parisc: sba_iommu: fix build bug when CONFIG_PARISC_AGP=y
[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
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                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
168                 /* fallthrough */
169         case -1:
170                 fw_load_abort(fw_priv);
171                 break;
172         }
173
174         return count;
175 }
176
177 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
178
179 static ssize_t
180 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
181                    char *buffer, loff_t offset, size_t count)
182 {
183         struct device *dev = to_dev(kobj);
184         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
185         struct firmware *fw;
186         ssize_t ret_count;
187
188         mutex_lock(&fw_lock);
189         fw = fw_priv->fw;
190         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
191                 ret_count = -ENODEV;
192                 goto out;
193         }
194         ret_count = memory_read_from_buffer(buffer, count, &offset,
195                                                 fw->data, fw->size);
196 out:
197         mutex_unlock(&fw_lock);
198         return ret_count;
199 }
200
201 static int
202 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
203 {
204         u8 *new_data;
205         int new_size = fw_priv->alloc_size;
206
207         if (min_size <= fw_priv->alloc_size)
208                 return 0;
209
210         new_size = ALIGN(min_size, PAGE_SIZE);
211         new_data = vmalloc(new_size);
212         if (!new_data) {
213                 printk(KERN_ERR "%s: unable to alloc buffer\n", __func__);
214                 /* Make sure that we don't keep incomplete data */
215                 fw_load_abort(fw_priv);
216                 return -ENOMEM;
217         }
218         fw_priv->alloc_size = new_size;
219         if (fw_priv->fw->data) {
220                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
221                 vfree(fw_priv->fw->data);
222         }
223         fw_priv->fw->data = new_data;
224         BUG_ON(min_size > fw_priv->alloc_size);
225         return 0;
226 }
227
228 /**
229  * firmware_data_write - write method for firmware
230  * @kobj: kobject for the device
231  * @bin_attr: bin_attr structure
232  * @buffer: buffer being written
233  * @offset: buffer offset for write in total data store area
234  * @count: buffer size
235  *
236  *      Data written to the 'data' attribute will be later handed to
237  *      the driver as a firmware image.
238  **/
239 static ssize_t
240 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
241                     char *buffer, loff_t offset, size_t count)
242 {
243         struct device *dev = to_dev(kobj);
244         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
245         struct firmware *fw;
246         ssize_t retval;
247
248         if (!capable(CAP_SYS_RAWIO))
249                 return -EPERM;
250
251         mutex_lock(&fw_lock);
252         fw = fw_priv->fw;
253         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
254                 retval = -ENODEV;
255                 goto out;
256         }
257         retval = fw_realloc_buffer(fw_priv, offset + count);
258         if (retval)
259                 goto out;
260
261         memcpy((u8 *)fw->data + offset, buffer, count);
262
263         fw->size = max_t(size_t, offset + count, fw->size);
264         retval = count;
265 out:
266         mutex_unlock(&fw_lock);
267         return retval;
268 }
269
270 static struct bin_attribute firmware_attr_data_tmpl = {
271         .attr = {.name = "data", .mode = 0644},
272         .size = 0,
273         .read = firmware_data_read,
274         .write = firmware_data_write,
275 };
276
277 static void fw_dev_release(struct device *dev)
278 {
279         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
280
281         kfree(fw_priv);
282         kfree(dev);
283
284         module_put(THIS_MODULE);
285 }
286
287 static void
288 firmware_class_timeout(u_long data)
289 {
290         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
291         fw_load_abort(fw_priv);
292 }
293
294 static int fw_register_device(struct device **dev_p, const char *fw_name,
295                               struct device *device)
296 {
297         int retval;
298         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
299                                                 GFP_KERNEL);
300         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
301
302         *dev_p = NULL;
303
304         if (!fw_priv || !f_dev) {
305                 dev_err(device, "%s: kmalloc failed\n", __func__);
306                 retval = -ENOMEM;
307                 goto error_kfree;
308         }
309
310         init_completion(&fw_priv->completion);
311         fw_priv->attr_data = firmware_attr_data_tmpl;
312         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
313
314         fw_priv->timeout.function = firmware_class_timeout;
315         fw_priv->timeout.data = (u_long) fw_priv;
