Messages in this thread | | | Date | Wed, 8 May 2024 15:13:48 +0530 | Subject | Re: [PATCH v4 1/4] arm64/mm: generalize PMD_PRESENT_INVALID for all levels | From | Anshuman Khandual <> |
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On 5/3/24 20:15, Ryan Roberts wrote: > As preparation for the next patch, which frees up the PTE_PROT_NONE > present pte and swap pte bit, generalize PMD_PRESENT_INVALID to > PTE_PRESENT_INVALID. This will then be used to mark PROT_NONE ptes (and > entries at any other level) in the next patch. > > While we're at it, fix up the swap pte format comment to include > PTE_PRESENT_INVALID. This is not new, it just wasn't previously > documented. > > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> --- > arch/arm64/include/asm/pgtable-prot.h | 8 ++++---- > arch/arm64/include/asm/pgtable.h | 21 ++++++++++++--------- > 2 files changed, 16 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index dd9ee67d1d87..cdbf51eef7a6 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -21,11 +21,11 @@ > #define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */ > > /* > - * This bit indicates that the entry is present i.e. pmd_page() > - * still points to a valid huge page in memory even if the pmd > - * has been invalidated. > + * PTE_PRESENT_INVALID=1 & PTE_VALID=0 indicates that the pte's fields should be > + * interpreted according to the HW layout by SW but any attempted HW access to > + * the address will result in a fault. pte_present() returns true. > */ > -#define PMD_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PMD_SECT_VALID */ > +#define PTE_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PTE_VALID */ > > #define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) > #define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index afdd56d26ad7..7156c940ac4f 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -132,6 +132,8 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) > #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) > > #define pte_valid(pte) (!!(pte_val(pte) & PTE_VALID)) > +#define pte_present_invalid(pte) \ > + ((pte_val(pte) & (PTE_VALID | PTE_PRESENT_INVALID)) == PTE_PRESENT_INVALID) > /* > * Execute-only user mappings do not have the PTE_USER bit set. All valid > * kernel mappings have the PTE_UXN bit set. > @@ -261,6 +263,13 @@ static inline pte_t pte_mkpresent(pte_t pte) > return set_pte_bit(pte, __pgprot(PTE_VALID)); > } > > +static inline pte_t pte_mkinvalid(pte_t pte) > +{ > + pte = set_pte_bit(pte, __pgprot(PTE_PRESENT_INVALID)); > + pte = clear_pte_bit(pte, __pgprot(PTE_VALID)); > + return pte; > +} > + > static inline pmd_t pmd_mkcont(pmd_t pmd) > { > return __pmd(pmd_val(pmd) | PMD_SECT_CONT); > @@ -478,7 +487,7 @@ static inline int pmd_protnone(pmd_t pmd) > } > #endif > > -#define pmd_present_invalid(pmd) (!!(pmd_val(pmd) & PMD_PRESENT_INVALID)) > +#define pmd_present_invalid(pmd) pte_present_invalid(pmd_pte(pmd)) > > static inline int pmd_present(pmd_t pmd) > { > @@ -508,14 +517,7 @@ static inline int pmd_trans_huge(pmd_t pmd) > #define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) > #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) > #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) > - > -static inline pmd_t pmd_mkinvalid(pmd_t pmd) > -{ > - pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID)); > - pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID)); > - > - return pmd; > -} > +#define pmd_mkinvalid(pmd) pte_pmd(pte_mkinvalid(pmd_pte(pmd))) > > #define pmd_thp_or_huge(pmd) (pmd_huge(pmd) || pmd_trans_huge(pmd)) > > @@ -1251,6 +1253,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > * bits 3-7: swap type > * bits 8-57: swap offset > * bit 58: PTE_PROT_NONE (must be zero) > + * bit 59: PTE_PRESENT_INVALID (must be zero) > */ > #define __SWP_TYPE_SHIFT 3 > #define __SWP_TYPE_BITS 5
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