[RFC v00 1/1] PowerCap: Documentation
From: Srinivas Pandruvada
Date: Thu Jul 18 2013 - 15:34:28 EST
Added power cap framework documentation. This explains the use of power capping framework,
sys-fs and programming interface.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
Documentation/powercap/PowerCappingFramework.txt | 1008 ++++++++++++++++++++++
1 file changed, 1008 insertions(+)
create mode 100644 Documentation/powercap/PowerCappingFramework.txt
diff --git a/Documentation/powercap/PowerCappingFramework.txt b/Documentation/powercap/PowerCappingFramework.txt
new file mode 100644
index 0000000..76eb63d
--- /dev/null
+++ b/Documentation/powercap/PowerCappingFramework.txt
@@ -0,0 +1,1008 @@
+Power Capping Framework
+==================================
+
+The Linux Power Capping Framework provides user-space with a common
+API to kernel-mode power-capping drivers. At the same time,
+it provides the hardware-specific power-capping drivers with
+a uniform API to user-space.
+
+Terminology
+=========================
+The Power Capping framework organizes power capping devices under a tree structure.
+At the root level, each device is under some "controller", which is the enabler
+of technology. For example this can be "RAPL".
+Under each controllers, there are multiple power zones, which can be independently
+monitored and controlled using this technology.
+Each power zone can be organized as a tree with parent, children and siblings.
+Each power zone defines attributes to enable power monitoring and apply
+constraints on power consumption.
+
+For example, using RAPL, one can independently control CPU packages. Each package is
+further divided in to multiple domains for core uncore, dram devices, which can
+be independently controlled. As the technology gets matured, each uncore and core,
+devices will be further divided into multiple domain. Here domains are called "zones"
+in this documentation.
+
+
+Experimental implantation is using two options:
+Option 1: Use simple device model. Since we can't have duplicate file names under
+a class even if there parents are different (Unlike a Linux directory tree), each
+child will be named using their hierarchy in the tree. For example, a RAPL power
+zone such as a CPU package can be called intel-rapl-0, then its children will be
+named as intel-rapl-0:0, intel-rapl-0:1 etc.
+
+Option 2: Each controller is a device and zones and constraints under it are
+created using kobjects. Here exact names of power zones can be used in the sys-fs
+file names.
+
+The two tree's below presents representation using above options.
+In this system RAPL functionality is implemented in a client driver using power-capping
+framework described here. The sys-fs tree below is generated on a server system,
+with two CPU packages. Each package is further divided into "core", and "dram".
+============================
+Option 1
+
+/sys/devices/virtual/power_cap
+âââ intel-rapl
+ âââ intel-rapl:0
+ â âââ constraint_0_name
+ â âââ constraint_0_power_limit_uw
+ â âââ constraint_0_time_window_us
+ â âââ constraint_1_name
+ â âââ constraint_1_power_limit_uw
+ â âââ constraint_1_time_window_us
+ â âââ device -> ../../intel-rapl [recursive, not followed]
+ â âââ energy_uj
+ â âââ intel-rapl:0:0
+ â â âââ constraint_0_name
+ â â âââ constraint_0_power_limit_uw
+ â â âââ constraint_0_time_window_us
+ â â âââ device -> ../../intel-rapl:0 [recursive, not followed]
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â â âââ name
