drivers/base/firmware_class.c - kernel/msm-4.9 - Gitiles

 /*
  * firmware_class.c - Multi purpose firmware loading support
  *
  * Copyright (c) 2003 Manuel Estrada Sainz
  *
  * Please see Documentation/firmware_class/ for more information.
  *
  */

 #include <linux/capability.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/timer.h>
 #include <linux/vmalloc.h>
 #include <linux/interrupt.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
 #include <linux/kthread.h>
 #include <linux/highmem.h>
 #include <linux/firmware.h>
 #include <linux/slab.h>

 #define to_dev(obj) container_of(obj, struct device, kobj)

 MODULE_AUTHOR("Manuel Estrada Sainz");
 MODULE_DESCRIPTION("Multi purpose firmware loading support");
 MODULE_LICENSE("GPL");

 /* Builtin firmware support */

 #ifdef CONFIG_FW_LOADER

 extern struct builtin_fw __start_builtin_fw[];
 extern struct builtin_fw __end_builtin_fw[];

 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
 {
 	struct builtin_fw *b_fw;

 	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 		if (strcmp(name, b_fw->name) == 0) {
 			fw->size = b_fw->size;
 			fw->data = b_fw->data;
 			return true;
 		}
 	}

 	return false;
 }

 static bool fw_is_builtin_firmware(const struct firmware *fw)
 {
 	struct builtin_fw *b_fw;

 	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
 		if (fw->data == b_fw->data)
 			return true;

 	return false;
 }

 #else /* Module case - no builtin firmware support */

 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
 {
 	return false;
 }

 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
 {
 	return false;
 }
 #endif

 enum {
 	FW_STATUS_LOADING,
 	FW_STATUS_DONE,
 	FW_STATUS_ABORT,
 };

 static int loading_timeout = 60;	/* In seconds */

 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
  * guarding for corner cases a global lock should be OK */
 static DEFINE_MUTEX(fw_lock);

 struct firmware_priv {
 	struct completion completion;
 	struct firmware *fw;
 	unsigned long status;
 	struct page **pages;
 	int nr_pages;
 	int page_array_size;
 	struct timer_list timeout;
 	struct device dev;
 	bool nowait;
 	char fw_id[];
 };

 static struct firmware_priv *to_firmware_priv(struct device *dev)
 {
 	return container_of(dev, struct firmware_priv, dev);
 }

 static void fw_load_abort(struct firmware_priv *fw_priv)
 {
 	set_bit(FW_STATUS_ABORT, &fw_priv->status);
 	wmb();
 	complete(&fw_priv->completion);
 }

 static ssize_t firmware_timeout_show(struct class *class,
 				     struct class_attribute *attr,
 				     char *buf)
 {
 	return sprintf(buf, "%d\n", loading_timeout);
 }

 /**
  * firmware_timeout_store - set number of seconds to wait for firmware
  * @class: device class pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for timeout value
  * @count: number of bytes in @buf
  *
  *	Sets the number of seconds to wait for the firmware.  Once
  *	this expires an error will be returned to the driver and no
  *	firmware will be provided.
  *
  *	Note: zero means 'wait forever'.
  **/
 static ssize_t firmware_timeout_store(struct class *class,
 				      struct class_attribute *attr,
 				      const char *buf, size_t count)
 {
 	loading_timeout = simple_strtol(buf, NULL, 10);
 	if (loading_timeout < 0)
 		loading_timeout = 0;

 	return count;
 }

 static struct class_attribute firmware_class_attrs[] = {
 	__ATTR(timeout, S_IWUSR | S_IRUGO,
 		firmware_timeout_show, firmware_timeout_store),
 	__ATTR_NULL
 };

 static void fw_dev_release(struct device *dev)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 	int i;

 	for (i = 0; i < fw_priv->nr_pages; i++)
 		__free_page(fw_priv->pages[i]);
 	kfree(fw_priv->pages);
 	kfree(fw_priv);

 	module_put(THIS_MODULE);
 }

 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);

 	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
 		return -ENOMEM;
 	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
 		return -ENOMEM;
 	if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
 		return -ENOMEM;

 	return 0;
 }

 static struct class firmware_class = {
 	.name		= "firmware",
 	.class_attrs	= firmware_class_attrs,
 	.dev_uevent	= firmware_uevent,
 	.dev_release	= fw_dev_release,
 };

 static ssize_t firmware_loading_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 	int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);

 	return sprintf(buf, "%d\n", loading);
 }

 static void firmware_free_data(const struct firmware *fw)
 {
 	int i;
 	vunmap(fw->data);
 	if (fw->pages) {
 		for (i = 0; i < PFN_UP(fw->size); i++)
 			__free_page(fw->pages[i]);
 		kfree(fw->pages);
 	}
 }

