* [RFC PATCH v4 1/7] thermal: document struct thermal_zone_device and thermal_governor
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 2/7] thermal: let governors have private data for each thermal zone Javi Merino
` (5 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin
Document struct thermal_zone_device and struct thermal_governor fields
and their use by the thermal framework code.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
Hi linux-pm,
This patch is independent of the whole series and can be merged independently
include/linux/thermal.h | 46 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index f7e11c7ea7d9..0305cde21a74 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -158,6 +158,42 @@ struct thermal_attr {
char name[THERMAL_NAME_LENGTH];
};
+/**
+ * struct thermal_zone_device - structure for a thermal zone
+ * @id: unique id number for each thermal zone
+ * @type: the thermal zone device type
+ * @device: &struct device for this thermal zone
+ * @trip_temp_attrs: attributes for trip points for sysfs: trip temperature
+ * @trip_type_attrs: attributes for trip points for sysfs: trip type
+ * @trip_hyst_attrs: attributes for trip points for sysfs: trip hysteresis
+ * @devdata: private pointer for device private data
+ * @trips: number of trip points the thermal zone supports
+ * @passive_delay: number of milliseconds to wait between polls when
+ * performing passive cooling. Currenty only used by the
+ * step-wise governor
+ * @polling_delay: number of milliseconds to wait between polls when
+ * checking whether trip points have been crossed (0 for
+ * interrupt driven systems)
+ * @temperature: current temperature. This is only for core code,
+ * drivers should use thermal_zone_get_temp() to get the
+ * current temperature
+ * @last_temperature: previous temperature read
+ * @emul_temperature: emulated temperature when using CONFIG_THERMAL_EMULATION
+ * @passive: 1 if you've crossed a passive trip point, 0 otherwise.
+ * Currenty only used by the step-wise governor.
+ * @forced_passive: If > 0, temperature at which to switch on all ACPI
+ * processor cooling devices. Currently only used by the
+ * step-wise governor.
+ * @ops: operations this &thermal_zone_device supports
+ * @tzp: thermal zone parameters
+ * @governor: pointer to the governor for this thermal zone
+ * @thermal_instances: list of &struct thermal_instance of this thermal zone
+ * @idr: &struct idr to generate unique id for this zone's cooling
+ * devices
+ * @lock: lock to protect thermal_instances list
+ * @node: node in thermal_tz_list (in thermal_core.c)
+ * @poll_queue: delayed work for polling
+ */
struct thermal_zone_device {
int id;
char type[THERMAL_NAME_LENGTH];
@@ -179,12 +215,18 @@ struct thermal_zone_device {
struct thermal_governor *governor;
struct list_head thermal_instances;
struct idr idr;
- struct mutex lock; /* protect thermal_instances list */
+ struct mutex lock;
struct list_head node;
struct delayed_work poll_queue;
};
-/* Structure that holds thermal governor information */
+/**
+ * struct thermal_governor - structure that holds thermal governor information
+ * @name: name of the governor
+ * @throttle: callback called for every trip point even if temperature is
+ * below the trip point temperature
+ * @governor_list: node in thermal_governor_list (in thermal_core.c)
+ */
struct thermal_governor {
char name[THERMAL_NAME_LENGTH];
int (*throttle)(struct thermal_zone_device *tz, int trip);
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH v4 2/7] thermal: let governors have private data for each thermal zone
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 1/7] thermal: document struct thermal_zone_device and thermal_governor Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 3/7] thermal: introduce the Power Actor API Javi Merino
` (4 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin
A governor may need to store its current state between calls to
throttle(). That state depends on the thermal zone, so store it as
private data in struct thermal_zone_device.
The governors may have two new ops: bind_to_tz() and unbind_from_tz().
When provided, these functions let governors do some initialization
and teardown when they are bound/unbound to a tz and possibly store that
information in the governor_data field of the struct
thermal_zone_device.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
drivers/thermal/thermal_core.c | 83 ++++++++++++++++++++++++++++++++++++++----
include/linux/thermal.h | 9 +++++
2 files changed, 84 insertions(+), 8 deletions(-)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 71b0ec0c370d..3da99dd80ad5 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -72,6 +72,58 @@ static struct thermal_governor *__find_governor(const char *name)
return NULL;
}
+/**
+ * bind_previous_governor() - bind the previous governor of the thermal zone
+ * @tz: a valid pointer to a struct thermal_zone_device
+ * @failed_gov_name: the name of the governor that failed to register
+ *
+ * Register the previous governor of the thermal zone after a new
+ * governor has failed to be bound.
+ */
+static void bind_previous_governor(struct thermal_zone_device *tz,
+ const char *failed_gov_name)
+{
+ if (tz->governor && tz->governor->bind_to_tz) {
+ if (tz->governor->bind_to_tz(tz)) {
+ dev_warn(&tz->device,
+ "governor %s failed to bind and the previous one (%s) failed to register again, thermal zone %s has no governor\n",
+ failed_gov_name, tz->governor->name, tz->type);
+ tz->governor = NULL;
+ }
+ }
+}
+
+/**
+ * thermal_set_governor() - Switch to another governor
+ * @tz: a valid pointer to a struct thermal_zone_device
+ * @new_gov: pointer to the new governor
+ *
+ * Change the governor of thermal zone @tz.
+ *
+ * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
+ */
+static int thermal_set_governor(struct thermal_zone_device *tz,
+ struct thermal_governor *new_gov)
+{
+ int ret = 0;
+
+ if (tz->governor && tz->governor->unbind_from_tz)
+ tz->governor->unbind_from_tz(tz);
+
+ if (new_gov && new_gov->bind_to_tz) {
+ ret = new_gov->bind_to_tz(tz);
+ if (ret) {
+ bind_previous_governor(tz, new_gov->name);
+
+ return ret;
+ }
+ }
+
+ tz->governor = new_gov;
+
+ return ret;
+}
+
int thermal_register_governor(struct thermal_governor *governor)
{
int err;
@@ -104,8 +156,15 @@ int thermal_register_governor(struct thermal_governor *governor)
name = pos->tzp->governor_name;
- if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH))
- pos->governor = governor;
+ if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH)) {
+ int ret;
+
+ ret = thermal_set_governor(pos, governor);
+ if (ret)
+ dev_warn(&pos->device,
+ "Failed to set governor %s for thermal zone %s: %d\n",
+ governor->name, pos->type, ret);
+ }
}
mutex_unlock(&thermal_list_lock);
@@ -131,7 +190,7 @@ void thermal_unregister_governor(struct thermal_governor *governor)
list_for_each_entry(pos, &thermal_tz_list, node) {
if (!strnicmp(pos->governor->name, governor->name,
THERMAL_NAME_LENGTH))
- pos->governor = NULL;
+ thermal_set_governor(pos, NULL);
}
mutex_unlock(&thermal_list_lock);
@@ -756,8 +815,9 @@ policy_store(struct device *dev, struct device_attribute *attr,
if (!gov)
goto exit;
- tz->governor = gov;
- ret = count;
+ ret = thermal_set_governor(tz, gov);
+ if (!ret)
+ ret = count;
exit:
mutex_unlock(&thermal_governor_lock);
@@ -1452,6 +1512,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
int result;
int count;
int passive = 0;
+ struct thermal_governor *governor;
if (type && strlen(type) >= THERMAL_NAME_LENGTH)
return ERR_PTR(-EINVAL);
@@ -1542,9 +1603,15 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
mutex_lock(&thermal_governor_lock);
if (tz->tzp)
- tz->governor = __find_governor(tz->tzp->governor_name);
+ governor = __find_governor(tz->tzp->governor_name);
else
- tz->governor = def_governor;
+ governor = def_governor;
+
+ result = thermal_set_governor(tz, governor);
+ if (result) {
+ mutex_unlock(&thermal_governor_lock);
+ goto unregister;
+ }
mutex_unlock(&thermal_governor_lock);
@@ -1634,7 +1701,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
device_remove_file(&tz->device, &dev_attr_mode);
device_remove_file(&tz->device, &dev_attr_policy);
remove_trip_attrs(tz);
- tz->governor = NULL;
+ thermal_set_governor(tz, NULL);
thermal_remove_hwmon_sysfs(tz);
release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 0305cde21a74..1124b7a9358a 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -187,6 +187,7 @@ struct thermal_attr {
* @ops: operations this &thermal_zone_device supports
* @tzp: thermal zone parameters
* @governor: pointer to the governor for this thermal zone
+ * @governor_data: private pointer for governor data
* @thermal_instances: list of &struct thermal_instance of this thermal zone
* @idr: &struct idr to generate unique id for this zone's cooling
* devices
@@ -213,6 +214,7 @@ struct thermal_zone_device {
struct thermal_zone_device_ops *ops;
const struct thermal_zone_params *tzp;
struct thermal_governor *governor;
+ void *governor_data;
struct list_head thermal_instances;
struct idr idr;
struct mutex lock;
@@ -223,12 +225,19 @@ struct thermal_zone_device {
/**
* struct thermal_governor - structure that holds thermal governor information
* @name: name of the governor
+ * @bind_to_tz: callback called when binding to a thermal zone. If it
+ * returns 0, the governor is bound to the thermal zone,
+ * otherwise it fails.
