LXR linux/include/linux/bitmap.h

   1#ifndef __LINUX_BITMAP_H
   2#define __LINUX_BITMAP_H
   3
   4#ifndef __ASSEMBLY__
   5
   6#include <linux/types.h>
   7#include <linux/bitops.h>
   8#include <linux/string.h>
   9#include <linux/kernel.h>
  10
  11/*
  12 * bitmaps provide bit arrays that consume one or more unsigned
  13 * longs.  The bitmap interface and available operations are listed
  14 * here, in bitmap.h
  15 *
  16 * Function implementations generic to all architectures are in
  17 * lib/bitmap.c.  Functions implementations that are architecture
  18 * specific are in various include/asm-<arch>/bitops.h headers
  19 * and other arch/<arch> specific files.
  20 *
  21 * See lib/bitmap.c for more details.
  22 */
  23
  24/*
  25 * The available bitmap operations and their rough meaning in the
  26 * case that the bitmap is a single unsigned long are thus:
  27 *
  28 * Note that nbits should be always a compile time evaluable constant.
  29 * Otherwise many inlines will generate horrible code.
  30 *
  31 * bitmap_zero(dst, nbits)                      *dst = 0UL
  32 * bitmap_fill(dst, nbits)                      *dst = ~0UL
  33 * bitmap_copy(dst, src, nbits)                 *dst = *src
  34 * bitmap_and(dst, src1, src2, nbits)           *dst = *src1 & *src2
  35 * bitmap_or(dst, src1, src2, nbits)            *dst = *src1 | *src2
  36 * bitmap_xor(dst, src1, src2, nbits)           *dst = *src1 ^ *src2
  37 * bitmap_andnot(dst, src1, src2, nbits)        *dst = *src1 & ~(*src2)
  38 * bitmap_complement(dst, src, nbits)           *dst = ~(*src)
  39 * bitmap_equal(src1, src2, nbits)              Are *src1 and *src2 equal?
  40 * bitmap_intersects(src1, src2, nbits)         Do *src1 and *src2 overlap?
  41 * bitmap_subset(src1, src2, nbits)             Is *src1 a subset of *src2?
  42 * bitmap_empty(src, nbits)                     Are all bits zero in *src?
  43 * bitmap_full(src, nbits)                      Are all bits set in *src?
  44 * bitmap_weight(src, nbits)                    Hamming Weight: number set bits
  45 * bitmap_set(dst, pos, nbits)                  Set specified bit area
  46 * bitmap_clear(dst, pos, nbits)                Clear specified bit area
  47 * bitmap_find_next_zero_area(buf, len, pos, n, mask)   Find bit free area
  48 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask)       as above
  49 * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  50 * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  51 * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  52 * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  53 * bitmap_onto(dst, orig, relmap, nbits)        *dst = orig relative to relmap
  54 * bitmap_fold(dst, orig, sz, nbits)            dst bits = orig bits mod sz
  55 * bitmap_parse(buf, buflen, dst, nbits)        Parse bitmap dst from kernel buf
  56 * bitmap_parse_user(ubuf, ulen, dst, nbits)    Parse bitmap dst from user buf
  57 * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from kernel buf
  58 * bitmap_parselist_user(buf, dst, nbits)       Parse bitmap dst from user buf
  59 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  60 * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  61 * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  62 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
  63 * bitmap_to_u32array(buf, nwords, src, nbits)  *buf = *dst (nwords 32b words)
  64 */
  65
  66/*
  67 * Also the following operations in asm/bitops.h apply to bitmaps.
  68 *
  69 * set_bit(bit, addr)                   *addr |= bit
  70 * clear_bit(bit, addr)                 *addr &= ~bit
  71 * change_bit(bit, addr)                *addr ^= bit
  72 * test_bit(bit, addr)                  Is bit set in *addr?
  73 * test_and_set_bit(bit, addr)          Set bit and return old value
  74 * test_and_clear_bit(bit, addr)        Clear bit and return old value
  75 * test_and_change_bit(bit, addr)       Change bit and return old value
  76 * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  77 * find_first_bit(addr, nbits)          Position first set bit in *addr
  78 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  79 * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  80 */
  81
  82/*
  83 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  84 * to declare an array named 'name' of just enough unsigned longs to
  85 * contain all bit positions from 0 to 'bits' - 1.
