1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BITMAP_H
3 #define __LINUX_BITMAP_H
4 
5 #ifndef __ASSEMBLY__
6 
7 #include <linux/align.h>
8 #include <linux/bitops.h>
9 #include <linux/find.h>
10 #include <linux/limits.h>
11 #include <linux/string.h>
12 #include <linux/types.h>
13 
14 struct device;
15 
16 /*
17  * bitmaps provide bit arrays that consume one or more unsigned
18  * longs.  The bitmap interface and available operations are listed
19  * here, in bitmap.h
20  *
21  * Function implementations generic to all architectures are in
22  * lib/bitmap.c.  Functions implementations that are architecture
23  * specific are in various include/asm-<arch>/bitops.h headers
24  * and other arch/<arch> specific files.
25  *
26  * See lib/bitmap.c for more details.
27  */
28 
29 /**
30  * DOC: bitmap overview
31  *
32  * The available bitmap operations and their rough meaning in the
33  * case that the bitmap is a single unsigned long are thus:
34  *
35  * The generated code is more efficient when nbits is known at
36  * compile-time and at most BITS_PER_LONG.
37  *
38  * ::
39  *
40  *  bitmap_zero(dst, nbits)                     *dst = 0UL
41  *  bitmap_fill(dst, nbits)                     *dst = ~0UL
42  *  bitmap_copy(dst, src, nbits)                *dst = *src
43  *  bitmap_and(dst, src1, src2, nbits)          *dst = *src1 & *src2
44  *  bitmap_or(dst, src1, src2, nbits)           *dst = *src1 | *src2
45  *  bitmap_xor(dst, src1, src2, nbits)          *dst = *src1 ^ *src2
46  *  bitmap_andnot(dst, src1, src2, nbits)       *dst = *src1 & ~(*src2)
47  *  bitmap_complement(dst, src, nbits)          *dst = ~(*src)
48  *  bitmap_equal(src1, src2, nbits)             Are *src1 and *src2 equal?
49  *  bitmap_intersects(src1, src2, nbits)        Do *src1 and *src2 overlap?
50  *  bitmap_subset(src1, src2, nbits)            Is *src1 a subset of *src2?
51  *  bitmap_empty(src, nbits)                    Are all bits zero in *src?
52  *  bitmap_full(src, nbits)                     Are all bits set in *src?
53  *  bitmap_weight(src, nbits)                   Hamming Weight: number set bits
54  *  bitmap_weight_and(src1, src2, nbits)        Hamming Weight of and'ed bitmap
55  *  bitmap_set(dst, pos, nbits)                 Set specified bit area
56  *  bitmap_clear(dst, pos, nbits)               Clear specified bit area
57  *  bitmap_find_next_zero_area(buf, len, pos, n, mask)  Find bit free area
58  *  bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off)  as above
59  *  bitmap_shift_right(dst, src, n, nbits)      *dst = *src >> n
60  *  bitmap_shift_left(dst, src, n, nbits)       *dst = *src << n
61  *  bitmap_cut(dst, src, first, n, nbits)       Cut n bits from first, copy rest
62  *  bitmap_replace(dst, old, new, mask, nbits)  *dst = (*old & ~(*mask)) | (*new & *mask)
63  *  bitmap_remap(dst, src, old, new, nbits)     *dst = map(old, new)(src)
64  *  bitmap_bitremap(oldbit, old, new, nbits)    newbit = map(old, new)(oldbit)
65  *  bitmap_onto(dst, orig, relmap, nbits)       *dst = orig relative to relmap
66  *  bitmap_fold(dst, orig, sz, nbits)           dst bits = orig bits mod sz
67  *  bitmap_parse(buf, buflen, dst, nbits)       Parse bitmap dst from kernel buf
68  *  bitmap_parse_user(ubuf, ulen, dst, nbits)   Parse bitmap dst from user buf
69  *  bitmap_parselist(buf, dst, nbits)           Parse bitmap dst from kernel buf
70  *  bitmap_parselist_user(buf, dst, nbits)      Parse bitmap dst from user buf
71  *  bitmap_find_free_region(bitmap, bits, order)  Find and allocate bit region
72  *  bitmap_release_region(bitmap, pos, order)   Free specified bit region
73  *  bitmap_allocate_region(bitmap, pos, order)  Allocate specified bit region
74  *  bitmap_from_arr32(dst, buf, nbits)          Copy nbits from u32[] buf to dst
75  *  bitmap_from_arr64(dst, buf, nbits)          Copy nbits from u64[] buf to dst
76  *  bitmap_to_arr32(buf, src, nbits)            Copy nbits from buf to u32[] dst
77  *  bitmap_to_arr64(buf, src, nbits)            Copy nbits from buf to u64[] dst
78  *  bitmap_get_value8(map, start)               Get 8bit value from map at start
