1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * lib/bitmap.c 3 * lib/bitmap.c
4 * Helper functions for bitmap.h. 4 * Helper functions for bitmap.h.
5 */ 5 */
6 6
7 #include <linux/bitmap.h> 7 #include <linux/bitmap.h>
8 #include <linux/bitops.h> 8 #include <linux/bitops.h>
>> 9 #include <linux/bug.h>
9 #include <linux/ctype.h> 10 #include <linux/ctype.h>
10 #include <linux/device.h> 11 #include <linux/device.h>
>> 12 #include <linux/errno.h>
11 #include <linux/export.h> 13 #include <linux/export.h>
>> 14 #include <linux/kernel.h>
>> 15 #include <linux/mm.h>
12 #include <linux/slab.h> 16 #include <linux/slab.h>
>> 17 #include <linux/string.h>
>> 18 #include <linux/thread_info.h>
>> 19 #include <linux/uaccess.h>
>> 20
>> 21 #include <asm/page.h>
>> 22
>> 23 #include "kstrtox.h"
13 24
14 /** 25 /**
15 * DOC: bitmap introduction 26 * DOC: bitmap introduction
16 * 27 *
17 * bitmaps provide an array of bits, implement 28 * bitmaps provide an array of bits, implemented using an
18 * array of unsigned longs. The number of val 29 * array of unsigned longs. The number of valid bits in a
19 * given bitmap does _not_ need to be an exact 30 * given bitmap does _not_ need to be an exact multiple of
20 * BITS_PER_LONG. 31 * BITS_PER_LONG.
21 * 32 *
22 * The possible unused bits in the last, parti 33 * The possible unused bits in the last, partially used word
23 * of a bitmap are 'don't care'. The implemen 34 * of a bitmap are 'don't care'. The implementation makes
24 * no particular effort to keep them zero. It 35 * no particular effort to keep them zero. It ensures that
25 * their value will not affect the results of 36 * their value will not affect the results of any operation.
26 * The bitmap operations that return Boolean ( 37 * The bitmap operations that return Boolean (bitmap_empty,
27 * for example) or scalar (bitmap_weight, for 38 * for example) or scalar (bitmap_weight, for example) results
28 * carefully filter out these unused bits from 39 * carefully filter out these unused bits from impacting their
29 * results. 40 * results.
30 * 41 *
31 * The byte ordering of bitmaps is more natura 42 * The byte ordering of bitmaps is more natural on little
32 * endian architectures. See the big-endian h 43 * endian architectures. See the big-endian headers
33 * include/asm-ppc64/bitops.h and include/asm- 44 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
34 * for the best explanations of this ordering. 45 * for the best explanations of this ordering.
35 */ 46 */
36 47
37 bool __bitmap_equal(const unsigned long *bitma !! 48 int __bitmap_equal(const unsigned long *bitmap1,
38 const unsigned long *bitma !! 49 const unsigned long *bitmap2, unsigned int bits)
39 { 50 {
40 unsigned int k, lim = bits/BITS_PER_LO 51 unsigned int k, lim = bits/BITS_PER_LONG;
41 for (k = 0; k < lim; ++k) 52 for (k = 0; k < lim; ++k)
42 if (bitmap1[k] != bitmap2[k]) 53 if (bitmap1[k] != bitmap2[k])
43 return false; !! 54 return 0;
44 55
45 if (bits % BITS_PER_LONG) 56 if (bits % BITS_PER_LONG)
46 if ((bitmap1[k] ^ bitmap2[k]) 57 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
47 return false; !! 58 return 0;
48 59
49 return true; !! 60 return 1;
50 } 61 }
51 EXPORT_SYMBOL(__bitmap_equal); 62 EXPORT_SYMBOL(__bitmap_equal);
52 63
53 bool __bitmap_or_equal(const unsigned long *bi 64 bool __bitmap_or_equal(const unsigned long *bitmap1,
54 const unsigned long *bi 65 const unsigned long *bitmap2,
55 const unsigned long *bi 66 const unsigned long *bitmap3,
56 unsigned int bits) 67 unsigned int bits)
57 { 68 {
58 unsigned int k, lim = bits / BITS_PER_ 69 unsigned int k, lim = bits / BITS_PER_LONG;
59 unsigned long tmp; 70 unsigned long tmp;
60 71
61 for (k = 0; k < lim; ++k) { 72 for (k = 0; k < lim; ++k) {
62 if ((bitmap1[k] | bitmap2[k]) 73 if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
63 return false; 74 return false;
64 } 75 }
65 76
66 if (!(bits % BITS_PER_LONG)) 77 if (!(bits % BITS_PER_LONG))
67 return true; 78 return true;
68 79
69 tmp = (bitmap1[k] | bitmap2[k]) ^ bitm 80 tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
70 return (tmp & BITMAP_LAST_WORD_MASK(bi 81 return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
71 } 82 }
72 83
73 void __bitmap_complement(unsigned long *dst, c 84 void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
74 { 85 {
75 unsigned int k, lim = BITS_TO_LONGS(bi 86 unsigned int k, lim = BITS_TO_LONGS(bits);
76 for (k = 0; k < lim; ++k) 87 for (k = 0; k < lim; ++k)
77 dst[k] = ~src[k]; 88 dst[k] = ~src[k];
78 } 89 }
79 EXPORT_SYMBOL(__bitmap_complement); 90 EXPORT_SYMBOL(__bitmap_complement);
80 91
81 /** 92 /**
82 * __bitmap_shift_right - logical right shift 93 * __bitmap_shift_right - logical right shift of the bits in a bitmap
83 * @dst : destination bitmap 94 * @dst : destination bitmap
84 * @src : source bitmap 95 * @src : source bitmap
85 * @shift : shift by this many bits 96 * @shift : shift by this many bits
86 * @nbits : bitmap size, in bits 97 * @nbits : bitmap size, in bits
87 * 98 *
88 * Shifting right (dividing) means moving bits 99 * Shifting right (dividing) means moving bits in the MS -> LS bit
89 * direction. Zeros are fed into the vacated 100 * direction. Zeros are fed into the vacated MS positions and the
90 * LS bits shifted off the bottom are lost. 101 * LS bits shifted off the bottom are lost.
91 */ 102 */
92 void __bitmap_shift_right(unsigned long *dst, 103 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
93 unsigned shift, unsign 104 unsigned shift, unsigned nbits)
94 { 105 {
95 unsigned k, lim = BITS_TO_LONGS(nbits) 106 unsigned k, lim = BITS_TO_LONGS(nbits);
96 unsigned off = shift/BITS_PER_LONG, re 107 unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
97 unsigned long mask = BITMAP_LAST_WORD_ 108 unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
98 for (k = 0; off + k < lim; ++k) { 109 for (k = 0; off + k < lim; ++k) {
99 unsigned long upper, lower; 110 unsigned long upper, lower;
100 111
101 /* 112 /*
102 * If shift is not word aligne 113 * If shift is not word aligned, take lower rem bits of
103 * word above and make them th 114 * word above and make them the top rem bits of result.
104 */ 115 */
105 if (!rem || off + k + 1 >= lim 116 if (!rem || off + k + 1 >= lim)
106 upper = 0; 117 upper = 0;
107 else { 118 else {
108 upper = src[off + k + 119 upper = src[off + k + 1];
109 if (off + k + 1 == lim 120 if (off + k + 1 == lim - 1)
110 upper &= mask; 121 upper &= mask;
111 upper <<= (BITS_PER_LO 122 upper <<= (BITS_PER_LONG - rem);
112 } 123 }
113 lower = src[off + k]; 124 lower = src[off + k];
114 if (off + k == lim - 1) 125 if (off + k == lim - 1)
115 lower &= mask; 126 lower &= mask;
116 lower >>= rem; 127 lower >>= rem;
117 dst[k] = lower | upper; 128 dst[k] = lower | upper;
118 } 129 }
119 if (off) 130 if (off)
120 memset(&dst[lim - off], 0, off 131 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
121 } 132 }
122 EXPORT_SYMBOL(__bitmap_shift_right); 133 EXPORT_SYMBOL(__bitmap_shift_right);
123 134
124 135
125 /** 136 /**
126 * __bitmap_shift_left - logical left shift of 137 * __bitmap_shift_left - logical left shift of the bits in a bitmap
127 * @dst : destination bitmap 138 * @dst : destination bitmap
128 * @src : source bitmap 139 * @src : source bitmap
129 * @shift : shift by this many bits 140 * @shift : shift by this many bits
130 * @nbits : bitmap size, in bits 141 * @nbits : bitmap size, in bits
131 * 142 *
132 * Shifting left (multiplying) means moving bi 143 * Shifting left (multiplying) means moving bits in the LS -> MS
133 * direction. Zeros are fed into the vacated 144 * direction. Zeros are fed into the vacated LS bit positions
134 * and those MS bits shifted off the top are l 145 * and those MS bits shifted off the top are lost.
135 */ 146 */
136 147
137 void __bitmap_shift_left(unsigned long *dst, c 148 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
138 unsigned int shift, un 149 unsigned int shift, unsigned int nbits)
139 { 150 {
140 int k; 151 int k;
141 unsigned int lim = BITS_TO_LONGS(nbits 152 unsigned int lim = BITS_TO_LONGS(nbits);
142 unsigned int off = shift/BITS_PER_LONG 153 unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
143 for (k = lim - off - 1; k >= 0; --k) { 154 for (k = lim - off - 1; k >= 0; --k) {
144 unsigned long upper, lower; 155 unsigned long upper, lower;
145 156
146 /* 157 /*
147 * If shift is not word aligne 158 * If shift is not word aligned, take upper rem bits of
148 * word below and make them th 159 * word below and make them the bottom rem bits of result.
