drivers/opp/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  * @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  */
  43 int dev_pm_opp_init_cpufreq_table(struct device *dev,
  44                                   struct cpufreq_frequency_table **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         *table = &freq_table[0];
  80
  81 out:
  82         if (ret)
  83                 kfree(freq_table);
  84
  85         return ret;
  86 }
  87 EXPORT_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  * @table:      table to free
  93  *
  94  * Free up the table allocated by dev_pm_opp_init_cpufreq_table
  95  */
  96 void dev_pm_opp_free_cpufreq_table(struct device *dev,
  97                                    struct cpufreq_frequency_table **table)
  98 {
  99         if (!table)
 100                 return;
 101
 102         kfree(*table);
 103         *table = NULL;
 104 }
 105 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
 106 #endif  /* CONFIG_CPU_FREQ */
 107
 108 void _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  */
 139 void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
 140 {
 141         _dev_pm_opp_cpumask_remove_table(cpumask, -1);
 142 }
 143 EXPORT_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  */
 155 int 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 }
 193 EXPORT_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  */
 205 int 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
 231 put_opp_table:
 232         dev_pm_opp_put_opp_table(opp_table);
 233
 234         return ret;
 235 }
 236 EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);