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[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;
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         ret_count = memory_read_from_buffer(buffer, count, &offset,
196                                                 fw->data, fw->size);
197 out:
198         mutex_unlock(&fw_lock);
199         return ret_count;
200 }
201
202 static int
203 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
204 {
205         u8 *new_data;
206         int new_size = fw_priv->alloc_size;
207
208         if (min_size <= fw_priv->alloc_size)
209                 return 0;
210
211         new_size = ALIGN(min_size, PAGE_SIZE);
212         new_data = vmalloc(new_size);
213         if (!new_data) {
214                 printk(KERN_ERR "%s: unable to alloc buffer\n", __func__);
215                 /* Make sure that we don't keep incomplete data */
216                 fw_load_abort(fw_priv);
217                 return -ENOMEM;
218         }
219         fw_priv->alloc_size = new_size;
220         if (fw_priv->fw->data) {
221                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
222                 vfree(fw_priv->fw->data);
223         }
224         fw_priv->fw->data = new_data;
225         BUG_ON(min_size > fw_priv->alloc_size);
226         return 0;
227 }
228
229 /**
230  * firmware_data_write - write method for firmware
231  * @kobj: kobject for the device
232  * @bin_attr: bin_attr structure
233  * @buffer: buffer being written
234  * @offset: buffer offset for write in total data store area
235  * @count: buffer size
236  *
237  *      Data written to the 'data' attribute will be later handed to
238  *      the driver as a firmware image.
239  **/
240 static ssize_t
241 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
242                     char *buffer, loff_t offset, size_t count)
243 {
244         struct device *dev = to_dev(kobj);
245         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
246         struct firmware *fw;
247         ssize_t retval;
248
249         if (!capable(CAP_SYS_RAWIO))
250                 return -EPERM;
251
252         mutex_lock(&fw_lock);
253         fw = fw_priv->fw;
254         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
255                 retval = -ENODEV;
256                 goto out;
257         }
258         retval = fw_realloc_buffer(fw_priv, offset + count);
259         if (retval)
260                 goto out;
261
262         memcpy((u8 *)fw->data + offset, buffer, count);
263
264         fw->size = max_t(size_t, offset + count, fw->size);
265         retval = count;
266 out:
267         mutex_unlock(&fw_lock);
268         return retval;
269 }
270
271 static struct bin_attribute firmware_attr_data_tmpl = {
272         .attr = {.name = "data", .mode = 0644},
273         .size = 0,
274         .read = firmware_data_read,
275         .write = firmware_data_write,
276 };
277
278 static void fw_dev_release(struct device *dev)
279 {
280         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
281
282         kfree(fw_priv);
283         kfree(dev);
284
285         module_put(THIS_MODULE);
286 }
287
288 static void
289 firmware_class_timeout(u_long data)
290 {
291         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
292         fw_load_abort(fw_priv);
293 }
294
295 static inline void fw_setup_device_id(struct device *f_dev, struct device *dev)
296 {
297         /* XXX warning we should watch out for name collisions */
298         strlcpy(f_dev->bus_id, dev->bus_id, BUS_ID_SIZE);
299 }
300
301 static int fw_register_device(struct device **dev_p, const char *fw_name,
302                               struct device *device)
303 {
304         int retval;
305         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
306                                                 GFP_KERNEL);
307         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
308
309         *dev_p = NULL;
310
311         if (!fw_priv || !f_dev) {
312                 printk(KERN_ERR "%s: kmalloc failed\n", __func__);
313                 retval = -ENOMEM;
314                 goto error_kfree;
315         }
316
317         init_completion(&fw_priv->completion);
318         fw_priv->attr_data = firmware_attr_data_tmpl;
319         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
320
321         fw_priv->timeout.function = firmware_class_timeout;
322         fw_priv->timeout.data = (u_long) fw_priv;
323         init_timer(&fw_priv->timeout);
324
325         fw_setup_device_id(f_dev, device);
326         f_dev->parent = device;
327         f_dev->class = &firmware_class;
328         dev_set_drvdata(f_dev, fw_priv);
329         f_dev->uevent_suppress = 1;
330         retval = device_register(f_dev);
331         if (retval) {
