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