From patchwork Mon Nov 23 14:28:41 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juri Lelli X-Patchwork-Id: 7682551 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0CB5BBF90C for ; Mon, 23 Nov 2015 14:30:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 070D320708 for ; Mon, 23 Nov 2015 14:30:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F83F20704 for ; Mon, 23 Nov 2015 14:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752420AbbKWOaF (ORCPT ); Mon, 23 Nov 2015 09:30:05 -0500 Received: from foss.arm.com ([217.140.101.70]:56181 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754149AbbKWO3P (ORCPT ); Mon, 23 Nov 2015 09:29:15 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2D06A5EA; Mon, 23 Nov 2015 06:28:58 -0800 (PST) Received: from e106622-lin.cambridge.arm.com (e106622-lin.cambridge.arm.com [10.1.208.152]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6C1293F308; Mon, 23 Nov 2015 06:29:12 -0800 (PST) From: Juri Lelli To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, linux@arm.linux.org.uk, sudeep.holla@arm.com, lorenzo.pieralisi@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, juri.lelli@arm.com, Mark Brown Subject: [RFC PATCH 8/8] arm64: add sysfs cpu_capacity attribute Date: Mon, 23 Nov 2015 14:28:41 +0000 Message-Id: <1448288921-30307-9-git-send-email-juri.lelli@arm.com> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1448288921-30307-1-git-send-email-juri.lelli@arm.com> References: <1448288921-30307-1-git-send-email-juri.lelli@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add a sysfs cpu_capacity attribute with which it is possible to read and write (thus over-writing default values) CPUs capacity. This might be useful in situation where there is no way to get proper default values at boot time. The new attribute shows up as: /sys/devices/system/cpu/cpu*/cpu_capacity Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Brown Cc: Sudeep Holla Signed-off-by: Juri Lelli --- arch/arm64/kernel/topology.c | 68 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 4423cc5..5c9e477 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -35,6 +35,74 @@ static void set_capacity_scale(unsigned int cpu, unsigned long capacity) per_cpu(cpu_scale, cpu) = capacity; } +#ifdef CONFIG_PROC_SYSCTL +#include +#include +static ssize_t show_cpu_capacity(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct cpu *cpu = container_of(dev, struct cpu, dev); + ssize_t rc; + int cpunum = cpu->dev.id; + unsigned long capacity = arch_scale_cpu_capacity(NULL, cpunum); + + rc = sprintf(buf, "%lu\n", capacity); + + return rc; +} + +static ssize_t store_cpu_capacity(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct cpu *cpu = container_of(dev, struct cpu, dev); + int this_cpu = cpu->dev.id, i; + unsigned long new_capacity; + ssize_t ret; + + if (count) { + char *p = (char *) buf; + + ret = kstrtoul(p, 0, &new_capacity); + if (ret) + return ret; + if (new_capacity > SCHED_CAPACITY_SCALE) + return -EINVAL; + + for_each_cpu(i, &cpu_topology[this_cpu].core_sibling) + set_capacity_scale(i, new_capacity); + } + + return count; +} + +static DEVICE_ATTR(cpu_capacity, + 0644, + show_cpu_capacity, + store_cpu_capacity); + +static int register_cpu_capacity_sysctl(void) +{ + int i; + struct device *cpu; + + for_each_possible_cpu(i) { + cpu = get_cpu_device(i); + if (!cpu) { + pr_err("%s: too early to get CPU%d device!\n", + __func__, i); + continue; + } + device_create_file(cpu, &dev_attr_cpu_capacity); + } + + return 0; +} +late_initcall(register_cpu_capacity_sysctl); +#endif + static u32 capacity_scale = SCHED_CAPACITY_SCALE; static void __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)