+ * @unbind_from_tz: callback called when a governor is unbound from a
+ * thermal zone.
* @throttle: callback called for every trip point even if temperature is
* below the trip point temperature
* @governor_list: node in thermal_governor_list (in thermal_core.c)
*/
struct thermal_governor {
char name[THERMAL_NAME_LENGTH];
+ int (*bind_to_tz)(struct thermal_zone_device *tz);
+ void (*unbind_from_tz)(struct thermal_zone_device *tz);
int (*throttle)(struct thermal_zone_device *tz, int trip);
struct list_head governor_list;
};
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH v4 3/7] thermal: introduce the Power Actor API
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 1/7] thermal: document struct thermal_zone_device and thermal_governor Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 2/7] thermal: let governors have private data for each thermal zone Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 4/7] thermal: add a basic cpu power actor Javi Merino
` (3 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin
This patch introduces the Power Actor API in the thermal framework.
With it, devices that can report their power consumption and control
it can be registered. This base interface is meant to be used to
derive specific power actors, such as a cpu power actor.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
Documentation/thermal/power_actor.txt | 56 +++++++++++++++++++++++++++++
drivers/thermal/Kconfig | 3 ++
drivers/thermal/Makefile | 3 ++
drivers/thermal/power_actor.c | 68 +++++++++++++++++++++++++++++++++++
drivers/thermal/power_actor.h | 61 +++++++++++++++++++++++++++++++
5 files changed, 191 insertions(+)
create mode 100644 Documentation/thermal/power_actor.txt
create mode 100644 drivers/thermal/power_actor.c
create mode 100644 drivers/thermal/power_actor.h
diff --git a/Documentation/thermal/power_actor.txt b/Documentation/thermal/power_actor.txt
new file mode 100644
index 000000000000..11ca2d0bf0bd
--- /dev/null
+++ b/Documentation/thermal/power_actor.txt
@@ -0,0 +1,56 @@
+Power Actor API
+===============
+
+The base power actor API is meant to be used to derive specific power
+actors, such as a cpu power actor. Power actors can be registered by
+calling `power_actor_register()` and should be unregistered by calling
+`power_actor_unregister()` with the `struct power_actor *` received in
+the call to `power_actor_register()`.
+
+This can't be implemented using the cooling device API because:
+
+1. get_max_state() gives you the maximum cooling state which, for
+ passive devices, is the minimum performance (frequency in case of
+ cpufreq cdev). get_max_power() gives you the maximum power, which
+ gives you the maximum performance (frequency in the case of CPUs,
+ GPUs and buses)
+
+2. You need to pass the thermal_zone_device to all the callbacks,
+ something that the current cooling device API doesn't do.
+
+Callbacks
+---------
+
+1. u32 get_req_power(struct power_actor *actor,
+ struct thermal_zone_device *tz)
+@actor: a valid `struct power_actor *` registered with
+ `power_actor_register()`
+@tz: the thermal zone closest to the actor (typically, the thermal
+ zone the caller is operating on)
+
+`get_req_power()` returns the current requested power in milliwatts.
+
+2. u32 get_max_power(struct power_actor *actor,
+ struct thermal_zone_device *tz)
+@actor: a valid `struct power_actor *` registered with
+ `power_actor_register()`
+@tz: the thermal zone closest to the actor (typically, the thermal
+ zone the caller is operating on)
+
+`get_max_power()` returns the maximum power that the device could
+consume if it was fully utilized. It's a function as some devices'
+maximum power consumption can change due to external factors such as
+temperature.
+
+3. int set_power(struct power_actor *actor,
+ struct thermal_zone_device *tz, u32 power)
+@actor: a valid `struct power_actor *` registered with
+ `power_actor_register()`
+@tz: the thermal zone closest to the actor (typically, the thermal
+ zone the caller is operating on)
+@power: power in milliwatts
+
+`set_power()` should configure the device to consume @power
+milliwatts.
+
+Returns 0 on success, -E* on error.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index f9a13867cb70..ce4ebe17252c 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -89,6 +89,9 @@ config THERMAL_GOV_USER_SPACE
help
Enable this to let the user space manage the platform thermals.
+config THERMAL_POWER_ACTOR
+ bool
+
config CPU_THERMAL
bool "generic cpu cooling support"
depends on CPU_FREQ
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index de0636a57a64..d83aa42ab573 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -14,6 +14,9 @@ thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o
thermal_sys-$(CONFIG_THERMAL_GOV_STEP_WISE) += step_wise.o
thermal_sys-$(CONFIG_THERMAL_GOV_USER_SPACE) += user_space.o
+# power actors
+obj-$(CONFIG_THERMAL_POWER_ACTOR) += power_actor.o
+
# cpufreq cooling
thermal_sys-$(CONFIG_CPU_THERMAL) += cpu_cooling.o
diff --git a/drivers/thermal/power_actor.c b/drivers/thermal/power_actor.c
new file mode 100644
index 000000000000..d4f7bdbe371e
--- /dev/null
+++ b/drivers/thermal/power_actor.c
@@ -0,0 +1,68 @@
+/*
+ * Basic interface for power actors
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "Power actor: " fmt
+
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include "power_actor.h"
+
+LIST_HEAD(actor_list);
+DEFINE_MUTEX(actor_list_lock);
+
+/**
+ * power_actor_register() - Register an actor in the power actor API
+ * @ops: &struct power_actor_ops for this actor
+ * @privdata: pointer to private data related to the actor
+ *
+ * Return: The &struct power_actor * on success, ERR_PTR() on failure
+ */
+struct power_actor *power_actor_register(struct power_actor_ops *ops,
+ void *privdata)
+{
+ struct power_actor *actor;
+
+ if (!ops->get_req_power || !ops->get_max_power || !ops->set_power)
+ return ERR_PTR(-EINVAL);
+
+ actor = kzalloc(sizeof(*actor), GFP_KERNEL);
+ if (!actor)
+ return ERR_PTR(-ENOMEM);
+
+ actor->ops = ops;
+ actor->data = privdata;
+
+ mutex_lock(&actor_list_lock);
+ list_add(&actor->actor_node, &actor_list);
+ mutex_unlock(&actor_list_lock);
+
+ return actor;
+}
+
+/**
+ * power_actor_unregister() - Unregister an actor
+ * @actor: the actor to unregister
+ */
+void power_actor_unregister(struct power_actor *actor)
+{
+ mutex_lock(&actor_list_lock);
+ list_del(&actor->actor_node);
+ mutex_unlock(&actor_list_lock);
+
+ kfree(actor);
+}
diff --git a/drivers/thermal/power_actor.h b/drivers/thermal/power_actor.h
new file mode 100644
index 000000000000..d3ae3ea80387
--- /dev/null
+++ b/drivers/thermal/power_actor.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __POWER_ACTOR_H__
+#define __POWER_ACTOR_H__
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+
+struct power_actor;
+
+/**
+ * struct power_actor_ops - callbacks for power actors
+ * @get_req_power: return the current requested power in milliwatts
+ * @get_max_power: return the max power that the device can currently
+ * consume in milliwatts
+ * @set_power: configure the device to consume a certain power in
+ * milliwatts
+ */
+struct power_actor_ops {
+ u32 (*get_req_power)(struct power_actor *,
+ struct thermal_zone_device *);
+ u32 (*get_max_power)(struct power_actor *,
+ struct thermal_zone_device *);
+ int (*set_power)(struct power_actor *, struct thermal_zone_device *,
+ u32);
+};
+
+/**
+ * struct power_actor - structure for a power actor
+ * @ops: callbacks for the power actor
+ * @data: a private pointer for type-specific data
+ * @actor_node: node in actor_list
+ */
+struct power_actor {
+ struct power_actor_ops *ops;
+ void *data;
+ struct list_head actor_node;
+};
+
+struct power_actor *power_actor_register(struct power_actor_ops *ops,
+ void *privdata);
+void power_actor_unregister(struct power_actor *actor);
+
+extern struct list_head actor_list;
+extern struct mutex actor_list_lock;
+
+#endif /* __POWER_ACTOR_H__ */
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH v4 4/7] thermal: add a basic cpu power actor
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
` (2 preceding siblings ...)
2014-06-17 9:14 ` [RFC PATCH v4 3/7] thermal: introduce the Power Actor API Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 5/7] thermal: introduce the Power Allocator governor Javi Merino
` (2 subsequent siblings)
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin
Introduce a power actor for cpus. It has a basic power model to get
the current power utilization and uses cpufreq cooling devices to set
the desired power. It uses the current frequency (as reported by
cpufreq) as well as load and OPPs for the power calculations. The
cpus must have registered their OPPs in the OPP library.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
Documentation/thermal/power_actor.txt | 125 +++++++++
drivers/thermal/Kconfig | 3 +
drivers/thermal/Makefile | 1 +
drivers/thermal/cpu_actor.c | 479 ++++++++++++++++++++++++++++++++++
drivers/thermal/power_actor.h | 30 +++
5 files changed, 638 insertions(+)
create mode 100644 drivers/thermal/cpu_actor.c
diff --git a/Documentation/thermal/power_actor.txt b/Documentation/thermal/power_actor.txt
index 11ca2d0bf0bd..c96344f12599 100644
--- a/Documentation/thermal/power_actor.txt
+++ b/Documentation/thermal/power_actor.txt
@@ -54,3 +54,128 @@ temperature.
milliwatts.
