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1/*
2 * firmware_class.c - Multi purpose firmware loading support
3 *
4 * Copyright (c) 2003 Manuel Estrada Sainz
5 *
6 * Please see Documentation/firmware_class/ for more information.
7 *
8 */
9
10#include <linux/capability.h>
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/timer.h>
15#include <linux/vmalloc.h>
16#include <linux/interrupt.h>
17#include <linux/bitops.h>
18#include <linux/mutex.h>
19#include <linux/workqueue.h>
20#include <linux/highmem.h>
21#include <linux/firmware.h>
22#include <linux/slab.h>
23#include <linux/sched.h>
24
25#define to_dev(obj) container_of(obj, struct device, kobj)
26
27MODULE_AUTHOR("Manuel Estrada Sainz");
28MODULE_DESCRIPTION("Multi purpose firmware loading support");
29MODULE_LICENSE("GPL");
30
31/* Builtin firmware support */
32
33#ifdef CONFIG_FW_LOADER
34
35extern struct builtin_fw __start_builtin_fw[];
36extern struct builtin_fw __end_builtin_fw[];
37
38static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
39{
40 struct builtin_fw *b_fw;
41
42 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
43 if (strcmp(name, b_fw->name) == 0) {
44 fw->size = b_fw->size;
45 fw->data = b_fw->data;
46 return true;
47 }
48 }
49
50 return false;
51}
52
53static bool fw_is_builtin_firmware(const struct firmware *fw)
54{
55 struct builtin_fw *b_fw;
56
57 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
58 if (fw->data == b_fw->data)
59 return true;
60
61 return false;
62}
63
64#else /* Module case - no builtin firmware support */
65
66static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
67{
68 return false;
69}
70
71static inline bool fw_is_builtin_firmware(const struct firmware *fw)
72{
73 return false;
74}
75#endif
76
77enum {
78 FW_STATUS_LOADING,
79 FW_STATUS_DONE,
80 FW_STATUS_ABORT,
81};
82
83static int loading_timeout = 60; /* In seconds */
84
85static inline long firmware_loading_timeout(void)
86{
87 return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
88}
89
90/* fw_lock could be moved to 'struct firmware_priv' but since it is just
91 * guarding for corner cases a global lock should be OK */
92static DEFINE_MUTEX(fw_lock);
93
94struct firmware_priv {
95 struct completion completion;
96 struct firmware *fw;
97 unsigned long status;
98 struct page **pages;
99 int nr_pages;
100 int page_array_size;
101 struct timer_list timeout;
102 struct device dev;
103 bool nowait;
104 char fw_id[];
105};
106
107static struct firmware_priv *to_firmware_priv(struct device *dev)
108{
109 return container_of(dev, struct firmware_priv, dev);
110}
111
112static void fw_load_abort(struct firmware_priv *fw_priv)
113{
114 set_bit(FW_STATUS_ABORT, &fw_priv->status);
115 wmb();
116 complete(&fw_priv->completion);
117}
118
119static ssize_t firmware_timeout_show(struct class *class,
120 struct class_attribute *attr,
121 char *buf)
122{
123 return sprintf(buf, "%d\n", loading_timeout);
124}
125
126/**
127 * firmware_timeout_store - set number of seconds to wait for firmware
128 * @class: device class pointer
129 * @attr: device attribute pointer
130 * @buf: buffer to scan for timeout value
131 * @count: number of bytes in @buf
132 *
133 * Sets the number of seconds to wait for the firmware. Once
134 * this expires an error will be returned to the driver and no
135 * firmware will be provided.
136 *
137 * Note: zero means 'wait forever'.