316         init_timer(&fw_priv->timeout);
317
318         dev_set_name(f_dev, dev_name(device));
319         f_dev->parent = device;
320         f_dev->class = &firmware_class;
321         dev_set_drvdata(f_dev, fw_priv);
322         f_dev->uevent_suppress = 1;
323         retval = device_register(f_dev);
324         if (retval) {
325                 dev_err(device, "%s: device_register failed\n", __func__);
326                 goto error_kfree;
327         }
328         *dev_p = f_dev;
329         return 0;
330
331 error_kfree:
332         kfree(fw_priv);
333         kfree(f_dev);
334         return retval;
335 }
336
337 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
338                            const char *fw_name, struct device *device,
339                            int uevent)
340 {
341         struct device *f_dev;
342         struct firmware_priv *fw_priv;
343         int retval;
344
345         *dev_p = NULL;
346         retval = fw_register_device(&f_dev, fw_name, device);
347         if (retval)
348                 goto out;
349
350         /* Need to pin this module until class device is destroyed */
351         __module_get(THIS_MODULE);
352
353         fw_priv = dev_get_drvdata(f_dev);
354
355         fw_priv->fw = fw;
356         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
357         if (retval) {
358                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
359                 goto error_unreg;
360         }
361
362         retval = device_create_file(f_dev, &dev_attr_loading);
363         if (retval) {
364                 dev_err(device, "%s: device_create_file failed\n", __func__);
365                 goto error_unreg;
366         }
367
368         if (uevent)
369                 f_dev->uevent_suppress = 0;
370         *dev_p = f_dev;
371         goto out;
372
373 error_unreg:
374         device_unregister(f_dev);
375 out:
376         return retval;
377 }
378
379 static int
380 _request_firmware(const struct firmware **firmware_p, const char *name,
381                  struct device *device, int uevent)
382 {
383         struct device *f_dev;
384         struct firmware_priv *fw_priv;
385         struct firmware *firmware;
386         struct builtin_fw *builtin;
387         int retval;
388
389         if (!firmware_p)
390                 return -EINVAL;
391
392         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
393         if (!firmware) {
394                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
395                         __func__);
396                 retval = -ENOMEM;
397                 goto out;
398         }
399
400         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
401              builtin++) {
402                 if (strcmp(name, builtin->name))
403                         continue;
404                 dev_info(device, "firmware: using built-in firmware %s\n",
405                          name);
406                 firmware->size = builtin->size;
407                 firmware->data = builtin->data;
408                 return 0;
409         }
410
411         if (uevent)
412                 dev_info(device, "firmware: requesting %s\n", name);
413
414         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
415         if (retval)
416                 goto error_kfree_fw;
417
418         fw_priv = dev_get_drvdata(f_dev);
419
420         if (uevent) {
421                 if (loading_timeout > 0) {
422                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
423                         add_timer(&fw_priv->timeout);
424                 }
425
426                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
427                 wait_for_completion(&fw_priv->completion);
428                 set_bit(FW_STATUS_DONE, &fw_priv->status);
429                 del_timer_sync(&fw_priv->timeout);
430         } else
431                 wait_for_completion(&fw_priv->completion);
432
433         mutex_lock(&fw_lock);
434         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
435                 retval = -ENOENT;
436                 release_firmware(fw_priv->fw);
437                 *firmware_p = NULL;
438         }
439         fw_priv->fw = NULL;
440         mutex_unlock(&fw_lock);
441         device_unregister(f_dev);
442         goto out;
443
444 error_kfree_fw:
445         kfree(firmware);
446         *firmware_p = NULL;
447 out:
448         return retval;
449 }
450
451 /**
452  * request_firmware: - send firmware request and wait for it
453  * @firmware_p: pointer to firmware image
454  * @name: name of firmware file
455  * @device: device for which firmware is being loaded
456  *
457  *      @firmware_p will be used to return a firmware image by the name
458  *      of @name for device @device.
459  *
460  *      Should be called from user context where sleeping is allowed.
461  *
462  *      @name will be used as $FIRMWARE in the uevent environment and
463  *      should be distinctive enough not to be confused with any other
464  *      firmware image for this or any other device.
