include/asm-m68k/atomic.h

   1 #ifndef __ARCH_M68K_ATOMIC__
   2 #define __ARCH_M68K_ATOMIC__
   3
   4 #include <linux/config.h>
   5
   6 #include <asm/system.h> /* local_irq_XXX() */
   7
   8 /*
   9  * Atomic operations that C can't guarantee us.  Useful for
  10  * resource counting etc..
  11  */
  12
  13 /*
  14  * We do not have SMP m68k systems, so we don't have to deal with that.
  15  */
  16
  17 typedef struct { int counter; } atomic_t;
  18 #define ATOMIC_INIT(i)  { (i) }
  19
  20 #define atomic_read(v)          ((v)->counter)
  21 #define atomic_set(v, i)        (((v)->counter) = i)
  22
  23 static inline void atomic_add(int i, atomic_t *v)
  24 {
  25         __asm__ __volatile__("addl %1,%0" : "+m" (*v) : "id" (i));
  26 }
  27
  28 static inline void atomic_sub(int i, atomic_t *v)
  29 {
  30         __asm__ __volatile__("subl %1,%0" : "+m" (*v) : "id" (i));
  31 }
  32
  33 static inline void atomic_inc(atomic_t *v)
  34 {
  35         __asm__ __volatile__("addql #1,%0" : "+m" (*v));
  36 }
  37
  38 static inline void atomic_dec(atomic_t *v)
  39 {
  40         __asm__ __volatile__("subql #1,%0" : "+m" (*v));
  41 }
  42
  43 static inline int atomic_dec_and_test(atomic_t *v)
  44 {
  45         char c;
  46         __asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
  47         return c != 0;
  48 }
  49
  50 static inline int atomic_inc_and_test(atomic_t *v)
  51 {
  52         char c;
  53         __asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
  54         return c != 0;
  55 }
  56
  57 #ifdef CONFIG_RMW_INSNS
  58
  59 static inline int atomic_add_return(int i, atomic_t *v)
  60 {
  61         int t, tmp;
  62
  63         __asm__ __volatile__(
  64                         "1:     movel %2,%1\n"
  65                         "       addl %3,%1\n"
  66                         "       casl %2,%1,%0\n"
  67                         "       jne 1b"
  68                         : "+m" (*v), "=&d" (t), "=&d" (tmp)
  69                         : "g" (i), "2" (atomic_read(v)));
  70         return t;
  71 }
  72
  73 static inline int atomic_sub_return(int i, atomic_t *v)
  74 {
  75         int t, tmp;
  76
  77         __asm__ __volatile__(
  78                         "1:     movel %2,%1\n"
  79                         "       subl %3,%1\n"
  80                         "       casl %2,%1,%0\n"
  81                         "       jne 1b"
  82                         : "+m" (*v), "=&d" (t), "=&d" (tmp)
  83                         : "g" (i), "2" (atomic_read(v)));
  84         return t;
  85 }
  86
  87 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
  88 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
  89
  90 #else /* !CONFIG_RMW_INSNS */
  91
  92 static inline int atomic_add_return(int i, atomic_t * v)
  93 {
  94         unsigned long flags;
  95         int t;
  96
  97         local_irq_save(flags);
  98         t = atomic_read(v);
  99         t += i;
 100         atomic_set(v, t);
 101         local_irq_restore(flags);
 102
 103         return t;
 104 }
 105
 106 static inline int atomic_sub_return(int i, atomic_t * v)
 107 {
 108         unsigned long flags;
 109         int t;
 110
 111         local_irq_save(flags);
 112         t = atomic_read(v);
 113         t -= i;
 114         atomic_set(v, t);
 115         local_irq_restore(flags);
 116
 117         return t;
 118 }
 119
 120 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 121 {
 122         unsigned long flags;
 123         int prev;
 124
 125         local_irq_save(flags);
 126         prev = atomic_read(v);
 127         if (prev == old)
 128                 atomic_set(v, new);
 129         local_irq_restore(flags);
 130         return prev;
 131 }
 132
 133 static inline int atomic_xchg(atomic_t *v, int new)
 134 {
 135         unsigned long flags;
 136         int prev;
 137
 138         local_irq_save(flags);
 139         prev = atomic_read(v);
 140         atomic_set(v, new);
 141         local_irq_restore(flags);
 142         return prev;
 143 }
 144
 145 #endif /* !CONFIG_RMW_INSNS */
 146
 147 #define atomic_dec_return(v)    atomic_sub_return(1, (v))
 148 #define atomic_inc_return(v)    atomic_add_return(1, (v))
 149
 150 static inline int atomic_sub_and_test(int i, atomic_t *v)
 151 {
 152         char c;
 153         __asm__ __volatile__("subl %2,%1; seq %0" : "=d" (c), "+m" (*v): "g" (i));
 154         return c != 0;
 155 }
 156
 157 static inline int atomic_add_negative(int i, atomic_t *v)
 158 {
 159         char c;
 160         __asm__ __volatile__("addl %2,%1; smi %0" : "=d" (c), "+m" (*v): "g" (i));
 161         return c != 0;
 162 }
 163
 164 static inline void atomic_clear_mask(unsigned long mask, unsigned long *v)
 165 {
 166         __asm__ __volatile__("andl %1,%0" : "+m" (*v) : "id" (~(mask)));
 167 }
 168
 169 static inline void atomic_set_mask(unsigned long mask, unsigned long *v)
 170 {
 171         __asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (mask));
 172 }
 173
 174 #define atomic_add_unless(v, a, u)                              \
 175 ({                                                              \
 176         int c, old;                                             \
 177         c = atomic_read(v);                                     \
 178         for (;;) {                                              \
 179                 if (unlikely(c == (u)))                         \
 180                         break;                                  \
 181                 old = atomic_cmpxchg((v), c, c + (a));          \
 182                 if (likely(old == c))                           \
 183                         break;                                  \
 184                 c = old;                                        \
 185         }                                                       \
 186         c != (u);                                               \
 187 })
 188 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 189
 190 /* Atomic operations are already serializing */
 191 #define smp_mb__before_atomic_dec()     barrier()
 192 #define smp_mb__after_atomic_dec()      barrier()
 193 #define smp_mb__before_atomic_inc()     barrier()
 194 #define smp_mb__after_atomic_inc()      barrier()
 195
 196 #include <asm-generic/atomic.h>
 197 #endif /* __ARCH_M68K_ATOMIC __ */