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_onto(dst, orig, relmap, nbits)        *dst = orig relative to relmap
  50  * bitmap_fold(dst, orig, sz, nbits)            dst bits = orig bits mod sz
  51  * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  52  * bitmap_parse(buf, buflen, dst, nbits)        Parse bitmap dst from kernel buf
  53  * bitmap_parse_user(ubuf, ulen, dst, nbits)    Parse bitmap dst from user buf
  54  * bitmap_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  55  * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  56  * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  57  * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  58  * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  59  */
  60
  61 /*
  62  * Also the following operations in asm/bitops.h apply to bitmaps.
  63  *
  64  * set_bit(bit, addr)                   *addr |= bit
  65  * clear_bit(bit, addr)                 *addr &= ~bit
  66  * change_bit(bit, addr)                *addr ^= bit
  67  * test_bit(bit, addr)                  Is bit set in *addr?
  68  * test_and_set_bit(bit, addr)          Set bit and return old value
  69  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  70  * test_and_change_bit(bit, addr)       Change bit and return old value
  71  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  72  * find_first_bit(addr, nbits)          Position first set bit in *addr
  73  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  74  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  75  */
  76
  77 /*
  78  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  79  * to declare an array named 'name' of just enough unsigned longs to
  80  * contain all bit positions from 0 to 'bits' - 1.
  81  */
  82
  83 /*
  84  * lib/bitmap.c provides these functions:
  85  */
  86
  87 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  88 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  89 extern int __bitmap_equal(const unsigned long *bitmap1,
  90                         const unsigned long *bitmap2, int bits);
  91 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  92                         int bits);
  93 extern void __bitmap_shift_right(unsigned long *dst,
  94                         const unsigned long *src, int shift, int bits);
  95 extern void __bitmap_shift_left(unsigned long *dst,
  96                         const unsigned long *src, int shift, int bits);
  97 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  98                         const unsigned long *bitmap2, int bits);
  99 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 100                         const unsigned long *bitmap2, int bits);
 101 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 102                         const unsigned long *bitmap2, int bits);
 103 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 104                         const unsigned long *bitmap2, int bits);
 105 extern int __bitmap_intersects(const unsigned long *bitmap1,
 106                         const unsigned long *bitmap2, int bits);
 107 extern int __bitmap_subset(const unsigned long *bitmap1,
 108                         const unsigned long *bitmap2, int bits);
 109 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 110
 111 extern int bitmap_scnprintf(char *buf, unsigned int len,
 112                         const unsigned long *src, int nbits);
 113 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 114                         unsigned long *dst, int nbits);
 115 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 116                         unsigned long *dst, int nbits);
 117 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 118                         const unsigned long *src, int nbits);
 119 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 120                         int nmaskbits);
 121 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 122                 const unsigned long *old, const unsigned long *new, int bits);
 123 extern int bitmap_bitremap(int oldbit,
 124                 const unsigned long *old, const unsigned long *new, int bits);
 125 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 126                 const unsigned long *relmap, int bits);
 127 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 128                 int sz, int bits);
 129 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 130 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 131 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 132
 133 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 134 (                                                                       \
 135         ((nbits) % BITS_PER_LONG) ?                                     \
 136                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 137 )
 138
 139 static inline void bitmap_zero(unsigned long *dst, int nbits)
 140 {
 141         if (nbits <= BITS_PER_LONG)
 142                 *dst = 0UL;
 143         else {
 144                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 145                 memset(dst, 0, len);
