arch/m68k/include/asm/atomic.h

   1 #ifndef __ARCH_M68K_ATOMIC__
   2 #define __ARCH_M68K_ATOMIC__
   3
   4 #include <linux/types.h>
   5 #include <linux/irqflags.h>
   6 #include <asm/cmpxchg.h>
   7 #include <asm/barrier.h>
   8
   9 /*
  10  * Atomic operations that C can't guarantee us.  Useful for
  11  * resource counting etc..
  12  */
  13
  14 /*
  15  * We do not have SMP m68k systems, so we don't have to deal with that.
  16  */
  17
  18 #define ATOMIC_INIT(i)  { (i) }
  19
  20 #define atomic_read(v)          READ_ONCE((v)->counter)
  21 #define atomic_set(v, i)        WRITE_ONCE(((v)->counter), (i))
  22
  23 /*
  24  * The ColdFire parts cannot do some immediate to memory operations,
  25  * so for them we do not specify the "i" asm constraint.
  26  */
  27 #ifdef CONFIG_COLDFIRE
  28 #define ASM_DI  "d"
  29 #else
  30 #define ASM_DI  "di"
  31 #endif
  32
  33 #define ATOMIC_OP(op, c_op, asm_op)                                     \
  34 static inline void atomic_##op(int i, atomic_t *v)                      \
  35 {                                                                       \
  36         __asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\
  37 }                                                                       \
  38
  39 #ifdef CONFIG_RMW_INSNS
  40
  41 #define ATOMIC_OP_RETURN(op, c_op, asm_op)                              \
  42 static inline int atomic_##op##_return(int i, atomic_t *v)              \
  43 {                                                                       \
  44         int t, tmp;                                                     \
  45                                                                         \
  46         __asm__ __volatile__(                                           \
  47                         "1:     movel %2,%1\n"                          \
  48                         "       " #asm_op "l %3,%1\n"                   \
  49                         "       casl %2,%1,%0\n"                        \
  50                         "       jne 1b"                                 \
  51                         : "+m" (*v), "=&d" (t), "=&d" (tmp)             \
  52                         : "g" (i), "2" (atomic_read(v)));               \
  53         return t;                                                       \
  54 }
  55
  56 #define ATOMIC_FETCH_OP(op, c_op, asm_op)                               \
  57 static inline int atomic_fetch_##op(int i, atomic_t *v)                 \
  58 {                                                                       \
  59         int t, tmp;                                                     \
  60                                                                         \
  61         __asm__ __volatile__(                                           \
  62                         "1:     movel %2,%1\n"                          \
  63                         "       " #asm_op "l %3,%1\n"                   \
  64                         "       casl %2,%1,%0\n"                        \
  65                         "       jne 1b"                                 \
  66                         : "+m" (*v), "=&d" (t), "=&d" (tmp)             \
  67                         : "g" (i), "2" (atomic_read(v)));               \
  68         return tmp;                                                     \
  69 }
  70
  71 #else
  72
  73 #define ATOMIC_OP_RETURN(op, c_op, asm_op)                              \
  74 static inline int atomic_##op##_return(int i, atomic_t * v)             \
  75 {                                                                       \
  76         unsigned long flags;                                            \
  77         int t;                                                          \
  78                                                                         \
  79         local_irq_save(flags);                                          \
  80         t = (v->counter c_op i);                                        \
  81         local_irq_restore(flags);                                       \
  82                                                                         \
  83         return t;                                                       \
  84 }
  85
  86 #define ATOMIC_FETCH_OP(op, c_op, asm_op)                               \
  87 static inline int atomic_fetch_##op(int i, atomic_t * v)                \
  88 {                                                                       \
