Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[linux-2.6] / 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
21 #include <linux/firmware.h>
22 #include "base.h"
23
24 #define to_dev(obj) container_of(obj, struct device, kobj)
25
26 MODULE_AUTHOR("Manuel Estrada Sainz");
27 MODULE_DESCRIPTION("Multi purpose firmware loading support");
28 MODULE_LICENSE("GPL");
29
30 enum {
31         FW_STATUS_LOADING,
32         FW_STATUS_DONE,
33         FW_STATUS_ABORT,
34 };
35
36 static int loading_timeout = 60;        /* In seconds */
37
38 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
39  * guarding for corner cases a global lock should be OK */
40 static DEFINE_MUTEX(fw_lock);
41
42 struct firmware_priv {
43         char fw_id[FIRMWARE_NAME_MAX];
44         struct completion completion;
45         struct bin_attribute attr_data;
46         struct firmware *fw;
47         unsigned long status;
48         int alloc_size;
49         struct timer_list timeout;
50 };
51
52 #ifdef CONFIG_FW_LOADER
53 extern struct builtin_fw __start_builtin_fw[];
54 extern struct builtin_fw __end_builtin_fw[];
55 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
56 static struct builtin_fw *__start_builtin_fw;
57 static struct builtin_fw *__end_builtin_fw;
58 #endif
59
60 static void
61 fw_load_abort(struct firmware_priv *fw_priv)
62 {
63         set_bit(FW_STATUS_ABORT, &fw_priv->status);
64         wmb();
65         complete(&fw_priv->completion);
66 }
67
68 static ssize_t
69 firmware_timeout_show(struct class *class, char *buf)
70 {
71         return sprintf(buf, "%d\n", loading_timeout);
72 }
73
74 /**
75  * firmware_timeout_store - set number of seconds to wait for firmware
76  * @class: device class pointer
77  * @buf: buffer to scan for timeout value
78  * @count: number of bytes in @buf
79  *
80  *      Sets the number of seconds to wait for the firmware.  Once
81  *      this expires an error will be returned to the driver and no
82  *      firmware will be provided.
83  *
84  *      Note: zero means 'wait forever'.
85  **/
86 static ssize_t
87 firmware_timeout_store(struct class *class, const char *buf, size_t count)
88 {
89         loading_timeout = simple_strtol(buf, NULL, 10);
90         if (loading_timeout < 0)
91                 loading_timeout = 0;
92         return count;
93 }
94
95 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
96
97 static void fw_dev_release(struct device *dev);
98
99 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
100 {
101         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
102
103         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
104                 return -ENOMEM;
105         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
106                 return -ENOMEM;
107
108         return 0;
109 }
110
111 static struct class firmware_class = {
112         .name           = "firmware",
113         .dev_uevent     = firmware_uevent,
114         .dev_release    = fw_dev_release,
115 };
116
117 static ssize_t firmware_loading_show(struct device *dev,
118                                      struct device_attribute *attr, char *buf)
119 {
120         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
121         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
122         return sprintf(buf, "%d\n", loading);
123 }
124
125 /**
126  * firmware_loading_store - set value in the 'loading' control file
127  * @dev: device pointer
128  * @attr: device attribute pointer
129  * @buf: buffer to scan for loading control value
130  * @count: number of bytes in @buf
131  *
132  *      The relevant values are:
133  *
134  *       1: Start a load, discarding any previous partial load.
135  *       0: Conclude the load and hand the data to the driver code.
136  *      -1: Conclude the load with an error and discard any written data.
