/*
* firmware_class.c - Multi purpose firmware loading support
*
* Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
*
* Please see Documentation/firmware_class/ for more information.
*
*/
#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 <asm/semaphore.h>
#include <linux/firmware.h>
#include "base.h"
MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");
enum {
FW_STATUS_LOADING,
FW_STATUS_DONE,
FW_STATUS_ABORT,
FW_STATUS_READY,
};
static int loading_timeout = 10; /* 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 DECLARE_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 inline 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:
* Description:
* Sets the number of seconds to wait for the firmware. Once
* this expires an error will be return to the driver and no
* firmware will be provided.
*
* Note: zero means 'wait for ever'
*
**/
static ssize_t
firmware_timeout_store(struct class *class, const char *buf, size_t count)
{
loading_timeout = simple_strtol(buf, NULL, 10);
return count;
}
static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
static void fw_class_dev_release(struct class_device *class_dev);
int firmware_class_hotplug(struct class_device *dev, char **envp,
int num_envp, char *buffer, int buffer_size);
static struct class firmware_class = {
.name = "firmware",
.hotplug = firmware_class_hotplug,
.release = fw_class_dev_release,
};
int
firmware_class_hotplug(struct class_device *class_dev, char **envp,
int num_envp, char *buffer, int buffer_size)
{
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
int i = 0, len = 0;
if (!test_bit(FW_STATUS_READY, &fw_priv->status))
return -ENODEV;
if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len,
"FIRMWARE=%s", fw_priv->fw_id))
return -ENOMEM;
envp[i] = NULL;
return 0;
}
static ssize_t
firmware_loading_show(struct class_device *class_dev, char *buf)
{
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
return sprintf(buf, "%d\n", loading);
}
/**
* firmware_loading_store: - loading control file
* Description:
* The relevant values are:
*
* 1: Start a load, discarding any previous partial load.
* 0: Conclude the load and handle 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 class_device *class_dev,
const char *buf, size_t count)
{
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
int loading = simple_strtol(buf, NULL, 10);
switch (loading) {
case 1:
down(&fw_lock);
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);
up(&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 CLASS_DEVICE_ATTR(loading, 0644,
firmware_loading_show, firmware_loading_store);
static ssize_t
firmware_data_read(struct kobject *kobj,
char *buffer, loff_t offset, size_t count)
{
struct class_device *class_dev = to_class_dev(kobj);
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
struct firmware *fw;
ssize_t ret_count = count;
down(&fw_lock);
fw = fw_priv->fw;
if (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:
up(&fw_lock);
return ret_count;
}
static int
fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
{
u8 *new_data;
if (min_size <= fw_priv->alloc_size)
return 0;
new_data = vmalloc(fw_priv->alloc_size + PAGE_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 += PAGE_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:
*
* Description:
*
* Data written to the 'data' attribute will be later handled to
* the driver as a firmware image.
**/
static ssize_t
firmware_data_write(struct kobject *kobj,
char *buffer, loff_t offset, size_t count)
{
struct class_device *class_dev = to_class_dev(kobj);
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
struct firmware *fw;
ssize_t retval;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
down(&fw_lock);
fw = fw_priv->fw;
if (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:
up(&fw_lock);
return retval;
}
static struct bin_attribute firmware_attr_data_tmpl = {
.attr = {.name = "data", .mode = 0644, .owner = THIS_MODULE},
.size = 0,
.read = firmware_data_read,
.write = firmware_data_write,
};
static void
fw_class_dev_release(struct class_device *class_dev)
{
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
kfree(fw_priv);
kfree(class_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_class_device_id(struct class_device *class_dev, struct device *dev)
{
/* XXX warning we should watch out for name collisions */
strlcpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
}
static int
fw_register_class_device(struct class_device **class_dev_p,
const char *fw_name, struct device *device)
{
int retval;
struct firmware_priv *fw_priv = kmalloc(sizeof (struct firmware_priv),
GFP_KERNEL);
struct class_device *class_dev = kmalloc(sizeof (struct class_device),
GFP_KERNEL);
*class_dev_p = NULL;
if (!fw_priv || !class_dev) {
printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);
retval = -ENOMEM;