  89         unsigned long flags;                                            \
  90         int t;                                                          \
  91                                                                         \
  92         local_irq_save(flags);                                          \
  93         t = v->counter;                                                 \
  94         v->counter c_op i;                                              \
  95         local_irq_restore(flags);                                       \
  96                                                                         \
  97         return t;                                                       \
  98 }
  99
 100 #endif /* CONFIG_RMW_INSNS */
 101
 102 #define ATOMIC_OPS(op, c_op, asm_op)                                    \
 103         ATOMIC_OP(op, c_op, asm_op)                                     \
 104         ATOMIC_OP_RETURN(op, c_op, asm_op)                              \
 105         ATOMIC_FETCH_OP(op, c_op, asm_op)
 106
 107 ATOMIC_OPS(add, +=, add)
 108 ATOMIC_OPS(sub, -=, sub)
 109
 110 #undef ATOMIC_OPS
 111 #define ATOMIC_OPS(op, c_op, asm_op)                                    \
 112         ATOMIC_OP(op, c_op, asm_op)                                     \
 113         ATOMIC_FETCH_OP(op, c_op, asm_op)
 114
 115 ATOMIC_OPS(and, &=, and)
 116 ATOMIC_OPS(or, |=, or)
 117 ATOMIC_OPS(xor, ^=, eor)
 118
 119 #undef ATOMIC_OPS
 120 #undef ATOMIC_FETCH_OP
 121 #undef ATOMIC_OP_RETURN
 122 #undef ATOMIC_OP
 123
 124 static inline void atomic_inc(atomic_t *v)
 125 {
 126         __asm__ __volatile__("addql #1,%0" : "+m" (*v));
 127 }
 128
 129 static inline void atomic_dec(atomic_t *v)
 130 {
 131         __asm__ __volatile__("subql #1,%0" : "+m" (*v));
 132 }
 133
 134 static inline int atomic_dec_and_test(atomic_t *v)
 135 {
 136         char c;
 137         __asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
 138         return c != 0;
 139 }
 140
 141 static inline int atomic_dec_and_test_lt(atomic_t *v)
 142 {
 143         char c;
 144         __asm__ __volatile__(
 145                 "subql #1,%1; slt %0"
 146                 : "=d" (c), "=m" (*v)
 147                 : "m" (*v));
 148         return c != 0;
 149 }
 150
 151 static inline int atomic_inc_and_test(atomic_t *v)
 152 {
 153         char c;
 154         __asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
 155         return c != 0;
 156 }
 157
 158 #ifdef CONFIG_RMW_INSNS
 159
 160 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
 161 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 162
 163 #else /* !CONFIG_RMW_INSNS */
 164
 165 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 166 {
 167         unsigned long flags;
 168         int prev;
 169
 170         local_irq_save(flags);
 171         prev = atomic_read(v);
 172         if (prev == old)
 173                 atomic_set(v, new);
 174         local_irq_restore(flags);
 175         return prev;
 176 }
 177
 178 static inline int atomic_xchg(atomic_t *v, int new)
 179 {
 180         unsigned long flags;
 181         int prev;
 182
 183         local_irq_save(flags);
 184         prev = atomic_read(v);
 185         atomic_set(v, new);
 186         local_irq_restore(flags);
 187         return prev;
 188 }
 189
 190 #endif /* !CONFIG_RMW_INSNS */
 191
 192 #define atomic_dec_return(v)    atomic_sub_return(1, (v))
 193 #define atomic_inc_return(v)    atomic_add_return(1, (v))
 194
 195 static inline int atomic_sub_and_test(int i, atomic_t *v)
 196 {
 197         char c;
 198         __asm__ __volatile__("subl %2,%1; seq %0"
 199                              : "=d" (c), "+m" (*v)
 200                              : ASM_DI (i));
 201         return c != 0;
 202 }
 203
 204 static inline int atomic_add_negative(int i, atomic_t *v)
 205 {
 206         char c;
 207         __asm__ __volatile__("addl %2,%1; smi %0"
 208                              : "=d" (c), "+m" (*v)
 209                              : ASM_DI (i));
 210         return c != 0;
 211 }
 212
 213 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 214 {
 215         int c, old;
 216         c = atomic_read(v);
 217         for (;;) {
 218                 if (unlikely(c == (u)))
 219                         break;
 220                 old = atomic_cmpxchg((v), c, c + (a));
 221                 if (likely(old == c))
 222                         break;
 223                 c = old;
 224         }
 225         return c;
 226 }
 227
 228 #endif /* __ARCH_M68K_ATOMIC __ */