xref: /linux-6.15/include/linux/bitmap.h (revision 4e57b681)
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  * bitmap_zero(dst, nbits)			*dst = 0UL
28  * bitmap_fill(dst, nbits)			*dst = ~0UL
29  * bitmap_copy(dst, src, nbits)			*dst = *src
30  * bitmap_and(dst, src1, src2, nbits)		*dst = *src1 & *src2
31  * bitmap_or(dst, src1, src2, nbits)		*dst = *src1 | *src2
32  * bitmap_xor(dst, src1, src2, nbits)		*dst = *src1 ^ *src2
33  * bitmap_andnot(dst, src1, src2, nbits)	*dst = *src1 & ~(*src2)
34  * bitmap_complement(dst, src, nbits)		*dst = ~(*src)
35  * bitmap_equal(src1, src2, nbits)		Are *src1 and *src2 equal?
36  * bitmap_intersects(src1, src2, nbits) 	Do *src1 and *src2 overlap?
37  * bitmap_subset(src1, src2, nbits)		Is *src1 a subset of *src2?
38  * bitmap_empty(src, nbits)			Are all bits zero in *src?
39  * bitmap_full(src, nbits)			Are all bits set in *src?
40  * bitmap_weight(src, nbits)			Hamming Weight: number set bits
41  * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
42  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
43  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
44  * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
45  * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
46  * bitmap_parse(ubuf, ulen, dst, nbits)		Parse bitmap dst from user buf
47  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
48  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from list
49  */
50 
51 /*
52  * Also the following operations in asm/bitops.h apply to bitmaps.
53  *
54  * set_bit(bit, addr)			*addr |= bit
55  * clear_bit(bit, addr)			*addr &= ~bit
56  * change_bit(bit, addr)		*addr ^= bit
57  * test_bit(bit, addr)			Is bit set in *addr?
58  * test_and_set_bit(bit, addr)		Set bit and return old value
59  * test_and_clear_bit(bit, addr)	Clear bit and return old value
60  * test_and_change_bit(bit, addr)	Change bit and return old value
61  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
62  * find_first_bit(addr, nbits)		Position first set bit in *addr
63  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
64  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
65  */
66 
67 /*
68  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
69  * to declare an array named 'name' of just enough unsigned longs to
70  * contain all bit positions from 0 to 'bits' - 1.
71  */
72 
73 /*
74  * lib/bitmap.c provides these functions:
75  */
76 
77 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
78 extern int __bitmap_full(const unsigned long *bitmap, int bits);
79 extern int __bitmap_equal(const unsigned long *bitmap1,
80                 	const unsigned long *bitmap2, int bits);
81 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
82 			int bits);
83 extern void __bitmap_shift_right(unsigned long *dst,
84                         const unsigned long *src, int shift, int bits);
85 extern void __bitmap_shift_left(unsigned long *dst,
86                         const unsigned long *src, int shift, int bits);
87 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
88 			const unsigned long *bitmap2, int bits);
89 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
90 			const unsigned long *bitmap2, int bits);
91 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
92 			const unsigned long *bitmap2, int bits);
93 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
94 			const unsigned long *bitmap2, int bits);
95 extern int __bitmap_intersects(const unsigned long *bitmap1,
96 			const unsigned long *bitmap2, int bits);
97 extern int __bitmap_subset(const unsigned long *bitmap1,
98 			const unsigned long *bitmap2, int bits);
99 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
100 
101 extern int bitmap_scnprintf(char *buf, unsigned int len,
102 			const unsigned long *src, int nbits);
103 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
104 			unsigned long *dst, int nbits);
105 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
106 			const unsigned long *src, int nbits);
107 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
108 			int nmaskbits);
109 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
110 		const unsigned long *old, const unsigned long *new, int bits);
111 extern int bitmap_bitremap(int oldbit,
112 		const unsigned long *old, const unsigned long *new, int bits);
113 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
114 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
115 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
116 
117 #define BITMAP_LAST_WORD_MASK(nbits)					\
118 (									\
119 	((nbits) % BITS_PER_LONG) ?					\
120 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
121 )
122 
123 static inline void bitmap_zero(unsigned long *dst, int nbits)
124 {
125 	if (nbits <= BITS_PER_LONG)
126 		*dst = 0UL;
127 	else {
128 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
129 		memset(dst, 0, len);
130 	}
131 }
132 
133 static inline void bitmap_fill(unsigned long *dst, int nbits)
134 {
135 	size_t nlongs = BITS_TO_LONGS(nbits);
136 	if (nlongs > 1) {
137 		int len = (nlongs - 1) * sizeof(unsigned long);
138 		memset(dst, 0xff,  len);
139 	}
140 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
141 }
142 
143 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
144 			int nbits)
145 {
146 	if (nbits <= BITS_PER_LONG)
147 		*dst = *src;
148 	else {
149 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
150 		memcpy(dst, src, len);
151 	}
152 }
153 
154 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
155 			const unsigned long *src2, int nbits)
156 {
157 	if (nbits <= BITS_PER_LONG)
158 		*dst = *src1 & *src2;
159 	else
160 		__bitmap_and(dst, src1, src2, nbits);
161 }
162 
163 static inline void bitmap_or(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_or(dst, src1, src2, nbits);
170 }
171 
172 static inline void bitmap_xor(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_xor(dst, src1, src2, nbits);
179 }
180 
181 static inline void bitmap_andnot(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_andnot(dst, src1, src2, nbits);
188 }
189 
190 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
191 			int nbits)
192 {
193 	if (nbits <= BITS_PER_LONG)
194 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
195 	else
196 		__bitmap_complement(dst, src, nbits);
197 }
198 
199 static inline int bitmap_equal(const unsigned long *src1,
200 			const unsigned long *src2, int nbits)
201 {
202 	if (nbits <= BITS_PER_LONG)
203 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
204 	else
205 		return __bitmap_equal(src1, src2, nbits);
206 }
207 
208 static inline int bitmap_intersects(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)) != 0;
213 	else
214 		return __bitmap_intersects(src1, src2, nbits);
215 }
216 
217 static inline int bitmap_subset(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));
222 	else
223 		return __bitmap_subset(src1, src2, nbits);
224 }
225 
226 static inline int bitmap_empty(const unsigned long *src, int nbits)
227 {
228 	if (nbits <= BITS_PER_LONG)
229 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
230 	else
231 		return __bitmap_empty(src, nbits);
232 }
233 
234 static inline int bitmap_full(const unsigned long *src, int nbits)
235 {
236 	if (nbits <= BITS_PER_LONG)
237 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
238 	else
239 		return __bitmap_full(src, nbits);
240 }
241 
242 static inline int bitmap_weight(const unsigned long *src, int nbits)
243 {
244 	return __bitmap_weight(src, nbits);
245 }
246 
247 static inline void bitmap_shift_right(unsigned long *dst,
248 			const unsigned long *src, int n, int nbits)
249 {
250 	if (nbits <= BITS_PER_LONG)
251 		*dst = *src >> n;
252 	else
253 		__bitmap_shift_right(dst, src, n, nbits);
254 }
255 
256 static inline void bitmap_shift_left(unsigned long *dst,
257 			const unsigned long *src, int n, int nbits)
258 {
259 	if (nbits <= BITS_PER_LONG)
260 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
261 	else
262 		__bitmap_shift_left(dst, src, n, nbits);
263 }
264 
265 #endif /* __ASSEMBLY__ */
266 
267 #endif /* __LINUX_BITMAP_H */
268