1721 строка
47 KiB
C
1721 строка
47 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_PGTABLE_H
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#define _LINUX_PGTABLE_H
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#include <linux/pfn.h>
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#include <asm/pgtable.h>
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_MMU
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#include <linux/mm_types.h>
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#include <linux/bug.h>
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#include <linux/errno.h>
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#include <asm-generic/pgtable_uffd.h>
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#include <linux/page_table_check.h>
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#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
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defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
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#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
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#endif
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/*
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* On almost all architectures and configurations, 0 can be used as the
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* upper ceiling to free_pgtables(): on many architectures it has the same
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* effect as using TASK_SIZE. However, there is one configuration which
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* must impose a more careful limit, to avoid freeing kernel pgtables.
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*/
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#ifndef USER_PGTABLES_CEILING
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#define USER_PGTABLES_CEILING 0UL
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#endif
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/*
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* This defines the first usable user address. Platforms
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* can override its value with custom FIRST_USER_ADDRESS
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* defined in their respective <asm/pgtable.h>.
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*/
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#ifndef FIRST_USER_ADDRESS
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#define FIRST_USER_ADDRESS 0UL
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#endif
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/*
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* This defines the generic helper for accessing PMD page
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* table page. Although platforms can still override this
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* via their respective <asm/pgtable.h>.
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*/
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#ifndef pmd_pgtable
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif
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/*
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* A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
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*
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* The pXx_index() functions return the index of the entry in the page
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* table page which would control the given virtual address
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*
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* As these functions may be used by the same code for different levels of
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* the page table folding, they are always available, regardless of
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* CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
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* because in such cases PTRS_PER_PxD equals 1.
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*/
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static inline unsigned long pte_index(unsigned long address)
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{
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return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
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}
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#define pte_index pte_index
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#ifndef pmd_index
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static inline unsigned long pmd_index(unsigned long address)
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{
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return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
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}
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#define pmd_index pmd_index
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#endif
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#ifndef pud_index
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static inline unsigned long pud_index(unsigned long address)
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{
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return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
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}
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#define pud_index pud_index
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#endif
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#ifndef pgd_index
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/* Must be a compile-time constant, so implement it as a macro */
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#define pgd_index(a) (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
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#endif
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#ifndef pte_offset_kernel
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static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
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{
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return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
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}
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#define pte_offset_kernel pte_offset_kernel
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#endif
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#if defined(CONFIG_HIGHPTE)
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#define pte_offset_map(dir, address) \
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((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
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pte_index((address)))
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#define pte_unmap(pte) kunmap_atomic((pte))
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#else
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#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
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#define pte_unmap(pte) ((void)(pte)) /* NOP */
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#endif
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/* Find an entry in the second-level page table.. */
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#ifndef pmd_offset
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static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
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{
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return pud_pgtable(*pud) + pmd_index(address);
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}
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#define pmd_offset pmd_offset
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#endif
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#ifndef pud_offset
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static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
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{
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return p4d_pgtable(*p4d) + pud_index(address);
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}
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#define pud_offset pud_offset
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#endif
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static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
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{
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return (pgd + pgd_index(address));
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};
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/*
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* a shortcut to get a pgd_t in a given mm
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*/
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#ifndef pgd_offset
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#define pgd_offset(mm, address) pgd_offset_pgd((mm)->pgd, (address))
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#endif
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/*
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* a shortcut which implies the use of the kernel's pgd, instead
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* of a process's
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*/
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#ifndef pgd_offset_k
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#define pgd_offset_k(address) pgd_offset(&init_mm, (address))
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#endif
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/*
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* In many cases it is known that a virtual address is mapped at PMD or PTE
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* level, so instead of traversing all the page table levels, we can get a
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* pointer to the PMD entry in user or kernel page table or translate a virtual
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* address to the pointer in the PTE in the kernel page tables with simple
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* helpers.
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*/
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static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
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{
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return pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, va), va), va), va);
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}
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static inline pmd_t *pmd_off_k(unsigned long va)
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{
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return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
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}
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static inline pte_t *virt_to_kpte(unsigned long vaddr)
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{
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pmd_t *pmd = pmd_off_k(vaddr);
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return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr);
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}
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#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
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extern int ptep_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep,
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pte_t entry, int dirty);
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#endif
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#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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extern int pmdp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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pmd_t entry, int dirty);
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extern int pudp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pud_t *pudp,
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pud_t entry, int dirty);
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#else
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static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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pmd_t entry, int dirty)
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{
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BUILD_BUG();
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return 0;
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}
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static inline int pudp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pud_t *pudp,
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pud_t entry, int dirty)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
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static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pte_t *ptep)
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{
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pte_t pte = *ptep;
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int r = 1;
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if (!pte_young(pte))
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r = 0;
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else
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set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
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return r;
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}
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#endif
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#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd = *pmdp;
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int r = 1;
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if (!pmd_young(pmd))
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r = 0;
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else
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set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
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return r;
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}
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#else
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static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pmd_t *pmdp)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
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int ptep_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep);
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#endif
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#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp);
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#else
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/*
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* Despite relevant to THP only, this API is called from generic rmap code
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* under PageTransHuge(), hence needs a dummy implementation for !THP
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*/
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static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
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static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
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unsigned long address,
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pte_t *ptep)
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{
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pte_t pte = *ptep;
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pte_clear(mm, address, ptep);
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page_table_check_pte_clear(mm, address, pte);
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return pte;
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}
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#endif
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static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep)
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{
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ptep_get_and_clear(mm, addr, ptep);
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}
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#ifndef __HAVE_ARCH_PTEP_GET
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static inline pte_t ptep_get(pte_t *ptep)
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{
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return READ_ONCE(*ptep);
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}
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#endif
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#ifdef CONFIG_GUP_GET_PTE_LOW_HIGH
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/*
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* WARNING: only to be used in the get_user_pages_fast() implementation.
