[PATCH 17/24] make atomic_read() behave consistently on sh64
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From: Chris Snook <hidden>
Date: 2007-08-09 14:09:57
Also in:
linux-arch, lkml
From: Chris Snook <redacted> Purify volatile use for atomic_t on sh64. Signed-off-by: Chris Snook <redacted>
--- 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>