From: Chris Snook <[EMAIL PROTECTED]>

Purify volatile use for atomic_t on avr32.

Signed-off-by: Chris Snook <[EMAIL PROTECTED]>

--- linux-2.6.23-rc2-orig/include/asm-avr32/atomic.h    2007-08-08 
17:48:52.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-avr32/atomic.h 2007-08-09 06:33:39.000000000 
-0400
@@ -16,10 +16,14 @@
 
 #include <asm/system.h>
 
-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)
 
 /*
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to