 /* Some architectures don't have PAGE_KERNEL_RO */
 #ifndef PAGE_KERNEL_RO
 #define PAGE_KERNEL_RO PAGE_KERNEL
 #endif
 /**
  * firmware_loading_store - set value in the 'loading' control file
  * @dev: device pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for loading control value
  * @count: number of bytes in @buf
  *
  *	The relevant values are:
  *
  *	 1: Start a load, discarding any previous partial load.
  *	 0: Conclude the load and hand the data to the driver code.
  *	-1: Conclude the load with an error and discard any written data.
  **/
 static ssize_t firmware_loading_store(struct device *dev,
 				      struct device_attribute *attr,
 				      const char *buf, size_t count)
 {
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 	int loading = simple_strtol(buf, NULL, 10);
 	int i;

 	switch (loading) {
 	case 1:
 		mutex_lock(&fw_lock);
 		if (!fw_priv->fw) {
 			mutex_unlock(&fw_lock);
 			break;
 		}
 		firmware_free_data(fw_priv->fw);
 		memset(fw_priv->fw, 0, sizeof(struct firmware));
 		/* If the pages are not owned by 'struct firmware' */
 		for (i = 0; i < fw_priv->nr_pages; i++)
 			__free_page(fw_priv->pages[i]);
 		kfree(fw_priv->pages);
 		fw_priv->pages = NULL;
 		fw_priv->page_array_size = 0;
 		fw_priv->nr_pages = 0;
 		set_bit(FW_STATUS_LOADING, &fw_priv->status);
 		mutex_unlock(&fw_lock);
 		break;
 	case 0:
 		if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
 			vunmap(fw_priv->fw->data);
 			fw_priv->fw->data = vmap(fw_priv->pages,
 						 fw_priv->nr_pages,
 						 0, PAGE_KERNEL_RO);
 			if (!fw_priv->fw->data) {
 				dev_err(dev, "%s: vmap() failed\n", __func__);
 				goto err;
 			}
 			/* Pages are now owned by 'struct firmware' */
 			fw_priv->fw->pages = fw_priv->pages;
 			fw_priv->pages = NULL;

 			fw_priv->page_array_size = 0;
 			fw_priv->nr_pages = 0;
 			complete(&fw_priv->completion);
 			clear_bit(FW_STATUS_LOADING, &fw_priv->status);
 			break;
 		}
 		/* fallthrough */
 	default:
 		dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
 		/* fallthrough */
 	case -1:
 	err:
 		fw_load_abort(fw_priv);
 		break;
 	}

 	return count;
 }

 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);

 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
 				  struct bin_attribute *bin_attr,
 				  char *buffer, loff_t offset, size_t count)
 {
 	struct device *dev = to_dev(kobj);
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 	struct firmware *fw;
 	ssize_t ret_count;

 	mutex_lock(&fw_lock);
 	fw = fw_priv->fw;
 	if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 		ret_count = -ENODEV;
 		goto out;
 	}
 	if (offset > fw->size) {
 		ret_count = 0;
 		goto out;
 	}
 	if (count > fw->size - offset)
 		count = fw->size - offset;

 	ret_count = count;

 	while (count) {
 		void *page_data;
 		int page_nr = offset >> PAGE_SHIFT;
 		int page_ofs = offset & (PAGE_SIZE-1);
 		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);

 		page_data = kmap(fw_priv->pages[page_nr]);

 		memcpy(buffer, page_data + page_ofs, page_cnt);

 		kunmap(fw_priv->pages[page_nr]);
 		buffer += page_cnt;
 		offset += page_cnt;
 		count -= page_cnt;
 	}
 out:
 	mutex_unlock(&fw_lock);
 	return ret_count;
 }

 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
 {
 	int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;

 	/* If the array of pages is too small, grow it... */
 	if (fw_priv->page_array_size < pages_needed) {
 		int new_array_size = max(pages_needed,
 					 fw_priv->page_array_size * 2);
 		struct page **new_pages;

 		new_pages = kmalloc(new_array_size * sizeof(void *),
 				    GFP_KERNEL);
 		if (!new_pages) {
 			fw_load_abort(fw_priv);
 			return -ENOMEM;
 		}
 		memcpy(new_pages, fw_priv->pages,
 		       fw_priv->page_array_size * sizeof(void *));
 		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
 		       (new_array_size - fw_priv->page_array_size));
 		kfree(fw_priv->pages);
 		fw_priv->pages = new_pages;
 		fw_priv->page_array_size = new_array_size;
 	}

 	while (fw_priv->nr_pages < pages_needed) {
 		fw_priv->pages[fw_priv->nr_pages] =
 			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);

 		if (!fw_priv->pages[fw_priv->nr_pages]) {
 			fw_load_abort(fw_priv);
 			return -ENOMEM;
 		}
 		fw_priv->nr_pages++;
 	}
 	return 0;
 }

