linux/include/linux/cpumask.h
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   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
  14typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  15
  16/**
  17 * cpumask_bits - get the bits in a cpumask
  18 * @maskp: the struct cpumask *
  19 *
  20 * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  21 * a macro so it's const-correct.
  22 */
  23#define cpumask_bits(maskp) ((maskp)->bits)
  24
  25/**
  26 * cpumask_pr_args - printf args to output a cpumask
  27 * @maskp: cpumask to be printed
  28 *
  29 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
  30 */
  31#define cpumask_pr_args(maskp)          nr_cpu_ids, cpumask_bits(maskp)
  32
  33#if NR_CPUS == 1
  34#define nr_cpu_ids              1
  35#else
  36extern int nr_cpu_ids;
  37#endif
  38
  39#ifdef CONFIG_CPUMASK_OFFSTACK
  40/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  41 * not all bits may be allocated. */
  42#define nr_cpumask_bits nr_cpu_ids
  43#else
  44#define nr_cpumask_bits NR_CPUS
  45#endif
  46
  47/*
  48 * The following particular system cpumasks and operations manage
  49 * possible, present, active and online cpus.
  50 *
  51 *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  52 *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  53 *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  54 *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  55 *
  56 *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  57 *
  58 *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  59 *  that it is possible might ever be plugged in at anytime during the
  60 *  life of that system boot.  The cpu_present_mask is dynamic(*),
  61 *  representing which CPUs are currently plugged in.  And
  62 *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  63 *  indicating those CPUs available for scheduling.
  64 *
  65 *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  66 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  67 *  ACPI reports present at boot.
  68 *
  69 *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  70 *  depending on what ACPI reports as currently plugged in, otherwise
  71 *  cpu_present_mask is just a copy of cpu_possible_mask.
  72 *
  73 *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  74 *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  75 *
  76 * Subtleties:
  77 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  78 *    assumption that their single CPU is online.  The UP
  79 *    cpu_{online,possible,present}_masks are placebos.  Changing them
  80 *    will have no useful affect on the following num_*_cpus()
  81 *    and cpu_*() macros in the UP case.  This ugliness is a UP
  82 *    optimization - don't waste any instructions or memory references
  83 *    asking if you're online or how many CPUs there are if there is
  84 *    only one CPU.
  85 */
  86
  87extern const struct cpumask *const cpu_possible_mask;
  88extern const struct cpumask *const cpu_online_mask;
  89extern const struct cpumask *const cpu_present_mask;
  90extern const struct cpumask *const cpu_active_mask;
  91
  92#if NR_CPUS > 1
  93#define num_online_cpus()       cpumask_weight(cpu_online_mask)
  94#define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  95#define num_present_cpus()      cpumask_weight(cpu_present_mask)
  96#define num_active_cpus()       cpumask_weight(cpu_active_mask)
  97#define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  98#define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
  99#define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
 100#define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
 101#else
 102#define num_online_cpus()       1U
 103#define num_possible_cpus()     1U
 104#define num_present_cpus()      1U
 105#define num_active_cpus()       1U
 106#define cpu_online(cpu)         ((cpu) == 0)
 107#define cpu_possible(cpu)       ((cpu) == 0)
 108#define cpu_present(cpu)        ((cpu) == 0)
 109#define cpu_active(cpu)         ((cpu) == 0)
 110#endif
 111
 112/* verify cpu argument to cpumask_* operators */
 113static inline unsigned int cpumask_check(unsigned int cpu)
 114{
 115#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 116        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 117#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 118        return cpu;
 119}
 120
 121#if NR_CPUS == 1
 122/* Uniprocessor.  Assume all masks are "1". */
 123static inline unsigned int cpumask_first(const struct cpumask *srcp)
 124{
 125        return 0;
 126}
 127
 128/* Valid inputs for n are -1 and 0. */
 129static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 130{
 131        return n+1;
 132}
 133
 134static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 135{
 136        return n+1;
 137}
 138
 139static inline unsigned int cpumask_next_and(int n,
 140                                            const struct cpumask *srcp,
 141                                            const struct cpumask *andp)
 142{
 143        return n+1;
 144}
 145
 146/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 147static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 148                                           unsigned int cpu)
 149{
 150        return 1;
 151}
 152
 153static inline int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
 154{
 155        set_bit(0, cpumask_bits(dstp));
 156
 157        return 0;
 158}
 159
 160#define for_each_cpu(cpu, mask)                 \
 161        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 162#define for_each_cpu_not(cpu, mask)             \
 163        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 164#define for_each_cpu_and(cpu, mask, and)        \
 165        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 166#else
 167/**
 168 * cpumask_first - get the first cpu in a cpumask
 169 * @srcp: the cpumask pointer
 170 *
 171 * Returns >= nr_cpu_ids if no cpus set.
