From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 813DF6B0276 for ; Fri, 12 Oct 2018 14:01:44 -0400 (EDT) Received: by mail-pl1-f199.google.com with SMTP id t18-v6so1544561plo.16 for ; Fri, 12 Oct 2018 11:01:44 -0700 (PDT) Received: from mga12.intel.com (mga12.intel.com. [192.55.52.136]) by mx.google.com with ESMTPS id v12-v6si1911386pgn.547.2018.10.12.11.01.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Oct 2018 11:01:43 -0700 (PDT) Subject: [PATCH v7 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support From: Dan Williams Date: Fri, 12 Oct 2018 10:49:42 -0700 Message-ID: <153936658214.1198040.2213860996894588505.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <153936657159.1198040.4489957977352276272.stgit@dwillia2-desk3.amr.corp.intel.com> References: <153936657159.1198040.4489957977352276272.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: =?utf-8?b?SsOpcsO0bWU=?= Glisse , Christoph Hellwig , Logan Gunthorpe , linux-mm@kvack.org, 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. Support for remapping "System RAM" has been broken since the beginning and there is no existing user of this this code path, so just kill the support and make it an explicit error. This cleanup also simplifies a follow-on patch to fix the error path when setting a devm release action for devm_memremap_pages_release() fails. Reviewed-by: "JA(C)rA'me Glisse" Reviewed-by: Christoph Hellwig Reviewed-by: 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 1bbb2e892941..871d81bf0c69 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -167,15 +167,12 @@ 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);