From patchwork Tue Mar 26 16:47:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jerome Glisse X-Patchwork-Id: 10871635 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A12EE13B5 for ; Tue, 26 Mar 2019 16:48:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A6F528D00 for ; Tue, 26 Mar 2019 16:48:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E49028D5D; Tue, 26 Mar 2019 16:48:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 183C928D00 for ; Tue, 26 Mar 2019 16:48:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EDAFF6E082; Tue, 26 Mar 2019 16:48:28 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2931B6E083 for ; Tue, 26 Mar 2019 16:48:27 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7399A3086212; Tue, 26 Mar 2019 16:48:26 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.20.6.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 485878428A; Tue, 26 Mar 2019 16:48:24 +0000 (UTC) From: jglisse@redhat.com To: linux-kernel@vger.kernel.org Subject: [PATCH v6 8/8] mm/mmu_notifier: mmu_notifier_range_update_to_read_only() helper Date: Tue, 26 Mar 2019 12:47:47 -0400 Message-Id: <20190326164747.24405-9-jglisse@redhat.com> In-Reply-To: <20190326164747.24405-1-jglisse@redhat.com> References: <20190326164747.24405-1-jglisse@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Tue, 26 Mar 2019 16:48:26 +0000 (UTC) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , kvm@vger.kernel.org, =?utf-8?b?UmFkaW0gS3LEjW0=?= =?utf-8?b?w6HFmQ==?= , dri-devel@lists.freedesktop.org, Michal Hocko , linux-mm@kvack.org, Ross Zwisler , Andrea Arcangeli , linux-rdma@vger.kernel.org, Jason Gunthorpe , Ralph Campbell , Arnd Bergmann , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Peter Xu , Rodrigo Vivi , Dan Williams , Felix Kuehling , Paolo Bonzini , Andrew Morton , =?utf-8?q?Christian_K=C3=B6nig?= Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Jérôme Glisse Helper to test if a range is updated to read only (it is still valid to read from the range). This is useful for device driver or anyone who wish to optimize out update when they know that they already have the range map read only. Signed-off-by: Jérôme Glisse Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: Christian König Cc: Joonas Lahtinen Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Jan Kara Cc: Andrea Arcangeli Cc: Peter Xu Cc: Felix Kuehling Cc: Jason Gunthorpe Cc: Ross Zwisler Cc: Dan Williams Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Michal Hocko Cc: Christian Koenig Cc: Ralph Campbell Cc: John Hubbard Cc: kvm@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-rdma@vger.kernel.org Cc: Arnd Bergmann --- include/linux/mmu_notifier.h | 4 ++++ mm/mmu_notifier.c | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 0379956fff23..b6c004bd9f6a 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -259,6 +259,8 @@ extern void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *r, bool only_end); extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end); +extern bool +mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range); static inline bool mmu_notifier_range_blockable(const struct mmu_notifier_range *range) @@ -568,6 +570,8 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm) { } +#define mmu_notifier_range_update_to_read_only(r) false + #define ptep_clear_flush_young_notify ptep_clear_flush_young #define pmdp_clear_flush_young_notify pmdp_clear_flush_young #define ptep_clear_young_notify ptep_test_and_clear_young diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index abd88c466eb2..ee36068077b6 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -395,3 +395,13 @@ void mmu_notifier_unregister_no_release(struct mmu_notifier *mn, mmdrop(mm); } EXPORT_SYMBOL_GPL(mmu_notifier_unregister_no_release); + +bool +mmu_notifier_range_update_to_read_only(const struct mmu_notifier_range *range) +{ + if (!range->vma || range->event != MMU_NOTIFY_PROTECTION_VMA) + return false; + /* Return true if the vma still have the read flag set. */ + return range->vma->vm_flags & VM_READ; +} +EXPORT_SYMBOL_GPL(mmu_notifier_range_update_to_read_only);