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