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Diffstat (limited to 'kernel/arch/alpha/include/asm/atomic.h')
| -rw-r--r-- | kernel/arch/alpha/include/asm/atomic.h | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/kernel/arch/alpha/include/asm/atomic.h b/kernel/arch/alpha/include/asm/atomic.h new file mode 100644 index 000000000..8f8eafbed --- /dev/null +++ b/kernel/arch/alpha/include/asm/atomic.h @@ -0,0 +1,242 @@ +#ifndef _ALPHA_ATOMIC_H +#define _ALPHA_ATOMIC_H + +#include <linux/types.h> +#include <asm/barrier.h> +#include <asm/cmpxchg.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. + */ + + +#define ATOMIC_INIT(i) { (i) } +#define ATOMIC64_INIT(i) { (i) } + +#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic64_read(v) ACCESS_ONCE((v)->counter) + +#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. + */ + +#define ATOMIC_OP(op) \ +static __inline__ void atomic_##op(int i, atomic_t * v) \ +{ \ + unsigned long temp; \ + __asm__ __volatile__( \ + "1: ldl_l %0,%1\n" \ + " " #op "l %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)); \ +} \ + +#define ATOMIC_OP_RETURN(op) \ +static inline int atomic_##op##_return(int i, atomic_t *v) \ +{ \ + long temp, result; \ + smp_mb(); \ + __asm__ __volatile__( \ + "1: ldl_l %0,%1\n" \ + " " #op "l %0,%3,%2\n" \ + " " #op "l %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; \ +} + +#define ATOMIC64_OP(op) \ +static __inline__ void atomic64_##op(long i, atomic64_t * v) \ +{ \ + unsigned long temp; \ + __asm__ __volatile__( \ + "1: ldq_l %0,%1\n" \ + " " #op "q %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)); \ +} \ + +#define ATOMIC64_OP_RETURN(op) \ +static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ +{ \ + long temp, result; \ + smp_mb(); \ + __asm__ __volatile__( \ + "1: ldq_l %0,%1\n" \ + " " #op "q %0,%3,%2\n" \ + " " #op "q %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_OPS(opg) \ + ATOMIC_OP(opg) \ + ATOMIC_OP_RETURN(opg) \ + ATOMIC64_OP(opg) \ + ATOMIC64_OP_RETURN(opg) + +ATOMIC_OPS(add) +ATOMIC_OPS(sub) + +#undef ATOMIC_OPS +#undef ATOMIC64_OP_RETURN +#undef ATOMIC64_OP +#undef ATOMIC_OP_RETURN +#undef ATOMIC_OP + +#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 the old value of @v. + */ +static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, new, old; + smp_mb(); + __asm__ __volatile__( + "1: ldl_l %[old],%[mem]\n" + " cmpeq %[old],%[u],%[c]\n" + " addl %[old],%[a],%[new]\n" + " bne %[c],2f\n" + " stl_c %[new],%[mem]\n" + " beq %[new],3f\n" + "2:\n" + ".subsection 2\n" + "3: br 1b\n" + ".previous" + : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) + : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u) + : "memory"); + smp_mb(); + return old; +} + + +/** + * 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 true iff @v was not @u. + */ +static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) +{ + long c, tmp; + smp_mb(); + __asm__ __volatile__( + "1: ldq_l %[tmp],%[mem]\n" + " cmpeq %[tmp],%[u],%[c]\n" + " addq %[tmp],%[a],%[tmp]\n" + " bne %[c],2f\n" + " stq_c %[tmp],%[mem]\n" + " beq %[tmp],3f\n" + "2:\n" + ".subsection 2\n" + "3: br 1b\n" + ".previous" + : [tmp] "=&r"(tmp), [c] "=&r"(c) + : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) + : "memory"); + smp_mb(); + return !c; +} + +/* + * 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 old, tmp; + smp_mb(); + __asm__ __volatile__( + "1: ldq_l %[old],%[mem]\n" + " subq %[old],1,%[tmp]\n" + " ble %[old],2f\n" + " stq_c %[tmp],%[mem]\n" + " beq %[tmp],3f\n" + "2:\n" + ".subsection 2\n" + "3: br 1b\n" + ".previous" + : [old] "=&r"(old), [tmp] "=&r"(tmp) + : [mem] "m"(*v) + : "memory"); + smp_mb(); + return old - 1; +} + +#define atomic64_inc_not_zero(v) atomic64_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)) + +#endif /* _ALPHA_ATOMIC_H */ |