#ifndef __ARCH_X86_64_ATOMIC__ #define __ARCH_X86_64_ATOMIC__ #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.. */ #ifdef CONFIG_SMP #define LOCK "lock ; " #else #define LOCK "" #endif /* * 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) :"ir" (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) :"ir" (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) :"ir" (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) :"ir" (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); } #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