d45d1e1c40a4fab88a4283f146885cfab41601c8
[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 <linux/slab.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         bool nowait;
54 };
55
56 #ifdef CONFIG_FW_LOADER
57 extern struct builtin_fw __start_builtin_fw[];
58 extern struct builtin_fw __end_builtin_fw[];
59 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
60 static struct builtin_fw *__start_builtin_fw;
61 static struct builtin_fw *__end_builtin_fw;
62 #endif
63
64 static void
65 fw_load_abort(struct firmware_priv *fw_priv)
66 {
67         set_bit(FW_STATUS_ABORT, &fw_priv->status);
68         wmb();
69         complete(&fw_priv->completion);
70 }
71
72 static ssize_t
73 firmware_timeout_show(struct class *class,
74                       struct class_attribute *attr,
75                       char *buf)
76 {
77         return sprintf(buf, "%d\n", loading_timeout);
78 }
79
80 /**
81  * firmware_timeout_store - set number of seconds to wait for firmware
82  * @class: device class pointer
83  * @attr: device attribute pointer
84  * @buf: buffer to scan for timeout value
85  * @count: number of bytes in @buf
86  *
87  *      Sets the number of seconds to wait for the firmware.  Once
88  *      this expires an error will be returned to the driver and no
89  *      firmware will be provided.
90  *
91  *      Note: zero means 'wait forever'.
92  **/
93 static ssize_t
94 firmware_timeout_store(struct class *class,
95                         struct class_attribute *attr,
96                         const char *buf, size_t count)
97 {
98         loading_timeout = simple_strtol(buf, NULL, 10);
99         if (loading_timeout < 0)
100                 loading_timeout = 0;
101         return count;
102 }
103
104 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
105
106 static void fw_dev_release(struct device *dev);
107
108 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
109 {
110         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
111
112         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
113                 return -ENOMEM;
114         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
115                 return -ENOMEM;
116         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
117                 return -ENOMEM;
118
119         return 0;
120 }
121
122 static struct class firmware_class = {
123         .name           = "firmware",
124         .dev_uevent     = firmware_uevent,
125         .dev_release    = fw_dev_release,
126 };
127
128 static ssize_t firmware_loading_show(struct device *dev,
129                                      struct device_attribute *attr, char *buf)
130 {
131         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
132         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
133         return sprintf(buf, "%d\n", loading);
134 }
135
136 static void firmware_free_data(const struct firmware *fw)
137 {
138         int i;
139         vunmap(fw->data);
140         if (fw->pages) {
141                 for (i = 0; i < PFN_UP(fw->size); i++)
142                         __free_page(fw->pages[i]);
143                 kfree(fw->pages);
144         }
145 }
146
147 /* Some architectures don't have PAGE_KERNEL_RO */
148 #ifndef PAGE_KERNEL_RO
149 #define PAGE_KERNEL_RO PAGE_KERNEL
150 #endif
151 /**
152  * firmware_loading_store - set value in the 'loading' control file
153  * @dev: device pointer
154  * @attr: device attribute pointer
155  * @buf: buffer to scan for loading control value
156  * @count: number of bytes in @buf
157  *
158  *      The relevant values are:
159  *
160  *       1: Start a load, discarding any previous partial load.
161  *       0: Conclude the load and hand the data to the driver code.
162  *      -1: Conclude the load with an error and discard any written data.
