diff options
Diffstat (limited to 'include/asm-generic/atomic.h')
| -rw-r--r-- | include/asm-generic/atomic.h | 59 |
1 files changed, 47 insertions, 12 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index e994197f84b7..e37963c1df4d 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -1,5 +1,7 @@ /* - * Generic C implementation of atomic counter operations + * Generic C implementation of atomic counter operations. Usable on + * UP systems only. Do not include in machine independent code. + * * Originally implemented for MN10300. * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. @@ -14,7 +16,11 @@ #define __ASM_GENERIC_ATOMIC_H #ifdef CONFIG_SMP -#error not SMP safe +/* Force people to define core atomics */ +# if !defined(atomic_add_return) || !defined(atomic_sub_return) || \ + !defined(atomic_clear_mask) || !defined(atomic_set_mask) +# error "SMP requires a little arch-specific magic" +# endif #endif /* @@ -32,7 +38,9 @@ * * Atomically reads the value of @v. */ +#ifndef atomic_read #define atomic_read(v) (*(volatile int *)&(v)->counter) +#endif /** * atomic_set - set atomic variable @@ -53,6 +61,7 @@ * * Atomically adds @i to @v and returns the result */ +#ifndef atomic_add_return static inline int atomic_add_return(int i, atomic_t *v) { unsigned long flags; @@ -66,6 +75,7 @@ static inline int atomic_add_return(int i, atomic_t *v) return temp; } +#endif /** * atomic_sub_return - subtract integer from atomic variable @@ -74,6 +84,7 @@ static inline int atomic_add_return(int i, atomic_t *v) * * Atomically subtracts @i from @v and returns the result */ +#ifndef atomic_sub_return static inline int atomic_sub_return(int i, atomic_t *v) { unsigned long flags; @@ -87,6 +98,7 @@ static inline int atomic_sub_return(int i, atomic_t *v) return temp; } +#endif static inline int atomic_add_negative(int i, atomic_t *v) { @@ -117,8 +129,8 @@ static inline void atomic_dec(atomic_t *v) #define atomic_inc_return(v) atomic_add_return(1, (v)) #define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) -#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) -#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) +#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) +#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) #define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v))) #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) @@ -129,26 +141,51 @@ static inline void atomic_dec(atomic_t *v) #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) -static inline int atomic_add_unless(atomic_t *v, int a, int u) +static inline int __atomic_add_unless(atomic_t *v, int a, int u) { int c, old; c = atomic_read(v); while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c) c = old; - return c != u; + return c; } -#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) - -static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +/** + * atomic_clear_mask - Atomically clear bits in atomic variable + * @mask: Mask of the bits to be cleared + * @v: pointer of type atomic_t + * + * Atomically clears the bits set in @mask from @v + */ +#ifndef atomic_clear_mask +static inline void atomic_clear_mask(unsigned long mask, atomic_t *v) { unsigned long flags; mask = ~mask; raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */ - *addr &= mask; + v->counter &= mask; raw_local_irq_restore(flags); } +#endif + +/** + * atomic_set_mask - Atomically set bits in atomic variable + * @mask: Mask of the bits to be set + * @v: pointer of type atomic_t + * + * Atomically sets the bits set in @mask in @v + */ +#ifndef atomic_set_mask +static inline void atomic_set_mask(unsigned int mask, atomic_t *v) +{ + unsigned long flags; + + raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */ + v->counter |= mask; + raw_local_irq_restore(flags); +} +#endif /* Assume that atomic operations are already serializing */ #define smp_mb__before_atomic_dec() barrier() @@ -156,7 +193,5 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) #define smp_mb__before_atomic_inc() barrier() #define smp_mb__after_atomic_inc() barrier() -#include <asm-generic/atomic-long.h> - #endif /* __KERNEL__ */ #endif /* __ASM_GENERIC_ATOMIC_H */ |