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1 | // SPDX-License-Identifier: GPL-2.0 | |
2 | /* | |
3 | * Range add and subtract | |
4 | */ | |
5 | #include <linux/init.h> | |
6 | #include <linux/minmax.h> | |
7 | #include <linux/printk.h> | |
8 | #include <linux/sort.h> | |
9 | #include <linux/string.h> | |
10 | #include <linux/range.h> | |
11 | ||
12 | int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) | |
13 | { | |
14 | if (start >= end) | |
15 | return nr_range; | |
16 | ||
17 | /* Out of slots: */ | |
18 | if (nr_range >= az) | |
19 | return nr_range; | |
20 | ||
21 | range[nr_range].start = start; | |
22 | range[nr_range].end = end; | |
23 | ||
24 | nr_range++; | |
25 | ||
26 | return nr_range; | |
27 | } | |
28 | ||
29 | int add_range_with_merge(struct range *range, int az, int nr_range, | |
30 | u64 start, u64 end) | |
31 | { | |
32 | int i; | |
33 | ||
34 | if (start >= end) | |
35 | return nr_range; | |
36 | ||
37 | /* get new start/end: */ | |
38 | for (i = 0; i < nr_range; i++) { | |
39 | u64 common_start, common_end; | |
40 | ||
41 | if (!range[i].end) | |
42 | continue; | |
43 | ||
44 | common_start = max(range[i].start, start); | |
45 | common_end = min(range[i].end, end); | |
46 | if (common_start > common_end) | |
47 | continue; | |
48 | ||
49 | /* new start/end, will add it back at last */ | |
50 | start = min(range[i].start, start); | |
51 | end = max(range[i].end, end); | |
52 | ||
53 | memmove(&range[i], &range[i + 1], | |
54 | (nr_range - (i + 1)) * sizeof(range[i])); | |
55 | range[nr_range - 1].start = 0; | |
56 | range[nr_range - 1].end = 0; | |
57 | nr_range--; | |
58 | i--; | |
59 | } | |
60 | ||
61 | /* Need to add it: */ | |
62 | return add_range(range, az, nr_range, start, end); | |
63 | } | |
64 | ||
65 | void subtract_range(struct range *range, int az, u64 start, u64 end) | |
66 | { | |
67 | int i, j; | |
68 | ||
69 | if (start >= end) | |
70 | return; | |
71 | ||
72 | for (j = 0; j < az; j++) { | |
73 | if (!range[j].end) | |
74 | continue; | |
75 | ||
76 | if (start <= range[j].start && end >= range[j].end) { | |
77 | range[j].start = 0; | |
78 | range[j].end = 0; | |
79 | continue; | |
80 | } | |
81 | ||
82 | if (start <= range[j].start && end < range[j].end && | |
83 | range[j].start < end) { | |
84 | range[j].start = end; | |
85 | continue; | |
86 | } | |
87 | ||
88 | ||
89 | if (start > range[j].start && end >= range[j].end && | |
90 | range[j].end > start) { | |
91 | range[j].end = start; | |
92 | continue; | |
93 | } | |
94 | ||
95 | if (start > range[j].start && end < range[j].end) { | |
96 | /* Find the new spare: */ | |
97 | for (i = 0; i < az; i++) { | |
98 | if (range[i].end == 0) | |
99 | break; | |
100 | } | |
101 | if (i < az) { | |
102 | range[i].end = range[j].end; | |
103 | range[i].start = end; | |
104 | } else { | |
105 | pr_err("%s: run out of slot in ranges\n", | |
106 | __func__); | |
107 | } | |
108 | range[j].end = start; | |
109 | continue; | |
110 | } | |
111 | } | |
112 | } | |
113 | ||
114 | static int cmp_range(const void *x1, const void *x2) | |
115 | { | |
116 | const struct range *r1 = x1; | |
117 | const struct range *r2 = x2; | |
118 | ||
119 | if (r1->start < r2->start) | |
120 | return -1; | |
121 | if (r1->start > r2->start) | |
122 | return 1; | |
123 | return 0; | |
124 | } | |
125 | ||
126 | int clean_sort_range(struct range *range, int az) | |
127 | { | |
128 | int i, j, k = az - 1, nr_range = az; | |
129 | ||
130 | for (i = 0; i < k; i++) { | |
131 | if (range[i].end) | |
132 | continue; | |
133 | for (j = k; j > i; j--) { | |
134 | if (range[j].end) { | |
135 | k = j; | |
136 | break; | |
137 | } | |
138 | } | |
139 | if (j == i) | |
140 | break; | |
141 | range[i].start = range[k].start; | |
142 | range[i].end = range[k].end; | |
143 | range[k].start = 0; | |
144 | range[k].end = 0; | |
145 | k--; | |
146 | } | |
147 | /* count it */ | |
148 | for (i = 0; i < az; i++) { | |
149 | if (!range[i].end) { | |
150 | nr_range = i; | |
151 | break; | |
152 | } | |
153 | } | |
154 | ||
155 | /* sort them */ | |
156 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); | |
157 | ||
158 | return nr_range; | |
159 | } | |
160 | ||
161 | void sort_range(struct range *range, int nr_range) | |
162 | { | |
163 | /* sort them */ | |
164 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); | |
165 | } |