// SPDX-License-Identifier: GPL-2.0/* *  mm/pgtable-generic.c * *  Generic pgtable methods declared in linux/pgtable.h * *  Copyright (C) 2010  Linus Torvalds */ #include <linux/pagemap.h>#include <linux/hugetlb.h>#include <linux/pgtable.h>#include <asm/tlb.h> /* * If a p?d_bad entry is found while walking page tables, report * the error, before resetting entry to p?d_none.  Usually (but * very seldom) called out from the p?d_none_or_clear_bad macros. */ void pgd_clear_bad(pgd_t *pgd){	pgd_ERROR(*pgd);	pgd_clear(pgd);} #ifndef __PAGETABLE_P4D_FOLDEDvoid p4d_clear_bad(p4d_t *p4d){	p4d_ERROR(*p4d);	p4d_clear(p4d);}#endif #ifndef __PAGETABLE_PUD_FOLDEDvoid pud_clear_bad(pud_t *pud){	pud_ERROR(*pud);	pud_clear(pud);}#endif /* * Note that the pmd variant below can't be stub'ed out just as for p4d/pud * above. pmd folding is special and typically pmd_* macros refer to upper * level even when folded */void pmd_clear_bad(pmd_t *pmd){	pmd_ERROR(*pmd);	pmd_clear(pmd);} #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS/* * Only sets the access flags (dirty, accessed), as well as write * permission. Furthermore, we know it always gets set to a "more * permissive" setting, which allows most architectures to optimize * this. We return whether the PTE actually changed, which in turn * instructs the caller to do things like update__mmu_cache.  This * used to be done in the caller, but sparc needs minor faults to * force that call on sun4c so we changed this macro slightly */int ptep_set_access_flags(struct vm_area_struct *vma,			  unsigned long address, pte_t *ptep,			  pte_t entry, int dirty){	int changed = !pte_same(*ptep, entry);	if (changed) {		set_pte_at(vma->vm_mm, address, ptep, entry);		flush_tlb_fix_spurious_fault(vma, address);	}	return changed;}#endif #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSHint ptep_clear_flush_young(struct vm_area_struct *vma,			   unsigned long address, pte_t *ptep){	int young;	young = ptep_test_and_clear_young(vma, address, ptep);	if (young)		flush_tlb_page(vma, address);	return young;}#endif #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSHpte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,		       pte_t *ptep){	struct mm_struct *mm = (vma)->vm_mm;	pte_t pte;	pte = ptep_get_and_clear(mm, address, ptep);	if (pte_accessible(mm, pte))		flush_tlb_page(vma, address);	return pte;}#endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGSint pmdp_set_access_flags(struct vm_area_struct *vma,			  unsigned long address, pmd_t *pmdp,			  pmd_t entry, int dirty){	int changed = !pmd_same(*pmdp, entry);	VM_BUG_ON(address & ~HPAGE_PMD_MASK);	if (changed) {		set_pmd_at(vma->vm_mm, address, pmdp, entry);		flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);	}	return changed;}#endif #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSHint pmdp_clear_flush_young(struct vm_area_struct *vma,			   unsigned long address, pmd_t *pmdp){	int young;	VM_BUG_ON(address & ~HPAGE_PMD_MASK);	young = pmdp_test_and_clear_young(vma, address, pmdp);	if (young)		flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);	return young;}#endif #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSHpmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,			    pmd_t *pmdp){	pmd_t pmd;	VM_BUG_ON(address & ~HPAGE_PMD_MASK);	VM_BUG_ON((pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) &&			   !pmd_devmap(*pmdp)) || !pmd_present(*pmdp));	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);	return pmd;} #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUDpud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,			    pud_t *pudp){	pud_t pud; 	VM_BUG_ON(address & ~HPAGE_PUD_MASK);	VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp));	pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp);	flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);	return pud;}#endif#endif #ifndef __HAVE_ARCH_PGTABLE_DEPOSITvoid pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,				pgtable_t pgtable){	assert_spin_locked(pmd_lockptr(mm, pmdp)); 	/* FIFO */	if (!pmd_huge_pte(mm, pmdp))		INIT_LIST_HEAD(&pgtable->lru);	else		list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);	pmd_huge_pte(mm, pmdp) = pgtable;}#endif #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW/* no "address" argument so destroys page coloring of some arch */pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp){	pgtable_t pgtable; 	assert_spin_locked(pmd_lockptr(mm, pmdp)); 	/* FIFO */	pgtable = pmd_huge_pte(mm, pmdp);	pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru,							  struct page, lru);	if (pmd_huge_pte(mm, pmdp))		list_del(&pgtable->lru);	return pgtable;}#endif #ifndef __HAVE_ARCH_PMDP_INVALIDATEpmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,		     pmd_t *pmdp){	pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp));	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);	return old;}#endif #ifndef pmdp_collapse_flushpmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,			  pmd_t *pmdp){	/*	 * pmd and hugepage pte format are same. So we could	 * use the same function.	 */	pmd_t pmd; 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);	VM_BUG_ON(pmd_trans_huge(*pmdp));	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); 	/* collapse entails shooting down ptes not pmd */	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);	return pmd;}#endif#endif /* CONFIG_TRANSPARENT_HUGEPAGE */