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