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