xref: /linux/tools/lib/bitmap.c (revision f7af616c632ee2ac3af0876fe33bf9e0232e665a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * From lib/bitmap.c
4  * Helper functions for bitmap.h.
5  */
6 #include <linux/bitmap.h>
7 
8 int __bitmap_weight(const unsigned long *bitmap, int bits)
9 {
10 	int k, w = 0, lim = bits/BITS_PER_LONG;
11 
12 	for (k = 0; k < lim; k++)
13 		w += hweight_long(bitmap[k]);
14 
15 	if (bits % BITS_PER_LONG)
16 		w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
17 
18 	return w;
19 }
20 
21 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
22 		 const unsigned long *bitmap2, int bits)
23 {
24 	int k;
25 	int nr = BITS_TO_LONGS(bits);
26 
27 	for (k = 0; k < nr; k++)
28 		dst[k] = bitmap1[k] | bitmap2[k];
29 }
30 
31 size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
32 			char *buf, size_t size)
33 {
34 	/* current bit is 'cur', most recently seen range is [rbot, rtop] */
35 	unsigned int cur, rbot, rtop;
36 	bool first = true;
37 	size_t ret = 0;
38 
39 	rbot = cur = find_first_bit(bitmap, nbits);
40 	while (cur < nbits) {
41 		rtop = cur;
42 		cur = find_next_bit(bitmap, nbits, cur + 1);
43 		if (cur < nbits && cur <= rtop + 1)
44 			continue;
45 
46 		if (!first)
47 			ret += scnprintf(buf + ret, size - ret, ",");
48 
49 		first = false;
50 
51 		ret += scnprintf(buf + ret, size - ret, "%d", rbot);
52 		if (rbot < rtop)
53 			ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
54 
55 		rbot = cur;
56 	}
57 	return ret;
58 }
59 
60 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
61 		 const unsigned long *bitmap2, unsigned int bits)
62 {
63 	unsigned int k;
64 	unsigned int lim = bits/BITS_PER_LONG;
65 	unsigned long result = 0;
66 
67 	for (k = 0; k < lim; k++)
68 		result |= (dst[k] = bitmap1[k] & bitmap2[k]);
69 	if (bits % BITS_PER_LONG)
70 		result |= (dst[k] = bitmap1[k] & bitmap2[k] &
71 			   BITMAP_LAST_WORD_MASK(bits));
72 	return result != 0;
73 }
74 
75 int __bitmap_equal(const unsigned long *bitmap1,
76 		const unsigned long *bitmap2, unsigned int bits)
77 {
78 	unsigned int k, lim = bits/BITS_PER_LONG;
79 	for (k = 0; k < lim; ++k)
80 		if (bitmap1[k] != bitmap2[k])
81 			return 0;
82 
83 	if (bits % BITS_PER_LONG)
84 		if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
85 			return 0;
86 
87 	return 1;
88 }
89