xref: /linux-6.15/include/linux/bitmap.h (revision de2fe5e0)
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  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
50  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
51  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
52  */
53 
54 /*
55  * Also the following operations in asm/bitops.h apply to bitmaps.
56  *
57  * set_bit(bit, addr)			*addr |= bit
58  * clear_bit(bit, addr)			*addr &= ~bit
59  * change_bit(bit, addr)		*addr ^= bit
60  * test_bit(bit, addr)			Is bit set in *addr?
61  * test_and_set_bit(bit, addr)		Set bit and return old value
62  * test_and_clear_bit(bit, addr)	Clear bit and return old value
63  * test_and_change_bit(bit, addr)	Change bit and return old value
64  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
65  * find_first_bit(addr, nbits)		Position first set bit in *addr
66  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
67  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
68  */
69 
70 /*
71  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
72  * to declare an array named 'name' of just enough unsigned longs to
73  * contain all bit positions from 0 to 'bits' - 1.
74  */
75 
76 /*
77  * lib/bitmap.c provides these functions:
78  */
79 
80 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
81 extern int __bitmap_full(const unsigned long *bitmap, int bits);
82 extern int __bitmap_equal(const unsigned long *bitmap1,
83                 	const unsigned long *bitmap2, int bits);
84 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
85 			int bits);
86 extern void __bitmap_shift_right(unsigned long *dst,
87                         const unsigned long *src, int shift, int bits);
88 extern void __bitmap_shift_left(unsigned long *dst,
89                         const unsigned long *src, int shift, int bits);
90 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
91 			const unsigned long *bitmap2, int bits);
92 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
93 			const unsigned long *bitmap2, int bits);
94 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
95 			const unsigned long *bitmap2, int bits);
96 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
97 			const unsigned long *bitmap2, int bits);
98 extern int __bitmap_intersects(const unsigned long *bitmap1,
99 			const unsigned long *bitmap2, int bits);
100 extern int __bitmap_subset(const unsigned long *bitmap1,
101 			const unsigned long *bitmap2, int bits);
102 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
103 
104 extern int bitmap_scnprintf(char *buf, unsigned int len,
105 			const unsigned long *src, int nbits);
106 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
107 			unsigned long *dst, int nbits);
108 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
109 			const unsigned long *src, int nbits);
110 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
111 			int nmaskbits);
112 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
113 		const unsigned long *old, const unsigned long *new, int bits);
114 extern int bitmap_bitremap(int oldbit,
115 		const unsigned long *old, const unsigned long *new, int bits);
116 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
117 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
118 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
119 
120 #define BITMAP_LAST_WORD_MASK(nbits)					\
121 (									\
122 	((nbits) % BITS_PER_LONG) ?					\
123 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
124 )
125 
126 static inline void bitmap_zero(unsigned long *dst, int nbits)
127 {
128 	if (nbits <= BITS_PER_LONG)
129 		*dst = 0UL;
130 	else {
131 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
132 		memset(dst, 0, len);
133 	}
134 }
135 
136 static inline void bitmap_fill(unsigned long *dst, int nbits)
137 {
138 	size_t nlongs = BITS_TO_LONGS(nbits);
139 	if (nlongs > 1) {
140 		int len = (nlongs - 1) * sizeof(unsigned long);
141 		memset(dst, 0xff,  len);
142 	}
143 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
144 }
145 
146 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
147 			int nbits)
148 {
149 	if (nbits <= BITS_PER_LONG)
150 		*dst = *src;
151 	else {
152 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
153 		memcpy(dst, src, len);
154 	}
155 }
156 
157 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
158 			const unsigned long *src2, int nbits)
159 {
160 	if (nbits <= BITS_PER_LONG)
161 		*dst = *src1 & *src2;
162 	else
163 		__bitmap_and(dst, src1, src2, nbits);
164 }
165 
166 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
167 			const unsigned long *src2, int nbits)
168 {
169 	if (nbits <= BITS_PER_LONG)
170 		*dst = *src1 | *src2;
171 	else
172 		__bitmap_or(dst, src1, src2, nbits);
173 }
174 
175 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
176 			const unsigned long *src2, int nbits)
177 {
178 	if (nbits <= BITS_PER_LONG)
179 		*dst = *src1 ^ *src2;
180 	else
181 		__bitmap_xor(dst, src1, src2, nbits);
182 }
183 
184 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
185 			const unsigned long *src2, int nbits)
186 {
187 	if (nbits <= BITS_PER_LONG)
188 		*dst = *src1 & ~(*src2);
189 	else
190 		__bitmap_andnot(dst, src1, src2, nbits);
191 }
192 
193 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
194 			int nbits)
195 {
196 	if (nbits <= BITS_PER_LONG)
197 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
198 	else
199 		__bitmap_complement(dst, src, nbits);
200 }
201 
202 static inline int bitmap_equal(const unsigned long *src1,
203 			const unsigned long *src2, int nbits)
204 {
205 	if (nbits <= BITS_PER_LONG)
206 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
207 	else
208 		return __bitmap_equal(src1, src2, nbits);
209 }
210 
211 static inline int bitmap_intersects(const unsigned long *src1,
212 			const unsigned long *src2, int nbits)
213 {
214 	if (nbits <= BITS_PER_LONG)
215 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
216 	else
217 		return __bitmap_intersects(src1, src2, nbits);
218 }
219 
220 static inline int bitmap_subset(const unsigned long *src1,
221 			const unsigned long *src2, int nbits)
222 {
223 	if (nbits <= BITS_PER_LONG)
224 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
225 	else
226 		return __bitmap_subset(src1, src2, nbits);
227 }
228 
229 static inline int bitmap_empty(const unsigned long *src, int nbits)
230 {
231 	if (nbits <= BITS_PER_LONG)
232 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
233 	else
234 		return __bitmap_empty(src, nbits);
235 }
236 
237 static inline int bitmap_full(const unsigned long *src, int nbits)
238 {
239 	if (nbits <= BITS_PER_LONG)
240 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
241 	else
242 		return __bitmap_full(src, nbits);
243 }
244 
245 static inline int bitmap_weight(const unsigned long *src, int nbits)
246 {
247 	return __bitmap_weight(src, nbits);
248 }
249 
250 static inline void bitmap_shift_right(unsigned long *dst,
251 			const unsigned long *src, int n, int nbits)
252 {
253 	if (nbits <= BITS_PER_LONG)
254 		*dst = *src >> n;
255 	else
256 		__bitmap_shift_right(dst, src, n, nbits);
257 }
258 
259 static inline void bitmap_shift_left(unsigned long *dst,
260 			const unsigned long *src, int n, int nbits)
261 {
262 	if (nbits <= BITS_PER_LONG)
263 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
264 	else
265 		__bitmap_shift_left(dst, src, n, nbits);
266 }
267 
268 #endif /* __ASSEMBLY__ */
269 
270 #endif /* __LINUX_BITMAP_H */
271