xref: /linux-6.15/include/linux/bitmap.h (revision 757dea93)
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 
10 /*
11  * bitmaps provide bit arrays that consume one or more unsigned
12  * longs.  The bitmap interface and available operations are listed
13  * here, in bitmap.h
14  *
15  * Function implementations generic to all architectures are in
16  * lib/bitmap.c.  Functions implementations that are architecture
17  * specific are in various include/asm-<arch>/bitops.h headers
18  * and other arch/<arch> specific files.
19  *
20  * See lib/bitmap.c for more details.
21  */
22 
23 /*
24  * The available bitmap operations and their rough meaning in the
25  * case that the bitmap is a single unsigned long are thus:
26  *
27  * Note that nbits should be always a compile time evaluable constant.
28  * Otherwise many inlines will generate horrible code.
29  *
30  * bitmap_zero(dst, nbits)			*dst = 0UL
31  * bitmap_fill(dst, nbits)			*dst = ~0UL
32  * bitmap_copy(dst, src, nbits)			*dst = *src
33  * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
34  * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
35  * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
36  * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
37  * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
38  * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
39  * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
40  * bitmap_subset(src1, src2, nbits)		Is *src1 a subset of *src2?
41  * bitmap_empty(src, nbits)			Are all bits zero in *src?
42  * bitmap_full(src, nbits)			Are all bits set in *src?
43  * bitmap_weight(src, nbits)			Hamming Weight: number set bits
44  * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
45  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
46  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
47  * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
48  * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
49  * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
50  * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
51  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
52  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from list
53  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
54  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
55  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
56  */
57 
58 /*
59  * Also the following operations in asm/bitops.h apply to bitmaps.
60  *
61  * set_bit(bit, addr)			*addr |= bit
62  * clear_bit(bit, addr)			*addr &= ~bit
63  * change_bit(bit, addr)		*addr ^= bit
64  * test_bit(bit, addr)			Is bit set in *addr?
65  * test_and_set_bit(bit, addr)		Set bit and return old value
66  * test_and_clear_bit(bit, addr)	Clear bit and return old value
67  * test_and_change_bit(bit, addr)	Change bit and return old value
68  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
69  * find_first_bit(addr, nbits)		Position first set bit in *addr
70  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
71  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
72  */
73 
74 /*
75  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
76  * to declare an array named 'name' of just enough unsigned longs to
77  * contain all bit positions from 0 to 'bits' - 1.
78  */
79 
80 /*
81  * lib/bitmap.c provides these functions:
82  */
83 
84 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
85 extern int __bitmap_full(const unsigned long *bitmap, int bits);
86 extern int __bitmap_equal(const unsigned long *bitmap1,
87                 	const unsigned long *bitmap2, int bits);
88 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
89 			int bits);
90 extern void __bitmap_shift_right(unsigned long *dst,
91                         const unsigned long *src, int shift, int bits);
92 extern void __bitmap_shift_left(unsigned long *dst,
93                         const unsigned long *src, int shift, int bits);
94 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
95 			const unsigned long *bitmap2, int bits);
96 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
97 			const unsigned long *bitmap2, int bits);
98 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
99 			const unsigned long *bitmap2, int bits);
100 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
101 			const unsigned long *bitmap2, int bits);
102 extern int __bitmap_intersects(const unsigned long *bitmap1,
103 			const unsigned long *bitmap2, int bits);
104 extern int __bitmap_subset(const unsigned long *bitmap1,
105 			const unsigned long *bitmap2, int bits);
106 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
107 
108 extern int bitmap_scnprintf(char *buf, unsigned int len,
109 			const unsigned long *src, int nbits);
110 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
111 			unsigned long *dst, int nbits);
112 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
113 			unsigned long *dst, int nbits);
114 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
