firmware loader: split out builtin firmware handling
[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 /* Builtin firmware support */
31
32 #ifdef CONFIG_FW_LOADER
33
34 extern struct builtin_fw __start_builtin_fw[];
35 extern struct builtin_fw __end_builtin_fw[];
36
37 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
38 {
39         struct builtin_fw *b_fw;
40
41         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
42                 if (strcmp(name, b_fw->name) == 0) {
43                         fw->size = b_fw->size;
44                         fw->data = b_fw->data;
45                         return true;
46                 }
47         }
48
49         return false;
50 }
51
52 static bool fw_is_builtin_firmware(const struct firmware *fw)
53 {
54         struct builtin_fw *b_fw;
55
56         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
57                 if (fw->data == b_fw->data)
58                         return true;
59
60         return false;
61 }
62
63 #else /* Module case - no builtin firmware support */
64
65 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
66 {
67         return false;
68 }
69
70 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
71 {
72         return false;
73 }
74 #endif
75
76 enum {
77         FW_STATUS_LOADING,
78         FW_STATUS_DONE,
79         FW_STATUS_ABORT,
80 };
81
82 static int loading_timeout = 60;        /* In seconds */
83
84 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
85  * guarding for corner cases a global lock should be OK */
86 static DEFINE_MUTEX(fw_lock);
87
88 struct firmware_priv {
89         char *fw_id;
90         struct completion completion;
91         struct bin_attribute attr_data;
92         struct firmware *fw;
93         unsigned long status;
94         struct page **pages;
95         int nr_pages;
96         int page_array_size;
97         const char *vdata;
98         struct timer_list timeout;
99         bool nowait;
100 };
101
102 static void
103 fw_load_abort(struct firmware_priv *fw_priv)
104 {
105         set_bit(FW_STATUS_ABORT, &fw_priv->status);
106         wmb();
107         complete(&fw_priv->completion);
108 }
109
110 static ssize_t
111 firmware_timeout_show(struct class *class,
112                       struct class_attribute *attr,
113                       char *buf)
114 {
115         return sprintf(buf, "%d\n", loading_timeout);
116 }
117
118 /**
119  * firmware_timeout_store - set number of seconds to wait for firmware
120  * @class: device class pointer
121  * @attr: device attribute pointer
122  * @buf: buffer to scan for timeout value
123  * @count: number of bytes in @buf
124  *
125  *      Sets the number of seconds to wait for the firmware.  Once
126  *      this expires an error will be returned to the driver and no
127  *      firmware will be provided.
128  *
129  *      Note: zero means 'wait forever'.
130  **/
131 static ssize_t
132 firmware_timeout_store(struct class *class,
133                         struct class_attribute *attr,
134                         const char *buf, size_t count)
135 {
136         loading_timeout = simple_strtol(buf, NULL, 10);
137         if (loading_timeout < 0)
138                 loading_timeout = 0;
139         return count;
140 }
141
142 static struct class_attribute firmware_class_attrs[] = {
143         __ATTR(timeout, S_IWUSR | S_IRUGO,
144                 firmware_timeout_show, firmware_timeout_store),
145         __ATTR_NULL
146 };
147
148 static void fw_dev_release(struct device *dev)
149 {
150         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
151         int i;
152
153         for (i = 0; i < fw_priv->nr_pages; i++)
154                 __free_page(fw_priv->pages[i]);
155         kfree(fw_priv->pages);
156         kfree(fw_priv->fw_id);
157         kfree(fw_priv);
158         kfree(dev);
159
160         module_put(THIS_MODULE);
161 }
162
163 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
164 {
165         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
166
167         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
168                 return -ENOMEM;
169         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
170                 return -ENOMEM;
171         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
172                 return -ENOMEM;
173
174         return 0;
175 }
176
177 static struct class firmware_class = {
178         .name           = "firmware",
179         .class_attrs    = firmware_class_attrs,
180         .dev_uevent     = firmware_uevent,
181         .dev_release    = fw_dev_release,
182 };
183
184 static ssize_t firmware_loading_show(struct device *dev,
185                                      struct device_attribute *attr, char *buf)
186 {
187         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
188         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
189         return sprintf(buf, "%d\n", loading);
190 }
191
192 static void firmware_free_data(const struct firmware *fw)
193 {
194         int i;
195         vunmap(fw->data);
196         if (fw->pages) {
197                 for (i = 0; i < PFN_UP(fw->size); i++)
198                         __free_page(fw->pages[i]);
199                 kfree(fw->pages);
200         }
201 }
202
203 /* Some architectures don't have PAGE_KERNEL_RO */
204 #ifndef PAGE_KERNEL_RO
205 #define PAGE_KERNEL_RO PAGE_KERNEL
206 #endif
207 /**
208  * firmware_loading_store - set value in the 'loading' control file
209  * @dev: device pointer
210  * @attr: device attribute pointer
211  * @buf: buffer to scan for loading control value
212  * @count: number of bytes in @buf
213  *
214  *      The relevant values are:
215  *
216  *       1: Start a load, discarding any previous partial load.
