1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * drivers/cpufreq/cpufreq_governor.h
4 *
5 * Header file for CPUFreq governors common code
6 *
7 * Copyright	(C) 2001 Russell King
8 *		(C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
9 *		(C) 2003 Jun Nakajima <jun.nakajima@intel.com>
10 *		(C) 2009 Alexander Clouter <alex@digriz.org.uk>
11 *		(c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
12 */
13
14#ifndef _CPUFREQ_GOVERNOR_H
15#define _CPUFREQ_GOVERNOR_H
16
17#include <linux/atomic.h>
18#include <linux/irq_work.h>
19#include <linux/cpufreq.h>
20#include <linux/sched/cpufreq.h>
21#include <linux/kernel_stat.h>
22#include <linux/module.h>
23#include <linux/mutex.h>
24
25/* Ondemand Sampling types */
26enum {OD_NORMAL_SAMPLE, OD_SUB_SAMPLE};
27
28/*
29 * Abbreviations:
30 * dbs: used as a shortform for demand based switching It helps to keep variable
31 *	names smaller, simpler
32 * cdbs: common dbs
33 * od_*: On-demand governor
34 * cs_*: Conservative governor
35 */
36
37/* Governor demand based switching data (per-policy or global). */
38struct dbs_data {
39	struct gov_attr_set attr_set;
40	struct dbs_governor *gov;
41	void *tuners;
42	unsigned int ignore_nice_load;
43	unsigned int sampling_rate;
44	unsigned int sampling_down_factor;
45	unsigned int up_threshold;
46	unsigned int io_is_busy;
47};
48
49static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
50{
51	return container_of(attr_set, struct dbs_data, attr_set);
52}
53
54#define gov_show_one(_gov, file_name)					\
55static ssize_t file_name##_show						\
56(struct gov_attr_set *attr_set, char *buf)				\
57{									\
58	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
59	struct _gov##_dbs_tuners *tuners = dbs_data->tuners;		\
60	return sprintf(buf, "%u\n", tuners->file_name);			\
61}
62
63#define gov_show_one_common(file_name)					\
64static ssize_t file_name##_show						\
65(struct gov_attr_set *attr_set, char *buf)				\
66{									\
67	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
68	return sprintf(buf, "%u\n", dbs_data->file_name);		\
69}
70
71#define gov_attr_ro(_name)						\
72static struct governor_attr _name = __ATTR_RO(_name)
73
74#define gov_attr_rw(_name)						\
75static struct governor_attr _name = __ATTR_RW(_name)
76
77/* Common to all CPUs of a policy */
78struct policy_dbs_info {
79	struct cpufreq_policy *policy;
80	/*
81	 * Per policy mutex that serializes load evaluation from limit-change
82	 * and work-handler.
83	 */
84	struct mutex update_mutex;
85
86	u64 last_sample_time;
87	s64 sample_delay_ns;
88	atomic_t work_count;
89	struct irq_work irq_work;
90	struct work_struct work;
91	/* dbs_data may be shared between multiple policy objects */
92	struct dbs_data *dbs_data;
93	struct list_head list;
94	/* Multiplier for increasing sample delay temporarily. */
95	unsigned int rate_mult;
96	unsigned int idle_periods;	/* For conservative */
97	/* Status indicators */
98	bool is_shared;		/* This object is used by multiple CPUs */
99	bool work_in_progress;	/* Work is being queued up or in progress */
100};
101
102static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
103					   unsigned int delay_us)
104{
105	policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
106}
107
108/* Per cpu structures */
109struct cpu_dbs_info {
110	u64 prev_cpu_idle;
111	u64 prev_update_time;
112	u64 prev_cpu_nice;
113	/*
114	 * Used to keep track of load in the previous interval. However, when
115	 * explicitly set to zero, it is used as a flag to ensure that we copy
116	 * the previous load to the current interval only once, upon the first
117	 * wake-up from idle.
118	 */
119	unsigned int prev_load;
120	struct update_util_data update_util;
121	struct policy_dbs_info *policy_dbs;
122};
123
124/* Common Governor data across policies */
125struct dbs_governor {
126	struct cpufreq_governor gov;
127	struct kobj_type kobj_type;
128
129	/*
130	 * Common data for platforms that don't set
131	 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
132	 */
133	struct dbs_data *gdbs_data;
134
135	unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
136	struct policy_dbs_info *(*alloc)(void);
137	void (*free)(struct policy_dbs_info *policy_dbs);
138	int (*init)(struct dbs_data *dbs_data);
139	void (*exit)(struct dbs_data *dbs_data);
140	void (*start)(struct cpufreq_policy *policy);
141};
142
143static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
144{
145	return container_of(policy->governor, struct dbs_governor, gov);
146}
147
148/* Governor callback routines */
149int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
150void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
151int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
152void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
153void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
154
155#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_)			\
156	{								\
157		.name = _name_,						\
158		.flags = CPUFREQ_GOV_DYNAMIC_SWITCHING,			\
159		.owner = THIS_MODULE,					\
160		.init = cpufreq_dbs_governor_init,			\
161		.exit = cpufreq_dbs_governor_exit,			\
162		.start = cpufreq_dbs_governor_start,			\
163		.stop = cpufreq_dbs_governor_stop,			\
164		.limits = cpufreq_dbs_governor_limits,			\
165	}
166
167/* Governor specific operations */
168struct od_ops {
169	unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
170			unsigned int freq_next, unsigned int relation);
171};
172
173unsigned int dbs_update(struct cpufreq_policy *policy);
174void od_register_powersave_bias_handler(unsigned int (*f)
175		(struct cpufreq_policy *, unsigned int, unsigned int),
176		unsigned int powersave_bias);
177void od_unregister_powersave_bias_handler(void);
178ssize_t sampling_rate_store(struct gov_attr_set *attr_set, const char *buf,
179			    size_t count);
180void gov_update_cpu_data(struct dbs_data *dbs_data);
181#endif /* _CPUFREQ_GOVERNOR_H */
182