| Message ID | 20181205030931.12037-6-aneesh.kumar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | NestMMU pte upgrade workaround for mprotect | expand |
Le 05/12/2018 à 04:09, Aneesh Kumar K.V a écrit : > NestMMU requires us to mark the pte invalid and flush the tlb when we do a > RW upgrade of pte. We fixed a variant of this in the fault path in commit > Fixes: bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to handle nest MMU hang") > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > --- > arch/powerpc/include/asm/book3s/64/hugetlb.h | 12 ++++++++ > arch/powerpc/mm/hugetlbpage-radix.c | 17 ++++++++++++ > arch/powerpc/mm/hugetlbpage.c | 29 ++++++++++++++++++++ > 3 files changed, 58 insertions(+) > > diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h > index 5b0177733994..66c1e4f88d65 100644 > --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h > +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h > @@ -13,6 +13,10 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > unsigned long len, unsigned long pgoff, > unsigned long flags); > > +extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep, > + pte_t old_pte, pte_t pte); > + > static inline int hstate_get_psize(struct hstate *hstate) > { > unsigned long shift; > @@ -42,4 +46,12 @@ static inline bool gigantic_page_supported(void) > /* hugepd entry valid bit */ > #define HUGEPD_VAL_BITS (0x8000000000000000UL) > > +#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start > +extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep); > + > +#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit > +extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep, > + pte_t old_pte, pte_t new_pte); > #endif > diff --git a/arch/powerpc/mm/hugetlbpage-radix.c b/arch/powerpc/mm/hugetlbpage-radix.c > index 2486bee0f93e..11d9ea28a816 100644 > --- a/arch/powerpc/mm/hugetlbpage-radix.c > +++ b/arch/powerpc/mm/hugetlbpage-radix.c > @@ -90,3 +90,20 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, > > return vm_unmapped_area(&info); > } > + > +void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep, > + pte_t old_pte, pte_t pte) > +{ > + struct mm_struct *mm = vma->vm_mm; > + > + /* > + * To avoid NMMU hang while relaxing access we need to flush the tlb before > + * we set the new value. > + */ > + if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) && > + (atomic_read(&mm->context.copros) > 0)) > + radix__flush_hugetlb_page(vma, addr); > + > + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); > +} > diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c > index 8cf035e68378..39d33a3d0dc6 100644 > --- a/arch/powerpc/mm/hugetlbpage.c > +++ b/arch/powerpc/mm/hugetlbpage.c > @@ -912,3 +912,32 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, > > return 1; > } > + > +#ifdef CONFIG_PPC_BOOK3S_64 Could this go in hugetlbpage-hash64.c instead to avoid the #ifdef sequence ? Christophe > +pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep) > +{ > + unsigned long pte_val; > + /* > + * Clear the _PAGE_PRESENT so that no hardware parallel update is > + * possible. Also keep the pte_present true so that we don't take > + * wrong fault. > + */ > + pte_val = pte_update(vma->vm_mm, addr, ptep, > + _PAGE_PRESENT, _PAGE_INVALID, 1); > + > + return __pte(pte_val); > +} > +EXPORT_SYMBOL(huge_ptep_modify_prot_start); > + > +void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, > + pte_t *ptep, pte_t old_pte, pte_t pte) > +{ > + > + if (radix_enabled()) > + return radix__huge_ptep_modify_prot_commit(vma, addr, ptep, > + old_pte, pte); > + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); > +} > +EXPORT_SYMBOL(huge_ptep_modify_prot_commit); > +#endif >
Christophe LEROY <christophe.leroy@c-s.fr> writes: > diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c >> index 8cf035e68378..39d33a3d0dc6 100644 >> --- a/arch/powerpc/mm/hugetlbpage.c >> +++ b/arch/powerpc/mm/hugetlbpage.c >> @@ -912,3 +912,32 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, >> >> return 1; >> } >> + >> +#ifdef CONFIG_PPC_BOOK3S_64 > > Could this go in hugetlbpage-hash64.c instead to avoid the #ifdef sequence ? > yes. I will send updated patch as reply -aneesh
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h index 5b0177733994..66c1e4f88d65 100644 --- a/arch/powerpc/include/asm/book3s/64/hugetlb.h +++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h @@ -13,6 +13,10 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags); +extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t old_pte, pte_t pte); + static inline int hstate_get_psize(struct hstate *hstate) { unsigned long shift; @@ -42,4 +46,12 @@ static inline bool gigantic_page_supported(void) /* hugepd entry valid bit */ #define HUGEPD_VAL_BITS (0x8000000000000000UL) +#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start +extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); + +#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit +extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t old_pte, pte_t new_pte); #endif diff --git a/arch/powerpc/mm/hugetlbpage-radix.c b/arch/powerpc/mm/hugetlbpage-radix.c index 2486bee0f93e..11d9ea28a816 100644 --- a/arch/powerpc/mm/hugetlbpage-radix.c +++ b/arch/powerpc/mm/hugetlbpage-radix.c @@ -90,3 +90,20 @@ radix__hugetlb_get_unmapped_area(struct file *file, unsigned long addr, return vm_unmapped_area(&info); } + +void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep, + pte_t old_pte, pte_t pte) +{ + struct mm_struct *mm = vma->vm_mm; + + /* + * To avoid NMMU hang while relaxing access we need to flush the tlb before + * we set the new value. + */ + if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) && + (atomic_read(&mm->context.copros) > 0)) + radix__flush_hugetlb_page(vma, addr); + + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); +} diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 8cf035e68378..39d33a3d0dc6 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -912,3 +912,32 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, return 1; } + +#ifdef CONFIG_PPC_BOOK3S_64 +pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + unsigned long pte_val; + /* + * Clear the _PAGE_PRESENT so that no hardware parallel update is + * possible. Also keep the pte_present true so that we don't take + * wrong fault. + */ + pte_val = pte_update(vma->vm_mm, addr, ptep, + _PAGE_PRESENT, _PAGE_INVALID, 1); + + return __pte(pte_val); +} +EXPORT_SYMBOL(huge_ptep_modify_prot_start); + +void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte) +{ + + if (radix_enabled()) + return radix__huge_ptep_modify_prot_commit(vma, addr, ptep, + old_pte, pte); + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); +} +EXPORT_SYMBOL(huge_ptep_modify_prot_commit); +#endif
NestMMU requires us to mark the pte invalid and flush the tlb when we do a RW upgrade of pte. We fixed a variant of this in the fault path in commit Fixes: bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to handle nest MMU hang") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- arch/powerpc/include/asm/book3s/64/hugetlb.h | 12 ++++++++ arch/powerpc/mm/hugetlbpage-radix.c | 17 ++++++++++++ arch/powerpc/mm/hugetlbpage.c | 29 ++++++++++++++++++++ 3 files changed, 58 insertions(+)