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
  10 /*
  11  * bitmaps provide bit arrays that consume one or more unsigned
  12  * longs.  The bitmap interface and available operations are listed
  13  * here, in bitmap.h
  14  *
  15  * Function implementations generic to all architectures are in
  16  * lib/bitmap.c.  Functions implementations that are architecture
  17  * specific are in various include/asm-<arch>/bitops.h headers
  18  * and other arch/<arch> specific files.
  19  *
  20  * See lib/bitmap.c for more details.
  21  */
  22
  23 /*
  24  * The available bitmap operations and their rough meaning in the
  25  * case that the bitmap is a single unsigned long are thus:
  26  *
  27  * bitmap_zero(dst, nbits)                      *dst = 0UL
  28  * bitmap_fill(dst, nbits)                      *dst = ~0UL
  29  * bitmap_copy(dst, src, nbits)                 *dst = *src
  30  * bitmap_and(dst, src1, src2, nbits)           *dst = *src1 & *src2
  31  * bitmap_or(dst, src1, src2, nbits)            *dst = *src1 | *src2
  32  * bitmap_xor(dst, src1, src2, nbits)           *dst = *src1 ^ *src2
  33  * bitmap_andnot(dst, src1, src2, nbits)        *dst = *src1 & ~(*src2)
  34  * bitmap_complement(dst, src, nbits)           *dst = ~(*src)
  35  * bitmap_equal(src1, src2, nbits)              Are *src1 and *src2 equal?
  36  * bitmap_intersects(src1, src2, nbits)         Do *src1 and *src2 overlap?
  37  * bitmap_subset(src1, src2, nbits)             Is *src1 a subset of *src2?
  38  * bitmap_empty(src, nbits)                     Are all bits zero in *src?
  39  * bitmap_full(src, nbits)                      Are all bits set in *src?
  40  * bitmap_weight(src, nbits)                    Hamming Weight: number set bits
  41  * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  42  * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  43  * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  44  * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  45  * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  46  * bitmap_parse(ubuf, ulen, dst, nbits)         Parse bitmap dst from user buf
  47  * bitmap_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  48  * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  49  */
  50
  51 /*
  52  * Also the following operations in asm/bitops.h apply to bitmaps.
  53  *
  54  * set_bit(bit, addr)                   *addr |= bit
  55  * clear_bit(bit, addr)                 *addr &= ~bit
  56  * change_bit(bit, addr)                *addr ^= bit
  57  * test_bit(bit, addr)                  Is bit set in *addr?
  58  * test_and_set_bit(bit, addr)          Set bit and return old value
  59  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  60  * test_and_change_bit(bit, addr)       Change bit and return old value
  61  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  62  * find_first_bit(addr, nbits)          Position first set bit in *addr
  63  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  64  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  65  */
  66
  67 /*
  68  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  69  * to declare an array named 'name' of just enough unsigned longs to
  70  * contain all bit positions from 0 to 'bits' - 1.
  71  */
  72
  73 /*
  74  * lib/bitmap.c provides these functions:
  75  */
  76
  77 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  78 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  79 extern int __bitmap_equal(const unsigned long *bitmap1,
  80                         const unsigned long *bitmap2, int bits);
  81 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  82                         int bits);
  83 extern void __bitmap_shift_right(unsigned long *dst,
  84                         const unsigned long *src, int shift, int bits);
  85 extern void __bitmap_shift_left(unsigned long *dst,
  86                         const unsigned long *src, int shift, int bits);
  87 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  88                         const unsigned long *bitmap2, int bits);
  89 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  90                         const unsigned long *bitmap2, int bits);
  91 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  92                         const unsigned long *bitmap2, int bits);
  93 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
  94                         const unsigned long *bitmap2, int bits);
  95 extern int __bitmap_intersects(const unsigned long *bitmap1,
  96                         const unsigned long *bitmap2, int bits);
  97 extern int __bitmap_subset(const unsigned long *bitmap1,
  98                         const unsigned long *bitmap2, int bits);
  99 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 100
 101 extern int bitmap_scnprintf(char *buf, unsigned int len,
 102                         const unsigned long *src, int nbits);
 103 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
 104                         unsigned long *dst, int nbits);
 105 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 106                         const unsigned long *src, int nbits);
 107 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 108                         int nmaskbits);
 109 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 110                 const unsigned long *old, const unsigned long *new, int bits);
 111 extern int bitmap_bitremap(int oldbit,
 112                 const unsigned long *old, const unsigned long *new, int bits);
