Merge branch 'fix/hda' into for-linus

[pandora-kernel.git] / arch / x86 / include / asm / atomic_32.h

diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h
index aa045de..dc5a667 100644 (file)
--- a/arch/x86/include/asm/atomic_32.h
+++ b/arch/x86/include/asm/atomic_32.h
@@ -268,15 +268,6 @@ typedef struct {
 
 #define ATOMIC64_INIT(val)     { (val) }
 
-/**
- * atomic64_read - read atomic64 variable
- * @ptr: pointer of type atomic64_t
- *
- * Atomically reads the value of @v.
- * Doesn't imply a read memory barrier.
- */
-#define __atomic64_read(ptr)           ((ptr)->counter)
-
 extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
 
 /**
@@ -304,6 +295,28 @@ extern void atomic64_set(atomic64_t *ptr, u64 new_val);
  *
  * Atomically reads the value of @ptr and returns it.
  */
+static inline u64 atomic64_read(atomic64_t *ptr)
+{
+       u64 res;
+
+       /*
+        * Note, we inline this atomic64_t primitive because
+        * it only clobbers EAX/EDX and leaves the others
+        * untouched. We also (somewhat subtly) rely on the
+        * fact that cmpxchg8b returns the current 64-bit value
+        * of the memory location we are touching:
+        */
+       asm volatile(
+               "mov %%ebx, %%eax\n\t"
+               "mov %%ecx, %%edx\n\t"
+               LOCK_PREFIX "cmpxchg8b %1\n"
+                       : "=&A" (res)
+                       : "m" (*ptr)
+               );
+
+       return res;
+}
+
 extern u64 atomic64_read(atomic64_t *ptr);
 
 /**