include/linux/cpumask.h

   1 #ifndef __LINUX_CPUMASK_H
   2 #define __LINUX_CPUMASK_H
   3
   4 /*
   5  * Cpumasks provide a bitmap suitable for representing the
   6  * set of CPU's in a system, one bit position per CPU number.  In general,
   7  * only nr_cpu_ids (<= NR_CPUS) bits are valid.
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/threads.h>
  11 #include <linux/bitmap.h>
  12 #include <linux/bug.h>
  13
  14 /* Don't assign or return these: may not be this big! */
  15 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  16
  17 /**
  18  * cpumask_bits - get the bits in a cpumask
  19  * @maskp: the struct cpumask *
  20  *
  21  * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  22  * a macro so it's const-correct.
  23  */
  24 #define cpumask_bits(maskp) ((maskp)->bits)
  25
  26 /**
  27  * cpumask_pr_args - printf args to output a cpumask
  28  * @maskp: cpumask to be printed
  29  *
  30  * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
  31  */
  32 #define cpumask_pr_args(maskp)          nr_cpu_ids, cpumask_bits(maskp)
  33
  34 #if NR_CPUS == 1
  35 #define nr_cpu_ids              1
  36 #else
  37 extern int nr_cpu_ids;
  38 #endif
  39
  40 #ifdef CONFIG_CPUMASK_OFFSTACK
  41 /* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  42  * not all bits may be allocated. */
  43 #define nr_cpumask_bits nr_cpu_ids
  44 #else
  45 #define nr_cpumask_bits NR_CPUS
  46 #endif
  47
  48 /*
  49  * The following particular system cpumasks and operations manage
  50  * possible, present, active and online cpus.
  51  *
  52  *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  53  *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  54  *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  55  *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  56  *
  57  *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  58  *
  59  *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  60  *  that it is possible might ever be plugged in at anytime during the
  61  *  life of that system boot.  The cpu_present_mask is dynamic(*),
  62  *  representing which CPUs are currently plugged in.  And
  63  *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  64  *  indicating those CPUs available for scheduling.
  65  *
  66  *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  67  *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  68  *  ACPI reports present at boot.
  69  *
  70  *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  71  *  depending on what ACPI reports as currently plugged in, otherwise
  72  *  cpu_present_mask is just a copy of cpu_possible_mask.
  73  *
  74  *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  75  *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  76  *
  77  * Subtleties:
  78  * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  79  *    assumption that their single CPU is online.  The UP
  80  *    cpu_{online,possible,present}_masks are placebos.  Changing them
  81  *    will have no useful affect on the following num_*_cpus()
  82  *    and cpu_*() macros in the UP case.  This ugliness is a UP
  83  *    optimization - don't waste any instructions or memory references
  84  *    asking if you're online or how many CPUs there are if there is
  85  *    only one CPU.
  86  */
  87
  88 extern struct cpumask __cpu_possible_mask;
  89 extern struct cpumask __cpu_online_mask;
  90 extern struct cpumask __cpu_present_mask;
  91 extern struct cpumask __cpu_active_mask;
  92 #define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask)
  93 #define cpu_online_mask   ((const struct cpumask *)&__cpu_online_mask)
  94 #define cpu_present_mask  ((const struct cpumask *)&__cpu_present_mask)
  95 #define cpu_active_mask   ((const struct cpumask *)&__cpu_active_mask)
  96
  97 #if NR_CPUS > 1
  98 #define num_online_cpus()       cpumask_weight(cpu_online_mask)
  99 #define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
 100 #define num_present_cpus()      cpumask_weight(cpu_present_mask)
 101 #define num_active_cpus()       cpumask_weight(cpu_active_mask)
 102 #define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
 103 #define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
 104 #define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
 105 #define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
 106 #else
 107 #define num_online_cpus()       1U
 108 #define num_possible_cpus()     1U
 109 #define num_present_cpus()      1U
 110 #define num_active_cpus()       1U
 111 #define cpu_online(cpu)         ((cpu) == 0)
 112 #define cpu_possible(cpu)       ((cpu) == 0)
 113 #define cpu_present(cpu)        ((cpu) == 0)
 114 #define cpu_active(cpu)         ((cpu) == 0)
