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 unsigned int __bitmap_weight(const unsigned long *bitmap, int bits)
9 {
10 unsigned 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 bool __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 bool __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 false;
82
83 if (bits % BITS_PER_LONG)
84 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
85 return false;
86
87 return true;
88 }
89
90 bool __bitmap_intersects(const unsigned long *bitmap1,
91 const unsigned long *bitmap2, unsigned int bits)
92 {
93 unsigned int k, lim = bits/BITS_PER_LONG;
94 for (k = 0; k < lim; ++k)
95 if (bitmap1[k] & bitmap2[k])
96 return true;
97
98 if (bits % BITS_PER_LONG)
99 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
100 return true;
101 return false;
102 }
103
104 void __bitmap_clear(unsigned long *map, unsigned int start, int len)
105 {
106 unsigned long *p = map + BIT_WORD(start);
107 const unsigned int size = start + len;
108 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
109 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
110
111 while (len - bits_to_clear >= 0) {
112 *p &= ~mask_to_clear;
113 len -= bits_to_clear;
114 bits_to_clear = BITS_PER_LONG;
115 mask_to_clear = ~0UL;
116 p++;
117 }
118 if (len) {
119 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
120 *p &= ~mask_to_clear;
121 }
122 }
123
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.