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  * bitmap_print_to_pagebuf(list, buf, mask, nbits) Print bitmap src as list/hex
  64  */
  65
  66 /*
  67  * Also the following operations in asm/bitops.h apply to bitmaps.
  68  *
  69  * set_bit(bit, addr)                   *addr |= bit
  70  * clear_bit(bit, addr)                 *addr &= ~bit
  71  * change_bit(bit, addr)                *addr ^= bit
  72  * test_bit(bit, addr)                  Is bit set in *addr?
  73  * test_and_set_bit(bit, addr)          Set bit and return old value
  74  * test_and_clear_bit(bit, addr)        Clear bit and return old value
  75  * test_and_change_bit(bit, addr)       Change bit and return old value
  76  * find_first_zero_bit(addr, nbits)     Position first zero bit in *addr
  77  * find_first_bit(addr, nbits)          Position first set bit in *addr
  78  * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  79  * find_next_bit(addr, nbits, bit)      Position next set bit in *addr >= bit
  80  */
  81
  82 /*
  83  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  84  * to declare an array named 'name' of just enough unsigned longs to
  85  * contain all bit positions from 0 to 'bits' - 1.
  86  */
  87
  88 /*
  89  * lib/bitmap.c provides these functions:
  90  */
  91
  92 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  93 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  94 extern int __bitmap_equal(const unsigned long *bitmap1,
  95                           const unsigned long *bitmap2, unsigned int nbits);
  96 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  97                         unsigned int nbits);
  98 extern void __bitmap_shift_right(unsigned long *dst,
  99                         const unsigned long *src, int shift, int bits);
 100 extern void __bitmap_shift_left(unsigned long *dst,
 101                         const unsigned long *src, int shift, int bits);
 102 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
 103                         const unsigned long *bitmap2, unsigned int nbits);
 104 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
 105                         const unsigned long *bitmap2, unsigned int nbits);
 106 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
 107                         const unsigned long *bitmap2, unsigned int nbits);
 108 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 109                         const unsigned long *bitmap2, unsigned int nbits);
 110 extern int __bitmap_intersects(const unsigned long *bitmap1,
 111                         const unsigned long *bitmap2, unsigned int nbits);
 112 extern int __bitmap_subset(const unsigned long *bitmap1,
 113                         const unsigned long *bitmap2, unsigned int nbits);
 114 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
 115
 116 extern void bitmap_set(unsigned long *map, unsigned int start, int len);
 117 extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
 118 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
 119                                          unsigned long size,
 120                                          unsigned long start,
 121                                          unsigned int nr,
 122                                          unsigned long align_mask);
 123
 124 extern int bitmap_scnprintf(char *buf, unsigned int len,
 125                         const unsigned long *src, int nbits);
 126 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
 127                         unsigned long *dst, int nbits);
 128 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
 129                         unsigned long *dst, int nbits);
 130 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
 131                         const unsigned long *src, int nbits);
 132 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
 133                         int nmaskbits);
 134 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
 135                         unsigned long *dst, int nbits);
 136 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
 137                 const unsigned long *old, const unsigned long *new, int bits);
 138 extern int bitmap_bitremap(int oldbit,
 139                 const unsigned long *old, const unsigned long *new, int bits);
 140 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 141                 const unsigned long *relmap, int bits);
 142 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 143                 int sz, int bits);
 144 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
 145 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
 146 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 147 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 148 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
 149 extern int bitmap_print_to_pagebuf(bool list, char *buf,
 150                                    const unsigned long *maskp, int nmaskbits);
 151
 152 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
 153 #define BITMAP_LAST_WORD_MASK(nbits)                                    \
 154 (                                                                       \
 155         ((nbits) % BITS_PER_LONG) ?                                     \
 156                 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL               \
 157 )
 158
 159 #define small_const_nbits(nbits) \
 160         (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 161
