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 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 133
 134 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 135 (                                                                       \
 136         ((nbits) % BITS_PER_LONG) ?                                     \
 137                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 138 )
 139
 140 #define small_const_nbits(nbits) \
 141         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 142
 143 static inline void bitmap_zero(unsigned long *dst, int nbits)
 144 {
 145         if (small_const_nbits(nbits))
 146                 *dst = 0UL;
 147         else {
 148                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 149                 memset(dst, 0, len);
 150         }
 151 }
 152
 153 static inline void bitmap_fill(unsigned long *dst, int nbits)
 154 {
 155         size_t nlongs = BITS_TO_LONGS(nbits);
 156         if (!small_const_nbits(nbits)) {
 157                 int len = (nlongs - 1) * sizeof(unsigned long);
 158                 memset(dst, 0xff,  len);
 159         }
 160         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 161 }
 162
 163 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 164                         int nbits)
 165 {
 166         if (small_const_nbits(nbits))
 167                 *dst = *src;
 168         else {
 169                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 170                 memcpy(dst, src, len);
 171         }
 172 }
 173
 174 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 175                         const unsigned long *src2, int nbits)
 176 {
 177         if (small_const_nbits(nbits))
 178                 *dst = *src1 & *src2;
 179         else
 180                 __bitmap_and(dst, src1, src2, nbits);
 181 }
 182
 183 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 184                         const unsigned long *src2, int nbits)
 185 {
 186         if (small_const_nbits(nbits))
 187                 *dst = *src1 | *src2;
 188         else
 189                 __bitmap_or(dst, src1, src2, nbits);
 190 }
 191
 192 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 193                         const unsigned long *src2, int nbits)
 194 {
 195         if (small_const_nbits(nbits))
 196                 *dst = *src1 ^ *src2;
 197         else
 198                 __bitmap_xor(dst, src1, src2, nbits);
 199 }
 200
 201 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 202                         const unsigned long *src2, int nbits)
 203 {
 204         if (small_const_nbits(nbits))
 205                 *dst = *src1 & ~(*src2);
 206         else
 207                 __bitmap_andnot(dst, src1, src2, nbits);
 208 }
 209
 210 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 211                         int nbits)
 212 {
 213         if (small_const_nbits(nbits))
 214                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 215         else
 216                 __bitmap_complement(dst, src, nbits);
 217 }
 218
 219 static inline int bitmap_equal(const unsigned long *src1,
 220                         const unsigned long *src2, int nbits)
 221 {
 222         if (small_const_nbits(nbits))
 223                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 224         else
 225                 return __bitmap_equal(src1, src2, nbits);
 226 }
 227
 228 static inline int bitmap_intersects(const unsigned long *src1,
 229                         const unsigned long *src2, int nbits)
 230 {
 231         if (small_const_nbits(nbits))
 232                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 233         else
 234                 return __bitmap_intersects(src1, src2, nbits);
 235 }
 236
 237 static inline int bitmap_subset(const unsigned long *src1,
 238                         const unsigned long *src2, int nbits)
 239 {
 240         if (small_const_nbits(nbits))
 241                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 242         else
 243                 return __bitmap_subset(src1, src2, nbits);
 244 }
 245
 246 static inline int bitmap_empty(const unsigned long *src, int nbits)
 247 {
 248         if (small_const_nbits(nbits))
 249                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 250         else
 251                 return __bitmap_empty(src, nbits);
 252 }
 253
 254 static inline int bitmap_full(const unsigned long *src, int nbits)
 255 {
 256         if (small_const_nbits(nbits))
 257                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 258         else
 259                 return __bitmap_full(src, nbits);
 260 }
 261
 262 static inline int bitmap_weight(const unsigned long *src, int nbits)
 263 {
 264         if (small_const_nbits(nbits))
 265                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 266         return __bitmap_weight(src, nbits);
 267 }
 268
 269 static inline void bitmap_shift_right(unsigned long *dst,
 270                         const unsigned long *src, int n, int nbits)
 271 {
 272         if (small_const_nbits(nbits))
 273                 *dst = *src >> n;
 274         else
 275                 __bitmap_shift_right(dst, src, n, nbits);
 276 }
 277
 278 static inline void bitmap_shift_left(unsigned long *dst,
 279                         const unsigned long *src, int n, int nbits)
 280 {
 281         if (small_const_nbits(nbits))
 282                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 283         else
 284                 __bitmap_shift_left(dst, src, n, nbits);
 285 }
 286
 287 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 288                         unsigned long *maskp, int nmaskbits)
 289 {
 290         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 291 }
 292
 293 #endif /* __ASSEMBLY__ */
 294
 295 #endif /* __LINUX_BITMAP_H */