| Message ID | 20170725135308.18173-7-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 25, 2017 at 02:53:08PM +0100, Catalin Marinas wrote: > Since the pte handling for hardware AF/DBM works even when the hardware > feature is not present, make the implementation permanent and remove the > Kconfig option. > > Cc: Will Deacon <will.deacon@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Christoffer Dall <christoffer.dall@linaro.org> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > --- > arch/arm64/Kconfig | 17 ----------------- > arch/arm64/include/asm/pgtable.h | 9 +-------- > arch/arm64/kvm/hyp/s2-setup.c | 2 +- > arch/arm64/mm/fault.c | 2 -- > arch/arm64/mm/proc.S | 3 +-- > 5 files changed, 3 insertions(+), 30 deletions(-) Largely in favour of this, but I'd prefer to keep the option so that we can build kernels where the enabling: > diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > index 877d42fb0df6..ba82f8bf3cf1 100644 > --- a/arch/arm64/mm/proc.S > +++ b/arch/arm64/mm/proc.S > @@ -234,7 +234,7 @@ ENTRY(__cpu_setup) > */ > mrs x9, ID_AA64MMFR0_EL1 > bfi x10, x9, #32, #3 > -#ifdef CONFIG_ARM64_HW_AFDBM > + > /* > * Hardware update of the Access and Dirty bits. > */ > @@ -246,7 +246,6 @@ ENTRY(__cpu_setup) > orr x10, x10, #TCR_HD // hardware Dirty flag update > 1: orr x10, x10, #TCR_HA // hardware Access flag update > 2: > -#endif /* CONFIG_ARM64_HW_AFDBM */ > msr tcr_el1, x10 > ret // return to head.S > ENDPROC(__cpu_setup) is still configurable. That might help for debugging suspected races in this area. Will
On Thu, Aug 17, 2017 at 02:31:54PM +0100, Will Deacon wrote: > On Tue, Jul 25, 2017 at 02:53:08PM +0100, Catalin Marinas wrote: > > Since the pte handling for hardware AF/DBM works even when the hardware > > feature is not present, make the implementation permanent and remove the > > Kconfig option. > > > > Cc: Will Deacon <will.deacon@arm.com> > > Cc: Marc Zyngier <marc.zyngier@arm.com> > > Cc: Christoffer Dall <christoffer.dall@linaro.org> > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > > --- > > arch/arm64/Kconfig | 17 ----------------- > > arch/arm64/include/asm/pgtable.h | 9 +-------- > > arch/arm64/kvm/hyp/s2-setup.c | 2 +- > > arch/arm64/mm/fault.c | 2 -- > > arch/arm64/mm/proc.S | 3 +-- > > 5 files changed, 3 insertions(+), 30 deletions(-) > > Largely in favour of this, but I'd prefer to keep the option so that > we can build kernels where the enabling: > > > diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S > > index 877d42fb0df6..ba82f8bf3cf1 100644 > > --- a/arch/arm64/mm/proc.S > > +++ b/arch/arm64/mm/proc.S > > @@ -234,7 +234,7 @@ ENTRY(__cpu_setup) > > */ > > mrs x9, ID_AA64MMFR0_EL1 > > bfi x10, x9, #32, #3 > > -#ifdef CONFIG_ARM64_HW_AFDBM > > + > > /* > > * Hardware update of the Access and Dirty bits. > > */ > > @@ -246,7 +246,6 @@ ENTRY(__cpu_setup) > > orr x10, x10, #TCR_HD // hardware Dirty flag update > > 1: orr x10, x10, #TCR_HA // hardware Access flag update > > 2: > > -#endif /* CONFIG_ARM64_HW_AFDBM */ > > msr tcr_el1, x10 > > ret // return to head.S > > ENDPROC(__cpu_setup) > > is still configurable. That might help for debugging suspected races in > this area. Makes sense. Fixed it locally.
