#ifndef _ALPHA_ATOMIC_H #define _ALPHA_ATOMIC_H #include <asm/barrier.h> /* * Atomic operations that C can't guarantee us. Useful for * resource counting etc... * * But use these as seldom as possible since they are much slower * than regular operations. */ /* * Counter is volatile to 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; typedef struct { volatile long counter; } atomic64_t; #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) #define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } ) #define atomic_read(v) ((v)->counter + 0) #define atomic64_read(v) ((v)->counter + 0) #define atomic_set(v,i) ((v)->counter = (i)) #define atomic64_set(v,i) ((v)->counter = (i)) /* * To get proper branch prediction for the main line, we must branch * forward to code at the end of this object's .text section, then * branch back to restart the operation. */ static __inline__ void atomic_add(int i, atomic_t * v) { unsigned long temp; __asm__ __volatile__( "1: ldl_l %0,%1\n" " addl %0,%2,%0\n" " stl_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter) :"Ir" (i), "m" (v->counter)); } static __inline__ void atomic64_add(long i, atomic64_t * v) { unsigned long temp; __asm__ __volatile__( "1: ldq_l %0,%1\n" " addq %0,%2,%0\n" " stq_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter) :"Ir" (i), "m" (v->counter)); } static __inline__ void atomic_sub(int i, atomic_t * v) { unsigned long temp; __asm__ __volatile__( "1: ldl_l %0,%1\n" " subl %0,%2,%0\n" " stl_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter) :"Ir" (i), "m" (v->counter)); } static __inline__ void atomic64_sub(long i, atomic64_t * v) { unsigned long temp; __asm__ __volatile__( "1: ldq_l %0,%1\n" " subq %0,%2,%0\n" " stq_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter) :"Ir" (i), "m" (v->counter)); } /* * Same as above, but return the result value */ static __inline__ long atomic_add_return(int i, atomic_t * v) { long temp, result; smp_mb(); __asm__ __volatile__( "1: ldl_l %0,%1\n" " addl %0,%3,%2\n" " addl %0,%3,%0\n" " stl_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter), "=&r" (result) :"Ir" (i), "m" (v->counter) : "memory"); smp_mb(); return result; } static __inline__ long atomic64_add_return(long i, atomic64_t * v) { long temp, result; smp_mb(); __asm__ __volatile__( "1: ldq_l %0,%1\n" " addq %0,%3,%2\n" " addq %0,%3,%0\n" " stq_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter), "=&r" (result) :"Ir" (i), "m" (v->counter) : "memory"); smp_mb(); return result; } static __inline__ long atomic_sub_return(int i, atomic_t * v) { long temp, result; smp_mb(); __asm__ __volatile__( "1: ldl_l %0,%1\n" " subl %0,%3,%2\n" " subl %0,%3,%0\n" " stl_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter), "=&r" (result) :"Ir" (i), "m" (v->counter) : "memory"); smp_mb(); return result; } static __inline__ long atomic64_sub_return(long i, atomic64_t * v) { long temp, result; smp_mb(); __asm__ __volatile__( "1: ldq_l %0,%1\n" " subq %0,%3,%2\n" " subq %0,%3,%0\n" " stq_c %0,%1\n" " beq %0,2f\n" ".subsection 2\n" "2: br 1b\n" ".previous" :"=&r" (temp), "=m" (v->counter), "=&r" (result) :"Ir" (i), "m" (v->counter) : "memory"); smp_mb(); return result; } #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) #define atomic_add_unless(v, a, u) \ ({ \ int c, old; \ c = atomic_read(v); \ while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ c = old; \ c != (u); \ }) #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) #define atomic_dec_return(v) atomic_sub_return(1,(v)) #define atomic64_dec_return(v) atomic64_sub_return(1,(v)) #define atomic_inc_return(v) atomic_add_return(1,(v)) #define atomic64_inc_return(v) atomic64_add_return(1,(v)) #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0) #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0) #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) #define atomic_inc(v) atomic_add(1,(v)) #define atomic64_inc(v) atomic64_add(1,(v)) #define atomic_dec(v) atomic_sub(1,(v)) #define atomic64_dec(v) atomic64_sub(1,(v)) #define smp_mb__before_atomic_dec() smp_mb() #define smp_mb__after_atomic_dec() smp_mb() #define smp_mb__before_atomic_inc() smp_mb() #define smp_mb__after_atomic_inc() smp_mb() #include <asm-generic/atomic.h> #endif /* _ALPHA_ATOMIC_H */