1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
|
/*
* Enclosure Services
*
* Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
*
**-----------------------------------------------------------------------------
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License
** version 2 as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**-----------------------------------------------------------------------------
*/
#include <linux/device.h>
#include <linux/enclosure.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
static LIST_HEAD(container_list);
static DEFINE_MUTEX(container_list_lock);
static struct class enclosure_class;
/**
* enclosure_find - find an enclosure given a parent device
* @dev: the parent to match against
* @start: Optional enclosure device to start from (NULL if none)
*
* Looks through the list of registered enclosures to find all those
* with @dev as a parent. Returns NULL if no enclosure is
* found. @start can be used as a starting point to obtain multiple
* enclosures per parent (should begin with NULL and then be set to
* each returned enclosure device). Obtains a reference to the
* enclosure class device which must be released with device_put().
* If @start is not NULL, a reference must be taken on it which is
* released before returning (this allows a loop through all
* enclosures to exit with only the reference on the enclosure of
* interest held). Note that the @dev may correspond to the actual
* device housing the enclosure, in which case no iteration via @start
* is required.
*/
struct enclosure_device *enclosure_find(struct device *dev,
struct enclosure_device *start)
{
struct enclosure_device *edev;
mutex_lock(&container_list_lock);
edev = list_prepare_entry(start, &container_list, node);
if (start)
put_device(&start->edev);
list_for_each_entry_continue(edev, &container_list, node) {
struct device *parent = edev->edev.parent;
/* parent might not be immediate, so iterate up to
* the root of the tree if necessary */
while (parent) {
if (parent == dev) {
get_device(&edev->edev);
mutex_unlock(&container_list_lock);
return edev;
}
parent = parent->parent;
}
}
mutex_unlock(&container_list_lock);
return NULL;
}
EXPORT_SYMBOL_GPL(enclosure_find);
/**
* enclosure_for_each_device - calls a function for each enclosure
* @fn: the function to call
* @data: the data to pass to each call
*
* Loops over all the enclosures calling the function.
*
* Note, this function uses a mutex which will be held across calls to
* @fn, so it must have non atomic context, and @fn may (although it
* should not) sleep or otherwise cause the mutex to be held for
* indefinite periods
*/
int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
void *data)
{
int error = 0;
struct enclosure_device *edev;
mutex_lock(&container_list_lock);
list_for_each_entry(edev, &container_list, node) {
error = fn(edev, data);
if (error)
break;
}
mutex_unlock(&container_list_lock);
return error;
}
EXPORT_SYMBOL_GPL(enclosure_for_each_device);
/**
* enclosure_register - register device as an enclosure
*
* @dev: device containing the enclosure
* @components: number of components in the enclosure
*
* This sets up the device for being an enclosure. Note that @dev does
* not have to be a dedicated enclosure device. It may be some other type
* of device that additionally responds to enclosure services
*/
struct enclosure_device *
enclosure_register(struct device *dev, const char *name, int components,
struct enclosure_component_callbacks *cb)
{
struct enclosure_device *edev =
kzalloc(sizeof(struct enclosure_device) +
sizeof(struct enclosure_component)*components,
GFP_KERNEL);
int err, i;
BUG_ON(!cb);
if (!edev)
return ERR_PTR(-ENOMEM);
edev->components = components;
edev->edev.class = &enclosure_class;
edev->edev.parent = get_device(dev);
edev->cb = cb;
dev_set_name(&edev->edev, "%s", name);
err = device_register(&edev->edev);
if (err)
goto err;
for (i = 0; i < components; i++)
edev->component[i].number = -1;
mutex_lock(&container_list_lock);
list_add_tail(&edev->node, &container_list);
mutex_unlock(&container_list_lock);
return edev;
err:
put_device(edev->edev.parent);
kfree(edev);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(enclosure_register);
static struct enclosure_component_callbacks enclosure_null_callbacks;
/**
* enclosure_unregister - remove an enclosure
*
* @edev: the registered enclosure to remove;
*/
void enclosure_unregister(struct enclosure_device *edev)
{
int i;
mutex_lock(&container_list_lock);
list_del(&edev->node);
mutex_unlock(&container_list_lock);
for (i = 0; i < edev->components; i++)
if (edev->component[i].number != -1)
device_unregister(&edev->component[i].cdev);
/* prevent any callbacks into service user */
edev->cb = &enclosure_null_callbacks;
device_unregister(&edev->edev);
}
EXPORT_SYMBOL_GPL(enclosure_unregister);
#define ENCLOSURE_NAME_SIZE 64
static void enclosure_link_name(struct enclosure_component *cdev, char *name)
{
strcpy(name, "enclosure_device:");
strcat(name, dev_name(&cdev->cdev));
}
static void enclosure_remove_links(struct enclosure_component *cdev)
{
char name[ENCLOSURE_NAME_SIZE];
/*
* In odd circumstances, like multipath devices, something else may
* already have removed the links, so check for this condition first.
*/
if (!cdev->dev->kobj.sd)
return;
enclosure_link_name(cdev, name);
sysfs_remove_link(&cdev->dev->kobj, name);
sysfs_remove_link(&cdev->cdev.kobj, "device");
}
static int enclosure_add_links(struct enclosure_component *cdev)
{
int error;
char name[ENCLOSURE_NAME_SIZE];
error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
if (error)
return error;
enclosure_link_name(cdev, name);
error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
if (error)
sysfs_remove_link(&cdev->cdev.kobj, "device");
return error;
}
static void enclosure_release(struct device *cdev)
{
struct enclosure_device *edev = to_enclosure_device(cdev);
put_device(cdev->parent);
kfree(edev);
}
static void enclosure_component_release(struct device *dev)
{
struct enclosure_component *cdev = to_enclosure_component(dev);
if (cdev->dev) {
enclosure_remove_links(cdev);
put_device(cdev->dev);
}
put_device(dev->parent);
}
static const struct attribute_group *enclosure_component_groups[];
/**
* enclosure_component_register - add a particular component to an enclosure
* @edev: the enclosure to add the component
* @num: the device number
* @type: the type of component being added
* @name: an optional name to appear in sysfs (leave NULL if none)
*
* Registers the component. The name is optional for enclosures that
* give their components a unique name. If not, leave the field NULL
* and a name will be assigned.
*
* Returns a pointer to the enclosure component or an error.
*/
struct enclosure_component *
enclosure_component_register(struct enclosure_device *edev,
unsigned int number,
enum enclosure_component_type type,
const char *name)
{
struct enclosure_component *ecomp;
struct device *cdev;
int err;
if (number >= edev->components)
return ERR_PTR(-EINVAL);
ecomp = &edev->component[number];
if (ecomp->number != -1)
return ERR_PTR(-EINVAL);
ecomp->type = type;
ecomp->number
|