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index dfd908630631..eeb61d800441 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -879,23 +879,6 @@ config ARM64_SW_TTBR0_PAN menu "ARMv8.1 architectural features" -config ARM64_HW_AFDBM - bool "Support for hardware updates of the Access and Dirty page flags" - default y - help - The ARMv8.1 architecture extensions introduce support for - hardware updates of the access and dirty information in page - table entries. When enabled in TCR_EL1 (HA and HD bits) on - capable processors, accesses to pages with PTE_AF cleared will - set this bit instead of raising an access flag fault. - Similarly, writes to read-only pages with the DBM bit set will - clear the read-only bit (AP[2]) instead of raising a - permission fault. - - Kernels built with this configuration option enabled continue - to work on pre-ARMv8.1 hardware and the performance impact is - minimal. If unsure, say Y. - config ARM64_PAN bool "Enable support for Privileged Access Never (PAN)" default y diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 3fefcc0182c7..e23811f6b9da 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -85,11 +85,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; (__boundary - 1 < (end) - 1) ? __boundary : (end); \ }) -#ifdef CONFIG_ARM64_HW_AFDBM #define pte_hw_dirty(pte) (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY)) -#else -#define pte_hw_dirty(pte) (0) -#endif #define pte_sw_dirty(pte) (!!(pte_val(pte) & PTE_DIRTY)) #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) @@ -228,8 +224,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, * hardware updates of the pte (ptep_set_access_flags safely changes * valid ptes without going through an invalid entry). */ - if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) && - pte_valid(*ptep) && pte_valid(pte)) { + if (pte_valid(*ptep) && pte_valid(pte)) { VM_WARN_ONCE(!pte_young(pte), "%s: racy access flag clearing: 0x%016llx -> 0x%016llx", __func__, pte_val(*ptep), pte_val(pte)); @@ -565,7 +560,6 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) return pte_pmd(pte_modify(pmd_pte(pmd), newprot)); } -#ifdef CONFIG_ARM64_HW_AFDBM #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, @@ -666,7 +660,6 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm, ptep_set_wrprotect(mm, address, (pte_t *)pmdp); } #endif -#endif /* CONFIG_ARM64_HW_AFDBM */ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c index b81f4091c909..a81f5e10fc8c 100644 --- a/arch/arm64/kvm/hyp/s2-setup.c +++ b/arch/arm64/kvm/hyp/s2-setup.c @@ -70,7 +70,7 @@ u32 __hyp_text __init_stage2_translation(void) * Management in ID_AA64MMFR1_EL1 and enable the feature in VTCR_EL2. */ tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_HADBS_SHIFT) & 0xf; - if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM) && tmp) + if (tmp) val |= VTCR_EL2_HA; /* diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index cfff98a97a7c..ce361234e78b 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -140,7 +140,6 @@ void show_pte(unsigned long addr) pr_cont("\n"); } -#ifdef CONFIG_ARM64_HW_AFDBM /* * This function sets the access flags (dirty, accessed), as well as write * permission, and only to a more permissive setting. @@ -181,7 +180,6 @@ int ptep_set_access_flags(struct vm_area_struct *vma, flush_tlb_fix_spurious_fault(vma, address); return 1; } -#endif static bool is_el1_instruction_abort(unsigned int esr) { diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 877d42fb0df6..ba82f8bf3cf1 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -234,7 +234,7 @@ ENTRY(__cpu_setup) */ mrs x9, ID_AA64MMFR0_EL1 bfi x10, x9, #32, #3 -#ifdef CONFIG_ARM64_HW_AFDBM + /* * Hardware update of the Access and Dirty bits. */ @@ -246,7 +246,6 @@ ENTRY(__cpu_setup) orr x10, x10, #TCR_HD // hardware Dirty flag update 1: orr x10, x10, #TCR_HA // hardware Access flag update 2: -#endif /* CONFIG_ARM64_HW_AFDBM */ msr tcr_el1, x10 ret // return to head.S ENDPROC(__cpu_setup)
Since the pte handling for hardware AF/DBM works even when the hardware feature is not present, make the implementation permanent and remove the Kconfig option. Cc: Will Deacon <will.deacon@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> --- arch/arm64/Kconfig | 17 ----------------- arch/arm64/include/asm/pgtable.h | 9 +-------- arch/arm64/kvm/hyp/s2-setup.c | 2 +- arch/arm64/mm/fault.c | 2 -- arch/arm64/mm/proc.S | 3 +-- 5 files changed, 3 insertions(+), 30 deletions(-)