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.
   7 *
   8 * The new cpumask_ ops take a "struct cpumask *"; the old ones
   9 * use cpumask_t.
  10 *
  11 * See detailed comments in the file linux/bitmap.h describing the
  12 * data type on which these cpumasks are based.
  13 *
  14 * For details of cpumask_scnprintf() and cpumask_parse_user(),
  15 * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
  16 * For details of cpulist_scnprintf() and cpulist_parse(), see
  17 * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
  18 * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
  19 * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
  20 * For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
  21 * For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
  22 *
  23 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  24 * Note: The alternate operations with the suffix "_nr" are used
  25 *       to limit the range of the loop to nr_cpu_ids instead of
  26 *       NR_CPUS when NR_CPUS > 64 for performance reasons.
  27 *       If NR_CPUS is <= 64 then most assembler bitmask
  28 *       operators execute faster with a constant range, so
  29 *       the operator will continue to use NR_CPUS.
  30 *
  31 *       Another consideration is that nr_cpu_ids is initialized
  32 *       to NR_CPUS and isn't lowered until the possible cpus are
  33 *       discovered (including any disabled cpus).  So early uses
  34 *       will span the entire range of NR_CPUS.
  35 * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
  36 *
  37 * The obsolescent cpumask operations are:
  38 *
  39 * void cpu_set(cpu, mask)              turn on bit 'cpu' in mask
  40 * void cpu_clear(cpu, mask)            turn off bit 'cpu' in mask
  41 * void cpus_setall(mask)               set all bits
  42 * void cpus_clear(mask)                clear all bits
  43 * int cpu_isset(cpu, mask)             true iff bit 'cpu' set in mask
  44 * int cpu_test_and_set(cpu, mask)      test and set bit 'cpu' in mask
  45 *
  46 * void cpus_and(dst, src1, src2)       dst = src1 & src2  [intersection]
  47 * void cpus_or(dst, src1, src2)        dst = src1 | src2  [union]
  48 * void cpus_xor(dst, src1, src2)       dst = src1 ^ src2
  49 * void cpus_andnot(dst, src1, src2)    dst = src1 & ~src2
  50 * void cpus_complement(dst, src)       dst = ~src
  51 *
  52 * int cpus_equal(mask1, mask2)         Does mask1 == mask2?
  53 * int cpus_intersects(mask1, mask2)    Do mask1 and mask2 intersect?
  54 * int cpus_subset(mask1, mask2)        Is mask1 a subset of mask2?
  55 * int cpus_empty(mask)                 Is mask empty (no bits sets)?
  56 * int cpus_full(mask)                  Is mask full (all bits sets)?
  57 * int cpus_weight(mask)                Hamming weigh - number of set bits
  58 * int cpus_weight_nr(mask)             Same using nr_cpu_ids instead of NR_CPUS
  59 *
  60 * void cpus_shift_right(dst, src, n)   Shift right
  61 * void cpus_shift_left(dst, src, n)    Shift left
  62 *
  63 * int first_cpu(mask)                  Number lowest set bit, or NR_CPUS
  64 * int next_cpu(cpu, mask)              Next cpu past 'cpu', or NR_CPUS
  65 * int next_cpu_nr(cpu, mask)           Next cpu past 'cpu', or nr_cpu_ids
  66 *
  67 * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
  68 *                                      (can be used as an lvalue)
  69 * CPU_MASK_ALL                         Initializer - all bits set
  70 * CPU_MASK_NONE                        Initializer - no bits set
  71 * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
  72 *
  73 * CPUMASK_ALLOC kmalloc's a structure that is a composite of many cpumask_t
  74 * variables, and CPUMASK_PTR provides pointers to each field.
  75 *
  76 * The structure should be defined something like this:
  77 * struct my_cpumasks {
  78 *      cpumask_t mask1;
  79 *      cpumask_t mask2;
  80 * };
  81 *
  82 * Usage is then:
  83 *      CPUMASK_ALLOC(my_cpumasks);
  84 *      CPUMASK_PTR(mask1, my_cpumasks);
  85 *      CPUMASK_PTR(mask2, my_cpumasks);
  86 *
  87 *      --- DO NOT reference cpumask_t pointers until this check ---
  88 *      if (my_cpumasks == NULL)
  89 *              "kmalloc failed"...
  90 *
  91 * References are now pointers to the cpumask_t variables (*mask1, ...)
