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  * Note that nbits should be always a compile time evaluable constant.
  28  * Otherwise many inlines will generate horrible code.
  29  *
  30  * bitmap_zero(dst, nbits)                      *dst = 0UL
  31  * bitmap_fill(dst, nbits)                      *dst = ~0UL
  32  * bitmap_copy(dst, src, nbits)                 *dst = *src
  33  * bitmap_and(dst, src1, src2, nbits)           *dst = *src1 & *src2
  34  * bitmap_or(dst, src1, src2, nbits)            *dst = *src1 | *src2
  35  * bitmap_xor(dst, src1, src2, nbits)           *dst = *src1 ^ *src2
  36  * bitmap_andnot(dst, src1, src2, nbits)        *dst = *src1 & ~(*src2)
  37  * bitmap_complement(dst, src, nbits)           *dst = ~(*src)
  38  * bitmap_equal(src1, src2, nbits)              Are *src1 and *src2 equal?
  39  * bitmap_intersects(src1, src2, nbits)         Do *src1 and *src2 overlap?
  40  * bitmap_subset(src1, src2, nbits)             Is *src1 a subset of *src2?
  41  * bitmap_empty(src, nbits)                     Are all bits zero in *src?
  42  * bitmap_full(src, nbits)                      Are all bits set in *src?
  43  * bitmap_weight(src, nbits)                    Hamming Weight: number set bits
  44  * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  45  * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  46  * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  47  * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  48  * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  49  * bitmap_parse(ubuf, ulen, dst, nbits)         Parse bitmap dst from user buf
  50  * bitmap_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  51  * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  52  * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  53  * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  54  * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  55  */
  56
  57 /*
  58  * Also the following operations in asm/bitops.h apply to bitmaps.
  59  *
  60  * set_bit(bit, addr)                   *addr |= bit
  61  * clear_bit(bit, addr)                 *addr &= ~bit
  62  * change_bit(bit, addr)                *addr ^= bit
  63  * test_bit(bit, addr)                  Is bit set in *addr?
  64  * test_and_set_bit(bit, addr)          Set bit and return old value
  65  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  66  * test_and_change_bit(bit, addr)       Change bit and return old value
  67  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  68  * find_first_bit(addr, nbits)          Position first set bit in *addr
  69  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  70  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  71  */
  72
  73 /*
  74  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  75  * to declare an array named 'name' of just enough unsigned longs to
  76  * contain all bit positions from 0 to 'bits' - 1.
  77  */
  78
  79 /*
  80  * lib/bitmap.c provides these functions:
  81  */
  82
  83 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  84 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  85 extern int __bitmap_equal(const unsigned long *bitmap1,
  86                         const unsigned long *bitmap2, int bits);
  87 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  88                         int bits);
  89 extern void __bitmap_shift_right(unsigned long *dst,
  90                         const unsigned long *src, int shift, int bits);
  91 extern void __bitmap_shift_left(unsigned long *dst,
  92                         const unsigned long *src, int shift, int bits);
  93 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  94                         const unsigned long *bitmap2, int bits);
  95 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  96                         const unsigned long *bitmap2, int bits);
  97 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  98                         const unsigned long *bitmap2, int bits);
  99 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 100                         const unsigned long *bitmap2, int bits);
 101 extern int __bitmap_intersects(const unsigned long *bitmap1,
 102                         const unsigned long *bitmap2, int bits);
 103 extern int __bitmap_subset(const unsigned long *bitmap1,
 104                         const unsigned long *bitmap2, int bits);
 105 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 106
 107 extern int bitmap_scnprintf(char *buf, unsigned int len,
 108                         const unsigned long *src, int nbits);
 109 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
 110                         unsigned long *dst, int nbits);
 111 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 112                         const unsigned long *src, int nbits);
 113 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 114                         int nmaskbits);
 115 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 116                 const unsigned long *old, const unsigned long *new, int bits);
 117 extern int bitmap_bitremap(int oldbit,
