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