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