1 /* 2 * Range add and subtract 3 */ 4 #include <linux/kernel.h> 5 #include <linux/init.h> 6 #include <linux/sort.h> 7 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 /* 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); 45 if (common_start > common_end) 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 64 if (start >= end) 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 && 78 range[j].start < end) { 79 range[j].start = end; 80 continue; 81 } 82 83 84 if (start > range[j].start && end >= range[j].end && 85 range[j].end > start) { 86 range[j].end = start; 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; 98 range[i].start = end; 99 } else { 100 pr_err("%s: run out of slot in ranges\n", 101 __func__); 102 } 103 range[j].end = start; 104 continue; 105 } 106 } 107 } 108 109 static int cmp_range(const void *x1, const void *x2) 110 { 111 const struct range *r1 = x1; 112 const struct range *r2 = x2; 113 s64 start1, start2; 114 115 start1 = r1->start; 116 start2 = r2->start; 117 118 return start1 - start2; 119 } 120 121 int clean_sort_range(struct range *range, int az) 122 { 123 int i, j, k = az - 1, nr_range = az; 124 125 for (i = 0; i < k; i++) { 126 if (range[i].end) 127 continue; 128 for (j = k; j > i; j--) { 129 if (range[j].end) { 130 k = j; 131 break; 132 } 133 } 134 if (j == i) 135 break; 136 range[i].start = range[k].start; 137 range[i].end = range[k].end; 138 range[k].start = 0; 139 range[k].end = 0; 140 k--; 141 } 142 /* count it */ 143 for (i = 0; i < az; i++) { 144 if (!range[i].end) { 145 nr_range = i; 146 break; 147 } 148 } 149 150 /* sort them */ 151 sort(range, nr_range, sizeof(struct range), cmp_range, NULL); 152 153 return nr_range; 154 } 155 156 void sort_range(struct range *range, int nr_range) 157 { 158 /* sort them */ 159 sort(range, nr_range, sizeof(struct range), cmp_range, NULL); 160 } 161