[PATCH 22/23] make atomic_read() and atomic_set() behavior consistent on x86_64

From: Chris Snook
Date: Mon Aug 13 2007 - 10:42:52 EST


From: Chris Snook <csnook@xxxxxxxxxx>

Use volatile consistently in atomic.h on x86_64.

Signed-off-by: Chris Snook <csnook@xxxxxxxxxx>

--- linux-2.6.23-rc3-orig/include/asm-x86_64/atomic.h 2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc3/include/asm-x86_64/atomic.h 2007-08-13 06:22:43.000000000 -0400
@@ -32,7 +32,10 @@ typedef struct { int counter; } atomic_t
*
* Atomically reads the value of @v.
*/
-#define atomic_read(v) ((v)->counter)
+static __inline__ int atomic_read(atomic_t *v)
+{
+ return *(volatile int *)&v->counter;
+}

/**
* atomic_set - set atomic variable
@@ -41,7 +44,10 @@ typedef struct { int counter; } atomic_t
*
* Atomically sets the value of @v to @i.
*/
-#define atomic_set(v,i) (((v)->counter) = (i))
+static __inline__ void atomic_set(atomic_t *v, int i)
+{
+ *(volatile int *)&v->counter = i;
+}

/**
* atomic_add - add integer to atomic variable
@@ -206,7 +212,7 @@ static __inline__ int atomic_sub_return(

/* An 64bit atomic type */

-typedef struct { volatile long counter; } atomic64_t;
+typedef struct { long counter; } atomic64_t;

#define ATOMIC64_INIT(i) { (i) }

@@ -217,7 +223,10 @@ typedef struct { volatile long counter;
* Atomically reads the value of @v.
* Doesn't imply a read memory barrier.
*/
-#define atomic64_read(v) ((v)->counter)
+static __inline__ long atomic64_read(atomic64_t *v)
+{
+ return *(volatile long *)&v->counter;
+}

/**
* atomic64_set - set atomic64 variable
@@ -226,7 +235,10 @@ typedef struct { volatile long counter;
*
* Atomically sets the value of @v to @i.
*/
-#define atomic64_set(v,i) (((v)->counter) = (i))
+static __inline__ void atomic64_set(atomic64_t *v, long i)
+{
+ *(volatile long *)&v->counter = i;
+}

/**
* atomic64_add - add integer to atomic64 variable
-
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