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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> | |
27 | #include <linux/string.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/completion.h> | |
31 | #include <linux/transport_class.h> | |
32 | ||
33 | #include <scsi/scsi_device.h> | |
34 | #include <scsi/scsi_host.h> | |
35 | #include <scsi/scsi_transport.h> | |
36 | ||
37 | #include "scsi_priv.h" | |
38 | #include "scsi_logging.h" | |
39 | ||
40 | ||
41 | static int scsi_host_next_hn; /* host_no for next new host */ | |
42 | ||
43 | ||
44 | static void scsi_host_cls_release(struct class_device *class_dev) | |
45 | { | |
46 | put_device(&class_to_shost(class_dev)->shost_gendev); | |
47 | } | |
48 | ||
49 | static struct class shost_class = { | |
50 | .name = "scsi_host", | |
51 | .release = scsi_host_cls_release, | |
52 | }; | |
53 | ||
d3301874 MA |
54 | /** |
55 | * scsi_host_set_state - Take the given host through the host | |
56 | * state model. | |
57 | * @shost: scsi host to change the state of. | |
58 | * @state: state to change to. | |
59 | * | |
60 | * Returns zero if unsuccessful or an error if the requested | |
61 | * transition is illegal. | |
62 | **/ | |
63 | int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) | |
64 | { | |
65 | enum scsi_host_state oldstate = shost->shost_state; | |
66 | ||
67 | if (state == oldstate) | |
68 | return 0; | |
69 | ||
70 | switch (state) { | |
71 | case SHOST_CREATED: | |
72 | /* There are no legal states that come back to | |
73 | * created. This is the manually initialised start | |
74 | * state */ | |
75 | goto illegal; | |
76 | ||
77 | case SHOST_RUNNING: | |
78 | switch (oldstate) { | |
79 | case SHOST_CREATED: | |
80 | case SHOST_RECOVERY: | |
81 | break; | |
82 | default: | |
83 | goto illegal; | |
84 | } | |
85 | break; | |
86 | ||
87 | case SHOST_RECOVERY: | |
88 | switch (oldstate) { | |
89 | case SHOST_RUNNING: | |
90 | break; | |
91 | default: | |
92 | goto illegal; | |
93 | } | |
94 | break; | |
95 | ||
96 | case SHOST_CANCEL: | |
97 | switch (oldstate) { | |
98 | case SHOST_CREATED: | |
99 | case SHOST_RUNNING: | |
100 | break; | |
101 | default: | |
102 | goto illegal; | |
103 | } | |
104 | break; | |
105 | ||
106 | case SHOST_DEL: | |
107 | switch (oldstate) { | |
108 | case SHOST_CANCEL: | |
109 | break; | |
110 | default: | |
111 | goto illegal; | |
112 | } | |
113 | break; | |
114 | ||
115 | } | |
116 | shost->shost_state = state; | |
117 | return 0; | |
118 | ||
119 | illegal: | |
120 | SCSI_LOG_ERROR_RECOVERY(1, | |
121 | dev_printk(KERN_ERR, &shost->shost_gendev, | |
122 | "Illegal host state transition" | |
123 | "%s->%s\n", | |
124 | scsi_host_state_name(oldstate), | |
125 | scsi_host_state_name(state))); | |
126 | return -EINVAL; | |
127 | } | |
128 | EXPORT_SYMBOL(scsi_host_set_state); | |
129 | ||
1da177e4 LT |
130 | /** |
131 | * scsi_host_cancel - cancel outstanding IO to this host | |
132 | * @shost: pointer to struct Scsi_Host | |
133 | * recovery: recovery requested to run. | |
134 | **/ | |
52c1da39 | 135 | static void scsi_host_cancel(struct Scsi_Host *shost, int recovery) |
1da177e4 LT |
136 | { |
137 | struct scsi_device *sdev; | |
138 | ||
d3301874 | 139 | scsi_host_set_state(shost, SHOST_CANCEL); |
1da177e4 LT |
140 | shost_for_each_device(sdev, shost) { |
141 | scsi_device_cancel(sdev, recovery); | |
142 | } | |
d3301874 | 143 | wait_event(shost->host_wait, (shost->shost_state != SHOST_RECOVERY)); |
1da177e4 LT |
144 | } |
145 | ||
146 | /** | |
147 | * scsi_remove_host - remove a scsi host | |
148 | * @shost: a pointer to a scsi host to remove | |
149 | **/ | |
150 | void scsi_remove_host(struct Scsi_Host *shost) | |
151 | { | |
152 | scsi_forget_host(shost); | |
153 | scsi_host_cancel(shost, 0); | |
154 | scsi_proc_host_rm(shost); | |
155 | ||
d3301874 | 156 | scsi_host_set_state(shost, SHOST_DEL); |
1da177e4 LT |
157 | |
158 | transport_unregister_device(&shost->shost_gendev); | |
159 | class_device_unregister(&shost->shost_classdev); | |
160 | device_del(&shost->shost_gendev); | |
161 | } | |
162 | EXPORT_SYMBOL(scsi_remove_host); | |
163 | ||
