Messages in this thread Patch in this message | | | Date | Thu, 9 Aug 2007 09:30:28 -0400 | From | Chris Snook <> | Subject | [PATCH 2/24] make atomic_read() behave consistently on arm |
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From: Chris Snook <csnook@redhat.com>
Purify volatile use for atomic_t on arm.
Signed-off-by: Chris Snook <csnook@redhat.com>
--- linux-2.6.23-rc2-orig/include/asm-arm/atomic.h 2007-07-08 19:32:17.000000000 -0400 +++ linux-2.6.23-rc2/include/asm-arm/atomic.h 2007-08-09 06:30:40.000000000 -0400 @@ -14,13 +14,17 @@ #include <linux/compiler.h> #include <asm/system.h> -typedef struct { volatile int counter; } atomic_t; +typedef struct { int counter; } atomic_t; #define ATOMIC_INIT(i) { (i) } #ifdef __KERNEL__ -#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) #if __LINUX_ARM_ARCH__ >= 6 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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