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Diffstat (limited to 'arch/x86/include/asm/atomic_64.h')
-rw-r--r-- | arch/x86/include/asm/atomic_64.h | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/arch/x86/include/asm/atomic_64.h b/arch/x86/include/asm/atomic_64.h new file mode 100644 index 00000000000..2cb218c4a35 --- /dev/null +++ b/arch/x86/include/asm/atomic_64.h @@ -0,0 +1,473 @@ +#ifndef ASM_X86__ATOMIC_64_H +#define ASM_X86__ATOMIC_64_H + +#include <asm/alternative.h> +#include <asm/cmpxchg.h> + +/* atomic_t should be 32 bit signed type */ + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +/* + * Make sure gcc doesn't try to be clever and move things around + * on us. We need to use _exactly_ the address the user gave us, + * not some alias that contains the same information. + */ +typedef struct { + int counter; +} atomic_t; + +#define ATOMIC_INIT(i) { (i) } + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +#define atomic_read(v) ((v)->counter) + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +#define atomic_set(v, i) (((v)->counter) = (i)) + +/** + * atomic_add - add integer to atomic variable + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v. + */ +static inline void atomic_add(int i, atomic_t *v) +{ + asm volatile(LOCK_PREFIX "addl %1,%0" + : "=m" (v->counter) + : "ir" (i), "m" (v->counter)); +} + +/** + * atomic_sub - subtract the atomic variable + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v. + */ +static inline void atomic_sub(int i, atomic_t *v) +{ + asm volatile(LOCK_PREFIX "subl %1,%0" + : "=m" (v->counter) + : "ir" (i), "m" (v->counter)); +} + +/** + * 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. + */ +static inline int atomic_sub_and_test(int i, atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "ir" (i), "m" (v->counter) : "memory"); + return c; +} + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +static inline void atomic_inc(atomic_t *v) +{ + asm volatile(LOCK_PREFIX "incl %0" + : "=m" (v->counter) + : "m" (v->counter)); +} + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +static inline void atomic_dec(atomic_t *v) +{ + asm volatile(LOCK_PREFIX "decl %0" + : "=m" (v->counter) + : "m" (v->counter)); +} + +/** + * 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, or false for all other + * cases. + */ +static inline int atomic_dec_and_test(atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "decl %0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "m" (v->counter) : "memory"); + return c != 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 zero, or false for all + * other cases. + */ +static inline int atomic_inc_and_test(atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "incl %0; sete %1" + : "=m" (v->counter), "=qm" (c) + : "m" (v->counter) : "memory"); + return c != 0; +} + +/** + * atomic_add_negative - add and test if negative + * @i: integer value to add + * @v: pointer of type atomic_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 atomic_add_negative(int i, atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" + : "=m" (v->counter), "=qm" (c) + : "ir" (i), "m" (v->counter) : "memory"); + return c; +} + +/** + * atomic_add_return - add and return + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline int atomic_add_return(int i, atomic_t *v) +{ + int __i = i; + asm volatile(LOCK_PREFIX "xaddl %0, %1" + : "+r" (i), "+m" (v->counter) + : : "memory"); + return i + __i; +} + +static inline int atomic_sub_return(int i, atomic_t *v) +{ + return atomic_add_return(-i, v); +} + +#define atomic_inc_return(v) (atomic_add_return(1, v)) +#define atomic_dec_return(v) (atomic_sub_return(1, v)) + +/* An 64bit atomic type */ + +typedef struct { + long counter; +} atomic64_t; + +#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. + */ +#define atomic64_read(v) ((v)->counter) + +/** + * atomic64_set - set atomic64 variable + * @v: pointer to type atomic64_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +#define atomic64_set(v, 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) +{ + long __i = i; + asm volatile(LOCK_PREFIX "xaddq %0, %1;" + : "+r" (i), "+m" (v->counter) + : : "memory"); + return i + __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))) + +#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) +#define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) + +#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) +#define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) + +/** + * atomic_add_unless - add unless the number is a given value + * @v: pointer of type atomic_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 non-zero if @v was not @u, and zero otherwise. + */ +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + c = atomic_read(v); + for (;;) { + if (unlikely(c == (u))) + break; + old = atomic_cmpxchg((v), c, c + (a)); + if (likely(old == c)) + break; + c = old; + } + return c != (u); +} + +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +/** + * 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 non-zero if @v was not @u, and zero otherwise. + */ +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); +} + +/** + * atomic_inc_short - increment of a short integer + * @v: pointer to type int + * + * Atomically adds 1 to @v + * Returns the new value of @u + */ +static inline short int atomic_inc_short(short int *v) +{ + asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); + return *v; +} + +/** + * atomic_or_long - OR of two long integers + * @v1: pointer to type unsigned long + * @v2: pointer to type unsigned long + * + * Atomically ORs @v1 and @v2 + * Returns the result of the OR + */ +static inline void atomic_or_long(unsigned long *v1, unsigned long v2) +{ + asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); +} + +#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) + +/* These are x86-specific, used by some header files */ +#define atomic_clear_mask(mask, addr) \ + asm volatile(LOCK_PREFIX "andl %0,%1" \ + : : "r" (~(mask)), "m" (*(addr)) : "memory") + +#define atomic_set_mask(mask, addr) \ + asm volatile(LOCK_PREFIX "orl %0,%1" \ + : : "r" ((unsigned)(mask)), "m" (*(addr)) \ + : "memory") + +/* Atomic operations are already serializing on x86 */ +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + +#include <asm-generic/atomic.h> +#endif /* ASM_X86__ATOMIC_64_H */ |