137  **/
138 static ssize_t firmware_loading_store(struct device *dev,
139                                       struct device_attribute *attr,
140                                       const char *buf, size_t count)
141 {
142         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
143         int loading = simple_strtol(buf, NULL, 10);
144
145         switch (loading) {
146         case 1:
147                 mutex_lock(&fw_lock);
148                 if (!fw_priv->fw) {
149                         mutex_unlock(&fw_lock);
150                         break;
151                 }
152                 vfree(fw_priv->fw->data);
153                 fw_priv->fw->data = NULL;
154                 fw_priv->fw->size = 0;
155                 fw_priv->alloc_size = 0;
156                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
157                 mutex_unlock(&fw_lock);
158                 break;
159         case 0:
160                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
161                         complete(&fw_priv->completion);
162                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
163                         break;
164                 }
165                 /* fallthrough */
166         default:
167                 printk(KERN_ERR "%s: unexpected value (%d)\n", __func__,
168                        loading);
169                 /* fallthrough */
170         case -1:
171                 fw_load_abort(fw_priv);
172                 break;
173         }
174
175         return count;
176 }
177
178 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
179
180 static ssize_t
181 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
182                    char *buffer, loff_t offset, size_t count)
183 {
184         struct device *dev = to_dev(kobj);
185         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
186         struct firmware *fw;
187         ssize_t ret_count = count;
188
189         mutex_lock(&fw_lock);
190         fw = fw_priv->fw;
191         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
192                 ret_count = -ENODEV;
193                 goto out;
194         }
195         if (offset > fw->size) {
196                 ret_count = 0;
197                 goto out;
198         }
199         if (offset + ret_count > fw->size)
200                 ret_count = fw->size - offset;
201
202         memcpy(buffer, fw->data + offset, ret_count);
203 out:
204         mutex_unlock(&fw_lock);
205         return ret_count;
206 }
207
208 static int
209 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
210 {
211         u8 *new_data;
212         int new_size = fw_priv->alloc_size;
213
214         if (min_size <= fw_priv->alloc_size)
215                 return 0;
216
217         new_size = ALIGN(min_size, PAGE_SIZE);
218         new_data = vmalloc(new_size);
219         if (!new_data) {
220                 printk(KERN_ERR "%s: unable to alloc buffer\n", __func__);
221                 /* Make sure that we don't keep incomplete data */
222                 fw_load_abort(fw_priv);
223                 return -ENOMEM;
224         }
225         fw_priv->alloc_size = new_size;
226         if (fw_priv->fw->data) {
227                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
228                 vfree(fw_priv->fw->data);
229         }
230         fw_priv->fw->data = new_data;
231         BUG_ON(min_size > fw_priv->alloc_size);
232         return 0;
233 }
234
235 /**
236  * firmware_data_write - write method for firmware
237  * @kobj: kobject for the device
238  * @bin_attr: bin_attr structure
239  * @buffer: buffer being written
240  * @offset: buffer offset for write in total data store area
241  * @count: buffer size
242  *
243  *      Data written to the 'data' attribute will be later handed to
244  *      the driver as a firmware image.
245  **/
246 static ssize_t
247 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
248                     char *buffer, loff_t offset, size_t count)
249 {
250         struct device *dev = to_dev(kobj);
251         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
252         struct firmware *fw;
253         ssize_t retval;
254
255         if (!capable(CAP_SYS_RAWIO))
256                 return -EPERM;
257
258         mutex_lock(&fw_lock);
259         fw = fw_priv->fw;
260         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
261                 retval = -ENODEV;
262                 goto out;
263         }
264         retval = fw_realloc_buffer(fw_priv, offset + count);
265         if (retval)
266                 goto out;
267
268         memcpy((u8 *)fw->data + offset, buffer, count);
269
270         fw->size = max_t(size_t, offset + count, fw->size);
271         retval = count;
272 out:
273         mutex_unlock(&fw_lock);
274         return retval;
275 }
276
277 static struct bin_attribute firmware_attr_data_tmpl = {
278         .attr = {.name = "data", .mode = 0644},
279         .size = 0,
280         .read = firmware_data_read,
281         .write = firmware_data_write,
282 };
283
284 static void fw_dev_release(struct device *dev)
285 {
286         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
287
288         kfree(fw_priv);
289         kfree(dev);
290
291         module_put(THIS_MODULE);
292 }
293
294 static void
295 firmware_class_timeout(u_long data)
296 {
297         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
298         fw_load_abort(fw_priv);
299 }
300
301 static inline void fw_setup_device_id(struct device *f_dev, struct device *dev)
302 {
303         /* XXX warning we should watch out for name collisions */
304         strlcpy(f_dev->bus_id, dev->bus_id, BUS_ID_SIZE);
305 }
306
