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=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D93D4C31E51 for ; Sat, 15 Jun 2019 01:11:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B74D221841 for ; Sat, 15 Jun 2019 01:11:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726369AbfFOBLC (ORCPT ); Fri, 14 Jun 2019 21:11:02 -0400 Received: from foss.arm.com ([217.140.110.172]:45090 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726340AbfFOBLA (ORCPT ); Fri, 14 Jun 2019 21:11:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3E813346; Fri, 14 Jun 2019 18:11:00 -0700 (PDT) Received: from mammon-tx2.austin.arm.com (mammon-tx2.austin.arm.com [10.118.30.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2D9823F718; Fri, 14 Jun 2019 18:11:00 -0700 (PDT) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com, Jeremy Linton Subject: [PATCH 2/4] ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens Date: Fri, 14 Jun 2019 20:09:08 -0500 Message-Id: <20190615010910.33921-3-jeremy.linton@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190615010910.33921-1-jeremy.linton@arm.com> References: <20190615010910.33921-1-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org ACPI 6.3 adds a flag to indicate that child nodes are all identical cores. This is useful to authoritatively determine if a set of (possibly offline) cores are identical or not. Since the flag doesn't give us a unique id we can generate one and use it to create bitmaps of sibling nodes, or simply in a loop to determine if a subset of cores are identical. Reviewed-by: Sudeep Holla Signed-off-by: Jeremy Linton --- drivers/acpi/pptt.c | 26 ++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 05344413f199..1e7ac0bd0d3a 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -683,3 +683,29 @@ int find_acpi_cpu_topology_package(unsigned int cpu) return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, ACPI_PPTT_PHYSICAL_PACKAGE); } + +/** + * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag + * @cpu: Kernel logical CPU number + * + * Determine a unique heterogeneous tag for the given CPU. CPUs with the same + * implementation should have matching tags. + * + * The returned tag can be used to group peers with identical implementation. + * + * The search terminates when a level is found with the identical implementation + * flag set or we reach a root node. + * + * Due to limitations in the PPTT data structure, there may be rare situations + * where two cores in a heterogeneous machine may be identical, but won't have + * the same tag. + * + * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. + * Otherwise returns a value which represents a group of identical cores + * similar to this CPU. + */ +int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, + ACPI_PPTT_ACPI_IDENTICAL); +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d315d86844e4..5bcd23e5ccd6 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1303,6 +1303,7 @@ static inline int lpit_read_residency_count_address(u64 *address) #ifdef CONFIG_ACPI_PPTT int find_acpi_cpu_topology(unsigned int cpu, int level); int find_acpi_cpu_topology_package(unsigned int cpu); +int find_acpi_cpu_topology_hetero_id(unsigned int cpu); int find_acpi_cpu_cache_topology(unsigned int cpu, int level); #else static inline int find_acpi_cpu_topology(unsigned int cpu, int level) @@ -1313,6 +1314,10 @@ static inline int find_acpi_cpu_topology_package(unsigned int cpu) { return -EINVAL; } +static inline int find_acpi_cpu_topology_hetero_id(unsigned int cpu) +{ + return -EINVAL; +} static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) { return -EINVAL; -- 2.21.0