1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Definitions related to Power Management Quality of Service (PM QoS).
4 *
5 * Copyright (C) 2020 Intel Corporation
6 *
7 * Authors:
8 * Mark Gross <mgross@linux.intel.com>
9 * Rafael J. Wysocki <rafael.j.wysocki@intel.com>
10 */
11
12#ifndef _LINUX_PM_QOS_H
13#define _LINUX_PM_QOS_H
14
15#include <linux/plist.h>
16#include <linux/notifier.h>
17#include <linux/device.h>
18
19enum pm_qos_flags_status {
20 PM_QOS_FLAGS_UNDEFINED = -1,
21 PM_QOS_FLAGS_NONE,
22 PM_QOS_FLAGS_SOME,
23 PM_QOS_FLAGS_ALL,
24};
25
26#define PM_QOS_DEFAULT_VALUE (-1)
27#define PM_QOS_LATENCY_ANY S32_MAX
28#define PM_QOS_LATENCY_ANY_NS ((s64)PM_QOS_LATENCY_ANY * NSEC_PER_USEC)
29
30#define PM_QOS_CPU_LATENCY_DEFAULT_VALUE (2000 * USEC_PER_SEC)
31#define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE PM_QOS_LATENCY_ANY
32#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT PM_QOS_LATENCY_ANY
33#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS PM_QOS_LATENCY_ANY_NS
34#define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE 0
35#define PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE 0
36#define PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE FREQ_QOS_MAX_DEFAULT_VALUE
37#define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT (-1)
38
39#define PM_QOS_FLAG_NO_POWER_OFF (1 << 0)
40
41enum pm_qos_type {
42 PM_QOS_UNITIALIZED,
43 PM_QOS_MAX, /* return the largest value */
44 PM_QOS_MIN, /* return the smallest value */
45};
46
47/*
48 * Note: The lockless read path depends on the CPU accessing target_value
49 * or effective_flags atomically. Atomic access is only guaranteed on all CPU
50 * types linux supports for 32 bit quantites
51 */
52struct pm_qos_constraints {
53 struct plist_head list;
54 s32 target_value; /* Do not change to 64 bit */
55 s32 default_value;
56 s32 no_constraint_value;
57 enum pm_qos_type type;
58 struct blocking_notifier_head *notifiers;
59};
60
61struct pm_qos_request {
62 struct plist_node node;
63 struct pm_qos_constraints *qos;
64};
65
66struct pm_qos_flags_request {
67 struct list_head node;
68 s32 flags; /* Do not change to 64 bit */
69};
70
71struct pm_qos_flags {
72 struct list_head list;
73 s32 effective_flags; /* Do not change to 64 bit */
74};
75
76
77#define FREQ_QOS_MIN_DEFAULT_VALUE 0
78#define FREQ_QOS_MAX_DEFAULT_VALUE S32_MAX
79
80enum freq_qos_req_type {
81 FREQ_QOS_MIN = 1,
82 FREQ_QOS_MAX,
83};
84
85struct freq_constraints {
86 struct pm_qos_constraints min_freq;
87 struct blocking_notifier_head min_freq_notifiers;
88 struct pm_qos_constraints max_freq;
89 struct blocking_notifier_head max_freq_notifiers;
90};
91
92struct freq_qos_request {
93 enum freq_qos_req_type type;
94 struct plist_node pnode;
95 struct freq_constraints *qos;
96};
97
98
99enum dev_pm_qos_req_type {
100 DEV_PM_QOS_RESUME_LATENCY = 1,
101 DEV_PM_QOS_LATENCY_TOLERANCE,
102 DEV_PM_QOS_MIN_FREQUENCY,
103 DEV_PM_QOS_MAX_FREQUENCY,
104 DEV_PM_QOS_FLAGS,
105};
106
107struct dev_pm_qos_request {
108 enum dev_pm_qos_req_type type;
109 union {
110 struct plist_node pnode;
111 struct pm_qos_flags_request flr;
112 struct freq_qos_request freq;
113 } data;
114 struct device *dev;
115};
116
117struct dev_pm_qos {
118 struct pm_qos_constraints resume_latency;
119 struct pm_qos_constraints latency_tolerance;
120 struct freq_constraints freq;
121 struct pm_qos_flags flags;
122 struct dev_pm_qos_request *resume_latency_req;
123 struct dev_pm_qos_request *latency_tolerance_req;