79  *  bitmap_set_value8(map, value, start)        Set 8bit value to map at start
80  *
81  * Note, bitmap_zero() and bitmap_fill() operate over the region of
82  * unsigned longs, that is, bits behind bitmap till the unsigned long
83  * boundary will be zeroed or filled as well. Consider to use
84  * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
85  * respectively.
86  */
87 
88 /**
89  * DOC: bitmap bitops
90  *
91  * Also the following operations in asm/bitops.h apply to bitmaps.::
92  *
93  *  set_bit(bit, addr)                  *addr |= bit
94  *  clear_bit(bit, addr)                *addr &= ~bit
95  *  change_bit(bit, addr)               *addr ^= bit
96  *  test_bit(bit, addr)                 Is bit set in *addr?
97  *  test_and_set_bit(bit, addr)         Set bit and return old value
98  *  test_and_clear_bit(bit, addr)       Clear bit and return old value
99  *  test_and_change_bit(bit, addr)      Change bit and return old value
100  *  find_first_zero_bit(addr, nbits)    Position first zero bit in *addr
101  *  find_first_bit(addr, nbits)         Position first set bit in *addr
102  *  find_next_zero_bit(addr, nbits, bit)
103  *                                      Position next zero bit in *addr >= bit
104  *  find_next_bit(addr, nbits, bit)     Position next set bit in *addr >= bit
105  *  find_next_and_bit(addr1, addr2, nbits, bit)
106  *                                      Same as find_next_bit, but in
107  *                                      (*addr1 & *addr2)
108  *
109  */
110 
111 /**
112  * DOC: declare bitmap
113  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
114  * to declare an array named 'name' of just enough unsigned longs to
115  * contain all bit positions from 0 to 'bits' - 1.
116  */
117 
118 /*
119  * Allocation and deallocation of bitmap.
120  * Provided in lib/bitmap.c to avoid circular dependency.
121  */
122 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
123 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
124 unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
125 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
126 void bitmap_free(const unsigned long *bitmap);
127 
128 /* Managed variants of the above. */
129 unsigned long *devm_bitmap_alloc(struct device *dev,
130 				 unsigned int nbits, gfp_t flags);
131 unsigned long *devm_bitmap_zalloc(struct device *dev,
132 				  unsigned int nbits, gfp_t flags);
133 
134 /*
135  * lib/bitmap.c provides these functions:
136  */
137 
138 bool __bitmap_equal(const unsigned long *bitmap1,
139 		    const unsigned long *bitmap2, unsigned int nbits);
140 bool __pure __bitmap_or_equal(const unsigned long *src1,
141 			      const unsigned long *src2,
142 			      const unsigned long *src3,
143 			      unsigned int nbits);
144 void __bitmap_complement(unsigned long *dst, const unsigned long *src,
145 			 unsigned int nbits);
146 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
147 			  unsigned int shift, unsigned int nbits);
148 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
149 			 unsigned int shift, unsigned int nbits);
150 void bitmap_cut(unsigned long *dst, const unsigned long *src,
151 		unsigned int first, unsigned int cut, unsigned int nbits);
152 bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
153 		 const unsigned long *bitmap2, unsigned int nbits);
154 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
155 		 const unsigned long *bitmap2, unsigned int nbits);
156 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
157 		  const unsigned long *bitmap2, unsigned int nbits);
158 bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
159 		    const unsigned long *bitmap2, unsigned int nbits);
160 void __bitmap_replace(unsigned long *dst,
161 		      const unsigned long *old, const unsigned long *new,
162 		      const unsigned long *mask, unsigned int nbits);
163 bool __bitmap_intersects(const unsigned long *bitmap1,
164 			 const unsigned long *bitmap2, unsigned int nbits);
165 bool __bitmap_subset(const unsigned long *bitmap1,
166 		     const unsigned long *bitmap2, unsigned int nbits);
167 unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
