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authorSteve Capper <steve.capper@linaro.org>2014-11-19 16:53:43 +0000
committerWill Deacon <will.deacon@arm.com>2014-11-20 12:05:18 +0000
commitf97fc810798c261b2790c2a1660461a508a479e0 (patch)
treed0778121159f47b0337c368e5f2f1be35082d1fb /arch/arm64/include/asm/cmpxchg.h
parent15670ef1eac9817cf48da12c885aabcdd88e9add (diff)
downloadop-kernel-dev-f97fc810798c261b2790c2a1660461a508a479e0.zip
op-kernel-dev-f97fc810798c261b2790c2a1660461a508a479e0.tar.gz
arm64: percpu: Implement this_cpu operations
The generic this_cpu operations disable interrupts to ensure that the requested operation is protected from pre-emption. For arm64, this is overkill and can hurt throughput and latency. This patch provides arm64 specific implementations for the this_cpu operations. Rather than disable interrupts, we use the exclusive monitor or atomic operations as appropriate. The following operations are implemented: add, add_return, and, or, read, write, xchg. We also wire up a cmpxchg implementation from cmpxchg.h. Testing was performed using the percpu_test module and hackbench on a Juno board running 3.18-rc4. Signed-off-by: Steve Capper <steve.capper@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/cmpxchg.h')
-rw-r--r--arch/arm64/include/asm/cmpxchg.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index 89e397b..cb95930 100644
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -246,8 +246,10 @@ static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
__ret; \
})
-#define this_cpu_cmpxchg_8(ptr, o, n) \
- cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
+#define this_cpu_cmpxchg_1(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
+#define this_cpu_cmpxchg_2(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
+#define this_cpu_cmpxchg_4(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
+#define this_cpu_cmpxchg_8(ptr, o, n) cmpxchg_local(raw_cpu_ptr(&(ptr)), o, n)
#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
cmpxchg_double_local(raw_cpu_ptr(&(ptr1)), raw_cpu_ptr(&(ptr2)), \
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