root/arch/alpha/include/asm/local.h

INCLUDED FROM

DEFINITIONS

1. local_add_return
2. local_sub_return

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ALPHA_LOCAL_H
   3 #define _ALPHA_LOCAL_H
   4 
   5 #include <linux/percpu.h>
   6 #include <linux/atomic.h>
   7 
   8 typedef struct
   9 {
  10         atomic_long_t a;
  11 } local_t;
  12 
  13 #define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
  14 #define local_read(l)   atomic_long_read(&(l)->a)
  15 #define local_set(l,i)  atomic_long_set(&(l)->a, (i))
  16 #define local_inc(l)    atomic_long_inc(&(l)->a)
  17 #define local_dec(l)    atomic_long_dec(&(l)->a)
  18 #define local_add(i,l)  atomic_long_add((i),(&(l)->a))
  19 #define local_sub(i,l)  atomic_long_sub((i),(&(l)->a))
  20 
  21 static __inline__ long local_add_return(long i, local_t * l)
  22 {
  23         long temp, result;
  24         __asm__ __volatile__(
  25         "1:     ldq_l %0,%1\n"
  26         "       addq %0,%3,%2\n"
  27         "       addq %0,%3,%0\n"
  28         "       stq_c %0,%1\n"
  29         "       beq %0,2f\n"
  30         ".subsection 2\n"
  31         "2:     br 1b\n"
  32         ".previous"
  33         :"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
  34         :"Ir" (i), "m" (l->a.counter) : "memory");
  35         return result;
  36 }
  37 
  38 static __inline__ long local_sub_return(long i, local_t * l)
  39 {
  40         long temp, result;
  41         __asm__ __volatile__(
  42         "1:     ldq_l %0,%1\n"
  43         "       subq %0,%3,%2\n"
  44         "       subq %0,%3,%0\n"
  45         "       stq_c %0,%1\n"
  46         "       beq %0,2f\n"
  47         ".subsection 2\n"
  48         "2:     br 1b\n"
  49         ".previous"
  50         :"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
  51         :"Ir" (i), "m" (l->a.counter) : "memory");
  52         return result;
  53 }
  54 
  55 #define local_cmpxchg(l, o, n) \
  56         (cmpxchg_local(&((l)->a.counter), (o), (n)))
  57 #define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
  58 
  59 /**
  60  * local_add_unless - add unless the number is a given value
  61  * @l: pointer of type local_t
  62  * @a: the amount to add to l...
  63  * @u: ...unless l is equal to u.
  64  *
  65  * Atomically adds @a to @l, so long as it was not @u.
  66  * Returns non-zero if @l was not @u, and zero otherwise.
  67  */
  68 #define local_add_unless(l, a, u)                               \
  69 ({                                                              \
  70         long c, old;                                            \
  71         c = local_read(l);                                      \
  72         for (;;) {                                              \
  73                 if (unlikely(c == (u)))                         \
  74                         break;                                  \
  75                 old = local_cmpxchg((l), c, c + (a));   \
  76                 if (likely(old == c))                           \
  77                         break;                                  \
  78                 c = old;                                        \
  79         }                                                       \
  80         c != (u);                                               \
  81 })
  82 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
  83 
  84 #define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
  85 
  86 #define local_dec_return(l) local_sub_return(1,(l))
  87 
  88 #define local_inc_return(l) local_add_return(1,(l))
  89 
  90 #define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
  91 
  92 #define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
  93 
  94 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
  95 
  96 /* Verify if faster than atomic ops */
  97 #define __local_inc(l)          ((l)->a.counter++)
  98 #define __local_dec(l)          ((l)->a.counter++)
  99 #define __local_add(i,l)        ((l)->a.counter+=(i))
 100 #define __local_sub(i,l)        ((l)->a.counter-=(i))
 101 
 102 #endif /* _ALPHA_LOCAL_H */