LXR linux/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)                                           \
  33static __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)                                    \
  49static inline int atomic_##op##_return_relaxed(int i, atomic_t *v)      \
  50{                                                                       \
  51        long temp, result;                                              \
  52        __asm__ __volatile__(                                           \
  53        "1:     ldl_l %0,%1\n"                                          \
  54        "       " #asm_op " %0,%3,%2\n"                                 \
  55        "       " #asm_op " %0,%3,%0\n"                                 \
  56        "       stl_c %0,%1\n"                                          \
  57        "       beq %0,2f\n"                                            \
  58        ".subsection 2\n"                                               \
  59        "2:     br 1b\n"                                                \
  60        ".previous"                                                     \
  61        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  62        :"Ir" (i), "m" (v->counter) : "memory");                        \
  63        return result;                                                  \
  64}
  65
  66#define ATOMIC_FETCH_OP(op, asm_op)                                     \
  67static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v)       \
  68{                                                                       \
  69        long temp, result;                                              \
  70        __asm__ __volatile__(                                           \
  71        "1:     ldl_l %2,%1\n"                                          \
  72        "       " #asm_op " %2,%3,%0\n"                                 \
  73        "       stl_c %0,%1\n"                                          \
  74        "       beq %0,2f\n"                                            \
  75        ".subsection 2\n"                                               \
  76        "2:     br 1b\n"                                                \
  77        ".previous"                                                     \
  78        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  79        :"Ir" (i), "m" (v->counter) : "memory");                        \
  80        return result;                                                  \
  81}
  82
  83#define ATOMIC64_OP(op, asm_op)                                         \
  84static __inline__ void atomic64_##op(long i, atomic64_t * v)            \
  85{                                                                       \
  86        unsigned long temp;                                             \
  87        __asm__ __volatile__(                                           \
  88        "1:     ldq_l %0,%1\n"                                          \
  89        "       " #asm_op " %0,%2,%0\n"                                 \
  90        "       stq_c %0,%1\n"                                          \
  91        "       beq %0,2f\n"                                            \
  92        ".subsection 2\n"                                               \
  93        "2:     br 1b\n"                                                \
  94        ".previous"                                                     \
  95        :"=&r" (temp), "=m" (v->counter)                                \
  96        :"Ir" (i), "m" (v->counter));                                   \
  97}                                                                       \
  98
  99#define ATOMIC64_OP_RETURN(op, asm_op)                                  \
 100static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v)   \
 101{                                                                       \
 102        long temp, result;                                              \
 103        __asm__ __volatile__(                                           \
 104        "1:     ldq_l %0,%1\n"                                          \
 105        "       " #asm_op " %0,%3,%2\n"                                 \
 106        "       " #asm_op " %0,%3,%0\n"                                 \
 107        "       stq_c %0,%1\n"                                          \
 108        "       beq %0,2f\n"                                            \
 109        ".subsection 2\n"                                               \
 110        "2:     br 1b\n"                                                \
 111        ".previous"                                                     \
 112        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 113        :"Ir" (i), "m" (v->counter) : "memory");                        \
 114        return result;                                                  \
 115}
 116
 117#define ATOMIC64_FETCH_OP(op, asm_op)                                   \
 118static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v)    \
 119{                                                                       \
 120        long temp, result;                                              \
 121        __asm__ __volatile__(                                           \
 122        "1:     ldq_l %2,%1\n"                                          \
 123        "       " #asm_op " %2,%3,%0\n"                                 \
 124        "       stq_c %0,%1\n"                                          \
 125        "       beq %0,2f\n"                                            \
 126        ".subsection 2\n"                                               \
 127        "2:     br 1b\n"                                                \
 128        ".previous"                                                     \
 129        :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 130        :"Ir" (i), "m" (v->counter) : "memory");                        \
 131        return result;                                                  \
 132}
 133
 134#define ATOMIC_OPS(op)                                                  \
 135        ATOMIC_OP(op, op##l)                                            \
 136        ATOMIC_OP_RETURN(op, op##l)                                     \
 137        ATOMIC_FETCH_OP(op, op##l)                                      \
