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 | |
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 | * bitmap_copy_with_src_offset(dst, src, offset, nbits) |
45 | * *dst = *src (with an offset into src) |
46 | * bitmap_copy_with_dst_offset(dst, src, offset, nbits) |
47 | * *dst = *src (with an offset into dst) |
48 | */ |
49 | |
50 | /* |
51 | * Also the following operations apply to bitmaps. |
52 | * |
53 | * set_bit(bit, addr) *addr |= bit |
54 | * clear_bit(bit, addr) *addr &= ~bit |
55 | * change_bit(bit, addr) *addr ^= bit |
56 | * test_bit(bit, addr) Is bit set in *addr? |
57 | * test_and_set_bit(bit, addr) Set bit and return old value |
58 | * test_and_clear_bit(bit, addr) Clear bit and return old value |
59 | * test_and_change_bit(bit, addr) Change bit and return old value |
60 | * find_first_zero_bit(addr, nbits) Position first zero bit in *addr |
61 | * find_first_bit(addr, nbits) Position first set bit in *addr |
62 | * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit |
63 | * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit |
64 | */ |
65 | |
66 | #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) |
67 | #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) |
68 | |
69 | #define DECLARE_BITMAP(name,bits) \ |
70 | unsigned long name[BITS_TO_LONGS(bits)] |
71 | |
72 | #define small_nbits(nbits) \ |
73 | ((nbits) <= BITS_PER_LONG) |
74 | |
75 | int slow_bitmap_empty(const unsigned long *bitmap, long bits); |
76 | int slow_bitmap_full(const unsigned long *bitmap, long bits); |
77 | int slow_bitmap_equal(const unsigned long *bitmap1, |
78 | const unsigned long *bitmap2, long bits); |
79 | void slow_bitmap_complement(unsigned long *dst, const unsigned long *src, |
80 | long bits); |
81 | int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
82 | const unsigned long *bitmap2, long bits); |
83 | void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
84 | const unsigned long *bitmap2, long bits); |
85 | void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
86 | const unsigned long *bitmap2, long bits); |
87 | int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
88 | const unsigned long *bitmap2, long bits); |
89 | int slow_bitmap_intersects(const unsigned long *bitmap1, |
90 | const unsigned long *bitmap2, long bits); |
91 | long slow_bitmap_count_one(const unsigned long *bitmap, long nbits); |
92 | |
93 | static inline unsigned long *bitmap_try_new(long nbits) |
94 | { |
95 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); |
96 | return g_try_malloc0(len); |
97 | } |
98 | |
99 | static inline unsigned long *bitmap_new(long nbits) |
100 | { |
101 | unsigned long *ptr = bitmap_try_new(nbits); |
102 | if (ptr == NULL) { |
103 | abort(); |
104 | } |
105 | return ptr; |
106 | } |
107 | |
108 | static inline void bitmap_zero(unsigned long *dst, long nbits) |
109 | { |
110 | if (small_nbits(nbits)) { |
111 | *dst = 0UL; |
112 | } else { |
113 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); |
114 | memset(dst, 0, len); |
115 | } |
116 | } |
117 | |
118 | static inline void bitmap_fill(unsigned long *dst, long nbits) |
119 | { |
120 | size_t nlongs = BITS_TO_LONGS(nbits); |
121 | if (!small_nbits(nbits)) { |
122 | long len = (nlongs - 1) * sizeof(unsigned long); |
123 | memset(dst, 0xff, len); |
124 | } |
125 | dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); |
126 | } |
127 | |
128 | static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, |
129 | long nbits) |
130 | { |
131 | if (small_nbits(nbits)) { |
132 | *dst = *src; |
133 | } else { |
134 | long len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); |
135 | memcpy(dst, src, len); |
136 | } |
137 | } |
138 | |
139 | static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, |
140 | const unsigned long *src2, long nbits) |
141 | { |
142 | if (small_nbits(nbits)) { |
143 | return (*dst = *src1 & *src2) != 0; |
144 | } |
145 | return slow_bitmap_and(dst, src1, src2, nbits); |
146 | } |
147 | |
148 | static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, |
149 | const unsigned long *src2, long nbits) |
150 | { |
151 | if (small_nbits(nbits)) { |
152 | *dst = *src1 | *src2; |
153 | } else { |
154 | slow_bitmap_or(dst, src1, src2, nbits); |
155 | } |
156 | } |
157 | |
158 | static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, |
