LXR linux-bk/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
  10/*
  11 * bitmaps provide bit arrays that consume one or more unsigned
  12 * longs.  The bitmap interface and available operations are listed
  13 * here, in bitmap.h
  14 *
  15 * Function implementations generic to all architectures are in
  16 * lib/bitmap.c.  Functions implementations that are architecture
  17 * specific are in various include/asm-<arch>/bitops.h headers
  18 * and other arch/<arch> specific files.
  19 *
  20 * See lib/bitmap.c for more details.
  21 */
  22
  23/*
  24 * The available bitmap operations and their rough meaning in the
  25 * case that the bitmap is a single unsigned long are thus:
  26 *
  27 * bitmap_zero(dst, nbits)                      *dst = 0UL
  28 * bitmap_fill(dst, nbits)                      *dst = ~0UL
  29 * bitmap_copy(dst, src, nbits)                 *dst = *src
  30 * bitmap_and(dst, src1, src2, nbits)           *dst = *src1 & *src2
  31 * bitmap_or(dst, src1, src2, nbits)            *dst = *src1 | *src2
  32 * bitmap_xor(dst, src1, src2, nbits)           *dst = *src1 ^ *src2
  33 * bitmap_andnot(dst, src1, src2, nbits)        *dst = *src1 & ~(*src2)
  34 * bitmap_complement(dst, src, nbits)           *dst = ~(*src)
  35 * bitmap_equal(src1, src2, nbits)              Are *src1 and *src2 equal?
  36 * bitmap_intersects(src1, src2, nbits)         Do *src1 and *src2 overlap?
  37 * bitmap_subset(src1, src2, nbits)             Is *src1 a subset of *src2?
  38 * bitmap_empty(src, nbits)                     Are all bits zero in *src?
  39 * bitmap_full(src, nbits)                      Are all bits set in *src?
  40 * bitmap_weight(src, nbits)                    Hamming Weight: number set bits
  41 * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  42 * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  43 * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  44 * bitmap_parse(ubuf, ulen, dst, nbits)         Parse bitmap dst from buf
  45 */
  46
  47/*
  48 * Also the following operations in asm/bitops.h apply to bitmaps.
  49 *
  50 * set_bit(bit, addr)                   *addr |= bit
  51 * clear_bit(bit, addr)                 *addr &= ~bit
  52 * change_bit(bit, addr)                *addr ^= bit
  53 * test_bit(bit, addr)                  Is bit set in *addr?
  54 * test_and_set_bit(bit, addr)          Set bit and return old value
  55 * test_and_clear_bit(bit, addr)        Clear bit and return old value
  56 * test_and_change_bit(bit, addr)       Change bit and return old value
  57 * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  58 * find_first_bit(addr, nbits)          Position first set bit in *addr
  59 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  60 * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  61 */
  62
  63/*
  64 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  65 * to declare an array named 'name' of just enough unsigned longs to
  66 * contain all bit positions from 0 to 'bits' - 1.
  67 */
  68
  69/*
  70 * lib/bitmap.c provides these functions:
  71 */
  72
  73extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  74extern int __bitmap_full(const unsigned long *bitmap, int bits);
  75extern int __bitmap_equal(const unsigned long *bitmap1,
  76                        const unsigned long *bitmap2, int bits);
  77extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  78                        int bits);
  79extern void __bitmap_shift_right(unsigned long *dst,
  80                        const unsigned long *src, int shift, int bits);
  81extern void __bitmap_shift_left(unsigned long *dst,
  82                        const unsigned long *src, int shift, int bits);
  83extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  84                        const unsigned long *bitmap2, int bits);
  85extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  86                        const unsigned long *bitmap2, int bits);
  87extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  88                        const unsigned long *bitmap2, int bits);
  89extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
  90                        const unsigned long *bitmap2, int bits);
  91extern int __bitmap_intersects(const unsigned long *bitmap1,
  92                        const unsigned long *bitmap2, int bits);
  93extern int __bitmap_subset(const unsigned long *bitmap1,
  94                        const unsigned long *bitmap2, int bits);
  95extern int __bitmap_weight(const unsigned long *bitmap, int bits);
  96
  97extern int bitmap_scnprintf(char *buf, unsigned int len,
  98                        const unsigned long *src, int nbits);
  99extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
 100                        unsigned long *dst, int nbits);
 101extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 102extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 103extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 104
 105#define BITMAP_LAST_WORD_MASK(nbits)                                    \
 106(                                                                       \
