From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 0C7616B0007 for ; Tue, 19 Jun 2018 02:14:48 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id g5-v6so6052982pgv.12 for ; Mon, 18 Jun 2018 23:14:48 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id m14-v6si14217352pgc.361.2018.06.18.23.14.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 Jun 2018 23:14:47 -0700 (PDT) Subject: [PATCH v3 2/8] mm, devm_memremap_pages: Kill mapping "System RAM" support From: Dan Williams Date: Mon, 18 Jun 2018 23:04:49 -0700 Message-ID: <152938828948.17797.2438243316611072486.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152938827880.17797.439879736804291936.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152938827880.17797.439879736804291936.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. 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: "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);