Returns 0 on success, -E* on error.
+
+CPU Power Actor API
+===================
+
+A simple power model for CPUs. The current power is calculated as
+dynamic + (optionally) static power. This power model requires that
+the operating-points of the CPUs are registered using the kernel's opp
+library and the `cpufreq_frequency_table` is assigned to the `struct
+device` of the cpu. If you are using the `cpufreq-cpu0.c` driver then
+the `cpufreq_frequency_table` should already be assigned to the cpu
+device.
+
+The `plat_static_func` parameter of `power_cpu_actor_register()` is
+optional. If you don't provide it, only dynamic power will be
+considered.
+
+Dynamic power
+-------------
+
+The dynamic power consumption of a processor depends on many factors.
+For a given processor implementation the primary factors are:
+
+- The time the processor spends running, consuming dynamic power, as
+ compared to the time in idle states where dynamic consumption is
+ negligible. Herein we refer to this as 'utilisation'.
+- The voltage and frequency levels as a result of DVFS. The DVFS
+ level is a dominant factor governing power consumption.
+- In running time the 'execution' behaviour (instruction types, memory
+ access patterns and so forth) causes, in most cases, a second order
+ variation. In pathological cases this variation can be significant,
+ but typically it is of a much lesser impact than the factors above.
+
+A high level dynamic power consumption model may then be represented as:
+
+Pdyn = f(run) * Voltage^2 * Frequency * Utilisation
+
+f(run) here represents the described execution behaviour and its
+result has a units of Watts/Hz/Volt^2 (this often expressed in
+mW/MHz/uVolt^2)
+
+The detailed behaviour for f(run) could be modelled on-line. However,
+in practice, such an on-line model has dependencies on a number of
+implementation specific processor support and characterisation
+factors. Therefore, in initial implementation that contribution is
+represented as a constant coefficient. This is a simplification
+consistent with the relative contribution to overall power variation.
+
+In this simplified representation our model becomes:
+
+Pdyn = Kd * Voltage^2 * Frequency * Utilisation
+
+Where Kd (capacitance) represents an indicative running time dynamic
+power coefficient in fundamental units of mW/MHz/uVolt^2
+
+Static Power
+------------
+
+Static leakage power consumption depends on a number of factors. For a
+given circuit implementation the primary factors are:
+
+- Time the circuit spends in each 'power state'
+- Temperature
+- Operating voltage
+- Process grade
+
+The time the circuit spends in each 'power state' for a given
+evaluation period at first order means OFF or ON. However,
+'retention' states can also be supported that reduce power during
+inactive periods without loss of context.
+
+Note: The visibility of state entries to the OS can vary, according to
+platform specifics, and this can then impact the accuracy of a model
+based on OS state information alone. It might be possible in some
+cases to extract more accurate information from system resources.
+
+The temperature, operating voltage and process 'grade' (slow to fast)
+of the circuit are all significant factors in static leakage power
+consumption. All of these have complex relationships to static power.
+
+Circuit implementation specific factors include the chosen silicon
+process as well as the type, number and size of transistors in both
+the logic gates and any RAM elements included.
+
+The static power consumption modelling must take into account the
+power managed regions that are implemented. Taking the example of an
+ARM processor cluster, the modelling would take into account whether
+each CPU can be powered OFF separately or if only a single power
+region is implemented for the complete cluster.
+
+In one view, there are others, a static power consumption model can
+then start from a set of reference values for each power managed
+region (e.g. CPU, Cluster/L2) in each state (e.g. ON, OFF) at an
+arbitrary process grade, voltage and temperature point. These values
+are then scaled for all of the following: the time in each state, the
+process grade, the current temperature and the operating
+voltage. However, since both implementation specific and complex
+relationships dominate the estimate, the appropriate interface to the
+model from the cpu power actor is to provide a function callback that
+calculates the static power in this platform. When registering the
+power cpu actor, pass the thermal zone closest to the cpu (to get the
+temperature) and a function pointer that follows the `get_static_t`
+prototype:
+
+ u32 plat_get_static(cpumask_t *cpumask, unsigned long voltage,
+ unsigned long temperature);
+
+with `cpumask` a cpumask of the cpus involved in the calculation,
+`voltage` the voltage at which they are opperating and `temperature`
+their current temperature.
+
+If `plat_static_func` is NULL when registering the power cpu actor,
+static power is considered to be negligible for this platform and only
+dynamic power is considered.
+
+The platform specific callback can then use any combination of tables
+and/or equations to permute the estimated value. Process grade
+information is not passed to the model since access to such data, from
+on-chip measurement capability or manufacture time data, is platform
+specific.
+
+Note: the significance of static power for CPUs in comparison to
+dynamic power is highly dependent on implementation. Given the
+potential complexity in implementation, the importance and accuracy of
+its inclusion when using cpu power actors should be assessed on a case by
+cases basis.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index ce4ebe17252c..c3cb4be49695 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -92,6 +92,9 @@ config THERMAL_GOV_USER_SPACE
config THERMAL_POWER_ACTOR
bool
+config THERMAL_POWER_ACTOR_CPU
+ bool
+
config CPU_THERMAL
bool "generic cpu cooling support"
depends on CPU_FREQ
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index d83aa42ab573..74f97c90a46c 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -16,6 +16,7 @@ thermal_sys-$(CONFIG_THERMAL_GOV_USER_SPACE) += user_space.o
# power actors
obj-$(CONFIG_THERMAL_POWER_ACTOR) += power_actor.o
+obj-$(CONFIG_THERMAL_POWER_ACTOR_CPU) += cpu_actor.o
# cpufreq cooling
thermal_sys-$(CONFIG_CPU_THERMAL) += cpu_cooling.o
diff --git a/drivers/thermal/cpu_actor.c b/drivers/thermal/cpu_actor.c
new file mode 100644
index 000000000000..67897b1ded62
--- /dev/null
+++ b/drivers/thermal/cpu_actor.c
@@ -0,0 +1,479 @@
+/*
+ * A basic cpu power_actor
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "CPU actor: " fmt
+
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_cooling.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/pm_opp.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+
+#include "power_actor.h"
+
+/**
+ * struct power_table - frequency to power conversion
+ * @frequency: frequency in KHz
+ * @power: power in mW
+ *
+ * This structure is built when the cooling device registers and helps
+ * in translating frequency to power and viceversa.
+ */
+struct power_table {
+ u32 frequency;
+ u32 power;
+};
+
+/**
+ * struct cpu_actor - information for each cpu actor
+ * @cpumask: cpus covered by this actor
+ * @last_load: load measured by the latest call to cpu_get_req_power()
+ * @time_in_idle: previous reading of the absolute time that this cpu was
+ * idle
+ * @time_in_idle_timestamp: wall time of the last invocation of
+ * get_cpu_idle_time_us()
+ * @dyn_power_table: array of struct power_table for frequency to power
+ * conversion
+ * @dyn_power_table_entries: number of entries in the @dyn_power_table array
+ * @cdev: cpufreq cooling device associated with this actor
+ * @plat_get_static_power: callback to calculate the static power
+ */
+struct cpu_actor {
+ cpumask_t cpumask;
+ u32 last_load;
+ u64 time_in_idle[NR_CPUS];
+ u64 time_in_idle_timestamp[NR_CPUS];
+ struct power_table *dyn_power_table;
+ int dyn_power_table_entries;
+ struct thermal_cooling_device *cdev;
+ get_static_t plat_get_static_power;
+};
+
+static u32 cpu_freq_to_power(struct cpu_actor *cpu_actor, u32 freq)
+{
+ int i;
+ struct power_table *pt = cpu_actor->dyn_power_table;
+
+ for (i = 0; i < cpu_actor->dyn_power_table_entries - 1; i++)
+ if (freq <= pt[i].frequency)
+ break;
+
+ return pt[i].power;
+}
+
+static u32 cpu_power_to_freq(struct cpu_actor *cpu_actor, u32 power)
+{
+ int i;
+ struct power_table *pt = cpu_actor->dyn_power_table;
+
+ for (i = 0; i < cpu_actor->dyn_power_table_entries - 1; i++)
+ if (power <= pt[i].power)
+ break;
+
+ return pt[i].frequency;
+}
+
+/**
+ * get_load() - get load for a cpu since last updated
+ * @cpu_actor: &struct cpu_actor for this actor
+ * @cpu: cpu number
+ *
+ * Return: The average load of cpu @cpu in percentage since this
+ * function was last called.
