linux/include/linux/bitmap.h
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   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 kernel buf
  59 * bitmap_parselist_user(buf, dst, nbits)       Parse bitmap dst from user buf
  60 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  61 * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  62 * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  63 */
  64
  65/*
  66 * Also the following operations in asm/bitops.h apply to bitmaps.
  67 *
  68 * set_bit(bit, addr)                   *addr |= bit
  69 * clear_bit(bit, addr)                 *addr &= ~bit
  70 * change_bit(bit, addr)                *addr ^= bit
  71 * test_bit(bit, addr)                  Is bit set in *addr?
  72 * test_and_set_bit(bit, addr)          Set bit and return old value
  73 * test_and_clear_bit(bit, addr)        Clear bit and return old value
  74 * test_and_change_bit(bit, addr)       Change bit and return old value
  75 * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  76 * find_first_bit(addr, nbits)          Position first set bit in *addr
  77 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  78 * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  79 */
  80
  81/*
  82 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  83 * to declare an array named 'name' of just enough unsigned longs to
  84 * contain all bit positions from 0 to 'bits' - 1.
  85 */
  86
  87/*
  88 * lib/bitmap.c provides these functions:
  89 */
  90
  91extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  92extern int __bitmap_full(const unsigned long *bitmap, int bits);
  93extern int __bitmap_equal(const unsigned long *bitmap1,
  94                        const unsigned long *bitmap2, int bits);
  95extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  96                        int bits);
  97extern void __bitmap_shift_right(unsigned long *dst,
  98                        const unsigned long *src, int shift, int bits);
  99extern void __bitmap_shift_left(unsigned long *dst,
 100                        const unsigned long *src, int shift, int bits);
 101extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 102                        const unsigned long *bitmap2, int bits);
 103extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 104                        const unsigned long *bitmap2, int bits);
 105extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 106                        const unsigned long *bitmap2, int bits);
 107extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 108                        const unsigned long *bitmap2, int bits);
 109extern int __bitmap_intersects(const unsigned long *bitmap1,
 110                        const unsigned long *bitmap2, int bits);
 111extern int __bitmap_subset(const unsigned long *bitmap1,
 112                        const unsigned long *bitmap2, int bits);
 113extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 114
 115extern void bitmap_set(unsigned long *map, int i, int len);
 116extern void bitmap_clear(unsigned long *map, int start, int nr);
 117extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 118                                         unsigned long size,
 119                                         unsigned long start,
 120                                         unsigned int nr,
 121                                         unsigned long align_mask);
 122
 123extern int bitmap_scnprintf(char *buf, unsigned int len,
 124                        const unsigned long *src, int nbits);
 125extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 126                        unsigned long *dst, int nbits);
 127extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 128                        unsigned long *dst, int nbits);
 129extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 130                        const unsigned long *src, int nbits);
 131extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 132                        int nmaskbits);
 133extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 134                        unsigned long *dst, int nbits);
 135extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 136                const unsigned long *old, const unsigned long *new, int bits);
 137extern int bitmap_bitremap(int oldbit,
 138                const unsigned long *old, const unsigned long *new, int bits);
 139extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 140                const unsigned long *relmap, int bits);
 141extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 142                int sz, int bits);
 143extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 144extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 145extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 146extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 147extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
 148
 149#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
 150#define BITMAP_LAST_WORD_MASK(nbits)                                    \
 151(                                                                       \
 152        ((nbits) % BITS_PER_LONG) ?                                     \
 153                (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 154)
 155
 156#define small_const_nbits(nbits) \
 157        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 158
