[linux-2.6-block.git] / drivers / powercap / dtpm_cpu.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2020 Linaro Limited
 *
 * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
 *
 * The DTPM CPU is based on the energy model. It hooks the CPU in the
 * DTPM tree which in turns update the power number by propagating the
 * power number from the CPU energy model information to the parents.
 *
 * The association between the power and the performance state, allows
 * to set the power of the CPU at the OPP granularity.
 *
 * The CPU hotplug is supported and the power numbers will be updated
 * if a CPU is hot plugged / unplugged.
 */
#include <linux/cpumask.h>
#include <linux/cpufreq.h>
#include <linux/cpuhotplug.h>
#include <linux/dtpm.h>
#include <linux/energy_model.h>
#include <linux/pm_qos.h>
#include <linux/slab.h>
#include <linux/units.h>

static struct dtpm *__parent;

static DEFINE_PER_CPU(struct dtpm *, dtpm_per_cpu);

struct dtpm_cpu {
	struct freq_qos_request qos_req;
	int cpu;
};

/*
 * When a new CPU is inserted at hotplug or boot time, add the power
 * contribution and update the dtpm tree.
 */
static int power_add(struct dtpm *dtpm, struct em_perf_domain *em)
{
	u64 power_min, power_max;

	power_min = em->table[0].power;
	power_min *= MICROWATT_PER_MILLIWATT;
	power_min += dtpm->power_min;

	power_max = em->table[em->nr_perf_states - 1].power;
	power_max *= MICROWATT_PER_MILLIWATT;
	power_max += dtpm->power_max;

	return dtpm_update_power(dtpm, power_min, power_max);
}

/*
 * When a CPU is unplugged, remove its power contribution from the
 * dtpm tree.
 */
static int power_sub(struct dtpm *dtpm, struct em_perf_domain *em)
{
	u64 power_min, power_max;

	power_min = em->table[0].power;
	power_min *= MICROWATT_PER_MILLIWATT;
	power_min = dtpm->power_min - power_min;

	power_max = em->table[em->nr_perf_states - 1].power;
	power_max *= MICROWATT_PER_MILLIWATT;
	power_max = dtpm->power_max - power_max;

	return dtpm_update_power(dtpm, power_min, power_max);
}

static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit)
{
	struct dtpm_cpu *dtpm_cpu = dtpm->private;
	struct em_perf_domain *pd;
	struct cpumask cpus;
	unsigned long freq;
	u64 power;
	int i, nr_cpus;

	pd = em_cpu_get(dtpm_cpu->cpu);

	cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus));

	nr_cpus = cpumask_weight(&cpus);

	for (i = 0; i < pd->nr_perf_states; i++) {

		power = pd->table[i].power * MICROWATT_PER_MILLIWATT * nr_cpus;

		if (power > power_limit)
			break;
	}

	freq = pd->table[i - 1].frequency;

	freq_qos_update_request(&dtpm_cpu->qos_req, freq);

	power_limit = pd->table[i - 1].power *
		MICROWATT_PER_MILLIWATT * nr_cpus;

	return power_limit;
}

static u64 get_pd_power_uw(struct dtpm *dtpm)
{
	struct dtpm_cpu *dtpm_cpu = dtpm->private;
	struct em_perf_domain *pd;
	struct cpumask cpus;
	unsigned long freq;
	int i, nr_cpus;

	pd = em_cpu_get(dtpm_cpu->cpu);
	freq = cpufreq_quick_get(dtpm_cpu->cpu);
	cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus));
	nr_cpus = cpumask_weight(&cpus);

	for (i = 0; i < pd->nr_perf_states; i++) {

		if (pd->table[i].frequency < freq)
			continue;

		return pd->table[i].power *
			MICROWATT_PER_MILLIWATT * nr_cpus;
	}

	return 0;
}

static void pd_release(struct dtpm *dtpm)
{
	struct dtpm_cpu *dtpm_cpu = dtpm->private;

	if (freq_qos_request_active(&dtpm_cpu->qos_req))
		freq_qos_remove_request(&dtpm_cpu->qos_req);

