diff options
Diffstat (limited to 'kernel/range.c')
-rw-r--r-- | kernel/range.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/kernel/range.c b/kernel/range.c new file mode 100644 index 000000000000..74e2e6114927 --- /dev/null +++ b/kernel/range.c | |||
@@ -0,0 +1,163 @@ | |||
1 | /* | ||
2 | * Range add and subtract | ||
3 | */ | ||
4 | #include <linux/module.h> | ||
5 | #include <linux/init.h> | ||
6 | #include <linux/sort.h> | ||
7 | |||
8 | #include <linux/range.h> | ||
9 | |||
10 | #ifndef ARRAY_SIZE | ||
11 | #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) | ||
12 | #endif | ||
13 | |||
14 | int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) | ||
15 | { | ||
16 | if (start >= end) | ||
17 | return nr_range; | ||
18 | |||
19 | /* Out of slots: */ | ||
20 | if (nr_range >= az) | ||
21 | return nr_range; | ||
22 | |||
23 | range[nr_range].start = start; | ||
24 | range[nr_range].end = end; | ||
25 | |||
26 | nr_range++; | ||
27 | |||
28 | return nr_range; | ||
29 | } | ||
30 | |||
31 | int add_range_with_merge(struct range *range, int az, int nr_range, | ||
32 | u64 start, u64 end) | ||
33 | { | ||
34 | int i; | ||
35 | |||
36 | if (start >= end) | ||
37 | return nr_range; | ||
38 | |||
39 | /* Try to merge it with old one: */ | ||
40 | for (i = 0; i < nr_range; i++) { | ||
41 | u64 final_start, final_end; | ||
42 | u64 common_start, common_end; | ||
43 | |||
44 | if (!range[i].end) | ||
45 | continue; | ||
46 | |||
47 | common_start = max(range[i].start, start); | ||
48 | common_end = min(range[i].end, end); | ||
49 | if (common_start > common_end) | ||
50 | continue; | ||
51 | |||
52 | final_start = min(range[i].start, start); | ||
53 | final_end = max(range[i].end, end); | ||
54 | |||
55 | range[i].start = final_start; | ||
56 | range[i].end = final_end; | ||
57 | return nr_range; | ||
58 | } | ||
59 | |||
60 | /* Need to add it: */ | ||
61 | return add_range(range, az, nr_range, start, end); | ||
62 | } | ||
63 | |||
64 | void subtract_range(struct range *range, int az, u64 start, u64 end) | ||
65 | { | ||
66 | int i, j; | ||
67 | |||
68 | if (start >= end) | ||
69 | return; | ||
70 | |||
71 | for (j = 0; j < az; j++) { | ||
72 | if (!range[j].end) | ||
73 | continue; | ||
74 | |||
75 | if (start <= range[j].start && end >= range[j].end) { | ||
76 | range[j].start = 0; | ||
77 | range[j].end = 0; | ||
78 | continue; | ||
79 | } | ||
80 | |||
81 | if (start <= range[j].start && end < range[j].end && | ||
82 | range[j].start < end) { | ||
83 | range[j].start = end; | ||
84 | continue; | ||
85 | } | ||
86 | |||
87 | |||
88 | if (start > range[j].start && end >= range[j].end && | ||
89 | range[j].end > start) { | ||
90 | range[j].end = start; | ||
91 | continue; | ||
92 | } | ||
93 | |||
94 | if (start > range[j].start && end < range[j].end) { | ||
95 | /* Find the new spare: */ | ||
96 | for (i = 0; i < az; i++) { | ||
97 | if (range[i].end == 0) | ||
98 | break; | ||
99 | } | ||
100 | if (i < az) { | ||
101 | range[i].end = range[j].end; | ||
102 | range[i].start = end; | ||
103 | } else { | ||
104 | printk(KERN_ERR "run of slot in ranges\n"); | ||
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 | s64 start1, start2; | ||
117 | |||
118 | start1 = r1->start; | ||
119 | start2 = r2->start; | ||
120 | |||
121 | return start1 - start2; | ||
122 | } | ||
123 | |||
124 | int clean_sort_range(struct range *range, int az) | ||
125 | { | ||
126 | int i, j, k = az - 1, nr_range = 0; | ||
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 | } | ||