  92 *
  93 *if NR_CPUS > BITS_PER_LONG
  94 *   CPUMASK_ALLOC(m)                   Declares and allocates struct m *m =
  95 *                                              kmalloc(sizeof(*m), GFP_KERNEL)
  96 *   CPUMASK_FREE(m)                    Macro for kfree(m)
  97 *else
  98 *   CPUMASK_ALLOC(m)                   Declares struct m _m, *m = &_m
  99 *   CPUMASK_FREE(m)                    Nop
 100 *endif
 101 *   CPUMASK_PTR(v, m)                  Declares cpumask_t *v = &(m->v)
 102 * ------------------------------------------------------------------------
 103 *
 104 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
 105 * int cpumask_parse_user(ubuf, ulen, mask)     Parse ascii string as cpumask
 106 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
 107 * int cpulist_parse(buf, map)          Parse ascii string as cpulist
 108 * int cpu_remap(oldbit, old, new)      newbit = map(old, new)(oldbit)
 109 * void cpus_remap(dst, src, old, new)  *dst = map(old, new)(src)
 110 * void cpus_onto(dst, orig, relmap)    *dst = orig relative to relmap
 111 * void cpus_fold(dst, orig, sz)        dst bits = orig bits mod sz
 112 *
 113 * for_each_cpu_mask(cpu, mask)         for-loop cpu over mask using NR_CPUS
 114 * for_each_cpu_mask_nr(cpu, mask)      for-loop cpu over mask using nr_cpu_ids
 115 *
 116 * int num_online_cpus()                Number of online CPUs
 117 * int num_possible_cpus()              Number of all possible CPUs
 118 * int num_present_cpus()               Number of present CPUs
 119 *
 120 * int cpu_online(cpu)                  Is some cpu online?
 121 * int cpu_possible(cpu)                Is some cpu possible?
 122 * int cpu_present(cpu)                 Is some cpu present (can schedule)?
 123 *
 124 * int any_online_cpu(mask)             First online cpu in mask
 125 *
 126 * for_each_possible_cpu(cpu)           for-loop cpu over cpu_possible_map
 127 * for_each_online_cpu(cpu)             for-loop cpu over cpu_online_map
 128 * for_each_present_cpu(cpu)            for-loop cpu over cpu_present_map
 129 *
 130 * Subtlety:
 131 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
 132 *    to generate slightly worse code.  Note for example the additional
 133 *    40 lines of assembly code compiling the "for each possible cpu"
 134 *    loops buried in the disk_stat_read() macros calls when compiling
 135 *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
 136 *    one-line #define for cpu_isset(), instead of wrapping an inline
 137 *    inside a macro, the way we do the other calls.
 138 */
 139
 140#include <linux/kernel.h>
 141#include <linux/threads.h>
 142#include <linux/bitmap.h>
 143
 144typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
 145extern cpumask_t _unused_cpumask_arg_;
 146
 147#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 148static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 149{
 150        set_bit(cpu, dstp->bits);
 151}
 152
 153#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 154static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 155{
 156        clear_bit(cpu, dstp->bits);
 157}
 158
 159#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 160static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 161{
 162        bitmap_fill(dstp->bits, nbits);
 163}
 164
 165#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 166static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 167{
 168        bitmap_zero(dstp->bits, nbits);
 169}
 170
 171/* No static inline type checking - see Subtlety (1) above. */
 172#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 173
 174#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 175static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 176{
 177        return test_and_set_bit(cpu, addr->bits);
 178}
 179
 180#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 181static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 182                                        const cpumask_t *src2p, int nbits)
 183{
 184        bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 185}
 186
 187#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 188static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 189                                        const cpumask_t *src2p, int nbits)
 190{
 191        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 192}
 193
 194#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 195static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 196                                        const cpumask_t *src2p, int nbits)
 197{
 198        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 199}
 200
 201#define cpus_andnot(dst, src1, src2) \
 202                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 203static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 204                                        const cpumask_t *src2p, int nbits)
 205{
 206        bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 207}
 208
 209#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
 210static inline void __cpus_complement(cpumask_t *dstp,
 211                                        const cpumask_t *srcp, int nbits)
 212{
 213        bitmap_complement(dstp->bits, srcp->bits, nbits);
 214}
 215
 216#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 217static inline int __cpus_equal(const cpumask_t *src1p,
 218                                        const cpumask_t *src2p, int nbits)
 219{
 220        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 221}
 222
 223#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 224static inline int __cpus_intersects(const cpumask_t *src1p,
 225                                        const cpumask_t *src2p, int nbits)
 226{
 227        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 228}
 229
 230#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 231static inline int __cpus_subset(const cpumask_t *src1p,
 232                                        const cpumask_t *src2p, int nbits)
 233{
 234        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 235}
 236
 237#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 238static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 239{
 240        return bitmap_empty(srcp->bits, nbits);
 241}
 242
 243#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
 244static inline int __cpus_full(const cpumask_t *srcp, int nbits)
 245{
 246        return bitmap_full(srcp->bits, nbits);
 247}
 248
 249#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 250static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 251{
 252        return bitmap_weight(srcp->bits, nbits);
 253}
 254
 255#define cpus_shift_right(dst, src, n) \
 256                        __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
 257static inline void __cpus_shift_right(cpumask_t *dstp,
 258                                        const cpumask_t *srcp, int n, int nbits)
 259{
 260        bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
 261}
 262
 263#define cpus_shift_left(dst, src, n) \
 264                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 265static inline void __cpus_shift_left(cpumask_t *dstp,
 266                                        const cpumask_t *srcp, int n, int nbits)
 267{
 268        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 269}
 270
 271/*
 272 * Special-case data structure for "single bit set only" constant CPU masks.
