From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Date: Mon, 09 Dec 2019 19:23:33 +0000 Subject: Re: [PATCH 5/6] mm, memory_hotplug: Provide argument for the pgprot_t in arch_add_memory() Message-Id: List-Id: References: <20191209191346.5197-1-logang@deltatee.com> <20191209191346.5197-6-logang@deltatee.com> In-Reply-To: <20191209191346.5197-6-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Logan Gunthorpe , 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: Michal Hocko , Peter Zijlstra , Catalin Marinas , Dave Hansen , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Benjamin Herrenschmidt , Thomas Gleixner , Will Deacon On 09.12.19 20:13, Logan Gunthorpe wrote: > 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, add an argument to arch_add_memory() to explicitly > set the pgprot value to a specific value. > > Of the arches that support MEMORY_HOTPLUG: x86_64, s390 and arm64 is 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 sh, reject > anything but PAGE_KERNEL settings -- this should be fine, for now, seeing > sh doesn't support ZONE_DEVICE anyway. > > Cc: Dan Williams > Cc: David Hildenbrand > Cc: Michal Hocko > Signed-off-by: Logan Gunthorpe > --- > arch/arm64/mm/mmu.c | 4 ++-- > arch/ia64/mm/init.c | 5 ++++- > arch/powerpc/mm/mem.c | 4 ++-- > arch/s390/mm/init.c | 4 ++-- > arch/sh/mm/init.c | 5 ++++- > arch/x86/mm/init_32.c | 7 ++++++- > arch/x86/mm/init_64.c | 4 ++-- > include/linux/memory_hotplug.h | 2 +- > mm/memory_hotplug.c | 2 +- > mm/memremap.c | 2 +- > 10 files changed, 25 insertions(+), 14 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 60c929f3683b..48b65272df15 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1050,7 +1050,7 @@ int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) > } > > #ifdef CONFIG_MEMORY_HOTPLUG > -int arch_add_memory(int nid, u64 start, u64 size, > +int arch_add_memory(int nid, u64 start, u64 size, pgprot_t prot, > struct mhp_restrictions *restrictions) Can we fiddle that into "struct mhp_restrictions" instead? -- Thanks, David / dhildenb 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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 D3D6EC00454 for ; Mon, 9 Dec 2019 19:23:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B41B206E0 for ; Mon, 9 Dec 2019 19:23:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YCNOsS8V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726901AbfLITXs (ORCPT ); Mon, 9 Dec 2019 14:23:48 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:40133 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726342AbfLITXs (ORCPT ); Mon, 9 Dec 2019 14:23:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575919425; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=00YX7DspdEWQKLHyHwK2miKeLnhqyZ2f3RIwSXrO4z0=; b=YCNOsS8VEBLd6A/oczB38UnFRsaUJ88ti/Vv8YdoWFFJ+oo+lfXjG9RuPVmdMgfJ5APZJW 7QVpOSscWhCEBayQUzs5zDha58ZCvavMBnprYqu3a1VDBk1eiXaO6VhEslfQrKdYAr1U2C rIa5DdtokSj8ttGUi9FJjizLy6e6oxY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-164-CGOrIuU7M-WKL-Tj27NBfA-1; Mon, 09 Dec 2019 14:23:42 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EA7421852E22; Mon, 9 Dec 2019 19:23:38 +0000 (UTC) Received: from [10.36.116.214] (ovpn-116-214.ams2.redhat.com [10.36.116.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 59312194BB; Mon, 9 Dec 2019 19:23:34 +0000 (UTC) Subject: Re: [PATCH 5/6] mm, memory_hotplug: Provide argument for the pgprot_t in arch_add_memory() To: Logan Gunthorpe , 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 , Michal Hocko References: <20191209191346.5197-1-logang@deltatee.com> <20191209191346.5197-6-logang@deltatee.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191209191346.5197-6-logang@deltatee.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: CGOrIuU7M-WKL-Tj27NBfA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09.12.19 20:13, Logan Gunthorpe wrote: > 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, add an argument to arch_add_memory() to explicitly > set the pgprot value to a specific value. > > Of the arches that support MEMORY_HOTPLUG: x86_64, s390 and arm64 is 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 sh, reject > anything but PAGE_KERNEL settings -- this should be fine, for now, seeing > sh doesn't support ZONE_DEVICE anyway. > > Cc: Dan Williams > Cc: David Hildenbrand > Cc: Michal Hocko > Signed-off-by: Logan Gunthorpe > --- > arch/arm64/mm/mmu.c | 4 ++-- > arch/ia64/mm/init.c | 5 ++++- > arch/powerpc/mm/mem.c | 4 ++-- > arch/s390/mm/init.c | 4 ++-- > arch/sh/mm/init.c | 5 ++++- > arch/x86/mm/init_32.c | 7 ++++++- > arch/x86/mm/init_64.c | 4 ++-- > include/linux/memory_hotplug.h | 2 +- > mm/memory_hotplug.c | 2 +- > mm/memremap.c | 2 +- > 10 files changed, 25 insertions(+), 14 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 60c929f3683b..48b65272df15 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1050,7 +1050,7 @@ int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) > } > > #ifdef CONFIG_MEMORY_HOTPLUG > -int arch_add_memory(int nid, u64 start, u64 size, > +int arch_add_memory(int nid, u64 start, u64 size, pgprot_t prot, > struct mhp_restrictions *restrictions) Can we fiddle that into "struct mhp_restrictions" instead? -- Thanks, David / dhildenb 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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 783A9C43603 for ; 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helo=us-smtp-1.mimecast.com; envelope-from=david@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="A4uZ4EVm"; dkim-atps=neutral Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 47WtQs6RTFzDqHY for ; Tue, 10 Dec 2019 06:23:49 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575919426; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=00YX7DspdEWQKLHyHwK2miKeLnhqyZ2f3RIwSXrO4z0=; b=A4uZ4EVmKJzzpZv2a1dPQcPKJeJtvwKn1rGkNq2JUgUDe6c2Mn2eSYFQYXLqaVZjZQCKcc KA4ChU3FsO9uwM4c6Rsdov+nYf7ncaWeBSxHcv2fTVhZMxX8x6rkA5LOPM/5aigd5IKQVA OLY25guonKLAkB0DxXlYMI75/lT/Z1I= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-164-CGOrIuU7M-WKL-Tj27NBfA-1; Mon, 09 Dec 2019 14:23:42 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EA7421852E22; Mon, 9 Dec 2019 19:23:38 +0000 (UTC) Received: from [10.36.116.214] (ovpn-116-214.ams2.redhat.com [10.36.116.