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1da177e4 LT |
1 | /* |
2 | * firmware_class.c - Multi purpose firmware loading support | |
3 | * | |
4 | * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org> | |
5 | * | |
6 | * Please see Documentation/firmware_class/ for more information. | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <linux/device.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/timer.h> | |
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/bitops.h> | |
17 | #include <asm/semaphore.h> | |
18 | ||
19 | #include <linux/firmware.h> | |
20 | #include "base.h" | |
21 | ||
22 | MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>"); | |
23 | MODULE_DESCRIPTION("Multi purpose firmware loading support"); | |
24 | MODULE_LICENSE("GPL"); | |
25 | ||
26 | enum { | |
27 | FW_STATUS_LOADING, | |
28 | FW_STATUS_DONE, | |
29 | FW_STATUS_ABORT, | |
30 | FW_STATUS_READY, | |
31 | }; | |
32 | ||
33 | static int loading_timeout = 10; /* In seconds */ | |
34 | ||
35 | /* fw_lock could be moved to 'struct firmware_priv' but since it is just | |
36 | * guarding for corner cases a global lock should be OK */ | |
37 | static DECLARE_MUTEX(fw_lock); | |
38 | ||
39 | struct firmware_priv { | |
40 | char fw_id[FIRMWARE_NAME_MAX]; | |
41 | struct completion completion; | |
42 | struct bin_attribute attr_data; | |
43 | struct firmware *fw; | |
44 | unsigned long status; | |
45 | int alloc_size; | |
46 | struct timer_list timeout; | |
47 | }; | |
48 | ||
49 | static inline void | |
50 | fw_load_abort(struct firmware_priv *fw_priv) | |
51 | { | |
52 | set_bit(FW_STATUS_ABORT, &fw_priv->status); | |
53 | wmb(); | |
54 | complete(&fw_priv->completion); | |
55 | } | |
56 | ||
57 | static ssize_t | |
58 | firmware_timeout_show(struct class *class, char *buf) | |
59 | { | |
60 | return sprintf(buf, "%d\n", loading_timeout); | |
61 | } | |
62 | ||
63 | /** | |
64 | * firmware_timeout_store: | |
65 | * Description: | |
66 | * Sets the number of seconds to wait for the firmware. Once | |
67 | * this expires an error will be return to the driver and no | |
68 | * firmware will be provided. | |
69 | * | |
70 | * Note: zero means 'wait for ever' | |
71 | * | |
72 | **/ | |
73 | static ssize_t | |
74 | firmware_timeout_store(struct class *class, const char *buf, size_t count) | |
75 | { | |
76 | loading_timeout = simple_strtol(buf, NULL, 10); | |
b92eac01 SG |
77 | if (loading_timeout < 0) |
78 | loading_timeout = 0; | |
1da177e4 LT |
79 | return count; |
80 | } | |
81 | ||
82 | static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store); | |
83 | ||
84 | static void fw_class_dev_release(struct class_device *class_dev); | |
85 | int firmware_class_hotplug(struct class_device *dev, char **envp, | |
86 | int num_envp, char *buffer, int buffer_size); | |
87 | ||
88 | static struct class firmware_class = { | |
89 | .name = "firmware", | |
90 | .hotplug = firmware_class_hotplug, | |
91 | .release = fw_class_dev_release, | |
92 | }; | |
93 | ||
94 | int | |
95 | firmware_class_hotplug(struct class_device *class_dev, char **envp, | |
96 | int num_envp, char *buffer, int buffer_size) | |
97 | { | |
98 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
99 | int i = 0, len = 0; | |
100 | ||
101 | if (!test_bit(FW_STATUS_READY, &fw_priv->status)) | |
102 | return -ENODEV; | |
103 | ||
104 | if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len, | |
105 | "FIRMWARE=%s", fw_priv->fw_id)) | |
106 | return -ENOMEM; | |
6897089c KS |
107 | if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len, |
108 | "TIMEOUT=%i", loading_timeout)) | |
109 | return -ENOMEM; | |
1da177e4 LT |
110 | |
111 | envp[i] = NULL; | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static ssize_t | |
117 | firmware_loading_show(struct class_device *class_dev, char *buf) | |
118 | { | |
