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_shift_right(dst, src, n, nbits)       *dst = *src >> n
  46  * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  47  * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  48  * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  49  * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  50  * bitmap_parse(buf, buflen, dst, nbits)        Parse bitmap dst from kernel buf
  51  * bitmap_parse_user(ubuf, ulen, dst, nbits)    Parse bitmap dst from user buf
  52  * bitmap_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  53  * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  54  * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  55  * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  56  * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  57  */
  58
  59 /*
  60  * Also the following operations in asm/bitops.h apply to bitmaps.
  61  *
  62  * set_bit(bit, addr)                   *addr |= bit
  63  * clear_bit(bit, addr)                 *addr &= ~bit
  64  * change_bit(bit, addr)                *addr ^= bit
  65  * test_bit(bit, addr)                  Is bit set in *addr?
  66  * test_and_set_bit(bit, addr)          Set bit and return old value
  67  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  68  * test_and_change_bit(bit, addr)       Change bit and return old value
  69  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  70  * find_first_bit(addr, nbits)          Position first set bit in *addr
  71  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  72  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  73  */
  74
  75 /*
  76  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  77  * to declare an array named 'name' of just enough unsigned longs to
  78  * contain all bit positions from 0 to 'bits' - 1.
  79  */
  80
  81 /*
  82  * lib/bitmap.c provides these functions:
  83  */
  84
  85 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  86 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  87 extern int __bitmap_equal(const unsigned long *bitmap1,
  88                         const unsigned long *bitmap2, int bits);
  89 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  90                         int bits);
  91 extern void __bitmap_shift_right(unsigned long *dst,
  92                         const unsigned long *src, int shift, int bits);
  93 extern void __bitmap_shift_left(unsigned long *dst,
  94                         const unsigned long *src, int shift, int bits);
  95 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  96                         const unsigned long *bitmap2, int bits);
  97 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  98                         const unsigned long *bitmap2, int bits);
  99 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 100                         const unsigned long *bitmap2, int bits);
 101 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 102                         const unsigned long *bitmap2, int bits);
 103 extern int __bitmap_intersects(const unsigned long *bitmap1,
 104                         const unsigned long *bitmap2, int bits);
 105 extern int __bitmap_subset(const unsigned long *bitmap1,
 106                         const unsigned long *bitmap2, int bits);
 107 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 108
 109 extern int bitmap_scnprintf(char *buf, unsigned int len,
 110                         const unsigned long *src, int nbits);
 111 extern int bitmap_scnprintf_len(unsigned int len);
 112 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 113                         unsigned long *dst, int nbits);
 114 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 115                         unsigned long *dst, int nbits);
 116 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 117                         const unsigned long *src, int nbits);
 118 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 119                         int nmaskbits);
 120 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 121                 const unsigned long *old, const unsigned long *new, int bits);
 122 extern int bitmap_bitremap(int oldbit,
 123                 const unsigned long *old, const unsigned long *new, int bits);
 124 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 125 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 126 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 127
 128 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 129 (                                                                       \
 130         ((nbits) % BITS_PER_LONG) ?                                     \
 131                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 132 )
 133
 134 static inline void bitmap_zero(unsigned long *dst, int nbits)
 135 {
 136         if (nbits <= BITS_PER_LONG)
 137                 *dst = 0UL;
 138         else {
 139                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 140                 memset(dst, 0, len);
 141         }
 142 }
 143
 144 static inline void bitmap_fill(unsigned long *dst, int nbits)
 145 {
 146         size_t nlongs = BITS_TO_LONGS(nbits);
 147         if (nlongs > 1) {
 148                 int len = (nlongs - 1) * sizeof(unsigned long);
 149                 memset(dst, 0xff,  len);
 150         }
 151         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 152 }
 153
 154 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 155                         int nbits)
 156 {
 157         if (nbits <= BITS_PER_LONG)
 158                 *dst = *src;
 159         else {
 160                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 161                 memcpy(dst, src, len);
 162         }
 163 }
 164
 165 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 166                         const unsigned long *src2, int nbits)
 167 {
 168         if (nbits <= BITS_PER_LONG)
 169                 *dst = *src1 & *src2;
 170         else
 171                 __bitmap_and(dst, src1, src2, nbits);
 172 }
 173
 174 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 175                         const unsigned long *src2, int nbits)
 176 {
 177         if (nbits <= BITS_PER_LONG)
 178                 *dst = *src1 | *src2;
 179         else
 180                 __bitmap_or(dst, src1, src2, nbits);
 181 }
 182
 183 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 184                         const unsigned long *src2, int nbits)
 185 {
 186         if (nbits <= BITS_PER_LONG)
 187                 *dst = *src1 ^ *src2;
 188         else
 189                 __bitmap_xor(dst, src1, src2, nbits);
 190 }
 191
 192 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 193                         const unsigned long *src2, int nbits)
 194 {
 195         if (nbits <= BITS_PER_LONG)
 196                 *dst = *src1 & ~(*src2);
 197         else
 198                 __bitmap_andnot(dst, src1, src2, nbits);
 199 }
 200
 201 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 202                         int nbits)
 203 {
 204         if (nbits <= BITS_PER_LONG)
 205                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 206         else
 207                 __bitmap_complement(dst, src, nbits);
 208 }
 209
 210 static inline int bitmap_equal(const unsigned long *src1,
 211                         const unsigned long *src2, int nbits)
 212 {
 213         if (nbits <= BITS_PER_LONG)
 214                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 215         else
 216                 return __bitmap_equal(src1, src2, nbits);
 217 }
 218
 219 static inline int bitmap_intersects(const unsigned long *src1,
 220                         const unsigned long *src2, int nbits)
 221 {
 222         if (nbits <= BITS_PER_LONG)
 223                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 224         else
 225                 return __bitmap_intersects(src1, src2, nbits);
 226 }
 227
 228 static inline int bitmap_subset(const unsigned long *src1,
 229                         const unsigned long *src2, int nbits)
 230 {
 231         if (nbits <= BITS_PER_LONG)
 232                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 233         else
 234                 return __bitmap_subset(src1, src2, nbits);
 235 }
 236
 237 static inline int bitmap_empty(const unsigned long *src, int nbits)
 238 {
 239         if (nbits <= BITS_PER_LONG)
 240                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 241         else
 242                 return __bitmap_empty(src, nbits);
 243 }
 244
 245 static inline int bitmap_full(const unsigned long *src, int nbits)
 246 {
 247         if (nbits <= BITS_PER_LONG)
 248                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 249         else
 250                 return __bitmap_full(src, nbits);
 251 }
 252
 253 static inline int bitmap_weight(const unsigned long *src, int nbits)
 254 {
 255         if (nbits <= BITS_PER_LONG)
 256                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 257         return __bitmap_weight(src, nbits);
 258 }
 259
 260 static inline void bitmap_shift_right(unsigned long *dst,
 261                         const unsigned long *src, int n, int nbits)
 262 {
 263         if (nbits <= BITS_PER_LONG)
 264                 *dst = *src >> n;
 265         else
 266                 __bitmap_shift_right(dst, src, n, nbits);
 267 }
 268
 269 static inline void bitmap_shift_left(unsigned long *dst,
 270                         const unsigned long *src, int n, int nbits)
 271 {
 272         if (nbits <= BITS_PER_LONG)
 273                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 274         else
 275                 __bitmap_shift_left(dst, src, n, nbits);
 276 }
 277
 278 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 279                         unsigned long *maskp, int nmaskbits)
 280 {
 281         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 282 }
 283
 284 #endif /* __ASSEMBLY__ */
 285
 286 #endif /* __LINUX_BITMAP_H */