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*
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* With get_user_pages_fast(), we walk down the pagetables without taking any
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* locks. For this we would like to load the pointers atomically, but sometimes
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* that is not possible (e.g. without expensive cmpxchg8b on x86_32 PAE). What
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* we do have is the guarantee that a PTE will only either go from not present
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* to present, or present to not present or both -- it will not switch to a
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* completely different present page without a TLB flush in between; something
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* that we are blocking by holding interrupts off.
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*
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* Setting ptes from not present to present goes:
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*
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* ptep->pte_high = h;
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* smp_wmb();
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* ptep->pte_low = l;
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*
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* And present to not present goes:
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*
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* ptep->pte_low = 0;
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* smp_wmb();
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* ptep->pte_high = 0;
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*
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* We must ensure here that the load of pte_low sees 'l' IFF pte_high sees 'h'.
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* We load pte_high *after* loading pte_low, which ensures we don't see an older
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* value of pte_high. *Then* we recheck pte_low, which ensures that we haven't
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* picked up a changed pte high. We might have gotten rubbish values from
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* pte_low and pte_high, but we are guaranteed that pte_low will not have the
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* present bit set *unless* it is 'l'. Because get_user_pages_fast() only
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* operates on present ptes we're safe.
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*/
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static inline pte_t ptep_get_lockless(pte_t *ptep)
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{
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pte_t pte;
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do {
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pte.pte_low = ptep->pte_low;
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smp_rmb();
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pte.pte_high = ptep->pte_high;
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smp_rmb();
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} while (unlikely(pte.pte_low != ptep->pte_low));
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return pte;
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}
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#else /* CONFIG_GUP_GET_PTE_LOW_HIGH */
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/*
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* We require that the PTE can be read atomically.
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*/
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static inline pte_t ptep_get_lockless(pte_t *ptep)
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{
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return ptep_get(ptep);
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}
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#endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
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static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
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unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd = *pmdp;
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pmd_clear(pmdp);
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page_table_check_pmd_clear(mm, address, pmd);
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return pmd;
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}
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#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
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#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
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static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
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unsigned long address,
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pud_t *pudp)
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{
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pud_t pud = *pudp;
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pud_clear(pudp);
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page_table_check_pud_clear(mm, address, pud);
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return pud;
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}
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#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
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static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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int full)
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{
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return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
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}
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#endif
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#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
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static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
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unsigned long address, pud_t *pudp,
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int full)
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{
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return pudp_huge_get_and_clear(mm, address, pudp);
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}
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#endif
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
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static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
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unsigned long address, pte_t *ptep,
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int full)
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{
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pte_t pte;
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pte = ptep_get_and_clear(mm, address, ptep);
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return pte;
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}
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#endif
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/*
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* If two threads concurrently fault at the same page, the thread that
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* won the race updates the PTE and its local TLB/Cache. The other thread
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* gives up, simply does nothing, and continues; on architectures where
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* software can update TLB, local TLB can be updated here to avoid next page
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* fault. This function updates TLB only, do nothing with cache or others.
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* It is the difference with function update_mmu_cache.
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*/
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#ifndef __HAVE_ARCH_UPDATE_MMU_TLB
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static inline void update_mmu_tlb(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep)
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{
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}
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#define __HAVE_ARCH_UPDATE_MMU_TLB
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#endif
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/*
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* Some architectures may be able to avoid expensive synchronization
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* primitives when modifications are made to PTE's which are already
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* not present, or in the process of an address space destruction.
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*/
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#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
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static inline void pte_clear_not_present_full(struct mm_struct *mm,
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unsigned long address,
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pte_t *ptep,
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int full)
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{
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pte_clear(mm, address, ptep);
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}
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
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extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
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unsigned long address,
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pte_t *ptep);
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#endif
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#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
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extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
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unsigned long address,
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pmd_t *pmdp);
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extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
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unsigned long address,
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pud_t *pudp);
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#endif
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#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
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struct mm_struct;
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static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
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{
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pte_t old_pte = *ptep;
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set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
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}
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#endif
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/*
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* On some architectures hardware does not set page access bit when accessing
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* memory page, it is responsibility of software setting this bit. It brings
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* out extra page fault penalty to track page access bit. For optimization page
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* access bit can be set during all page fault flow on these arches.
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* To be differentiate with macro pte_mkyoung, this macro is used on platforms
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* where software maintains page access bit.
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*/
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#ifndef pte_sw_mkyoung
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static inline pte_t pte_sw_mkyoung(pte_t pte)
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{
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return pte;
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}
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#define pte_sw_mkyoung pte_sw_mkyoung
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#endif
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#ifndef pte_savedwrite
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#define pte_savedwrite pte_write
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#endif
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#ifndef pte_mk_savedwrite
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#define pte_mk_savedwrite pte_mkwrite
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#endif
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#ifndef pte_clear_savedwrite
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#define pte_clear_savedwrite pte_wrprotect
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#endif
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|
|
#ifndef pmd_savedwrite
|
|
#define pmd_savedwrite pmd_write
|
|
#endif
|
|
|
|
#ifndef pmd_mk_savedwrite
|
|
#define pmd_mk_savedwrite pmd_mkwrite
|
|
#endif
|
|
|
|
#ifndef pmd_clear_savedwrite
|
|
#define pmd_clear_savedwrite pmd_wrprotect
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
|
|
unsigned long address, pmd_t *pmdp)
|
|
{
|
|
pmd_t old_pmd = *pmdp;
|
|
set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
|
|
}
|
|
#else
|
|
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
|
|
unsigned long address, pmd_t *pmdp)
|
|
{
|
|
BUILD_BUG();
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
#endif
|
|
#ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
|
|
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
|
|
static inline void pudp_set_wrprotect(struct mm_struct *mm,
|
|
unsigned long address, pud_t *pudp)
|
|
{
|
|
pud_t old_pud = *pudp;
|
|
|
|
set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
|
|
}
|
|
#else
|
|
static inline void pudp_set_wrprotect(struct mm_struct *mm,
|
|
unsigned long address, pud_t *pudp)
|
|
{
|
|
BUILD_BUG();
|
|
}
|
|
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
|
|
#endif
|
|
|
|
#ifndef pmdp_collapse_flush
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
|
|
unsigned long address, pmd_t *pmdp);
|
|
#else
|
|
static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
|
|
unsigned long address,
|
|
pmd_t *pmdp)
|
|
{
|
|
BUILD_BUG();
|
|
return *pmdp;
|
|
}
|
|
#define pmdp_collapse_flush pmdp_collapse_flush
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
|
|
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
|
|
pgtable_t pgtable);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
|
|
extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* This is an implementation of pmdp_establish() that is only suitable for an
|
|
* architecture that doesn't have hardware dirty/accessed bits. In this case we
|
|
* can't race with CPU which sets these bits and non-atomic approach is fine.
