From: Chris Snook <[email protected]>
Purify volatile use for atomic_t on sh64.
Signed-off-by: Chris Snook <[email protected]>
--- linux-2.6.23-rc2-orig/include/asm-sh64/atomic.h 2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-sh64/atomic.h 2007-08-09 07:22:50.000000000 -0400
@@ -19,11 +19,15 @@
*
*/
-typedef struct { volatile int counter; } atomic_t;
+typedef struct { int counter; } atomic_t;
#define ATOMIC_INIT(i) ( (atomic_t) { (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))
#include <asm/system.h>