119 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
120 | int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status); | |
121 | return sprintf(buf, "%d\n", loading); | |
122 | } | |
123 | ||
124 | /** | |
125 | * firmware_loading_store: - loading control file | |
126 | * Description: | |
127 | * The relevant values are: | |
128 | * | |
129 | * 1: Start a load, discarding any previous partial load. | |
130 | * 0: Conclude the load and handle the data to the driver code. | |
131 | * -1: Conclude the load with an error and discard any written data. | |
132 | **/ | |
133 | static ssize_t | |
134 | firmware_loading_store(struct class_device *class_dev, | |
135 | const char *buf, size_t count) | |
136 | { | |
137 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
138 | int loading = simple_strtol(buf, NULL, 10); | |
139 | ||
140 | switch (loading) { | |
141 | case 1: | |
142 | down(&fw_lock); | |
b92eac01 SG |
143 | if (!fw_priv->fw) { |
144 | up(&fw_lock); | |
145 | break; | |
146 | } | |
1da177e4 LT |
147 | vfree(fw_priv->fw->data); |
148 | fw_priv->fw->data = NULL; | |
149 | fw_priv->fw->size = 0; | |
150 | fw_priv->alloc_size = 0; | |
151 | set_bit(FW_STATUS_LOADING, &fw_priv->status); | |
152 | up(&fw_lock); | |
153 | break; | |
154 | case 0: | |
155 | if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) { | |
156 | complete(&fw_priv->completion); | |
157 | clear_bit(FW_STATUS_LOADING, &fw_priv->status); | |
158 | break; | |
159 | } | |
160 | /* fallthrough */ | |
161 | default: | |
162 | printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__, | |
163 | loading); | |
164 | /* fallthrough */ | |
165 | case -1: | |
166 | fw_load_abort(fw_priv); | |
167 | break; | |
168 | } | |
169 | ||
170 | return count; | |
171 | } | |
172 | ||
173 | static CLASS_DEVICE_ATTR(loading, 0644, | |
174 | firmware_loading_show, firmware_loading_store); | |
175 | ||
176 | static ssize_t | |
177 | firmware_data_read(struct kobject *kobj, | |
178 | char *buffer, loff_t offset, size_t count) | |
179 | { | |
180 | struct class_device *class_dev = to_class_dev(kobj); | |
181 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
182 | struct firmware *fw; | |
183 | ssize_t ret_count = count; | |
184 | ||
185 | down(&fw_lock); | |
186 | fw = fw_priv->fw; | |
b92eac01 | 187 | if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { |
1da177e4 LT |
188 | ret_count = -ENODEV; |
189 | goto out; | |
190 | } | |
191 | if (offset > fw->size) { | |
192 | ret_count = 0; | |
193 | goto out; | |
194 | } | |
195 | if (offset + ret_count > fw->size) | |
196 | ret_count = fw->size - offset; | |
197 | ||
198 | memcpy(buffer, fw->data + offset, ret_count); | |
199 | out: | |
200 | up(&fw_lock); | |
201 | return ret_count; | |
202 | } | |
203 | static int | |
204 | fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size) | |
205 | { | |
206 | u8 *new_data; | |
207 | ||
208 | if (min_size <= fw_priv->alloc_size) | |
209 | return 0; | |
210 | ||
211 | new_data = vmalloc(fw_priv->alloc_size + PAGE_SIZE); | |
212 | if (!new_data) { | |
213 | printk(KERN_ERR "%s: unable to alloc buffer\n", __FUNCTION__); | |
214 | /* Make sure that we don't keep incomplete data */ | |
215 | fw_load_abort(fw_priv); | |
216 | return -ENOMEM; | |
217 | } | |
218 | fw_priv->alloc_size += PAGE_SIZE; | |
219 | if (fw_priv->fw->data) { | |
220 | memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size); | |
221 | vfree(fw_priv->fw->data); | |
222 | } | |
223 | fw_priv->fw->data = new_data; | |
224 | BUG_ON(min_size > fw_priv->alloc_size); | |
225 | return 0; | |
226 | } | |
227 | ||
228 | /** | |
229 | * firmware_data_write: | |
230 | * | |
231 | * Description: | |
232 | * | |
233 | * Data written to the 'data' attribute will be later handled to | |
234 | * the driver as a firmware image. | |
235 | **/ | |
236 | static ssize_t | |
