xref: /linux-6.15/include/linux/bitmap.h (revision 60063497)
1 #ifndef __LINUX_BITMAP_H
2 #define __LINUX_BITMAP_H
3 
4 #ifndef __ASSEMBLY__
5 
6 #include <linux/types.h>
7 #include <linux/bitops.h>
8 #include <linux/string.h>
9 #include <linux/kernel.h>
10 
11 /*
12  * bitmaps provide bit arrays that consume one or more unsigned
13  * longs.  The bitmap interface and available operations are listed
14  * here, in bitmap.h
15  *
16  * Function implementations generic to all architectures are in
17  * lib/bitmap.c.  Functions implementations that are architecture
18  * specific are in various include/asm-<arch>/bitops.h headers
19  * and other arch/<arch> specific files.
20  *
21  * See lib/bitmap.c for more details.
22  */
23 
24 /*
25  * The available bitmap operations and their rough meaning in the
26  * case that the bitmap is a single unsigned long are thus:
27  *
28  * Note that nbits should be always a compile time evaluable constant.
29  * Otherwise many inlines will generate horrible code.
30  *
31  * bitmap_zero(dst, nbits)			*dst = 0UL
32  * bitmap_fill(dst, nbits)			*dst = ~0UL
33  * bitmap_copy(dst, src, nbits)			*dst = *src
34  * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
35  * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
36  * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
37  * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
38  * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
39  * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
40  * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
41  * bitmap_subset(src1, src2, nbits)		Is *src1 a subset of *src2?
42  * bitmap_empty(src, nbits)			Are all bits zero in *src?
43  * bitmap_full(src, nbits)			Are all bits set in *src?
44  * bitmap_weight(src, nbits)			Hamming Weight: number set bits
45  * bitmap_set(dst, pos, nbits)			Set specified bit area
46  * bitmap_clear(dst, pos, nbits)		Clear specified bit area
47  * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
48  * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
49  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
50  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
51  * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
52  * bitmap_onto(dst, orig, relmap, nbits)	*dst = orig relative to relmap
53  * bitmap_fold(dst, orig, sz, nbits)		dst bits = orig bits mod sz
54  * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
55  * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
56  * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
57  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
58  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from kernel buf
59  * bitmap_parselist_user(buf, dst, nbits)	Parse bitmap dst from user buf
60  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
61  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
62  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
63  */
64 
65 /*
66  * Also the following operations in asm/bitops.h apply to bitmaps.
67  *
68  * set_bit(bit, addr)			*addr |= bit
69  * clear_bit(bit, addr)			*addr &= ~bit
70  * change_bit(bit, addr)		*addr ^= bit
71  * test_bit(bit, addr)			Is bit set in *addr?
72  * test_and_set_bit(bit, addr)		Set bit and return old value
73  * test_and_clear_bit(bit, addr)	Clear bit and return old value
74  * test_and_change_bit(bit, addr)	Change bit and return old value
75  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
76  * find_first_bit(addr, nbits)		Position first set bit in *addr
77  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
78  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
79  */
80 
81 /*
82  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
83  * to declare an array named 'name' of just enough unsigned longs to
84  * contain all bit positions from 0 to 'bits' - 1.
85  */
86 
87 /*
88  * lib/bitmap.c provides these functions:
89  */
90 
91 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
92 extern int __bitmap_full(const unsigned long *bitmap, int bits);
93 extern int __bitmap_equal(const unsigned long *bitmap1,
94                 	const unsigned long *bitmap2, int bits);
95 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
96 			int bits);
97 extern void __bitmap_shift_right(unsigned long *dst,
98                         const unsigned long *src, int shift, int bits);
99 extern void __bitmap_shift_left(unsigned long *dst,
100                         const unsigned long *src, int shift, int bits);
101 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
102 			const unsigned long *bitmap2, int bits);
103 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
104 			const unsigned long *bitmap2, int bits);
105 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
106 			const unsigned long *bitmap2, int bits);
107 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
108 			const unsigned long *bitmap2, int bits);
109 extern int __bitmap_intersects(const unsigned long *bitmap1,
110 			const unsigned long *bitmap2, int bits);
111 extern int __bitmap_subset(const unsigned long *bitmap1,
112 			const unsigned long *bitmap2, int bits);
113 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
114 
115 extern void bitmap_set(unsigned long *map, int i, int len);
116 extern void bitmap_clear(unsigned long *map, int start, int nr);
117 extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
118 					 unsigned long size,
119 					 unsigned long start,
120 					 unsigned int nr,
121 					 unsigned long align_mask);
122 
123 extern int bitmap_scnprintf(char *buf, unsigned int len,
124 			const unsigned long *src, int nbits);
125 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
126 			unsigned long *dst, int nbits);
