From 8f1d97c79eb65de1d05799d6b81d79cd94169114 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 6 Dec 2010 11:40:00 -0600 Subject: [PATCH] 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 Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- arch/x86/include/asm/percpu.h | 43 +++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) 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 */