From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753861AbbAUOZj (ORCPT ); Wed, 21 Jan 2015 09:25:39 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:55652 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753376AbbAUOZd (ORCPT ); Wed, 21 Jan 2015 09:25:33 -0500 From: "Rafael J. Wysocki" To: Jiang Liu Cc: Thomas Gleixner , Bjorn Helgaas , Yinghai Lu , Borislav Petkov , Len Brown , Tony Luck , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [RFC Patch 14/19] ACPI: Translate resource into master side address for bridge window resources Date: Wed, 21 Jan 2015 15:48:09 +0100 Message-ID: <1713566.DBAG4gnLzK@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <54BF3AD5.4070600@linux.intel.com> References: <1420684386-5975-1-git-send-email-jiang.liu@linux.intel.com> <2697984.BuF6Nq9EvE@vostro.rjw.lan> <54BF3AD5.4070600@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, January 21, 2015 01:36:21 PM Jiang Liu wrote: > On 2015/1/21 8:50, Rafael J. Wysocki wrote: > > On Thursday, January 08, 2015 10:33:01 AM Jiang Liu wrote: > >> Add translation_offset into the result address for bridge window > >> resources to form the master side address. > >> > >> Currently acpi_dev_resource_{ext_}address_space() are only used for > >> devices instead of bridges, so it won't break current users. Later > >> it will be used to support PCI host bridge drivers. > >> > >> Signed-off-by: Jiang Liu > >> --- > >> drivers/acpi/resource.c | 14 ++++++++++++++ > >> 1 file changed, 14 insertions(+) > >> > >> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c > >> index d3aa56674bd4..16d334a1ee25 100644 > >> --- a/drivers/acpi/resource.c > >> +++ b/drivers/acpi/resource.c > >> @@ -203,6 +203,20 @@ static bool acpi_decode_space(struct resource *res, resource_size_t *offset, > >> res->start = addr->minimum; > >> res->end = addr->maximum; > >> > >> + /* > >> + * For bridges that translate addresses across the bridge, > >> + * translation_offset is the offset that must be added to the > >> + * address on the secondary side to obtain the address on the > >> + * primary side. Non-bridge devices must list 0 for all Address > >> + * Translation offset bits. > >> + */ > >> + if (base->producer_consumer == ACPI_PRODUCER) { > > > > OK, so the assumption is that this check is never true in the current code, right? > Yes. > > > >> + res->start += addr->translation_offset; > >> + res->end += addr->translation_offset; > >> + } else if (addr->translation_offset) { > > > > And won't this break anything even if so? > I'm trying to follow the spec, how about giving a warning here > instead of failure? Yes, that would be safer IMO. -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.