@@ -64,4 +64,11 @@ config DTPM_CPU
help
This enables support for CPU power limitation based on
energy model.
+
+config DTPM_DEVFREQ
+ bool "Add device power capping based on the energy model"
+ depends on DTPM && ENERGY_MODEL
+ help
+ This enables support for device power limitation based on
+ energy model.
endif
@@ -2,6 +2,7 @@
obj-$(CONFIG_DTPM) += dtpm.o
obj-$(CONFIG_DTPM_CONFIGFS) += dtpm_configfs.o
obj-$(CONFIG_DTPM_CPU) += dtpm_cpu.o
+obj-$(CONFIG_DTPM_DEVFREQ) += dtpm_devfreq.o
obj-$(CONFIG_POWERCAP) += powercap_sys.o
obj-$(CONFIG_INTEL_RAPL_CORE) += intel_rapl_common.o
obj-$(CONFIG_INTEL_RAPL) += intel_rapl_msr.o
new file mode 100644
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021 Linaro Limited
+ *
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *
+ * The devfreq device combined with the energy model and the load can
+ * give an estimation of the power consumption as well as limiting the
+ * power.
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpumask.h>
+#include <linux/devfreq.h>
+#include <linux/dtpm.h>
+#include <linux/energy_model.h>
+#include <linux/pm_qos.h>
+#include <linux/slab.h>
+#include <linux/units.h>
+
+#ifndef HZ_PER_KHZ
+#define HZ_PER_KHZ 1000UL
+#endif
+
+struct dtpm_devfreq {
+ struct dtpm dtpm;
+ struct dev_pm_qos_request qos_req;
+ struct devfreq *devfreq;
+};
+
+struct dtpm_devfreq *to_dtpm_devfreq(struct dtpm *dtpm)
+{
+ return container_of(dtpm, struct dtpm_devfreq, dtpm);
+}
+
+static int update_pd_power_uw(struct dtpm *dtpm)
+{
+ struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
+ struct devfreq *devfreq = dtpm_devfreq->devfreq;
+ struct device *dev = devfreq->dev.parent;
+ struct em_perf_domain *pd = em_pd_get(dev);
+
+ dtpm->power_min = pd->table[0].power;
+ dtpm->power_min *= MICROWATT_PER_MILLIWATT;
+
+ dtpm->power_max = pd->table[pd->nr_perf_states - 1].power;
+ dtpm->power_max *= MICROWATT_PER_MILLIWATT;
+
+ return 0;
+}
+
+static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit)
+{
+ struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
+ struct devfreq *devfreq = dtpm_devfreq->devfreq;
+ struct device *dev = devfreq->dev.parent;
+ struct em_perf_domain *pd = em_pd_get(dev);
+ unsigned long freq;
+ u64 power;
+ int i;
+
+ for (i = 0; i < pd->nr_perf_states; i++) {
+
+ power = pd->table[i].power * MICROWATT_PER_MILLIWATT;
+ if (power > power_limit)
+ break;
+ }
+
+ freq = pd->table[i - 1].frequency;
+
+ dev_pm_qos_update_request(&dtpm_devfreq->qos_req, freq);
+
+ power_limit = pd->table[i - 1].power * MICROWATT_PER_MILLIWATT;
+
+ return power_limit;
+}
+
+static void _normalize_load(struct devfreq_dev_status *status)
+{
+ if (status->total_time > 0xfffff) {
+ status->total_time >>= 10;
+ status->busy_time >>= 10;
+ }
+
+ status->busy_time <<= 10;
+ status->busy_time /= status->total_time ? : 1;
+
+ status->busy_time = status->busy_time ? : 1;
+ status->total_time = 1024;
+}
+
+static u64 get_pd_power_uw(struct dtpm *dtpm)
+{
+ struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
+ struct devfreq *devfreq = dtpm_devfreq->devfreq;
+ struct device *dev = devfreq->dev.parent;
+ struct em_perf_domain *pd = em_pd_get(dev);
+ struct devfreq_dev_status status;
+ unsigned long freq;
+ u64 power;
+ int i;
+