307 static int fw_register_device(struct device **dev_p, const char *fw_name,
308                               struct device *device)
309 {
310         int retval;
311         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
312                                                 GFP_KERNEL);
313         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
314
315         *dev_p = NULL;
316
317         if (!fw_priv || !f_dev) {
318                 printk(KERN_ERR "%s: kmalloc failed\n", __func__);
319                 retval = -ENOMEM;
320                 goto error_kfree;
321         }
322
323         init_completion(&fw_priv->completion);
324         fw_priv->attr_data = firmware_attr_data_tmpl;
325         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
326
327         fw_priv->timeout.function = firmware_class_timeout;
328         fw_priv->timeout.data = (u_long) fw_priv;
329         init_timer(&fw_priv->timeout);
330
331         fw_setup_device_id(f_dev, device);
332         f_dev->parent = device;
333         f_dev->class = &firmware_class;
334         dev_set_drvdata(f_dev, fw_priv);
335         f_dev->uevent_suppress = 1;
336         retval = device_register(f_dev);
337         if (retval) {
338                 printk(KERN_ERR "%s: device_register failed\n",
339                        __func__);
340                 goto error_kfree;
341         }
342         *dev_p = f_dev;
343         return 0;
344
345 error_kfree:
346         kfree(fw_priv);
347         kfree(f_dev);
348         return retval;
349 }
350
351 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
352                            const char *fw_name, struct device *device,
353                            int uevent)
354 {
355         struct device *f_dev;
356         struct firmware_priv *fw_priv;
357         int retval;
358
359         *dev_p = NULL;
360         retval = fw_register_device(&f_dev, fw_name, device);
361         if (retval)
362                 goto out;
363
364         /* Need to pin this module until class device is destroyed */
365         __module_get(THIS_MODULE);
366
367         fw_priv = dev_get_drvdata(f_dev);
368
369         fw_priv->fw = fw;
370         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
371         if (retval) {
372                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
373                        __func__);
374                 goto error_unreg;
375         }
376
377         retval = device_create_file(f_dev, &dev_attr_loading);
378         if (retval) {
379                 printk(KERN_ERR "%s: device_create_file failed\n",
380                        __func__);
381                 goto error_unreg;
382         }
383
384         if (uevent)
385                 f_dev->uevent_suppress = 0;
386         *dev_p = f_dev;
387         goto out;
388
389 error_unreg:
390         device_unregister(f_dev);
391 out:
392         return retval;
393 }
394
395 static int
396 _request_firmware(const struct firmware **firmware_p, const char *name,
397                  struct device *device, int uevent)
398 {
399         struct device *f_dev;
400         struct firmware_priv *fw_priv;
401         struct firmware *firmware;
402         struct builtin_fw *builtin;
403         int retval;
404
405         if (!firmware_p)
406                 return -EINVAL;
407
408         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
409         if (!firmware) {
410                 printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
411                        __func__);
412                 retval = -ENOMEM;
413                 goto out;
414         }
415
416         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
417              builtin++) {
418                 if (strcmp(name, builtin->name))
419                         continue;
420                 printk(KERN_INFO "firmware: using built-in firmware %s\n",
421                        name);
422                 firmware->size = builtin->size;
423                 firmware->data = builtin->data;
424                 return 0;
425         }
426
427         if (uevent)
428                 printk(KERN_INFO "firmware: requesting %s\n", name);
429
430         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
431         if (retval)
432                 goto error_kfree_fw;
433
434         fw_priv = dev_get_drvdata(f_dev);
435
436         if (uevent) {
437                 if (loading_timeout > 0) {
438                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
439                         add_timer(&fw_priv->timeout);
440                 }
441
442                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
443                 wait_for_completion(&fw_priv->completion);
444                 set_bit(FW_STATUS_DONE, &fw_priv->status);
445                 del_timer_sync(&fw_priv->timeout);
446         } else
447                 wait_for_completion(&fw_priv->completion);
448
449         mutex_lock(&fw_lock);
450         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
451                 retval = -ENOENT;
452                 release_firmware(fw_priv->fw);
453                 *firmware_p = NULL;
454         }
455         fw_priv->fw = NULL;
456         mutex_unlock(&fw_lock);
457         device_unregister(f_dev);
458         goto out;
459
460 error_kfree_fw:
461         kfree(firmware);
462         *firmware_p = NULL;
463 out:
464         return retval;
465 }
466
467 /**
468  * request_firmware: - send firmware request and wait for it
469  * @firmware_p: pointer to firmware image
470  * @name: name of firmware file
471  * @device: device for which firmware is being loaded
472  *
473  *      @firmware_p will be used to return a firmware image by the name
474  *      of @name for device @device.
