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_scnprintf_len(unsigned int nr_bits);
 114 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 115                         unsigned long *dst, int nbits);
 116 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 117                         unsigned long *dst, int nbits);
 118 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 119                         const unsigned long *src, int nbits);
 120 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 121                         int nmaskbits);
 122 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 123                 const unsigned long *old, const unsigned long *new, int bits);
 124 extern int bitmap_bitremap(int oldbit,
 125                 const unsigned long *old, const unsigned long *new, int bits);
 126 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 127                 const unsigned long *relmap, int bits);
 128 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 129                 int sz, int bits);
 130 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
 131 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
 132 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
 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 static inline void bitmap_zero(unsigned long *dst, int nbits)
 141 {
 142         if (nbits <= BITS_PER_LONG)
 143                 *dst = 0UL;
 144         else {
 145                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 146                 memset(dst, 0, len);
 147         }
 148 }
 149
 150 static inline void bitmap_fill(unsigned long *dst, int nbits)
 151 {
 152         size_t nlongs = BITS_TO_LONGS(nbits);
 153         if (nlongs > 1) {
 154                 int len = (nlongs - 1) * sizeof(unsigned long);
 155                 memset(dst, 0xff,  len);
 156         }
 157         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 158 }
 159
 160 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 161                         int nbits)
 162 {
 163         if (nbits <= BITS_PER_LONG)
 164                 *dst = *src;
 165         else {
 166                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 167                 memcpy(dst, src, len);
 168         }
 169 }
 170
 171 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
 172                         const unsigned long *src2, int nbits)
 173 {
 174         if (nbits <= BITS_PER_LONG)
 175                 *dst = *src1 & *src2;
 176         else
 177                 __bitmap_and(dst, src1, src2, nbits);
 178 }
 179
 180 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 181                         const unsigned long *src2, int nbits)
 182 {
 183         if (nbits <= BITS_PER_LONG)
 184                 *dst = *src1 | *src2;
 185         else
 186                 __bitmap_or(dst, src1, src2, nbits);
 187 }
 188
 189 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 190                         const unsigned long *src2, int nbits)
 191 {
 192         if (nbits <= BITS_PER_LONG)
 193                 *dst = *src1 ^ *src2;
 194         else
 195                 __bitmap_xor(dst, src1, src2, nbits);
 196 }
 197
 198 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 199                         const unsigned long *src2, int nbits)
 200 {
 201         if (nbits <= BITS_PER_LONG)
 202                 *dst = *src1 & ~(*src2);
 203         else
 204                 __bitmap_andnot(dst, src1, src2, nbits);
 205 }
 206
 207 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 208                         int nbits)
 209 {
 210         if (nbits <= BITS_PER_LONG)
 211                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 212         else
 213                 __bitmap_complement(dst, src, nbits);
 214 }
 215
 216 static inline int bitmap_equal(const unsigned long *src1,
 217                         const unsigned long *src2, int nbits)
 218 {
 219         if (nbits <= BITS_PER_LONG)
 220                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 221         else
 222                 return __bitmap_equal(src1, src2, nbits);
 223 }
 224
 225 static inline int bitmap_intersects(const unsigned long *src1,
 226                         const unsigned long *src2, int nbits)
 227 {
 228         if (nbits <= BITS_PER_LONG)
 229                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 230         else
 231                 return __bitmap_intersects(src1, src2, nbits);
 232 }
 233
 234 static inline int bitmap_subset(const unsigned long *src1,
 235                         const unsigned long *src2, int nbits)
 236 {
 237         if (nbits <= BITS_PER_LONG)
 238                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 239         else
 240                 return __bitmap_subset(src1, src2, nbits);
 241 }
 242
 243 static inline int bitmap_empty(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_empty(src, nbits);
 249 }
 250
 251 static inline int bitmap_full(const unsigned long *src, int nbits)
 252 {
 253         if (nbits <= BITS_PER_LONG)
 254                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 255         else
 256                 return __bitmap_full(src, nbits);
 257 }
 258
 259 static inline int bitmap_weight(const unsigned long *src, int nbits)
 260 {
 261         if (nbits <= BITS_PER_LONG)
 262                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 263         return __bitmap_weight(src, nbits);
 264 }
 265
 266 static inline void bitmap_shift_right(unsigned long *dst,
 267                         const unsigned long *src, int n, int nbits)
 268 {
 269         if (nbits <= BITS_PER_LONG)
 270                 *dst = *src >> n;
 271         else
 272                 __bitmap_shift_right(dst, src, n, nbits);
 273 }
 274
 275 static inline void bitmap_shift_left(unsigned long *dst,
 276                         const unsigned long *src, int n, int nbits)
 277 {
 278         if (nbits <= BITS_PER_LONG)
 279                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 280         else
 281                 __bitmap_shift_left(dst, src, n, nbits);
 282 }
 283
 284 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 285                         unsigned long *maskp, int nmaskbits)
 286 {
 287         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 288 }
 289
 290 #endif /* __ASSEMBLY__ */
 291
 292 #endif /* __LINUX_BITMAP_H */