 172 */
 173static inline unsigned int cpumask_first(const struct cpumask *srcp)
 174{
 175        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 176}
 177
 178/**
 179 * cpumask_next - get the next cpu in a cpumask
 180 * @n: the cpu prior to the place to search (ie. return will be > @n)
 181 * @srcp: the cpumask pointer
 182 *
 183 * Returns >= nr_cpu_ids if no further cpus set.
 184 */
 185static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 186{
 187        /* -1 is a legal arg here. */
 188        if (n != -1)
 189                cpumask_check(n);
 190        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 191}
 192
 193/**
 194 * cpumask_next_zero - get the next unset cpu in a cpumask
 195 * @n: the cpu prior to the place to search (ie. return will be > @n)
 196 * @srcp: the cpumask pointer
 197 *
 198 * Returns >= nr_cpu_ids if no further cpus unset.
 199 */
 200static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 201{
 202        /* -1 is a legal arg here. */
 203        if (n != -1)
 204                cpumask_check(n);
 205        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 206}
 207
 208int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 209int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 210int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp);
 211
 212/**
 213 * for_each_cpu - iterate over every cpu in a mask
 214 * @cpu: the (optionally unsigned) integer iterator
 215 * @mask: the cpumask pointer
 216 *
 217 * After the loop, cpu is >= nr_cpu_ids.
 218 */
 219#define for_each_cpu(cpu, mask)                         \
 220        for ((cpu) = -1;                                \
 221                (cpu) = cpumask_next((cpu), (mask)),    \
 222                (cpu) < nr_cpu_ids;)
 223
 224/**
 225 * for_each_cpu_not - iterate over every cpu in a complemented mask
 226 * @cpu: the (optionally unsigned) integer iterator
 227 * @mask: the cpumask pointer
 228 *
 229 * After the loop, cpu is >= nr_cpu_ids.
 230 */
 231#define for_each_cpu_not(cpu, mask)                             \
 232        for ((cpu) = -1;                                        \
 233                (cpu) = cpumask_next_zero((cpu), (mask)),       \
 234                (cpu) < nr_cpu_ids;)
 235
 236/**
 237 * for_each_cpu_and - iterate over every cpu in both masks
 238 * @cpu: the (optionally unsigned) integer iterator
 239 * @mask: the first cpumask pointer
 240 * @and: the second cpumask pointer
 241 *
 242 * This saves a temporary CPU mask in many places.  It is equivalent to:
 243 *      struct cpumask tmp;
 244 *      cpumask_and(&tmp, &mask, &and);
 245 *      for_each_cpu(cpu, &tmp)
 246 *              ...
 247 *
 248 * After the loop, cpu is >= nr_cpu_ids.