+ */
+static u32 get_load(struct cpu_actor *cpu_actor, int cpu)
+{
+ u32 load;
+ u64 now, now_idle, delta_time, delta_idle;
+
+ now_idle = get_cpu_idle_time(cpu, &now, 0);
+ delta_idle = now_idle - cpu_actor->time_in_idle[cpu];
+ delta_time = now - cpu_actor->time_in_idle_timestamp[cpu];
+
+ if (delta_time <= delta_idle)
+ load = 0;
+ else
+ load = div64_u64(100 * (delta_time - delta_idle), delta_time);
+
+ cpu_actor->time_in_idle[cpu] = now_idle;
+ cpu_actor->time_in_idle_timestamp[cpu] = now;
+
+ return load;
+}
+
+/**
+ * get_static_power() - calculate the static power consumed by the cpus
+ * @cpu_actor: &struct cpu_actor for this cpu
+ * @tz: &struct thermal_zone_device closest to the cpu
+ * @freq: frequency in KHz
+ *
+ * Calculate the static power consumed by the cpus described by
+ * @cpu_actor running at frequency @freq. This function relies on a
+ * platform specific function that should have been provided when the
+ * actor was registered. If it wasn't, the static power is assumed to
+ * be negligible.
+ *
+ * Return: The static power consumed by the cpus. It returns 0 on
+ * error or if there is no plat_get_static_power().
+ */
+static u32 get_static_power(struct cpu_actor *cpu_actor,
+ struct thermal_zone_device *tz, unsigned long freq)
+{
+ int err;
+ struct device *cpu_dev;
+ struct dev_pm_opp *opp;
+ unsigned long voltage, temperature;
+ cpumask_t *cpumask = &cpu_actor->cpumask;
+ unsigned long freq_hz = freq * 1000;
+
+ if (!cpu_actor->plat_get_static_power)
+ return 0;
+
+ if (freq == 0)
+ return 0;
+
+ cpu_dev = get_cpu_device(cpumask_any(cpumask));
+
+ rcu_read_lock();
+
+ opp = dev_pm_opp_find_freq_exact(cpu_dev, freq_hz, true);
+ voltage = dev_pm_opp_get_voltage(opp);
+
+ rcu_read_unlock();
+
+ if (voltage == 0) {
+ dev_warn_ratelimited(cpu_dev,
+ "Failed to get voltage for frequency %lu: %ld\n",
+ freq_hz, IS_ERR(opp) ? PTR_ERR(opp) : 0);
+ return 0;
+ }
+
+ err = thermal_zone_get_temp(tz, &temperature);
+ if (err) {
+ dev_warn(&tz->device, "Unable to read temperature: %d\n", err);
+ return 0;
+ }
+
+ return cpu_actor->plat_get_static_power(cpumask, voltage, temperature);
+}
+
+/**
+ * get_dynamic_power() - calculate the dynamic power
+ * @cpu_actor: cpu_actor pointer
+ * @freq: current frequency
+ *
+ * Return: the dynamic power consumed by the cpus described by
+ * @cpu_actor.
+ */
+static u32 get_dynamic_power(struct cpu_actor *cpu_actor, unsigned long freq)
+{
+ int cpu;
+ u32 power = 0, raw_cpu_power, total_load = 0;
+
+ raw_cpu_power = cpu_freq_to_power(cpu_actor, freq);
+
+ for_each_cpu(cpu, &cpu_actor->cpumask) {
+ u32 load;
+
+ if (!cpu_online(cpu))
+ continue;
+
+ load = get_load(cpu_actor, cpu);
+ power += (raw_cpu_power * load) / 100;
+ total_load += load;
+ }
+
+ cpu_actor->last_load = total_load;
+
+ return power;
+}
+
+/**
+ * cpu_get_req_power() - get the current power
+ * @actor: power actor pointer
+ * @tz: &thermal_zone_device closest to the CPU
+ *
+ * Callback for the power actor to return the current power
+ * consumption in milliwatts.
+ */
+static u32 cpu_get_req_power(struct power_actor *actor,
+ struct thermal_zone_device *tz)
+{
+ u32 static_power, dynamic_power;
+ unsigned long freq;
+ struct cpu_actor *cpu_actor = actor->data;
+
+ freq = cpufreq_quick_get(cpumask_any(&cpu_actor->cpumask));
+
+ static_power = get_static_power(cpu_actor, tz, freq);
+ dynamic_power = get_dynamic_power(cpu_actor, freq);
+
+ return static_power + dynamic_power;
+}
+
+/**
+ * cpu_get_max_power() - get the maximum power that the cpu could currently consume
+ * @actor: power actor pointer
+ * @tz: &thermal_zone_device closest to the CPU
+ *
+ * Callback for the power actor to return the maximum power
+ * consumption in milliwatts that the cpu could currently consume.
+ * The static power depends on temperature so the maximum power will
+ * vary over time.
+ */
+static u32 cpu_get_max_power(struct power_actor *actor,
+ struct thermal_zone_device *tz)
+{
+ u32 max_static_power, max_dyn_power;
+ cpumask_t *cpumask;
+ unsigned int max_freq, last_entry, num_cpus;
+ struct cpu_actor *cpu_actor = actor->data;
+
+ cpumask = &cpu_actor->cpumask;
+ max_freq = cpufreq_quick_get_max(cpumask_any(cpumask));
+ max_static_power = get_static_power(cpu_actor, tz, max_freq);
+
+ last_entry = cpu_actor->dyn_power_table_entries - 1;
+ num_cpus = cpumask_weight(cpumask);
+ max_dyn_power = cpu_actor->dyn_power_table[last_entry].power * num_cpus;
+
+ return max_static_power + max_dyn_power;
+}
+
+/**
+ * cpu_set_power() - set cpufreq cooling device to consume a certain power
+ * @actor: power actor pointer
+ * @tz: &thermal_zone_device closest to the CPU
+ * @power: the power in milliwatts that should be set
+ *
+ * Callback for the power actor to configure the power consumption of
+ * the CPU to be @power milliwatts at most. This function assumes
+ * that the load will remain constant. The power is translated into a
+ * cooling state that the cpu cooling device then sets.
+ *
+ * Return: 0 on success, -EINVAL if it couldn't convert the frequency
+ * to a cpufreq cooling device state.
+ */
+static int cpu_set_power(struct power_actor *actor,
+ struct thermal_zone_device *tz, u32 power)
+{
+ unsigned int cpu, cur_freq, target_freq;
+ unsigned long cdev_state;
+ u32 dyn_power, normalised_power, last_load;
+ struct thermal_cooling_device *cdev;
+ struct cpu_actor *cpu_actor = actor->data;
+
+ cdev = cpu_actor->cdev;
+ cpu = cpumask_any(&cpu_actor->cpumask);
+ cur_freq = cpufreq_quick_get(cpu);
+
+ dyn_power = power - get_static_power(cpu_actor, tz, cur_freq);
+ last_load = cpu_actor->last_load ? cpu_actor->last_load : 1;
+ normalised_power = (dyn_power * 100) / last_load;
+ target_freq = cpu_power_to_freq(cpu_actor, normalised_power);
+
+ cdev_state = cpufreq_cooling_get_level(cpu, target_freq);
+ if (cdev_state == THERMAL_CSTATE_INVALID) {
+ pr_err("Failed to convert %dKHz for cpu %d into a cdev state\n",
+ target_freq, cpu);
+ return -EINVAL;
+ }
+
+ return cdev->ops->set_cur_state(cdev, cdev_state);
+}
+
+static struct power_actor_ops cpu_actor_ops = {
+ .get_req_power = cpu_get_req_power,
+ .get_max_power = cpu_get_max_power,
+ .set_power = cpu_set_power,
+};
+
+/**
+ * build_dyn_power_table() - create a dynamic power to frequency table
+ * @cpu_actor: the cpu_actor in which to store the table
+ * @capacitance: dynamic power coefficient for these cpus
+ *
+ * Build a dynamic power to frequency table for this cpu and store it
+ * in @cpu_actor. This table will be used in cpu_power_to_freq() and
+ * cpu_freq_to_power() to convert between power and frequency
+ * efficiently. Power is stored in mW, frequency in KHz. The
+ * resulting table is in ascending order.
+ *
+ * Return: 0 on success, -E* on error.
+ */
+static int build_dyn_power_table(struct cpu_actor *cpu_actor, u32 capacitance)
+{
+ struct power_table *power_table;
+ struct dev_pm_opp *opp;
+ struct device *dev = NULL;
+ int num_opps, cpu, i, ret = 0;
+ unsigned long freq;
+
+ num_opps = 0;
+
+ rcu_read_lock();
+
+ for_each_cpu(cpu, &cpu_actor->cpumask) {
+ dev = get_cpu_device(cpu);
+ if (!dev)
+ continue;
+
+ num_opps = dev_pm_opp_get_opp_count(dev);
+ if (num_opps > 0) {
+ break;
+ } else if (num_opps < 0) {
+ ret = num_opps;
+ goto unlock;
+ }
+ }
+
+ if (num_opps == 0) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ power_table = kcalloc(num_opps, sizeof(*power_table), GFP_KERNEL);
+
+ i = 0;
+ for (freq = 0;
+ opp = dev_pm_opp_find_freq_ceil(dev, &freq), !IS_ERR(opp);
+ freq++) {
+ u32 freq_mhz, voltage_mv;
+ u64 power;
+
+ freq_mhz = freq / 1000000;
+ voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
+
+ /*
+ * Do the multiplication with MHz and millivolt so as
+ * to not overflow.
