cpu.c

  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 cpufreq_frequency_table *freq_table = NULL;
 47	int i, max_opps, ret = 0;
 48	unsigned long rate;
 49
 50	max_opps = dev_pm_opp_get_opp_count(dev);
 51	if (max_opps <= 0)
 52		return max_opps ? max_opps : -ENODATA;
 53
 54	freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL);
 55	if (!freq_table)
 56		return -ENOMEM;
 57
 58	for (i = 0, rate = 0; i < max_opps; i++, rate++) {
 59		/* find next rate */
 60		struct dev_pm_opp *opp __free(put_opp) =
 61			dev_pm_opp_find_freq_ceil(dev, &rate);
 62
 63		if (IS_ERR(opp)) {
 64			ret = PTR_ERR(opp);
 65			goto out;
 66		}
 67		freq_table[i].driver_data = i;
 68		freq_table[i].frequency = rate / 1000;
 69
 70		/* Is Boost/turbo opp ? */
 71		if (dev_pm_opp_is_turbo(opp))
 72			freq_table[i].flags = CPUFREQ_BOOST_FREQ;
 73	}
 74
 75	freq_table[i].driver_data = i;
 76	freq_table[i].frequency = CPUFREQ_TABLE_END;
 77
 78	*opp_table = &freq_table[0];
 79
 80out:
 81	if (ret)
 82		kfree(freq_table);
 83
 84	return ret;
 85}
 86EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);
 87
 88/**
 89 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
 90 * @dev:	device for which we do this operation
 91 * @opp_table:	table to free
 92 *
 93 * Free up the table allocated by dev_pm_opp_init_cpufreq_table
 94 */
 95void dev_pm_opp_free_cpufreq_table(struct device *dev,
 96				   struct cpufreq_frequency_table **opp_table)
 97{
 98	if (!opp_table)
 99		return;
100
101	kfree(*opp_table);
102	*opp_table = NULL;
103}
104EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
105#endif	/* CONFIG_CPU_FREQ */
106
107void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask,
108				      int last_cpu)
109{
110	struct device *cpu_dev;
111	int cpu;
112
113	WARN_ON(cpumask_empty(cpumask));
114
115	for_each_cpu(cpu, cpumask) {
116		if (cpu == last_cpu)
117			break;
118
119		cpu_dev = get_cpu_device(cpu);
120		if (!cpu_dev) {
121			pr_err("%s: failed to get cpu%d device\n", __func__,
122			       cpu);
123			continue;
124		}
125
126		dev_pm_opp_remove_table(cpu_dev);
127	}
128}
129
130/**
131 * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask
132 * @cpumask:	cpumask for which OPP table needs to be removed
133 *
134 * This removes the OPP tables for CPUs present in the @cpumask.
135 * This should be used to remove all the OPPs entries associated with
136 * the cpus in @cpumask.
137 */
138void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
139{
140	_dev_pm_opp_cpumask_remove_table(cpumask, -1);
141}
142EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table);
143
144/**
145 * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs
146 * @cpu_dev:	CPU device for which we do this operation
147 * @cpumask:	cpumask of the CPUs which share the OPP table with @cpu_dev
148 *
149 * This marks OPP table of the @cpu_dev as shared by the CPUs present in
150 * @cpumask.
151 *
152 * Returns -ENODEV if OPP table isn't already present.
153 */
154int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
155				const struct cpumask *cpumask)
156{
157	struct opp_device *opp_dev;
158	struct device *dev;
159	int cpu;
160
161	struct opp_table *opp_table __free(put_opp_table) =
162		_find_opp_table(cpu_dev);
163
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	return 0;
190}
191EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
192
193/**
194 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
195 * @cpu_dev:	CPU device for which we do this operation
196 * @cpumask:	cpumask to update with information of sharing CPUs
197 *
198 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
199 *
200 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
201 * table's status is access-unknown.
202 */
203int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
204{
205	struct opp_device *opp_dev;
206
207	struct opp_table *opp_table __free(put_opp_table) =
208		_find_opp_table(cpu_dev);
209
210	if (IS_ERR(opp_table))
211		return PTR_ERR(opp_table);
212
213	if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN)
214		return -EINVAL;
215
216	cpumask_clear(cpumask);
217
218	if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
219		guard(mutex)(&opp_table->lock);
220		list_for_each_entry(opp_dev, &opp_table->dev_list, node)
221			cpumask_set_cpu(opp_dev->dev->id, cpumask);
222	} else {
223		cpumask_set_cpu(cpu_dev->id, cpumask);
224	}
225
226	return 0;
227}
228EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);