From 5917dae83cb02dfe74c9167b79e86e6d65183fa3 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 5 Jan 2010 15:34:50 +0900 Subject: [PATCH] percpu, x86: Generic inc / dec percpu instructions Optimize code generated for percpu access by checking for increment and decrements. tj: fix incorrect usage of __builtin_constant_p() and restructure percpu_add_op() macro. Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- arch/x86/include/asm/percpu.h | 86 +++++++++++++++++++++++++++++------ 1 file changed, 72 insertions(+), 14 deletions(-) diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 4c170ccc72ed..66a272dfd8b8 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -103,6 +103,64 @@ do { \ } \ } while (0) +/* + * Generate a percpu add to memory instruction and optimize code + * if a one is added or subtracted. + */ +#define percpu_add_op(var, val) \ +do { \ + typedef typeof(var) pao_T__; \ + const int pao_ID__ = (__builtin_constant_p(val) && \ + ((val) == 1 || (val) == -1)) ? (val) : 0; \ + if (0) { \ + pao_T__ pao_tmp__; \ + pao_tmp__ = (val); \ + } \ + switch (sizeof(var)) { \ + case 1: \ + if (pao_ID__ == 1) \ + asm("incb "__percpu_arg(0) : "+m" (var)); \ + else if (pao_ID__ == -1) \ + asm("decb "__percpu_arg(0) : "+m" (var)); \ + else \ + asm("addb %1, "__percpu_arg(0) \ + : "+m" (var) \ + : "qi" ((pao_T__)(val))); \ + break; \ + case 2: \ + if (pao_ID__ == 1) \ + asm("incw "__percpu_arg(0) : "+m" (var)); \ + else if (pao_ID__ == -1) \ + asm("decw "__percpu_arg(0) : "+m" (var)); \ + else \ + asm("addw %1, "__percpu_arg(0) \ + : "+m" (var) \ + : "ri" ((pao_T__)(val))); \ + break; \ + case 4: \ + if (pao_ID__ == 1) \ + asm("incl "__percpu_arg(0) : "+m" (var)); \ + else if (pao_ID__ == -1) \ + asm("decl "__percpu_arg(0) : "+m" (var)); \ + else \ + asm("addl %1, "__percpu_arg(0) \ + : "+m" (var) \ + : "ri" ((pao_T__)(val))); \ + break; \ + case 8: \ + if (pao_ID__ == 1) \ + asm("incq "__percpu_arg(0) : "+m" (var)); \ + else if (pao_ID__ == -1) \ + asm("decq "__percpu_arg(0) : "+m" (var)); \ + else \ + asm("addq %1, "__percpu_arg(0) \ + : "+m" (var) \ + : "re" ((pao_T__)(val))); \ + break; \ + default: __bad_percpu_size(); \ + } \ +} while (0) + #define percpu_from_op(op, var, constraint) \ ({ \ typeof(var) pfo_ret__; \ @@ -144,8 +202,8 @@ do { \ #define percpu_read(var) percpu_from_op("mov", var, "m" (var)) #define percpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var))) #define percpu_write(var, val) percpu_to_op("mov", var, val) -#define percpu_add(var, val) percpu_to_op("add", var, val) -#define percpu_sub(var, val) percpu_to_op("sub", var, val) +#define percpu_add(var, val) percpu_add_op(var, val) +#define percpu_sub(var, val) percpu_add_op(var, -(val)) #define percpu_and(var, val) percpu_to_op("and", var, val) #define percpu_or(var, val) percpu_to_op("or", var, val) #define percpu_xor(var, val) percpu_to_op("xor", var, val) @@ -157,9 +215,9 @@ do { \ #define __this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) #define __this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) #define __this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) -#define __this_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val) -#define __this_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val) -#define __this_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val) +#define __this_cpu_add_1(pcp, val) percpu_add_op((pcp), val) +#define __this_cpu_add_2(pcp, val) percpu_add_op((pcp), val) +#define __this_cpu_add_4(pcp, val) percpu_add_op((pcp), val) #define __this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) #define __this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) #define __this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) @@ -176,9 +234,9 @@ do { \ #define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) -#define this_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val) -#define this_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val) -#define this_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val) +#define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val) +#define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val) +#define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val) #define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) @@ -189,9 +247,9 @@ do { \ #define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val) #define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val) -#define irqsafe_cpu_add_1(pcp, val) percpu_to_op("add", (pcp), val) -#define irqsafe_cpu_add_2(pcp, val) percpu_to_op("add", (pcp), val) -#define irqsafe_cpu_add_4(pcp, val) percpu_to_op("add", (pcp), val) +#define irqsafe_cpu_add_1(pcp, val) percpu_add_op((pcp), val) +#define irqsafe_cpu_add_2(pcp, val) percpu_add_op((pcp), val) +#define irqsafe_cpu_add_4(pcp, val) percpu_add_op((pcp), val) #define irqsafe_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) #define irqsafe_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) #define irqsafe_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) @@ -209,19 +267,19 @@ do { \ #ifdef CONFIG_X86_64 #define __this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) #define __this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) -#define __this_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val) +#define __this_cpu_add_8(pcp, val) percpu_add_op((pcp), val) #define __this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) #define __this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) #define __this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) #define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp)) #define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) -#define this_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val) +#define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val) #define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) #define this_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val) -#define irqsafe_cpu_add_8(pcp, val) percpu_to_op("add", (pcp), val) +#define irqsafe_cpu_add_8(pcp, val) percpu_add_op((pcp), val) #define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) #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) -- 2.39.5