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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 23DF4C00454 for ; Mon, 9 Dec 2019 19:14:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2808206E0 for ; Mon, 9 Dec 2019 19:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726890AbfLITOE (ORCPT ); Mon, 9 Dec 2019 14:14:04 -0500 Received: from ale.deltatee.com ([207.54.116.67]:56026 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfLITOE (ORCPT ); Mon, 9 Dec 2019 14:14:04 -0500 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 1ieOTk-00025k-Lg; Mon, 09 Dec 2019 12:13:57 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1ieOTd-0001Me-0k; Mon, 09 Dec 2019 12:13:49 -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, Christoph Hellwig , Dan Williams , Andrew Morton Cc: Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Logan Gunthorpe Date: Mon, 9 Dec 2019 12:13:40 -0700 Message-Id: <20191209191346.5197-1-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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, hch@lst.de, dan.j.williams@intel.com, akpm@linux-foundation.org, catalin.marinas@arm.com, benh@kernel.crashing.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, will@kernel.org, luto@kernel.org, peterz@infradead.org, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH 0/6] Allow setting caching mode in arch_add_memory() for P2PDMA 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) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Currently, the page tables created using memremap_pages() are always created with the PAGE_KERNEL cacheing mode. However, the P2PDMA code is creating pages for PCI BAR memory which should never be accessed through the cache and instead use either WC or UC. This still works in most cases, on x86, because the MTRR registers typically override the caching settings in the page tables for all of the IO memory to be UC-. However, this tends not to work so well on other arches or some rare x86 machines that have firmware which does not setup the MTRR registers in this way. Instead of this, this series proposes a change to arch_add_memory() to take the pgprot required by the mapping which allows us to explicitly set pagetable entries for P2PDMA memory to WC. This changes is pretty routine for most of the arches: x86_64, s390, arm64 and powerpc simply need to thread the pgprot through to where the page tables are setup. x86_32 unfortunately sets up the page tables at boot so must use _set_memory_prot() to change their caching mode. ia64 and sh don't appear to have an easy way to change the page tables so, for now at least, we just return -EINVAL on such mappings and thus they will not support P2PDMA memory until the work for this is done. Thanks, Logan -- Logan Gunthorpe (6): x86/mm: Thread pgprot_t through init_memory_mapping() x86/mm: Introduce _set_memory_prot() powerpc/mm: Thread pgprot_t through create_section_mapping() s390/mm: Thread pgprot_t through vmem_add_mapping() mm, memory_hotplug: Provide argument for the pgprot_t in arch_add_memory() mm/memremap: Set caching mode for PCI P2PDMA memory to WC arch/arm64/mm/mmu.c | 4 +-- arch/ia64/mm/init.c | 5 +++- arch/powerpc/include/asm/book3s/64/hash.h | 3 +- arch/powerpc/include/asm/book3s/64/radix.h | 3 +- arch/powerpc/include/asm/sparsemem.h | 3 +- arch/powerpc/mm/book3s64/hash_utils.c | 5 ++-- arch/powerpc/mm/book3s64/pgtable.c | 7 +++-- arch/powerpc/mm/book3s64/radix_pgtable.c | 18 +++++++----- arch/powerpc/mm/mem.c | 7 +++-- arch/s390/include/asm/pgtable.h | 3 +- arch/s390/mm/extmem.c | 3 +- arch/s390/mm/init.c | 4 +-- arch/s390/mm/vmem.c | 10 +++---- arch/sh/mm/init.c | 5 +++- arch/x86/include/asm/page_types.h | 3 -- arch/x86/include/asm/pgtable.h | 3 ++ arch/x86/include/asm/set_memory.h | 1 + arch/x86/kernel/amd_gart_64.c | 3 +- arch/x86/mm/init.c | 9 +++--- arch/x86/mm/init_32.c | 10 +++++-- arch/x86/mm/init_64.c | 34 ++++++++++++---------- arch/x86/mm/mm_internal.h | 3 +- arch/x86/mm/pageattr.c | 7 +++++ arch/x86/platform/efi/efi_64.c | 3 +- include/linux/memory_hotplug.h | 2 +- mm/memory_hotplug.c | 2 +- mm/memremap.c | 5 +++- 27 files changed, 104 insertions(+), 61 deletions(-) -- 2.20.1