|
|
*/
|
|
static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
|
|
unsigned long address, pmd_t *pmdp, pmd_t pmd)
|
|
{
|
|
pmd_t old_pmd = *pmdp;
|
|
set_pmd_at(vma->vm_mm, address, pmdp, pmd);
|
|
return old_pmd;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PMDP_INVALIDATE
|
|
extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
|
|
pmd_t *pmdp);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PMDP_INVALIDATE_AD
|
|
|
|
/*
|
|
* pmdp_invalidate_ad() invalidates the PMD while changing a transparent
|
|
* hugepage mapping in the page tables. This function is similar to
|
|
* pmdp_invalidate(), but should only be used if the access and dirty bits would
|
|
* not be cleared by the software in the new PMD value. The function ensures
|
|
* that hardware changes of the access and dirty bits updates would not be lost.
|
|
*
|
|
* Doing so can allow in certain architectures to avoid a TLB flush in most
|
|
* cases. Yet, another TLB flush might be necessary later if the PMD update
|
|
* itself requires such flush (e.g., if protection was set to be stricter). Yet,
|
|
* even when a TLB flush is needed because of the update, the caller may be able
|
|
* to batch these TLB flushing operations, so fewer TLB flush operations are
|
|
* needed.
|
|
*/
|
|
extern pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma,
|
|
unsigned long address, pmd_t *pmdp);
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PTE_SAME
|
|
static inline int pte_same(pte_t pte_a, pte_t pte_b)
|
|
{
|
|
return pte_val(pte_a) == pte_val(pte_b);
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PTE_UNUSED
|
|
/*
|
|
* Some architectures provide facilities to virtualization guests
|
|
* so that they can flag allocated pages as unused. This allows the
|
|
* host to transparently reclaim unused pages. This function returns
|
|
* whether the pte's page is unused.
|
|
*/
|
|
static inline int pte_unused(pte_t pte)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifndef pte_access_permitted
|
|
#define pte_access_permitted(pte, write) \
|
|
(pte_present(pte) && (!(write) || pte_write(pte)))
|
|
#endif
|
|
|
|
#ifndef pmd_access_permitted
|
|
#define pmd_access_permitted(pmd, write) \
|
|
(pmd_present(pmd) && (!(write) || pmd_write(pmd)))
|
|
#endif
|
|
|
|
#ifndef pud_access_permitted
|
|
#define pud_access_permitted(pud, write) \
|
|
(pud_present(pud) && (!(write) || pud_write(pud)))
|
|
#endif
|
|
|
|
#ifndef p4d_access_permitted
|
|
#define p4d_access_permitted(p4d, write) \
|
|
(p4d_present(p4d) && (!(write) || p4d_write(p4d)))
|
|
#endif
|
|
|
|
#ifndef pgd_access_permitted
|
|
#define pgd_access_permitted(pgd, write) \
|
|
(pgd_present(pgd) && (!(write) || pgd_write(pgd)))
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PMD_SAME
|
|
static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
|
|
{
|
|
return pmd_val(pmd_a) == pmd_val(pmd_b);
|
|
}
|
|
|
|
static inline int pud_same(pud_t pud_a, pud_t pud_b)
|
|
{
|
|
return pud_val(pud_a) == pud_val(pud_b);
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_P4D_SAME
|
|
static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
|
|
{
|
|
return p4d_val(p4d_a) == p4d_val(p4d_b);
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PGD_SAME
|
|
static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b)
|
|
{
|
|
return pgd_val(pgd_a) == pgd_val(pgd_b);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Use set_p*_safe(), and elide TLB flushing, when confident that *no*
|
|
* TLB flush will be required as a result of the "set". For example, use
|
|
* in scenarios where it is known ahead of time that the routine is
|
|
* setting non-present entries, or re-setting an existing entry to the
|
|
* same value. Otherwise, use the typical "set" helpers and flush the
|
|
* TLB.
|
|
*/
|
|
#define set_pte_safe(ptep, pte) \
|
|
({ \
|
|
WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
|
|
set_pte(ptep, pte); \
|
|
})
|
|
|
|
#define set_pmd_safe(pmdp, pmd) \
|
|
({ \
|
|
WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
|
|
set_pmd(pmdp, pmd); \
|
|
})
|
|
|
|
#define set_pud_safe(pudp, pud) \
|
|
({ \
|
|
WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
|
|
set_pud(pudp, pud); \
|
|
})
|
|
|
|
#define set_p4d_safe(p4dp, p4d) \
|
|
({ \
|
|
WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
|
|
set_p4d(p4dp, p4d); \
|
|
})
|
|
|
|
#define set_pgd_safe(pgdp, pgd) \
|
|
({ \
|
|
WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
|
|
set_pgd(pgdp, pgd); \
|
|
})
|
|
|
|
#ifndef __HAVE_ARCH_DO_SWAP_PAGE
|
|
/*
|
|
* Some architectures support metadata associated with a page. When a
|
|
* page is being swapped out, this metadata must be saved so it can be
|
|
* restored when the page is swapped back in. SPARC M7 and newer
|
|
* processors support an ADI (Application Data Integrity) tag for the
|
|
* page as metadata for the page. arch_do_swap_page() can restore this
|
|
* metadata when a page is swapped back in.
