1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
#include <linux/module.h>
#include "bit-radix.h"
#define BIT_ARRAY_BYTES 256
#define BIT_RADIX_BITS_PER_ARRAY ((BIT_ARRAY_BYTES - sizeof(unsigned long)) * 8)
int set_radix_bit(struct radix_tree_root *radix, unsigned long bit)
{
unsigned long *bits;
unsigned long slot;
int bit_slot;
int ret;
slot = bit / BIT_RADIX_BITS_PER_ARRAY;
bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;
bits = radix_tree_lookup(radix, slot);
if (!bits) {
bits = kmalloc(BIT_ARRAY_BYTES, GFP_NOFS);
if (!bits)
return -ENOMEM;
memset(bits + 1, 0, BIT_ARRAY_BYTES - sizeof(unsigned long));
bits[0] = slot;
radix_tree_preload(GFP_NOFS);
ret = radix_tree_insert(radix, slot, bits);
radix_tree_preload_end();
if (ret)
return ret;
}
set_bit(bit_slot, bits + 1);
return 0;
}
int test_radix_bit(struct radix_tree_root *radix, unsigned long bit)
{
unsigned long *bits;
unsigned long slot;
int bit_slot;
slot = bit / BIT_RADIX_BITS_PER_ARRAY;
bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;
bits = radix_tree_lookup(radix, slot);
if (!bits)
return 0;
return test_bit(bit_slot, bits + 1);
}
int clear_radix_bit(struct radix_tree_root *radix, unsigned long bit)
{
unsigned long *bits;
unsigned long slot;
int bit_slot;
int i;
int empty = 1;
slot = bit / BIT_RADIX_BITS_PER_ARRAY;
bit_slot = bit % BIT_RADIX_BITS_PER_ARRAY;
bits = radix_tree_lookup(radix, slot);
if (!bits)
return 0;
clear_bit(bit_slot, bits + 1);
#if 0
for (i = 1; i < BIT_ARRAY_BYTES / sizeof(unsigned long); i++) {
if (bits[i]) {
empty = 0;
break;
}
}
if (empty) {
bits = radix_tree_delete(radix, slot);
synchronize_rcu();
BUG_ON(!bits);
kfree(bits);
}
#endif
return 0;
}
int find_first_radix_bit(struct radix_tree_root *radix, unsigned long *retbits,
int nr)
{
unsigned long *bits;
unsigned long *gang[4];
int found;
int ret;
int i;
int total_found = 0;
ret = radix_tree_gang_lookup(radix, (void *)&gang, 0, ARRAY_SIZE(gang));
for (i = 0; i < ret && nr > 0; i++) {
found = 0;
bits = gang[i];
while(nr > 0) {
found = find_next_bit(bits + 1,
BIT_RADIX_BITS_PER_ARRAY,
found);
if (found < BIT_RADIX_BITS_PER_ARRAY) {
*retbits = bits[0] *
BIT_RADIX_BITS_PER_ARRAY + found;
retbits++;
nr--;
total_found++;
found++;
} else
break;
}
}
return total_found;
}
|
