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 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 struct dev_pm_opp *opp __free(put_opp);
60
61 /* find next rate */
62 opp = dev_pm_opp_find_freq_ceil(dev, &rate);
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
80 out:
81 if (ret)
82 kfree(freq_table);
83
84 return ret;
85 }
86 EXPORT_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 */
dev_pm_opp_free_cpufreq_table(struct device * dev,struct cpufreq_frequency_table ** opp_table)95 void 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 }
104 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
105 #endif /* CONFIG_CPU_FREQ */
106
_dev_pm_opp_cpumask_remove_table(const struct cpumask * cpumask,int last_cpu)107 void _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 */
dev_pm_opp_cpumask_remove_table(const struct cpumask * cpumask)138 void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
139 {
140 _dev_pm_opp_cpumask_remove_table(cpumask, -1);
141 }
142 EXPORT_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 */
dev_pm_opp_set_sharing_cpus(struct device * cpu_dev,const struct cpumask * cpumask)154 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
155 const struct cpumask *cpumask)
156 {
157 struct opp_table *opp_table __free(put_opp_table);
158 struct opp_device *opp_dev;
159 struct device *dev;
160 int cpu;
161
162 opp_table = _find_opp_table(cpu_dev);
163 if (IS_ERR(opp_table))
164 return PTR_ERR(opp_table);
165
166 for_each_cpu(cpu, cpumask) {
167 if (cpu == cpu_dev->id)
168 continue;
169
170 dev = get_cpu_device(cpu);
171 if (!dev) {
172 dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
173 __func__, cpu);
174 continue;
175 }
176
177 opp_dev = _add_opp_dev(dev, opp_table);
178 if (!opp_dev) {
179 dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n",
180 __func__, cpu);
181 continue;
182 }
183
184 /* Mark opp-table as multiple CPUs are sharing it now */
185 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
186 }
187
188 return 0;
189 }
190 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
191
192 /**
193 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
194 * @cpu_dev: CPU device for which we do this operation
195 * @cpumask: cpumask to update with information of sharing CPUs
196 *
197 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
198 *
199 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
200 * table's status is access-unknown.
201 */
dev_pm_opp_get_sharing_cpus(struct device * cpu_dev,struct cpumask * cpumask)202 int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
203 {
204 struct opp_table *opp_table __free(put_opp_table);
205 struct opp_device *opp_dev;
206
207 opp_table = _find_opp_table(cpu_dev);
208 if (IS_ERR(opp_table))
209 return PTR_ERR(opp_table);
210
211 if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN)
212 return -EINVAL;
213
214 cpumask_clear(cpumask);
215
216 if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
217 guard(mutex)(&opp_table->lock);
218 list_for_each_entry(opp_dev, &opp_table->dev_list, node)
219 cpumask_set_cpu(opp_dev->dev->id, cpumask);
220 } else {
221 cpumask_set_cpu(cpu_dev->id, cpumask);
222 }
223
224 return 0;
225 }
226 EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);
227