sys/dev/drm/include/linux/atomic.h

   1 /*-
   2  * Copyright (c) 2010 Isilon Systems, Inc.
   3  * Copyright (c) 2010 iX Systems, Inc.
   4  * Copyright (c) 2010 Panasas, Inc.
   5  * Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
   6  * Copyright (c) 2013-2017 François Tigeot
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice unmodified, this list of conditions, and the following
  14  *    disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef _LINUX_ATOMIC_H_
  32 #define _LINUX_ATOMIC_H_
  33
  34 #include <asm/atomic.h>
  35
  36 typedef struct {
  37         volatile u_int counter;
  38 } atomic_t;
  39
  40 typedef struct {
  41         volatile u_long counter;
  42 } atomic64_t;
  43
  44 #define atomic_add(i, v)                atomic_add_return((i), (v))
  45 #define atomic_sub(i, v)                atomic_sub_return((i), (v))
  46 #define atomic_inc_return(v)            atomic_add_return(1, (v))
  47 #define atomic_add_negative(i, v)       (atomic_add_return((i), (v)) < 0)
  48 #define atomic_sub_and_test(i, v)       (atomic_sub_return((i), (v)) == 0)
  49 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
  50 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
  51 #define atomic_dec_return(v)             atomic_sub_return(1, (v))
  52
  53 #define atomic64_add(i, v)              atomic_add_return_long((i), (v))
  54 #define atomic64_sub(i, v)              atomic_sub_return_long((i), (v))
  55
  56 #define atomic_xchg(p, v)               atomic_swap_int(&((p)->counter), v)
  57 #define atomic64_xchg(p, v)             atomic_swap_long(&((p)->counter), v)
  58
  59 #define atomic_cmpset(p, o, n)          atomic_cmpset_32(&((p)->counter), o, n)
  60
  61 #define atomic64_cmpxchg(p, o, n)                                               \
  62         (atomic_cmpset_long((volatile uint64_t *)(p),(o),(n)) ? (o) : (0))
  63
  64 static inline int
  65 atomic_add_return(int i, atomic_t *v)
  66 {
  67         return i + atomic_fetchadd_int(&v->counter, i);
  68 }
  69
  70 static inline int64_t
  71 atomic_add_return_long(int64_t i, atomic64_t *v)
  72 {
  73         return i + atomic_fetchadd_long(&v->counter, i);
  74 }
  75
  76 static inline int
  77 atomic_sub_return(int i, atomic_t *v)
  78 {
  79         return atomic_fetchadd_int(&v->counter, -i) - i;
  80 }
  81
  82 static inline int64_t
  83 atomic_sub_return_long(int64_t i, atomic64_t *v)
  84 {
  85         return atomic_fetchadd_long(&v->counter, -i) - i;
  86 }
  87
  88 static inline void
  89 atomic_set(atomic_t *v, int i)
  90 {
  91         atomic_store_rel_int(&v->counter, i);
  92 }
  93
  94 static inline void
  95 atomic64_set(atomic64_t *v, long i)
  96 {
  97         atomic_store_rel_long(&v->counter, i);
  98 }
  99
 100 static inline int
 101 atomic_read(atomic_t *v)
 102 {
 103         return atomic_load_acq_int(&v->counter);
 104 }
 105
 106 static inline int64_t
 107 atomic64_read(atomic64_t *v)
 108 {
 109         return atomic_load_acq_long(&v->counter);
 110 }
 111
 112 static inline int
 113 atomic_inc(atomic_t *v)
 114 {
 115         return atomic_fetchadd_int(&v->counter, 1) + 1;
 116 }
 117
 118 static inline int
 119 atomic_dec(atomic_t *v)
 120 {
 121         return atomic_fetchadd_int(&v->counter, -1) - 1;
 122 }
 123
 124 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 125 {
 126         return atomic_cmpxchg_int(&v->counter, old, new);
 127 }
 128
 129 static inline int atomic_add_unless(atomic_t *v, int add, int unless)
 130 {
 131         int c, old;
 132         c = atomic_read(v);
 133         for (;;) {
 134                 if (unlikely(c == unless))
 135                         break;
 136                 old = atomic_cmpxchg_int(&v->counter, c, c + add);
 137                 if (likely(old == c))
 138                         break;
 139                 c = old;
 140         }
 141         return c != unless;
 142 }
 143
 144 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 145
 146 /* atomic_clear_mask: atomically clears a variable from the bit set in mask */
 147 #define atomic_clear_mask(mask, addr)           \
 148         /* atomic *addr &= ~mask; */            \
 149         __asm __volatile("lock andl %0, %1"     \
 150                 :                               \
 151                 : "r" (~mask), "m" (*addr)      \
 152                 : "memory");
 153
 154 #define smp_mb__before_atomic() cpu_ccfence()
 155 #define smp_mb__after_atomic()  cpu_ccfence()
 156
 157 static inline void
 158 atomic_andnot(int i, atomic_t *v)
 159 {
 160         /* v->counter = v->counter & ~i; */
 161         atomic_clear_int(&v->counter, i);
 162 }
 163
 164 #define cmpxchg(ptr, old, new) ({                               \
 165         __typeof(*(ptr)) __ret;                                 \
 166                                                                 \
 167         CTASSERT(sizeof(__ret) == 1 || sizeof(__ret) == 2 ||    \
 168             sizeof(__ret) == 4 || sizeof(__ret) == 8);          \
 169                                                                 \
 170         __ret = (old);                                          \
 171         switch (sizeof(__ret)) {                                \
 172         case 1:                                                 \
 173                 while (!atomic_fcmpset_8((volatile int8_t *)(ptr), \
 174                     (int8_t *)&__ret, (new)) && __ret == (old)) \
 175                         ;                                       \
 176                 break;                                          \
 177         case 2:                                                 \
 178                 while (!atomic_fcmpset_16((volatile int16_t *)(ptr), \
 179                     (int16_t *)&__ret, (new)) && __ret == (old)) \
 180                         ;                                       \
 181                 break;                                          \
 182         case 4:                                                 \
 183                 while (!atomic_fcmpset_32((volatile int32_t *)(ptr), \
 184                     (int32_t *)&__ret, (new)) && __ret == (old)) \
 185                         ;                                       \
 186                 break;                                          \
 187         case 8:                                                 \
 188                 while (!atomic_fcmpset_64((volatile int64_t *)(ptr), \
 189                     (int64_t *)&__ret, (new)) && __ret == (old)) \
 190                         ;                                       \
 191                 break;                                          \
 192         }                                                       \
 193         __ret;                                                  \
 194 })
 195
 196 #define cmpxchg_relaxed(...)    cmpxchg(__VA_ARGS__)
 197
 198 #endif  /* _LINUX_ATOMIC_H_ */