 /**
  * firmware_data_write - write method for firmware
  * @filp: open sysfs file
  * @kobj: kobject for the device
  * @bin_attr: bin_attr structure
  * @buffer: buffer being written
  * @offset: buffer offset for write in total data store area
  * @count: buffer size
  *
  *	Data written to the 'data' attribute will be later handed to
  *	the driver as a firmware image.
  **/
 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
 				   struct bin_attribute *bin_attr,
 				   char *buffer, loff_t offset, size_t count)
 {
 	struct device *dev = to_dev(kobj);
 	struct firmware_priv *fw_priv = to_firmware_priv(dev);
 	struct firmware *fw;
 	ssize_t retval;

 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;

 	mutex_lock(&fw_lock);
 	fw = fw_priv->fw;
 	if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
 		retval = -ENODEV;
 		goto out;
 	}
 	retval = fw_realloc_buffer(fw_priv, offset + count);
 	if (retval)
 		goto out;

 	retval = count;

 	while (count) {
 		void *page_data;
 		int page_nr = offset >> PAGE_SHIFT;
 		int page_ofs = offset & (PAGE_SIZE - 1);
 		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);

 		page_data = kmap(fw_priv->pages[page_nr]);

 		memcpy(page_data + page_ofs, buffer, page_cnt);

 		kunmap(fw_priv->pages[page_nr]);
 		buffer += page_cnt;
 		offset += page_cnt;
 		count -= page_cnt;
 	}

 	fw->size = max_t(size_t, offset, fw->size);
 out:
 	mutex_unlock(&fw_lock);
 	return retval;
 }

 static struct bin_attribute firmware_attr_data = {
 	.attr = { .name = "data", .mode = 0644 },
 	.size = 0,
 	.read = firmware_data_read,
 	.write = firmware_data_write,
 };

 static void firmware_class_timeout(u_long data)
 {
 	struct firmware_priv *fw_priv = (struct firmware_priv *) data;

 	fw_load_abort(fw_priv);
 }

 static struct firmware_priv *
 fw_create_instance(struct firmware *firmware, const char *fw_name,
 		   struct device *device, bool uevent, bool nowait)
 {
 	struct firmware_priv *fw_priv;
 	struct device *f_dev;
 	int error;

 	fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
 	if (!fw_priv) {
 		dev_err(device, "%s: kmalloc failed\n", __func__);
 		error = -ENOMEM;
 		goto err_out;
 	}

 	fw_priv->fw = firmware;
 	fw_priv->nowait = nowait;
 	strcpy(fw_priv->fw_id, fw_name);
 	init_completion(&fw_priv->completion);
 	setup_timer(&fw_priv->timeout,
 		    firmware_class_timeout, (u_long) fw_priv);

 	f_dev = &fw_priv->dev;

 	device_initialize(f_dev);
 	dev_set_name(f_dev, "%s", dev_name(device));
 	f_dev->parent = device;
 	f_dev->class = &firmware_class;

 	dev_set_uevent_suppress(f_dev, true);

 	/* Need to pin this module until class device is destroyed */
 	__module_get(THIS_MODULE);

 	error = device_add(f_dev);
 	if (error) {
 		dev_err(device, "%s: device_register failed\n", __func__);
 		goto err_put_dev;
 	}

 	error = device_create_bin_file(f_dev, &firmware_attr_data);
 	if (error) {
 		dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
 		goto err_del_dev;
 	}

 	error = device_create_file(f_dev, &dev_attr_loading);
 	if (error) {
 		dev_err(device, "%s: device_create_file failed\n", __func__);
 		goto err_del_bin_attr;
 	}

 	if (uevent)
 		dev_set_uevent_suppress(f_dev, false);

 	return fw_priv;

 err_del_bin_attr:
 	device_remove_bin_file(f_dev, &firmware_attr_data);
 err_del_dev:
 	device_del(f_dev);
 err_put_dev:
 	put_device(f_dev);
 err_out:
 	return ERR_PTR(error);
 }

 static void fw_destroy_instance(struct firmware_priv *fw_priv)
 {
 	struct device *f_dev = &fw_priv->dev;

 	device_remove_file(f_dev, &dev_attr_loading);
 	device_remove_bin_file(f_dev, &firmware_attr_data);
 	device_unregister(f_dev);
 }

 static int _request_firmware(const struct firmware **firmware_p,
 			     const char *name, struct device *device,
 			     bool uevent, bool nowait)
 {
 	struct firmware_priv *fw_priv;
 	struct firmware *firmware;
 	int retval = 0;

 	if (!firmware_p)
 		return -EINVAL;