124 struct dev_pm_qos_request *flags_req;
125};
126
127/* Action requested to pm_qos_update_target */
128enum pm_qos_req_action {
129 PM_QOS_ADD_REQ, /* Add a new request */
130 PM_QOS_UPDATE_REQ, /* Update an existing request */
131 PM_QOS_REMOVE_REQ /* Remove an existing request */
132};
133
134static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
135{
136 return req->dev != NULL;
137}
138
139s32 pm_qos_read_value(struct pm_qos_constraints *c);
140int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
141 enum pm_qos_req_action action, int value);
142bool pm_qos_update_flags(struct pm_qos_flags *pqf,
143 struct pm_qos_flags_request *req,
144 enum pm_qos_req_action action, s32 val);
145
146#ifdef CONFIG_CPU_IDLE
147s32 cpu_latency_qos_limit(void);
148bool cpu_latency_qos_request_active(struct pm_qos_request *req);
149void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value);
150void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value);
151void cpu_latency_qos_remove_request(struct pm_qos_request *req);
152#else
153static inline s32 cpu_latency_qos_limit(void) { return INT_MAX; }
154static inline bool cpu_latency_qos_request_active(struct pm_qos_request *req)
155{
156 return false;
157}
158static inline void cpu_latency_qos_add_request(struct pm_qos_request *req,
159 s32 value) {}
160static inline void cpu_latency_qos_update_request(struct pm_qos_request *req,
161 s32 new_value) {}
162static inline void cpu_latency_qos_remove_request(struct pm_qos_request *req) {}
163#endif
164
165#ifdef CONFIG_PM
166enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask);
167enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev, s32 mask);
168s32 __dev_pm_qos_resume_latency(struct device *dev);
169s32 dev_pm_qos_read_value(struct device *dev, enum dev_pm_qos_req_type type);
170int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
171 enum dev_pm_qos_req_type type, s32 value);
172int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
173int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
174int dev_pm_qos_add_notifier(struct device *dev,
175 struct notifier_block *notifier,
176 enum dev_pm_qos_req_type type);
177int dev_pm_qos_remove_notifier(struct device *dev,
178 struct notifier_block *notifier,
179 enum dev_pm_qos_req_type type);
180void dev_pm_qos_constraints_init(struct device *dev);
181void dev_pm_qos_constraints_destroy(struct device *dev);
182int dev_pm_qos_add_ancestor_request(struct device *dev,
183 struct dev_pm_qos_request *req,
184 enum dev_pm_qos_req_type type, s32 value);
185int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
186void dev_pm_qos_hide_latency_limit(struct device *dev);
187int dev_pm_qos_expose_flags(struct device *dev, s32 value);
188void dev_pm_qos_hide_flags(struct device *dev);
189int dev_pm_qos_update_flags(struct device *dev, s32 mask, bool set);
190s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev);
191int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val);
192int dev_pm_qos_expose_latency_tolerance(struct device *dev);
193void dev_pm_qos_hide_latency_tolerance(struct device *dev);
194
195static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
196{
197 return dev->power.qos->resume_latency_req->data.pnode.prio;
198}
199
200static inline s32 dev_pm_qos_requested_flags(struct device *dev)
201{
202 return dev->power.qos->flags_req->data.flr.flags;
203}
204
205static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
206{
207 return IS_ERR_OR_NULL(ptr: dev->power.qos) ?