 138        ATOMIC64_OP(op, op##q)                                          \
 139        ATOMIC64_OP_RETURN(op, op##q)                                   \
 140        ATOMIC64_FETCH_OP(op, op##q)
 141
 142ATOMIC_OPS(add)
 143ATOMIC_OPS(sub)
 144
 145#define atomic_add_return_relaxed       atomic_add_return_relaxed
 146#define atomic_sub_return_relaxed       atomic_sub_return_relaxed
 147#define atomic_fetch_add_relaxed        atomic_fetch_add_relaxed
 148#define atomic_fetch_sub_relaxed        atomic_fetch_sub_relaxed
 149
 150#define atomic64_add_return_relaxed     atomic64_add_return_relaxed
 151#define atomic64_sub_return_relaxed     atomic64_sub_return_relaxed
 152#define atomic64_fetch_add_relaxed      atomic64_fetch_add_relaxed
 153#define atomic64_fetch_sub_relaxed      atomic64_fetch_sub_relaxed
 154
 155#define atomic_andnot atomic_andnot
 156#define atomic64_andnot atomic64_andnot
 157
 158#undef ATOMIC_OPS
 159#define ATOMIC_OPS(op, asm)                                             \
 160        ATOMIC_OP(op, asm)                                              \
 161        ATOMIC_FETCH_OP(op, asm)                                        \
 162        ATOMIC64_OP(op, asm)                                            \
 163        ATOMIC64_FETCH_OP(op, asm)
 164
 165ATOMIC_OPS(and, and)
 166ATOMIC_OPS(andnot, bic)
 167ATOMIC_OPS(or, bis)
 168ATOMIC_OPS(xor, xor)
 169
 170#define atomic_fetch_and_relaxed        atomic_fetch_and_relaxed
 171#define atomic_fetch_andnot_relaxed     atomic_fetch_andnot_relaxed
 172#define atomic_fetch_or_relaxed         atomic_fetch_or_relaxed
 173#define atomic_fetch_xor_relaxed        atomic_fetch_xor_relaxed
 174
 175#define atomic64_fetch_and_relaxed      atomic64_fetch_and_relaxed
 176#define atomic64_fetch_andnot_relaxed   atomic64_fetch_andnot_relaxed
 177#define atomic64_fetch_or_relaxed       atomic64_fetch_or_relaxed
 178#define atomic64_fetch_xor_relaxed      atomic64_fetch_xor_relaxed
 179
 180#undef ATOMIC_OPS
 181#undef ATOMIC64_FETCH_OP
 182#undef ATOMIC64_OP_RETURN
 183#undef ATOMIC64_OP
 184#undef ATOMIC_FETCH_OP
 185#undef ATOMIC_OP_RETURN
 186#undef ATOMIC_OP
 187
 188#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 189#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 190
 191#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 192#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 193
 194/**
 195 * __atomic_add_unless - add unless the number is a given value
 196 * @v: pointer of type atomic_t
 197 * @a: the amount to add to v...
 198 * @u: ...unless v is equal to u.
 199 *
 200 * Atomically adds @a to @v, so long as it was not @u.
 201 * Returns the old value of @v.
 202 */
 203static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 204{
 205        int c, new, old;
 206        smp_mb();
 207        __asm__ __volatile__(
 208        "1:     ldl_l   %[old],%[mem]\n"
 209        "       cmpeq   %[old],%[u],%[c]\n"
 210        "       addl    %[old],%[a],%[new]\n"
 211        "       bne     %[c],2f\n"
 212        "       stl_c   %[new],%[mem]\n"
 213        "       beq     %[new],3f\n"
 214        "2:\n"
 215        ".subsection 2\n"
 216        "3:     br      1b\n"
 217        ".previous"
 218        : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
 219        : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
 220        : "memory");
 221        smp_mb();
 222        return old;
 223}
 224
 225
 226/**
 227 * atomic64_add_unless - add unless the number is a given value
 228 * @v: pointer of type atomic64_t
 229 * @a: the amount to add to v...
 230 * @u: ...unless v is equal to u.
 231 *
 232 * Atomically adds @a to @v, so long as it was not @u.
 233 * Returns true iff @v was not @u.
 234 */
 235static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 236{
 237        long c, tmp;
 238        smp_mb();
 239        __asm__ __volatile__(
 240        "1:     ldq_l   %[tmp],%[mem]\n"
 241        "       cmpeq   %[tmp],%[u],%[c]\n"
 242        "       addq    %[tmp],%[a],%[tmp]\n"
 243        "       bne     %[c],2f\n"
 244        "       stq_c   %[tmp],%[mem]\n"
 245        "       beq     %[tmp],3f\n"
 246        "2:\n"
 247        ".subsection 2\n"
 248        "3:     br      1b\n"
 249        ".previous"
 250        : [tmp] "=&r"(tmp), [c] "=&r"(c)
 251        : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
 252        : "memory");
 253        smp_mb();
 254        return !c;
 255}
 256
 257/*
 258 * atomic64_dec_if_positive - decrement by 1 if old value positive
 259 * @v: pointer of type atomic_t
 260 *
 261 * The function returns the old value of *v minus 1, even if
 262 * the atomic variable, v, was not decremented.
 263 */
 264static inline long atomic64_dec_if_positive(atomic64_t *v)
 265{
 266        long old, tmp;
 267        smp_mb();
 268        __asm__ __volatile__(
 269        "1:     ldq_l   %[old],%[mem]\n"
 270        "       subq    %[old],1,%[tmp]\n"
 271        "       ble     %[old],2f\n"
 272        "       stq_c   %[tmp],%[mem]\n"
 273        "       beq     %[tmp],3f\n"
 274        "2:\n"
 275        ".subsection 2\n"
 276        "3:     br      1b\n"
 277        ".previous"
 278        : [old] "=&r"(old), [tmp] "=&r"(tmp)
 279        : [mem] "m"(*v)
 280        : "memory");
 281        smp_mb();
 282        return old - 1;
 283}
 284
 285#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 286
 287#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 288#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 289
 290#define atomic_dec_return(v) atomic_sub_return(1,(v))
 291#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 292
 293#define atomic_inc_return(v) atomic_add_return(1,(v))
 294#define atomic64_inc_return(v) atomic64_add_return(1,(v))
 295
 296#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 297#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 298
 299#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 300#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 301
 302#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 303#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 304
 305#define atomic_inc(v) atomic_add(1,(v))
 306#define atomic64_inc(v) atomic64_add(1,(v))
 307
 308#define atomic_dec(v) atomic_sub(1,(v))
 309#define atomic64_dec(v) atomic64_sub(1,(v))
 310
 311#endif /* _ALPHA_ATOMIC_H */
 312