+ â â âââ power
+ â â â âââ async
+ â â â âââ autosuspend_delay_ms
+ â â â âââ control
+ â â â âââ runtime_active_kids
+ â â â âââ runtime_active_time
+ â â â âââ runtime_enabled
+ â â â âââ runtime_status
+ â â â âââ runtime_suspended_time
+ â â â âââ runtime_usage
+ â â âââ subsystem -> ../../../../../../class/power_cap
+ â â â âââ intel-rapl -> ../../devices/virtual/power_cap/intel-rapl [recursive, not followed]
+ â â â âââ intel-rapl:0 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:0 [recursive, not followed]
+ â â â âââ intel-rapl:0:0 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:0/intel-rapl:0:0 [recursive, not followed]
+ â â â âââ intel-rapl:0:1 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:0/intel-rapl:0:1
+ â â â â âââ constraint_0_name
+ â â â â âââ constraint_0_power_limit_uw
+ â â â â âââ constraint_0_time_window_us
+ â â â â âââ device -> ../../intel-rapl:0 [recursive, not followed]
+ â â â â âââ energy_uj
+ â â â â âââ max_energy_range_uj
+ â â â â âââ name
+ â â â â âââ power
+ â â â â â âââ async
+ â â â â â âââ autosuspend_delay_ms
+ â â â â â âââ control
+ â â â â â âââ runtime_active_kids
+ â â â â â âââ runtime_active_time
+ â â â â â âââ runtime_enabled
+ â â â â â âââ runtime_status
+ â â â â â âââ runtime_suspended_time
+ â â â â â âââ runtime_usage
+ â â â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â â â âââ uevent
+ â â â âââ intel-rapl:1 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:1
+ â â â â âââ constraint_0_name
+ â â â â âââ constraint_0_power_limit_uw
+ â â â â âââ constraint_0_time_window_us
+ â â â â âââ constraint_1_name
+ â â â â âââ constraint_1_power_limit_uw
+ â â â â âââ constraint_1_time_window_us
+ â â â â âââ device -> ../../intel-rapl [recursive, not followed]
+ â â â â âââ energy_uj
+ â â â â âââ intel-rapl:1:0
+ â â â â â âââ constraint_0_name
+ â â â â â âââ constraint_0_power_limit_uw
+ â â â â â âââ constraint_0_time_window_us
+ â â â â â âââ device -> ../../intel-rapl:1 [recursive, not followed]
+ â â â â â âââ energy_uj
+ â â â â â âââ max_energy_range_uj
+ â â â â â âââ name
+ â â â â â âââ power
+ â â â â â â âââ async
+ â â â â â â âââ autosuspend_delay_ms
+ â â â â â â âââ control
+ â â â â â â âââ runtime_active_kids
+ â â â â â â âââ runtime_active_time
+ â â â â â â âââ runtime_enabled
+ â â â â â â âââ runtime_status
+ â â â â â â âââ runtime_suspended_time
+ â â â â â â âââ runtime_usage
+ â â â â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â â â â âââ uevent
+ â â â â âââ intel-rapl:1:1
+ â â â â â âââ constraint_0_name
+ â â â â â âââ constraint_0_power_limit_uw
+ â â â â â âââ constraint_0_time_window_us
+ â â â â â âââ device -> ../../intel-rapl:1 [recursive, not followed]
+ â â â â â âââ energy_uj
+ â â â â â âââ max_energy_range_uj
+ â â â â â âââ name
+ â â â â â âââ power
+ â â â â â â âââ async
+ â â â â â â âââ autosuspend_delay_ms
+ â â â â â â âââ control
+ â â â â â â âââ runtime_active_kids
+ â â â â â â âââ runtime_active_time
+ â â â â â â âââ runtime_enabled
+ â â â â â â âââ runtime_status
+ â â â â â â âââ runtime_suspended_time
+ â â â â â â âââ runtime_usage
+ â â â â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â â â â âââ uevent
+ â â â â âââ max_energy_range_uj
+ â â â â âââ max_power_range_uw
+ â â â â âââ name
+ â â â â âââ power
+ â â â â â âââ async
+ â â â â â âââ autosuspend_delay_ms
+ â â â â â âââ control
+ â â â â â âââ runtime_active_kids
+ â â â â â âââ runtime_active_time
+ â â â â â âââ runtime_enabled
+ â â â â â âââ runtime_status
+ â â â â â âââ runtime_suspended_time
+ â â â â â âââ runtime_usage
+ â â â â âââ subsystem -> ../../../../../class/power_cap [recursive, not followed]
+ â â â â âââ uevent
+ â â â âââ intel-rapl:1:0 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:1/intel-rapl:1:0 [recursive, not followed]
+ â â â âââ intel-rapl:1:1 -> ../../devices/virtual/power_cap/intel-rapl/intel-rapl:1/intel-rapl:1:1 [recursive, not followed]
+ â â âââ uevent
+ â âââ intel-rapl:0:1
+ â â âââ constraint_0_name
+ â â âââ constraint_0_power_limit_uw
+ â â âââ constraint_0_time_window_us
+ â â âââ device -> ../../intel-rapl:0 [recursive, not followed]
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â â âââ name
+ â â âââ power
+ â â â âââ async
+ â â â âââ autosuspend_delay_ms
+ â â â âââ control
+ â â â âââ runtime_active_kids
+ â â â âââ runtime_active_time
+ â â â âââ runtime_enabled
+ â â â âââ runtime_status
+ â â â âââ runtime_suspended_time
+ â â â âââ runtime_usage
+ â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â âââ uevent
+ â âââ max_energy_range_uj
+ â âââ max_power_range_uw
+ â âââ name
+ â âââ power
+ â â âââ async
+ â â âââ autosuspend_delay_ms
+ â â âââ control
+ â â âââ runtime_active_kids
+ â â âââ runtime_active_time
+ â â âââ runtime_enabled
+ â â âââ runtime_status
+ â â âââ runtime_suspended_time
+ â â âââ runtime_usage
+ â âââ subsystem -> ../../../../../class/power_cap [recursive, not followed]
+ â âââ uevent
+ âââ intel-rapl:1
+ â âââ constraint_0_name
+ â âââ constraint_0_power_limit_uw
+ â âââ constraint_0_time_window_us
+ â âââ constraint_1_name
+ â âââ constraint_1_power_limit_uw
+ â âââ constraint_1_time_window_us
+ â âââ device -> ../../intel-rapl [recursive, not followed]
+ â âââ energy_uj
+ â âââ intel-rapl:1:0
+ â â âââ constraint_0_name
+ â â âââ constraint_0_power_limit_uw
+ â â âââ constraint_0_time_window_us
+ â â âââ device -> ../../intel-rapl:1 [recursive, not followed]
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â â âââ name
+ â â âââ power
+ â â â âââ async
+ â â â âââ autosuspend_delay_ms
+ â â â âââ control
+ â â â âââ runtime_active_kids
+ â â â âââ runtime_active_time
+ â â â âââ runtime_enabled
+ â â â âââ runtime_status
+ â â â âââ runtime_suspended_time
+ â â â âââ runtime_usage
+ â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â âââ uevent
+ â âââ intel-rapl:1:1
+ â â âââ constraint_0_name
+ â â âââ constraint_0_power_limit_uw
+ â â âââ constraint_0_time_window_us
+ â â âââ device -> ../../intel-rapl:1 [recursive, not followed]
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â â âââ name
+ â â âââ power
+ â â â âââ async
+ â â â âââ autosuspend_delay_ms
+ â â â âââ control
+ â â â âââ runtime_active_kids
+ â â â âââ runtime_active_time
+ â â â âââ runtime_enabled
+ â â â âââ runtime_status
+ â â â âââ runtime_suspended_time
+ â â â âââ runtime_usage
+ â â âââ subsystem -> ../../../../../../class/power_cap [recursive, not followed]
+ â â âââ uevent
+ â âââ max_energy_range_uj
+ â âââ max_power_range_uw
+ â âââ name
+ â âââ power
+ â â âââ async
+ â â âââ autosuspend_delay_ms
+ â â âââ control
+ â â âââ runtime_active_kids
+ â â âââ runtime_active_time
+ â â âââ runtime_enabled
+ â â âââ runtime_status
+ â â âââ runtime_suspended_time
+ â â âââ runtime_usage
+ â âââ subsystem -> ../../../../../class/power_cap [recursive, not followed]
+ â âââ uevent
+ âââ power
+ â âââ async
+ â âââ autosuspend_delay_ms
