arch/x86/include/asm/atomic64_64.h

   1 #ifndef _ASM_X86_ATOMIC64_64_H
   2 #define _ASM_X86_ATOMIC64_64_H
   3
   4 #include <linux/types.h>
   5 #include <asm/alternative.h>
   6 #include <asm/cmpxchg.h>
   7
   8 /* The 64-bit atomic type */
   9
  10 #define ATOMIC64_INIT(i)        { (i) }
  11
  12 /**
  13  * atomic64_read - read atomic64 variable
  14  * @v: pointer of type atomic64_t
  15  *
  16  * Atomically reads the value of @v.
  17  * Doesn't imply a read memory barrier.
  18  */
  19 static inline long atomic64_read(const atomic64_t *v)
  20 {
  21         return READ_ONCE((v)->counter);
  22 }
  23
  24 /**
  25  * atomic64_set - set atomic64 variable
  26  * @v: pointer to type atomic64_t
  27  * @i: required value
  28  *
  29  * Atomically sets the value of @v to @i.
  30  */
  31 static inline void atomic64_set(atomic64_t *v, long i)
  32 {
  33         WRITE_ONCE(v->counter, i);
  34 }
  35
  36 /**
  37  * atomic64_add - add integer to atomic64 variable
  38  * @i: integer value to add
  39  * @v: pointer to type atomic64_t
  40  *
  41  * Atomically adds @i to @v.
  42  */
  43 static __always_inline void atomic64_add(long i, atomic64_t *v)
  44 {
  45         asm volatile(LOCK_PREFIX "addq %1,%0"
  46                      : "=m" (v->counter)
  47                      : "er" (i), "m" (v->counter));
  48 }
  49
  50 /**
  51  * atomic64_sub - subtract the atomic64 variable
  52  * @i: integer value to subtract
  53  * @v: pointer to type atomic64_t
  54  *
  55  * Atomically subtracts @i from @v.
  56  */
  57 static inline void atomic64_sub(long i, atomic64_t *v)
  58 {
  59         asm volatile(LOCK_PREFIX "subq %1,%0"
  60                      : "=m" (v->counter)
  61                      : "er" (i), "m" (v->counter));
  62 }
  63
  64 /**
  65  * atomic64_sub_and_test - subtract value from variable and test result
  66  * @i: integer value to subtract
  67  * @v: pointer to type atomic64_t
  68  *
  69  * Atomically subtracts @i from @v and returns
  70  * true if the result is zero, or false for all
  71  * other cases.
  72  */
  73 static inline bool atomic64_sub_and_test(long i, atomic64_t *v)
  74 {
  75         GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", e);
  76 }
  77
  78 /**
  79  * atomic64_inc - increment atomic64 variable
  80  * @v: pointer to type atomic64_t
  81  *
  82  * Atomically increments @v by 1.
  83  */
  84 static __always_inline void atomic64_inc(atomic64_t *v)
  85 {
  86         asm volatile(LOCK_PREFIX "incq %0"
  87                      : "=m" (v->counter)
  88                      : "m" (v->counter));
  89 }
  90
  91 /**
  92  * atomic64_dec - decrement atomic64 variable
  93  * @v: pointer to type atomic64_t
  94  *
  95  * Atomically decrements @v by 1.
  96  */
  97 static __always_inline void atomic64_dec(atomic64_t *v)
  98 {
  99         asm volatile(LOCK_PREFIX "decq %0"
 100                      : "=m" (v->counter)
 101                      : "m" (v->counter));
 102 }
 103
 104 /**
 105  * atomic64_dec_and_test - decrement and test
 106  * @v: pointer to type atomic64_t
 107  *
 108  * Atomically decrements @v by 1 and
 109  * returns true if the result is 0, or false for all other
 110  * cases.
 111  */
 112 static inline bool atomic64_dec_and_test(atomic64_t *v)
 113 {
 114         GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", e);
 115 }
 116
 117 /**
 118  * atomic64_inc_and_test - increment and test
 119  * @v: pointer to type atomic64_t
 120  *
 121  * Atomically increments @v by 1
 122  * and returns true if the result is zero, or false for all
 123  * other cases.
 124  */
 125 static inline bool atomic64_inc_and_test(atomic64_t *v)
 126 {
 127         GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", e);
 128 }
 129
 130 /**
 131  * atomic64_add_negative - add and test if negative
 132  * @i: integer value to add
 133  * @v: pointer to type atomic64_t
 134  *
 135  * Atomically adds @i to @v and returns true
 136  * if the result is negative, or false when
 137  * result is greater than or equal to zero.