|
|
*/
|
|
static inline void arch_do_swap_page(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t pte, pte_t oldpte)
|
|
{
|
|
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_UNMAP_ONE
|
|
/*
|
|
* Some architectures support metadata associated with a page. When a
|
|
* page is being swapped out, this metadata must be saved so it can be
|
|
* restored when the page is swapped back in. SPARC M7 and newer
|
|
* processors support an ADI (Application Data Integrity) tag for the
|
|
* page as metadata for the page. arch_unmap_one() can save this
|
|
* metadata on a swap-out of a page.
|
|
*/
|
|
static inline int arch_unmap_one(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t orig_pte)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Allow architectures to preserve additional metadata associated with
|
|
* swapped-out pages. The corresponding __HAVE_ARCH_SWAP_* macros and function
|
|
* prototypes must be defined in the arch-specific asm/pgtable.h file.
|
|
*/
|
|
#ifndef __HAVE_ARCH_PREPARE_TO_SWAP
|
|
static inline int arch_prepare_to_swap(struct page *page)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_SWAP_INVALIDATE
|
|
static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
|
|
{
|
|
}
|
|
|
|
static inline void arch_swap_invalidate_area(int type)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_SWAP_RESTORE
|
|
static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
|
|
#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_MOVE_PTE
|
|
#define move_pte(pte, prot, old_addr, new_addr) (pte)
|
|
#endif
|
|
|
|
#ifndef pte_accessible
|
|
# define pte_accessible(mm, pte) ((void)(pte), 1)
|
|
#endif
|
|
|
|
#ifndef flush_tlb_fix_spurious_fault
|
|
#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
|
|
#endif
|
|
|
|
/*
|
|
* When walking page tables, get the address of the next boundary,
|
|
* or the end address of the range if that comes earlier. Although no
|
|
* vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
|
|
*/
|
|
|
|
#define pgd_addr_end(addr, end) \
|
|
({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
|
|
(__boundary - 1 < (end) - 1)? __boundary: (end); \
|
|
})
|
|
|
|
#ifndef p4d_addr_end
|
|
#define p4d_addr_end(addr, end) \
|
|
({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
|
|
(__boundary - 1 < (end) - 1)? __boundary: (end); \
|
|
})
|
|
#endif
|
|
|
|
#ifndef pud_addr_end
|
|
#define pud_addr_end(addr, end) \
|
|
({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
|
|
(__boundary - 1 < (end) - 1)? __boundary: (end); \
|
|
})
|
|
#endif
|
|
|
|
#ifndef pmd_addr_end
|
|
#define pmd_addr_end(addr, end) \
|
|
({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
|
|
(__boundary - 1 < (end) - 1)? __boundary: (end); \
|
|
})
|
|
#endif
|
|
|
|
/*
|
|
* When walking page tables, we usually want to skip any p?d_none entries;
|
|
* and any p?d_bad entries - reporting the error before resetting to none.
|
|
* Do the tests inline, but report and clear the bad entry in mm/memory.c.
|
|
*/
|
|
void pgd_clear_bad(pgd_t *);
|
|
|
|
#ifndef __PAGETABLE_P4D_FOLDED
|
|
void p4d_clear_bad(p4d_t *);
|
|
#else
|
|
#define p4d_clear_bad(p4d) do { } while (0)
|
|
#endif
|
|
|
|
#ifndef __PAGETABLE_PUD_FOLDED
|
|
void pud_clear_bad(pud_t *);
|
|
#else
|
|
#define pud_clear_bad(p4d) do { } while (0)
|
|
#endif
|
|
|
|
void pmd_clear_bad(pmd_t *);
|
|
|
|
static inline int pgd_none_or_clear_bad(pgd_t *pgd)
|
|
{
|
|
if (pgd_none(*pgd))
|
|
return 1;
|
|
if (unlikely(pgd_bad(*pgd))) {
|
|
pgd_clear_bad(pgd);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline int p4d_none_or_clear_bad(p4d_t *p4d)
|
|
{
|
|
if (p4d_none(*p4d))
|
|
return 1;
|
|
if (unlikely(p4d_bad(*p4d))) {
|
|
p4d_clear_bad(p4d);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline int pud_none_or_clear_bad(pud_t *pud)
|
|
{
|
|
if (pud_none(*pud))
|
|
return 1;
|
|
if (unlikely(pud_bad(*pud))) {
|
|
pud_clear_bad(pud);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline int pmd_none_or_clear_bad(pmd_t *pmd)
|
|
{
|
|
if (pmd_none(*pmd))
|
|
return 1;
|
|
if (unlikely(pmd_bad(*pmd))) {
|
|
pmd_clear_bad(pmd);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
/*
|
|
* Get the current pte state, but zero it out to make it
|
|
* non-present, preventing the hardware from asynchronously
|
|
* updating it.
|
|
*/
|
|
return ptep_get_and_clear(vma->vm_mm, addr, ptep);
|
|
}
|
|
|
|
static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep, pte_t pte)
|
|
{
|
|
/*
|
|
* The pte is non-present, so there's no hardware state to
|
|
* preserve.
|
|
*/
|
|
set_pte_at(vma->vm_mm, addr, ptep, pte);
|
|
}
|
|
|
|
#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
|
|
/*
|
|
* Start a pte protection read-modify-write transaction, which
|
|
* protects against asynchronous hardware modifications to the pte.
|
|
* The intention is not to prevent the hardware from making pte
|
|
* updates, but to prevent any updates it may make from being lost.
|
|
*
|
|
* This does not protect against other software modifications of the
|
|
* pte; the appropriate pte lock must be held over the transaction.
|
|
*
|
|
* Note that this interface is intended to be batchable, meaning that
|
|
* ptep_modify_prot_commit may not actually update the pte, but merely
|
|
* queue the update to be done at some later time. The update must be
|
|
* actually committed before the pte lock is released, however.
|
|
*/
|
|
static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
return __ptep_modify_prot_start(vma, addr, ptep);
|
|
}
|
|
|
|
/*
|
|
* Commit an update to a pte, leaving any hardware-controlled bits in
|
|
* the PTE unmodified.
|
|
*/
|
|
static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep, pte_t old_pte, pte_t pte)
|
|
{
|
|
__ptep_modify_prot_commit(vma, addr, ptep, pte);
|
|
}
|
|
#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
|
|
#endif /* CONFIG_MMU */
|
|
|
|
/*
|
|
* No-op macros that just return the current protection value. Defined here
|
|
* because these macros can be used even if CONFIG_MMU is not defined.
