projects/linux·blob v3.19-rc5 · refs

163 lines · 3.0 KiB

1/*
2 * Range add and subtract
3 */
4#include <linux/kernel.h>
5#include <linux/init.h>
6#include <linux/sort.h>
7#include <linux/string.h>
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 /* get new start/end: */
36 for (i = 0; i < nr_range; i++) {
37 u64 common_start, common_end;
38
39 if (!range[i].end)
40 continue;
41
42 common_start = max(range[i].start, start);
43 common_end = min(range[i].end, end);
44 if (common_start > common_end)
45 continue;
46
47 /* new start/end, will add it back at last */
48 start = min(range[i].start, start);
49 end = max(range[i].end, end);
50
51 memmove(&range[i], &range[i + 1],
52 (nr_range - (i + 1)) * sizeof(range[i]));
53 range[nr_range - 1].start = 0;
54 range[nr_range - 1].end = 0;
55 nr_range--;
56 i--;
57 }
58
59 /* Need to add it: */
60 return add_range(range, az, nr_range, start, end);
61}
62
63void subtract_range(struct range *range, int az, u64 start, u64 end)
64{
65 int i, j;
66
67 if (start >= end)
68 return;
69
70 for (j = 0; j < az; j++) {
71 if (!range[j].end)
72 continue;
73
74 if (start <= range[j].start && end >= range[j].end) {
75 range[j].start = 0;
76 range[j].end = 0;
77 continue;
78 }
79
80 if (start <= range[j].start && end < range[j].end &&
81 range[j].start < end) {
82 range[j].start = end;
83 continue;
84 }
85
86
87 if (start > range[j].start && end >= range[j].end &&
88 range[j].end > start) {
89 range[j].end = start;
90 continue;
91 }
92
93 if (start > range[j].start && end < range[j].end) {
94 /* Find the new spare: */
95 for (i = 0; i < az; i++) {
96 if (range[i].end == 0)
97 break;
98 }
99 if (i < az) {
100 range[i].end = range[j].end;
101 range[i].start = end;
102 } else {
103 pr_err("%s: run out of slot in ranges\n",
104 __func__);
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
117 if (r1->start < r2->start)
118 return -1;
119 if (r1->start > r2->start)
120 return 1;
121 return 0;
122}
123
124int clean_sort_range(struct range *range, int az)
125{
126 int i, j, k = az - 1, nr_range = az;
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}