From patchwork Fri Feb 21 18:25:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 1242305 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 48PLB552rSz9sR4 for ; Sat, 22 Feb 2020 05:50:21 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=deltatee.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48PLB52fF6zDqNS for ; Sat, 22 Feb 2020 05:50:21 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=deltatee.com (client-ip=207.54.116.67; helo=ale.deltatee.com; envelope-from=gunthorp@deltatee.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=deltatee.com X-Greylist: delayed 1441 seconds by postgrey-1.36 at bilbo; Sat, 22 Feb 2020 05:49:19 AEDT Received: from ale.deltatee.com (ale.deltatee.com [207.54.116.67]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48PL8v2PXMzDqlK for ; Sat, 22 Feb 2020 05:49:18 +1100 (AEDT) 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 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 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on ale.deltatee.com X-Spam-Level: X-Spam-Status: No, score=-8.7 required=5.0 tests=ALL_TRUSTED,BAYES_00, GREYLIST_ISWHITE,MYRULES_NO_TEXT,SURBL_BLOCKED,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 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) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Badger , Peter Zijlstra , Catalin Marinas , Dave Hansen , Jason Gunthorpe , Logan Gunthorpe , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Will Deacon , Christoph Hellwig Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 Reviewed-by: Dan Williams --- 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 = false; + break; case MEMORY_DEVICE_PCI_P2PDMA: + params.pgprot = pgprot_writecombine(params.pgprot); need_devmap_managed = false; break; default: