drivers/opp/cpu.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Generic OPP helper interface for CPU device
0004  *
0005  * Copyright (C) 2009-2014 Texas Instruments Incorporated.
0006  *  Nishanth Menon
0007  *  Romit Dasgupta
0008  *  Kevin Hilman
0009  */
0010
0011 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0012
0013 #include <linux/cpu.h>
0014 #include <linux/cpufreq.h>
0015 #include <linux/err.h>
0016 #include <linux/errno.h>
0017 #include <linux/export.h>
0018 #include <linux/slab.h>
0019
0020 #include "opp.h"
0021
0022 #ifdef CONFIG_CPU_FREQ
0023
0024 /**
0025  * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
0026  * @dev:    device for which we do this operation
0027  * @table:  Cpufreq table returned back to caller
0028  *
0029  * Generate a cpufreq table for a provided device- this assumes that the
0030  * opp table is already initialized and ready for usage.
0031  *
0032  * This function allocates required memory for the cpufreq table. It is
0033  * expected that the caller does the required maintenance such as freeing
0034  * the table as required.
0035  *
0036  * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
0037  * if no memory available for the operation (table is not populated), returns 0
0038  * if successful and table is populated.
0039  *
0040  * WARNING: It is  important for the callers to ensure refreshing their copy of
0041  * the table if any of the mentioned functions have been invoked in the interim.
0042  */
0043 int dev_pm_opp_init_cpufreq_table(struct device *dev,
0044                   struct cpufreq_frequency_table **opp_table)
0045 {
0046     struct dev_pm_opp *opp;
0047     struct cpufreq_frequency_table *freq_table = NULL;
0048     int i, max_opps, ret = 0;
0049     unsigned long rate;
0050
0051     max_opps = dev_pm_opp_get_opp_count(dev);
0052     if (max_opps <= 0)
0053         return max_opps ? max_opps : -ENODATA;
0054
0055     freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL);
0056     if (!freq_table)
0057         return -ENOMEM;
0058
0059     for (i = 0, rate = 0; i < max_opps; i++, rate++) {
0060         /* find next rate */
0061         opp = dev_pm_opp_find_freq_ceil(dev, &rate);
0062         if (IS_ERR(opp)) {
0063             ret = PTR_ERR(opp);
0064             goto out;
0065         }
0066         freq_table[i].driver_data = i;
0067         freq_table[i].frequency = rate / 1000;
0068
0069         /* Is Boost/turbo opp ? */
0070         if (dev_pm_opp_is_turbo(opp))
0071             freq_table[i].flags = CPUFREQ_BOOST_FREQ;
0072
0073         dev_pm_opp_put(opp);
0074     }
0075
0076     freq_table[i].driver_data = i;
0077     freq_table[i].frequency = CPUFREQ_TABLE_END;
0078
0079     *opp_table = &freq_table[0];
0080
0081 out:
0082     if (ret)
0083         kfree(freq_table);
0084
0085     return ret;
0086 }
0087 EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);
0088
0089 /**
0090  * dev_pm_opp_free_cpufreq_table() - free the cpufreq table
0091  * @dev:    device for which we do this operation
0092  * @table:  table to free
0093  *
0094  * Free up the table allocated by dev_pm_opp_init_cpufreq_table
0095  */
0096 void dev_pm_opp_free_cpufreq_table(struct device *dev,
0097                    struct cpufreq_frequency_table **opp_table)
0098 {
0099     if (!opp_table)
0100         return;
0101
0102     kfree(*opp_table);
0103     *opp_table = NULL;
0104 }
0105 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
0106 #endif  /* CONFIG_CPU_FREQ */
0107
0108 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask,
0109                       int last_cpu)
0110 {
0111     struct device *cpu_dev;
0112     int cpu;
0113
0114     WARN_ON(cpumask_empty(cpumask));
0115
0116     for_each_cpu(cpu, cpumask) {
0117         if (cpu == last_cpu)
0118             break;
0119
0120         cpu_dev = get_cpu_device(cpu);
0121         if (!cpu_dev) {
0122             pr_err("%s: failed to get cpu%d device\n", __func__,
0123                    cpu);
0124             continue;
0125         }
0126
0127         dev_pm_opp_remove_table(cpu_dev);
0128     }
0129 }
0130
0131 /**
0132  * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask
0133  * @cpumask:    cpumask for which OPP table needs to be removed
0134  *
0135  * This removes the OPP tables for CPUs present in the @cpumask.
0136  * This should be used to remove all the OPPs entries associated with
0137  * the cpus in @cpumask.
0138  */
0139 void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
0140 {
0141     _dev_pm_opp_cpumask_remove_table(cpumask, -1);
0142 }
0143 EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table);
0144
0145 /**
0146  * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs
0147  * @cpu_dev:    CPU device for which we do this operation
0148  * @cpumask:    cpumask of the CPUs which share the OPP table with @cpu_dev
0149  *
0150  * This marks OPP table of the @cpu_dev as shared by the CPUs present in
0151  * @cpumask.
0152  *
0153  * Returns -ENODEV if OPP table isn't already present.
0154  */
0155 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
0156                 const struct cpumask *cpumask)
0157 {
0158     struct opp_device *opp_dev;
0159     struct opp_table *opp_table;
0160     struct device *dev;
0161     int cpu, ret = 0;
0162
0163     opp_table = _find_opp_table(cpu_dev);
0164     if (IS_ERR(opp_table))
0165         return PTR_ERR(opp_table);
0166
0167     for_each_cpu(cpu, cpumask) {
0168         if (cpu == cpu_dev->id)
0169             continue;
0170
0171         dev = get_cpu_device(cpu);
0172         if (!dev) {
0173             dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
0174                 __func__, cpu);
0175             continue;
0176         }
0177
0178         opp_dev = _add_opp_dev(dev, opp_table);
0179         if (!opp_dev) {
0180             dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n",
0181                 __func__, cpu);
0182             continue;
0183         }
0184
0185         /* Mark opp-table as multiple CPUs are sharing it now */
0186         opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
0187     }
0188
0189     dev_pm_opp_put_opp_table(opp_table);
0190
0191     return ret;
0192 }
0193 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
0194
0195 /**
0196  * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
0197  * @cpu_dev:    CPU device for which we do this operation
0198  * @cpumask:    cpumask to update with information of sharing CPUs
0199  *
0200  * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
0201  *
0202  * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
0203  * table's status is access-unknown.
0204  */
0205 int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
0206 {
0207     struct opp_device *opp_dev;
0208     struct opp_table *opp_table;
0209     int ret = 0;
0210
0211     opp_table = _find_opp_table(cpu_dev);
0212     if (IS_ERR(opp_table))
0213         return PTR_ERR(opp_table);
0214
0215     if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN) {
0216         ret = -EINVAL;
0217         goto put_opp_table;
0218     }
0219
0220     cpumask_clear(cpumask);
0221
0222     if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
0223         mutex_lock(&opp_table->lock);
0224         list_for_each_entry(opp_dev, &opp_table->dev_list, node)
0225             cpumask_set_cpu(opp_dev->dev->id, cpumask);
0226         mutex_unlock(&opp_table->lock);
0227     } else {
0228         cpumask_set_cpu(cpu_dev->id, cpumask);
0229     }
0230
0231 put_opp_table:
0232     dev_pm_opp_put_opp_table(opp_table);
0233
0234     return ret;
0235 }
0236 EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);