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 ATOMIC_FETCH_OP(op, asm_op)                                     \
  69 static inline int atomic_fetch_##op(int i, atomic_t *v)                 \
  70 {                                                                       \
  71         long temp, result;                                              \
  72         smp_mb();                                                       \
  73         __asm__ __volatile__(                                           \
  74         "1:     ldl_l %2,%1\n"                                          \
  75         "       " #asm_op " %2,%3,%0\n"                                 \
  76         "       stl_c %0,%1\n"                                          \
  77         "       beq %0,2f\n"                                            \
  78         ".subsection 2\n"                                               \
  79         "2:     br 1b\n"                                                \
  80         ".previous"                                                     \
  81         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  82         :"Ir" (i), "m" (v->counter) : "memory");                        \
  83         smp_mb();                                                       \
  84         return result;                                                  \
  85 }
  86
  87 #define ATOMIC64_OP(op, asm_op)                                         \
  88 static __inline__ void atomic64_##op(long i, atomic64_t * v)            \
  89 {                                                                       \
  90         unsigned long temp;                                             \
  91         __asm__ __volatile__(                                           \
  92         "1:     ldq_l %0,%1\n"                                          \
  93         "       " #asm_op " %0,%2,%0\n"                                 \
  94         "       stq_c %0,%1\n"                                          \
  95         "       beq %0,2f\n"                                            \
  96         ".subsection 2\n"                                               \
  97         "2:     br 1b\n"                                                \
  98         ".previous"                                                     \
  99         :"=&r" (temp), "=m" (v->counter)                                \
 100         :"Ir" (i), "m" (v->counter));                                   \
 101 }                                                                       \
 102
 103 #define ATOMIC64_OP_RETURN(op, asm_op)                                  \
 104 static __inline__ long atomic64_##op##_return(long i, atomic64_t * v)   \
 105 {                                                                       \
 106         long temp, result;                                              \
 107         smp_mb();                                                       \
 108         __asm__ __volatile__(                                           \
 109         "1:     ldq_l %0,%1\n"                                          \
 110         "       " #asm_op " %0,%3,%2\n"                                 \
 111         "       " #asm_op " %0,%3,%0\n"                                 \
 112         "       stq_c %0,%1\n"                                          \
 113         "       beq %0,2f\n"                                            \
 114         ".subsection 2\n"                                               \
 115         "2:     br 1b\n"                                                \
 116         ".previous"                                                     \
 117         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 118         :"Ir" (i), "m" (v->counter) : "memory");                        \
 119         smp_mb();                                                       \
 120         return result;                                                  \
 121 }
 122
 123 #define ATOMIC64_FETCH_OP(op, asm_op)                                   \
 124 static __inline__ long atomic64_fetch_##op(long i, atomic64_t * v)      \
 125 {                                                                       \
 126         long temp, result;                                              \
 127         smp_mb();                                                       \
 128         __asm__ __volatile__(                                           \
 129         "1:     ldq_l %2,%1\n"                                          \
 130         "       " #asm_op " %2,%3,%0\n"                                 \
 131         "       stq_c %0,%1\n"                                          \
 132         "       beq %0,2f\n"                                            \
 133         ".subsection 2\n"                                               \
 134         "2:     br 1b\n"                                                \
 135         ".previous"                                                     \
 136         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 137         :"Ir" (i), "m" (v->counter) : "memory");                        \
 138         smp_mb();                                                       \
 139         return result;                                                  \
 140 }
 141
 142 #define ATOMIC_OPS(op)                                                  \
 143         ATOMIC_OP(op, op##l)                                            \
 144         ATOMIC_OP_RETURN(op, op##l)                                     \
 145         ATOMIC_FETCH_OP(op, op##l)                                      \
 146         ATOMIC64_OP(op, op##q)                                          \
 147         ATOMIC64_OP_RETURN(op, op##q)                                   \
 148         ATOMIC64_FETCH_OP(op, op##q)
 149
 150 ATOMIC_OPS(add)
 151 ATOMIC_OPS(sub)
 152
 153 #define atomic_andnot atomic_andnot
 154 #define atomic64_andnot atomic64_andnot
 155
 156 #undef ATOMIC_OPS
 157 #define ATOMIC_OPS(op, asm)                                             \
 158         ATOMIC_OP(op, asm)                                              \
 159         ATOMIC_FETCH_OP(op, asm)                                        \
 160         ATOMIC64_OP(op, asm)                                            \
 161         ATOMIC64_FETCH_OP(op, asm)
 162
 163 ATOMIC_OPS(and, and)
 164 ATOMIC_OPS(andnot, bic)
 165 ATOMIC_OPS(or, bis)
 166 ATOMIC_OPS(xor, xor)
 167
 168 #undef ATOMIC_OPS
 169 #undef ATOMIC64_FETCH_OP
 170 #undef ATOMIC64_OP_RETURN
 171 #undef ATOMIC64_OP
 172 #undef ATOMIC_FETCH_OP
 173 #undef ATOMIC_OP_RETURN
 174 #undef ATOMIC_OP
 175
 176 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 177 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 178
 179 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 180 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 181
 182 /**
 183  * __atomic_add_unless - add unless the number is a given value
 184  * @v: pointer of type atomic_t
 185  * @a: the amount to add to v...