115 			const unsigned long *src, int nbits);
116 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
117 			int nmaskbits);
118 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
119 		const unsigned long *old, const unsigned long *new, int bits);
120 extern int bitmap_bitremap(int oldbit,
121 		const unsigned long *old, const unsigned long *new, int bits);
122 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
123 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
124 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
125 
126 #define BITMAP_LAST_WORD_MASK(nbits)					\
127 (									\
128 	((nbits) % BITS_PER_LONG) ?					\
129 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
130 )
131 
132 static inline void bitmap_zero(unsigned long *dst, int nbits)
133 {
134 	if (nbits <= BITS_PER_LONG)
135 		*dst = 0UL;
136 	else {
137 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
138 		memset(dst, 0, len);
139 	}
140 }
141 
142 static inline void bitmap_fill(unsigned long *dst, int nbits)
143 {
144 	size_t nlongs = BITS_TO_LONGS(nbits);
145 	if (nlongs > 1) {
146 		int len = (nlongs - 1) * sizeof(unsigned long);
147 		memset(dst, 0xff,  len);
148 	}
149 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
150 }
151 
152 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
153 			int nbits)
154 {
155 	if (nbits <= BITS_PER_LONG)
156 		*dst = *src;
157 	else {
158 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
159 		memcpy(dst, src, len);
160 	}
161 }
162 
163 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
164 			const unsigned long *src2, int nbits)
165 {
166 	if (nbits <= BITS_PER_LONG)
167 		*dst = *src1 & *src2;
168 	else
169 		__bitmap_and(dst, src1, src2, nbits);
170 }
171 
172 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
173 			const unsigned long *src2, int nbits)
174 {
175 	if (nbits <= BITS_PER_LONG)
176 		*dst = *src1 | *src2;
177 	else
178 		__bitmap_or(dst, src1, src2, nbits);
179 }
180 
181 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
182 			const unsigned long *src2, int nbits)
183 {
184 	if (nbits <= BITS_PER_LONG)
185 		*dst = *src1 ^ *src2;
186 	else
187 		__bitmap_xor(dst, src1, src2, nbits);
188 }
189 
190 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
191 			const unsigned long *src2, int nbits)
192 {
193 	if (nbits <= BITS_PER_LONG)
194 		*dst = *src1 & ~(*src2);
195 	else
196 		__bitmap_andnot(dst, src1, src2, nbits);
197 }
198 
199 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
200 			int nbits)
201 {
202 	if (nbits <= BITS_PER_LONG)
203 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
204 	else
205 		__bitmap_complement(dst, src, nbits);
206 }
207 
208 static inline int bitmap_equal(const unsigned long *src1,
209 			const unsigned long *src2, int nbits)
210 {
211 	if (nbits <= BITS_PER_LONG)
212 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
213 	else
214 		return __bitmap_equal(src1, src2, nbits);
215 }
216 
217 static inline int bitmap_intersects(const unsigned long *src1,
218 			const unsigned long *src2, int nbits)
219 {
220 	if (nbits <= BITS_PER_LONG)
221 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
222 	else
223 		return __bitmap_intersects(src1, src2, nbits);
224 }
225 
226 static inline int bitmap_subset(const unsigned long *src1,
227 			const unsigned long *src2, int nbits)
228 {
229 	if (nbits <= BITS_PER_LONG)
230 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
231 	else
232 		return __bitmap_subset(src1, src2, nbits);
233 }
234 
235 static inline int bitmap_empty(const unsigned long *src, int nbits)
236 {
237 	if (nbits <= BITS_PER_LONG)
238 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
239 	else
240 		return __bitmap_empty(src, nbits);
241 }
242 
243 static inline int bitmap_full(const unsigned long *src, int nbits)
244 {
245 	if (nbits <= BITS_PER_LONG)
246 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
247 	else
248 		return __bitmap_full(src, nbits);
249 }
250 
251 static inline int bitmap_weight(const unsigned long *src, int nbits)
252 {
253 	if (nbits <= BITS_PER_LONG)
254 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
255 	return __bitmap_weight(src, nbits);
256 }
257 
258 static inline void bitmap_shift_right(unsigned long *dst,
259 			const unsigned long *src, int n, int nbits)
260 {
261 	if (nbits <= BITS_PER_LONG)
262 		*dst = *src >> n;
263 	else
264 		__bitmap_shift_right(dst, src, n, nbits);
265 }
266 
267 static inline void bitmap_shift_left(unsigned long *dst,
268 			const unsigned long *src, int n, int nbits)
269 {
270 	if (nbits <= BITS_PER_LONG)
271 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
272 	else
273 		__bitmap_shift_left(dst, src, n, nbits);
274 }
275 
276 static inline int bitmap_parse(const char *buf, unsigned int buflen,
277 			unsigned long *maskp, int nmaskbits)
278 {
279 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
280 }
281 
282 #endif /* __ASSEMBLY__ */
283 
284 #endif /* __LINUX_BITMAP_H */
285