43 | static int scsi_host_next_hn; /* host_no for next new host */ | |
44 | ||
45 | ||
46 | static void scsi_host_cls_release(struct class_device *class_dev) | |
47 | { | |
48 | put_device(&class_to_shost(class_dev)->shost_gendev); | |
49 | } | |
50 | ||
51 | static struct class shost_class = { | |
52 | .name = "scsi_host", | |
53 | .release = scsi_host_cls_release, | |
54 | }; | |
55 | ||
d3301874 MA |
56 | /** |
57 | * scsi_host_set_state - Take the given host through the host | |
58 | * state model. | |
59 | * @shost: scsi host to change the state of. | |
60 | * @state: state to change to. | |
61 | * | |
62 | * Returns zero if unsuccessful or an error if the requested | |
63 | * transition is illegal. | |
64 | **/ | |
65 | int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) | |
66 | { | |
67 | enum scsi_host_state oldstate = shost->shost_state; | |
68 | ||
69 | if (state == oldstate) | |
70 | return 0; | |
71 | ||
72 | switch (state) { | |
73 | case SHOST_CREATED: | |
74 | /* There are no legal states that come back to | |
75 | * created. This is the manually initialised start | |
76 | * state */ | |
77 | goto illegal; | |
78 | ||
79 | case SHOST_RUNNING: | |
80 | switch (oldstate) { | |
81 | case SHOST_CREATED: | |
82 | case SHOST_RECOVERY: | |
83 | break; | |
84 | default: | |
85 | goto illegal; | |
86 | } | |
87 | break; | |
88 | ||
89 | case SHOST_RECOVERY: | |
90 | switch (oldstate) { | |
91 | case SHOST_RUNNING: | |
92 | break; | |
93 | default: | |
94 | goto illegal; | |
95 | } | |
96 | break; | |
97 | ||
98 | case SHOST_CANCEL: | |
99 | switch (oldstate) { | |
100 | case SHOST_CREATED: | |
101 | case SHOST_RUNNING: | |
939647ee | 102 | case SHOST_CANCEL_RECOVERY: |
d3301874 MA |
103 | break; |
104 | default: | |
105 | goto illegal; | |
106 | } | |
107 | break; | |
108 | ||
109 | case SHOST_DEL: | |
110 | switch (oldstate) { | |
111 | case SHOST_CANCEL: | |
939647ee | 112 | case SHOST_DEL_RECOVERY: |
d3301874 MA |
113 | break; |
114 | default: | |
115 | goto illegal; | |
116 | } | |
117 | break; | |
118 | ||
939647ee JB |
119 | case SHOST_CANCEL_RECOVERY: |
120 | switch (oldstate) { | |
121 | case SHOST_CANCEL: | |
122 | case SHOST_RECOVERY: | |
123 | break; | |
124 | default: | |
125 | goto illegal; | |
126 | } | |
127 | break; | |
128 | ||
129 | case SHOST_DEL_RECOVERY: | |
130 | switch (oldstate) { | |
131 | case SHOST_CANCEL_RECOVERY: | |
132 | break; | |
133 | default: | |
134 | goto illegal; | |
135 | } | |
136 | break; | |
d3301874 MA |
137 | } |
138 | shost->shost_state = state; | |
139 | return 0; | |
140 | ||
141 | illegal: | |
142 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
143 | shost_printk(KERN_ERR, shost, |
144 | "Illegal host state transition" | |
145 | "%s->%s\n", | |
146 | scsi_host_state_name(oldstate), | |
147 | scsi_host_state_name(state))); | |
d3301874 MA |
148 | return -EINVAL; |
149 | } | |
150 | EXPORT_SYMBOL(scsi_host_set_state); | |
151 | ||
1da177e4 LT |
152 | /** |
153 | * scsi_remove_host - remove a scsi host | |
154 | * @shost: a pointer to a scsi host to remove | |
155 | **/ | |
156 | void scsi_remove_host(struct Scsi_Host *shost) | |
157 | { | |
939647ee | 158 | unsigned long flags; |
82f29467 | 159 | down(&shost->scan_mutex); |
939647ee JB |
160 | spin_lock_irqsave(shost->host_lock, flags); |
161 | if (scsi_host_set_state(shost, SHOST_CANCEL)) | |
162 | if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { | |
163 | spin_unlock_irqrestore(shost->host_lock, flags); | |
164 | up(&shost->scan_mutex); | |
165 | return; | |
166 | } | |
167 | spin_unlock_irqrestore(shost->host_lock, flags); | |
82f29467 | 168 | up(&shost->scan_mutex); |
1da177e4 | 169 | scsi_forget_host(shost); |
1da177e4 LT |
170 | scsi_proc_host_rm(shost); |
171 | ||
939647ee JB |
172 | spin_lock_irqsave(shost->host_lock, flags); |
173 | if (scsi_host_set_state(shost, SHOST_DEL)) | |
174 | BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); | |
175 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1da177e4 LT |
176 | |
177 | transport_unregister_device(&shost->shost_gendev); | |
178 | class_device_unregister(&shost->shost_classdev); | |
