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_find_next_zero_area_off(buf, len, pos, n, mask)       as above
  49 * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  50 * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  51 * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  52 * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  53 * bitmap_onto(dst, orig, relmap, nbits)        *dst = orig relative to relmap
  54 * bitmap_fold(dst, orig, sz, nbits)            dst bits = orig bits mod sz
  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_parselist(buf, dst, nbits)            Parse bitmap dst from kernel buf
  58 * bitmap_parselist_user(buf, dst, nbits)       Parse bitmap dst from user buf
  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, unsigned int nbits);
  91extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  92extern int __bitmap_equal(const unsigned long *bitmap1,
  93                          const unsigned long *bitmap2, unsigned int nbits);
  94extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  95                        unsigned int nbits);
  96extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
  97                                unsigned int shift, unsigned int nbits);
  98extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
  99                                unsigned int shift, unsigned int nbits);
 100extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 101                        const unsigned long *bitmap2, unsigned int nbits);
 102extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 103                        const unsigned long *bitmap2, unsigned int nbits);
 104extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 105                        const unsigned long *bitmap2, unsigned int nbits);
 106extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 107                        const unsigned long *bitmap2, unsigned int nbits);
 108extern int __bitmap_intersects(const unsigned long *bitmap1,
 109                        const unsigned long *bitmap2, unsigned int nbits);
 110extern int __bitmap_subset(const unsigned long *bitmap1,
 111                        const unsigned long *bitmap2, unsigned int nbits);
 112extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 113
 114extern void bitmap_set(unsigned long *map, unsigned int start, int len);
 115extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
 116
 117extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
 118                                                    unsigned long size,
 119                                                    unsigned long start,
 120                                                    unsigned int nr,
 121                                                    unsigned long align_mask,
 122                                                    unsigned long align_offset);
 123
 124/**
 125 * bitmap_find_next_zero_area - find a contiguous aligned zero area
 126 * @map: The address to base the search on
 127 * @size: The bitmap size in bits
 128 * @start: The bitnumber to start searching at
 129 * @nr: The number of zeroed bits we're looking for
 130 * @align_mask: Alignment mask for zero area
 131 *
 132 * The @align_mask should be one less than a power of 2; the effect is that
 133 * the bit offset of all zero areas this function finds is multiples of that
 134 * power of 2. A @align_mask of 0 means no alignment is required.
 135 */
 136static inline unsigned long
 137bitmap_find_next_zero_area(unsigned long *map,
 138                           unsigned long size,
 139                           unsigned long start,
 140                           unsigned int nr,
 141                           unsigned long align_mask)
 142{
 143        return bitmap_find_next_zero_area_off(map, size, start, nr,
 144                                              align_mask, 0);
 145}
 146
 147extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 148                        unsigned long *dst, int nbits);
 149extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 150                        unsigned long *dst, int nbits);
 151extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 152                        int nmaskbits);
 153extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 154                        unsigned long *dst, int nbits);
 155extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 156                const unsigned long *old, const unsigned long *new, unsigned int nbits);
 157extern int bitmap_bitremap(int oldbit,
 158                const unsigned long *old, const unsigned long *new, int bits);
 159extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 160                const unsigned long *relmap, unsigned int bits);
 161extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 162                unsigned int sz, unsigned int nbits);
 163extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 164extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 165extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 166#ifdef __BIG_ENDIAN
 167extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
 168#else
 169#define bitmap_copy_le bitmap_copy
 170#endif
 171extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 172extern int bitmap_print_to_pagebuf(bool list, char *buf,
 173                                   const unsigned long *maskp, int nmaskbits);
 174
 175#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 176#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 177
 178#define small_const_nbits(nbits) \
 179        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 180
 181static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 182{
 183        if (small_const_nbits(nbits))
 184                *dst = 0UL;
 185        else {
 186                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 187                memset(dst, 0, len);
 188        }
 189}
 190
 191static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 192{
 193        unsigned int nlongs = BITS_TO_LONGS(nbits);
 194        if (!small_const_nbits(nbits)) {
 195                unsigned int len = (nlongs - 1) * sizeof(unsigned long);
 196                memset(dst, 0xff,  len);
 197        }
 198        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 199}
 200
 201static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 202                        unsigned int nbits)
 203{
 204        if (small_const_nbits(nbits))
 205                *dst = *src;
 206        else {
 207                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 208                memcpy(dst, src, len);
 209        }
 210}
 211
 212static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 213                        const unsigned long *src2, unsigned int nbits)
 214{
 215        if (small_const_nbits(nbits))
 216                return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 217        return __bitmap_and(dst, src1, src2, nbits);
 218}
 219
 220static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 221                        const unsigned long *src2, unsigned int nbits)
 222{
 223        if (small_const_nbits(nbits))
 224                *dst = *src1 | *src2;
 225        else
 226                __bitmap_or(dst, src1, src2, nbits);
 227}
 228
 229static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 230                        const unsigned long *src2, unsigned int nbits)
 231{
 232        if (small_const_nbits(nbits))
 233                *dst = *src1 ^ *src2;
 234        else
 235                __bitmap_xor(dst, src1, src2, nbits);
 236}
 237
 238static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 239                        const unsigned long *src2, unsigned int nbits)
 240{
 241        if (small_const_nbits(nbits))
 242                return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 243        return __bitmap_andnot(dst, src1, src2, nbits);
 244}
 245
 246static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 247                        unsigned int nbits)
 248{
 249        if (small_const_nbits(nbits))
 250                *dst = ~(*src);
 251        else
 252                __bitmap_complement(dst, src, nbits);
 253}
 254
 255static inline int bitmap_equal(const unsigned long *src1,
 256                        const unsigned long *src2, unsigned int nbits)
 257{
 258        if (small_const_nbits(nbits))
 259                return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 260        else
 261                return __bitmap_equal(src1, src2, nbits);
 262}
 263
 264static inline int bitmap_intersects(const unsigned long *src1,
 265                        const unsigned long *src2, unsigned int nbits)
 266{
 267        if (small_const_nbits(nbits))
 268                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 269        else
 270                return __bitmap_intersects(src1, src2, nbits);
 271}
 272
 273static inline int bitmap_subset(const unsigned long *src1,
 274                        const unsigned long *src2, unsigned int nbits)
 275{
 276        if (small_const_nbits(nbits))
 277                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 278        else
 279                return __bitmap_subset(src1, src2, nbits);
 280}
 281
 282static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 283{
 284        if (small_const_nbits(nbits))
 285                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 286
 287        return find_first_bit(src, nbits) == nbits;
 288}
 289
 290static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 291{
 292        if (small_const_nbits(nbits))
 293                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 294
 295        return find_first_zero_bit(src, nbits) == nbits;
 296}
 297
 298static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
 299{
 300        if (small_const_nbits(nbits))
 301                return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 302        return __bitmap_weight(src, nbits);
 303}
 304
 305static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
 306                                unsigned int shift, int nbits)
 307{
 308        if (small_const_nbits(nbits))
 309                *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
 310        else
 311                __bitmap_shift_right(dst, src, shift, nbits);
 312}
 313
 314static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 315                                unsigned int shift, unsigned int nbits)
 316{
 317        if (small_const_nbits(nbits))
 318                *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
 319        else
 320                __bitmap_shift_left(dst, src, shift, nbits);
 321}
 322
 323static inline int bitmap_parse(const char *buf, unsigned int buflen,
 324                        unsigned long *maskp, int nmaskbits)
 325{
 326        return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 327}
 328
 329#endif /* __ASSEMBLY__ */
 330
 331#endif /* __LINUX_BITMAP_H */
 332