| 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/target-info-impl.h" |
| 24 | #include "exec/page-vary.h" |
| 25 | |
| 26 | /* WARNING: This file must *not* be complied with -flto. */ |
| 27 | |
| 28 | TargetPageBits target_page; |
| 29 | |
| 30 | bool set_preferred_target_page_bits(int bits) |
| 31 | { |
| 32 | const TargetInfo *ti = target_info(); |
| 33 | |
| 34 | assert(bits >= TARGET_PAGE_BITS_MIN); |
| 35 | if (ti->page_bits_vary) { |
| 36 | |
| 37 | /* |
| 38 | * The target page size is the lowest common denominator for all |
| 39 | * the CPUs in the system, so we can only make it smaller, never |
| 40 | * larger. And we can't make it smaller once we've committed to |
| 41 | * a particular size. |
| 42 | */ |
| 43 | if (target_page.bits == 0 || target_page.bits > bits) { |
| 44 | if (target_page.decided) { |
| 45 | return false; |
| 46 | } |
| 47 | target_page.bits = bits; |
| 48 | } |
| 49 | } |
| 50 | return true; |
| 51 | } |
| 52 | |
| 53 | void finalize_target_page_bits(void) |
| 54 | { |
| 55 | int bits = target_page.bits; |
| 56 | |
| 57 | if (bits == 0) { |
| 58 | const TargetInfo *ti = target_info(); |
| 59 | |
| 60 | bits = ti->page_bits_init; |
| 61 | assert(bits != 0); |
| 62 | target_page.bits = bits; |
| 63 | } |
| 64 | |
| 65 | target_page.mask = -1ull << bits; |
| 66 | target_page.decided = true; |
| 67 | } |