 159static inline void bitmap_zero(unsigned long *dst, int nbits)
 160{
 161        if (small_const_nbits(nbits))
 162                *dst = 0UL;
 163        else {
 164                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 165                memset(dst, 0, len);
 166        }
 167}
 168
 169static inline void bitmap_fill(unsigned long *dst, int nbits)
 170{
 171        size_t nlongs = BITS_TO_LONGS(nbits);
 172        if (!small_const_nbits(nbits)) {
 173                int len = (nlongs - 1) * sizeof(unsigned long);
 174                memset(dst, 0xff,  len);
 175        }
 176        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 177}
 178
 179static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 180                        int nbits)
 181{
 182        if (small_const_nbits(nbits))
 183                *dst = *src;
 184        else {
 185                int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 186                memcpy(dst, src, len);
 187        }
 188}
 189
 190static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 191                        const unsigned long *src2, int nbits)
 192{
 193        if (small_const_nbits(nbits))
 194                return (*dst = *src1 & *src2) != 0;
 195        return __bitmap_and(dst, src1, src2, nbits);
 196}
 197
 198static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 199                        const unsigned long *src2, int nbits)
 200{
 201        if (small_const_nbits(nbits))
 202                *dst = *src1 | *src2;
 203        else
 204                __bitmap_or(dst, src1, src2, nbits);
 205}
 206
 207static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 208                        const unsigned long *src2, int nbits)
 209{
 210        if (small_const_nbits(nbits))
 211                *dst = *src1 ^ *src2;
 212        else
 213                __bitmap_xor(dst, src1, src2, nbits);
 214}
 215
 216static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 217                        const unsigned long *src2, int nbits)
 218{
 219        if (small_const_nbits(nbits))
 220                return (*dst = *src1 & ~(*src2)) != 0;
 221        return __bitmap_andnot(dst, src1, src2, nbits);
 222}
 223
 224static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 225                        int nbits)
 226{
 227        if (small_const_nbits(nbits))
 228                *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 229        else
 230                __bitmap_complement(dst, src, nbits);
 231}
 232
 233static inline int bitmap_equal(const unsigned long *src1,
 234                        const unsigned long *src2, int nbits)
 235{
 236        if (small_const_nbits(nbits))
 237                return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 238        else
 239                return __bitmap_equal(src1, src2, nbits);
 240}
 241
 242static inline int bitmap_intersects(const unsigned long *src1,
 243                        const unsigned long *src2, int nbits)
 244{
 245        if (small_const_nbits(nbits))
 246                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 247        else
 248                return __bitmap_intersects(src1, src2, nbits);
 249}
 250
 251static inline int bitmap_subset(const unsigned long *src1,
 252                        const unsigned long *src2, int nbits)
 253{
 254        if (small_const_nbits(nbits))
 255                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 256        else
 257                return __bitmap_subset(src1, src2, nbits);
 258}
 259
 260static inline int bitmap_empty(const unsigned long *src, int nbits)
 261{
 262        if (small_const_nbits(nbits))
 263                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 264        else
 265                return __bitmap_empty(src, nbits);
 266}
 267
 268static inline int bitmap_full(const unsigned long *src, int nbits)
 269{
 270        if (small_const_nbits(nbits))
 271                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 272        else
 273                return __bitmap_full(src, nbits);
 274}
 275
 276static inline int bitmap_weight(const unsigned long *src, int nbits)
 277{
 278        if (small_const_nbits(nbits))
 279                return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 280        return __bitmap_weight(src, nbits);
 281}
 282
 283static inline void bitmap_shift_right(unsigned long *dst,
 284                        const unsigned long *src, int n, int nbits)
 285{
 286        if (small_const_nbits(nbits))
 287                *dst = *src >> n;
 288        else
 289                __bitmap_shift_right(dst, src, n, nbits);
 290}
 291
 292static inline void bitmap_shift_left(unsigned long *dst,
 293                        const unsigned long *src, int n, int nbits)
 294{
 295        if (small_const_nbits(nbits))
 296                *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 297        else
 298                __bitmap_shift_left(dst, src, n, nbits);
 299}
 300
 301static inline int bitmap_parse(const char *buf, unsigned int buflen,
 302                        unsigned long *maskp, int nmaskbits)
 303{
 304        return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 305}
 306
 307#endif /* __ASSEMBLY__ */
 308
 309#endif /* __LINUX_BITMAP_H */
 310
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