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 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
  63 * bitmap_to_u32array(buf, nwords, src, nbits)  *buf = *dst (nwords 32b words)
  64 */
  65
  66/*
  67 * Also the following operations in asm/bitops.h apply to bitmaps.
  68 *
  69 * set_bit(bit, addr)                   *addr |= bit
  70 * clear_bit(bit, addr)                 *addr &= ~bit
  71 * change_bit(bit, addr)                *addr ^= bit
  72 * test_bit(bit, addr)                  Is bit set in *addr?
  73 * test_and_set_bit(bit, addr)          Set bit and return old value
  74 * test_and_clear_bit(bit, addr)        Clear bit and return old value
  75 * test_and_change_bit(bit, addr)       Change bit and return old value
  76 * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  77 * find_first_bit(addr, nbits)          Position first set bit in *addr
  78 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  79 * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  80 */
  81
  82/*
  83 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  84 * to declare an array named 'name' of just enough unsigned longs to
  85 * contain all bit positions from 0 to 'bits' - 1.
  86 */
  87
  88/*
  89 * lib/bitmap.c provides these functions:
  90 */
  91
  92extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  93extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  94extern int __bitmap_equal(const unsigned long *bitmap1,
  95                          const unsigned long *bitmap2, unsigned int nbits);
  96extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  97                        unsigned int nbits);
  98extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
  99                                unsigned int shift, unsigned int nbits);
 100extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 101                                unsigned int shift, unsigned int nbits);
 102extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 103                        const unsigned long *bitmap2, unsigned int nbits);
 104extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 105                        const unsigned long *bitmap2, unsigned int nbits);
 106extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 107                        const unsigned long *bitmap2, unsigned int nbits);
 108extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 109                        const unsigned long *bitmap2, unsigned int nbits);
 110extern int __bitmap_intersects(const unsigned long *bitmap1,
 111                        const unsigned long *bitmap2, unsigned int nbits);
 112extern int __bitmap_subset(const unsigned long *bitmap1,
 113                        const unsigned long *bitmap2, unsigned int nbits);
 114extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 115
 116extern void bitmap_set(unsigned long *map, unsigned int start, int len);
 117extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
 118
 119extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
 120                                                    unsigned long size,
 121                                                    unsigned long start,
 122                                                    unsigned int nr,
 123                                                    unsigned long align_mask,
 124                                                    unsigned long align_offset);
 125
 126/**
 127 * bitmap_find_next_zero_area - find a contiguous aligned zero area
 128 * @map: The address to base the search on
 129 * @size: The bitmap size in bits
 130 * @start: The bitnumber to start searching at
 131 * @nr: The number of zeroed bits we're looking for
 132 * @align_mask: Alignment mask for zero area
 133 *
 134 * The @align_mask should be one less than a power of 2; the effect is that
 135 * the bit offset of all zero areas this function finds is multiples of that
 136 * power of 2. A @align_mask of 0 means no alignment is required.
 137 */
 138static inline unsigned long
 139bitmap_find_next_zero_area(unsigned long *map,
 140                           unsigned long size,
 141                           unsigned long start,
 142                           unsigned int nr,
 143                           unsigned long align_mask)
 144{
 145        return bitmap_find_next_zero_area_off(map, size, start, nr,
 146                                              align_mask, 0);
 147}
 148
 149extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 150                        unsigned long *dst, int nbits);
 151extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 152                        unsigned long *dst, int nbits);
 153extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 154                        int nmaskbits);
 155extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 156                        unsigned long *dst, int nbits);
 157extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 158                const unsigned long *old, const unsigned long *new, unsigned int nbits);
 159extern int bitmap_bitremap(int oldbit,
 160                const unsigned long *old, const unsigned long *new, int bits);
 161extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 162                const unsigned long *relmap, unsigned int bits);
 163extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 164                unsigned int sz, unsigned int nbits);
 165extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 166extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 167extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 168extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
 169                                         unsigned int nbits,
 170                                         const u32 *buf,
 171                                         unsigned int nwords);
 172extern unsigned int bitmap_to_u32array(u32 *buf,
 173                                       unsigned int nwords,
 174                                       const unsigned long *bitmap,
 175                                       unsigned int nbits);
 176#ifdef __BIG_ENDIAN
 177extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
 178#else
 179#define bitmap_copy_le bitmap_copy
 180#endif
 181extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 182extern int bitmap_print_to_pagebuf(bool list, char *buf,
 183                                   const unsigned long *maskp, int nmaskbits);
