From: Luis Chamberlain <mcgrof@xxxxxxxxxx> The built-in firmware is always supported when a user enables FW_LOADER=y today, that is, it is built-in to the kernel. When the firmware loader is built as a module, support for built-in firmware is skipped. This requirement is not really clear to users or even developers. Also, by default the EXTRA_FIRMWARE is always set to an empty string and so by default we really have nothing built-in to that kernel's sections for built-in firmware, so today a all FW_LOADER=y kernels spins their wheels on an empty set of built-in firmware for each firmware request with no true need for it. Add a new kconfig entry to represent built-in firmware support more clearly. This let's knock 3 birds with one stone: o Clarifies that support for built-in firmware requires the firmware loader to be built-in to the kernel o By default we now always skip built-in firmware even if a FW_LOADER=y o This also lets us make it clear that the EXTRA_FIRMWARE_DIR kconfig entry is only used for built-in firmware Reviewed-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> --- .../driver-api/firmware/built-in-fw.rst | 2 ++ Documentation/x86/microcode.rst | 5 ++-- drivers/base/firmware_loader/Kconfig | 25 +++++++++++++------ drivers/base/firmware_loader/Makefile | 3 +-- drivers/base/firmware_loader/main.c | 4 +-- 5 files changed, 26 insertions(+), 13 deletions(-) diff --git a/Documentation/driver-api/firmware/built-in-fw.rst b/Documentation/driver-api/firmware/built-in-fw.rst index bc1c961bace1..9dd2b1df44f0 100644 --- a/Documentation/driver-api/firmware/built-in-fw.rst +++ b/Documentation/driver-api/firmware/built-in-fw.rst @@ -8,6 +8,7 @@ the filesystem. Instead, firmware can be looked for inside the kernel directly. You can enable built-in firmware using the kernel configuration options: + * CONFIG_FW_LOADER_BUILTIN * CONFIG_EXTRA_FIRMWARE * CONFIG_EXTRA_FIRMWARE_DIR @@ -17,6 +18,7 @@ into the kernel with CONFIG_EXTRA_FIRMWARE: * Speed * Firmware is needed for accessing the boot device, and the user doesn't want to stuff the firmware into the boot initramfs. +* Testing built-in firmware Even if you have these needs there are a few reasons why you may not be able to make use of built-in firmware: diff --git a/Documentation/x86/microcode.rst b/Documentation/x86/microcode.rst index a320d37982ed..d199f0b98869 100644 --- a/Documentation/x86/microcode.rst +++ b/Documentation/x86/microcode.rst @@ -114,11 +114,12 @@ Builtin microcode ================= The loader supports also loading of a builtin microcode supplied through -the regular builtin firmware method CONFIG_EXTRA_FIRMWARE. Only 64-bit is -currently supported. +the regular builtin firmware method using CONFIG_FW_LOADER_BUILTIN and +CONFIG_EXTRA_FIRMWARE. Only 64-bit is currently supported. Here's an example:: + CONFIG_FW_LOADER_BUILTIN=y CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09 amd-ucode/microcode_amd_fam15h.bin" CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware" diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig index 5b24f3959255..de4fcd9d41f3 100644 --- a/drivers/base/firmware_loader/Kconfig +++ b/drivers/base/firmware_loader/Kconfig @@ -29,8 +29,10 @@ if FW_LOADER config FW_LOADER_PAGED_BUF bool -config EXTRA_FIRMWARE - string "Build named firmware blobs into the kernel binary" +config FW_LOADER_BUILTIN + bool "Enable support for built-in firmware" + default n + depends on FW_LOADER=y help Device drivers which require firmware can typically deal with having the kernel load firmware from the various supported @@ -43,7 +45,14 @@ config EXTRA_FIRMWARE in boot and cannot rely on the firmware being placed in an initrd or initramfs. - This option is a string and takes the (space-separated) names of the + Support for built-in firmware is not supported if you are using + the firmware loader as a module. + +config EXTRA_FIRMWARE + string "Build named firmware blobs into the kernel binary" + depends on FW_LOADER_BUILTIN + help + This option is a string and takes the space-separated names of the firmware files -- the same names that appear in MODULE_FIRMWARE() and request_firmware() in the source. These files should exist under the directory specified by the EXTRA_FIRMWARE_DIR option, which is @@ -61,12 +70,14 @@ config EXTRA_FIRMWARE consult a lawyer of your own before distributing such an image. config EXTRA_FIRMWARE_DIR - string "Firmware blobs root directory" - depends on EXTRA_FIRMWARE != "" + string "Directory with firmware to be built-in to the kernel" + depends on FW_LOADER_BUILTIN default "/lib/firmware" help - This option controls the directory in which the kernel build system - looks for the firmware files listed in the EXTRA_FIRMWARE option. + This option specifies the directory which the kernel build system + will use to look for the firmware files which are going to be + built into the kernel using the space-separated EXTRA_FIRMWARE + entries. config FW_LOADER_USER_HELPER bool "Enable the firmware sysfs fallback mechanism" diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile index e87843408fe6..a2dbfa19201c 100644 --- a/drivers/base/firmware_loader/Makefile +++ b/drivers/base/firmware_loader/Makefile @@ -1,10 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 # Makefile for the Linux firmware loader +obj-$(CONFIG_FW_LOADER_BUILTIN) += builtin/ obj-$(CONFIG_FW_LOADER_USER_HELPER) += fallback_table.o obj-$(CONFIG_FW_LOADER) += firmware_class.o firmware_class-objs := main.o firmware_class-$(CONFIG_FW_LOADER_USER_HELPER) += fallback.o firmware_class-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += fallback_platform.o - -obj-y += builtin/ diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index d95b5fe5f700..45075c7f9290 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -95,7 +95,7 @@ static struct firmware_cache fw_cache; /* Builtin firmware support */ -#ifdef CONFIG_FW_LOADER +#ifdef CONFIG_FW_LOADER_BUILTIN extern struct builtin_fw __start_builtin_fw[]; extern struct builtin_fw __end_builtin_fw[]; @@ -148,7 +148,7 @@ static bool fw_is_builtin_firmware(const struct firmware *fw) return false; } -#else /* Module case - no builtin firmware support */ +#else static inline bool firmware_request_builtin(struct firmware *fw, const char *name) -- 2.30.2
