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Diffstat (limited to 'arch/x86/include/asm/atomic64_64.h')
| -rw-r--r-- | arch/x86/include/asm/atomic64_64.h | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h new file mode 100644 index 00000000..0e1cbfc8 --- /dev/null +++ b/arch/x86/include/asm/atomic64_64.h @@ -0,0 +1,243 @@ +#ifndef _ASM_X86_ATOMIC64_64_H +#define _ASM_X86_ATOMIC64_64_H + +#include <linux/types.h> +#include <asm/alternative.h> +#include <asm/cmpxchg.h> + +/* The 64-bit atomic type */ + +#define ATOMIC64_INIT(i) { (i) } + +/** + * atomic64_read - read atomic64 variable + * @v: pointer of type atomic64_t + * + * Atomically reads the value of @v. + * Doesn't imply a read memory barrier. + */ +static inline long atomic64_read(const atomic64_t *v) +{ + return (*(volatile long *)&(v)->counter); +} + +/** + * atomic64_set - set atomic64 variable + * @v: pointer to type atomic64_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +static inline void atomic64_set(atomic64_t *v, long i) +{ + v->counter = i; +} + +/** + * atomic64_add - add integer to atomic64 variable + * @i: integer value to add + * @v: pointer to type atomic64_t + * + * Atomically adds @i to @v. + */ +static inline void atomic64_add(long i, atomic64_t *v) +{ + asm volatile(LOCK_PREFIX "addq %1,%0" + : "=m" (v->counter) + : "er" (i), "m" (v->counter)); +} + +/** + * atomic64_sub - subtract the atomic64 variable + * @i: integer value to subtract + * @v: pointer to type atomic64_t + * + * Atomically subtracts @i from @v. + */ +static inline void atomic64_sub(long i, atomic64_t *v) +{ + asm volatile(LOCK_PREFIX "subq %1,%0" + : "=m" (v->counter) + : "er" (i), "m" (v->counter)); +} + +/** + * atomic64_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @v: pointer to type atomic64_t + * + * Atomically subtracts @i from @v and returns + * true if the result is zero, or false for all + * other cases. + */ +static inline int atomic64_sub_and_test(long i, atomic64_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "subq %2,%0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "er" (i), "m" (v->counter) : "memory"); + return c; +} + +/** + * atomic64_inc - increment atomic64 variable + * @v: pointer to type atomic64_t + * + * Atomically increments @v by 1. + */ +static inline void atomic64_inc(atomic64_t *v) +{ + asm volatile(LOCK_PREFIX "incq %0" + : "=m" (v->counter) + : "m" (v->counter)); +} + +/** + * atomic64_dec - decrement atomic64 variable + * @v: pointer to type atomic64_t + * + * Atomically decrements @v by 1. + */ +static inline void atomic64_dec(atomic64_t *v) +{ + asm volatile(LOCK_PREFIX "decq %0" + : "=m" (v->counter) + : "m" (v->counter)); +} + +/** + * atomic64_dec_and_test - decrement and test + * @v: pointer to type atomic64_t + * + * Atomically decrements @v by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +static inline int atomic64_dec_and_test(atomic64_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "decq %0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "m" (v->counter) : "memory"); + return c != 0; +} + +/** + * atomic64_inc_and_test - increment and test + * @v: pointer to type atomic64_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +static inline int atomic64_inc_and_test(atomic64_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "incq %0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "m" (v->counter) : "memory"); + return c != 0; +} + +/** + * atomic64_add_negative - add and test if negative + * @i: integer value to add + * @v: pointer to type atomic64_t + * + * Atomically adds @i to @v and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +static inline int atomic64_add_negative(long i, atomic64_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "addq %2,%0; sets %1" + : "=m" (v->counter), "=qm" (c) + : "er" (i), "m" (v->counter) : "memory"); + return c; +} + +/** + * atomic64_add_return - add and return + * @i: integer value to add + * @v: pointer to type atomic64_t + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline long atomic64_add_return(long i, atomic64_t *v) +{ + return i + xadd(&v->counter, i); +} + +static inline long atomic64_sub_return(long i, atomic64_t *v) +{ + return atomic64_add_return(-i, v); +} + +#define atomic64_inc_return(v) (atomic64_add_return(1, (v))) +#define atomic64_dec_return(v) (atomic64_sub_return(1, (v))) + +static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new) +{ + return cmpxchg(&v->counter, old, new); +} + +static inline long atomic64_xchg(atomic64_t *v, long new) +{ + return xchg(&v->counter, new); +} + +/** + * atomic64_add_unless - add unless the number is a given value + * @v: pointer of type atomic64_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as it was not @u. + * Returns the old value of @v. + */ +static inline int atomic64_add_unless(atomic64_t *v, long a, long u) +{ + long c, old; + c = atomic64_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic64_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c != (u); +} + +#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) + +/* + * atomic64_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline long atomic64_dec_if_positive(atomic64_t *v) +{ + 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 /* _ASM_X86_ATOMIC64_64_H */ |