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 static inline long atomic64_xchg(atomic64_t *v, long new) 180 { 181 return xchg(&v->counter, new); 182 } 183 184 /** 185 * atomic64_add_unless - add unless the number is a given value 186 * @v: pointer of type atomic64_t 187 * @a: the amount to add to v... 188 * @u: ...unless v is equal to u. 189 * 190 * Atomically adds @a to @v, so long as it was not @u. 191 * Returns the old value of @v. 192 */ 193 static inline bool atomic64_add_unless(atomic64_t *v, long a, long u) 194 { 195 long c, old; 196 c = atomic64_read(v); 197 for (;;) { 198 if (unlikely(c == (u))) 199 break; 200 old = atomic64_cmpxchg((v), c, c + (a)); 201 if (likely(old == c)) 202 break; 203 c = old; 204 } 205 return c != (u); 206 } 207 208 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 209 210 /* 211 * atomic64_dec_if_positive - decrement by 1 if old value positive 212 * @v: pointer of type atomic_t 213 * 214 * The function returns the old value of *v minus 1, even if 215 * the atomic variable, v, was not decremented. 216 */ 217 static inline long atomic64_dec_if_positive(atomic64_t *v) 218 { 219 long c, old, dec; 220 c = atomic64_read(v); 221 for (;;) { 222 dec = c - 1; 223 if (unlikely(dec < 0)) 224 break; 225 old = atomic64_cmpxchg((v), c, dec); 226 if (likely(old == c)) 227 break; 228 c = old; 229 } 230 return dec; 231 } 232 233 #define ATOMIC64_OP(op) \ 234 static inline void atomic64_##op(long i, atomic64_t *v) \ 235 { \ 236 asm volatile(LOCK_PREFIX #op"q %1,%0" \ 237 : "+m" (v->counter) \ 238 : "er" (i) \ 239 : "memory"); \ 240 } 241 242 #define ATOMIC64_FETCH_OP(op, c_op) \ 243 static inline long atomic64_fetch_##op(long i, atomic64_t *v) \ 244 { \ 245 long old, val = atomic64_read(v); \ 246 for (;;) { \ 247 old = atomic64_cmpxchg(v, val, val c_op i); \ 248 if (old == val) \ 249 break; \ 250 val = old; \ 251 } \ 252 return old; \ 253 } 254 255 #define ATOMIC64_OPS(op, c_op) \ 256 ATOMIC64_OP(op) \ 257 ATOMIC64_FETCH_OP(op, c_op) 258 259 ATOMIC64_OPS(and, &) 260 ATOMIC64_OPS(or, |) 261 ATOMIC64_OPS(xor, ^) 262 263 #undef ATOMIC64_OPS 264 #undef ATOMIC64_FETCH_OP 265 #undef ATOMIC64_OP 266 267 #endif /* _ASM_X86_ATOMIC64_64_H */ 268