163  **/
164 static ssize_t firmware_loading_store(struct device *dev,
165                                       struct device_attribute *attr,
166                                       const char *buf, size_t count)
167 {
168         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
169         int loading = simple_strtol(buf, NULL, 10);
170         int i;
171
172         switch (loading) {
173         case 1:
174                 mutex_lock(&fw_lock);
175                 if (!fw_priv->fw) {
176                         mutex_unlock(&fw_lock);
177                         break;
178                 }
179                 firmware_free_data(fw_priv->fw);
180                 memset(fw_priv->fw, 0, sizeof(struct firmware));
181                 /* If the pages are not owned by 'struct firmware' */
182                 for (i = 0; i < fw_priv->nr_pages; i++)
183                         __free_page(fw_priv->pages[i]);
184                 kfree(fw_priv->pages);
185                 fw_priv->pages = NULL;
186                 fw_priv->page_array_size = 0;
187                 fw_priv->nr_pages = 0;
188                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
189                 mutex_unlock(&fw_lock);
190                 break;
191         case 0:
192                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
193                         vunmap(fw_priv->fw->data);
194                         fw_priv->fw->data = vmap(fw_priv->pages,
195                                                  fw_priv->nr_pages,
196                                                  0, PAGE_KERNEL_RO);
197                         if (!fw_priv->fw->data) {
198                                 dev_err(dev, "%s: vmap() failed\n", __func__);
199                                 goto err;
200                         }
201                         /* Pages are now owned by 'struct firmware' */
202                         fw_priv->fw->pages = fw_priv->pages;
203                         fw_priv->pages = NULL;
204
205                         fw_priv->page_array_size = 0;
206                         fw_priv->nr_pages = 0;
207                         complete(&fw_priv->completion);
208                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
209                         break;
210                 }
211                 /* fallthrough */
212         default:
213                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
214                 /* fallthrough */
215         case -1:
216         err:
217                 fw_load_abort(fw_priv);
218                 break;
219         }
220
221         return count;
222 }
223
224 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
225
226 static ssize_t
227 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
228                    char *buffer, loff_t offset, size_t count)
229 {
230         struct device *dev = to_dev(kobj);
231         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
232         struct firmware *fw;
233         ssize_t ret_count;
234
235         mutex_lock(&fw_lock);
236         fw = fw_priv->fw;
237         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
238                 ret_count = -ENODEV;
239                 goto out;
240         }
241         if (offset > fw->size) {
242                 ret_count = 0;
243                 goto out;
244         }
245         if (count > fw->size - offset)
246                 count = fw->size - offset;
247
248         ret_count = count;
249
250         while (count) {
251                 void *page_data;
252                 int page_nr = offset >> PAGE_SHIFT;
253                 int page_ofs = offset & (PAGE_SIZE-1);
254                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
255
256                 page_data = kmap(fw_priv->pages[page_nr]);
257
258                 memcpy(buffer, page_data + page_ofs, page_cnt);
259
260                 kunmap(fw_priv->pages[page_nr]);
261                 buffer += page_cnt;
262                 offset += page_cnt;
263                 count -= page_cnt;
264         }
265 out:
266         mutex_unlock(&fw_lock);
267         return ret_count;
268 }
269
270 static int
271 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
272 {
273         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
274
275         /* If the array of pages is too small, grow it... */
276         if (fw_priv->page_array_size < pages_needed) {
277                 int new_array_size = max(pages_needed,
278                                          fw_priv->page_array_size * 2);
279                 struct page **new_pages;
280
281                 new_pages = kmalloc(new_array_size * sizeof(void *),
282                                     GFP_KERNEL);
283                 if (!new_pages) {
284                         fw_load_abort(fw_priv);
285                         return -ENOMEM;
286                 }
287                 memcpy(new_pages, fw_priv->pages,
288                        fw_priv->page_array_size * sizeof(void *));
289                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
290                        (new_array_size - fw_priv->page_array_size));
291                 kfree(fw_priv->pages);
292                 fw_priv->pages = new_pages;
293                 fw_priv->page_array_size = new_array_size;
294         }
295
296         while (fw_priv->nr_pages < pages_needed) {
297                 fw_priv->pages[fw_priv->nr_pages] =
298                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
299
300                 if (!fw_priv->pages[fw_priv->nr_pages]) {
301                         fw_load_abort(fw_priv);
302                         return -ENOMEM;
303                 }
304                 fw_priv->nr_pages++;
305         }
306         return 0;
307 }
308
309 /**
310  * firmware_data_write - write method for firmware
311  * @kobj: kobject for the device
312  * @bin_attr: bin_attr structure
313  * @buffer: buffer being written
314  * @offset: buffer offset for write in total data store area
315  * @count: buffer size
316  *
317  *      Data written to the 'data' attribute will be later handed to
318  *      the driver as a firmware image.