127 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
128 			unsigned long *dst, int nbits);
129 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
130 			const unsigned long *src, int nbits);
131 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
132 			int nmaskbits);
133 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
134 			unsigned long *dst, int nbits);
135 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
136 		const unsigned long *old, const unsigned long *new, int bits);
137 extern int bitmap_bitremap(int oldbit,
138 		const unsigned long *old, const unsigned long *new, int bits);
139 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
140 		const unsigned long *relmap, int bits);
141 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
142 		int sz, int bits);
143 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
144 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
145 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
146 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
147 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
148 
149 #define BITMAP_LAST_WORD_MASK(nbits)					\
150 (									\
151 	((nbits) % BITS_PER_LONG) ?					\
152 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
153 )
154 
155 #define small_const_nbits(nbits) \
156 	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
157 
158 static inline void bitmap_zero(unsigned long *dst, int nbits)
159 {
160 	if (small_const_nbits(nbits))
161 		*dst = 0UL;
162 	else {
163 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
164 		memset(dst, 0, len);
165 	}
166 }
167 
168 static inline void bitmap_fill(unsigned long *dst, int nbits)
169 {
170 	size_t nlongs = BITS_TO_LONGS(nbits);
171 	if (!small_const_nbits(nbits)) {
172 		int len = (nlongs - 1) * sizeof(unsigned long);
173 		memset(dst, 0xff,  len);
174 	}
175 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
176 }
177 
178 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
179 			int nbits)
180 {
181 	if (small_const_nbits(nbits))
182 		*dst = *src;
183 	else {
184 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
185 		memcpy(dst, src, len);
186 	}
187 }
188 
189 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
190 			const unsigned long *src2, int nbits)
191 {
192 	if (small_const_nbits(nbits))
193 		return (*dst = *src1 & *src2) != 0;
194 	return __bitmap_and(dst, src1, src2, nbits);
195 }
196 
197 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
198 			const unsigned long *src2, int nbits)
199 {
200 	if (small_const_nbits(nbits))
201 		*dst = *src1 | *src2;
202 	else
203 		__bitmap_or(dst, src1, src2, nbits);
204 }
205 
206 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
207 			const unsigned long *src2, int nbits)
208 {
209 	if (small_const_nbits(nbits))
210 		*dst = *src1 ^ *src2;
211 	else
212 		__bitmap_xor(dst, src1, src2, nbits);
213 }
214 
215 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
216 			const unsigned long *src2, int nbits)
217 {
218 	if (small_const_nbits(nbits))
219 		return (*dst = *src1 & ~(*src2)) != 0;
220 	return __bitmap_andnot(dst, src1, src2, nbits);
221 }
222 
223 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
224 			int nbits)
225 {
226 	if (small_const_nbits(nbits))
227 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
228 	else
229 		__bitmap_complement(dst, src, nbits);
230 }
231 
232 static inline int bitmap_equal(const unsigned long *src1,
233 			const unsigned long *src2, int nbits)
234 {
235 	if (small_const_nbits(nbits))
236 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
237 	else
238 		return __bitmap_equal(src1, src2, nbits);
239 }
240 
241 static inline int bitmap_intersects(const unsigned long *src1,
242 			const unsigned long *src2, int nbits)
243 {
244 	if (small_const_nbits(nbits))
245 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
246 	else
247 		return __bitmap_intersects(src1, src2, nbits);
248 }
249 
250 static inline int bitmap_subset(const unsigned long *src1,
251 			const unsigned long *src2, int nbits)
252 {
253 	if (small_const_nbits(nbits))
254 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
255 	else
256 		return __bitmap_subset(src1, src2, nbits);
257 }
258 
259 static inline int bitmap_empty(const unsigned long *src, int nbits)
260 {
261 	if (small_const_nbits(nbits))
262 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
263 	else
264 		return __bitmap_empty(src, nbits);
265 }
266 
267 static inline int bitmap_full(const unsigned long *src, int nbits)
268 {
269 	if (small_const_nbits(nbits))
270 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
271 	else
272 		return __bitmap_full(src, nbits);
273 }
274 
275 static inline int bitmap_weight(const unsigned long *src, int nbits)
276 {
277 	if (small_const_nbits(nbits))
278 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
279 	return __bitmap_weight(src, nbits);
280 }
281 
282 static inline void bitmap_shift_right(unsigned long *dst,
283 			const unsigned long *src, int n, int nbits)
284 {
285 	if (small_const_nbits(nbits))
286 		*dst = *src >> n;
287 	else
288 		__bitmap_shift_right(dst, src, n, nbits);
289 }
290 
291 static inline void bitmap_shift_left(unsigned long *dst,
292 			const unsigned long *src, int n, int nbits)
293 {
294 	if (small_const_nbits(nbits))
295 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
296 	else
297 		__bitmap_shift_left(dst, src, n, nbits);
298 }
299 
300 static inline int bitmap_parse(const char *buf, unsigned int buflen,
301 			unsigned long *maskp, int nmaskbits)
302 {
303 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
304 }
305 
306 #endif /* __ASSEMBLY__ */
307 
308 #endif /* __LINUX_BITMAP_H */
309