arch/alpha/include/asm/atomic.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ALPHA_ATOMIC_H
   3 #define _ALPHA_ATOMIC_H
   4
   5 #include <linux/types.h>
   6 #include <asm/barrier.h>
   7 #include <asm/cmpxchg.h>
   8
   9 /*
  10  * Atomic operations that C can't guarantee us.  Useful for
  11  * resource counting etc...
  12  *
  13  * But use these as seldom as possible since they are much slower
  14  * than regular operations.
  15  */
  16
  17
  18 #define ATOMIC_INIT(i)          { (i) }
  19 #define ATOMIC64_INIT(i)        { (i) }
  20
  21 #define atomic_read(v)          READ_ONCE((v)->counter)
  22 #define atomic64_read(v)        READ_ONCE((v)->counter)
  23
  24 #define atomic_set(v,i)         WRITE_ONCE((v)->counter, (i))
  25 #define atomic64_set(v,i)       WRITE_ONCE((v)->counter, (i))
  26
  27 /*
  28  * To get proper branch prediction for the main line, we must branch
  29  * forward to code at the end of this object's .text section, then
  30  * branch back to restart the operation.
  31  */
  32
  33 #define ATOMIC_OP(op, asm_op)                                           \
  34 static __inline__ void atomic_##op(int i, atomic_t * v)                 \
  35 {                                                                       \
  36         unsigned long temp;                                             \
  37         __asm__ __volatile__(                                           \
  38         "1:     ldl_l %0,%1\n"                                          \
  39         "       " #asm_op " %0,%2,%0\n"                                 \
  40         "       stl_c %0,%1\n"                                          \
  41         "       beq %0,2f\n"                                            \
  42         ".subsection 2\n"                                               \
  43         "2:     br 1b\n"                                                \
  44         ".previous"                                                     \
  45         :"=&r" (temp), "=m" (v->counter)                                \
  46         :"Ir" (i), "m" (v->counter));                                   \
  47 }                                                                       \
  48
  49 #define ATOMIC_OP_RETURN(op, asm_op)                                    \
  50 static inline int atomic_##op##_return_relaxed(int i, atomic_t *v)      \
  51 {                                                                       \
  52         long temp, result;                                              \
  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         return result;                                                  \
  65 }
  66
  67 #define ATOMIC_FETCH_OP(op, asm_op)                                     \
  68 static inline int atomic_fetch_##op##_relaxed(int i, atomic_t *v)       \
  69 {                                                                       \
  70         long temp, result;                                              \
  71         __asm__ __volatile__(                                           \
  72         "1:     ldl_l %2,%1\n"                                          \
  73         "       " #asm_op " %2,%3,%0\n"                                 \
  74         "       stl_c %0,%1\n"                                          \
  75         "       beq %0,2f\n"                                            \
  76         ".subsection 2\n"                                               \
  77         "2:     br 1b\n"                                                \
  78         ".previous"                                                     \
  79         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
  80         :"Ir" (i), "m" (v->counter) : "memory");                        \
  81         return result;                                                  \
  82 }
  83
  84 #define ATOMIC64_OP(op, asm_op)                                         \
  85 static __inline__ void atomic64_##op(long i, atomic64_t * v)            \
  86 {                                                                       \
  87         unsigned long temp;                                             \
  88         __asm__ __volatile__(                                           \
  89         "1:     ldq_l %0,%1\n"                                          \
  90         "       " #asm_op " %0,%2,%0\n"                                 \
  91         "       stq_c %0,%1\n"                                          \
  92         "       beq %0,2f\n"                                            \
  93         ".subsection 2\n"                                               \
  94         "2:     br 1b\n"                                                \
  95         ".previous"                                                     \
  96         :"=&r" (temp), "=m" (v->counter)                                \
  97         :"Ir" (i), "m" (v->counter));                                   \
  98 }                                                                       \
  99
 100 #define ATOMIC64_OP_RETURN(op, asm_op)                                  \
 101 static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v)   \
