xref: /linux-6.15/include/linux/bitmap.h (revision 40d3057a)
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_scnprintf_len(unsigned int nr_bits);
114 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
115 			unsigned long *dst, int nbits);
116 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
117 			unsigned long *dst, int nbits);
118 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
119 			const unsigned long *src, int nbits);
120 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
121 			int nmaskbits);
122 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
123 		const unsigned long *old, const unsigned long *new, int bits);
124 extern int bitmap_bitremap(int oldbit,
125 		const unsigned long *old, const unsigned long *new, int bits);
126 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
127 		const unsigned long *relmap, int bits);
128 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
129 		int sz, int bits);
130 extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
131 extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
132 extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);
133 
134 #define BITMAP_LAST_WORD_MASK(nbits)					\
135 (									\
136 	((nbits) % BITS_PER_LONG) ?					\
137 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
138 )
139 
140 static inline void bitmap_zero(unsigned long *dst, int nbits)
141 {
142 	if (nbits <= BITS_PER_LONG)
143 		*dst = 0UL;
144 	else {
145 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
146 		memset(dst, 0, len);
147 	}
148 }
149 
150 static inline void bitmap_fill(unsigned long *dst, int nbits)
151 {
152 	size_t nlongs = BITS_TO_LONGS(nbits);
153 	if (nlongs > 1) {
154 		int len = (nlongs - 1) * sizeof(unsigned long);
155 		memset(dst, 0xff,  len);
156 	}
157 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
158 }
159 
160 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
161 			int nbits)
162 {
163 	if (nbits <= BITS_PER_LONG)
164 		*dst = *src;
165 	else {
166 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
167 		memcpy(dst, src, len);
168 	}
169 }
170 
171 static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
172 			const unsigned long *src2, int nbits)
173 {
174 	if (nbits <= BITS_PER_LONG)
175 		*dst = *src1 & *src2;
176 	else
177 		__bitmap_and(dst, src1, src2, nbits);
178 }
179 
180 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
181 			const unsigned long *src2, int nbits)
182 {
183 	if (nbits <= BITS_PER_LONG)
184 		*dst = *src1 | *src2;
185 	else
186 		__bitmap_or(dst, src1, src2, nbits);
187 }
188 
189 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
190 			const unsigned long *src2, int nbits)
191 {
192 	if (nbits <= BITS_PER_LONG)
193 		*dst = *src1 ^ *src2;
194 	else
195 		__bitmap_xor(dst, src1, src2, nbits);
196 }
197 
198 static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
199 			const unsigned long *src2, int nbits)
200 {
201 	if (nbits <= BITS_PER_LONG)
202 		*dst = *src1 & ~(*src2);
203 	else
204 		__bitmap_andnot(dst, src1, src2, nbits);
205 }
206 
207 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
208 			int nbits)
209 {
210 	if (nbits <= BITS_PER_LONG)
211 		*dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);
212 	else
213 		__bitmap_complement(dst, src, nbits);
214 }
215 
216 static inline int bitmap_equal(const unsigned long *src1,
217 			const unsigned long *src2, int nbits)
218 {
219 	if (nbits <= BITS_PER_LONG)
220 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
221 	else
222 		return __bitmap_equal(src1, src2, nbits);
223 }
224 
225 static inline int bitmap_intersects(const unsigned long *src1,
226 			const unsigned long *src2, int nbits)
227 {
228 	if (nbits <= BITS_PER_LONG)
229 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
230 	else
231 		return __bitmap_intersects(src1, src2, nbits);
232 }
233 
234 static inline int bitmap_subset(const unsigned long *src1,
235 			const unsigned long *src2, int nbits)
236 {
237 	if (nbits <= BITS_PER_LONG)
238 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
239 	else
240 		return __bitmap_subset(src1, src2, nbits);
241 }
242 
243 static inline int bitmap_empty(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_empty(src, nbits);
249 }
250 
251 static inline int bitmap_full(const unsigned long *src, int nbits)
252 {
253 	if (nbits <= BITS_PER_LONG)
254 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
255 	else
256 		return __bitmap_full(src, nbits);
257 }
258 
259 static inline int bitmap_weight(const unsigned long *src, int nbits)
260 {
261 	if (nbits <= BITS_PER_LONG)
262 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
263 	return __bitmap_weight(src, nbits);
264 }
265 
266 static inline void bitmap_shift_right(unsigned long *dst,
267 			const unsigned long *src, int n, int nbits)
268 {
269 	if (nbits <= BITS_PER_LONG)
270 		*dst = *src >> n;
271 	else
272 		__bitmap_shift_right(dst, src, n, nbits);
273 }
274 
275 static inline void bitmap_shift_left(unsigned long *dst,
276 			const unsigned long *src, int n, int nbits)
277 {
278 	if (nbits <= BITS_PER_LONG)
279 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
280 	else
281 		__bitmap_shift_left(dst, src, n, nbits);
282 }
283 
284 static inline int bitmap_parse(const char *buf, unsigned int buflen,
285 			unsigned long *maskp, int nmaskbits)
286 {
287 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
288 }
289 
290 #endif /* __ASSEMBLY__ */
291 
292 #endif /* __LINUX_BITMAP_H */
293