PowerCap: Add class driver

The power capping framework providing a consistent interface between the
kernel and user space that allows power capping drivers to expose their
settings to user space in a uniform way.
The overall design of the framework is described in the documentation
added by the previous patch in this series.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 325 insertions, 0 deletions

diff --git a/include/linux/powercap.h b/include/linux/powercap.h
new file mode 100644
index 000000000000..4e250417ee30
--- /dev/null
+++ b/include/linux/powercap.h
@@ -0,0 +1,325 @@
+/*
+ * powercap.h: Data types and headers for sysfs power capping interface
+ * Copyright (c) 2013, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, write to the Free Software Foundation, Inc.
+ *
+ */
+
+#ifndef __POWERCAP_H__
+#define __POWERCAP_H__
+
+#include <linux/device.h>
+#include <linux/idr.h>
+
+/*
+ * A power cap class device can contain multiple powercap control_types.
+ * Each control_type can have multiple power zones, which can be independently
+ * controlled. Each power zone can have one or more constraints.
+ */
+
+struct powercap_control_type;
+struct powercap_zone;
+struct powercap_zone_constraint;
+
+/**
+ * struct powercap_control_type_ops - Define control type callbacks
+ * @set_enable:		Enable/Disable whole control type.
+ *			Default is enabled. But this callback allows all zones
+ *			to be in disable state and remove any applied power
+ *			limits. If disabled power zone can only be monitored
+ *			not controlled.
+ * @get_enable:		get Enable/Disable status.
+ * @release:		Callback to inform that last reference to this
+ *			control type is closed. So it is safe to free data
+ *			structure associated with this control type.
+ *			This callback is mandatory if the client own memory
+ *			for the control type.
+ *
+ * This structure defines control type callbacks to be implemented by client
+ * drivers
+ */
+struct powercap_control_type_ops {
+	int (*set_enable) (struct powercap_control_type *, bool mode);
+	int (*get_enable) (struct powercap_control_type *, bool *mode);
+	int (*release) (struct powercap_control_type *);
+};
+
+/**
+ * struct powercap_control_type- Defines a powercap control_type
+ * @name:		name of control_type
+ * @dev:		device for this control_type
+ * @idr:		idr to have unique id for its child
+ * @root_node:		Root holding power zones for this control_type
+ * @ops:		Pointer to callback struct
+ * @node_lock:		mutex for control type
+ * @allocated:		This is possible that client owns the memory
+ *			used by this structure. In this case
+ *			this flag is set to false by framework to
+ *			prevent deallocation during release process.
+ *			Otherwise this flag is set to true.
+ * @ctrl_inst:		link to the control_type list
+ *
+ * Defines powercap control_type. This acts as a container for power
+ * zones, which use same method to control power. E.g. RAPL, RAPL-PCI etc.
+ * All fields are private and should not be used by client drivers.
+ */
+struct powercap_control_type {
+	struct device dev;
+	struct idr idr;
+	int nr_zones;
+	const struct powercap_control_type_ops *ops;
+	struct mutex lock;
+	bool allocated;
+	struct list_head node;
+};
+
+/**
+ * struct powercap_zone_ops - Define power zone callbacks
+ * @get_max_energy_range_uj:	Get maximum range of energy counter in
+ *				micro-joules.
+ * @get_energy_uj:		Get current energy counter in micro-joules.
+ * @reset_energy_uj:		Reset micro-joules energy counter.
+ * @get_max_power_range_uw:	Get maximum range of power counter in
+ *				micro-watts.
+ * @get_power_uw:		Get current power counter in micro-watts.
+ * @set_enable:			Enable/Disable power zone controls.
+ *				Default is enabled.
+ * @get_enable:			get Enable/Disable status.
+ * @release:			Callback to inform that last reference to this
+ *				control type is closed. So it is safe to free
+ *				data structure associated with this
+ *				control type. Mandatory, if client driver owns
+ *				the power_zone memory.
+ *
+ * This structure defines zone callbacks to be implemented by client drivers.
+ * Client drives can define both energy and power related callbacks. But at
+ * the least one type (either power or energy) is mandatory. Client drivers
+ * should handle mutual exclusion, if required in callbacks.