 107        ((nbits) % BITS_PER_LONG) ?                                     \
 108                (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 109)
 110
 111static inline void bitmap_zero(unsigned long *dst, int nbits)
 112{
 113        if (nbits <= BITS_PER_LONG)
 114                *dst = 0UL;
 115        else {
 116                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 117                memset(dst, 0, len);
 118        }
 119}
 120
 121static inline void bitmap_fill(unsigned long *dst, int nbits)
 122{
 123        size_t nlongs = BITS_TO_LONGS(nbits);
 124        if (nlongs > 1) {
 125                int len = (nlongs - 1) * sizeof(unsigned long);
 126                memset(dst, 0xff,  len);
 127        }
 128        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 129}
 130
 131static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 132                        int nbits)
 133{
 134        if (nbits <= BITS_PER_LONG)
 135                *dst = *src;
 136        else {
 137                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 138                memcpy(dst, src, len);
 139        }
 140}
 141
 142static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 143                        const unsigned long *src2, int nbits)
 144{
 145        if (nbits <= BITS_PER_LONG)
 146                *dst = *src1 & *src2;
 147        else
 148                __bitmap_and(dst, src1, src2, nbits);
 149}
 150
 151static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 152                        const unsigned long *src2, int nbits)
 153{
 154        if (nbits <= BITS_PER_LONG)
 155                *dst = *src1 | *src2;
 156        else
 157                __bitmap_or(dst, src1, src2, nbits);
 158}
 159
 160static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 161                        const unsigned long *src2, int nbits)
 162{
 163        if (nbits <= BITS_PER_LONG)
 164                *dst = *src1 ^ *src2;
 165        else
 166                __bitmap_xor(dst, src1, src2, nbits);
 167}
 168
 169static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 170                        const unsigned long *src2, int nbits)
 171{
 172        if (nbits <= BITS_PER_LONG)
 173                *dst = *src1 & ~(*src2);
 174        else
 175                __bitmap_andnot(dst, src1, src2, nbits);
 176}
 177
 178static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 179                        int nbits)
 180{
 181        if (nbits <= BITS_PER_LONG)
 182                *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 183        else
 184                __bitmap_complement(dst, src, nbits);
 185}
 186
 187static inline int bitmap_equal(const unsigned long *src1,
 188                        const unsigned long *src2, int nbits)
 189{
 190        if (nbits <= BITS_PER_LONG)
 191                return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 192        else
 193                return __bitmap_equal(src1, src2, nbits);
 194}
 195
 196static inline int bitmap_intersects(const unsigned long *src1,
 197                        const unsigned long *src2, int nbits)
 198{
 199        if (nbits <= BITS_PER_LONG)
 200                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 201        else
 202                return __bitmap_intersects(src1, src2, nbits);
 203}
 204
 205static inline int bitmap_subset(const unsigned long *src1,
 206                        const unsigned long *src2, int nbits)
 207{
 208        if (nbits <= BITS_PER_LONG)
 209                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 210        else
 211                return __bitmap_subset(src1, src2, nbits);
 212}
 213
 214static inline int bitmap_empty(const unsigned long *src, int nbits)
 215{
 216        if (nbits <= BITS_PER_LONG)
 217                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 218        else
 219                return __bitmap_empty(src, nbits);
 220}
 221
 222static inline int bitmap_full(const unsigned long *src, int nbits)
 223{
 224        if (nbits <= BITS_PER_LONG)
 225                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 226        else
 227                return __bitmap_full(src, nbits);
 228}
 229
 230static inline int bitmap_weight(const unsigned long *src, int nbits)
 231{
 232        return __bitmap_weight(src, nbits);
 233}
 234
 235static inline void bitmap_shift_right(unsigned long *dst,
 236                        const unsigned long *src, int n, int nbits)
 237{
 238        if (nbits <= BITS_PER_LONG)
 239                *dst = *src >> n;
 240        else
 241                __bitmap_shift_right(dst, src, n, nbits);
 242}
 243
 244static inline void bitmap_shift_left(unsigned long *dst,
 245                        const unsigned long *src, int n, int nbits)
 246{
 247        if (nbits <= BITS_PER_LONG)
 248                *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 249        else
 250                __bitmap_shift_left(dst, src, n, nbits);
 251}
 252
 253#endif /* __ASSEMBLY__ */
 254
 255#endif /* __LINUX_BITMAP_H */
 256