168 unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
169 				 const unsigned long *bitmap2, unsigned int nbits);
170 void __bitmap_set(unsigned long *map, unsigned int start, int len);
171 void __bitmap_clear(unsigned long *map, unsigned int start, int len);
172 
173 unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
174 					     unsigned long size,
175 					     unsigned long start,
176 					     unsigned int nr,
177 					     unsigned long align_mask,
178 					     unsigned long align_offset);
179 
180 /**
181  * bitmap_find_next_zero_area - find a contiguous aligned zero area
182  * @map: The address to base the search on
183  * @size: The bitmap size in bits
184  * @start: The bitnumber to start searching at
185  * @nr: The number of zeroed bits we're looking for
186  * @align_mask: Alignment mask for zero area
187  *
188  * The @align_mask should be one less than a power of 2; the effect is that
189  * the bit offset of all zero areas this function finds is multiples of that
190  * power of 2. A @align_mask of 0 means no alignment is required.
191  */
192 static inline unsigned long
bitmap_find_next_zero_area(unsigned long * map,unsigned long size,unsigned long start,unsigned int nr,unsigned long align_mask)193 bitmap_find_next_zero_area(unsigned long *map,
194 			   unsigned long size,
195 			   unsigned long start,
196 			   unsigned int nr,
197 			   unsigned long align_mask)
198 {
199 	return bitmap_find_next_zero_area_off(map, size, start, nr,
200 					      align_mask, 0);
201 }
202 
203 int bitmap_parse(const char *buf, unsigned int buflen,
204 			unsigned long *dst, int nbits);
205 int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
206 			unsigned long *dst, int nbits);
207 int bitmap_parselist(const char *buf, unsigned long *maskp,
208 			int nmaskbits);
209 int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
210 			unsigned long *dst, int nbits);
211 void bitmap_remap(unsigned long *dst, const unsigned long *src,
212 		const unsigned long *old, const unsigned long *new, unsigned int nbits);
213 int bitmap_bitremap(int oldbit,
214 		const unsigned long *old, const unsigned long *new, int bits);
215 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
216 		const unsigned long *relmap, unsigned int bits);
217 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
218 		unsigned int sz, unsigned int nbits);
219 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
220 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
221 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
222 
223 #ifdef __BIG_ENDIAN
224 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
225 #else
226 #define bitmap_copy_le bitmap_copy
227 #endif
228 int bitmap_print_to_pagebuf(bool list, char *buf,
229 				   const unsigned long *maskp, int nmaskbits);
230 
231 extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
232 				      int nmaskbits, loff_t off, size_t count);
233 
234 extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
235 				      int nmaskbits, loff_t off, size_t count);
236 
237 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
238 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
239 
bitmap_zero(unsigned long * dst,unsigned int nbits)240 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
241 {
242 	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
243 
244 	if (small_const_nbits(nbits))
245 		*dst = 0;
246 	else
247 		memset(dst, 0, len);
248 }
249 
bitmap_fill(unsigned long * dst,unsigned int nbits)250 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
251 {
252 	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
253 
254 	if (small_const_nbits(nbits))
255 		*dst = ~0UL;
256 	else
257 		memset(dst, 0xff, len);
258 }
259 
bitmap_copy(unsigned long * dst,const unsigned long * src,unsigned int nbits)260 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
261 			unsigned int nbits)
262 {
263 	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
264 
265 	if (small_const_nbits(nbits))
266 		*dst = *src;
267 	else
268 		memcpy(dst, src, len);
269 }
270 
271 /*
272  * Copy bitmap and clear tail bits in last word.
