make atomic_read() behave consistently on m68k
PATCH 12/24 make atomic_read() behave consistently on m68k
From: Chris Snook <[email protected]>
Make atomic_read() volatile on m68k. This ensures that busy-waiting for an interrupt handler to change an atomic_t won't get compiled to an infinite loop, consistent with SMP architectures.
Signed-off-by Chris Snook <[email protected]>
include/asm-m68k/atomic.h +5 -1
@@ -16,7 +16,11 @@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)static inline void atomic_add (int i,atomic_t *v)