164 | /** | |
165 | * scsi_add_host - add a scsi host | |
166 | * @shost: scsi host pointer to add | |
167 | * @dev: a struct device of type scsi class | |
168 | * | |
169 | * Return value: | |
170 | * 0 on success / != 0 for error | |
171 | **/ | |
172 | int scsi_add_host(struct Scsi_Host *shost, struct device *dev) | |
173 | { | |
174 | struct scsi_host_template *sht = shost->hostt; | |
175 | int error = -EINVAL; | |
176 | ||
177 | printk(KERN_INFO "scsi%d : %s\n", shost->host_no, | |
178 | sht->info ? sht->info(shost) : sht->name); | |
179 | ||
180 | if (!shost->can_queue) { | |
181 | printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", | |
182 | sht->name); | |
183 | goto out; | |
184 | } | |
185 | ||
186 | if (!shost->shost_gendev.parent) | |
187 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
188 | ||
189 | error = device_add(&shost->shost_gendev); | |
190 | if (error) | |
191 | goto out; | |
192 | ||
d3301874 | 193 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
194 | get_device(shost->shost_gendev.parent); |
195 | ||
196 | error = class_device_add(&shost->shost_classdev); | |
197 | if (error) | |
198 | goto out_del_gendev; | |
199 | ||
200 | get_device(&shost->shost_gendev); | |
201 | ||
202 | if (shost->transportt->host_size && | |
203 | (shost->shost_data = kmalloc(shost->transportt->host_size, | |
204 | GFP_KERNEL)) == NULL) | |
205 | goto out_del_classdev; | |
206 | ||
207 | if (shost->transportt->create_work_queue) { | |
208 | snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", | |
209 | shost->host_no); | |
210 | shost->work_q = create_singlethread_workqueue( | |
211 | shost->work_q_name); | |
212 | if (!shost->work_q) | |
213 | goto out_free_shost_data; | |
214 | } | |
215 | ||
216 | error = scsi_sysfs_add_host(shost); | |
217 | if (error) | |
218 | goto out_destroy_host; | |
219 | ||
220 | scsi_proc_host_add(shost); | |
221 | return error; | |
222 | ||
223 | out_destroy_host: | |
224 | if (shost->work_q) | |
225 | destroy_workqueue(shost->work_q); | |
226 | out_free_shost_data: | |
227 | kfree(shost->shost_data); | |
228 | out_del_classdev: | |
229 | class_device_del(&shost->shost_classdev); | |
230 | out_del_gendev: | |
231 | device_del(&shost->shost_gendev); | |
232 | out: | |
233 | return error; | |
234 | } | |
235 | EXPORT_SYMBOL(scsi_add_host); | |
236 | ||
237 | static void scsi_host_dev_release(struct device *dev) | |
238 | { | |
239 | struct Scsi_Host *shost = dev_to_shost(dev); | |
240 | struct device *parent = dev->parent; | |
241 | ||
242 | if (shost->ehandler) { | |
243 | DECLARE_COMPLETION(sem); | |
244 | shost->eh_notify = &sem; | |
245 | shost->eh_kill = 1; | |
246 | up(shost->eh_wait); | |
247 | wait_for_completion(&sem); | |
248 | shost->eh_notify = NULL; | |
249 | } | |
250 | ||
251 | if (shost->work_q) | |
252 | destroy_workqueue(shost->work_q); | |
253 | ||
254 | scsi_proc_hostdir_rm(shost->hostt); | |
255 | scsi_destroy_command_freelist(shost); | |
256 | kfree(shost->shost_data); | |
257 | ||
1da177e4 LT |
258 | if (parent) |
259 | put_device(parent); | |
260 | kfree(shost); | |
261 | } | |
262 | ||
263 | /** | |
264 | * scsi_host_alloc - register a scsi host adapter instance. | |
265 | * @sht: pointer to scsi host template | |
266 | * @privsize: extra bytes to allocate for driver | |
267 | * | |
268 | * Note: | |
269 | * Allocate a new Scsi_Host and perform basic initialization. | |
270 | * The host is not published to the scsi midlayer until scsi_add_host | |
271 | * is called. | |
272 | * | |
273 | * Return value: | |
274 | * Pointer to a new Scsi_Host | |
275 | **/ | |
276 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
277 | { | |
278 | struct Scsi_Host *shost; | |
279 | int gfp_mask = GFP_KERNEL, rval; | |
280 | DECLARE_COMPLETION(complete); | |
281 | ||
282 | if (sht->unchecked_isa_dma && privsize) | |
283 | gfp_mask |= __GFP_DMA; | |
284 | ||
285 | /* Check to see if this host has any error handling facilities */ | |
286 | if (!sht->eh_strategy_handler && !sht->eh_abort_handler && | |
287 | !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && | |
288 | !sht->eh_host_reset_handler) { | |