475  *
476  *      Should be called from user context where sleeping is allowed.
477  *
478  *      @name will be used as $FIRMWARE in the uevent environment and
479  *      should be distinctive enough not to be confused with any other
480  *      firmware image for this or any other device.
481  **/
482 int
483 request_firmware(const struct firmware **firmware_p, const char *name,
484                  struct device *device)
485 {
486         int uevent = 1;
487         return _request_firmware(firmware_p, name, device, uevent);
488 }
489
490 /**
491  * release_firmware: - release the resource associated with a firmware image
492  * @fw: firmware resource to release
493  **/
494 void
495 release_firmware(const struct firmware *fw)
496 {
497         struct builtin_fw *builtin;
498
499         if (fw) {
500                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
501                      builtin++) {
502                         if (fw->data == builtin->data)
503                                 goto free_fw;
504                 }
505                 vfree(fw->data);
506         free_fw:
507                 kfree(fw);
508         }
509 }
510
511 /* Async support */
512 struct firmware_work {
513         struct work_struct work;
514         struct module *module;
515         const char *name;
516         struct device *device;
517         void *context;
518         void (*cont)(const struct firmware *fw, void *context);
519         int uevent;
520 };
521
522 static int
523 request_firmware_work_func(void *arg)
524 {
525         struct firmware_work *fw_work = arg;
526         const struct firmware *fw;
527         int ret;
528         if (!arg) {
529                 WARN_ON(1);
530                 return 0;
531         }
532         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
533                 fw_work->uevent);
534         if (ret < 0)
535                 fw_work->cont(NULL, fw_work->context);
536         else {
537                 fw_work->cont(fw, fw_work->context);
538                 release_firmware(fw);
539         }
540         module_put(fw_work->module);
541         kfree(fw_work);
542         return ret;
543 }
544
545 /**
546  * request_firmware_nowait: asynchronous version of request_firmware
547  * @module: module requesting the firmware
548  * @uevent: sends uevent to copy the firmware image if this flag
549  *      is non-zero else the firmware copy must be done manually.
550  * @name: name of firmware file
551  * @device: device for which firmware is being loaded
552  * @context: will be passed over to @cont, and
553  *      @fw may be %NULL if firmware request fails.
554  * @cont: function will be called asynchronously when the firmware
555  *      request is over.
556  *
557  *      Asynchronous variant of request_firmware() for contexts where
558  *      it is not possible to sleep.
559  **/
560 int
561 request_firmware_nowait(
562         struct module *module, int uevent,
563         const char *name, struct device *device, void *context,
564         void (*cont)(const struct firmware *fw, void *context))
565 {
566         struct task_struct *task;
567         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
568                                                 GFP_ATOMIC);
569
570         if (!fw_work)
571                 return -ENOMEM;
572         if (!try_module_get(module)) {
573                 kfree(fw_work);
574                 return -EFAULT;
575         }
576
577         *fw_work = (struct firmware_work) {
578                 .module = module,
579                 .name = name,
580                 .device = device,
581                 .context = context,
582                 .cont = cont,
583                 .uevent = uevent,
584         };
585
586         task = kthread_run(request_firmware_work_func, fw_work,
587                             "firmware/%s", name);
588
589         if (IS_ERR(task)) {
590                 fw_work->cont(NULL, fw_work->context);
591                 module_put(fw_work->module);
592                 kfree(fw_work);
593                 return PTR_ERR(task);
594         }
595         return 0;
596 }
597
598 static int __init
599 firmware_class_init(void)
600 {
601         int error;
602         error = class_register(&firmware_class);
603         if (error) {
604                 printk(KERN_ERR "%s: class_register failed\n", __func__);
605                 return error;
606         }
607         error = class_create_file(&firmware_class, &class_attr_timeout);
608         if (error) {
609                 printk(KERN_ERR "%s: class_create_file failed\n",
610                        __func__);
611                 class_unregister(&firmware_class);
612         }
613         return error;
614
615 }
616 static void __exit
617 firmware_class_exit(void)
618 {
619         class_unregister(&firmware_class);
620 }
621
622 fs_initcall(firmware_class_init);
623 module_exit(firmware_class_exit);
624
625 EXPORT_SYMBOL(release_firmware);
626 EXPORT_SYMBOL(request_firmware);
627 EXPORT_SYMBOL(request_firmware_nowait);