7376367bcb8053dec4951945f916d47c882fd59a
[linux-2.6.git] / drivers / base / firmware_class.c
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/kthread.h>
20 #include <linux/highmem.h>
21 #include <linux/firmware.h>
22 #include "base.h"
23
24 #define to_dev(obj) container_of(obj, struct device, kobj)
25
26 MODULE_AUTHOR("Manuel Estrada Sainz");
27 MODULE_DESCRIPTION("Multi purpose firmware loading support");
28 MODULE_LICENSE("GPL");
29
30 enum {
31         FW_STATUS_LOADING,
32         FW_STATUS_DONE,
33         FW_STATUS_ABORT,
34 };
35
36 static int loading_timeout = 60;        /* In seconds */
37
38 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
39  * guarding for corner cases a global lock should be OK */
40 static DEFINE_MUTEX(fw_lock);
41
42 struct firmware_priv {
43         char *fw_id;
44         struct completion completion;
45         struct bin_attribute attr_data;
46         struct firmware *fw;
47         unsigned long status;
48         struct page **pages;
49         int nr_pages;
50         int page_array_size;
51         const char *vdata;
52         struct timer_list timeout;
53 };
54
55 #ifdef CONFIG_FW_LOADER
56 extern struct builtin_fw __start_builtin_fw[];
57 extern struct builtin_fw __end_builtin_fw[];
58 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
59 static struct builtin_fw *__start_builtin_fw;
60 static struct builtin_fw *__end_builtin_fw;
61 #endif
62
63 static void
64 fw_load_abort(struct firmware_priv *fw_priv)
65 {
66         set_bit(FW_STATUS_ABORT, &fw_priv->status);
67         wmb();
68         complete(&fw_priv->completion);
69 }
70
71 static ssize_t
72 firmware_timeout_show(struct class *class, char *buf)
73 {
74         return sprintf(buf, "%d\n", loading_timeout);
75 }
76
77 /**
78  * firmware_timeout_store - set number of seconds to wait for firmware
79  * @class: device class pointer
80  * @buf: buffer to scan for timeout value
81  * @count: number of bytes in @buf
82  *
83  *      Sets the number of seconds to wait for the firmware.  Once
84  *      this expires an error will be returned to the driver and no
85  *      firmware will be provided.
86  *
87  *      Note: zero means 'wait forever'.
88  **/
89 static ssize_t
90 firmware_timeout_store(struct class *class, const char *buf, size_t count)
91 {
92         loading_timeout = simple_strtol(buf, NULL, 10);
93         if (loading_timeout < 0)
94                 loading_timeout = 0;
95         return count;
96 }
97
98 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
99
100 static void fw_dev_release(struct device *dev);
101
102 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
103 {
104         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
105
106         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
107                 return -ENOMEM;
108         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
109                 return -ENOMEM;
110
111         return 0;
112 }
113
114 static struct class firmware_class = {
115         .name           = "firmware",
116         .dev_uevent     = firmware_uevent,
117         .dev_release    = fw_dev_release,
118 };
119
120 static ssize_t firmware_loading_show(struct device *dev,
121                                      struct device_attribute *attr, char *buf)
122 {
123         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
124         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
125         return sprintf(buf, "%d\n", loading);
126 }
127
128 /* Some architectures don't have PAGE_KERNEL_RO */
129 #ifndef PAGE_KERNEL_RO
130 #define PAGE_KERNEL_RO PAGE_KERNEL
131 #endif
132 /**
133  * firmware_loading_store - set value in the 'loading' control file
134  * @dev: device pointer
135  * @attr: device attribute pointer
136  * @buf: buffer to scan for loading control value
137  * @count: number of bytes in @buf
138  *
139  *      The relevant values are:
140  *
141  *       1: Start a load, discarding any previous partial load.
142  *       0: Conclude the load and hand the data to the driver code.
143  *      -1: Conclude the load with an error and discard any written data.