 102 {                                                                       \
 103         long temp, result;                                              \
 104         __asm__ __volatile__(                                           \
 105         "1:     ldq_l %0,%1\n"                                          \
 106         "       " #asm_op " %0,%3,%2\n"                                 \
 107         "       " #asm_op " %0,%3,%0\n"                                 \
 108         "       stq_c %0,%1\n"                                          \
 109         "       beq %0,2f\n"                                            \
 110         ".subsection 2\n"                                               \
 111         "2:     br 1b\n"                                                \
 112         ".previous"                                                     \
 113         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 114         :"Ir" (i), "m" (v->counter) : "memory");                        \
 115         return result;                                                  \
 116 }
 117
 118 #define ATOMIC64_FETCH_OP(op, asm_op)                                   \
 119 static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v)    \
 120 {                                                                       \
 121         long temp, result;                                              \
 122         __asm__ __volatile__(                                           \
 123         "1:     ldq_l %2,%1\n"                                          \
 124         "       " #asm_op " %2,%3,%0\n"                                 \
 125         "       stq_c %0,%1\n"                                          \
 126         "       beq %0,2f\n"                                            \
 127         ".subsection 2\n"                                               \
 128         "2:     br 1b\n"                                                \
 129         ".previous"                                                     \
 130         :"=&r" (temp), "=m" (v->counter), "=&r" (result)                \
 131         :"Ir" (i), "m" (v->counter) : "memory");                        \
 132         return result;                                                  \
 133 }
 134
 135 #define ATOMIC_OPS(op)                                                  \
 136         ATOMIC_OP(op, op##l)                                            \
 137         ATOMIC_OP_RETURN(op, op##l)                                     \
 138         ATOMIC_FETCH_OP(op, op##l)                                      \
 139         ATOMIC64_OP(op, op##q)                                          \
 140         ATOMIC64_OP_RETURN(op, op##q)                                   \
 141         ATOMIC64_FETCH_OP(op, op##q)
 142
 143 ATOMIC_OPS(add)
 144 ATOMIC_OPS(sub)
 145
 146 #define atomic_add_return_relaxed       atomic_add_return_relaxed
 147 #define atomic_sub_return_relaxed       atomic_sub_return_relaxed
 148 #define atomic_fetch_add_relaxed        atomic_fetch_add_relaxed
 149 #define atomic_fetch_sub_relaxed        atomic_fetch_sub_relaxed
 150
 151 #define atomic64_add_return_relaxed     atomic64_add_return_relaxed
 152 #define atomic64_sub_return_relaxed     atomic64_sub_return_relaxed
 153 #define atomic64_fetch_add_relaxed      atomic64_fetch_add_relaxed
 154 #define atomic64_fetch_sub_relaxed      atomic64_fetch_sub_relaxed
 155
 156 #define atomic_andnot atomic_andnot
 157 #define atomic64_andnot atomic64_andnot
 158
 159 #undef ATOMIC_OPS
 160 #define ATOMIC_OPS(op, asm)                                             \
 161         ATOMIC_OP(op, asm)                                              \
 162         ATOMIC_FETCH_OP(op, asm)                                        \
 163         ATOMIC64_OP(op, asm)                                            \
 164         ATOMIC64_FETCH_OP(op, asm)
 165
 166 ATOMIC_OPS(and, and)
 167 ATOMIC_OPS(andnot, bic)
 168 ATOMIC_OPS(or, bis)
 169 ATOMIC_OPS(xor, xor)
 170
 171 #define atomic_fetch_and_relaxed        atomic_fetch_and_relaxed
 172 #define atomic_fetch_andnot_relaxed     atomic_fetch_andnot_relaxed
 173 #define atomic_fetch_or_relaxed         atomic_fetch_or_relaxed
 174 #define atomic_fetch_xor_relaxed        atomic_fetch_xor_relaxed
 175
 176 #define atomic64_fetch_and_relaxed      atomic64_fetch_and_relaxed
 177 #define atomic64_fetch_andnot_relaxed   atomic64_fetch_andnot_relaxed
 178 #define atomic64_fetch_or_relaxed       atomic64_fetch_or_relaxed
 179 #define atomic64_fetch_xor_relaxed      atomic64_fetch_xor_relaxed
 180
 181 #undef ATOMIC_OPS
 182 #undef ATOMIC64_FETCH_OP
 183 #undef ATOMIC64_OP_RETURN
 184 #undef ATOMIC64_OP
 185 #undef ATOMIC_FETCH_OP
 186 #undef ATOMIC_OP_RETURN
 187 #undef ATOMIC_OP
 188
 189 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 190 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 191
 192 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 193 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 194
 195 /**
 196  * __atomic_add_unless - add unless the number is a given value
 197  * @v: pointer of type atomic_t
 198  * @a: the amount to add to v...
