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kernel_pgtable.h 3.43 KiB
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/**
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 * @file kernel_pgtable.h
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 * @author jihongbin (longma@orbbec.com)
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 * @brief
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 * @version 0.1
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 * @date 2022-05-07
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 * @copyright Copyright (c) {2015-2021} Orbbec
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 *
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 */
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#ifndef __ASM_KERNEL_PGTABLE_H
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#define __ASM_KERNEL_PGTABLE_H
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#include <asm/pgtable_hwdef.h>
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/*
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 * The linear mapping and the start of memory are both 2M aligned (per
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 * the arm64 booting.txt requirements). Hence we can use section mapping
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 * with 4K (section size = 2M) but not with 16K (section size = 32M) or
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 * 64K (section size = 512M).
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 */
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#ifdef CONFIG_ARM64_4K_PAGES
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#define ARM64_KERNEL_USES_PMD_MAPS 1
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#else
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#define ARM64_KERNEL_USES_PMD_MAPS 0
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#endif
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/*
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 * The idmap and swapper page tables need some space reserved in the kernel
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 * image. Both require pgd, pud (4 levels only) and pmd tables to (section)
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 * map the kernel. With the 64K page configuration, swapper and idmap need to
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 * map to pte level. The swapper also maps the FDT (see __create_page_tables
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 * for more information). Note that the number of ID map translation levels
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 * could be increased on the fly if system RAM is out of reach for the default
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 * VA range, so pages required to map highest possible PA are reserved in all
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 * cases.
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 */
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#if ARM64_KERNEL_USES_PMD_MAPS
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#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1)
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#define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT) - 1)
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#else
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#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS)
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#define IDMAP_PGTABLE_LEVELS (ARM64_HW_PGTABLE_LEVELS(PHYS_MASK_SHIFT))
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#endif
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#define EARLY_KASLR (0)
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#define EARLY_ENTRIES(vstart, vend, shift)                                     \
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	((((vend)-1) >> (shift)) - ((vstart) >> (shift)) + 1 + EARLY_KASLR)
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#define EARLY_PGDS(vstart, vend) (EARLY_ENTRIES(vstart, vend, PGDIR_SHIFT))
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#if SWAPPER_PGTABLE_LEVELS > 3
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#define EARLY_PUDS(vstart, vend) (EARLY_ENTRIES(vstart, vend, PUD_SHIFT))
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#else
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#define EARLY_PUDS(vstart, vend) (0)
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#endif
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#if SWAPPER_PGTABLE_LEVELS > 2
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#define EARLY_PMDS(vstart, vend)                                               \
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	(EARLY_ENTRIES(vstart, vend, SWAPPER_TABLE_SHIFT))
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#else
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#define EARLY_PMDS(vstart, vend) (0)
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#endif
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#define EARLY_PAGES(vstart, vend)                                              \
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	(1 /* PGDIR page */                                                    \
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	 + EARLY_PGDS((vstart),                                                \
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		      (vend)) /* each PGDIR needs a next level page table */   \
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	 + EARLY_PUDS((vstart),                                                \
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(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, __kimage_end)) #define IDMAP_DIR_SIZE (IDMAP_PGTABLE_LEVELS * PAGE_SIZE) /* Initial memory map size */ #if ARM64_KERNEL_USES_PMD_MAPS #define SWAPPER_BLOCK_SHIFT PMD_SHIFT #define SWAPPER_BLOCK_SIZE PMD_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 /* * 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_KERNEL_USES_PMD_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