138 **/
139static ssize_t firmware_timeout_store(struct class *class,
140 struct class_attribute *attr,
141 const char *buf, size_t count)
142{
143 loading_timeout = simple_strtol(buf, NULL, 10);
144 if (loading_timeout < 0)
145 loading_timeout = 0;
146
147 return count;
148}
149
150static struct class_attribute firmware_class_attrs[] = {
151 __ATTR(timeout, S_IWUSR | S_IRUGO,
152 firmware_timeout_show, firmware_timeout_store),
153 __ATTR_NULL
154};
155
156static void fw_dev_release(struct device *dev)
157{
158 struct firmware_priv *fw_priv = to_firmware_priv(dev);
159 int i;
160
161 for (i = 0; i < fw_priv->nr_pages; i++)
162 __free_page(fw_priv->pages[i]);
163 kfree(fw_priv->pages);
164 kfree(fw_priv);
165
166 module_put(THIS_MODULE);
167}
168
169static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
170{
171 struct firmware_priv *fw_priv = to_firmware_priv(dev);
172
173 if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
174 return -ENOMEM;
175 if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
176 return -ENOMEM;
177 if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
178 return -ENOMEM;
179
180 return 0;
181}
182
183static struct class firmware_class = {
184 .name = "firmware",
185 .class_attrs = firmware_class_attrs,
186 .dev_uevent = firmware_uevent,
187 .dev_release = fw_dev_release,
188};
189
190static ssize_t firmware_loading_show(struct device *dev,
191 struct device_attribute *attr, char *buf)
192{
193 struct firmware_priv *fw_priv = to_firmware_priv(dev);
194 int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
195
196 return sprintf(buf, "%d\n", loading);
197}
198
199static void firmware_free_data(const struct firmware *fw)
200{
201 int i;
202 vunmap(fw->data);
203 if (fw->pages) {
204 for (i = 0; i < PFN_UP(fw->size); i++)
205 __free_page(fw->pages[i]);
206 kfree(fw->pages);
207 }
208}
209
210/* Some architectures don't have PAGE_KERNEL_RO */
211#ifndef PAGE_KERNEL_RO
212#define PAGE_KERNEL_RO PAGE_KERNEL
213#endif
214/**
215 * firmware_loading_store - set value in the 'loading' control file
216 * @dev: device pointer
217 * @attr: device attribute pointer
218 * @buf: buffer to scan for loading control value
219 * @count: number of bytes in @buf
220 *
221 * The relevant values are:
222 *
223 * 1: Start a load, discarding any previous partial load.
224 * 0: Conclude the load and hand the data to the driver code.
225 * -1: Conclude the load with an error and discard any written data.
226 **/
227static ssize_t firmware_loading_store(struct device *dev,
228 struct device_attribute *attr,
229 const char *buf, size_t count)
230{
231 struct firmware_priv *fw_priv = to_firmware_priv(dev);
232 int loading = simple_strtol(buf, NULL, 10);
233 int i;
234
235 mutex_lock(&fw_lock);
236
237 if (!fw_priv->fw)
238 goto out;
239
240 switch (loading) {
241 case 1:
242 firmware_free_data(fw_priv->fw);
243 memset(fw_priv->fw, 0, sizeof(struct firmware));
244 /* If the pages are not owned by 'struct firmware' */
245 for (i = 0; i < fw_priv->nr_pages; i++)
246 __free_page(fw_priv->pages[i]);
247 kfree(fw_priv->pages);
248 fw_priv->pages = NULL;
249 fw_priv->page_array_size = 0;
250 fw_priv->nr_pages = 0;
251 set_bit(FW_STATUS_LOADING, &fw_priv->status);
252 break;
253 case 0:
254 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
255 vunmap(fw_priv->fw->data);
256 fw_priv->fw->data = vmap(fw_priv->pages,
257 fw_priv->nr_pages,
258 0, PAGE_KERNEL_RO);
259 if (!fw_priv->fw->data) {
260 dev_err(dev, "%s: vmap() failed\n", __func__);
261 goto err;
262 }
263 /* Pages are now owned by 'struct firmware' */
264 fw_priv->fw->pages = fw_priv->pages;
265 fw_priv->pages = NULL;
266
267 fw_priv->page_array_size = 0;
268 fw_priv->nr_pages = 0;
269 complete(&fw_priv->completion);
270 clear_bit(FW_STATUS_LOADING, &fw_priv->status);
271 break;
272 }
273 /* fallthrough */
274 default:
275 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
276 /* fallthrough */
277 case -1:
278 err:
279 fw_load_abort(fw_priv);
280 break;
281 }
282out:
283 mutex_unlock(&fw_lock);
284 return count;
285}
286