144  **/
145 static ssize_t firmware_loading_store(struct device *dev,
146                                       struct device_attribute *attr,
147                                       const char *buf, size_t count)
148 {
149         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
150         int loading = simple_strtol(buf, NULL, 10);
151         int i;
152
153         switch (loading) {
154         case 1:
155                 mutex_lock(&fw_lock);
156                 if (!fw_priv->fw) {
157                         mutex_unlock(&fw_lock);
158                         break;
159                 }
160                 vfree(fw_priv->fw->data);
161                 fw_priv->fw->data = NULL;
162                 for (i = 0; i < fw_priv->nr_pages; i++)
163                         __free_page(fw_priv->pages[i]);
164                 kfree(fw_priv->pages);
165                 fw_priv->pages = NULL;
166                 fw_priv->page_array_size = 0;
167                 fw_priv->nr_pages = 0;
168                 fw_priv->fw->size = 0;
169                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
170                 mutex_unlock(&fw_lock);
171                 break;
172         case 0:
173                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
174                         vfree(fw_priv->fw->data);
175                         fw_priv->fw->data = vmap(fw_priv->pages,
176                                                  fw_priv->nr_pages,
177                                                  0, PAGE_KERNEL_RO);
178                         if (!fw_priv->fw->data) {
179                                 dev_err(dev, "%s: vmap() failed\n", __func__);
180                                 goto err;
181                         }
182                         /* Pages will be freed by vfree() */
183                         fw_priv->page_array_size = 0;
184                         fw_priv->nr_pages = 0;
185                         complete(&fw_priv->completion);
186                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
187                         break;
188                 }
189                 /* fallthrough */
190         default:
191                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
192                 /* fallthrough */
193         case -1:
194         err:
195                 fw_load_abort(fw_priv);
196                 break;
197         }
198
199         return count;
200 }
201
202 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
203
204 static ssize_t
205 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
206                    char *buffer, loff_t offset, size_t count)
207 {
208         struct device *dev = to_dev(kobj);
209         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
210         struct firmware *fw;
211         ssize_t ret_count;
212
213         mutex_lock(&fw_lock);
214         fw = fw_priv->fw;
215         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
216                 ret_count = -ENODEV;
217                 goto out;
218         }
219         if (offset > fw->size) {
220                 ret_count = 0;
221                 goto out;
222         }
223         if (count > fw->size - offset)
224                 count = fw->size - offset;
225
226         ret_count = count;
227
228         while (count) {
229                 void *page_data;
230                 int page_nr = offset >> PAGE_SHIFT;
231                 int page_ofs = offset & (PAGE_SIZE-1);
232                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
233
234                 page_data = kmap(fw_priv->pages[page_nr]);
235
236                 memcpy(buffer, page_data + page_ofs, page_cnt);
237
238                 kunmap(fw_priv->pages[page_nr]);
239                 buffer += page_cnt;
240                 offset += page_cnt;
241                 count -= page_cnt;
242         }
243 out:
244         mutex_unlock(&fw_lock);
245         return ret_count;
246 }
247
248 static int
249 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
250 {
251         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
252
253         /* If the array of pages is too small, grow it... */
254         if (fw_priv->page_array_size < pages_needed) {
255                 int new_array_size = max(pages_needed,
256                                          fw_priv->page_array_size * 2);
257                 struct page **new_pages;
258
259                 new_pages = kmalloc(new_array_size * sizeof(void *),
260                                     GFP_KERNEL);
261                 if (!new_pages) {
262                         fw_load_abort(fw_priv);
263                         return -ENOMEM;
264                 }
265                 memcpy(new_pages, fw_priv->pages,
266                        fw_priv->page_array_size * sizeof(void *));
267                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
268                        (new_array_size - fw_priv->page_array_size));
269                 kfree(fw_priv->pages);
270                 fw_priv->pages = new_pages;
271                 fw_priv->page_array_size = new_array_size;
272         }
273
274         while (fw_priv->nr_pages < pages_needed) {
275                 fw_priv->pages[fw_priv->nr_pages] =
276                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
277
278                 if (!fw_priv->pages[fw_priv->nr_pages]) {
279                         fw_load_abort(fw_priv);
280                         return -ENOMEM;
281                 }
282                 fw_priv->nr_pages++;
283         }
284         return 0;
285 }
286
287 /**
288  * firmware_data_write - write method for firmware
289  * @kobj: kobject for the device
290  * @bin_attr: bin_attr structure
291  * @buffer: buffer being written
292  * @offset: buffer offset for write in total data store area
293  * @count: buffer size
294  *
295  *      Data written to the 'data' attribute will be later handed to
296  *      the driver as a firmware image.