 	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 	if (!firmware) {
 		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
 			__func__);
 		retval = -ENOMEM;
 		goto out;
 	}

 	if (fw_get_builtin_firmware(firmware, name)) {
 		dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 		return 0;
 	}

 	if (uevent)
 		dev_dbg(device, "firmware: requesting %s\n", name);

 	fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
 	if (IS_ERR(fw_priv)) {
 		retval = PTR_ERR(fw_priv);
 		goto out;
 	}

 	if (uevent) {
 		if (loading_timeout > 0)
 			mod_timer(&fw_priv->timeout,
 				  round_jiffies_up(jiffies +
 						   loading_timeout * HZ));

 		kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
 	}

 	wait_for_completion(&fw_priv->completion);

 	set_bit(FW_STATUS_DONE, &fw_priv->status);
 	del_timer_sync(&fw_priv->timeout);

 	mutex_lock(&fw_lock);
 	if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status))
 		retval = -ENOENT;
 	fw_priv->fw = NULL;
 	mutex_unlock(&fw_lock);

 	fw_destroy_instance(fw_priv);

 out:
 	if (retval) {
 		release_firmware(firmware);
 		*firmware_p = NULL;
 	}

 	return retval;
 }

 /**
  * request_firmware: - send firmware request and wait for it
  * @firmware_p: pointer to firmware image
  * @name: name of firmware file
  * @device: device for which firmware is being loaded
  *
  *      @firmware_p will be used to return a firmware image by the name
  *      of @name for device @device.
  *
  *      Should be called from user context where sleeping is allowed.
  *
  *      @name will be used as $FIRMWARE in the uevent environment and
  *      should be distinctive enough not to be confused with any other
  *      firmware image for this or any other device.
  **/
 int
 request_firmware(const struct firmware **firmware_p, const char *name,
                  struct device *device)
 {
         return _request_firmware(firmware_p, name, device, true, false);
 }

 /**
  * release_firmware: - release the resource associated with a firmware image
  * @fw: firmware resource to release
  **/
 void release_firmware(const struct firmware *fw)
 {
 	if (fw) {
 		if (!fw_is_builtin_firmware(fw))
 			firmware_free_data(fw);
 		kfree(fw);
 	}
 }

 /* Async support */
 struct firmware_work {
 	struct work_struct work;
 	struct module *module;
 	const char *name;
 	struct device *device;
 	void *context;
 	void (*cont)(const struct firmware *fw, void *context);
 	bool uevent;
 };

 static int request_firmware_work_func(void *arg)
 {
 	struct firmware_work *fw_work = arg;
 	const struct firmware *fw;
 	int ret;

 	if (!arg) {
 		WARN_ON(1);
 		return 0;
 	}

 	ret = _request_firmware(&fw, fw_work->name, fw_work->device,
 				fw_work->uevent, true);
 	fw_work->cont(fw, fw_work->context);

 	module_put(fw_work->module);
 	kfree(fw_work);

 	return ret;
 }

 /**
  * request_firmware_nowait - asynchronous version of request_firmware
  * @module: module requesting the firmware
  * @uevent: sends uevent to copy the firmware image if this flag
  *	is non-zero else the firmware copy must be done manually.
  * @name: name of firmware file
  * @device: device for which firmware is being loaded
  * @gfp: allocation flags
  * @context: will be passed over to @cont, and
  *	@fw may be %NULL if firmware request fails.
  * @cont: function will be called asynchronously when the firmware
  *	request is over.
  *
  *	Asynchronous variant of request_firmware() for user contexts where
  *	it is not possible to sleep for long time. It can't be called
  *	in atomic contexts.
  **/
 int
 request_firmware_nowait(
 	struct module *module, bool uevent,
 	const char *name, struct device *device, gfp_t gfp, void *context,
 	void (*cont)(const struct firmware *fw, void *context))
 {
 	struct task_struct *task;
 	struct firmware_work *fw_work;

 	fw_work = kzalloc(sizeof (struct firmware_work), gfp);
 	if (!fw_work)
 		return -ENOMEM;

 	fw_work->module = module;
 	fw_work->name = name;
 	fw_work->device = device;
 	fw_work->context = context;
 	fw_work->cont = cont;
 	fw_work->uevent = uevent;

 	if (!try_module_get(module)) {
 		kfree(fw_work);
 		return -EFAULT;
 	}

 	task = kthread_run(request_firmware_work_func, fw_work,
 			    "firmware/%s", name);
 	if (IS_ERR(task)) {
 		fw_work->cont(NULL, fw_work->context);
 		module_put(fw_work->module);
 		kfree(fw_work);
 		return PTR_ERR(task);
 	}

 	return 0;
 }

 static int __init firmware_class_init(void)
 {
 	return class_register(&firmware_class);
 }

 static void __exit firmware_class_exit(void)
 {
 	class_unregister(&firmware_class);
 }

 fs_initcall(firmware_class_init);
 module_exit(firmware_class_exit);

 EXPORT_SYMBOL(release_firmware);
 EXPORT_SYMBOL(request_firmware);
 EXPORT_SYMBOL(request_firmware_nowait);
	/*
	* firmware_class.c - Multi purpose firmware loading support
	*
	* Copyright (c) 2003 Manuel Estrada Sainz
	*
	* Please see Documentation/firmware_class/ for more information.
	*
	*/