+ */
+ power = (u64)capacitance * freq_mhz * voltage_mv * voltage_mv;
+ do_div(power, 1000000000);
+
+ /* frequency is stored in power_table in KHz */
+ power_table[i].frequency = freq / 1000;
+ power_table[i].power = power;
+
+ i++;
+ }
+
+ if (i == 0) {
+ ret = PTR_ERR(opp);
+ goto unlock;
+ }
+
+ cpu_actor->dyn_power_table = power_table;
+ cpu_actor->dyn_power_table_entries = i;
+
+unlock:
+ rcu_read_unlock();
+ return ret;
+}
+
+/**
+ * power_cpu_actor_register() - register a cpu_actor within the power actor API
+ * @np: DT node for the cpus.
+ * @cpumask: cpumask of cpus covered by this power_actor
+ * @capacitance: dynamic power coefficient for these cpus
+ * @plat_static_func: function to calculate the static power consumed by these
+ * cpus (optional)
+ *
+ * Create a cpufreq cooling device for the cpus in @cpumask and
+ * register it with the power actor API using a simple cpu power
+ * model. If @np is not NULL, the cpufreq cooling device is
+ * registered with of_cpufreq_cooling_register(), otherwise
+ * cpufreq_cooling_register() is used. The cpus must have registered
+ * their OPPs in the OPP library.
+ *
+ * An optional @plat_static_func may be provided to calculate the
+ * static power consumed by these cpus. If the platform's static
+ * power consumption is unknown or negligible, make it NULL.
+ *
+ * The actor registered should be freed using
+ * power_cpu_actor_unregister() when it's no longer needed.
+ *
+ * Return: The power_actor created on success or the corresponding
+ * ERR_PTR() on failure.
+ */
+struct power_actor *
+power_cpu_actor_register(struct device_node *np,
+ cpumask_t *cpumask,
+ u32 capacitance,
+ get_static_t plat_static_func)
+{
+ int ret;
+ struct thermal_cooling_device *cdev;
+ struct power_actor *actor, *err_ret;
+ struct cpu_actor *cpu_actor;
+
+ if (!np)
+ cdev = cpufreq_cooling_register(cpumask);
+ else
+ cdev = of_cpufreq_cooling_register(np, cpumask);
+
+ if (!cdev)
+ return ERR_PTR(PTR_ERR(cdev));
+
+ cpu_actor = kzalloc(sizeof(*cpu_actor), GFP_KERNEL);
+ if (!cpu_actor) {
+ err_ret = ERR_PTR(-ENOMEM);
+ goto cdev_unregister;
+ }
+
+ cpumask_copy(&cpu_actor->cpumask, cpumask);
+ cpu_actor->cdev = cdev;
+ cpu_actor->plat_get_static_power = plat_static_func;
+
+ ret = build_dyn_power_table(cpu_actor, capacitance);
+ if (ret) {
+ err_ret = ERR_PTR(ret);
+ goto kfree;
+ }
+
+ actor = power_actor_register(&cpu_actor_ops, cpu_actor);
+ if (IS_ERR(actor)) {
+ err_ret = actor;
+ goto kfree;
+ }
+
+ return actor;
+
+kfree:
+ kfree(cpu_actor);
+cdev_unregister:
+ cpufreq_cooling_unregister(cdev);
+
+ return err_ret;
+}
+
+/**
+ * power_cpu_actor_unregister() - Unregister a power cpu actor
+ * @actor: the actor to unregister
+ */
+void power_cpu_actor_unregister(struct power_actor *actor)
+{
+ struct cpu_actor *cpu_actor = actor->data;
+
+ kfree(cpu_actor->dyn_power_table);
+ kfree(cpu_actor);
+ power_actor_unregister(actor);
+}
diff --git a/drivers/thermal/power_actor.h b/drivers/thermal/power_actor.h
index d3ae3ea80387..c395728518ea 100644
--- a/drivers/thermal/power_actor.h
+++ b/drivers/thermal/power_actor.h
@@ -17,8 +17,12 @@
#ifndef __POWER_ACTOR_H__
#define __POWER_ACTOR_H__
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
+#include <linux/thermal.h>
struct power_actor;
@@ -55,6 +59,32 @@ struct power_actor *power_actor_register(struct power_actor_ops *ops,
void *privdata);
void power_actor_unregister(struct power_actor *actor);
+typedef u32 (*get_static_t)(cpumask_t *cpumask,
+ unsigned long voltage,
+ unsigned long temperature);
+
+#ifdef CONFIG_THERMAL_POWER_ACTOR_CPU
+struct power_actor *
+power_cpu_actor_register(struct device_node *np,
+ cpumask_t *cpumask,
+ u32 capacitance,
+ get_static_t plat_static_func);
+void power_cpu_actor_unregister(struct power_actor *actor);
+#else
+static inline
+struct power_actor *
+power_cpu_actor_register(struct device_node *np,
+ cpumask_t *cpumask,
+ u32 capacitance,
+ get_static_t plat_static_func)
+{
+ return ERR_PTR(-ENOSYS);
+}
+static inline void power_cpu_actor_unregister(struct power_actor *actor)
+{
+}
+#endif
+
extern struct list_head actor_list;
extern struct mutex actor_list_lock;
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH v4 5/7] thermal: introduce the Power Allocator governor
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
` (3 preceding siblings ...)
2014-06-17 9:14 ` [RFC PATCH v4 4/7] thermal: add a basic cpu power actor Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor Javi Merino
2014-06-17 9:14 ` [RFC PATCH v4 7/7] of: thermal: Introduce sustainable power for a thermal zone Javi Merino
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin
The power allocator governor is a thermal governor that controls system
and device power allocation to control temperature. Conceptually, the
implementation divides the sustainable power of a thermal zone among
all the heat sources in that zone.
This governor relies on "power actors", entities that represent heat
sources. They can report current and maximum power consumption and
can set a given maximum power consumption, usually via a cooling
device.
The governor uses a Proportional Integral Derivative (PID) controller
driven by the temperature of the thermal zone. The output of the
controller is a power budget that is then allocated to each power
actor that can have bearing on the temperature we are trying to
control. It decides how much power to give each cooling device based
on the performance they are requesting. The PID controller ensures
that the total power budget does not exceed the control temperature.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
Documentation/thermal/power_allocator.txt | 41 +++
drivers/thermal/Kconfig | 15 +
drivers/thermal/Makefile | 1 +
drivers/thermal/power_allocator.c | 467 ++++++++++++++++++++++++++++++
drivers/thermal/thermal_core.c | 7 +-
drivers/thermal/thermal_core.h | 8 +
include/linux/thermal.h | 8 +
7 files changed, 546 insertions(+), 1 deletion(-)
create mode 100644 Documentation/thermal/power_allocator.txt
create mode 100644 drivers/thermal/power_allocator.c
diff --git a/Documentation/thermal/power_allocator.txt b/Documentation/thermal/power_allocator.txt
new file mode 100644
index 000000000000..93a3ce90322d
--- /dev/null
+++ b/Documentation/thermal/power_allocator.txt
@@ -0,0 +1,41 @@
+Integration of the power_allocator governor in a platform
+=========================================================
+
+Registering thermal_zone_device
+-------------------------------
+
+An estimate of the sustainable dissipatable power (in mW) should be
+provided while registering the thermal zone. This is the maximum
+sustained power for allocation at the desired maximum temperature.
+This number can vary for different conditions, but the closed-loop of
+the controller should take care of those variations, the
+`sustainable_power` should be an estimation of it. Register your
+thermal zone with `thermal_zone_params` that have a
+`sustainable_power`. If you weren't passing any
+`thermal_zone_params`, then something like this will do:
+
+ static const struct thermal_zone_params tz_params = {
+ .sustainable_power = 3500,
+ };
+
+and then pass `tz_params` as the 5th parameter to
+`thermal_zone_device_register()`
+
+Trip points
+-----------
+
+The governor requires the following two trip points:
+
+1. "switch on" trip point: temperature above which the governor
+ control loop starts operating
+2. "desired temperature" trip point: it should be higher than the
+ "switch on" trip point. It is the target temperature the governor
+ is controlling for.
+
+The trip points can be either active or passive.
+
+Power actors
+------------
+
+Devices controlled by this governor must be registered with the power
+actor API. Read `power_actor.txt` for more information about them.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index c3cb4be49695..fef56342450a 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -71,6 +71,14 @@ config THERMAL_DEFAULT_GOV_USER_SPACE
Select this if you want to let the user space manage the
platform thermals.
+config THERMAL_DEFAULT_GOV_POWER_ALLOCATOR
+ bool "power_allocator"
+ select THERMAL_GOV_POWER_ALLOCATOR
+ help
+ Select this if you want to control temperature based on
+ system and device power allocation. This governor relies on
+ power actors to operate.
+
endchoice
config THERMAL_GOV_FAIR_SHARE
@@ -89,6 +97,13 @@ config THERMAL_GOV_USER_SPACE
help
Enable this to let the user space manage the platform thermals.
+config THERMAL_GOV_POWER_ALLOCATOR
+ bool "Power allocator thermal governor"
+ select THERMAL_POWER_ACTOR
+ help
+ Enable this to manage platform thermals by dynamically
+ allocating and limiting power to devices.
