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
  92 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  93 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  94 extern int __bitmap_equal(const unsigned long *bitmap1,
  95                           const unsigned long *bitmap2, unsigned int nbits);
  96 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  97                         unsigned int nbits);
  98 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
  99                                 unsigned int shift, unsigned int nbits);
 100 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 101                                 unsigned int shift, unsigned int nbits);
 102 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 103                         const unsigned long *bitmap2, unsigned int nbits);
 104 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 105                         const unsigned long *bitmap2, unsigned int nbits);
 106 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 107                         const unsigned long *bitmap2, unsigned int nbits);
 108 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 109                         const unsigned long *bitmap2, unsigned int nbits);
 110 extern int __bitmap_intersects(const unsigned long *bitmap1,
 111                         const unsigned long *bitmap2, unsigned int nbits);
 112 extern int __bitmap_subset(const unsigned long *bitmap1,
 113                         const unsigned long *bitmap2, unsigned int nbits);
 114 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 115 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
 116 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
 117
 118 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
 119                                                     unsigned long size,
 120                                                     unsigned long start,
 121                                                     unsigned int nr,
 122                                                     unsigned long align_mask,
 123                                                     unsigned long align_offset);
 124
 125 /**
 126  * bitmap_find_next_zero_area - find a contiguous aligned zero area
 127  * @map: The address to base the search on
 128  * @size: The bitmap size in bits
 129  * @start: The bitnumber to start searching at
 130  * @nr: The number of zeroed bits we're looking for
 131  * @align_mask: Alignment mask for zero area
 132  *
 133  * The @align_mask should be one less than a power of 2; the effect is that
 134  * the bit offset of all zero areas this function finds is multiples of that
 135  * power of 2. A @align_mask of 0 means no alignment is required.
 136  */
 137 static inline unsigned long
 138 bitmap_find_next_zero_area(unsigned long *map,
 139                            unsigned long size,
 140                            unsigned long start,
 141                            unsigned int nr,
 142                            unsigned long align_mask)
 143 {
 144         return bitmap_find_next_zero_area_off(map, size, start, nr,
 145                                               align_mask, 0);
 146 }
 147
 148 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 149                         unsigned long *dst, int nbits);
 150 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 151                         unsigned long *dst, int nbits);
 152 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 153                         int nmaskbits);
 154 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 155                         unsigned long *dst, int nbits);
 156 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 157                 const unsigned long *old, const unsigned long *new, unsigned int nbits);
 158 extern int bitmap_bitremap(int oldbit,
 159                 const unsigned long *old, const unsigned long *new, int bits);
 160 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 161                 const unsigned long *relmap, unsigned int bits);
 162 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 163                 unsigned int sz, unsigned int nbits);
 164 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 165 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 166 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 167 extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
 168                                          unsigned int nbits,
 169                                          const u32 *buf,
 170                                          unsigned int nwords);
 171 extern unsigned int bitmap_to_u32array(u32 *buf,
 172                                        unsigned int nwords,
 173                                        const unsigned long *bitmap,
 174                                        unsigned int nbits);
 175 #ifdef __BIG_ENDIAN
 176 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
 177 #else
 178 #define bitmap_copy_le bitmap_copy
 179 #endif
 180 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
 181 extern int bitmap_print_to_pagebuf(bool list, char *buf,
 182                                    const unsigned long *maskp, int nmaskbits);
 183
 184 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 185 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 186
 187 #define small_const_nbits(nbits) \
 188         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 189
 190 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 191 {
 192         if (small_const_nbits(nbits))
 193                 *dst = 0UL;
 194         else {
 195                 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 196                 memset(dst, 0, len);
 197         }
 198 }
 199
 200 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 201 {
 202         unsigned int nlongs = BITS_TO_LONGS(nbits);
 203         if (!small_const_nbits(nbits)) {
 204                 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
 205                 memset(dst, 0xff,  len);
 206         }
 207         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 208 }