 115 #endif
 116
 117 /* verify cpu argument to cpumask_* operators */
 118 static inline unsigned int cpumask_check(unsigned int cpu)
 119 {
 120 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
 121         WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 122 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 123         return cpu;
 124 }
 125
 126 #if NR_CPUS == 1
 127 /* Uniprocessor.  Assume all masks are "1". */
 128 static inline unsigned int cpumask_first(const struct cpumask *srcp)
 129 {
 130         return 0;
 131 }
 132
 133 /* Valid inputs for n are -1 and 0. */
 134 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 135 {
 136         return n+1;
 137 }
 138
 139 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 140 {
 141         return n+1;
 142 }
 143
 144 static inline unsigned int cpumask_next_and(int n,
 145                                             const struct cpumask *srcp,
 146                                             const struct cpumask *andp)
 147 {
 148         return n+1;
 149 }
 150
 151 /* cpu must be a valid cpu, ie 0, so there's no other choice. */
 152 static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 153                                            unsigned int cpu)
 154 {
 155         return 1;
 156 }
 157
 158 static inline unsigned int cpumask_local_spread(unsigned int i, int node)
 159 {
 160         return 0;
 161 }
 162
 163 #define for_each_cpu(cpu, mask)                 \
 164         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 165 #define for_each_cpu_not(cpu, mask)             \
 166         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 167 #define for_each_cpu_and(cpu, mask, and)        \
 168         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 169 #else
 170 /**
 171  * cpumask_first - get the first cpu in a cpumask
 172  * @srcp: the cpumask pointer
 173  *
 174  * Returns >= nr_cpu_ids if no cpus set.
 175  */
 176 static inline unsigned int cpumask_first(const struct cpumask *srcp)
 177 {
 178         return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 179 }
 180
 181 /**
 182  * cpumask_next - get the next cpu in a cpumask
 183  * @n: the cpu prior to the place to search (ie. return will be > @n)
 184  * @srcp: the cpumask pointer
 185  *
 186  * Returns >= nr_cpu_ids if no further cpus set.
 187  */
 188 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 189 {
 190         /* -1 is a legal arg here. */
 191         if (n != -1)
 192                 cpumask_check(n);
 193         return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 194 }
 195
 196 /**
 197  * cpumask_next_zero - get the next unset cpu in a cpumask
 198  * @n: the cpu prior to the place to search (ie. return will be > @n)
 199  * @srcp: the cpumask pointer
 200  *
 201  * Returns >= nr_cpu_ids if no further cpus unset.
 202  */
 203 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 204 {
 205         /* -1 is a legal arg here. */
 206         if (n != -1)
 207                 cpumask_check(n);
 208         return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 209 }
 210
 211 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 212 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 213 unsigned int cpumask_local_spread(unsigned int i, int node);
 214
 215 /**
 216  * for_each_cpu - iterate over every cpu in a mask
 217  * @cpu: the (optionally unsigned) integer iterator
 218  * @mask: the cpumask pointer
 219  *
 220  * After the loop, cpu is >= nr_cpu_ids.
 221  */
 222 #define for_each_cpu(cpu, mask)                         \
 223         for ((cpu) = -1;                                \
 224                 (cpu) = cpumask_next((cpu), (mask)),    \
 225                 (cpu) < nr_cpu_ids;)
 226
 227 /**
 228  * for_each_cpu_not - iterate over every cpu in a complemented mask
 229  * @cpu: the (optionally unsigned) integer iterator
 230  * @mask: the cpumask pointer
 231  *
 232  * After the loop, cpu is >= nr_cpu_ids.
 233  */
 234 #define for_each_cpu_not(cpu, mask)                             \
 235         for ((cpu) = -1;                                        \
 236                 (cpu) = cpumask_next_zero((cpu), (mask)),       \
 237                 (cpu) < nr_cpu_ids;)
 238
 239 /**
 240  * for_each_cpu_and - iterate over every cpu in both masks
 241  * @cpu: the (optionally unsigned) integer iterator
 242  * @mask: the first cpumask pointer
 243  * @and: the second cpumask pointer
 244  *
 245  * This saves a temporary CPU mask in many places.  It is equivalent to:
 246  *      struct cpumask tmp;
 247  *      cpumask_and(&tmp, &mask, &and);
 248  *      for_each_cpu(cpu, &tmp)
 249  *              ...
 250  *
 251  * After the loop, cpu is >= nr_cpu_ids.