+ */
+struct powercap_zone_ops {
+	int (*get_max_energy_range_uj) (struct powercap_zone *, u64 *);
+	int (*get_energy_uj) (struct powercap_zone *, u64 *);
+	int (*reset_energy_uj) (struct powercap_zone *);
+	int (*get_max_power_range_uw) (struct powercap_zone *, u64 *);
+	int (*get_power_uw) (struct powercap_zone *, u64 *);
+	int (*set_enable) (struct powercap_zone *, bool mode);
+	int (*get_enable) (struct powercap_zone *, bool *mode);
+	int (*release) (struct powercap_zone *);
+};
+
+#define	POWERCAP_ZONE_MAX_ATTRS		6
+#define	POWERCAP_CONSTRAINTS_ATTRS	8
+#define MAX_CONSTRAINTS_PER_ZONE	10
+/**
+ * struct powercap_zone- Defines instance of a power cap zone
+ * @id:			Unique id
+ * @name:		Power zone name.
+ * @control_type_inst:	Control type instance for this zone.
+ * @ops:		Pointer to the zone operation structure.
+ * @dev:		Instance of a device.
+ * @const_id_cnt:	Number of constraint defined.
+ * @idr:		Instance to an idr entry for children zones.
+ * @parent_idr:		To remove reference from the parent idr.
+ * @private_data:	Private data pointer if any for this zone.
+ * @zone_dev_attrs:	Attributes associated with this device.
+ * @zone_attr_count:	Attribute count.
+ * @dev_zone_attr_group: Attribute group for attributes.
+ * @dev_attr_groups:	Attribute group store to register with device.
+ * @allocated:		This is possible that client owns the memory
+ *			used by this structure. In this case
+ *			this flag is set to false by framework to
+ *			prevent deallocation during release process.
+ *			Otherwise this flag is set to true.
+ * @constraint_ptr:	List of constraints for this zone.
+ *
+ * This defines a power zone instance. The fields of this structure are
+ * private, and should not be used by client drivers.
+ */
+struct powercap_zone {
+	int id;
+	char *name;
+	void *control_type_inst;
+	const struct powercap_zone_ops *ops;
+	struct device dev;
+	int const_id_cnt;
+	struct idr idr;
+	struct idr *parent_idr;
+	void *private_data;
+	struct attribute **zone_dev_attrs;
+	int zone_attr_count;
+	struct attribute_group dev_zone_attr_group;
+	const struct attribute_group *dev_attr_groups[2]; /* 1 group + NULL */
+	bool allocated;
+	struct powercap_zone_constraint *constraints;
+};
+
+/**
+ * struct powercap_zone_constraint_ops - Define constraint callbacks
+ * @set_power_limit_uw:		Set power limit in micro-watts.
+ * @get_power_limit_uw:		Get power limit in micro-watts.
+ * @set_time_window_us:		Set time window in micro-seconds.
+ * @get_time_window_us:		Get time window in micro-seconds.
+ * @get_max_power_uw:		Get max power allowed in micro-watts.
+ * @get_min_power_uw:		Get min power allowed in micro-watts.
+ * @get_max_time_window_us:	Get max time window allowed in micro-seconds.
+ * @get_min_time_window_us:	Get min time window allowed in micro-seconds.
+ * @get_name:			Get the name of constraint
+ *
+ * This structure is used to define the constraint callbacks for the client
+ * drivers. The following callbacks are mandatory and can't be NULL:
+ *  set_power_limit_uw
+ *  get_power_limit_uw
+ *  set_time_window_us
+ *  get_time_window_us
+ *  get_name
+ *  Client drivers should handle mutual exclusion, if required in callbacks.
+ */
+struct powercap_zone_constraint_ops {
+	int (*set_power_limit_uw) (struct powercap_zone *, int, u64);
+	int (*get_power_limit_uw) (struct powercap_zone *, int, u64 *);
+	int (*set_time_window_us) (struct powercap_zone *, int, u64);
+	int (*get_time_window_us) (struct powercap_zone *, int, u64 *);
+	int (*get_max_power_uw) (struct powercap_zone *, int, u64 *);
+	int (*get_min_power_uw) (struct powercap_zone *, int, u64 *);
+	int (*get_max_time_window_us) (struct powercap_zone *, int, u64 *);
+	int (*get_min_time_window_us) (struct powercap_zone *, int, u64 *);
+	const char *(*get_name) (struct powercap_zone *, int);
+};
+
+/**
+ * struct powercap_zone_constraint- Defines instance of a constraint
+ * @id:			Instance Id of this constraint.
+ * @power_zone:		Pointer to the power zone for this constraint.
+ * @ops:		Pointer to the constraint callbacks.
+ *
+ * This defines a constraint instance.