465  **/
466 int
467 request_firmware(const struct firmware **firmware_p, const char *name,
468                  struct device *device)
469 {
470         int uevent = 1;
471         return _request_firmware(firmware_p, name, device, uevent);
472 }
473
474 /**
475  * release_firmware: - release the resource associated with a firmware image
476  * @fw: firmware resource to release
477  **/
478 void
479 release_firmware(const struct firmware *fw)
480 {
481         struct builtin_fw *builtin;
482
483         if (fw) {
484                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
485                      builtin++) {
486                         if (fw->data == builtin->data)
487                                 goto free_fw;
488                 }
489                 vfree(fw->data);
490         free_fw:
491                 kfree(fw);
492         }
493 }
494
495 /* Async support */
496 struct firmware_work {
497         struct work_struct work;
498         struct module *module;
499         const char *name;
500         struct device *device;
501         void *context;
502         void (*cont)(const struct firmware *fw, void *context);
503         int uevent;
504 };
505
506 static int
507 request_firmware_work_func(void *arg)
508 {
509         struct firmware_work *fw_work = arg;
510         const struct firmware *fw;
511         int ret;
512         if (!arg) {
513                 WARN_ON(1);
514                 return 0;
515         }
516         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
517                 fw_work->uevent);
518         if (ret < 0)
519                 fw_work->cont(NULL, fw_work->context);
520         else {
521                 fw_work->cont(fw, fw_work->context);
522                 release_firmware(fw);
523         }
524         module_put(fw_work->module);
525         kfree(fw_work);
526         return ret;
527 }
528
529 /**
530  * request_firmware_nowait: asynchronous version of request_firmware
531  * @module: module requesting the firmware
532  * @uevent: sends uevent to copy the firmware image if this flag
533  *      is non-zero else the firmware copy must be done manually.
534  * @name: name of firmware file
535  * @device: device for which firmware is being loaded
536  * @context: will be passed over to @cont, and
537  *      @fw may be %NULL if firmware request fails.
538  * @cont: function will be called asynchronously when the firmware
539  *      request is over.
540  *
541  *      Asynchronous variant of request_firmware() for contexts where
542  *      it is not possible to sleep.
543  **/
544 int
545 request_firmware_nowait(
546         struct module *module, int uevent,
547         const char *name, struct device *device, void *context,
548         void (*cont)(const struct firmware *fw, void *context))
549 {
550         struct task_struct *task;
551         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
552                                                 GFP_ATOMIC);
553
554         if (!fw_work)
555                 return -ENOMEM;
556         if (!try_module_get(module)) {
557                 kfree(fw_work);
558                 return -EFAULT;
559         }
560
561         *fw_work = (struct firmware_work) {
562                 .module = module,
563                 .name = name,
564                 .device = device,
565                 .context = context,
566                 .cont = cont,
567                 .uevent = uevent,
568         };
569
570         task = kthread_run(request_firmware_work_func, fw_work,
571                             "firmware/%s", name);
572
573         if (IS_ERR(task)) {
574                 fw_work->cont(NULL, fw_work->context);
575                 module_put(fw_work->module);
576                 kfree(fw_work);
577                 return PTR_ERR(task);
578         }
579         return 0;
580 }
581
582 static int __init
583 firmware_class_init(void)
584 {
585         int error;
586         error = class_register(&firmware_class);
587         if (error) {
588                 printk(KERN_ERR "%s: class_register failed\n", __func__);
589                 return error;
590         }
591         error = class_create_file(&firmware_class, &class_attr_timeout);
592         if (error) {
593                 printk(KERN_ERR "%s: class_create_file failed\n",
594                        __func__);
595                 class_unregister(&firmware_class);
596         }
597         return error;
598
599 }
600 static void __exit
601 firmware_class_exit(void)
602 {
603         class_unregister(&firmware_class);
604 }
605
606 fs_initcall(firmware_class_init);
607 module_exit(firmware_class_exit);
608
609 EXPORT_SYMBOL(release_firmware);
610 EXPORT_SYMBOL(request_firmware);
611 EXPORT_SYMBOL(request_firmware_nowait);