[PATCH] kthread: drivers/base/firmware_class.c
[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 <ranty@debian.org>
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 MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
25 MODULE_DESCRIPTION("Multi purpose firmware loading support");
26 MODULE_LICENSE("GPL");
27
28 enum {
29         FW_STATUS_LOADING,
30         FW_STATUS_DONE,
31         FW_STATUS_ABORT,
32         FW_STATUS_READY,
33         FW_STATUS_READY_NOHOTPLUG,
34 };
35
36 static int loading_timeout = 10;        /* 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 static void
53 fw_load_abort(struct firmware_priv *fw_priv)
54 {
55         set_bit(FW_STATUS_ABORT, &fw_priv->status);
56         wmb();
57         complete(&fw_priv->completion);
58 }
59
60 static ssize_t
61 firmware_timeout_show(struct class *class, char *buf)
62 {
63         return sprintf(buf, "%d\n", loading_timeout);
64 }
65
66 /**
67  * firmware_timeout_store - set number of seconds to wait for firmware
68  * @class: device class pointer
69  * @buf: buffer to scan for timeout value
70  * @count: number of bytes in @buf
71  *
72  *      Sets the number of seconds to wait for the firmware.  Once
73  *      this expires an error will be returned to the driver and no
74  *      firmware will be provided.
75  *
76  *      Note: zero means 'wait forever'.
77  **/
78 static ssize_t
79 firmware_timeout_store(struct class *class, const char *buf, size_t count)
80 {
81         loading_timeout = simple_strtol(buf, NULL, 10);
82         if (loading_timeout < 0)
83                 loading_timeout = 0;
84         return count;
85 }
86
87 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
88
89 static void  fw_class_dev_release(struct class_device *class_dev);
90
91 static int firmware_class_uevent(struct class_device *class_dev, char **envp,
92                                  int num_envp, char *buffer, int buffer_size)
93 {
94         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
95         int i = 0, len = 0;
96
97         if (!test_bit(FW_STATUS_READY, &fw_priv->status))
98                 return -ENODEV;
99
100         if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
101                            "FIRMWARE=%s", fw_priv->fw_id))
102                 return -ENOMEM;
103         if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
104                            "TIMEOUT=%i", loading_timeout))
105                 return -ENOMEM;
106         envp[i] = NULL;
107
108         return 0;
109 }
110
111 static struct class firmware_class = {
112         .name           = "firmware",
113         .uevent         = firmware_class_uevent,
114         .release        = fw_class_dev_release,
115 };
116
117 static ssize_t
118 firmware_loading_show(struct class_device *class_dev, char *buf)
119 {
120         struct firmware_priv *fw_priv = class_get_devdata(class_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  * @class_dev: class_device pointer
128  * @buf: buffer to scan for loading control value
129  * @count: number of bytes in @buf
130  *
131  *      The relevant values are:
132  *
133  *       1: Start a load, discarding any previous partial load.
134  *       0: Conclude the load and hand the data to the driver code.
135  *      -1: Conclude the load with an error and discard any written data.
136  **/
137 static ssize_t
138 firmware_loading_store(struct class_device *class_dev,
139                        const char *buf, size_t count)
140 {
141         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
142         int loading = simple_strtol(buf, NULL, 10);
143
144         switch (loading) {
145         case 1:
146                 mutex_lock(&fw_lock);
147                 if (!fw_priv->fw) {
148                         mutex_unlock(&fw_lock);
149                         break;
150                 }
151                 vfree(fw_priv->fw->data);
152                 fw_priv->fw->data = NULL;
153                 fw_priv->fw->size = 0;
154                 fw_priv->alloc_size = 0;
155                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
156                 mutex_unlock(&fw_lock);
157                 break;
158         case 0:
159                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
160                         complete(&fw_priv->completion);
161                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
162                         break;
163                 }
164                 /* fallthrough */
165         default:
166                 printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__,
167                        loading);
168                 /* fallthrough */
169         case -1:
170                 fw_load_abort(fw_priv);
171                 break;
172         }
173
174         return count;
175 }
176
177 static CLASS_DEVICE_ATTR(loading, 0644,
178                         firmware_loading_show, firmware_loading_store);
179
180 static ssize_t
181 firmware_data_read(struct kobject *kobj,
182                    char *buffer, loff_t offset, size_t count)
183 {
184         struct class_device *class_dev = to_class_dev(kobj);
185         struct firmware_priv *fw_priv = class_get_devdata(class_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", __FUNCTION__);
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 class_device
238  * @buffer: buffer being written
239  * @offset: buffer offset for write in total data store area
240  * @count: buffer size
241  *
242  *      Data written to the 'data' attribute will be later handed to
243  *      the driver as a firmware image.