179 | device_del(&shost->shost_gendev); | |
9e70592f | 180 | scsi_proc_hostdir_rm(shost->hostt); |
1da177e4 LT |
181 | } |
182 | EXPORT_SYMBOL(scsi_remove_host); | |
183 | ||
184 | /** | |
185 | * scsi_add_host - add a scsi host | |
186 | * @shost: scsi host pointer to add | |
187 | * @dev: a struct device of type scsi class | |
188 | * | |
189 | * Return value: | |
190 | * 0 on success / != 0 for error | |
191 | **/ | |
192 | int scsi_add_host(struct Scsi_Host *shost, struct device *dev) | |
193 | { | |
194 | struct scsi_host_template *sht = shost->hostt; | |
195 | int error = -EINVAL; | |
196 | ||
197 | printk(KERN_INFO "scsi%d : %s\n", shost->host_no, | |
198 | sht->info ? sht->info(shost) : sht->name); | |
199 | ||
200 | if (!shost->can_queue) { | |
201 | printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", | |
202 | sht->name); | |
203 | goto out; | |
204 | } | |
205 | ||
206 | if (!shost->shost_gendev.parent) | |
207 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
208 | ||
209 | error = device_add(&shost->shost_gendev); | |
210 | if (error) | |
211 | goto out; | |
212 | ||
d3301874 | 213 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
214 | get_device(shost->shost_gendev.parent); |
215 | ||
216 | error = class_device_add(&shost->shost_classdev); | |
217 | if (error) | |
218 | goto out_del_gendev; | |
219 | ||
220 | get_device(&shost->shost_gendev); | |
221 | ||
222 | if (shost->transportt->host_size && | |
223 | (shost->shost_data = kmalloc(shost->transportt->host_size, | |
224 | GFP_KERNEL)) == NULL) | |
225 | goto out_del_classdev; | |
226 | ||
227 | if (shost->transportt->create_work_queue) { | |
228 | snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", | |
229 | shost->host_no); | |
230 | shost->work_q = create_singlethread_workqueue( | |
231 | shost->work_q_name); | |
232 | if (!shost->work_q) | |
233 | goto out_free_shost_data; | |
234 | } | |
235 | ||
236 | error = scsi_sysfs_add_host(shost); | |
237 | if (error) | |
238 | goto out_destroy_host; | |
239 | ||
240 | scsi_proc_host_add(shost); | |
241 | return error; | |
242 | ||
243 | out_destroy_host: | |
244 | if (shost->work_q) | |
245 | destroy_workqueue(shost->work_q); | |
246 | out_free_shost_data: | |
247 | kfree(shost->shost_data); | |
248 | out_del_classdev: | |
249 | class_device_del(&shost->shost_classdev); | |
250 | out_del_gendev: | |
251 | device_del(&shost->shost_gendev); | |
252 | out: | |
253 | return error; | |
254 | } | |
255 | EXPORT_SYMBOL(scsi_add_host); | |
256 | ||
257 | static void scsi_host_dev_release(struct device *dev) | |
258 | { | |
259 | struct Scsi_Host *shost = dev_to_shost(dev); | |
260 | struct device *parent = dev->parent; | |
261 | ||
c5478def CH |
262 | if (shost->ehandler) |
263 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
264 | if (shost->work_q) |
265 | destroy_workqueue(shost->work_q); | |
266 | ||
1da177e4 LT |
267 | scsi_destroy_command_freelist(shost); |
268 | kfree(shost->shost_data); | |
269 | ||
1da177e4 LT |
270 | if (parent) |
271 | put_device(parent); | |
272 | kfree(shost); | |
273 | } | |
274 | ||
275 | /** | |
276 | * scsi_host_alloc - register a scsi host adapter instance. | |
277 | * @sht: pointer to scsi host template | |
278 | * @privsize: extra bytes to allocate for driver | |
279 | * | |
280 | * Note: | |
281 | * Allocate a new Scsi_Host and perform basic initialization. | |
282 | * The host is not published to the scsi midlayer until scsi_add_host | |
283 | * is called. | |
284 | * | |
285 | * Return value: | |
286 | * Pointer to a new Scsi_Host | |
287 | **/ | |
288 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
289 | { | |
290 | struct Scsi_Host *shost; | |
c53033f6 AV |
291 | gfp_t gfp_mask = GFP_KERNEL; |
292 | int rval; | |
1da177e4 LT |
293 | |
294 | if (sht->unchecked_isa_dma && privsize) | |
295 | gfp_mask |= __GFP_DMA; | |
296 | ||
297 | /* Check to see if this host has any error handling facilities */ | |
298 | if (!sht->eh_strategy_handler && !sht->eh_abort_handler && | |
299 | !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && | |
300 | !sht->eh_host_reset_handler) { | |