  86 */
  87
  88/*
  89 * lib/bitmap.c provides these functions:
  90 */
  91
  92extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  93extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  94extern int __bitmap_equal(const unsigned long *bitmap1,
  95                          const unsigned long *bitmap2, unsigned int nbits);
  96extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  97                        unsigned int nbits);
  98extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
  99                                unsigned int shift, unsigned int nbits);
 100extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 101                                unsigned int shift, unsigned int nbits);
 102extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 103                        const unsigned long *bitmap2, unsigned int nbits);
 104extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 105                        const unsigned long *bitmap2, unsigned int nbits);
 106extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 107                        const unsigned long *bitmap2, unsigned int nbits);
 108extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 109                        const unsigned long *bitmap2, unsigned int nbits);
 110extern int __bitmap_intersects(const unsigned long *bitmap1,
 111                        const unsigned long *bitmap2, unsigned int nbits);
 112extern int __bitmap_subset(const unsigned long *bitmap1,
 113                        const unsigned long *bitmap2, unsigned int nbits);
 114extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 115extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
 116extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
 117
 118extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
 119                                                    unsigned long size,
 120                                                    unsigned long start,
 121                                                    unsigned int nr,
 122                                                    unsigned long align_mask,
 123                                                    unsigned long align_offset);
 124
 125/**
 126 * bitmap_find_next_zero_area - find a contiguous aligned zero area
 127 * @map: The address to base the search on
 128 * @size: The bitmap size in bits
 129 * @start: The bitnumber to start searching at
 130 * @nr: The number of zeroed bits we're looking for
 131 * @align_mask: Alignment mask for zero area
 132 *
 133 * The @align_mask should be one less than a power of 2; the effect is that
 134 * the bit offset of all zero areas this function finds is multiples of that
 135 * power of 2. A @align_mask of 0 means no alignment is required.
 136 */
 137static inline unsigned long
 138bitmap_find_next_zero_area(unsigned long *map,
 139                           unsigned long size,
 140                           unsigned long start,
 141                           unsigned int nr,
 142                           unsigned long align_mask)
 143{
 144        return bitmap_find_next_zero_area_off(map, size, start, nr,
 145                                              align_mask, 0);
 146}
 147
 148extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 149                        unsigned long *dst, int nbits);
 150extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 151                        unsigned long *dst, int nbits);
 152extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 153                        int nmaskbits);
 154extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 155                        unsigned long *dst, int nbits);
 156extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 157                const unsigned long *old, const unsigned long *new, unsigned int nbits);
 158extern int bitmap_bitremap(int oldbit,
 159                const unsigned long *old, const unsigned long *new, int bits);
 160extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 161                const unsigned long *relmap, unsigned int bits);
 162extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 163                unsigned int sz, unsigned int nbits);
 164extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 165extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 166extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 167extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
 168                                         unsigned int nbits,
 169                                         const u32 *buf,
 170                                         unsigned int nwords);
 171extern unsigned int bitmap_to_u32array(u32 *buf,
 172                                       unsigned int nwords,
 173                                       const unsigned long *bitmap,
 174                                       unsigned int nbits);
 175#ifdef __BIG_ENDIAN
 176extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
 177#else
 178#define bitmap_copy_le bitmap_copy
 179#endif
 180extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 181extern int bitmap_print_to_pagebuf(bool list, char *buf,
 182                                   const unsigned long *maskp, int nmaskbits);
 183
 184#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 185#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 186
 187#define small_const_nbits(nbits) \
 188        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 189
 190static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 191{
 192        if (small_const_nbits(nbits))
 193                *dst = 0UL;
 194        else {
 195                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 196                memset(dst, 0, len);
 197        }
 198}
 199
 200static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 201{
 202        unsigned int nlongs = BITS_TO_LONGS(nbits);
 203        if (!small_const_nbits(nbits)) {
 204                unsigned int len = (nlongs - 1) * sizeof(unsigned long);
 205                memset(dst, 0xff,  len);
 206        }
 207        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 208}
 209
 210static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 211                        unsigned int nbits)
 212{
 213        if (small_const_nbits(nbits))
