include/asm-x86/atomic_64.h

   1 #ifndef __ARCH_X86_64_ATOMIC__
   2 #define __ARCH_X86_64_ATOMIC__
   3
   4 #include <asm/alternative.h>
   5 #include <asm/cmpxchg.h>
   6
   7 /* atomic_t should be 32 bit signed type */
   8
   9 /*
  10  * Atomic operations that C can't guarantee us.  Useful for
  11  * resource counting etc..
  12  */
  13
  14 #ifdef CONFIG_SMP
  15 #define LOCK "lock ; "
  16 #else
  17 #define LOCK ""
  18 #endif
  19
  20 /*
  21  * Make sure gcc doesn't try to be clever and move things around
  22  * on us. We need to use _exactly_ the address the user gave us,
  23  * not some alias that contains the same information.
  24  */
  25 typedef struct {
  26         int counter;
  27 } atomic_t;
  28
  29 #define ATOMIC_INIT(i)  { (i) }
  30
  31 /**
  32  * atomic_read - read atomic variable
  33  * @v: pointer of type atomic_t
  34  *
  35  * Atomically reads the value of @v.
  36  */
  37 #define atomic_read(v)          ((v)->counter)
  38
  39 /**
  40  * atomic_set - set atomic variable
  41  * @v: pointer of type atomic_t
  42  * @i: required value
  43  *
  44  * Atomically sets the value of @v to @i.
  45  */
  46 #define atomic_set(v, i)                (((v)->counter) = (i))
  47
  48 /**
  49  * atomic_add - add integer to atomic variable
  50  * @i: integer value to add
  51  * @v: pointer of type atomic_t
  52  *
  53  * Atomically adds @i to @v.
  54  */
  55 static inline void atomic_add(int i, atomic_t *v)
  56 {
  57         asm volatile(LOCK_PREFIX "addl %1,%0"
  58                      : "=m" (v->counter)
  59                      : "ir" (i), "m" (v->counter));
  60 }
  61
  62 /**
  63  * atomic_sub - subtract the atomic variable
  64  * @i: integer value to subtract
  65  * @v: pointer of type atomic_t
  66  *
  67  * Atomically subtracts @i from @v.
  68  */
  69 static inline void atomic_sub(int i, atomic_t *v)
  70 {
  71         asm volatile(LOCK_PREFIX "subl %1,%0"
  72                      : "=m" (v->counter)
  73                      : "ir" (i), "m" (v->counter));
  74 }
  75
  76 /**
  77  * atomic_sub_and_test - subtract value from variable and test result
  78  * @i: integer value to subtract
  79  * @v: pointer of type atomic_t
  80  *
  81  * Atomically subtracts @i from @v and returns
  82  * true if the result is zero, or false for all
  83  * other cases.
  84  */
  85 static inline int atomic_sub_and_test(int i, atomic_t *v)
  86 {
  87         unsigned char c;
  88
  89         asm volatile(LOCK_PREFIX "subl %2,%0; sete %1"
  90                      : "=m" (v->counter), "=qm" (c)
  91                      : "ir" (i), "m" (v->counter) : "memory");
  92         return c;
  93 }
  94
  95 /**
  96  * atomic_inc - increment atomic variable
  97  * @v: pointer of type atomic_t
  98  *
  99  * Atomically increments @v by 1.
 100  */
 101 static inline void atomic_inc(atomic_t *v)
 102 {
 103         asm volatile(LOCK_PREFIX "incl %0"
 104                      : "=m" (v->counter)
 105                      : "m" (v->counter));
 106 }
 107
 108 /**
 109  * atomic_dec - decrement atomic variable
 110  * @v: pointer of type atomic_t
 111  *
 112  * Atomically decrements @v by 1.
 113  */
 114 static inline void atomic_dec(atomic_t *v)
 115 {
 116         asm volatile(LOCK_PREFIX "decl %0"
 117                      : "=m" (v->counter)
 118                      : "m" (v->counter));
 119 }
 120
 121 /**
 122  * atomic_dec_and_test - decrement and test
 123  * @v: pointer of type atomic_t
 124  *
 125  * Atomically decrements @v by 1 and
 126  * returns true if the result is 0, or false for all other
 127  * cases.
 128  */
 129 static inline int atomic_dec_and_test(atomic_t *v)
 130 {
 131         unsigned char c;
 132
 133         asm volatile(LOCK_PREFIX "decl %0; sete %1"
 134                      : "=m" (v->counter), "=qm" (c)
 135                      : "m" (v->counter) : "memory");
 136         return c != 0;
 137 }
 138
 139 /**
 140  * atomic_inc_and_test - increment and test
 141  * @v: pointer of type atomic_t
 142  *
 143  * Atomically increments @v by 1
 144  * and returns true if the result is zero, or false for all
 145  * other cases.
 146  */
 147 static inline int atomic_inc_and_test(atomic_t *v)
 148 {
 149         unsigned char c;
 150
 151         asm volatile(LOCK_PREFIX "incl %0; sete %1"
 152                      : "=m" (v->counter), "=qm" (c)
 153                      : "m" (v->counter) : "memory");
 154         return c != 0;
 155 }
 156
 157 /**
 158  * atomic_add_negative - add and test if negative
 159  * @i: integer value to add
 160  * @v: pointer of type atomic_t
 161  *
 162  * Atomically adds @i to @v and returns true
 163  * if the result is negative, or false when
 164  * result is greater than or equal to zero.
