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