319  **/
320 static ssize_t
321 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
322                     char *buffer, loff_t offset, size_t count)
323 {
324         struct device *dev = to_dev(kobj);
325         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
326         struct firmware *fw;
327         ssize_t retval;
328
329         if (!capable(CAP_SYS_RAWIO))
330                 return -EPERM;
331
332         mutex_lock(&fw_lock);
333         fw = fw_priv->fw;
334         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
335                 retval = -ENODEV;
336                 goto out;
337         }
338         retval = fw_realloc_buffer(fw_priv, offset + count);
339         if (retval)
340                 goto out;
341
342         retval = count;
343
344         while (count) {
345                 void *page_data;
346                 int page_nr = offset >> PAGE_SHIFT;
347                 int page_ofs = offset & (PAGE_SIZE - 1);
348                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
349
350                 page_data = kmap(fw_priv->pages[page_nr]);
351
352                 memcpy(page_data + page_ofs, buffer, page_cnt);
353
354                 kunmap(fw_priv->pages[page_nr]);
355                 buffer += page_cnt;
356                 offset += page_cnt;
357                 count -= page_cnt;
358         }
359
360         fw->size = max_t(size_t, offset, fw->size);
361 out:
362         mutex_unlock(&fw_lock);
363         return retval;
364 }
365
366 static struct bin_attribute firmware_attr_data_tmpl = {
367         .attr = {.name = "data", .mode = 0644},
368         .size = 0,
369         .read = firmware_data_read,
370         .write = firmware_data_write,
371 };
372
373 static void fw_dev_release(struct device *dev)
374 {
375         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
376         int i;
377
378         for (i = 0; i < fw_priv->nr_pages; i++)
379                 __free_page(fw_priv->pages[i]);
380         kfree(fw_priv->pages);
381         kfree(fw_priv->fw_id);
382         kfree(fw_priv);
383         kfree(dev);
384
385         module_put(THIS_MODULE);
386 }
387
388 static void
389 firmware_class_timeout(u_long data)
390 {
391         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
392         fw_load_abort(fw_priv);
393 }
394
395 static int fw_register_device(struct device **dev_p, const char *fw_name,
396                               struct device *device)
397 {
398         int retval;
399         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
400                                                 GFP_KERNEL);
401         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
402
403         *dev_p = NULL;
404
405         if (!fw_priv || !f_dev) {
406                 dev_err(device, "%s: kmalloc failed\n", __func__);
407                 retval = -ENOMEM;
408                 goto error_kfree;
409         }
410
411         init_completion(&fw_priv->completion);
412         fw_priv->attr_data = firmware_attr_data_tmpl;
413         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
414         if (!fw_priv->fw_id) {
415                 dev_err(device, "%s: Firmware name allocation failed\n",
416                         __func__);
417                 retval = -ENOMEM;
418                 goto error_kfree;
419         }
420
421         fw_priv->timeout.function = firmware_class_timeout;
422         fw_priv->timeout.data = (u_long) fw_priv;
423         init_timer(&fw_priv->timeout);
424
425         dev_set_name(f_dev, "%s", dev_name(device));
426         f_dev->parent = device;
427         f_dev->class = &firmware_class;
428         dev_set_drvdata(f_dev, fw_priv);
429         dev_set_uevent_suppress(f_dev, 1);
430         retval = device_register(f_dev);
431         if (retval) {
432                 dev_err(device, "%s: device_register failed\n", __func__);
433                 put_device(f_dev);
434                 return retval;
435         }
436         *dev_p = f_dev;
437         return 0;
438
439 error_kfree:
440         kfree(f_dev);
441         kfree(fw_priv);
442         return retval;
443 }
444
445 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
446                            const char *fw_name, struct device *device,
447                            int uevent, bool nowait)
448 {
449         struct device *f_dev;
