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