 273 *
 274 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 275 * padding to the left and the right, and return the constant pointer
 276 * appropriately offset.
 277 */
 278extern const unsigned long
 279        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 280
 281static inline const cpumask_t *get_cpu_mask(unsigned int cpu)
 282{
 283        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 284        p -= cpu / BITS_PER_LONG;
 285        return (const cpumask_t *)p;
 286}
 287
 288/*
 289 * In cases where we take the address of the cpumask immediately,
 290 * gcc optimizes it out (it's a constant) and there's no huge stack
 291 * variable created:
 292 */
 293#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 294
 295
 296#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 297
 298#if NR_CPUS <= BITS_PER_LONG
 299
 300#define CPU_MASK_ALL                                                    \
 301(cpumask_t) { {                                                         \
 302        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 303} }
 304
 305#define CPU_MASK_ALL_PTR        (&CPU_MASK_ALL)
 306
 307#else
 308
 309#define CPU_MASK_ALL                                                    \
 310(cpumask_t) { {                                                         \
 311        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 312        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 313} }
 314
 315/* cpu_mask_all is in init/main.c */
 316extern cpumask_t cpu_mask_all;
 317#define CPU_MASK_ALL_PTR        (&cpu_mask_all)
 318
 319#endif
 320
 321#define CPU_MASK_NONE                                                   \
 322(cpumask_t) { {                                                         \
 323        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 324} }
 325
 326#define CPU_MASK_CPU0                                                   \
 327(cpumask_t) { {                                                         \
 328        [0] =  1UL                                                      \
 329} }
 330
 331#define cpus_addr(src) ((src).bits)
 332
 333#if NR_CPUS > BITS_PER_LONG
 334#define CPUMASK_ALLOC(m)        struct m *m = kmalloc(sizeof(*m), GFP_KERNEL)
 335#define CPUMASK_FREE(m)         kfree(m)
 336#else
 337#define CPUMASK_ALLOC(m)        struct m _m, *m = &_m
 338#define CPUMASK_FREE(m)
 339#endif
 340#define CPUMASK_PTR(v, m)       cpumask_t *v = &(m->v)
 341
 342#define cpumask_scnprintf(buf, len, src) \
 343                        __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
 344static inline int __cpumask_scnprintf(char *buf, int len,
 345                                        const cpumask_t *srcp, int nbits)
 346{
 347        return bitmap_scnprintf(buf, len, srcp->bits, nbits);
 348}
 349
 350#define cpumask_parse_user(ubuf, ulen, dst) \
 351                        __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
 352static inline int __cpumask_parse_user(const char __user *buf, int len,
 353                                        cpumask_t *dstp, int nbits)
 354{
 355        return bitmap_parse_user(buf, len, dstp->bits, nbits);
 356}
 357
 358#define cpulist_scnprintf(buf, len, src) \
 359                        __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
 360static inline int __cpulist_scnprintf(char *buf, int len,
 361                                        const cpumask_t *srcp, int nbits)
 362{
 363        return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
 364}
 365
 366#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
 367static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
 368{
 369        return bitmap_parselist(buf, dstp->bits, nbits);
 370}
 371
 372#define cpu_remap(oldbit, old, new) \
 373                __cpu_remap((oldbit), &(old), &(new), NR_CPUS)
 374static inline int __cpu_remap(int oldbit,
 375                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 376{
 377        return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
 378}
 379
 380#define cpus_remap(dst, src, old, new) \
 381                __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
 382static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
 383                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 384{
 385        bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
 386}
 387
 388#define cpus_onto(dst, orig, relmap) \
