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_set(dst, pos, nbits)                  Set specified bit area
  46  * bitmap_clear(dst, pos, nbits)                Clear specified bit area
  47  * bitmap_find_next_zero_area(buf, len, pos, n, mask)   Find bit free area
  48  * bitmap_shift_right(dst, src, n, nbits)       *dst = *src >> n
  49  * bitmap_shift_left(dst, src, n, nbits)        *dst = *src << n
  50  * bitmap_remap(dst, src, old, new, nbits)      *dst = map(old, new)(src)
  51  * bitmap_bitremap(oldbit, old, new, nbits)     newbit = map(old, new)(oldbit)
  52  * bitmap_onto(dst, orig, relmap, nbits)        *dst = orig relative to relmap
  53  * bitmap_fold(dst, orig, sz, nbits)            dst bits = orig bits mod sz
  54  * bitmap_scnprintf(buf, len, src, nbits)       Print bitmap src to buf
  55  * bitmap_parse(buf, buflen, dst, nbits)        Parse bitmap dst from kernel buf
  56  * bitmap_parse_user(ubuf, ulen, dst, nbits)    Parse bitmap dst from user buf
  57  * bitmap_scnlistprintf(buf, len, src, nbits)   Print bitmap src as list to buf
  58  * bitmap_parselist(buf, dst, nbits)            Parse bitmap dst from list
  59  * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  60  * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  61  * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  62  */
  63
  64 /*
  65  * Also the following operations in asm/bitops.h apply to bitmaps.
  66  *
  67  * set_bit(bit, addr)                   *addr |= bit
  68  * clear_bit(bit, addr)                 *addr &= ~bit
  69  * change_bit(bit, addr)                *addr ^= bit
  70  * test_bit(bit, addr)                  Is bit set in *addr?
  71  * test_and_set_bit(bit, addr)          Set bit and return old value
  72  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  73  * test_and_change_bit(bit, addr)       Change bit and return old value
  74  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  75  * find_first_bit(addr, nbits)          Position first set bit in *addr
  76  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  77  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  78  */
  79
  80 /*
  81  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  82  * to declare an array named 'name' of just enough unsigned longs to
  83  * contain all bit positions from 0 to 'bits' - 1.
  84  */
  85
  86 /*
  87  * lib/bitmap.c provides these functions:
  88  */
  89
  90 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  91 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  92 extern int __bitmap_equal(const unsigned long *bitmap1,
  93                         const unsigned long *bitmap2, int bits);
  94 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  95                         int bits);
  96 extern void __bitmap_shift_right(unsigned long *dst,
  97                         const unsigned long *src, int shift, int bits);
  98 extern void __bitmap_shift_left(unsigned long *dst,
  99                         const unsigned long *src, int shift, int bits);
 100 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 101                         const unsigned long *bitmap2, int bits);
 102 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 103                         const unsigned long *bitmap2, int bits);
 104 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 105                         const unsigned long *bitmap2, int bits);
 106 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 107                         const unsigned long *bitmap2, int bits);
 108 extern int __bitmap_intersects(const unsigned long *bitmap1,
 109                         const unsigned long *bitmap2, int bits);
 110 extern int __bitmap_subset(const unsigned long *bitmap1,
 111                         const unsigned long *bitmap2, int bits);
 112 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 113
 114 extern void bitmap_set(unsigned long *map, int i, int len);
 115 extern void bitmap_clear(unsigned long *map, int start, int nr);
 116 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 117                                          unsigned long size,
 118                                          unsigned long start,
 119                                          unsigned int nr,
 120                                          unsigned long align_mask);
 121
 122 extern int bitmap_scnprintf(char *buf, unsigned int len,
 123                         const unsigned long *src, int nbits);
 124 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 125                         unsigned long *dst, int nbits);
 126 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 127                         unsigned long *dst, int nbits);
 128 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 129                         const unsigned long *src, int nbits);
 130 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 131                         int nmaskbits);
 132 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 133                 const unsigned long *old, const unsigned long *new, int bits);
 134 extern int bitmap_bitremap(int oldbit,
 135                 const unsigned long *old, const unsigned long *new, int bits);
 136 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 137                 const unsigned long *relmap, int bits);
 138 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 139                 int sz, int bits);
 140 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 141 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 142 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 143 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 144 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
 145
