ia64/xen-unstable

view xen/common/bitmap.c @ 6832:5959fae4722a

Set NE bit for VMX guest CR0. VMCS guest CR0.NE bit must
be set, else it will cause "vm-entry failed".

Signed-off-by: Chengyuan Li <chengyuan.li@intel.com>
author kaf24@firebug.cl.cam.ac.uk
date Wed Sep 14 13:37:50 2005 +0000 (2005-09-14)
parents ddd290cc8f0d
children b866ed85fad3
line source
1 /*
2 * lib/bitmap.c
3 * Helper functions for bitmap.h.
4 *
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
7 */
8 #include <xen/config.h>
9 #include <xen/types.h>
10 #include <xen/errno.h>
11 #include <xen/bitmap.h>
12 #include <xen/bitops.h>
13 #include <asm/uaccess.h>
15 /*
16 * bitmaps provide an array of bits, implemented using an an
17 * array of unsigned longs. The number of valid bits in a
18 * given bitmap does _not_ need to be an exact multiple of
19 * BITS_PER_LONG.
20 *
21 * The possible unused bits in the last, partially used word
22 * of a bitmap are 'don't care'. The implementation makes
23 * no particular effort to keep them zero. It ensures that
24 * their value will not affect the results of any operation.
25 * The bitmap operations that return Boolean (bitmap_empty,
26 * for example) or scalar (bitmap_weight, for example) results
27 * carefully filter out these unused bits from impacting their
28 * results.
29 *
30 * These operations actually hold to a slightly stronger rule:
31 * if you don't input any bitmaps to these ops that have some
32 * unused bits set, then they won't output any set unused bits
33 * in output bitmaps.
34 *
35 * The byte ordering of bitmaps is more natural on little
36 * endian architectures. See the big-endian headers
37 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
38 * for the best explanations of this ordering.
39 */
41 int __bitmap_empty(const unsigned long *bitmap, int bits)
42 {
43 int k, lim = bits/BITS_PER_LONG;
44 for (k = 0; k < lim; ++k)
45 if (bitmap[k])
46 return 0;
48 if (bits % BITS_PER_LONG)
49 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
50 return 0;
52 return 1;
53 }
54 EXPORT_SYMBOL(__bitmap_empty);
56 int __bitmap_full(const unsigned long *bitmap, int bits)
57 {
58 int k, lim = bits/BITS_PER_LONG;
59 for (k = 0; k < lim; ++k)
60 if (~bitmap[k])
61 return 0;
63 if (bits % BITS_PER_LONG)
64 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
65 return 0;
67 return 1;
68 }
69 EXPORT_SYMBOL(__bitmap_full);
71 int __bitmap_equal(const unsigned long *bitmap1,
72 const unsigned long *bitmap2, int bits)
73 {
74 int k, lim = bits/BITS_PER_LONG;
75 for (k = 0; k < lim; ++k)
76 if (bitmap1[k] != bitmap2[k])
77 return 0;
79 if (bits % BITS_PER_LONG)
80 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
81 return 0;
83 return 1;
84 }
85 EXPORT_SYMBOL(__bitmap_equal);
87 void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits)
88 {
89 int k, lim = bits/BITS_PER_LONG;
90 for (k = 0; k < lim; ++k)
91 dst[k] = ~src[k];
93 if (bits % BITS_PER_LONG)
94 dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
95 }
96 EXPORT_SYMBOL(__bitmap_complement);
98 /*
99 * __bitmap_shift_right - logical right shift of the bits in a bitmap
100 * @dst - destination bitmap
101 * @src - source bitmap
102 * @nbits - shift by this many bits
103 * @bits - bitmap size, in bits
104 *
105 * Shifting right (dividing) means moving bits in the MS -> LS bit
106 * direction. Zeros are fed into the vacated MS positions and the
107 * LS bits shifted off the bottom are lost.
