include/asm-alpha/local.h

   1 #ifndef _ALPHA_LOCAL_H
   2 #define _ALPHA_LOCAL_H
   3
   4 #include <linux/percpu.h>
   5 #include <asm/atomic.h>
   6
   7 typedef 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
  20 static __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
  37 static __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 /* Use these for per-cpu local_t variables: on some archs they are
 102  * much more efficient than these naive implementations.  Note they take
 103  * a variable, not an address.
 104  */
 105 #define cpu_local_read(l)       local_read(&__get_cpu_var(l))
 106 #define cpu_local_set(l, i)     local_set(&__get_cpu_var(l), (i))
 107
 108 #define cpu_local_inc(l)        local_inc(&__get_cpu_var(l))
 109 #define cpu_local_dec(l)        local_dec(&__get_cpu_var(l))
 110 #define cpu_local_add(i, l)     local_add((i), &__get_cpu_var(l))
 111 #define cpu_local_sub(i, l)     local_sub((i), &__get_cpu_var(l))
 112
 113 #define __cpu_local_inc(l)      __local_inc(&__get_cpu_var(l))
 114 #define __cpu_local_dec(l)      __local_dec(&__get_cpu_var(l))
 115 #define __cpu_local_add(i, l)   __local_add((i), &__get_cpu_var(l))
 116 #define __cpu_local_sub(i, l)   __local_sub((i), &__get_cpu_var(l))
 117
 118 #endif /* _ALPHA_LOCAL_H */