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 kernel buf
  59  * bitmap_parselist_user(buf, dst, nbits)       Parse bitmap dst from user buf
  60  * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  61  * bitmap_release_region(bitmap, pos, order)    Free specified bit region
  62  * bitmap_allocate_region(bitmap, pos, order)   Allocate specified bit region
  63  */
  64
  65 /*
  66  * Also the following operations in asm/bitops.h apply to bitmaps.
  67  *
  68  * set_bit(bit, addr)                   *addr |= bit
  69  * clear_bit(bit, addr)                 *addr &= ~bit
  70  * change_bit(bit, addr)                *addr ^= bit
  71  * test_bit(bit, addr)                  Is bit set in *addr?
  72  * test_and_set_bit(bit, addr)          Set bit and return old value
  73  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  74  * test_and_change_bit(bit, addr)       Change bit and return old value
  75  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  76  * find_first_bit(addr, nbits)          Position first set bit in *addr
  77  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  78  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  79  */
  80
  81 /*
  82  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  83  * to declare an array named 'name' of just enough unsigned longs to
  84  * contain all bit positions from 0 to 'bits' - 1.
  85  */
  86
  87 /*
  88  * lib/bitmap.c provides these functions:
  89  */
  90
  91 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  92 extern int __bitmap_full(const unsigned long *bitmap, int bits);
  93 extern int __bitmap_equal(const unsigned long *bitmap1,
  94                         const unsigned long *bitmap2, int bits);
  95 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  96                         int bits);
  97 extern void __bitmap_shift_right(unsigned long *dst,
  98                         const unsigned long *src, int shift, int bits);
  99 extern void __bitmap_shift_left(unsigned long *dst,
 100                         const unsigned long *src, int shift, int bits);
 101 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 102                         const unsigned long *bitmap2, int bits);
 103 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 104                         const unsigned long *bitmap2, int bits);
 105 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 106                         const unsigned long *bitmap2, int bits);
 107 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 108                         const unsigned long *bitmap2, int bits);
 109 extern int __bitmap_intersects(const unsigned long *bitmap1,
 110                         const unsigned long *bitmap2, int bits);
 111 extern int __bitmap_subset(const unsigned long *bitmap1,
 112                         const unsigned long *bitmap2, int bits);
 113 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 114
 115 extern void bitmap_set(unsigned long *map, int i, int len);
 116 extern void bitmap_clear(unsigned long *map, int start, int nr);
 117 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 118                                          unsigned long size,
 119                                          unsigned long start,
 120                                          unsigned int nr,
 121                                          unsigned long align_mask);
 122
 123 extern int bitmap_scnprintf(char *buf, unsigned int len,
 124                         const unsigned long *src, int nbits);
 125 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 126                         unsigned long *dst, int nbits);
 127 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 128                         unsigned long *dst, int nbits);
 129 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 130                         const unsigned long *src, int nbits);
 131 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 132                         int nmaskbits);
 133 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 134                         unsigned long *dst, int nbits);
 135 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 136                 const unsigned long *old, const unsigned long *new, int bits);
 137 extern int bitmap_bitremap(int oldbit,
 138                 const unsigned long *old, const unsigned long *new, int bits);
 139 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 140                 const unsigned long *relmap, int bits);
 141 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 142                 int sz, int bits);
 143 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 144 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 145 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 146 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 147
 148 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 149 (                                                                       \
 150         ((nbits) % BITS_PER_LONG) ?                                     \
 151                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 152 )
 153
 154 #define small_const_nbits(nbits) \
 155         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 156
 157 static inline void bitmap_zero(unsigned long *dst, int nbits)