149 */ 160 */
150 if (rem && k > 0) 161 if (rem && k > 0)
151 lower = src[k - 1] >> 162 lower = src[k - 1] >> (BITS_PER_LONG - rem);
152 else 163 else
153 lower = 0; 164 lower = 0;
154 upper = src[k] << rem; 165 upper = src[k] << rem;
155 dst[k + off] = lower | upper; 166 dst[k + off] = lower | upper;
156 } 167 }
157 if (off) 168 if (off)
158 memset(dst, 0, off*sizeof(unsi 169 memset(dst, 0, off*sizeof(unsigned long));
159 } 170 }
160 EXPORT_SYMBOL(__bitmap_shift_left); 171 EXPORT_SYMBOL(__bitmap_shift_left);
161 172
162 /** 173 /**
163 * bitmap_cut() - remove bit region from bitma 174 * bitmap_cut() - remove bit region from bitmap and right shift remaining bits
164 * @dst: destination bitmap, might overlap wit 175 * @dst: destination bitmap, might overlap with src
165 * @src: source bitmap 176 * @src: source bitmap
166 * @first: start bit of region to be removed 177 * @first: start bit of region to be removed
167 * @cut: number of bits to remove 178 * @cut: number of bits to remove
168 * @nbits: bitmap size, in bits 179 * @nbits: bitmap size, in bits
169 * 180 *
170 * Set the n-th bit of @dst iff the n-th bit o 181 * Set the n-th bit of @dst iff the n-th bit of @src is set and
171 * n is less than @first, or the m-th bit of @ 182 * n is less than @first, or the m-th bit of @src is set for any
172 * m such that @first <= n < nbits, and m = n 183 * m such that @first <= n < nbits, and m = n + @cut.
173 * 184 *
174 * In pictures, example for a big-endian 32-bi 185 * In pictures, example for a big-endian 32-bit architecture:
175 * 186 *
176 * The @src bitmap is:: 187 * The @src bitmap is::
177 * 188 *
178 * 31 63 189 * 31 63
179 * | | 190 * | |
180 * 10000000 11000001 11110010 00010101 1000 191 * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
181 * | | | 192 * | | | |
182 * 16 14 0 193 * 16 14 0 32
183 * 194 *
184 * if @cut is 3, and @first is 14, bits 14-16 195 * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
185 * 196 *
186 * 31 63 197 * 31 63
187 * | | 198 * | |
188 * 10110000 00011000 00110010 00010101 0001 199 * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
189 * | | 200 * | | |
190 * 14 (bit 17 0 201 * 14 (bit 17 0 32
191 * from @src) 202 * from @src)
192 * 203 *
193 * Note that @dst and @src might overlap parti 204 * Note that @dst and @src might overlap partially or entirely.
194 * 205 *
195 * This is implemented in the obvious way, wit 206 * This is implemented in the obvious way, with a shift and carry
196 * step for each moved bit. Optimisation is le 207 * step for each moved bit. Optimisation is left as an exercise
197 * for the compiler. 208 * for the compiler.
198 */ 209 */
199 void bitmap_cut(unsigned long *dst, const unsi 210 void bitmap_cut(unsigned long *dst, const unsigned long *src,
200 unsigned int first, unsigned i 211 unsigned int first, unsigned int cut, unsigned int nbits)
201 { 212 {
202 unsigned int len = BITS_TO_LONGS(nbits 213 unsigned int len = BITS_TO_LONGS(nbits);
203 unsigned long keep = 0, carry; 214 unsigned long keep = 0, carry;
204 int i; 215 int i;
205 216
206 if (first % BITS_PER_LONG) { 217 if (first % BITS_PER_LONG) {
207 keep = src[first / BITS_PER_LO 218 keep = src[first / BITS_PER_LONG] &
208 (~0UL >> (BITS_PER_LONG 219 (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
209 } 220 }
210 221
211 memmove(dst, src, len * sizeof(*dst)); 222 memmove(dst, src, len * sizeof(*dst));
212 223
213 while (cut--) { 224 while (cut--) {
214 for (i = first / BITS_PER_LONG 225 for (i = first / BITS_PER_LONG; i < len; i++) {
215 if (i < len - 1) 226 if (i < len - 1)
216 carry = dst[i 227 carry = dst[i + 1] & 1UL;
217 else 228 else
218 carry = 0; 229 carry = 0;
219 230
220 dst[i] = (dst[i] >> 1) 231 dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
221 } 232 }
222 } 233 }
223 234
224 dst[first / BITS_PER_LONG] &= ~0UL << 235 dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
225 dst[first / BITS_PER_LONG] |= keep; 236 dst[first / BITS_PER_LONG] |= keep;
226 } 237 }
227 EXPORT_SYMBOL(bitmap_cut); 238 EXPORT_SYMBOL(bitmap_cut);
228 239
229 bool __bitmap_and(unsigned long *dst, const un !! 240 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
230 const unsigned 241 const unsigned long *bitmap2, unsigned int bits)
231 { 242 {
232 unsigned int k; 243 unsigned int k;
233 unsigned int lim = bits/BITS_PER_LONG; 244 unsigned int lim = bits/BITS_PER_LONG;
234 unsigned long result = 0; 245 unsigned long result = 0;
235 246
236 for (k = 0; k < lim; k++) 247 for (k = 0; k < lim; k++)
237 result |= (dst[k] = bitmap1[k] 248 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
238 if (bits % BITS_PER_LONG) 249 if (bits % BITS_PER_LONG)
239 result |= (dst[k] = bitmap1[k] 250 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
240 BITMAP_LAST_WORD_MA 251 BITMAP_LAST_WORD_MASK(bits));
241 return result != 0; 252 return result != 0;
242 } 253 }
243 EXPORT_SYMBOL(__bitmap_and); 254 EXPORT_SYMBOL(__bitmap_and);
244 255
245 void __bitmap_or(unsigned long *dst, const uns 256 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
246 const unsigned 257 const unsigned long *bitmap2, unsigned int bits)
247 { 258 {
248 unsigned int k; 259 unsigned int k;
249 unsigned int nr = BITS_TO_LONGS(bits); 260 unsigned int nr = BITS_TO_LONGS(bits);
250 261
251 for (k = 0; k < nr; k++) 262 for (k = 0; k < nr; k++)
252 dst[k] = bitmap1[k] | bitmap2[ 263 dst[k] = bitmap1[k] | bitmap2[k];
253 } 264 }
254 EXPORT_SYMBOL(__bitmap_or); 265 EXPORT_SYMBOL(__bitmap_or);
255 266
256 void __bitmap_xor(unsigned long *dst, const un 267 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
257 const unsigned 268 const unsigned long *bitmap2, unsigned int bits)
258 { 269 {
259 unsigned int k; 270 unsigned int k;
260 unsigned int nr = BITS_TO_LONGS(bits); 271 unsigned int nr = BITS_TO_LONGS(bits);
261 272
262 for (k = 0; k < nr; k++) 273 for (k = 0; k < nr; k++)
263 dst[k] = bitmap1[k] ^ bitmap2[ 274 dst[k] = bitmap1[k] ^ bitmap2[k];
264 } 275 }
265 EXPORT_SYMBOL(__bitmap_xor); 276 EXPORT_SYMBOL(__bitmap_xor);
266 277
267 bool __bitmap_andnot(unsigned long *dst, const !! 278 int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
268 const unsigned 279 const unsigned long *bitmap2, unsigned int bits)
269 { 280 {
270 unsigned int k; 281 unsigned int k;
271 unsigned int lim = bits/BITS_PER_LONG; 282 unsigned int lim = bits/BITS_PER_LONG;
272 unsigned long result = 0; 283 unsigned long result = 0;
273 284
274 for (k = 0; k < lim; k++) 285 for (k = 0; k < lim; k++)
275 result |= (dst[k] = bitmap1[k] 286 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
276 if (bits % BITS_PER_LONG) 287 if (bits % BITS_PER_LONG)
277 result |= (dst[k] = bitmap1[k] 288 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
278 BITMAP_LAST_WORD_MA 289 BITMAP_LAST_WORD_MASK(bits));
279 return result != 0; 290 return result != 0;
280 } 291 }
281 EXPORT_SYMBOL(__bitmap_andnot); 292 EXPORT_SYMBOL(__bitmap_andnot);
282 293
283 void __bitmap_replace(unsigned long *dst, 294 void __bitmap_replace(unsigned long *dst,
284 const unsigned long *old 295 const unsigned long *old, const unsigned long *new,
285 const unsigned long *mas 296 const unsigned long *mask, unsigned int nbits)
286 { 297 {
287 unsigned int k; 298 unsigned int k;
288 unsigned int nr = BITS_TO_LONGS(nbits) 299 unsigned int nr = BITS_TO_LONGS(nbits);
289 300
290 for (k = 0; k < nr; k++) 301 for (k = 0; k < nr; k++)
291 dst[k] = (old[k] & ~mask[k]) | 302 dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
292 } 303 }
293 EXPORT_SYMBOL(__bitmap_replace); 304 EXPORT_SYMBOL(__bitmap_replace);
294 305
295 bool __bitmap_intersects(const unsigned long * !! 306 int __bitmap_intersects(const unsigned long *bitmap1,
296 const unsigned long * !! 307 const unsigned long *bitmap2, unsigned int bits)
297 { 308 {
298 unsigned int k, lim = bits/BITS_PER_LO 309 unsigned int k, lim = bits/BITS_PER_LONG;
299 for (k = 0; k < lim; ++k) 310 for (k = 0; k < lim; ++k)
300 if (bitmap1[k] & bitmap2[k]) 311 if (bitmap1[k] & bitmap2[k])
301 return true; !! 312 return 1;
302 313
303 if (bits % BITS_PER_LONG) 314 if (bits % BITS_PER_LONG)
304 if ((bitmap1[k] & bitmap2[k]) 315 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
305 return true; !! 316 return 1;
306 return false; !! 317 return 0;
307 } 318 }
308 EXPORT_SYMBOL(__bitmap_intersects); 319 EXPORT_SYMBOL(__bitmap_intersects);
309 320
310 bool __bitmap_subset(const unsigned long *bitm !! 321 int __bitmap_subset(const unsigned long *bitmap1,
311 const unsigned long *bitm !! 322 const unsigned long *bitmap2, unsigned int bits)
312 { 323 {
313 unsigned int k, lim = bits/BITS_PER_LO 324 unsigned int k, lim = bits/BITS_PER_LONG;
314 for (k = 0; k < lim; ++k) 325 for (k = 0; k < lim; ++k)
315 if (bitmap1[k] & ~bitmap2[k]) 326 if (bitmap1[k] & ~bitmap2[k])
316 return false; !! 327 return 0;
317 328
318 if (bits % BITS_PER_LONG) 329 if (bits % BITS_PER_LONG)
319 if ((bitmap1[k] & ~bitmap2[k]) 330 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
320 return false; !! 331 return 0;
321 return true; !! 332 return 1;
322 } 333 }
323 EXPORT_SYMBOL(__bitmap_subset); 334 EXPORT_SYMBOL(__bitmap_subset);
324 335
325 #define BITMAP_WEIGHT(FETCH, bits) \ !! 336 int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
326 ({ <<
327 unsigned int __bits = (bits), idx, w = <<
328 <<
329 for (idx = 0; idx < __bits / BITS_PER_ <<
330 w += hweight_long(FETCH); <<
331 <<
332 if (__bits % BITS_PER_LONG) <<
