include/asm-mips/atomic.h

   1 /*
   2  * Atomic operations that C can't guarantee us.  Useful for
   3  * resource counting etc..
   4  *
   5  * But use these as seldom as possible since they are much more slower
   6  * than regular operations.
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  *
  12  * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
  13  */
  14 #ifndef _ASM_ATOMIC_H
  15 #define _ASM_ATOMIC_H
  16
  17 #include <linux/irqflags.h>
  18 #include <asm/barrier.h>
  19 #include <asm/cpu-features.h>
  20 #include <asm/war.h>
  21
  22 typedef struct { volatile int counter; } atomic_t;
  23
  24 #define ATOMIC_INIT(i)    { (i) }
  25
  26 /*
  27  * atomic_read - read atomic variable
  28  * @v: pointer of type atomic_t
  29  *
  30  * Atomically reads the value of @v.
  31  */
  32 #define atomic_read(v)          ((v)->counter)
  33
  34 /*
  35  * atomic_set - set atomic variable
  36  * @v: pointer of type atomic_t
  37  * @i: required value
  38  *
  39  * Atomically sets the value of @v to @i.
  40  */
  41 #define atomic_set(v,i)         ((v)->counter = (i))
  42
  43 /*
  44  * atomic_add - add integer to atomic variable
  45  * @i: integer value to add
  46  * @v: pointer of type atomic_t
  47  *
  48  * Atomically adds @i to @v.
  49  */
  50 static __inline__ void atomic_add(int i, atomic_t * v)
  51 {
  52         if (cpu_has_llsc && R10000_LLSC_WAR) {
  53                 unsigned long temp;
  54
  55                 __asm__ __volatile__(
  56                 "       .set    mips3                                   \n"
  57                 "1:     ll      %0, %1          # atomic_add            \n"
  58                 "       addu    %0, %2                                  \n"
  59                 "       sc      %0, %1                                  \n"
  60                 "       beqzl   %0, 1b                                  \n"
  61                 "       .set    mips0                                   \n"
  62                 : "=&r" (temp), "=m" (v->counter)
  63                 : "Ir" (i), "m" (v->counter));
  64         } else if (cpu_has_llsc) {
  65                 unsigned long temp;
  66
  67                 __asm__ __volatile__(
  68                 "       .set    mips3                                   \n"
  69                 "1:     ll      %0, %1          # atomic_add            \n"
  70                 "       addu    %0, %2                                  \n"
  71                 "       sc      %0, %1                                  \n"
  72                 "       beqz    %0, 1b                                  \n"
  73                 "       .set    mips0                                   \n"
  74                 : "=&r" (temp), "=m" (v->counter)
  75                 : "Ir" (i), "m" (v->counter));
  76         } else {
  77                 unsigned long flags;
  78
  79                 local_irq_save(flags);
  80                 v->counter += i;
  81                 local_irq_restore(flags);
  82         }
  83 }
  84
  85 /*
  86  * atomic_sub - subtract the atomic variable
  87  * @i: integer value to subtract
  88  * @v: pointer of type atomic_t
  89  *
  90  * Atomically subtracts @i from @v.
