diff options
author | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-02 00:08:05 -0500 |
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committer | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-02 00:08:05 -0500 |
commit | 95d465fd750897ab32462a6702fbfe1b122cbbc0 (patch) | |
tree | 65c38b2f11c51bb6932e44dd6c92f15b0091abfe /include/asm-generic/local.h | |
parent | 642fde17dceceb56c7ba2762733ac688666ae657 (diff) | |
parent | 683aa4012f53b2ada0f430487e05d37b0d94e90a (diff) |
Manual merge with Linus.
Conflicts:
arch/powerpc/kernel/setup-common.c
drivers/input/keyboard/hil_kbd.c
drivers/input/mouse/hil_ptr.c
Diffstat (limited to 'include/asm-generic/local.h')
-rw-r--r-- | include/asm-generic/local.h | 91 |
1 files changed, 18 insertions, 73 deletions
diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h index 16fc00360f7..9291c24f581 100644 --- a/include/asm-generic/local.h +++ b/include/asm-generic/local.h @@ -4,28 +4,35 @@ #include <linux/config.h> #include <linux/percpu.h> #include <linux/hardirq.h> +#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. + */ -#if BITS_PER_LONG == 32 /* Implement in terms of atomics. */ /* Don't use typedef: don't want them to be mixed with atomic_t's. */ typedef struct { - atomic_t a; + atomic_long_t a; } local_t; -#define LOCAL_INIT(i) { ATOMIC_INIT(i) } +#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } -#define local_read(l) ((unsigned long)atomic_read(&(l)->a)) -#define local_set(l,i) atomic_set((&(l)->a),(i)) -#define local_inc(l) atomic_inc(&(l)->a) -#define local_dec(l) atomic_dec(&(l)->a) -#define local_add(i,l) atomic_add((i),(&(l)->a)) -#define local_sub(i,l) atomic_sub((i),(&(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) +#define local_add(i,l) atomic_long_add((i),(&(l)->a)) +#define local_sub(i,l) atomic_long_sub((i),(&(l)->a)) /* Non-atomic variants, ie. preemption disabled and won't be touched * in interrupt, etc. Some archs can optimize this case well. */ @@ -34,68 +41,6 @@ typedef struct #define __local_add(i,l) local_set((l), local_read(l) + (i)) #define __local_sub(i,l) local_set((l), local_read(l) - (i)) -#else /* ... can't use atomics. */ -/* Implement in terms of three variables. - Another option would be to use local_irq_save/restore. */ - -typedef struct -{ - /* 0 = in hardirq, 1 = in softirq, 2 = usermode. */ - unsigned long v[3]; -} local_t; - -#define _LOCAL_VAR(l) ((l)->v[!in_interrupt() + !in_irq()]) - -#define LOCAL_INIT(i) { { (i), 0, 0 } } - -static inline unsigned long local_read(local_t *l) -{ - return l->v[0] + l->v[1] + l->v[2]; -} - -static inline void local_set(local_t *l, unsigned long v) -{ - l->v[0] = v; - l->v[1] = l->v[2] = 0; -} - -static inline void local_inc(local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l)++; - preempt_enable(); -} - -static inline void local_dec(local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l)--; - preempt_enable(); -} - -static inline void local_add(unsigned long v, local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l) += v; - preempt_enable(); -} - -static inline void local_sub(unsigned long v, local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l) -= v; - preempt_enable(); -} - -/* Non-atomic variants, ie. preemption disabled and won't be touched - * in interrupt, etc. Some archs can optimize this case well. */ -#define __local_inc(l) ((l)->v[0]++) -#define __local_dec(l) ((l)->v[0]--) -#define __local_add(i,l) ((l)->v[0] += (i)) -#define __local_sub(i,l) ((l)->v[0] -= (i)) - -#endif /* Non-atomic implementation */ - /* Use these for per-cpu local_t variables: on some archs they are * much more efficient than these naive implementations. Note they take * a variable (eg. mystruct.foo), not an address. |