 389                __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
 390static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
 391                const cpumask_t *relmapp, int nbits)
 392{
 393        bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
 394}
 395
 396#define cpus_fold(dst, orig, sz) \
 397                __cpus_fold(&(dst), &(orig), sz, NR_CPUS)
 398static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
 399                int sz, int nbits)
 400{
 401        bitmap_fold(dstp->bits, origp->bits, sz, nbits);
 402}
 403
 404#if NR_CPUS == 1
 405
 406#define nr_cpu_ids              1
 407#define first_cpu(src)          ({ (void)(src); 0; })
 408#define next_cpu(n, src)        ({ (void)(src); 1; })
 409#define any_online_cpu(mask)    0
 410#define for_each_cpu_mask(cpu, mask)    \
 411        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 412
 413#else /* NR_CPUS > 1 */
 414
 415extern int nr_cpu_ids;
 416int __first_cpu(const cpumask_t *srcp);
 417int __next_cpu(int n, const cpumask_t *srcp);
 418int __any_online_cpu(const cpumask_t *mask);
 419
 420#define first_cpu(src)          __first_cpu(&(src))
 421#define next_cpu(n, src)        __next_cpu((n), &(src))
 422#define any_online_cpu(mask) __any_online_cpu(&(mask))
 423#define for_each_cpu_mask(cpu, mask)                    \
 424        for ((cpu) = -1;                                \
 425                (cpu) = next_cpu((cpu), (mask)),        \
 426                (cpu) < NR_CPUS; )
 427#endif
 428
 429#if NR_CPUS <= 64
 430
 431#define next_cpu_nr(n, src)             next_cpu(n, src)
 432#define cpus_weight_nr(cpumask)         cpus_weight(cpumask)
 433#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 434
 435#else /* NR_CPUS > 64 */
 436
 437int __next_cpu_nr(int n, const cpumask_t *srcp);
 438#define next_cpu_nr(n, src)     __next_cpu_nr((n), &(src))
 439#define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
 440#define for_each_cpu_mask_nr(cpu, mask)                 \
 441        for ((cpu) = -1;                                \
 442                (cpu) = next_cpu_nr((cpu), (mask)),     \
 443                (cpu) < nr_cpu_ids; )
 444
 445#endif /* NR_CPUS > 64 */
 446
 447/*
 448 * The following particular system cpumasks and operations manage
 449 * possible, present, active and online cpus.  Each of them is a fixed size
 450 * bitmap of size NR_CPUS.
 451 *
 452 *  #ifdef CONFIG_HOTPLUG_CPU
 453 *     cpu_possible_map - has bit 'cpu' set iff cpu is populatable
 454 *     cpu_present_map  - has bit 'cpu' set iff cpu is populated
 455 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 456 *     cpu_active_map   - has bit 'cpu' set iff cpu available to migration
 457 *  #else
 458 *     cpu_possible_map - has bit 'cpu' set iff cpu is populated
 459 *     cpu_present_map  - copy of cpu_possible_map
 460 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 461 *  #endif
 462 *
 463 *  In either case, NR_CPUS is fixed at compile time, as the static
 464 *  size of these bitmaps.  The cpu_possible_map is fixed at boot
 465 *  time, as the set of CPU id's that it is possible might ever
 466 *  be plugged in at anytime during the life of that system boot.
 467 *  The cpu_present_map is dynamic(*), representing which CPUs
 468 *  are currently plugged in.  And cpu_online_map is the dynamic
 469 *  subset of cpu_present_map, indicating those CPUs available
 470 *  for scheduling.
 471 *
 472 *  If HOTPLUG is enabled, then cpu_possible_map is forced to have
 473 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
 474 *  ACPI reports present at boot.
 475 *
 476 *  If HOTPLUG is enabled, then cpu_present_map varies dynamically,
 477 *  depending on what ACPI reports as currently plugged in, otherwise
 478 *  cpu_present_map is just a copy of cpu_possible_map.
 479 *
 480 *  (*) Well, cpu_present_map is dynamic in the hotplug case.  If not
 481 *      hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
 482 *
 483 * Subtleties:
 484 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
 485 *    assumption that their single CPU is online.  The UP
 486 *    cpu_{online,possible,present}_maps are placebos.  Changing them
 487 *    will have no useful affect on the following num_*_cpus()
 488 *    and cpu_*() macros in the UP case.  This ugliness is a UP
 489 *    optimization - don't waste any instructions or memory references
 490 *    asking if you're online or how many CPUs there are if there is
 491 *    only one CPU.
