xref: /linux-6.15/include/linux/bitmap.h (revision 1da177e4)
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_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
44  * bitmap_parse(ubuf, ulen, dst, nbits)		Parse bitmap dst from user buf
45  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
46  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from list
47  */
48 
49 /*
50  * Also the following operations in asm/bitops.h apply to bitmaps.
51  *
52  * set_bit(bit, addr)			*addr |= bit
53  * clear_bit(bit, addr)			*addr &= ~bit
54  * change_bit(bit, addr)		*addr ^= bit
55  * test_bit(bit, addr)			Is bit set in *addr?
56  * test_and_set_bit(bit, addr)		Set bit and return old value
57  * test_and_clear_bit(bit, addr)	Clear bit and return old value
58  * test_and_change_bit(bit, addr)	Change bit and return old value
59  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
60  * find_first_bit(addr, nbits)		Position first set bit in *addr
61  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
62  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
63  */
64 
65 /*
66  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
67  * to declare an array named 'name' of just enough unsigned longs to
68  * contain all bit positions from 0 to 'bits' - 1.
69  */
70 
71 /*
72  * lib/bitmap.c provides these functions:
73  */
74 
75 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
76 extern int __bitmap_full(const unsigned long *bitmap, int bits);
77 extern int __bitmap_equal(const unsigned long *bitmap1,
78                 	const unsigned long *bitmap2, int bits);
79 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
80 			int bits);
81 extern void __bitmap_shift_right(unsigned long *dst,
82                         const unsigned long *src, int shift, int bits);
83 extern void __bitmap_shift_left(unsigned long *dst,
84                         const unsigned long *src, int shift, int bits);
85 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
86 			const unsigned long *bitmap2, int bits);
87 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
88 			const unsigned long *bitmap2, int bits);
89 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
90 			const unsigned long *bitmap2, int bits);
91 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
92 			const unsigned long *bitmap2, int bits);
93 extern int __bitmap_intersects(const unsigned long *bitmap1,
94 			const unsigned long *bitmap2, int bits);
95 extern int __bitmap_subset(const unsigned long *bitmap1,
96 			const unsigned long *bitmap2, int bits);
97 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
98 
99 extern int bitmap_scnprintf(char *buf, unsigned int len,
100 			const unsigned long *src, int nbits);
101 extern int bitmap_parse(const char __user *ubuf, unsigned int ulen,
102 			unsigned long *dst, int nbits);
103 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
104 			const unsigned long *src, int nbits);
105 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
106 			int nmaskbits);
107 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
108 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
109 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
110 
111 #define BITMAP_LAST_WORD_MASK(nbits)					\
112 (									\
113 	((nbits) % BITS_PER_LONG) ?					\
114 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
115 )
116 
117 static inline void bitmap_zero(unsigned long *dst, int nbits)
118 {
119 	if (nbits <= BITS_PER_LONG)
120 		*dst = 0UL;
121 	else {
122 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
123 		memset(dst, 0, len);
124 	}
125 }
126 
127 static inline void bitmap_fill(unsigned long *dst, int nbits)
128 {
129 	size_t nlongs = BITS_TO_LONGS(nbits);
130 	if (nlongs > 1) {
131 		int len = (nlongs - 1) * sizeof(unsigned long);
132 		memset(dst, 0xff,  len);
133 	}
134 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
135 }
136 
137 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
138 			int nbits)
139 {
140 	if (nbits <= BITS_PER_LONG)
141 		*dst = *src;
142 	else {
143 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
144 		memcpy(dst, src, len);
145 	}
146 }
147 
148 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
149 			const unsigned long *src2, int nbits)
150 {
151 	if (nbits <= BITS_PER_LONG)
152 		*dst = *src1 & *src2;
153 	else
154 		__bitmap_and(dst, src1, src2, nbits);
155 }
156 
157 static inline void bitmap_or(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_or(dst, src1, src2, nbits);
164 }
165 
166 static inline void bitmap_xor(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_xor(dst, src1, src2, nbits);
173 }
174 
175 static inline void bitmap_andnot(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_andnot(dst, src1, src2, nbits);
182 }
183 
184 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
185 			int nbits)
186 {
187 	if (nbits <= BITS_PER_LONG)
188 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
189 	else
190 		__bitmap_complement(dst, src, nbits);
191 }
192 
193 static inline int bitmap_equal(const unsigned long *src1,
194 			const unsigned long *src2, int nbits)
195 {
196 	if (nbits <= BITS_PER_LONG)
197 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
198 	else
199 		return __bitmap_equal(src1, src2, nbits);
200 }
201 
202 static inline int bitmap_intersects(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)) != 0;
207 	else
208 		return __bitmap_intersects(src1, src2, nbits);
209 }
210 
211 static inline int bitmap_subset(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));
216 	else
217 		return __bitmap_subset(src1, src2, nbits);
218 }
219 
220 static inline int bitmap_empty(const unsigned long *src, int nbits)
221 {
222 	if (nbits <= BITS_PER_LONG)
223 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
224 	else
225 		return __bitmap_empty(src, nbits);
226 }
227 
228 static inline int bitmap_full(const unsigned long *src, int nbits)
229 {
230 	if (nbits <= BITS_PER_LONG)
231 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
232 	else
233 		return __bitmap_full(src, nbits);
234 }
235 
236 static inline int bitmap_weight(const unsigned long *src, int nbits)
237 {
238 	return __bitmap_weight(src, nbits);
239 }
240 
241 static inline void bitmap_shift_right(unsigned long *dst,
242 			const unsigned long *src, int n, int nbits)
243 {
244 	if (nbits <= BITS_PER_LONG)
245 		*dst = *src >> n;
246 	else
247 		__bitmap_shift_right(dst, src, n, nbits);
248 }
249 
250 static inline void bitmap_shift_left(unsigned long *dst,
251 			const unsigned long *src, int n, int nbits)
252 {
253 	if (nbits <= BITS_PER_LONG)
254 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
255 	else
256 		__bitmap_shift_left(dst, src, n, nbits);
257 }
258 
259 #endif /* __ASSEMBLY__ */
260 
261 #endif /* __LINUX_BITMAP_H */
262