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| author | Christoph Lameter <cl@linux.com> | 2010-12-06 18:40:00 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-12-17 15:15:28 +0100 |
| commit | 8f1d97c79eb65de1d05799d6b81d79cd94169114 (patch) | |
| tree | f9732488505ee3782b48bed139a14190095911d6 /arch/x86/include/asm/percpu.h | |
| parent | percpu: Generic support for this_cpu_add, sub, dec, inc_return (diff) | |
| download | linux-8f1d97c79eb65de1d05799d6b81d79cd94169114.tar.xz linux-8f1d97c79eb65de1d05799d6b81d79cd94169114.zip | |
x86: Support for this_cpu_add, sub, dec, inc_return
Supply an implementation for x86 in order to generate more efficient code.
V2->V3:
- Cleanup
- Remove strange type checking from percpu_add_return_op.
tj: - Dropped unused typedef from percpu_add_return_op().
- Renamed ret__ to paro_ret__ in percpu_add_return_op().
- Minor indentation adjustments.
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/percpu.h')
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index f899e01a8ac9..38f9e965ff96 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -177,6 +177,39 @@ do { \ } \ } while (0) +/* + * Add return operation + */ +#define percpu_add_return_op(var, val) \ +({ \ + typeof(var) paro_ret__ = val; \ + switch (sizeof(var)) { \ + case 1: \ + asm("xaddb %0, "__percpu_arg(1) \ + : "+q" (paro_ret__), "+m" (var) \ + : : "memory"); \ + break; \ + case 2: \ + asm("xaddw %0, "__percpu_arg(1) \ + : "+r" (paro_ret__), "+m" (var) \ + : : "memory"); \ + break; \ + case 4: \ + asm("xaddl %0, "__percpu_arg(1) \ + : "+r" (paro_ret__), "+m" (var) \ + : : "memory"); \ + break; \ + case 8: \ + asm("xaddq %0, "__percpu_arg(1) \ + : "+re" (paro_ret__), "+m" (var) \ + : : "memory"); \ + break; \ + default: __bad_percpu_size(); \ + } \ + paro_ret__ += val; \ + paro_ret__; \ +}) + #define percpu_from_op(op, var, constraint) \ ({ \ typeof(var) pfo_ret__; \ @@ -300,6 +333,14 @@ do { \ #define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val) #define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val) +#ifndef CONFIG_M386 +#define __this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val) +#define __this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val) +#define __this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val) +#define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val) +#define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val) +#define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val) +#endif /* * Per cpu atomic 64 bit operations are only available under 64 bit. * 32 bit must fall back to generic operations. @@ -324,6 +365,8 @@ do { \ #define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) #define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) +#define __this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val) +#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val) #endif /* This is not atomic against other CPUs -- CPU preemption needs to be off */ |