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 const struct cpumask *const cpu_possible_mask;
  89 extern const struct cpumask *const cpu_online_mask;
  90 extern const struct cpumask *const cpu_present_mask;
  91 extern const struct cpumask *const cpu_active_mask;
  92
  93 #if NR_CPUS > 1
  94 #define num_online_cpus()       cpumask_weight(cpu_online_mask)
  95 #define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  96 #define num_present_cpus()      cpumask_weight(cpu_present_mask)
  97 #define num_active_cpus()       cpumask_weight(cpu_active_mask)
  98 #define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  99 #define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
 100 #define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
 101 #define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
 102 #else
 103 #define num_online_cpus()       1U
 104 #define num_possible_cpus()     1U
 105 #define num_present_cpus()      1U
 106 #define num_active_cpus()       1U
 107 #define cpu_online(cpu)         ((cpu) == 0)
 108 #define cpu_possible(cpu)       ((cpu) == 0)
 109 #define cpu_present(cpu)        ((cpu) == 0)
 110 #define cpu_active(cpu)         ((cpu) == 0)
 111 #endif
 112
 113 /* verify cpu argument to cpumask_* operators */
 114 static inline unsigned int cpumask_check(unsigned int cpu)
 115 {
 116 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
 117         WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 118 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 119         return cpu;
 120 }
 121
 122 #if NR_CPUS == 1
 123 /* Uniprocessor.  Assume all masks are "1". */
 124 static inline unsigned int cpumask_first(const struct cpumask *srcp)
 125 {
 126         return 0;
 127 }
 128
 129 /* Valid inputs for n are -1 and 0. */
 130 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 131 {
 132         return n+1;
 133 }
 134
 135 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 136 {
 137         return n+1;
 138 }
 139
 140 static inline unsigned int cpumask_next_and(int n,
 141                                             const struct cpumask *srcp,
 142                                             const struct cpumask *andp)
 143 {
 144         return n+1;
 145 }
 146
 147 /* cpu must be a valid cpu, ie 0, so there's no other choice. */
 148 static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 149                                            unsigned int cpu)
 150 {
 151         return 1;
 152 }
 153
 154 static inline int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp)
 155 {
 156         set_bit(0, cpumask_bits(dstp));
 157
 158         return 0;
 159 }
 160
 161 #define for_each_cpu(cpu, mask)                 \
 162         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 163 #define for_each_cpu_not(cpu, mask)             \
 164         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 165 #define for_each_cpu_and(cpu, mask, and)        \
 166         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 167 #else
 168 /**
 169  * cpumask_first - get the first cpu in a cpumask
 170  * @srcp: the cpumask pointer
 171  *
 172  * Returns >= nr_cpu_ids if no cpus set.
 173  */
 174 static inline unsigned int cpumask_first(const struct cpumask *srcp)
 175 {
 176         return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 177 }
 178
 179 /**
 180  * cpumask_next - get the next cpu in a cpumask
 181  * @n: the cpu prior to the place to search (ie. return will be > @n)
 182  * @srcp: the cpumask pointer
 183  *
 184  * Returns >= nr_cpu_ids if no further cpus set.
 185  */
 186 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 187 {
 188         /* -1 is a legal arg here. */
 189         if (n != -1)
 190                 cpumask_check(n);
 191         return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 192 }
 193
 194 /**
 195  * cpumask_next_zero - get the next unset cpu in a cpumask
 196  * @n: the cpu prior to the place to search (ie. return will be > @n)
 197  * @srcp: the cpumask pointer
 198  *
 199  * Returns >= nr_cpu_ids if no further cpus unset.
 200  */
 201 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 202 {
 203         /* -1 is a legal arg here. */
 204         if (n != -1)
 205                 cpumask_check(n);
 206         return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 207 }
 208
 209 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 210 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 211 int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp);
 212
 213 /**
 214  * for_each_cpu - iterate over every cpu in a mask
 215  * @cpu: the (optionally unsigned) integer iterator
 216  * @mask: the cpumask pointer
 217  *
 218  * After the loop, cpu is >= nr_cpu_ids.
 219  */
 220 #define for_each_cpu(cpu, mask)                         \
 221         for ((cpu) = -1;                                \
 222                 (cpu) = cpumask_next((cpu), (mask)),    \
 223                 (cpu) < nr_cpu_ids;)
 224
 225 /**
 226  * for_each_cpu_not - iterate over every cpu in a complemented mask
 227  * @cpu: the (optionally unsigned) integer iterator
 228  * @mask: the cpumask pointer
 229  *
 230  * After the loop, cpu is >= nr_cpu_ids.