289 | printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" | |
290 | "ERROR: This is not a safe way to run your " | |
291 | "SCSI host\n" | |
292 | "ERROR: The error handling must be added to " | |
293 | "this driver\n", sht->proc_name); | |
294 | dump_stack(); | |
295 | } | |
296 | ||
297 | shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); | |
298 | if (!shost) | |
299 | return NULL; | |
300 | memset(shost, 0, sizeof(struct Scsi_Host) + privsize); | |
301 | ||
302 | spin_lock_init(&shost->default_lock); | |
303 | scsi_assign_lock(shost, &shost->default_lock); | |
d3301874 | 304 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
305 | INIT_LIST_HEAD(&shost->__devices); |
306 | INIT_LIST_HEAD(&shost->__targets); | |
307 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
308 | INIT_LIST_HEAD(&shost->starved_list); | |
309 | init_waitqueue_head(&shost->host_wait); | |
310 | ||
311 | init_MUTEX(&shost->scan_mutex); | |
312 | ||
313 | shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ | |
314 | shost->dma_channel = 0xff; | |
315 | ||
316 | /* These three are default values which can be overridden */ | |
317 | shost->max_channel = 0; | |
318 | shost->max_id = 8; | |
319 | shost->max_lun = 8; | |
320 | ||
321 | /* Give each shost a default transportt */ | |
322 | shost->transportt = &blank_transport_template; | |
323 | ||
324 | /* | |
325 | * All drivers right now should be able to handle 12 byte | |
326 | * commands. Every so often there are requests for 16 byte | |
327 | * commands, but individual low-level drivers need to certify that | |
328 | * they actually do something sensible with such commands. | |
329 | */ | |
330 | shost->max_cmd_len = 12; | |
331 | shost->hostt = sht; | |
332 | shost->this_id = sht->this_id; | |
333 | shost->can_queue = sht->can_queue; | |
334 | shost->sg_tablesize = sht->sg_tablesize; | |
335 | shost->cmd_per_lun = sht->cmd_per_lun; | |
336 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
337 | shost->use_clustering = sht->use_clustering; | |
338 | shost->ordered_flush = sht->ordered_flush; | |
339 | shost->ordered_tag = sht->ordered_tag; | |
340 | ||
341 | /* | |
342 | * hosts/devices that do queueing must support ordered tags | |
343 | */ | |
344 | if (shost->can_queue > 1 && shost->ordered_flush) { | |
345 | printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); | |
346 | shost->ordered_flush = 0; | |
347 | } | |
348 | ||
349 | if (sht->max_host_blocked) | |
350 | shost->max_host_blocked = sht->max_host_blocked; | |
351 | else | |
352 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
353 | ||
354 | /* | |
355 | * If the driver imposes no hard sector transfer limit, start at | |
356 | * machine infinity initially. | |
357 | */ | |
358 | if (sht->max_sectors) | |
359 | shost->max_sectors = sht->max_sectors; | |
360 | else | |
361 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
362 | ||
363 | /* | |
364 | * assume a 4GB boundary, if not set | |
365 | */ | |
366 | if (sht->dma_boundary) | |
367 | shost->dma_boundary = sht->dma_boundary; | |
368 | else | |
369 | shost->dma_boundary = 0xffffffff; | |
370 | ||
371 | rval = scsi_setup_command_freelist(shost); | |
372 | if (rval) | |
373 | goto fail_kfree; | |
374 | ||
375 | device_initialize(&shost->shost_gendev); | |
376 | snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", | |
377 | shost->host_no); | |
378 | shost->shost_gendev.release = scsi_host_dev_release; | |
379 | ||
380 | class_device_initialize(&shost->shost_classdev); | |
381 | shost->shost_classdev.dev = &shost->shost_gendev; | |
382 | shost->shost_classdev.class = &shost_class; | |
383 | snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", | |
384 | shost->host_no); | |
385 | ||
386 | shost->eh_notify = &complete; | |
387 | rval = kernel_thread(scsi_error_handler, shost, 0); | |
388 | if (rval < 0) | |
389 | goto fail_destroy_freelist; | |
390 | wait_for_completion(&complete); | |
391 | shost->eh_notify = NULL; | |
392 | ||
393 | scsi_proc_hostdir_add(shost->hostt); | |
394 | return shost; | |
395 | ||
396 | fail_destroy_freelist: | |
