From patchwork Wed Nov 16 07:57:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13044487 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 1E378C4332F for ; Wed, 16 Nov 2022 07:57:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232831AbiKPH5v (ORCPT ); Wed, 16 Nov 2022 02:57:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232793AbiKPH5u (ORCPT ); Wed, 16 Nov 2022 02:57:50 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DB5123154; Tue, 15 Nov 2022 23:57:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668585470; x=1700121470; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=verj7hVUBInaUTF3sejWeZjrgjgv2y6v3Lf9mbwz5Qg=; b=ktiYYRaVPz2+PliAKTwVkG3LO+dbbsgvG4mS+EWHYgtczXej+6FLOe6x nA4gyqwT5Z8+sHjvI4mZalfPbu+GzQUpU/Zf9sU19/W9UtfhAjHtoRuAe hKFRtiu95z7BKsLCIkJArAC1zPtX8Pd5p8L+whwy3HgAbrCerdif6YPGJ XUylVolqsURspS+4z4SSVNIAmBuHtP6v/K/2LKn8knwwUwqSSb0xKsFLr TlLRBsT0+DmnBLbhwMfbc41uj5+NMLuY2lwYEXhfklSQfW9C7FwINn3e9 uGEgw55HJpF7uoY9YsBxHQzmTl5mZ7mB3/NUmGqVFL4R/o+7l0BLzU1QR Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="398767160" X-IronPort-AV: E=Sophos;i="5.96,167,1665471600"; d="scan'208";a="398767160" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2022 23:57:49 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10532"; a="702769368" X-IronPort-AV: E=Sophos;i="5.96,167,1665471600"; d="scan'208";a="702769368" Received: from ake-mobl.amr.corp.intel.com (HELO vverma7-desk1.intel.com) ([10.209.189.231]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Nov 2022 23:57:48 -0800 From: Vishal Verma To: Cc: , , "Rafael J. Wysocki" , Dan Williams , liushixin2@huawei.com, Vishal Verma , Chris Piper , stable@vger.kernel.org, "Rafael J . Wysocki" Subject: [PATCH 2/2] ACPI: HMAT: Fix initiator registration for single-initiator systems Date: Wed, 16 Nov 2022 00:57:36 -0700 Message-Id: <20221116075736.1909690-3-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221116075736.1909690-1-vishal.l.verma@intel.com> References: <20221116075736.1909690-1-vishal.l.verma@intel.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3279; h=from:subject; bh=verj7hVUBInaUTF3sejWeZjrgjgv2y6v3Lf9mbwz5Qg=; b=owGbwMvMwCXGf25diOft7jLG02pJDMkl0z9svJ/buO2c3Rtu9enxRRNuzgtbEmQ67VaDm8jbhSIb 5/RP7ShlYRDjYpAVU2T5u+cj4zG57fk8gQmOMHNYmUCGMHBxCsBECqIY/vs7MtucytbScuKRXbFYMr ro6v09R37KLFjgFX8/0Z2j8AnDH47sSynStb89puWtldx+bNK/fQLWPxZavtp/xEj2bdZzRjYA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org In a system with a single initiator node, and one or more memory-only 'target' nodes, the memory-only node(s) would fail to register their initiator node correctly. i.e. in sysfs: # ls /sys/devices/system/node/node0/access0/targets/ node0 Where as the correct behavior should be: # ls /sys/devices/system/node/node0/access0/targets/ node0 node1 This happened because hmat_register_target_initiators() uses list_sort() to sort the initiator list, but the sort comparision function (initiator_cmp()) is overloaded to also set the node mask's bits. In a system with a single initiator, the list is singular, and list_sort elides the comparision helper call. Thus the node mask never gets set, and the subsequent search for the best initiator comes up empty. Add a new helper to sort the initiator list, and handle the singular list corner case by setting the node mask for that explicitly. Reported-by: Chris Piper Cc: Cc: Rafael J. Wysocki Cc: Liu Shixin Cc: Dan Williams Signed-off-by: Vishal Verma --- drivers/acpi/numa/hmat.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 144a84f429ed..cd20b0e9cdfa 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -573,6 +573,30 @@ static int initiator_cmp(void *priv, const struct list_head *a, return ia->processor_pxm - ib->processor_pxm; } +static int initiators_to_nodemask(unsigned long *p_nodes) +{ + /* + * list_sort doesn't call @cmp (initiator_cmp) for 0 or 1 sized lists. + * For a single-initiator system with other memory-only nodes, this + * means an empty p_nodes mask, since that is set by initiator_cmp(). + * Special case the singular list, and make sure the node mask gets set + * appropriately. + */ + if (list_empty(&initiators)) + return -ENXIO; + + if (list_is_singular(&initiators)) { + struct memory_initiator *initiator = list_first_entry( + &initiators, struct memory_initiator, node); + + set_bit(initiator->processor_pxm, p_nodes); + return 0; + } + + list_sort(p_nodes, &initiators, initiator_cmp); + return 0; +} + static void hmat_register_target_initiators(struct memory_target *target) { static DECLARE_BITMAP(p_nodes, MAX_NUMNODES); @@ -609,7 +633,9 @@ static void hmat_register_target_initiators(struct memory_target *target) * initiators. */ bitmap_zero(p_nodes, MAX_NUMNODES); - list_sort(p_nodes, &initiators, initiator_cmp); + if (initiators_to_nodemask(p_nodes) < 0) + return; + if (!access0done) { for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { loc = localities_types[i]; @@ -643,7 +669,9 @@ static void hmat_register_target_initiators(struct memory_target *target) /* Access 1 ignores Generic Initiators */ bitmap_zero(p_nodes, MAX_NUMNODES); - list_sort(p_nodes, &initiators, initiator_cmp); + if (initiators_to_nodemask(p_nodes) < 0) + return; + for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { loc = localities_types[i]; if (!loc)