1 | /* |
2 | * QEMU 64-bit address ranges |
3 | * |
4 | * Copyright (c) 2015-2016 Red Hat, Inc. |
5 | * |
6 | * This program 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 program 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 | * General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
18 | */ |
19 | |
20 | #include "qemu/osdep.h" |
21 | #include "qemu/range.h" |
22 | |
23 | /* |
24 | * Return -1 if @a < @b, 1 @a > @b, and 0 if they touch or overlap. |
25 | * Both @a and @b must not be empty. |
26 | */ |
27 | static inline int range_compare(Range *a, Range *b) |
28 | { |
29 | assert(!range_is_empty(a) && !range_is_empty(b)); |
30 | |
31 | /* Careful, avoid wraparound */ |
32 | if (b->lob && b->lob - 1 > a->upb) { |
33 | return -1; |
34 | } |
35 | if (a->lob && a->lob - 1 > b->upb) { |
36 | return 1; |
37 | } |
38 | return 0; |
39 | } |
40 | |
41 | /* Insert @data into @list of ranges; caller no longer owns @data */ |
42 | GList *range_list_insert(GList *list, Range *data) |
43 | { |
44 | GList *l; |
45 | |
46 | assert(!range_is_empty(data)); |
47 | |
48 | /* Skip all list elements strictly less than data */ |
49 | for (l = list; l && range_compare(l->data, data) < 0; l = l->next) { |
50 | } |
51 | |
52 | if (!l || range_compare(l->data, data) > 0) { |
53 | /* Rest of the list (if any) is strictly greater than @data */ |
54 | return g_list_insert_before(list, l, data); |
55 | } |
56 | |
57 | /* Current list element overlaps @data, merge the two */ |
58 | range_extend(l->data, data); |
59 | g_free(data); |
60 | |
61 | /* Merge any subsequent list elements that now also overlap */ |
62 | while (l->next && range_compare(l->data, l->next->data) == 0) { |
63 | GList *new_l; |
64 | |
65 | range_extend(l->data, l->next->data); |
66 | g_free(l->next->data); |
67 | new_l = g_list_delete_link(list, l->next); |
68 | assert(new_l == list); |
69 | } |
70 | |
71 | return list; |
72 | } |
73 | |