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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 2E7D9C3F2C6 for ; Sat, 29 Feb 2020 22:44:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B61532467B for ; Sat, 29 Feb 2020 22:44:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="CqI85+c/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B61532467B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 240166B0005; Sat, 29 Feb 2020 17:44:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1CA4B6B0006; Sat, 29 Feb 2020 17:44:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 092346B0007; Sat, 29 Feb 2020 17:44:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id E22B76B0005 for ; Sat, 29 Feb 2020 17:44:31 -0500 (EST) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9EE8B181AEF21 for ; Sat, 29 Feb 2020 22:44:31 +0000 (UTC) X-FDA: 76544645142.26.pump15_2779fcc4f414e X-HE-Tag: pump15_2779fcc4f414e X-Filterd-Recvd-Size: 9352 Received: from mail-oi1-f194.google.com (mail-oi1-f194.google.com [209.85.167.194]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Sat, 29 Feb 2020 22:44:31 +0000 (UTC) Received: by mail-oi1-f194.google.com with SMTP id i1so6637604oie.8 for ; Sat, 29 Feb 2020 14:44:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7fImmI76PTkUm0FnhIT75xAfAmVx1VzhBKKsN9mVGyw=; b=CqI85+c/yRtEkfdvKZhyimiv+7VpsWo116oMWIFfgpozuKdLs8C42nteZDsX5BGC18 YFA3FIVS39K+jrHV363NgaZbyyIgxeUDc50ebfZEV6Dg195VTUcmJ5ks4GK7LLMTfdRG eyz/jrExrPaaWO449Bs08Z5ZvCBAF8pQBclZvBaZdySo4pDGyePu6OJWj4OeXrvOl5KY ro66cJo/Qcj1ASkeP0uL8RRPE1gEVH5S6C3g2weZyNNFDalPOuYmVgtTK4js076KGUP1 sjl87SdTRjtqnsitz4qtdRmuFsvpmQAbp/SMu5PjS/fDvEIs6oFk7/24LGUbW+6A+6f/ UVDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7fImmI76PTkUm0FnhIT75xAfAmVx1VzhBKKsN9mVGyw=; b=KUrDVqTa7xoIm7SKDNFNfZ0u7djC7DAXu4Xxp1CbwP+GplQtznGvoP1Vwa6c6G3C+j MZj4rhTH+X2i2svUilpDdELgPcyOG1w7YOKEt/ujJoz5hLhImbCrX0RLkiBruVffGKs9 ST/COJe11fdWWncvFl7k4d5crmbZ2sBud57kxGTfqB1UWDhmS9dI4xHOBLnKEirLaT0w iUw8Njj7BeA79ni7+/BxS9dA3MCOJWtya8+/7DImo+3NNM27W4PhxB0xSQUniZcxFsqR jqbzFpzx6TL9SC7eflIcEu7rR3lUwKu9EsfdjyzvTuzEa9nIdFKvL5LXZQpTLshyD1NK RA6g== X-Gm-Message-State: APjAAAWwRjRMnNqFS1VER+aZO48qMq25kQ7r8MZ9YySoE1pGcbxvvHDu e6KXarT4LFsLPh1XuNDGrrOSmftcG5PloCiXDkJvEw== X-Google-Smtp-Source: APXvYqyGByPH6pnWrwmTwQrskzg89P8NSyX2Okxw9rUGjppQ4dvnm0/DLDGVxjpQFnKlb3H7KIX7HBwNZb3emn/5hZY= X-Received: by 2002:aca:ec02:: with SMTP id k2mr7594496oih.105.1583016270294; Sat, 29 Feb 2020 14:44:30 -0800 (PST) MIME-Version: 1.0 References: <20200221182503.28317-1-logang@deltatee.com> <20200221182503.28317-7-logang@deltatee.com> In-Reply-To: <20200221182503.28317-7-logang@deltatee.com> From: Dan Williams Date: Sat, 29 Feb 2020 14:44:19 -0800 Message-ID: Subject: Re: [PATCH v3 6/7] mm/memory_hotplug: Add pgprot_t to mhp_params To: Logan Gunthorpe Cc: Linux Kernel Mailing List , Linux ARM , linux-ia64@vger.kernel.org, linuxppc-dev , linux-s390 , Linux-sh , platform-driver-x86@vger.kernel.org, Linux MM , Michal Hocko , David Hildenbrand , Andrew Morton , Christoph Hellwig , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Eric Badger , Michal Hocko Content-Type: text/plain; charset="UTF-8" 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: On Fri, Feb 21, 2020 at 10:25 AM 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, 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. > > Cc: Dan Williams > Signed-off-by: Logan Gunthorpe > Acked-by: David Hildenbrand > Acked-by: Michal Hocko > --- > 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 | 5 +++++ > arch/x86/mm/init_64.c | 2 +- > include/linux/memory_hotplug.h | 2 ++ > mm/memory_hotplug.c | 5 ++++- > mm/memremap.c | 6 +++--- > 10 files changed, 28 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..96d8e4fb1cc8 100644 > --- a/arch/x86/mm/init_32.c > +++ b/arch/x86/mm/init_32.c > @@ -858,6 +858,11 @@ 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; > + > + ret = _set_memory_prot(start, nr_pages, params->pgprot); Perhaps a comment since it's not immediately obvious where the PAGE_KERNEL prot was established, and perhaps add a conditional to skip this call in the param->pgprot == PAGE_KERNEL case? Other than that looks good to me, but only an ack since I'm only testing the x86 changes. Acked-by: Dan Williams