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From: Quentin Perret <quentin.perret@arm.com>
To: viresh.kumar@linaro.org, sudeep.holla@arm.com, rjw@rjwysocki.net,
	nm@ti.com, sboyd@kernel.org, mka@chromium.org
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, dietmar.eggemann@arm.com,
	quentin.perret@arm.com
Subject: [PATCH v4 5/5] cpufreq: scmi: Register an Energy Model
Date: Mon,  4 Feb 2019 11:09:52 +0000
Message-ID: <20190204110952.16025-6-quentin.perret@arm.com> (raw)
In-Reply-To: <20190204110952.16025-1-quentin.perret@arm.com>

The Energy Model (EM) framework provides an API to register the active
power of CPUs. Call this API from the scmi-cpufreq driver by using the
power costs obtained from firmware. This is done to ensure interested
subsystems (the task scheduler, for example) can make use of the EM
when available.

Signed-off-by: Quentin Perret <quentin.perret@arm.com>
---
 drivers/cpufreq/scmi-cpufreq.c | 39 +++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index 242c3370544e..0d87e1433296 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -12,6 +12,7 @@
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/cpu_cooling.h>
+#include <linux/energy_model.h>
 #include <linux/export.h>
 #include <linux/module.h>
 #include <linux/pm_opp.h>
@@ -103,13 +104,42 @@ scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
 	return 0;
 }
 
+static int __maybe_unused
+scmi_get_cpu_power(unsigned long *power, unsigned long *KHz, int cpu)
+{
+	struct device *cpu_dev = get_cpu_device(cpu);
+	unsigned long Hz;
+	int ret, domain;
+
+	if (!cpu_dev) {
+		pr_err("failed to get cpu%d device\n", cpu);
+		return -ENODEV;
+	}
+
+	domain = handle->perf_ops->device_domain_id(cpu_dev);
+	if (domain < 0)
+		return domain;
+
+	/* Get the power cost of the performance domain. */
+	Hz = *KHz * 1000;
+	ret = handle->perf_ops->est_power_get(handle, domain, &Hz, power);
+	if (ret)
+		return ret;
+
+	/* The EM framework specifies the frequency in KHz. */
+	*KHz = Hz / 1000;
+
+	return 0;
+}
+
 static int scmi_cpufreq_init(struct cpufreq_policy *policy)
 {
-	int ret;
+	int ret, nr_opp;
 	unsigned int latency;
 	struct device *cpu_dev;
 	struct scmi_data *priv;
 	struct cpufreq_frequency_table *freq_table;
+	struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
 
 	cpu_dev = get_cpu_device(policy->cpu);
 	if (!cpu_dev) {
@@ -136,8 +166,8 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
 		return ret;
 	}
 
-	ret = dev_pm_opp_get_opp_count(cpu_dev);
-	if (ret <= 0) {
+	nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
+	if (nr_opp <= 0) {
 		dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
 		ret = -EPROBE_DEFER;
 		goto out_free_opp;
@@ -171,6 +201,9 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.transition_latency = latency;
 
 	policy->fast_switch_possible = true;
+
+	em_register_perf_domain(policy->cpus, nr_opp, &em_cb);
+
 	return 0;
 
 out_free_priv:
-- 
2.20.1


  parent reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-04 11:09 [PATCH v4 0/5] Register an Energy Model for Arm reference platforms Quentin Perret
2019-02-04 11:09 ` [PATCH v4 1/5] PM / OPP: Introduce a power estimation helper Quentin Perret
2019-02-04 18:03   ` Matthias Kaehlcke
2019-02-04 18:21     ` Quentin Perret
2019-02-04 11:09 ` [PATCH v4 2/5] cpufreq: dt: Register an Energy Model Quentin Perret
2019-02-04 11:09 ` [PATCH v4 3/5] cpufreq: scpi: " Quentin Perret
2019-02-04 11:09 ` [PATCH v4 4/5] cpufreq: arm_big_little: " Quentin Perret
2019-02-04 11:09 ` Quentin Perret [this message]
2019-02-05  4:55 ` [PATCH v4 0/5] Register an Energy Model for Arm reference platforms Viresh Kumar

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