287static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
288
289static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
290 struct bin_attribute *bin_attr,
291 char *buffer, loff_t offset, size_t count)
292{
293 struct device *dev = to_dev(kobj);
294 struct firmware_priv *fw_priv = to_firmware_priv(dev);
295 struct firmware *fw;
296 ssize_t ret_count;
297
298 mutex_lock(&fw_lock);
299 fw = fw_priv->fw;
300 if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
301 ret_count = -ENODEV;
302 goto out;
303 }
304 if (offset > fw->size) {
305 ret_count = 0;
306 goto out;
307 }
308 if (count > fw->size - offset)
309 count = fw->size - offset;
310
311 ret_count = count;
312
313 while (count) {
314 void *page_data;
315 int page_nr = offset >> PAGE_SHIFT;
316 int page_ofs = offset & (PAGE_SIZE-1);
317 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
318
319 page_data = kmap(fw_priv->pages[page_nr]);
320
321 memcpy(buffer, page_data + page_ofs, page_cnt);
322
323 kunmap(fw_priv->pages[page_nr]);
324 buffer += page_cnt;
325 offset += page_cnt;
326 count -= page_cnt;
327 }
328out:
329 mutex_unlock(&fw_lock);
330 return ret_count;
331}
332
333static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
334{
335 int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
336
337 /* If the array of pages is too small, grow it... */
338 if (fw_priv->page_array_size < pages_needed) {
339 int new_array_size = max(pages_needed,
340 fw_priv->page_array_size * 2);
341 struct page **new_pages;
342
343 new_pages = kmalloc(new_array_size * sizeof(void *),
344 GFP_KERNEL);
345 if (!new_pages) {
346 fw_load_abort(fw_priv);
347 return -ENOMEM;
348 }
349 memcpy(new_pages, fw_priv->pages,
350 fw_priv->page_array_size * sizeof(void *));
351 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
352 (new_array_size - fw_priv->page_array_size));
353 kfree(fw_priv->pages);
354 fw_priv->pages = new_pages;
355 fw_priv->page_array_size = new_array_size;
356 }
357
358 while (fw_priv->nr_pages < pages_needed) {
359 fw_priv->pages[fw_priv->nr_pages] =
360 alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
361
362 if (!fw_priv->pages[fw_priv->nr_pages]) {
363 fw_load_abort(fw_priv);
364 return -ENOMEM;
365 }
366 fw_priv->nr_pages++;
367 }
368 return 0;
369}
370
371/**
372 * firmware_data_write - write method for firmware
373 * @filp: open sysfs file
374 * @kobj: kobject for the device
375 * @bin_attr: bin_attr structure
376 * @buffer: buffer being written
377 * @offset: buffer offset for write in total data store area
378 * @count: buffer size
379 *
380 * Data written to the 'data' attribute will be later handed to
381 * the driver as a firmware image.
382 **/
383static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
384 struct bin_attribute *bin_attr,
385 char *buffer, loff_t offset, size_t count)
386{
387 struct device *dev = to_dev(kobj);
388 struct firmware_priv *fw_priv = to_firmware_priv(dev);
389 struct firmware *fw;
390 ssize_t retval;
391
392 if (!capable(CAP_SYS_RAWIO))
393 return -EPERM;
394
395 mutex_lock(&fw_lock);
396 fw = fw_priv->fw;
397 if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
398 retval = -ENODEV;
399 goto out;
400 }
401 retval = fw_realloc_buffer(fw_priv, offset + count);
402 if (retval)
403 goto out;
404
405 retval = count;
406
407 while (count) {
408 void *page_data;
409 int page_nr = offset >> PAGE_SHIFT;
410 int page_ofs = offset & (PAGE_SIZE - 1);
411 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
412
413 page_data = kmap(fw_priv->pages[page_nr]);
414
415 memcpy(page_data + page_ofs, buffer, page_cnt);
416
417 kunmap(fw_priv->pages[page_nr]);
418 buffer += page_cnt;
419 offset += page_cnt;
420 count -= page_cnt;
421 }
422
423 fw->size = max_t(size_t, offset, fw->size);
424out:
425 mutex_unlock(&fw_lock);
426 return retval;
427}
428
429static struct bin_attribute firmware_attr_data = {
430 .attr = { .name = "data", .mode = 0644 },
431 .size = 0,
432 .read = firmware_data_read,
433 .write = firmware_data_write,
434};
435
436static void firmware_class_timeout(u_long data)
437{
438 struct firmware_priv *fw_priv = (struct firmware_priv *) data;
