Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 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 | |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 10 | int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) |
| 11 | { |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 12 | if (start >= end) |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 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 | |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 32 | if (start >= end) |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 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); |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 45 | if (common_start > common_end) |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 46 | continue; |
| 47 | |
| 48 | final_start = min(range[i].start, start); |
| 49 | final_end = max(range[i].end, end); |
| 50 | |
| 51 | range[i].start = final_start; |
| 52 | range[i].end = final_end; |
| 53 | return nr_range; |
| 54 | } |
| 55 | |
| 56 | /* Need to add it: */ |
| 57 | return add_range(range, az, nr_range, start, end); |
| 58 | } |
| 59 | |
| 60 | void subtract_range(struct range *range, int az, u64 start, u64 end) |
| 61 | { |
| 62 | int i, j; |
| 63 | |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 64 | if (start >= end) |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 65 | return; |
| 66 | |
| 67 | for (j = 0; j < az; j++) { |
| 68 | if (!range[j].end) |
| 69 | continue; |
| 70 | |
| 71 | if (start <= range[j].start && end >= range[j].end) { |
| 72 | range[j].start = 0; |
| 73 | range[j].end = 0; |
| 74 | continue; |
| 75 | } |
| 76 | |
| 77 | if (start <= range[j].start && end < range[j].end && |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 78 | range[j].start < end) { |
| 79 | range[j].start = end; |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 80 | continue; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | if (start > range[j].start && end >= range[j].end && |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 85 | range[j].end > start) { |
| 86 | range[j].end = start; |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 87 | continue; |
| 88 | } |
| 89 | |
| 90 | if (start > range[j].start && end < range[j].end) { |
| 91 | /* Find the new spare: */ |
| 92 | for (i = 0; i < az; i++) { |
| 93 | if (range[i].end == 0) |
| 94 | break; |
| 95 | } |
| 96 | if (i < az) { |
| 97 | range[i].end = range[j].end; |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 98 | range[i].start = end; |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 99 | } else { |
| 100 | printk(KERN_ERR "run of slot in ranges\n"); |
| 101 | } |
Yinghai Lu | e9a0064 | 2010-02-10 01:20:13 -0800 | [diff] [blame] | 102 | range[j].end = start; |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 103 | continue; |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | static int cmp_range(const void *x1, const void *x2) |
| 109 | { |
| 110 | const struct range *r1 = x1; |
| 111 | const struct range *r2 = x2; |
| 112 | s64 start1, start2; |
| 113 | |
| 114 | start1 = r1->start; |
| 115 | start2 = r2->start; |
| 116 | |
| 117 | return start1 - start2; |
| 118 | } |
| 119 | |
| 120 | int clean_sort_range(struct range *range, int az) |
| 121 | { |
Alexey Khoroshilov | 834b403 | 2010-11-11 14:05:14 -0800 | [diff] [blame] | 122 | int i, j, k = az - 1, nr_range = az; |
Yinghai Lu | 27811d8 | 2010-02-10 01:20:07 -0800 | [diff] [blame] | 123 | |
| 124 | for (i = 0; i < k; i++) { |
| 125 | if (range[i].end) |
| 126 | continue; |
| 127 | for (j = k; j > i; j--) { |
| 128 | if (range[j].end) { |
| 129 | k = j; |
| 130 | break; |
| 131 | } |
| 132 | } |
| 133 | if (j == i) |
| 134 | break; |
| 135 | range[i].start = range[k].start; |
| 136 | range[i].end = range[k].end; |
| 137 | range[k].start = 0; |
| 138 | range[k].end = 0; |
| 139 | k--; |
| 140 | } |
| 141 | /* count it */ |
| 142 | for (i = 0; i < az; i++) { |
| 143 | if (!range[i].end) { |
| 144 | nr_range = i; |
| 145 | break; |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | /* sort them */ |
| 150 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); |
| 151 | |
| 152 | return nr_range; |
| 153 | } |
| 154 | |
| 155 | void sort_range(struct range *range, int nr_range) |
| 156 | { |
| 157 | /* sort them */ |
| 158 | sort(range, nr_range, sizeof(struct range), cmp_range, NULL); |
| 159 | } |