 249 */
 250#define for_each_cpu_and(cpu, mask, and)                                \
 251        for ((cpu) = -1;                                                \
 252                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 253                (cpu) < nr_cpu_ids;)
 254#endif /* SMP */
 255
 256#define CPU_BITS_NONE                                           \
 257{                                                               \
 258        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 259}
 260
 261#define CPU_BITS_CPU0                                           \
 262{                                                               \
 263        [0] =  1UL                                              \
 264}
 265
 266/**
 267 * cpumask_set_cpu - set a cpu in a cpumask
 268 * @cpu: cpu number (< nr_cpu_ids)
 269 * @dstp: the cpumask pointer
 270 */
 271static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 272{
 273        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 274}
 275
 276/**
 277 * cpumask_clear_cpu - clear a cpu in a cpumask
 278 * @cpu: cpu number (< nr_cpu_ids)
 279 * @dstp: the cpumask pointer
 280 */
 281static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 282{
 283        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 284}
 285
 286/**
 287 * cpumask_test_cpu - test for a cpu in a cpumask
 288 * @cpu: cpu number (< nr_cpu_ids)
 289 * @cpumask: the cpumask pointer
 290 *
 291 * Returns 1 if @cpu is set in @cpumask, else returns 0
 292 *
 293 * No static inline type checking - see Subtlety (1) above.
 294 */
 295#define cpumask_test_cpu(cpu, cpumask) \
 296        test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
 297
 298/**
 299 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 300 * @cpu: cpu number (< nr_cpu_ids)
 301 * @cpumask: the cpumask pointer
 302 *
 303 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 304 *
 305 * test_and_set_bit wrapper for cpumasks.
 306 */
 307static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 308{
 309        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 310}
 311
 312/**
 313 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
 314 * @cpu: cpu number (< nr_cpu_ids)
 315 * @cpumask: the cpumask pointer
 316 *
 317 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 318 *
 319 * test_and_clear_bit wrapper for cpumasks.
 320 */
 321static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 322{
 323        return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 324}
 325
 326/**
 327 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 328 * @dstp: the cpumask pointer
 329 */
 330static inline void cpumask_setall(struct cpumask *dstp)
 331{
 332        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 333}
 334
 335/**
 336 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 337 * @dstp: the cpumask pointer
 338 */
 339static inline void cpumask_clear(struct cpumask *dstp)
 340{
 341        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 342}
 343
 344/**
 345 * cpumask_and - *dstp = *src1p & *src2p
 346 * @dstp: the cpumask result
 347 * @src1p: the first input
 348 * @src2p: the second input
 349 *
 350 * If *@dstp is empty, returns 0, else returns 1
 351 */
 352static inline int cpumask_and(struct cpumask *dstp,
 353                               const struct cpumask *src1p,
 354                               const struct cpumask *src2p)
 355{
 356        return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 357                                       cpumask_bits(src2p), nr_cpumask_bits);
 358}
 359
 360/**
 361 * cpumask_or - *dstp = *src1p | *src2p
 362 * @dstp: the cpumask result
 363 * @src1p: the first input
 364 * @src2p: the second input
 365 */
 366static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 367                              const struct cpumask *src2p)
 368{
 369        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 370                                      cpumask_bits(src2p), nr_cpumask_bits);
 371}
 372
 373/**
 374 * cpumask_xor - *dstp = *src1p ^ *src2p
 375 * @dstp: the cpumask result
 376 * @src1p: the first input
 377 * @src2p: the second input
 378 */
 379static inline void cpumask_xor(struct cpumask *dstp,
 380                               const struct cpumask *src1p,
 381                               const struct cpumask *src2p)
 382{
 383        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 384                                       cpumask_bits(src2p), nr_cpumask_bits);
 385}
 386
 387/**
 388 * cpumask_andnot - *dstp = *src1p & ~*src2p
 389 * @dstp: the cpumask result
 390 * @src1p: the first input
 391 * @src2p: the second input
 392 *
 393 * If *@dstp is empty, returns 0, else returns 1
 394 */
 395static inline int cpumask_andnot(struct cpumask *dstp,
 396                                  const struct cpumask *src1p,
 397                                  const struct cpumask *src2p)
 398{