 231  */
 232 #define for_each_cpu_not(cpu, mask)                             \
 233         for ((cpu) = -1;                                        \
 234                 (cpu) = cpumask_next_zero((cpu), (mask)),       \
 235                 (cpu) < nr_cpu_ids;)
 236
 237 /**
 238  * for_each_cpu_and - iterate over every cpu in both masks
 239  * @cpu: the (optionally unsigned) integer iterator
 240  * @mask: the first cpumask pointer
 241  * @and: the second cpumask pointer
 242  *
 243  * This saves a temporary CPU mask in many places.  It is equivalent to:
 244  *      struct cpumask tmp;
 245  *      cpumask_and(&tmp, &mask, &and);
 246  *      for_each_cpu(cpu, &tmp)
 247  *              ...
 248  *
 249  * After the loop, cpu is >= nr_cpu_ids.
 250  */
 251 #define for_each_cpu_and(cpu, mask, and)                                \
 252         for ((cpu) = -1;                                                \
 253                 (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 254                 (cpu) < nr_cpu_ids;)
 255 #endif /* SMP */
 256
 257 #define CPU_BITS_NONE                                           \
 258 {                                                               \
 259         [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 260 }
 261
 262 #define CPU_BITS_CPU0                                           \
 263 {                                                               \
 264         [0] =  1UL                                              \
 265 }
 266
 267 /**
 268  * cpumask_set_cpu - set a cpu in a cpumask
 269  * @cpu: cpu number (< nr_cpu_ids)
 270  * @dstp: the cpumask pointer
 271  */
 272 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 273 {
 274         set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 275 }
 276
 277 /**
 278  * cpumask_clear_cpu - clear a cpu in a cpumask
 279  * @cpu: cpu number (< nr_cpu_ids)
 280  * @dstp: the cpumask pointer
 281  */
 282 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 283 {
 284         clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 285 }
 286
 287 /**
 288  * cpumask_test_cpu - test for a cpu in a cpumask
 289  * @cpu: cpu number (< nr_cpu_ids)
 290  * @cpumask: the cpumask pointer
 291  *
 292  * Returns 1 if @cpu is set in @cpumask, else returns 0
 293  */
 294 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
 295 {
 296         return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
 297 }
 298
 299 /**
 300  * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 301  * @cpu: cpu number (< nr_cpu_ids)
 302  * @cpumask: the cpumask pointer
 303  *
 304  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 305  *
 306  * test_and_set_bit wrapper for cpumasks.
 307  */
 308 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 309 {
 310         return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 311 }
 312
 313 /**
 314  * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
 315  * @cpu: cpu number (< nr_cpu_ids)
 316  * @cpumask: the cpumask pointer
 317  *
 318  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 319  *
 320  * test_and_clear_bit wrapper for cpumasks.
 321  */
 322 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 323 {
 324         return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 325 }
 326
 327 /**
 328  * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 329  * @dstp: the cpumask pointer
 330  */
 331 static inline void cpumask_setall(struct cpumask *dstp)
 332 {
 333         bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 334 }
 335
 336 /**
 337  * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 338  * @dstp: the cpumask pointer
 339  */
 340 static inline void cpumask_clear(struct cpumask *dstp)
 341 {
 342         bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 343 }
 344
 345 /**
 346  * cpumask_and - *dstp = *src1p & *src2p
 347  * @dstp: the cpumask result
 348  * @src1p: the first input
 349  * @src2p: the second input
 350  *
 351  * If *@dstp is empty, returns 0, else returns 1
 352  */
 353 static inline int cpumask_and(struct cpumask *dstp,
 354                                const struct cpumask *src1p,
 355                                const struct cpumask *src2p)
 356 {
 357         return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 358                                        cpumask_bits(src2p), nr_cpumask_bits);
 359 }
 360
 361 /**
 362  * cpumask_or - *dstp = *src1p | *src2p
 363  * @dstp: the cpumask result
 364  * @src1p: the first input
 365  * @src2p: the second input
 366  */
 367 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 368                               const struct cpumask *src2p)
 369 {
 370         bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 371                                       cpumask_bits(src2p), nr_cpumask_bits);
 372 }
 373
 374 /**
 375  * cpumask_xor - *dstp = *src1p ^ *src2p
 376  * @dstp: the cpumask result
 377  * @src1p: the first input
 378  * @src2p: the second input
 379  */
 380 static inline void cpumask_xor(struct cpumask *dstp,
 381                                const struct cpumask *src1p,
 382                                const struct cpumask *src2p)
 383 {
 384         bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 385                                        cpumask_bits(src2p), nr_cpumask_bits);
 386 }
 387
 388 /**
 389  * cpumask_andnot - *dstp = *src1p & ~*src2p
 390  * @dstp: the cpumask result
 391  * @src1p: the first input
