1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * powercap.h: Data types and headers for sysfs power capping interface
4  * Copyright (c) 2013, Intel Corporation.
5  */
6 
7 #ifndef __POWERCAP_H__
8 #define __POWERCAP_H__
9 
10 #include <linux/device.h>
11 #include <linux/idr.h>
12 
13 /*
14  * A power cap class device can contain multiple powercap control_types.
15  * Each control_type can have multiple power zones, which can be independently
16  * controlled. Each power zone can have one or more constraints.
17  */
18 
19 struct powercap_control_type;
20 struct powercap_zone;
21 struct powercap_zone_constraint;
22 
23 /**
24  * struct powercap_control_type_ops - Define control type callbacks
25  * @set_enable:		Enable/Disable whole control type.
26  *			Default is enabled. But this callback allows all zones
27  *			to be in disable state and remove any applied power
28  *			limits. If disabled power zone can only be monitored
29  *			not controlled.
30  * @get_enable:		get Enable/Disable status.
31  * @release:		Callback to inform that last reference to this
32  *			control type is closed. So it is safe to free data
33  *			structure associated with this control type.
34  *			This callback is mandatory if the client own memory
35  *			for the control type.
36  *
37  * This structure defines control type callbacks to be implemented by client
38  * drivers
39  */
40 struct powercap_control_type_ops {
41 	int (*set_enable) (struct powercap_control_type *, bool mode);
42 	int (*get_enable) (struct powercap_control_type *, bool *mode);
43 	int (*release) (struct powercap_control_type *);
44 };
45 
46 /**
47  * struct powercap_control_type - Defines a powercap control_type
48  * @dev:		device for this control_type
49  * @idr:		idr to have unique id for its child
50  * @nr_zones:		counter for number of zones of this type
51  * @ops:		Pointer to callback struct
52  * @lock:		mutex for control type
53  * @allocated:		This is possible that client owns the memory
54  *			used by this structure. In this case
55  *			this flag is set to false by framework to
56  *			prevent deallocation during release process.
57  *			Otherwise this flag is set to true.
58  * @node:		linked-list node
59  *
60  * Defines powercap control_type. This acts as a container for power
61  * zones, which use same method to control power. E.g. RAPL, RAPL-PCI etc.
62  * All fields are private and should not be used by client drivers.
63  */
64 struct powercap_control_type {
65 	struct device dev;
66 	struct idr idr;
67 	int nr_zones;
68 	const struct powercap_control_type_ops *ops;
69 	struct mutex lock;
70 	bool allocated;
71 	struct list_head node;
72 };
73 
74 /**
75  * struct powercap_zone_ops - Define power zone callbacks
76  * @get_max_energy_range_uj:	Get maximum range of energy counter in
77  *				micro-joules.
78  * @get_energy_uj:		Get current energy counter in micro-joules.
79  * @reset_energy_uj:		Reset micro-joules energy counter.
80  * @get_max_power_range_uw:	Get maximum range of power counter in
81  *				micro-watts.
82  * @get_power_uw:		Get current power counter in micro-watts.
83  * @set_enable:			Enable/Disable power zone controls.
84  *				Default is enabled.
85  * @get_enable:			get Enable/Disable status.
86  * @release:			Callback to inform that last reference to this
87  *				control type is closed. So it is safe to free
88  *				data structure associated with this
89  *				control type. Mandatory, if client driver owns
90  *				the power_zone memory.
91  *
92  * This structure defines zone callbacks to be implemented by client drivers.
93  * Client drives can define both energy and power related callbacks. But at
94  * the least one type (either power or energy) is mandatory. Client drivers
95  * should handle mutual exclusion, if required in callbacks.
96  */
97 struct powercap_zone_ops {
98 	int (*get_max_energy_range_uj) (struct powercap_zone *, u64 *);
99 	int (*get_energy_uj) (struct powercap_zone *, u64 *);
100 	int (*reset_energy_uj) (struct powercap_zone *);
101 	int (*get_max_power_range_uw) (struct powercap_zone *, u64 *);
102 	int (*get_power_uw) (struct powercap_zone *, u64 *);
103 	int (*set_enable) (struct powercap_zone *, bool mode);
104 	int (*get_enable) (struct powercap_zone *, bool *mode);
105 	int (*release) (struct powercap_zone *);
106 };
107 
108 #define	POWERCAP_ZONE_MAX_ATTRS		6
109 #define	POWERCAP_CONSTRAINTS_ATTRS	8
110 #define MAX_CONSTRAINTS_PER_ZONE	10
111 /**
112  * struct powercap_zone- Defines instance of a power cap zone
113  * @id:			Unique id
114  * @name:		Power zone name.