244  **/
245 static ssize_t
246 firmware_data_write(struct kobject *kobj,
247                     char *buffer, loff_t offset, size_t count)
248 {
249         struct class_device *class_dev = to_class_dev(kobj);
250         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
251         struct firmware *fw;
252         ssize_t retval;
253
254         if (!capable(CAP_SYS_RAWIO))
255                 return -EPERM;
256
257         mutex_lock(&fw_lock);
258         fw = fw_priv->fw;
259         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
260                 retval = -ENODEV;
261                 goto out;
262         }
263         retval = fw_realloc_buffer(fw_priv, offset + count);
264         if (retval)
265                 goto out;
266
267         memcpy(fw->data + offset, buffer, count);
268
269         fw->size = max_t(size_t, offset + count, fw->size);
270         retval = count;
271 out:
272         mutex_unlock(&fw_lock);
273         return retval;
274 }
275
276 static struct bin_attribute firmware_attr_data_tmpl = {
277         .attr = {.name = "data", .mode = 0644, .owner = THIS_MODULE},
278         .size = 0,
279         .read = firmware_data_read,
280         .write = firmware_data_write,
281 };
282
283 static void
284 fw_class_dev_release(struct class_device *class_dev)
285 {
286         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
287
288         kfree(fw_priv);
289         kfree(class_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
302 fw_setup_class_device_id(struct class_device *class_dev, struct device *dev)
303 {
304         /* XXX warning we should watch out for name collisions */
305         strlcpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
306 }
307
308 static int
309 fw_register_class_device(struct class_device **class_dev_p,
310                          const char *fw_name, struct device *device)
311 {
312         int retval;
313         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
314                                                 GFP_KERNEL);
315         struct class_device *class_dev = kzalloc(sizeof(*class_dev),
316                                                  GFP_KERNEL);
317
318         *class_dev_p = NULL;
319
320         if (!fw_priv || !class_dev) {
321                 printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);
322                 retval = -ENOMEM;
323                 goto error_kfree;
324         }
325
326         init_completion(&fw_priv->completion);
327         fw_priv->attr_data = firmware_attr_data_tmpl;
328         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
329
330         fw_priv->timeout.function = firmware_class_timeout;
331         fw_priv->timeout.data = (u_long) fw_priv;
332         init_timer(&fw_priv->timeout);
333
334         fw_setup_class_device_id(class_dev, device);
335         class_dev->dev = device;
336         class_dev->class = &firmware_class;
337         class_set_devdata(class_dev, fw_priv);
338         retval = class_device_register(class_dev);
339         if (retval) {
340                 printk(KERN_ERR "%s: class_device_register failed\n",
341                        __FUNCTION__);
342                 goto error_kfree;
343         }
344         *class_dev_p = class_dev;
345         return 0;
346
347 error_kfree:
348         kfree(fw_priv);
349         kfree(class_dev);
350         return retval;
351 }
352
353 static int
354 fw_setup_class_device(struct firmware *fw, struct class_device **class_dev_p,
355                       const char *fw_name, struct device *device, int uevent)
356 {
357         struct class_device *class_dev;
358         struct firmware_priv *fw_priv;
359         int retval;
360
361         *class_dev_p = NULL;
362         retval = fw_register_class_device(&class_dev, fw_name, device);
363         if (retval)
364                 goto out;
365
366         /* Need to pin this module until class device is destroyed */
367         __module_get(THIS_MODULE);
368
369         fw_priv = class_get_devdata(class_dev);
370
371         fw_priv->fw = fw;
372         retval = sysfs_create_bin_file(&class_dev->kobj, &fw_priv->attr_data);
373         if (retval) {
374                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
375                        __FUNCTION__);
376                 goto error_unreg;
377         }
378
379         retval = class_device_create_file(class_dev,
380                                           &class_device_attr_loading);
381         if (retval) {
382                 printk(KERN_ERR "%s: class_device_create_file failed\n",
383                        __FUNCTION__);
384                 goto error_unreg;
385         }
386
387         if (uevent)
388                 set_bit(FW_STATUS_READY, &fw_priv->status);
389         else
390                 set_bit(FW_STATUS_READY_NOHOTPLUG, &fw_priv->status);
391         *class_dev_p = class_dev;
392         goto out;
393
394 error_unreg:
395         class_device_unregister(class_dev);
396 out:
397         return retval;
398 }
399
400 static int
401 _request_firmware(const struct firmware **firmware_p, const char *name,
402                  struct device *device, int uevent)
403 {
404         struct class_device *class_dev;
405         struct firmware_priv *fw_priv;
406         struct firmware *firmware;
407         int retval;
408
409         if (!firmware_p)
410                 return -EINVAL;
411
412         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
413         if (!firmware) {
414                 printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
415                        __FUNCTION__);
416                 retval = -ENOMEM;
417                 goto out;
418         }
419
420         retval = fw_setup_class_device(firmware, &class_dev, name, device,
421                                        uevent);
422         if (retval)
423                 goto error_kfree_fw;
424
425         fw_priv = class_get_devdata(class_dev);
426
427         if (uevent) {
428                 if (loading_timeout > 0) {
429                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
430                         add_timer(&fw_priv->timeout);
431                 }
432
433                 kobject_uevent(&class_dev->kobj, KOBJ_ADD);
434                 wait_for_completion(&fw_priv->completion);
435                 set_bit(FW_STATUS_DONE, &fw_priv->status);
436                 del_timer_sync(&fw_priv->timeout);
437         } else
438                 wait_for_completion(&fw_priv->completion);
439
440         mutex_lock(&fw_lock);
441         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
442                 retval = -ENOENT;
443                 release_firmware(fw_priv->fw);
444                 *firmware_p = NULL;
445         }
446         fw_priv->fw = NULL;
447         mutex_unlock(&fw_lock);
448         class_device_unregister(class_dev);
449         goto out;
450
451 error_kfree_fw:
452         kfree(firmware);
453         *firmware_p = NULL;
454 out:
455         return retval;
456 }
457
458 /**
459  * request_firmware: - send firmware request and wait for it
460  * @firmware_p: pointer to firmware image
461  * @name: name of firmware file
462  * @device: device for which firmware is being loaded
463  *
464  *      @firmware_p will be used to return a firmware image by the name
465  *      of @name for device @device.