 399        return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 400                                          cpumask_bits(src2p), nr_cpumask_bits);
 401}
 402
 403/**
 404 * cpumask_complement - *dstp = ~*srcp
 405 * @dstp: the cpumask result
 406 * @srcp: the input to invert
 407 */
 408static inline void cpumask_complement(struct cpumask *dstp,
 409                                      const struct cpumask *srcp)
 410{
 411        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 412                                              nr_cpumask_bits);
 413}
 414
 415/**
 416 * cpumask_equal - *src1p == *src2p
 417 * @src1p: the first input
 418 * @src2p: the second input
 419 */
 420static inline bool cpumask_equal(const struct cpumask *src1p,
 421                                const struct cpumask *src2p)
 422{
 423        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 424                                                 nr_cpumask_bits);
 425}
 426
 427/**
 428 * cpumask_intersects - (*src1p & *src2p) != 0
 429 * @src1p: the first input
 430 * @src2p: the second input
 431 */
 432static inline bool cpumask_intersects(const struct cpumask *src1p,
 433                                     const struct cpumask *src2p)
 434{
 435        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 436                                                      nr_cpumask_bits);
 437}
 438
 439/**
 440 * cpumask_subset - (*src1p & ~*src2p) == 0
 441 * @src1p: the first input
 442 * @src2p: the second input
 443 *
 444 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
 445 */
 446static inline int cpumask_subset(const struct cpumask *src1p,
 447                                 const struct cpumask *src2p)
 448{
 449        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 450                                                  nr_cpumask_bits);
 451}
 452
 453/**
 454 * cpumask_empty - *srcp == 0
 455 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 456 */
 457static inline bool cpumask_empty(const struct cpumask *srcp)
 458{
 459        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 460}
 461
 462/**
 463 * cpumask_full - *srcp == 0xFFFFFFFF...
 464 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 465 */
 466static inline bool cpumask_full(const struct cpumask *srcp)
 467{
 468        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 469}
 470
 471/**
 472 * cpumask_weight - Count of bits in *srcp
 473 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 474 */
 475static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 476{
 477        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 478}
 479
 480/**
 481 * cpumask_shift_right - *dstp = *srcp >> n
 482 * @dstp: the cpumask result
 483 * @srcp: the input to shift
 484 * @n: the number of bits to shift by
 485 */
 486static inline void cpumask_shift_right(struct cpumask *dstp,
 487                                       const struct cpumask *srcp, int n)
 488{
 489        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 490                                               nr_cpumask_bits);
 491}
 492
 493/**
 494 * cpumask_shift_left - *dstp = *srcp << n
 495 * @dstp: the cpumask result
 496 * @srcp: the input to shift
 497 * @n: the number of bits to shift by
 498 */
 499static inline void cpumask_shift_left(struct cpumask *dstp,
 500                                      const struct cpumask *srcp, int n)
 501{
 502        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 503                                              nr_cpumask_bits);
 504}
 505
 506/**
 507 * cpumask_copy - *dstp = *srcp
 508 * @dstp: the result
 509 * @srcp: the input cpumask
 510 */
 511static inline void cpumask_copy(struct cpumask *dstp,
 512                                const struct cpumask *srcp)
 513{
 514        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 515}
 516
 517/**
 518 * cpumask_any - pick a "random" cpu from *srcp
 519 * @srcp: the input cpumask
 520 *
 521 * Returns >= nr_cpu_ids if no cpus set.
 522 */
 523#define cpumask_any(srcp) cpumask_first(srcp)
 524
 525/**
 526 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 527 * @src1p: the first input
 528 * @src2p: the second input
 529 *
 530 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 531 */
 532#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 533
 534/**
 535 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 536 * @mask1: the first input cpumask
 537 * @mask2: the second input cpumask
 538 *
 539 * Returns >= nr_cpu_ids if no cpus set.
 540 */
 541#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 542
 543/**
 544 * cpumask_of - the cpumask containing just a given cpu
 545 * @cpu: the cpu (<= nr_cpu_ids)
 546 */
 547#define cpumask_of(cpu) (get_cpu_mask(cpu))
 548
 549/**
 550 * cpumask_parse_user - extract a cpumask from a user string
 551 * @buf: the buffer to extract from
 552 * @len: the length of the buffer
 553 * @dstp: the cpumask to set.