  91  */
  92 static __inline__ void atomic_sub(int i, atomic_t * v)
  93 {
  94         if (cpu_has_llsc && R10000_LLSC_WAR) {
  95                 unsigned long temp;
  96
  97                 __asm__ __volatile__(
  98                 "       .set    mips3                                   \n"
  99                 "1:     ll      %0, %1          # atomic_sub            \n"
 100                 "       subu    %0, %2                                  \n"
 101                 "       sc      %0, %1                                  \n"
 102                 "       beqzl   %0, 1b                                  \n"
 103                 "       .set    mips0                                   \n"
 104                 : "=&r" (temp), "=m" (v->counter)
 105                 : "Ir" (i), "m" (v->counter));
 106         } else if (cpu_has_llsc) {
 107                 unsigned long temp;
 108
 109                 __asm__ __volatile__(
 110                 "       .set    mips3                                   \n"
 111                 "1:     ll      %0, %1          # atomic_sub            \n"
 112                 "       subu    %0, %2                                  \n"
 113                 "       sc      %0, %1                                  \n"
 114                 "       beqz    %0, 1b                                  \n"
 115                 "       .set    mips0                                   \n"
 116                 : "=&r" (temp), "=m" (v->counter)
 117                 : "Ir" (i), "m" (v->counter));
 118         } else {
 119                 unsigned long flags;
 120
 121                 local_irq_save(flags);
 122                 v->counter -= i;
 123                 local_irq_restore(flags);
 124         }
 125 }
 126
 127 /*
 128  * Same as above, but return the result value
 129  */
 130 static __inline__ int atomic_add_return(int i, atomic_t * v)
 131 {
 132         unsigned long result;
 133
 134         smp_mb();
 135
 136         if (cpu_has_llsc && R10000_LLSC_WAR) {
 137                 unsigned long temp;
 138
 139                 __asm__ __volatile__(
 140                 "       .set    mips3                                   \n"
 141                 "1:     ll      %1, %2          # atomic_add_return     \n"
 142                 "       addu    %0, %1, %3                              \n"
 143                 "       sc      %0, %2                                  \n"
 144                 "       beqzl   %0, 1b                                  \n"
 145                 "       addu    %0, %1, %3                              \n"
 146                 "       .set    mips0                                   \n"
 147                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 148                 : "Ir" (i), "m" (v->counter)
 149                 : "memory");
 150         } else if (cpu_has_llsc) {
 151                 unsigned long temp;
 152
 153                 __asm__ __volatile__(
 154                 "       .set    mips3                                   \n"
 155                 "1:     ll      %1, %2          # atomic_add_return     \n"
 156                 "       addu    %0, %1, %3                              \n"
 157                 "       sc      %0, %2                                  \n"
 158                 "       beqz    %0, 1b                                  \n"
 159                 "       addu    %0, %1, %3                              \n"
 160                 "       .set    mips0                                   \n"
 161                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 162                 : "Ir" (i), "m" (v->counter)
 163                 : "memory");
 164         } else {
 165                 unsigned long flags;
 166
 167                 local_irq_save(flags);
 168                 result = v->counter;
 169                 result += i;
 170                 v->counter = result;
 171                 local_irq_restore(flags);
 172         }
 173
 174         smp_mb();
 175
 176         return result;
 177 }
 178
 179 static __inline__ int atomic_sub_return(int i, atomic_t * v)
 180 {
 181         unsigned long result;
 182
 183         smp_mb();
 184
 185         if (cpu_has_llsc && R10000_LLSC_WAR) {
 186                 unsigned long temp;
 187
 188                 __asm__ __volatile__(
 189                 "       .set    mips3                                   \n"
 190                 "1:     ll      %1, %2          # atomic_sub_return     \n"
 191                 "       subu    %0, %1, %3                              \n"
 192                 "       sc      %0, %2                                  \n"
 193                 "       beqzl   %0, 1b                                  \n"
 194                 "       subu    %0, %1, %3                              \n"
 195                 "       .set    mips0                                   \n"
 196                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 197                 : "Ir" (i), "m" (v->counter)
 198                 : "memory");
 199         } else if (cpu_has_llsc) {
 200                 unsigned long temp;
 201
 202                 __asm__ __volatile__(
 203                 "       .set    mips3                                   \n"
 204                 "1:     ll      %1, %2          # atomic_sub_return     \n"
 205                 "       subu    %0, %1, %3                              \n"
 206                 "       sc      %0, %2                                  \n"
 207                 "       beqz    %0, 1b                                  \n"
 208                 "       subu    %0, %1, %3                              \n"
 209                 "       .set    mips0                                   \n"
 210                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 211                 : "Ir" (i), "m" (v->counter)
 212                 : "memory");
 213         } else {
 214                 unsigned long flags;
 215
 216                 local_irq_save(flags);
 217                 result = v->counter;
 218                 result -= i;
 219                 v->counter = result;
 220                 local_irq_restore(flags);
 221         }
 222
 223         smp_mb();
 224
 225         return result;
 226 }
 227
 228 /*
 229  * atomic_sub_if_positive - conditionally subtract integer from atomic variable
 230  * @i: integer value to subtract
 231  * @v: pointer of type atomic_t
 232  *
 233  * Atomically test @v and subtract @i if @v is greater or equal than @i.
 234  * The function returns the old value of @v minus @i.
