From: Ryan Roberts <ryan.roberts@arm.com> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Ard Biesheuvel <ardb@kernel.org>, David Hildenbrand <david@redhat.com>, Donald Dutile <ddutile@redhat.com>, Eric Chanudet <echanude@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] arm64: mm: Batch dsb and isb when populating pgtables Date: Wed, 27 Mar 2024 19:07:23 +0000 [thread overview] Message-ID: <20240327190723.185232-1-ryan.roberts@arm.com> (raw) In-Reply-To: <20240326101448.3453626-1-ryan.roberts@arm.com> After removing uneccessary TLBIs, the next bottleneck when creating the page tables for the linear map is DSB and ISB, which were previously issued per-pte in __set_pte(). Since we are writing multiple ptes in a given pte table, we can elide these barriers and insert them once we have finished writing to the table. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- arch/arm64/include/asm/pgtable.h | 7 ++++++- arch/arm64/mm/mmu.c | 13 ++++++++++++- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index bd5d02f3f0a3..81e427b23b3f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -271,9 +271,14 @@ static inline pte_t pte_mkdevmap(pte_t pte) return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL)); } -static inline void __set_pte(pte_t *ptep, pte_t pte) +static inline void ___set_pte(pte_t *ptep, pte_t pte) { WRITE_ONCE(*ptep, pte); +} + +static inline void __set_pte(pte_t *ptep, pte_t pte) +{ + ___set_pte(ptep, pte); /* * Only if the new pte is valid and kernel, otherwise TLB maintenance diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 1b2a2a2d09b7..c6d5a76732d4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -301,7 +301,11 @@ static pte_t *init_pte(pte_t *ptep, unsigned long addr, unsigned long end, do { pte_t old_pte = __ptep_get(ptep); - __set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); + /* + * Required barriers to make this visible to the table walker + * are deferred to the end of alloc_init_cont_pte(). + */ + ___set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); /* * After the PTE entry has been populated once, we @@ -358,6 +362,13 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, } while (addr = next, addr != end); ops->unmap(TYPE_PTE); + + /* + * Ensure all previous pgtable writes are visible to the table walker. + * See init_pte(). + */ + dsb(ishst); + isb(); } static pmd_t *init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end, -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Ryan Roberts <ryan.roberts@arm.com> To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Ard Biesheuvel <ardb@kernel.org>, David Hildenbrand <david@redhat.com>, Donald Dutile <ddutile@redhat.com>, Eric Chanudet <echanude@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] arm64: mm: Batch dsb and isb when populating pgtables Date: Wed, 27 Mar 2024 19:07:23 +0000 [thread overview] Message-ID: <20240327190723.185232-1-ryan.roberts@arm.com> (raw) In-Reply-To: <20240326101448.3453626-1-ryan.roberts@arm.com> After removing uneccessary TLBIs, the next bottleneck when creating the page tables for the linear map is DSB and ISB, which were previously issued per-pte in __set_pte(). Since we are writing multiple ptes in a given pte table, we can elide these barriers and insert them once we have finished writing to the table. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- arch/arm64/include/asm/pgtable.h | 7 ++++++- arch/arm64/mm/mmu.c | 13 ++++++++++++- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index bd5d02f3f0a3..81e427b23b3f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -271,9 +271,14 @@ static inline pte_t pte_mkdevmap(pte_t pte) return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL)); } -static inline void __set_pte(pte_t *ptep, pte_t pte) +static inline void ___set_pte(pte_t *ptep, pte_t pte) { WRITE_ONCE(*ptep, pte); +} + +static inline void __set_pte(pte_t *ptep, pte_t pte) +{ + ___set_pte(ptep, pte); /* * Only if the new pte is valid and kernel, otherwise TLB maintenance diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 1b2a2a2d09b7..c6d5a76732d4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -301,7 +301,11 @@ static pte_t *init_pte(pte_t *ptep, unsigned long addr, unsigned long end, do { pte_t old_pte = __ptep_get(ptep); - __set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); + /* + * Required barriers to make this visible to the table walker + * are deferred to the end of alloc_init_cont_pte(). + */ + ___set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); /* * After the PTE entry has been populated once, we @@ -358,6 +362,13 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, } while (addr = next, addr != end); ops->unmap(TYPE_PTE); + + /* + * Ensure all previous pgtable writes are visible to the table walker. + * See init_pte(). + */ + dsb(ishst); + isb(); } static pmd_t *init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end, -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-03-27 19:07 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-26 10:14 [PATCH v1 0/3] Speed up boot with faster linear map creation Ryan Roberts 2024-03-26 10:14 ` Ryan Roberts 2024-03-26 10:14 ` [PATCH v1 1/3] arm64: mm: Don't remap pgtables per- cont(pte|pmd) block Ryan Roberts 2024-03-26 10:14 ` Ryan Roberts 2024-03-26 10:14 ` [PATCH v1 2/3] arm64: mm: Don't remap pgtables for allocate vs populate Ryan Roberts 2024-03-26 10:14 ` Ryan Roberts 2024-03-27 2:05 ` kernel test robot 2024-03-27 2:05 ` kernel test robot 2024-03-26 10:14 ` [PATCH v1 3/3] arm64: mm: Lazily clear pte table mappings from fixmap Ryan Roberts 2024-03-26 10:14 ` Ryan Roberts 2024-03-27 10:09 ` [PATCH v1 0/3] Speed up boot with faster linear map creation Ard Biesheuvel 2024-03-27 10:09 ` Ard Biesheuvel 2024-03-27 10:43 ` Ryan Roberts 2024-03-27 10:43 ` Ryan Roberts 2024-03-27 13:36 ` Ard Biesheuvel 2024-03-27 13:36 ` Ard Biesheuvel 2024-03-27 15:01 ` Ryan Roberts 2024-03-27 15:01 ` Ryan Roberts 2024-03-27 15:57 ` Ard Biesheuvel 2024-03-27 15:57 ` Ard Biesheuvel 2024-03-27 16:11 ` Ryan Roberts 2024-03-27 16:11 ` Ryan Roberts 2024-03-27 11:06 ` Itaru Kitayama 2024-03-27 11:06 ` Itaru Kitayama 2024-03-27 11:10 ` Ryan Roberts 2024-03-27 11:10 ` Ryan Roberts 2024-03-27 19:07 ` Ryan Roberts [this message] 2024-03-27 19:07 ` [PATCH v1] arm64: mm: Batch dsb and isb when populating pgtables Ryan Roberts 2024-03-28 7:23 ` Ard Biesheuvel 2024-03-28 7:23 ` Ard Biesheuvel 2024-03-28 8:45 ` Ryan Roberts 2024-03-28 8:45 ` Ryan Roberts 2024-03-28 8:56 ` Ard Biesheuvel 2024-03-28 8:56 ` Ard Biesheuvel 2024-03-27 19:12 ` [PATCH v1 0/3] Speed up boot with faster linear map creation Ryan Roberts 2024-03-27 19:12 ` Ryan Roberts 2024-03-28 23:08 ` Eric Chanudet 2024-03-28 23:08 ` Eric Chanudet
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