466  *
467  *      Should be called from user context where sleeping is allowed.
468  *
469  *      @name will be used as $FIRMWARE in the uevent environment and
470  *      should be distinctive enough not to be confused with any other
471  *      firmware image for this or any other device.
472  **/
473 int
474 request_firmware(const struct firmware **firmware_p, const char *name,
475                  struct device *device)
476 {
477         int uevent = 1;
478         return _request_firmware(firmware_p, name, device, uevent);
479 }
480
481 /**
482  * release_firmware: - release the resource associated with a firmware image
483  * @fw: firmware resource to release
484  **/
485 void
486 release_firmware(const struct firmware *fw)
487 {
488         if (fw) {
489                 vfree(fw->data);
490                 kfree(fw);
491         }
492 }
493
494 /* Async support */
495 struct firmware_work {
496         struct work_struct work;
497         struct module *module;
498         const char *name;
499         struct device *device;
500         void *context;
501         void (*cont)(const struct firmware *fw, void *context);
502         int uevent;
503 };
504
505 static int
506 request_firmware_work_func(void *arg)
507 {
508         struct firmware_work *fw_work = arg;
509         const struct firmware *fw;
510         int ret;
511         if (!arg) {
512                 WARN_ON(1);
513                 return 0;
514         }
515         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
516                 fw_work->uevent);
517         if (ret < 0)
518                 fw_work->cont(NULL, fw_work->context);
519         else {
520                 fw_work->cont(fw, fw_work->context);
521                 release_firmware(fw);
522         }
523         module_put(fw_work->module);
524         kfree(fw_work);
525         return ret;
526 }
527
528 /**
529  * request_firmware_nowait: asynchronous version of request_firmware
530  * @module: module requesting the firmware
531  * @uevent: sends uevent to copy the firmware image if this flag
532  *      is non-zero else the firmware copy must be done manually.
533  * @name: name of firmware file
534  * @device: device for which firmware is being loaded
535  * @context: will be passed over to @cont, and
536  *      @fw may be %NULL if firmware request fails.
537  * @cont: function will be called asynchronously when the firmware
538  *      request is over.
539  *
540  *      Asynchronous variant of request_firmware() for contexts where
541  *      it is not possible to sleep.
542  **/
543 int
544 request_firmware_nowait(
545         struct module *module, int uevent,
546         const char *name, struct device *device, void *context,
547         void (*cont)(const struct firmware *fw, void *context))
548 {
549         struct task_struct *task;
550         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
551                                                 GFP_ATOMIC);
552
553         if (!fw_work)
554                 return -ENOMEM;
555         if (!try_module_get(module)) {
556                 kfree(fw_work);
557                 return -EFAULT;
558         }
559
560         *fw_work = (struct firmware_work) {
561                 .module = module,
562                 .name = name,
563                 .device = device,
564                 .context = context,
565                 .cont = cont,
566                 .uevent = uevent,
567         };
568
569         task = kthread_run(request_firmware_work_func, fw_work,
570                             "firmware/%s", name);
571
572         if (IS_ERR(task)) {
573                 fw_work->cont(NULL, fw_work->context);
574                 module_put(fw_work->module);
575                 kfree(fw_work);
576                 return PTR_ERR(task);
577         }
578         return 0;
579 }
580
581 static int __init
582 firmware_class_init(void)
583 {
584         int error;
585         error = class_register(&firmware_class);
586         if (error) {
587                 printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__);
588                 return error;
589         }
590         error = class_create_file(&firmware_class, &class_attr_timeout);
591         if (error) {
592                 printk(KERN_ERR "%s: class_create_file failed\n",
593                        __FUNCTION__);
594                 class_unregister(&firmware_class);
595         }
596         return error;
597
598 }
599 static void __exit
600 firmware_class_exit(void)
601 {
602         class_unregister(&firmware_class);
603 }
604
605 fs_initcall(firmware_class_init);
606 module_exit(firmware_class_exit);
607
608 EXPORT_SYMBOL(release_firmware);
609 EXPORT_SYMBOL(request_firmware);
610 EXPORT_SYMBOL(request_firmware_nowait);