From patchwork Mon Oct 14 09:56:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Garry X-Patchwork-Id: 11188139 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 196D215AB for ; Mon, 14 Oct 2019 10:00:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0331B217F9 for ; Mon, 14 Oct 2019 10:00:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731244AbfJNJ7z (ORCPT ); Mon, 14 Oct 2019 05:59:55 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:3746 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731119AbfJNJ7y (ORCPT ); Mon, 14 Oct 2019 05:59:54 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id ED61E115E732E4B2A4FA; Mon, 14 Oct 2019 17:59:50 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.439.0; Mon, 14 Oct 2019 17:59:43 +0800 From: John Garry To: CC: , , , , , , , , , , , , , , , , John Garry Subject: [PATCH for-stable-4.19 3/3] arm64: topology: Use PPTT to determine if PE is a thread Date: Mon, 14 Oct 2019 17:56:26 +0800 Message-ID: <1571046986-231263-4-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1571046986-231263-1-git-send-email-john.garry@huawei.com> References: <1571046986-231263-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org From: Jeremy Linton Commit 98dc19902a0b2e5348e43d6a2c39a0a7d0fc639e upstream. ACPI 6.3 adds a thread flag to represent if a CPU/PE is actually a thread. Given that the MPIDR_MT bit may not represent this information consistently on homogeneous machines we should prefer the PPTT flag if its available. Signed-off-by: Jeremy Linton Reviewed-by: Sudeep Holla Reviewed-by: Robert Richter [will: made acpi_cpu_is_threaded() return 'bool'] Signed-off-by: Will Deacon Signed-off-by: John Garry --- arch/arm64/kernel/topology.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 0825c4a856e3..6106c49f84bc 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -340,17 +340,28 @@ void remove_cpu_topology(unsigned int cpu) } #ifdef CONFIG_ACPI +static bool __init acpi_cpu_is_threaded(int cpu) +{ + int is_threaded = acpi_pptt_cpu_is_thread(cpu); + + /* + * if the PPTT doesn't have thread information, assume a homogeneous + * machine and return the current CPU's thread state. + */ + if (is_threaded < 0) + is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK; + + return !!is_threaded; +} + /* * Propagate the topology information of the processor_topology_node tree to the * cpu_topology array. */ static int __init parse_acpi_topology(void) { - bool is_threaded; int cpu, topology_id; - is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK; - for_each_possible_cpu(cpu) { int i, cache_id; @@ -358,7 +369,7 @@ static int __init parse_acpi_topology(void) if (topology_id < 0) return topology_id; - if (is_threaded) { + if (acpi_cpu_is_threaded(cpu)) { cpu_topology[cpu].thread_id = topology_id; topology_id = find_acpi_cpu_topology(cpu, 1); cpu_topology[cpu].core_id = topology_id;