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