333 w += hweight_long((FETCH) & BI <<
334 <<
335 w; <<
336 }) <<
337 <<
338 unsigned int __bitmap_weight(const unsigned lo <<
339 { 337 {
340 return BITMAP_WEIGHT(bitmap[idx], bits !! 338 unsigned int k, lim = bits/BITS_PER_LONG;
341 } !! 339 int w = 0;
342 EXPORT_SYMBOL(__bitmap_weight); <<
343 340
344 unsigned int __bitmap_weight_and(const unsigne !! 341 for (k = 0; k < lim; k++)
345 const unsigned !! 342 w += hweight_long(bitmap[k]);
346 { <<
347 return BITMAP_WEIGHT(bitmap1[idx] & bi <<
348 } <<
349 EXPORT_SYMBOL(__bitmap_weight_and); <<
350 343
351 unsigned int __bitmap_weight_andnot(const unsi !! 344 if (bits % BITS_PER_LONG)
352 const unsigned !! 345 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
353 { !! 346
354 return BITMAP_WEIGHT(bitmap1[idx] & ~b !! 347 return w;
355 } 348 }
356 EXPORT_SYMBOL(__bitmap_weight_andnot); !! 349 EXPORT_SYMBOL(__bitmap_weight);
357 350
358 void __bitmap_set(unsigned long *map, unsigned 351 void __bitmap_set(unsigned long *map, unsigned int start, int len)
359 { 352 {
360 unsigned long *p = map + BIT_WORD(star 353 unsigned long *p = map + BIT_WORD(start);
361 const unsigned int size = start + len; 354 const unsigned int size = start + len;
362 int bits_to_set = BITS_PER_LONG - (sta 355 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
363 unsigned long mask_to_set = BITMAP_FIR 356 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
364 357
365 while (len - bits_to_set >= 0) { 358 while (len - bits_to_set >= 0) {
366 *p |= mask_to_set; 359 *p |= mask_to_set;
367 len -= bits_to_set; 360 len -= bits_to_set;
368 bits_to_set = BITS_PER_LONG; 361 bits_to_set = BITS_PER_LONG;
369 mask_to_set = ~0UL; 362 mask_to_set = ~0UL;
370 p++; 363 p++;
371 } 364 }
372 if (len) { 365 if (len) {
373 mask_to_set &= BITMAP_LAST_WOR 366 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
374 *p |= mask_to_set; 367 *p |= mask_to_set;
375 } 368 }
376 } 369 }
377 EXPORT_SYMBOL(__bitmap_set); 370 EXPORT_SYMBOL(__bitmap_set);
378 371
379 void __bitmap_clear(unsigned long *map, unsign 372 void __bitmap_clear(unsigned long *map, unsigned int start, int len)
380 { 373 {
381 unsigned long *p = map + BIT_WORD(star 374 unsigned long *p = map + BIT_WORD(start);
382 const unsigned int size = start + len; 375 const unsigned int size = start + len;
383 int bits_to_clear = BITS_PER_LONG - (s 376 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
384 unsigned long mask_to_clear = BITMAP_F 377 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
385 378
386 while (len - bits_to_clear >= 0) { 379 while (len - bits_to_clear >= 0) {
387 *p &= ~mask_to_clear; 380 *p &= ~mask_to_clear;
388 len -= bits_to_clear; 381 len -= bits_to_clear;
389 bits_to_clear = BITS_PER_LONG; 382 bits_to_clear = BITS_PER_LONG;
390 mask_to_clear = ~0UL; 383 mask_to_clear = ~0UL;
391 p++; 384 p++;
392 } 385 }
393 if (len) { 386 if (len) {
394 mask_to_clear &= BITMAP_LAST_W 387 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
395 *p &= ~mask_to_clear; 388 *p &= ~mask_to_clear;
396 } 389 }
397 } 390 }
398 EXPORT_SYMBOL(__bitmap_clear); 391 EXPORT_SYMBOL(__bitmap_clear);
399 392
400 /** 393 /**
401 * bitmap_find_next_zero_area_off - find a con 394 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
402 * @map: The address to base the search on 395 * @map: The address to base the search on
403 * @size: The bitmap size in bits 396 * @size: The bitmap size in bits
404 * @start: The bitnumber to start searching at 397 * @start: The bitnumber to start searching at
405 * @nr: The number of zeroed bits we're lookin 398 * @nr: The number of zeroed bits we're looking for
406 * @align_mask: Alignment mask for zero area 399 * @align_mask: Alignment mask for zero area
407 * @align_offset: Alignment offset for zero ar 400 * @align_offset: Alignment offset for zero area.
408 * 401 *
409 * The @align_mask should be one less than a p 402 * The @align_mask should be one less than a power of 2; the effect is that
410 * the bit offset of all zero areas this funct 403 * the bit offset of all zero areas this function finds plus @align_offset
411 * is multiple of that power of 2. 404 * is multiple of that power of 2.
412 */ 405 */
413 unsigned long bitmap_find_next_zero_area_off(u 406 unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
414 u 407 unsigned long size,
415 u 408 unsigned long start,
416 u 409 unsigned int nr,
417 u 410 unsigned long align_mask,
418 u 411 unsigned long align_offset)
419 { 412 {
420 unsigned long index, end, i; 413 unsigned long index, end, i;
421 again: 414 again:
422 index = find_next_zero_bit(map, size, 415 index = find_next_zero_bit(map, size, start);
423 416
424 /* Align allocation */ 417 /* Align allocation */
425 index = __ALIGN_MASK(index + align_off 418 index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
426 419
427 end = index + nr; 420 end = index + nr;
428 if (end > size) 421 if (end > size)
429 return end; 422 return end;
430 i = find_next_bit(map, end, index); 423 i = find_next_bit(map, end, index);
431 if (i < end) { 424 if (i < end) {
432 start = i + 1; 425 start = i + 1;
433 goto again; 426 goto again;
434 } 427 }
435 return index; 428 return index;
436 } 429 }
437 EXPORT_SYMBOL(bitmap_find_next_zero_area_off); 430 EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
438 431
>> 432 /*
>> 433 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
>> 434 * second version by Paul Jackson, third by Joe Korty.
>> 435 */
>> 436
>> 437 /**
>> 438 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
>> 439 *
>> 440 * @ubuf: pointer to user buffer containing string.
>> 441 * @ulen: buffer size in bytes. If string is smaller than this
>> 442 * then it must be terminated with a \0.
>> 443 * @maskp: pointer to bitmap array that will contain result.
>> 444 * @nmaskbits: size of bitmap, in bits.
>> 445 */
>> 446 int bitmap_parse_user(const char __user *ubuf,
>> 447 unsigned int ulen, unsigned long *maskp,
>> 448 int nmaskbits)
>> 449 {
>> 450 char *buf;
>> 451 int ret;
>> 452
>> 453 buf = memdup_user_nul(ubuf, ulen);
>> 454 if (IS_ERR(buf))
>> 455 return PTR_ERR(buf);
>> 456
>> 457 ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits);
>> 458
>> 459 kfree(buf);
>> 460 return ret;
>> 461 }
>> 462 EXPORT_SYMBOL(bitmap_parse_user);
>> 463
>> 464 /**
>> 465 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
>> 466 * @list: indicates whether the bitmap must be list
>> 467 * @buf: page aligned buffer into which string is placed
>> 468 * @maskp: pointer to bitmap to convert
>> 469 * @nmaskbits: size of bitmap, in bits
>> 470 *
>> 471 * Output format is a comma-separated list of decimal numbers and
>> 472 * ranges if list is specified or hex digits grouped into comma-separated
>> 473 * sets of 8 digits/set. Returns the number of characters written to buf.
>> 474 *
>> 475 * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
>> 476 * area and that sufficient storage remains at @buf to accommodate the
>> 477 * bitmap_print_to_pagebuf() output. Returns the number of characters
>> 478 * actually printed to @buf, excluding terminating '\0'.
>> 479 */
>> 480 int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
>> 481 int nmaskbits)
>> 482 {
>> 483 ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
>> 484
>> 485 return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
>> 486 scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
>> 487 }
>> 488 EXPORT_SYMBOL(bitmap_print_to_pagebuf);
>> 489
>> 490 /**
>> 491 * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string
>> 492 * @list: indicates whether the bitmap must be list
>> 493 * true: print in decimal list format
>> 494 * false: print in hexadecimal bitmask format
>> 495 */
>> 496 static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp,
>> 497 int nmaskbits, loff_t off, size_t count)
>> 498 {
>> 499 const char *fmt = list ? "%*pbl\n" : "%*pb\n";
>> 500 ssize_t size;
>> 501 void *data;
>> 502
>> 503 data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp);
>> 504 if (!data)
>> 505 return -ENOMEM;
>> 506
>> 507 size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1);
>> 508 kfree(data);
>> 509
>> 510 return size;
>> 511 }
>> 512
>> 513 /**
>> 514 * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string
>> 515 *
>> 516 * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper
>> 517 * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal
>> 518 * bitmask and decimal list to userspace by sysfs ABI.
>> 519 * Drivers might be using a normal attribute for this kind of ABIs. A
>> 520 * normal attribute typically has show entry as below:
>> 521 * static ssize_t example_attribute_show(struct device *dev,
>> 522 * struct device_attribute *attr, char *buf)
>> 523 * {
>> 524 * ...
>> 525 * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max);
>> 526 * }
>> 527 * show entry of attribute has no offset and count parameters and this
>> 528 * means the file is limited to one page only.
>> 529 * bitmap_print_to_pagebuf() API works terribly well for this kind of
>> 530 * normal attribute with buf parameter and without offset, count:
>> 531 * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
>> 532 * int nmaskbits)
>> 533 * {
>> 534 * }
>> 535 * The problem is once we have a large bitmap, we have a chance to get a
>> 536 * bitmask or list more than one page. Especially for list, it could be
>> 537 * as complex as 0,3,5,7,9,... We have no simple way to know it exact size.