 235  */
 236 static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
 237 {
 238         unsigned long result;
 239
 240         smp_mb();
 241
 242         if (cpu_has_llsc && R10000_LLSC_WAR) {
 243                 unsigned long temp;
 244
 245                 __asm__ __volatile__(
 246                 "       .set    mips3                                   \n"
 247                 "1:     ll      %1, %2          # atomic_sub_if_positive\n"
 248                 "       subu    %0, %1, %3                              \n"
 249                 "       bltz    %0, 1f                                  \n"
 250                 "       sc      %0, %2                                  \n"
 251                 "       .set    noreorder                               \n"
 252                 "       beqzl   %0, 1b                                  \n"
 253                 "        subu   %0, %1, %3                              \n"
 254                 "       .set    reorder                                 \n"
 255                 "1:                                                     \n"
 256                 "       .set    mips0                                   \n"
 257                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 258                 : "Ir" (i), "m" (v->counter)
 259                 : "memory");
 260         } else if (cpu_has_llsc) {
 261                 unsigned long temp;
 262
 263                 __asm__ __volatile__(
 264                 "       .set    mips3                                   \n"
 265                 "1:     ll      %1, %2          # atomic_sub_if_positive\n"
 266                 "       subu    %0, %1, %3                              \n"
 267                 "       bltz    %0, 1f                                  \n"
 268                 "       sc      %0, %2                                  \n"
 269                 "       .set    noreorder                               \n"
 270                 "       beqz    %0, 1b                                  \n"
 271                 "        subu   %0, %1, %3                              \n"
 272                 "       .set    reorder                                 \n"
 273                 "1:                                                     \n"
 274                 "       .set    mips0                                   \n"
 275                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 276                 : "Ir" (i), "m" (v->counter)
 277                 : "memory");
 278         } else {
 279                 unsigned long flags;
 280
 281                 local_irq_save(flags);
 282                 result = v->counter;
 283                 result -= i;
 284                 if (result >= 0)
 285                         v->counter = result;
 286                 local_irq_restore(flags);
 287         }
 288
 289         smp_mb();
 290
 291         return result;
 292 }
 293
 294 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
 295 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 296
 297 /**
 298  * atomic_add_unless - add unless the number is a given value
 299  * @v: pointer of type atomic_t
 300  * @a: the amount to add to v...
 301  * @u: ...unless v is equal to u.
 302  *
 303  * Atomically adds @a to @v, so long as it was not @u.
 304  * Returns non-zero if @v was not @u, and zero otherwise.
 305  */
 306 #define atomic_add_unless(v, a, u)                              \
 307 ({                                                              \
 308         int c, old;                                             \
 309         c = atomic_read(v);                                     \
 310         while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
 311                 c = old;                                        \
 312         c != (u);                                               \
 313 })
 314 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 315
 316 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 317 #define atomic_inc_return(v) atomic_add_return(1,(v))
 318
 319 /*
 320  * atomic_sub_and_test - subtract value from variable and test result
 321  * @i: integer value to subtract
 322  * @v: pointer of type atomic_t
 323  *
 324  * Atomically subtracts @i from @v and returns
 325  * true if the result is zero, or false for all
 326  * other cases.
 327  */
 328 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 329
 330 /*
 331  * atomic_inc_and_test - increment and test
 332  * @v: pointer of type atomic_t
 333  *
 334  * Atomically increments @v by 1
 335  * and returns true if the result is zero, or false for all
 336  * other cases.
 337  */
 338 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
 339
 340 /*
 341  * atomic_dec_and_test - decrement by 1 and test
 342  * @v: pointer of type atomic_t
 343  *
 344  * Atomically decrements @v by 1 and
 345  * returns true if the result is 0, or false for all other
 346  * cases.
 347  */
 348 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 349
 350 /*
 351  * atomic_dec_if_positive - decrement by 1 if old value positive
 352  * @v: pointer of type atomic_t
 353  */
 354 #define atomic_dec_if_positive(v)       atomic_sub_if_positive(1, v)
 355
 356 /*
 357  * atomic_inc - increment atomic variable
 358  * @v: pointer of type atomic_t
 359  *
 360  * Atomically increments @v by 1.
 361  */
 362 #define atomic_inc(v) atomic_add(1,(v))
 363
 364 /*
 365  * atomic_dec - decrement and test
 366  * @v: pointer of type atomic_t
 367  *
 368  * Atomically decrements @v by 1.
 369  */
 370 #define atomic_dec(v) atomic_sub(1,(v))
 371
 372 /*
 373  * atomic_add_negative - add and test if negative
 374  * @v: pointer of type atomic_t
 375  * @i: integer value to add
 376  *
 377  * Atomically adds @i to @v and returns true
 378  * if the result is negative, or false when
 379  * result is greater than or equal to zero.
