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
  90 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  91 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  92 extern int __bitmap_equal(const unsigned long *bitmap1,
  93                           const unsigned long *bitmap2, unsigned int nbits);
  94 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  95                         unsigned int nbits);
  96 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
  97                                 unsigned int shift, unsigned int nbits);
  98 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
  99                                 unsigned int shift, unsigned int nbits);
 100 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 101                         const unsigned long *bitmap2, unsigned int nbits);
 102 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 103                         const unsigned long *bitmap2, unsigned int nbits);
 104 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 105                         const unsigned long *bitmap2, unsigned int nbits);
 106 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 107                         const unsigned long *bitmap2, unsigned int nbits);
 108 extern int __bitmap_intersects(const unsigned long *bitmap1,
 109                         const unsigned long *bitmap2, unsigned int nbits);
 110 extern int __bitmap_subset(const unsigned long *bitmap1,
 111                         const unsigned long *bitmap2, unsigned int nbits);
 112 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 113
 114 extern void bitmap_set(unsigned long *map, unsigned int start, int len);
 115 extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
 116
 117 extern 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  */
 136 static inline unsigned long
 137 bitmap_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
 147 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 148                         unsigned long *dst, int nbits);
 149 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 150                         unsigned long *dst, int nbits);
 151 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 152                         int nmaskbits);
 153 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 154                         unsigned long *dst, int nbits);
 155 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 156                 const unsigned long *old, const unsigned long *new, unsigned int nbits);
 157 extern int bitmap_bitremap(int oldbit,
 158                 const unsigned long *old, const unsigned long *new, int bits);
 159 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 160                 const unsigned long *relmap, unsigned int bits);
 161 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 162                 unsigned int sz, unsigned int nbits);
 163 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 164 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 165 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 166 #ifdef __BIG_ENDIAN
 167 extern 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
 171 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 172 extern 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
 181 static 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
 191 static 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
 201 static 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
 212 static 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
 220 static 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
 229 static 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
 238 static 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
 246 static 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
 255 static 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
 264 static 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
 273 static 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
 282 static 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
 290 static 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
 298 static 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
 305 static 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
 314 static 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
 323 static 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 */