Commit 27571616 authored Sep 06, 2016 by Lukas Wunner Committed by Matt Fleming Sep 09, 2016

x86/efi: Optimize away setup_gop32/64 if unused



Commit 2c23b73c ("x86/efi: Prepare GOP handling code for reuse
as generic code") introduced an efi_is_64bit() macro to x86 which
previously only existed for arm arches.  The macro is used to
choose between the 64 bit or 32 bit code path in gop.c at runtime.

However the code path that's going to be taken is known at compile
time when compiling for x86_32 or for x86_64 with mixed mode disabled.
Amend the macro to eliminate the unused code path in those cases.

Size of gop.o text section:
CONFIG_X86_32:                         1758 before, 1299 after
CONFIG_X86_64 && !CONFIG_EFI_MIXED:    2201 before, 1406 after
CONFIG_X86_64 &&  CONFIG_EFI_MIXED:    2201 before and after

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

parent 20ebc15e

arch/x86/include/asm/efi.h

+11 −2

Original line number	Diff line number	Diff line
		@@ -206,14 +206,23 @@ struct efi_config {

		__pure const struct efi_config *__efi_early(void);

		static inline bool efi_is_64bit(void)
		{
		if (!IS_ENABLED(CONFIG_X86_64))
		return false;

		if (!IS_ENABLED(CONFIG_EFI_MIXED))
		return true;

		return __efi_early()->is64;
		}

		#define efi_call_early(f, ...) \
		__efi_early()->call(__efi_early()->f, __VA_ARGS__);

		#define __efi_call_early(f, ...) \
		__efi_early()->call((unsigned long)f, __VA_ARGS__);

		#define efi_is_64bit() __efi_early()->is64

		extern bool efi_reboot_required(void);

		#else

Admin message