 146 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 147 (                                                                       \
 148         ((nbits) % BITS_PER_LONG) ?                                     \
 149                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 150 )
 151
 152 #define small_const_nbits(nbits) \
 153         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 154
 155 static inline void bitmap_zero(unsigned long *dst, int nbits)
 156 {
 157         if (small_const_nbits(nbits))
 158                 *dst = 0UL;
 159         else {
 160                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 161                 memset(dst, 0, len);
 162         }
 163 }
 164
 165 static inline void bitmap_fill(unsigned long *dst, int nbits)
 166 {
 167         size_t nlongs = BITS_TO_LONGS(nbits);
 168         if (!small_const_nbits(nbits)) {
 169                 int len = (nlongs - 1) * sizeof(unsigned long);
 170                 memset(dst, 0xff,  len);
 171         }
 172         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 173 }
 174
 175 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 176                         int nbits)
 177 {
 178         if (small_const_nbits(nbits))
 179                 *dst = *src;
 180         else {
 181                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 182                 memcpy(dst, src, len);
 183         }
 184 }
 185
 186 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 187                         const unsigned long *src2, int nbits)
 188 {
 189         if (small_const_nbits(nbits))
 190                 return (*dst = *src1 & *src2) != 0;
 191         return __bitmap_and(dst, src1, src2, nbits);
 192 }
 193
 194 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 195                         const unsigned long *src2, int nbits)
 196 {
 197         if (small_const_nbits(nbits))
 198                 *dst = *src1 | *src2;
 199         else
 200                 __bitmap_or(dst, src1, src2, nbits);
 201 }
 202
 203 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 204                         const unsigned long *src2, int nbits)
 205 {
 206         if (small_const_nbits(nbits))
 207                 *dst = *src1 ^ *src2;
 208         else
 209                 __bitmap_xor(dst, src1, src2, nbits);
 210 }
 211
 212 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 213                         const unsigned long *src2, int nbits)
 214 {
 215         if (small_const_nbits(nbits))
 216                 return (*dst = *src1 & ~(*src2)) != 0;
 217         return __bitmap_andnot(dst, src1, src2, nbits);
 218 }
 219
 220 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 221                         int nbits)
 222 {
 223         if (small_const_nbits(nbits))
 224                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 225         else
 226                 __bitmap_complement(dst, src, nbits);
 227 }
 228
 229 static inline int bitmap_equal(const unsigned long *src1,
 230                         const unsigned long *src2, int nbits)
 231 {
 232         if (small_const_nbits(nbits))
 233                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 234         else
 235                 return __bitmap_equal(src1, src2, nbits);
 236 }
 237
 238 static inline int bitmap_intersects(const unsigned long *src1,
 239                         const unsigned long *src2, int nbits)
 240 {
 241         if (small_const_nbits(nbits))
 242                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 243         else
 244                 return __bitmap_intersects(src1, src2, nbits);
 245 }
 246
 247 static inline int bitmap_subset(const unsigned long *src1,
 248                         const unsigned long *src2, int nbits)
 249 {
 250         if (small_const_nbits(nbits))
 251                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 252         else
 253                 return __bitmap_subset(src1, src2, nbits);
 254 }
 255
 256 static inline int bitmap_empty(const unsigned long *src, int nbits)
 257 {
 258         if (small_const_nbits(nbits))
 259                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 260         else
 261                 return __bitmap_empty(src, nbits);
 262 }
 263
 264 static inline int bitmap_full(const unsigned long *src, int nbits)
 265 {
 266         if (small_const_nbits(nbits))
 267                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 268         else
 269                 return __bitmap_full(src, nbits);
 270 }
 271
 272 static inline int bitmap_weight(const unsigned long *src, int nbits)
 273 {
 274         if (small_const_nbits(nbits))
 275                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 276         return __bitmap_weight(src, nbits);
 277 }
 278
 279 static inline void bitmap_shift_right(unsigned long *dst,
 280                         const unsigned long *src, int n, int nbits)
 281 {
 282         if (small_const_nbits(nbits))
 283                 *dst = *src >> n;
 284         else
 285                 __bitmap_shift_right(dst, src, n, nbits);
 286 }
 287
 288 static inline void bitmap_shift_left(unsigned long *dst,
 289                         const unsigned long *src, int n, int nbits)
 290 {
 291         if (small_const_nbits(nbits))
 292                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 293         else
 294                 __bitmap_shift_left(dst, src, n, nbits);
 295 }
 296
 297 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 298                         unsigned long *maskp, int nmaskbits)
 299 {
 300         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 301 }
 302
 303 #endif /* __ASSEMBLY__ */
 304
 305 #endif /* __LINUX_BITMAP_H */