LXR qemu/page-vary-common.c

   1/*
   2 * Variable page size handling -- target independent part.
   3 *
   4 *  Copyright (c) 2003 Fabrice Bellard
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2.1 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 Lesser General Public
  17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20#define IN_PAGE_VARY 1
  21
  22#include "qemu/osdep.h"
  23#include "qemu-common.h"
  24#include "exec/page-vary.h"
  25
  26/* WARNING: This file must *not* be complied with -flto. */
  27
  28TargetPageBits target_page;
  29
  30bool set_preferred_target_page_bits_common(int bits)
  31{
  32    /*
  33     * The target page size is the lowest common denominator for all
  34     * the CPUs in the system, so we can only make it smaller, never
  35     * larger. And we can't make it smaller once we've committed to
  36     * a particular size.
  37     */
  38    if (target_page.bits == 0 || target_page.bits > bits) {
  39        if (target_page.decided) {
  40            return false;
  41        }
  42        target_page.bits = bits;
  43    }
  44    return true;
  45}
  46
  47void finalize_target_page_bits_common(int min)
  48{
  49    if (target_page.bits == 0) {
  50        target_page.bits = min;
  51    }
  52    target_page.mask = -1ull << target_page.bits;
  53    target_page.decided = true;
  54}
  55