arch/mn10300/include/asm/atomic.h

   1 /* MN10300 Atomic counter operations
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #ifndef _ASM_ATOMIC_H
  12 #define _ASM_ATOMIC_H
  13
  14 #include <asm/irqflags.h>
  15 #include <asm/cmpxchg.h>
  16 #include <asm/barrier.h>
  17
  18 #ifndef CONFIG_SMP
  19 #include <asm-generic/atomic.h>
  20 #else
  21
  22 /*
  23  * Atomic operations that C can't guarantee us.  Useful for
  24  * resource counting etc..
  25  */
  26
  27 #define ATOMIC_INIT(i)  { (i) }
  28
  29 #ifdef __KERNEL__
  30
  31 /**
  32  * atomic_read - read atomic variable
  33  * @v: pointer of type atomic_t
  34  *
  35  * Atomically reads the value of @v.  Note that the guaranteed
  36  */
  37 #define atomic_read(v)  READ_ONCE((v)->counter)
  38
  39 /**
  40  * atomic_set - set atomic variable
  41  * @v: pointer of type atomic_t
  42  * @i: required value
  43  *
  44  * Atomically sets the value of @v to @i.  Note that the guaranteed
  45  */
  46 #define atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
  47
  48 #define ATOMIC_OP(op)                                                   \
  49 static inline void atomic_##op(int i, atomic_t *v)                      \
  50 {                                                                       \
  51         int retval, status;                                             \
  52                                                                         \
  53         asm volatile(                                                   \
  54                 "1:     mov     %4,(_AAR,%3)    \n"                     \
  55                 "       mov     (_ADR,%3),%1    \n"                     \
  56                 "       " #op " %5,%1           \n"                     \
  57                 "       mov     %1,(_ADR,%3)    \n"                     \
  58                 "       mov     (_ADR,%3),%0    \n"     /* flush */     \
  59                 "       mov     (_ASR,%3),%0    \n"                     \
  60                 "       or      %0,%0           \n"                     \
  61                 "       bne     1b              \n"                     \
  62                 : "=&r"(status), "=&r"(retval), "=m"(v->counter)        \
  63                 : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)   \
  64                 : "memory", "cc");                                      \
  65 }
  66
  67 #define ATOMIC_OP_RETURN(op)                                            \
  68 static inline int atomic_##op##_return(int i, atomic_t *v)              \
  69 {                                                                       \
  70         int retval, status;                                             \
  71                                                                         \
  72         asm volatile(                                                   \
  73                 "1:     mov     %4,(_AAR,%3)    \n"                     \
  74                 "       mov     (_ADR,%3),%1    \n"                     \
  75                 "       " #op " %5,%1           \n"                     \
  76                 "       mov     %1,(_ADR,%3)    \n"                     \
  77                 "       mov     (_ADR,%3),%0    \n"     /* flush */     \
  78                 "       mov     (_ASR,%3),%0    \n"                     \
  79                 "       or      %0,%0           \n"                     \
  80                 "       bne     1b              \n"                     \
  81                 : "=&r"(status), "=&r"(retval), "=m"(v->counter)        \
  82                 : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)   \
  83                 : "memory", "cc");                                      \
  84         return retval;                                                  \
  85 }
  86
  87 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
  88
  89 ATOMIC_OPS(add)
  90 ATOMIC_OPS(sub)
  91
  92 ATOMIC_OP(and)
  93 ATOMIC_OP(or)
  94 ATOMIC_OP(xor)
  95
  96 #undef ATOMIC_OPS
  97 #undef ATOMIC_OP_RETURN
  98 #undef ATOMIC_OP
  99
 100 static inline int atomic_add_negative(int i, atomic_t *v)
 101 {
 102         return atomic_add_return(i, v) < 0;
 103 }
 104
 105 static inline void atomic_inc(atomic_t *v)
 106 {
 107         atomic_add_return(1, v);
 108 }
 109
 110 static inline void atomic_dec(atomic_t *v)
 111 {
 112         atomic_sub_return(1, v);
 113 }
 114
 115 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
 116 #define atomic_inc_return(v)            atomic_add_return(1, (v))
 117
 118 #define atomic_sub_and_test(i, v)       (atomic_sub_return((i), (v)) == 0)
 119 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
 120 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
 121
 122 #define __atomic_add_unless(v, a, u)                            \
 123 ({                                                              \
 124         int c, old;                                             \
 125         c = atomic_read(v);                                     \
 126         while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
 127                 c = old;                                        \
 128         c;                                                      \
 129 })
 130
 131 #define atomic_xchg(ptr, v)             (xchg(&(ptr)->counter, (v)))
 132 #define atomic_cmpxchg(v, old, new)     (cmpxchg(&((v)->counter), (old), (new)))
 133
 134 #endif /* __KERNEL__ */
 135 #endif /* CONFIG_SMP */
 136 #endif /* _ASM_ATOMIC_H */