108 */
109 void __bitmap_shift_right(unsigned long *dst,
110 const unsigned long *src, int shift, int bits)
111 {
112 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
113 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
114 unsigned long mask = (1UL << left) - 1;
115 for (k = 0; off + k < lim; ++k) {
116 unsigned long upper, lower;
118 /*
119 * If shift is not word aligned, take lower rem bits of
120 * word above and make them the top rem bits of result.
121 */
122 if (!rem || off + k + 1 >= lim)
123 upper = 0;
124 else {
125 upper = src[off + k + 1];
126 if (off + k + 1 == lim - 1 && left)
127 upper &= mask;
128 }
129 lower = src[off + k];
130 if (left && off + k == lim - 1)
131 lower &= mask;
132 dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
133 if (left && k == lim - 1)
134 dst[k] &= mask;
135 }
136 if (off)
137 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
138 }
139 EXPORT_SYMBOL(__bitmap_shift_right);
142 /*
143 * __bitmap_shift_left - logical left shift of the bits in a bitmap
144 * @dst - destination bitmap
145 * @src - source bitmap
146 * @nbits - shift by this many bits
147 * @bits - bitmap size, in bits
148 *
149 * Shifting left (multiplying) means moving bits in the LS -> MS
150 * direction. Zeros are fed into the vacated LS bit positions
151 * and those MS bits shifted off the top are lost.
152 */
154 void __bitmap_shift_left(unsigned long *dst,
155 const unsigned long *src, int shift, int bits)
156 {
157 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
158 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
159 for (k = lim - off - 1; k >= 0; --k) {
160 unsigned long upper, lower;
162 /*
163 * If shift is not word aligned, take upper rem bits of
164 * word below and make them the bottom rem bits of result.
165 */
166 if (rem && k > 0)
167 lower = src[k - 1];
168 else
169 lower = 0;
170 upper = src[k];
171 if (left && k == lim - 1)
172 upper &= (1UL << left) - 1;
173 dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
174 if (left && k + off == lim - 1)
175 dst[k + off] &= (1UL << left) - 1;
176 }
177 if (off)
178 memset(dst, 0, off*sizeof(unsigned long));
179 }
180 EXPORT_SYMBOL(__bitmap_shift_left);
182 void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
183 const unsigned long *bitmap2, int bits)
184 {
185 int k;
186 int nr = BITS_TO_LONGS(bits);
188 for (k = 0; k < nr; k++)
189 dst[k] = bitmap1[k] & bitmap2[k];
190 }
191 EXPORT_SYMBOL(__bitmap_and);
193 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
194 const unsigned long *bitmap2, int bits)
195 {
196 int k;
197 int nr = BITS_TO_LONGS(bits);
199 for (k = 0; k < nr; k++)
200 dst[k] = bitmap1[k] | bitmap2[k];
201 }
202 EXPORT_SYMBOL(__bitmap_or);
204 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
205 const unsigned long *bitmap2, int bits)
206 {
207 int k;
208 int nr = BITS_TO_LONGS(bits);
210 for (k = 0; k < nr; k++)
211 dst[k] = bitmap1[k] ^ bitmap2[k];
212 }
213 EXPORT_SYMBOL(__bitmap_xor);
215 void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
216 const unsigned long *bitmap2, int bits)
217 {
218 int k;
219 int nr = BITS_TO_LONGS(bits);
221 for (k = 0; k < nr; k++)
222 dst[k] = bitmap1[k] & ~bitmap2[k];
223 }
224 EXPORT_SYMBOL(__bitmap_andnot);
226 int __bitmap_intersects(const unsigned long *bitmap1,
227 const unsigned long *bitmap2, int bits)
228 {
229 int k, lim = bits/BITS_PER_LONG;
230 for (k = 0; k < lim; ++k)
231 if (bitmap1[k] & bitmap2[k])
232 return 1;
234 if (bits % BITS_PER_LONG)
235 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
236 return 1;
237 return 0;
238 }
239 EXPORT_SYMBOL(__bitmap_intersects);
241 int __bitmap_subset(const unsigned long *bitmap1,