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 59312194BB; Mon, 9 Dec 2019 19:23:34 +0000 (UTC) Subject: Re: [PATCH 5/6] mm, memory_hotplug: Provide argument for the pgprot_t in arch_add_memory() To: Logan Gunthorpe , 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 References: <20191209191346.5197-1-logang@deltatee.com> <20191209191346.5197-6-logang@deltatee.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191209191346.5197-6-logang@deltatee.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: CGOrIuU7M-WKL-Tj27NBfA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit 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: Michal Hocko , Peter Zijlstra , Catalin Marinas , Dave Hansen , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Will Deacon Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 09.12.19 20:13, Logan Gunthorpe wrote: > 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, add an argument to arch_add_memory() to explicitly > set the pgprot value to a specific value. > > Of the arches that support MEMORY_HOTPLUG: x86_64, s390 and arm64 is 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 sh, reject > anything but PAGE_KERNEL settings -- this should be fine, for now, seeing > sh doesn't support ZONE_DEVICE anyway. > > Cc: Dan Williams > Cc: David Hildenbrand > Cc: Michal Hocko > Signed-off-by: Logan Gunthorpe > --- > arch/arm64/mm/mmu.c | 4 ++-- > arch/ia64/mm/init.c | 5 ++++- > arch/powerpc/mm/mem.c | 4 ++-- > arch/s390/mm/init.c | 4 ++-- > arch/sh/mm/init.c | 5 ++++- > arch/x86/mm/init_32.c | 7 ++++++- > arch/x86/mm/init_64.c | 4 ++-- > include/linux/memory_hotplug.h | 2 +- > mm/memory_hotplug.c | 2 +- > mm/memremap.c | 2 +- > 10 files changed, 25 insertions(+), 14 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 60c929f3683b..48b65272df15 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1050,7 +1050,7 @@ int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) > } > > #ifdef CONFIG_MEMORY_HOTPLUG > -int arch_add_memory(int nid, u64 start, u64 size, > +int arch_add_memory(int nid, u64 start, u64 size, pgprot_t prot, > struct mhp_restrictions *restrictions) Can we fiddle that into "struct mhp_restrictions" instead? -- Thanks, David / dhildenb 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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 B7900C43603 for ; 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Mon, 9 Dec 2019 19:23:38 +0000 (UTC) Received: from [10.36.116.214] (ovpn-116-214.ams2.redhat.com [10.36.116.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 59312194BB; Mon, 9 Dec 2019 19:23:34 +0000 (UTC) Subject: Re: [PATCH 5/6] mm, memory_hotplug: Provide argument for the pgprot_t in arch_add_memory() To: Logan Gunthorpe , 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 References: <20191209191346.5197-1-logang@deltatee.com> <20191209191346.5197-6-logang@deltatee.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: Date: Mon, 9 Dec 2019 20:23:33 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191209191346.5197-6-logang@deltatee.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: CGOrIuU7M-WKL-Tj27NBfA-1 X-Mimecast-Spam-Score: 0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191209_112350_537018_D12B38BB X-CRM114-Status: GOOD ( 20.95 ) 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: Michal Hocko , Peter Zijlstra , Catalin Marinas , Dave Hansen , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Benjamin Herrenschmidt , Thomas Gleixner , Will Deacon Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 09.12.19 20:13, Logan Gunthorpe wrote: > 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, add an argument to arch_add_memory() to explicitly > set the pgprot value to a specific value. > > Of the arches that support MEMORY_HOTPLUG: x86_64, s390 and arm64 is 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 sh, reject > anything but PAGE_KERNEL settings -- this should be fine, for now, seeing > sh doesn't support ZONE_DEVICE anyway. > > Cc: Dan Williams > Cc: David Hildenbrand > Cc: Michal Hocko > Signed-off-by: Logan Gunthorpe > --- > arch/arm64/mm/mmu.c | 4 ++-- > arch/ia64/mm/init.c | 5 ++++- > arch/powerpc/mm/mem.c | 4 ++-- > arch/s390/mm/init.c | 4 ++-- > arch/sh/mm/init.c | 5 ++++- > arch/x86/mm/init_32.c | 7 ++++++- > arch/x86/mm/init_64.c | 4 ++-- > include/linux/memory_hotplug.h | 2 +- > mm/memory_hotplug.c | 2 +- > mm/memremap.c | 2 +- > 10 files changed, 25 insertions(+), 14 deletions(-) > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 60c929f3683b..48b65272df15 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -1050,7 +1050,7 @@ int p4d_free_pud_page(p4d_t *p4d, unsigned long addr) > } > > #ifdef CONFIG_MEMORY_HOTPLUG > -int arch_add_memory(int nid, u64 start, u64 size, > +int arch_add_memory(int nid, u64 start, u64 size, pgprot_t prot, > struct mhp_restrictions *restrictions) Can we fiddle that into "struct mhp_restrictions" instead? -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel