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/*

 * 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/firmware.h>

#include "base.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");

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 {

        char fw_id[FIRMWARE_NAME_MAX];

        struct completion completion;

        struct bin_attribute attr_data;

        struct firmware *fw;

        unsigned long status;

        int alloc_size;

        struct timer_list timeout;

};

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, char *buf)

{

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

}

/**

 * firmware_timeout_store - set number of seconds to wait for firmware

 * @class: device class 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, const char *buf, size_t count)

{

        loading_timeout = simple_strtol(buf, NULL, 10);

        if (loading_timeout < 0)

                loading_timeout = 0;

        return count;

}

static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);

static void fw_dev_release(struct device *dev);

static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)

{

        struct firmware_priv *fw_priv = dev_get_drvdata(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;

        return 0;

}

static struct class firmware_class = {

        .name           = "firmware",

        .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 = dev_get_drvdata(dev);

        int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);

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

}

/**

 * 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 = dev_get_drvdata(dev);

        int loading = simple_strtol(buf, NULL, 10);

        switch (loading) {

        case 1:

                mutex_lock(&fw_lock);

                if (!fw_priv->fw) {

                        mutex_unlock(&fw_lock);

                        break;

                }

                vfree(fw_priv->fw->data);

                fw_priv->fw->data = NULL;

                fw_priv->fw->size = 0;

                fw_priv->alloc_size = 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)) {

                        complete(&fw_priv->completion);

                        clear_bit(FW_STATUS_LOADING, &fw_priv->status);

                        break;

                }

                /* fallthrough */

        default:

                printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__,

                       loading);

                /* fallthrough */

        case -1:

                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 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 = dev_get_drvdata(dev);

        struct firmware *fw;

        ssize_t ret_count = 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 (offset + ret_count > fw->size)

                ret_count = fw->size - offset;

        memcpy(buffer, fw->data + offset, ret_count);

out:

        mutex_unlock(&fw_lock);

        return ret_count;

}

static int

fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)

{

        u8 *new_data;

        int new_size = fw_priv->alloc_size;

        if (min_size <= fw_priv->alloc_size)

                return 0;

        new_size = ALIGN(min_size, PAGE_SIZE);

        new_data = vmalloc(new_size);

        if (!new_data) {

                printk(KERN_ERR "%s: unable to alloc buffer\n", __FUNCTION__);

                /* Make sure that we don't keep incomplete data */

                fw_load_abort(fw_priv);

                return -ENOMEM;

        }

        fw_priv->alloc_size = new_size;

        if (fw_priv->fw->data) {

                memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);

                vfree(fw_priv->fw->data);

        }

        fw_priv->fw->data = new_data;

        BUG_ON(min_size > fw_priv->alloc_size);

        return 0;

}

/**

 * firmware_data_write - write method for firmware

 * @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 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 = dev_get_drvdata(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;

        memcpy(fw->data + offset, buffer, count);

        fw->size = max_t(size_t, offset + count, fw->size);

        retval = count;

out:

        mutex_unlock(&fw_lock);

        return retval;

}

static struct bin_attribute firmware_attr_data_tmpl = {

        .attr = {.name = "data", .mode = 0644},

        .size = 0,

        .read = firmware_data_read,

        .write = firmware_data_write,

};

static void fw_dev_release(struct device *dev)

{

        struct firmware_priv *fw_priv = dev_get_drvdata(dev);

        kfree(fw_priv);

        kfree(dev);

        module_put(THIS_MODULE);

}

static void

firmware_class_timeout(u_long data)

{

        struct firmware_priv *fw_priv = (struct firmware_priv *) data;

        fw_load_abort(fw_priv);

}

static inline void fw_setup_device_id(struct device *f_dev, struct device *dev)

{

        snprintf(f_dev->bus_id, BUS_ID_SIZE, "firmware-%s", dev->bus_id);

}

static int fw_register_device(struct device **dev_p, const char *fw_name,

                              struct device *device)

{

        int retval;

        struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),

                                                GFP_KERNEL);

        struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);

        *dev_p = NULL;

        if (!fw_priv || !f_dev) {

                printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);

                retval = -ENOMEM;

                goto error_kfree;

        }

        init_completion(&fw_priv->completion);

        fw_priv->attr_data = firmware_attr_data_tmpl;

        strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);

        fw_priv->timeout.function = firmware_class_timeout;

        fw_priv->timeout.data = (u_long) fw_priv;

        init_timer(&fw_priv->timeout);

        fw_setup_device_id(f_dev, device);

        f_dev->parent = device;

        f_dev->class = &firmware_class;

        dev_set_drvdata(f_dev, fw_priv);

        f_dev->uevent_suppress = 1;

        retval = device_register(f_dev);

        if (retval) {

                printk(KERN_ERR "%s: device_register failed\n",

                       __FUNCTION__);

                goto error_kfree;

