projects/linux·blob v3.6 · refs

159 lines · 2.9 KiB

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