	#include <linux/capability.h>
	#include <linux/device.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/timer.h>
	#include <linux/vmalloc.h>
	#include <linux/interrupt.h>
	#include <linux/bitops.h>
	#include <linux/mutex.h>
	#include <linux/kthread.h>
	#include <linux/highmem.h>
	#include <linux/firmware.h>
	#include <linux/slab.h>

	#define to_dev(obj) container_of(obj, struct device, kobj)

	MODULE_AUTHOR("Manuel Estrada Sainz");
	MODULE_DESCRIPTION("Multi purpose firmware loading support");
	MODULE_LICENSE("GPL");

	/* Builtin firmware support */

	#ifdef CONFIG_FW_LOADER

	extern struct builtin_fw __start_builtin_fw[];
	extern struct builtin_fw __end_builtin_fw[];

	static bool fw_get_builtin_firmware(struct firmware fw, const char name)
	{
	struct builtin_fw *b_fw;

	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
	if (strcmp(name, b_fw->name) == 0) {
	fw->size = b_fw->size;
	fw->data = b_fw->data;
	return true;
	}
	}

	return false;
	}

	static bool fw_is_builtin_firmware(const struct firmware *fw)
	{
	struct builtin_fw *b_fw;

	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
	if (fw->data == b_fw->data)
	return true;

	return false;
	}

	#else /* Module case - no builtin firmware support */

	static inline bool fw_get_builtin_firmware(struct firmware fw, const char name)
	{
	return false;
	}

	static inline bool fw_is_builtin_firmware(const struct firmware *fw)
	{
	return false;
	}
	#endif

	enum {
	FW_STATUS_LOADING,
	FW_STATUS_DONE,
	FW_STATUS_ABORT,
	};

	static int loading_timeout = 60; /* In seconds */

	/* fw_lock could be moved to 'struct firmware_priv' but since it is just
	* guarding for corner cases a global lock should be OK */
	static DEFINE_MUTEX(fw_lock);

	struct firmware_priv {
	struct completion completion;
	struct firmware *fw;
	unsigned long status;
	struct page **pages;
	int nr_pages;
	int page_array_size;
	struct timer_list timeout;
	struct device dev;
	bool nowait;
	char fw_id[];
	};

	static struct firmware_priv to_firmware_priv(struct device dev)
	{
	return container_of(dev, struct firmware_priv, dev);
	}

	static void fw_load_abort(struct firmware_priv *fw_priv)
	{
	set_bit(FW_STATUS_ABORT, &fw_priv->status);
	wmb();
	complete(&fw_priv->completion);
	}

	static ssize_t firmware_timeout_show(struct class *class,
	struct class_attribute *attr,
	char *buf)
	{
	return sprintf(buf, "%d\n", loading_timeout);
	}

	/**
	* firmware_timeout_store - set number of seconds to wait for firmware
	* @class: device class pointer
	* @attr: device attribute pointer
	* @buf: buffer to scan for timeout value
	* @count: number of bytes in @buf
	*
	* Sets the number of seconds to wait for the firmware. Once
	* this expires an error will be returned to the driver and no
	* firmware will be provided.
	*
	* Note: zero means 'wait forever'.
	**/
	static ssize_t firmware_timeout_store(struct class *class,
	struct class_attribute *attr,
	const char *buf, size_t count)
	{
	loading_timeout = simple_strtol(buf, NULL, 10);
	if (loading_timeout < 0)
	loading_timeout = 0;

	return count;
	}

	static struct class_attribute firmware_class_attrs[] = {
	__ATTR(timeout, S_IWUSR \| S_IRUGO,
	firmware_timeout_show, firmware_timeout_store),
	__ATTR_NULL
	};

	static void fw_dev_release(struct device *dev)
	{
	struct firmware_priv *fw_priv = to_firmware_priv(dev);
	int i;

	for (i = 0; i < fw_priv->nr_pages; i++)
	__free_page(fw_priv->pages[i]);
	kfree(fw_priv->pages);
	kfree(fw_priv);

	module_put(THIS_MODULE);
	}

	static int firmware_uevent(struct device dev, struct kobj_uevent_env env)
	{
	struct firmware_priv *fw_priv = to_firmware_priv(dev);

	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
	return -ENOMEM;
	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
	return -ENOMEM;
	if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
	return -ENOMEM;

	return 0;
	}

	static struct class firmware_class = {
	.name = "firmware",
	.class_attrs = firmware_class_attrs,
	.dev_uevent = firmware_uevent,
	.dev_release = fw_dev_release,
	};

	static ssize_t firmware_loading_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct firmware_priv *fw_priv = to_firmware_priv(dev);
	int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);

	return sprintf(buf, "%d\n", loading);
	}

	static void firmware_free_data(const struct firmware *fw)
	{
	int i;
	vunmap(fw->data);
	if (fw->pages) {
	for (i = 0; i < PFN_UP(fw->size); i++)
	__free_page(fw->pages[i]);
	kfree(fw->pages);
	}
	}

