x86: unify prefetch operations
This patch moves the prefetch[w]? functions to processor.h
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index c6b749a..bfac973 100644
--- a/include/asm-x86/processor.h
+++ b/include/asm-x86/processor.h
@@ -596,6 +596,36 @@
#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.