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// SPDX-License-Identifier: GPL-2.0
/* Builtin firmware support */
#include <linux/firmware.h>
#include "../firmware.h"
/* Only if FW_LOADER=y */
#ifdef CONFIG_FW_LOADER
struct builtin_fw {
char *name;
void *data;
unsigned long size;
};
extern struct builtin_fw __start_builtin_fw[];
extern struct builtin_fw __end_builtin_fw[];
static bool fw_copy_to_prealloc_buf(struct firmware *fw,
void *buf, size_t size)
{
if (!buf)
return true;
if (size < fw->size)
return false;
memcpy(buf, fw->data, fw->size);
return true;
}
/**
* firmware_request_builtin() - load builtin firmware
* @fw: pointer to firmware struct
* @name: name of firmware file
*
* Some use cases in the kernel have a requirement so that no memory allocator
* is involved as these calls take place early in boot process. An example is
* the x86 CPU microcode loader. In these cases all the caller wants is to see
* if the firmware was built-in and if so use it right away. This can be used
* for such cases.
*
* This looks for the firmware in the built-in kernel. Only if the kernel was
* built-in with the firmware you are looking for will this return successfully.
*
* Callers of this API do not need to use release_firmware() as the pointer to
* the firmware is expected to be provided locally on the stack of the caller.
**/
bool firmware_request_builtin(struct firmware *fw, const char *name)
{
struct builtin_fw *b_fw;
if (!fw)
return false;
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;
}
EXPORT_SYMBOL_NS_GPL(firmware_request_builtin, TEST_FIRMWARE);
/**
* firmware_request_builtin_buf() - load builtin firmware into optional buffer
* @fw: pointer to firmware struct
* @name: name of firmware file
* @buf: If set this lets you use a pre-allocated buffer so that the built-in
* firmware into is copied into. This field can be NULL. It is used by
* callers such as request_firmware_into_buf() and
* request_partial_firmware_into_buf()
* @size: if buf was provided, the max size of the allocated buffer available.
* If the built-in firmware does not fit into the pre-allocated @buf this
* call will fail.
*
* This looks for the firmware in the built-in kernel. Only if the kernel was
* built-in with the firmware you are looking for will this call possibly
* succeed. If you passed a @buf the firmware will be copied into it *iff* the
* built-in firmware fits into the pre-allocated buffer size specified in
* @size.
*
* This caller is to be used internally by the firmware_loader only.
**/
bool firmware_request_builtin_buf(struct firmware *fw, const char *name,
void *buf, size_t size)
{
if (!firmware_request_builtin(fw, name))
return false;
return fw_copy_to_prealloc_buf(fw, buf, size);
}
bool firmware_is_builtin(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;
}
#endif
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