439
440 fw_load_abort(fw_priv);
441}
442
443static struct firmware_priv *
444fw_create_instance(struct firmware *firmware, const char *fw_name,
445 struct device *device, bool uevent, bool nowait)
446{
447 struct firmware_priv *fw_priv;
448 struct device *f_dev;
449
450 fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
451 if (!fw_priv) {
452 dev_err(device, "%s: kmalloc failed\n", __func__);
453 return ERR_PTR(-ENOMEM);
454 }
455
456 fw_priv->fw = firmware;
457 fw_priv->nowait = nowait;
458 strcpy(fw_priv->fw_id, fw_name);
459 init_completion(&fw_priv->completion);
460 setup_timer(&fw_priv->timeout,
461 firmware_class_timeout, (u_long) fw_priv);
462
463 f_dev = &fw_priv->dev;
464
465 device_initialize(f_dev);
466 dev_set_name(f_dev, "%s", dev_name(device));
467 f_dev->parent = device;
468 f_dev->class = &firmware_class;
469
470 return fw_priv;
471}
472
473static struct firmware_priv *
474_request_firmware_prepare(const struct firmware **firmware_p, const char *name,
475 struct device *device, bool uevent, bool nowait)
476{
477 struct firmware *firmware;
478 struct firmware_priv *fw_priv;
479
480 if (!firmware_p)
481 return ERR_PTR(-EINVAL);
482
483 *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
484 if (!firmware) {
485 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
486 __func__);
487 return ERR_PTR(-ENOMEM);
488 }
489
490 if (fw_get_builtin_firmware(firmware, name)) {
491 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
492 return NULL;
493 }
494
495 fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
496 if (IS_ERR(fw_priv)) {
497 release_firmware(firmware);
498 *firmware_p = NULL;
499 }
500 return fw_priv;
501}
502
503static void _request_firmware_cleanup(const struct firmware **firmware_p)
504{
505 release_firmware(*firmware_p);
506 *firmware_p = NULL;
507}
508
509static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
510 long timeout)
511{
512 int retval = 0;
513 struct device *f_dev = &fw_priv->dev;
514
515 dev_set_uevent_suppress(f_dev, true);
516
517 /* Need to pin this module until class device is destroyed */
518 __module_get(THIS_MODULE);
519
520 retval = device_add(f_dev);
521 if (retval) {
522 dev_err(f_dev, "%s: device_register failed\n", __func__);
523 goto err_put_dev;
524 }
525
526 retval = device_create_bin_file(f_dev, &firmware_attr_data);
527 if (retval) {
528 dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
529 goto err_del_dev;
530 }
531
532 retval = device_create_file(f_dev, &dev_attr_loading);
533 if (retval) {
534 dev_err(f_dev, "%s: device_create_file failed\n", __func__);
535 goto err_del_bin_attr;
536 }
537
538 if (uevent) {
539 dev_set_uevent_suppress(f_dev, false);
540 dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_id);
541 if (timeout != MAX_SCHEDULE_TIMEOUT)
542 mod_timer(&fw_priv->timeout,
543 round_jiffies_up(jiffies + timeout));
544
545 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
546 }
547
548 wait_for_completion(&fw_priv->completion);
549
550 set_bit(FW_STATUS_DONE, &fw_priv->status);
551 del_timer_sync(&fw_priv->timeout);
552
553 mutex_lock(&fw_lock);
554 if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status))
555 retval = -ENOENT;
556 fw_priv->fw = NULL;
557 mutex_unlock(&fw_lock);
558
559 device_remove_file(f_dev, &dev_attr_loading);
560err_del_bin_attr:
561 device_remove_bin_file(f_dev, &firmware_attr_data);
562err_del_dev:
563 device_del(f_dev);
564err_put_dev:
565 put_device(f_dev);
566 return retval;
567}
568
569/**
570 * request_firmware: - send firmware request and wait for it
571 * @firmware_p: pointer to firmware image
572 * @name: name of firmware file
573 * @device: device for which firmware is being loaded
574 *
575 * @firmware_p will be used to return a firmware image by the name
576 * of @name for device @device.
577 *
578 * Should be called from user context where sleeping is allowed.
579 *
580 * @name will be used as $FIRMWARE in the uevent environment and
581 * should be distinctive enough not to be confused with any other
582 * firmware image for this or any other device.