 380  */
 381 #define atomic_add_negative(i,v) (atomic_add_return(i, (v)) < 0)
 382
 383 #ifdef CONFIG_64BIT
 384
 385 typedef struct { volatile long counter; } atomic64_t;
 386
 387 #define ATOMIC64_INIT(i)    { (i) }
 388
 389 /*
 390  * atomic64_read - read atomic variable
 391  * @v: pointer of type atomic64_t
 392  *
 393  */
 394 #define atomic64_read(v)        ((v)->counter)
 395
 396 /*
 397  * atomic64_set - set atomic variable
 398  * @v: pointer of type atomic64_t
 399  * @i: required value
 400  */
 401 #define atomic64_set(v,i)       ((v)->counter = (i))
 402
 403 /*
 404  * atomic64_add - add integer to atomic variable
 405  * @i: integer value to add
 406  * @v: pointer of type atomic64_t
 407  *
 408  * Atomically adds @i to @v.
 409  */
 410 static __inline__ void atomic64_add(long i, atomic64_t * v)
 411 {
 412         if (cpu_has_llsc && R10000_LLSC_WAR) {
 413                 unsigned long temp;
 414
 415                 __asm__ __volatile__(
 416                 "       .set    mips3                                   \n"
 417                 "1:     lld     %0, %1          # atomic64_add          \n"
 418                 "       addu    %0, %2                                  \n"
 419                 "       scd     %0, %1                                  \n"
 420                 "       beqzl   %0, 1b                                  \n"
 421                 "       .set    mips0                                   \n"
 422                 : "=&r" (temp), "=m" (v->counter)
 423                 : "Ir" (i), "m" (v->counter));
 424         } else if (cpu_has_llsc) {
 425                 unsigned long temp;
 426
 427                 __asm__ __volatile__(
 428                 "       .set    mips3                                   \n"
 429                 "1:     lld     %0, %1          # atomic64_add          \n"
 430                 "       addu    %0, %2                                  \n"
 431                 "       scd     %0, %1                                  \n"
 432                 "       beqz    %0, 1b                                  \n"
 433                 "       .set    mips0                                   \n"
 434                 : "=&r" (temp), "=m" (v->counter)
 435                 : "Ir" (i), "m" (v->counter));
 436         } else {
 437                 unsigned long flags;
 438
 439                 local_irq_save(flags);
 440                 v->counter += i;
 441                 local_irq_restore(flags);
 442         }
 443 }
 444
 445 /*
 446  * atomic64_sub - subtract the atomic variable
 447  * @i: integer value to subtract
 448  * @v: pointer of type atomic64_t
 449  *
 450  * Atomically subtracts @i from @v.
 451  */
 452 static __inline__ void atomic64_sub(long i, atomic64_t * v)
 453 {
 454         if (cpu_has_llsc && R10000_LLSC_WAR) {
 455                 unsigned long temp;
 456
 457                 __asm__ __volatile__(
 458                 "       .set    mips3                                   \n"
 459                 "1:     lld     %0, %1          # atomic64_sub          \n"
 460                 "       subu    %0, %2                                  \n"
 461                 "       scd     %0, %1                                  \n"
 462                 "       beqzl   %0, 1b                                  \n"
 463                 "       .set    mips0                                   \n"
 464                 : "=&r" (temp), "=m" (v->counter)
 465                 : "Ir" (i), "m" (v->counter));
 466         } else if (cpu_has_llsc) {
 467                 unsigned long temp;
 468
 469                 __asm__ __volatile__(
 470                 "       .set    mips3                                   \n"
 471                 "1:     lld     %0, %1          # atomic64_sub          \n"
 472                 "       subu    %0, %2                                  \n"
 473                 "       scd     %0, %1                                  \n"
 474                 "       beqz    %0, 1b                                  \n"
 475                 "       .set    mips0                                   \n"
 476                 : "=&r" (temp), "=m" (v->counter)
 477                 : "Ir" (i), "m" (v->counter));
 478         } else {
 479                 unsigned long flags;
 480
 481                 local_irq_save(flags);
 482                 v->counter -= i;
 483                 local_irq_restore(flags);
 484         }
 485 }
 486
 487 /*
 488  * Same as above, but return the result value
 489  */
 490 static __inline__ long atomic64_add_return(long i, atomic64_t * v)
 491 {
 492         unsigned long result;
 493