        }

        *dev_p = f_dev;

        return 0;

error_kfree:

        kfree(fw_priv);

        kfree(f_dev);

        return retval;

}

static int fw_setup_device(struct firmware *fw, struct device **dev_p,

                           const char *fw_name, struct device *device,

                           int uevent)

{

        struct device *f_dev;

        struct firmware_priv *fw_priv;

        int retval;

        *dev_p = NULL;

        retval = fw_register_device(&f_dev, fw_name, device);

        if (retval)

                goto out;

        /* Need to pin this module until class device is destroyed */

        __module_get(THIS_MODULE);

        fw_priv = dev_get_drvdata(f_dev);

        fw_priv->fw = fw;

        retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);

        if (retval) {

                printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",

                       __FUNCTION__);

                goto error_unreg;

        }

        retval = device_create_file(f_dev, &dev_attr_loading);

        if (retval) {

                printk(KERN_ERR "%s: device_create_file failed\n",

                       __FUNCTION__);

                goto error_unreg;

        }

        if (uevent)

                f_dev->uevent_suppress = 0;

        *dev_p = f_dev;

        goto out;

error_unreg:

        device_unregister(f_dev);

out:

        return retval;

}

static int

_request_firmware(const struct firmware **firmware_p, const char *name,

                 struct device *device, int uevent)

{

        struct device *f_dev;

        struct firmware_priv *fw_priv;

        struct firmware *firmware;

        int retval;

        if (!firmware_p)

                return -EINVAL;

        *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);

        if (!firmware) {

                printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",

                       __FUNCTION__);

                retval = -ENOMEM;

                goto out;

        }

        retval = fw_setup_device(firmware, &f_dev, name, device, uevent);

        if (retval)

                goto error_kfree_fw;

        fw_priv = dev_get_drvdata(f_dev);

        if (uevent) {

                if (loading_timeout > 0) {

                        fw_priv->timeout.expires = jiffies + loading_timeout * HZ;

                        add_timer(&fw_priv->timeout);

                }

                kobject_uevent(&f_dev->kobj, KOBJ_ADD);

                wait_for_completion(&fw_priv->completion);

                set_bit(FW_STATUS_DONE, &fw_priv->status);

                del_timer_sync(&fw_priv->timeout);

        } else

                wait_for_completion(&fw_priv->completion);

        mutex_lock(&fw_lock);

        if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {

                retval = -ENOENT;

                release_firmware(fw_priv->fw);

                *firmware_p = NULL;

        }

        fw_priv->fw = NULL;

        mutex_unlock(&fw_lock);

        device_unregister(f_dev);

        goto out;

error_kfree_fw:

        kfree(firmware);

        *firmware_p = NULL;

out:

        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)

{

        int uevent = 1;

        return _request_firmware(firmware_p, name, device, uevent);

}

/**

 * release_firmware: - release the resource associated with a firmware image

 * @fw: firmware resource to release

 **/

void

release_firmware(const struct firmware *fw)

{

        if (fw) {

                vfree(fw->data);

                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);

        int 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);

        if (ret < 0)

                fw_work->cont(NULL, fw_work->context);

        else {

                fw_work->cont(fw, fw_work->context);

                release_firmware(fw);

        }

        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

 * @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 contexts where

 *      it is not possible to sleep.

 **/

int

request_firmware_nowait(

        struct module *module, int uevent,

        const char *name, struct device *device, void *context,

        void (*cont)(const struct firmware *fw, void *context))

{

        struct task_struct *task;

        struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),

                                                GFP_ATOMIC);

        if (!fw_work)

                return -ENOMEM;

        if (!try_module_get(module)) {

                kfree(fw_work);

                return -EFAULT;

        }

        *fw_work = (struct firmware_work) {

                .module = module,

                .name = name,

                .device = device,

                .context = context,

                .cont = cont,

                .uevent = uevent,

        };

        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)

{

        int error;

        error = class_register(&firmware_class);

        if (error) {

                printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__);

                return error;

        }

        error = class_create_file(&firmware_class, &class_attr_timeout);

        if (error) {

                printk(KERN_ERR "%s: class_create_file failed\n",

                       __FUNCTION__);

                class_unregister(&firmware_class);

        }

        return error;

}

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);