332                 printk(KERN_ERR "%s: device_register failed\n",
333                        __func__);
334                 goto error_kfree;
335         }
336         *dev_p = f_dev;
337         return 0;
338
339 error_kfree:
340         kfree(fw_priv);
341         kfree(f_dev);
342         return retval;
343 }
344
345 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
346                            const char *fw_name, struct device *device,
347                            int uevent)
348 {
349         struct device *f_dev;
350         struct firmware_priv *fw_priv;
351         int retval;
352
353         *dev_p = NULL;
354         retval = fw_register_device(&f_dev, fw_name, device);
355         if (retval)
356                 goto out;
357
358         /* Need to pin this module until class device is destroyed */
359         __module_get(THIS_MODULE);
360
361         fw_priv = dev_get_drvdata(f_dev);
362
363         fw_priv->fw = fw;
364         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
365         if (retval) {
366                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
367                        __func__);
368                 goto error_unreg;
369         }
370
371         retval = device_create_file(f_dev, &dev_attr_loading);
372         if (retval) {
373                 printk(KERN_ERR "%s: device_create_file failed\n",
374                        __func__);
375                 goto error_unreg;
376         }
377
378         if (uevent)
379                 f_dev->uevent_suppress = 0;
380         *dev_p = f_dev;
381         goto out;
382
383 error_unreg:
384         device_unregister(f_dev);
385 out:
386         return retval;
387 }
388
389 static int
390 _request_firmware(const struct firmware **firmware_p, const char *name,
391                  struct device *device, int uevent)
392 {
393         struct device *f_dev;
394         struct firmware_priv *fw_priv;
395         struct firmware *firmware;
396         struct builtin_fw *builtin;
397         int retval;
398
399         if (!firmware_p)
400                 return -EINVAL;
401
402         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
403         if (!firmware) {
404                 printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
405                        __func__);
406                 retval = -ENOMEM;
407                 goto out;
408         }
409
410         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
411              builtin++) {
412                 if (strcmp(name, builtin->name))
413                         continue;
414                 printk(KERN_INFO "firmware: using built-in firmware %s\n",
415                        name);
416                 firmware->size = builtin->size;
417                 firmware->data = builtin->data;
418                 return 0;
419         }
420
421         if (uevent)
422                 printk(KERN_INFO "firmware: requesting %s\n", name);
423
424         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
425         if (retval)
426                 goto error_kfree_fw;
427
428         fw_priv = dev_get_drvdata(f_dev);
429
430         if (uevent) {
431                 if (loading_timeout > 0) {
432                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
433                         add_timer(&fw_priv->timeout);
434                 }
435
436                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
437                 wait_for_completion(&fw_priv->completion);
438                 set_bit(FW_STATUS_DONE, &fw_priv->status);
439                 del_timer_sync(&fw_priv->timeout);
440         } else
441                 wait_for_completion(&fw_priv->completion);
442
443         mutex_lock(&fw_lock);
444         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
445                 retval = -ENOENT;
446                 release_firmware(fw_priv->fw);
447                 *firmware_p = NULL;
448         }
449         fw_priv->fw = NULL;
450         mutex_unlock(&fw_lock);
451         device_unregister(f_dev);
452         goto out;
453
454 error_kfree_fw:
455         kfree(firmware);
456         *firmware_p = NULL;
457 out:
458         return retval;
459 }
460
461 /**
462  * request_firmware: - send firmware request and wait for it
463  * @firmware_p: pointer to firmware image
464  * @name: name of firmware file
465  * @device: device for which firmware is being loaded
466  *
467  *      @firmware_p will be used to return a firmware image by the name
468  *      of @name for device @device.
469  *
470  *      Should be called from user context where sleeping is allowed.
471  *
472  *      @name will be used as $FIRMWARE in the uevent environment and
473  *      should be distinctive enough not to be confused with any other
474  *      firmware image for this or any other device.
