85 lines
2.3 KiB
C
85 lines
2.3 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_PGTABLE_32_H
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#define _ASM_X86_PGTABLE_32_H
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#include <asm/pgtable_32_types.h>
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/*
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* The Linux memory management assumes a three-level page table setup. On
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* the i386, we use that, but "fold" the mid level into the top-level page
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* table, so that we physically have the same two-level page table as the
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* i386 mmu expects.
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*
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* This file contains the functions and defines necessary to modify and use
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* the i386 page table tree.
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*/
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#ifndef __ASSEMBLY__
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#include <asm/processor.h>
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#include <linux/threads.h>
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#include <asm/paravirt.h>
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#include <linux/bitops.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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struct mm_struct;
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struct vm_area_struct;
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extern pgd_t swapper_pg_dir[1024];
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extern pgd_t initial_page_table[1024];
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extern pmd_t initial_pg_pmd[];
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void paging_init(void);
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void sync_initial_page_table(void);
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#ifdef CONFIG_X86_PAE
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# include <asm/pgtable-3level.h>
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#else
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# include <asm/pgtable-2level.h>
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#endif
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/* Clear a kernel PTE and flush it from the TLB */
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#define kpte_clear_flush(ptep, vaddr) \
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do { \
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pte_clear(&init_mm, (vaddr), (ptep)); \
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flush_tlb_one_kernel((vaddr)); \
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} while (0)
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#endif /* !__ASSEMBLY__ */
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/*
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* kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM
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*/
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#ifdef CONFIG_FLATMEM
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#define kern_addr_valid(addr) (1)
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#else
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#define kern_addr_valid(kaddr) (0)
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#endif
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/*
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* This is used to calculate the .brk reservation for initial pagetables.
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* Enough space is reserved to allocate pagetables sufficient to cover all
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* of LOWMEM_PAGES, which is an upper bound on the size of the direct map of
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* lowmem.
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*
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* With PAE paging (PTRS_PER_PMD > 1), we allocate PTRS_PER_PGD == 4 pages for
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* the PMD's in addition to the pages required for the last level pagetables.
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*/
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#if PTRS_PER_PMD > 1
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#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
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#else
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#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
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#endif
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/*
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* Number of possible pages in the lowmem region.
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*
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* We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a
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* gas warning about overflowing shift count when gas has been compiled
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* with only a host target support using a 32-bit type for internal
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* representation.
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*/
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#define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))
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#endif /* _ASM_X86_PGTABLE_32_H */
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