From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754017AbeEWFU3 (ORCPT ); Wed, 23 May 2018 01:20:29 -0400 Received: from mga07.intel.com ([134.134.136.100]:43642 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754004AbeEWFU0 (ORCPT ); Wed, 23 May 2018 01:20:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,431,1520924400"; d="scan'208";a="230872848" Subject: [PATCH v2 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support From: Dan Williams To: akpm@linux-foundation.org Cc: Christoph Hellwig , =?utf-8?b?SsOpcsO0bWU=?= Glisse , Logan Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Tue, 22 May 2018 22:10:28 -0700 Message-ID: <152705222840.21414.15768182848742318988.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152705221686.21414.771870778478134768.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152705221686.21414.771870778478134768.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Given the fact that devm_memremap_pages() requires a percpu_ref that is torn down by devm_memremap_pages_release() the current support for mapping RAM is broken. This has been broken since forever and there is no use case to map RAM in this way, so just kill the support and make it an explicit error. Cc: Christoph Hellwig Cc: "Jérôme Glisse" Cc: Logan Gunthorpe Signed-off-by: Dan Williams --- kernel/memremap.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index c614645227a7..dd11607671eb 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -355,15 +355,12 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) is_ram = region_intersects(align_start, align_size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); - if (is_ram == REGION_MIXED) { - WARN_ONCE(1, "%s attempted on mixed region %pr\n", - __func__, res); + if (is_ram != REGION_DISJOINT) { + WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__, + is_ram == REGION_MIXED ? "mixed" : "ram", res); return ERR_PTR(-ENXIO); } - if (is_ram == REGION_INTERSECTS) - return __va(res->start); - if (!pgmap->ref) return ERR_PTR(-EINVAL);