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1 | /* | |
2 | * Bitmap Module | |
3 | * | |
4 | * Copyright (C) 2010 Corentin Chary <[email protected]> | |
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 | ||
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_set_atomic(dst, pos, nbits) Set specified bit area with atomic ops | |
39 | * bitmap_clear(dst, pos, nbits) Clear specified bit area | |
40 | * bitmap_test_and_clear_atomic(dst, pos, nbits) Test and clear area | |
41 | * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area | |
42 | * bitmap_to_le(dst, src, nbits) Convert bitmap to little endian | |
43 | * bitmap_from_le(dst, src, nbits) Convert bitmap from little endian | |
44 | */ | |
45 | ||
46 | /* | |
47 | * Also the following operations apply to bitmaps. | |
48 | * | |
49 | * set_bit(bit, addr) *addr |= bit | |
50 | * clear_bit(bit, addr) *addr &= ~bit | |
51 | * change_bit(bit, addr) *addr ^= bit | |
52 | * test_bit(bit, addr) Is bit set in *addr? | |
53 | * test_and_set_bit(bit, addr) Set bit and return old value | |
54 | * test_and_clear_bit(bit, addr) Clear bit and return old value | |
55 | * test_and_change_bit(bit, addr) Change bit and return old value | |
56 | * find_first_zero_bit(addr, nbits) Position first zero bit in *addr | |
57 | * find_first_bit(addr, nbits) Position first set bit in *addr | |
58 | * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit | |
59 | * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit | |
60 | */ | |
61 | ||
62 | #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) | |
63 | #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) | |
64 | ||
65 | #define DECLARE_BITMAP(name,bits) \ | |
66 | unsigned long name[BITS_TO_LONGS(bits)] | |
67 | ||
68 | #define small_nbits(nbits) \ | |
69 | ((nbits) <= BITS_PER_LONG) | |
70 | ||
71 | int slow_bitmap_empty(const unsigned long *bitmap, long bits); | |
72 | int slow_bitmap_full(const unsigned long *bitmap, long bits); | |
73 | int slow_bitmap_equal(const unsigned long *bitmap1, | |
74 | const unsigned long *bitmap2, long bits); | |
75 | void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, | |
76 | long bits); | |
77 | int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, | |
78 | const unsigned long *bitmap2, long bits); | |
79 | void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
80 | const unsigned long *bitmap2, long bits); | |
81 | void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
82 | const unsigned long *bitmap2, long bits); | |
83 | int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, | |
84 | const unsigned long *bitmap2, long bits); | |
85 | int slow_bitmap_intersects(const unsigned long *bitmap1, | |
86 | const unsigned long *bitmap2, long bits); | |
87 | long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); | |
88 | ||
89 | static inline unsigned long *bitmap_try_new(long nbits) | |
90 | { | |
91 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); | |
92 | return g_try_malloc0(len); | |
93 | } | |
94 | ||
95 | static inline unsigned long *bitmap_new(long nbits) | |
96 | { | |
97 | unsigned long *ptr = bitmap_try_new(nbits); | |
98 | if (ptr == NULL) { | |
99 | abort(); | |
100 | } | |
101 | return ptr; | |
102 | } | |
103 | ||
104 | static inline void bitmap_zero(unsigned long *dst, long nbits) | |
105 | { | |
106 | if (small_nbits(nbits)) { | |
107 | *dst = 0UL; | |
108 | } else { | |
109 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); | |
110 | memset(dst, 0, len); | |
111 | } | |
112 | } | |
113 | ||
114 | static inline void bitmap_fill(unsigned long *dst, long nbits) | |
115 | { | |
116 | size_t nlongs = BITS_TO_LONGS(nbits); | |
117 | if (!small_nbits(nbits)) { | |
118 | long len = (nlongs - 1) * sizeof(unsigned long); | |
119 | memset(dst, 0xff, len); | |
120 | } | |
121 | dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); | |
122 | } | |
123 | ||
124 | static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, | |
125 | long nbits) | |
126 | { | |
127 | if (small_nbits(nbits)) { | |
128 | *dst = *src; | |
129 | } else { | |
130 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); | |
131 | memcpy(dst, src, len); | |
132 | } | |
133 | } | |
134 | ||
135 | static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, | |
136 | const unsigned long *src2, long nbits) | |
137 | { | |
138 | if (small_nbits(nbits)) { | |
139 | return (*dst = *src1 & *src2) != 0; | |
140 | } | |
141 | return slow_bitmap_and(dst, src1, src2, nbits); | |
142 | } | |
143 | ||
144 | static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, | |
