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>

1 files changed, 30 insertions, 0 deletions

diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index c6b749a018a7..bfac9739f57e 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.