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Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/atomic_32.h22
-rw-r--r--arch/x86/lib/atomic64_32.c23
2 files changed, 23 insertions, 22 deletions
diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h
index d7c8849b8c6..dc5a667ff79 100644
--- a/arch/x86/include/asm/atomic_32.h
+++ b/arch/x86/include/asm/atomic_32.h
@@ -295,6 +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);
/**
diff --git a/arch/x86/lib/atomic64_32.c b/arch/x86/lib/atomic64_32.c
index 1d98c9eb6ea..824fa0be55a 100644
--- a/arch/x86/lib/atomic64_32.c
+++ b/arch/x86/lib/atomic64_32.c
@@ -66,31 +66,10 @@ void atomic64_set(atomic64_t *ptr, u64 new_val)
{
atomic64_xchg(ptr, new_val);
}
-EXPORT_SYMBOL(atomic64_read);
+EXPORT_SYMBOL(atomic64_set);
/**
- * atomic64_read - read atomic64 variable
- * @ptr: pointer to type atomic64_t
- *
- * Atomically reads the value of @ptr and returns it.
- */
-u64 atomic64_read(atomic64_t *ptr)
-{
- u64 res;
-
- asm volatile(
- "mov %%ebx, %%eax\n\t"
- "mov %%ecx, %%edx\n\t"
- LOCK_PREFIX "cmpxchg8b %1\n"
- : "+A" (res)
- : "m" (*ptr)
- );
-
- return res;
-}
EXPORT_SYMBOL(atomic64_read);
-
-/**
* atomic64_add_return - add and return
* @delta: integer value to add
* @ptr: pointer to type atomic64_t