projects/linux·blob v7.2 · refs

181 lines · 4.4 KiB

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
8unsigned 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
21void __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
31size_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
60bool __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
75bool __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
90bool __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
104void __bitmap_set(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_set = BITS_PER_LONG - (start % BITS_PER_LONG);
109 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
110
111 while (len - bits_to_set >= 0) {
112 *p |= mask_to_set;
113 len -= bits_to_set;
114 bits_to_set = BITS_PER_LONG;
115 mask_to_set = ~0UL;
116 p++;
117 }
118 if (len) {
119 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
120 *p |= mask_to_set;
121 }
122}
123
124void __bitmap_clear(unsigned long *map, unsigned int start, int len)
125{
126 unsigned long *p = map + BIT_WORD(start);
127 const unsigned int size = start + len;
128 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
129 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
130
131 while (len - bits_to_clear >= 0) {
132 *p &= ~mask_to_clear;
133 len -= bits_to_clear;
134 bits_to_clear = BITS_PER_LONG;
135 mask_to_clear = ~0UL;
136 p++;
137 }
138 if (len) {
139 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
140 *p &= ~mask_to_clear;
141 }
142}
143
144bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
145 const unsigned long *bitmap2, unsigned int bits)
146{
147 unsigned int k;
148 unsigned int lim = bits/BITS_PER_LONG;
149 unsigned long result = 0;
150
151 for (k = 0; k < lim; k++)
152 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
153 if (bits % BITS_PER_LONG)
154 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
155 BITMAP_LAST_WORD_MASK(bits));
156 return result != 0;
157}
158
159bool __bitmap_subset(const unsigned long *bitmap1,
160 const unsigned long *bitmap2, unsigned int bits)
161{
162 unsigned int k, lim = bits/BITS_PER_LONG;
163 for (k = 0; k < lim; ++k)
164 if (bitmap1[k] & ~bitmap2[k])
165 return false;
166
167 if (bits % BITS_PER_LONG)
168 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
169 return false;
170 return true;
171}
172
173void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
174 const unsigned long *bitmap2, unsigned int bits)
175{
176 unsigned int k;
177 unsigned int nr = BITS_TO_LONGS(bits);
178
179 for (k = 0; k < nr; k++)
180 dst[k] = bitmap1[k] ^ bitmap2[k];
181}