 492 * 2) Most SMP arch's #define some of these maps to be some
 493 *    other map specific to that arch.  Therefore, the following
 494 *    must be #define macros, not inlines.  To see why, examine
 495 *    the assembly code produced by the following.  Note that
 496 *    set1() writes phys_x_map, but set2() writes x_map:
 497 *        int x_map, phys_x_map;
 498 *        #define set1(a) x_map = a
 499 *        inline void set2(int a) { x_map = a; }
 500 *        #define x_map phys_x_map
 501 *        main(){ set1(3); set2(5); }
 502 */
 503
 504extern cpumask_t cpu_possible_map;
 505extern cpumask_t cpu_online_map;
 506extern cpumask_t cpu_present_map;
 507extern cpumask_t cpu_active_map;
 508
 509#if NR_CPUS > 1
 510#define num_online_cpus()       cpus_weight_nr(cpu_online_map)
 511#define num_possible_cpus()     cpus_weight_nr(cpu_possible_map)
 512#define num_present_cpus()      cpus_weight_nr(cpu_present_map)
 513#define cpu_online(cpu)         cpu_isset((cpu), cpu_online_map)
 514#define cpu_possible(cpu)       cpu_isset((cpu), cpu_possible_map)
 515#define cpu_present(cpu)        cpu_isset((cpu), cpu_present_map)
 516#define cpu_active(cpu)         cpu_isset((cpu), cpu_active_map)
 517#else
 518#define num_online_cpus()       1
 519#define num_possible_cpus()     1
 520#define num_present_cpus()      1
 521#define cpu_online(cpu)         ((cpu) == 0)
 522#define cpu_possible(cpu)       ((cpu) == 0)
 523#define cpu_present(cpu)        ((cpu) == 0)
 524#define cpu_active(cpu)         ((cpu) == 0)
 525#endif
 526
 527#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 528
 529#define for_each_possible_cpu(cpu) for_each_cpu_mask_nr((cpu), cpu_possible_map)
 530#define for_each_online_cpu(cpu)   for_each_cpu_mask_nr((cpu), cpu_online_map)
 531#define for_each_present_cpu(cpu)  for_each_cpu_mask_nr((cpu), cpu_present_map)
 532
 533/* These are the new versions of the cpumask operators: passed by pointer.
 534 * The older versions will be implemented in terms of these, then deleted. */
 535#define cpumask_bits(maskp) ((maskp)->bits)
 536
 537#if NR_CPUS <= BITS_PER_LONG
 538#define CPU_BITS_ALL                                            \
 539{                                                               \
 540        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 541}
 542
 543/* This produces more efficient code. */
 544#define nr_cpumask_bits NR_CPUS
 545
 546#else /* NR_CPUS > BITS_PER_LONG */
 547
 548#define CPU_BITS_ALL                                            \
 549{                                                               \
 550        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 551        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 552}
 553
 554#define nr_cpumask_bits nr_cpu_ids
 555#endif /* NR_CPUS > BITS_PER_LONG */
 556
 557/* verify cpu argument to cpumask_* operators */
 558static inline unsigned int cpumask_check(unsigned int cpu)
 559{
 560#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 561        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 562#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 563        return cpu;
 564}
 565
 566#if NR_CPUS == 1
 567/* Uniprocessor.  Assume all masks are "1". */
 568static inline unsigned int cpumask_first(const struct cpumask *srcp)
 569{
 570        return 0;
 571}
 572
 573/* Valid inputs for n are -1 and 0. */
 574static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 575{
 576        return n+1;
 577}
 578
 579static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 580{
 581        return n+1;
 582}
 583
 584static inline unsigned int cpumask_next_and(int n,
 585                                            const struct cpumask *srcp,
 586                                            const struct cpumask *andp)
 587{
 588        return n+1;
 589}
 590
 591/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 592static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 593                                           unsigned int cpu)
 594{
 595        return 1;
 596}
 597
 598#define for_each_cpu(cpu, mask)                 \
 599        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 600#define for_each_cpu_and(cpu, mask, and)        \
 601        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 602#else
 603/**
 604 * cpumask_first - get the first cpu in a cpumask
 605 * @srcp: the cpumask pointer
 606 *
 607 * Returns >= nr_cpu_ids if no cpus set.
 608 */
 609static inline unsigned int cpumask_first(const struct cpumask *srcp)
 610{
 611        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 612}
 613
 614/**
 615 * cpumask_next - get the next cpu in a cpumask
 616 * @n: the cpu prior to the place to search (ie. return will be > @n)
 617 * @srcp: the cpumask pointer
 618 *
 619 * Returns >= nr_cpu_ids if no further cpus set.