	/* Some architectures don't have PAGE_KERNEL_RO */
	#ifndef PAGE_KERNEL_RO
	#define PAGE_KERNEL_RO PAGE_KERNEL
	#endif
	/**
	* firmware_loading_store - set value in the 'loading' control file
	* @dev: device pointer
	* @attr: device attribute pointer
	* @buf: buffer to scan for loading control value
	* @count: number of bytes in @buf
	*
	* The relevant values are:
	*
	* 1: Start a load, discarding any previous partial load.
	* 0: Conclude the load and hand the data to the driver code.
	* -1: Conclude the load with an error and discard any written data.
	**/
	static ssize_t firmware_loading_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct firmware_priv *fw_priv = to_firmware_priv(dev);
	int loading = simple_strtol(buf, NULL, 10);
	int i;

	switch (loading) {
	case 1:
	mutex_lock(&fw_lock);
	if (!fw_priv->fw) {
	mutex_unlock(&fw_lock);
	break;
	}
	firmware_free_data(fw_priv->fw);
	memset(fw_priv->fw, 0, sizeof(struct firmware));
	/* If the pages are not owned by 'struct firmware' */
	for (i = 0; i < fw_priv->nr_pages; i++)
	__free_page(fw_priv->pages[i]);
	kfree(fw_priv->pages);
	fw_priv->pages = NULL;
	fw_priv->page_array_size = 0;
	fw_priv->nr_pages = 0;
	set_bit(FW_STATUS_LOADING, &fw_priv->status);
	mutex_unlock(&fw_lock);
	break;
	case 0:
	if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
	vunmap(fw_priv->fw->data);
	fw_priv->fw->data = vmap(fw_priv->pages,
	fw_priv->nr_pages,
	0, PAGE_KERNEL_RO);
	if (!fw_priv->fw->data) {
	dev_err(dev, "%s: vmap() failed\n", __func__);
	goto err;
	}
	/* Pages are now owned by 'struct firmware' */
	fw_priv->fw->pages = fw_priv->pages;
	fw_priv->pages = NULL;

	fw_priv->page_array_size = 0;
	fw_priv->nr_pages = 0;
	complete(&fw_priv->completion);
	clear_bit(FW_STATUS_LOADING, &fw_priv->status);
	break;
	}
	/* fallthrough */
	default:
	dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
	/* fallthrough */
	case -1:
	err:
	fw_load_abort(fw_priv);
	break;
	}

	return count;
	}

	static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);

	static ssize_t firmware_data_read(struct file filp, struct kobject kobj,
	struct bin_attribute *bin_attr,
	char *buffer, loff_t offset, size_t count)
	{
	struct device *dev = to_dev(kobj);
	struct firmware_priv *fw_priv = to_firmware_priv(dev);
	struct firmware *fw;
	ssize_t ret_count;

	mutex_lock(&fw_lock);
	fw = fw_priv->fw;
	if (!fw \|\| test_bit(FW_STATUS_DONE, &fw_priv->status)) {
	ret_count = -ENODEV;
	goto out;
	}
	if (offset > fw->size) {
	ret_count = 0;
	goto out;
	}
	if (count > fw->size - offset)
	count = fw->size - offset;

	ret_count = count;

	while (count) {
	void *page_data;
	int page_nr = offset >> PAGE_SHIFT;
	int page_ofs = offset & (PAGE_SIZE-1);
	int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);

	page_data = kmap(fw_priv->pages[page_nr]);

	memcpy(buffer, page_data + page_ofs, page_cnt);

	kunmap(fw_priv->pages[page_nr]);
	buffer += page_cnt;
	offset += page_cnt;
	count -= page_cnt;
	}
	out:
	mutex_unlock(&fw_lock);
	return ret_count;
	}

	static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
	{
	int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;

	/* If the array of pages is too small, grow it... */
	if (fw_priv->page_array_size < pages_needed) {
	int new_array_size = max(pages_needed,
	fw_priv->page_array_size * 2);
	struct page **new_pages;

	new_pages = kmalloc(new_array_size * sizeof(void *),
	GFP_KERNEL);
	if (!new_pages) {
	fw_load_abort(fw_priv);
	return -ENOMEM;
	}
	memcpy(new_pages, fw_priv->pages,
	fw_priv->page_array_size * sizeof(void *));
	memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void )
	(new_array_size - fw_priv->page_array_size));
	kfree(fw_priv->pages);
	fw_priv->pages = new_pages;
	fw_priv->page_array_size = new_array_size;
	}

	while (fw_priv->nr_pages < pages_needed) {
	fw_priv->pages[fw_priv->nr_pages] =
	alloc_page(GFP_KERNEL \| __GFP_HIGHMEM);

	if (!fw_priv->pages[fw_priv->nr_pages]) {
	fw_load_abort(fw_priv);
	return -ENOMEM;
	}
	fw_priv->nr_pages++;
	}
	return 0;
	}