237 | firmware_data_write(struct kobject *kobj, | |
238 | char *buffer, loff_t offset, size_t count) | |
239 | { | |
240 | struct class_device *class_dev = to_class_dev(kobj); | |
241 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
242 | struct firmware *fw; | |
243 | ssize_t retval; | |
244 | ||
245 | if (!capable(CAP_SYS_RAWIO)) | |
246 | return -EPERM; | |
b92eac01 | 247 | |
1da177e4 LT |
248 | down(&fw_lock); |
249 | fw = fw_priv->fw; | |
b92eac01 | 250 | if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { |
1da177e4 LT |
251 | retval = -ENODEV; |
252 | goto out; | |
253 | } | |
254 | retval = fw_realloc_buffer(fw_priv, offset + count); | |
255 | if (retval) | |
256 | goto out; | |
257 | ||
258 | memcpy(fw->data + offset, buffer, count); | |
259 | ||
260 | fw->size = max_t(size_t, offset + count, fw->size); | |
261 | retval = count; | |
262 | out: | |
263 | up(&fw_lock); | |
264 | return retval; | |
265 | } | |
266 | static struct bin_attribute firmware_attr_data_tmpl = { | |
267 | .attr = {.name = "data", .mode = 0644, .owner = THIS_MODULE}, | |
268 | .size = 0, | |
269 | .read = firmware_data_read, | |
270 | .write = firmware_data_write, | |
271 | }; | |
272 | ||
273 | static void | |
274 | fw_class_dev_release(struct class_device *class_dev) | |
275 | { | |
276 | struct firmware_priv *fw_priv = class_get_devdata(class_dev); | |
277 | ||
278 | kfree(fw_priv); | |
279 | kfree(class_dev); | |
280 | ||
281 | module_put(THIS_MODULE); | |
282 | } | |
283 | ||
284 | static void | |
285 | firmware_class_timeout(u_long data) | |
286 | { | |
287 | struct firmware_priv *fw_priv = (struct firmware_priv *) data; | |
288 | fw_load_abort(fw_priv); | |
289 | } | |
290 | ||
291 | static inline void | |
292 | fw_setup_class_device_id(struct class_device *class_dev, struct device *dev) | |
293 | { | |
294 | /* XXX warning we should watch out for name collisions */ | |
295 | strlcpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE); | |
296 | } | |
297 | ||
298 | static int | |
299 | fw_register_class_device(struct class_device **class_dev_p, | |
300 | const char *fw_name, struct device *device) | |
301 | { | |
302 | int retval; | |
303 | struct firmware_priv *fw_priv = kmalloc(sizeof (struct firmware_priv), | |
304 | GFP_KERNEL); | |
305 | struct class_device *class_dev = kmalloc(sizeof (struct class_device), | |
306 | GFP_KERNEL); | |
307 | ||
308 | *class_dev_p = NULL; | |
309 | ||
310 | if (!fw_priv || !class_dev) { | |
311 | printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__); | |
312 | retval = -ENOMEM; | |
313 | goto error_kfree; | |
314 | } | |
315 | memset(fw_priv, 0, sizeof (*fw_priv)); | |
316 | memset(class_dev, 0, sizeof (*class_dev)); | |
317 | ||
318 | init_completion(&fw_priv->completion); | |
319 | fw_priv->attr_data = firmware_attr_data_tmpl; | |
320 | strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX); | |
321 | ||
322 | fw_priv->timeout.function = firmware_class_timeout; | |
323 | fw_priv->timeout.data = (u_long) fw_priv; | |
324 | init_timer(&fw_priv->timeout); | |
325 | ||
326 | fw_setup_class_device_id(class_dev, device); | |
327 | class_dev->dev = device; | |
328 | class_dev->class = &firmware_class; | |
329 | class_set_devdata(class_dev, fw_priv); | |
330 | retval = class_device_register(class_dev); | |
331 | if (retval) { | |
332 | printk(KERN_ERR "%s: class_device_register failed\n", | |
333 | __FUNCTION__); | |
334 | goto error_kfree; | |
335 | } | |
336 | *class_dev_p = class_dev; | |
337 | return 0; | |
338 | ||
339 | error_kfree: | |
340 | kfree(fw_priv); | |
341 | kfree(class_dev); | |
342 | return retval; | |
343 | } | |
344 | ||
345 | static int | |
346 | fw_setup_class_device(struct firmware *fw, struct class_device **class_dev_p, | |
347 | const char *fw_name, struct device *device) | |
348 | { | |
349 | struct class_device *class_dev; | |