	kfree(dtpm_cpu);
}

static struct dtpm_ops dtpm_ops = {
	.set_power_uw = set_pd_power_limit,
	.get_power_uw = get_pd_power_uw,
	.release = pd_release,
};

static int cpuhp_dtpm_cpu_offline(unsigned int cpu)
{
	struct cpufreq_policy *policy;
	struct em_perf_domain *pd;
	struct dtpm *dtpm;

	policy = cpufreq_cpu_get(cpu);

	if (!policy)
		return 0;

	pd = em_cpu_get(cpu);
	if (!pd)
		return -EINVAL;

	dtpm = per_cpu(dtpm_per_cpu, cpu);

	power_sub(dtpm, pd);

	if (cpumask_weight(policy->cpus) != 1)
		return 0;

	for_each_cpu(cpu, policy->related_cpus)
		per_cpu(dtpm_per_cpu, cpu) = NULL;

	dtpm_unregister(dtpm);

	return 0;
}

static int cpuhp_dtpm_cpu_online(unsigned int cpu)
{
	struct dtpm *dtpm;
	struct dtpm_cpu *dtpm_cpu;
	struct cpufreq_policy *policy;
	struct em_perf_domain *pd;
	char name[CPUFREQ_NAME_LEN];
	int ret = -ENOMEM;

	policy = cpufreq_cpu_get(cpu);

	if (!policy)
		return 0;

	pd = em_cpu_get(cpu);
	if (!pd)
		return -EINVAL;

	dtpm = per_cpu(dtpm_per_cpu, cpu);
	if (dtpm)
		return power_add(dtpm, pd);

	dtpm = dtpm_alloc(&dtpm_ops);
	if (!dtpm)
		return -EINVAL;

	dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);
	if (!dtpm_cpu)
		goto out_kfree_dtpm;

	dtpm->private = dtpm_cpu;
	dtpm_cpu->cpu = cpu;

	for_each_cpu(cpu, policy->related_cpus)
		per_cpu(dtpm_per_cpu, cpu) = dtpm;

	sprintf(name, "cpu%d", dtpm_cpu->cpu);

	ret = dtpm_register(name, dtpm, __parent);
	if (ret)
		goto out_kfree_dtpm_cpu;

	ret = power_add(dtpm, pd);
	if (ret)
		goto out_dtpm_unregister;

	ret = freq_qos_add_request(&policy->constraints,
				   &dtpm_cpu->qos_req, FREQ_QOS_MAX,
				   pd->table[pd->nr_perf_states - 1].frequency);
	if (ret)
		goto out_power_sub;

	return 0;

out_power_sub:
	power_sub(dtpm, pd);

out_dtpm_unregister:
	dtpm_unregister(dtpm);
	dtpm_cpu = NULL;
	dtpm = NULL;

out_kfree_dtpm_cpu:
	for_each_cpu(cpu, policy->related_cpus)
		per_cpu(dtpm_per_cpu, cpu) = NULL;
	kfree(dtpm_cpu);

out_kfree_dtpm:
	kfree(dtpm);
	return ret;
}

int dtpm_register_cpu(struct dtpm *parent)
{
	__parent = parent;