 494         smp_mb();
 495
 496         if (cpu_has_llsc && R10000_LLSC_WAR) {
 497                 unsigned long temp;
 498
 499                 __asm__ __volatile__(
 500                 "       .set    mips3                                   \n"
 501                 "1:     lld     %1, %2          # atomic64_add_return   \n"
 502                 "       addu    %0, %1, %3                              \n"
 503                 "       scd     %0, %2                                  \n"
 504                 "       beqzl   %0, 1b                                  \n"
 505                 "       addu    %0, %1, %3                              \n"
 506                 "       .set    mips0                                   \n"
 507                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 508                 : "Ir" (i), "m" (v->counter)
 509                 : "memory");
 510         } else if (cpu_has_llsc) {
 511                 unsigned long temp;
 512
 513                 __asm__ __volatile__(
 514                 "       .set    mips3                                   \n"
 515                 "1:     lld     %1, %2          # atomic64_add_return   \n"
 516                 "       addu    %0, %1, %3                              \n"
 517                 "       scd     %0, %2                                  \n"
 518                 "       beqz    %0, 1b                                  \n"
 519                 "       addu    %0, %1, %3                              \n"
 520                 "       .set    mips0                                   \n"
 521                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 522                 : "Ir" (i), "m" (v->counter)
 523                 : "memory");
 524         } else {
 525                 unsigned long flags;
 526
 527                 local_irq_save(flags);
 528                 result = v->counter;
 529                 result += i;
 530                 v->counter = result;
 531                 local_irq_restore(flags);
 532         }
 533
 534         smp_mb();
 535
 536         return result;
 537 }
 538
 539 static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
 540 {
 541         unsigned long result;
 542
 543         smp_mb();
 544
 545         if (cpu_has_llsc && R10000_LLSC_WAR) {
 546                 unsigned long temp;
 547
 548                 __asm__ __volatile__(
 549                 "       .set    mips3                                   \n"
 550                 "1:     lld     %1, %2          # atomic64_sub_return   \n"
 551                 "       subu    %0, %1, %3                              \n"
 552                 "       scd     %0, %2                                  \n"
 553                 "       beqzl   %0, 1b                                  \n"
 554                 "       subu    %0, %1, %3                              \n"
 555                 "       .set    mips0                                   \n"
 556                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 557                 : "Ir" (i), "m" (v->counter)
 558                 : "memory");
 559         } else if (cpu_has_llsc) {
 560                 unsigned long temp;
 561
 562                 __asm__ __volatile__(
 563                 "       .set    mips3                                   \n"
 564                 "1:     lld     %1, %2          # atomic64_sub_return   \n"
 565                 "       subu    %0, %1, %3                              \n"
 566                 "       scd     %0, %2                                  \n"
 567                 "       beqz    %0, 1b                                  \n"
 568                 "       subu    %0, %1, %3                              \n"
 569                 "       .set    mips0                                   \n"
 570                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 571                 : "Ir" (i), "m" (v->counter)
 572                 : "memory");
 573         } else {
 574                 unsigned long flags;
 575
 576                 local_irq_save(flags);
 577                 result = v->counter;
 578                 result -= i;
 579                 v->counter = result;
 580                 local_irq_restore(flags);
 581         }
 582
 583         smp_mb();
 584
 585         return result;
 586 }
 587
 588 /*
 589  * atomic64_sub_if_positive - conditionally subtract integer from atomic variable
 590  * @i: integer value to subtract
 591  * @v: pointer of type atomic64_t
 592  *
 593  * Atomically test @v and subtract @i if @v is greater or equal than @i.
 594  * The function returns the old value of @v minus @i.