217  *       0: Conclude the load and hand the data to the driver code.
218  *      -1: Conclude the load with an error and discard any written data.
219  **/
220 static ssize_t firmware_loading_store(struct device *dev,
221                                       struct device_attribute *attr,
222                                       const char *buf, size_t count)
223 {
224         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
225         int loading = simple_strtol(buf, NULL, 10);
226         int i;
227
228         switch (loading) {
229         case 1:
230                 mutex_lock(&fw_lock);
231                 if (!fw_priv->fw) {
232                         mutex_unlock(&fw_lock);
233                         break;
234                 }
235                 firmware_free_data(fw_priv->fw);
236                 memset(fw_priv->fw, 0, sizeof(struct firmware));
237                 /* If the pages are not owned by 'struct firmware' */
238                 for (i = 0; i < fw_priv->nr_pages; i++)
239                         __free_page(fw_priv->pages[i]);
240                 kfree(fw_priv->pages);
241                 fw_priv->pages = NULL;
242                 fw_priv->page_array_size = 0;
243                 fw_priv->nr_pages = 0;
244                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
245                 mutex_unlock(&fw_lock);
246                 break;
247         case 0:
248                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
249                         vunmap(fw_priv->fw->data);
250                         fw_priv->fw->data = vmap(fw_priv->pages,
251                                                  fw_priv->nr_pages,
252                                                  0, PAGE_KERNEL_RO);
253                         if (!fw_priv->fw->data) {
254                                 dev_err(dev, "%s: vmap() failed\n", __func__);
255                                 goto err;
256                         }
257                         /* Pages are now owned by 'struct firmware' */
258                         fw_priv->fw->pages = fw_priv->pages;
259                         fw_priv->pages = NULL;
260
261                         fw_priv->page_array_size = 0;
262                         fw_priv->nr_pages = 0;
263                         complete(&fw_priv->completion);
264                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
265                         break;
266                 }
267                 /* fallthrough */
268         default:
269                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
270                 /* fallthrough */
271         case -1:
272         err:
273                 fw_load_abort(fw_priv);
274                 break;
275         }
276
277         return count;
278 }
279
280 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
281
282 static ssize_t
283 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
284                    char *buffer, loff_t offset, size_t count)
285 {
286         struct device *dev = to_dev(kobj);
287         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
288         struct firmware *fw;
289         ssize_t ret_count;
290
291         mutex_lock(&fw_lock);
292         fw = fw_priv->fw;
293         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
294                 ret_count = -ENODEV;
295                 goto out;
296         }
297         if (offset > fw->size) {
298                 ret_count = 0;
299                 goto out;
300         }
301         if (count > fw->size - offset)
302                 count = fw->size - offset;
303
304         ret_count = count;
305
306         while (count) {
307                 void *page_data;
308                 int page_nr = offset >> PAGE_SHIFT;
309                 int page_ofs = offset & (PAGE_SIZE-1);
310                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
311
312                 page_data = kmap(fw_priv->pages[page_nr]);
313
314                 memcpy(buffer, page_data + page_ofs, page_cnt);
315
316                 kunmap(fw_priv->pages[page_nr]);
317                 buffer += page_cnt;
318                 offset += page_cnt;
319                 count -= page_cnt;
320         }
321 out:
322         mutex_unlock(&fw_lock);
323         return ret_count;
324 }
325
326 static int
327 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
328 {
329         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
330
331         /* If the array of pages is too small, grow it... */
332         if (fw_priv->page_array_size < pages_needed) {
333                 int new_array_size = max(pages_needed,
334                                          fw_priv->page_array_size * 2);