 620 */
 621static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 622{
 623        /* -1 is a legal arg here. */
 624        if (n != -1)
 625                cpumask_check(n);
 626        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 627}
 628
 629/**
 630 * cpumask_next_zero - get the next unset cpu in a cpumask
 631 * @n: the cpu prior to the place to search (ie. return will be > @n)
 632 * @srcp: the cpumask pointer
 633 *
 634 * Returns >= nr_cpu_ids if no further cpus unset.
 635 */
 636static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 637{
 638        /* -1 is a legal arg here. */
 639        if (n != -1)
 640                cpumask_check(n);
 641        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 642}
 643
 644int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 645int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 646
 647/**
 648 * for_each_cpu - iterate over every cpu in a mask
 649 * @cpu: the (optionally unsigned) integer iterator
 650 * @mask: the cpumask pointer
 651 *
 652 * After the loop, cpu is >= nr_cpu_ids.
 653 */
 654#define for_each_cpu(cpu, mask)                         \
 655        for ((cpu) = -1;                                \
 656                (cpu) = cpumask_next((cpu), (mask)),    \
 657                (cpu) < nr_cpu_ids;)
 658
 659/**
 660 * for_each_cpu_and - iterate over every cpu in both masks
 661 * @cpu: the (optionally unsigned) integer iterator
 662 * @mask: the first cpumask pointer
 663 * @and: the second cpumask pointer
 664 *
 665 * This saves a temporary CPU mask in many places.  It is equivalent to:
 666 *      struct cpumask tmp;
 667 *      cpumask_and(&tmp, &mask, &and);
 668 *      for_each_cpu(cpu, &tmp)
 669 *              ...
 670 *
 671 * After the loop, cpu is >= nr_cpu_ids.
 672 */
 673#define for_each_cpu_and(cpu, mask, and)                                \
 674        for ((cpu) = -1;                                                \
 675                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 676                (cpu) < nr_cpu_ids;)
 677#endif /* SMP */
 678
 679#define CPU_BITS_NONE                                           \
 680{                                                               \
 681        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 682}
 683
 684#define CPU_BITS_CPU0                                           \
 685{                                                               \
 686        [0] =  1UL                                              \
 687}
 688
 689/**
 690 * cpumask_set_cpu - set a cpu in a cpumask
 691 * @cpu: cpu number (< nr_cpu_ids)
 692 * @dstp: the cpumask pointer
 693 */
 694static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 695{
 696        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 697}
 698
 699/**
 700 * cpumask_clear_cpu - clear a cpu in a cpumask
 701 * @cpu: cpu number (< nr_cpu_ids)
 702 * @dstp: the cpumask pointer
 703 */
 704static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 705{
 706        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 707}
 708
 709/**
 710 * cpumask_test_cpu - test for a cpu in a cpumask
 711 * @cpu: cpu number (< nr_cpu_ids)
 712 * @cpumask: the cpumask pointer
 713 *
 714 * No static inline type checking - see Subtlety (1) above.
 715 */
 716#define cpumask_test_cpu(cpu, cpumask) \
 717        test_bit(cpumask_check(cpu), (cpumask)->bits)
 718
 719/**
 720 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 721 * @cpu: cpu number (< nr_cpu_ids)
 722 * @cpumask: the cpumask pointer
 723 *
 724 * test_and_set_bit wrapper for cpumasks.
 725 */
 726static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 727{
 728        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 729}
 730
 731/**
 732 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 733 * @dstp: the cpumask pointer
 734 */
 735static inline void cpumask_setall(struct cpumask *dstp)
 736{
 737        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 738}
 739
 740/**
 741 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 742 * @dstp: the cpumask pointer
 743 */
 744static inline void cpumask_clear(struct cpumask *dstp)
 745{
 746        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 747}
 748
 749/**
 750 * cpumask_and - *dstp = *src1p & *src2p
 751 * @dstp: the cpumask result
 752 * @src1p: the first input
 753 * @src2p: the second input
 754 */
 755static inline void cpumask_and(struct cpumask *dstp,
 756                               const struct cpumask *src1p,
 757                               const struct cpumask *src2p)
 758{
 759        bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 760                                       cpumask_bits(src2p), nr_cpumask_bits);
 761}
 762
 763/**
 764 * cpumask_or - *dstp = *src1p | *src2p
 765 * @dstp: the cpumask result
 766 * @src1p: the first input
 767 * @src2p: the second input
 768 */
 769static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 770                              const struct cpumask *src2p)
 771{
 772        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 773                                      cpumask_bits(src2p), nr_cpumask_bits);
 774}
 775
 776/**
 777 * cpumask_xor - *dstp = *src1p ^ *src2p
 778 * @dstp: the cpumask result