>> 538 * It turns out bin_attribute is a way to break this limit. bin_attribute
>> 539 * has show entry as below:
>> 540 * static ssize_t
>> 541 * example_bin_attribute_show(struct file *filp, struct kobject *kobj,
>> 542 * struct bin_attribute *attr, char *buf,
>> 543 * loff_t offset, size_t count)
>> 544 * {
>> 545 * ...
>> 546 * }
>> 547 * With the new offset and count parameters, this makes sysfs ABI be able
>> 548 * to support file size more than one page. For example, offset could be
>> 549 * >= 4096.
>> 550 * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their
>> 551 * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf()
>> 552 * make those drivers be able to support large bitmask and list after they
>> 553 * move to use bin_attribute. In result, we have to pass the corresponding
>> 554 * parameters such as off, count from bin_attribute show entry to this API.
>> 555 *
>> 556 * @buf: buffer into which string is placed
>> 557 * @maskp: pointer to bitmap to convert
>> 558 * @nmaskbits: size of bitmap, in bits
>> 559 * @off: in the string from which we are copying, We copy to @buf
>> 560 * @count: the maximum number of bytes to print
>> 561 *
>> 562 * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf()
>> 563 * is similar with cpumap_print_to_pagebuf(), the difference is that
>> 564 * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption
>> 565 * the destination buffer is exactly one page and won't be more than one page.
>> 566 * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other
>> 567 * hand, mainly serves bin_attribute which doesn't work with exact one page,
>> 568 * and it can break the size limit of converted decimal list and hexadecimal
>> 569 * bitmask.
>> 570 *
>> 571 * WARNING!
>> 572 *
>> 573 * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf().
>> 574 * It is intended to workaround sysfs limitations discussed above and should be
>> 575 * used carefully in general case for the following reasons:
>> 576 * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf().
>> 577 * - Memory complexity is O(nbits), comparing to O(1) for snprintf().
>> 578 * - @off and @count are NOT offset and number of bits to print.
>> 579 * - If printing part of bitmap as list, the resulting string is not a correct
>> 580 * list representation of bitmap. Particularly, some bits within or out of
>> 581 * related interval may be erroneously set or unset. The format of the string
>> 582 * may be broken, so bitmap_parselist-like parser may fail parsing it.
>> 583 * - If printing the whole bitmap as list by parts, user must ensure the order
>> 584 * of calls of the function such that the offset is incremented linearly.
>> 585 * - If printing the whole bitmap as list by parts, user must keep bitmap
>> 586 * unchanged between the very first and very last call. Otherwise concatenated
>> 587 * result may be incorrect, and format may be broken.
>> 588 *
>> 589 * Returns the number of characters actually printed to @buf
>> 590 */
>> 591 int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
>> 592 int nmaskbits, loff_t off, size_t count)
>> 593 {
>> 594 return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count);
>> 595 }
>> 596 EXPORT_SYMBOL(bitmap_print_bitmask_to_buf);
>> 597
>> 598 /**
>> 599 * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string
>> 600 *
>> 601 * Everything is same with the above bitmap_print_bitmask_to_buf() except
>> 602 * the print format.
>> 603 */
>> 604 int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
>> 605 int nmaskbits, loff_t off, size_t count)
>> 606 {
>> 607 return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count);
>> 608 }
>> 609 EXPORT_SYMBOL(bitmap_print_list_to_buf);
>> 610
>> 611 /*
>> 612 * Region 9-38:4/10 describes the following bitmap structure:
>> 613 * 0 9 12 18 38 N
>> 614 * .........****......****......****..................
>> 615 * ^ ^ ^ ^ ^
>> 616 * start off group_len end nbits
>> 617 */
>> 618 struct region {
>> 619 unsigned int start;
>> 620 unsigned int off;
>> 621 unsigned int group_len;
>> 622 unsigned int end;
>> 623 unsigned int nbits;
>> 624 };
>> 625
>> 626 static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
>> 627 {
>> 628 unsigned int start;
>> 629
>> 630 for (start = r->start; start <= r->end; start += r->group_len)
>> 631 bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
>> 632 }
>> 633
>> 634 static int bitmap_check_region(const struct region *r)
>> 635 {
>> 636 if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
>> 637 return -EINVAL;
>> 638
>> 639 if (r->end >= r->nbits)
>> 640 return -ERANGE;
>> 641
>> 642 return 0;
>> 643 }
>> 644
>> 645 static const char *bitmap_getnum(const char *str, unsigned int *num,
>> 646 unsigned int lastbit)
>> 647 {
>> 648 unsigned long long n;
>> 649 unsigned int len;
>> 650
>> 651 if (str[0] == 'N') {
>> 652 *num = lastbit;
>> 653 return str + 1;
>> 654 }
>> 655
>> 656 len = _parse_integer(str, 10, &n);
>> 657 if (!len)
>> 658 return ERR_PTR(-EINVAL);
>> 659 if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
>> 660 return ERR_PTR(-EOVERFLOW);
>> 661
>> 662 *num = n;
>> 663 return str + len;
>> 664 }
>> 665
>> 666 static inline bool end_of_str(char c)
>> 667 {
>> 668 return c == '\0' || c == '\n';
>> 669 }
>> 670
>> 671 static inline bool __end_of_region(char c)
>> 672 {
>> 673 return isspace(c) || c == ',';
>> 674 }
>> 675
>> 676 static inline bool end_of_region(char c)
>> 677 {
>> 678 return __end_of_region(c) || end_of_str(c);
>> 679 }
>> 680
>> 681 /*
>> 682 * The format allows commas and whitespaces at the beginning
>> 683 * of the region.
>> 684 */
>> 685 static const char *bitmap_find_region(const char *str)
>> 686 {
>> 687 while (__end_of_region(*str))
>> 688 str++;
>> 689
>> 690 return end_of_str(*str) ? NULL : str;
>> 691 }
>> 692
>> 693 static const char *bitmap_find_region_reverse(const char *start, const char *end)
>> 694 {
>> 695 while (start <= end && __end_of_region(*end))
>> 696 end--;
>> 697
>> 698 return end;
>> 699 }
>> 700
>> 701 static const char *bitmap_parse_region(const char *str, struct region *r)
>> 702 {
>> 703 unsigned int lastbit = r->nbits - 1;
>> 704
>> 705 if (!strncasecmp(str, "all", 3)) {
>> 706 r->start = 0;
>> 707 r->end = lastbit;
>> 708 str += 3;
>> 709
>> 710 goto check_pattern;
>> 711 }
>> 712
>> 713 str = bitmap_getnum(str, &r->start, lastbit);
>> 714 if (IS_ERR(str))
>> 715 return str;
>> 716
>> 717 if (end_of_region(*str))
>> 718 goto no_end;
>> 719
>> 720 if (*str != '-')
>> 721 return ERR_PTR(-EINVAL);
>> 722
>> 723 str = bitmap_getnum(str + 1, &r->end, lastbit);
>> 724 if (IS_ERR(str))
>> 725 return str;
>> 726
>> 727 check_pattern:
>> 728 if (end_of_region(*str))
>> 729 goto no_pattern;
>> 730
>> 731 if (*str != ':')
>> 732 return ERR_PTR(-EINVAL);
>> 733
>> 734 str = bitmap_getnum(str + 1, &r->off, lastbit);
>> 735 if (IS_ERR(str))
>> 736 return str;
>> 737
>> 738 if (*str != '/')
>> 739 return ERR_PTR(-EINVAL);
>> 740
>> 741 return bitmap_getnum(str + 1, &r->group_len, lastbit);
>> 742
>> 743 no_end:
>> 744 r->end = r->start;
>> 745 no_pattern:
>> 746 r->off = r->end + 1;
>> 747 r->group_len = r->end + 1;
>> 748
>> 749 return end_of_str(*str) ? NULL : str;
>> 750 }
>> 751
>> 752 /**
>> 753 * bitmap_parselist - convert list format ASCII string to bitmap
>> 754 * @buf: read user string from this buffer; must be terminated
>> 755 * with a \0 or \n.
>> 756 * @maskp: write resulting mask here
>> 757 * @nmaskbits: number of bits in mask to be written
>> 758 *
>> 759 * Input format is a comma-separated list of decimal numbers and
>> 760 * ranges. Consecutively set bits are shown as two hyphen-separated
>> 761 * decimal numbers, the smallest and largest bit numbers set in
>> 762 * the range.
>> 763 * Optionally each range can be postfixed to denote that only parts of it
>> 764 * should be set. The range will divided to groups of specific size.
>> 765 * From each group will be used only defined amount of bits.
>> 766 * Syntax: range:used_size/group_size
>> 767 * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
>> 768 * The value 'N' can be used as a dynamically substituted token for the
>> 769 * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is
>> 770 * dynamic, so if system changes cause the bitmap width to change, such
>> 771 * as more cores in a CPU list, then any ranges using N will also change.
>> 772 *
>> 773 * Returns: 0 on success, -errno on invalid input strings. Error values:
>> 774 *
>> 775 * - ``-EINVAL``: wrong region format
>> 776 * - ``-EINVAL``: invalid character in string
>> 777 * - ``-ERANGE``: bit number specified too large for mask
>> 778 * - ``-EOVERFLOW``: integer overflow in the input parameters
>> 779 */
>> 780 int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
>> 781 {
>> 782 struct region r;
>> 783 long ret;
>> 784
>> 785 r.nbits = nmaskbits;
>> 786 bitmap_zero(maskp, r.nbits);
>> 787
>> 788 while (buf) {
>> 789 buf = bitmap_find_region(buf);
>> 790 if (buf == NULL)
>> 791 return 0;
>> 792
>> 793 buf = bitmap_parse_region(buf, &r);
>> 794 if (IS_ERR(buf))
>> 795 return PTR_ERR(buf);
>> 796
>> 797 ret = bitmap_check_region(&r);
>> 798 if (ret)
>> 799 return ret;
>> 800
>> 801 bitmap_set_region(&r, maskp);
>> 802 }
>> 803
>> 804 return 0;
>> 805 }
>> 806 EXPORT_SYMBOL(bitmap_parselist);
>> 807
>> 808
>> 809 /**
>> 810 * bitmap_parselist_user()
>> 811 *
>> 812 * @ubuf: pointer to user buffer containing string.