|
|
*/
|
|
|
|
#ifndef pgprot_nx
|
|
#define pgprot_nx(prot) (prot)
|
|
#endif
|
|
|
|
#ifndef pgprot_noncached
|
|
#define pgprot_noncached(prot) (prot)
|
|
#endif
|
|
|
|
#ifndef pgprot_writecombine
|
|
#define pgprot_writecombine pgprot_noncached
|
|
#endif
|
|
|
|
#ifndef pgprot_writethrough
|
|
#define pgprot_writethrough pgprot_noncached
|
|
#endif
|
|
|
|
#ifndef pgprot_device
|
|
#define pgprot_device pgprot_noncached
|
|
#endif
|
|
|
|
#ifndef pgprot_mhp
|
|
#define pgprot_mhp(prot) (prot)
|
|
#endif
|
|
|
|
#ifdef CONFIG_MMU
|
|
#ifndef pgprot_modify
|
|
#define pgprot_modify pgprot_modify
|
|
static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
|
|
{
|
|
if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
|
|
newprot = pgprot_noncached(newprot);
|
|
if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
|
|
newprot = pgprot_writecombine(newprot);
|
|
if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
|
|
newprot = pgprot_device(newprot);
|
|
return newprot;
|
|
}
|
|
#endif
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#ifndef pgprot_encrypted
|
|
#define pgprot_encrypted(prot) (prot)
|
|
#endif
|
|
|
|
#ifndef pgprot_decrypted
|
|
#define pgprot_decrypted(prot) (prot)
|
|
#endif
|
|
|
|
/*
|
|
* A facility to provide lazy MMU batching. This allows PTE updates and
|
|
* page invalidations to be delayed until a call to leave lazy MMU mode
|
|
* is issued. Some architectures may benefit from doing this, and it is
|
|
* beneficial for both shadow and direct mode hypervisors, which may batch
|
|
* the PTE updates which happen during this window. Note that using this
|
|
* interface requires that read hazards be removed from the code. A read
|
|
* hazard could result in the direct mode hypervisor case, since the actual
|
|
* write to the page tables may not yet have taken place, so reads though
|
|
* a raw PTE pointer after it has been modified are not guaranteed to be
|
|
* up to date. This mode can only be entered and left under the protection of
|
|
* the page table locks for all page tables which may be modified. In the UP
|
|
* case, this is required so that preemption is disabled, and in the SMP case,
|
|
* it must synchronize the delayed page table writes properly on other CPUs.
|
|
*/
|
|
#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
|
|
#define arch_enter_lazy_mmu_mode() do {} while (0)
|
|
#define arch_leave_lazy_mmu_mode() do {} while (0)
|
|
#define arch_flush_lazy_mmu_mode() do {} while (0)
|
|
#endif
|
|
|
|
/*
|
|
* A facility to provide batching of the reload of page tables and
|
|
* other process state with the actual context switch code for
|
|
* paravirtualized guests. By convention, only one of the batched
|
|
* update (lazy) modes (CPU, MMU) should be active at any given time,
|
|
* entry should never be nested, and entry and exits should always be
|
|
* paired. This is for sanity of maintaining and reasoning about the
|
|
* kernel code. In this case, the exit (end of the context switch) is
|
|
* in architecture-specific code, and so doesn't need a generic
|
|
* definition.
|
|
*/
|
|
#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
|
|
#define arch_start_context_switch(prev) do {} while (0)
|
|
#endif
|
|
|
|
/*
|
|
* When replacing an anonymous page by a real (!non) swap entry, we clear
|
|
* PG_anon_exclusive from the page and instead remember whether the flag was
|
|
* set in the swp pte. During fork(), we have to mark the entry as !exclusive
|
|
* (possibly shared). On swapin, we use that information to restore
|
|
* PG_anon_exclusive, which is very helpful in cases where we might have
|
|
* additional (e.g., FOLL_GET) references on a page and wouldn't be able to
|
|
* detect exclusivity.
|
|
*
|
|
* These functions don't apply to non-swap entries (e.g., migration, hwpoison,
|
|
* ...).
|
|
*/
|
|
#ifndef __HAVE_ARCH_PTE_SWP_EXCLUSIVE
|
|
static inline pte_t pte_swp_mkexclusive(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline int pte_swp_exclusive(pte_t pte)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline pte_t pte_swp_clear_exclusive(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
|
|
#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
|
|
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
|
|
static inline int pmd_swp_soft_dirty(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
#endif
|
|
#else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
|
|
static inline int pte_soft_dirty(pte_t pte)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int pmd_soft_dirty(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline pte_t pte_mksoft_dirty(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
|
|
static inline pte_t pte_clear_soft_dirty(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
|
|
static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline int pte_swp_soft_dirty(pte_t pte)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
|
|
static inline int pmd_swp_soft_dirty(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
|
|
{
|
|
return pmd;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_PFNMAP_TRACKING
|
|
/*
|
|
* Interfaces that can be used by architecture code to keep track of
|
|
* memory type of pfn mappings specified by the remap_pfn_range,
|
|
* vmf_insert_pfn.
|
|
*/
|
|
|
|
/*
|
|
* track_pfn_remap is called when a _new_ pfn mapping is being established
|
|
* by remap_pfn_range() for physical range indicated by pfn and size.
|
|
*/
|
|
static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
|
|
unsigned long pfn, unsigned long addr,
|
|
unsigned long size)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* track_pfn_insert is called when a _new_ single pfn is established
|
|
* by vmf_insert_pfn().
|
|
*/
|
|
static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
|
|
pfn_t pfn)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* track_pfn_copy is called when vma that is covering the pfnmap gets
|
|
* copied through copy_page_range().
|
|
*/
|
|
static inline int track_pfn_copy(struct vm_area_struct *vma)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* untrack_pfn is called while unmapping a pfnmap for a region.