297  **/
298 static ssize_t
299 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
300                     char *buffer, loff_t offset, size_t count)
301 {
302         struct device *dev = to_dev(kobj);
303         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
304         struct firmware *fw;
305         ssize_t retval;
306
307         if (!capable(CAP_SYS_RAWIO))
308                 return -EPERM;
309
310         mutex_lock(&fw_lock);
311         fw = fw_priv->fw;
312         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
313                 retval = -ENODEV;
314                 goto out;
315         }
316         retval = fw_realloc_buffer(fw_priv, offset + count);
317         if (retval)
318                 goto out;
319
320         retval = count;
321
322         while (count) {
323                 void *page_data;
324                 int page_nr = offset >> PAGE_SHIFT;
325                 int page_ofs = offset & (PAGE_SIZE - 1);
326                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
327
328                 page_data = kmap(fw_priv->pages[page_nr]);
329
330                 memcpy(page_data + page_ofs, buffer, page_cnt);
331
332                 kunmap(fw_priv->pages[page_nr]);
333                 buffer += page_cnt;
334                 offset += page_cnt;
335                 count -= page_cnt;
336         }
337
338         fw->size = max_t(size_t, offset, fw->size);
339 out:
340         mutex_unlock(&fw_lock);
341         return retval;
342 }
343
344 static struct bin_attribute firmware_attr_data_tmpl = {
345         .attr = {.name = "data", .mode = 0644},
346         .size = 0,
347         .read = firmware_data_read,
348         .write = firmware_data_write,
349 };
350
351 static void fw_dev_release(struct device *dev)
352 {
353         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
354         int i;
355
356         for (i = 0; i < fw_priv->nr_pages; i++)
357                 __free_page(fw_priv->pages[i]);
358         kfree(fw_priv->pages);
359         kfree(fw_priv->fw_id);
360         kfree(fw_priv);
361         kfree(dev);
362
363         module_put(THIS_MODULE);
364 }
365
366 static void
367 firmware_class_timeout(u_long data)
368 {
369         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
370         fw_load_abort(fw_priv);
371 }
372
373 static int fw_register_device(struct device **dev_p, const char *fw_name,
374                               struct device *device)
375 {
376         int retval;
377         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
378                                                 GFP_KERNEL);
379         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
380
381         *dev_p = NULL;
382
383         if (!fw_priv || !f_dev) {
384                 dev_err(device, "%s: kmalloc failed\n", __func__);
385                 retval = -ENOMEM;
386                 goto error_kfree;
387         }
388
389         init_completion(&fw_priv->completion);
390         fw_priv->attr_data = firmware_attr_data_tmpl;
391         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
392         if (!fw_priv->fw_id) {
393                 dev_err(device, "%s: Firmware name allocation failed\n",
394                         __func__);
395                 retval = -ENOMEM;
396                 goto error_kfree;
397         }
398
399         fw_priv->timeout.function = firmware_class_timeout;
400         fw_priv->timeout.data = (u_long) fw_priv;
401         init_timer(&fw_priv->timeout);
402
403         dev_set_name(f_dev, "%s", dev_name(device));
404         f_dev->parent = device;
405         f_dev->class = &firmware_class;
406         dev_set_drvdata(f_dev, fw_priv);
407         dev_set_uevent_suppress(f_dev, 1);
408         retval = device_register(f_dev);
409         if (retval) {
410                 dev_err(device, "%s: device_register failed\n", __func__);
411                 put_device(f_dev);
412                 return retval;
413         }
414         *dev_p = f_dev;
415         return 0;
416
417 error_kfree:
418         kfree(f_dev);
419         kfree(fw_priv);
420         return retval;
421 }
422
423 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
424                            const char *fw_name, struct device *device,
425                            int uevent)