+
config THERMAL_POWER_ACTOR
bool
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 74f97c90a46c..e74d57d0fe61 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -13,6 +13,7 @@ thermal_sys-$(CONFIG_THERMAL_OF) += of-thermal.o
thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o
thermal_sys-$(CONFIG_THERMAL_GOV_STEP_WISE) += step_wise.o
thermal_sys-$(CONFIG_THERMAL_GOV_USER_SPACE) += user_space.o
+thermal_sys-$(CONFIG_THERMAL_GOV_POWER_ALLOCATOR) += power_allocator.o
# power actors
obj-$(CONFIG_THERMAL_POWER_ACTOR) += power_actor.o
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
new file mode 100644
index 000000000000..dd781eb29568
--- /dev/null
+++ b/drivers/thermal/power_allocator.c
@@ -0,0 +1,467 @@
+/*
+ * A power allocator to manage temperature
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "Power allocator: " fmt
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+#include "power_actor.h"
+#include "thermal_core.h"
+
+#define FRAC_BITS 8
+#define int_to_frac(x) ((x) << FRAC_BITS)
+#define frac_to_int(x) ((x) >> FRAC_BITS)
+
+/**
+ * mul_frac() - multiply two fixed-point numbers
+ * @x: first multiplicand
+ * @y: second multiplicand
+ *
+ * Return: the result of multiplying two fixed-point numbers. The
+ * result is also a fixed-point number.
+ */
+static inline s64 mul_frac(s64 x, s64 y)
+{
+ return (x * y) >> FRAC_BITS;
+}
+
+enum power_allocator_trip_levels {
+ TRIP_SWITCH_ON = 0, /* Switch on PID controller */
+ TRIP_MAX_DESIRED_TEMPERATURE, /* Temperature we are controlling for */
+};
+
+/**
+ * struct power_allocator_params - parameters for the power allocator governor
+ * @k_po: Proportional parameter of the PID controller when overshooting
+ * (i.e., when temperature is below the target)
+ * @k_pi: Proportional parameter of the PID controller when undershooting
+ * @k_i: Integral parameter of the PID controller
+ * @k_d: Derivative parameter of the PID controller
+ * @integral_cutoff: threshold below which the error is no longer accumulated
+ in the PID controller
+ * @err_integral: accumulated error in the PID controller.
+ * @prev_err: error in the previous iteration of the PID controller.
+ * Used to calculate the derivative term.
+ */
+struct power_allocator_params {
+ s32 k_po;
+ s32 k_pu;
+ s32 k_i;
+ s32 k_d;
+ s32 integral_cutoff;
+ s32 err_integral;
+ s32 prev_err;
+};
+
+/**
+ * pid_controller() - PID controller
+ * @tz: thermal zone we are operating in
+ * @current_temp: the current temperature
+ * @control_temp: the target temperature
+ * @max_allocatable_power: maximum allocatable power for this thermal zone
+ *
+ * This PID controller increases the available power budget so that the
+ * temperature of the thermal zone gets as close as possible to
+ * @control_temp and limits the power if it exceeds it. k_po is the
+ * proportional term when we are overshooting, k_pu is the
+ * proportional term when we are undershooting. integral_cutoff is a
+ * threshold below which we stop accumulating the error. The
+ * accumulated error is only valid if the requested power will make
+ * the system warmer. If the system is mostly idle, there's no point
+ * in accumulating positive error.
+ *
+ * Return: The power budget for the next period.
+ */
+static u32 pid_controller(struct thermal_zone_device *tz,
+ unsigned long current_temp, unsigned long control_temp,
+ u32 max_allocatable_power)
+{
+ s64 p, i, d, power_range;
+ s32 err;
+ struct power_allocator_params *params = tz->governor_data;
+
+ err = ((s32)control_temp - (s32)current_temp) / 1000;
+ err = int_to_frac(err);
+
+ /* Calculate the proportional term */
+ p = mul_frac(err < 0 ? params->k_po : params->k_pu, err);
+
+ /*
+ * Calculate the integral term
+ *
+ * if the error s less than cut off allow integration (but
+ * the integral is limited to max power)
+ */
+ i = mul_frac(params->k_i, params->err_integral);
+
+ if (err < int_to_frac(params->integral_cutoff)) {
+ s64 tmpi = mul_frac(params->k_i, err);
+
+ tmpi += i;
+ if (tmpi <= int_to_frac(max_allocatable_power)) {
+ i = tmpi;
+ params->err_integral += err;
+ }
+ }
+
+ /*
+ * Calculate the derivative term
+ *
+ * We do err - prev_err, so with a positive k_d, a decreasing
+ * error (i.e. driving closer to the line) results in less
+ * power being applied, slowing down the controller)
+ */
+ d = mul_frac(params->k_d, err - params->prev_err);
+ params->prev_err = err;
+
+ power_range = p + i + d;
+
+ /* feed-forward the known sustainable dissipatable power */
+ power_range = tz->tzp->sustainable_power + frac_to_int(power_range);
+
+ return clamp(power_range, (s64)0, (s64)max_allocatable_power);
+}
+
+/**
+ * divvy_up_power() - divvy the allocated power between the actors
+ * @req_power: each actor's requested power
+ * @max_power: each actor's maximum available power
+ * @num_actors: size of the @req_power, @max_power and @granted_power's array
+ * @total_req_power: sum of @req_power
+ * @power_range: total allocated power
+ * @granted_power: ouput array: each actor's granted power
+ *
+ * This function divides the total allocated power (@power_range)
+ * fairly between the actors. It first tries to give each actor a
+ * share of the @power_range according to how much power it requested
+ * compared to the rest of the actors. For example, if only one actor
+ * requests power, then it receives all the @power_range. If
+ * three actors each requests 1mW, each receives a third of the
+ * @power_range.
+ *
+ * If any actor received more than their maximum power, then that
+ * surplus is re-divvied among the actors based on how far they are
+ * from their respective maximums.
+ *
+ * Granted power for each actor is written to @granted_power, which
+ * should've been allocated by the calling function.
+ */
+static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors,
+ u32 total_req_power, u32 power_range,
+ u32 *granted_power)
+{
+ u32 extra_power, capped_extra_power, extra_actor_power[num_actors];
+ int i;
+
+ if (!total_req_power) {
+ /*
+ * Nobody requested anything, so just give everybody
+ * the maximum power
+ */
+ for (i = 0; i < num_actors; i++)
+ granted_power[i] = max_power[i];
+
+ return;
+ }
+
+ capped_extra_power = 0;
+ extra_power = 0;
+ for (i = 0; i < num_actors; i++) {
+ u64 req_range = req_power[i] * power_range;
+
+ granted_power[i] = div_u64(req_range, total_req_power);
+
+ if (granted_power[i] > max_power[i]) {
+ extra_power += granted_power[i] - max_power[i];
+ granted_power[i] = max_power[i];
+ }
+
+ extra_actor_power[i] = max_power[i] - granted_power[i];
+ capped_extra_power += extra_actor_power[i];
+ }
+
+ if (!extra_power)
+ return;
+
+ /*
+ * Re-divvy the reclaimed extra among actors based on
+ * how far they are from the max
+ */
+ extra_power = min(extra_power, capped_extra_power);
+ if (capped_extra_power > 0)
+ for (i = 0; i < num_actors; i++)
+ granted_power[i] += (extra_actor_power[i] *
+ extra_power) / capped_extra_power;
+}
+
+static int allocate_power(struct thermal_zone_device *tz,
+ unsigned long current_temp, unsigned long control_temp)
+{
+ struct power_actor *actor;
+ u32 *req_power, *max_power, *granted_power;
+ u32 total_req_power, max_allocatable_power;
+ u32 power_range;
+ int i, num_actors, ret = 0;
+
+ mutex_lock(&tz->lock);
+ mutex_lock(&actor_list_lock);
+
+ num_actors = 0;
+ list_for_each_entry(actor, &actor_list, actor_node)
+ num_actors++;
+
+ req_power = devm_kcalloc(&tz->device, num_actors, sizeof(*req_power),
+ GFP_KERNEL);
+ if (!req_power) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ max_power = devm_kcalloc(&tz->device, num_actors, sizeof(*max_power),
+ GFP_KERNEL);
+ if (!max_power) {
+ ret = -ENOMEM;
+ goto free_req_power;
+ }
+
+ granted_power = devm_kcalloc(&tz->device, num_actors,
+ sizeof(*granted_power), GFP_KERNEL);
+ if (!granted_power) {
+ ret = -ENOMEM;
+ goto free_max_power;
+ }
+
+ i = 0;
+ total_req_power = 0;
+ max_allocatable_power = 0;
+
+ list_for_each_entry(actor, &actor_list, actor_node) {
+ req_power[i] = actor->ops->get_req_power(actor, tz);
+ total_req_power += req_power[i];
+
+ max_power[i] = actor->ops->get_max_power(actor, tz);
+ max_allocatable_power += max_power[i];
+
+ i++;
+ }
+
+ power_range = pid_controller(tz, current_temp, control_temp,
+ max_allocatable_power);
+
+ divvy_up_power(req_power, max_power, num_actors, total_req_power,
+ power_range, granted_power);
+
+ i = 0;
+ list_for_each_entry(actor, &actor_list, actor_node) {
+ actor->ops->set_power(actor, tz, granted_power[i]);
+ i++;
+ }
+
+ devm_kfree(&tz->device, granted_power);
+free_max_power:
+ devm_kfree(&tz->device, max_power);
+free_req_power:
+ devm_kfree(&tz->device, req_power);
+unlock:
+ mutex_unlock(&actor_list_lock);
+ mutex_unlock(&tz->lock);
+
+ return ret;
+}
+
+static int check_trips(struct thermal_zone_device *tz)
+{
+ int ret;
+ enum thermal_trip_type type;
+
+ if (tz->trips < 2)
+ return -EINVAL;
+
+ ret = tz->ops->get_trip_type(tz, TRIP_SWITCH_ON, &type);
+ if (ret)
+ return ret;
+
+ if ((type != THERMAL_TRIP_PASSIVE) && (type != THERMAL_TRIP_ACTIVE))
+ return -EINVAL;
+
+ ret = tz->ops->get_trip_type(tz, TRIP_MAX_DESIRED_TEMPERATURE, &type);
+ if (ret)
+ return ret;
+
+ if ((type != THERMAL_TRIP_PASSIVE) && (type != THERMAL_TRIP_ACTIVE))
+ return -EINVAL;
+
+ return ret;
+}
+
+static void reset_pid_controller(struct power_allocator_params *params)
+{
+ params->err_integral = 0;
+ params->prev_err = 0;
+}
+
+static void allow_maximum_power(struct thermal_zone_device *tz)
+{
+ struct power_actor *actor;
+
+ mutex_lock(&actor_list_lock);
+
+ list_for_each_entry(actor, &actor_list, actor_node) {
+ u32 max_power = actor->ops->get_max_power(actor, tz);
+
+ actor->ops->set_power(actor, tz, max_power);
+ }
+
+ mutex_unlock(&actor_list_lock);
+}
+
+/**
+ * power_allocator_bind() - bind the power_allocator governor to a thermal zone
+ * @tz: thermal zone to bind it to
+ *
+ * Check that the thermal zone is valid for this governor, that is, it
+ * has two thermal trips. If so, initialize the PID controller
+ * parameters and bind it to the thermal zone.