 595  */
 596 static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
 597 {
 598         unsigned long result;
 599
 600         smp_mb();
 601
 602         if (cpu_has_llsc && R10000_LLSC_WAR) {
 603                 unsigned long temp;
 604
 605                 __asm__ __volatile__(
 606                 "       .set    mips3                                   \n"
 607                 "1:     lld     %1, %2          # atomic64_sub_if_positive\n"
 608                 "       dsubu   %0, %1, %3                              \n"
 609                 "       bltz    %0, 1f                                  \n"
 610                 "       scd     %0, %2                                  \n"
 611                 "       .set    noreorder                               \n"
 612                 "       beqzl   %0, 1b                                  \n"
 613                 "        dsubu  %0, %1, %3                              \n"
 614                 "       .set    reorder                                 \n"
 615                 "1:                                                     \n"
 616                 "       .set    mips0                                   \n"
 617                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 618                 : "Ir" (i), "m" (v->counter)
 619                 : "memory");
 620         } else if (cpu_has_llsc) {
 621                 unsigned long temp;
 622
 623                 __asm__ __volatile__(
 624                 "       .set    mips3                                   \n"
 625                 "1:     lld     %1, %2          # atomic64_sub_if_positive\n"
 626                 "       dsubu   %0, %1, %3                              \n"
 627                 "       bltz    %0, 1f                                  \n"
 628                 "       scd     %0, %2                                  \n"
 629                 "       .set    noreorder                               \n"
 630                 "       beqz    %0, 1b                                  \n"
 631                 "        dsubu  %0, %1, %3                              \n"
 632                 "       .set    reorder                                 \n"
 633                 "1:                                                     \n"
 634                 "       .set    mips0                                   \n"
 635                 : "=&r" (result), "=&r" (temp), "=m" (v->counter)
 636                 : "Ir" (i), "m" (v->counter)
 637                 : "memory");
 638         } else {
 639                 unsigned long flags;
 640
 641                 local_irq_save(flags);
 642                 result = v->counter;
 643                 result -= i;
 644                 if (result >= 0)
 645                         v->counter = result;
 646                 local_irq_restore(flags);
 647         }
 648
 649         smp_mb();
 650
 651         return result;
 652 }
 653
 654 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 655 #define atomic64_inc_return(v) atomic64_add_return(1,(v))
 656
 657 /*
 658  * atomic64_sub_and_test - subtract value from variable and test result
 659  * @i: integer value to subtract
 660  * @v: pointer of type atomic64_t
 661  *
 662  * Atomically subtracts @i from @v and returns
 663  * true if the result is zero, or false for all
 664  * other cases.
 665  */
 666 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 667
 668 /*
 669  * atomic64_inc_and_test - increment and test
 670  * @v: pointer of type atomic64_t
 671  *
 672  * Atomically increments @v by 1
 673  * and returns true if the result is zero, or false for all
 674  * other cases.
 675  */
 676 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
 677
 678 /*
 679  * atomic64_dec_and_test - decrement by 1 and test
 680  * @v: pointer of type atomic64_t
 681  *
 682  * Atomically decrements @v by 1 and
 683  * returns true if the result is 0, or false for all other
 684  * cases.
 685  */
 686 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 687
 688 /*
 689  * atomic64_dec_if_positive - decrement by 1 if old value positive
 690  * @v: pointer of type atomic64_t
 691  */
 692 #define atomic64_dec_if_positive(v)     atomic64_sub_if_positive(1, v)
 693
 694 /*
 695  * atomic64_inc - increment atomic variable
 696  * @v: pointer of type atomic64_t
 697  *
 698  * Atomically increments @v by 1.
 699  */
 700 #define atomic64_inc(v) atomic64_add(1,(v))
 701
 702 /*
 703  * atomic64_dec - decrement and test
 704  * @v: pointer of type atomic64_t
 705  *
 706  * Atomically decrements @v by 1.
 707  */
 708 #define atomic64_dec(v) atomic64_sub(1,(v))
 709
 710 /*
 711  * atomic64_add_negative - add and test if negative
 712  * @v: pointer of type atomic64_t
 713  * @i: integer value to add
 714  *
 715  * Atomically adds @i to @v and returns true
 716  * if the result is negative, or false when
 717  * result is greater than or equal to zero.
 718  */
 719 #define atomic64_add_negative(i,v) (atomic64_add_return(i, (v)) < 0)
 720
 721 #endif /* CONFIG_64BIT */
 722
 723 /*
 724  * atomic*_return operations are serializing but not the non-*_return
 725  * versions.
 726  */
 727 #define smp_mb__before_atomic_dec()     smp_mb()
 728 #define smp_mb__after_atomic_dec()      smp_mb()
 729 #define smp_mb__before_atomic_inc()     smp_mb()
 730 #define smp_mb__after_atomic_inc()      smp_mb()
 731
 732 #include <asm-generic/atomic.h>
 733 #endif /* _ASM_ATOMIC_H */