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_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  44  * bitmap_parse(ubuf, ulen, dst, nbits)         Parse bitmap dst from buf
  45  */
  46
  47 /*
  48  * Also the following operations in asm/bitops.h apply to bitmaps.
  49  *
  50  * set_bit(bit, addr)                   *addr |= bit
  51  * clear_bit(bit, addr)                 *addr &= ~bit
  52  * change_bit(bit, addr)                *addr ^= bit
  53  * test_bit(bit, addr)                  Is bit set in *addr?
  54  * test_and_set_bit(bit, addr)          Set bit and return old value
  55  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  56  * test_and_change_bit(bit, addr)       Change bit and return old value
  57  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  58  * find_first_bit(addr, nbits)          Position first set bit in *addr
  59  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  60  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  61  */
  62
  63 /*
  64  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  65  * to declare an array named 'name' of just enough unsigned longs to
  66  * contain all bit positions from 0 to 'bits' - 1.
  67  */
  68
  69 /*
  70  * lib/bitmap.c provides these functions:
  71  */
  72
  73 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  74 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  75 extern int __bitmap_equal(const unsigned long *bitmap1,
  76                         const unsigned long *bitmap2, int bits);
  77 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  78                         int bits);
  79 extern void __bitmap_shift_right(unsigned long *dst,
  80                         const unsigned long *src, int shift, int bits);
  81 extern void __bitmap_shift_left(unsigned long *dst,
  82                         const unsigned long *src, int shift, int bits);
  83 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  84                         const unsigned long *bitmap2, int bits);
  85 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  86                         const unsigned long *bitmap2, int bits);
  87 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  88                         const unsigned long *bitmap2, int bits);
  89 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
  90                         const unsigned long *bitmap2, int bits);
  91 extern int __bitmap_intersects(const unsigned long *bitmap1,
  92                         const unsigned long *bitmap2, int bits);
  93 extern int __bitmap_subset(const unsigned long *bitmap1,
  94                         const unsigned long *bitmap2, int bits);
  95 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
  96
  97 extern int bitmap_scnprintf(char *buf, unsigned int len,
  98                         const unsigned long *src, int nbits);
  99 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
 100                         unsigned long *dst, int nbits);
 101 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 102 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 103 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 104
 105 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 106 (                                                                       \
 107         ((nbits) % BITS_PER_LONG) ?                                     \
 108                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 109 )
 110
 111 static inline void bitmap_zero(unsigned long *dst, int nbits)
 112 {
 113         if (nbits <= BITS_PER_LONG)
 114                 *dst = 0UL;
 115         else {
 116                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 117                 memset(dst, 0, len);
 118         }
 119 }
 120
 121 static inline void bitmap_fill(unsigned long *dst, int nbits)
 122 {
 123         size_t nlongs = BITS_TO_LONGS(nbits);
 124         if (nlongs > 1) {
 125                 int len = (nlongs - 1) * sizeof(unsigned long);
 126                 memset(dst, 0xff,  len);
 127         }
 128         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 129 }
 130
 131 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 132                         int nbits)
 133 {
 134         if (nbits <= BITS_PER_LONG)
 135                 *dst = *src;
 136         else {
 137                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 138                 memcpy(dst, src, len);
 139         }
 140 }
 141
 142 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 143                         const unsigned long *src2, int nbits)
 144 {
 145         if (nbits <= BITS_PER_LONG)
 146                 *dst = *src1 & *src2;
 147         else
 148                 __bitmap_and(dst, src1, src2, nbits);
 149 }
 150
 151 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 152                         const unsigned long *src2, int nbits)
 153 {
 154         if (nbits <= BITS_PER_LONG)
 155                 *dst = *src1 | *src2;
 156         else
 157                 __bitmap_or(dst, src1, src2, nbits);
 158 }
 159
 160 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 161                         const unsigned long *src2, int nbits)
 162 {
 163         if (nbits <= BITS_PER_LONG)
 164                 *dst = *src1 ^ *src2;
 165         else
 166                 __bitmap_xor(dst, src1, src2, nbits);
 167 }
 168
 169 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 170                         const unsigned long *src2, int nbits)
 171 {
 172         if (nbits <= BITS_PER_LONG)
 173                 *dst = *src1 & ~(*src2);
 174         else
 175                 __bitmap_andnot(dst, src1, src2, nbits);
 176 }
 177
 178 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 179                         int nbits)
 180 {
 181         if (nbits <= BITS_PER_LONG)
 182                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 183         else
 184                 __bitmap_complement(dst, src, nbits);
 185 }
 186
 187 static inline int bitmap_equal(const unsigned long *src1,
 188                         const unsigned long *src2, int nbits)
 189 {
 190         if (nbits <= BITS_PER_LONG)
 191                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 192         else
 193                 return __bitmap_equal(src1, src2, nbits);
 194 }
 195
 196 static inline int bitmap_intersects(const unsigned long *src1,
 197                         const unsigned long *src2, int nbits)
 198 {
 199         if (nbits <= BITS_PER_LONG)
 200                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 201         else
 202                 return __bitmap_intersects(src1, src2, nbits);
 203 }
 204
 205 static inline int bitmap_subset(const unsigned long *src1,
 206                         const unsigned long *src2, int nbits)
 207 {
 208         if (nbits <= BITS_PER_LONG)
 209                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 210         else
 211                 return __bitmap_subset(src1, src2, nbits);
 212 }
 213
 214 static inline int bitmap_empty(const unsigned long *src, int nbits)
 215 {
 216         if (nbits <= BITS_PER_LONG)
 217                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 218         else
 219                 return __bitmap_empty(src, nbits);
 220 }
 221
 222 static inline int bitmap_full(const unsigned long *src, int nbits)
 223 {
 224         if (nbits <= BITS_PER_LONG)
 225                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 226         else
 227                 return __bitmap_full(src, nbits);
 228 }
 229
 230 static inline int bitmap_weight(const unsigned long *src, int nbits)
 231 {
 232         return __bitmap_weight(src, nbits);
 233 }
 234
 235 static inline void bitmap_shift_right(unsigned long *dst,
 236                         const unsigned long *src, int n, int nbits)
 237 {
 238         if (nbits <= BITS_PER_LONG)
 239                 *dst = *src >> n;
 240         else
 241                 __bitmap_shift_right(dst, src, n, nbits);
 242 }
 243
 244 static inline void bitmap_shift_left(unsigned long *dst,
 245                         const unsigned long *src, int n, int nbits)
 246 {
 247         if (nbits <= BITS_PER_LONG)
 248                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 249         else
 250                 __bitmap_shift_left(dst, src, n, nbits);
 251 }
 252
 253 #endif /* __ASSEMBLY__ */
 254
 255 #endif /* __LINUX_BITMAP_H */