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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_set(dst, pos, nbits)			Set specified bit area
46  * bitmap_clear(dst, pos, nbits)		Clear specified bit area
47  * bitmap_find_next_zero_area(buf, len, pos, n, mask)	Find bit free area
48  * bitmap_find_next_zero_area_off(buf, len, pos, n, mask)	as above
49  * bitmap_shift_right(dst, src, n, nbits)	*dst = *src >> n
50  * bitmap_shift_left(dst, src, n, nbits)	*dst = *src << n
51  * bitmap_remap(dst, src, old, new, nbits)	*dst = map(old, new)(src)
52  * bitmap_bitremap(oldbit, old, new, nbits)	newbit = map(old, new)(oldbit)
53  * bitmap_onto(dst, orig, relmap, nbits)	*dst = orig relative to relmap
54  * bitmap_fold(dst, orig, sz, nbits)		dst bits = orig bits mod sz
55  * bitmap_scnprintf(buf, len, src, nbits)	Print bitmap src to buf
56  * bitmap_parse(buf, buflen, dst, nbits)	Parse bitmap dst from kernel buf
57  * bitmap_parse_user(ubuf, ulen, dst, nbits)	Parse bitmap dst from user buf
58  * bitmap_scnlistprintf(buf, len, src, nbits)	Print bitmap src as list to buf
59  * bitmap_parselist(buf, dst, nbits)		Parse bitmap dst from kernel buf
60  * bitmap_parselist_user(buf, dst, nbits)	Parse bitmap dst from user buf
61  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
62  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
63  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
64  */
65 
66 /*
67  * Also the following operations in asm/bitops.h apply to bitmaps.
68  *
69  * set_bit(bit, addr)			*addr |= bit
70  * clear_bit(bit, addr)			*addr &= ~bit
71  * change_bit(bit, addr)		*addr ^= bit
72  * test_bit(bit, addr)			Is bit set in *addr?
73  * test_and_set_bit(bit, addr)		Set bit and return old value
74  * test_and_clear_bit(bit, addr)	Clear bit and return old value
75  * test_and_change_bit(bit, addr)	Change bit and return old value
76  * find_first_zero_bit(addr, nbits)	Position first zero bit in *addr
77  * find_first_bit(addr, nbits)		Position first set bit in *addr
78  * find_next_zero_bit(addr, nbits, bit)	Position next zero bit in *addr >= bit
79  * find_next_bit(addr, nbits, bit)	Position next set bit in *addr >= bit
80  */
81 
82 /*
83  * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
84  * to declare an array named 'name' of just enough unsigned longs to
85  * contain all bit positions from 0 to 'bits' - 1.
86  */
87 
88 /*
89  * lib/bitmap.c provides these functions:
90  */
91 
92 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
93 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
94 extern int __bitmap_equal(const unsigned long *bitmap1,
95 			  const unsigned long *bitmap2, unsigned int nbits);
96 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
97 			unsigned int nbits);
98 extern void __bitmap_shift_right(unsigned long *dst,
99                         const unsigned long *src, int shift, int bits);
100 extern void __bitmap_shift_left(unsigned long *dst,
101                         const unsigned long *src, int shift, int bits);
102 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
103 			const unsigned long *bitmap2, unsigned int nbits);
104 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
105 			const unsigned long *bitmap2, unsigned int nbits);
106 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
107 			const unsigned long *bitmap2, unsigned int nbits);
108 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
109 			const unsigned long *bitmap2, unsigned int nbits);
110 extern int __bitmap_intersects(const unsigned long *bitmap1,
111 			const unsigned long *bitmap2, unsigned int nbits);
112 extern int __bitmap_subset(const unsigned long *bitmap1,
113 			const unsigned long *bitmap2, unsigned int nbits);
114 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
115 
116 extern void bitmap_set(unsigned long *map, unsigned int start, int len);
117 extern void bitmap_clear(unsigned long *map, unsigned int start, int len);
118 
119 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
120 						    unsigned long size,
121 						    unsigned long start,
122 						    unsigned int nr,
123 						    unsigned long align_mask,
124 						    unsigned long align_offset);
125 
126 /**
127  * bitmap_find_next_zero_area - find a contiguous aligned zero area
128  * @map: The address to base the search on
129  * @size: The bitmap size in bits
130  * @start: The bitnumber to start searching at
131  * @nr: The number of zeroed bits we're looking for
132  * @align_mask: Alignment mask for zero area
133  *
134  * The @align_mask should be one less than a power of 2; the effect is that
135  * the bit offset of all zero areas this function finds is multiples of that
136  * power of 2. A @align_mask of 0 means no alignment is required.
