arch/alpha/include/asm/atomic.h

   1 #ifndef _ALPHA_ATOMIC_H
   2 #define _ALPHA_ATOMIC_H
   3
   4 #include <linux/types.h>
   5 #include <asm/barrier.h>
   6 #include <asm/cmpxchg.h>
   7
   8 /*
   9  * Atomic operations that C can't guarantee us.  Useful for
  10  * resource counting etc...
  11  *
  12  * But use these as seldom as possible since they are much slower
  13  * than regular operations.
  14  */
  15
  16
  17 #define ATOMIC_INIT(i)          { (i) }
  18 #define ATOMIC64_INIT(i)        { (i) }
  19
  20 #define atomic_read(v)          READ_ONCE((v)->counter)
  21 #define atomic64_read(v)        READ_ONCE((v)->counter)
  22
  23 #define atomic_set(v,i)         WRITE_ONCE((v)->counter, (i))
  24 #define atomic64_set(v,i)       WRITE_ONCE((v)->counter, (i))
  25
  26 /*
  27  * To get proper branch prediction for the main line, we must branch
  28  * forward to code at the end of this object's .text section, then
  29  * branch back to restart the operation.
  30  */
  31
  32 #define ATOMIC_OP(op, asm_op)                                           \
  33 static __inline__ void atomic_##op(int i, atomic_t * v)                 \
  34 {                                                                       \
  35         unsigned long temp;                                             \
  36         __asm__ __volatile__(                                           \
  37         "1:     ldl_l %0,%1\n"                                          \
  38         "       " #asm_op " %0,%2,%0\n"                                 \
  39         "       stl_c %0,%1\n"                                          \
  40         "       beq %0,2f\n"                                            \
  41         ".subsection 2\n"                                               \
  42         "2:     br 1b\n"                                                \
  43         ".previous"                                                     \
  44         :"=&r" (temp), "=m" (v->counter)                                \
  45         :"Ir" (i), "m" (v->counter));                                   \
  46 }                                                                       \
  47
  48 #define ATOMIC_OP_RETURN(op, asm_op)                                    \
  49 static inline int atomic_##op##_return(int i, atomic_t *v)              \
  50 {                                                                       \
  51         long temp, result;                                              \
  52         smp_mb();                                                       \
  53         __asm__ __volatile__(                                           \
  54         "1:     ldl_l %0,%1\n"                                          \
  55         "       " #asm_op " %0,%3,%2\n"                                 \
  56         "       " #asm_op " %0,%3,%0\n"                                 \
  57         "       stl_c %0,%1\n"                                          \
  58         "       beq %0,2f\n"                                            \
  59         ".subsection 2\n"                                               \
  60         "2:     br 1b\n"                                                \
  61         ".previous"                                                     \
  62         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  63         :"Ir" (i), "m" (v->counter) : "memory");                        \
  64         smp_mb();                                                       \
  65         return result;                                                  \
  66 }
  67
  68 #define ATOMIC64_OP(op, asm_op)                                         \
  69 static __inline__ void atomic64_##op(long i, atomic64_t * v)            \
  70 {                                                                       \
  71         unsigned long temp;                                             \
  72         __asm__ __volatile__(                                           \
  73         "1:     ldq_l %0,%1\n"                                          \
  74         "       " #asm_op " %0,%2,%0\n"                                 \
  75         "       stq_c %0,%1\n"                                          \
  76         "       beq %0,2f\n"                                            \
  77         ".subsection 2\n"                                               \
  78         "2:     br 1b\n"                                                \
  79         ".previous"                                                     \
  80         :"=&r" (temp), "=m" (v->counter)                                \
  81         :"Ir" (i), "m" (v->counter));                                   \
  82 }                                                                       \
  83
  84 #define ATOMIC64_OP_RETURN(op, asm_op)                                  \
  85 static __inline__ long atomic64_##op##_return(long i, atomic64_t * v)   \
  86 {                                                                       \
  87         long temp, result;                                              \
  88         smp_mb();                                                       \
  89         __asm__ __volatile__(                                           \
  90         "1:     ldq_l %0,%1\n"                                          \
  91         "       " #asm_op " %0,%3,%2\n"                                 \
  92         "       " #asm_op " %0,%3,%0\n"                                 \
  93         "       stq_c %0,%1\n"                                          \
  94         "       beq %0,2f\n"                                            \
  95         ".subsection 2\n"                                               \
  96         "2:     br 1b\n"                                                \
  97         ".previous"                                                     \
  98         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  99         :"Ir" (i), "m" (v->counter) : "memory");                        \
 100         smp_mb();                                                       \
 101         return result;                                                  \
 102 }
 103
 104 #define ATOMIC_OPS(op)                                                  \
 105         ATOMIC_OP(op, op##l)                                            \
 106         ATOMIC_OP_RETURN(op, op##l)                                     \
 107         ATOMIC64_OP(op, op##q)                                          \
 108         ATOMIC64_OP_RETURN(op, op##q)
 109
 110 ATOMIC_OPS(add)
 111 ATOMIC_OPS(sub)
 112
 113 #define atomic_andnot atomic_andnot
 114 #define atomic64_andnot atomic64_andnot
 115
 116 ATOMIC_OP(and, and)
 117 ATOMIC_OP(andnot, bic)
 118 ATOMIC_OP(or, bis)
 119 ATOMIC_OP(xor, xor)
 120 ATOMIC64_OP(and, and)
 121 ATOMIC64_OP(andnot, bic)
 122 ATOMIC64_OP(or, bis)
 123 ATOMIC64_OP(xor, xor)
 124
 125 #undef ATOMIC_OPS
 126 #undef ATOMIC64_OP_RETURN
 127 #undef ATOMIC64_OP
 128 #undef ATOMIC_OP_RETURN
 129 #undef ATOMIC_OP
 130
 131 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 132 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 133
 134 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 135 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 136
 137 /**
 138  * __atomic_add_unless - add unless the number is a given value
 139  * @v: pointer of type atomic_t
 140  * @a: the amount to add to v...
