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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9EB0C433E4 for ; Sat, 1 Aug 2020 03:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C18E52083E for ; Sat, 1 Aug 2020 03:41:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbgHADls (ORCPT ); Fri, 31 Jul 2020 23:41:48 -0400 Received: from mga11.intel.com ([192.55.52.93]:46865 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727978AbgHADlr (ORCPT ); Fri, 31 Jul 2020 23:41:47 -0400 IronPort-SDR: hQuKz9bHwjrp0etibrcwWTihhJDYFJKuJ9gbKPg/ucf0aqPhjloW1KygMu8GcF8bdt2KxJitgJ BZty5ohI5D4w== X-IronPort-AV: E=McAfee;i="6000,8403,9699"; a="149715999" X-IronPort-AV: E=Sophos;i="5.75,420,1589266800"; d="scan'208";a="149715999" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jul 2020 20:41:47 -0700 IronPort-SDR: e3n7QjNdU9Y2kvg/YuTFVsHi/u3CvHT/O+EWhzOCkRhj3ddVnVfce6sMGJY08fskipYBVKlcP+ 3mllkaRHMBNQ== X-IronPort-AV: E=Sophos;i="5.75,420,1589266800"; d="scan'208";a="321647307" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jul 2020 20:41:47 -0700 Subject: [PATCH v3 05/23] resource: Report parent to walk_iomem_res_desc() callback From: Dan Williams To: akpm@linux-foundation.org Cc: Jason Gunthorpe , Dave Hansen , Wei Yang , Tom Lendacky , peterz@infradead.org, vishal.l.verma@intel.com, ard.biesheuvel@linaro.org, vishal.l.verma@intel.com, linux-mm@kvack.org, linux-nvdimm@lists.01.org, joao.m.martins@oracle.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, dri-devel@lists.freedesktop.org Date: Fri, 31 Jul 2020 20:25:29 -0700 Message-ID: <159625232903.3040297.3259451012924415121.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <159625229779.3040297.11363509688097221416.stgit@dwillia2-desk3.amr.corp.intel.com> References: <159625229779.3040297.11363509688097221416.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org In support of detecting whether a resource might have been been claimed, report the parent to the walk_iomem_res_desc() callback. For example, the ACPI HMAT parser publishes "hmem" platform devices per target range. However, if the HMAT is disabled / missing a fallback driver can attach devices to the raw memory ranges as a fallback if it sees unclaimed / orphan "Soft Reserved" resources in the resource tree. Otherwise, find_next_iomem_res() returns a resource with garbage data from the stack allocation in __walk_iomem_res_desc() for the res->parent field. There are currently no users that expect ->child and ->sibling to be valid, and the resource_lock would be needed to traverse them. Use a compound literal to implicitly zero initialize the fields that are not being returned in addition to setting ->parent. Cc: Jason Gunthorpe Cc: Dave Hansen Cc: Wei Yang Cc: Tom Lendacky Signed-off-by: Dan Williams --- kernel/resource.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 841737bbda9e..f1175ce93a1d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -382,10 +382,13 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, if (p) { /* copy data */ - res->start = max(start, p->start); - res->end = min(end, p->end); - res->flags = p->flags; - res->desc = p->desc; + *res = (struct resource) { + .start = max(start, p->start), + .end = min(end, p->end), + .flags = p->flags, + .desc = p->desc, + .parent = p->parent, + }; } read_unlock(&resource_lock);