From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751964AbcCAC45 (ORCPT ); Mon, 29 Feb 2016 21:56:57 -0500 Received: from mga04.intel.com ([192.55.52.120]:54893 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751877AbcCAC4z (ORCPT ); Mon, 29 Feb 2016 21:56:55 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,521,1449561600"; d="scan'208";a="755671518" Subject: [PATCH 2/2] mm: fix mixed zone detection in devm_memremap_pages From: Dan Williams To: linux-nvdimm@ml01.01.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Date: Mon, 29 Feb 2016 18:56:31 -0800 Message-ID: <20160301025631.12812.85197.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20160301025620.12812.87268.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20160301025620.12812.87268.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The check for whether we overlap "System RAM" needs to be done at section granularity. For example a system with the following mapping: 100000000-37bffffff : System RAM 37c000000-837ffffff : Persistent Memory ...is unable to use devm_memremap_pages() as it would result in two zones colliding within a given section. Signed-off-by: Dan Williams --- kernel/memremap.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index b981a7b023f0..4c7d08339f62 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -270,9 +270,10 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys) void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap) { - int is_ram = region_intersects(res->start, resource_size(res), - "System RAM"); - resource_size_t key, align_start, align_size, align_end; + resource_size_t align_start = res->start & ~(SECTION_SIZE - 1); + resource_size_t align_size = ALIGN(resource_size(res), SECTION_SIZE); + int is_ram = region_intersects(align_start, align_size, "System RAM"); + resource_size_t key, align_end; struct dev_pagemap *pgmap; struct page_map *page_map; unsigned long pfn; @@ -314,8 +315,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, mutex_lock(&pgmap_lock); error = 0; - align_start = res->start & ~(SECTION_SIZE - 1); - align_size = ALIGN(resource_size(res), SECTION_SIZE); align_end = align_start + align_size - 1; for (key = align_start; key <= align_end; key += SECTION_SIZE) { struct dev_pagemap *dup;