 184
 185#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 186#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 187
 188#define small_const_nbits(nbits) \
 189        (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 190
 191static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 192{
 193        if (small_const_nbits(nbits))
 194                *dst = 0UL;
 195        else {
 196                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 197                memset(dst, 0, len);
 198        }
 199}
 200
 201static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 202{
 203        unsigned int nlongs = BITS_TO_LONGS(nbits);
 204        if (!small_const_nbits(nbits)) {
 205                unsigned int len = (nlongs - 1) * sizeof(unsigned long);
 206                memset(dst, 0xff,  len);
 207        }
 208        dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 209}
 210
 211static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 212                        unsigned int nbits)
 213{
 214        if (small_const_nbits(nbits))
 215                *dst = *src;
 216        else {
 217                unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 218                memcpy(dst, src, len);
 219        }
 220}
 221
 222static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 223                        const unsigned long *src2, unsigned int nbits)
 224{
 225        if (small_const_nbits(nbits))
 226                return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 227        return __bitmap_and(dst, src1, src2, nbits);
 228}
 229
 230static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 231                        const unsigned long *src2, unsigned int nbits)
 232{
 233        if (small_const_nbits(nbits))
 234                *dst = *src1 | *src2;
 235        else
 236                __bitmap_or(dst, src1, src2, nbits);
 237}
 238
 239static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 240                        const unsigned long *src2, unsigned int nbits)
 241{
 242        if (small_const_nbits(nbits))
 243                *dst = *src1 ^ *src2;
 244        else
 245                __bitmap_xor(dst, src1, src2, nbits);
 246}
 247
 248static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 249                        const unsigned long *src2, unsigned int nbits)
 250{
 251        if (small_const_nbits(nbits))
 252                return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 253        return __bitmap_andnot(dst, src1, src2, nbits);
 254}
 255
 256static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 257                        unsigned int nbits)
 258{
 259        if (small_const_nbits(nbits))
 260                *dst = ~(*src);
 261        else
 262                __bitmap_complement(dst, src, nbits);
 263}
 264
 265static inline int bitmap_equal(const unsigned long *src1,
 266                        const unsigned long *src2, unsigned int nbits)
 267{
 268        if (small_const_nbits(nbits))
 269                return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 270#ifdef CONFIG_S390
 271        if (__builtin_constant_p(nbits) && (nbits % BITS_PER_LONG) == 0)
 272                return !memcmp(src1, src2, nbits / 8);
 273#endif
 274        return __bitmap_equal(src1, src2, nbits);
 275}
 276
 277static inline int bitmap_intersects(const unsigned long *src1,
 278                        const unsigned long *src2, unsigned int nbits)
 279{
 280        if (small_const_nbits(nbits))
 281                return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 282        else
 283                return __bitmap_intersects(src1, src2, nbits);
 284}
 285
 286static inline int bitmap_subset(const unsigned long *src1,
 287                        const unsigned long *src2, unsigned int nbits)
 288{
 289        if (small_const_nbits(nbits))
 290                return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 291        else
 292                return __bitmap_subset(src1, src2, nbits);
 293}
 294
 295static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 296{
 297        if (small_const_nbits(nbits))
 298                return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 299
 300        return find_first_bit(src, nbits) == nbits;
 301}
 302
 303static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 304{
 305        if (small_const_nbits(nbits))
 306                return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 307
 308        return find_first_zero_bit(src, nbits) == nbits;
 309}
 310
 311static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
 312{
 313        if (small_const_nbits(nbits))
 314                return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 315        return __bitmap_weight(src, nbits);
 316}
 317
 318static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
 319                                unsigned int shift, int nbits)
 320{
 321        if (small_const_nbits(nbits))
 322                *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
 323        else
 324                __bitmap_shift_right(dst, src, shift, nbits);
 325}
 326
 327static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 328                                unsigned int shift, unsigned int nbits)
 329{
 330        if (small_const_nbits(nbits))
 331                *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
 332        else
 333                __bitmap_shift_left(dst, src, shift, nbits);
 334}
 335
 336static inline int bitmap_parse(const char *buf, unsigned int buflen,
 337                        unsigned long *maskp, int nmaskbits)
 338{
 339        return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 340}
 341
 342/*
 343 * bitmap_from_u64 - Check and swap words within u64.
 344 *  @mask: source bitmap
 345 *  @dst:  destination bitmap
 346 *
 347 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
 348 * to read u64 mask, we will get the wrong word.
 349 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
 350 * but we expect the lower 32-bits of u64.
 351 */
 352static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
 353{
 354        dst[0] = mask & ULONG_MAX;
 355
 356        if (sizeof(mask) > sizeof(unsigned long))
 357                dst[1] = mask >> 32;
 358}
 359
 360#endif /* __ASSEMBLY__ */
 361
 362#endif /* __LINUX_BITMAP_H */
 363