145 | const unsigned long *src2, long nbits) | |
146 | { | |
147 | if (small_nbits(nbits)) { | |
148 | *dst = *src1 | *src2; | |
149 | } else { | |
150 | slow_bitmap_or(dst, src1, src2, nbits); | |
151 | } | |
152 | } | |
153 | ||
154 | static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, | |
155 | const unsigned long *src2, long nbits) | |
156 | { | |
157 | if (small_nbits(nbits)) { | |
158 | *dst = *src1 ^ *src2; | |
159 | } else { | |
160 | slow_bitmap_xor(dst, src1, src2, nbits); | |
161 | } | |
162 | } | |
163 | ||
164 | static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, | |
165 | const unsigned long *src2, long nbits) | |
166 | { | |
167 | if (small_nbits(nbits)) { | |
168 | return (*dst = *src1 & ~(*src2)) != 0; | |
169 | } | |
170 | return slow_bitmap_andnot(dst, src1, src2, nbits); | |
171 | } | |
172 | ||
173 | static inline void bitmap_complement(unsigned long *dst, | |
174 | const unsigned long *src, | |
175 | long nbits) | |
176 | { | |
177 | if (small_nbits(nbits)) { | |
178 | *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); | |
179 | } else { | |
180 | slow_bitmap_complement(dst, src, nbits); | |
181 | } | |
182 | } | |
183 | ||
184 | static inline int bitmap_equal(const unsigned long *src1, | |
185 | const unsigned long *src2, long nbits) | |
186 | { | |
187 | if (small_nbits(nbits)) { | |
188 | return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); | |
189 | } else { | |
190 | return slow_bitmap_equal(src1, src2, nbits); | |
191 | } | |
192 | } | |
193 | ||
194 | static inline int bitmap_empty(const unsigned long *src, long nbits) | |
195 | { | |
196 | if (small_nbits(nbits)) { | |
197 | return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); | |
198 | } else { | |
199 | return slow_bitmap_empty(src, nbits); | |
200 | } | |
201 | } | |
202 | ||
203 | static inline int bitmap_full(const unsigned long *src, long nbits) | |
204 | { | |
205 | if (small_nbits(nbits)) { | |
206 | return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); | |
207 | } else { | |
208 | return slow_bitmap_full(src, nbits); | |
209 | } | |
210 | } | |
211 | ||
212 | static inline int bitmap_intersects(const unsigned long *src1, | |
213 | const unsigned long *src2, long nbits) | |
214 | { | |
215 | if (small_nbits(nbits)) { | |
216 | return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; | |
217 | } else { | |
218 | return slow_bitmap_intersects(src1, src2, nbits); | |
219 | } | |
220 | } | |
221 | ||
222 | static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) | |
223 | { | |
224 | if (unlikely(!nbits)) { | |
225 | return 0; | |
226 | } | |
227 | ||
228 | if (small_nbits(nbits)) { | |
229 | return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); | |
230 | } else { | |
231 | return slow_bitmap_count_one(bitmap, nbits); | |
232 | } | |
233 | } | |
234 | ||
235 | static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, | |
236 | long offset, long nbits) | |
237 | { | |
238 | long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); | |
239 | long redundant_bits = offset - aligned_offset; | |
240 | long bits_to_count = nbits + redundant_bits; | |
241 | const unsigned long *bitmap_start = bitmap + | |
242 | aligned_offset / BITS_PER_LONG; | |
243 | ||
244 | return bitmap_count_one(bitmap_start, bits_to_count) - | |
245 | bitmap_count_one(bitmap_start, redundant_bits); | |
246 | } | |
247 | ||
248 | void bitmap_set(unsigned long *map, long i, long len); | |
249 | void bitmap_set_atomic(unsigned long *map, long i, long len); | |
250 | void bitmap_clear(unsigned long *map, long start, long nr); | |
251 | bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); | |
252 | void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, | |
253 | long nr); | |
254 | unsigned long bitmap_find_next_zero_area(unsigned long *map, | |
255 | unsigned long size, | |
256 | unsigned long start, | |
257 | unsigned long nr, | |
258 | unsigned long align_mask); | |
259 | ||
260 | static inline unsigned long *bitmap_zero_extend(unsigned long *old, | |
261 | long old_nbits, long new_nbits) | |
262 | { | |
263 | long new_len = BITS_TO_LONGS(new_nbits) * sizeof(unsigned long); | |
264 | unsigned long *new = g_realloc(old, new_len); | |
265 | bitmap_clear(new, old_nbits, new_nbits - old_nbits); | |
266 | return new; | |
267 | } | |
268 | ||
269 | void bitmap_to_le(unsigned long *dst, const unsigned long *src, | |
270 | long nbits); | |
271 | void bitmap_from_le(unsigned long *dst, const unsigned long *src, | |
272 | long nbits); | |
273 | ||
274 | #endif /* BITMAP_H */ |