 158 {
 159         if (small_const_nbits(nbits))
 160                 *dst = 0UL;
 161         else {
 162                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 163                 memset(dst, 0, len);
 164         }
 165 }
 166
 167 static inline void bitmap_fill(unsigned long *dst, int nbits)
 168 {
 169         size_t nlongs = BITS_TO_LONGS(nbits);
 170         if (!small_const_nbits(nbits)) {
 171                 int len = (nlongs - 1) * sizeof(unsigned long);
 172                 memset(dst, 0xff,  len);
 173         }
 174         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 175 }
 176
 177 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 178                         int nbits)
 179 {
 180         if (small_const_nbits(nbits))
 181                 *dst = *src;
 182         else {
 183                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 184                 memcpy(dst, src, len);
 185         }
 186 }
 187
 188 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 189                         const unsigned long *src2, int nbits)
 190 {
 191         if (small_const_nbits(nbits))
 192                 return (*dst = *src1 & *src2) != 0;
 193         return __bitmap_and(dst, src1, src2, nbits);
 194 }
 195
 196 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 197                         const unsigned long *src2, int nbits)
 198 {
 199         if (small_const_nbits(nbits))
 200                 *dst = *src1 | *src2;
 201         else
 202                 __bitmap_or(dst, src1, src2, nbits);
 203 }
 204
 205 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 206                         const unsigned long *src2, int nbits)
 207 {
 208         if (small_const_nbits(nbits))
 209                 *dst = *src1 ^ *src2;
 210         else
 211                 __bitmap_xor(dst, src1, src2, nbits);
 212 }
 213
 214 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 215                         const unsigned long *src2, int nbits)
 216 {
 217         if (small_const_nbits(nbits))
 218                 return (*dst = *src1 & ~(*src2)) != 0;
 219         return __bitmap_andnot(dst, src1, src2, nbits);
 220 }
 221
 222 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 223                         int nbits)
 224 {
 225         if (small_const_nbits(nbits))
 226                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 227         else
 228                 __bitmap_complement(dst, src, nbits);
 229 }
 230
 231 static inline int bitmap_equal(const unsigned long *src1,
 232                         const unsigned long *src2, int nbits)
 233 {
 234         if (small_const_nbits(nbits))
 235                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 236         else
 237                 return __bitmap_equal(src1, src2, nbits);
 238 }
 239
 240 static inline int bitmap_intersects(const unsigned long *src1,
 241                         const unsigned long *src2, int nbits)
 242 {
 243         if (small_const_nbits(nbits))
 244                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 245         else
 246                 return __bitmap_intersects(src1, src2, nbits);
 247 }
 248
 249 static inline int bitmap_subset(const unsigned long *src1,
 250                         const unsigned long *src2, int nbits)
 251 {
 252         if (small_const_nbits(nbits))
 253                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 254         else
 255                 return __bitmap_subset(src1, src2, nbits);
 256 }
 257
 258 static inline int bitmap_empty(const unsigned long *src, int nbits)
 259 {
 260         if (small_const_nbits(nbits))
 261                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 262         else
 263                 return __bitmap_empty(src, nbits);
 264 }
 265
 266 static inline int bitmap_full(const unsigned long *src, int nbits)
 267 {
 268         if (small_const_nbits(nbits))
 269                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 270         else
 271                 return __bitmap_full(src, nbits);
 272 }
 273
 274 static inline int bitmap_weight(const unsigned long *src, int nbits)
 275 {
 276         if (small_const_nbits(nbits))
 277                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 278         return __bitmap_weight(src, nbits);
 279 }
 280
 281 static inline void bitmap_shift_right(unsigned long *dst,
 282                         const unsigned long *src, int n, int nbits)
 283 {
 284         if (small_const_nbits(nbits))
 285                 *dst = *src >> n;
 286         else
 287                 __bitmap_shift_right(dst, src, n, nbits);
 288 }
 289
 290 static inline void bitmap_shift_left(unsigned long *dst,
 291                         const unsigned long *src, int n, int nbits)
 292 {
 293         if (small_const_nbits(nbits))
 294                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 295         else
 296                 __bitmap_shift_left(dst, src, n, nbits);
 297 }
 298
 299 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 300                         unsigned long *maskp, int nmaskbits)
 301 {
 302         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 303 }
 304
 305 #endif /* __ASSEMBLY__ */
 306
 307 #endif /* __LINUX_BITMAP_H */