350 | struct firmware_priv *fw_priv; | |
351 | int retval; | |
352 | ||
353 | *class_dev_p = NULL; | |
354 | retval = fw_register_class_device(&class_dev, fw_name, device); | |
355 | if (retval) | |
356 | goto out; | |
357 | ||
358 | /* Need to pin this module until class device is destroyed */ | |
359 | __module_get(THIS_MODULE); | |
360 | ||
361 | fw_priv = class_get_devdata(class_dev); | |
362 | ||
363 | fw_priv->fw = fw; | |
364 | retval = sysfs_create_bin_file(&class_dev->kobj, &fw_priv->attr_data); | |
365 | if (retval) { | |
366 | printk(KERN_ERR "%s: sysfs_create_bin_file failed\n", | |
367 | __FUNCTION__); | |
368 | goto error_unreg; | |
369 | } | |
370 | ||
371 | retval = class_device_create_file(class_dev, | |
372 | &class_device_attr_loading); | |
373 | if (retval) { | |
374 | printk(KERN_ERR "%s: class_device_create_file failed\n", | |
375 | __FUNCTION__); | |
376 | goto error_unreg; | |
377 | } | |
378 | ||
379 | set_bit(FW_STATUS_READY, &fw_priv->status); | |
380 | *class_dev_p = class_dev; | |
381 | goto out; | |
382 | ||
383 | error_unreg: | |
384 | class_device_unregister(class_dev); | |
385 | out: | |
386 | return retval; | |
387 | } | |
388 | ||
389 | /** | |
390 | * request_firmware: - request firmware to hotplug and wait for it | |
391 | * Description: | |
392 | * @firmware will be used to return a firmware image by the name | |
393 | * of @name for device @device. | |
394 | * | |
395 | * Should be called from user context where sleeping is allowed. | |
396 | * | |
397 | * @name will be use as $FIRMWARE in the hotplug environment and | |
398 | * should be distinctive enough not to be confused with any other | |
399 | * firmware image for this or any other device. | |
400 | **/ | |
401 | int | |
402 | request_firmware(const struct firmware **firmware_p, const char *name, | |
403 | struct device *device) | |
404 | { | |
405 | struct class_device *class_dev; | |
406 | struct firmware_priv *fw_priv; | |
407 | struct firmware *firmware; | |
408 | int retval; | |
409 | ||
410 | if (!firmware_p) | |
411 | return -EINVAL; | |
412 | ||
413 | *firmware_p = firmware = kmalloc(sizeof (struct firmware), GFP_KERNEL); | |
414 | if (!firmware) { | |
415 | printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n", | |
416 | __FUNCTION__); | |
417 | retval = -ENOMEM; | |
418 | goto out; | |
419 | } | |
420 | memset(firmware, 0, sizeof (*firmware)); | |
421 | ||
422 | retval = fw_setup_class_device(firmware, &class_dev, name, device); | |
423 | if (retval) | |
424 | goto error_kfree_fw; | |
425 | ||
426 | fw_priv = class_get_devdata(class_dev); | |
427 | ||
b92eac01 | 428 | if (loading_timeout > 0) { |
1da177e4 LT |
429 | fw_priv->timeout.expires = jiffies + loading_timeout * HZ; |
430 | add_timer(&fw_priv->timeout); | |
431 | } | |
432 | ||
433 | kobject_hotplug(&class_dev->kobj, KOBJ_ADD); | |
434 | wait_for_completion(&fw_priv->completion); | |
435 | set_bit(FW_STATUS_DONE, &fw_priv->status); | |
436 | ||
437 | del_timer_sync(&fw_priv->timeout); | |
438 | ||
439 | down(&fw_lock); | |
440 | if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) { | |
441 | retval = -ENOENT; | |
442 | release_firmware(fw_priv->fw); | |
443 | *firmware_p = NULL; | |
444 | } | |
445 | fw_priv->fw = NULL; | |
446 | up(&fw_lock); | |
447 | class_device_unregister(class_dev); | |
448 | goto out; | |
449 | ||
450 | error_kfree_fw: | |
451 | kfree(firmware); | |
452 | *firmware_p = NULL; | |
453 | out: | |
454 | return retval; | |
455 | } | |
456 | ||
457 | /** | |
458 | * release_firmware: - release the resource associated with a firmware image | |
459 | **/ | |
460 | void | |
461 | release_firmware(const struct firmware *fw) | |
462 | { | |
463 | if (fw) { | |
464 | vfree(fw->data); | |
465 | kfree(fw); | |
466 | } | |
467 | } | |
468 | ||
469 | /** | |