 113 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 114 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 115 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 116
 117 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 118 (                                                                       \
 119         ((nbits) % BITS_PER_LONG) ?                                     \
 120                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 121 )
 122
 123 static inline void bitmap_zero(unsigned long *dst, int nbits)
 124 {
 125         if (nbits <= BITS_PER_LONG)
 126                 *dst = 0UL;
 127         else {
 128                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 129                 memset(dst, 0, len);
 130         }
 131 }
 132
 133 static inline void bitmap_fill(unsigned long *dst, int nbits)
 134 {
 135         size_t nlongs = BITS_TO_LONGS(nbits);
 136         if (nlongs > 1) {
 137                 int len = (nlongs - 1) * sizeof(unsigned long);
 138                 memset(dst, 0xff,  len);
 139         }
 140         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 141 }
 142
 143 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 144                         int nbits)
 145 {
 146         if (nbits <= BITS_PER_LONG)
 147                 *dst = *src;
 148         else {
 149                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 150                 memcpy(dst, src, len);
 151         }
 152 }
 153
 154 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 155                         const unsigned long *src2, int nbits)
 156 {
 157         if (nbits <= BITS_PER_LONG)
 158                 *dst = *src1 & *src2;
 159         else
 160                 __bitmap_and(dst, src1, src2, nbits);
 161 }
 162
 163 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 164                         const unsigned long *src2, int nbits)
 165 {
 166         if (nbits <= BITS_PER_LONG)
 167                 *dst = *src1 | *src2;
 168         else
 169                 __bitmap_or(dst, src1, src2, nbits);
 170 }
 171
 172 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 173                         const unsigned long *src2, int nbits)
 174 {
 175         if (nbits <= BITS_PER_LONG)
 176                 *dst = *src1 ^ *src2;
 177         else
 178                 __bitmap_xor(dst, src1, src2, nbits);
 179 }
 180
 181 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 182                         const unsigned long *src2, int nbits)
 183 {
 184         if (nbits <= BITS_PER_LONG)
 185                 *dst = *src1 & ~(*src2);
 186         else
 187                 __bitmap_andnot(dst, src1, src2, nbits);
 188 }
 189
 190 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 191                         int nbits)
 192 {
 193         if (nbits <= BITS_PER_LONG)
 194                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 195         else
 196                 __bitmap_complement(dst, src, nbits);
 197 }
 198
 199 static inline int bitmap_equal(const unsigned long *src1,
 200                         const unsigned long *src2, int nbits)
 201 {
 202         if (nbits <= BITS_PER_LONG)
 203                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 204         else
 205                 return __bitmap_equal(src1, src2, nbits);
 206 }
 207
 208 static inline int bitmap_intersects(const unsigned long *src1,
 209                         const unsigned long *src2, int nbits)
 210 {
 211         if (nbits <= BITS_PER_LONG)
 212                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 213         else
 214                 return __bitmap_intersects(src1, src2, nbits);
 215 }
 216
 217 static inline int bitmap_subset(const unsigned long *src1,
 218                         const unsigned long *src2, int nbits)
 219 {
 220         if (nbits <= BITS_PER_LONG)
 221                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 222         else
 223                 return __bitmap_subset(src1, src2, nbits);
 224 }
 225
 226 static inline int bitmap_empty(const unsigned long *src, int nbits)
 227 {
 228         if (nbits <= BITS_PER_LONG)
 229                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 230         else
 231                 return __bitmap_empty(src, nbits);
 232 }
 233
 234 static inline int bitmap_full(const unsigned long *src, int nbits)
 235 {
 236         if (nbits <= BITS_PER_LONG)
 237                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 238         else
 239                 return __bitmap_full(src, nbits);
 240 }
 241
 242 static inline int bitmap_weight(const unsigned long *src, int nbits)
 243 {
 244         return __bitmap_weight(src, nbits);
 245 }
 246
 247 static inline void bitmap_shift_right(unsigned long *dst,
 248                         const unsigned long *src, int n, int nbits)
 249 {
 250         if (nbits <= BITS_PER_LONG)
 251                 *dst = *src >> n;
 252         else
 253                 __bitmap_shift_right(dst, src, n, nbits);
 254 }
 255
 256 static inline void bitmap_shift_left(unsigned long *dst,
 257                         const unsigned long *src, int n, int nbits)
 258 {
 259         if (nbits <= BITS_PER_LONG)
 260                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 261         else
 262                 __bitmap_shift_left(dst, src, n, nbits);
 263 }
 264
 265 #endif /* __ASSEMBLY__ */
 266
 267 #endif /* __LINUX_BITMAP_H */