 165  */
 166 static inline int atomic_add_negative(int i, atomic_t *v)
 167 {
 168         unsigned char c;
 169
 170         asm volatile(LOCK_PREFIX "addl %2,%0; sets %1"
 171                      : "=m" (v->counter), "=qm" (c)
 172                      : "ir" (i), "m" (v->counter) : "memory");
 173         return c;
 174 }
 175
 176 /**
 177  * atomic_add_return - add and return
 178  * @i: integer value to add
 179  * @v: pointer of type atomic_t
 180  *
 181  * Atomically adds @i to @v and returns @i + @v
 182  */
 183 static inline int atomic_add_return(int i, atomic_t *v)
 184 {
 185         int __i = i;
 186         asm volatile(LOCK_PREFIX "xaddl %0, %1"
 187                      : "+r" (i), "+m" (v->counter)
 188                      : : "memory");
 189         return i + __i;
 190 }
 191
 192 static inline int atomic_sub_return(int i, atomic_t *v)
 193 {
 194         return atomic_add_return(-i, v);
 195 }
 196
 197 #define atomic_inc_return(v)  (atomic_add_return(1, v))
 198 #define atomic_dec_return(v)  (atomic_sub_return(1, v))
 199
 200 /* An 64bit atomic type */
 201
 202 typedef struct {
 203         long counter;
 204 } atomic64_t;
 205
 206 #define ATOMIC64_INIT(i)        { (i) }
 207
 208 /**
 209  * atomic64_read - read atomic64 variable
 210  * @v: pointer of type atomic64_t
 211  *
 212  * Atomically reads the value of @v.
 213  * Doesn't imply a read memory barrier.
 214  */
 215 #define atomic64_read(v)                ((v)->counter)
 216
 217 /**
 218  * atomic64_set - set atomic64 variable
 219  * @v: pointer to type atomic64_t
 220  * @i: required value
 221  *
 222  * Atomically sets the value of @v to @i.
 223  */
 224 #define atomic64_set(v, i)              (((v)->counter) = (i))
 225
 226 /**
 227  * atomic64_add - add integer to atomic64 variable
 228  * @i: integer value to add
 229  * @v: pointer to type atomic64_t
 230  *
 231  * Atomically adds @i to @v.
 232  */
 233 static inline void atomic64_add(long i, atomic64_t *v)
 234 {
 235         asm volatile(LOCK_PREFIX "addq %1,%0"
 236                      : "=m" (v->counter)
 237                      : "ir" (i), "m" (v->counter));
 238 }
 239
 240 /**
 241  * atomic64_sub - subtract the atomic64 variable
 242  * @i: integer value to subtract
 243  * @v: pointer to type atomic64_t
 244  *
 245  * Atomically subtracts @i from @v.
 246  */
 247 static inline void atomic64_sub(long i, atomic64_t *v)
 248 {
 249         asm volatile(LOCK_PREFIX "subq %1,%0"
 250                      : "=m" (v->counter)
 251                      : "ir" (i), "m" (v->counter));
 252 }
 253
 254 /**
 255  * atomic64_sub_and_test - subtract value from variable and test result
 256  * @i: integer value to subtract
 257  * @v: pointer to type atomic64_t
 258  *
 259  * Atomically subtracts @i from @v and returns
 260  * true if the result is zero, or false for all
 261  * other cases.
 262  */
 263 static inline int atomic64_sub_and_test(long i, atomic64_t *v)
 264 {
 265         unsigned char c;
 266
 267         asm volatile(LOCK_PREFIX "subq %2,%0; sete %1"
 268                      : "=m" (v->counter), "=qm" (c)
 269                      : "ir" (i), "m" (v->counter) : "memory");
 270         return c;
 271 }
 272
 273 /**
 274  * atomic64_inc - increment atomic64 variable
 275  * @v: pointer to type atomic64_t
 276  *
 277  * Atomically increments @v by 1.
 278  */
 279 static inline void atomic64_inc(atomic64_t *v)
 280 {
 281         asm volatile(LOCK_PREFIX "incq %0"
 282                      : "=m" (v->counter)
 283                      : "m" (v->counter));
 284 }
 285
 286 /**
 287  * atomic64_dec - decrement atomic64 variable
 288  * @v: pointer to type atomic64_t
 289  *
 290  * Atomically decrements @v by 1.
 291  */
 292 static inline void atomic64_dec(atomic64_t *v)
 293 {
 294         asm volatile(LOCK_PREFIX "decq %0"
 295                      : "=m" (v->counter)
 296                      : "m" (v->counter));
 297 }
 298
 299 /**
 300  * atomic64_dec_and_test - decrement and test
 301  * @v: pointer to type atomic64_t
 302  *
 303  * Atomically decrements @v by 1 and
 304  * returns true if the result is 0, or false for all other
 305  * cases.
