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=-8.5 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_MUTT 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 7F70EC28CC3 for ; Fri, 7 Jun 2019 10:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E29820B7C for ; Fri, 7 Jun 2019 10:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726851AbfFGKDN (ORCPT ); Fri, 7 Jun 2019 06:03:13 -0400 Received: from foss.arm.com ([217.140.110.172]:37038 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbfFGKDN (ORCPT ); Fri, 7 Jun 2019 06:03:13 -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 1A12E28; Fri, 7 Jun 2019 03:03:13 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5B24E3F96A; Fri, 7 Jun 2019 03:04:52 -0700 (PDT) Date: Fri, 7 Jun 2019 11:03:09 +0100 From: Sudeep Holla To: Jeremy Linton Cc: linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, Sudeep Holla Subject: Re: [PATCH 1/2] ACPI/PPTT: Add support for ACPI 6.3 thread flag Message-ID: <20190607100309.GE2429@e107155-lin> References: <20190523224015.56270-1-jeremy.linton@arm.com> <20190523224015.56270-2-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190523224015.56270-2-jeremy.linton@arm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Thu, May 23, 2019 at 05:40:14PM -0500, Jeremy Linton wrote: > ACPI 6.3 adds a flag to the CPU node to indicate whether > the given PE is a thread. Add a function to return that > information for a given linux logical CPU. > > Signed-off-by: Jeremy Linton > --- > drivers/acpi/pptt.c | 53 +++++++++++++++++++++++++++++++++++++++++++- > include/linux/acpi.h | 5 +++++ > 2 files changed, 57 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c > index b72e6afaa8fb..6f43a0c05f61 100644 > --- a/drivers/acpi/pptt.c > +++ b/drivers/acpi/pptt.c > @@ -517,6 +517,43 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) > return retval; > } > > +/** > + * check_acpi_cpu_flag() - Determine if CPU node has a flag set > + * @cpu: Kernel logical CPU number > + * @rev: The PPTT revision defining the flag > + * @flag: The flag itself > + * > + * Check the node representing a CPU for a given flag. > + * > + * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or > + * the table revision isn't new enough. > + * Otherwise returns flag value > + */ > +static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) Initially, I thought we already have similar function, but I was wrong. > +{ > + struct acpi_table_header *table; > + acpi_status status; > + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); > + struct acpi_pptt_processor *cpu_node = NULL; > + int ret = -ENONET; Unfortunately even ENONET is defined and will silently compile fine, but I assume you need ENOENT as mentioned in the comment/doc. > + > + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); > + if (ACPI_FAILURE(status)) { > + acpi_pptt_warn_missing(); > + return ret; > + } > + > + if (table->revision >= rev) > + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); > + > + if (cpu_node) > + ret = cpu_node->flags & flag; > + > + acpi_put_table(table); > + > + return ret; > +} > + > /** > * acpi_find_last_cache_level() - Determines the number of cache levels for a PE > * @cpu: Kernel logical CPU number > @@ -581,6 +618,21 @@ int cache_setup_acpi(unsigned int cpu) > return status; > } > > +/** > + * acpi_pptt_cpu_is_thread() - Determine if logical CPU is a thread > + * @cpu: Kernel logical CPU number > + * > + * > + * Return: 1, a thread > + * 0, not a thread > + * -ENOENT if the PPTT doesn't exist, the CPU cannot be found or > + * the table revision isn't new enough. > + */ > +int acpi_pptt_cpu_is_thread(unsigned int cpu) > +{ > + return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); > +} > + > /** > * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU > * @cpu: Kernel logical CPU number > @@ -641,7 +693,6 @@ int find_acpi_cpu_cache_topology(unsigned int cpu, int level) > return ret; > } > > - Spurious ? > /** > * find_acpi_cpu_topology_package() - Determine a unique CPU package value > * @cpu: Kernel logical CPU number > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 98440df7fe42..513833233c65 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -1314,10 +1314,15 @@ static inline int lpit_read_residency_count_address(u64 *address) > #endif > > #ifdef CONFIG_ACPI_PPTT > +int acpi_pptt_cpu_is_thread(unsigned int cpu); > int find_acpi_cpu_topology(unsigned int cpu, int level); > int find_acpi_cpu_topology_package(unsigned int cpu); > int find_acpi_cpu_cache_topology(unsigned int cpu, int level); > #else > +static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) > +{ > + return -EINVAL; > +} > static inline int find_acpi_cpu_topology(unsigned int cpu, int level) > { > return -EINVAL; > -- > 2.21.0 >