	/**
	* firmware_data_write - write method for firmware
	* @filp: open sysfs file
	* @kobj: kobject for the device
	* @bin_attr: bin_attr structure
	* @buffer: buffer being written
	* @offset: buffer offset for write in total data store area
	* @count: buffer size
	*
	* Data written to the 'data' attribute will be later handed to
	* the driver as a firmware image.
	**/
	static ssize_t firmware_data_write(struct file filp, struct kobject kobj,
	struct bin_attribute *bin_attr,
	char *buffer, loff_t offset, size_t count)
	{
	struct device *dev = to_dev(kobj);
	struct firmware_priv *fw_priv = to_firmware_priv(dev);
	struct firmware *fw;
	ssize_t retval;

	if (!capable(CAP_SYS_RAWIO))
	return -EPERM;

	mutex_lock(&fw_lock);
	fw = fw_priv->fw;
	if (!fw \|\| test_bit(FW_STATUS_DONE, &fw_priv->status)) {
	retval = -ENODEV;
	goto out;
	}
	retval = fw_realloc_buffer(fw_priv, offset + count);
	if (retval)
	goto out;

	retval = count;

	while (count) {
	void *page_data;
	int page_nr = offset >> PAGE_SHIFT;
	int page_ofs = offset & (PAGE_SIZE - 1);
	int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);

	page_data = kmap(fw_priv->pages[page_nr]);

	memcpy(page_data + page_ofs, buffer, page_cnt);

	kunmap(fw_priv->pages[page_nr]);
	buffer += page_cnt;
	offset += page_cnt;
	count -= page_cnt;
	}

	fw->size = max_t(size_t, offset, fw->size);
	out:
	mutex_unlock(&fw_lock);
	return retval;
	}

	static struct bin_attribute firmware_attr_data = {
	.attr = { .name = "data", .mode = 0644 },
	.size = 0,
	.read = firmware_data_read,
	.write = firmware_data_write,
	};

	static void firmware_class_timeout(u_long data)
	{
	struct firmware_priv fw_priv = (struct firmware_priv ) data;

	fw_load_abort(fw_priv);
	}

	static struct firmware_priv *
	fw_create_instance(struct firmware firmware, const char fw_name,
	struct device *device, bool uevent, bool nowait)
	{
	struct firmware_priv *fw_priv;
	struct device *f_dev;
	int error;

	fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
	if (!fw_priv) {
	dev_err(device, "%s: kmalloc failed\n", __func__);
	error = -ENOMEM;
	goto err_out;
	}

	fw_priv->fw = firmware;
	fw_priv->nowait = nowait;
	strcpy(fw_priv->fw_id, fw_name);
	init_completion(&fw_priv->completion);
	setup_timer(&fw_priv->timeout,
	firmware_class_timeout, (u_long) fw_priv);

	f_dev = &fw_priv->dev;

	device_initialize(f_dev);
	dev_set_name(f_dev, "%s", dev_name(device));
	f_dev->parent = device;
	f_dev->class = &firmware_class;

	dev_set_uevent_suppress(f_dev, true);

	/* Need to pin this module until class device is destroyed */
	__module_get(THIS_MODULE);

	error = device_add(f_dev);
	if (error) {
	dev_err(device, "%s: device_register failed\n", __func__);
	goto err_put_dev;
	}

	error = device_create_bin_file(f_dev, &firmware_attr_data);
	if (error) {
	dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
	goto err_del_dev;
	}

	error = device_create_file(f_dev, &dev_attr_loading);
	if (error) {
	dev_err(device, "%s: device_create_file failed\n", __func__);
	goto err_del_bin_attr;
	}

	if (uevent)
	dev_set_uevent_suppress(f_dev, false);

	return fw_priv;

	err_del_bin_attr:
	device_remove_bin_file(f_dev, &firmware_attr_data);
	err_del_dev:
	device_del(f_dev);
	err_put_dev:
	put_device(f_dev);
	err_out:
	return ERR_PTR(error);
	}

	static void fw_destroy_instance(struct firmware_priv *fw_priv)
	{
	struct device *f_dev = &fw_priv->dev;

	device_remove_file(f_dev, &dev_attr_loading);
	device_remove_bin_file(f_dev, &firmware_attr_data);
	device_unregister(f_dev);
	}

	static int _request_firmware(const struct firmware **firmware_p,
	const char name, struct device device,
	bool uevent, bool nowait)
	{
	struct firmware_priv *fw_priv;
	struct firmware *firmware;
	int retval = 0;

	if (!firmware_p)
	return -EINVAL;

	firmware_p = firmware = kzalloc(sizeof(firmware), GFP_KERNEL);
	if (!firmware) {
	dev_err(device, "%s: kmalloc(struct firmware) failed\n",
	__func__);
	retval = -ENOMEM;
	goto out;
	}

