* [PATCH 17/24] make atomic_read() behave consistently on sh64
@ 2007-08-09 14:09 ` Chris Snook
2007-08-09 16:40 ` Paul Mundt
0 siblings, 1 reply; 3+ messages in thread
From: Chris Snook @ 2007-08-09 14:09 UTC (permalink / raw)
To: linux-kernel, linux-arch, torvalds
Cc: netdev, akpm, ak, heiko.carstens, davem, schwidefsky, wensong,
horms, wjiang, cfriesen, zlynx, rpjday, jesper.juhl
From: Chris Snook <csnook@redhat.com>
Purify volatile use for atomic_t on sh64.
Signed-off-by: Chris Snook <csnook@redhat.com>
--- 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>
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 18/24] make atomic_read() behave consistently on sh
@ 2007-08-09 14:10 Chris Snook
2007-08-09 14:09 ` [PATCH 17/24] make atomic_read() behave consistently on sh64 Chris Snook
0 siblings, 1 reply; 3+ messages in thread
From: Chris Snook @ 2007-08-09 14:10 UTC (permalink / raw)
To: linux-kernel, linux-arch, torvalds
Cc: netdev, akpm, ak, heiko.carstens, davem, schwidefsky, wensong,
horms, wjiang, cfriesen, zlynx, rpjday, jesper.juhl
From: Chris Snook <csnook@redhat.com>
Purify volatile use for atomic_t on sh.
Signed-off-by: Chris Snook <csnook@redhat.com>
--- linux-2.6.23-rc2-orig/include/asm-sh/atomic.h 2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-sh/atomic.h 2007-08-09 07:21:33.000000000 -0400
@@ -7,11 +7,15 @@
*
*/
-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 <linux/compiler.h>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 17/24] make atomic_read() behave consistently on sh64
2007-08-09 14:09 ` [PATCH 17/24] make atomic_read() behave consistently on sh64 Chris Snook
@ 2007-08-09 16:40 ` Paul Mundt
0 siblings, 0 replies; 3+ messages in thread
From: Paul Mundt @ 2007-08-09 16:40 UTC (permalink / raw)
To: Chris Snook
Cc: linux-kernel, linux-arch, torvalds, netdev, akpm, ak,
heiko.carstens, davem, schwidefsky, wensong, horms, wjiang,
cfriesen, zlynx, rpjday, jesper.juhl
On Thu, Aug 09, 2007 at 10:09:08AM -0400, Chris Snook wrote:
> Purify volatile use for atomic_t on sh64.
>
> Signed-off-by: Chris Snook <csnook@redhat.com>
On Thu, Aug 09, 2007 at 10:10:34AM -0400, Chris Snook wrote:
> Purify volatile use for atomic_t on sh.
>
> Signed-off-by: Chris Snook <csnook@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2007-08-09 16:41 UTC | newest]
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2007-08-09 16:40 ` Paul Mundt
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