1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2021 Linaro Limited
*
* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
*
* The devfreq device combined with the energy model and the load can
* give an estimation of the power consumption as well as limiting the
* power.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cpumask.h>
#include <linux/devfreq.h>
#include <linux/dtpm.h>
#include <linux/energy_model.h>
#include <linux/of.h>
#include <linux/pm_qos.h>
#include <linux/slab.h>
#include <linux/units.h>
struct dtpm_devfreq {
struct dtpm dtpm;
struct dev_pm_qos_request qos_req;
struct devfreq *devfreq;
};
static struct dtpm_devfreq *to_dtpm_devfreq(struct dtpm *dtpm)
{
return container_of(dtpm, struct dtpm_devfreq, dtpm);
}
static int update_pd_power_uw(struct dtpm *dtpm)
{
struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
struct devfreq *devfreq = dtpm_devfreq->devfreq;
struct device *dev = devfreq->dev.parent;
struct em_perf_domain *pd = em_pd_get(dev);
struct em_perf_state *table;
rcu_read_lock();
table = em_perf_state_from_pd(pd);
dtpm->power_min = table[0].power;
dtpm->power_max = table[pd->nr_perf_states - 1].power;
rcu_read_unlock();
return 0;
}
static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit)
{
struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
struct devfreq *devfreq = dtpm_devfreq->devfreq;
struct device *dev = devfreq->dev.parent;
struct em_perf_domain *pd = em_pd_get(dev);
struct em_perf_state *table;
unsigned long freq;
int i;
rcu_read_lock();
table = em_perf_state_from_pd(pd);
for (i = 0; i < pd->nr_perf_states; i++) {
if (table[i].power > power_limit)
break;
}
freq = table[i - 1].frequency;
power_limit = table[i - 1].power;
rcu_read_unlock();
dev_pm_qos_update_request(&dtpm_devfreq->qos_req, freq);
return power_limit;
}
static void _normalize_load(struct devfreq_dev_status *status)
{
if (status->total_time > 0xfffff) {
status->total_time >>= 10;
status->busy_time >>= 10;
}
status->busy_time <<= 10;
status->busy_time /= status->total_time ? : 1;
status->busy_time = status->busy_time ? : 1;
status->total_time = 1024;
}
static u64 get_pd_power_uw(struct dtpm *dtpm)
{
struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
struct devfreq *devfreq = dtpm_devfreq->devfreq;
struct device *dev = devfreq->dev.parent;
struct em_perf_domain *pd = em_pd_get(dev);
struct devfreq_dev_status status;
struct em_perf_state *table;
unsigned long freq;
u64 power = 0;
int i;
mutex_lock(&devfreq->lock);
status = devfreq->last_status;
mutex_unlock(&devfreq->lock);
freq = DIV_ROUND_UP(status.current_frequency, HZ_PER_KHZ);
_normalize_load(&status);
rcu_read_lock();
table = em_perf_state_from_pd(pd);
for (i = 0; i < pd->nr_perf_states; i++) {
if (table[i].frequency < freq)
continue;
power = table[i].power;
power *= status.busy_time;
power >>= 10;
break;
}
rcu_read_unlock();
return power;
}
static void pd_release(struct dtpm *dtpm)
{
struct dtpm_devfreq *dtpm_devfreq = to_dtpm_devfreq(dtpm);
if (dev_pm_qos_request_active(&dtpm_devfreq->qos_req))
dev_pm_qos_remove_request(&dtpm_devfreq->qos_req);
kfree(dtpm_devfreq);
}
static struct dtpm_ops dtpm_ops = {
.set_power_uw = set_pd_power_limit,
.get_power_uw = get_pd_power_uw,
.update_power_uw = update_pd_power_uw,
.release = pd_release,
};
static int __dtpm_devfreq_setup(struct devfreq *devfreq, struct dtpm *parent)
{
struct device *dev = devfreq->dev.parent;
struct dtpm_devfreq *dtpm_devfreq;
struct em_perf_domain *pd;
int ret = -ENOMEM;
pd = em_pd_get(dev);
if (!pd) {
ret = dev_pm_opp_of_register_em(dev, NULL);
if (ret) {
pr_err("No energy model available for '%s'\n", dev_name(dev));
return -EINVAL;
}
}
dtpm_devfreq = kzalloc(sizeof(*dtpm_devfreq), GFP_KERNEL);
if (!dtpm_devfreq)
return -ENOMEM;
dtpm_init(&dtpm_devfreq->dtpm, &dtpm_ops);
dtpm_devfreq->devfreq = devfreq;
ret = dtpm_register(dev_name(dev), &dtpm_devfreq->dtpm, parent);
if (ret) {
pr_err("Failed to register '%s': %d\n", dev_name(dev), ret);
kfree(dtpm_devfreq);
return ret;
}
ret = dev_pm_qos_add_request(dev, &dtpm_devfreq->qos_req,
DEV_PM_QOS_MAX_FREQUENCY,
PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
if (ret) {
pr_err("Failed to add QoS request: %d\n", ret);
goto out_dtpm_unregister;
}
dtpm_update_power(&dtpm_devfreq->dtpm);
return 0;
out_dtpm_unregister:
dtpm_unregister(&dtpm_devfreq->dtpm);
return ret;
}
static int dtpm_devfreq_setup(struct dtpm *dtpm, struct device_node *np)
{
struct devfreq *devfreq;
devfreq = devfreq_get_devfreq_by_node(np);
if (IS_ERR(devfreq))
return 0;
return __dtpm_devfreq_setup(devfreq, dtpm);
}
struct dtpm_subsys_ops dtpm_devfreq_ops = {
.name = KBUILD_MODNAME,
.setup = dtpm_devfreq_setup,
};
|
