From patchwork Tue Oct 16 10:15:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Quentin Perret X-Patchwork-Id: 10643345 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 919AE13B0 for ; Tue, 16 Oct 2018 10:16:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 856D52920A for ; Tue, 16 Oct 2018 10:16:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 79A1F29314; Tue, 16 Oct 2018 10:16:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EB2F62920A for ; Tue, 16 Oct 2018 10:16:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727160AbeJPSFZ (ORCPT ); Tue, 16 Oct 2018 14:05:25 -0400 Received: from foss.arm.com ([217.140.101.70]:33798 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727082AbeJPSFY (ORCPT ); Tue, 16 Oct 2018 14:05:24 -0400 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 AD38B341; Tue, 16 Oct 2018 03:15:41 -0700 (PDT) Received: from queper01-lin.local (unknown [10.1.195.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C0E33F59C; Tue, 16 Oct 2018 03:15:37 -0700 (PDT) From: Quentin Perret To: peterz@infradead.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: gregkh@linuxfoundation.org, mingo@redhat.com, dietmar.eggemann@arm.com, morten.rasmussen@arm.com, chris.redpath@arm.com, patrick.bellasi@arm.com, valentin.schneider@arm.com, vincent.guittot@linaro.org, thara.gopinath@linaro.org, viresh.kumar@linaro.org, tkjos@google.com, joel@joelfernandes.org, smuckle@google.com, adharmap@codeaurora.org, skannan@codeaurora.org, pkondeti@codeaurora.org, juri.lelli@redhat.com, edubezval@gmail.com, srinivas.pandruvada@linux.intel.com, currojerez@riseup.net, javi.merino@kernel.org, quentin.perret@arm.com Subject: [PATCH v8 04/15] PM / EM: Expose the Energy Model in sysfs Date: Tue, 16 Oct 2018 11:15:02 +0100 Message-Id: <20181016101513.26919-5-quentin.perret@arm.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181016101513.26919-1-quentin.perret@arm.com> References: <20181016101513.26919-1-quentin.perret@arm.com> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Expose the Energy Model (read-only) of all performance domains in sysfs for convenience. To do so, add a kobject to the CPU subsystem under the umbrella of which a kobject for each performance domain is attached. The resulting hierarchy is as follows for a platform with two performance domains for example: /sys/devices/system/cpu/energy_model ├── pd0 │   ├── cost │   ├── cpus │   ├── frequency │   └── power └── pd4 ├── cost ├── cpus ├── frequency └── power In this implementation, the kobject abstraction is only used as a convenient way of exposing data to sysfs. However, it could also be used in the future to allocate and release performance domains in a more dynamic way using reference counting. Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Signed-off-by: Quentin Perret --- include/linux/energy_model.h | 2 + kernel/power/energy_model.c | 90 ++++++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index aa027f7bcb3e..55deab2b38dc 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -27,6 +27,7 @@ struct em_cap_state { * em_perf_domain - Performance domain * @table: List of capacity states, in ascending order * @nr_cap_states: Number of capacity states + * @kobj: Kobject used to expose the domain in sysfs * @cpus: Cpumask covering the CPUs of the domain * * A "performance domain" represents a group of CPUs whose performance is @@ -37,6 +38,7 @@ struct em_cap_state { struct em_perf_domain { struct em_cap_state *table; int nr_cap_states; + struct kobject kobj; unsigned long cpus[0]; }; diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index d9dc2c38764a..5ec376d4f2f3 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -23,6 +23,82 @@ static DEFINE_PER_CPU(struct em_perf_domain *, em_data); */ static DEFINE_MUTEX(em_pd_mutex); +static struct kobject *em_kobject; + +/* Getters for the attributes of em_perf_domain objects */ +struct em_pd_attr { + struct attribute attr; + ssize_t (*show)(struct em_perf_domain *pd, char *buf); + ssize_t (*store)(struct em_perf_domain *pd, const char *buf, size_t s); +}; + +#define EM_ATTR_LEN 13 +#define show_table_attr(_attr) \ +static ssize_t show_##_attr(struct em_perf_domain *pd, char *buf) \ +{ \ + ssize_t cnt = 0; \ + int i; \ + for (i = 0; i < pd->nr_cap_states; i++) { \ + if (cnt >= (ssize_t) (PAGE_SIZE / sizeof(char) \ + - (EM_ATTR_LEN + 2))) \ + goto out; \ + cnt += scnprintf(&buf[cnt], EM_ATTR_LEN + 1, "%lu ", \ + pd->table[i]._attr); \ + } \ +out: \ + cnt += sprintf(&buf[cnt], "\n"); \ + return cnt; \ +} + +show_table_attr(power); +show_table_attr(frequency); +show_table_attr(cost); + +static ssize_t show_cpus(struct em_perf_domain *pd, char *buf) +{ + return sprintf(buf, "%*pbl\n", cpumask_pr_args(to_cpumask(pd->cpus))); +} + +#define pd_attr(_name) em_pd_##_name##_attr +#define define_pd_attr(_name) static struct em_pd_attr pd_attr(_name) = \ + __ATTR(_name, 0444, show_##_name, NULL) + +define_pd_attr(power); +define_pd_attr(frequency); +define_pd_attr(cost); +define_pd_attr(cpus); + +static struct attribute *em_pd_default_attrs[] = { + &pd_attr(power).attr, + &pd_attr(frequency).attr, + &pd_attr(cost).attr, + &pd_attr(cpus).attr, + NULL +}; + +#define to_pd(k) container_of(k, struct em_perf_domain, kobj) +#define to_pd_attr(a) container_of(a, struct em_pd_attr, attr) + +static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + struct em_perf_domain *pd = to_pd(kobj); + struct em_pd_attr *pd_attr = to_pd_attr(attr); + ssize_t ret; + + ret = pd_attr->show(pd, buf); + + return ret; +} + +static const struct sysfs_ops em_pd_sysfs_ops = { + .show = show, +}; + +static struct kobj_type ktype_em_pd = { + .sysfs_ops = &em_pd_sysfs_ops, + .default_attrs = em_pd_default_attrs, +}; + static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, struct em_data_callback *cb) { @@ -102,6 +178,11 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, pd->nr_cap_states = nr_states; cpumask_copy(to_cpumask(pd->cpus), span); + ret = kobject_init_and_add(&pd->kobj, &ktype_em_pd, em_kobject, + "pd%u", cpu); + if (ret) + pr_err("pd%d: failed kobject_init_and_add(): %d\n", cpu, ret); + return pd; free_cs_table: @@ -155,6 +236,15 @@ int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, */ mutex_lock(&em_pd_mutex); + if (!em_kobject) { + em_kobject = kobject_create_and_add("energy_model", + &cpu_subsys.dev_root->kobj); + if (!em_kobject) { + ret = -ENODEV; + goto unlock; + } + } + for_each_cpu(cpu, span) { /* Make sure we don't register again an existing domain. */ if (READ_ONCE(per_cpu(em_data, cpu))) {