 252  */
 253 #define for_each_cpu_and(cpu, mask, and)                                \
 254         for ((cpu) = -1;                                                \
 255                 (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 256                 (cpu) < nr_cpu_ids;)
 257 #endif /* SMP */
 258
 259 #define CPU_BITS_NONE                                           \
 260 {                                                               \
 261         [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 262 }
 263
 264 #define CPU_BITS_CPU0                                           \
 265 {                                                               \
 266         [0] =  1UL                                              \
 267 }
 268
 269 /**
 270  * cpumask_set_cpu - set a cpu in a cpumask
 271  * @cpu: cpu number (< nr_cpu_ids)
 272  * @dstp: the cpumask pointer
 273  */
 274 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 275 {
 276         set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 277 }
 278
 279 /**
 280  * cpumask_clear_cpu - clear a cpu in a cpumask
 281  * @cpu: cpu number (< nr_cpu_ids)
 282  * @dstp: the cpumask pointer
 283  */
 284 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 285 {
 286         clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 287 }
 288
 289 /**
 290  * cpumask_test_cpu - test for a cpu in a cpumask
 291  * @cpu: cpu number (< nr_cpu_ids)
 292  * @cpumask: the cpumask pointer
 293  *
 294  * Returns 1 if @cpu is set in @cpumask, else returns 0
 295  */
 296 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
 297 {
 298         return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
 299 }
 300
 301 /**
 302  * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 303  * @cpu: cpu number (< nr_cpu_ids)
 304  * @cpumask: the cpumask pointer
 305  *
 306  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 307  *
 308  * test_and_set_bit wrapper for cpumasks.
 309  */
 310 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 311 {
 312         return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 313 }
 314
 315 /**
 316  * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
 317  * @cpu: cpu number (< nr_cpu_ids)
 318  * @cpumask: the cpumask pointer
 319  *
 320  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 321  *
 322  * test_and_clear_bit wrapper for cpumasks.
 323  */
 324 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 325 {
 326         return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 327 }
 328
 329 /**
 330  * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 331  * @dstp: the cpumask pointer
 332  */
 333 static inline void cpumask_setall(struct cpumask *dstp)
 334 {
 335         bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 336 }
 337
 338 /**
 339  * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 340  * @dstp: the cpumask pointer
 341  */
 342 static inline void cpumask_clear(struct cpumask *dstp)
 343 {
 344         bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 345 }
 346
 347 /**
 348  * cpumask_and - *dstp = *src1p & *src2p
 349  * @dstp: the cpumask result
 350  * @src1p: the first input
 351  * @src2p: the second input
 352  *
 353  * If *@dstp is empty, returns 0, else returns 1
 354  */
 355 static inline int cpumask_and(struct cpumask *dstp,
 356                                const struct cpumask *src1p,
 357                                const struct cpumask *src2p)
 358 {
 359         return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 360                                        cpumask_bits(src2p), nr_cpumask_bits);
 361 }
 362
 363 /**
 364  * cpumask_or - *dstp = *src1p | *src2p
 365  * @dstp: the cpumask result
 366  * @src1p: the first input
 367  * @src2p: the second input
 368  */
 369 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 370                               const struct cpumask *src2p)
 371 {
 372         bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 373                                       cpumask_bits(src2p), nr_cpumask_bits);
 374 }
 375
 376 /**
 377  * cpumask_xor - *dstp = *src1p ^ *src2p
 378  * @dstp: the cpumask result
 379  * @src1p: the first input
 380  * @src2p: the second input
 381  */
 382 static inline void cpumask_xor(struct cpumask *dstp,
 383                                const struct cpumask *src1p,
 384                                const struct cpumask *src2p)
 385 {
 386         bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 387                                        cpumask_bits(src2p), nr_cpumask_bits);
 388 }
 389
 390 /**
 391  * cpumask_andnot - *dstp = *src1p & ~*src2p
 392  * @dstp: the cpumask result
 393  * @src1p: the first input
 394  * @src2p: the second input
 395  *
 396  * If *@dstp is empty, returns 0, else returns 1
 397  */
 398 static inline int cpumask_andnot(struct cpumask *dstp,
 399                                   const struct cpumask *src1p,
 400                                   const struct cpumask *src2p)
 401 {
 402         return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 403                                           cpumask_bits(src2p), nr_cpumask_bits);