273  */
bitmap_copy_clear_tail(unsigned long * dst,const unsigned long * src,unsigned int nbits)274 static inline void bitmap_copy_clear_tail(unsigned long *dst,
275 		const unsigned long *src, unsigned int nbits)
276 {
277 	bitmap_copy(dst, src, nbits);
278 	if (nbits % BITS_PER_LONG)
279 		dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
280 }
281 
282 /*
283  * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
284  * machines the order of hi and lo parts of numbers match the bitmap structure.
285  * In both cases conversion is not needed when copying data from/to arrays of
286  * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead
287  * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit
288  * architectures are not using bitmap_copy_clear_tail().
289  */
290 #if BITS_PER_LONG == 64
291 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
292 							unsigned int nbits);
293 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
294 							unsigned int nbits);
295 #else
296 #define bitmap_from_arr32(bitmap, buf, nbits)			\
297 	bitmap_copy_clear_tail((unsigned long *) (bitmap),	\
298 			(const unsigned long *) (buf), (nbits))
299 #define bitmap_to_arr32(buf, bitmap, nbits)			\
300 	bitmap_copy_clear_tail((unsigned long *) (buf),		\
301 			(const unsigned long *) (bitmap), (nbits))
302 #endif
303 
304 /*
305  * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
306  * the conversion is not needed when copying data from/to arrays of u64.
307  */
308 #if BITS_PER_LONG == 32
309 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
310 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
311 #else
312 #define bitmap_from_arr64(bitmap, buf, nbits)			\
313 	bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
314 #define bitmap_to_arr64(buf, bitmap, nbits)			\
315 	bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
316 #endif
317 
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)318 static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1,
319 			const unsigned long *src2, unsigned int nbits)
320 {
321 	if (small_const_nbits(nbits))
322 		return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
323 	return __bitmap_and(dst, src1, src2, nbits);
324 }
325 
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)326 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
327 			const unsigned long *src2, unsigned int nbits)
328 {
329 	if (small_const_nbits(nbits))
330 		*dst = *src1 | *src2;
331 	else
332 		__bitmap_or(dst, src1, src2, nbits);
333 }
334 
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)335 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
336 			const unsigned long *src2, unsigned int nbits)
337 {
338 	if (small_const_nbits(nbits))
339 		*dst = *src1 ^ *src2;
340 	else
341 		__bitmap_xor(dst, src1, src2, nbits);
342 }
343 
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)344 static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
345 			const unsigned long *src2, unsigned int nbits)
346 {
347 	if (small_const_nbits(nbits))
348 		return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
349 	return __bitmap_andnot(dst, src1, src2, nbits);
350 }
351 
bitmap_complement(unsigned long * dst,const unsigned long * src,unsigned int nbits)352 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
353 			unsigned int nbits)
354 {
355 	if (small_const_nbits(nbits))
356 		*dst = ~(*src);
357 	else
358 		__bitmap_complement(dst, src, nbits);
359 }
360 
361 #ifdef __LITTLE_ENDIAN
362 #define BITMAP_MEM_ALIGNMENT 8
363 #else
364 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
365 #endif
366 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
367 
bitmap_equal(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)368 static inline bool bitmap_equal(const unsigned long *src1,
369 				const unsigned long *src2, unsigned int nbits)
370 {
371 	if (small_const_nbits(nbits))
372 		return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
373 	if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
374 	    IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
375 		return !memcmp(src1, src2, nbits / 8);
376 	return __bitmap_equal(src1, src2, nbits);
377 }
378 
379 /**
380  * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
381  * @src1:	Pointer to bitmap 1
382  * @src2:	Pointer to bitmap 2 will be or'ed with bitmap 1
383  * @src3:	Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
