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_shift_right(dst, src, n, nbits)       *dst = *src >> n
  49 * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  50 * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  51 * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  52 * bitmap_onto(dst, orig, relmap, nbits)        *dst = orig relative to relmap
  53 * bitmap_fold(dst, orig, sz, nbits)            dst bits = orig bits mod sz
  54 * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  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_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  58 * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  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 */
  63
  64/*
  65 * Also the following operations in asm/bitops.h apply to bitmaps.
  66 *
  67 * set_bit(bit, addr)                   *addr |= bit
  68 * clear_bit(bit, addr)                 *addr &= ~bit
  69 * change_bit(bit, addr)                *addr ^= bit
  70 * test_bit(bit, addr)                  Is bit set in *addr?
  71 * test_and_set_bit(bit, addr)          Set bit and return old value
  72 * test_and_clear_bit(bit, addr)        Clear bit and return old value
  73 * test_and_change_bit(bit, addr)       Change bit and return old value
  74 * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  75 * find_first_bit(addr, nbits)          Position first set bit in *addr
  76 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  77 * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  78 */
  79
  80/*
  81 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  82 * to declare an array named 'name' of just enough unsigned longs to
  83 * contain all bit positions from 0 to 'bits' - 1.
  84 */
  85
  86/*
  87 * lib/bitmap.c provides these functions:
  88 */
  89
  90extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  91extern int __bitmap_full(const unsigned long *bitmap, int bits);
  92extern int __bitmap_equal(const unsigned long *bitmap1,
  93                        const unsigned long *bitmap2, int bits);
  94extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  95                        int bits);
  96extern void __bitmap_shift_right(unsigned long *dst,
  97                        const unsigned long *src, int shift, int bits);
  98extern void __bitmap_shift_left(unsigned long *dst,
  99                        const unsigned long *src, int shift, int bits);
 100extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 101                        const unsigned long *bitmap2, int bits);
 102extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 103                        const unsigned long *bitmap2, int bits);
 104extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 105                        const unsigned long *bitmap2, int bits);
 106extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 107                        const unsigned long *bitmap2, int bits);
 108extern int __bitmap_intersects(const unsigned long *bitmap1,
 109                        const unsigned long *bitmap2, int bits);
 110extern int __bitmap_subset(const unsigned long *bitmap1,
 111                        const unsigned long *bitmap2, int bits);
 112extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 113
 114extern void bitmap_set(unsigned long *map, int i, int len);
 115extern void bitmap_clear(unsigned long *map, int start, int nr);
 116extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 117                                         unsigned long size,
 118                                         unsigned long start,
 119                                         unsigned int nr,
 120                                         unsigned long align_mask);
 121
 122extern int bitmap_scnprintf(char *buf, unsigned int len,
 123                        const unsigned long *src, int nbits);
 124extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 125                        unsigned long *dst, int nbits);
 126extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 127                        unsigned long *dst, int nbits);
 128extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 129                        const unsigned long *src, int nbits);
 130extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 131                        int nmaskbits);
 132extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 133                const unsigned long *old, const unsigned long *new, int bits);
 134extern int bitmap_bitremap(int oldbit,
 135                const unsigned long *old, const unsigned long *new, int bits);
 136extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 137                const unsigned long *relmap, int bits);
 138extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 139                int sz, int bits);
 140extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 141extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 142extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 143extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 144
 145#define BITMAP_LAST_WORD_MASK(nbits)                                    \
 146(                                                                       \
 147        ((nbits) % BITS_PER_LONG) ?                                     \
 148                (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 149)
 150
 151#define small_const_nbits(nbits) \