 404 }
 405
 406 /**
 407  * cpumask_complement - *dstp = ~*srcp
 408  * @dstp: the cpumask result
 409  * @srcp: the input to invert
 410  */
 411 static inline void cpumask_complement(struct cpumask *dstp,
 412                                       const struct cpumask *srcp)
 413 {
 414         bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 415                                               nr_cpumask_bits);
 416 }
 417
 418 /**
 419  * cpumask_equal - *src1p == *src2p
 420  * @src1p: the first input
 421  * @src2p: the second input
 422  */
 423 static inline bool cpumask_equal(const struct cpumask *src1p,
 424                                 const struct cpumask *src2p)
 425 {
 426         return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 427                                                  nr_cpumask_bits);
 428 }
 429
 430 /**
 431  * cpumask_intersects - (*src1p & *src2p) != 0
 432  * @src1p: the first input
 433  * @src2p: the second input
 434  */
 435 static inline bool cpumask_intersects(const struct cpumask *src1p,
 436                                      const struct cpumask *src2p)
 437 {
 438         return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 439                                                       nr_cpumask_bits);
 440 }
 441
 442 /**
 443  * cpumask_subset - (*src1p & ~*src2p) == 0
 444  * @src1p: the first input
 445  * @src2p: the second input
 446  *
 447  * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
 448  */
 449 static inline int cpumask_subset(const struct cpumask *src1p,
 450                                  const struct cpumask *src2p)
 451 {
 452         return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 453                                                   nr_cpumask_bits);
 454 }
 455
 456 /**
 457  * cpumask_empty - *srcp == 0
 458  * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 459  */
 460 static inline bool cpumask_empty(const struct cpumask *srcp)
 461 {
 462         return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 463 }
 464
 465 /**
 466  * cpumask_full - *srcp == 0xFFFFFFFF...
 467  * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 468  */
 469 static inline bool cpumask_full(const struct cpumask *srcp)
 470 {
 471         return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 472 }
 473
 474 /**
 475  * cpumask_weight - Count of bits in *srcp
 476  * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 477  */
 478 static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 479 {
 480         return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 481 }
 482
 483 /**
 484  * cpumask_shift_right - *dstp = *srcp >> n
 485  * @dstp: the cpumask result
 486  * @srcp: the input to shift
 487  * @n: the number of bits to shift by
 488  */
 489 static inline void cpumask_shift_right(struct cpumask *dstp,
 490                                        const struct cpumask *srcp, int n)
 491 {
 492         bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 493                                                nr_cpumask_bits);
 494 }
 495
 496 /**
 497  * cpumask_shift_left - *dstp = *srcp << n
 498  * @dstp: the cpumask result
 499  * @srcp: the input to shift
 500  * @n: the number of bits to shift by
 501  */
 502 static inline void cpumask_shift_left(struct cpumask *dstp,
 503                                       const struct cpumask *srcp, int n)
 504 {
 505         bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 506                                               nr_cpumask_bits);
 507 }
 508
 509 /**
 510  * cpumask_copy - *dstp = *srcp
 511  * @dstp: the result
 512  * @srcp: the input cpumask
 513  */
 514 static inline void cpumask_copy(struct cpumask *dstp,
 515                                 const struct cpumask *srcp)
 516 {
 517         bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 518 }
 519
 520 /**
 521  * cpumask_any - pick a "random" cpu from *srcp
 522  * @srcp: the input cpumask
 523  *
 524  * Returns >= nr_cpu_ids if no cpus set.
 525  */
 526 #define cpumask_any(srcp) cpumask_first(srcp)
 527
 528 /**
 529  * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 530  * @src1p: the first input
 531  * @src2p: the second input
 532  *
 533  * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 534  */
 535 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 536
 537 /**
 538  * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 539  * @mask1: the first input cpumask
 540  * @mask2: the second input cpumask
 541  *
 542  * Returns >= nr_cpu_ids if no cpus set.
 543  */
 544 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 545
 546 /**
 547  * cpumask_of - the cpumask containing just a given cpu
 548  * @cpu: the cpu (<= nr_cpu_ids)
 549  */
 550 #define cpumask_of(cpu) (get_cpu_mask(cpu))
 551
 552 /**
 553  * cpumask_parse_user - extract a cpumask from a user string
 554  * @buf: the buffer to extract from
 555  * @len: the length of the buffer
 556  * @dstp: the cpumask to set.
 557  *
 558  * Returns -errno, or 0 for success.