	if (fw_get_builtin_firmware(firmware, name)) {
	dev_dbg(device, "firmware: using built-in firmware %s\n", name);
	return 0;
	}

	if (uevent)
	dev_dbg(device, "firmware: requesting %s\n", name);

	fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
	if (IS_ERR(fw_priv)) {
	retval = PTR_ERR(fw_priv);
	goto out;
	}

	if (uevent) {
	if (loading_timeout > 0)
	mod_timer(&fw_priv->timeout,
	round_jiffies_up(jiffies +
	loading_timeout * HZ));

	kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
	}

	wait_for_completion(&fw_priv->completion);

	set_bit(FW_STATUS_DONE, &fw_priv->status);
	del_timer_sync(&fw_priv->timeout);

	mutex_lock(&fw_lock);
	if (!fw_priv->fw->size \|\| test_bit(FW_STATUS_ABORT, &fw_priv->status))
	retval = -ENOENT;
	fw_priv->fw = NULL;
	mutex_unlock(&fw_lock);

	fw_destroy_instance(fw_priv);

	out:
	if (retval) {
	release_firmware(firmware);
	*firmware_p = NULL;
	}

	return retval;
	}

	/**
	* request_firmware: - send firmware request and wait for it
	* @firmware_p: pointer to firmware image
	* @name: name of firmware file
	* @device: device for which firmware is being loaded
	*
	* @firmware_p will be used to return a firmware image by the name
	* of @name for device @device.
	*
	* Should be called from user context where sleeping is allowed.
	*
	* @name will be used as $FIRMWARE in the uevent environment and
	* should be distinctive enough not to be confused with any other
	* firmware image for this or any other device.
	**/
	int
	request_firmware(const struct firmware *firmware_p, const char name,
	struct device *device)
	{
	return _request_firmware(firmware_p, name, device, true, false);
	}

	/**
	* release_firmware: - release the resource associated with a firmware image
	* @fw: firmware resource to release
	**/
	void release_firmware(const struct firmware *fw)
	{
	if (fw) {
	if (!fw_is_builtin_firmware(fw))
	firmware_free_data(fw);
	kfree(fw);
	}
	}

	/* Async support */
	struct firmware_work {
	struct work_struct work;
	struct module *module;
	const char *name;
	struct device *device;
	void *context;
	void (cont)(const struct firmware fw, void *context);
	bool uevent;
	};

	static int request_firmware_work_func(void *arg)
	{
	struct firmware_work *fw_work = arg;
	const struct firmware *fw;
	int ret;

	if (!arg) {
	WARN_ON(1);
	return 0;
	}

	ret = _request_firmware(&fw, fw_work->name, fw_work->device,
	fw_work->uevent, true);
	fw_work->cont(fw, fw_work->context);

	module_put(fw_work->module);
	kfree(fw_work);

	return ret;
	}

	/**
	* request_firmware_nowait - asynchronous version of request_firmware
	* @module: module requesting the firmware
	* @uevent: sends uevent to copy the firmware image if this flag
	* is non-zero else the firmware copy must be done manually.
	* @name: name of firmware file
	* @device: device for which firmware is being loaded
	* @gfp: allocation flags
	* @context: will be passed over to @cont, and
	* @fw may be %NULL if firmware request fails.
	* @cont: function will be called asynchronously when the firmware
	* request is over.
	*
	* Asynchronous variant of request_firmware() for user contexts where
	* it is not possible to sleep for long time. It can't be called
	* in atomic contexts.
	**/
	int
	request_firmware_nowait(
	struct module *module, bool uevent,
	const char name, struct device device, gfp_t gfp, void *context,
	void (cont)(const struct firmware fw, void *context))
	{
	struct task_struct *task;
	struct firmware_work *fw_work;

	fw_work = kzalloc(sizeof (struct firmware_work), gfp);
	if (!fw_work)
	return -ENOMEM;

	fw_work->module = module;
	fw_work->name = name;
	fw_work->device = device;
	fw_work->context = context;
	fw_work->cont = cont;
	fw_work->uevent = uevent;

	if (!try_module_get(module)) {
	kfree(fw_work);
	return -EFAULT;
	}

	task = kthread_run(request_firmware_work_func, fw_work,
	"firmware/%s", name);
	if (IS_ERR(task)) {
	fw_work->cont(NULL, fw_work->context);
	module_put(fw_work->module);
	kfree(fw_work);
	return PTR_ERR(task);
	}

	return 0;
	}

	static int __init firmware_class_init(void)
	{
	return class_register(&firmware_class);
	}

	static void __exit firmware_class_exit(void)
	{
	class_unregister(&firmware_class);
	}

	fs_initcall(firmware_class_init);
	module_exit(firmware_class_exit);

	EXPORT_SYMBOL(release_firmware);
	EXPORT_SYMBOL(request_firmware);
	EXPORT_SYMBOL(request_firmware_nowait);