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