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Diffstat (limited to 'arch/tile/include/asm/atomic.h')
| -rw-r--r-- | arch/tile/include/asm/atomic.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/arch/tile/include/asm/atomic.h b/arch/tile/include/asm/atomic.h new file mode 100644 index 000000000..709798460 --- /dev/null +++ b/arch/tile/include/asm/atomic.h @@ -0,0 +1,208 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * Atomic primitives. + */ + +#ifndef _ASM_TILE_ATOMIC_H +#define _ASM_TILE_ATOMIC_H + +#include <asm/cmpxchg.h> + +#ifndef __ASSEMBLY__ + +#include <linux/compiler.h> +#include <linux/types.h> + +#define ATOMIC_INIT(i) { (i) } + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +static inline int atomic_read(const atomic_t *v) +{ + return ACCESS_ONCE(v->counter); +} + +/** + * atomic_sub_return - subtract integer and return + * @v: pointer of type atomic_t + * @i: integer value to subtract + * + * Atomically subtracts @i from @v and returns @v - @i + */ +#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v)) + +/** + * atomic_sub - subtract integer from atomic variable + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v. + */ +#define atomic_sub(i, v) atomic_add((int)(-(i)), (v)) + +/** + * atomic_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v and returns true if the result is + * zero, or false for all other cases. + */ +#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) + +/** + * atomic_inc_return - increment memory and return + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 and returns the new value. + */ +#define atomic_inc_return(v) atomic_add_return(1, (v)) + +/** + * atomic_dec_return - decrement memory and return + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and returns the new value. + */ +#define atomic_dec_return(v) atomic_sub_return(1, (v)) + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +#define atomic_inc(v) atomic_add(1, (v)) + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +#define atomic_dec(v) atomic_sub(1, (v)) + +/** + * atomic_dec_and_test - decrement and test + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and returns true if the result is 0. + */ +#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) + +/** + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 and returns true if the result is 0. + */ +#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) + +/** + * atomic_xchg - atomically exchange contents of memory with a new value + * @v: pointer of type atomic_t + * @i: integer value to store in memory + * + * Atomically sets @v to @i and returns old @v + */ +static inline int atomic_xchg(atomic_t *v, int n) +{ + return xchg(&v->counter, n); +} + +/** + * atomic_cmpxchg - atomically exchange contents of memory if it matches + * @v: pointer of type atomic_t + * @o: old value that memory should have + * @n: new value to write to memory if it matches + * + * Atomically checks if @v holds @o and replaces it with @n if so. + * Returns the old value at @v. + */ +static inline int atomic_cmpxchg(atomic_t *v, int o, int n) +{ + return cmpxchg(&v->counter, o, n); +} + +/** + * atomic_add_negative - add and test if negative + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns true if the result is + * negative, or false when result is greater than or equal to zero. + */ +#define atomic_add_negative(i, v) (atomic_add_return((i), (v)) < 0) + +#endif /* __ASSEMBLY__ */ + +#ifndef __tilegx__ +#include <asm/atomic_32.h> +#else +#include <asm/atomic_64.h> +#endif + +#ifndef __ASSEMBLY__ + +/** + * atomic64_xchg - atomically exchange contents of memory with a new value + * @v: pointer of type atomic64_t + * @i: integer value to store in memory + * + * Atomically sets @v to @i and returns old @v + */ +static inline long long atomic64_xchg(atomic64_t *v, long long n) +{ + return xchg64(&v->counter, n); +} + +/** + * atomic64_cmpxchg - atomically exchange contents of memory if it matches + * @v: pointer of type atomic64_t + * @o: old value that memory should have + * @n: new value to write to memory if it matches + * + * Atomically checks if @v holds @o and replaces it with @n if so. + * Returns the old value at @v. + */ +static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, + long long n) +{ + return cmpxchg64(&v->counter, o, n); +} + +static inline long long atomic64_dec_if_positive(atomic64_t *v) +{ + long long c, old, dec; + + c = atomic64_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic64_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_TILE_ATOMIC_H */ |