LXR linux/arch/alpha/include/asm/local.h

   1#ifndef _ALPHA_LOCAL_H
   2#define _ALPHA_LOCAL_H
   3
   4#include <linux/percpu.h>
   5#include <linux/atomic.h>
   6
   7typedef struct
   8{
   9        atomic_long_t a;
  10} local_t;
  11
  12#define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  13#define local_read(l)   atomic_long_read(&(l)->a)
  14#define local_set(l,i)  atomic_long_set(&(l)->a, (i))
  15#define local_inc(l)    atomic_long_inc(&(l)->a)
  16#define local_dec(l)    atomic_long_dec(&(l)->a)
  17#define local_add(i,l)  atomic_long_add((i),(&(l)->a))
  18#define local_sub(i,l)  atomic_long_sub((i),(&(l)->a))
  19
  20static __inline__ long local_add_return(long i, local_t * l)
  21{
  22        long temp, result;
  23        __asm__ __volatile__(
  24        "1:     ldq_l %0,%1\n"
  25        "       addq %0,%3,%2\n"
  26        "       addq %0,%3,%0\n"
  27        "       stq_c %0,%1\n"
  28        "       beq %0,2f\n"
  29        ".subsection 2\n"
  30        "2:     br 1b\n"
  31        ".previous"
  32        :"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
  33        :"Ir" (i), "m" (l->a.counter) : "memory");
  34        return result;
  35}
  36
  37static __inline__ long local_sub_return(long i, local_t * l)
  38{
  39        long temp, result;
  40        __asm__ __volatile__(
  41        "1:     ldq_l %0,%1\n"
  42        "       subq %0,%3,%2\n"
  43        "       subq %0,%3,%0\n"
  44        "       stq_c %0,%1\n"
  45        "       beq %0,2f\n"
  46        ".subsection 2\n"
  47        "2:     br 1b\n"
  48        ".previous"
  49        :"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
  50        :"Ir" (i), "m" (l->a.counter) : "memory");
  51        return result;
  52}
  53
  54#define local_cmpxchg(l, o, n) \
  55        (cmpxchg_local(&((l)->a.counter), (o), (n)))
  56#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
  57
  58/**
  59 * local_add_unless - add unless the number is a given value
  60 * @l: pointer of type local_t
  61 * @a: the amount to add to l...
  62 * @u: ...unless l is equal to u.
  63 *
  64 * Atomically adds @a to @l, so long as it was not @u.
  65 * Returns non-zero if @l was not @u, and zero otherwise.
  66 */
  67#define local_add_unless(l, a, u)                               \
  68({                                                              \
  69        long c, old;                                            \
  70        c = local_read(l);                                      \
  71        for (;;) {                                              \
  72                if (unlikely(c == (u)))                         \
  73                        break;                                  \
  74                old = local_cmpxchg((l), c, c + (a));   \
  75                if (likely(old == c))                           \
  76                        break;                                  \
  77                c = old;                                        \
  78        }                                                       \
  79        c != (u);                                               \
  80})
  81#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
  82
  83#define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
  84
  85#define local_dec_return(l) local_sub_return(1,(l))
  86
  87#define local_inc_return(l) local_add_return(1,(l))
  88
  89#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
  90
  91#define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
  92
  93#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
  94
  95/* Verify if faster than atomic ops */
  96#define __local_inc(l)          ((l)->a.counter++)
  97#define __local_dec(l)          ((l)->a.counter++)
  98#define __local_add(i,l)        ((l)->a.counter+=(i))
  99#define __local_sub(i,l)        ((l)->a.counter-=(i))
 100
 101#endif /* _ALPHA_LOCAL_H */
 102