 554 *
 555 * Returns -errno, or 0 for success.
 556 */
 557static inline int cpumask_parse_user(const char __user *buf, int len,
 558                                     struct cpumask *dstp)
 559{
 560        return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 561}
 562
 563/**
 564 * cpumask_parselist_user - extract a cpumask from a user string
 565 * @buf: the buffer to extract from
 566 * @len: the length of the buffer
 567 * @dstp: the cpumask to set.
 568 *
 569 * Returns -errno, or 0 for success.
 570 */
 571static inline int cpumask_parselist_user(const char __user *buf, int len,
 572                                     struct cpumask *dstp)
 573{
 574        return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
 575                                     nr_cpu_ids);
 576}
 577
 578/**
 579 * cpumask_parse - extract a cpumask from from a string
 580 * @buf: the buffer to extract from
 581 * @dstp: the cpumask to set.
 582 *
 583 * Returns -errno, or 0 for success.
 584 */
 585static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
 586{
 587        char *nl = strchr(buf, '\n');
 588        unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
 589
 590        return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 591}
 592
 593/**
 594 * cpulist_parse - extract a cpumask from a user string of ranges
 595 * @buf: the buffer to extract from
 596 * @dstp: the cpumask to set.
 597 *
 598 * Returns -errno, or 0 for success.
 599 */
 600static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 601{
 602        return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpu_ids);
 603}
 604
 605/**
 606 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 607 *
 608 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 609 */
 610static inline size_t cpumask_size(void)
 611{
 612        /* FIXME: Once all cpumask assignments are eliminated, this
 613         * can be nr_cpumask_bits */
 614        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
 615}
 616
 617/*
 618 * cpumask_var_t: struct cpumask for stack usage.
 619 *
 620 * Oh, the wicked games we play!  In order to make kernel coding a
 621 * little more difficult, we typedef cpumask_var_t to an array or a
 622 * pointer: doing &mask on an array is a noop, so it still works.
 623 *
 624 * ie.
 625 *      cpumask_var_t tmpmask;
 626 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 627 *              return -ENOMEM;
 628 *
 629 *        ... use 'tmpmask' like a normal struct cpumask * ...
 630 *
 631 *      free_cpumask_var(tmpmask);
 632 *
 633 *
 634 * However, one notable exception is there. alloc_cpumask_var() allocates
 635 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
 636 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
 637 *
 638 *      cpumask_var_t tmpmask;
 639 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 640 *              return -ENOMEM;
 641 *
 642 *      var = *tmpmask;
 643 *
 644 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
 645 * cpumask_copy() provide safe copy functionality.
 646 *
 647 * Note that there is another evil here: If you define a cpumask_var_t
 648 * as a percpu variable then the way to obtain the address of the cpumask
 649 * structure differently influences what this_cpu_* operation needs to be
 650 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
 651 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
 652 * other type of cpumask_var_t implementation is configured.
