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	void *tuners;
 41	unsigned int ignore_nice_load;
 42	unsigned int sampling_rate;
 43	unsigned int sampling_down_factor;
 44	unsigned int up_threshold;
 45	unsigned int io_is_busy;
 46};
 47
 48static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set)
 49{
 50	return container_of(attr_set, struct dbs_data, attr_set);
 51}
 52
 53#define gov_show_one(_gov, file_name)					\
 54static ssize_t show_##file_name						\
 55(struct gov_attr_set *attr_set, char *buf)				\
 56{									\
 57	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
 58	struct _gov##_dbs_tuners *tuners = dbs_data->tuners;		\
 59	return sprintf(buf, "%u\n", tuners->file_name);			\
 60}
 61
 62#define gov_show_one_common(file_name)					\
 63static ssize_t show_##file_name						\
 64(struct gov_attr_set *attr_set, char *buf)				\
 65{									\
 66	struct dbs_data *dbs_data = to_dbs_data(attr_set);		\
 67	return sprintf(buf, "%u\n", dbs_data->file_name);		\
 68}
 69
 70#define gov_attr_ro(_name)						\
 71static struct governor_attr _name =					\
 72__ATTR(_name, 0444, show_##_name, NULL)
 73
 74#define gov_attr_rw(_name)						\
 75static struct governor_attr _name =					\
 76__ATTR(_name, 0644, show_##_name, store_##_name)
 77
 78/* Common to all CPUs of a policy */
 79struct policy_dbs_info {
 80	struct cpufreq_policy *policy;
 81	/*
 82	 * Per policy mutex that serializes load evaluation from limit-change
 83	 * and work-handler.
 84	 */
 85	struct mutex update_mutex;
 86
 87	u64 last_sample_time;
 88	s64 sample_delay_ns;
 89	atomic_t work_count;
 90	struct irq_work irq_work;
 91	struct work_struct work;
 92	/* dbs_data may be shared between multiple policy objects */
 93	struct dbs_data *dbs_data;
 94	struct list_head list;
 95	/* Multiplier for increasing sample delay temporarily. */
 96	unsigned int rate_mult;
 97	unsigned int idle_periods;	/* For conservative */
 98	/* Status indicators */
 99	bool is_shared;		/* This object is used by multiple CPUs */
100	bool work_in_progress;	/* Work is being queued up or in progress */
101};
102
103static inline void gov_update_sample_delay(struct policy_dbs_info *policy_dbs,
104					   unsigned int delay_us)
105{
106	policy_dbs->sample_delay_ns = delay_us * NSEC_PER_USEC;
107}
108
109/* Per cpu structures */
110struct cpu_dbs_info {
111	u64 prev_cpu_idle;
112	u64 prev_update_time;
113	u64 prev_cpu_nice;
114	/*
115	 * Used to keep track of load in the previous interval. However, when
116	 * explicitly set to zero, it is used as a flag to ensure that we copy
117	 * the previous load to the current interval only once, upon the first
118	 * wake-up from idle.
119	 */
120	unsigned int prev_load;
121	struct update_util_data update_util;
122	struct policy_dbs_info *policy_dbs;
123};
124
125/* Common Governor data across policies */
126struct dbs_governor {
127	struct cpufreq_governor gov;
128	struct kobj_type kobj_type;
129
130	/*
131	 * Common data for platforms that don't set
132	 * CPUFREQ_HAVE_GOVERNOR_PER_POLICY
133	 */
134	struct dbs_data *gdbs_data;
135
136	unsigned int (*gov_dbs_update)(struct cpufreq_policy *policy);
137	struct policy_dbs_info *(*alloc)(void);
138	void (*free)(struct policy_dbs_info *policy_dbs);
139	int (*init)(struct dbs_data *dbs_data);
140	void (*exit)(struct dbs_data *dbs_data);
141	void (*start)(struct cpufreq_policy *policy);
142};
143
144static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
145{
146	return container_of(policy->governor, struct dbs_governor, gov);
147}
148
149/* Governor callback routines */
150int cpufreq_dbs_governor_init(struct cpufreq_policy *policy);
151void cpufreq_dbs_governor_exit(struct cpufreq_policy *policy);
152int cpufreq_dbs_governor_start(struct cpufreq_policy *policy);
153void cpufreq_dbs_governor_stop(struct cpufreq_policy *policy);
154void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy);
155
156#define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_)			\
157	{								\
158		.name = _name_,						\
159		.flags = CPUFREQ_GOV_DYNAMIC_SWITCHING,			\
160		.owner = THIS_MODULE,					\
161		.init = cpufreq_dbs_governor_init,			\
162		.exit = cpufreq_dbs_governor_exit,			\
163		.start = cpufreq_dbs_governor_start,			\
164		.stop = cpufreq_dbs_governor_stop,			\
165		.limits = cpufreq_dbs_governor_limits,			\
166	}
167
168/* Governor specific operations */
169struct od_ops {
170	unsigned int (*powersave_bias_target)(struct cpufreq_policy *policy,
171			unsigned int freq_next, unsigned int relation);
172};
173
174unsigned int dbs_update(struct cpufreq_policy *policy);
175void od_register_powersave_bias_handler(unsigned int (*f)
176		(struct cpufreq_policy *, unsigned int, unsigned int),
177		unsigned int powersave_bias);
178void od_unregister_powersave_bias_handler(void);
179ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
180			    size_t count);
181void gov_update_cpu_data(struct dbs_data *dbs_data);
182#endif /* _CPUFREQ_GOVERNOR_H */