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| author | Will Deacon <will.deacon@arm.com> | 2013-03-28 11:25:03 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-04-03 17:00:00 +0100 |
| commit | 4fd75911f6970478444eece952dacb2db9d1e5a5 (patch) | |
| tree | 310800b1a6ad447f697f1dccd12d3e6cf11179cf /arch/arm/include/asm | |
| parent | 029baf14a027a44b3ac8a9fe5cb1e516cbb9007e (diff) | |
| download | linux-4fd75911f6970478444eece952dacb2db9d1e5a5.tar.gz linux-4fd75911f6970478444eece952dacb2db9d1e5a5.tar.bz2 linux-4fd75911f6970478444eece952dacb2db9d1e5a5.zip | |
ARM: 7687/1: atomics: don't use exclusives for atomic64 read/set with LPAE
To ease page table updates with 64-bit descriptors, CPUs implementing
LPAE are required to implement ldrd/strd as atomic operations.
This patch uses these accessors instead of the exclusive variants when
performing atomic64_{read,set} on LPAE systems.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm')
| -rw-r--r-- | arch/arm/include/asm/atomic.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index c79f61faa3a5..da1c77d39327 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -243,6 +243,29 @@ typedef struct { #define ATOMIC64_INIT(i) { (i) } +#ifdef CONFIG_ARM_LPAE +static inline u64 atomic64_read(const atomic64_t *v) +{ + u64 result; + + __asm__ __volatile__("@ atomic64_read\n" +" ldrd %0, %H0, [%1]" + : "=&r" (result) + : "r" (&v->counter), "Qo" (v->counter) + ); + + return result; +} + +static inline void atomic64_set(atomic64_t *v, u64 i) +{ + __asm__ __volatile__("@ atomic64_set\n" +" strd %2, %H2, [%1]" + : "=Qo" (v->counter) + : "r" (&v->counter), "r" (i) + ); +} +#else static inline u64 atomic64_read(const atomic64_t *v) { u64 result; @@ -269,6 +292,7 @@ static inline void atomic64_set(atomic64_t *v, u64 i) : "r" (&v->counter), "r" (i) : "cc"); } +#endif static inline void atomic64_add(u64 i, atomic64_t *v) { |