diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2020-12-09 17:21:43 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2021-02-01 20:41:30 +0100 |
| commit | 6468e898c67b905ec0f95d9678929135bcaf7f67 (patch) | |
| tree | 687e1b123aa0dde8858dd81c3ad731416a1269f6 /arch | |
| parent | Linux 5.11-rc1 (diff) | |
| download | linux-6468e898c67b905ec0f95d9678929135bcaf7f67.tar.xz linux-6468e898c67b905ec0f95d9678929135bcaf7f67.zip | |
ARM: 9039/1: assembler: generalize byte swapping macro into rev_l
Take the 4 instruction byte swapping sequence from the decompressor's
head.S, and turn it into a rev_l GAS macro for general use. While
at it, make it use the 'rev' instruction when compiling for v6 or
later.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/boot/compressed/head.S | 5 | ||||
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 17 |
2 files changed, 18 insertions, 4 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index d9cce7238a36..d4837c2d0359 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -174,10 +174,7 @@ .macro be32tocpu, val, tmp #ifndef __ARMEB__ /* convert to little endian */ - eor \tmp, \val, \val, ror #16 - bic \tmp, \tmp, #0x00ff0000 - mov \val, \val, ror #8 - eor \val, \val, \tmp, lsr #8 + rev_l \val, \tmp #endif .endm diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 6ed30421f697..e2b1fd558bf3 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -578,4 +578,21 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) __adldst_l str, \src, \sym, \tmp, \cond .endm + /* + * rev_l - byte-swap a 32-bit value + * + * @val: source/destination register + * @tmp: scratch register + */ + .macro rev_l, val:req, tmp:req + .if __LINUX_ARM_ARCH__ < 6 + eor \tmp, \val, \val, ror #16 + bic \tmp, \tmp, #0x00ff0000 + mov \val, \val, ror #8 + eor \val, \val, \tmp, lsr #8 + .else + rev \val, \val + .endif + .endm + #endif /* __ASM_ASSEMBLER_H__ */ |