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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 57495C32789 for ; Tue, 6 Nov 2018 12:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29BD520862 for ; Tue, 6 Nov 2018 12:44:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 29BD520862 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388123AbeKFWJ7 (ORCPT ); Tue, 6 Nov 2018 17:09:59 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:47597 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387704AbeKFWJ7 (ORCPT ); Tue, 6 Nov 2018 17:09:59 -0500 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 19DE1D1928E0C; Tue, 6 Nov 2018 20:44:53 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.408.0; Tue, 6 Nov 2018 20:44:44 +0800 From: John Garry To: , CC: , , , , , , John Garry Subject: [PATCH] of, numa: Validate some distance map rules Date: Tue, 6 Nov 2018 20:39:33 +0800 Message-ID: <1541507973-149965-1-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently the NUMA distance map parsing does not validate the distance table for the distance-matrix rules 1-2 in [1]. However the arch NUMA code may enforce some of these rules, but not all. Such is the case for the arm64 port, which does not enforce the rule that the distance between separates nodes cannot equal LOCAL_DISTANCE. The patch adds the following rules validation: - distance of node to self equals LOCAL_DISTANCE - distance of separate nodes > LOCAL_DISTANCE A note on dealing with symmetrical distances between nodes: Validating symmetrical distances between nodes is difficult. If it were mandated in the bindings that every distance must be recorded in the table, validating symmetrical distances would be straightforward. However, it isn't. In addition to this, it is also possible to record [b, a] distance only (and not [a, b]). So, when processing the table for [b, a], we cannot assert that current distance of [a, b] != [b, a] as invalid, as [a, b] distance may not be present in the table and current distance would be default at REMOTE_DISTANCE. As such, we maintain the policy that we overwrite distance [a, b] = [b, a] for b > a. This policy is different to kernel ACPI SLIT validation, which allows non-symmetrical distances (ACPI spec SLIT rules allow it). However, the debug message is dropped as it may be misleading (for a distance which is later overwritten). Some final notes on semantics: - It is implied that it is the responsibility of the arch NUMA code to reset the NUMA distance map for an error in distance map parsing. - It is the responsibility of the FW NUMA topology parsing (whether OF or ACPI) to enforce NUMA distance rules, and not arch NUMA code. [1] Documents/devicetree/bindings/numa.txt Signed-off-by: John Garry diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c index 35c64a4295e0..fe6b13608e51 100644 --- a/drivers/of/of_numa.c +++ b/drivers/of/of_numa.c @@ -104,9 +104,14 @@ static int __init of_numa_parse_distance_map_v1(struct device_node *map) distance = of_read_number(matrix, 1); matrix++; + if ((nodea == nodeb && distance != LOCAL_DISTANCE) || + (nodea != nodeb && distance <= LOCAL_DISTANCE)) { + pr_err("Invalid distance[node%d -> node%d] = %d\n", + nodea, nodeb, distance); + return -EINVAL; + } + numa_set_distance(nodea, nodeb, distance); - pr_debug("distance[node%d -> node%d] = %d\n", - nodea, nodeb, distance); /* Set default distance of node B->A same as A->B */ if (nodeb > nodea) -- 1.9.1