>> 813 * @ulen: buffer size in bytes. If string is smaller than this
>> 814 * then it must be terminated with a \0.
>> 815 * @maskp: pointer to bitmap array that will contain result.
>> 816 * @nmaskbits: size of bitmap, in bits.
>> 817 *
>> 818 * Wrapper for bitmap_parselist(), providing it with user buffer.
>> 819 */
>> 820 int bitmap_parselist_user(const char __user *ubuf,
>> 821 unsigned int ulen, unsigned long *maskp,
>> 822 int nmaskbits)
>> 823 {
>> 824 char *buf;
>> 825 int ret;
>> 826
>> 827 buf = memdup_user_nul(ubuf, ulen);
>> 828 if (IS_ERR(buf))
>> 829 return PTR_ERR(buf);
>> 830
>> 831 ret = bitmap_parselist(buf, maskp, nmaskbits);
>> 832
>> 833 kfree(buf);
>> 834 return ret;
>> 835 }
>> 836 EXPORT_SYMBOL(bitmap_parselist_user);
>> 837
>> 838 static const char *bitmap_get_x32_reverse(const char *start,
>> 839 const char *end, u32 *num)
>> 840 {
>> 841 u32 ret = 0;
>> 842 int c, i;
>> 843
>> 844 for (i = 0; i < 32; i += 4) {
>> 845 c = hex_to_bin(*end--);
>> 846 if (c < 0)
>> 847 return ERR_PTR(-EINVAL);
>> 848
>> 849 ret |= c << i;
>> 850
>> 851 if (start > end || __end_of_region(*end))
>> 852 goto out;
>> 853 }
>> 854
>> 855 if (hex_to_bin(*end--) >= 0)
>> 856 return ERR_PTR(-EOVERFLOW);
>> 857 out:
>> 858 *num = ret;
>> 859 return end;
>> 860 }
>> 861
>> 862 /**
>> 863 * bitmap_parse - convert an ASCII hex string into a bitmap.
>> 864 * @start: pointer to buffer containing string.
>> 865 * @buflen: buffer size in bytes. If string is smaller than this
>> 866 * then it must be terminated with a \0 or \n. In that case,
>> 867 * UINT_MAX may be provided instead of string length.
>> 868 * @maskp: pointer to bitmap array that will contain result.
>> 869 * @nmaskbits: size of bitmap, in bits.
>> 870 *
>> 871 * Commas group hex digits into chunks. Each chunk defines exactly 32
>> 872 * bits of the resultant bitmask. No chunk may specify a value larger
>> 873 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
>> 874 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
>> 875 * characters. Grouping such as "1,,5", ",44", "," or "" is allowed.
>> 876 * Leading, embedded and trailing whitespace accepted.
>> 877 */
>> 878 int bitmap_parse(const char *start, unsigned int buflen,
>> 879 unsigned long *maskp, int nmaskbits)
>> 880 {
>> 881 const char *end = strnchrnul(start, buflen, '\n') - 1;
>> 882 int chunks = BITS_TO_U32(nmaskbits);
>> 883 u32 *bitmap = (u32 *)maskp;
>> 884 int unset_bit;
>> 885 int chunk;
>> 886
>> 887 for (chunk = 0; ; chunk++) {
>> 888 end = bitmap_find_region_reverse(start, end);
>> 889 if (start > end)
>> 890 break;
>> 891
>> 892 if (!chunks--)
>> 893 return -EOVERFLOW;
>> 894
>> 895 #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
>> 896 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]);
>> 897 #else
>> 898 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]);
>> 899 #endif
>> 900 if (IS_ERR(end))
>> 901 return PTR_ERR(end);
>> 902 }
>> 903
>> 904 unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
>> 905 if (unset_bit < nmaskbits) {
>> 906 bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit);
>> 907 return 0;
>> 908 }
>> 909
>> 910 if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit)
>> 911 return -EOVERFLOW;
>> 912
>> 913 return 0;
>> 914 }
>> 915 EXPORT_SYMBOL(bitmap_parse);
>> 916
439 /** 917 /**
440 * bitmap_pos_to_ord - find ordinal of set bit 918 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
441 * @buf: pointer to a bitmap 919 * @buf: pointer to a bitmap
442 * @pos: a bit position in @buf (0 <= @po 920 * @pos: a bit position in @buf (0 <= @pos < @nbits)
443 * @nbits: number of valid bit positions 921 * @nbits: number of valid bit positions in @buf
444 * 922 *
445 * Map the bit at position @pos in @buf (of le 923 * Map the bit at position @pos in @buf (of length @nbits) to the
446 * ordinal of which set bit it is. If it is n 924 * ordinal of which set bit it is. If it is not set or if @pos
447 * is not a valid bit position, map to -1. 925 * is not a valid bit position, map to -1.
448 * 926 *
449 * If for example, just bits 4 through 7 are s 927 * If for example, just bits 4 through 7 are set in @buf, then @pos
450 * values 4 through 7 will get mapped to 0 thr 928 * values 4 through 7 will get mapped to 0 through 3, respectively,
451 * and other @pos values will get mapped to -1 929 * and other @pos values will get mapped to -1. When @pos value 7
452 * gets mapped to (returns) @ord value 3 in th 930 * gets mapped to (returns) @ord value 3 in this example, that means
453 * that bit 7 is the 3rd (starting with 0th) s 931 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
454 * 932 *
455 * The bit positions 0 through @bits are valid 933 * The bit positions 0 through @bits are valid positions in @buf.
456 */ 934 */
457 static int bitmap_pos_to_ord(const unsigned lo 935 static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
458 { 936 {
459 if (pos >= nbits || !test_bit(pos, buf 937 if (pos >= nbits || !test_bit(pos, buf))
460 return -1; 938 return -1;
461 939
462 return bitmap_weight(buf, pos); !! 940 return __bitmap_weight(buf, pos);
>> 941 }
>> 942
>> 943 /**
>> 944 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
>> 945 * @buf: pointer to bitmap
>> 946 * @ord: ordinal bit position (n-th set bit, n >= 0)
>> 947 * @nbits: number of valid bit positions in @buf
>> 948 *
>> 949 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
>> 950 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
>> 951 * >= weight(buf), returns @nbits.
>> 952 *
>> 953 * If for example, just bits 4 through 7 are set in @buf, then @ord
>> 954 * values 0 through 3 will get mapped to 4 through 7, respectively,
>> 955 * and all other @ord values returns @nbits. When @ord value 3
>> 956 * gets mapped to (returns) @pos value 7 in this example, that means
>> 957 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
>> 958 *
>> 959 * The bit positions 0 through @nbits-1 are valid positions in @buf.
>> 960 */
>> 961 unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
>> 962 {
>> 963 unsigned int pos;
>> 964
>> 965 for (pos = find_first_bit(buf, nbits);
>> 966 pos < nbits && ord;
>> 967 pos = find_next_bit(buf, nbits, pos + 1))
>> 968 ord--;
>> 969
>> 970 return pos;
463 } 971 }
464 972
465 /** 973 /**
466 * bitmap_remap - Apply map defined by a pair 974 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
467 * @dst: remapped result 975 * @dst: remapped result
468 * @src: subset to be remapped 976 * @src: subset to be remapped
469 * @old: defines domain of map 977 * @old: defines domain of map
470 * @new: defines range of map 978 * @new: defines range of map
471 * @nbits: number of bits in each of thes 979 * @nbits: number of bits in each of these bitmaps
472 * 980 *
473 * Let @old and @new define a mapping of bit p 981 * Let @old and @new define a mapping of bit positions, such that
474 * whatever position is held by the n-th set b 982 * whatever position is held by the n-th set bit in @old is mapped
475 * to the n-th set bit in @new. In the more g 983 * to the n-th set bit in @new. In the more general case, allowing
476 * for the possibility that the weight 'w' of 984 * for the possibility that the weight 'w' of @new is less than the
477 * weight of @old, map the position of the n-t 985 * weight of @old, map the position of the n-th set bit in @old to
478 * the position of the m-th set bit in @new, w 986 * the position of the m-th set bit in @new, where m == n % w.
479 * 987 *
480 * If either of the @old and @new bitmaps are 988 * If either of the @old and @new bitmaps are empty, or if @src and
481 * @dst point to the same location, then this 989 * @dst point to the same location, then this routine copies @src
482 * to @dst. 990 * to @dst.
483 * 991 *
484 * The positions of unset bits in @old are map 992 * The positions of unset bits in @old are mapped to themselves
485 * (the identity map). !! 993 * (the identify map).
486 * 994 *
487 * Apply the above specified mapping to @src, 995 * Apply the above specified mapping to @src, placing the result in
488 * @dst, clearing any bits previously set in @ 996 * @dst, clearing any bits previously set in @dst.
489 * 997 *
490 * For example, lets say that @old has bits 4 998 * For example, lets say that @old has bits 4 through 7 set, and
491 * @new has bits 12 through 15 set. This defi 999 * @new has bits 12 through 15 set. This defines the mapping of bit
492 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 1000 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
493 * bit positions unchanged. So if say @src co 1001 * bit positions unchanged. So if say @src comes into this routine
494 * with bits 1, 5 and 7 set, then @dst should 1002 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
495 * 13 and 15 set. 1003 * 13 and 15 set.