|
|
* untrack can be called for a specific region indicated by pfn and size or
|
|
* can be for the entire vma (in which case pfn, size are zero).
|
|
*/
|
|
static inline void untrack_pfn(struct vm_area_struct *vma,
|
|
unsigned long pfn, unsigned long size)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* untrack_pfn_moved is called while mremapping a pfnmap for a new region.
|
|
*/
|
|
static inline void untrack_pfn_moved(struct vm_area_struct *vma)
|
|
{
|
|
}
|
|
#else
|
|
extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
|
|
unsigned long pfn, unsigned long addr,
|
|
unsigned long size);
|
|
extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
|
|
pfn_t pfn);
|
|
extern int track_pfn_copy(struct vm_area_struct *vma);
|
|
extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
|
|
unsigned long size);
|
|
extern void untrack_pfn_moved(struct vm_area_struct *vma);
|
|
#endif
|
|
|
|
#ifdef CONFIG_MMU
|
|
#ifdef __HAVE_COLOR_ZERO_PAGE
|
|
static inline int is_zero_pfn(unsigned long pfn)
|
|
{
|
|
extern unsigned long zero_pfn;
|
|
unsigned long offset_from_zero_pfn = pfn - zero_pfn;
|
|
return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
|
|
}
|
|
|
|
#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
|
|
|
|
#else
|
|
static inline int is_zero_pfn(unsigned long pfn)
|
|
{
|
|
extern unsigned long zero_pfn;
|
|
return pfn == zero_pfn;
|
|
}
|
|
|
|
static inline unsigned long my_zero_pfn(unsigned long addr)
|
|
{
|
|
extern unsigned long zero_pfn;
|
|
return zero_pfn;
|
|
}
|
|
#endif
|
|
#else
|
|
static inline int is_zero_pfn(unsigned long pfn)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned long my_zero_pfn(unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
|
|
static inline int pmd_trans_huge(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
#ifndef pmd_write
|
|
static inline int pmd_write(pmd_t pmd)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
#endif /* pmd_write */
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
#ifndef pud_write
|
|
static inline int pud_write(pud_t pud)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
#endif /* pud_write */
|
|
|
|
#if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
|
|
static inline int pmd_devmap(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pud_devmap(pud_t pud)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pgd_devmap(pgd_t pgd)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
|
|
(defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
|
|
!defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
|
|
static inline int pud_trans_huge(pud_t pud)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/* See pmd_none_or_trans_huge_or_clear_bad for discussion. */
|
|
static inline int pud_none_or_trans_huge_or_dev_or_clear_bad(pud_t *pud)
|
|
{
|
|
pud_t pudval = READ_ONCE(*pud);
|
|
|
|
if (pud_none(pudval) || pud_trans_huge(pudval) || pud_devmap(pudval))
|
|
return 1;
|
|
if (unlikely(pud_bad(pudval))) {
|
|
pud_clear_bad(pud);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* See pmd_trans_unstable for discussion. */
|
|
static inline int pud_trans_unstable(pud_t *pud)
|
|
{
|
|
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
|
|
defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
|
|
return pud_none_or_trans_huge_or_dev_or_clear_bad(pud);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
#ifndef pmd_read_atomic
|
|
static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
|
|
{
|
|
/*
|
|
* Depend on compiler for an atomic pmd read. NOTE: this is
|
|
* only going to work, if the pmdval_t isn't larger than
|
|
* an unsigned long.
|
|
*/
|
|
return *pmdp;
|
|
}
|
|
#endif
|
|
|
|
#ifndef arch_needs_pgtable_deposit
|
|
#define arch_needs_pgtable_deposit() (false)
|
|
#endif
|
|
/*
|
|
* This function is meant to be used by sites walking pagetables with
|
|
* the mmap_lock held in read mode to protect against MADV_DONTNEED and
|
|
* transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
|
|
* into a null pmd and the transhuge page fault can convert a null pmd
|
|
* into an hugepmd or into a regular pmd (if the hugepage allocation
|
|
* fails). While holding the mmap_lock in read mode the pmd becomes
|
|
* stable and stops changing under us only if it's not null and not a
|
|
* transhuge pmd. When those races occurs and this function makes a
|
|
* difference vs the standard pmd_none_or_clear_bad, the result is
|
|
* undefined so behaving like if the pmd was none is safe (because it
|
|
* can return none anyway). The compiler level barrier() is critically
|
|
* important to compute the two checks atomically on the same pmdval.
|
|
*
|
|
* For 32bit kernels with a 64bit large pmd_t this automatically takes
|
|
* care of reading the pmd atomically to avoid SMP race conditions
|
|
* against pmd_populate() when the mmap_lock is hold for reading by the
|
|
* caller (a special atomic read not done by "gcc" as in the generic
|
|
* version above, is also needed when THP is disabled because the page
|
|
* fault can populate the pmd from under us).
|
|
*/
|
|
static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
|
|
{
|
|
pmd_t pmdval = pmd_read_atomic(pmd);
|
|
/*
|
|
* The barrier will stabilize the pmdval in a register or on
|
|
* the stack so that it will stop changing under the code.
|
|
*
|
|
* When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
|
|
* pmd_read_atomic is allowed to return a not atomic pmdval
|
|
* (for example pointing to an hugepage that has never been
|
|
* mapped in the pmd). The below checks will only care about
|
|
* the low part of the pmd with 32bit PAE x86 anyway, with the
|
|
* exception of pmd_none(). So the important thing is that if
|
|
* the low part of the pmd is found null, the high part will
|
|
* be also null or the pmd_none() check below would be
|
|
* confused.
|
|
*/
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
barrier();
|
|
#endif
|
|
/*
|
|
* !pmd_present() checks for pmd migration entries
|
|
*
|
|
* The complete check uses is_pmd_migration_entry() in linux/swapops.h
|
|
* But using that requires moving current function and pmd_trans_unstable()
|
|
* to linux/swapops.h to resolve dependency, which is too much code move.
|
|
*
|
|
* !pmd_present() is equivalent to is_pmd_migration_entry() currently,
|
|
* because !pmd_present() pages can only be under migration not swapped
|
|
* out.
