#ifndef _ASM_X86_ATOMIC64_64_H #define _ASM_X86_ATOMIC64_64_H #include #include #include /* 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 READ_ONCE((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) { WRITE_ONCE(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 __always_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 bool atomic64_sub_and_test(long i, atomic64_t *v) { GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", e); } /** * atomic64_inc - increment atomic64 variable * @v: pointer to type atomic64_t * * Atomically increments @v by 1. */ static __always_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 __always_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 bool atomic64_dec_and_test(atomic64_t *v) { GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", e); } /** * 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 bool atomic64_inc_and_test(atomic64_t *v) { GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", e); } /** * 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 bool atomic64_add_negative(long i, atomic64_t *v) { GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", s); } /** * 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 __always_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 bool 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; } #define ATOMIC64_OP(op) \ static inline void atomic64_##op(long i, atomic64_t *v) \ { \ asm volatile(LOCK_PREFIX #op"q %1,%0" \ : "+m" (v->counter) \ : "er" (i) \ : "memory"); \ } ATOMIC64_OP(and) ATOMIC64_OP(or) ATOMIC64_OP(xor) #undef ATOMIC64_OP #endif /* _ASM_X86_ATOMIC64_64_H */