From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) by kanga.kvack.org (Postfix) with ESMTP id 252C26B228A for ; Tue, 20 Nov 2018 18:25:29 -0500 (EST) Received: by mail-pl1-f198.google.com with SMTP id 89so4178574ple.19 for ; Tue, 20 Nov 2018 15:25:29 -0800 (PST) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id z1si13048299plo.202.2018.11.20.15.25.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Nov 2018 15:25:28 -0800 (PST) Subject: [PATCH v8 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support From: Dan Williams Date: Tue, 20 Nov 2018 15:13:00 -0800 Message-ID: <154275557997.76910.14689813630968180480.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <154275556908.76910.8966087090637564219.stgit@dwillia2-desk3.amr.corp.intel.com> References: <154275556908.76910.8966087090637564219.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 , torvalds@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.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 61dbcaa95530..99d14940acfa 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);