137  */
138 static inline unsigned long
bitmap_find_next_zero_area(unsigned long * map,unsigned long size,unsigned long start,unsigned int nr,unsigned long align_mask)139 bitmap_find_next_zero_area(unsigned long *map,
140 			   unsigned long size,
141 			   unsigned long start,
142 			   unsigned int nr,
143 			   unsigned long align_mask)
144 {
145 	return bitmap_find_next_zero_area_off(map, size, start, nr,
146 					      align_mask, 0);
147 }
148 
149 extern int bitmap_scnprintf(char *buf, unsigned int len,
150 			const unsigned long *src, int nbits);
151 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
152 			unsigned long *dst, int nbits);
153 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
154 			unsigned long *dst, int nbits);
155 extern int bitmap_scnlistprintf(char *buf, unsigned int len,
156 			const unsigned long *src, int nbits);
157 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
158 			int nmaskbits);
159 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
160 			unsigned long *dst, int nbits);
161 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
162 		const unsigned long *old, const unsigned long *new, int bits);
163 extern int bitmap_bitremap(int oldbit,
164 		const unsigned long *old, const unsigned long *new, int bits);
165 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
166 		const unsigned long *relmap, int bits);
167 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
168 		int sz, int bits);
169 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
170 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
171 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
172 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
173 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
174 
175 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
176 #define BITMAP_LAST_WORD_MASK(nbits)					\
177 (									\
178 	((nbits) % BITS_PER_LONG) ?					\
179 		(1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL		\
180 )
181 
182 #define small_const_nbits(nbits) \
183 	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
184 
bitmap_zero(unsigned long * dst,int nbits)185 static inline void bitmap_zero(unsigned long *dst, int nbits)
186 {
187 	if (small_const_nbits(nbits))
188 		*dst = 0UL;
189 	else {
190 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
191 		memset(dst, 0, len);
192 	}
193 }
194 
bitmap_fill(unsigned long * dst,int nbits)195 static inline void bitmap_fill(unsigned long *dst, int nbits)
196 {
197 	size_t nlongs = BITS_TO_LONGS(nbits);
198 	if (!small_const_nbits(nbits)) {
199 		int len = (nlongs - 1) * sizeof(unsigned long);
200 		memset(dst, 0xff,  len);
201 	}
202 	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
203 }
204 
bitmap_copy(unsigned long * dst,const unsigned long * src,int nbits)205 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
206 			int nbits)
207 {
208 	if (small_const_nbits(nbits))
209 		*dst = *src;
210 	else {
211 		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
212 		memcpy(dst, src, len);
213 	}
214 }
215 
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)216 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
217 			const unsigned long *src2, unsigned int nbits)
218 {
219 	if (small_const_nbits(nbits))
220 		return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
221 	return __bitmap_and(dst, src1, src2, nbits);
222 }
223 
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)224 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
225 			const unsigned long *src2, unsigned int nbits)
226 {
227 	if (small_const_nbits(nbits))
228 		*dst = *src1 | *src2;
229 	else
230 		__bitmap_or(dst, src1, src2, nbits);
231 }
232 
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)233 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
234 			const unsigned long *src2, unsigned int nbits)
235 {
236 	if (small_const_nbits(nbits))
237 		*dst = *src1 ^ *src2;
238 	else
239 		__bitmap_xor(dst, src1, src2, nbits);
240 }
241 
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)242 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
243 			const unsigned long *src2, unsigned int nbits)
244 {
245 	if (small_const_nbits(nbits))
246 		return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
247 	return __bitmap_andnot(dst, src1, src2, nbits);
248 }
249 
bitmap_complement(unsigned long * dst,const unsigned long * src,unsigned int nbits)250 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
251 			unsigned int nbits)
252 {
253 	if (small_const_nbits(nbits))
254 		*dst = ~(*src);
255 	else
256 		__bitmap_complement(dst, src, nbits);
257 }
258 
bitmap_equal(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)259 static inline int bitmap_equal(const unsigned long *src1,
260 			const unsigned long *src2, unsigned int nbits)
261 {
262 	if (small_const_nbits(nbits))
263 		return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
264 	else
265 		return __bitmap_equal(src1, src2, nbits);
266 }
267 
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)268 static inline int bitmap_intersects(const unsigned long *src1,
269 			const unsigned long *src2, unsigned int nbits)
270 {
271 	if (small_const_nbits(nbits))
272 		return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
273 	else
274 		return __bitmap_intersects(src1, src2, nbits);
275 }
276 
bitmap_subset(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)277 static inline int bitmap_subset(const unsigned long *src1,
278 			const unsigned long *src2, unsigned int nbits)
279 {
280 	if (small_const_nbits(nbits))
281 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
282 	else
283 		return __bitmap_subset(src1, src2, nbits);
284 }
285 
bitmap_empty(const unsigned long * src,unsigned nbits)286 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
287 {
288 	if (small_const_nbits(nbits))
289 		return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
290 	else
291 		return __bitmap_empty(src, nbits);
292 }
293 
bitmap_full(const unsigned long * src,unsigned int nbits)294 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
295 {
296 	if (small_const_nbits(nbits))
297 		return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
298 	else
299 		return __bitmap_full(src, nbits);
300 }
301 
bitmap_weight(const unsigned long * src,unsigned int nbits)302 static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
303 {
304 	if (small_const_nbits(nbits))
305 		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
306 	return __bitmap_weight(src, nbits);
307 }
308 
bitmap_shift_right(unsigned long * dst,const unsigned long * src,int n,int nbits)309 static inline void bitmap_shift_right(unsigned long *dst,
310 			const unsigned long *src, int n, int nbits)
311 {
312 	if (small_const_nbits(nbits))
313 		*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> n;
314 	else
315 		__bitmap_shift_right(dst, src, n, nbits);
316 }
317 
bitmap_shift_left(unsigned long * dst,const unsigned long * src,int n,int nbits)318 static inline void bitmap_shift_left(unsigned long *dst,
319 			const unsigned long *src, int n, int nbits)
320 {
321 	if (small_const_nbits(nbits))
322 		*dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits);
323 	else
324 		__bitmap_shift_left(dst, src, n, nbits);
325 }
326 
bitmap_parse(const char * buf,unsigned int buflen,unsigned long * maskp,int nmaskbits)327 static inline int bitmap_parse(const char *buf, unsigned int buflen,
328 			unsigned long *maskp, int nmaskbits)
329 {
330 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
331 }
332 
333 #endif /* __ASSEMBLY__ */
334 
335 #endif /* __LINUX_BITMAP_H */
336