From patchwork Fri Mar 6 17:08:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 11424419 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 95ED6138D for ; Fri, 6 Mar 2020 17:10:31 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7339820658 for ; Fri, 6 Mar 2020 17:10:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="l6cnvNzd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7339820658 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=deltatee.com Authentication-Results: mail.kernel.org; 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Fri, 06 Mar 2020 17:10:27 +0000 Received: from ale.deltatee.com ([207.54.116.67]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jAGT6-0002c2-3b for linux-arm-kernel@lists.infradead.org; Fri, 06 Mar 2020 17:09:03 +0000 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 1jAGSz-0004aV-SV; Fri, 06 Mar 2020 10:08:59 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1jAGSv-0002Rf-Tz; Fri, 06 Mar 2020 10:08:49 -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, Dan Williams , Michal Hocko , David Hildenbrand , Andrew Morton Date: Fri, 6 Mar 2020 10:08:45 -0700 Message-Id: <20200306170846.9333-7-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200306170846.9333-1-logang@deltatee.com> References: <20200306170846.9333-1-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, mhocko@suse.com 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=-6.7 required=5.0 tests=ALL_TRUSTED,BAYES_00, MYRULES_NO_TEXT,SURBL_BLOCKED,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.2 Subject: [PATCH v4 6/7] mm/memory_hotplug: Add pgprot_t to mhp_params 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200306_090900_470382_6169F547 X-CRM114-Status: GOOD ( 19.44 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [207.54.116.67 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Badger , Peter Zijlstra , Catalin Marinas , Dave Hansen , Michal Hocko , Logan Gunthorpe , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Benjamin Herrenschmidt , Thomas Gleixner , Will Deacon , Christoph Hellwig Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org devm_memremap_pages() is currently used by the PCI P2PDMA code to create struct page mappings for IO memory. At present, these mappings are created with PAGE_KERNEL which implies setting the PAT bits to be WB. However, on x86, an mtrr register will typically override this and force the cache type to be UC-. In the case firmware doesn't set this register it is effectively WB and will typically result in a machine check exception when it's accessed. Other arches are not currently likely to function correctly seeing they don't have any MTRR registers to fall back on. To solve this, provide a way to specify the pgprot value explicitly to arch_add_memory(). Of the arches that support MEMORY_HOTPLUG: x86_64, and arm64 need a simple change to pass the pgprot_t down to their respective functions which set up the page tables. For x86_32, set the page tables explicitly using _set_memory_prot() (seeing they are already mapped). For ia64, s390 and sh, reject anything but PAGE_KERNEL settings -- this should be fine, for now, seeing these architectures don't support ZONE_DEVICE. A check in __add_pages() is also added to ensure the pgprot parameter was set for all arches. Signed-off-by: Logan Gunthorpe Acked-by: David Hildenbrand Acked-by: Michal Hocko Acked-by: Dan Williams --- arch/arm64/mm/mmu.c | 3 ++- arch/ia64/mm/init.c | 3 +++ arch/powerpc/mm/mem.c | 3 ++- arch/s390/mm/init.c | 3 +++ arch/sh/mm/init.c | 3 +++ arch/x86/mm/init_32.c | 12 ++++++++++++ arch/x86/mm/init_64.c | 2 +- include/linux/memory_hotplug.h | 3 +++ mm/memory_hotplug.c | 5 ++++- mm/memremap.c | 6 +++--- 10 files changed, 36 insertions(+), 7 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ee37bca8aba8..ea3fa844a8a2 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1058,7 +1058,8 @@ int arch_add_memory(int nid, u64 start, u64 size, flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start), - size, PAGE_KERNEL, __pgd_pgtable_alloc, flags); + size, params->pgprot, __pgd_pgtable_alloc, + flags); memblock_clear_nomap(start, size); diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index 97bbc23ea1e3..d637b4ea3147 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -676,6 +676,9 @@ int arch_add_memory(int nid, u64 start, u64 size, unsigned long nr_pages = size >> PAGE_SHIFT; int ret; + if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) + return -EINVAL; + ret = __add_pages(nid, start_pfn, nr_pages, params); if (ret) printk("%s: Problem encountered in __add_pages() as ret=%d\n", diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 19b1da5d7eca..832412bc7fad 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -138,7 +138,8 @@ int __ref arch_add_memory(int nid, u64 start, u64 size, resize_hpt_for_hotplug(memblock_phys_mem_size()); start = (unsigned long)__va(start); - rc = create_section_mapping(start, start + size, nid, PAGE_KERNEL); + rc = create_section_mapping(start, start + size, nid, + params->pgprot); if (rc) { pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n", start, start + size, rc); diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index e9e4a7abd0cc..87b2d024e75a 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -277,6 +277,9 @@ int arch_add_memory(int nid, u64 start, u64 size, if (WARN_ON_ONCE(params->altmap)) return -EINVAL; + if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) + return -EINVAL; + rc = vmem_add_mapping(start, size); if (rc) return rc; diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c index e5114c053364..b9de2d4fa57e 100644 --- a/arch/sh/mm/init.c +++ b/arch/sh/mm/init.c @@ -412,6 +412,9 @@ int arch_add_memory(int nid, u64 start, u64 size, unsigned long nr_pages = size >> PAGE_SHIFT; int ret; + if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot) + return -EINVAL; + /* We only have ZONE_NORMAL, so this is easy.. */ ret = __add_pages(nid, start_pfn, nr_pages, params); if (unlikely(ret)) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index e25a4218e6ff..69128f1a22ac 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -858,6 +858,18 @@ int arch_add_memory(int nid, u64 start, u64 size, { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; + int ret; + + /* + * The page tables were already mapped at boot so if the caller + * requests a different mapping type then we must change all the + * pages with __set_memory_prot(). + */ + if (params->pgprot.pgprot != PAGE_KERNEL.pgprot) { + ret = __set_memory_prot(start, nr_pages, params->pgprot); + if (ret) + return ret; + } return __add_pages(nid, start_pfn, nr_pages, params); } diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 9e7692080dda..230240af38b4 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -868,7 +868,7 @@ int arch_add_memory(int nid, u64 start, u64 size, unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; - init_memory_mapping(start, start + size, PAGE_KERNEL); + init_memory_mapping(start, start + size, params->pgprot); return add_pages(nid, start_pfn, nr_pages, params); } diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index c5df1b3dada0..3195d11876ea 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -56,9 +56,12 @@ enum { /* * Extended parameters for memory hotplug: * altmap: alternative allocator for memmap array (optional) + * pgprot: page protection flags to apply to newly created page tables + * (required) */ struct mhp_params { struct vmem_altmap *altmap; + pgprot_t pgprot; }; /* diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index c69469e1b40e..d7d4806ad81b 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -305,6 +305,9 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, unsigned long nr, start_sec, end_sec; struct vmem_altmap *altmap = params->altmap; + if (WARN_ON_ONCE(!params->pgprot.pgprot)) + return -EINVAL; + err = check_hotplug_memory_addressable(pfn, nr_pages); if (err) return err; @@ -993,7 +996,7 @@ static int online_memory_block(struct memory_block *mem, void *arg) */ int __ref add_memory_resource(int nid, struct resource *res) { - struct mhp_params params = {}; + struct mhp_params params = { .pgprot = PAGE_KERNEL }; u64 start, size; bool new_node = false; int ret; diff --git a/mm/memremap.c b/mm/memremap.c index 6891a503a078..06742372a203 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -166,8 +166,8 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) * We do not want any optional features only our own memmap */ .altmap = pgmap_altmap(pgmap), + .pgprot = PAGE_KERNEL, }; - pgprot_t pgprot = PAGE_KERNEL; int error, is_ram; bool need_devmap_managed = true; @@ -255,8 +255,8 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) if (nid < 0) nid = numa_mem_id(); - error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(res->start), 0, - resource_size(res)); + error = track_pfn_remap(NULL, ¶ms.pgprot, PHYS_PFN(res->start), + 0, resource_size(res)); if (error) goto err_pfn_remap;