+ â âââ control
+ â âââ runtime_active_kids
+ â âââ runtime_active_time
+ â âââ runtime_enabled
+ â âââ runtime_status
+ â âââ runtime_suspended_time
+ â âââ runtime_usage
+ âââ subsystem -> ../../../../class/power_cap [recursive, not followed]
+ âââ uevent
+
+=============================
+Option 2
+
+/sys/devices/virtual/power_cap
+âââ intel-rapl
+ âââ package-0
+ â âââ constraint-0
+ â â âââ name
+ â â âââ power_limit_uw
+ â â âââ time_window_us
+ â âââ constraint-1
+ â â âââ name
+ â â âââ power_limit_uw
+ â â âââ time_window_us
+ â âââ core
+ â â âââ constraint-0
+ â â â âââ name
+ â â â âââ power_limit_uw
+ â â â âââ time_window_us
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â âââ dram
+ â â âââ constraint-0
+ â â â âââ name
+ â â â âââ power_limit_uw
+ â â â âââ time_window_us
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â âââ energy_uj
+ â âââ max_energy_range_uj
+ â âââ max_power_range_uw
+ âââ package-1
+ â âââ constraint-0
+ â â âââ name
+ â â âââ power_limit_uw
+ â â âââ time_window_us
+ â âââ constraint-1
+ â â âââ name
+ â â âââ power_limit_uw
+ â â âââ time_window_us
+ â âââ core
+ â â âââ constraint-0
+ â â â âââ name
+ â â â âââ power_limit_uw
+ â â â âââ time_window_us
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â âââ dram
+ â â âââ constraint-0
+ â â â âââ name
+ â â â âââ power_limit_uw
+ â â â âââ time_window_us
+ â â âââ energy_uj
+ â â âââ max_energy_range_uj
+ â âââ energy_uj
+ â âââ max_energy_range_uj
+ â âââ max_power_range_uw
+ âââ power
+ â âââ async
+ â âââ autosuspend_delay_ms
+ â âââ control
+ â âââ runtime_active_kids
+ â âââ runtime_active_time
+ â âââ runtime_enabled
+ â âââ runtime_status
+ â âââ runtime_suspended_time
+ â âââ runtime_usage
+ âââ subsystem -> ../../../../class/power_cap
+ â âââ intel-rapl -> ../../devices/virtual/power_cap/intel-rapl [recursive, not followed]
+ âââ uevent
+
+18 directories, 48 files
+
+
+=================================
+
+Power Zone Attributes
+=================================
+Monitoring attributes
+----------------------
+
+energy_uj (rw): Current energy counter in micro-joules. Write to energy counter
+resets the counter to zero. If the counter can not be reset, then this attribute
+is read-only.
+
+max_energy_range_uj (r): Range of the above energy counter in micro-joules.
+
+power_uw (rw): Current power counter in micro-watts. Write to this counter
+resets the counter to zero. If the counter can not be reset, then this attribute
+is read-only.
+max_power_range_uw (r): Range of the above energy counter in micro-watts.
+
+It is possible that some domains can have both power and energy counters and
+ranges, but at least one is mandatory.
+
+Constraints
+----------------
+power_limit_uw (rw): Power limit in micro-watts, which should be applicable for
+the time window specified by "time_window_us".
+time_window_us (rw): Time window in micro seconds.
+name (ro): An optional name of the constraint
+
+Power Cap Client Driver Interface
+==================================
+
+Interface API
+----------------------------------
+powercap_allocate_controller - Allocates a controller
+
+Synopsis:
+
+void * powercap_allocate_controller (const char * controller_name);
+
+Arguments:
+
+controller_name
+ The Name of this controller, which will be shown
+ in the Sys-Fs Interface.
+
+
+Description:
+
+Used to create a controller with the power capping class. Here controller
+can represent a type of technology, which can control a range of power zones.