470 | * register_firmware: - provide a firmware image for later usage | |
471 | * | |
472 | * Description: | |
473 | * Make sure that @data will be available by requesting firmware @name. | |
474 | * | |
475 | * Note: This will not be possible until some kind of persistence | |
476 | * is available. | |
477 | **/ | |
478 | void | |
479 | register_firmware(const char *name, const u8 *data, size_t size) | |
480 | { | |
481 | /* This is meaningless without firmware caching, so until we | |
482 | * decide if firmware caching is reasonable just leave it as a | |
483 | * noop */ | |
484 | } | |
485 | ||
486 | /* Async support */ | |
487 | struct firmware_work { | |
488 | struct work_struct work; | |
489 | struct module *module; | |
490 | const char *name; | |
491 | struct device *device; | |
492 | void *context; | |
493 | void (*cont)(const struct firmware *fw, void *context); | |
494 | }; | |
495 | ||
496 | static int | |
497 | request_firmware_work_func(void *arg) | |
498 | { | |
499 | struct firmware_work *fw_work = arg; | |
500 | const struct firmware *fw; | |
501 | if (!arg) { | |
502 | WARN_ON(1); | |
503 | return 0; | |
504 | } | |
505 | daemonize("%s/%s", "firmware", fw_work->name); | |
506 | request_firmware(&fw, fw_work->name, fw_work->device); | |
507 | fw_work->cont(fw, fw_work->context); | |
508 | release_firmware(fw); | |
509 | module_put(fw_work->module); | |
510 | kfree(fw_work); | |
511 | return 0; | |
512 | } | |
513 | ||
514 | /** | |
515 | * request_firmware_nowait: | |
516 | * | |
517 | * Description: | |
518 | * Asynchronous variant of request_firmware() for contexts where | |
519 | * it is not possible to sleep. | |
520 | * | |
521 | * @cont will be called asynchronously when the firmware request is over. | |
522 | * | |
523 | * @context will be passed over to @cont. | |
524 | * | |
525 | * @fw may be %NULL if firmware request fails. | |
526 | * | |
527 | **/ | |
528 | int | |
529 | request_firmware_nowait( | |
530 | struct module *module, | |
531 | const char *name, struct device *device, void *context, | |
532 | void (*cont)(const struct firmware *fw, void *context)) | |
533 | { | |
534 | struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work), | |
535 | GFP_ATOMIC); | |
536 | int ret; | |
537 | ||
538 | if (!fw_work) | |
539 | return -ENOMEM; | |
540 | if (!try_module_get(module)) { | |
541 | kfree(fw_work); | |
542 | return -EFAULT; | |
543 | } | |
544 | ||
545 | *fw_work = (struct firmware_work) { | |
546 | .module = module, | |
547 | .name = name, | |
548 | .device = device, | |
549 | .context = context, | |
550 | .cont = cont, | |
551 | }; | |
552 | ||
553 | ret = kernel_thread(request_firmware_work_func, fw_work, | |
554 | CLONE_FS | CLONE_FILES); | |
555 | ||
556 | if (ret < 0) { | |
557 | fw_work->cont(NULL, fw_work->context); | |
558 | return ret; | |
559 | } | |
560 | return 0; | |
561 | } | |
562 | ||
563 | static int __init | |
564 | firmware_class_init(void) | |
565 | { | |
566 | int error; | |
567 | error = class_register(&firmware_class); | |
568 | if (error) { | |
569 | printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__); | |
570 | return error; | |
571 | } | |
572 | error = class_create_file(&firmware_class, &class_attr_timeout); | |
573 | if (error) { | |
574 | printk(KERN_ERR "%s: class_create_file failed\n", | |
575 | __FUNCTION__); | |
576 | class_unregister(&firmware_class); | |
577 | } | |
578 | return error; | |
579 | ||
580 | } | |
581 | static void __exit | |
582 | firmware_class_exit(void) | |
583 | { | |
584 | class_unregister(&firmware_class); | |
585 | } | |
586 | ||
587 | module_init(firmware_class_init); | |
588 | module_exit(firmware_class_exit); | |
589 | ||
590 | EXPORT_SYMBOL(release_firmware); | |
591 | EXPORT_SYMBOL(request_firmware); | |
592 | EXPORT_SYMBOL(request_firmware_nowait); | |
593 | EXPORT_SYMBOL(register_firmware); |