301 | printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" | |
302 | "ERROR: This is not a safe way to run your " | |
303 | "SCSI host\n" | |
304 | "ERROR: The error handling must be added to " | |
305 | "this driver\n", sht->proc_name); | |
306 | dump_stack(); | |
307 | } | |
308 | ||
309 | shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); | |
310 | if (!shost) | |
311 | return NULL; | |
312 | memset(shost, 0, sizeof(struct Scsi_Host) + privsize); | |
313 | ||
314 | spin_lock_init(&shost->default_lock); | |
315 | scsi_assign_lock(shost, &shost->default_lock); | |
d3301874 | 316 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
317 | INIT_LIST_HEAD(&shost->__devices); |
318 | INIT_LIST_HEAD(&shost->__targets); | |
319 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
320 | INIT_LIST_HEAD(&shost->starved_list); | |
321 | init_waitqueue_head(&shost->host_wait); | |
322 | ||
323 | init_MUTEX(&shost->scan_mutex); | |
324 | ||
325 | shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ | |
326 | shost->dma_channel = 0xff; | |
327 | ||
328 | /* These three are default values which can be overridden */ | |
329 | shost->max_channel = 0; | |
330 | shost->max_id = 8; | |
331 | shost->max_lun = 8; | |
332 | ||
333 | /* Give each shost a default transportt */ | |
334 | shost->transportt = &blank_transport_template; | |
335 | ||
336 | /* | |
337 | * All drivers right now should be able to handle 12 byte | |
338 | * commands. Every so often there are requests for 16 byte | |
339 | * commands, but individual low-level drivers need to certify that | |
340 | * they actually do something sensible with such commands. | |
341 | */ | |
342 | shost->max_cmd_len = 12; | |
343 | shost->hostt = sht; | |
344 | shost->this_id = sht->this_id; | |
345 | shost->can_queue = sht->can_queue; | |
346 | shost->sg_tablesize = sht->sg_tablesize; | |
347 | shost->cmd_per_lun = sht->cmd_per_lun; | |
348 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
349 | shost->use_clustering = sht->use_clustering; | |
350 | shost->ordered_flush = sht->ordered_flush; | |
351 | shost->ordered_tag = sht->ordered_tag; | |
352 | ||
353 | /* | |
354 | * hosts/devices that do queueing must support ordered tags | |
355 | */ | |
356 | if (shost->can_queue > 1 && shost->ordered_flush) { | |
357 | printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); | |
358 | shost->ordered_flush = 0; | |
359 | } | |
360 | ||
361 | if (sht->max_host_blocked) | |
362 | shost->max_host_blocked = sht->max_host_blocked; | |
363 | else | |
364 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
365 | ||
366 | /* | |
367 | * If the driver imposes no hard sector transfer limit, start at | |
368 | * machine infinity initially. | |
369 | */ | |
370 | if (sht->max_sectors) | |
371 | shost->max_sectors = sht->max_sectors; | |
372 | else | |
373 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
374 | ||
375 | /* | |
376 | * assume a 4GB boundary, if not set | |
377 | */ | |
378 | if (sht->dma_boundary) | |
379 | shost->dma_boundary = sht->dma_boundary; | |
380 | else | |
381 | shost->dma_boundary = 0xffffffff; | |
382 | ||
383 | rval = scsi_setup_command_freelist(shost); | |
384 | if (rval) | |
385 | goto fail_kfree; | |
386 | ||
387 | device_initialize(&shost->shost_gendev); | |
388 | snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", | |
389 | shost->host_no); | |
390 | shost->shost_gendev.release = scsi_host_dev_release; | |
391 | ||
392 | class_device_initialize(&shost->shost_classdev); | |
393 | shost->shost_classdev.dev = &shost->shost_gendev; | |
394 | shost->shost_classdev.class = &shost_class; | |
395 | snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", | |
396 | shost->host_no); | |
397 | ||
c5478def CH |
398 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
399 | "scsi_eh_%d", shost->host_no); | |
400 | if (IS_ERR(shost->ehandler)) { | |
401 | rval = PTR_ERR(shost->ehandler); | |
1da177e4 | 402 | goto fail_destroy_freelist; |
c5478def | 403 | } |
1da177e4 LT |
404 | |
405 | scsi_proc_hostdir_add(shost->hostt); | |
406 | return shost; | |
407 | ||
408 | fail_destroy_freelist: | |
409 | scsi_destroy_command_freelist(shost); | |
