projects/linux·blob v4.5-rc6 · refs

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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_find_next_zero_area_off(buf, len, pos, n, mask) as above
49 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
50 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
51 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
52 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
53 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
54 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
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_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
58 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
59 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
60 * bitmap_release_region(bitmap, pos, order) Free specified bit region
61 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
62 */
63
64/*
65 * Also the following operations in asm/bitops.h apply to bitmaps.
66 *
67 * set_bit(bit, addr) *addr |= bit
68 * clear_bit(bit, addr) *addr &= ~bit
69 * change_bit(bit, addr) *addr ^= bit
70 * test_bit(bit, addr) Is bit set in *addr?
71 * test_and_set_bit(bit, addr) Set bit and return old value
72 * test_and_clear_bit(bit, addr) Clear bit and return old value
73 * test_and_change_bit(bit, addr) Change bit and return old value
74 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
75 * find_first_bit(addr, nbits) Position first set bit in *addr
76 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
77 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
78 */
79
80/*
81 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
82 * to declare an array named 'name' of just enough unsigned longs to
83 * contain all bit positions from 0 to 'bits' - 1.
84 */
85
86/*
87 * lib/bitmap.c provides these functions:
88 */
89
90extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
91extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
92extern int __bitmap_equal(const unsigned long *bitmap1,
93 const unsigned long *bitmap2, unsigned int nbits);
94extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
95 unsigned int nbits);
96extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
97 unsigned int shift, unsigned int nbits);
98extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
99 unsigned int shift, unsigned int nbits);
100extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
101 const unsigned long *bitmap2, unsigned int nbits);
102extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
103 const unsigned long *bitmap2, unsigned int nbits);
104extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
105 const unsigned long *bitmap2, unsigned int nbits);
106extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
107 const unsigned long *bitmap2, unsigned int nbits);
108extern int __bitmap_intersects(const unsigned long *bitmap1,
109 const unsigned long *bitmap2, unsigned int nbits);
110extern int __bitmap_subset(const unsigned long *bitmap1,
111 const unsigned long *bitmap2, unsigned int nbits);
112extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
113
114extern void bitmap_set(unsigned long *map, unsigned int start, int len);
115extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
116
117extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
118 unsigned long size,
119 unsigned long start,
120 unsigned int nr,
121 unsigned long align_mask,
122 unsigned long align_offset);
123
124/**
125 * bitmap_find_next_zero_area - find a contiguous aligned zero area
126 * @map: The address to base the search on
127 * @size: The bitmap size in bits
128 * @start: The bitnumber to start searching at
129 * @nr: The number of zeroed bits we're looking for
130 * @align_mask: Alignment mask for zero area
131 *
132 * The @align_mask should be one less than a power of 2; the effect is that
133 * the bit offset of all zero areas this function finds is multiples of that
134 * power of 2. A @align_mask of 0 means no alignment is required.
135 */
136static inline unsigned long
137bitmap_find_next_zero_area(unsigned long *map,
138 unsigned long size,
139 unsigned long start,
140 unsigned int nr,
141 unsigned long align_mask)
142{
143 return bitmap_find_next_zero_area_off(map, size, start, nr,
144 align_mask, 0);
145}
146
147extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
148 unsigned long *dst, int nbits);
149extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
150 unsigned long *dst, int nbits);
151extern int bitmap_parselist(const char *buf, unsigned long *maskp,
152 int nmaskbits);
153extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
154 unsigned long *dst, int nbits);
155extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
156 const unsigned long *old, const unsigned long *new, unsigned int nbits);
157extern int bitmap_bitremap(int oldbit,
158 const unsigned long *old, const unsigned long *new, int bits);
159extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
160 const unsigned long *relmap, unsigned int bits);
161extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
162 unsigned int sz, unsigned int nbits);
163extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
164extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
165extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
166#ifdef __BIG_ENDIAN
167extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
168#else
169#define bitmap_copy_le bitmap_copy
170#endif
171extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
172extern int bitmap_print_to_pagebuf(bool list, char *buf,
173 const unsigned long *maskp, int nmaskbits);
174
175#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
176#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
177
178#define small_const_nbits(nbits) \
179 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
180
181static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
182{
183 if (small_const_nbits(nbits))
184 *dst = 0UL;
185 else {
186 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
187 memset(dst, 0, len);
188 }
189}
190
191static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
192{
193 unsigned int nlongs = BITS_TO_LONGS(nbits);
194 if (!small_const_nbits(nbits)) {
195 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
196 memset(dst, 0xff, len);
197 }
198 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
199}
200
201static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
202 unsigned int nbits)
203{
204 if (small_const_nbits(nbits))
205 *dst = *src;
206 else {
207 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
208 memcpy(dst, src, len);
209 }
210}
211
212static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
213 const unsigned long *src2, unsigned int nbits)
214{
215 if (small_const_nbits(nbits))
216 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
217 return __bitmap_and(dst, src1, src2, nbits);
218}
219
220static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
221 const unsigned long *src2, unsigned int nbits)
222{
223 if (small_const_nbits(nbits))
224 *dst = *src1 | *src2;
225 else
226 __bitmap_or(dst, src1, src2, nbits);
227}
228
229static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
230 const unsigned long *src2, unsigned int nbits)
231{
232 if (small_const_nbits(nbits))
233 *dst = *src1 ^ *src2;
234 else
235 __bitmap_xor(dst, src1, src2, nbits);
236}
237
238static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
239 const unsigned long *src2, unsigned int nbits)
240{
241 if (small_const_nbits(nbits))
242 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
243 return __bitmap_andnot(dst, src1, src2, nbits);
244}
245
246static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
247 unsigned int nbits)
248{
249 if (small_const_nbits(nbits))
250 *dst = ~(*src);
251 else
252 __bitmap_complement(dst, src, nbits);
253}
254
255static inline int bitmap_equal(const unsigned long *src1,
256 const unsigned long *src2, unsigned int nbits)
257{
258 if (small_const_nbits(nbits))
259 return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
260 else
261 return __bitmap_equal(src1, src2, nbits);
262}
263
264static inline int bitmap_intersects(const unsigned long *src1,
265 const unsigned long *src2, unsigned int nbits)
266{
267 if (small_const_nbits(nbits))
268 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
269 else
270 return __bitmap_intersects(src1, src2, nbits);
271}
272
273static inline int bitmap_subset(const unsigned long *src1,
274 const unsigned long *src2, unsigned int nbits)
275{
276 if (small_const_nbits(nbits))
277 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
278 else
279 return __bitmap_subset(src1, src2, nbits);
280}
281
282static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
283{
284 if (small_const_nbits(nbits))
285 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
286
287 return find_first_bit(src, nbits) == nbits;
288}
289
290static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
291{
292 if (small_const_nbits(nbits))
293 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
294
295 return find_first_zero_bit(src, nbits) == nbits;
296}
297
298static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
299{
300 if (small_const_nbits(nbits))
301 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
302 return __bitmap_weight(src, nbits);
303}
304
305static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
306 unsigned int shift, int nbits)
307{
308 if (small_const_nbits(nbits))
309 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
310 else
311 __bitmap_shift_right(dst, src, shift, nbits);
312}
313
314static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
315 unsigned int shift, unsigned int nbits)
316{
317 if (small_const_nbits(nbits))
318 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
319 else
320 __bitmap_shift_left(dst, src, shift, nbits);
321}
322
323static inline int bitmap_parse(const char *buf, unsigned int buflen,
324 unsigned long *maskp, int nmaskbits)
325{
326 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
327}
328
329#endif /* __ASSEMBLY__ */
330
331#endif /* __LINUX_BITMAP_H */