 209
 210 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 211                         unsigned int nbits)
 212 {
 213         if (small_const_nbits(nbits))
 214                 *dst = *src;
 215         else {
 216                 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 217                 memcpy(dst, src, len);
 218         }
 219 }
 220
 221 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 222                         const unsigned long *src2, unsigned int nbits)
 223 {
 224         if (small_const_nbits(nbits))
 225                 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 226         return __bitmap_and(dst, src1, src2, nbits);
 227 }
 228
 229 static inline void bitmap_or(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_or(dst, src1, src2, nbits);
 236 }
 237
 238 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 239                         const unsigned long *src2, unsigned int nbits)
 240 {
 241         if (small_const_nbits(nbits))
 242                 *dst = *src1 ^ *src2;
 243         else
 244                 __bitmap_xor(dst, src1, src2, nbits);
 245 }
 246
 247 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 248                         const unsigned long *src2, unsigned int nbits)
 249 {
 250         if (small_const_nbits(nbits))
 251                 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 252         return __bitmap_andnot(dst, src1, src2, nbits);
 253 }
 254
 255 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 256                         unsigned int nbits)
 257 {
 258         if (small_const_nbits(nbits))
 259                 *dst = ~(*src);
 260         else
 261                 __bitmap_complement(dst, src, nbits);
 262 }
 263
 264 static inline int bitmap_equal(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));
 269         if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 270                 return !memcmp(src1, src2, nbits / 8);
 271         return __bitmap_equal(src1, src2, nbits);
 272 }
 273
 274 static inline int bitmap_intersects(const unsigned long *src1,
 275                         const unsigned long *src2, unsigned int nbits)
 276 {
 277         if (small_const_nbits(nbits))
 278                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 279         else
 280                 return __bitmap_intersects(src1, src2, nbits);
 281 }
 282
 283 static inline int bitmap_subset(const unsigned long *src1,
 284                         const unsigned long *src2, unsigned int nbits)
 285 {
 286         if (small_const_nbits(nbits))
 287                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 288         else
 289                 return __bitmap_subset(src1, src2, nbits);
 290 }
 291
 292 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 293 {
 294         if (small_const_nbits(nbits))
 295                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 296
 297         return find_first_bit(src, nbits) == nbits;
 298 }
 299
 300 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 301 {
 302         if (small_const_nbits(nbits))
 303                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 304
 305         return find_first_zero_bit(src, nbits) == nbits;
 306 }
 307
 308 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
 309 {
 310         if (small_const_nbits(nbits))
 311                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 312         return __bitmap_weight(src, nbits);
 313 }
 314
 315 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
 316                 unsigned int nbits)
 317 {
 318         if (__builtin_constant_p(nbits) && nbits == 1)
 319                 __set_bit(start, map);
 320         else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
 321                  __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 322                 memset((char *)map + start / 8, 0xff, nbits / 8);
 323         else
 324                 __bitmap_set(map, start, nbits);
 325 }
 326
 327 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
 328                 unsigned int nbits)
 329 {
 330         if (__builtin_constant_p(nbits) && nbits == 1)
 331                 __clear_bit(start, map);
 332         else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
 333                  __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
 334                 memset((char *)map + start / 8, 0, nbits / 8);
 335         else
 336                 __bitmap_clear(map, start, nbits);
 337 }
 338
 339 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
 340                                 unsigned int shift, int nbits)
 341 {
 342         if (small_const_nbits(nbits))
 343                 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
 344         else
 345                 __bitmap_shift_right(dst, src, shift, nbits);
 346 }
 347
 348 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
 349                                 unsigned int shift, unsigned int nbits)
 350 {
 351         if (small_const_nbits(nbits))
 352                 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
 353         else
 354                 __bitmap_shift_left(dst, src, shift, nbits);
 355 }
 356
 357 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 358                         unsigned long *maskp, int nmaskbits)
 359 {
 360         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 361 }
 362
 363 /*
 364  * bitmap_from_u64 - Check and swap words within u64.
 365  *  @mask: source bitmap
 366  *  @dst:  destination bitmap
 367  *
 368  * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
 369  * to read u64 mask, we will get the wrong word.
 370  * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
 371  * but we expect the lower 32-bits of u64.
 372  */
 373 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
 374 {
 375         dst[0] = mask & ULONG_MAX;
 376
 377         if (sizeof(mask) > sizeof(unsigned long))
 378                 dst[1] = mask >> 32;
 379 }
 380
 381 #endif /* __ASSEMBLY__ */
 382
 383 #endif /* __LINUX_BITMAP_H */