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