115  * @control_type_inst:	Control type instance for this zone.
116  * @ops:		Pointer to the zone operation structure.
117  * @dev:		Instance of a device.
118  * @const_id_cnt:	Number of constraint defined.
119  * @idr:		Instance to an idr entry for children zones.
120  * @parent_idr:		To remove reference from the parent idr.
121  * @private_data:	Private data pointer if any for this zone.
122  * @zone_dev_attrs:	Attributes associated with this device.
123  * @zone_attr_count:	Attribute count.
124  * @dev_zone_attr_group: Attribute group for attributes.
125  * @dev_attr_groups:	Attribute group store to register with device.
126  * @allocated:		This is possible that client owns the memory
127  *			used by this structure. In this case
128  *			this flag is set to false by framework to
129  *			prevent deallocation during release process.
130  *			Otherwise this flag is set to true.
131  * @constraints:	List of constraints for this zone.
132  *
133  * This defines a power zone instance. The fields of this structure are
134  * private, and should not be used by client drivers.
135  */
136 struct powercap_zone {
137 	int id;
138 	char *name;
139 	void *control_type_inst;
140 	const struct powercap_zone_ops *ops;
141 	struct device dev;
142 	int const_id_cnt;
143 	struct idr idr;
144 	struct idr *parent_idr;
145 	void *private_data;
146 	struct attribute **zone_dev_attrs;
147 	int zone_attr_count;
148 	struct attribute_group dev_zone_attr_group;
149 	const struct attribute_group *dev_attr_groups[2]; /* 1 group + NULL */
150 	bool allocated;
151 	struct powercap_zone_constraint *constraints;
152 };
153 
154 /**
155  * struct powercap_zone_constraint_ops - Define constraint callbacks
156  * @set_power_limit_uw:		Set power limit in micro-watts.
157  * @get_power_limit_uw:		Get power limit in micro-watts.
158  * @set_time_window_us:		Set time window in micro-seconds.
159  * @get_time_window_us:		Get time window in micro-seconds.
160  * @get_max_power_uw:		Get max power allowed in micro-watts.
161  * @get_min_power_uw:		Get min power allowed in micro-watts.
162  * @get_max_time_window_us:	Get max time window allowed in micro-seconds.
163  * @get_min_time_window_us:	Get min time window allowed in micro-seconds.
164  * @get_name:			Get the name of constraint
165  *
166  * This structure is used to define the constraint callbacks for the client
167  * drivers. The following callbacks are mandatory and can't be NULL:
168  *  set_power_limit_uw
169  *  get_power_limit_uw
170  *  set_time_window_us
171  *  get_time_window_us
172  *  get_name
173  *  Client drivers should handle mutual exclusion, if required in callbacks.
174  */
175 struct powercap_zone_constraint_ops {
176 	int (*set_power_limit_uw) (struct powercap_zone *, int, u64);
177 	int (*get_power_limit_uw) (struct powercap_zone *, int, u64 *);
178 	int (*set_time_window_us) (struct powercap_zone *, int, u64);
179 	int (*get_time_window_us) (struct powercap_zone *, int, u64 *);
180 	int (*get_max_power_uw) (struct powercap_zone *, int, u64 *);
181 	int (*get_min_power_uw) (struct powercap_zone *, int, u64 *);
182 	int (*get_max_time_window_us) (struct powercap_zone *, int, u64 *);
183 	int (*get_min_time_window_us) (struct powercap_zone *, int, u64 *);
184 	const char *(*get_name) (struct powercap_zone *, int);
185 };
186 
187 /**
188  * struct powercap_zone_constraint- Defines instance of a constraint
189  * @id:			Instance Id of this constraint.
190  * @power_zone:		Pointer to the power zone for this constraint.
191  * @ops:		Pointer to the constraint callbacks.
192  *
193  * This defines a constraint instance.
194  */
195 struct powercap_zone_constraint {
196 	int id;
197 	struct powercap_zone *power_zone;
198 	const struct powercap_zone_constraint_ops *ops;
199 };
200 
201 
202 /* For clients to get their device pointer, may be used for dev_dbgs */
203 #define POWERCAP_GET_DEV(power_zone)	(&power_zone->dev)
204 
205 /**
206 * powercap_set_zone_data() - Set private data for a zone
207 * @power_zone:	A pointer to the valid zone instance.