159 | const unsigned long *src2, long nbits) |
160 | { |
161 | if (small_nbits(nbits)) { |
162 | *dst = *src1 ^ *src2; |
163 | } else { |
164 | slow_bitmap_xor(dst, src1, src2, nbits); |
165 | } |
166 | } |
167 | |
168 | static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, |
169 | const unsigned long *src2, long nbits) |
170 | { |
171 | if (small_nbits(nbits)) { |
172 | return (*dst = *src1 & ~(*src2)) != 0; |
173 | } |
174 | return slow_bitmap_andnot(dst, src1, src2, nbits); |
175 | } |
176 | |
177 | static inline void bitmap_complement(unsigned long *dst, |
178 | const unsigned long *src, |
179 | long nbits) |
180 | { |
181 | if (small_nbits(nbits)) { |
182 | *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits); |
183 | } else { |
184 | slow_bitmap_complement(dst, src, nbits); |
185 | } |
186 | } |
187 | |
188 | static inline int bitmap_equal(const unsigned long *src1, |
189 | const unsigned long *src2, long nbits) |
190 | { |
191 | if (small_nbits(nbits)) { |
192 | return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); |
193 | } else { |
194 | return slow_bitmap_equal(src1, src2, nbits); |
195 | } |
196 | } |
197 | |
198 | static inline int bitmap_empty(const unsigned long *src, long nbits) |
199 | { |
200 | if (small_nbits(nbits)) { |
201 | return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); |
202 | } else { |
203 | return slow_bitmap_empty(src, nbits); |
204 | } |
205 | } |
206 | |
207 | static inline int bitmap_full(const unsigned long *src, long nbits) |
208 | { |
209 | if (small_nbits(nbits)) { |
210 | return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); |
211 | } else { |
212 | return slow_bitmap_full(src, nbits); |
213 | } |
214 | } |
215 | |
216 | static inline int bitmap_intersects(const unsigned long *src1, |
217 | const unsigned long *src2, long nbits) |
218 | { |
219 | if (small_nbits(nbits)) { |
220 | return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; |
221 | } else { |
222 | return slow_bitmap_intersects(src1, src2, nbits); |
223 | } |
224 | } |
225 | |
226 | static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) |
227 | { |
228 | if (unlikely(!nbits)) { |
229 | return 0; |
230 | } |
231 | |
232 | if (small_nbits(nbits)) { |
233 | return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); |
234 | } else { |
235 | return slow_bitmap_count_one(bitmap, nbits); |
236 | } |
237 | } |
238 | |
239 | static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, |
240 | long offset, long nbits) |
241 | { |
242 | long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); |
243 | long redundant_bits = offset - aligned_offset; |
244 | long bits_to_count = nbits + redundant_bits; |
245 | const unsigned long *bitmap_start = bitmap + |
246 | aligned_offset / BITS_PER_LONG; |
247 | |
248 | return bitmap_count_one(bitmap_start, bits_to_count) - |
249 | bitmap_count_one(bitmap_start, redundant_bits); |
250 | } |
251 | |
252 | void bitmap_set(unsigned long *map, long i, long len); |
253 | void bitmap_set_atomic(unsigned long *map, long i, long len); |
254 | void bitmap_clear(unsigned long *map, long start, long nr); |
255 | bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); |
256 | void bitmap_copy_and_clear_atomic(unsigned long *dst, unsigned long *src, |
257 | long nr); |
258 | unsigned long bitmap_find_next_zero_area(unsigned long *map, |
259 | unsigned long size, |
260 | unsigned long start, |
261 | unsigned long nr, |
262 | unsigned long align_mask); |
263 | |
264 | static inline unsigned long *bitmap_zero_extend(unsigned long *old, |
265 | long old_nbits, long new_nbits) |
266 | { |
267 | long new_len = BITS_TO_LONGS(new_nbits) * sizeof(unsigned long); |
268 | unsigned long *new = g_realloc(old, new_len); |
269 | bitmap_clear(new, old_nbits, new_nbits - old_nbits); |
270 | return new; |
271 | } |
272 | |
273 | void bitmap_to_le(unsigned long *dst, const unsigned long *src, |
274 | long nbits); |
275 | void bitmap_from_le(unsigned long *dst, const unsigned long *src, |
276 | long nbits); |
277 | |
278 | void bitmap_copy_with_src_offset(unsigned long *dst, const unsigned long *src, |
279 | unsigned long offset, unsigned long nbits); |
280 | void bitmap_copy_with_dst_offset(unsigned long *dst, const unsigned long *src, |
281 | unsigned long shift, unsigned long nbits); |
282 | |
283 | #endif /* BITMAP_H */ |
284 | |