From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AECFECAAD4 for ; Wed, 31 Aug 2022 10:20:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230143AbiHaKUn (ORCPT ); Wed, 31 Aug 2022 06:20:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229692AbiHaKUd (ORCPT ); Wed, 31 Aug 2022 06:20:33 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4D1C1D33C; Wed, 31 Aug 2022 03:20:31 -0700 (PDT) Received: from fraeml738-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4MHg7x5JrLz68BVJ; Wed, 31 Aug 2022 18:16:45 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (7.191.163.240) by fraeml738-chm.china.huawei.com (10.206.15.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 31 Aug 2022 12:20:29 +0200 Received: from localhost (10.202.226.42) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 31 Aug 2022 11:20:29 +0100 Date: Wed, 31 Aug 2022 11:20:28 +0100 From: Jonathan Cameron To: Robert Richter CC: Alison Schofield , Vishal Verma , Ira Weiny , Ben Widawsky , Dan Williams , , , Bjorn Helgaas , "Rafael J. Wysocki" , Len Brown Subject: Re: [PATCH 07/15] cxl/acpi: Check RCH's PCIe Host Bridge ACPI ID Message-ID: <20220831112028.00002566@huawei.com> In-Reply-To: <20220831081603.3415-8-rrichter@amd.com> References: <20220831081603.3415-1-rrichter@amd.com> <20220831081603.3415-8-rrichter@amd.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.42] X-ClientProxiedBy: lhrpeml100006.china.huawei.com (7.191.160.224) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 Aug 2022 10:15:55 +0200 Robert Richter wrote: > An RCH is a root bridge and has "PNP0A08" or "ACPI0016" ACPI ID set. > Check this. > > Signed-off-by: Robert Richter Hi Robert, I'm a little uncomfortable with repurposing acpi_device_id as you have done here. Might be better to do the same as in pci_root.c where the matches are done more directly. > --- > drivers/cxl/acpi.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > index a19e3154dd44..ffdf439adb87 100644 > --- a/drivers/cxl/acpi.c > +++ b/drivers/cxl/acpi.c > @@ -312,9 +312,16 @@ static int add_root_nvdimm_bridge(struct device *match, void *data) > return 1; > } > > +static const struct acpi_device_id cxl_host_ids[] = { > + { "ACPI0016", 0 }, > + { "PNP0A08", 0 }, > + { }, Trivial but no comma after a null terminator. Always good to make it harder for people to add things where they really shouldn't! pci_root.c avoids using an acpi_device_id table for similar matching. I think the point being to separate probe type use of this table from cases where we aren't using a normal device probe. So to remain consistent with that, I would just grab the hid and match it directly in this code. I don't feel that strongly about this if the ACPI maintainers are fine with reusing this infrastructure as you have it here. > +}; > + > struct pci_host_bridge *cxl_find_next_rch(struct pci_host_bridge *host) > { > struct pci_bus *bus = host ? host->bus : NULL; > + struct acpi_device *adev; > > while ((bus = pci_find_next_bus(bus)) != NULL) { > host = bus ? to_pci_host_bridge(bus->bridge) : NULL; > @@ -323,6 +330,19 @@ struct pci_host_bridge *cxl_find_next_rch(struct pci_host_bridge *host) > > dev_dbg(&host->dev, "PCI bridge found\n"); > > + /* Must be a root bridge */ > + if (host->bus->parent) > + continue; > + > + dev_dbg(&host->dev, "PCI bridge is root bridge\n"); > + > + adev = ACPI_COMPANION(&host->dev); > + if (acpi_match_device_ids(adev, cxl_host_ids)) > + continue; > + > + dev_dbg(&host->dev, "PCI ACPI host found: %s\n", > + acpi_dev_name(adev)); > + > return host; > } >