 559  */
 560 static inline int cpumask_parse_user(const char __user *buf, int len,
 561                                      struct cpumask *dstp)
 562 {
 563         return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 564 }
 565
 566 /**
 567  * cpumask_parselist_user - extract a cpumask from a user string
 568  * @buf: the buffer to extract from
 569  * @len: the length of the buffer
 570  * @dstp: the cpumask to set.
 571  *
 572  * Returns -errno, or 0 for success.
 573  */
 574 static inline int cpumask_parselist_user(const char __user *buf, int len,
 575                                      struct cpumask *dstp)
 576 {
 577         return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
 578                                      nr_cpu_ids);
 579 }
 580
 581 /**
 582  * cpumask_parse - extract a cpumask from from a string
 583  * @buf: the buffer to extract from
 584  * @dstp: the cpumask to set.
 585  *
 586  * Returns -errno, or 0 for success.
 587  */
 588 static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
 589 {
 590         char *nl = strchr(buf, '\n');
 591         unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
 592
 593         return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 594 }
 595
 596 /**
 597  * cpulist_parse - extract a cpumask from a user string of ranges
 598  * @buf: the buffer to extract from
 599  * @dstp: the cpumask to set.
 600  *
 601  * Returns -errno, or 0 for success.
 602  */
 603 static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 604 {
 605         return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpu_ids);
 606 }
 607
 608 /**
 609  * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 610  */
 611 static inline size_t cpumask_size(void)
 612 {
 613         return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
 614 }
 615
 616 /*
 617  * cpumask_var_t: struct cpumask for stack usage.
 618  *
 619  * Oh, the wicked games we play!  In order to make kernel coding a
 620  * little more difficult, we typedef cpumask_var_t to an array or a
 621  * pointer: doing &mask on an array is a noop, so it still works.
 622  *
 623  * ie.
 624  *      cpumask_var_t tmpmask;
 625  *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 626  *              return -ENOMEM;
 627  *
 628  *        ... use 'tmpmask' like a normal struct cpumask * ...
 629  *
 630  *      free_cpumask_var(tmpmask);
 631  *
 632  *
 633  * However, one notable exception is there. alloc_cpumask_var() allocates
 634  * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
 635  * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
 636  *
 637  *      cpumask_var_t tmpmask;
 638  *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 639  *              return -ENOMEM;
 640  *
 641  *      var = *tmpmask;
 642  *
 643  * This code makes NR_CPUS length memcopy and brings to a memory corruption.
 644  * cpumask_copy() provide safe copy functionality.
 645  *
 646  * Note that there is another evil here: If you define a cpumask_var_t
 647  * as a percpu variable then the way to obtain the address of the cpumask
 648  * structure differently influences what this_cpu_* operation needs to be
 649  * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
 650  * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
 651  * other type of cpumask_var_t implementation is configured.
 652  */
 653 #ifdef CONFIG_CPUMASK_OFFSTACK
 654 typedef struct cpumask *cpumask_var_t;
 655
 656 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
 657
 658 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 659 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 660 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 661 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 662 void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
 663 void free_cpumask_var(cpumask_var_t mask);
 664 void free_bootmem_cpumask_var(cpumask_var_t mask);
 665
 666 #else
 667 typedef struct cpumask cpumask_var_t[1];
 668
 669 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
 670
 671 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 672 {
 673         return true;
 674 }
 675
 676 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 677                                           int node)
 678 {
 679         return true;
 680 }
 681
 682 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 683 {
 684         cpumask_clear(*mask);
 685         return true;
 686 }
 687
 688 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 689                                           int node)
 690 {
 691         cpumask_clear(*mask);
 692         return true;
 693 }
 694
 695 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 696 {
 697 }
 698
 699 static inline void free_cpumask_var(cpumask_var_t mask)
 700 {
 701 }
 702
 703 static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
 704 {
 705 }
 706 #endif /* CONFIG_CPUMASK_OFFSTACK */
 707
 708 /* It's common to want to use cpu_all_mask in struct member initializers,
 709  * so it has to refer to an address rather than a pointer. */
 710 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
 711 #define cpu_all_mask to_cpumask(cpu_all_bits)
 712
 713 /* First bits of cpu_bit_bitmap are in fact unset. */
 714 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 715