+ *
+ * Return: 0 on success, -EINVAL if the trips were invalid or -ENOMEM
+ * if we ran out of memory.
+ */
+static int power_allocator_bind(struct thermal_zone_device *tz)
+{
+ int ret;
+ struct power_allocator_params *params;
+ unsigned long switch_on_temp, control_temp;
+ u32 temperature_threshold;
+
+ ret = check_trips(tz);
+ if (ret) {
+ dev_err(&tz->device,
+ "thermal zone %s has the wrong number of trips for this governor\n",
+ tz->type);
+ return ret;
+ }
+
+ if (!tz->tzp || !tz->tzp->sustainable_power) {
+ dev_err(&tz->device,
+ "power_allocator: missing sustainable_power\n");
+ return -EINVAL;
+ }
+
+ params = devm_kzalloc(&tz->device, sizeof(*params), GFP_KERNEL);
+ if (!params)
+ return -ENOMEM;
+
+ ret = tz->ops->get_trip_temp(tz, TRIP_SWITCH_ON, &switch_on_temp);
+ if (ret)
+ goto free;
+
+ ret = tz->ops->get_trip_temp(tz, TRIP_MAX_DESIRED_TEMPERATURE,
+ &control_temp);
+ if (ret)
+ goto free;
+
+ temperature_threshold = (control_temp - switch_on_temp) / 1000;
+
+ params->k_po = int_to_frac(tz->tzp->sustainable_power) /
+ temperature_threshold;
+ params->k_pu = int_to_frac(2 * tz->tzp->sustainable_power) /
+ temperature_threshold;
+ params->k_i = int_to_frac(10);
+ params->k_d = int_to_frac(0);
+ params->integral_cutoff = 0;
+
+ reset_pid_controller(params);
+
+ tz->governor_data = params;
+
+ return 0;
+
+free:
+ devm_kfree(&tz->device, params);
+ return ret;
+}
+
+static void power_allocator_unbind(struct thermal_zone_device *tz)
+{
+ dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
+ devm_kfree(&tz->device, tz->governor_data);
+ tz->governor_data = NULL;
+}
+
+static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
+{
+ int ret;
+ unsigned long switch_on_temp, control_temp, current_temp;
+ struct power_allocator_params *params = tz->governor_data;
+
+ /*
+ * We get called for every trip point but we only need to do
+ * our calculations once
+ */
+ if (trip != TRIP_MAX_DESIRED_TEMPERATURE)
+ return 0;
+
+ ret = thermal_zone_get_temp(tz, ¤t_temp);
+ if (ret) {
+ dev_warn(&tz->device, "Failed to get temperature: %d\n", ret);
+ return ret;
+ }
+
+ ret = tz->ops->get_trip_temp(tz, TRIP_SWITCH_ON, &switch_on_temp);
+ if (ret) {
+ dev_warn(&tz->device,
+ "Failed to get switch on temperature: %d\n", ret);
+ return ret;
+ }
+
+ if (current_temp < switch_on_temp) {
+ tz->passive = 0;
+ reset_pid_controller(params);
+ allow_maximum_power(tz);
+ return 0;
+ }
+
+ tz->passive = 1;
+
+ ret = tz->ops->get_trip_temp(tz, TRIP_MAX_DESIRED_TEMPERATURE,
+ &control_temp);
+ if (ret) {
+ dev_warn(&tz->device,
+ "Failed to get the maximum desired temperature: %d\n",
+ ret);
+ return ret;
+ }
+
+ return allocate_power(tz, current_temp, control_temp);
+}
+
+static struct thermal_governor thermal_gov_power_allocator = {
+ .name = "power_allocator",
+ .bind_to_tz = power_allocator_bind,
+ .unbind_from_tz = power_allocator_unbind,
+ .throttle = power_allocator_throttle,
+};
+
+int thermal_gov_power_allocator_register(void)
+{
+ return thermal_register_governor(&thermal_gov_power_allocator);
+}
+
+void thermal_gov_power_allocator_unregister(void)
+{
+ thermal_unregister_governor(&thermal_gov_power_allocator);
+}
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 3da99dd80ad5..1415d3d8a9eb 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1857,7 +1857,11 @@ static int __init thermal_register_governors(void)
if (result)
return result;
- return thermal_gov_user_space_register();
+ result = thermal_gov_user_space_register();
+ if (result)
+ return result;
+
+ return thermal_gov_power_allocator_register();
}
static void thermal_unregister_governors(void)
@@ -1865,6 +1869,7 @@ static void thermal_unregister_governors(void)
thermal_gov_step_wise_unregister();
thermal_gov_fair_share_unregister();
thermal_gov_user_space_unregister();
+ thermal_gov_power_allocator_unregister();
}
static int __init thermal_init(void)
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 3db339fb636f..b24cde2c71cc 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -77,6 +77,14 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
static inline void thermal_gov_user_space_unregister(void) {}
#endif /* CONFIG_THERMAL_GOV_USER_SPACE */
+#ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR
+int thermal_gov_power_allocator_register(void);
+void thermal_gov_power_allocator_unregister(void);
+#else
+static inline int thermal_gov_power_allocator_register(void) { return 0; }
+static inline void thermal_gov_power_allocator_unregister(void) {}
+#endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */
+
/* device tree support */
#ifdef CONFIG_THERMAL_OF
int of_parse_thermal_zones(void);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 1124b7a9358a..e01141261756 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -57,6 +57,8 @@
#define DEFAULT_THERMAL_GOVERNOR "fair_share"
#elif defined(CONFIG_THERMAL_DEFAULT_GOV_USER_SPACE)
#define DEFAULT_THERMAL_GOVERNOR "user_space"
+#elif defined(CONFIG_THERMAL_DEFAULT_GOV_POWER_ALLOCATOR)
+#define DEFAULT_THERMAL_GOVERNOR "power_allocator"
#endif
struct thermal_zone_device;
@@ -287,6 +289,12 @@ struct thermal_zone_params {
int num_tbps; /* Number of tbp entries */
struct thermal_bind_params *tbp;
+
+ /*
+ * Sustainable power (heat) that this thermal zone can dissipate in
+ * mW
+ */
+ u32 sustainable_power;
};
struct thermal_genl_event {
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
` (4 preceding siblings ...)