goto error_kfree;
}
memset(fw_priv, 0, sizeof (*fw_priv));
memset(class_dev, 0, sizeof (*class_dev));
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_class_device_id(class_dev, device);
class_dev->dev = device;
class_dev->class = &firmware_class;
class_set_devdata(class_dev, fw_priv);
retval = class_device_register(class_dev);
if (retval) {
printk(KERN_ERR "%s: class_device_register failed\n",
__FUNCTION__);
goto error_kfree;
}
*class_dev_p = class_dev;
return 0;
error_kfree:
kfree(fw_priv);
kfree(class_dev);
return retval;
}
static int
fw_setup_class_device(struct firmware *fw, struct class_device **class_dev_p,
const char *fw_name, struct device *device)
{
struct class_device *class_dev;
struct firmware_priv *fw_priv;
int retval;
*class_dev_p = NULL;
retval = fw_register_class_device(&class_dev, fw_name, device);
if (retval)
goto out;
/* Need to pin this module until class device is destroyed */
__module_get(THIS_MODULE);
fw_priv = class_get_devdata(class_dev);
fw_priv->fw = fw;
retval = sysfs_create_bin_file(&class_dev->kobj, &fw_priv->attr_data);
if (retval) {
printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
__FUNCTION__);
goto error_unreg;
}
retval = class_device_create_file(class_dev,
&class_device_attr_loading);
if (retval) {
printk(KERN_ERR "%s: class_device_create_file failed\n",
__FUNCTION__);
goto error_unreg;
}
set_bit(FW_STATUS_READY, &fw_priv->status);
*class_dev_p = class_dev;
goto out;
error_unreg:
class_device_unregister(class_dev);
out:
return retval;
}
/**
* request_firmware: - request firmware to hotplug and wait for it
* Description:
* @firmware 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 use as $FIRMWARE in the hotplug 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)
{
struct class_device *class_dev;
struct firmware_priv *fw_priv;
struct firmware *firmware;
int retval;
if (!firmware_p)
return -EINVAL;
*firmware_p = firmware = kmalloc(sizeof (struct firmware), GFP_KERNEL);
if (!firmware) {
printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
__FUNCTION__);
retval = -ENOMEM;
goto out;
}
memset(firmware, 0, sizeof (*firmware));
retval = fw_setup_class_device(firmware, &class_dev, name, device);
if (retval)
goto error_kfree_fw;
fw_priv = class_get_devdata(class_dev);
if (loading_timeout) {
fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
add_timer(&fw_priv->timeout);
}
kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
wait_for_completion(&fw_priv->completion);
set_bit(FW_STATUS_DONE, &fw_priv->status);
del_timer_sync(&fw_priv->timeout);
down(&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;
up(&fw_lock);
class_device_unregister(class_dev);
goto out;
error_kfree_fw:
kfree(firmware);
*firmware_p = NULL;
out:
return retval;
}
/**
* release_firmware: - release the resource associated with a firmware image
**/
void
release_firmware(const struct firmware *fw)
{
if (fw) {
vfree(fw->data);
kfree(fw);
}
}
/**
* register_firmware: - provide a firmware image for later usage
*
* Description:
* Make sure that @data will be available by requesting firmware @name.
*
* Note: This will not be possible until some kind of persistence
* is available.
**/
void
register_firmware(const char *name, const u8 *data, size_t size)
{
/* This is meaningless without firmware caching, so until we
* decide if firmware caching is reasonable just leave it as a
* noop */
}
/* 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);
};
static int
request_firmware_work_func(void *arg)
{
struct firmware_work *fw_work = arg;
const struct firmware *fw;
if (!arg) {
WARN_ON(1);
return 0;
}
daemonize("%s/%s", "firmware", fw_work->name);
request_firmware(&fw, fw_work->name, fw_work->device);
fw_work->cont(fw, fw_work->context);
release_firmware(fw);
module_put(fw_work->module);
kfree(fw_work);
return 0;
}
/**
* request_firmware_nowait:
*
* Description:
* Asynchronous variant of request_firmware() for contexts where
* it is not possible to sleep.
*
* @cont will be called asynchronously when the firmware request is over.
*
* @context will be passed over to @cont.
*
* @fw may be %NULL if firmware request fails.
*
**/
int
request_firmware_nowait(
struct module *module,
const char *name, struct device *device, void *context,
void (*cont)(const struct firmware *fw, void *context))
{
struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
GFP_ATOMIC);
int ret;
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,
};
ret = kernel_thread(request_firmware_work_func, fw_work,
CLONE_FS | CLONE_FILES);
if (ret < 0) {
fw_work->cont(NULL, fw_work->context);
return ret;
}
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);
}
module_init(firmware_class_init);
module_exit(firmware_class_exit);
EXPORT_SYMBOL(release_firmware);
EXPORT_SYMBOL(request_firmware);
EXPORT_SYMBOL(request_firmware_nowait);
EXPORT_SYMBOL(register_firmware);