+For example a controller 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.
+On successful allocation, this API returns a pointer to the
+controller instance.
+
+
+Name:
+
+powercap_deallocate_controller - Deallocates a controller
+
+Synopsis:
+
+void powercap_deallocate_controller (void * instance);
+
+Arguments:
+
+instance
+ A pointer to the valid controller instance.
+
+
+Description:
+
+Used to deallocate a controller with the power capping class. This
+takes only one argument, which is the pointer to the instance returned
+by a call to powercap_allocate_controller.
+When a controller is deallocated, all zones and associated constraints
+are freed.
+
+
+Name:
+
+powercap_zone_register - Register a power zone
+
+Synopsis:
+
+struct powercap_zone_device * powercap_zone_register (void * controller,
+ const char * name,
+ const struct powercap_zone_ops * ops,
+ struct powercap_zone_device * parent);
+
+Arguments:
+
+controller
+ A controller instance under which this zone operates.
+
+name
+ A name for this zone, this will appear in Sys-Fs I/F under
+ a controller or a parent zone name.
+
+ops
+ Pointer to zone operation callback structure.
+
+parent
+ A pointer to the parent power zone instance if any or NULL
+
+
+Description:
+
+Used to register a power zone for a controller. Zones are organized in
+a tree like structure in Sys-Fs under a controller. A power zone name
+may not be unique, if they are in different level of hierarchy similar to
+a file system directory tree.
+A power zone must a register a pointer to a structure representing zone
+callbacks.
+A power zone can have a some other power zone as a parent or it can be
+NULL to appear as a direct descendant of a controller.
+
+
+Name:
+
+powercap_zone_unregister - Unregister a zone device
+
+Synopsis:
+
+int powercap_zone_unregister (void * controller,
+ struct powercap_zone_device * pcd_dev);
+
+Arguments:
+
+controller
+ A pointer to the valid instance of a controller.
+
+pcd_dev
+ A pointer to the valid zone instance for a controller
+
+
+Description:
+
+Used to unregister a zone device for a controller. Once a zone is
+unregistered then all its children and associated constraints are freed.
+
+
+Name:
+
+powercap_zone_add_constraint - Register a constraint
+
+Synopsis:
+
+struct powercap_zone_constraint * powercap_zone_add_constraint (struct powercap_zone_device * pcd_dev,
+ struct powercap_zone_constraint_ops * ops);
+
+Arguments:
+
+pcd_dev
+ A pointer to the valid zone instance
+
+ops
+ A pointer to the structure defining constraint callbacks
+
+
+Description:
+
+Used to unregister a register a constraint. Multiple constraints can be
+registered to a zone. Each constraint define some power limits and a time
+window over which this constraint is applicable. Time window and power limit
+should be with in limits specified in the corresponding max/min limits.
+On successful registration, it returns a pointer an instance of a constraint.
+
+
+Name:
+
+powercap_zone_remove_constraint - Unregister a constraint
+
+Synopsis:
+
+int powercap_zone_remove_constraint (struct powercap_zone_device * pcd_dev,
+ struct powercap_zone_constraint * pconst);
+
+Arguments:
+
+pcd_dev
+ A pointer to the valid zone instance
+
+pconst
+ A valid constraint instance
+
+
+Description:
+
+Used to unregister a constraint from a zone.
+
+
+struct powercap_zone_constraint_ops - Define constraint callbacks
+
+struct powercap_zone_constraint_ops {
+ int (* set_power_limit_uw) (struct powercap_zone_constraint *, unsigned long);
+ int (* get_power_limit_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* set_time_window_us) (struct powercap_zone_constraint *, unsigned long);
+ int (* get_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_max_power_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_min_power_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_max_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_min_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+};
+
+Members:
+
+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.