426 {
427         struct device *f_dev;
428         struct firmware_priv *fw_priv;
429         int retval;
430
431         *dev_p = NULL;
432         retval = fw_register_device(&f_dev, fw_name, device);
433         if (retval)
434                 goto out;
435
436         /* Need to pin this module until class device is destroyed */
437         __module_get(THIS_MODULE);
438
439         fw_priv = dev_get_drvdata(f_dev);
440
441         fw_priv->fw = fw;
442         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
443         if (retval) {
444                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
445                 goto error_unreg;
446         }
447
448         retval = device_create_file(f_dev, &dev_attr_loading);
449         if (retval) {
450                 dev_err(device, "%s: device_create_file failed\n", __func__);
451                 goto error_unreg;
452         }
453
454         if (uevent)
455                 dev_set_uevent_suppress(f_dev, 0);
456         *dev_p = f_dev;
457         goto out;
458
459 error_unreg:
460         device_unregister(f_dev);
461 out:
462         return retval;
463 }
464
465 static int
466 _request_firmware(const struct firmware **firmware_p, const char *name,
467                  struct device *device, int uevent)
468 {
469         struct device *f_dev;
470         struct firmware_priv *fw_priv;
471         struct firmware *firmware;
472         struct builtin_fw *builtin;
473         int retval;
474
475         if (!firmware_p)
476                 return -EINVAL;
477
478         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
479         if (!firmware) {
480                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
481                         __func__);
482                 retval = -ENOMEM;
483                 goto out;
484         }
485
486         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
487              builtin++) {
488                 if (strcmp(name, builtin->name))
489                         continue;
490                 dev_info(device, "firmware: using built-in firmware %s\n",
491                          name);
492                 firmware->size = builtin->size;
493                 firmware->data = builtin->data;
494                 return 0;
495         }
496
497         if (uevent)
498                 dev_info(device, "firmware: requesting %s\n", name);
499
500         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
501         if (retval)
502                 goto error_kfree_fw;
503
504         fw_priv = dev_get_drvdata(f_dev);
505
506         if (uevent) {
507                 if (loading_timeout > 0) {
508                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
509                         add_timer(&fw_priv->timeout);
510                 }
511
512                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
513                 wait_for_completion(&fw_priv->completion);
514                 set_bit(FW_STATUS_DONE, &fw_priv->status);
515                 del_timer_sync(&fw_priv->timeout);
516         } else
517                 wait_for_completion(&fw_priv->completion);
518
519         mutex_lock(&fw_lock);
520         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
521                 retval = -ENOENT;
522                 release_firmware(fw_priv->fw);
523                 *firmware_p = NULL;
524         }
525         fw_priv->fw = NULL;
526         mutex_unlock(&fw_lock);
527         device_unregister(f_dev);
528         goto out;
529
530 error_kfree_fw:
531         kfree(firmware);
532         *firmware_p = NULL;
533 out:
534         return retval;
535 }
536
537 /**
538  * request_firmware: - send firmware request and wait for it
539  * @firmware_p: pointer to firmware image
540  * @name: name of firmware file
541  * @device: device for which firmware is being loaded
542  *
543  *      @firmware_p will be used to return a firmware image by the name
544  *      of @name for device @device.
545  *
546  *      Should be called from user context where sleeping is allowed.
547  *
548  *      @name will be used as $FIRMWARE in the uevent environment and
549  *      should be distinctive enough not to be confused with any other
550  *      firmware image for this or any other device.
