summaryrefslogtreecommitdiffstats
path: root/include/qemu/bitmap.h
blob: c318da12d7f106abc05fb1127090433881072e1f (plain) (blame)
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
/*
 * Bitmap Module
 *
 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
 *
 * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 * See the COPYING.LIB file in the top-level directory.
 */

#ifndef BITMAP_H
#define BITMAP_H


#include "qemu/bitops.h"

/*
 * 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_empty(src, nbits)			Are all bits zero in *src?
 * bitmap_full(src, nbits)			Are all bits set in *src?
 * bitmap_set(dst, pos, nbits)			Set specified bit area
 * bitmap_set_atomic(dst, pos, nbits)   Set specified bit area with atomic ops
 * bitmap_clear(dst, pos, nbits)		Clear specified bit area
 * bitmap_test_and_clear_atomic(dst, pos, nbits)    Test and clear area
 * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
 */

/*
 * Also the following operations 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
 */

#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))

#define DECLARE_BITMAP(name,bits)                  \
        unsigned long name[BITS_TO_LONGS(bits)]

#define small_nbits(nbits)                      \
        ((nbits) <= BITS_PER_LONG)

int slow_bitmap_empty(const unsigned long *bitmap, long bits);
int slow_bitmap_full(const unsigned long *bitmap, long bits);
int slow_bitmap_equal(const unsigned long *bitmap1,
                      const unsigned long *bitmap2, long bits);
void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
                            long bits);
int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
                    const unsigned long *bitmap2, long bits);
void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
                    const unsigned long *bitmap2, long bits);
void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
                     const unsigned long *bitmap2, long bits);
int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
                       const unsigned long *bitmap2, long bits);
int slow_bitmap_intersects(const unsigned long *bitmap1,
                           const unsigned long *bitmap2, long bits);

static inline unsigned long *bitmap_try_new(long nbits)
{
    long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
    return g_try_malloc0(len);
}

static inline unsigned long *bitmap_new(long nbits)
{
    unsigned long *ptr = bitmap_try_new(nbits);
    if (ptr == NULL) {
        abort();
    }
    return ptr;
}

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

static inline void bitmap_fill(unsigned long *dst, long nbits)
{
    size_t nlongs = BITS_TO_LONGS(nbits);
    if (!small_nbits(nbits)) {
        long 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,
                               long nbits)
{
    if (small_nbits(nbits)) {
        *dst = *src;
    } else {
        long 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, long nbits)
{
    if (small_nbits(nbits)) {
        return (*dst = *src1 & *src2) != 0;
    }
    return slow_bitmap_and(dst, src1, src2, nbits);
}

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

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

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

static inline void bitmap_complement(unsigned long *dst,
                                     const unsigned long *src,
                                     long nbits)
{
    if (small_nbits(nbits)) {
        *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
    } else {
        slow_bitmap_complement(dst, src, nbits);
    }
}

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

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

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

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

void bitmap_set(unsigned long *map, long i, long len);
void bitmap_set_atomic(unsigned long *map, long i, long len);
void bitmap_clear(unsigned long *map, long start, long nr);
bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr);
void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src,
                                  long nr);
unsigned long bitmap_find_next_zero_area(unsigned long *map,
                                         unsigned long size,
                                         unsigned long start,
                                         unsigned long nr,
                                         unsigned long align_mask);

static inline unsigned long *bitmap_zero_extend(unsigned long *old,
                                                long old_nbits, long new_nbits)
{
    long new_len = BITS_TO_LONGS(new_nbits) * sizeof(unsigned long);
    unsigned long *new = g_realloc(old, new_len);
    bitmap_clear(new, old_nbits, new_nbits - old_nbits);
    return new;
}

#endif /* BITMAP_H */