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 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
 148
 149 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
 150 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 151 (                                                                       \
 152         ((nbits) % BITS_PER_LONG) ?                                     \
 153                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 154 )
 155
 156 #define small_const_nbits(nbits) \
 157         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 158
 159 static inline void bitmap_zero(unsigned long *dst, int nbits)
 160 {
 161         if (small_const_nbits(nbits))
 162                 *dst = 0UL;
 163         else {
 164                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 165                 memset(dst, 0, len);
 166         }
 167 }
 168
 169 static inline void bitmap_fill(unsigned long *dst, int nbits)
 170 {
 171         size_t nlongs = BITS_TO_LONGS(nbits);
 172         if (!small_const_nbits(nbits)) {
 173                 int len = (nlongs - 1) * sizeof(unsigned long);
 174                 memset(dst, 0xff,  len);
 175         }
 176         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 177 }
 178
 179 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 180                         int nbits)
 181 {
 182         if (small_const_nbits(nbits))
 183                 *dst = *src;
 184         else {
 185                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 186                 memcpy(dst, src, len);
 187         }
 188 }
 189
 190 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 191                         const unsigned long *src2, int nbits)
 192 {
 193         if (small_const_nbits(nbits))
 194                 return (*dst = *src1 & *src2) != 0;
 195         return __bitmap_and(dst, src1, src2, nbits);
 196 }
 197
 198 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 199                         const unsigned long *src2, int nbits)
 200 {
 201         if (small_const_nbits(nbits))
 202                 *dst = *src1 | *src2;
 203         else
 204                 __bitmap_or(dst, src1, src2, nbits);
 205 }
 206
 207 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 208                         const unsigned long *src2, int nbits)
 209 {
 210         if (small_const_nbits(nbits))
 211                 *dst = *src1 ^ *src2;
 212         else
 213                 __bitmap_xor(dst, src1, src2, nbits);
 214 }
 215
 216 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 217                         const unsigned long *src2, int nbits)
 218 {
 219         if (small_const_nbits(nbits))
 220                 return (*dst = *src1 & ~(*src2)) != 0;
 221         return __bitmap_andnot(dst, src1, src2, nbits);
 222 }
 223
 224 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 225                         int nbits)
 226 {
 227         if (small_const_nbits(nbits))
 228                 *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
 229         else
 230                 __bitmap_complement(dst, src, nbits);
 231 }
 232
 233 static inline int bitmap_equal(const unsigned long *src1,
 234                         const unsigned long *src2, int nbits)
 235 {
 236         if (small_const_nbits(nbits))
 237                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 238         else
 239                 return __bitmap_equal(src1, src2, nbits);
 240 }
 241
 242 static inline int bitmap_intersects(const unsigned long *src1,
 243                         const unsigned long *src2, int nbits)
 244 {
 245         if (small_const_nbits(nbits))
 246                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 247         else
 248                 return __bitmap_intersects(src1, src2, nbits);
 249 }
 250
 251 static inline int bitmap_subset(const unsigned long *src1,
 252                         const unsigned long *src2, int nbits)
 253 {
 254         if (small_const_nbits(nbits))
 255                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 256         else
 257                 return __bitmap_subset(src1, src2, nbits);
 258 }
 259
 260 static inline int bitmap_empty(const unsigned long *src, int nbits)
 261 {
 262         if (small_const_nbits(nbits))
 263                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 264         else
 265                 return __bitmap_empty(src, nbits);
 266 }
 267
 268 static inline int bitmap_full(const unsigned long *src, int nbits)
 269 {
 270         if (small_const_nbits(nbits))
 271                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 272         else
 273                 return __bitmap_full(src, nbits);
 274 }
 275
 276 static inline int bitmap_weight(const unsigned long *src, int nbits)
 277 {
 278         if (small_const_nbits(nbits))
 279                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 280         return __bitmap_weight(src, nbits);
 281 }
 282
 283 static inline void bitmap_shift_right(unsigned long *dst,
 284                         const unsigned long *src, int n, int nbits)
 285 {
 286         if (small_const_nbits(nbits))
 287                 *dst = *src >> n;
 288         else
 289                 __bitmap_shift_right(dst, src, n, nbits);
 290 }
 291
 292 static inline void bitmap_shift_left(unsigned long *dst,
 293                         const unsigned long *src, int n, int nbits)
 294 {
 295         if (small_const_nbits(nbits))
 296                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 297         else
 298                 __bitmap_shift_left(dst, src, n, nbits);
 299 }
 300
 301 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 302                         unsigned long *maskp, int nmaskbits)
 303 {
 304         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 305 }
 306
 307 #endif /* __ASSEMBLY__ */
 308
 309 #endif /* __LINUX_BITMAP_H */