From nobody Mon Dec 15 14:51:03 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 827472690FA for ; Mon, 19 May 2025 07:49:10 +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=1747640952; cv=none; b=gNJqYaFSOk+Ug90q9P8VX5XGYpclbwIrKmMvp+wxo/woU9ZF7jwnAeLFbjDqG1wCSnOaCLyymJHRY0ZLW3kD7uAk6ezFGNVxOPcLYdTeQyAxeH/hbz5+Eo8JNJLwcRwDQ39ZZE5WpjOUObN+FllsV8mTNXQ90gk5oyaT0w5als0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747640952; c=relaxed/simple; bh=SUvq8+/P1bH8HQn7a35qaXBHPdO8YqeMux3tV7BsN10=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=iHVM+IkucumH+cKl5BhLw04SzCgUUjcCG2oKh0qrAPfBTrnklGLVsYMtDL99g8QiYOXQ9RwHf92ClgGat94lsl1Mb3S9EzKiZSeCX+84S88O5Ict8NiJGw1+m+XMxXfDcTtWj9GE7BHD45L7k+PClbilkJ7t5o/WJpF0yBmuwlc= 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 D5B2D14BF; Mon, 19 May 2025 00:48:56 -0700 (PDT) Received: from K4MQJ0H1H2.blr.arm.com (unknown [10.164.18.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 3537C3F6A8; Mon, 19 May 2025 00:49:02 -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 v3 4/5] arm64: Add batched version of ptep_modify_prot_start Date: Mon, 19 May 2025 13:18:23 +0530 Message-Id: <20250519074824.42909-5-dev.jain@arm.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20250519074824.42909-1-dev.jain@arm.com> References: <20250519074824.42909-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" Override the generic definition to use get_and_clear_full_ptes(). This help= er does a TLBI only for the starting and ending contpte block of the range, wh= ereas 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 cl= ear_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 --- 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/pgta= ble.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_s= truct *vma, unsigned long addr, pte_t *ptep, pte_t old_pte, pte_t new_pte); =20 +#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 =20 /* 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 =20 -pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long add= r, pte_t *ptep) +pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long add= r, + 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); +} + +pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long add= r, pte_t *ptep) +{ + return modify_prot_start_ptes(vma, addr, ptep, 1); } =20 void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long add= r, 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 *v= ma, pte_t *ptep); #endif =20 +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 =20 -#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 =3D (vma)->vm_mm; pte_t pte; - pte =3D ptep_get_and_clear(mm, address, ptep); + pte =3D 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; } + +#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 =20 #ifdef CONFIG_TRANSPARENT_HUGEPAGE --=20 2.30.2