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