 146         }
 147 }
 148
 149 static inline void bitmap_fill(unsigned long *dst, int nbits)
 150 {
 151         size_t nlongs = BITS_TO_LONGS(nbits);
 152         if (nlongs > 1) {
 153                 int len = (nlongs - 1) * sizeof(unsigned long);
 154                 memset(dst, 0xff,  len);
 155         }
 156         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 157 }
 158
 159 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 160                         int nbits)
 161 {
 162         if (nbits <= BITS_PER_LONG)
 163                 *dst = *src;
 164         else {
 165                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 166                 memcpy(dst, src, len);
 167         }
 168 }
 169
 170 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 171                         const unsigned long *src2, int nbits)
 172 {
 173         if (nbits <= BITS_PER_LONG)
 174                 *dst = *src1 & *src2;
 175         else
 176                 __bitmap_and(dst, src1, src2, nbits);
 177 }
 178
 179 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 180                         const unsigned long *src2, int nbits)
 181 {
 182         if (nbits <= BITS_PER_LONG)
 183                 *dst = *src1 | *src2;
 184         else
 185                 __bitmap_or(dst, src1, src2, nbits);
 186 }
 187
 188 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 189                         const unsigned long *src2, int nbits)
 190 {
 191         if (nbits <= BITS_PER_LONG)
 192                 *dst = *src1 ^ *src2;
 193         else
 194                 __bitmap_xor(dst, src1, src2, nbits);
 195 }
 196
 197 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 198                         const unsigned long *src2, int nbits)
 199 {
 200         if (nbits <= BITS_PER_LONG)
 201                 *dst = *src1 & ~(*src2);
 202         else
 203                 __bitmap_andnot(dst, src1, src2, nbits);
 204 }
 205
 206 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 207                         int nbits)
 208 {
 209         if (nbits <= BITS_PER_LONG)
 210                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 211         else
 212                 __bitmap_complement(dst, src, nbits);
 213 }
 214
 215 static inline int bitmap_equal(const unsigned long *src1,
 216                         const unsigned long *src2, int nbits)
 217 {
 218         if (nbits <= BITS_PER_LONG)
 219                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 220         else
 221                 return __bitmap_equal(src1, src2, nbits);
 222 }
 223
 224 static inline int bitmap_intersects(const unsigned long *src1,
 225                         const unsigned long *src2, int nbits)
 226 {
 227         if (nbits <= BITS_PER_LONG)
 228                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 229         else
 230                 return __bitmap_intersects(src1, src2, nbits);
 231 }
 232
 233 static inline int bitmap_subset(const unsigned long *src1,
 234                         const unsigned long *src2, int nbits)
 235 {
 236         if (nbits <= BITS_PER_LONG)
 237                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 238         else
 239                 return __bitmap_subset(src1, src2, nbits);
 240 }
 241
 242 static inline int bitmap_empty(const unsigned long *src, int nbits)
 243 {
 244         if (nbits <= BITS_PER_LONG)
 245                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 246         else
 247                 return __bitmap_empty(src, nbits);
 248 }
 249
 250 static inline int bitmap_full(const unsigned long *src, int nbits)
 251 {
 252         if (nbits <= BITS_PER_LONG)
 253                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 254         else
 255                 return __bitmap_full(src, nbits);
 256 }
 257
 258 static inline int bitmap_weight(const unsigned long *src, int nbits)
 259 {
 260         if (nbits <= BITS_PER_LONG)
 261                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 262         return __bitmap_weight(src, nbits);
 263 }
 264
 265 static inline void bitmap_shift_right(unsigned long *dst,
 266                         const unsigned long *src, int n, int nbits)
 267 {
 268         if (nbits <= BITS_PER_LONG)
 269                 *dst = *src >> n;
 270         else
 271                 __bitmap_shift_right(dst, src, n, nbits);
 272 }
 273
 274 static inline void bitmap_shift_left(unsigned long *dst,
 275                         const unsigned long *src, int n, int nbits)
 276 {
 277         if (nbits <= BITS_PER_LONG)
 278                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 279         else
 280                 __bitmap_shift_left(dst, src, n, nbits);
 281 }
 282
 283 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 284                         unsigned long *maskp, int nmaskbits)
 285 {
 286         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 287 }
 288
 289 #endif /* __ASSEMBLY__ */
 290
 291 #endif /* __LINUX_BITMAP_H */