 186  * @u: ...unless v is equal to u.
 187  *
 188  * Atomically adds @a to @v, so long as it was not @u.
 189  * Returns the old value of @v.
 190  */
 191 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 192 {
 193         int c, new, old;
 194         smp_mb();
 195         __asm__ __volatile__(
 196         "1:     ldl_l   %[old],%[mem]\n"
 197         "       cmpeq   %[old],%[u],%[c]\n"
 198         "       addl    %[old],%[a],%[new]\n"
 199         "       bne     %[c],2f\n"
 200         "       stl_c   %[new],%[mem]\n"
 201         "       beq     %[new],3f\n"
 202         "2:\n"
 203         ".subsection 2\n"
 204         "3:     br      1b\n"
 205         ".previous"
 206         : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
 207         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
 208         : "memory");
 209         smp_mb();
 210         return old;
 211 }
 212
 213
 214 /**
 215  * atomic64_add_unless - add unless the number is a given value
 216  * @v: pointer of type atomic64_t
 217  * @a: the amount to add to v...
 218  * @u: ...unless v is equal to u.
 219  *
 220  * Atomically adds @a to @v, so long as it was not @u.
 221  * Returns true iff @v was not @u.
 222  */
 223 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 224 {
 225         long c, tmp;
 226         smp_mb();
 227         __asm__ __volatile__(
 228         "1:     ldq_l   %[tmp],%[mem]\n"
 229         "       cmpeq   %[tmp],%[u],%[c]\n"
 230         "       addq    %[tmp],%[a],%[tmp]\n"
 231         "       bne     %[c],2f\n"
 232         "       stq_c   %[tmp],%[mem]\n"
 233         "       beq     %[tmp],3f\n"
 234         "2:\n"
 235         ".subsection 2\n"
 236         "3:     br      1b\n"
 237         ".previous"
 238         : [tmp] "=&r"(tmp), [c] "=&r"(c)
 239         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
 240         : "memory");
 241         smp_mb();
 242         return !c;
 243 }
 244
 245 /*
 246  * atomic64_dec_if_positive - decrement by 1 if old value positive
 247  * @v: pointer of type atomic_t
 248  *
 249  * The function returns the old value of *v minus 1, even if
 250  * the atomic variable, v, was not decremented.
 251  */
 252 static inline long atomic64_dec_if_positive(atomic64_t *v)
 253 {
 254         long old, tmp;
 255         smp_mb();
 256         __asm__ __volatile__(
 257         "1:     ldq_l   %[old],%[mem]\n"
 258         "       subq    %[old],1,%[tmp]\n"
 259         "       ble     %[old],2f\n"
 260         "       stq_c   %[tmp],%[mem]\n"
 261         "       beq     %[tmp],3f\n"
 262         "2:\n"
 263         ".subsection 2\n"
 264         "3:     br      1b\n"
 265         ".previous"
 266         : [old] "=&r"(old), [tmp] "=&r"(tmp)
 267         : [mem] "m"(*v)
 268         : "memory");
 269         smp_mb();
 270         return old - 1;
 271 }
 272
 273 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 274
 275 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 276 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 277
 278 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 279 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 280
 281 #define atomic_inc_return(v) atomic_add_return(1,(v))
 282 #define atomic64_inc_return(v) atomic64_add_return(1,(v))
 283
 284 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 285 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 286
 287 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 288 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 289
 290 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 291 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 292
 293 #define atomic_inc(v) atomic_add(1,(v))
 294 #define atomic64_inc(v) atomic64_add(1,(v))
 295
 296 #define atomic_dec(v) atomic_sub(1,(v))
 297 #define atomic64_dec(v) atomic64_sub(1,(v))
 298
 299 #endif /* _ALPHA_ATOMIC_H */