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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E6DE040008 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: q65gofkk1kd31xcngjdewftbqo9thnkw X-HE-Tag: 1747836866-753291 X-HE-Meta: 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 0Odu+zlV MIx8K16T1729mnH2dzyw4cjezBckqc85FxD9zJ7oOFaQSAaV/iwofKgIfw6K5PqktRpvbQE9Paz4QVt0qE3EkvEcI8n1L4DkdfO+iRBm2SZw+SdtVFqhpbEdABWT+0RzkxGYjN135hYGmqIvoVw7vA96iweArJClDlJJGZIjgg8T9qFDvjkmURyOYAQSelnkdGqhWdcSsRtn6iaYOYXhbbcCTz/TULhMpdzVy7oq6+1mbBcEcKCIo0qUpDw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 19/05/2025 08:48, Dev Jain wrote: > Override the generic definition to use get_and_clear_full_ptes(). This helper > does a TLBI only for the starting and ending contpte block of the range, whereas > the current implementation will call ptep_get_and_clear() for every contpte block, > thus doing a TLBI on every contpte block. Therefore, we have a performance win. > The arm64 definition of pte_accessible() allows us to batch around it in clear_flush_ptes(): > #define pte_accessible(mm, pte) \ > (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte)) > > All ptes are obviously present in the folio batch, and they are also valid. > > Signed-off-by: Dev Jain Please squash this with the > --- > arch/arm64/include/asm/pgtable.h | 5 +++++ > arch/arm64/mm/mmu.c | 12 +++++++++--- > include/linux/pgtable.h | 4 ++++ > mm/pgtable-generic.c | 16 +++++++++++----- > 4 files changed, 29 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 2a77f11b78d5..8872ea5f0642 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -1553,6 +1553,11 @@ extern void ptep_modify_prot_commit(struct vm_area_struct *vma, > unsigned long addr, pte_t *ptep, > pte_t old_pte, pte_t new_pte); > > +#define modify_prot_start_ptes modify_prot_start_ptes > +extern pte_t modify_prot_start_ptes(struct vm_area_struct *vma, > + unsigned long addr, pte_t *ptep, > + unsigned int nr); > + > #ifdef CONFIG_ARM64_CONTPTE > > /* > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 8fcf59ba39db..fe60be8774f4 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1523,7 +1523,8 @@ static int __init prevent_bootmem_remove_init(void) > early_initcall(prevent_bootmem_remove_init); > #endif > > -pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) > +pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long addr, > + pte_t *ptep, unsigned int nr) > { > if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) { > /* > @@ -1532,9 +1533,14 @@ pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte > * in cases where cpu is affected with errata #2645198. > */ > if (pte_user_exec(ptep_get(ptep))) > - return ptep_clear_flush(vma, addr, ptep); > + return clear_flush_ptes(vma, addr, ptep, nr); > } > - return ptep_get_and_clear(vma->vm_mm, addr, ptep); > + return get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, 0); > +} I think we can do this more precisely with respect to tlbis and also without needing to create a new clear_flush_ptes() helper: pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, unsigned int nr) { pte_t pte = get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, 0); if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) { /* * Break-before-make (BBM) is required for all user space mappings * when the permission changes from executable to non-executable * in cases where cpu is affected with errata #2645198. */ if (pte_accessible(vma->vm_mm, pte) && pte_user_exec(pte)) __flush_tlb_range(vma, addr, nr * PAGE_SIZE, PAGE_SIZE, true, 3); } return pte; } > + > +pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) > +{ > + return modify_prot_start_ptes(vma, addr, ptep, 1); > } > > void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index e40ed57e034d..41f4a8de5c28 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -828,6 +828,10 @@ extern pte_t ptep_clear_flush(struct vm_area_struct *vma, > pte_t *ptep); > #endif > > +extern pte_t clear_flush_ptes(struct vm_area_struct *vma, > + unsigned long address, > + pte_t *ptep, unsigned int nr); > + > #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH > extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, > unsigned long address, > diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c > index 5a882f2b10f9..e238f88c3cac 100644 > --- a/mm/pgtable-generic.c > +++ b/mm/pgtable-generic.c > @@ -90,17 +90,23 @@ int ptep_clear_flush_young(struct vm_area_struct *vma, > } > #endif > > -#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH > -pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, > - pte_t *ptep) > +pte_t clear_flush_ptes(struct vm_area_struct *vma, unsigned long address, > + pte_t *ptep, unsigned int nr) > { > struct mm_struct *mm = (vma)->vm_mm; > pte_t pte; > - pte = ptep_get_and_clear(mm, address, ptep); > + pte = get_and_clear_full_ptes(mm, address, ptep, nr, 0); > if (pte_accessible(mm, pte)) > - flush_tlb_page(vma, address); > + flush_tlb_range(vma, address, address + nr * PAGE_SIZE); > return pte; > } Let's not create a new generic helper if only arm64 is using it. We would also want to add a doc header to describe this helper. My proposal avoids this. Thanks, Ryan > + > +#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH > +pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, > + pte_t *ptep) > +{ > + return clear_flush_ptes(vma, address, ptep, 1); > +} > #endif > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE