bitmap.h 10 KB

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  1. #ifndef __LINUX_BITMAP_H
  2. #define __LINUX_BITMAP_H
  3. #ifndef __ASSEMBLY__
  4. #include <linux/types.h>
  5. #include <linux/bitops.h>
  6. #include <linux/string.h>
  7. #include <linux/kernel.h>
  8. /*
  9. * bitmaps provide bit arrays that consume one or more unsigned
  10. * longs. The bitmap interface and available operations are listed
  11. * here, in bitmap.h
  12. *
  13. * Function implementations generic to all architectures are in
  14. * lib/bitmap.c. Functions implementations that are architecture
  15. * specific are in various include/asm-<arch>/bitops.h headers
  16. * and other arch/<arch> specific files.
  17. *
  18. * See lib/bitmap.c for more details.
  19. */
  20. /*
  21. * The available bitmap operations and their rough meaning in the
  22. * case that the bitmap is a single unsigned long are thus:
  23. *
  24. * Note that nbits should be always a compile time evaluable constant.
  25. * Otherwise many inlines will generate horrible code.
  26. *
  27. * bitmap_zero(dst, nbits) *dst = 0UL
  28. * bitmap_fill(dst, nbits) *dst = ~0UL
  29. * bitmap_copy(dst, src, nbits) *dst = *src
  30. * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
  31. * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
  32. * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
  33. * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
  34. * bitmap_complement(dst, src, nbits) *dst = ~(*src)
  35. * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
  36. * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
  37. * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
  38. * bitmap_empty(src, nbits) Are all bits zero in *src?
  39. * bitmap_full(src, nbits) Are all bits set in *src?
  40. * bitmap_weight(src, nbits) Hamming Weight: number set bits
  41. * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
  42. * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
  43. * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
  44. * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
  45. * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
  46. * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
  47. * bitmap_scnprintf(buf, len, src, nbits) Print bitmap src to buf
  48. * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
  49. * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
  50. * bitmap_scnlistprintf(buf, len, src, nbits) Print bitmap src as list to buf
  51. * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from list
  52. * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  53. * bitmap_release_region(bitmap, pos, order) Free specified bit region
  54. * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
  55. */
  56. /*
  57. * Also the following operations in asm/bitops.h apply to bitmaps.
  58. *
  59. * set_bit(bit, addr) *addr |= bit
  60. * clear_bit(bit, addr) *addr &= ~bit
  61. * change_bit(bit, addr) *addr ^= bit
  62. * test_bit(bit, addr) Is bit set in *addr?
  63. * test_and_set_bit(bit, addr) Set bit and return old value
  64. * test_and_clear_bit(bit, addr) Clear bit and return old value
  65. * test_and_change_bit(bit, addr) Change bit and return old value
  66. * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
  67. * find_first_bit(addr, nbits) Position first set bit in *addr
  68. * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
  69. * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
  70. */
  71. /*
  72. * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  73. * to declare an array named 'name' of just enough unsigned longs to
  74. * contain all bit positions from 0 to 'bits' - 1.
  75. */
  76. /*
  77. * lib/bitmap.c provides these functions:
  78. */
  79. extern int __bitmap_empty(const unsigned long *bitmap, int bits);
  80. extern int __bitmap_full(const unsigned long *bitmap, int bits);
  81. extern int __bitmap_equal(const unsigned long *bitmap1,
  82. const unsigned long *bitmap2, int bits);
  83. extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  84. int bits);
  85. extern void __bitmap_shift_right(unsigned long *dst,
  86. const unsigned long *src, int shift, int bits);
  87. extern void __bitmap_shift_left(unsigned long *dst,
  88. const unsigned long *src, int shift, int bits);
  89. extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  90. const unsigned long *bitmap2, int bits);
  91. extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  92. const unsigned long *bitmap2, int bits);
  93. extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  94. const unsigned long *bitmap2, int bits);
  95. extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
  96. const unsigned long *bitmap2, int bits);
  97. extern int __bitmap_intersects(const unsigned long *bitmap1,
  98. const unsigned long *bitmap2, int bits);
  99. extern int __bitmap_subset(const unsigned long *bitmap1,
  100. const unsigned long *bitmap2, int bits);
  101. extern int __bitmap_weight(const unsigned long *bitmap, int bits);
  102. extern int bitmap_scnprintf(char *buf, unsigned int len,
  103. const unsigned long *src, int nbits);
  104. extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
  105. unsigned long *dst, int nbits);
  106. extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
  107. unsigned long *dst, int nbits);
  108. extern int bitmap_scnlistprintf(char *buf, unsigned int len,
  109. const unsigned long *src, int nbits);
  110. extern int bitmap_parselist(const char *buf, unsigned long *maskp,
