bitmap.h 12 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_set(dst, pos, nbits) Set specified bit area
  42. * bitmap_clear(dst, pos, nbits) Clear specified bit area
  43. * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
  44. * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
  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 kernel buf
  56. * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
  57. * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
  58. * bitmap_release_region(bitmap, pos, order) Free specified bit region
  59. * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
  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. * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
  78. * to declare an array named 'name' of just enough unsigned longs to
  79. * contain all bit positions from 0 to 'bits' - 1.
  80. */
  81. /*
  82. * lib/bitmap.c provides these functions:
  83. */
  84. extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
  85. extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
  86. extern int __bitmap_equal(const unsigned long *bitmap1,
  87. const unsigned long *bitmap2, unsigned int nbits);
  88. extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
  89. unsigned int nbits);
  90. extern void __bitmap_shift_right(unsigned long *dst,
  91. const unsigned long *src, int shift, int bits);
  92. extern void __bitmap_shift_left(unsigned long *dst,
  93. const unsigned long *src, int shift, int bits);
  94. extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  95. const unsigned long *bitmap2, unsigned int nbits);
  96. extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  97. const unsigned long *bitmap2, unsigned int nbits);
  98. extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
  99. const unsigned long *bitmap2, unsigned int nbits);
  100. extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
  101. const unsigned long *bitmap2, unsigned int nbits);
  102. extern int __bitmap_intersects(const unsigned long *bitmap1,
  103. const unsigned long *bitmap2, unsigned int nbits);
  104. extern int __bitmap_subset(const unsigned long *bitmap1,
  105. const unsigned long *bitmap2, unsigned int nbits);
  106. extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
  107. extern void bitmap_set(unsigned long *map, unsigned int start, int len);
  108. extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
  109. extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
  110. unsigned long size,
  111. unsigned long start,
  112. unsigned int nr,
  113. unsigned long align_mask,
  114. unsigned long align_offset);
  115. /**
  116. * bitmap_find_next_zero_area - find a contiguous aligned zero area
  117. * @map: The address to base the search on
  118. * @size: The bitmap size in bits
  119. * @start: The bitnumber to start searching at
  120. * @nr: The number of zeroed bits we're looking for
  121. * @align_mask: Alignment mask for zero area
  122. *
  123. * The @align_mask should be one less than a power of 2; the effect is that
  124. * the bit offset of all zero areas this function finds is multiples of that
  125. * power of 2. A @align_mask of 0 means no alignment is required.
  126. */
  127. static inline unsigned long
  128. bitmap_find_next_zero_area(unsigned long *map,
  129. unsigned long size,
  130. unsigned long start,
  131. unsigned int nr,
  132. unsigned long align_mask)
  133. {
  134. return bitmap_find_next_zero_area_off(map, size, start, nr,
  135. align_mask, 0);
  136. }
  137. extern int bitmap_scnprintf(char *buf, unsigned int len,
  138. const unsigned long *src, int nbits);
  139. extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
  140. unsigned long *dst, int nbits);
  141. extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
  142. unsigned long *dst, int nbits);
  143. extern int bitmap_scnlistprintf(char *buf, unsigned int len,
  144. const unsigned long *src, int nbits);
  145. extern int bitmap_parselist(const char *buf, unsigned long *maskp,
  146. int nmaskbits);
  147. extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
  148. unsigned long *dst, int nbits);
  149. extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
  150. const unsigned long *old, const unsigned long *new, int bits);
  151. extern int bitmap_bitremap(int oldbit,
  152. const unsigned long *old, const unsigned long *new, int bits);
  153. extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
  154. const unsigned long *relmap, int bits);
  155. extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
  156. int sz, int bits);
  157. extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
  158. extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
  159. extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