+ */
+struct powercap_zone_constraint {
+	int id;
+	struct powercap_zone *power_zone;
+	struct powercap_zone_constraint_ops *ops;
+};
+
+
+/* For clients to get their device pointer, may be used for dev_dbgs */
+#define POWERCAP_GET_DEV(power_zone)	(&power_zone->dev)
+
+/**
+* powercap_set_zone_data() - Set private data for a zone
+* @power_zone:	A pointer to the valid zone instance.
+* @pdata:	A pointer to the user private data.
+*
+* Allows client drivers to associate some private data to zone instance.
+*/
+static inline void powercap_set_zone_data(struct powercap_zone *power_zone,
+						void *pdata)
+{
+	if (power_zone)
+		power_zone->private_data = pdata;
+}
+
+/**
+* powercap_get_zone_data() - Get private data for a zone
+* @power_zone:	A pointer to the valid zone instance.
+*
+* Allows client drivers to get private data associate with a zone,
+* using call to powercap_set_zone_data.
+*/
+static inline void *powercap_get_zone_data(struct powercap_zone *power_zone)
+{
+	if (power_zone)
+		return power_zone->private_data;
+	return NULL;
+}
+
+/**
+* powercap_register_control_type() - Register a control_type with framework
+* @control_type:	Pointer to client allocated memory for the control type
+*			structure storage. If this is NULL, powercap framework
+*			will allocate memory and own it.
+*			Advantage of this parameter is that client can embed
+*			this data in its data structures and allocate in a
+*			single call, preventing multiple allocations.
+* @control_type_name:	The Name of this control_type, which will be shown
+*			in the sysfs Interface.
+* @ops:			Callbacks for control type. This parameter is optional.
+*
+* Used to create a control_type with the power capping class. Here control_type
+* can represent a type of technology, which can control a range of power zones.
+* For example a control_type can be RAPL (Running Average Power Limit)
+* Intel® 64 and IA-32 Processor Architectures. The name can be any string
+* which must be unique, otherwise this function returns NULL.
+* A pointer to the control_type instance is returned on success.
+*/
+struct powercap_control_type *powercap_register_control_type(
+				struct powercap_control_type *control_type,
+				const char *name,
+				const struct powercap_control_type_ops *ops);
+
+/**
+* powercap_unregister_control_type() - Unregister a control_type from framework
+* @instance:	A pointer to the valid control_type instance.
+*
+* Used to unregister a control_type with the power capping class.
+* All power zones registered under this control type have to be unregistered
+* before calling this function, or it will fail with an error code.
+*/
+int powercap_unregister_control_type(struct powercap_control_type *instance);
+
+/* Zone register/unregister API */
+
+/**
+* powercap_register_zone() - Register a power zone
+* @power_zone:	Pointer to client allocated memory for the power zone structure
+*		storage. If this is NULL, powercap framework will allocate
+*		memory and own it. Advantage of this parameter is that client
+*		can embed this data in its data structures and allocate in a
+*		single call, preventing multiple allocations.
+* @control_type: A control_type instance under which this zone operates.
+* @name:	A name for this zone.
+* @parent:	A pointer to the parent power zone instance if any or NULL
+* @ops:		Pointer to zone operation callback structure.
+* @no_constraints: Number of constraints for this zone
+* @const_ops:	Pointer to constraint callback structure
+*
+* Register a power zone under a given control type. A power zone must register
+* a pointer to a structure representing zone callbacks.
+* A power zone can be located under a parent power zone, in which case @parent
+* should point to it.  Otherwise, if @parent is NULL, the new power zone will
+* be located directly under the given control type
+* For each power zone there may be a number of constraints that appear in the
+* sysfs under that zone as attributes with unique numeric IDs.
+* Returns pointer to the power_zone on success.
+*/
+struct powercap_zone *powercap_register_zone(
+			struct powercap_zone *power_zone,
+			struct powercap_control_type *control_type,
+			const char *name,
+			struct powercap_zone *parent,
+			const struct powercap_zone_ops *ops,
+			int nr_constraints,
+			struct powercap_zone_constraint_ops *const_ops);
+
+/**
+* powercap_unregister_zone() - Unregister a zone device
+* @control_type:	A pointer to the valid instance of a control_type.
+* @power_zone:	A pointer to the valid zone instance for a control_type
+*
+* Used to unregister a zone device for a control_type.  Caller should
+* make sure that children for this zone are unregistered first.
+*/
+int powercap_unregister_zone(struct powercap_control_type *control_type,
+				struct powercap_zone *power_zone);
+
+#endif