1 /* 2 * QEMU 64-bit address ranges 3 * 4 * Copyright (c) 2015-2016 Red Hat, Inc. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21 #include "qemu/osdep.h" 22 #include "qemu/range.h" 23 24 /* 25 * Return -1 if @a < @b, 1 @a > @b, and 0 if they touch or overlap. 26 * Both @a and @b must not be empty. 27 */ 28 static inline int range_compare(Range *a, Range *b) 29 { 30 assert(!range_is_empty(a) && !range_is_empty(b)); 31 32 /* Careful, avoid wraparound */ 33 if (b->lob && b->lob - 1 > a->upb) { 34 return -1; 35 } 36 if (a->lob && a->lob - 1 > b->upb) { 37 return 1; 38 } 39 return 0; 40 } 41 42 /* Insert @data into @list of ranges; caller no longer owns @data */ 43 GList *range_list_insert(GList *list, Range *data) 44 { 45 GList *l; 46 47 assert(!range_is_empty(data)); 48 49 /* Skip all list elements strictly less than data */ 50 for (l = list; l && range_compare(l->data, data) < 0; l = l->next) { 51 } 52 53 if (!l || range_compare(l->data, data) > 0) { 54 /* Rest of the list (if any) is strictly greater than @data */ 55 return g_list_insert_before(list, l, data); 56 } 57 58 /* Current list element overlaps @data, merge the two */ 59 range_extend(l->data, data); 60 g_free(data); 61 62 /* Merge any subsequent list elements that now also overlap */ 63 while (l->next && range_compare(l->data, l->next->data) == 0) { 64 GList *new_l; 65 66 range_extend(l->data, l->next->data); 67 g_free(l->next->data); 68 new_l = g_list_delete_link(list, l->next); 69 assert(new_l == list); 70 } 71 72 return list; 73 } 74