diff options
| author | Will Deacon <will.deacon@arm.com> | 2015-02-12 07:17:37 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-07-27 17:28:51 +0300 |
| commit | 084f903727e1c3a61d6bcdaeeed30bddc6d7f65a (patch) | |
| tree | 614b95211ba1f8b103ed8f8b9de13ee14a5fab8b /arch/arm64/include/asm/lse.h | |
| parent | 81bb5c6420635dfd058c210bd342c29c95ccd145 (diff) | |
| download | linux-084f903727e1c3a61d6bcdaeeed30bddc6d7f65a.tar.xz | |
arm64: bitops: patch in lse instructions when supported by the CPU
On CPUs which support the LSE atomic instructions introduced in ARMv8.1,
it makes sense to use them in preference to ll/sc sequences.
This patch introduces runtime patching of our bitops functions so that
LSE atomic instructions are used instead.
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/lse.h')
| -rw-r--r-- | arch/arm64/include/asm/lse.h | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h index d516624a461e..fb3ac56a2cc0 100644 --- a/arch/arm64/include/asm/lse.h +++ b/arch/arm64/include/asm/lse.h @@ -4,10 +4,19 @@ #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS) #include <linux/stringify.h> - #include <asm/alternative.h> #include <asm/cpufeature.h> +#ifdef __ASSEMBLER__ + +.arch_extension lse + +.macro alt_lse, llsc, lse + alternative_insn "\llsc", "\lse", ARM64_CPU_FEAT_LSE_ATOMICS +.endm + +#else /* __ASSEMBLER__ */ + __asm__(".arch_extension lse"); /* Move the ll/sc atomics out-of-line */ @@ -22,7 +31,16 @@ __asm__(".arch_extension lse"); #define ARM64_LSE_ATOMIC_INSN(llsc, lse) \ ALTERNATIVE(llsc, lse, ARM64_CPU_FEAT_LSE_ATOMICS) -#else +#endif /* __ASSEMBLER__ */ +#else /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */ + +#ifdef __ASSEMBLER__ + +.macro alt_lse, llsc, lse + \llsc +.endm + +#else /* __ASSEMBLER__ */ #define __LL_SC_INLINE static inline #define __LL_SC_PREFIX(x) x @@ -30,5 +48,6 @@ __asm__(".arch_extension lse"); #define ARM64_LSE_ATOMIC_INSN(llsc, lse) llsc +#endif /* __ASSEMBLER__ */ #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */ #endif /* __ASM_LSE_H */ |