|
|
*
|
|
* pmd_none() is preserved for future condition checks on pmd migration
|
|
* entries and not confusing with this function name, although it is
|
|
* redundant with !pmd_present().
|
|
*/
|
|
if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
|
|
(IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
|
|
return 1;
|
|
if (unlikely(pmd_bad(pmdval))) {
|
|
pmd_clear_bad(pmd);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is a noop if Transparent Hugepage Support is not built into
|
|
* the kernel. Otherwise it is equivalent to
|
|
* pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
|
|
* places that already verified the pmd is not none and they want to
|
|
* walk ptes while holding the mmap sem in read mode (write mode don't
|
|
* need this). If THP is not enabled, the pmd can't go away under the
|
|
* code even if MADV_DONTNEED runs, but if THP is enabled we need to
|
|
* run a pmd_trans_unstable before walking the ptes after
|
|
* split_huge_pmd returns (because it may have run when the pmd become
|
|
* null, but then a page fault can map in a THP and not a regular page).
|
|
*/
|
|
static inline int pmd_trans_unstable(pmd_t *pmd)
|
|
{
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
return pmd_none_or_trans_huge_or_clear_bad(pmd);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* the ordering of these checks is important for pmds with _page_devmap set.
|
|
* if we check pmd_trans_unstable() first we will trip the bad_pmd() check
|
|
* inside of pmd_none_or_trans_huge_or_clear_bad(). this will end up correctly
|
|
* returning 1 but not before it spams dmesg with the pmd_clear_bad() output.
|
|
*/
|
|
static inline int pmd_devmap_trans_unstable(pmd_t *pmd)
|
|
{
|
|
return pmd_devmap(*pmd) || pmd_trans_unstable(pmd);
|
|
}
|
|
|
|
#ifndef CONFIG_NUMA_BALANCING
|
|
/*
|
|
* Technically a PTE can be PROTNONE even when not doing NUMA balancing but
|
|
* the only case the kernel cares is for NUMA balancing and is only ever set
|
|
* when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
|
|
* _PAGE_PROTNONE so by default, implement the helper as "always no". It
|
|
* is the responsibility of the caller to distinguish between PROT_NONE
|
|
* protections and NUMA hinting fault protections.
|
|
*/
|
|
static inline int pte_protnone(pte_t pte)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int pmd_protnone(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA_BALANCING */
|
|
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
|
|
|
|
#ifndef __PAGETABLE_P4D_FOLDED
|
|
int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
|
|
void p4d_clear_huge(p4d_t *p4d);
|
|
#else
|
|
static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void p4d_clear_huge(p4d_t *p4d) { }
|
|
#endif /* !__PAGETABLE_P4D_FOLDED */
|
|
|
|
int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
|
|
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
|
|
int pud_clear_huge(pud_t *pud);
|
|
int pmd_clear_huge(pmd_t *pmd);
|
|
int p4d_free_pud_page(p4d_t *p4d, unsigned long addr);
|
|
int pud_free_pmd_page(pud_t *pud, unsigned long addr);
|
|
int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
|
|
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
|
|
static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void p4d_clear_huge(p4d_t *p4d) { }
|
|
static inline int pud_clear_huge(pud_t *pud)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pmd_clear_huge(pmd_t *pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
|
|
|
|
#ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* ARCHes with special requirements for evicting THP backing TLB entries can
|
|
* implement this. Otherwise also, it can help optimize normal TLB flush in
|
|
* THP regime. Stock flush_tlb_range() typically has optimization to nuke the
|
|
* entire TLB if flush span is greater than a threshold, which will
|
|
* likely be true for a single huge page. Thus a single THP flush will
|
|
* invalidate the entire TLB which is not desirable.
|
|
* e.g. see arch/arc: flush_pmd_tlb_range
|
|
*/
|
|
#define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
|
|
#define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
|
|
#else
|
|
#define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG()
|
|
#define flush_pud_tlb_range(vma, addr, end) BUILD_BUG()
|
|
#endif
|
|
#endif
|
|
|
|
struct file;
|
|
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
|
|
unsigned long size, pgprot_t *vma_prot);
|
|
|
|
#ifndef CONFIG_X86_ESPFIX64
|
|
static inline void init_espfix_bsp(void) { }
|
|
#endif
|
|
|
|
extern void __init pgtable_cache_init(void);
|
|
|
|
#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
|
|
static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
static inline bool arch_has_pfn_modify_check(void)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
|
|
|
|
/*
|
|
* Architecture PAGE_KERNEL_* fallbacks
|
|
*
|
|
* Some architectures don't define certain PAGE_KERNEL_* flags. This is either
|
|
* because they really don't support them, or the port needs to be updated to
|
|
* reflect the required functionality. Below are a set of relatively safe
|
|
* fallbacks, as best effort, which we can count on in lieu of the architectures
|
|
* not defining them on their own yet.
|
|
*/
|
|
|
|
#ifndef PAGE_KERNEL_RO
|
|
# define PAGE_KERNEL_RO PAGE_KERNEL
|
|
#endif
|
|
|
|
#ifndef PAGE_KERNEL_EXEC
|
|
# define PAGE_KERNEL_EXEC PAGE_KERNEL
|
|
#endif
|
|
|
|
/*
|
|
* Page Table Modification bits for pgtbl_mod_mask.
|
|
*
|
|
* These are used by the p?d_alloc_track*() set of functions an in the generic
|
|
* vmalloc/ioremap code to track at which page-table levels entries have been
|
|
* modified. Based on that the code can better decide when vmalloc and ioremap
|
|
* mapping changes need to be synchronized to other page-tables in the system.
