blob: 82cfc285b046d8e320559a48cf08007a19742dc0
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 | |
10 | int 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 | |
27 | int 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 | |
63 | void 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 | |
112 | static 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 | |
124 | int 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 | |
159 | void sort_range(struct range *range, int nr_range) |
160 | { |
161 | /* sort them */ |
162 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); |
163 | } |
164 |