 779 * @src1p: the first input
 780 * @src2p: the second input
 781 */
 782static inline void cpumask_xor(struct cpumask *dstp,
 783                               const struct cpumask *src1p,
 784                               const struct cpumask *src2p)
 785{
 786        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 787                                       cpumask_bits(src2p), nr_cpumask_bits);
 788}
 789
 790/**
 791 * cpumask_andnot - *dstp = *src1p & ~*src2p
 792 * @dstp: the cpumask result
 793 * @src1p: the first input
 794 * @src2p: the second input
 795 */
 796static inline void cpumask_andnot(struct cpumask *dstp,
 797                                  const struct cpumask *src1p,
 798                                  const struct cpumask *src2p)
 799{
 800        bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 801                                          cpumask_bits(src2p), nr_cpumask_bits);
 802}
 803
 804/**
 805 * cpumask_complement - *dstp = ~*srcp
 806 * @dstp: the cpumask result
 807 * @srcp: the input to invert
 808 */
 809static inline void cpumask_complement(struct cpumask *dstp,
 810                                      const struct cpumask *srcp)
 811{
 812        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 813                                              nr_cpumask_bits);
 814}
 815
 816/**
 817 * cpumask_equal - *src1p == *src2p
 818 * @src1p: the first input
 819 * @src2p: the second input
 820 */
 821static inline bool cpumask_equal(const struct cpumask *src1p,
 822                                const struct cpumask *src2p)
 823{
 824        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 825                                                 nr_cpumask_bits);
 826}
 827
 828/**
 829 * cpumask_intersects - (*src1p & *src2p) != 0
 830 * @src1p: the first input
 831 * @src2p: the second input
 832 */
 833static inline bool cpumask_intersects(const struct cpumask *src1p,
 834                                     const struct cpumask *src2p)
 835{
 836        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 837                                                      nr_cpumask_bits);
 838}
 839
 840/**
 841 * cpumask_subset - (*src1p & ~*src2p) == 0
 842 * @src1p: the first input
 843 * @src2p: the second input
 844 */
 845static inline int cpumask_subset(const struct cpumask *src1p,
 846                                 const struct cpumask *src2p)
 847{
 848        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 849                                                  nr_cpumask_bits);
 850}
 851
 852/**
 853 * cpumask_empty - *srcp == 0
 854 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 855 */
 856static inline bool cpumask_empty(const struct cpumask *srcp)
 857{
 858        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 859}
 860
 861/**
 862 * cpumask_full - *srcp == 0xFFFFFFFF...
 863 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 864 */
 865static inline bool cpumask_full(const struct cpumask *srcp)
 866{
 867        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 868}
 869
 870/**
 871 * cpumask_weight - Count of bits in *srcp
 872 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 873 */
 874static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 875{
 876        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 877}
 878
 879/**
 880 * cpumask_shift_right - *dstp = *srcp >> n
 881 * @dstp: the cpumask result
 882 * @srcp: the input to shift
 883 * @n: the number of bits to shift by
 884 */
 885static inline void cpumask_shift_right(struct cpumask *dstp,
 886                                       const struct cpumask *srcp, int n)
 887{
 888        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 889                                               nr_cpumask_bits);
 890}
 891
 892/**
 893 * cpumask_shift_left - *dstp = *srcp << n
 894 * @dstp: the cpumask result
 895 * @srcp: the input to shift
 896 * @n: the number of bits to shift by
 897 */
 898static inline void cpumask_shift_left(struct cpumask *dstp,
 899                                      const struct cpumask *srcp, int n)
 900{
 901        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 902                                              nr_cpumask_bits);
 903}
 904
 905/**
 906 * cpumask_copy - *dstp = *srcp
 907 * @dstp: the result
 908 * @srcp: the input cpumask
 909 */
 910static inline void cpumask_copy(struct cpumask *dstp,
 911                                const struct cpumask *srcp)
 912{
 913        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 914}
 915
 916/**
 917 * cpumask_any - pick a "random" cpu from *srcp
 918 * @srcp: the input cpumask
 919 *
 920 * Returns >= nr_cpu_ids if no cpus set.
 921 */
 922#define cpumask_any(srcp) cpumask_first(srcp)
 923
 924/**
 925 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 926 * @src1p: the first input
 927 * @src2p: the second input
 928 *
 929 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 930 */
 931#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 932
 933/**
 934 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 935 * @mask1: the first input cpumask
 936 * @mask2: the second input cpumask
 937 *
 938 * Returns >= nr_cpu_ids if no cpus set.