|
|
*/
|
|
#define __PGTBL_PGD_MODIFIED 0
|
|
#define __PGTBL_P4D_MODIFIED 1
|
|
#define __PGTBL_PUD_MODIFIED 2
|
|
#define __PGTBL_PMD_MODIFIED 3
|
|
#define __PGTBL_PTE_MODIFIED 4
|
|
|
|
#define PGTBL_PGD_MODIFIED BIT(__PGTBL_PGD_MODIFIED)
|
|
#define PGTBL_P4D_MODIFIED BIT(__PGTBL_P4D_MODIFIED)
|
|
#define PGTBL_PUD_MODIFIED BIT(__PGTBL_PUD_MODIFIED)
|
|
#define PGTBL_PMD_MODIFIED BIT(__PGTBL_PMD_MODIFIED)
|
|
#define PGTBL_PTE_MODIFIED BIT(__PGTBL_PTE_MODIFIED)
|
|
|
|
/* Page-Table Modification Mask */
|
|
typedef unsigned int pgtbl_mod_mask;
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#if !defined(MAX_POSSIBLE_PHYSMEM_BITS) && !defined(CONFIG_64BIT)
|
|
#ifdef CONFIG_PHYS_ADDR_T_64BIT
|
|
/*
|
|
* ZSMALLOC needs to know the highest PFN on 32-bit architectures
|
|
* with physical address space extension, but falls back to
|
|
* BITS_PER_LONG otherwise.
|
|
*/
|
|
#error Missing MAX_POSSIBLE_PHYSMEM_BITS definition
|
|
#else
|
|
#define MAX_POSSIBLE_PHYSMEM_BITS 32
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef has_transparent_hugepage
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
#define has_transparent_hugepage() 1
|
|
#else
|
|
#define has_transparent_hugepage() 0
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* On some architectures it depends on the mm if the p4d/pud or pmd
|
|
* layer of the page table hierarchy is folded or not.
|
|
*/
|
|
#ifndef mm_p4d_folded
|
|
#define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED)
|
|
#endif
|
|
|
|
#ifndef mm_pud_folded
|
|
#define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED)
|
|
#endif
|
|
|
|
#ifndef mm_pmd_folded
|
|
#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
|
|
#endif
|
|
|
|
#ifndef p4d_offset_lockless
|
|
#define p4d_offset_lockless(pgdp, pgd, address) p4d_offset(&(pgd), address)
|
|
#endif
|
|
#ifndef pud_offset_lockless
|
|
#define pud_offset_lockless(p4dp, p4d, address) pud_offset(&(p4d), address)
|
|
#endif
|
|
#ifndef pmd_offset_lockless
|
|
#define pmd_offset_lockless(pudp, pud, address) pmd_offset(&(pud), address)
|
|
#endif
|
|
|
|
/*
|
|
* p?d_leaf() - true if this entry is a final mapping to a physical address.
|
|
* This differs from p?d_huge() by the fact that they are always available (if
|
|
* the architecture supports large pages at the appropriate level) even
|
|
* if CONFIG_HUGETLB_PAGE is not defined.
|
|
* Only meaningful when called on a valid entry.
|
|
*/
|
|
#ifndef pgd_leaf
|
|
#define pgd_leaf(x) 0
|
|
#endif
|
|
#ifndef p4d_leaf
|
|
#define p4d_leaf(x) 0
|
|
#endif
|
|
#ifndef pud_leaf
|
|
#define pud_leaf(x) 0
|
|
#endif
|
|
#ifndef pmd_leaf
|
|
#define pmd_leaf(x) 0
|
|
#endif
|
|
|
|
#ifndef pgd_leaf_size
|
|
#define pgd_leaf_size(x) (1ULL << PGDIR_SHIFT)
|
|
#endif
|
|
#ifndef p4d_leaf_size
|
|
#define p4d_leaf_size(x) P4D_SIZE
|
|
#endif
|
|
#ifndef pud_leaf_size
|
|
#define pud_leaf_size(x) PUD_SIZE
|
|
#endif
|
|
#ifndef pmd_leaf_size
|
|
#define pmd_leaf_size(x) PMD_SIZE
|
|
#endif
|
|
#ifndef pte_leaf_size
|
|
#define pte_leaf_size(x) PAGE_SIZE
|
|
#endif
|
|
|
|
/*
|
|
* Some architectures have MMUs that are configurable or selectable at boot
|
|
* time. These lead to variable PTRS_PER_x. For statically allocated arrays it
|
|
* helps to have a static maximum value.
|
|
*/
|
|
|
|
#ifndef MAX_PTRS_PER_PTE
|
|
#define MAX_PTRS_PER_PTE PTRS_PER_PTE
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_PMD
|
|
#define MAX_PTRS_PER_PMD PTRS_PER_PMD
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_PUD
|
|
#define MAX_PTRS_PER_PUD PTRS_PER_PUD
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_P4D
|
|
#define MAX_PTRS_PER_P4D PTRS_PER_P4D
|
|
#endif
|
|
|
|
/* description of effects of mapping type and prot in current implementation.
|
|
* this is due to the limited x86 page protection hardware. The expected
|
|
* behavior is in parens:
|
|
*
|
|
* map_type prot
|
|
* PROT_NONE PROT_READ PROT_WRITE PROT_EXEC
|
|
* MAP_SHARED r: (no) no r: (yes) yes r: (no) yes r: (no) yes
|
|
* w: (no) no w: (no) no w: (yes) yes w: (no) no
|
|
* x: (no) no x: (no) yes x: (no) yes x: (yes) yes
|
|
*
|
|
* MAP_PRIVATE r: (no) no r: (yes) yes r: (no) yes r: (no) yes
|
|
* w: (no) no w: (no) no w: (copy) copy w: (no) no
|
|
* x: (no) no x: (no) yes x: (no) yes x: (yes) yes
|
|
*
|
|
* On arm64, PROT_EXEC has the following behaviour for both MAP_SHARED and
|
|
* MAP_PRIVATE (with Enhanced PAN supported):
|
|
* r: (no) no
|
|
* w: (no) no
|
|
* x: (yes) yes
|
|
*/
|
|
#define DECLARE_VM_GET_PAGE_PROT \
|
|
pgprot_t vm_get_page_prot(unsigned long vm_flags) \
|
|
{ \
|
|
return protection_map[vm_flags & \
|
|
(VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)]; \
|
|
} \
|
|
EXPORT_SYMBOL(vm_get_page_prot);
|
|
|
|
#endif /* _LINUX_PGTABLE_H */
|