496 */ 1004 */
497 void bitmap_remap(unsigned long *dst, const un 1005 void bitmap_remap(unsigned long *dst, const unsigned long *src,
498 const unsigned long *old, cons 1006 const unsigned long *old, const unsigned long *new,
499 unsigned int nbits) 1007 unsigned int nbits)
500 { 1008 {
501 unsigned int oldbit, w; 1009 unsigned int oldbit, w;
502 1010
503 if (dst == src) /* following d 1011 if (dst == src) /* following doesn't handle inplace remaps */
504 return; 1012 return;
505 bitmap_zero(dst, nbits); 1013 bitmap_zero(dst, nbits);
506 1014
507 w = bitmap_weight(new, nbits); 1015 w = bitmap_weight(new, nbits);
508 for_each_set_bit(oldbit, src, nbits) { 1016 for_each_set_bit(oldbit, src, nbits) {
509 int n = bitmap_pos_to_ord(old, 1017 int n = bitmap_pos_to_ord(old, oldbit, nbits);
510 1018
511 if (n < 0 || w == 0) 1019 if (n < 0 || w == 0)
512 set_bit(oldbit, dst); 1020 set_bit(oldbit, dst); /* identity map */
513 else 1021 else
514 set_bit(find_nth_bit(n !! 1022 set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
515 } 1023 }
516 } 1024 }
517 EXPORT_SYMBOL(bitmap_remap); 1025 EXPORT_SYMBOL(bitmap_remap);
518 1026
519 /** 1027 /**
520 * bitmap_bitremap - Apply map defined by a pa 1028 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
521 * @oldbit: bit position to be mapped 1029 * @oldbit: bit position to be mapped
522 * @old: defines domain of map 1030 * @old: defines domain of map
523 * @new: defines range of map 1031 * @new: defines range of map
524 * @bits: number of bits in each of these 1032 * @bits: number of bits in each of these bitmaps
525 * 1033 *
526 * Let @old and @new define a mapping of bit p 1034 * Let @old and @new define a mapping of bit positions, such that
527 * whatever position is held by the n-th set b 1035 * whatever position is held by the n-th set bit in @old is mapped
528 * to the n-th set bit in @new. In the more g 1036 * to the n-th set bit in @new. In the more general case, allowing
529 * for the possibility that the weight 'w' of 1037 * for the possibility that the weight 'w' of @new is less than the
530 * weight of @old, map the position of the n-t 1038 * weight of @old, map the position of the n-th set bit in @old to
531 * the position of the m-th set bit in @new, w 1039 * the position of the m-th set bit in @new, where m == n % w.
532 * 1040 *
533 * The positions of unset bits in @old are map 1041 * The positions of unset bits in @old are mapped to themselves
534 * (the identity map). !! 1042 * (the identify map).
535 * 1043 *
536 * Apply the above specified mapping to bit po 1044 * Apply the above specified mapping to bit position @oldbit, returning
537 * the new bit position. 1045 * the new bit position.
538 * 1046 *
539 * For example, lets say that @old has bits 4 1047 * For example, lets say that @old has bits 4 through 7 set, and
540 * @new has bits 12 through 15 set. This defi 1048 * @new has bits 12 through 15 set. This defines the mapping of bit
541 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 1049 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
542 * bit positions unchanged. So if say @oldbit 1050 * bit positions unchanged. So if say @oldbit is 5, then this routine
543 * returns 13. 1051 * returns 13.
544 */ 1052 */
545 int bitmap_bitremap(int oldbit, const unsigned 1053 int bitmap_bitremap(int oldbit, const unsigned long *old,
546 const unsigned 1054 const unsigned long *new, int bits)
547 { 1055 {
548 int w = bitmap_weight(new, bits); 1056 int w = bitmap_weight(new, bits);
549 int n = bitmap_pos_to_ord(old, oldbit, 1057 int n = bitmap_pos_to_ord(old, oldbit, bits);
550 if (n < 0 || w == 0) 1058 if (n < 0 || w == 0)
551 return oldbit; 1059 return oldbit;
552 else 1060 else
553 return find_nth_bit(new, bits, !! 1061 return bitmap_ord_to_pos(new, n % w, bits);
554 } 1062 }
555 EXPORT_SYMBOL(bitmap_bitremap); 1063 EXPORT_SYMBOL(bitmap_bitremap);
556 1064
557 #ifdef CONFIG_NUMA 1065 #ifdef CONFIG_NUMA
558 /** 1066 /**
559 * bitmap_onto - translate one bitmap relative 1067 * bitmap_onto - translate one bitmap relative to another
560 * @dst: resulting translated bitmap 1068 * @dst: resulting translated bitmap
561 * @orig: original untranslated bitmap 1069 * @orig: original untranslated bitmap
562 * @relmap: bitmap relative to which tran 1070 * @relmap: bitmap relative to which translated
563 * @bits: number of bits in each of these 1071 * @bits: number of bits in each of these bitmaps
564 * 1072 *
565 * Set the n-th bit of @dst iff there exists s 1073 * Set the n-th bit of @dst iff there exists some m such that the
566 * n-th bit of @relmap is set, the m-th bit of 1074 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
567 * the n-th bit of @relmap is also the m-th _s 1075 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
568 * (If you understood the previous sentence th 1076 * (If you understood the previous sentence the first time your
569 * read it, you're overqualified for your curr 1077 * read it, you're overqualified for your current job.)
570 * 1078 *
571 * In other words, @orig is mapped onto (surje 1079 * In other words, @orig is mapped onto (surjectively) @dst,
572 * using the map { <n, m> | the n-th bit of @r 1080 * using the map { <n, m> | the n-th bit of @relmap is the
573 * m-th set bit of @relmap }. 1081 * m-th set bit of @relmap }.
574 * 1082 *
575 * Any set bits in @orig above bit number W, w 1083 * Any set bits in @orig above bit number W, where W is the
576 * weight of (number of set bits in) @relmap a 1084 * weight of (number of set bits in) @relmap are mapped nowhere.
577 * In particular, if for all bits m set in @or 1085 * In particular, if for all bits m set in @orig, m >= W, then
578 * @dst will end up empty. In situations wher 1086 * @dst will end up empty. In situations where the possibility
579 * of such an empty result is not desired, one 1087 * of such an empty result is not desired, one way to avoid it is
580 * to use the bitmap_fold() operator, below, t 1088 * to use the bitmap_fold() operator, below, to first fold the
581 * @orig bitmap over itself so that all its se 1089 * @orig bitmap over itself so that all its set bits x are in the
582 * range 0 <= x < W. The bitmap_fold() operat 1090 * range 0 <= x < W. The bitmap_fold() operator does this by
583 * setting the bit (m % W) in @dst, for each b 1091 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
584 * 1092 *
585 * Example [1] for bitmap_onto(): 1093 * Example [1] for bitmap_onto():
586 * Let's say @relmap has bits 30-39 set, and 1094 * Let's say @relmap has bits 30-39 set, and @orig has bits
587 * 1, 3, 5, 7, 9 and 11 set. Then on return 1095 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
588 * @dst will have bits 31, 33, 35, 37 and 39 1096 * @dst will have bits 31, 33, 35, 37 and 39 set.
589 * 1097 *
590 * When bit 0 is set in @orig, it means turn 1098 * When bit 0 is set in @orig, it means turn on the bit in
591 * @dst corresponding to whatever is the firs 1099 * @dst corresponding to whatever is the first bit (if any)
592 * that is turned on in @relmap. Since bit 0 1100 * that is turned on in @relmap. Since bit 0 was off in the
593 * above example, we leave off that bit (bit 1101 * above example, we leave off that bit (bit 30) in @dst.
594 * 1102 *
595 * When bit 1 is set in @orig (as in the abov 1103 * When bit 1 is set in @orig (as in the above example), it
596 * means turn on the bit in @dst correspondin 1104 * means turn on the bit in @dst corresponding to whatever
597 * is the second bit that is turned on in @re 1105 * is the second bit that is turned on in @relmap. The second
598 * bit in @relmap that was turned on in the a 1106 * bit in @relmap that was turned on in the above example was
599 * bit 31, so we turned on bit 31 in @dst. 1107 * bit 31, so we turned on bit 31 in @dst.
600 * 1108 *
601 * Similarly, we turned on bits 33, 35, 37 an 1109 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
602 * because they were the 4th, 6th, 8th and 10 1110 * because they were the 4th, 6th, 8th and 10th set bits
603 * set in @relmap, and the 4th, 6th, 8th and 1111 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
604 * @orig (i.e. bits 3, 5, 7 and 9) were also 1112 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
605 * 1113 *
606 * When bit 11 is set in @orig, it means turn 1114 * When bit 11 is set in @orig, it means turn on the bit in
607 * @dst corresponding to whatever is the twel 1115 * @dst corresponding to whatever is the twelfth bit that is
608 * turned on in @relmap. In the above exampl 1116 * turned on in @relmap. In the above example, there were
609 * only ten bits turned on in @relmap (30..39 1117 * only ten bits turned on in @relmap (30..39), so that bit
610 * 11 was set in @orig had no affect on @dst. 1118 * 11 was set in @orig had no affect on @dst.
611 * 1119 *
612 * Example [2] for bitmap_fold() + bitmap_onto 1120 * Example [2] for bitmap_fold() + bitmap_onto():
613 * Let's say @relmap has these ten bits set:: 1121 * Let's say @relmap has these ten bits set::
614 * 1122 *
615 * 40 41 42 43 45 48 53 61 74 95 1123 * 40 41 42 43 45 48 53 61 74 95
616 * 1124 *
617 * (for the curious, that's 40 plus the first 1125 * (for the curious, that's 40 plus the first ten terms of the
618 * Fibonacci sequence.) 1126 * Fibonacci sequence.)
619 * 1127 *
620 * Further lets say we use the following code 1128 * Further lets say we use the following code, invoking
621 * bitmap_fold() then bitmap_onto, as suggest 1129 * bitmap_fold() then bitmap_onto, as suggested above to
622 * avoid the possibility of an empty @dst res 1130 * avoid the possibility of an empty @dst result::
623 * 1131 *
624 * unsigned long *tmp; // a temporary 1132 * unsigned long *tmp; // a temporary bitmap's bits
625 * 1133 *
626 * bitmap_fold(tmp, orig, bitmap_weight(r 1134 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
627 * bitmap_onto(dst, tmp, relmap, bits); 1135 * bitmap_onto(dst, tmp, relmap, bits);
628 * 1136 *
629 * Then this table shows what various values 1137 * Then this table shows what various values of @dst would be, for
630 * various @orig's. I list the zero-based po 1138 * various @orig's. I list the zero-based positions of each set bit.