 716 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 717 #define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 718 #define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
 719
 720 /* Wrappers for arch boot code to manipulate normally-constant masks */
 721 void init_cpu_present(const struct cpumask *src);
 722 void init_cpu_possible(const struct cpumask *src);
 723 void init_cpu_online(const struct cpumask *src);
 724
 725 static inline void
 726 set_cpu_possible(unsigned int cpu, bool possible)
 727 {
 728         if (possible)
 729                 cpumask_set_cpu(cpu, &__cpu_possible_mask);
 730         else
 731                 cpumask_clear_cpu(cpu, &__cpu_possible_mask);
 732 }
 733
 734 static inline void
 735 set_cpu_present(unsigned int cpu, bool present)
 736 {
 737         if (present)
 738                 cpumask_set_cpu(cpu, &__cpu_present_mask);
 739         else
 740                 cpumask_clear_cpu(cpu, &__cpu_present_mask);
 741 }
 742
 743 static inline void
 744 set_cpu_online(unsigned int cpu, bool online)
 745 {
 746         if (online)
 747                 cpumask_set_cpu(cpu, &__cpu_online_mask);
 748         else
 749                 cpumask_clear_cpu(cpu, &__cpu_online_mask);
 750 }
 751
 752 static inline void
 753 set_cpu_active(unsigned int cpu, bool active)
 754 {
 755         if (active)
 756                 cpumask_set_cpu(cpu, &__cpu_active_mask);
 757         else
 758                 cpumask_clear_cpu(cpu, &__cpu_active_mask);
 759 }
 760
 761
 762 /**
 763  * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 764  * @bitmap: the bitmap
 765  *
 766  * There are a few places where cpumask_var_t isn't appropriate and
 767  * static cpumasks must be used (eg. very early boot), yet we don't
 768  * expose the definition of 'struct cpumask'.
 769  *
 770  * This does the conversion, and can be used as a constant initializer.
 771  */
 772 #define to_cpumask(bitmap)                                              \
 773         ((struct cpumask *)(1 ? (bitmap)                                \
 774                             : (void *)sizeof(__check_is_bitmap(bitmap))))
 775
 776 static inline int __check_is_bitmap(const unsigned long *bitmap)
 777 {
 778         return 1;
 779 }
 780
 781 /*
 782  * Special-case data structure for "single bit set only" constant CPU masks.
 783  *
 784  * We pre-generate all the 64 (or 32) possible bit positions, with enough
 785  * padding to the left and the right, and return the constant pointer
 786  * appropriately offset.
 787  */
 788 extern const unsigned long
 789         cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 790
 791 static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 792 {
 793         const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 794         p -= cpu / BITS_PER_LONG;
 795         return to_cpumask(p);
 796 }
 797
 798 #define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 799
 800 #if NR_CPUS <= BITS_PER_LONG
 801 #define CPU_BITS_ALL                                            \
 802 {                                                               \
 803         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 804 }
 805
 806 #else /* NR_CPUS > BITS_PER_LONG */
 807
 808 #define CPU_BITS_ALL                                            \
 809 {                                                               \
 810         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 811         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 812 }
 813 #endif /* NR_CPUS > BITS_PER_LONG */
 814
 815 /**
 816  * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
 817  *      as comma-separated list of cpus or hex values of cpumask
 818  * @list: indicates whether the cpumap must be list
 819  * @mask: the cpumask to copy
 820  * @buf: the buffer to copy into
 821  *
 822  * Returns the length of the (null-terminated) @buf string, zero if
 823  * nothing is copied.
 824  */
 825 static inline ssize_t
 826 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
 827 {
 828         return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
 829                                       nr_cpu_ids);
 830 }
 831
 832 #if NR_CPUS <= BITS_PER_LONG
 833 #define CPU_MASK_ALL                                                    \
 834 (cpumask_t) { {                                                         \
 835         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 836 } }
 837 #else
 838 #define CPU_MASK_ALL                                                    \
 839 (cpumask_t) { {                                                         \
 840         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 841         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 842 } }
 843 #endif /* NR_CPUS > BITS_PER_LONG */
 844
 845 #define CPU_MASK_NONE                                                   \
 846 (cpumask_t) { {                                                         \
 847         [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 848 } }
 849
 850 #define CPU_MASK_CPU0                                                   \
 851 (cpumask_t) { {                                                         \
 852         [0] =  1UL                                                      \
 853 } }
 854
 855 #endif /* __LINUX_CPUMASK_H */