397 | scsi_destroy_command_freelist(shost); | |
398 | fail_kfree: | |
399 | kfree(shost); | |
400 | return NULL; | |
401 | } | |
402 | EXPORT_SYMBOL(scsi_host_alloc); | |
403 | ||
404 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
405 | { | |
406 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
407 | ||
408 | if (!sht->detect) { | |
409 | printk(KERN_WARNING "scsi_register() called on new-style " | |
410 | "template for driver %s\n", sht->name); | |
411 | dump_stack(); | |
412 | } | |
413 | ||
414 | if (shost) | |
415 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
416 | return shost; | |
417 | } | |
418 | EXPORT_SYMBOL(scsi_register); | |
419 | ||
420 | void scsi_unregister(struct Scsi_Host *shost) | |
421 | { | |
422 | list_del(&shost->sht_legacy_list); | |
423 | scsi_host_put(shost); | |
424 | } | |
425 | EXPORT_SYMBOL(scsi_unregister); | |
426 | ||
427 | /** | |
428 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
429 | * | |
430 | * @hostnum: host number to locate | |
431 | * | |
432 | * Return value: | |
433 | * A pointer to located Scsi_Host or NULL. | |
434 | **/ | |
435 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
436 | { | |
437 | struct class *class = &shost_class; | |
438 | struct class_device *cdev; | |
439 | struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; | |
440 | ||
441 | down_read(&class->subsys.rwsem); | |
442 | list_for_each_entry(cdev, &class->children, node) { | |
443 | p = class_to_shost(cdev); | |
444 | if (p->host_no == hostnum) { | |
445 | shost = scsi_host_get(p); | |
446 | break; | |
447 | } | |
448 | } | |
449 | up_read(&class->subsys.rwsem); | |
450 | ||
451 | return shost; | |
452 | } | |
453 | EXPORT_SYMBOL(scsi_host_lookup); | |
454 | ||
455 | /** | |
456 | * scsi_host_get - inc a Scsi_Host ref count | |
457 | * @shost: Pointer to Scsi_Host to inc. | |
458 | **/ | |
459 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
460 | { | |
d3301874 | 461 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
462 | !get_device(&shost->shost_gendev)) |
463 | return NULL; | |
464 | return shost; | |
465 | } | |
466 | EXPORT_SYMBOL(scsi_host_get); | |
467 | ||
468 | /** | |
469 | * scsi_host_put - dec a Scsi_Host ref count | |
470 | * @shost: Pointer to Scsi_Host to dec. | |
471 | **/ | |
472 | void scsi_host_put(struct Scsi_Host *shost) | |
473 | { | |
474 | put_device(&shost->shost_gendev); | |
475 | } | |
476 | EXPORT_SYMBOL(scsi_host_put); | |
477 | ||
478 | int scsi_init_hosts(void) | |
479 | { | |
480 | return class_register(&shost_class); | |
481 | } | |
482 | ||
483 | void scsi_exit_hosts(void) | |
484 | { | |
485 | class_unregister(&shost_class); | |
486 | } | |
487 | ||
488 | int scsi_is_host_device(const struct device *dev) | |
489 | { | |
490 | return dev->release == scsi_host_dev_release; | |
491 | } | |
492 | EXPORT_SYMBOL(scsi_is_host_device); | |
493 | ||
494 | /** | |
495 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
496 | * @shost: Pointer to Scsi_Host. | |
497 | * @work: Work to queue for execution. | |
498 | * | |
499 | * Return value: | |
500 | * 0 on success / != 0 for error | |
501 | **/ | |
502 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
503 | { | |
504 | if (unlikely(!shost->work_q)) { | |
505 | printk(KERN_ERR | |
506 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " | |
507 | "when no workqueue created.\n", shost->hostt->name); | |
508 | dump_stack(); | |
509 | ||
510 | return -EINVAL; | |
511 | } | |
512 | ||
513 | return queue_work(shost->work_q, work); | |
514 | } | |
515 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
516 | ||
517 | /** | |
518 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
519 | * @shost: Pointer to Scsi_Host. | |
520 | **/ | |
521 | void scsi_flush_work(struct Scsi_Host *shost) | |
522 | { | |
523 | if (!shost->work_q) { | |
524 | printk(KERN_ERR | |
525 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " | |
526 | "when no workqueue created.\n", shost->hostt->name); | |
527 | dump_stack(); | |
528 | return; | |
529 | } | |
530 | ||
531 | flush_workqueue(shost->work_q); | |
532 | } | |
533 | EXPORT_SYMBOL_GPL(scsi_flush_work); |