 118                 const unsigned long *old, const unsigned long *new, int bits);
 119 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 120 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 121 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 122
 123 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 124 (                                                                       \
 125         ((nbits) % BITS_PER_LONG) ?                                     \
 126                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 127 )
 128
 129 static inline void bitmap_zero(unsigned long *dst, int nbits)
 130 {
 131         if (nbits <= BITS_PER_LONG)
 132                 *dst = 0UL;
 133         else {
 134                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 135                 memset(dst, 0, len);
 136         }
 137 }
 138
 139 static inline void bitmap_fill(unsigned long *dst, int nbits)
 140 {
 141         size_t nlongs = BITS_TO_LONGS(nbits);
 142         if (nlongs > 1) {
 143                 int len = (nlongs - 1) * sizeof(unsigned long);
 144                 memset(dst, 0xff,  len);
 145         }
 146         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 147 }
 148
 149 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 150                         int nbits)
 151 {
 152         if (nbits <= BITS_PER_LONG)
 153                 *dst = *src;
 154         else {
 155                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 156                 memcpy(dst, src, len);
 157         }
 158 }
 159
 160 static inline void bitmap_and(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_and(dst, src1, src2, nbits);
 167 }
 168
 169 static inline void bitmap_or(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_or(dst, src1, src2, nbits);
 176 }
 177
 178 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 179                         const unsigned long *src2, int nbits)
 180 {
 181         if (nbits <= BITS_PER_LONG)
 182                 *dst = *src1 ^ *src2;
 183         else
 184                 __bitmap_xor(dst, src1, src2, nbits);
 185 }
 186
 187 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 188                         const unsigned long *src2, int nbits)
 189 {
 190         if (nbits <= BITS_PER_LONG)
 191                 *dst = *src1 & ~(*src2);
 192         else
 193                 __bitmap_andnot(dst, src1, src2, nbits);
 194 }
 195
 196 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 197                         int nbits)
 198 {
 199         if (nbits <= BITS_PER_LONG)
 200                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 201         else
 202                 __bitmap_complement(dst, src, nbits);
 203 }
 204
 205 static inline int bitmap_equal(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_equal(src1, src2, nbits);
 212 }
 213
 214 static inline int bitmap_intersects(const unsigned long *src1,
 215                         const unsigned long *src2, int nbits)
 216 {
 217         if (nbits <= BITS_PER_LONG)
 218                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 219         else
 220                 return __bitmap_intersects(src1, src2, nbits);
 221 }
 222
 223 static inline int bitmap_subset(const unsigned long *src1,
 224                         const unsigned long *src2, int nbits)
 225 {
 226         if (nbits <= BITS_PER_LONG)
 227                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 228         else
 229                 return __bitmap_subset(src1, src2, nbits);
 230 }
 231
 232 static inline int bitmap_empty(const unsigned long *src, int nbits)
 233 {
 234         if (nbits <= BITS_PER_LONG)
 235                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 236         else
 237                 return __bitmap_empty(src, nbits);
 238 }
 239
 240 static inline int bitmap_full(const unsigned long *src, int nbits)
 241 {
 242         if (nbits <= BITS_PER_LONG)
 243                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 244         else
 245                 return __bitmap_full(src, nbits);
 246 }
 247
 248 static inline int bitmap_weight(const unsigned long *src, int nbits)
 249 {
 250         if (nbits <= BITS_PER_LONG)
 251                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 252         return __bitmap_weight(src, nbits);
 253 }
 254
 255 static inline void bitmap_shift_right(unsigned long *dst,
 256                         const unsigned long *src, int n, int nbits)
 257 {
 258         if (nbits <= BITS_PER_LONG)
 259                 *dst = *src >> n;
 260         else
 261                 __bitmap_shift_right(dst, src, n, nbits);
 262 }
 263
 264 static inline void bitmap_shift_left(unsigned long *dst,
 265                         const unsigned long *src, int n, int nbits)
 266 {
 267         if (nbits <= BITS_PER_LONG)
 268                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 269         else
 270                 __bitmap_shift_left(dst, src, n, nbits);
 271 }
 272
 273 #endif /* __ASSEMBLY__ */
 274
 275 #endif /* __LINUX_BITMAP_H */