450         struct firmware_priv *fw_priv;
451         int retval;
452
453         *dev_p = NULL;
454         retval = fw_register_device(&f_dev, fw_name, device);
455         if (retval)
456                 goto out;
457
458         /* Need to pin this module until class device is destroyed */
459         __module_get(THIS_MODULE);
460
461         fw_priv = dev_get_drvdata(f_dev);
462
463         fw_priv->nowait = nowait;
464
465         fw_priv->fw = fw;
466         sysfs_bin_attr_init(&fw_priv->attr_data);
467         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
468         if (retval) {
469                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
470                 goto error_unreg;
471         }
472
473         retval = device_create_file(f_dev, &dev_attr_loading);
474         if (retval) {
475                 dev_err(device, "%s: device_create_file failed\n", __func__);
476                 goto error_unreg;
477         }
478
479         if (uevent)
480                 dev_set_uevent_suppress(f_dev, 0);
481         *dev_p = f_dev;
482         goto out;
483
484 error_unreg:
485         device_unregister(f_dev);
486 out:
487         return retval;
488 }
489
490 static int
491 _request_firmware(const struct firmware **firmware_p, const char *name,
492                  struct device *device, int uevent, bool nowait)
493 {
494         struct device *f_dev;
495         struct firmware_priv *fw_priv;
496         struct firmware *firmware;
497         struct builtin_fw *builtin;
498         int retval;
499
500         if (!firmware_p)
501                 return -EINVAL;
502
503         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
504         if (!firmware) {
505                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
506                         __func__);
507                 retval = -ENOMEM;
508                 goto out;
509         }
510
511         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
512              builtin++) {
513                 if (strcmp(name, builtin->name))
514                         continue;
515                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
516                 firmware->size = builtin->size;
517                 firmware->data = builtin->data;
518                 return 0;
519         }
520
521         if (uevent)
522                 dev_dbg(device, "firmware: requesting %s\n", name);
523
524         retval = fw_setup_device(firmware, &f_dev, name, device,
525                                  uevent, nowait);
526         if (retval)
527                 goto error_kfree_fw;
528
529         fw_priv = dev_get_drvdata(f_dev);
530
531         if (uevent) {
532                 if (loading_timeout > 0) {
533                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
534                         add_timer(&fw_priv->timeout);
535                 }
536
537                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
538                 wait_for_completion(&fw_priv->completion);
539                 set_bit(FW_STATUS_DONE, &fw_priv->status);
540                 del_timer_sync(&fw_priv->timeout);
541         } else
542                 wait_for_completion(&fw_priv->completion);
543
544         mutex_lock(&fw_lock);
545         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
546                 retval = -ENOENT;
547                 release_firmware(fw_priv->fw);
548                 *firmware_p = NULL;
549         }
550         fw_priv->fw = NULL;
551         mutex_unlock(&fw_lock);
552         device_unregister(f_dev);
553         goto out;
554
555 error_kfree_fw:
556         kfree(firmware);
557         *firmware_p = NULL;
558 out:
559         return retval;
560 }
561
562 /**
563  * request_firmware: - send firmware request and wait for it
564  * @firmware_p: pointer to firmware image
565  * @name: name of firmware file
566  * @device: device for which firmware is being loaded
567  *
568  *      @firmware_p will be used to return a firmware image by the name
569  *      of @name for device @device.
570  *
571  *      Should be called from user context where sleeping is allowed.
572  *
573  *      @name will be used as $FIRMWARE in the uevent environment and
574  *      should be distinctive enough not to be confused with any other
575  *      firmware image for this or any other device.
