xref: /linux-6.15/include/linux/bitmap.h (revision 930cc144)
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_shift_right(dst, src, n, nbits)	*dst = *src >> n
46  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
47  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
48  * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
49  * bitmap_onto(dst, orig, relmap, nbits)	*dst = orig relative to relmap
50  * bitmap_fold(dst, orig, sz, nbits)		dst bits = orig bits mod sz
51  * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
52  * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
53  * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
54  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
55  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from list
56  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
57  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
58  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
59  */
60 
61 /*
62  * Also the following operations in asm/bitops.h apply to bitmaps.
63  *
64  * set_bit(bit, addr)			*addr |= bit
65  * clear_bit(bit, addr)			*addr &= ~bit
66  * change_bit(bit, addr)		*addr ^= bit
67  * test_bit(bit, addr)			Is bit set in *addr?
68  * test_and_set_bit(bit, addr)		Set bit and return old value
69  * test_and_clear_bit(bit, addr)	Clear bit and return old value
70  * test_and_change_bit(bit, addr)	Change bit and return old value
71  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
72  * find_first_bit(addr, nbits)		Position first set bit in *addr
73  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
74  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
75  */
76 
77 /*
78  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
79  * to declare an array named 'name' of just enough unsigned longs to
80  * contain all bit positions from 0 to 'bits' - 1.
81  */
82 
83 /*
84  * lib/bitmap.c provides these functions:
85  */
86 
87 extern int __bitmap_empty(const unsigned long *bitmap, int bits);
88 extern int __bitmap_full(const unsigned long *bitmap, int bits);
89 extern int __bitmap_equal(const unsigned long *bitmap1,
90                 	const unsigned long *bitmap2, int bits);
91 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
92 			int bits);
93 extern void __bitmap_shift_right(unsigned long *dst,
94                         const unsigned long *src, int shift, int bits);
95 extern void __bitmap_shift_left(unsigned long *dst,
96                         const unsigned long *src, int shift, int bits);
97 extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
98 			const unsigned long *bitmap2, int bits);
99 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
100 			const unsigned long *bitmap2, int bits);
101 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
102 			const unsigned long *bitmap2, int bits);
103 extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
104 			const unsigned long *bitmap2, int bits);
105 extern int __bitmap_intersects(const unsigned long *bitmap1,
106 			const unsigned long *bitmap2, int bits);
107 extern int __bitmap_subset(const unsigned long *bitmap1,
108 			const unsigned long *bitmap2, int bits);
109 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
110 
111 extern int bitmap_scnprintf(char *buf, unsigned int len,
112 			const unsigned long *src, int nbits);
113 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
114 			unsigned long *dst, int nbits);
115 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
116 			unsigned long *dst, int nbits);
117 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
118 			const unsigned long *src, int nbits);
119 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
120 			int nmaskbits);
121 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
122 		const unsigned long *old, const unsigned long *new, int bits);
123 extern int bitmap_bitremap(int oldbit,
124 		const unsigned long *old, const unsigned long *new, int bits);
125 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
126 		const unsigned long *relmap, int bits);
127 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
128 		int sz, int bits);
129 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
130 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
131 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
132 
133 #define BITMAP_LAST_WORD_MASK(nbits)					\
