diff options
| author | Andrew Murray <andrew.murray@arm.com> | 2019-08-28 18:50:07 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2019-08-29 15:53:42 +0100 |
| commit | addfc38672c73efd5c4e559a2e455b086e3e20c5 (patch) | |
| tree | e3bc9622b3b208a628d081e37be257ab5ad99a84 /arch/arm64/include/asm/atomic.h | |
| parent | 580fa1b874711d633f9b145b7777b0e83ebf3787 (diff) | |
arm64: atomics: avoid out-of-line ll/sc atomics
When building for LSE atomics (CONFIG_ARM64_LSE_ATOMICS), if the hardware
or toolchain doesn't support it the existing code will fallback to ll/sc
atomics. It achieves this by branching from inline assembly to a function
that is built with special compile flags. Further this results in the
clobbering of registers even when the fallback isn't used increasing
register pressure.
Improve this by providing inline implementations of both LSE and
ll/sc and use a static key to select between them, which allows for the
compiler to generate better atomics code. Put the LL/SC fallback atomics
in their own subsection to improve icache performance.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/atomic.h')
| -rw-r--r-- | arch/arm64/include/asm/atomic.h | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 657b0457d83c..c70d3f389d29 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -17,16 +17,7 @@ #ifdef __KERNEL__ -#define __ARM64_IN_ATOMIC_IMPL - -#if defined(CONFIG_ARM64_LSE_ATOMICS) && defined(CONFIG_AS_LSE) -#include <asm/atomic_lse.h> -#else -#include <asm/atomic_ll_sc.h> -#endif - -#undef __ARM64_IN_ATOMIC_IMPL - +#include <asm/atomic_arch.h> #include <asm/cmpxchg.h> #define ATOMIC_INIT(i) { (i) } |