1/*
2 * Bitmap Module
3 *
4 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
5 *
6 * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h
7 *
8 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
9 * See the COPYING.LIB file in the top-level directory.
10 */
11
12#ifndef BITMAP_H
13#define BITMAP_H
14
15#include "qemu-common.h"
16#include "qemu/bitops.h"
17
18/*
19 * The available bitmap operations and their rough meaning in the
20 * case that the bitmap is a single unsigned long are thus:
21 *
22 * Note that nbits should be always a compile time evaluable constant.
23 * Otherwise many inlines will generate horrible code.
24 *
25 * bitmap_zero(dst, nbits)			*dst = 0UL
26 * bitmap_fill(dst, nbits)			*dst = ~0UL
27 * bitmap_copy(dst, src, nbits)			*dst = *src
28 * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
29 * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
30 * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
31 * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
32 * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
33 * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
34 * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
35 * bitmap_empty(src, nbits)			Are all bits zero in *src?
36 * bitmap_full(src, nbits)			Are all bits set in *src?
37 * bitmap_set(dst, pos, nbits)			Set specified bit area
38 * bitmap_clear(dst, pos, nbits)		Clear specified bit area
39 * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
40 */
41
42/*
43 * Also the following operations apply to bitmaps.
44 *
45 * set_bit(bit, addr)			*addr |= bit
46 * clear_bit(bit, addr)			*addr &= ~bit
47 * change_bit(bit, addr)		*addr ^= bit
48 * test_bit(bit, addr)			Is bit set in *addr?
49 * test_and_set_bit(bit, addr)		Set bit and return old value
50 * test_and_clear_bit(bit, addr)	Clear bit and return old value
51 * test_and_change_bit(bit, addr)	Change bit and return old value
52 * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
53 * find_first_bit(addr, nbits)		Position first set bit in *addr
54 * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
55 * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
56 */
57
58#define BITMAP_LAST_WORD_MASK(nbits)                                    \
59    (                                                                   \
60        ((nbits) % BITS_PER_LONG) ?                                     \
61        (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL                       \
62        )
63
64#define DECLARE_BITMAP(name,bits)                  \
65	unsigned long name[BITS_TO_LONGS(bits)]
66
67#define small_nbits(nbits)                      \
68	((nbits) <= BITS_PER_LONG)
69
70int slow_bitmap_empty(const unsigned long *bitmap, int bits);
71int slow_bitmap_full(const unsigned long *bitmap, int bits);
72int slow_bitmap_equal(const unsigned long *bitmap1,
73                   const unsigned long *bitmap2, int bits);
74void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
75                         int bits);
76void slow_bitmap_shift_right(unsigned long *dst,
77                          const unsigned long *src, int shift, int bits);
78void slow_bitmap_shift_left(unsigned long *dst,
79                         const unsigned long *src, int shift, int bits);
80int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
81                 const unsigned long *bitmap2, int bits);
82void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
83                 const unsigned long *bitmap2, int bits);
84void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
85                  const unsigned long *bitmap2, int bits);
86int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
87                    const unsigned long *bitmap2, int bits);
88int slow_bitmap_intersects(const unsigned long *bitmap1,
89			const unsigned long *bitmap2, int bits);
90
91static inline unsigned long *bitmap_new(int nbits)
92{
93    int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
94    return g_malloc0(len);
95}
96
97static inline void bitmap_zero(unsigned long *dst, int nbits)
98{
99    if (small_nbits(nbits)) {
100        *dst = 0UL;
101    } else {
102        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
103        memset(dst, 0, len);
104    }
105}
106
107static inline void bitmap_fill(unsigned long *dst, int nbits)
108{
109    size_t nlongs = BITS_TO_LONGS(nbits);
110    if (!small_nbits(nbits)) {
111        int len = (nlongs - 1) * sizeof(unsigned long);
112        memset(dst, 0xff,  len);
113    }
114    dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
115}
116
117static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
118                               int nbits)
119{
120    if (small_nbits(nbits)) {
121        *dst = *src;
122    } else {
123        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
124        memcpy(dst, src, len);
125    }
126}
127
128static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
129                             const unsigned long *src2, int nbits)
130{
131    if (small_nbits(nbits)) {
132        return (*dst = *src1 & *src2) != 0;
133    }
134    return slow_bitmap_and(dst, src1, src2, nbits);
135}
136
137static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
138			const unsigned long *src2, int nbits)
139{
140    if (small_nbits(nbits)) {
141        *dst = *src1 | *src2;
142    } else {
143        slow_bitmap_or(dst, src1, src2, nbits);
144    }
145}
146
147static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
148			const unsigned long *src2, int nbits)
149{
150    if (small_nbits(nbits)) {
151        *dst = *src1 ^ *src2;
152    } else {
153        slow_bitmap_xor(dst, src1, src2, nbits);
154    }
155}
156
157static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
158			const unsigned long *src2, int nbits)
159{
160    if (small_nbits(nbits)) {
161        return (*dst = *src1 & ~(*src2)) != 0;
162    }
163    return slow_bitmap_andnot(dst, src1, src2, nbits);
164}
165
166static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
167			int nbits)
168{
169    if (small_nbits(nbits)) {
170        *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
171    } else {
172        slow_bitmap_complement(dst, src, nbits);
173    }
174}
175
176static inline int bitmap_equal(const unsigned long *src1,
177			const unsigned long *src2, int nbits)
178{
179    if (small_nbits(nbits)) {
180        return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
181    } else {
182        return slow_bitmap_equal(src1, src2, nbits);
183    }
184}
185
186static inline int bitmap_empty(const unsigned long *src, int nbits)
187{
188    if (small_nbits(nbits)) {
189        return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
190    } else {
191        return slow_bitmap_empty(src, nbits);
192    }
193}
194
195static inline int bitmap_full(const unsigned long *src, int nbits)
196{
197    if (small_nbits(nbits)) {
198        return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
199    } else {
200        return slow_bitmap_full(src, nbits);
201    }
202}
203
204static inline int bitmap_intersects(const unsigned long *src1,
205			const unsigned long *src2, int nbits)
206{
207    if (small_nbits(nbits)) {
208        return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
209    } else {
210        return slow_bitmap_intersects(src1, src2, nbits);
211    }
212}
213
214void bitmap_set(unsigned long *map, int i, int len);
215void bitmap_clear(unsigned long *map, int start, int nr);
216unsigned long bitmap_find_next_zero_area(unsigned long *map,
217					 unsigned long size,
218					 unsigned long start,
219					 unsigned int nr,
220					 unsigned long align_mask);
221
222#endif /* BITMAP_H */
223