From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32CB0C7EE39 for ; Mon, 30 Jun 2025 10:43:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CAABA6B00AC; Mon, 30 Jun 2025 06:43:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C829B6B00AD; Mon, 30 Jun 2025 06:43:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBFC76B00AE; Mon, 30 Jun 2025 06:43:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id AA3D36B00AC for ; Mon, 30 Jun 2025 06:43:32 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 5AF36B9B6E for ; Mon, 30 Jun 2025 10:43:32 +0000 (UTC) X-FDA: 83611730664.18.08F466A Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf16.hostedemail.com (Postfix) with ESMTP id 09E0E18000A for ; Mon, 30 Jun 2025 10:43:29 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=none; spf=pass (imf16.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751280210; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wvoEtR1+d63fSfytSwYjnzAR6vEx6RNxsndD2+qi/5E=; b=aV54IkCkfsGhw8QutQcO7Mrph4rTpP/uihz65CNQsLMrQn6EfyepoYHOA/IDqtox3aGnQQ GFEn1UkGQwkqDM0/7voZGktm5+ppc3ZhjbckjLsUJPrwp6/APukp+o/IkkWE5yXH8vR7GO nHONB8/cuIN1i+RO5hFqc7At0r8286s= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=none; spf=pass (imf16.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751280210; a=rsa-sha256; cv=none; b=f7r0F9pFjNkMjJ8R++KWKE385d1TBW341oeTUjFgZ71DfWI1YnZufvd3hfgMiV7JYmyCrb MyLM6QVm9aysMjv6HVyrVqY00qZPinUhT4A3PM//r4dAB0zJqYvaEgxPScBeBi7mabfLT9 4UoE0TUAdcBuf6ZivdDIq5M6CrJmZGU= 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 1EE991D34; Mon, 30 Jun 2025 03:43:13 -0700 (PDT) Received: from [10.1.34.165] (XHFQ2J9959.cambridge.arm.com [10.1.34.165]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0E6C53F58B; Mon, 30 Jun 2025 03:43:24 -0700 (PDT) Message-ID: <051d5338-d073-4a92-abd2-c68367c17636@arm.com> Date: Mon, 30 Jun 2025 11:43:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 4/4] arm64: Add batched versions of ptep_modify_prot_start/commit Content-Language: en-GB To: Dev Jain , akpm@linux-foundation.org Cc: 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 References: <20250628113435.46678-1-dev.jain@arm.com> <20250628113435.46678-5-dev.jain@arm.com> From: Ryan Roberts In-Reply-To: <20250628113435.46678-5-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 09E0E18000A X-Stat-Signature: nn68egnpnw78kx94tnftxebmgcru3ads X-HE-Tag: 1751280209-922542 X-HE-Meta: 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 tVqkdV+C SutH49MCmNmhQU5xPfcy9h9dhPiKw6ZXcOvNLtJ1oRwFxPzJqbFKskC1T64RTKw23uiaCPidcS5lx/EBEn1A9wzPzga5KmBGaDc0jwk5w4vErcGdpWXDNISvgGJTMgcZdy9qO/Utxb8nr4IYhnoBQl9R8u9NFOmSNZx1F4Vx2+wWHR39LmN6Ul8qzisWx9M9bU5T/OcgglroIDfU5JSjmeXCkmfUo+poHLl7ETQLa4IhU/FOZiBqfYlNhs4iIifO+LN1EN2vx/FjqXrSBKWMyX6GxQg9p8LYWjoCE8Y4eVAOOIxJpwMeI0WFMItn+OEsT1+ib 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 28/06/2025 12:34, Dev Jain wrote: > 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. > > Signed-off-by: Dev Jain Reviewed-by: Ryan Roberts > --- > 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..38325616f467 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, 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); > } > > /*