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 */
dev_pm_opp_init_cpufreq_table(struct device * dev,struct cpufreq_frequency_table ** opp_table)43 int 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
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 * @opp_table: table to free
93 *
94 * Free up the table allocated by dev_pm_opp_init_cpufreq_table
95 */
dev_pm_opp_free_cpufreq_table(struct device * dev,struct cpufreq_frequency_table ** opp_table)96 void 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 }
105 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
106 #endif /* CONFIG_CPU_FREQ */
107
_dev_pm_opp_cpumask_remove_table(const struct cpumask * cpumask,int last_cpu)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 */
dev_pm_opp_cpumask_remove_table(const struct cpumask * cpumask)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 */
dev_pm_opp_set_sharing_cpus(struct device * cpu_dev,const struct cpumask * cpumask)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 */
dev_pm_opp_get_sharing_cpus(struct device * cpu_dev,struct cpumask * cpumask)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);
237