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Diffstat (limited to 'arch/arm64/include/asm/kernel-pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/kernel-pgtable.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h new file mode 100644 index 000000000000..a459714ee29e --- /dev/null +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -0,0 +1,83 @@ +/* + * Kernel page table mapping + * + * Copyright (C) 2015 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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/>. + */ + +#ifndef __ASM_KERNEL_PGTABLE_H +#define __ASM_KERNEL_PGTABLE_H + + +/* + * The linear mapping and the start of memory are both 2M aligned (per + * the arm64 booting.txt requirements). Hence we can use section mapping + * with 4K (section size = 2M) but not with 16K (section size = 32M) or + * 64K (section size = 512M). + */ +#ifdef CONFIG_ARM64_4K_PAGES +#define ARM64_SWAPPER_USES_SECTION_MAPS 1 +#else +#define ARM64_SWAPPER_USES_SECTION_MAPS 0 +#endif + +/* + * The idmap and swapper page tables need some space reserved in the kernel + * image. Both require pgd, pud (4 levels only) and pmd tables to (section) + * map the kernel. With the 64K page configuration, swapper and idmap need to + * map to pte level. The swapper also maps the FDT (see __create_page_tables + * for more information). Note that the number of ID map translation levels + * could be increased on the fly if system RAM is out of reach for the default + * VA range, so pages required to map highest possible PA are reserved in all + * cases. + */ +#if ARM64_SWAPPER_USES_SECTION_MAPS +#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1) +#define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT) - 1) +#else +#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS) +#define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT)) +#endif + +#define SWAPPER_DIR_SIZE (SWAPPER_PGTABLE_LEVELS * PAGE_SIZE) +#define IDMAP_DIR_SIZE (IDMAP_PGTABLE_LEVELS * PAGE_SIZE) + +/* Initial memory map size */ +#if ARM64_SWAPPER_USES_SECTION_MAPS +#define SWAPPER_BLOCK_SHIFT SECTION_SHIFT +#define SWAPPER_BLOCK_SIZE SECTION_SIZE +#define SWAPPER_TABLE_SHIFT PUD_SHIFT +#else +#define SWAPPER_BLOCK_SHIFT PAGE_SHIFT +#define SWAPPER_BLOCK_SIZE PAGE_SIZE +#define SWAPPER_TABLE_SHIFT PMD_SHIFT +#endif + +/* The size of the initial kernel direct mapping */ +#define SWAPPER_INIT_MAP_SIZE (_AC(1, UL) << SWAPPER_TABLE_SHIFT) + +/* + * Initial memory map attributes. + */ +#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) +#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) + +#if ARM64_SWAPPER_USES_SECTION_MAPS +#define SWAPPER_MM_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) +#else +#define SWAPPER_MM_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS) +#endif + + +#endif /* __ASM_KERNEL_PGTABLE_H */ |