1 /* 2 * Generic OPP helper interface for CPU device 3 * 4 * Copyright (C) 2009-2014 Texas Instruments Incorporated. 5 * Nishanth Menon 6 * Romit Dasgupta 7 * Kevin Hilman 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/cpu.h> 17 #include <linux/cpufreq.h> 18 #include <linux/err.h> 19 #include <linux/errno.h> 20 #include <linux/export.h> 21 #include <linux/slab.h> 22 23 #include "opp.h" 24 25 #ifdef CONFIG_CPU_FREQ 26 27 /** 28 * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device 29 * @dev: device for which we do this operation 30 * @table: Cpufreq table returned back to caller 31 * 32 * Generate a cpufreq table for a provided device- this assumes that the 33 * opp table is already initialized and ready for usage. 34 * 35 * This function allocates required memory for the cpufreq table. It is 36 * expected that the caller does the required maintenance such as freeing 37 * the table as required. 38 * 39 * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM 40 * if no memory available for the operation (table is not populated), returns 0 41 * if successful and table is populated. 42 * 43 * WARNING: It is important for the callers to ensure refreshing their copy of 44 * the table if any of the mentioned functions have been invoked in the interim. 45 */ 46 int dev_pm_opp_init_cpufreq_table(struct device *dev, 47 struct cpufreq_frequency_table **table) 48 { 49 struct dev_pm_opp *opp; 50 struct cpufreq_frequency_table *freq_table = NULL; 51 int i, max_opps, ret = 0; 52 unsigned long rate; 53 54 max_opps = dev_pm_opp_get_opp_count(dev); 55 if (max_opps <= 0) 56 return max_opps ? max_opps : -ENODATA; 57 58 freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL); 59 if (!freq_table) 60 return -ENOMEM; 61 62 for (i = 0, rate = 0; i < max_opps; i++, rate++) { 63 /* find next rate */ 64 opp = dev_pm_opp_find_freq_ceil(dev, &rate); 65 if (IS_ERR(opp)) { 66 ret = PTR_ERR(opp); 67 goto out; 68 } 69 freq_table[i].driver_data = i; 70 freq_table[i].frequency = rate / 1000; 71 72 /* Is Boost/turbo opp ? */ 73 if (dev_pm_opp_is_turbo(opp)) 74 freq_table[i].flags = CPUFREQ_BOOST_FREQ; 75 76 dev_pm_opp_put(opp); 77 } 78 79 freq_table[i].driver_data = i; 80 freq_table[i].frequency = CPUFREQ_TABLE_END; 81 82 *table = &freq_table[0]; 83 84 out: 85 if (ret) 86 kfree(freq_table); 87 88 return ret; 89 } 90 EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table); 91 92 /** 93 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table 94 * @dev: device for which we do this operation 95 * @table: table to free 96 * 97 * Free up the table allocated by dev_pm_opp_init_cpufreq_table 98 */ 99 void dev_pm_opp_free_cpufreq_table(struct device *dev, 100 struct cpufreq_frequency_table **table) 101 { 102 if (!table) 103 return; 104 105 kfree(*table); 106 *table = NULL; 107 } 108 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table); 109 #endif /* CONFIG_CPU_FREQ */ 110 111 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, 112 int last_cpu) 113 { 114 struct device *cpu_dev; 115 int cpu; 116 117 WARN_ON(cpumask_empty(cpumask)); 118 119 for_each_cpu(cpu, cpumask) { 120 if (cpu == last_cpu) 121 break; 122 123 cpu_dev = get_cpu_device(cpu); 124 if (!cpu_dev) { 125 pr_err("%s: failed to get cpu%d device\n", __func__, 126 cpu); 127 continue; 128 } 129 130 _dev_pm_opp_find_and_remove_table(cpu_dev); 131 } 132 } 133 134 /** 135 * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask 136 * @cpumask: cpumask for which OPP table needs to be removed 137 * 138 * This removes the OPP tables for CPUs present in the @cpumask. 139 * This should be used to remove all the OPPs entries associated with 140 * the cpus in @cpumask. 141 */ 142 void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask) 143 { 144 _dev_pm_opp_cpumask_remove_table(cpumask, -1); 145 } 146 EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table); 147 148 /** 149 * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs 150 * @cpu_dev: CPU device for which we do this operation 151 * @cpumask: cpumask of the CPUs which share the OPP table with @cpu_dev 152 * 153 * This marks OPP table of the @cpu_dev as shared by the CPUs present in 154 * @cpumask. 155 * 156 * Returns -ENODEV if OPP table isn't already present. 157 */ 158 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, 159 const struct cpumask *cpumask) 160 { 161 struct opp_device *opp_dev; 162 struct opp_table *opp_table; 163 struct device *dev; 164 int cpu, ret = 0; 165 166 opp_table = _find_opp_table(cpu_dev); 167 if (IS_ERR(opp_table)) 168 return PTR_ERR(opp_table); 169 170 for_each_cpu(cpu, cpumask) { 171 if (cpu == cpu_dev->id) 172 continue; 173 174 dev = get_cpu_device(cpu); 175 if (!dev) { 176 dev_err(cpu_dev, "%s: failed to get cpu%d device\n", 177 __func__, cpu); 178 continue; 179 } 180 181 opp_dev = _add_opp_dev(dev, opp_table); 182 if (!opp_dev) { 183 dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n", 184 __func__, cpu); 185 continue; 186 } 187 188 /* Mark opp-table as multiple CPUs are sharing it now */ 189 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED; 190 } 191 192 dev_pm_opp_put_opp_table(opp_table); 193 194 return ret; 195 } 196 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus); 197 198 /** 199 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev 200 * @cpu_dev: CPU device for which we do this operation 201 * @cpumask: cpumask to update with information of sharing CPUs 202 * 203 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev. 204 * 205 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP 206 * table's status is access-unknown. 207 */ 208 int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) 209 { 210 struct opp_device *opp_dev; 211 struct opp_table *opp_table; 212 int ret = 0; 213 214 opp_table = _find_opp_table(cpu_dev); 215 if (IS_ERR(opp_table)) 216 return PTR_ERR(opp_table); 217 218 if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN) { 219 ret = -EINVAL; 220 goto put_opp_table; 221 } 222 223 cpumask_clear(cpumask); 224 225 if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) { 226 mutex_lock(&opp_table->lock); 227 list_for_each_entry(opp_dev, &opp_table->dev_list, node) 228 cpumask_set_cpu(opp_dev->dev->id, cpumask); 229 mutex_unlock(&opp_table->lock); 230 } else { 231 cpumask_set_cpu(cpu_dev->id, cpumask); 232 } 233 234 put_opp_table: 235 dev_pm_opp_put_opp_table(opp_table); 236 237 return ret; 238 } 239 EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus); 240