Messages in this thread Patch in this message | | | Date | Wed, 24 Sep 2014 08:37:00 +0100 | From | "Jan Beulich" <> | Subject | [PATCH] x86-64: improve cmpxchg16b_emu.S |
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- don't include unneeded headers - don't open-code PER_CPU_VAR() - drop redundant entry point label - complete unwind annotations - use .L prefix on local label to not clutter the symbol table
Signed-off-by: Jan Beulich <jbeulich@suse.com> --- arch/x86/lib/cmpxchg16b_emu.S | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-)
--- 3.17-rc6/arch/x86/lib/cmpxchg16b_emu.S +++ 3.17-rc6-x86_64-improve-cmpxchg16b_emu/arch/x86/lib/cmpxchg16b_emu.S @@ -6,15 +6,8 @@ * */ #include <linux/linkage.h> -#include <asm/alternative-asm.h> -#include <asm/frame.h> #include <asm/dwarf2.h> - -#ifdef CONFIG_SMP -#define SEG_PREFIX %gs: -#else -#define SEG_PREFIX -#endif +#include <asm/percpu.h> .text @@ -39,24 +32,25 @@ CFI_STARTPROC # *atomic* on a single cpu (as provided by the this_cpu_xx class of # macros). # -this_cpu_cmpxchg16b_emu: - pushf + pushfq_cfi cli - cmpq SEG_PREFIX(%rsi), %rax - jne not_same - cmpq SEG_PREFIX 8(%rsi), %rdx - jne not_same + cmpq PER_CPU_VAR((%rsi)), %rax + jne .Lnot_same + cmpq PER_CPU_VAR(8(%rsi)), %rdx + jne .Lnot_same - movq %rbx, SEG_PREFIX(%rsi) - movq %rcx, SEG_PREFIX 8(%rsi) + movq %rbx, PER_CPU_VAR((%rsi)) + movq %rcx, PER_CPU_VAR(8(%rsi)) - popf + CFI_REMEMBER_STATE + popfq_cfi mov $1, %al ret - not_same: - popf + CFI_RESTORE_STATE +.Lnot_same: + popfq_cfi xor %al,%al ret
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