+
+
+
+Description:
+
+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
+
+
+struct powercap_zone_constraint - Defines instance of a constraint
+
+struct powercap_zone_constraint {
+ int id;
+ struct kobject kobj;
+ struct completion kobj_unregister;
+ struct powercap_zone_device * pcd_dev;
+ struct powercap_zone_constraint_ops * ops;
+ struct list_head node;
+};
+
+Members:
+
+id
+ Instance Id of this constraint.
+
+kobj
+ Kobject instance.
+
+kobj_unregister
+ Used for block on this completion variable
+
+pcd_dev
+ Pointer to the power zone for this constraint.
+
+ops
+ Pointer to the constraint callbacks.
+
+node
+ Link to other constraints for this power zone.
+
+
+
+Description:
+
+This defines a constraint instance. The fields of this structure are
+private, and should not be used by client drivers.
+
+
+struct powercap_zone_ops - Define power zone callbacks
+
+struct powercap_zone_ops {
+ int (* get_max_energy_range_uj) (struct powercap_zone_device *, unsigned long *);
+ int (* get_energy_uj) (struct powercap_zone_device *, unsigned long *);
+ int (* reset_energy_uj) (struct powercap_zone_device *);
+ int (* get_max_power_range_uw) (struct powercap_zone_device *, unsigned long *);
+ int (* get_power_uw) (struct powercap_zone_device *, unsigned long *);
+ int (* reset_power_uw) (struct powercap_zone_device *);
+};
+
+Members:
+
+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.
+
+reset_power_uw
+ Reset micro-watts power counter.
+
+
+
+Description:
+
+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.
+
+
+struct powercap_zone_device - Defines instance of a power cap zone
+
+struct powercap_zone_device {
+ char name[POWERCAP_ZONE_NAME_LENGTH];
+ const struct powercap_zone_ops * ops;
+ struct kobject kobj;
+ void * node;
+ struct completion kobj_unregister;
+ struct mutex lock;
+ struct idr idr;
+ struct list_head constraint_list;
+};
+
+Members:
+
+name[POWERCAP_ZONE_NAME_LENGTH]
+ Power zone name.
+
+ops
+ Pointer to the zone operation structure.
+
+kobj
+ Instance of a kobj.
+
+node
+ Node pointer to insert to a tree data structure.
+
+kobj_unregister
+ Used for block on this completion variable.
+
+lock
+ Mutex to protect zone related operations.
+
+idr
+ Instance to an idr entry.
+
+constraint_list
+ Link to the next power zone for this controller.
+
+
+
+Description:
+
+This defines a power zone instance. The fields of this structure are
+private, and should not be used by client drivers.
+
+
+struct powercap_zone_constraint_ops - Define constraint callbacks
+
+struct powercap_zone_constraint_ops {
+ int (* set_power_limit_uw) (struct powercap_zone_constraint *, unsigned long);
+ int (* get_power_limit_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* set_time_window_us) (struct powercap_zone_constraint *, unsigned long);
+ int (* get_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_max_power_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_min_power_uw) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_max_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+ int (* get_min_time_window_us) (struct powercap_zone_constraint *, unsigned long *);
+ char *(* get_name) (struct powercap_zone_constraint *);
+ void (* cleanup) (struct powercap_zone_constraint *);
+};
+
+Members:
+
+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
+
+cleanup
+ Do any clean up before the constraint is freed
+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
+
+
+
+
+
+struct powercap_zone_constraint - Defines instance of a constraint
+
+struct powercap_zone_constraint {
+ int id;
+ struct kobject kobj;
+ struct completion kobj_unregister;
+ struct powercap_zone_device * pcd_dev;
+ struct powercap_zone_constraint_ops * ops;
+ void * drv_data;
+ struct list_head node;
+};
+
+Members:
+
+id
+ Instance Id of this constraint.
+
+kobj
+ Kobject instance.
+
+kobj_unregister
+ Used for block on this completion variable
+
+pcd_dev
+ Pointer to the power zone for this constraint.
+
+ops
+ Pointer to the constraint callbacks.
+
+drv_data
+ Driver private data
+
+node
+ Link to other constraints for this power zone.
