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| 1 | +// SPDX-License-Identifier: GPL-2.0 |
| 2 | +/* Builtin firmware support */ |
| 3 | + |
| 4 | +#include <linux/firmware.h> |
| 5 | +#include "../firmware.h" |
| 6 | + |
| 7 | +/* Only if FW_LOADER=y */ |
| 8 | +#ifdef CONFIG_FW_LOADER |
| 9 | + |
| 10 | +extern struct builtin_fw __start_builtin_fw[]; |
| 11 | +extern struct builtin_fw __end_builtin_fw[]; |
| 12 | + |
| 13 | +static bool fw_copy_to_prealloc_buf(struct firmware *fw, |
| 14 | + void *buf, size_t size) |
| 15 | +{ |
| 16 | + if (!buf) |
| 17 | + return true; |
| 18 | + if (size < fw->size) |
| 19 | + return false; |
| 20 | + memcpy(buf, fw->data, fw->size); |
| 21 | + return true; |
| 22 | +} |
| 23 | + |
| 24 | +/** |
| 25 | + * firmware_request_builtin() - load builtin firmware |
| 26 | + * @fw: pointer to firmware struct |
| 27 | + * @name: name of firmware file |
| 28 | + * |
| 29 | + * Some use cases in the kernel have a requirement so that no memory allocator |
| 30 | + * is involved as these calls take place early in boot process. An example is |
| 31 | + * the x86 CPU microcode loader. In these cases all the caller wants is to see |
| 32 | + * if the firmware was built-in and if so use it right away. This can be used |
| 33 | + * for such cases. |
| 34 | + * |
| 35 | + * This looks for the firmware in the built-in kernel. Only if the kernel was |
| 36 | + * built-in with the firmware you are looking for will this return successfully. |
| 37 | + * |
| 38 | + * Callers of this API do not need to use release_firmware() as the pointer to |
| 39 | + * the firmware is expected to be provided locally on the stack of the caller. |
| 40 | + **/ |
| 41 | +bool firmware_request_builtin(struct firmware *fw, const char *name) |
| 42 | +{ |
| 43 | + struct builtin_fw *b_fw; |
| 44 | + |
| 45 | + if (!fw) |
| 46 | + return false; |
| 47 | + |
| 48 | + for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { |
| 49 | + if (strcmp(name, b_fw->name) == 0) { |
| 50 | + fw->size = b_fw->size; |
| 51 | + fw->data = b_fw->data; |
| 52 | + return true; |
| 53 | + } |
| 54 | + } |
| 55 | + |
| 56 | + return false; |
| 57 | +} |
| 58 | +EXPORT_SYMBOL_NS_GPL(firmware_request_builtin, TEST_FIRMWARE); |
| 59 | + |
| 60 | +/** |
| 61 | + * firmware_request_builtin_buf() - load builtin firmware into optional buffer |
| 62 | + * @fw: pointer to firmware struct |
| 63 | + * @name: name of firmware file |
| 64 | + * @buf: If set this lets you use a pre-allocated buffer so that the built-in |
| 65 | + * firmware into is copied into. This field can be NULL. It is used by |
| 66 | + * callers such as request_firmware_into_buf() and |
| 67 | + * request_partial_firmware_into_buf() |
| 68 | + * @size: if buf was provided, the max size of the allocated buffer available. |
| 69 | + * If the built-in firmware does not fit into the pre-allocated @buf this |
| 70 | + * call will fail. |
| 71 | + * |
| 72 | + * This looks for the firmware in the built-in kernel. Only if the kernel was |
| 73 | + * built-in with the firmware you are looking for will this call possibly |
| 74 | + * succeed. If you passed a @buf the firmware will be copied into it *iff* the |
| 75 | + * built-in firmware fits into the pre-allocated buffer size specified in |
| 76 | + * @size. |
| 77 | + * |
| 78 | + * This caller is to be used internally by the firmware_loader only. |
| 79 | + **/ |
| 80 | +bool firmware_request_builtin_buf(struct firmware *fw, const char *name, |
| 81 | + void *buf, size_t size) |
| 82 | +{ |
| 83 | + if (!firmware_request_builtin(fw, name)) |
| 84 | + return false; |
| 85 | + |
| 86 | + return fw_copy_to_prealloc_buf(fw, buf, size); |
| 87 | +} |
| 88 | + |
| 89 | +bool firmware_is_builtin(const struct firmware *fw) |
| 90 | +{ |
| 91 | + struct builtin_fw *b_fw; |
| 92 | + |
| 93 | + for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) |
| 94 | + if (fw->data == b_fw->data) |
| 95 | + return true; |
| 96 | + |
| 97 | + return false; |
| 98 | +} |
| 99 | + |
| 100 | +#endif |
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