335                 struct page **new_pages;
336
337                 new_pages = kmalloc(new_array_size * sizeof(void *),
338                                     GFP_KERNEL);
339                 if (!new_pages) {
340                         fw_load_abort(fw_priv);
341                         return -ENOMEM;
342                 }
343                 memcpy(new_pages, fw_priv->pages,
344                        fw_priv->page_array_size * sizeof(void *));
345                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
346                        (new_array_size - fw_priv->page_array_size));
347                 kfree(fw_priv->pages);
348                 fw_priv->pages = new_pages;
349                 fw_priv->page_array_size = new_array_size;
350         }
351
352         while (fw_priv->nr_pages < pages_needed) {
353                 fw_priv->pages[fw_priv->nr_pages] =
354                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
355
356                 if (!fw_priv->pages[fw_priv->nr_pages]) {
357                         fw_load_abort(fw_priv);
358                         return -ENOMEM;
359                 }
360                 fw_priv->nr_pages++;
361         }
362         return 0;
363 }
364
365 /**
366  * firmware_data_write - write method for firmware
367  * @kobj: kobject for the device
368  * @bin_attr: bin_attr structure
369  * @buffer: buffer being written
370  * @offset: buffer offset for write in total data store area
371  * @count: buffer size
372  *
373  *      Data written to the 'data' attribute will be later handed to
374  *      the driver as a firmware image.
375  **/
376 static ssize_t
377 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
378                     char *buffer, loff_t offset, size_t count)
379 {
380         struct device *dev = to_dev(kobj);
381         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
382         struct firmware *fw;
383         ssize_t retval;
384
385         if (!capable(CAP_SYS_RAWIO))
386                 return -EPERM;
387
388         mutex_lock(&fw_lock);
389         fw = fw_priv->fw;
390         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
391                 retval = -ENODEV;
392                 goto out;
393         }
394         retval = fw_realloc_buffer(fw_priv, offset + count);
395         if (retval)
396                 goto out;
397
398         retval = count;
399
400         while (count) {
401                 void *page_data;
402                 int page_nr = offset >> PAGE_SHIFT;
403                 int page_ofs = offset & (PAGE_SIZE - 1);
404                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
405
406                 page_data = kmap(fw_priv->pages[page_nr]);
407
408                 memcpy(page_data + page_ofs, buffer, page_cnt);
409
410                 kunmap(fw_priv->pages[page_nr]);
411                 buffer += page_cnt;
412                 offset += page_cnt;
413                 count -= page_cnt;
414         }
415
416         fw->size = max_t(size_t, offset, fw->size);
417 out:
418         mutex_unlock(&fw_lock);
419         return retval;
420 }
421
422 static struct bin_attribute firmware_attr_data_tmpl = {
423         .attr = {.name = "data", .mode = 0644},
424         .size = 0,
425         .read = firmware_data_read,
426         .write = firmware_data_write,
427 };
428
429 static void
430 firmware_class_timeout(u_long data)
431 {
432         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
433         fw_load_abort(fw_priv);
434 }
435
436 static int fw_register_device(struct device **dev_p, const char *fw_name,
437                               struct device *device)
438 {
439         int retval;
440         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
441                                                 GFP_KERNEL);
442         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
443
444         *dev_p = NULL;
445
446         if (!fw_priv || !f_dev) {
447                 dev_err(device, "%s: kmalloc failed\n", __func__);
448                 retval = -ENOMEM;
449                 goto error_kfree;
450         }
451
452         init_completion(&fw_priv->completion);
453         fw_priv->attr_data = firmware_attr_data_tmpl;
454         fw_priv->fw_id = kstrdup(fw_name, GFP_KERNEL);
455         if (!fw_priv->fw_id) {
456                 dev_err(device, "%s: Firmware name allocation failed\n",
457                         __func__);
458                 retval = -ENOMEM;
459                 goto error_kfree;
460         }
461
462         fw_priv->timeout.function = firmware_class_timeout;
463         fw_priv->timeout.data = (u_long) fw_priv;
