usb: renesas_usbhs: fixup usbhsg_for_each_uep 1st pos
[linux-2.6.git] / drivers / scsi / hosts.c
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
45 static atomic_t scsi_host_next_hn;      /* host_no for next new host */
46
47
48 static void scsi_host_cls_release(struct device *dev)
49 {
50         put_device(&class_to_shost(dev)->shost_gendev);
51 }
52
53 static 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  **/
66 int 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 }
151 EXPORT_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  **/
157 void 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 }
185 EXPORT_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  **/
200 int 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 }
283 EXPORT_SYMBOL(scsi_add_host_with_dma);
284
285 static 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
312 static 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  **/
330 struct 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 }
439 EXPORT_SYMBOL(scsi_host_alloc);
440
441 struct 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 }
455 EXPORT_SYMBOL(scsi_register);
456
457 void scsi_unregister(struct Scsi_Host *shost)
458 {
459         list_del(&shost->sht_legacy_list);
460         scsi_host_put(shost);
461 }
462 EXPORT_SYMBOL(scsi_unregister);
463
464 static 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  **/
484 struct 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 }
497 EXPORT_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  **/
503 struct 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 }
510 EXPORT_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  **/
516 void scsi_host_put(struct Scsi_Host *shost)
517 {
518         put_device(&shost->shost_gendev);
519 }
520 EXPORT_SYMBOL(scsi_host_put);
521
522 int scsi_init_hosts(void)
523 {
524         return class_register(&shost_class);
525 }
526
527 void scsi_exit_hosts(void)
528 {
529         class_unregister(&shost_class);
530 }
531
532 int scsi_is_host_device(const struct device *dev)
533 {
534         return dev->type == &scsi_host_type;
535 }
536 EXPORT_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  **/
548 int 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 }
561 EXPORT_SYMBOL_GPL(scsi_queue_work);
562
563 /**
564  * scsi_flush_work - Flush a Scsi_Host's workqueue.
565  * @shost:      Pointer to Scsi_Host.
566  **/
567 void 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 }
579 EXPORT_SYMBOL_GPL(scsi_flush_work);