 141  * @u: ...unless v is equal to u.
 142  *
 143  * Atomically adds @a to @v, so long as it was not @u.
 144  * Returns the old value of @v.
 145  */
 146 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 147 {
 148         int c, new, old;
 149         smp_mb();
 150         __asm__ __volatile__(
 151         "1:     ldl_l   %[old],%[mem]\n"
 152         "       cmpeq   %[old],%[u],%[c]\n"
 153         "       addl    %[old],%[a],%[new]\n"
 154         "       bne     %[c],2f\n"
 155         "       stl_c   %[new],%[mem]\n"
 156         "       beq     %[new],3f\n"
 157         "2:\n"
 158         ".subsection 2\n"
 159         "3:     br      1b\n"
 160         ".previous"
 161         : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
 162         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
 163         : "memory");
 164         smp_mb();
 165         return old;
 166 }
 167
 168
 169 /**
 170  * atomic64_add_unless - add unless the number is a given value
 171  * @v: pointer of type atomic64_t
 172  * @a: the amount to add to v...
 173  * @u: ...unless v is equal to u.
 174  *
 175  * Atomically adds @a to @v, so long as it was not @u.
 176  * Returns true iff @v was not @u.
 177  */
 178 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 179 {
 180         long c, tmp;
 181         smp_mb();
 182         __asm__ __volatile__(
 183         "1:     ldq_l   %[tmp],%[mem]\n"
 184         "       cmpeq   %[tmp],%[u],%[c]\n"
 185         "       addq    %[tmp],%[a],%[tmp]\n"
 186         "       bne     %[c],2f\n"
 187         "       stq_c   %[tmp],%[mem]\n"
 188         "       beq     %[tmp],3f\n"
 189         "2:\n"
 190         ".subsection 2\n"
 191         "3:     br      1b\n"
 192         ".previous"
 193         : [tmp] "=&r"(tmp), [c] "=&r"(c)
 194         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
 195         : "memory");
 196         smp_mb();
 197         return !c;
 198 }
 199
 200 /*
 201  * atomic64_dec_if_positive - decrement by 1 if old value positive
 202  * @v: pointer of type atomic_t
 203  *
 204  * The function returns the old value of *v minus 1, even if
 205  * the atomic variable, v, was not decremented.
 206  */
 207 static inline long atomic64_dec_if_positive(atomic64_t *v)
 208 {
 209         long old, tmp;
 210         smp_mb();
 211         __asm__ __volatile__(
 212         "1:     ldq_l   %[old],%[mem]\n"
 213         "       subq    %[old],1,%[tmp]\n"
 214         "       ble     %[old],2f\n"
 215         "       stq_c   %[tmp],%[mem]\n"
 216         "       beq     %[tmp],3f\n"
 217         "2:\n"
 218         ".subsection 2\n"
 219         "3:     br      1b\n"
 220         ".previous"
 221         : [old] "=&r"(old), [tmp] "=&r"(tmp)
 222         : [mem] "m"(*v)
 223         : "memory");
 224         smp_mb();
 225         return old - 1;
 226 }
 227
 228 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 229
 230 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 231 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 232
 233 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 234 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 235
 236 #define atomic_inc_return(v) atomic_add_return(1,(v))
 237 #define atomic64_inc_return(v) atomic64_add_return(1,(v))
 238
 239 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 240 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 241
 242 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 243 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 244
 245 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 246 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 247
 248 #define atomic_inc(v) atomic_add(1,(v))
 249 #define atomic64_inc(v) atomic64_add(1,(v))
 250
 251 #define atomic_dec(v) atomic_sub(1,(v))
 252 #define atomic64_dec(v) atomic64_sub(1,(v))
 253
 254 #endif /* _ALPHA_ATOMIC_H */