464         init_timer(&fw_priv->timeout);
465
466         dev_set_name(f_dev, "%s", dev_name(device));
467         f_dev->parent = device;
468         f_dev->class = &firmware_class;
469         dev_set_drvdata(f_dev, fw_priv);
470         dev_set_uevent_suppress(f_dev, 1);
471         retval = device_register(f_dev);
472         if (retval) {
473                 dev_err(device, "%s: device_register failed\n", __func__);
474                 put_device(f_dev);
475                 return retval;
476         }
477         *dev_p = f_dev;
478         return 0;
479
480 error_kfree:
481         kfree(f_dev);
482         kfree(fw_priv);
483         return retval;
484 }
485
486 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
487                            const char *fw_name, struct device *device,
488                            int uevent, bool nowait)
489 {
490         struct device *f_dev;
491         struct firmware_priv *fw_priv;
492         int retval;
493
494         *dev_p = NULL;
495         retval = fw_register_device(&f_dev, fw_name, device);
496         if (retval)
497                 goto out;
498
499         /* Need to pin this module until class device is destroyed */
500         __module_get(THIS_MODULE);
501
502         fw_priv = dev_get_drvdata(f_dev);
503
504         fw_priv->nowait = nowait;
505
506         fw_priv->fw = fw;
507         sysfs_bin_attr_init(&fw_priv->attr_data);
508         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
509         if (retval) {
510                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
511                 goto error_unreg;
512         }
513
514         retval = device_create_file(f_dev, &dev_attr_loading);
515         if (retval) {
516                 dev_err(device, "%s: device_create_file failed\n", __func__);
517                 goto error_unreg;
518         }
519
520         if (uevent)
521                 dev_set_uevent_suppress(f_dev, 0);
522         *dev_p = f_dev;
523         goto out;
524
525 error_unreg:
526         device_unregister(f_dev);
527 out:
528         return retval;
529 }
530
531 static int
532 _request_firmware(const struct firmware **firmware_p, const char *name,
533                  struct device *device, int uevent, bool nowait)
534 {
535         struct device *f_dev;
536         struct firmware_priv *fw_priv;
537         struct firmware *firmware;
538         int retval;
539
540         if (!firmware_p)
541                 return -EINVAL;
542
543         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
544         if (!firmware) {
545                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
546                         __func__);
547                 retval = -ENOMEM;
548                 goto out;
549         }
550
551         if (fw_get_builtin_firmware(firmware, name)) {
552                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
553                 return 0;
554         }
555
556         if (uevent)
557                 dev_dbg(device, "firmware: requesting %s\n", name);
558
559         retval = fw_setup_device(firmware, &f_dev, name, device,
560                                  uevent, nowait);
561         if (retval)
562                 goto error_kfree_fw;
563
564         fw_priv = dev_get_drvdata(f_dev);
565
566         if (uevent) {
567                 if (loading_timeout > 0) {
568                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
569                         add_timer(&fw_priv->timeout);
570                 }
571
572                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
573                 wait_for_completion(&fw_priv->completion);
574                 set_bit(FW_STATUS_DONE, &fw_priv->status);
575                 del_timer_sync(&fw_priv->timeout);
576         } else
577                 wait_for_completion(&fw_priv->completion);
578
579         mutex_lock(&fw_lock);
580         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
581                 retval = -ENOENT;
582                 release_firmware(fw_priv->fw);
583                 *firmware_p = NULL;
584         }
585         fw_priv->fw = NULL;
586         mutex_unlock(&fw_lock);
587         device_unregister(f_dev);
588         goto out;
589
590 error_kfree_fw:
591         kfree(firmware);
592         *firmware_p = NULL;
593 out:
594         return retval;
595 }
596
597 /**
598  * request_firmware: - send firmware request and wait for it
599  * @firmware_p: pointer to firmware image
600  * @name: name of firmware file
601  * @device: device for which firmware is being loaded
602  *
603  *      @firmware_p will be used to return a firmware image by the name
604  *      of @name for device @device.