208 * @pdata:	A pointer to the user private data.
209 *
210 * Allows client drivers to associate some private data to zone instance.
211 */
powercap_set_zone_data(struct powercap_zone * power_zone,void * pdata)212 static inline void powercap_set_zone_data(struct powercap_zone *power_zone,
213 						void *pdata)
214 {
215 	if (power_zone)
216 		power_zone->private_data = pdata;
217 }
218 
219 /**
220 * powercap_get_zone_data() - Get private data for a zone
221 * @power_zone:	A pointer to the valid zone instance.
222 *
223 * Allows client drivers to get private data associate with a zone,
224 * using call to powercap_set_zone_data.
225 */
powercap_get_zone_data(struct powercap_zone * power_zone)226 static inline void *powercap_get_zone_data(struct powercap_zone *power_zone)
227 {
228 	if (power_zone)
229 		return power_zone->private_data;
230 	return NULL;
231 }
232 
233 /**
234 * powercap_register_control_type() - Register a control_type with framework
235 * @control_type:	Pointer to client allocated memory for the control type
236 *			structure storage. If this is NULL, powercap framework
237 *			will allocate memory and own it.
238 *			Advantage of this parameter is that client can embed
239 *			this data in its data structures and allocate in a
240 *			single call, preventing multiple allocations.
241 * @control_type_name:	The Name of this control_type, which will be shown
242 *			in the sysfs Interface.
243 * @ops:			Callbacks for control type. This parameter is optional.
244 *
245 * Used to create a control_type with the power capping class. Here control_type
246 * can represent a type of technology, which can control a range of power zones.
247 * For example a control_type can be RAPL (Running Average Power Limit)
248 * Intel® 64 and IA-32 Processor Architectures. The name can be any string
249 * which must be unique, otherwise this function returns NULL.
250 * A pointer to the control_type instance is returned on success.
251 */
252 struct powercap_control_type *powercap_register_control_type(
253 				struct powercap_control_type *control_type,
254 				const char *name,
255 				const struct powercap_control_type_ops *ops);
256 
257 /**
258 * powercap_unregister_control_type() - Unregister a control_type from framework
259 * @instance:	A pointer to the valid control_type instance.
260 *
261 * Used to unregister a control_type with the power capping class.
262 * All power zones registered under this control type have to be unregistered
263 * before calling this function, or it will fail with an error code.
264 */
265 int powercap_unregister_control_type(struct powercap_control_type *instance);
266 
267 /* Zone register/unregister API */
268 
269 /**
270 * powercap_register_zone() - Register a power zone
271 * @power_zone:	Pointer to client allocated memory for the power zone structure
272 *		storage. If this is NULL, powercap framework will allocate
273 *		memory and own it. Advantage of this parameter is that client
274 *		can embed this data in its data structures and allocate in a
275 *		single call, preventing multiple allocations.
276 * @control_type: A control_type instance under which this zone operates.
277 * @name:	A name for this zone.
278 * @parent:	A pointer to the parent power zone instance if any or NULL
279 * @ops:		Pointer to zone operation callback structure.
280 * @no_constraints: Number of constraints for this zone
281 * @const_ops:	Pointer to constraint callback structure
282 *
283 * Register a power zone under a given control type. A power zone must register
284 * a pointer to a structure representing zone callbacks.
285 * A power zone can be located under a parent power zone, in which case @parent
286 * should point to it.  Otherwise, if @parent is NULL, the new power zone will
287 * be located directly under the given control type
288 * For each power zone there may be a number of constraints that appear in the
289 * sysfs under that zone as attributes with unique numeric IDs.
290 * Returns pointer to the power_zone on success.
291 */
292 struct powercap_zone *powercap_register_zone(
293 			struct powercap_zone *power_zone,
294 			struct powercap_control_type *control_type,
295 			const char *name,
296 			struct powercap_zone *parent,
297 			const struct powercap_zone_ops *ops,
298 			int nr_constraints,
299 			const struct powercap_zone_constraint_ops *const_ops);
300 
301 /**
302 * powercap_unregister_zone() - Unregister a zone device
303 * @control_type:	A pointer to the valid instance of a control_type.
304 * @power_zone:	A pointer to the valid zone instance for a control_type
305 *
306 * Used to unregister a zone device for a control_type.  Caller should
307 * make sure that children for this zone are unregistered first.
308 */
309 int powercap_unregister_zone(struct powercap_control_type *control_type,
310 				struct powercap_zone *power_zone);
311 
312 #endif
313