384  * @nbits:	number of bits in each of these bitmaps
385  *
386  * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
387  */
bitmap_or_equal(const unsigned long * src1,const unsigned long * src2,const unsigned long * src3,unsigned int nbits)388 static inline bool bitmap_or_equal(const unsigned long *src1,
389 				   const unsigned long *src2,
390 				   const unsigned long *src3,
391 				   unsigned int nbits)
392 {
393 	if (!small_const_nbits(nbits))
394 		return __bitmap_or_equal(src1, src2, src3, nbits);
395 
396 	return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
397 }
398 
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)399 static inline bool bitmap_intersects(const unsigned long *src1,
400 				     const unsigned long *src2,
401 				     unsigned int nbits)
402 {
403 	if (small_const_nbits(nbits))
404 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
405 	else
406 		return __bitmap_intersects(src1, src2, nbits);
407 }
408 
bitmap_subset(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)409 static inline bool bitmap_subset(const unsigned long *src1,
410 				 const unsigned long *src2, unsigned int nbits)
411 {
412 	if (small_const_nbits(nbits))
413 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
414 	else
415 		return __bitmap_subset(src1, src2, nbits);
416 }
417 
bitmap_empty(const unsigned long * src,unsigned nbits)418 static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
419 {
420 	if (small_const_nbits(nbits))
421 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
422 
423 	return find_first_bit(src, nbits) == nbits;
424 }
425 
bitmap_full(const unsigned long * src,unsigned int nbits)426 static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
427 {
428 	if (small_const_nbits(nbits))
429 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
430 
431 	return find_first_zero_bit(src, nbits) == nbits;
432 }
433 
434 static __always_inline
bitmap_weight(const unsigned long * src,unsigned int nbits)435 unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
436 {
437 	if (small_const_nbits(nbits))
438 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
439 	return __bitmap_weight(src, nbits);
440 }
441 
442 static __always_inline
bitmap_weight_and(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)443 unsigned long bitmap_weight_and(const unsigned long *src1,
444 				const unsigned long *src2, unsigned int nbits)
445 {
446 	if (small_const_nbits(nbits))
447 		return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits));
448 	return __bitmap_weight_and(src1, src2, nbits);
449 }
450 
bitmap_set(unsigned long * map,unsigned int start,unsigned int nbits)451 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
452 		unsigned int nbits)
453 {
454 	if (__builtin_constant_p(nbits) && nbits == 1)
455 		__set_bit(start, map);
456 	else if (small_const_nbits(start + nbits))
457 		*map |= GENMASK(start + nbits - 1, start);
458 	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
459 		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
460 		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
461 		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
462 		memset((char *)map + start / 8, 0xff, nbits / 8);
463 	else
464 		__bitmap_set(map, start, nbits);
465 }
466 
bitmap_clear(unsigned long * map,unsigned int start,unsigned int nbits)467 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
468 		unsigned int nbits)
469 {
470 	if (__builtin_constant_p(nbits) && nbits == 1)
471 		__clear_bit(start, map);
472 	else if (small_const_nbits(start + nbits))
473 		*map &= ~GENMASK(start + nbits - 1, start);
474 	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
475 		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
476 		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
477 		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
478 		memset((char *)map + start / 8, 0, nbits / 8);
479 	else
480 		__bitmap_clear(map, start, nbits);
481 }
482 
bitmap_shift_right(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)483 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
484 				unsigned int shift, unsigned int nbits)
485 {
486 	if (small_const_nbits(nbits))
487 		*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
488 	else
489 		__bitmap_shift_right(dst, src, shift, nbits);
490 }
491 
bitmap_shift_left(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)492 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