+ mutex_lock(&devfreq->lock);
+ status = devfreq->last_status;
+ mutex_unlock(&devfreq->lock);
+
+ freq = DIV_ROUND_UP(status.current_frequency, HZ_PER_KHZ);
+ _normalize_load(&status);
+
+ for (i = 0; i < pd->nr_perf_states; i++) {
+
+ if (pd->table[i].frequency < freq)
+ continue;
+
+ power = pd->table[i].power * MICROWATT_PER_MILLIWATT;
+ power *= status.busy_time;
+ power >>= 10;
+
+ return power;
+ }
+
+ return 0;
+}
+
+static void pd_release(struct dtpm *dtpm)
+{
+ struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
+
+ if (dev_pm_qos_request_active(&dtpm_devfreq->qos_req))
+ dev_pm_qos_remove_request(&dtpm_devfreq->qos_req);
+
+ kfree(dtpm_devfreq);
+}
+
+static struct dtpm_ops dtpm_ops = {
+ .set_power_uw = set_pd_power_limit,
+ .get_power_uw = get_pd_power_uw,
+ .update_power_uw = update_pd_power_uw,
+ .release = pd_release,
+};
+
+int dtpm_register_devfreq(struct devfreq *devfreq)
+{
+ struct device *dev = devfreq->dev.parent;
+ struct dtpm_devfreq *dtpm_devfreq;
+ struct em_perf_domain *pd;
+ char *name;
+ int ret = -ENOMEM;
+
+ pd = em_pd_get(dev);
+ if (!pd) {
+ ret = dev_pm_opp_of_register_em(dev, NULL);
+ if (ret) {
+ pr_err("No energy model available for '%s'\n", name);
+ return -EINVAL;
+ }
+ }
+
+ dtpm_devfreq = kzalloc(sizeof(*dtpm_devfreq), GFP_KERNEL);
+ if (!dtpm_devfreq)
+ return -ENOMEM;
+
+ dtpm_init(&dtpm_devfreq->dtpm, &dtpm_ops);
+
+ dtpm_devfreq->devfreq = devfreq;
+
+ name = kasprintf(GFP_KERNEL, "%s-devfreq", dev_name(dev));
+ if (!name)
+ goto out_dtpm_devfreq;
+
+ ret = dtpm_register(name, &dtpm_devfreq->dtpm);
+ if (ret) {
+ pr_err("Failed to register '%s': %d\n", name, ret);
+ goto out_kfree_name;
+ }
+
+ ret = dev_pm_qos_add_request(dev, &dtpm_devfreq->qos_req,
+ DEV_PM_QOS_MAX_FREQUENCY,
+ PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
+ if (ret) {
+ pr_err("Failed to add QoS request: %d\n", ret);
+ goto out_dtpm_unregister;
+ }
+
+ kfree(name);
+
+ return 0;
+
+out_dtpm_unregister:
+ dtpm_unregister(name);
+out_kfree_name:
+ kfree(name);
+out_dtpm_devfreq:
+ kfree(dtpm_devfreq);
+
+ return ret;
+}
@@ -80,4 +80,17 @@ void dtpm_unregister(const char *name);
struct dtpm *dtpm_get(const char *name);
void dtpm_put(struct dtpm *dtpm);
+
+#ifdef CONFIG_DTPM_DEVFREQ
+
+struct devfreq;
+
+int dtpm_register_devfreq(struct devfreq *devfreq);
+#else
+static inline int dtpm_register_devfreq(struct devfreq *devfreq)
+{
+ return 0;
+}
+#endif
+
#endif
Currently the dtpm supports the CPUs via cpufreq and the energy model. This change provides the same for the device which supports devfreq. Each device supporting devfreq and having an energy model can register themselves in the list of supported devices. The concept is the same as the cpufreq dtpm support: the QoS is used to aggregate the requests and the energy model gives the value of the instantaneous power consumption ponderated by the load of the device. Cc: Chanwoo Choi <cwchoi00@gmail.com> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> --- drivers/powercap/Kconfig | 7 ++ drivers/powercap/Makefile | 1 + drivers/powercap/dtpm_devfreq.c | 198 ++++++++++++++++++++++++++++++++ include/linux/dtpm.h | 13 +++ 4 files changed, 219 insertions(+) create mode 100644 drivers/powercap/dtpm_devfreq.c