 939 */
 940#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 941
 942/**
 943 * cpumask_of - the cpumask containing just a given cpu
 944 * @cpu: the cpu (<= nr_cpu_ids)
 945 */
 946#define cpumask_of(cpu) (get_cpu_mask(cpu))
 947
 948/**
 949 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 950 * @bitmap: the bitmap
 951 *
 952 * There are a few places where cpumask_var_t isn't appropriate and
 953 * static cpumasks must be used (eg. very early boot), yet we don't
 954 * expose the definition of 'struct cpumask'.
 955 *
 956 * This does the conversion, and can be used as a constant initializer.
 957 */
 958#define to_cpumask(bitmap)                                              \
 959        ((struct cpumask *)(1 ? (bitmap)                                \
 960                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 961
 962static inline int __check_is_bitmap(const unsigned long *bitmap)
 963{
 964        return 1;
 965}
 966
 967/**
 968 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 969 *
 970 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 971 */
 972static inline size_t cpumask_size(void)
 973{
 974        /* FIXME: Once all cpumask assignments are eliminated, this
 975         * can be nr_cpumask_bits */
 976        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
 977}
 978
 979/*
 980 * cpumask_var_t: struct cpumask for stack usage.
 981 *
 982 * Oh, the wicked games we play!  In order to make kernel coding a
 983 * little more difficult, we typedef cpumask_var_t to an array or a
 984 * pointer: doing &mask on an array is a noop, so it still works.
 985 *
 986 * ie.
 987 *      cpumask_var_t tmpmask;
 988 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 989 *              return -ENOMEM;
 990 *
 991 *        ... use 'tmpmask' like a normal struct cpumask * ...
 992 *
 993 *      free_cpumask_var(tmpmask);
 994 */
 995#ifdef CONFIG_CPUMASK_OFFSTACK
 996typedef struct cpumask *cpumask_var_t;
 997
 998bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 999void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
1000void free_cpumask_var(cpumask_var_t mask);
1001void free_bootmem_cpumask_var(cpumask_var_t mask);
1002
1003#else
1004typedef struct cpumask cpumask_var_t[1];
1005
1006static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
1007{
1008        return true;
1009}
1010
1011static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
1012{
1013}
1014
1015static inline void free_cpumask_var(cpumask_var_t mask)
1016{
1017}
1018
1019static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
1020{
1021}
1022#endif /* CONFIG_CPUMASK_OFFSTACK */
1023
1024/* The pointer versions of the maps, these will become the primary versions. */
1025#define cpu_possible_mask ((const struct cpumask *)&cpu_possible_map)
1026#define cpu_online_mask ((const struct cpumask *)&cpu_online_map)
1027#define cpu_present_mask ((const struct cpumask *)&cpu_present_map)
1028#define cpu_active_mask ((const struct cpumask *)&cpu_active_map)
1029
1030/* It's common to want to use cpu_all_mask in struct member initializers,
1031 * so it has to refer to an address rather than a pointer. */
1032extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
1033#define cpu_all_mask to_cpumask(cpu_all_bits)
1034
1035/* First bits of cpu_bit_bitmap are in fact unset. */
1036#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
1037
1038/* Wrappers for arch boot code to manipulate normally-constant masks */
1039static inline void set_cpu_possible(unsigned int cpu, bool possible)
1040{
1041        if (possible)
1042                cpumask_set_cpu(cpu, &cpu_possible_map);
1043        else
1044                cpumask_clear_cpu(cpu, &cpu_possible_map);
1045}
1046
1047static inline void set_cpu_present(unsigned int cpu, bool present)
1048{
1049        if (present)
1050                cpumask_set_cpu(cpu, &cpu_present_map);
1051        else
1052                cpumask_clear_cpu(cpu, &cpu_present_map);
1053}
1054
1055static inline void set_cpu_online(unsigned int cpu, bool online)
1056{
1057        if (online)
1058                cpumask_set_cpu(cpu, &cpu_online_map);
1059        else
1060                cpumask_clear_cpu(cpu, &cpu_online_map);
1061}
1062
1063static inline void set_cpu_active(unsigned int cpu, bool active)
1064{
1065        if (active)
1066                cpumask_set_cpu(cpu, &cpu_active_map);
1067        else
1068                cpumask_clear_cpu(cpu, &cpu_active_map);
1069}
1070
1071static inline void init_cpu_present(const struct cpumask *src)
1072{
1073        cpumask_copy(&cpu_present_map, src);
1074}
1075
1076static inline void init_cpu_possible(const struct cpumask *src)
1077{
1078        cpumask_copy(&cpu_possible_map, src);
1079}
1080
1081static inline void init_cpu_online(const struct cpumask *src)
1082{
1083        cpumask_copy(&cpu_online_map, src);
1084}
1085#endif /* __LINUX_CPUMASK_H */
1086
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