From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 736B22951C9 for ; Fri, 18 Jul 2025 09:04:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752829442; cv=none; b=gpKNGdy0/Opy+iMAh2lFLwZY/wSUv5di2zjyjKfFprexbL0XXPAiSKPwZwygcM73SQRDtjqOpaV/7QKe1Mr/HnaYB5wnmJtxkQAYpUIlQLhgAarTxGeawX/cxa4GbvUAXRZ2TE6GaKIbYn6K/8g3rZsUpCdyEVOXtNTNB9EMsog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752829442; c=relaxed/simple; bh=Lhj/0djTDWSJf1Z6VuMaPZsg4fHZNRtnhEy6yyfSKEo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eQ1Fg1JJnD/2WU8gy8znj+gFoJ0lj4jvPcAf61wQ2pooxK6F7j6MOqENMexeNwpA4MRGpBJJBfkoDdvaf+fGNIXfyl7ooAQ3o6LE9Fl8xq4lQVMRkumnnv207G4xnju6WyiVJIlPimPk37HPCLBeeQqW3aM3qLPAnvX742RqFao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5FAF325DE; Fri, 18 Jul 2025 02:03:53 -0700 (PDT) Received: from MacBook-Pro.blr.arm.com (unknown [10.164.18.51]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AF5A63F66E; Fri, 18 Jul 2025 02:03:52 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org Cc: ryan.roberts@arm.com, david@redhat.com, willy@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, anshuman.khandual@arm.com, peterx@redhat.com, joey.gouly@arm.com, ioworker0@gmail.com, baohua@kernel.org, kevin.brodsky@arm.com, quic_zhenhuah@quicinc.com, christophe.leroy@csgroup.eu, yangyicong@hisilicon.com, linux-arm-kernel@lists.infradead.org, hughd@google.com, yang@os.amperecomputing.com, ziy@nvidia.com, Dev Jain Subject: [PATCH v5 7/7] arm64: Add batched versions of ptep_modify_prot_start/commit Date: Fri, 18 Jul 2025 14:32:44 +0530 Message-Id: <20250718090244.21092-8-dev.jain@arm.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250718090244.21092-1-dev.jain@arm.com> References: <20250718090244.21092-1-dev.jain@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Override the generic definition of modify_prot_start_ptes() 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 in the errata specific case: #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. Override the generic definition of modify_prot_commit_ptes() to simply use set_ptes() to map the new ptes into the pagetable. Reviewed-by: Ryan Roberts Signed-off-by: Dev Jain --- arch/arm64/include/asm/pgtable.h | 10 ++++++++++ arch/arm64/mm/mmu.c | 28 +++++++++++++++++++++++----- 2 files changed, 33 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index ba63c8736666..abd2dee416b3 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1643,6 +1643,16 @@ 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); + +#define modify_prot_commit_ptes modify_prot_commit_ptes +extern void modify_prot_commit_ptes(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte, + unsigned int nr); + #ifdef CONFIG_ARM64_CONTPTE /* diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 3d5fb37424ab..abd9725796e9 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -1524,24 +1525,41 @@ 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) { + pte_t pte = get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, /* full = */ 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_user_exec(ptep_get(ptep))) - return ptep_clear_flush(vma, addr, ptep); + if (pte_accessible(vma->vm_mm, pte) && pte_user_exec(pte)) + __flush_tlb_range(vma, addr, nr * PAGE_SIZE, + PAGE_SIZE, true, 3); } - return ptep_get_and_clear(vma->vm_mm, addr, ptep); + + 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 modify_prot_commit_ptes(struct vm_area_struct *vma, unsigned long addr, + pte_t *ptep, pte_t old_pte, pte_t pte, + unsigned int nr) +{ + set_ptes(vma->vm_mm, addr, ptep, pte, nr); } void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, pte_t old_pte, pte_t pte) { - set_pte_at(vma->vm_mm, addr, ptep, pte); + modify_prot_commit_ptes(vma, addr, ptep, old_pte, pte, 1); } /* -- 2.30.2