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From: Quentin Perret <quentin.perret@arm.com>
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@quicinc.com, skannan@quicinc.com,
	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 v5 14/14] OPTIONAL: cpufreq: dt: Register an Energy Model
Date: Tue, 24 Jul 2018 13:25:21 +0100
Message-ID: <20180724122521.22109-15-quentin.perret@arm.com> (raw)
In-Reply-To: <20180724122521.22109-1-quentin.perret@arm.com>

*******************************************************************
* This patch illustrates the usage of the newly introduced Energy *
* Model framework and isn't supposed to be merged as-is.          *
*******************************************************************

The Energy Model framework provides an API to register the active power
of CPUs. Call this API from the cpufreq-dt driver with an estimation
of the power as P = C * V^2 * f with C, V, and f respectively the
capacitance of the CPU and the voltage and frequency of the OPP.

The CPU capacitance is read from the "dynamic-power-coefficient" DT
binding (originally introduced for thermal/IPA), and the voltage and
frequency values from PM_OPP.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
---
 drivers/cpufreq/cpufreq-dt.c | 45 +++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index 0a9ebf00be46..399f54d0abf2 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -16,6 +16,7 @@
 #include <linux/cpu_cooling.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
+#include <linux/energy_model.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -149,8 +150,47 @@ static int resources_available(void)
 	return 0;
 }
 
+static int of_est_power(unsigned long *mW, unsigned long *KHz, int cpu)
+{
+	unsigned long mV, Hz, MHz;
+	struct device *cpu_dev;
+	struct dev_pm_opp *opp;
+	struct device_node *np;
+	u32 cap;
+	u64 tmp;
+
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev)
+		return -ENODEV;
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np)
+		return -EINVAL;
+
+	if (of_property_read_u32(np, "dynamic-power-coefficient", &cap))
+		return -EINVAL;
+
+	Hz = *KHz * 1000;
+	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
+	if (IS_ERR(opp))
+		return -EINVAL;
+
+	mV = dev_pm_opp_get_voltage(opp) / 1000;
+	dev_pm_opp_put(opp);
+
+	MHz = Hz / 1000000;
+	tmp = (u64)cap * mV * mV * MHz;
+	do_div(tmp, 1000000000);
+
+	*mW = (unsigned long)tmp;
+	*KHz = Hz / 1000;
+
+	return 0;
+}
+
 static int cpufreq_init(struct cpufreq_policy *policy)
 {
+	struct em_data_callback em_cb = EM_DATA_CB(of_est_power);
 	struct cpufreq_frequency_table *freq_table;
 	struct opp_table *opp_table = NULL;
 	struct private_data *priv;
@@ -159,7 +199,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	unsigned int transition_latency;
 	bool fallback = false;
 	const char *name;
-	int ret;
+	int ret, nr_opp;
 
 	cpu_dev = get_cpu_device(policy->cpu);
 	if (!cpu_dev) {
@@ -226,6 +266,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 		ret = -EPROBE_DEFER;
 		goto out_free_opp;
 	}
+	nr_opp = ret;
 
 	if (fallback) {
 		cpumask_setall(policy->cpus);
@@ -278,6 +319,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.transition_latency = transition_latency;
 	policy->dvfs_possible_from_any_cpu = true;
 
+	em_register_freq_domain(policy->cpus, nr_opp, &em_cb);
+
 	return 0;
 
