From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/alpha/include/asm/atomic.h | 260 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 260 insertions(+) create mode 100644 arch/alpha/include/asm/atomic.h (limited to 'arch/alpha/include/asm/atomic.h') diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h new file mode 100644 index 00000000..e756d04b --- /dev/null +++ b/arch/alpha/include/asm/atomic.h @@ -0,0 +1,260 @@ +#ifndef _ALPHA_ATOMIC_H +#define _ALPHA_ATOMIC_H + +#include +#include +#include + +/* + * 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) ( (atomic_t) { (i) } ) +#define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } ) + +#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic64_read(v) (*(volatile long *)&(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. + */ + +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 int 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 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) + +#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 +#endif /* _ALPHA_ATOMIC_H */ -- cgit v1.2.3