410 | fail_kfree: | |
411 | kfree(shost); | |
412 | return NULL; | |
413 | } | |
414 | EXPORT_SYMBOL(scsi_host_alloc); | |
415 | ||
416 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
417 | { | |
418 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
419 | ||
420 | if (!sht->detect) { | |
421 | printk(KERN_WARNING "scsi_register() called on new-style " | |
422 | "template for driver %s\n", sht->name); | |
423 | dump_stack(); | |
424 | } | |
425 | ||
426 | if (shost) | |
427 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
428 | return shost; | |
429 | } | |
430 | EXPORT_SYMBOL(scsi_register); | |
431 | ||
432 | void scsi_unregister(struct Scsi_Host *shost) | |
433 | { | |
434 | list_del(&shost->sht_legacy_list); | |
435 | scsi_host_put(shost); | |
436 | } | |
437 | EXPORT_SYMBOL(scsi_unregister); | |
438 | ||
439 | /** | |
440 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
441 | * | |
442 | * @hostnum: host number to locate | |
443 | * | |
444 | * Return value: | |
445 | * A pointer to located Scsi_Host or NULL. | |
446 | **/ | |
447 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
448 | { | |
449 | struct class *class = &shost_class; | |
450 | struct class_device *cdev; | |
451 | struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; | |
452 | ||
453 | down_read(&class->subsys.rwsem); | |
454 | list_for_each_entry(cdev, &class->children, node) { | |
455 | p = class_to_shost(cdev); | |
456 | if (p->host_no == hostnum) { | |
457 | shost = scsi_host_get(p); | |
458 | break; | |
459 | } | |
460 | } | |
461 | up_read(&class->subsys.rwsem); | |
462 | ||
463 | return shost; | |
464 | } | |
465 | EXPORT_SYMBOL(scsi_host_lookup); | |
466 | ||
467 | /** | |
468 | * scsi_host_get - inc a Scsi_Host ref count | |
469 | * @shost: Pointer to Scsi_Host to inc. | |
470 | **/ | |
471 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
472 | { | |
d3301874 | 473 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
474 | !get_device(&shost->shost_gendev)) |
475 | return NULL; | |
476 | return shost; | |
477 | } | |
478 | EXPORT_SYMBOL(scsi_host_get); | |
479 | ||
480 | /** | |
481 | * scsi_host_put - dec a Scsi_Host ref count | |
482 | * @shost: Pointer to Scsi_Host to dec. | |
483 | **/ | |
484 | void scsi_host_put(struct Scsi_Host *shost) | |
485 | { | |
486 | put_device(&shost->shost_gendev); | |
487 | } | |
488 | EXPORT_SYMBOL(scsi_host_put); | |
489 | ||
490 | int scsi_init_hosts(void) | |
491 | { | |
492 | return class_register(&shost_class); | |
493 | } | |
494 | ||
495 | void scsi_exit_hosts(void) | |
496 | { | |
497 | class_unregister(&shost_class); | |
498 | } | |
499 | ||
500 | int scsi_is_host_device(const struct device *dev) | |
501 | { | |
502 | return dev->release == scsi_host_dev_release; | |
503 | } | |
504 | EXPORT_SYMBOL(scsi_is_host_device); | |
505 | ||
506 | /** | |
507 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
508 | * @shost: Pointer to Scsi_Host. | |
509 | * @work: Work to queue for execution. | |
510 | * | |
511 | * Return value: | |
512 | * 0 on success / != 0 for error | |
513 | **/ | |
514 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
515 | { | |
516 | if (unlikely(!shost->work_q)) { | |
517 | printk(KERN_ERR | |
518 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " | |
519 | "when no workqueue created.\n", shost->hostt->name); | |
520 | dump_stack(); | |
521 | ||
522 | return -EINVAL; | |
523 | } | |
524 | ||
525 | return queue_work(shost->work_q, work); | |
526 | } | |
527 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
528 | ||
529 | /** | |
530 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
531 | * @shost: Pointer to Scsi_Host. | |
532 | **/ | |
533 | void scsi_flush_work(struct Scsi_Host *shost) | |
534 | { | |
535 | if (!shost->work_q) { | |
536 | printk(KERN_ERR | |
537 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " | |
538 | "when no workqueue created.\n", shost->hostt->name); | |
539 | dump_stack(); | |
540 | return; | |
541 | } | |
542 | ||
543 | flush_workqueue(shost->work_q); | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(scsi_flush_work); |