aboutsummaryrefslogtreecommitdiff
path: root/include/linux/bitmap.h
blob: dbfbf4990005904ebfc4c1cd1a02a0914f2f4180 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
#ifndef __LINUX_BITMAP_H
#define __LINUX_BITMAP_H

#ifndef __ASSEMBLY__

#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/kernel.h>

/*
 * bitmaps provide bit arrays that consume one or more unsigned
 * longs.  The bitmap interface and available operations are listed
 * here, in bitmap.h
 *
 * Function implementations generic to all architectures are in
 * lib/bitmap.c.  Functions implementations that are architecture
 * specific are in various include/asm-<arch>/bitops.h headers
 * and other arch/<arch> specific files.
 *
 * See lib/bitmap.c for more details.
 */

/*
 * The available bitmap operations and their rough meaning in the
 * case that the bitmap is a single unsigned long are thus:
 *
 * Note that nbits should be always a compile time evaluable constant.
 * Otherwise many inlines will generate horrible code.
 *
 * bitmap_zero(dst, nbits)			*dst = 0UL
 * bitmap_fill(dst, nbits)			*dst = ~0UL
 * bitmap_copy(dst, src, nbits)			*dst = *src
 * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
 * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
 * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
 * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
 * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
 * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
 * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
 * bitmap_subset(src1, src2, nbits)		Is *src1 a subset of *src2?
 * bitmap_empty(src, nbits)			Are all bits zero in *src?
 * bitmap_full(src, nbits)			Are all bits set in *src?
 * bitmap_weight(src, nbits)			Hamming Weight: number set bits
 * bitmap_set(dst, pos, nbits)			Set specified bit area
 * bitmap_clear(dst, pos, nbits)		Clear specified bit area
 * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask)	as above
 * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
 * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
 * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
 * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
 * bitmap_onto(dst, orig, relmap, nbits)	*dst = orig relative to relmap
 * bitmap_fold(dst, orig, sz, nbits)		dst bits = orig bits mod sz
 * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
 * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
 * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from kernel buf
 * bitmap_parselist_user(buf, dst, nbits)	Parse bitmap dst from user buf
 * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
 * bitmap_release_region(bitmap, pos, order)	Free specified bit region
 * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
 */

/*
 * Also the following operations in asm/bitops.h apply to bitmaps.
 *
 * set_bit(bit, addr)			*addr |= bit
 * clear_bit(bit, addr)			*addr &= ~bit
 * change_bit(bit, addr)		*addr ^= bit
 * test_bit(bit, addr)			Is bit set in *addr?
 * test_and_set_bit(bit, addr)		Set bit and return old value
 * test_and_clear_bit(bit, addr)	Clear bit and return old value
 * test_and_change_bit(bit, addr)	Change bit and return old value
 * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
 * find_first_bit(addr, nbits)		Position first set bit in *addr
 * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
 * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
 */

/*
 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
 * to declare an array named 'name' of just enough unsigned longs to
 * contain all bit positions from 0 to 'bits' - 1.
 */

/*
 * lib/bitmap.c provides these functions:
 */

extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
extern int __bitmap_equal(const unsigned long *bitmap1,
			  const unsigned long *bitmap2, unsigned int nbits);
extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
			unsigned int nbits);
extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
				unsigned int shift, unsigned int nbits);
extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
				unsigned int shift, unsigned int nbits);
extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_intersects(const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_subset(const unsigned long *bitmap1,
			const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);

extern void bitmap_set(unsigned long *map, unsigned int start, int len);
extern void bitmap_clear(unsigned long *map, unsigned int start, int len);

extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
						    unsigned long size,
						    unsigned long start,
						    unsigned int nr,
						    unsigned long align_mask,
						    unsigned long align_offset);

/**
 * bitmap_find_next_zero_area - find a contiguous aligned zero area
 * @map: The address to base the search on
 * @size: The bitmap size in bits
 * @start: The bitnumber to start searching at
 * @nr: The number of zeroed bits we're looking for
 * @align_mask: Alignment mask for zero area
 *
 * The @align_mask should be one less than a power of 2; the effect is that
 * the bit offset of all zero areas this function finds is multiples of that
 * power of 2. A @align_mask of 0 means no alignment is required.
 */
static inline unsigned long
bitmap_find_next_zero_area(unsigned long *map,
			   unsigned long size,
			   unsigned long start,
			   unsigned int nr,
			   unsigned long align_mask)
{
	return bitmap_find_next_zero_area_off(map, size, start, nr,
					      align_mask, 0);
}

extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
			unsigned long *dst, int nbits);
extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
			unsigned long *dst, int nbits);
extern int bitmap_parselist(const char *buf, unsigned long *maskp,
			int nmaskbits);
extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
			unsigned long *dst, int nbits);
extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
		const unsigned long *old, const unsigned long *new, unsigned int nbits);
extern int bitmap_bitremap(int oldbit,
		const unsigned long *old, const unsigned long *new, int bits);
extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
		const unsigned long *relmap, unsigned int bits);
extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
		unsigned int sz, unsigned int nbits);
extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
#ifdef __BIG_ENDIAN
extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
#else
#define bitmap_copy_le bitmap_copy
#endif
extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
extern int bitmap_print_to_pagebuf(bool list, char *buf,
				   const unsigned long *maskp, int nmaskbits);

#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
#define BITMAP_LAST_WORD_MASK(nbits)					\
(									\
	((nbits) % BITS_PER_LONG) ?					\
		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
)

#define small_const_nbits(nbits) \
	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)

static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = 0UL;
	else {
		unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
		memset(dst, 0, len);
	}
}

static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
{
	unsigned int nlongs = BITS_TO_LONGS(nbits);
	if (!small_const_nbits(nbits)) {
		unsigned int len = (nlongs - 1) * sizeof(unsigned long);
		memset(dst, 0xff,  len);
	}
	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
}

static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
			unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = *src;
	else {
		unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
		memcpy(dst, src, len);
	}
}

static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
	return __bitmap_and(dst, src1, src2, nbits);
}

static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = *src1 | *src2;
	else
		__bitmap_or(dst, src1, src2, nbits);
}

static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = *src1 ^ *src2;
	else
		__bitmap_xor(dst, src1, src2, nbits);
}

static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
	return __bitmap_andnot(dst, src1, src2, nbits);
}

static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
			unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = ~(*src);
	else
		__bitmap_complement(dst, src, nbits);
}

static inline int bitmap_equal(const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
	else
		return __bitmap_equal(src1, src2, nbits);
}

static inline int bitmap_intersects(const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
	else
		return __bitmap_intersects(src1, src2, nbits);
}

static inline int bitmap_subset(const unsigned long *src1,
			const unsigned long *src2, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
	else
		return __bitmap_subset(src1, src2, nbits);
}

static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
{
	if (small_const_nbits(nbits))
		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
	else
		return __bitmap_empty(src, nbits);
}

static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
	else
		return __bitmap_full(src, nbits);
}

static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
	return __bitmap_weight(src, nbits);
}

static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
				unsigned int shift, int nbits)
{
	if (small_const_nbits(nbits))
		*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
	else
		__bitmap_shift_right(dst, src, shift, nbits);
}

static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
				unsigned int shift, unsigned int nbits)
{
	if (small_const_nbits(nbits))
		*dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
	else
		__bitmap_shift_left(dst, src, shift, nbits);
}

static inline int bitmap_parse(const char *buf, unsigned int buflen,
			unsigned long *maskp, int nmaskbits)
{
	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
}

#endif /* __ASSEMBLY__ */

#endif /* __LINUX_BITMAP_H */