From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 1C5B36B0007 for ; Wed, 11 Jul 2018 01:24:47 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id cf17-v6so6609238plb.2 for ; Tue, 10 Jul 2018 22:24:47 -0700 (PDT) Received: from mga09.intel.com (mga09.intel.com. [134.134.136.24]) by mx.google.com with ESMTPS id k14-v6si19678868pfd.23.2018.07.10.22.24.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Jul 2018 22:24:45 -0700 (PDT) Subject: [PATCH v4 2/8] mm, devm_memremap_pages: Kill mapping "System RAM" support From: Dan Williams Date: Tue, 10 Jul 2018 22:14:48 -0700 Message-ID: <153128608797.2928.10387598365462349830.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <153128607743.2928.4465435789810433432.stgit@dwillia2-desk3.amr.corp.intel.com> References: <153128607743.2928.4465435789810433432.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: Christoph Hellwig , =?utf-8?b?SsOpcsO0bWU=?= Glisse , 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. Cc: Christoph Hellwig Cc: "JA(C)rA'me 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 4478e4688bb7..2d2c901cbe23 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -183,15 +183,12 @@ 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);