+
+
+
+Description:
+
+This defines a constraint instance. The fields of this structure are
+private, and should not be used by client drivers.
+
+
+struct powercap_zone_ops - Define power zone callbacks
+
+struct powercap_zone_ops {
+ int (* get_max_energy_range_uj) (struct powercap_zone_device *, unsigned long *);
+ int (* get_energy_uj) (struct powercap_zone_device *, unsigned long *);
+ int (* reset_energy_uj) (struct powercap_zone_device *);
+ int (* get_max_power_range_uw) (struct powercap_zone_device *, unsigned long *);
+ int (* get_power_uw) (struct powercap_zone_device *, unsigned long *);
+ int (* reset_power_uw) (struct powercap_zone_device *);
+ void (* cleanup) (struct powercap_zone_device *);
+};
+
+Members:
+
+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.
+
+reset_power_uw
+ Reset micro-watts power counter.
+
+cleanup
+ Do any clean up before the zone is freed
+
+
+
+Description:
+
+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.
+
+
+struct powercap_zone_device - Defines instance of a power cap zone
+
+struct powercap_zone_device {
+ char name[POWERCAP_ZONE_NAME_LENGTH];
+ void * controller_inst;
+ const struct powercap_zone_ops * ops;
+ struct kobject kobj;
+ void * node;
+ struct completion kobj_unregister;
+ struct mutex lock;
+ struct idr idr;
+ void * drv_data;
+ struct list_head constraint_list;
+};
+
+Members:
+
+name[POWERCAP_ZONE_NAME_LENGTH]
+ Power zone name.
+
+controller_inst
+ Controller instance for this zone
+
+ops
+ Pointer to the zone operation structure.
+
+kobj
+ Instance of a kobj.
+
+node
+ Node pointer to insert to a tree data structure.
+
+kobj_unregister
+ Used for block on this completion variable.
+
+lock
+ Mutex to protect zone related operations.
+
+idr
+ Instance to an idr entry.
+
+drv_data
+ Driver private data
+
+constraint_list
+ Link to the next power zone for this controller.
+
+
+
+Description:
+
+This defines a power zone instance. The fields of this structure are
+private, and should not be used by client drivers.
+
+
+Name:
+
+powercap_set_zone_data - Set private data for a zone
+
+Synopsis:
+
+void powercap_set_zone_data (struct powercap_zone_device * pcd_dev,
+ void * pdata);
+
+Arguments:
+
+pcd_dev
+ A pointer to the valid zone instance.
+
+pdata
+ A pointer to the user private data.
+
+
+Description:
+
+Allows client drivers to associate some private data to zone instance.
+
+
+Name:
+
+powercap_get_zone_data - Get private data for a zone
+
+Synopsis:
+
+void * powercap_get_zone_data (struct powercap_zone_device * pcd_dev);
+
+Arguments:
+
+pcd_dev
+ A pointer to the valid zone instance.
+
+
+Description:
+
+Allows client drivers to get private data associate with a zone,
+using call to powercap_set_zone_data.
+
+
+Name:
+
+powercap_set_constraint_data - Set private data for a constraint
+
+Synopsis:
+
+void powercap_set_constraint_data (struct powercap_zone_constraint * pconst,
+ void * pdata);
+
+Arguments:
+
+pconst
+ A pointer to the valid constraint instance.
+
+pdata
+ A pointer to the user private data.
+
+
+Description:
+
+Allows client drivers to associate some private data to constraint instance.
+
+
+Name:
+
+powercap_get_constraint_data - Get private data for a constraint
+
+Synopsis:
+
+void * powercap_get_constraint_data (struct powercap_zone_constraint * pconst);
+
+Arguments:
+
+pconst
+ A pointer to the valid constraint instance.
+
+
+Description:
+
+Allows client drivers to get private data associate with a constraint,
+using call to powercap_set_constraint_data.
+
--
1.8.3.1
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