475  **/
476 int
477 request_firmware(const struct firmware **firmware_p, const char *name,
478                  struct device *device)
479 {
480         int uevent = 1;
481         return _request_firmware(firmware_p, name, device, uevent);
482 }
483
484 /**
485  * release_firmware: - release the resource associated with a firmware image
486  * @fw: firmware resource to release
487  **/
488 void
489 release_firmware(const struct firmware *fw)
490 {
491         struct builtin_fw *builtin;
492
493         if (fw) {
494                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
495                      builtin++) {
496                         if (fw->data == builtin->data)
497                                 goto free_fw;
498                 }
499                 vfree(fw->data);
500         free_fw:
501                 kfree(fw);
502         }
503 }
504
505 /* Async support */
506 struct firmware_work {
507         struct work_struct work;
508         struct module *module;
509         const char *name;
510         struct device *device;
511         void *context;
512         void (*cont)(const struct firmware *fw, void *context);
513         int uevent;
514 };
515
516 static int
517 request_firmware_work_func(void *arg)
518 {
519         struct firmware_work *fw_work = arg;
520         const struct firmware *fw;
521         int ret;
522         if (!arg) {
523                 WARN_ON(1);
524                 return 0;
525         }
526         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
527                 fw_work->uevent);
528         if (ret < 0)
529                 fw_work->cont(NULL, fw_work->context);
530         else {
531                 fw_work->cont(fw, fw_work->context);
532                 release_firmware(fw);
533         }
534         module_put(fw_work->module);
535         kfree(fw_work);
536         return ret;
537 }
538
539 /**
540  * request_firmware_nowait: asynchronous version of request_firmware
541  * @module: module requesting the firmware
542  * @uevent: sends uevent to copy the firmware image if this flag
543  *      is non-zero else the firmware copy must be done manually.
544  * @name: name of firmware file
545  * @device: device for which firmware is being loaded
546  * @context: will be passed over to @cont, and
547  *      @fw may be %NULL if firmware request fails.
548  * @cont: function will be called asynchronously when the firmware
549  *      request is over.
550  *
551  *      Asynchronous variant of request_firmware() for contexts where
552  *      it is not possible to sleep.
553  **/
554 int
555 request_firmware_nowait(
556         struct module *module, int uevent,
557         const char *name, struct device *device, void *context,
558         void (*cont)(const struct firmware *fw, void *context))
559 {
560         struct task_struct *task;
561         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
562                                                 GFP_ATOMIC);
563
564         if (!fw_work)
565                 return -ENOMEM;
566         if (!try_module_get(module)) {
567                 kfree(fw_work);
568                 return -EFAULT;
569         }
570
571         *fw_work = (struct firmware_work) {
572                 .module = module,
573                 .name = name,
574                 .device = device,
575                 .context = context,
576                 .cont = cont,
577                 .uevent = uevent,
578         };
579
580         task = kthread_run(request_firmware_work_func, fw_work,
581                             "firmware/%s", name);
582
583         if (IS_ERR(task)) {
584                 fw_work->cont(NULL, fw_work->context);
585                 module_put(fw_work->module);
586                 kfree(fw_work);
587                 return PTR_ERR(task);
588         }
589         return 0;
590 }
591
592 static int __init
593 firmware_class_init(void)
594 {
595         int error;
596         error = class_register(&firmware_class);
597         if (error) {
598                 printk(KERN_ERR "%s: class_register failed\n", __func__);
599                 return error;
600         }
601         error = class_create_file(&firmware_class, &class_attr_timeout);
602         if (error) {
603                 printk(KERN_ERR "%s: class_create_file failed\n",
604                        __func__);
605                 class_unregister(&firmware_class);
606         }
607         return error;
608
609 }
610 static void __exit
611 firmware_class_exit(void)
612 {
613         class_unregister(&firmware_class);
614 }
615
616 fs_initcall(firmware_class_init);
617 module_exit(firmware_class_exit);
618
619 EXPORT_SYMBOL(release_firmware);
620 EXPORT_SYMBOL(request_firmware);
621 EXPORT_SYMBOL(request_firmware_nowait);