493 				unsigned int shift, unsigned int nbits)
494 {
495 	if (small_const_nbits(nbits))
496 		*dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
497 	else
498 		__bitmap_shift_left(dst, src, shift, nbits);
499 }
500 
bitmap_replace(unsigned long * dst,const unsigned long * old,const unsigned long * new,const unsigned long * mask,unsigned int nbits)501 static inline void bitmap_replace(unsigned long *dst,
502 				  const unsigned long *old,
503 				  const unsigned long *new,
504 				  const unsigned long *mask,
505 				  unsigned int nbits)
506 {
507 	if (small_const_nbits(nbits))
508 		*dst = (*old & ~(*mask)) | (*new & *mask);
509 	else
510 		__bitmap_replace(dst, old, new, mask, nbits);
511 }
512 
bitmap_next_set_region(unsigned long * bitmap,unsigned int * rs,unsigned int * re,unsigned int end)513 static inline void bitmap_next_set_region(unsigned long *bitmap,
514 					  unsigned int *rs, unsigned int *re,
515 					  unsigned int end)
516 {
517 	*rs = find_next_bit(bitmap, end, *rs);
518 	*re = find_next_zero_bit(bitmap, end, *rs + 1);
519 }
520 
521 /**
522  * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
523  * @n: u64 value
524  *
525  * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
526  * integers in 32-bit environment, and 64-bit integers in 64-bit one.
527  *
528  * There are four combinations of endianness and length of the word in linux
529  * ABIs: LE64, BE64, LE32 and BE32.
530  *
531  * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
532  * bitmaps and therefore don't require any special handling.
533  *
534  * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
535  * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
536  * other hand is represented as an array of 32-bit words and the position of
537  * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
538  * word.  For example, bit #42 is located at 10th position of 2nd word.
539  * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
540  * values in memory as it usually does. But for BE we need to swap hi and lo
541  * words manually.
542  *
543  * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
544  * lo parts of u64.  For LE32 it does nothing, and for BE environment it swaps
545  * hi and lo words, as is expected by bitmap.
546  */
547 #if __BITS_PER_LONG == 64
548 #define BITMAP_FROM_U64(n) (n)
549 #else
550 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
551 				((unsigned long) ((u64)(n) >> 32))
552 #endif
553 
554 /**
555  * bitmap_from_u64 - Check and swap words within u64.
556  *  @mask: source bitmap
557  *  @dst:  destination bitmap
558  *
559  * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
560  * to read u64 mask, we will get the wrong word.
561  * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
562  * but we expect the lower 32-bits of u64.
563  */
bitmap_from_u64(unsigned long * dst,u64 mask)564 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
565 {
566 	bitmap_from_arr64(dst, &mask, 64);
567 }
568 
569 /**
570  * bitmap_get_value8 - get an 8-bit value within a memory region
571  * @map: address to the bitmap memory region
572  * @start: bit offset of the 8-bit value; must be a multiple of 8
573  *
574  * Returns the 8-bit value located at the @start bit offset within the @src
575  * memory region.
576  */
bitmap_get_value8(const unsigned long * map,unsigned long start)577 static inline unsigned long bitmap_get_value8(const unsigned long *map,
578 					      unsigned long start)
579 {
580 	const size_t index = BIT_WORD(start);
581 	const unsigned long offset = start % BITS_PER_LONG;
582 
583 	return (map[index] >> offset) & 0xFF;
584 }
585 
586 /**
587  * bitmap_set_value8 - set an 8-bit value within a memory region
588  * @map: address to the bitmap memory region
589  * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
590  * @start: bit offset of the 8-bit value; must be a multiple of 8
591  */
bitmap_set_value8(unsigned long * map,unsigned long value,unsigned long start)592 static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
593 				     unsigned long start)
594 {
595 	const size_t index = BIT_WORD(start);
596 	const unsigned long offset = start % BITS_PER_LONG;
597 
598 	map[index] &= ~(0xFFUL << offset);
599 	map[index] |= value << offset;
600 }
601 
602 #endif /* __ASSEMBLY__ */
603 
604 #endif /* __LINUX_BITMAP_H */
605