631 * The tmp column shows the intermediate resu 1139 * The tmp column shows the intermediate result, as computed by
632 * using bitmap_fold() to fold the @orig bitm 1140 * using bitmap_fold() to fold the @orig bitmap modulo ten
633 * (the weight of @relmap): 1141 * (the weight of @relmap):
634 * 1142 *
635 * =============== ============== ======= 1143 * =============== ============== =================
636 * @orig tmp @dst 1144 * @orig tmp @dst
637 * 0 0 40 1145 * 0 0 40
638 * 1 1 41 1146 * 1 1 41
639 * 9 9 95 1147 * 9 9 95
640 * 10 0 40 [#f1 1148 * 10 0 40 [#f1]_
641 * 1 3 5 7 1 3 5 7 41 43 4 1149 * 1 3 5 7 1 3 5 7 41 43 48 61
642 * 0 1 2 3 4 0 1 2 3 4 40 41 4 1150 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
643 * 0 9 18 27 0 9 8 7 40 61 7 1151 * 0 9 18 27 0 9 8 7 40 61 74 95
644 * 0 10 20 30 0 40 1152 * 0 10 20 30 0 40
645 * 0 11 22 33 0 1 2 3 40 41 4 1153 * 0 11 22 33 0 1 2 3 40 41 42 43
646 * 0 12 24 36 0 2 4 6 40 42 4 1154 * 0 12 24 36 0 2 4 6 40 42 45 53
647 * 78 102 211 1 2 8 41 42 7 1155 * 78 102 211 1 2 8 41 42 74 [#f1]_
648 * =============== ============== ======= 1156 * =============== ============== =================
649 * 1157 *
650 * .. [#f1] 1158 * .. [#f1]
651 * 1159 *
652 * For these marked lines, if we hadn't fi 1160 * For these marked lines, if we hadn't first done bitmap_fold()
653 * into tmp, then the @dst result would ha 1161 * into tmp, then the @dst result would have been empty.
654 * 1162 *
655 * If either of @orig or @relmap is empty (no 1163 * If either of @orig or @relmap is empty (no set bits), then @dst
656 * will be returned empty. 1164 * will be returned empty.
657 * 1165 *
658 * If (as explained above) the only set bits i 1166 * If (as explained above) the only set bits in @orig are in positions
659 * m where m >= W, (where W is the weight of @ 1167 * m where m >= W, (where W is the weight of @relmap) then @dst will
660 * once again be returned empty. 1168 * once again be returned empty.
661 * 1169 *
662 * All bits in @dst not set by the above rule 1170 * All bits in @dst not set by the above rule are cleared.
663 */ 1171 */
664 void bitmap_onto(unsigned long *dst, const uns 1172 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
665 const unsigned long *r 1173 const unsigned long *relmap, unsigned int bits)
666 { 1174 {
667 unsigned int n, m; /* same meanin 1175 unsigned int n, m; /* same meaning as in above comment */
668 1176
669 if (dst == orig) /* following d 1177 if (dst == orig) /* following doesn't handle inplace mappings */
670 return; 1178 return;
671 bitmap_zero(dst, bits); 1179 bitmap_zero(dst, bits);
672 1180
673 /* 1181 /*
674 * The following code is a more effici 1182 * The following code is a more efficient, but less
675 * obvious, equivalent to the loop: 1183 * obvious, equivalent to the loop:
676 * for (m = 0; m < bitmap_weight( 1184 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
677 * n = find_nth_bit(orig, !! 1185 * n = bitmap_ord_to_pos(orig, m, bits);
678 * if (test_bit(m, orig)) 1186 * if (test_bit(m, orig))
679 * set_bit(n, dst 1187 * set_bit(n, dst);
680 * } 1188 * }
681 */ 1189 */
682 1190
683 m = 0; 1191 m = 0;
684 for_each_set_bit(n, relmap, bits) { 1192 for_each_set_bit(n, relmap, bits) {
685 /* m == bitmap_pos_to_ord(relm 1193 /* m == bitmap_pos_to_ord(relmap, n, bits) */
686 if (test_bit(m, orig)) 1194 if (test_bit(m, orig))
687 set_bit(n, dst); 1195 set_bit(n, dst);
688 m++; 1196 m++;
689 } 1197 }
690 } 1198 }
691 1199
692 /** 1200 /**
693 * bitmap_fold - fold larger bitmap into small 1201 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
694 * @dst: resulting smaller bitmap 1202 * @dst: resulting smaller bitmap
695 * @orig: original larger bitmap 1203 * @orig: original larger bitmap
696 * @sz: specified size 1204 * @sz: specified size
697 * @nbits: number of bits in each of thes 1205 * @nbits: number of bits in each of these bitmaps
698 * 1206 *
699 * For each bit oldbit in @orig, set bit oldbi 1207 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
700 * Clear all other bits in @dst. See further 1208 * Clear all other bits in @dst. See further the comment and
701 * Example [2] for bitmap_onto() for why and h 1209 * Example [2] for bitmap_onto() for why and how to use this.
702 */ 1210 */
703 void bitmap_fold(unsigned long *dst, const uns 1211 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
704 unsigned int sz, unsig 1212 unsigned int sz, unsigned int nbits)
705 { 1213 {
706 unsigned int oldbit; 1214 unsigned int oldbit;
707 1215
708 if (dst == orig) /* following d 1216 if (dst == orig) /* following doesn't handle inplace mappings */
709 return; 1217 return;
710 bitmap_zero(dst, nbits); 1218 bitmap_zero(dst, nbits);
711 1219
712 for_each_set_bit(oldbit, orig, nbits) 1220 for_each_set_bit(oldbit, orig, nbits)
713 set_bit(oldbit % sz, dst); 1221 set_bit(oldbit % sz, dst);
714 } 1222 }
715 #endif /* CONFIG_NUMA */ 1223 #endif /* CONFIG_NUMA */
716 1224
>> 1225 /*
>> 1226 * Common code for bitmap_*_region() routines.
>> 1227 * bitmap: array of unsigned longs corresponding to the bitmap
>> 1228 * pos: the beginning of the region
>> 1229 * order: region size (log base 2 of number of bits)
>> 1230 * reg_op: operation(s) to perform on that region of bitmap
>> 1231 *
>> 1232 * Can set, verify and/or release a region of bits in a bitmap,
>> 1233 * depending on which combination of REG_OP_* flag bits is set.
>> 1234 *
>> 1235 * A region of a bitmap is a sequence of bits in the bitmap, of
>> 1236 * some size '1 << order' (a power of two), aligned to that same
>> 1237 * '1 << order' power of two.
>> 1238 *
>> 1239 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
>> 1240 * Returns 0 in all other cases and reg_ops.
>> 1241 */
>> 1242
>> 1243 enum {
>> 1244 REG_OP_ISFREE, /* true if region is all zero bits */
>> 1245 REG_OP_ALLOC, /* set all bits in region */
>> 1246 REG_OP_RELEASE, /* clear all bits in region */
>> 1247 };
>> 1248
>> 1249 static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
>> 1250 {
>> 1251 int nbits_reg; /* number of bits in region */
>> 1252 int index; /* index first long of region in bitmap */
>> 1253 int offset; /* bit offset region in bitmap[index] */
>> 1254 int nlongs_reg; /* num longs spanned by region in bitmap */
>> 1255 int nbitsinlong; /* num bits of region in each spanned long */
>> 1256 unsigned long mask; /* bitmask for one long of region */
>> 1257 int i; /* scans bitmap by longs */
>> 1258 int ret = 0; /* return value */
>> 1259
>> 1260 /*
>> 1261 * Either nlongs_reg == 1 (for small orders that fit in one long)
>> 1262 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
>> 1263 */
>> 1264 nbits_reg = 1 << order;
>> 1265 index = pos / BITS_PER_LONG;
>> 1266 offset = pos - (index * BITS_PER_LONG);
>> 1267 nlongs_reg = BITS_TO_LONGS(nbits_reg);
>> 1268 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
>> 1269
>> 1270 /*
>> 1271 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
>> 1272 * overflows if nbitsinlong == BITS_PER_LONG.
>> 1273 */
>> 1274 mask = (1UL << (nbitsinlong - 1));
>> 1275 mask += mask - 1;
>> 1276 mask <<= offset;
>> 1277
>> 1278 switch (reg_op) {
>> 1279 case REG_OP_ISFREE:
>> 1280 for (i = 0; i < nlongs_reg; i++) {
>> 1281 if (bitmap[index + i] & mask)
>> 1282 goto done;
>> 1283 }
>> 1284 ret = 1; /* all bits in region free (zero) */
>> 1285 break;
>> 1286
>> 1287 case REG_OP_ALLOC:
>> 1288 for (i = 0; i < nlongs_reg; i++)
>> 1289 bitmap[index + i] |= mask;
>> 1290 break;
>> 1291
>> 1292 case REG_OP_RELEASE:
>> 1293 for (i = 0; i < nlongs_reg; i++)
>> 1294 bitmap[index + i] &= ~mask;
>> 1295 break;
>> 1296 }
>> 1297 done:
>> 1298 return ret;
>> 1299 }
>> 1300
>> 1301 /**
>> 1302 * bitmap_find_free_region - find a contiguous aligned mem region
>> 1303 * @bitmap: array of unsigned longs corresponding to the bitmap
>> 1304 * @bits: number of bits in the bitmap
>> 1305 * @order: region size (log base 2 of number of bits) to find
>> 1306 *
>> 1307 * Find a region of free (zero) bits in a @bitmap of @bits bits and
>> 1308 * allocate them (set them to one). Only consider regions of length
>> 1309 * a power (@order) of two, aligned to that power of two, which
>> 1310 * makes the search algorithm much faster.
>> 1311 *
>> 1312 * Return the bit offset in bitmap of the allocated region,
>> 1313 * or -errno on failure.
>> 1314 */
>> 1315 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
>> 1316 {
>> 1317 unsigned int pos, end; /* scans bitmap by regions of size order */
>> 1318
>> 1319 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
>> 1320 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
>> 1321 continue;
>> 1322 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
>> 1323 return pos;
>> 1324 }
>> 1325 return -ENOMEM;
>> 1326 }
>> 1327 EXPORT_SYMBOL(bitmap_find_free_region);
>> 1328
>> 1329 /**
>> 1330 * bitmap_release_region - release allocated bitmap region
>> 1331 * @bitmap: array of unsigned longs corresponding to the bitmap
>> 1332 * @pos: beginning of bit region to release
>> 1333 * @order: region size (log base 2 of number of bits) to release
>> 1334 *
>> 1335 * This is the complement to __bitmap_find_free_region() and releases
>> 1336 * the found region (by clearing it in the bitmap).
>> 1337 *
>> 1338 * No return value.