	return cpuhp_setup_state(CPUHP_AP_DTPM_CPU_ONLINE,
				 "dtpm_cpu:online",
				 cpuhp_dtpm_cpu_online,
				 cpuhp_dtpm_cpu_offline);
}
Commit	Line	Data
0e8f68d7 DL	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Copyright 2020 Linaro Limited
	4	*
	5	* Author: Daniel Lezcano <daniel.lezcano@linaro.org>
	6	*
	7	* The DTPM CPU is based on the energy model. It hooks the CPU in the
	8	* DTPM tree which in turns update the power number by propagating the
	9	* power number from the CPU energy model information to the parents.
	10	*
	11	* The association between the power and the performance state, allows
	12	* to set the power of the CPU at the OPP granularity.
	13	*
	14	* The CPU hotplug is supported and the power numbers will be updated
	15	* if a CPU is hot plugged / unplugged.
	16	*/
	17	#include <linux/cpumask.h>
	18	#include <linux/cpufreq.h>
	19	#include <linux/cpuhotplug.h>
	20	#include <linux/dtpm.h>
	21	#include <linux/energy_model.h>
	22	#include <linux/pm_qos.h>
	23	#include <linux/slab.h>
	24	#include <linux/units.h>
	25
	26	static struct dtpm *__parent;
	27
	28	static DEFINE_PER_CPU(struct dtpm *, dtpm_per_cpu);
	29
	30	struct dtpm_cpu {
	31	struct freq_qos_request qos_req;
	32	int cpu;
	33	};
	34
	35	/*
	36	* When a new CPU is inserted at hotplug or boot time, add the power
	37	* contribution and update the dtpm tree.
	38	*/
	39	static int power_add(struct dtpm dtpm, struct em_perf_domain em)
	40	{
	41	u64 power_min, power_max;
	42
	43	power_min = em->table[0].power;
	44	power_min *= MICROWATT_PER_MILLIWATT;
	45	power_min += dtpm->power_min;
	46
	47	power_max = em->table[em->nr_perf_states - 1].power;
	48	power_max *= MICROWATT_PER_MILLIWATT;
	49	power_max += dtpm->power_max;
	50
	51	return dtpm_update_power(dtpm, power_min, power_max);
	52	}
	53
	54	/*
	55	* When a CPU is unplugged, remove its power contribution from the
	56	* dtpm tree.
	57	*/
	58	static int power_sub(struct dtpm dtpm, struct em_perf_domain em)
	59	{
	60	u64 power_min, power_max;
	61
	62	power_min = em->table[0].power;
	63	power_min *= MICROWATT_PER_MILLIWATT;
	64	power_min = dtpm->power_min - power_min;
65
66	power_max = em->table[em->nr_perf_states - 1].power;
67	power_max *= MICROWATT_PER_MILLIWATT;
68	power_max = dtpm->power_max - power_max;
69
70	return dtpm_update_power(dtpm, power_min, power_max);
71	}
72
73	static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit)
74	{
75	struct dtpm_cpu *dtpm_cpu = dtpm->private;
76	struct em_perf_domain *pd;
77	struct cpumask cpus;
78	unsigned long freq;
79	u64 power;
80	int i, nr_cpus;
81
82	pd = em_cpu_get(dtpm_cpu->cpu);
83
84	cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus));
85
86	nr_cpus = cpumask_weight(&cpus);
87
88	for (i = 0; i < pd->nr_perf_states; i++) {
89
90	power = pd->table[i].power * MICROWATT_PER_MILLIWATT * nr_cpus;
91
92	if (power > power_limit)
93	break;
94	}
95
96	freq = pd->table[i - 1].frequency;
97
98	freq_qos_update_request(&dtpm_cpu->qos_req, freq);
99
100	power_limit = pd->table[i - 1].power *
101	MICROWATT_PER_MILLIWATT * nr_cpus;
102
103	return power_limit;
104	}
105
106	static u64 get_pd_power_uw(struct dtpm *dtpm)
107	{
108	struct dtpm_cpu *dtpm_cpu = dtpm->private;
109	struct em_perf_domain *pd;
110	struct cpumask cpus;
