Add spinlocks

[fio.git] / arch / arch-x86_64.h

diff --git a/arch/arch-x86_64.h b/arch/arch-x86_64.h
index 216e74e2e32a409d1d7bbee30aa38f771cafdb40..71ba2240180f8937182725812529782f58dd8873 100644 (file)
--- a/arch/arch-x86_64.h
+++ b/arch/arch-x86_64.h
@@ -40,4 +40,35 @@ static inline unsigned int arch_ffz(unsigned int bitmask)
 }
 #define ARCH_HAVE_FFZ
 
+typedef struct {
+       unsigned int lock;
+} spinlock_t;
+
+static inline void spin_lock(spinlock_t *lock)
+{
+       short inc = 0x0100;
+
+       __asm__ __volatile__("xaddw %w0, %1\n"
+                       "1:\t"
+                       "cmpb %h0, %b0\n\t"
+                       "je 2f\n\t"
+                       "rep ; nop\n\t"
+                       "movb %1, %b0\n\t"
+                       "jmp 1b\n"
+                       "2:"
+                       : "+Q" (inc), "+m" (lock->lock)
+                       :
+                       : "memory", "cc");
+}
+
+static inline void spin_unlock(spinlock_t *lock)
+{
+       __asm__ __volatile__("incb %0"
+                       : "+m" (lock->lock)
+                       :
+                       : "memory", "cc");
+}
+
+#define __SPIN_LOCK_UNLOCKED   { 0 }
+
 #endif