diff options
Diffstat (limited to 'arch/x86/include/asm/percpu.h')
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index cd28f9ad910d..f899e01a8ac9 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -47,6 +47,20 @@ #ifdef CONFIG_SMP #define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x #define __my_cpu_offset percpu_read(this_cpu_off) + +/* + * Compared to the generic __my_cpu_offset version, the following + * saves one instruction and avoids clobbering a temp register. + */ +#define __this_cpu_ptr(ptr) \ +({ \ + unsigned long tcp_ptr__; \ + __verify_pcpu_ptr(ptr); \ + asm volatile("add " __percpu_arg(1) ", %0" \ + : "=r" (tcp_ptr__) \ + : "m" (this_cpu_off), "0" (ptr)); \ + (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ +}) #else #define __percpu_arg(x) "%P" #x #endif |