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12#include "qemu/osdep.h"
13#include "qemu/bitops.h"
14#include "qemu/bitmap.h"
15#include "qemu/atomic.h"
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41int slow_bitmap_empty(const unsigned long *bitmap, long bits)
42{
43 long k, lim = bits/BITS_PER_LONG;
44
45 for (k = 0; k < lim; ++k) {
46 if (bitmap[k]) {
47 return 0;
48 }
49 }
50 if (bits % BITS_PER_LONG) {
51 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) {
52 return 0;
53 }
54 }
55
56 return 1;
57}
58
59int slow_bitmap_full(const unsigned long *bitmap, long bits)
60{
61 long k, lim = bits/BITS_PER_LONG;
62
63 for (k = 0; k < lim; ++k) {
64 if (~bitmap[k]) {
65 return 0;
66 }
67 }
68
69 if (bits % BITS_PER_LONG) {
70 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) {
71 return 0;
72 }
73 }
74
75 return 1;
76}
77
78int slow_bitmap_equal(const unsigned long *bitmap1,
79 const unsigned long *bitmap2, long bits)
80{
81 long k, lim = bits/BITS_PER_LONG;
82
83 for (k = 0; k < lim; ++k) {
84 if (bitmap1[k] != bitmap2[k]) {
85 return 0;
86 }
87 }
88
89 if (bits % BITS_PER_LONG) {
90 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) {
91 return 0;
92 }
93 }
94
95 return 1;
96}
97
98void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,
99 long bits)
100{
101 long k, lim = bits/BITS_PER_LONG;
102
103 for (k = 0; k < lim; ++k) {
104 dst[k] = ~src[k];
105 }
106
107 if (bits % BITS_PER_LONG) {
108 dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
109 }
110}
111
112int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
113 const unsigned long *bitmap2, long bits)
114{
115 long k;
116 long nr = BITS_TO_LONGS(bits);
117 unsigned long result = 0;
118
119 for (k = 0; k < nr; k++) {
120 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
121 }
122 return result != 0;
123}
124
125void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
126 const unsigned long *bitmap2, long bits)
127{
128 long k;
129 long nr = BITS_TO_LONGS(bits);
130
131 for (k = 0; k < nr; k++) {
132 dst[k] = bitmap1[k] | bitmap2[k];
133 }
134}
135
136void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
137 const unsigned long *bitmap2, long bits)
138{
139 long k;
140 long nr = BITS_TO_LONGS(bits);
141
142 for (k = 0; k < nr; k++) {
143 dst[k] = bitmap1[k] ^ bitmap2[k];
144 }
145}
146
147int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
148 const unsigned long *bitmap2, long bits)
149{
150 long k;
151 long nr = BITS_TO_LONGS(bits);
152 unsigned long result = 0;
153
154 for (k = 0; k < nr; k++) {
155 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
156 }
157 return result != 0;
158}
159
160#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
161
162void bitmap_set(unsigned long *map, long start, long nr)
163{
164 unsigned long *p = map + BIT_WORD(start);
165 const long size = start + nr;
166 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
167 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
168
169 while (nr - bits_to_set >= 0) {
170 *p |= mask_to_set;
171 nr -= bits_to_set;
172 bits_to_set = BITS_PER_LONG;
173 mask_to_set = ~0UL;
174 p++;
175 }
176 if (nr) {
177 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
178 *p |= mask_to_set;
179 }
180}
181
182void bitmap_set_atomic(unsigned long *map, long start, long nr)
183{
184 unsigned long *p = map + BIT_WORD(start);
185 const long size = start + nr;
186 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
187 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
188
189
190 if (nr - bits_to_set > 0) {
191 atomic_or(p, mask_to_set);
192 nr -= bits_to_set;
193 bits_to_set = BITS_PER_LONG;
194 mask_to_set = ~0UL;
195 p++;
196 }
197
198
199 if (bits_to_set == BITS_PER_LONG) {
200 while (nr >= BITS_PER_LONG) {
201 *p = ~0UL;
202 nr -= BITS_PER_LONG;
203 p++;
204 }
205 }
206
207
208 if (nr) {
209 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
210 atomic_or(p, mask_to_set);
211 } else {
212
213
214
215 smp_mb();
216 }
217}
218
219void bitmap_clear(unsigned long *map, long start, long nr)
220{
221 unsigned long *p = map + BIT_WORD(start);
222 const long size = start + nr;
223 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
224 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
225
226 while (nr - bits_to_clear >= 0) {
227 *p &= ~mask_to_clear;
228 nr -= bits_to_clear;
229 bits_to_clear = BITS_PER_LONG;
230 mask_to_clear = ~0UL;
231 p++;
232 }
233 if (nr) {
234 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
235 *p &= ~mask_to_clear;
236 }
237}
238
239bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr)
240{
241 unsigned long *p = map + BIT_WORD(start);
242 const long size = start + nr;
243 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
244 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
245 unsigned long dirty = 0;
246 unsigned long old_bits;
247
248
249 if (nr - bits_to_clear > 0) {
250 old_bits = atomic_fetch_and(p, ~mask_to_clear);
251 dirty |= old_bits & mask_to_clear;
252 nr -= bits_to_clear;
253 bits_to_clear = BITS_PER_LONG;
254 mask_to_clear = ~0UL;
255 p++;
256 }
257
258
259 if (bits_to_clear == BITS_PER_LONG) {
260 while (nr >= BITS_PER_LONG) {
261 if (*p) {
262 old_bits = atomic_xchg(p, 0);
263 dirty |= old_bits;
264 }
265 nr -= BITS_PER_LONG;
266 p++;
267 }
268 }
269
270
271 if (nr) {
272 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
273 old_bits = atomic_fetch_and(p, ~mask_to_clear);
274 dirty |= old_bits & mask_to_clear;
275 } else {
276 if (!dirty) {
277 smp_mb();
278 }
279 }
280
281 return dirty != 0;
282}
283
284#define ALIGN_MASK(x,mask) (((x)+(mask))&~(mask))
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298unsigned long bitmap_find_next_zero_area(unsigned long *map,
299 unsigned long size,
300 unsigned long start,
301 unsigned long nr,
302 unsigned long align_mask)
303{
304 unsigned long index, end, i;
305again:
306 index = find_next_zero_bit(map, size, start);
307
308
309 index = ALIGN_MASK(index, align_mask);
310
311 end = index + nr;
312 if (end > size) {
313 return end;
314 }
315 i = find_next_bit(map, end, index);
316 if (i < end) {
317 start = i + 1;
318 goto again;
319 }
320 return index;
321}
322
323int slow_bitmap_intersects(const unsigned long *bitmap1,
324 const unsigned long *bitmap2, long bits)
325{
326 long k, lim = bits/BITS_PER_LONG;
327
328 for (k = 0; k < lim; ++k) {
329 if (bitmap1[k] & bitmap2[k]) {
330 return 1;
331 }
332 }
333
334 if (bits % BITS_PER_LONG) {
335 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) {
336 return 1;
337 }
338 }
339 return 0;
340}
341