 306  */
 307 static inline int atomic64_dec_and_test(atomic64_t *v)
 308 {
 309         unsigned char c;
 310
 311         asm volatile(LOCK_PREFIX "decq %0; sete %1"
 312                      : "=m" (v->counter), "=qm" (c)
 313                      : "m" (v->counter) : "memory");
 314         return c != 0;
 315 }
 316
 317 /**
 318  * atomic64_inc_and_test - increment and test
 319  * @v: pointer to type atomic64_t
 320  *
 321  * Atomically increments @v by 1
 322  * and returns true if the result is zero, or false for all
 323  * other cases.
 324  */
 325 static inline int atomic64_inc_and_test(atomic64_t *v)
 326 {
 327         unsigned char c;
 328
 329         asm volatile(LOCK_PREFIX "incq %0; sete %1"
 330                      : "=m" (v->counter), "=qm" (c)
 331                      : "m" (v->counter) : "memory");
 332         return c != 0;
 333 }
 334
 335 /**
 336  * atomic64_add_negative - add and test if negative
 337  * @i: integer value to add
 338  * @v: pointer to type atomic64_t
 339  *
 340  * Atomically adds @i to @v and returns true
 341  * if the result is negative, or false when
 342  * result is greater than or equal to zero.
 343  */
 344 static inline int atomic64_add_negative(long i, atomic64_t *v)
 345 {
 346         unsigned char c;
 347
 348         asm volatile(LOCK_PREFIX "addq %2,%0; sets %1"
 349                      : "=m" (v->counter), "=qm" (c)
 350                      : "ir" (i), "m" (v->counter) : "memory");
 351         return c;
 352 }
 353
 354 /**
 355  * atomic64_add_return - add and return
 356  * @i: integer value to add
 357  * @v: pointer to type atomic64_t
 358  *
 359  * Atomically adds @i to @v and returns @i + @v
 360  */
 361 static inline long atomic64_add_return(long i, atomic64_t *v)
 362 {
 363         long __i = i;
 364         asm volatile(LOCK_PREFIX "xaddq %0, %1;"
 365                      : "+r" (i), "+m" (v->counter)
 366                      : : "memory");
 367         return i + __i;
 368 }
 369
 370 static inline long atomic64_sub_return(long i, atomic64_t *v)
 371 {
 372         return atomic64_add_return(-i, v);
 373 }
 374
 375 #define atomic64_inc_return(v)  (atomic64_add_return(1, (v)))
 376 #define atomic64_dec_return(v)  (atomic64_sub_return(1, (v)))
 377
 378 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
 379 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 380
 381 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
 382 #define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
 383
 384 /**
 385  * atomic_add_unless - add unless the number is a given value
 386  * @v: pointer of type atomic_t
 387  * @a: the amount to add to v...
 388  * @u: ...unless v is equal to u.
 389  *
 390  * Atomically adds @a to @v, so long as it was not @u.
 391  * Returns non-zero if @v was not @u, and zero otherwise.
 392  */
 393 static inline int atomic_add_unless(atomic_t *v, int a, int u)
 394 {
 395         int c, old;
 396         c = atomic_read(v);
 397         for (;;) {
 398                 if (unlikely(c == (u)))
 399                         break;
 400                 old = atomic_cmpxchg((v), c, c + (a));
 401                 if (likely(old == c))
 402                         break;
 403                 c = old;
 404         }
 405         return c != (u);
 406 }
 407
 408 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 409
 410 /**
 411  * atomic64_add_unless - add unless the number is a given value
 412  * @v: pointer of type atomic64_t
 413  * @a: the amount to add to v...
 414  * @u: ...unless v is equal to u.
 415  *
 416  * Atomically adds @a to @v, so long as it was not @u.
 417  * Returns non-zero if @v was not @u, and zero otherwise.
 418  */
 419 static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
 420 {
 421         long c, old;
 422         c = atomic64_read(v);
 423         for (;;) {
 424                 if (unlikely(c == (u)))
 425                         break;
 426                 old = atomic64_cmpxchg((v), c, c + (a));
 427                 if (likely(old == c))
 428                         break;
 429                 c = old;
 430         }
 431         return c != (u);
 432 }
 433
 434 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 435
 436 /* These are x86-specific, used by some header files */
 437 #define atomic_clear_mask(mask, addr)                                   \
 438         asm volatile(LOCK_PREFIX "andl %0,%1"                           \
 439                      : : "r" (~(mask)), "m" (*(addr)) : "memory")
 440
 441 #define atomic_set_mask(mask, addr)                                     \
 442         asm volatile(LOCK_PREFIX "orl %0,%1"                            \
 443                      : : "r" ((unsigned)(mask)), "m" (*(addr))          \
 444                      : "memory")
 445
 446 /* Atomic operations are already serializing on x86 */
 447 #define smp_mb__before_atomic_dec()     barrier()
 448 #define smp_mb__after_atomic_dec()      barrier()
 449 #define smp_mb__before_atomic_inc()     barrier()
 450 #define smp_mb__after_atomic_inc()      barrier()
 451
 452 #include <asm-generic/atomic.h>
 453 #endif