projects/linux·blob v2.6.34-rc1 · refs

163 lines · 2.9 KiB

1/*
2 * Range add and subtract
3 */
4#include <linux/module.h>
5#include <linux/init.h>
6#include <linux/sort.h>
7
8#include <linux/range.h>
9
10#ifndef ARRAY_SIZE
11#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
12#endif
13
14int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
15{
16 if (start >= end)
17 return nr_range;
18
19 /* Out of slots: */
20 if (nr_range >= az)
21 return nr_range;
22
23 range[nr_range].start = start;
24 range[nr_range].end = end;
25
26 nr_range++;
27
28 return nr_range;
29}
30
31int add_range_with_merge(struct range *range, int az, int nr_range,
32 u64 start, u64 end)
33{
34 int i;
35
36 if (start >= end)
37 return nr_range;
38
39 /* Try to merge it with old one: */
40 for (i = 0; i < nr_range; i++) {
41 u64 final_start, final_end;
42 u64 common_start, common_end;
43
44 if (!range[i].end)
45 continue;
46
47 common_start = max(range[i].start, start);
48 common_end = min(range[i].end, end);
49 if (common_start > common_end)
50 continue;
51
52 final_start = min(range[i].start, start);
53 final_end = max(range[i].end, end);
54
55 range[i].start = final_start;
56 range[i].end = final_end;
57 return nr_range;
58 }
59
60 /* Need to add it: */
61 return add_range(range, az, nr_range, start, end);
62}
63
64void subtract_range(struct range *range, int az, u64 start, u64 end)
65{
66 int i, j;
67
68 if (start >= end)
69 return;
70
71 for (j = 0; j < az; j++) {
72 if (!range[j].end)
73 continue;
74
75 if (start <= range[j].start && end >= range[j].end) {
76 range[j].start = 0;
77 range[j].end = 0;
78 continue;
79 }
80
81 if (start <= range[j].start && end < range[j].end &&
82 range[j].start < end) {
83 range[j].start = end;
84 continue;
85 }
86
87
88 if (start > range[j].start && end >= range[j].end &&
89 range[j].end > start) {
90 range[j].end = start;
91 continue;
92 }
93
94 if (start > range[j].start && end < range[j].end) {
95 /* Find the new spare: */
96 for (i = 0; i < az; i++) {
97 if (range[i].end == 0)
98 break;
99 }
100 if (i < az) {
101 range[i].end = range[j].end;
102 range[i].start = end;
103 } else {
104 printk(KERN_ERR "run of slot in ranges\n");
105 }
106 range[j].end = start;
107 continue;
108 }
109 }
110}
111
112static int cmp_range(const void *x1, const void *x2)
113{
114 const struct range *r1 = x1;
115 const struct range *r2 = x2;
116 s64 start1, start2;
117
118 start1 = r1->start;
119 start2 = r2->start;
120
121 return start1 - start2;
122}
123
124int clean_sort_range(struct range *range, int az)
125{
126 int i, j, k = az - 1, nr_range = 0;
127
128 for (i = 0; i < k; i++) {
129 if (range[i].end)
130 continue;
131 for (j = k; j > i; j--) {
132 if (range[j].end) {
133 k = j;
134 break;
135 }
136 }
137 if (j == i)
138 break;
139 range[i].start = range[k].start;
140 range[i].end = range[k].end;
141 range[k].start = 0;
142 range[k].end = 0;
143 k--;
144 }
145 /* count it */
146 for (i = 0; i < az; i++) {
147 if (!range[i].end) {
148 nr_range = i;
149 break;
150 }
151 }
152
153 /* sort them */
154 sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
155
156 return nr_range;
157}
158
159void sort_range(struct range *range, int nr_range)
160{
161 /* sort them */
162 sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
163}