551  **/
552 int
553 request_firmware(const struct firmware **firmware_p, const char *name,
554                  struct device *device)
555 {
556         int uevent = 1;
557         return _request_firmware(firmware_p, name, device, uevent);
558 }
559
560 /**
561  * release_firmware: - release the resource associated with a firmware image
562  * @fw: firmware resource to release
563  **/
564 void
565 release_firmware(const struct firmware *fw)
566 {
567         struct builtin_fw *builtin;
568
569         if (fw) {
570                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
571                      builtin++) {
572                         if (fw->data == builtin->data)
573                                 goto free_fw;
574                 }
575                 vfree(fw->data);
576         free_fw:
577                 kfree(fw);
578         }
579 }
580
581 /* Async support */
582 struct firmware_work {
583         struct work_struct work;
584         struct module *module;
585         const char *name;
586         struct device *device;
587         void *context;
588         void (*cont)(const struct firmware *fw, void *context);
589         int uevent;
590 };
591
592 static int
593 request_firmware_work_func(void *arg)
594 {
595         struct firmware_work *fw_work = arg;
596         const struct firmware *fw;
597         int ret;
598         if (!arg) {
599                 WARN_ON(1);
600                 return 0;
601         }
602         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
603                 fw_work->uevent);
604         if (ret < 0)
605                 fw_work->cont(NULL, fw_work->context);
606         else {
607                 fw_work->cont(fw, fw_work->context);
608                 release_firmware(fw);
609         }
610         module_put(fw_work->module);
611         kfree(fw_work);
612         return ret;
613 }
614
615 /**
616  * request_firmware_nowait: asynchronous version of request_firmware
617  * @module: module requesting the firmware
618  * @uevent: sends uevent to copy the firmware image if this flag
619  *      is non-zero else the firmware copy must be done manually.
620  * @name: name of firmware file
621  * @device: device for which firmware is being loaded
622  * @context: will be passed over to @cont, and
623  *      @fw may be %NULL if firmware request fails.
624  * @cont: function will be called asynchronously when the firmware
625  *      request is over.
626  *
627  *      Asynchronous variant of request_firmware() for user contexts where
628  *      it is not possible to sleep for long time. It can't be called
629  *      in atomic contexts.
630  **/
631 int
632 request_firmware_nowait(
633         struct module *module, int uevent,
634         const char *name, struct device *device, void *context,
635         void (*cont)(const struct firmware *fw, void *context))
636 {
637         struct task_struct *task;
638         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
639                                                 GFP_ATOMIC);
640
641         if (!fw_work)
642                 return -ENOMEM;
643         if (!try_module_get(module)) {
644                 kfree(fw_work);
645                 return -EFAULT;
646         }
647
648         *fw_work = (struct firmware_work) {
649                 .module = module,
650                 .name = name,
651                 .device = device,
652                 .context = context,
653                 .cont = cont,
654                 .uevent = uevent,
655         };
656
657         task = kthread_run(request_firmware_work_func, fw_work,
658                             "firmware/%s", name);
659
660         if (IS_ERR(task)) {
661                 fw_work->cont(NULL, fw_work->context);
662                 module_put(fw_work->module);
663                 kfree(fw_work);
664                 return PTR_ERR(task);
665         }
666         return 0;
667 }
668
669 static int __init
670 firmware_class_init(void)
671 {
672         int error;
673         error = class_register(&firmware_class);
674         if (error) {
675                 printk(KERN_ERR "%s: class_register failed\n", __func__);
676                 return error;
677         }
678         error = class_create_file(&firmware_class, &class_attr_timeout);
679         if (error) {
680                 printk(KERN_ERR "%s: class_create_file failed\n",
681                        __func__);
682                 class_unregister(&firmware_class);
683         }
684         return error;
685
686 }
687 static void __exit
688 firmware_class_exit(void)
689 {
690         class_unregister(&firmware_class);
691 }
692
693 fs_initcall(firmware_class_init);
694 module_exit(firmware_class_exit);
695
696 EXPORT_SYMBOL(release_firmware);
697 EXPORT_SYMBOL(request_firmware);
698 EXPORT_SYMBOL(request_firmware_nowait);