diff options
Diffstat (limited to 'include/asm-generic/local.h')
| -rw-r--r-- | include/asm-generic/local.h | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h index de4614840c2..9291c24f581 100644 --- a/include/asm-generic/local.h +++ b/include/asm-generic/local.h @@ -7,8 +7,15 @@ #include <asm/atomic.h> #include <asm/types.h> -/* An unsigned long type for operations which are atomic for a single - * CPU. Usually used in combination with per-cpu variables. */ +/* + * A signed long type for operations which are atomic for a single CPU. + * Usually used in combination with per-cpu variables. + * + * This is the default implementation, which uses atomic_long_t. Which is + * rather pointless. The whole point behind local_t is that some processors + * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs + * running on this CPU. local_t allows exploitation of such capabilities. + */ /* Implement in terms of atomics. */ @@ -20,7 +27,7 @@ typedef struct #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } -#define local_read(l) ((unsigned long)atomic_long_read(&(l)->a)) +#define local_read(l) atomic_long_read(&(l)->a) #define local_set(l,i) atomic_long_set((&(l)->a),(i)) #define local_inc(l) atomic_long_inc(&(l)->a) #define local_dec(l) atomic_long_dec(&(l)->a) |