 214                *dst = *src;
 215        else {
 216                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 217                memcpy(dst, src, len);
 218        }
 219}
 220
 221static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 222                        const unsigned long *src2, unsigned int nbits)
 223{
 224        if (small_const_nbits(nbits))
 225                return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 226        return __bitmap_and(dst, src1, src2, nbits);
 227}
 228
 229static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 230                        const unsigned long *src2, unsigned int nbits)
 231{
 232        if (small_const_nbits(nbits))
 233                *dst = *src1 | *src2;
 234        else
 235                __bitmap_or(dst, src1, src2, nbits);
 236}
 237
 238static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 239                        const unsigned long *src2, unsigned int nbits)
 240{
 241        if (small_const_nbits(nbits))
 242                *dst = *src1 ^ *src2;
 243        else
 244                __bitmap_xor(dst, src1, src2, nbits);
 245}
 246
 247static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 248                        const unsigned long *src2, unsigned int nbits)
 249{
 250        if (small_const_nbits(nbits))
 251                return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 252        return __bitmap_andnot(dst, src1, src2, nbits);
 253}
 254
 255static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 256                        unsigned int nbits)
 257{
 258        if (small_const_nbits(nbits))
 259                *dst = ~(*src);
 260        else
 261                __bitmap_complement(dst, src, nbits);
 262}
 263
 264static inline int bitmap_equal(const unsigned long *src1,
 265                        const unsigned long *src2, unsigned int nbits)
 266{
 267        if (small_const_nbits(nbits))
 268                return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 269        if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 270                return !memcmp(src1, src2, nbits / 8);
 271        return __bitmap_equal(src1, src2, nbits);
 272}
 273
 274static inline int bitmap_intersects(const unsigned long *src1,
 275                        const unsigned long *src2, unsigned int nbits)
 276{
 277        if (small_const_nbits(nbits))
 278                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 279        else
 280                return __bitmap_intersects(src1, src2, nbits);
 281}
 282
 283static inline int bitmap_subset(const unsigned long *src1,
 284                        const unsigned long *src2, unsigned int nbits)
 285{
 286        if (small_const_nbits(nbits))
 287                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 288        else
 289                return __bitmap_subset(src1, src2, nbits);
 290}
 291
 292static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 293{
 294        if (small_const_nbits(nbits))
 295                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 296
 297        return find_first_bit(src, nbits) == nbits;
 298}
 299
 300static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 301{
 302        if (small_const_nbits(nbits))
 303                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 304
 305        return find_first_zero_bit(src, nbits) == nbits;
 306}
 307
 308static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
 309{
 310        if (small_const_nbits(nbits))
 311                return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 312        return __bitmap_weight(src, nbits);
 313}
 314
 315static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
 316                unsigned int nbits)
 317{
 318        if (__builtin_constant_p(nbits) && nbits == 1)
 319                __set_bit(start, map);
 320        else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
 321                 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 322                memset((char *)map + start / 8, 0xff, nbits / 8);
 323        else
 324                __bitmap_set(map, start, nbits);
 325}
 326
 327static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
 328                unsigned int nbits)
 329{
 330        if (__builtin_constant_p(nbits) && nbits == 1)
 331                __clear_bit(start, map);
 332        else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
 333                 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 334                memset((char *)map + start / 8, 0, nbits / 8);
 335        else
 336                __bitmap_clear(map, start, nbits);
 337}
 338
 339static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
 340                                unsigned int shift, int nbits)
 341{
 342        if (small_const_nbits(nbits))
 343                *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
 344        else
 345                __bitmap_shift_right(dst, src, shift, nbits);
 346}
 347
 348static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 349                                unsigned int shift, unsigned int nbits)
 350{
 351        if (small_const_nbits(nbits))
 352                *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
 353        else
 354                __bitmap_shift_left(dst, src, shift, nbits);
 355}
 356
 357static inline int bitmap_parse(const char *buf, unsigned int buflen,
 358                        unsigned long *maskp, int nmaskbits)
 359{
 360        return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 361}
 362
 363/*
 364 * bitmap_from_u64 - Check and swap words within u64.
 365 *  @mask: source bitmap
 366 *  @dst:  destination bitmap
 367 *
 368 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
 369 * to read u64 mask, we will get the wrong word.
 370 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
 371 * but we expect the lower 32-bits of u64.
 372 */
 373static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
 374{
 375        dst[0] = mask & ULONG_MAX;
 376
 377        if (sizeof(mask) > sizeof(unsigned long))
 378                dst[1] = mask >> 32;
 379}
 380
 381#endif /* __ASSEMBLY__ */
 382
 383#endif /* __LINUX_BITMAP_H */
 384