 392  * @src2p: the second input
 393  *
 394  * If *@dstp is empty, returns 0, else returns 1
 395  */
 396 static inline int cpumask_andnot(struct cpumask *dstp,
 397                                   const struct cpumask *src1p,
 398                                   const struct cpumask *src2p)
 399 {
 400         return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 401                                           cpumask_bits(src2p), nr_cpumask_bits);
 402 }
 403
 404 /**
 405  * cpumask_complement - *dstp = ~*srcp
 406  * @dstp: the cpumask result
 407  * @srcp: the input to invert
 408  */
 409 static inline void cpumask_complement(struct cpumask *dstp,
 410                                       const struct cpumask *srcp)
 411 {
 412         bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 413                                               nr_cpumask_bits);
 414 }
 415
 416 /**
 417  * cpumask_equal - *src1p == *src2p
 418  * @src1p: the first input
 419  * @src2p: the second input
 420  */
 421 static inline bool cpumask_equal(const struct cpumask *src1p,
 422                                 const struct cpumask *src2p)
 423 {
 424         return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 425                                                  nr_cpumask_bits);
 426 }
 427
 428 /**
 429  * cpumask_intersects - (*src1p & *src2p) != 0
 430  * @src1p: the first input
 431  * @src2p: the second input
 432  */
 433 static inline bool cpumask_intersects(const struct cpumask *src1p,
 434                                      const struct cpumask *src2p)
 435 {
 436         return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 437                                                       nr_cpumask_bits);
 438 }
 439
 440 /**
 441  * cpumask_subset - (*src1p & ~*src2p) == 0
 442  * @src1p: the first input
 443  * @src2p: the second input
 444  *
 445  * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
 446  */
 447 static inline int cpumask_subset(const struct cpumask *src1p,
 448                                  const struct cpumask *src2p)
 449 {
 450         return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 451                                                   nr_cpumask_bits);
 452 }
 453
 454 /**
 455  * cpumask_empty - *srcp == 0
 456  * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 457  */
 458 static inline bool cpumask_empty(const struct cpumask *srcp)
 459 {
 460         return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 461 }
 462
 463 /**
 464  * cpumask_full - *srcp == 0xFFFFFFFF...
 465  * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 466  */
 467 static inline bool cpumask_full(const struct cpumask *srcp)
 468 {
 469         return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 470 }
 471
 472 /**
 473  * cpumask_weight - Count of bits in *srcp
 474  * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 475  */
 476 static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 477 {
 478         return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 479 }
 480
 481 /**
 482  * cpumask_shift_right - *dstp = *srcp >> n
 483  * @dstp: the cpumask result
 484  * @srcp: the input to shift
 485  * @n: the number of bits to shift by
 486  */
 487 static inline void cpumask_shift_right(struct cpumask *dstp,
 488                                        const struct cpumask *srcp, int n)
 489 {
 490         bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 491                                                nr_cpumask_bits);
 492 }
 493
 494 /**
 495  * cpumask_shift_left - *dstp = *srcp << n
 496  * @dstp: the cpumask result
 497  * @srcp: the input to shift
 498  * @n: the number of bits to shift by
 499  */
 500 static inline void cpumask_shift_left(struct cpumask *dstp,
 501                                       const struct cpumask *srcp, int n)
 502 {
 503         bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 504                                               nr_cpumask_bits);
 505 }
 506
 507 /**
 508  * cpumask_copy - *dstp = *srcp
 509  * @dstp: the result
 510  * @srcp: the input cpumask
 511  */
 512 static inline void cpumask_copy(struct cpumask *dstp,
 513                                 const struct cpumask *srcp)
 514 {
 515         bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 516 }
 517
 518 /**
 519  * cpumask_any - pick a "random" cpu from *srcp
 520  * @srcp: the input cpumask
 521  *
 522  * Returns >= nr_cpu_ids if no cpus set.
 523  */
 524 #define cpumask_any(srcp) cpumask_first(srcp)
 525
 526 /**
 527  * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 528  * @src1p: the first input
 529  * @src2p: the second input
 530  *
 531  * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 532  */
 533 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 534
 535 /**
 536  * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 537  * @mask1: the first input cpumask
 538  * @mask2: the second input cpumask
 539  *
 540  * Returns >= nr_cpu_ids if no cpus set.
 541  */
 542 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 543
 544 /**
 545  * cpumask_of - the cpumask containing just a given cpu
 546  * @cpu: the cpu (<= nr_cpu_ids)
 547  */
 548 #define cpumask_of(cpu) (get_cpu_mask(cpu))
 549
 550 /**
 551  * cpumask_parse_user - extract a cpumask from a user string
 552  * @buf: the buffer to extract from
 553  * @len: the length of the buffer
 554  * @dstp: the cpumask to set.
 555  *
 556  * Returns -errno, or 0 for success.
