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
70 int slow_bitmap_empty(const unsigned long *bitmap, int bits);
71 int slow_bitmap_full(const unsigned long *bitmap, int bits);
72 int slow_bitmap_equal(const unsigned long *bitmap1,
73 const unsigned long *bitmap2, int bits);
74 void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
75 int bits);
76 void slow_bitmap_shift_right(unsigned long *dst,
77 const unsigned long *src, int shift, int bits);
78 void slow_bitmap_shift_left(unsigned long *dst,
79 const unsigned long *src, int shift, int bits);
80 int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
81 const unsigned long *bitmap2, int bits);
82 void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
83 const unsigned long *bitmap2, int bits);
84 void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
85 const unsigned long *bitmap2, int bits);
86 int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
87 const unsigned long *bitmap2, int bits);
88 int slow_bitmap_intersects(const unsigned long *bitmap1,
89 const unsigned long *bitmap2, int bits);
90
bitmap_new(int nbits)91 static 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
bitmap_zero(unsigned long * dst,int nbits)97 static 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
bitmap_fill(unsigned long * dst,int nbits)107 static 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
bitmap_copy(unsigned long * dst,const unsigned long * src,int nbits)117 static 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
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,int nbits)128 static 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
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,int nbits)137 static 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
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,int nbits)147 static 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
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,int nbits)157 static 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
bitmap_complement(unsigned long * dst,const unsigned long * src,int nbits)166 static 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
bitmap_equal(const unsigned long * src1,const unsigned long * src2,int nbits)176 static 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
bitmap_empty(const unsigned long * src,int nbits)186 static 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
bitmap_full(const unsigned long * src,int nbits)195 static 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
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,int nbits)204 static 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
214 void bitmap_set(unsigned long *map, int i, int len);
215 void bitmap_clear(unsigned long *map, int start, int nr);
216 unsigned 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