 653 */
 654#ifdef CONFIG_CPUMASK_OFFSTACK
 655typedef struct cpumask *cpumask_var_t;
 656
 657#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
 658
 659bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 660bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 661bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 662bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 663void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
 664void free_cpumask_var(cpumask_var_t mask);
 665void free_bootmem_cpumask_var(cpumask_var_t mask);
 666
 667#else
 668typedef struct cpumask cpumask_var_t[1];
 669
 670#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
 671
 672static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 673{
 674        return true;
 675}
 676
 677static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 678                                          int node)
 679{
 680        return true;
 681}
 682
 683static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 684{
 685        cpumask_clear(*mask);
 686        return true;
 687}
 688
 689static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 690                                          int node)
 691{
 692        cpumask_clear(*mask);
 693        return true;
 694}
 695
 696static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 697{
 698}
 699
 700static inline void free_cpumask_var(cpumask_var_t mask)
 701{
 702}
 703
 704static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
 705{
 706}
 707#endif /* CONFIG_CPUMASK_OFFSTACK */
 708
 709/* It's common to want to use cpu_all_mask in struct member initializers,
 710 * so it has to refer to an address rather than a pointer. */
 711extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
 712#define cpu_all_mask to_cpumask(cpu_all_bits)
 713
 714/* First bits of cpu_bit_bitmap are in fact unset. */
 715#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 716
 717#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 718#define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 719#define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
 720
 721/* Wrappers for arch boot code to manipulate normally-constant masks */
 722void set_cpu_possible(unsigned int cpu, bool possible);
 723void set_cpu_present(unsigned int cpu, bool present);
 724void set_cpu_online(unsigned int cpu, bool online);
 725void set_cpu_active(unsigned int cpu, bool active);
 726void init_cpu_present(const struct cpumask *src);
 727void init_cpu_possible(const struct cpumask *src);
 728void init_cpu_online(const struct cpumask *src);
 729
 730/**
 731 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 732 * @bitmap: the bitmap
 733 *
 734 * There are a few places where cpumask_var_t isn't appropriate and
 735 * static cpumasks must be used (eg. very early boot), yet we don't
 736 * expose the definition of 'struct cpumask'.
 737 *
 738 * This does the conversion, and can be used as a constant initializer.
 739 */
 740#define to_cpumask(bitmap)                                              \
 741        ((struct cpumask *)(1 ? (bitmap)                                \
 742                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 743
 744static inline int __check_is_bitmap(const unsigned long *bitmap)
 745{
 746        return 1;
 747}
 748
 749/*
 750 * Special-case data structure for "single bit set only" constant CPU masks.
 751 *
 752 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 753 * padding to the left and the right, and return the constant pointer
 754 * appropriately offset.
 755 */
 756extern const unsigned long
 757        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 758
 759static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 760{
 761        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 762        p -= cpu / BITS_PER_LONG;
 763        return to_cpumask(p);
 764}
 765
 766#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 767
 768#if NR_CPUS <= BITS_PER_LONG
 769#define CPU_BITS_ALL                                            \
 770{                                                               \
 771        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 772}
 773
 774#else /* NR_CPUS > BITS_PER_LONG */
 775
 776#define CPU_BITS_ALL                                            \
 777{                                                               \
 778        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 779        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 780}
 781#endif /* NR_CPUS > BITS_PER_LONG */
 782
 783/**
 784 * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
 785 *      as comma-separated list of cpus or hex values of cpumask
 786 * @list: indicates whether the cpumap must be list
 787 * @mask: the cpumask to copy
 788 * @buf: the buffer to copy into
 789 *
 790 * Returns the length of the (null-terminated) @buf string, zero if
 791 * nothing is copied.
 792 */
 793static inline ssize_t
 794cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
 795{
 796        return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
 797                                      nr_cpu_ids);
 798}
 799
 800/*
 801 *
 802 * From here down, all obsolete.  Use cpumask_ variants!