208 PM_QOS_RESUME_LATENCY_NO_CONSTRAINT :
209 pm_qos_read_value(c: &dev->power.qos->resume_latency);
210}
211#else
212static inline enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev,
213 s32 mask)
214 { return PM_QOS_FLAGS_UNDEFINED; }
215static inline enum pm_qos_flags_status dev_pm_qos_flags(struct device *dev,
216 s32 mask)
217 { return PM_QOS_FLAGS_UNDEFINED; }
218static inline s32 __dev_pm_qos_resume_latency(struct device *dev)
219 { return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; }
220static inline s32 dev_pm_qos_read_value(struct device *dev,
221 enum dev_pm_qos_req_type type)
222{
223 switch (type) {
224 case DEV_PM_QOS_RESUME_LATENCY:
225 return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
226 case DEV_PM_QOS_MIN_FREQUENCY:
227 return PM_QOS_MIN_FREQUENCY_DEFAULT_VALUE;
228 case DEV_PM_QOS_MAX_FREQUENCY:
229 return PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
230 default:
231 WARN_ON(1);
232 return 0;
233 }
234}
235
236static inline int dev_pm_qos_add_request(struct device *dev,
237 struct dev_pm_qos_request *req,
238 enum dev_pm_qos_req_type type,
239 s32 value)
240 { return 0; }
241static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
242 s32 new_value)
243 { return 0; }
244static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
245 { return 0; }
246static inline int dev_pm_qos_add_notifier(struct device *dev,
247 struct notifier_block *notifier,
248 enum dev_pm_qos_req_type type)
249 { return 0; }
250static inline int dev_pm_qos_remove_notifier(struct device *dev,
251 struct notifier_block *notifier,
252 enum dev_pm_qos_req_type type)
253 { return 0; }
254static inline void dev_pm_qos_constraints_init(struct device *dev)
255{
256 dev->power.power_state = PMSG_ON;
257}
258static inline void dev_pm_qos_constraints_destroy(struct device *dev)
259{
260 dev->power.power_state = PMSG_INVALID;
261}
262static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
263 struct dev_pm_qos_request *req,
264 enum dev_pm_qos_req_type type,
265 s32 value)
266 { return 0; }
267static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
268 { return 0; }
269static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
270static inline int dev_pm_qos_expose_flags(struct device *dev, s32 value)
271 { return 0; }
272static inline void dev_pm_qos_hide_flags(struct device *dev) {}
273static inline int dev_pm_qos_update_flags(struct device *dev, s32 m, bool set)
274 { return 0; }
275static inline s32 dev_pm_qos_get_user_latency_tolerance(struct device *dev)
276 { return PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT; }
277static inline int dev_pm_qos_update_user_latency_tolerance(struct device *dev, s32 val)
278 { return 0; }
279static inline int dev_pm_qos_expose_latency_tolerance(struct device *dev)
280 { return 0; }
281static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
282
283static inline s32 dev_pm_qos_requested_resume_latency(struct device *dev)
284{
285 return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
286}
287static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
288static inline s32 dev_pm_qos_raw_resume_latency(struct device *dev)
289{
290 return PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
291}
292#endif
293
294static inline int freq_qos_request_active(struct freq_qos_request *req)
295{
296 return !IS_ERR_OR_NULL(ptr: req->qos);
297}
298
299void freq_constraints_init(struct freq_constraints *qos);
300
301s32 freq_qos_read_value(struct freq_constraints *qos,
302 enum freq_qos_req_type type);
303
304int freq_qos_add_request(struct freq_constraints *qos,
305 struct freq_qos_request *req,
306 enum freq_qos_req_type type, s32 value);
307int freq_qos_update_request(struct freq_qos_request *req, s32 new_value);
308int freq_qos_remove_request(struct freq_qos_request *req);
309int freq_qos_apply(struct freq_qos_request *req,
310 enum pm_qos_req_action action, s32 value);
311
312int freq_qos_add_notifier(struct freq_constraints *qos,
313 enum freq_qos_req_type type,
314 struct notifier_block *notifier);
315int freq_qos_remove_notifier(struct freq_constraints *qos,
316 enum freq_qos_req_type type,
317 struct notifier_block *notifier);
318
319#endif
320