>> 1339 */
>> 1340 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
>> 1341 {
>> 1342 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
>> 1343 }
>> 1344 EXPORT_SYMBOL(bitmap_release_region);
>> 1345
>> 1346 /**
>> 1347 * bitmap_allocate_region - allocate bitmap region
>> 1348 * @bitmap: array of unsigned longs corresponding to the bitmap
>> 1349 * @pos: beginning of bit region to allocate
>> 1350 * @order: region size (log base 2 of number of bits) to allocate
>> 1351 *
>> 1352 * Allocate (set bits in) a specified region of a bitmap.
>> 1353 *
>> 1354 * Return 0 on success, or %-EBUSY if specified region wasn't
>> 1355 * free (not all bits were zero).
>> 1356 */
>> 1357 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
>> 1358 {
>> 1359 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
>> 1360 return -EBUSY;
>> 1361 return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
>> 1362 }
>> 1363 EXPORT_SYMBOL(bitmap_allocate_region);
>> 1364
>> 1365 /**
>> 1366 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
>> 1367 * @dst: destination buffer
>> 1368 * @src: bitmap to copy
>> 1369 * @nbits: number of bits in the bitmap
>> 1370 *
>> 1371 * Require nbits % BITS_PER_LONG == 0.
>> 1372 */
>> 1373 #ifdef __BIG_ENDIAN
>> 1374 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
>> 1375 {
>> 1376 unsigned int i;
>> 1377
>> 1378 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
>> 1379 if (BITS_PER_LONG == 64)
>> 1380 dst[i] = cpu_to_le64(src[i]);
>> 1381 else
>> 1382 dst[i] = cpu_to_le32(src[i]);
>> 1383 }
>> 1384 }
>> 1385 EXPORT_SYMBOL(bitmap_copy_le);
>> 1386 #endif
>> 1387
717 unsigned long *bitmap_alloc(unsigned int nbits 1388 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
718 { 1389 {
719 return kmalloc_array(BITS_TO_LONGS(nbi 1390 return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
720 flags); 1391 flags);
721 } 1392 }
722 EXPORT_SYMBOL(bitmap_alloc); 1393 EXPORT_SYMBOL(bitmap_alloc);
723 1394
724 unsigned long *bitmap_zalloc(unsigned int nbit 1395 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
725 { 1396 {
726 return bitmap_alloc(nbits, flags | __G 1397 return bitmap_alloc(nbits, flags | __GFP_ZERO);
727 } 1398 }
728 EXPORT_SYMBOL(bitmap_zalloc); 1399 EXPORT_SYMBOL(bitmap_zalloc);
729 1400
730 unsigned long *bitmap_alloc_node(unsigned int <<
731 { <<
732 return kmalloc_array_node(BITS_TO_LONG <<
733 flags, node) <<
734 } <<
735 EXPORT_SYMBOL(bitmap_alloc_node); <<
736 <<
737 unsigned long *bitmap_zalloc_node(unsigned int <<
738 { <<
739 return bitmap_alloc_node(nbits, flags <<
740 } <<
741 EXPORT_SYMBOL(bitmap_zalloc_node); <<
742 <<
743 void bitmap_free(const unsigned long *bitmap) 1401 void bitmap_free(const unsigned long *bitmap)
744 { 1402 {
745 kfree(bitmap); 1403 kfree(bitmap);
746 } 1404 }
747 EXPORT_SYMBOL(bitmap_free); 1405 EXPORT_SYMBOL(bitmap_free);
748 1406
749 static void devm_bitmap_free(void *data) 1407 static void devm_bitmap_free(void *data)
750 { 1408 {
751 unsigned long *bitmap = data; 1409 unsigned long *bitmap = data;
752 1410
753 bitmap_free(bitmap); 1411 bitmap_free(bitmap);
754 } 1412 }
755 1413
756 unsigned long *devm_bitmap_alloc(struct device 1414 unsigned long *devm_bitmap_alloc(struct device *dev,
757 unsigned int 1415 unsigned int nbits, gfp_t flags)
758 { 1416 {
759 unsigned long *bitmap; 1417 unsigned long *bitmap;
760 int ret; 1418 int ret;
761 1419
762 bitmap = bitmap_alloc(nbits, flags); 1420 bitmap = bitmap_alloc(nbits, flags);
763 if (!bitmap) 1421 if (!bitmap)
764 return NULL; 1422 return NULL;
765 1423
766 ret = devm_add_action_or_reset(dev, de 1424 ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap);
767 if (ret) 1425 if (ret)
768 return NULL; 1426 return NULL;
769 1427
770 return bitmap; 1428 return bitmap;
771 } 1429 }
772 EXPORT_SYMBOL_GPL(devm_bitmap_alloc); 1430 EXPORT_SYMBOL_GPL(devm_bitmap_alloc);
773 1431
774 unsigned long *devm_bitmap_zalloc(struct devic 1432 unsigned long *devm_bitmap_zalloc(struct device *dev,
775 unsigned int 1433 unsigned int nbits, gfp_t flags)
776 { 1434 {
777 return devm_bitmap_alloc(dev, nbits, f 1435 return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
778 } 1436 }
779 EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); 1437 EXPORT_SYMBOL_GPL(devm_bitmap_zalloc);
780 1438
781 #if BITS_PER_LONG == 64 1439 #if BITS_PER_LONG == 64
782 /** 1440 /**
783 * bitmap_from_arr32 - copy the contents of u3 1441 * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
784 * @bitmap: array of unsigned longs, the 1442 * @bitmap: array of unsigned longs, the destination bitmap
785 * @buf: array of u32 (in host byte order 1443 * @buf: array of u32 (in host byte order), the source bitmap
786 * @nbits: number of bits in @bitmap 1444 * @nbits: number of bits in @bitmap
787 */ 1445 */
788 void bitmap_from_arr32(unsigned long *bitmap, 1446 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
789 { 1447 {
790 unsigned int i, halfwords; 1448 unsigned int i, halfwords;
791 1449
792 halfwords = DIV_ROUND_UP(nbits, 32); 1450 halfwords = DIV_ROUND_UP(nbits, 32);
793 for (i = 0; i < halfwords; i++) { 1451 for (i = 0; i < halfwords; i++) {
794 bitmap[i/2] = (unsigned long) 1452 bitmap[i/2] = (unsigned long) buf[i];
795 if (++i < halfwords) 1453 if (++i < halfwords)
796 bitmap[i/2] |= ((unsig 1454 bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
797 } 1455 }
798 1456
799 /* Clear tail bits in last word beyond 1457 /* Clear tail bits in last word beyond nbits. */
800 if (nbits % BITS_PER_LONG) 1458 if (nbits % BITS_PER_LONG)
801 bitmap[(halfwords - 1) / 2] &= 1459 bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
802 } 1460 }
803 EXPORT_SYMBOL(bitmap_from_arr32); 1461 EXPORT_SYMBOL(bitmap_from_arr32);
804 1462
805 /** 1463 /**
806 * bitmap_to_arr32 - copy the contents of bitm 1464 * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
807 * @buf: array of u32 (in host byte order 1465 * @buf: array of u32 (in host byte order), the dest bitmap
808 * @bitmap: array of unsigned longs, the 1466 * @bitmap: array of unsigned longs, the source bitmap
809 * @nbits: number of bits in @bitmap 1467 * @nbits: number of bits in @bitmap
810 */ 1468 */
811 void bitmap_to_arr32(u32 *buf, const unsigned 1469 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
812 { 1470 {
813 unsigned int i, halfwords; 1471 unsigned int i, halfwords;
814 1472
815 halfwords = DIV_ROUND_UP(nbits, 32); 1473 halfwords = DIV_ROUND_UP(nbits, 32);
816 for (i = 0; i < halfwords; i++) { 1474 for (i = 0; i < halfwords; i++) {
817 buf[i] = (u32) (bitmap[i/2] & 1475 buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
818 if (++i < halfwords) 1476 if (++i < halfwords)
819 buf[i] = (u32) (bitmap 1477 buf[i] = (u32) (bitmap[i/2] >> 32);
820 } 1478 }
821 1479
822 /* Clear tail bits in last element of 1480 /* Clear tail bits in last element of array beyond nbits. */
823 if (nbits % BITS_PER_LONG) 1481 if (nbits % BITS_PER_LONG)
824 buf[halfwords - 1] &= (u32) (U 1482 buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
825 } 1483 }
826 EXPORT_SYMBOL(bitmap_to_arr32); 1484 EXPORT_SYMBOL(bitmap_to_arr32);
827 #endif <<
828 <<
829 #if BITS_PER_LONG == 32 <<
830 /** <<
831 * bitmap_from_arr64 - copy the contents of u6 <<
832 * @bitmap: array of unsigned longs, the <<
833 * @buf: array of u64 (in host byte order <<
834 * @nbits: number of bits in @bitmap <<
835 */ <<
836 void bitmap_from_arr64(unsigned long *bitmap, <<
837 { <<
838 int n; <<
839 <<
840 for (n = nbits; n > 0; n -= 64) { <<
841 u64 val = *buf++; <<
842 <<
843 *bitmap++ = val; <<
844 if (n > 32) <<
845 *bitmap++ = val >> 32; <<
846 } <<
847 <<
848 /* <<
849 * Clear tail bits in the last word be <<
850 * <<
851 * Negative index is OK because here w <<
852 * to the last word of the bitmap, exc <<
853 * is tested implicitly. <<
854 */ <<
855 if (nbits % BITS_PER_LONG) <<
856 bitmap[-1] &= BITMAP_LAST_WORD <<
857 } <<
858 EXPORT_SYMBOL(bitmap_from_arr64); <<
859 1485
860 /** <<
861 * bitmap_to_arr64 - copy the contents of bitm <<
862 * @buf: array of u64 (in host byte order <<
863 * @bitmap: array of unsigned longs, the <<
864 * @nbits: number of bits in @bitmap <<
865 */ <<
866 void bitmap_to_arr64(u64 *buf, const unsigned <<
867 { <<
868 const unsigned long *end = bitmap + BI <<
869 <<
870 while (bitmap < end) { <<
871 *buf = *bitmap++; <<
872 if (bitmap < end) <<
873 *buf |= (u64)(*bitmap+ <<
874 buf++; <<
875 } <<
876 <<
877 /* Clear tail bits in the last element <<
878 if (nbits % 64) <<
879 buf[-1] &= GENMASK_ULL((nbits <<
880 } <<
881 EXPORT_SYMBOL(bitmap_to_arr64); <<
882 #endif 1486 #endif
883 1487
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