diff options
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 42 |
1 files changed, 18 insertions, 24 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 7563e69838c4..f6ddbaaf80bc 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -59,36 +59,30 @@ #define __force_percpu_prefix "%%"__stringify(__percpu_seg)":" #define __my_cpu_offset this_cpu_read(this_cpu_off) -#ifdef CONFIG_USE_X86_SEG_SUPPORT -/* - * Efficient implementation for cases in which the compiler supports - * named address spaces. Allows the compiler to perform additional - * optimizations that can save more instructions. - */ -#define arch_raw_cpu_ptr(ptr) \ -({ \ - unsigned long tcp_ptr__; \ - tcp_ptr__ = __raw_cpu_read(, this_cpu_off); \ - \ - tcp_ptr__ += (unsigned long)(ptr); \ - (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ -}) -#else /* CONFIG_USE_X86_SEG_SUPPORT */ +#ifdef CONFIG_X86_64 +#define __raw_my_cpu_offset raw_cpu_read_8(this_cpu_off); +#else +#define __raw_my_cpu_offset raw_cpu_read_4(this_cpu_off); +#endif + /* * Compared to the generic __my_cpu_offset version, the following * saves one instruction and avoids clobbering a temp register. + * + * arch_raw_cpu_ptr should not be used in 32-bit VDSO for a 64-bit + * kernel, because games are played with CONFIG_X86_64 there and + * sizeof(this_cpu_off) becames 4. */ -#define arch_raw_cpu_ptr(ptr) \ +#ifndef BUILD_VDSO32_64 +#define arch_raw_cpu_ptr(_ptr) \ ({ \ - unsigned long tcp_ptr__; \ - asm ("mov " __percpu_arg(1) ", %0" \ - : "=r" (tcp_ptr__) \ - : "m" (__my_cpu_var(this_cpu_off))); \ - \ - tcp_ptr__ += (unsigned long)(ptr); \ - (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ + unsigned long tcp_ptr__ = __raw_my_cpu_offset; \ + tcp_ptr__ += (unsigned long)(_ptr); \ + (typeof(*(_ptr)) __kernel __force *)tcp_ptr__; \ }) -#endif /* CONFIG_USE_X86_SEG_SUPPORT */ +#else +#define arch_raw_cpu_ptr(_ptr) ({ BUILD_BUG(); (typeof(_ptr))0; }) +#endif #define PER_CPU_VAR(var) %__percpu_seg:(var)__percpu_rel |