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 | |