 out_free_cpufreq_table:
-- 
2.18.0


      parent reply index

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-24 12:25 [PATCH v5 00/14] Energy Aware Scheduling Quentin Perret
2018-07-24 12:25 ` [PATCH v5 01/14] sched: Relocate arch_scale_cpu_capacity Quentin Perret
2018-07-24 12:25 ` [PATCH v5 02/14] sched/cpufreq: Factor out utilization to frequency mapping Quentin Perret
2018-07-24 12:25 ` [PATCH v5 03/14] PM: Introduce an Energy Model management framework Quentin Perret
2018-08-09 21:52   ` Rafael J. Wysocki
2018-08-10  8:15     ` Quentin Perret
2018-08-10  8:41       ` Rafael J. Wysocki
2018-08-10  9:12         ` Quentin Perret
2018-08-10 11:13           ` Rafael J. Wysocki
2018-08-10 12:30             ` Quentin Perret
2018-08-12  9:49               ` Rafael J. Wysocki
2018-07-24 12:25 ` [PATCH v5 04/14] PM / EM: Expose the Energy Model in sysfs Quentin Perret
2018-07-24 12:25 ` [PATCH v5 05/14] sched/topology: Reference the Energy Model of CPUs when available Quentin Perret
2018-07-24 12:25 ` [PATCH v5 06/14] sched/topology: Lowest energy aware balancing sched_domain level pointer Quentin Perret
2018-07-26 16:00   ` Valentin Schneider
2018-07-26 17:01     ` Quentin Perret
2018-07-24 12:25 ` [PATCH v5 07/14] sched/topology: Introduce sched_energy_present static key Quentin Perret
2018-07-24 12:25 ` [PATCH v5 08/14] sched/fair: Clean-up update_sg_lb_stats parameters Quentin Perret
2018-07-24 12:25 ` [PATCH v5 09/14] sched: Add over-utilization/tipping point indicator Quentin Perret
2018-08-02 12:26   ` Peter Zijlstra
2018-08-02 13:03     ` Quentin Perret
2018-08-02 13:08       ` Peter Zijlstra
2018-08-02 13:18         ` Quentin Perret
2018-08-02 13:48           ` Vincent Guittot
2018-08-02 14:14             ` Quentin Perret
2018-08-02 15:14               ` Vincent Guittot
2018-08-02 15:30                 ` Quentin Perret
2018-08-02 15:55                   ` Vincent Guittot
2018-08-02 16:00                     ` Quentin Perret
2018-08-02 16:07                       ` Vincent Guittot
2018-08-02 16:10                         ` Quentin Perret
2018-08-02 16:38                           ` Vincent Guittot
2018-08-02 16:59                             ` Quentin Perret
2018-08-03  7:48                               ` Vincent Guittot
2018-08-03  8:18                                 ` Quentin Perret
2018-08-03 13:49                                   ` Vincent Guittot
2018-08-03 14:21                                     ` Vincent Guittot
2018-08-03 15:55                                     ` Quentin Perret
2018-08-06  8:40                                       ` Vincent Guittot
2018-08-06  9:43                                         ` Quentin Perret
2018-08-06 10:45                                           ` Vincent Guittot
2018-08-06 11:02                                             ` Quentin Perret
2018-08-06 10:08                                         ` Dietmar Eggemann
2018-08-06 10:33                                           ` Vincent Guittot
2018-08-06 12:29                                             ` Dietmar Eggemann
2018-08-06 12:37                                               ` Vincent Guittot
2018-08-06 13:20                                                 ` Dietmar Eggemann
2018-08-09  9:30   ` Vincent Guittot
2018-08-09  9:38     ` Quentin Perret
2018-07-24 12:25 ` [PATCH v5 10/14] sched/cpufreq: Refactor the utilization aggregation method Quentin Perret
2018-07-30 19:35   ` skannan
2018-07-31  7:59     ` Quentin Perret
2018-07-31 19:31       ` skannan
2018-08-01  7:32         ` Rafael J. Wysocki
2018-08-01  8:23           ` Quentin Perret
2018-08-01  8:35             ` Rafael J. Wysocki
2018-08-01  9:23               ` Quentin Perret
2018-08-01  9:40                 ` Rafael J. Wysocki
2018-08-02 13:04                 ` Peter Zijlstra
2018-08-02 15:39                   ` Quentin Perret
2018-08-03 13:04                     ` Quentin Perret
2018-08-02 12:33     ` Peter Zijlstra
2018-08-02 12:45       ` Peter Zijlstra
2018-08-02 15:21         ` Quentin Perret
2018-08-02 17:36           ` Peter Zijlstra
2018-08-03 12:42             ` Quentin Perret
2018-07-24 12:25 ` [PATCH v5 11/14] sched/fair: Introduce an energy estimation helper function Quentin Perret
2018-07-24 12:25 ` [PATCH v5 12/14] sched/fair: Select an energy-efficient CPU on task wake-up Quentin Perret
2018-08-02 13:54   ` Peter Zijlstra
2018-08-02 16:21     ` Quentin Perret
2018-07-24 12:25 ` [PATCH v5 13/14] OPTIONAL: arch_topology: Start Energy Aware Scheduling Quentin Perret
2018-07-24 12:25 ` Quentin Perret [this message]

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