576  **/
577 int
578 request_firmware(const struct firmware **firmware_p, const char *name,
579                  struct device *device)
580 {
581         int uevent = 1;
582         return _request_firmware(firmware_p, name, device, uevent, false);
583 }
584
585 /**
586  * release_firmware: - release the resource associated with a firmware image
587  * @fw: firmware resource to release
588  **/
589 void
590 release_firmware(const struct firmware *fw)
591 {
592         struct builtin_fw *builtin;
593
594         if (fw) {
595                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
596                      builtin++) {
597                         if (fw->data == builtin->data)
598                                 goto free_fw;
599                 }
600                 firmware_free_data(fw);
601         free_fw:
602                 kfree(fw);
603         }
604 }
605
606 /* Async support */
607 struct firmware_work {
608         struct work_struct work;
609         struct module *module;
610         const char *name;
611         struct device *device;
612         void *context;
613         void (*cont)(const struct firmware *fw, void *context);
614         int uevent;
615 };
616
617 static int
618 request_firmware_work_func(void *arg)
619 {
620         struct firmware_work *fw_work = arg;
621         const struct firmware *fw;
622         int ret;
623         if (!arg) {
624                 WARN_ON(1);
625                 return 0;
626         }
627         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
628                 fw_work->uevent, true);
629
630         fw_work->cont(fw, fw_work->context);
631
632         module_put(fw_work->module);
633         kfree(fw_work);
634         return ret;
635 }
636
637 /**
638  * request_firmware_nowait - asynchronous version of request_firmware
639  * @module: module requesting the firmware
640  * @uevent: sends uevent to copy the firmware image if this flag
641  *      is non-zero else the firmware copy must be done manually.
642  * @name: name of firmware file
643  * @device: device for which firmware is being loaded
644  * @gfp: allocation flags
645  * @context: will be passed over to @cont, and
646  *      @fw may be %NULL if firmware request fails.
647  * @cont: function will be called asynchronously when the firmware
648  *      request is over.
649  *
650  *      Asynchronous variant of request_firmware() for user contexts where
651  *      it is not possible to sleep for long time. It can't be called
652  *      in atomic contexts.
653  **/
654 int
655 request_firmware_nowait(
656         struct module *module, int uevent,
657         const char *name, struct device *device, gfp_t gfp, void *context,
658         void (*cont)(const struct firmware *fw, void *context))
659 {
660         struct task_struct *task;
661         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
662                                                 gfp);
663
664         if (!fw_work)
665                 return -ENOMEM;
666         if (!try_module_get(module)) {
667                 kfree(fw_work);
668                 return -EFAULT;
669         }
670
671         *fw_work = (struct firmware_work) {
672                 .module = module,
673                 .name = name,
674                 .device = device,
675                 .context = context,
676                 .cont = cont,
677                 .uevent = uevent,
678         };
679
680         task = kthread_run(request_firmware_work_func, fw_work,
681                             "firmware/%s", name);
682
683         if (IS_ERR(task)) {
684                 fw_work->cont(NULL, fw_work->context);
685                 module_put(fw_work->module);
686                 kfree(fw_work);
687                 return PTR_ERR(task);
688         }
689         return 0;
690 }
691
692 static int __init
693 firmware_class_init(void)
694 {
695         int error;
696         error = class_register(&firmware_class);
697         if (error) {
698                 printk(KERN_ERR "%s: class_register failed\n", __func__);
699                 return error;
700         }
701         error = class_create_file(&firmware_class, &class_attr_timeout);
702         if (error) {
703                 printk(KERN_ERR "%s: class_create_file failed\n",
704                        __func__);
705                 class_unregister(&firmware_class);
706         }
707         return error;
708
709 }
710 static void __exit
711 firmware_class_exit(void)
712 {
713         class_unregister(&firmware_class);
714 }
715
716 fs_initcall(firmware_class_init);
717 module_exit(firmware_class_exit);
718
719 EXPORT_SYMBOL(release_firmware);
720 EXPORT_SYMBOL(request_firmware);
721 EXPORT_SYMBOL(request_firmware_nowait);