605  *
606  *      Should be called from user context where sleeping is allowed.
607  *
608  *      @name will be used as $FIRMWARE in the uevent environment and
609  *      should be distinctive enough not to be confused with any other
610  *      firmware image for this or any other device.
611  **/
612 int
613 request_firmware(const struct firmware **firmware_p, const char *name,
614                  struct device *device)
615 {
616         int uevent = 1;
617         return _request_firmware(firmware_p, name, device, uevent, false);
618 }
619
620 /**
621  * release_firmware: - release the resource associated with a firmware image
622  * @fw: firmware resource to release
623  **/
624 void release_firmware(const struct firmware *fw)
625 {
626         if (fw) {
627                 if (!fw_is_builtin_firmware(fw))
628                         firmware_free_data(fw);
629                 kfree(fw);
630         }
631 }
632
633 /* Async support */
634 struct firmware_work {
635         struct work_struct work;
636         struct module *module;
637         const char *name;
638         struct device *device;
639         void *context;
640         void (*cont)(const struct firmware *fw, void *context);
641         int uevent;
642 };
643
644 static int
645 request_firmware_work_func(void *arg)
646 {
647         struct firmware_work *fw_work = arg;
648         const struct firmware *fw;
649         int ret;
650         if (!arg) {
651                 WARN_ON(1);
652                 return 0;
653         }
654         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
655                 fw_work->uevent, true);
656
657         fw_work->cont(fw, fw_work->context);
658
659         module_put(fw_work->module);
660         kfree(fw_work);
661         return ret;
662 }
663
664 /**
665  * request_firmware_nowait - asynchronous version of request_firmware
666  * @module: module requesting the firmware
667  * @uevent: sends uevent to copy the firmware image if this flag
668  *      is non-zero else the firmware copy must be done manually.
669  * @name: name of firmware file
670  * @device: device for which firmware is being loaded
671  * @gfp: allocation flags
672  * @context: will be passed over to @cont, and
673  *      @fw may be %NULL if firmware request fails.
674  * @cont: function will be called asynchronously when the firmware
675  *      request is over.
676  *
677  *      Asynchronous variant of request_firmware() for user contexts where
678  *      it is not possible to sleep for long time. It can't be called
679  *      in atomic contexts.
680  **/
681 int
682 request_firmware_nowait(
683         struct module *module, int uevent,
684         const char *name, struct device *device, gfp_t gfp, void *context,
685         void (*cont)(const struct firmware *fw, void *context))
686 {
687         struct task_struct *task;
688         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
689                                                 gfp);
690
691         if (!fw_work)
692                 return -ENOMEM;
693         if (!try_module_get(module)) {
694                 kfree(fw_work);
695                 return -EFAULT;
696         }
697
698         *fw_work = (struct firmware_work) {
699                 .module = module,
700                 .name = name,
701                 .device = device,
702                 .context = context,
703                 .cont = cont,
704                 .uevent = uevent,
705         };
706
707         task = kthread_run(request_firmware_work_func, fw_work,
708                             "firmware/%s", name);
709
710         if (IS_ERR(task)) {
711                 fw_work->cont(NULL, fw_work->context);
712                 module_put(fw_work->module);
713                 kfree(fw_work);
714                 return PTR_ERR(task);
715         }
716         return 0;
717 }
718
719 static int __init firmware_class_init(void)
720 {
721         return class_register(&firmware_class);
722 }
723
724 static void __exit firmware_class_exit(void)
725 {
726         class_unregister(&firmware_class);
727 }
728
729 fs_initcall(firmware_class_init);
730 module_exit(firmware_class_exit);
731
732 EXPORT_SYMBOL(release_firmware);
733 EXPORT_SYMBOL(request_firmware);
734 EXPORT_SYMBOL(request_firmware_nowait);