/* * Range add and subtract */ #include <linux/module.h> #include <linux/init.h> #include <linux/sort.h> #include <linux/range.h> int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) { if (start >= end) return nr_range; /* Out of slots: */ if (nr_range >= az) return nr_range; range[nr_range].start = start; range[nr_range].end = end; nr_range++; return nr_range; } int add_range_with_merge(struct range *range, int az, int nr_range, u64 start, u64 end) { int i; if (start >= end) return nr_range; /* Try to merge it with old one: */ for (i = 0; i < nr_range; i++) { u64 final_start, final_end; u64 common_start, common_end; if (!range[i].end) continue; common_start = max(range[i].start, start); common_end = min(range[i].end, end); if (common_start > common_end) continue; final_start = min(range[i].start, start); final_end = max(range[i].end, end); range[i].start = final_start; range[i].end = final_end; return nr_range; } /* Need to add it: */ return add_range(range, az, nr_range, start, end); } void subtract_range(struct range *range, int az, u64 start, u64 end) { int i, j; if (start >= end) return; for (j = 0; j < az; j++) { if (!range[j].end) continue; if (start <= range[j].start && end >= range[j].end) { range[j].start = 0; range[j].end = 0; continue; } if (start <= range[j].start && end < range[j].end && range[j].start < end) { range[j].start = end; continue; } if (start > range[j].start && end >= range[j].end && range[j].end > start) { range[j].end = start; continue; } if (start > range[j].start && end < range[j].end) { /* Find the new spare: */ for (i = 0; i < az; i++) { if (range[i].end == 0) break; } if (i < az) { range[i].end = range[j].end; range[i].start = end; } else { printk(KERN_ERR "run of slot in ranges\n"); } range[j].end = start; continue; } } } static int cmp_range(const void *x1, const void *x2) { const struct range *r1 = x1; const struct range *r2 = x2; s64 start1, start2; start1 = r1->start; start2 = r2->start; return start1 - start2; } int clean_sort_range(struct range *range, int az) { int i, j, k = az - 1, nr_range = az; for (i = 0; i < k; i++) { if (range[i].end) continue; for (j = k; j > i; j--) { if (range[j].end) { k = j; break; } } if (j == i) break; range[i].start = range[k].start; range[i].end = range[k].end; range[k].start = 0; range[k].end = 0; k--; } /* count it */ for (i = 0; i < az; i++) { if (!range[i].end) { nr_range = i; break; } } /* sort them */ sort(range, nr_range, sizeof(struct range), cmp_range, NULL); return nr_range; } void sort_range(struct range *range, int nr_range) { /* sort them */ sort(range, nr_range, sizeof(struct range), cmp_range, NULL); }