blob: 9605ccfcbed9749dc8c2a665a037300c97981d28 [file] [log] [blame]
/*
* QEMU 64-bit address ranges
*
* Copyright (c) 2015-2016 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/range.h"
int range_compare(Range *a, Range *b)
{
assert(!range_is_empty(a) && !range_is_empty(b));
/* Careful, avoid wraparound */
if (b->lob && b->lob - 1 > a->upb) {
return -1;
}
if (a->lob && a->lob - 1 > b->upb) {
return 1;
}
return 0;
}
/* Insert @data into @list of ranges; caller no longer owns @data */
GList *range_list_insert(GList *list, Range *data)
{
GList *l;
assert(!range_is_empty(data));
/* Skip all list elements strictly less than data */
for (l = list; l && range_compare(l->data, data) < 0; l = l->next) {
}
if (!l || range_compare(l->data, data) > 0) {
/* Rest of the list (if any) is strictly greater than @data */
return g_list_insert_before(list, l, data);
}
/* Current list element overlaps @data, merge the two */
range_extend(l->data, data);
g_free(data);
/* Merge any subsequent list elements that now also overlap */
while (l->next && range_compare(l->data, l->next->data) == 0) {
GList *new_l;
range_extend(l->data, l->next->data);
g_free(l->next->data);
new_l = g_list_delete_link(list, l->next);
assert(new_l == list);
}
return list;
}
static inline
GList *append_new_range(GList *list, uint64_t lob, uint64_t upb)
{
Range *new = g_new0(Range, 1);
range_set_bounds(new, lob, upb);
return g_list_append(list, new);
}
void range_inverse_array(GList *in, GList **rev,
uint64_t low, uint64_t high)
{
Range *r, *rn;
GList *l = in, *out = *rev;
for (l = in; l && range_upb(l->data) < low; l = l->next) {
continue;
}
if (!l) {
out = append_new_range(out, low, high);
goto exit;
}
r = (Range *)l->data;
/* first range lob is greater than min, insert a first range */
if (range_lob(r) > low) {
out = append_new_range(out, low, MIN(range_lob(r) - 1, high));
}
/* insert a range inbetween each original range until we reach high */
for (; l->next; l = l->next) {
r = (Range *)l->data;
rn = (Range *)l->next->data;
if (range_lob(r) >= high) {
goto exit;
}
if (range_compare(r, rn)) {
out = append_new_range(out, range_upb(r) + 1,
MIN(range_lob(rn) - 1, high));
}
}
/* last range */
r = (Range *)l->data;
/* last range upb is less than max, insert a last range */
if (range_upb(r) < high) {
out = append_new_range(out, range_upb(r) + 1, high);
}
exit:
*rev = out;
}