make atomic_read() behave consistently on v850
PATCH 21/24 make atomic_read() behave consistently on v850
From: Chris Snook <[email protected]>
Make atomic_read() volatile on v850. 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-v850/atomic.h +5 -1
@@ -27,7 +27,11 @@ typedef struct { int counter; } atomic_t#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)#define atomic_set (v,i) (((v)->counter) = (i))static inline int atomic_add_return (int i,volatile atomic_t *v)