#ifndef __ARCH_I386_ATOMIC__ #define __ARCH_I386_ATOMIC__ #include /* * 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 { volatile int counter; } atomic_t; #define ATOMIC_INIT(i) { (i) } #define atomic_read(v) ((v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) static __inline__ void atomic_add(int i, atomic_t *v) { __asm__ __volatile__( LOCK "addl %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } static __inline__ void atomic_sub(int i, atomic_t *v) { __asm__ __volatile__( LOCK "subl %1,%0" :"=m" (v->counter) :"ir" (i), "m" (v->counter)); } static __inline__ int atomic_sub_and_test(int i, atomic_t *v) { unsigned char c; __asm__ __volatile__( LOCK "subl %2,%0; sete %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; } static __inline__ void atomic_inc(atomic_t *v) { __asm__ __volatile__( LOCK "incl %0" :"=m" (v->counter) :"m" (v->counter)); } static __inline__ void atomic_dec(atomic_t *v) { __asm__ __volatile__( LOCK "decl %0" :"=m" (v->counter) :"m" (v->counter)); } static __inline__ int atomic_dec_and_test(atomic_t *v) { unsigned char c; __asm__ __volatile__( LOCK "decl %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; } static __inline__ int atomic_inc_and_test(atomic_t *v) { unsigned char c; __asm__ __volatile__( LOCK "incl %0; sete %1" :"=m" (v->counter), "=qm" (c) :"m" (v->counter) : "memory"); return c != 0; } static __inline__ int atomic_add_negative(int i, atomic_t *v) { unsigned char c; __asm__ __volatile__( LOCK "addl %2,%0; sets %1" :"=m" (v->counter), "=qm" (c) :"ir" (i), "m" (v->counter) : "memory"); return c; } /* These are x86-specific, used by some header files */ #define atomic_clear_mask(mask, addr) \ __asm__ __volatile__(LOCK "andl %0,%1" \ : : "r" (~(mask)),"m" (*addr) : "memory") #define atomic_set_mask(mask, addr) \ __asm__ __volatile__(LOCK "orl %0,%1" \ : : "r" (mask),"m" (*addr) : "memory") #endif