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| author | Will Deacon <will.deacon@arm.com> | 2015-02-03 15:39:03 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-07-27 17:28:50 +0300 |
| commit | c0385b24af15020a1e505f2c984db0d7c0d017e1 (patch) | |
| tree | 50cf977ef4ba5de29e1c9a931588bc340c9e103c /arch/arm64/include/asm/atomic.h | |
| parent | d964b7229e7f94428a1e8d26999adffbe8a69db2 (diff) | |
| download | linux-c0385b24af15020a1e505f2c984db0d7c0d017e1.tar.xz | |
arm64: introduce CONFIG_ARM64_LSE_ATOMICS as fallback to ll/sc atomics
In order to patch in the new atomic instructions at runtime, we need to
generate wrappers around the out-of-line exclusive load/store atomics.
This patch adds a new Kconfig option, CONFIG_ARM64_LSE_ATOMICS. which
causes our atomic functions to branch to the out-of-line ll/sc
implementations. To avoid the register spill overhead of the PCS, the
out-of-line functions are compiled with specific compiler flags to
force out-of-line save/restore of any registers that are usually
caller-saved.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/atomic.h')
| -rw-r--r-- | arch/arm64/include/asm/atomic.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 632c47064722..84635f2d3d0a 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -21,6 +21,7 @@ #define __ASM_ATOMIC_H #include <linux/compiler.h> +#include <linux/stringify.h> #include <linux/types.h> #include <asm/barrier.h> @@ -30,7 +31,15 @@ #ifdef __KERNEL__ +#define __ARM64_IN_ATOMIC_IMPL + +#ifdef CONFIG_ARM64_LSE_ATOMICS +#include <asm/atomic_lse.h> +#else #include <asm/atomic_ll_sc.h> +#endif + +#undef __ARM64_IN_ATOMIC_IMPL /* * On ARM, ordinary assignment (str instruction) doesn't clear the local |