Commit fc745410 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

arm64/lib: Handle CRC-32 alternative in C code 



In preparation for adding another code path for performing CRC-32, move
the alternative patching for ARM64_HAS_CRC32 into C code. The logic for
deciding whether to use this new code path will be implemented in C too.

Reviewed-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241018075347.2821102-6-ardb+git@google.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 9852d85e

arch/arm64/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ endif 


lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o



obj-$(CONFIG_CRC32) += crc32.o

obj-$(CONFIG_CRC32) += crc32.o crc32-glue.o



obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o

arch/arm64/lib/crc32-glue.c

0 → 100644
+34 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <linux/crc32.h>

#include <linux/linkage.h>



#include <asm/alternative.h>



asmlinkage u32 crc32_le_arm64(u32 crc, unsigned char const *p, size_t len);

asmlinkage u32 crc32c_le_arm64(u32 crc, unsigned char const *p, size_t len);

asmlinkage u32 crc32_be_arm64(u32 crc, unsigned char const *p, size_t len);



u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)

{

	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))

		return crc32_le_base(crc, p, len);



	return crc32_le_arm64(crc, p, len);

}



u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len)

{

	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))

		return __crc32c_le_base(crc, p, len);



	return crc32c_le_arm64(crc, p, len);

}



u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)

{

	if (!alternative_has_cap_likely(ARM64_HAS_CRC32))

		return crc32_be_base(crc, p, len);



	return crc32_be_arm64(crc, p, len);

}

arch/arm64/lib/crc32.S

+6 −16
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
 */



#include <linux/linkage.h>

#include <asm/alternative.h>

#include <asm/assembler.h>



	.arch		armv8-a+crc
@@ -136,25 +135,16 @@ CPU_BE( rev16 \reg, \reg ) 
	.endm



	.align		5

SYM_FUNC_START(crc32_le)

alternative_if_not ARM64_HAS_CRC32

	b		crc32_le_base

alternative_else_nop_endif

SYM_FUNC_START(crc32_le_arm64)

	__crc32

SYM_FUNC_END(crc32_le)

SYM_FUNC_END(crc32_le_arm64)



	.align		5

SYM_FUNC_START(__crc32c_le)

alternative_if_not ARM64_HAS_CRC32

	b		__crc32c_le_base

alternative_else_nop_endif

SYM_FUNC_START(crc32c_le_arm64)

	__crc32		c

SYM_FUNC_END(__crc32c_le)

SYM_FUNC_END(crc32c_le_arm64)



	.align		5

SYM_FUNC_START(crc32_be)

alternative_if_not ARM64_HAS_CRC32

	b		crc32_be_base

alternative_else_nop_endif

SYM_FUNC_START(crc32_be_arm64)

	__crc32		be=1

SYM_FUNC_END(crc32_be)
 
SYM_FUNC_END(crc32_be_arm64)