  111. int nmaskbits);
  112. extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
  113. const unsigned long *old, const unsigned long *new, int bits);
  114. extern int bitmap_bitremap(int oldbit,
  115. const unsigned long *old, const unsigned long *new, int bits);
  116. extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
  117. const unsigned long *relmap, int bits);
  118. extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
  119. int sz, int bits);
  120. extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
  121. extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
  122. extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
  123. extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
  124. #define BITMAP_LAST_WORD_MASK(nbits) \
  125. ( \
  126. ((nbits) % BITS_PER_LONG) ? \
  127. (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \
  128. )
  129. #define small_const_nbits(nbits) \
  130. (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
  131. static inline void bitmap_zero(unsigned long *dst, int nbits)
  132. {
  133. if (small_const_nbits(nbits))
  134. *dst = 0UL;
  135. else {
  136. int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
  137. memset(dst, 0, len);
  138. }
  139. }
  140. static inline void bitmap_fill(unsigned long *dst, int nbits)
  141. {
  142. size_t nlongs = BITS_TO_LONGS(nbits);
  143. if (!small_const_nbits(nbits)) {
  144. int len = (nlongs - 1) * sizeof(unsigned long);
  145. memset(dst, 0xff, len);
  146. }
  147. dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
  148. }
  149. static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
  150. int nbits)
  151. {
  152. if (small_const_nbits(nbits))
  153. *dst = *src;
  154. else {
  155. int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
  156. memcpy(dst, src, len);
  157. }
  158. }
  159. static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
  160. const unsigned long *src2, int nbits)
  161. {
  162. if (small_const_nbits(nbits))
  163. *dst = *src1 & *src2;
  164. else
  165. __bitmap_and(dst, src1, src2, nbits);
  166. }
  167. static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
  168. const unsigned long *src2, int nbits)
  169. {
  170. if (small_const_nbits(nbits))
  171. *dst = *src1 | *src2;
  172. else
  173. __bitmap_or(dst, src1, src2, nbits);
  174. }
  175. static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
  176. const unsigned long *src2, int nbits)
  177. {
  178. if (small_const_nbits(nbits))
  179. *dst = *src1 ^ *src2;
  180. else
  181. __bitmap_xor(dst, src1, src2, nbits);
  182. }
  183. static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
  184. const unsigned long *src2, int nbits)
  185. {
  186. if (small_const_nbits(nbits))
  187. *dst = *src1 & ~(*src2);
  188. else
  189. __bitmap_andnot(dst, src1, src2, nbits);
  190. }
  191. static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
  192. int nbits)
  193. {
  194. if (small_const_nbits(nbits))
  195. *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
  196. else
  197. __bitmap_complement(dst, src, nbits);
  198. }
  199. static inline int bitmap_equal(const unsigned long *src1,
  200. const unsigned long *src2, int nbits)
  201. {
  202. if (small_const_nbits(nbits))
  203. return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
  204. else
  205. return __bitmap_equal(src1, src2, nbits);
  206. }
  207. static inline int bitmap_intersects(const unsigned long *src1,
  208. const unsigned long *src2, int nbits)
  209. {
  210. if (small_const_nbits(nbits))
  211. return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
  212. else
  213. return __bitmap_intersects(src1, src2, nbits);
  214. }
  215. static inline int bitmap_subset(const unsigned long *src1,
  216. const unsigned long *src2, int nbits)
  217. {
  218. if (small_const_nbits(nbits))
  219. return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
  220. else
  221. return __bitmap_subset(src1, src2, nbits);
  222. }
  223. static inline int bitmap_empty(const unsigned long *src, int nbits)
  224. {
  225. if (small_const_nbits(nbits))
  226. return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
  227. else
  228. return __bitmap_empty(src, nbits);
  229. }
  230. static inline int bitmap_full(const unsigned long *src, int nbits)
  231. {
  232. if (small_const_nbits(nbits))
  233. return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
  234. else
  235. return __bitmap_full(src, nbits);
  236. }
  237. static inline int bitmap_weight(const unsigned long *src, int nbits)
  238. {
  239. if (small_const_nbits(nbits))
  240. return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
  241. return __bitmap_weight(src, nbits);
  242. }
  243. static inline void bitmap_shift_right(unsigned long *dst,
  244. const unsigned long *src, int n, int nbits)
  245. {
  246. if (small_const_nbits(nbits))
  247. *dst = *src >> n;
  248. else
  249. __bitmap_shift_right(dst, src, n, nbits);
  250. }
  251. static inline void bitmap_shift_left(unsigned long *dst,
  252. const unsigned long *src, int n, int nbits)
  253. {
  254. if (small_const_nbits(nbits))
  255. *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
  256. else
  257. __bitmap_shift_left(dst, src, n, nbits);
  258. }
  259. static inline int bitmap_parse(const char *buf, unsigned int buflen,
  260. unsigned long *maskp, int nmaskbits)
  261. {
  262. return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
  263. }
  264. #endif /* __ASSEMBLY__ */
  265. #endif /* __LINUX_BITMAP_H */