111	unsigned long freq;
112	int i, nr_cpus;
113
114	pd = em_cpu_get(dtpm_cpu->cpu);
115	freq = cpufreq_quick_get(dtpm_cpu->cpu);
116	cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus));
117	nr_cpus = cpumask_weight(&cpus);
118
119	for (i = 0; i < pd->nr_perf_states; i++) {
120
121	if (pd->table[i].frequency < freq)
122	continue;
123
124	return pd->table[i].power *
125	MICROWATT_PER_MILLIWATT * nr_cpus;
126	}
127
128	return 0;
129	}
130
131	static void pd_release(struct dtpm *dtpm)
132	{
133	struct dtpm_cpu *dtpm_cpu = dtpm->private;
134
135	if (freq_qos_request_active(&dtpm_cpu->qos_req))
136	freq_qos_remove_request(&dtpm_cpu->qos_req);
137
138	kfree(dtpm_cpu);
139	}
140
141	static struct dtpm_ops dtpm_ops = {
142	.set_power_uw = set_pd_power_limit,
143	.get_power_uw = get_pd_power_uw,
144	.release = pd_release,
145	};
146
147	static int cpuhp_dtpm_cpu_offline(unsigned int cpu)
148	{
149	struct cpufreq_policy *policy;
150	struct em_perf_domain *pd;
151	struct dtpm *dtpm;
152
153	policy = cpufreq_cpu_get(cpu);
154
155	if (!policy)
156	return 0;
157
158	pd = em_cpu_get(cpu);
159	if (!pd)
160	return -EINVAL;
161
162	dtpm = per_cpu(dtpm_per_cpu, cpu);
163
164	power_sub(dtpm, pd);
165
166	if (cpumask_weight(policy->cpus) != 1)
167	return 0;
168
169	for_each_cpu(cpu, policy->related_cpus)
170	per_cpu(dtpm_per_cpu, cpu) = NULL;
171
172	dtpm_unregister(dtpm);
173
174	return 0;
175	}
176
177	static int cpuhp_dtpm_cpu_online(unsigned int cpu)
178	{
179	struct dtpm *dtpm;
180	struct dtpm_cpu *dtpm_cpu;
181	struct cpufreq_policy *policy;
182	struct em_perf_domain *pd;
183	char name[CPUFREQ_NAME_LEN];
184	int ret = -ENOMEM;
185
186	policy = cpufreq_cpu_get(cpu);
187
188	if (!policy)
189	return 0;
190
191	pd = em_cpu_get(cpu);
192	if (!pd)
193	return -EINVAL;
194
195	dtpm = per_cpu(dtpm_per_cpu, cpu);
196	if (dtpm)
197	return power_add(dtpm, pd);
198
199	dtpm = dtpm_alloc(&dtpm_ops);
200	if (!dtpm)
201	return -EINVAL;
202
66e713fb	203	dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);
0e8f68d7 DL	204	if (!dtpm_cpu)
	205	goto out_kfree_dtpm;
	206
	207	dtpm->private = dtpm_cpu;
	208	dtpm_cpu->cpu = cpu;
	209
	210	for_each_cpu(cpu, policy->related_cpus)
	211	per_cpu(dtpm_per_cpu, cpu) = dtpm;
	212
	213	sprintf(name, "cpu%d", dtpm_cpu->cpu);
	214
	215	ret = dtpm_register(name, dtpm, __parent);
	216	if (ret)
	217	goto out_kfree_dtpm_cpu;
	218
	219	ret = power_add(dtpm, pd);
	220	if (ret)
	221	goto out_dtpm_unregister;
	222
	223	ret = freq_qos_add_request(&policy->constraints,
	224	&dtpm_cpu->qos_req, FREQ_QOS_MAX,
	225	pd->table[pd->nr_perf_states - 1].frequency);
	226	if (ret)
	227	goto out_power_sub;
	228
	229	return 0;
	230
	231	out_power_sub:
	232	power_sub(dtpm, pd);
	233
	234	out_dtpm_unregister:
	235	dtpm_unregister(dtpm);
	236	dtpm_cpu = NULL;
	237	dtpm = NULL;
	238
	239	out_kfree_dtpm_cpu:
	240	for_each_cpu(cpu, policy->related_cpus)
	241	per_cpu(dtpm_per_cpu, cpu) = NULL;
	242	kfree(dtpm_cpu);
	243
	244	out_kfree_dtpm:
	245	kfree(dtpm);
	246	return ret;
	247	}
	248
	249	int dtpm_register_cpu(struct dtpm *parent)
	250	{
	251	__parent = parent;
	252
	253	return cpuhp_setup_state(CPUHP_AP_DTPM_CPU_ONLINE,
	254	"dtpm_cpu:online",
	255	cpuhp_dtpm_cpu_online,
	256	cpuhp_dtpm_cpu_offline);
	257	}