134 (									\
135 	((nbits) % BITS_PER_LONG) ?					\
136 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
137 )
138 
139 static inline void bitmap_zero(unsigned long *dst, int nbits)
140 {
141 	if (nbits <= BITS_PER_LONG)
142 		*dst = 0UL;
143 	else {
144 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
145 		memset(dst, 0, len);
146 	}
147 }
148 
149 static inline void bitmap_fill(unsigned long *dst, int nbits)
150 {
151 	size_t nlongs = BITS_TO_LONGS(nbits);
152 	if (nlongs > 1) {
153 		int len = (nlongs - 1) * sizeof(unsigned long);
154 		memset(dst, 0xff,  len);
155 	}
156 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
157 }
158 
159 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
160 			int nbits)
161 {
162 	if (nbits <= BITS_PER_LONG)
163 		*dst = *src;
164 	else {
165 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
166 		memcpy(dst, src, len);
167 	}
168 }
169 
170 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
171 			const unsigned long *src2, int nbits)
172 {
173 	if (nbits <= BITS_PER_LONG)
174 		*dst = *src1 & *src2;
175 	else
176 		__bitmap_and(dst, src1, src2, nbits);
177 }
178 
179 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
180 			const unsigned long *src2, int nbits)
181 {
182 	if (nbits <= BITS_PER_LONG)
183 		*dst = *src1 | *src2;
184 	else
185 		__bitmap_or(dst, src1, src2, nbits);
186 }
187 
188 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
189 			const unsigned long *src2, int nbits)
190 {
191 	if (nbits <= BITS_PER_LONG)
192 		*dst = *src1 ^ *src2;
193 	else
194 		__bitmap_xor(dst, src1, src2, nbits);
195 }
196 
197 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
198 			const unsigned long *src2, int nbits)
199 {
200 	if (nbits <= BITS_PER_LONG)
201 		*dst = *src1 & ~(*src2);
202 	else
203 		__bitmap_andnot(dst, src1, src2, nbits);
204 }
205 
206 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
207 			int nbits)
208 {
209 	if (nbits <= BITS_PER_LONG)
210 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
211 	else
212 		__bitmap_complement(dst, src, nbits);
213 }
214 
215 static inline int bitmap_equal(const unsigned long *src1,
216 			const unsigned long *src2, int nbits)
217 {
218 	if (nbits <= BITS_PER_LONG)
219 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
220 	else
221 		return __bitmap_equal(src1, src2, nbits);
222 }
223 
224 static inline int bitmap_intersects(const unsigned long *src1,
225 			const unsigned long *src2, int nbits)
226 {
227 	if (nbits <= BITS_PER_LONG)
228 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
229 	else
230 		return __bitmap_intersects(src1, src2, nbits);
231 }
232 
233 static inline int bitmap_subset(const unsigned long *src1,
234 			const unsigned long *src2, int nbits)
235 {
236 	if (nbits <= BITS_PER_LONG)
237 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
238 	else
239 		return __bitmap_subset(src1, src2, nbits);
240 }
241 
242 static inline int bitmap_empty(const unsigned long *src, int nbits)
243 {
244 	if (nbits <= BITS_PER_LONG)
245 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
246 	else
247 		return __bitmap_empty(src, nbits);
248 }
249 
250 static inline int bitmap_full(const unsigned long *src, int nbits)
251 {
252 	if (nbits <= BITS_PER_LONG)
253 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
254 	else
255 		return __bitmap_full(src, nbits);
256 }
257 
258 static inline int bitmap_weight(const unsigned long *src, int nbits)
259 {
260 	if (nbits <= BITS_PER_LONG)
261 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
262 	return __bitmap_weight(src, nbits);
263 }
264 
265 static inline void bitmap_shift_right(unsigned long *dst,
266 			const unsigned long *src, int n, int nbits)
267 {
268 	if (nbits <= BITS_PER_LONG)
269 		*dst = *src >> n;
270 	else
271 		__bitmap_shift_right(dst, src, n, nbits);
272 }
273 
274 static inline void bitmap_shift_left(unsigned long *dst,
275 			const unsigned long *src, int n, int nbits)
276 {
277 	if (nbits <= BITS_PER_LONG)
278 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
279 	else
280 		__bitmap_shift_left(dst, src, n, nbits);
281 }
282 
283 static inline int bitmap_parse(const char *buf, unsigned int buflen,
284 			unsigned long *maskp, int nmaskbits)
285 {
286 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
287 }
288 
289 #endif /* __ASSEMBLY__ */
290 
291 #endif /* __LINUX_BITMAP_H */
292