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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 6A29AC43441 for ; Fri, 23 Nov 2018 10:48:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28A0420863 for ; Fri, 23 Nov 2018 10:48:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28A0420863 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394236AbeKWVci (ORCPT ); Fri, 23 Nov 2018 16:32:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54572 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387655AbeKWVci (ORCPT ); Fri, 23 Nov 2018 16:32:38 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 45B0530832E8; Fri, 23 Nov 2018 10:48:51 +0000 (UTC) Received: from [10.36.118.36] (unknown [10.36.118.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2F8936013A; Fri, 23 Nov 2018 10:48:49 +0000 (UTC) Subject: Re: [PATCH v8 4/7] mm, devm_memremap_pages: Add MEMORY_DEVICE_PRIVATE support To: Dan Williams , akpm@linux-foundation.org Cc: =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Christoph Hellwig , Logan Gunthorpe , torvalds@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org References: <154275556908.76910.8966087090637564219.stgit@dwillia2-desk3.amr.corp.intel.com> <154275559036.76910.12434636179931292607.stgit@dwillia2-desk3.amr.corp.intel.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <154275559036.76910.12434636179931292607.stgit@dwillia2-desk3.amr.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Fri, 23 Nov 2018 10:48:51 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21.11.18 00:13, Dan Williams wrote: > In preparation for consolidating all ZONE_DEVICE enabling via > devm_memremap_pages(), teach it how to handle the constraints of > MEMORY_DEVICE_PRIVATE ranges. > > Reviewed-by: Jérôme Glisse > [jglisse: call move_pfn_range_to_zone for MEMORY_DEVICE_PRIVATE] > Acked-by: Christoph Hellwig > Reported-by: Logan Gunthorpe > Reviewed-by: Logan Gunthorpe > Signed-off-by: Dan Williams > --- > kernel/memremap.c | 53 +++++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 41 insertions(+), 12 deletions(-) > > diff --git a/kernel/memremap.c b/kernel/memremap.c > index 5e45f0c327a5..3eef989ef035 100644 > --- a/kernel/memremap.c > +++ b/kernel/memremap.c > @@ -98,9 +98,15 @@ static void devm_memremap_pages_release(void *data) > - align_start; > > mem_hotplug_begin(); > - arch_remove_memory(align_start, align_size, pgmap->altmap_valid ? > - &pgmap->altmap : NULL); > - kasan_remove_zero_shadow(__va(align_start), align_size); > + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { > + pfn = align_start >> PAGE_SHIFT; > + __remove_pages(page_zone(pfn_to_page(pfn)), pfn, > + align_size >> PAGE_SHIFT, NULL); > + } else { > + arch_remove_memory(align_start, align_size, > + pgmap->altmap_valid ? &pgmap->altmap : NULL); > + kasan_remove_zero_shadow(__va(align_start), align_size); > + } > mem_hotplug_done(); > > untrack_pfn(NULL, PHYS_PFN(align_start), align_size); > @@ -187,17 +193,40 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) > goto err_pfn_remap; > > mem_hotplug_begin(); > - error = kasan_add_zero_shadow(__va(align_start), align_size); > - if (error) { > - mem_hotplug_done(); > - goto err_kasan; > + > + /* > + * For device private memory we call add_pages() as we only need to > + * allocate and initialize struct page for the device memory. More- > + * over the device memory is un-accessible thus we do not want to > + * create a linear mapping for the memory like arch_add_memory() > + * would do. > + * > + * For all other device memory types, which are accessible by > + * the CPU, we do want the linear mapping and thus use > + * arch_add_memory(). > + */ I consider this comment really useful. :) Short question: Right now, MEMORY_DEVICE_PRIVATE always indicates HMM, correct? (I am just confused by the naming but I assume MEMORY_DEVICE_PRIVATE is more generic than HMM) -- Thanks, David / dhildenb