583 **/
584int
585request_firmware(const struct firmware **firmware_p, const char *name,
586 struct device *device)
587{
588 struct firmware_priv *fw_priv;
589 int ret;
590
591 fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
592 false);
593 if (IS_ERR_OR_NULL(fw_priv))
594 return PTR_RET(fw_priv);
595
596 ret = usermodehelper_read_trylock();
597 if (WARN_ON(ret)) {
598 dev_err(device, "firmware: %s will not be loaded\n", name);
599 } else {
600 ret = _request_firmware_load(fw_priv, true,
601 firmware_loading_timeout());
602 usermodehelper_read_unlock();
603 }
604 if (ret)
605 _request_firmware_cleanup(firmware_p);
606
607 return ret;
608}
609
610/**
611 * release_firmware: - release the resource associated with a firmware image
612 * @fw: firmware resource to release
613 **/
614void release_firmware(const struct firmware *fw)
615{
616 if (fw) {
617 if (!fw_is_builtin_firmware(fw))
618 firmware_free_data(fw);
619 kfree(fw);
620 }
621}
622
623/* Async support */
624struct firmware_work {
625 struct work_struct work;
626 struct module *module;
627 const char *name;
628 struct device *device;
629 void *context;
630 void (*cont)(const struct firmware *fw, void *context);
631 bool uevent;
632};
633
634static void request_firmware_work_func(struct work_struct *work)
635{
636 struct firmware_work *fw_work;
637 const struct firmware *fw;
638 struct firmware_priv *fw_priv;
639 long timeout;
640 int ret;
641
642 fw_work = container_of(work, struct firmware_work, work);
643 fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
644 fw_work->uevent, true);
645 if (IS_ERR_OR_NULL(fw_priv)) {
646 ret = PTR_RET(fw_priv);
647 goto out;
648 }
649
650 timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
651 if (timeout) {
652 ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout);
653 usermodehelper_read_unlock();
654 } else {
655 dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
656 fw_work->name);
657 ret = -EAGAIN;
658 }
659 if (ret)
660 _request_firmware_cleanup(&fw);
661
662 out:
663 fw_work->cont(fw, fw_work->context);
664
665 module_put(fw_work->module);
666 kfree(fw_work);
667}
668
669/**
670 * request_firmware_nowait - asynchronous version of request_firmware
671 * @module: module requesting the firmware
672 * @uevent: sends uevent to copy the firmware image if this flag
673 * is non-zero else the firmware copy must be done manually.
674 * @name: name of firmware file
675 * @device: device for which firmware is being loaded
676 * @gfp: allocation flags
677 * @context: will be passed over to @cont, and
678 * @fw may be %NULL if firmware request fails.
679 * @cont: function will be called asynchronously when the firmware
680 * request is over.
681 *
682 * Asynchronous variant of request_firmware() for user contexts where
683 * it is not possible to sleep for long time. It can't be called
684 * in atomic contexts.
685 **/
686int
687request_firmware_nowait(
688 struct module *module, bool uevent,
689 const char *name, struct device *device, gfp_t gfp, void *context,
690 void (*cont)(const struct firmware *fw, void *context))
691{
692 struct firmware_work *fw_work;
693
694 fw_work = kzalloc(sizeof (struct firmware_work), gfp);
695 if (!fw_work)
696 return -ENOMEM;
697
698 fw_work->module = module;
699 fw_work->name = name;
700 fw_work->device = device;
701 fw_work->context = context;
702 fw_work->cont = cont;
703 fw_work->uevent = uevent;
704
705 if (!try_module_get(module)) {
706 kfree(fw_work);
707 return -EFAULT;
708 }
709
710 INIT_WORK(&fw_work->work, request_firmware_work_func);
711 schedule_work(&fw_work->work);
712 return 0;
713}
714
715static int __init firmware_class_init(void)
716{
717 return class_register(&firmware_class);
718}
719
720static void __exit firmware_class_exit(void)
721{
722 class_unregister(&firmware_class);
723}
724
725fs_initcall(firmware_class_init);
726module_exit(firmware_class_exit);
727
728EXPORT_SYMBOL(release_firmware);
729EXPORT_SYMBOL(request_firmware);
730EXPORT_SYMBOL(request_firmware_nowait);