1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic OPP helper interface for CPU device
4 *
5 * Copyright (C) 2009-2014 Texas Instruments Incorporated.
6 *	Nishanth Menon
7 *	Romit Dasgupta
8 *	Kevin Hilman
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/cpu.h>
14#include <linux/cpufreq.h>
15#include <linux/err.h>
16#include <linux/errno.h>
17#include <linux/export.h>
18#include <linux/slab.h>
19
20#include "opp.h"
21
22#ifdef CONFIG_CPU_FREQ
23
24/**
25 * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
26 * @dev:	device for which we do this operation
27 * @opp_table:	Cpufreq table returned back to caller
28 *
29 * Generate a cpufreq table for a provided device- this assumes that the
30 * opp table is already initialized and ready for usage.
31 *
32 * This function allocates required memory for the cpufreq table. It is
33 * expected that the caller does the required maintenance such as freeing
34 * the table as required.
35 *
36 * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
37 * if no memory available for the operation (table is not populated), returns 0
38 * if successful and table is populated.
39 *
40 * WARNING: It is  important for the callers to ensure refreshing their copy of
41 * the table if any of the mentioned functions have been invoked in the interim.
42 */
43int dev_pm_opp_init_cpufreq_table(struct device *dev,
44				  struct cpufreq_frequency_table **opp_table)
45{
46	struct dev_pm_opp *opp;
47	struct cpufreq_frequency_table *freq_table = NULL;
48	int i, max_opps, ret = 0;
49	unsigned long rate;
50
51	max_opps = dev_pm_opp_get_opp_count(dev);
52	if (max_opps <= 0)
53		return max_opps ? max_opps : -ENODATA;
54
55	freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL);
56	if (!freq_table)
57		return -ENOMEM;
58
59	for (i = 0, rate = 0; i < max_opps; i++, rate++) {
60		/* find next rate */
61		opp = dev_pm_opp_find_freq_ceil(dev, &rate);
62		if (IS_ERR(opp)) {
63			ret = PTR_ERR(opp);
64			goto out;
65		}
66		freq_table[i].driver_data = i;
67		freq_table[i].frequency = rate / 1000;
68
69		/* Is Boost/turbo opp ? */
70		if (dev_pm_opp_is_turbo(opp))
71			freq_table[i].flags = CPUFREQ_BOOST_FREQ;
72
73		dev_pm_opp_put(opp);
74	}
75
76	freq_table[i].driver_data = i;
77	freq_table[i].frequency = CPUFREQ_TABLE_END;
78
79	*opp_table = &freq_table[0];
80
81out:
82	if (ret)
83		kfree(freq_table);
84
85	return ret;
86}
87EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);
88
89/**
90 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
91 * @dev:	device for which we do this operation
92 * @opp_table:	table to free
93 *
94 * Free up the table allocated by dev_pm_opp_init_cpufreq_table
95 */
96void dev_pm_opp_free_cpufreq_table(struct device *dev,
97				   struct cpufreq_frequency_table **opp_table)
98{
99	if (!opp_table)
100		return;
101
102	kfree(*opp_table);
103	*opp_table = NULL;
104}
105EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
106#endif	/* CONFIG_CPU_FREQ */
107
108void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask,
109				      int last_cpu)
110{
111	struct device *cpu_dev;
112	int cpu;
113
114	WARN_ON(cpumask_empty(cpumask));
115
116	for_each_cpu(cpu, cpumask) {
117		if (cpu == last_cpu)
118			break;
119
120		cpu_dev = get_cpu_device(cpu);
121		if (!cpu_dev) {
122			pr_err("%s: failed to get cpu%d device\n", __func__,
123			       cpu);
124			continue;
125		}
126
127		dev_pm_opp_remove_table(cpu_dev);
128	}
129}
130
131/**
132 * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask
133 * @cpumask:	cpumask for which OPP table needs to be removed
134 *
135 * This removes the OPP tables for CPUs present in the @cpumask.
136 * This should be used to remove all the OPPs entries associated with
137 * the cpus in @cpumask.
138 */
139void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
140{
141	_dev_pm_opp_cpumask_remove_table(cpumask, -1);
142}
143EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table);
144
145/**
146 * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs
147 * @cpu_dev:	CPU device for which we do this operation
148 * @cpumask:	cpumask of the CPUs which share the OPP table with @cpu_dev
149 *
150 * This marks OPP table of the @cpu_dev as shared by the CPUs present in
151 * @cpumask.
152 *
153 * Returns -ENODEV if OPP table isn't already present.
154 */
155int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
156				const struct cpumask *cpumask)
157{
158	struct opp_device *opp_dev;
159	struct opp_table *opp_table;
160	struct device *dev;
161	int cpu, ret = 0;
162
163	opp_table = _find_opp_table(cpu_dev);
164	if (IS_ERR(opp_table))
165		return PTR_ERR(opp_table);
166
167	for_each_cpu(cpu, cpumask) {
168		if (cpu == cpu_dev->id)
169			continue;
170
171		dev = get_cpu_device(cpu);
172		if (!dev) {
173			dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
174				__func__, cpu);
175			continue;
176		}
177
178		opp_dev = _add_opp_dev(dev, opp_table);
179		if (!opp_dev) {
180			dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n",
181				__func__, cpu);
182			continue;
183		}
184
185		/* Mark opp-table as multiple CPUs are sharing it now */
186		opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
187	}
188
189	dev_pm_opp_put_opp_table(opp_table);
190
191	return ret;
192}
193EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
194
195/**
196 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
197 * @cpu_dev:	CPU device for which we do this operation
198 * @cpumask:	cpumask to update with information of sharing CPUs
199 *
200 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
201 *
202 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
203 * table's status is access-unknown.
204 */
205int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
206{
207	struct opp_device *opp_dev;
208	struct opp_table *opp_table;
209	int ret = 0;
210
211	opp_table = _find_opp_table(cpu_dev);
212	if (IS_ERR(opp_table))
213		return PTR_ERR(opp_table);
214
215	if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN) {
216		ret = -EINVAL;
217		goto put_opp_table;
218	}
219
220	cpumask_clear(cpumask);
221
222	if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
223		mutex_lock(&opp_table->lock);
224		list_for_each_entry(opp_dev, &opp_table->dev_list, node)
225			cpumask_set_cpu(opp_dev->dev->id, cpumask);
226		mutex_unlock(&opp_table->lock);
227	} else {
228		cpumask_set_cpu(cpu_dev->id, cpumask);
229	}
230
231put_opp_table:
232	dev_pm_opp_put_opp_table(opp_table);
233
234	return ret;
235}
236EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);
237