 162 static inline void bitmap_zero(unsigned long *dst, int nbits)
 163 {
 164         if (small_const_nbits(nbits))
 165                 *dst = 0UL;
 166         else {
 167                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 168                 memset(dst, 0, len);
 169         }
 170 }
 171
 172 static inline void bitmap_fill(unsigned long *dst, int nbits)
 173 {
 174         size_t nlongs = BITS_TO_LONGS(nbits);
 175         if (!small_const_nbits(nbits)) {
 176                 int len = (nlongs - 1) * sizeof(unsigned long);
 177                 memset(dst, 0xff,  len);
 178         }
 179         dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
 180 }
 181
 182 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 183                         int nbits)
 184 {
 185         if (small_const_nbits(nbits))
 186                 *dst = *src;
 187         else {
 188                 int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
 189                 memcpy(dst, src, len);
 190         }
 191 }
 192
 193 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
 194                         const unsigned long *src2, unsigned int nbits)
 195 {
 196         if (small_const_nbits(nbits))
 197                 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 198         return __bitmap_and(dst, src1, src2, nbits);
 199 }
 200
 201 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
 202                         const unsigned long *src2, unsigned int nbits)
 203 {
 204         if (small_const_nbits(nbits))
 205                 *dst = *src1 | *src2;
 206         else
 207                 __bitmap_or(dst, src1, src2, nbits);
 208 }
 209
 210 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
 211                         const unsigned long *src2, unsigned int nbits)
 212 {
 213         if (small_const_nbits(nbits))
 214                 *dst = *src1 ^ *src2;
 215         else
 216                 __bitmap_xor(dst, src1, src2, nbits);
 217 }
 218
 219 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
 220                         const unsigned long *src2, unsigned int nbits)
 221 {
 222         if (small_const_nbits(nbits))
 223                 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 224         return __bitmap_andnot(dst, src1, src2, nbits);
 225 }
 226
 227 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
 228                         unsigned int nbits)
 229 {
 230         if (small_const_nbits(nbits))
 231                 *dst = ~(*src);
 232         else
 233                 __bitmap_complement(dst, src, nbits);
 234 }
 235
 236 static inline int bitmap_equal(const unsigned long *src1,
 237                         const unsigned long *src2, unsigned int nbits)
 238 {
 239         if (small_const_nbits(nbits))
 240                 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
 241         else
 242                 return __bitmap_equal(src1, src2, nbits);
 243 }
 244
 245 static inline int bitmap_intersects(const unsigned long *src1,
 246                         const unsigned long *src2, unsigned int nbits)
 247 {
 248         if (small_const_nbits(nbits))
 249                 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
 250         else
 251                 return __bitmap_intersects(src1, src2, nbits);
 252 }
 253
 254 static inline int bitmap_subset(const unsigned long *src1,
 255                         const unsigned long *src2, unsigned int nbits)
 256 {
 257         if (small_const_nbits(nbits))
 258                 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
 259         else
 260                 return __bitmap_subset(src1, src2, nbits);
 261 }
 262
 263 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
 264 {
 265         if (small_const_nbits(nbits))
 266                 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
 267         else
 268                 return __bitmap_empty(src, nbits);
 269 }
 270
 271 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
 272 {
 273         if (small_const_nbits(nbits))
 274                 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
 275         else
 276                 return __bitmap_full(src, nbits);
 277 }
 278
 279 static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
 280 {
 281         if (small_const_nbits(nbits))
 282                 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
 283         return __bitmap_weight(src, nbits);
 284 }
 285
 286 static inline void bitmap_shift_right(unsigned long *dst,
 287                         const unsigned long *src, int n, int nbits)
 288 {
 289         if (small_const_nbits(nbits))
 290                 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> n;
 291         else
 292                 __bitmap_shift_right(dst, src, n, nbits);
 293 }
 294
 295 static inline void bitmap_shift_left(unsigned long *dst,
 296                         const unsigned long *src, int n, int nbits)
 297 {
 298         if (small_const_nbits(nbits))
 299                 *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
 300         else
 301                 __bitmap_shift_left(dst, src, n, nbits);
 302 }
 303
 304 static inline int bitmap_parse(const char *buf, unsigned int buflen,
 305                         unsigned long *maskp, int nmaskbits)
 306 {
 307         return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
 308 }
 309
 310 #endif /* __ASSEMBLY__ */
 311
 312 #endif /* __LINUX_BITMAP_H */