 557  */
 558 static inline int cpumask_parse_user(const char __user *buf, int len,
 559                                      struct cpumask *dstp)
 560 {
 561         return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 562 }
 563
 564 /**
 565  * cpumask_parselist_user - extract a cpumask from a user string
 566  * @buf: the buffer to extract from
 567  * @len: the length of the buffer
 568  * @dstp: the cpumask to set.
 569  *
 570  * Returns -errno, or 0 for success.
 571  */
 572 static inline int cpumask_parselist_user(const char __user *buf, int len,
 573                                      struct cpumask *dstp)
 574 {
 575         return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
 576                                      nr_cpu_ids);
 577 }
 578
 579 /**
 580  * cpumask_parse - extract a cpumask from from a string
 581  * @buf: the buffer to extract from
 582  * @dstp: the cpumask to set.
 583  *
 584  * Returns -errno, or 0 for success.
 585  */
 586 static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
 587 {
 588         char *nl = strchr(buf, '\n');
 589         unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
 590
 591         return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpu_ids);
 592 }
 593
 594 /**
 595  * cpulist_parse - extract a cpumask from a user string of ranges
 596  * @buf: the buffer to extract from
 597  * @dstp: the cpumask to set.
 598  *
 599  * Returns -errno, or 0 for success.
 600  */
 601 static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 602 {
 603         return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpu_ids);
 604 }
 605
 606 /**
 607  * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 608  *
 609  * This will eventually be a runtime variable, depending on nr_cpu_ids.
 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 set_cpu_possible(unsigned int cpu, bool possible);
 722 void set_cpu_present(unsigned int cpu, bool present);
 723 void set_cpu_online(unsigned int cpu, bool online);
 724 void set_cpu_active(unsigned int cpu, bool active);
 725 void init_cpu_present(const struct cpumask *src);
 726 void init_cpu_possible(const struct cpumask *src);
 727 void init_cpu_online(const struct cpumask *src);
 728
 729 /**
 730  * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 731  * @bitmap: the bitmap
 732  *
 733  * There are a few places where cpumask_var_t isn't appropriate and
 734  * static cpumasks must be used (eg. very early boot), yet we don't
 735  * expose the definition of 'struct cpumask'.
 736  *
 737  * This does the conversion, and can be used as a constant initializer.
 738  */
 739 #define to_cpumask(bitmap)                                              \
 740         ((struct cpumask *)(1 ? (bitmap)                                \
 741                             : (void *)sizeof(__check_is_bitmap(bitmap))))
 742
 743 static inline int __check_is_bitmap(const unsigned long *bitmap)
 744 {
 745         return 1;
 746 }
 747
 748 /*
 749  * Special-case data structure for "single bit set only" constant CPU masks.
 750  *
 751  * We pre-generate all the 64 (or 32) possible bit positions, with enough
 752  * padding to the left and the right, and return the constant pointer
 753  * appropriately offset.
 754  */
 755 extern const unsigned long
 756         cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 757
 758 static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 759 {
 760         const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 761         p -= cpu / BITS_PER_LONG;
 762         return to_cpumask(p);
 763 }
 764
 765 #define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 766
 767 #if NR_CPUS <= BITS_PER_LONG
 768 #define CPU_BITS_ALL                                            \
 769 {                                                               \
 770         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 771 }
 772
 773 #else /* NR_CPUS > BITS_PER_LONG */
 774
 775 #define CPU_BITS_ALL                                            \
 776 {                                                               \
 777         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 778         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 779 }
 780 #endif /* NR_CPUS > BITS_PER_LONG */
 781
 782 /**
 783  * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
 784  *      as comma-separated list of cpus or hex values of cpumask
 785  * @list: indicates whether the cpumap must be list
 786  * @mask: the cpumask to copy
 787  * @buf: the buffer to copy into
 788  *
 789  * Returns the length of the (null-terminated) @buf string, zero if
 790  * nothing is copied.
 791  */
 792 static inline ssize_t
 793 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
 794 {
 795         return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
 796                                       nr_cpu_ids);
 797 }
 798
 799 #if NR_CPUS <= BITS_PER_LONG
 800 #define CPU_MASK_ALL                                                    \
 801 (cpumask_t) { {                                                         \
 802         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 803 } }
 804 #else
 805 #define CPU_MASK_ALL                                                    \
 806 (cpumask_t) { {                                                         \
 807         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 808         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
 809 } }
 810 #endif /* NR_CPUS > BITS_PER_LONG */
 811
 812 #define CPU_MASK_NONE                                                   \
 813 (cpumask_t) { {                                                         \
 814         [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 815 } }
 816
 817 #define CPU_MASK_CPU0                                                   \
 818 (cpumask_t) { {                                                         \
 819         [0] =  1UL                                                      \
 820 } }
 821
 822 #endif /* __LINUX_CPUMASK_H */