1 /* 2 * Kernel page table mapping 3 * 4 * Copyright (C) 2015 ARM Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #ifndef __ASM_KERNEL_PGTABLE_H 20 #define __ASM_KERNEL_PGTABLE_H 21 22 23 /* 24 * The linear mapping and the start of memory are both 2M aligned (per 25 * the arm64 booting.txt requirements). Hence we can use section mapping 26 * with 4K (section size = 2M) but not with 16K (section size = 32M) or 27 * 64K (section size = 512M). 28 */ 29 #ifdef CONFIG_ARM64_4K_PAGES 30 #define ARM64_SWAPPER_USES_SECTION_MAPS 1 31 #else 32 #define ARM64_SWAPPER_USES_SECTION_MAPS 0 33 #endif 34 35 /* 36 * The idmap and swapper page tables need some space reserved in the kernel 37 * image. Both require pgd, pud (4 levels only) and pmd tables to (section) 38 * map the kernel. With the 64K page configuration, swapper and idmap need to 39 * map to pte level. The swapper also maps the FDT (see __create_page_tables 40 * for more information). Note that the number of ID map translation levels 41 * could be increased on the fly if system RAM is out of reach for the default 42 * VA range, so pages required to map highest possible PA are reserved in all 43 * cases. 44 */ 45 #if ARM64_SWAPPER_USES_SECTION_MAPS 46 #define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1) 47 #define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT) - 1) 48 #else 49 #define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS) 50 #define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT)) 51 #endif 52 53 #define SWAPPER_DIR_SIZE (SWAPPER_PGTABLE_LEVELS * PAGE_SIZE) 54 #define IDMAP_DIR_SIZE (IDMAP_PGTABLE_LEVELS * PAGE_SIZE) 55 56 /* Initial memory map size */ 57 #if ARM64_SWAPPER_USES_SECTION_MAPS 58 #define SWAPPER_BLOCK_SHIFT SECTION_SHIFT 59 #define SWAPPER_BLOCK_SIZE SECTION_SIZE 60 #define SWAPPER_TABLE_SHIFT PUD_SHIFT 61 #else 62 #define SWAPPER_BLOCK_SHIFT PAGE_SHIFT 63 #define SWAPPER_BLOCK_SIZE PAGE_SIZE 64 #define SWAPPER_TABLE_SHIFT PMD_SHIFT 65 #endif 66 67 /* The size of the initial kernel direct mapping */ 68 #define SWAPPER_INIT_MAP_SIZE (_AC(1, UL) << SWAPPER_TABLE_SHIFT) 69 70 /* 71 * Initial memory map attributes. 72 */ 73 #define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) 74 #define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) 75 76 #if ARM64_SWAPPER_USES_SECTION_MAPS 77 #define SWAPPER_MM_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) 78 #else 79 #define SWAPPER_MM_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) 80 #endif 81 82 83 #endif /* __ASM_KERNEL_PGTABLE_H */ 84