Subject: [PATCH 22/24] make atomic_read() behave consistently on x86_64

From: Chris Snook <[email-masked]>
Date: Thu, 9 Aug 2007 10:18:59 -0400

From: Chris Snook <[email-masked]>

Make atomic_read() consistent with atomic64_read() and other architectures
on x86_64.

Signed-off-by: Chris Snook <[email-masked]>

--- linux-2.6.23-rc2-orig/include/asm-x86_64/atomic.h	2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-x86_64/atomic.h	2007-08-09 07:51:40.000000000 -0400
@@ -32,7 +32,7 @@ typedef struct { int counter; } atomic_t
  * 
  * Atomically reads the value of @v.
  */ 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 
 /**
  * atomic_set - set atomic variable
@@ -206,7 +206,7 @@ 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 +217,7 @@ typedef struct { volatile long counter; 
  * Atomically reads the value of @v.
  * Doesn't imply a read memory barrier.
  */
-#define atomic64_read(v)		((v)->counter)
+#define atomic64_read(v)		(*(volatile long *)&(v)->counter)
 
 /**
  * atomic64_set - set atomic64 variable