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