 803 *
 804 */
 805#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 806#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 807
 808#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 809
 810#if NR_CPUS <= BITS_PER_LONG
 811
 812#define CPU_MASK_ALL                                                    \
 813(cpumask_t) { {                                                         \
 814        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 815} }
 816
 817#else
 818
 819#define CPU_MASK_ALL                                                    \
 820(cpumask_t) { {                                                         \
 821        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 822        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 823} }
 824
 825#endif
 826
 827#define CPU_MASK_NONE                                                   \
 828(cpumask_t) { {                                                         \
 829        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 830} }
 831
 832#define CPU_MASK_CPU0                                                   \
 833(cpumask_t) { {                                                         \
 834        [0] =  1UL                                                      \
 835} }
 836
 837#if NR_CPUS == 1
 838#define first_cpu(src)          ({ (void)(src); 0; })
 839#define next_cpu(n, src)        ({ (void)(src); 1; })
 840#define any_online_cpu(mask)    0
 841#define for_each_cpu_mask(cpu, mask)    \
 842        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 843#else /* NR_CPUS > 1 */
 844int __first_cpu(const cpumask_t *srcp);
 845int __next_cpu(int n, const cpumask_t *srcp);
 846
 847#define first_cpu(src)          __first_cpu(&(src))
 848#define next_cpu(n, src)        __next_cpu((n), &(src))
 849#define any_online_cpu(mask) cpumask_any_and(&mask, cpu_online_mask)
 850#define for_each_cpu_mask(cpu, mask)                    \
 851        for ((cpu) = -1;                                \
 852                (cpu) = next_cpu((cpu), (mask)),        \
 853                (cpu) < NR_CPUS; )
 854#endif /* SMP */
 855
 856#if NR_CPUS <= 64
 857
 858#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 859
 860#else /* NR_CPUS > 64 */
 861
 862int __next_cpu_nr(int n, const cpumask_t *srcp);
 863#define for_each_cpu_mask_nr(cpu, mask)                 \
 864        for ((cpu) = -1;                                \
 865                (cpu) = __next_cpu_nr((cpu), &(mask)),  \
 866                (cpu) < nr_cpu_ids; )
 867
 868#endif /* NR_CPUS > 64 */
 869
 870#define cpus_addr(src) ((src).bits)
 871
 872#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 873static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 874{
 875        set_bit(cpu, dstp->bits);
 876}
 877
 878#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 879static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 880{
 881        clear_bit(cpu, dstp->bits);
 882}
 883
 884#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 885static inline void __cpus_setall(cpumask_t *dstp, unsigned int nbits)
 886{
 887        bitmap_fill(dstp->bits, nbits);
 888}
 889
 890#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 891static inline void __cpus_clear(cpumask_t *dstp, unsigned int nbits)
 892{
 893        bitmap_zero(dstp->bits, nbits);
 894}
 895
 896/* No static inline type checking - see Subtlety (1) above. */
 897#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 898
 899#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 900static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 901{
 902        return test_and_set_bit(cpu, addr->bits);
 903}
 904
 905#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 906static inline int __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 907                                        const cpumask_t *src2p, unsigned int nbits)
 908{
 909        return bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 910}
 911
 912#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 913static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 914                                        const cpumask_t *src2p, unsigned int nbits)
 915{
 916        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 917}
 918
 919#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 920static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 921                                        const cpumask_t *src2p, unsigned int nbits)
 922{
 923        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 924}
 925
 926#define cpus_andnot(dst, src1, src2) \
 927                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 928static inline int __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 929                                        const cpumask_t *src2p, unsigned int nbits)
 930{
 931        return bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 932}
 933
 934#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 935static inline int __cpus_equal(const cpumask_t *src1p,
 936                                        const cpumask_t *src2p, unsigned int nbits)
 937{
 938        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 939}
 940
 941#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 942static inline int __cpus_intersects(const cpumask_t *src1p,
 943                                        const cpumask_t *src2p, unsigned int nbits)
 944{
 945        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 946}
 947
 948#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 949static inline int __cpus_subset(const cpumask_t *src1p,
 950                                        const cpumask_t *src2p, unsigned int nbits)
 951{
 952        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 953}
 954
 955#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 956static inline int __cpus_empty(const cpumask_t *srcp, unsigned int nbits)
 957{
 958        return bitmap_empty(srcp->bits, nbits);
 959}
 960
 961#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 962static inline int __cpus_weight(const cpumask_t *srcp, unsigned int nbits)
 963{
 964        return bitmap_weight(srcp->bits, nbits);
 965}
 966
 967#define cpus_shift_left(dst, src, n) \
 968                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 969static inline void __cpus_shift_left(cpumask_t *dstp,
 970                                        const cpumask_t *srcp, int n, int nbits)
 971{
 972        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 973}
 974#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 975
 976#endif /* __LINUX_CPUMASK_H */
 977