 199  * @u: ...unless v is equal to u.
 200  *
 201  * Atomically adds @a to @v, so long as it was not @u.
 202  * Returns the old value of @v.
 203  */
 204 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 205 {
 206         int c, new, old;
 207         smp_mb();
 208         __asm__ __volatile__(
 209         "1:     ldl_l   %[old],%[mem]\n"
 210         "       cmpeq   %[old],%[u],%[c]\n"
 211         "       addl    %[old],%[a],%[new]\n"
 212         "       bne     %[c],2f\n"
 213         "       stl_c   %[new],%[mem]\n"
 214         "       beq     %[new],3f\n"
 215         "2:\n"
 216         ".subsection 2\n"
 217         "3:     br      1b\n"
 218         ".previous"
 219         : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
 220         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
 221         : "memory");
 222         smp_mb();
 223         return old;
 224 }
 225
 226
 227 /**
 228  * atomic64_add_unless - add unless the number is a given value
 229  * @v: pointer of type atomic64_t
 230  * @a: the amount to add to v...
 231  * @u: ...unless v is equal to u.
 232  *
 233  * Atomically adds @a to @v, so long as it was not @u.
 234  * Returns true iff @v was not @u.
 235  */
 236 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 237 {
 238         long c, tmp;
 239         smp_mb();
 240         __asm__ __volatile__(
 241         "1:     ldq_l   %[tmp],%[mem]\n"
 242         "       cmpeq   %[tmp],%[u],%[c]\n"
 243         "       addq    %[tmp],%[a],%[tmp]\n"
 244         "       bne     %[c],2f\n"
 245         "       stq_c   %[tmp],%[mem]\n"
 246         "       beq     %[tmp],3f\n"
 247         "2:\n"
 248         ".subsection 2\n"
 249         "3:     br      1b\n"
 250         ".previous"
 251         : [tmp] "=&r"(tmp), [c] "=&r"(c)
 252         : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
 253         : "memory");
 254         smp_mb();
 255         return !c;
 256 }
 257
 258 /*
 259  * atomic64_dec_if_positive - decrement by 1 if old value positive
 260  * @v: pointer of type atomic_t
 261  *
 262  * The function returns the old value of *v minus 1, even if
 263  * the atomic variable, v, was not decremented.
 264  */
 265 static inline long atomic64_dec_if_positive(atomic64_t *v)
 266 {
 267         long old, tmp;
 268         smp_mb();
 269         __asm__ __volatile__(
 270         "1:     ldq_l   %[old],%[mem]\n"
 271         "       subq    %[old],1,%[tmp]\n"
 272         "       ble     %[old],2f\n"
 273         "       stq_c   %[tmp],%[mem]\n"
 274         "       beq     %[tmp],3f\n"
 275         "2:\n"
 276         ".subsection 2\n"
 277         "3:     br      1b\n"
 278         ".previous"
 279         : [old] "=&r"(old), [tmp] "=&r"(tmp)
 280         : [mem] "m"(*v)
 281         : "memory");
 282         smp_mb();
 283         return old - 1;
 284 }
 285
 286 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 287
 288 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 289 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 290
 291 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 292 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 293
 294 #define atomic_inc_return(v) atomic_add_return(1,(v))
 295 #define atomic64_inc_return(v) atomic64_add_return(1,(v))
 296
 297 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 298 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 299
 300 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 301 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 302
 303 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 304 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 305
 306 #define atomic_inc(v) atomic_add(1,(v))
 307 #define atomic64_inc(v) atomic64_add(1,(v))
 308
 309 #define atomic_dec(v) atomic_sub(1,(v))
 310 #define atomic64_dec(v) atomic64_sub(1,(v))
 311
 312 #endif /* _ALPHA_ATOMIC_H */