Subject: [PATCH 5/24] make atomic_read() behave consistently on cris

From: Chris Snook <[email-masked]>
Date: Thu, 9 Aug 2007 09:39:48 -0400

From: Chris Snook <[email-masked]>

Purify volatile use for atomic_t on cris.

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

--- linux-2.6.23-rc2-orig/include/asm-cris/atomic.h	2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-cris/atomic.h	2007-08-09 06:38:28.000000000 -0400
@@ -11,11 +11,15 @@
  * resource counting etc..
  */
 
-typedef struct { volatile int counter; } atomic_t;
+typedef struct { int counter; } atomic_t;
 
 #define ATOMIC_INIT(i)  { (i) }
 
-#define atomic_read(v) ((v)->counter)
+/*
+ * Casting to volatile here minimizes the need for barriers,
+ * without having to declare the type itself as volatile.
+ */
+#define atomic_read(v) (*(volatile int *)&(v)->counter)
 #define atomic_set(v,i) (((v)->counter) = (i))
 
 /* These should be written in asm but we do it in C for now. */