diff options
Diffstat (limited to 'include/asm-x86/processor.h')
| -rw-r--r-- | include/asm-x86/processor.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h index c6b749a018a..bfac9739f57 100644 --- a/include/asm-x86/processor.h +++ b/include/asm-x86/processor.h @@ -596,6 +596,36 @@ extern char ignore_fpu_irq; #define ARCH_HAS_PREFETCHW #define ARCH_HAS_SPINLOCK_PREFETCH +#ifdef CONFIG_X86_32 +#define BASE_PREFETCH ASM_NOP4 +#define ARCH_HAS_PREFETCH +#else +#define BASE_PREFETCH "prefetcht0 (%1)" +#endif + +/* Prefetch instructions for Pentium III and AMD Athlon */ +/* It's not worth to care about 3dnow! prefetches for the K6 + because they are microcoded there and very slow. + However we don't do prefetches for pre XP Athlons currently + That should be fixed. */ +static inline void prefetch(const void *x) +{ + alternative_input(BASE_PREFETCH, + "prefetchnta (%1)", + X86_FEATURE_XMM, + "r" (x)); +} + +/* 3dnow! prefetch to get an exclusive cache line. Useful for + spinlocks to avoid one state transition in the cache coherency protocol. */ +static inline void prefetchw(const void *x) +{ + alternative_input(BASE_PREFETCH, + "prefetchw (%1)", + X86_FEATURE_3DNOW, + "r" (x)); +} + #define spin_lock_prefetch(x) prefetchw(x) /* This decides where the kernel will search for a free chunk of vm * space during mmap's. |