 152        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 153
 154static inline void bitmap_zero(unsigned long *dst, int nbits)
 155{
 156        if (small_const_nbits(nbits))
 157                *dst = 0UL;
 158        else {
 159                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 160                memset(dst, 0, len);
 161        }
 162}
 163
 164static inline void bitmap_fill(unsigned long *dst, int nbits)
 165{
 166        size_t nlongs = BITS_TO_LONGS(nbits);
 167        if (!small_const_nbits(nbits)) {
 168                int len = (nlongs - 1) * sizeof(unsigned long);
 169                memset(dst, 0xff,  len);
 170        }
 171        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 172}
 173
 174static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 175                        int nbits)
 176{
 177        if (small_const_nbits(nbits))
 178                *dst = *src;
 179        else {
 180                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 181                memcpy(dst, src, len);
 182        }
 183}
 184
 185static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 186                        const unsigned long *src2, int nbits)
 187{
 188        if (small_const_nbits(nbits))
 189                return (*dst = *src1 & *src2) != 0;
 190        return __bitmap_and(dst, src1, src2, nbits);
 191}
 192
 193static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 194                        const unsigned long *src2, int nbits)
 195{
 196        if (small_const_nbits(nbits))
 197                *dst = *src1 | *src2;
 198        else
 199                __bitmap_or(dst, src1, src2, nbits);
 200}
 201
 202static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 203                        const unsigned long *src2, int nbits)
 204{
 205        if (small_const_nbits(nbits))
 206                *dst = *src1 ^ *src2;
 207        else
 208                __bitmap_xor(dst, src1, src2, nbits);
 209}
 210
 211static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 212                        const unsigned long *src2, int nbits)
 213{
 214        if (small_const_nbits(nbits))
 215                return (*dst = *src1 & ~(*src2)) != 0;
 216        return __bitmap_andnot(dst, src1, src2, nbits);
 217}
 218
 219static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 220                        int nbits)
 221{
 222        if (small_const_nbits(nbits))
 223                *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 224        else
 225                __bitmap_complement(dst, src, nbits);
 226}
 227
 228static inline int bitmap_equal(const unsigned long *src1,
 229                        const unsigned long *src2, int nbits)
 230{
 231        if (small_const_nbits(nbits))
 232                return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 233        else
 234                return __bitmap_equal(src1, src2, nbits);
 235}
 236
 237static inline int bitmap_intersects(const unsigned long *src1,
 238                        const unsigned long *src2, int nbits)
 239{
 240        if (small_const_nbits(nbits))
 241                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 242        else
 243                return __bitmap_intersects(src1, src2, nbits);
 244}
 245
 246static inline int bitmap_subset(const unsigned long *src1,
 247                        const unsigned long *src2, int nbits)
 248{
 249        if (small_const_nbits(nbits))
 250                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 251        else
 252                return __bitmap_subset(src1, src2, nbits);
 253}
 254
 255static inline int bitmap_empty(const unsigned long *src, int nbits)
 256{
 257        if (small_const_nbits(nbits))
 258                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 259        else
 260                return __bitmap_empty(src, nbits);
 261}
 262
 263static inline int bitmap_full(const unsigned long *src, int nbits)
 264{
 265        if (small_const_nbits(nbits))
 266                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 267        else
 268                return __bitmap_full(src, nbits);
 269}
 270
 271static inline int bitmap_weight(const unsigned long *src, int nbits)
 272{
 273        if (small_const_nbits(nbits))
 274                return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 275        return __bitmap_weight(src, nbits);
 276}
 277
 278static inline void bitmap_shift_right(unsigned long *dst,
 279                        const unsigned long *src, int n, int nbits)
 280{
 281        if (small_const_nbits(nbits))
 282                *dst = *src >> n;
 283        else
 284                __bitmap_shift_right(dst, src, n, nbits);
 285}
 286
 287static inline void bitmap_shift_left(unsigned long *dst,
 288                        const unsigned long *src, int n, int nbits)
 289{
 290        if (small_const_nbits(nbits))
 291                *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 292        else
 293                __bitmap_shift_left(dst, src, n, nbits);
 294}
 295
 296static inline int bitmap_parse(const char *buf, unsigned int buflen,
 297                        unsigned long *maskp, int nmaskbits)
 298{
 299        return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 300}
 301
 302#endif /* __ASSEMBLY__ */
 303
 304#endif /* __LINUX_BITMAP_H */
 305