2014-06-17 9:14 ` [RFC PATCH v4 5/7] thermal: introduce the Power Allocator governor Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
2014-06-17 11:18 ` Steven Rostedt
2014-06-17 9:14 ` [RFC PATCH v4 7/7] of: thermal: Introduce sustainable power for a thermal zone Javi Merino
6 siblings, 1 reply; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, Javi Merino, Zhang Rui, Eduardo Valentin,
Steven Rostedt, Frederic Weisbecker, Ingo Molnar
Add trace events for the power allocator governor and the power actor
interface of the cpu cooling device.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
trace-cmd needs the patched attached in
http://article.gmane.org/gmane.linux.kernel/1704423 for this to work.
drivers/thermal/cpu_actor.c | 5 +++
drivers/thermal/power_allocator.c | 12 ++++++-
include/trace/events/thermal_power.h | 62 ++++++++++++++++++++++++++++++++++++
3 files changed, 78 insertions(+), 1 deletion(-)
create mode 100644 include/trace/events/thermal_power.h
diff --git a/drivers/thermal/cpu_actor.c b/drivers/thermal/cpu_actor.c
index 67897b1ded62..4ef715dea87f 100644
--- a/drivers/thermal/cpu_actor.c
+++ b/drivers/thermal/cpu_actor.c
@@ -27,6 +27,8 @@
#include <linux/printk.h>
#include <linux/slab.h>
+#include <trace/events/thermal_power.h>
+
#include "power_actor.h"
/**
@@ -297,6 +299,9 @@ static int cpu_set_power(struct power_actor *actor,
return -EINVAL;
}
+ trace_thermal_power_limit(&cpu_actor->cpumask, target_freq, cdev_state,
+ power);
+
return cdev->ops->set_cur_state(cdev, cdev_state);
}
diff --git a/drivers/thermal/power_allocator.c b/drivers/thermal/power_allocator.c
index dd781eb29568..a10c5ed26820 100644
--- a/drivers/thermal/power_allocator.c
+++ b/drivers/thermal/power_allocator.c
@@ -19,6 +19,9 @@
#include <linux/slab.h>
#include <linux/thermal.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/thermal_power.h>
+
#include "power_actor.h"
#include "thermal_core.h"
@@ -133,7 +136,14 @@ static u32 pid_controller(struct thermal_zone_device *tz,
/* feed-forward the known sustainable dissipatable power */
power_range = tz->tzp->sustainable_power + frac_to_int(power_range);
- return clamp(power_range, (s64)0, (s64)max_allocatable_power);
+ power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power);
+
+ trace_thermal_power_allocator_pid(frac_to_int(err),
+ frac_to_int(params->err_integral),
+ frac_to_int(p), frac_to_int(i),
+ frac_to_int(d), power_range);
+
+ return power_range;
}
/**
diff --git a/include/trace/events/thermal_power.h b/include/trace/events/thermal_power.h
new file mode 100644
index 000000000000..6629f8b4ca9f
--- /dev/null
+++ b/include/trace/events/thermal_power.h
@@ -0,0 +1,62 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM thermal_power
+
+#if !defined(_TRACE_THERMAL_GOVERNOR_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_THERMAL_POWER_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(thermal_power_allocator_pid,
+ TP_PROTO(s32 err, s32 err_integral, s64 p, s64 i, s64 d, s32 output),
+ TP_ARGS(err, err_integral, p, i, d, output),
+ TP_STRUCT__entry(
+ __field(s32, err )
+ __field(s32, err_integral)
+ __field(s64, p )
+ __field(s64, i )
+ __field(s64, d )
+ __field(s32, output )
+ ),
+ TP_fast_assign(
+ __entry->err = err;
+ __entry->err_integral = err_integral;
+ __entry->p = p;
+ __entry->i = i;
+ __entry->d = d;
+ __entry->output = output;
+ ),
+
+ TP_printk("err=%d err_integral=%d p=%lld i=%lld d=%lld output=%d",
+ __entry->err, __entry->err_integral,
+ __entry->p, __entry->i, __entry->d, __entry->output)
+);
+
+TRACE_EVENT(thermal_power_limit,
+ TP_PROTO(const struct cpumask *cpus, unsigned int freq,
+ unsigned long cdev_state, u32 power),
+
+ TP_ARGS(cpus, freq, cdev_state, power),
+
+ TP_STRUCT__entry(
+ __bitmask(cpumask, num_possible_cpus())
+ __field(unsigned int, freq )
+ __field(unsigned long, cdev_state)
+ __field(u32, power )
+ ),
+
+ TP_fast_assign(
+ __assign_bitmask(cpumask, cpumask_bits(cpus),
+ num_possible_cpus());
+ __entry->freq = freq;
+ __entry->cdev_state = cdev_state;
+ __entry->power = power;
+ ),
+
+ TP_printk("cpus=%s freq=%u cdev_state=%lu power=%u",
+ __get_bitmask(cpumask), __entry->freq, __entry->cdev_state,
+ __entry->power)
+);
+#endif /* _TRACE_THERMAL_POWER_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor
2014-06-17 9:14 ` [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor Javi Merino
@ 2014-06-17 11:18 ` Steven Rostedt
2014-06-17 11:52 ` Javi Merino
0 siblings, 1 reply; 10+ messages in thread
From: Steven Rostedt @ 2014-06-17 11:18 UTC (permalink / raw)
To: Javi Merino
Cc: linux-pm, linux-kernel, punit.agrawal, broonie, Zhang Rui,
Eduardo Valentin, Frederic Weisbecker, Ingo Molnar
On Tue, 17 Jun 2014 10:14:52 +0100
"Javi Merino" <javi.merino@arm.com> wrote:
> Add trace events for the power allocator governor and the power actor
> interface of the cpu cooling device.
>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Signed-off-by: Javi Merino <javi.merino@arm.com>
>
> ---
>
> trace-cmd needs the patched attached in
> http://article.gmane.org/gmane.linux.kernel/1704423 for this to work.
The recently released trace-cmd v2.4 contains this.
-- Steve
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor
2014-06-17 11:18 ` Steven Rostedt
@ 2014-06-17 11:52 ` Javi Merino
0 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 11:52 UTC (permalink / raw)
To: Steven Rostedt; +Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
On Tue, Jun 17, 2014 at 12:18:38PM +0100, Steven Rostedt wrote:
> On Tue, 17 Jun 2014 10:14:52 +0100
> "Javi Merino" <javi.merino@arm.com> wrote:
>
> > Add trace events for the power allocator governor and the power actor
> > interface of the cpu cooling device.
> >
> > Cc: Zhang Rui <rui.zhang@intel.com>
> > Cc: Eduardo Valentin <edubezval@gmail.com>
> > Cc: Steven Rostedt <rostedt@goodmis.org>
> > Cc: Frederic Weisbecker <fweisbec@gmail.com>
> > Cc: Ingo Molnar <mingo@redhat.com>
> > Signed-off-by: Javi Merino <javi.merino@arm.com>
> >
> > ---
> >
> > trace-cmd needs the patched attached in
> > http://article.gmane.org/gmane.linux.kernel/1704423 for this to work.
>
> The recently released trace-cmd v2.4 contains this.
Good to know, I'll drop the text from future uploads. Thanks!
Javi
^ permalink raw reply [flat|nested] 10+ messages in thread
* [RFC PATCH v4 7/7] of: thermal: Introduce sustainable power for a thermal zone
2014-06-17 9:14 [RFC PATCH v4 0/7] The power allocator thermal governor Javi Merino
` (5 preceding siblings ...)
2014-06-17 9:14 ` [RFC PATCH v4 6/7] thermal: add trace events to the power allocator governor Javi Merino
@ 2014-06-17 9:14 ` Javi Merino
6 siblings, 0 replies; 10+ messages in thread
From: Javi Merino @ 2014-06-17 9:14 UTC (permalink / raw)
To: linux-pm, linux-kernel
Cc: punit.agrawal, broonie, devicetree, Zhang Rui, Eduardo Valentin
From: Punit Agrawal <punit.agrawal@arm.com>
Introduce an optional property called, sustainable-power, which
represents the power (in mW) which the thermal zone can safely
dissipate.
If provided the property is parsed and associated with the thermal
zone via the thermal zone parameters.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
---
Documentation/devicetree/bindings/thermal/thermal.txt | 4 ++++
drivers/thermal/of-thermal.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
index f5db6b72a36f..c6eb9a8d2aed 100644
--- a/Documentation/devicetree/bindings/thermal/thermal.txt
+++ b/Documentation/devicetree/bindings/thermal/thermal.txt
@@ -167,6 +167,10 @@ Optional property:
by means of sensor ID. Additional coefficients are
interpreted as constant offset.
+- sustainable-power: An estimate of the sustainable power (in mW) that the
+ Type: unsigned thermal zone can dissipate.
+ Size: one cell
+
Note: The delay properties are bound to the maximum dT/dt (temperature
derivative over time) in two situations for a thermal zone:
(i) - when passive cooling is activated (polling-delay-passive); and
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index 04b1be7fa018..eaf81ea654b9 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -769,6 +769,7 @@ int __init of_parse_thermal_zones(void)
for_each_child_of_node(np, child) {
struct thermal_zone_device *zone;
struct thermal_zone_params *tzp;
+ u32 prop;
tz = thermal_of_build_thermal_zone(child);
if (IS_ERR(tz)) {
@@ -791,6 +792,9 @@ int __init of_parse_thermal_zones(void)
/* No hwmon because there might be hwmon drivers registering */
tzp->no_hwmon = true;
+ if (!of_property_read_u32(child, "sustainable-power", &prop))
+ tzp->sustainable_power = prop;
+
zone = thermal_zone_device_register(child->name, tz->ntrips,
0, tz,
ops, tzp,
--
1.9.1
^ permalink raw reply related [flat|nested] 10+ messages in thread