| /* SPDX-License-Identifier: GPL-2.0-only */ | |
| /* | |
| * Kernel page table mapping | |
| * | |
| * Copyright (C) 2015 ARM Ltd. | |
| */ | |
| #ifndef __ASM_KERNEL_PGTABLE_H | |
| #define __ASM_KERNEL_PGTABLE_H | |
| #include <asm/pgtable-hwdef.h> | |
| #include <asm/sparsemem.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 | |
| /* | |
| * If KASLR is enabled, then an offset K is added to the kernel address | |
| * space. The bottom 21 bits of this offset are zero to guarantee 2MB | |
| * alignment for PA and VA. | |
| * | |
| * For each pagetable level of the swapper, we know that the shift will | |
| * be larger than 21 (for the 4KB granule case we use section maps thus | |
| * the smallest shift is actually 30) thus there is the possibility that | |
| * KASLR can increase the number of pagetable entries by 1, so we make | |
| * room for this extra entry. | |
| * | |
| * Note KASLR cannot increase the number of required entries for a level | |
| * by more than one because it increments both the virtual start and end | |
| * addresses equally (the extra entry comes from the case where the end | |
| * address is just pushed over a boundary and the start address isn't). | |
| */ | |
| #ifdef CONFIG_RANDOMIZE_BASE | |
| #define EARLY_KASLR (1) | |
| #else | |
| #define EARLY_KASLR (0) | |
| #endif | |
| #define EARLY_ENTRIES(vstart, vend, shift) (((vend) >> (shift)) \ | |
| - ((vstart) >> (shift)) + 1 + EARLY_KASLR) | |
| #define EARLY_PGDS(vstart, vend) (EARLY_ENTRIES(vstart, vend, PGDIR_SHIFT)) | |
| #if SWAPPER_PGTABLE_LEVELS > 3 | |
| #define EARLY_PUDS(vstart, vend) (EARLY_ENTRIES(vstart, vend, PUD_SHIFT)) | |
| #else | |
| #define EARLY_PUDS(vstart, vend) (0) | |
| #endif | |
| #if SWAPPER_PGTABLE_LEVELS > 2 | |
| #define EARLY_PMDS(vstart, vend) (EARLY_ENTRIES(vstart, vend, SWAPPER_TABLE_SHIFT)) | |
| #else | |
| #define EARLY_PMDS(vstart, vend) (0) | |
| #endif | |
| #define EARLY_PAGES(vstart, vend) ( 1 /* PGDIR page */ \ | |
| + EARLY_PGDS((vstart), (vend)) /* each PGDIR needs a next level page table */ \ | |
| + EARLY_PUDS((vstart), (vend)) /* each PUD needs a next level page table */ \ | |
| + EARLY_PMDS((vstart), (vend))) /* each PMD needs a next level page table */ | |
| #define INIT_DIR_SIZE (PAGE_SIZE * EARLY_PAGES(KIMAGE_VADDR, _end)) | |
| #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 | |
| /* | |
| * To make optimal use of block mappings when laying out the linear | |
| * mapping, round down the base of physical memory to a size that can | |
| * be mapped efficiently, i.e., either PUD_SIZE (4k granule) or PMD_SIZE | |
| * (64k granule), or a multiple that can be mapped using contiguous bits | |
| * in the page tables: 32 * PMD_SIZE (16k granule) | |
| */ | |
| #if defined(CONFIG_ARM64_4K_PAGES) | |
| #define ARM64_MEMSTART_SHIFT PUD_SHIFT | |
| #elif defined(CONFIG_ARM64_16K_PAGES) | |
| #define ARM64_MEMSTART_SHIFT (PMD_SHIFT + 5) | |
| #else | |
| #define ARM64_MEMSTART_SHIFT PMD_SHIFT | |
| #endif | |
| /* | |
| * sparsemem vmemmap imposes an additional requirement on the alignment of | |
| * memstart_addr, due to the fact that the base of the vmemmap region | |
| * has a direct correspondence, and needs to appear sufficiently aligned | |
| * in the virtual address space. | |
| */ | |
| #if defined(CONFIG_SPARSEMEM_VMEMMAP) && ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS | |
| #define ARM64_MEMSTART_ALIGN (1UL << SECTION_SIZE_BITS) | |
| #else | |
| #define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT) | |
| #endif | |
| #endif /* __ASM_KERNEL_PGTABLE_H */ |