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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69514C3565B for ; Fri, 21 Feb 2020 18:25:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3A7B7222C4 for ; Fri, 21 Feb 2020 18:25:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A7B7222C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=deltatee.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 928DC6B000A; Fri, 21 Feb 2020 13:25:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8879E6B000E; Fri, 21 Feb 2020 13:25:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6DCB96B000D; Fri, 21 Feb 2020 13:25:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id 4FCFA6B000C for ; Fri, 21 Feb 2020 13:25:31 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0CC15824805A for ; Fri, 21 Feb 2020 18:25:31 +0000 (UTC) X-FDA: 76514962062.11.sun36_4d39314e6d13d X-HE-Tag: sun36_4d39314e6d13d X-Filterd-Recvd-Size: 4314 Received: from ale.deltatee.com (ale.deltatee.com [207.54.116.67]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Fri, 21 Feb 2020 18:25:30 +0000 (UTC) Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j5CzA-00057s-B6; Fri, 21 Feb 2020 11:25:25 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1j5Cz3-0007Nt-Mw; Fri, 21 Feb 2020 11:25:05 -0700 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-mm@kvack.org, Dan Williams , Michal Hocko , David Hildenbrand , Andrew Morton Cc: Christoph Hellwig , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Eric Badger , Logan Gunthorpe , Jason Gunthorpe Date: Fri, 21 Feb 2020 11:25:03 -0700 Message-Id: <20200221182503.28317-8-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200221182503.28317-1-logang@deltatee.com> References: <20200221182503.28317-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-mm@kvack.org, dan.j.williams@intel.com, akpm@linux-foundation.org, hch@lst.de, catalin.marinas@arm.com, benh@kernel.crashing.org, tglx@linutronix.de, david@redhat.com, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, mhocko@kernel.org, will@kernel.org, luto@kernel.org, peterz@infradead.org, ebadger@gigaio.com, logang@deltatee.com, jgg@ziepe.ca X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v3 7/7] mm/memremap: Set caching mode for PCI P2PDMA memory to WC X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Content-Transfer-Encoding: quoted-printable 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: PCI BAR IO memory should never be mapped as WB, however prior to this the PAT bits were set WB and it was typically overridden by MTRR registers set by the firmware. Set PCI P2PDMA memory to be WC (writecombining) as the only current user (the NVMe CMB) was originally mapped WC before the P2PDMA code replaced the mapping with devm_memremap_pages(). Future use-cases may need to generalize this by adding flags to select the caching type, as some P2PDMA cases will not want WC. However, those use-cases are not upstream yet and this can be changed when they arrive. Cc: Dan Williams Cc: Christoph Hellwig Cc: Jason Gunthorpe Signed-off-by: Logan Gunthorpe --- mm/memremap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memremap.c b/mm/memremap.c index 06742372a203..8d141c3e3364 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -190,7 +190,10 @@ void *memremap_pages(struct dev_pagemap *pgmap, int = nid) } break; case MEMORY_DEVICE_DEVDAX: + need_devmap_managed =3D false; + break; case MEMORY_DEVICE_PCI_P2PDMA: + params.pgprot =3D pgprot_writecombine(params.pgprot); need_devmap_managed =3D false; break; default: --=20 2.20.1