 138  */
 139 static inline bool atomic64_add_negative(long i, atomic64_t *v)
 140 {
 141         GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", s);
 142 }
 143
 144 /**
 145  * atomic64_add_return - add and return
 146  * @i: integer value to add
 147  * @v: pointer to type atomic64_t
 148  *
 149  * Atomically adds @i to @v and returns @i + @v
 150  */
 151 static __always_inline long atomic64_add_return(long i, atomic64_t *v)
 152 {
 153         return i + xadd(&v->counter, i);
 154 }
 155
 156 static inline long atomic64_sub_return(long i, atomic64_t *v)
 157 {
 158         return atomic64_add_return(-i, v);
 159 }
 160
 161 static inline long atomic64_fetch_add(long i, atomic64_t *v)
 162 {
 163         return xadd(&v->counter, i);
 164 }
 165
 166 static inline long atomic64_fetch_sub(long i, atomic64_t *v)
 167 {
 168         return xadd(&v->counter, -i);
 169 }
 170
 171 #define atomic64_inc_return(v)  (atomic64_add_return(1, (v)))
 172 #define atomic64_dec_return(v)  (atomic64_sub_return(1, (v)))
 173
 174 static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
 175 {
 176         return cmpxchg(&v->counter, old, new);
 177 }
 178
 179 #define atomic64_try_cmpxchg atomic64_try_cmpxchg
 180 static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, long *old, long new)
 181 {
 182         return try_cmpxchg(&v->counter, old, new);
 183 }
 184
 185 static inline long atomic64_xchg(atomic64_t *v, long new)
 186 {
 187         return xchg(&v->counter, new);
 188 }
 189
 190 /**
 191  * atomic64_add_unless - add unless the number is a given value
 192  * @v: pointer of type atomic64_t
 193  * @a: the amount to add to v...
 194  * @u: ...unless v is equal to u.
 195  *
 196  * Atomically adds @a to @v, so long as it was not @u.
 197  * Returns the old value of @v.
 198  */
 199 static inline bool atomic64_add_unless(atomic64_t *v, long a, long u)
 200 {
 201         long c = atomic64_read(v);
 202         do {
 203                 if (unlikely(c == u))
 204                         return false;
 205         } while (!atomic64_try_cmpxchg(v, &c, c + a));
 206         return true;
 207 }
 208
 209 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 210
 211 /*
 212  * atomic64_dec_if_positive - decrement by 1 if old value positive
 213  * @v: pointer of type atomic_t
 214  *
 215  * The function returns the old value of *v minus 1, even if
 216  * the atomic variable, v, was not decremented.
 217  */
 218 static inline long atomic64_dec_if_positive(atomic64_t *v)
 219 {
 220         long dec, c = atomic64_read(v);
 221         do {
 222                 dec = c - 1;
 223                 if (unlikely(dec < 0))
 224                         break;
 225         } while (!atomic64_try_cmpxchg(v, &c, dec));
 226         return dec;
 227 }
 228
 229 #define ATOMIC64_OP(op)                                                 \
 230 static inline void atomic64_##op(long i, atomic64_t *v)                 \
 231 {                                                                       \
 232         asm volatile(LOCK_PREFIX #op"q %1,%0"                           \
 233                         : "+m" (v->counter)                             \
 234                         : "er" (i)                                      \
 235                         : "memory");                                    \
 236 }
 237
 238 #define ATOMIC64_FETCH_OP(op, c_op)                                     \
 239 static inline long atomic64_fetch_##op(long i, atomic64_t *v)           \
 240 {                                                                       \
 241         long val = atomic64_read(v);                                    \
 242         do {                                                            \
 243         } while (!atomic64_try_cmpxchg(v, &val, val c_op i));           \
 244         return val;                                                     \
 245 }
 246
 247 #define ATOMIC64_OPS(op, c_op)                                          \
 248         ATOMIC64_OP(op)                                                 \
 249         ATOMIC64_FETCH_OP(op, c_op)
 250
 251 ATOMIC64_OPS(and, &)
 252 ATOMIC64_OPS(or, |)
 253 ATOMIC64_OPS(xor, ^)
 254
 255 #undef ATOMIC64_OPS
 256 #undef ATOMIC64_FETCH_OP
 257 #undef ATOMIC64_OP
 258
 259 #endif /* _ASM_X86_ATOMIC64_64_H */