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Commit | Line | Data |
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27811d8c YL |
1 | /* |
2 | * Range add and subtract | |
3 | */ | |
9a418455 | 4 | #include <linux/kernel.h> |
27811d8c YL |
5 | #include <linux/init.h> |
6 | #include <linux/sort.h> | |
7 | ||
8 | #include <linux/range.h> | |
9 | ||
27811d8c YL |
10 | int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) |
11 | { | |
e9a0064a | 12 | if (start >= end) |
27811d8c YL |
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 | ||
e9a0064a | 32 | if (start >= end) |
27811d8c YL |
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); | |
e9a0064a | 45 | if (common_start > common_end) |
27811d8c YL |
46 | continue; |
47 | ||
48 | final_start = min(range[i].start, start); | |
49 | final_end = max(range[i].end, end); | |
50 | ||
fbe06b7b YL |
51 | /* clear it and add it back for further merge */ |
52 | range[i].start = 0; | |
53 | range[i].end = 0; | |
54 | return add_range_with_merge(range, az, nr_range, | |
55 | final_start, final_end); | |
27811d8c YL |
56 | } |
57 | ||
58 | /* Need to add it: */ | |
59 | return add_range(range, az, nr_range, start, end); | |
60 | } | |
61 | ||
62 | void subtract_range(struct range *range, int az, u64 start, u64 end) | |
63 | { | |
64 | int i, j; | |
65 | ||
e9a0064a | 66 | if (start >= end) |
27811d8c YL |
67 | return; |
68 | ||
69 | for (j = 0; j < az; j++) { | |
70 | if (!range[j].end) | |
71 | continue; | |
72 | ||
73 | if (start <= range[j].start && end >= range[j].end) { | |
74 | range[j].start = 0; | |
75 | range[j].end = 0; | |
76 | continue; | |
77 | } | |
78 | ||
79 | if (start <= range[j].start && end < range[j].end && | |
e9a0064a YL |
80 | range[j].start < end) { |
81 | range[j].start = end; | |
27811d8c YL |
82 | continue; |
83 | } | |
84 | ||
85 | ||
86 | if (start > range[j].start && end >= range[j].end && | |
e9a0064a YL |
87 | range[j].end > start) { |
88 | range[j].end = start; | |
27811d8c YL |
89 | continue; |
90 | } | |
91 | ||
92 | if (start > range[j].start && end < range[j].end) { | |
93 | /* Find the new spare: */ | |
94 | for (i = 0; i < az; i++) { | |
95 | if (range[i].end == 0) | |
96 | break; | |
97 | } | |
98 | if (i < az) { | |
99 | range[i].end = range[j].end; | |
e9a0064a | 100 | range[i].start = end; |
27811d8c | 101 | } else { |
7fba2c27 LF |
102 | pr_err("%s: run out of slot in ranges\n", |
103 | __func__); | |
27811d8c | 104 | } |
e9a0064a | 105 | range[j].end = start; |
27811d8c YL |
106 | continue; |
107 | } | |
108 | } | |
109 | } | |
110 | ||
111 | static int cmp_range(const void *x1, const void *x2) | |
112 | { | |
113 | const struct range *r1 = x1; | |
114 | const struct range *r2 = x2; | |
115 | s64 start1, start2; | |
116 | ||
117 | start1 = r1->start; | |
118 | start2 = r2->start; | |
119 | ||
120 | return start1 - start2; | |
121 | } | |
122 | ||
123 | int clean_sort_range(struct range *range, int az) | |
124 | { | |
834b4038 | 125 | int i, j, k = az - 1, nr_range = az; |
27811d8c YL |
126 | |
127 | for (i = 0; i < k; i++) { | |
128 | if (range[i].end) | |
129 | continue; | |
130 | for (j = k; j > i; j--) { | |
131 | if (range[j].end) { | |
132 | k = j; | |
133 | break; | |
134 | } | |
135 | } | |
136 | if (j == i) | |
137 | break; | |
138 | range[i].start = range[k].start; | |
139 | range[i].end = range[k].end; | |
140 | range[k].start = 0; | |
141 | range[k].end = 0; | |
142 | k--; | |
143 | } | |
144 | /* count it */ | |
145 | for (i = 0; i < az; i++) { | |
146 | if (!range[i].end) { | |
147 | nr_range = i; | |
148 | break; | |
149 | } | |
150 | } | |
151 | ||
152 | /* sort them */ | |
153 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); | |
154 | ||
155 | return nr_range; | |
156 | } | |
157 | ||
158 | void sort_range(struct range *range, int nr_range) | |
159 | { | |
160 | /* sort them */ | |
161 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); | |
162 | } |