  160. extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
  161. extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
  162. #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
  163. #define BITMAP_LAST_WORD_MASK(nbits) \
  164. ( \
  165. ((nbits) % BITS_PER_LONG) ? \
  166. (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \
  167. )
  168. #define small_const_nbits(nbits) \
  169. (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
  170. static inline void bitmap_zero(unsigned long *dst, int nbits)
  171. {
  172. if (small_const_nbits(nbits))
  173. *dst = 0UL;
  174. else {
  175. int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
  176. memset(dst, 0, len);
  177. }
  178. }
  179. static inline void bitmap_fill(unsigned long *dst, int nbits)
  180. {
  181. size_t nlongs = BITS_TO_LONGS(nbits);
  182. if (!small_const_nbits(nbits)) {
  183. int len = (nlongs - 1) * sizeof(unsigned long);
  184. memset(dst, 0xff, len);
  185. }
  186. dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
  187. }
  188. static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
  189. int nbits)
  190. {
  191. if (small_const_nbits(nbits))
  192. *dst = *src;
  193. else {
  194. int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
  195. memcpy(dst, src, len);
  196. }
  197. }
  198. static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
  199. const unsigned long *src2, unsigned int nbits)
  200. {
  201. if (small_const_nbits(nbits))
  202. return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
  203. return __bitmap_and(dst, src1, src2, nbits);
  204. }
  205. static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
  206. const unsigned long *src2, unsigned int nbits)
  207. {
  208. if (small_const_nbits(nbits))
  209. *dst = *src1 | *src2;
  210. else
  211. __bitmap_or(dst, src1, src2, nbits);
  212. }
  213. static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
  214. const unsigned long *src2, unsigned int nbits)
  215. {
  216. if (small_const_nbits(nbits))
  217. *dst = *src1 ^ *src2;
  218. else
  219. __bitmap_xor(dst, src1, src2, nbits);
  220. }
  221. static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
  222. const unsigned long *src2, unsigned int nbits)
  223. {
  224. if (small_const_nbits(nbits))
  225. return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
  226. return __bitmap_andnot(dst, src1, src2, nbits);
  227. }
  228. static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
  229. unsigned int nbits)
  230. {
  231. if (small_const_nbits(nbits))
  232. *dst = ~(*src);
  233. else
  234. __bitmap_complement(dst, src, nbits);
  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. static inline int bitmap_intersects(const unsigned long *src1,
  245. const unsigned long *src2, unsigned int nbits)
  246. {
  247. if (small_const_nbits(nbits))
  248. return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
  249. else
  250. return __bitmap_intersects(src1, src2, nbits);
  251. }
  252. static inline int bitmap_subset(const unsigned long *src1,
  253. const unsigned long *src2, unsigned int nbits)
  254. {
  255. if (small_const_nbits(nbits))
  256. return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
  257. else
  258. return __bitmap_subset(src1, src2, nbits);
  259. }
  260. static inline int bitmap_empty(const unsigned long *src, unsigned 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. static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
  268. {
  269. if (small_const_nbits(nbits))
  270. return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
  271. else
  272. return __bitmap_full(src, nbits);
  273. }
  274. static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
  275. {
  276. if (small_const_nbits(nbits))
  277. return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
  278. return __bitmap_weight(src, nbits);
  279. }
  280. static inline void bitmap_shift_right(unsigned long *dst,
  281. const unsigned long *src, int n, int nbits)
  282. {
  283. if (small_const_nbits(nbits))
  284. *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> n;
  285. else
  286. __bitmap_shift_right(dst, src, n, nbits);
  287. }
  288. static inline void bitmap_shift_left(unsigned long *dst,
  289. const unsigned long *src, int n, int nbits)
  290. {
  291. if (small_const_nbits(nbits))
  292. *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
  293. else
  294. __bitmap_shift_left(dst, src, n, nbits);
  295. }
  296. static inline int bitmap_parse(const char *buf, unsigned int buflen,
  297. unsigned long *maskp, int nmaskbits)
  298. {
  299. return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
  300. }
  301. #endif /* __ASSEMBLY__ */
  302. #endif /* __LINUX_BITMAP_H */