242 const unsigned long *bitmap2, int bits)
243 {
244 int k, lim = bits/BITS_PER_LONG;
245 for (k = 0; k < lim; ++k)
246 if (bitmap1[k] & ~bitmap2[k])
247 return 0;
249 if (bits % BITS_PER_LONG)
250 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
251 return 0;
252 return 1;
253 }
254 EXPORT_SYMBOL(__bitmap_subset);
256 #if BITS_PER_LONG == 32
257 int __bitmap_weight(const unsigned long *bitmap, int bits)
258 {
259 int k, w = 0, lim = bits/BITS_PER_LONG;
261 for (k = 0; k < lim; k++)
262 w += hweight32(bitmap[k]);
264 if (bits % BITS_PER_LONG)
265 w += hweight32(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
267 return w;
268 }
269 #else
270 int __bitmap_weight(const unsigned long *bitmap, int bits)
271 {
272 int k, w = 0, lim = bits/BITS_PER_LONG;
274 for (k = 0; k < lim; k++)
275 w += hweight64(bitmap[k]);
277 if (bits % BITS_PER_LONG)
278 w += hweight64(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
280 return w;
281 }
282 #endif
283 EXPORT_SYMBOL(__bitmap_weight);
285 /**
286 * bitmap_find_free_region - find a contiguous aligned mem region
287 * @bitmap: an array of unsigned longs corresponding to the bitmap
288 * @bits: number of bits in the bitmap
289 * @order: region size to find (size is actually 1<<order)
290 *
291 * This is used to allocate a memory region from a bitmap. The idea is
292 * that the region has to be 1<<order sized and 1<<order aligned (this
293 * makes the search algorithm much faster).
294 *
295 * The region is marked as set bits in the bitmap if a free one is
296 * found.
297 *
298 * Returns either beginning of region or negative error
299 */
300 int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
301 {
302 unsigned long mask;
303 int pages = 1 << order;
304 int i;
306 if(pages > BITS_PER_LONG)
307 return -EINVAL;
309 /* make a mask of the order */
310 mask = (1ul << (pages - 1));
311 mask += mask - 1;
313 /* run up the bitmap pages bits at a time */
314 for (i = 0; i < bits; i += pages) {
315 int index = i/BITS_PER_LONG;
316 int offset = i - (index * BITS_PER_LONG);
317 if((bitmap[index] & (mask << offset)) == 0) {
318 /* set region in bimap */
319 bitmap[index] |= (mask << offset);
320 return i;
321 }
322 }
323 return -ENOMEM;
324 }
325 EXPORT_SYMBOL(bitmap_find_free_region);
327 /**
328 * bitmap_release_region - release allocated bitmap region
329 * @bitmap: a pointer to the bitmap
330 * @pos: the beginning of the region
331 * @order: the order of the bits to release (number is 1<<order)
332 *
333 * This is the complement to __bitmap_find_free_region and releases
334 * the found region (by clearing it in the bitmap).
335 */
336 void bitmap_release_region(unsigned long *bitmap, int pos, int order)
337 {
338 int pages = 1 << order;
339 unsigned long mask = (1ul << (pages - 1));
340 int index = pos/BITS_PER_LONG;
341 int offset = pos - (index * BITS_PER_LONG);
342 mask += mask - 1;
343 bitmap[index] &= ~(mask << offset);
344 }
345 EXPORT_SYMBOL(bitmap_release_region);
347 int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
348 {
349 int pages = 1 << order;
350 unsigned long mask = (1ul << (pages - 1));
351 int index = pos/BITS_PER_LONG;
352 int offset = pos - (index * BITS_PER_LONG);
354 /* We don't do regions of pages > BITS_PER_LONG. The
355 * algorithm would be a simple look for multiple zeros in the
356 * array, but there's no driver today that needs this. If you
357 * trip this BUG(), you get to code it... */
358 BUG_ON(pages > BITS_PER_LONG);
359 mask += mask - 1;
360 if (bitmap[index] & (mask << offset))
361 return -EBUSY;
362 bitmap[index] |= (mask << offset);
363 return 0;
364 }
365 EXPORT_SYMBOL(bitmap_allocate_region);