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5477fb3b AC |
1 | /* |
2 | * CPPC (Collaborative Processor Performance Control) driver for | |
3 | * interfacing with the CPUfreq layer and governors. See | |
4 | * cppc_acpi.c for CPPC specific methods. | |
5 | * | |
6 | * (C) Copyright 2014, 2015 Linaro Ltd. | |
7 | * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; version 2 | |
12 | * of the License. | |
13 | */ | |
14 | ||
15 | #define pr_fmt(fmt) "CPPC Cpufreq:" fmt | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/cpufreq.h> | |
22 | #include <linux/vmalloc.h> | |
23 | ||
24 | #include <acpi/cppc_acpi.h> | |
25 | ||
26 | /* | |
27 | * These structs contain information parsed from per CPU | |
28 | * ACPI _CPC structures. | |
29 | * e.g. For each CPU the highest, lowest supported | |
30 | * performance capabilities, desired performance level | |
31 | * requested etc. | |
32 | */ | |
33 | static struct cpudata **all_cpu_data; | |
34 | ||
35 | static int cppc_cpufreq_set_target(struct cpufreq_policy *policy, | |
36 | unsigned int target_freq, | |
37 | unsigned int relation) | |
38 | { | |
39 | struct cpudata *cpu; | |
40 | struct cpufreq_freqs freqs; | |
41 | int ret = 0; | |
42 | ||
43 | cpu = all_cpu_data[policy->cpu]; | |
44 | ||
45 | cpu->perf_ctrls.desired_perf = target_freq; | |
46 | freqs.old = policy->cur; | |
47 | freqs.new = target_freq; | |
48 | ||
49 | cpufreq_freq_transition_begin(policy, &freqs); | |
50 | ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls); | |
51 | cpufreq_freq_transition_end(policy, &freqs, ret != 0); | |
52 | ||
53 | if (ret) | |
54 | pr_debug("Failed to set target on CPU:%d. ret:%d\n", | |
55 | cpu->cpu, ret); | |
56 | ||
57 | return ret; | |
58 | } | |
59 | ||
60 | static int cppc_verify_policy(struct cpufreq_policy *policy) | |
61 | { | |
62 | cpufreq_verify_within_cpu_limits(policy); | |
63 | return 0; | |
64 | } | |
65 | ||
66 | static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy) | |
67 | { | |
68 | int cpu_num = policy->cpu; | |
69 | struct cpudata *cpu = all_cpu_data[cpu_num]; | |
70 | int ret; | |
71 | ||
72 | cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf; | |
73 | ||
74 | ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls); | |
75 | if (ret) | |
76 | pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", | |
77 | cpu->perf_caps.lowest_perf, cpu_num, ret); | |
78 | } | |
79 | ||
80 | static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
81 | { | |
82 | struct cpudata *cpu; | |
83 | unsigned int cpu_num = policy->cpu; | |
84 | int ret = 0; | |
85 | ||
86 | cpu = all_cpu_data[policy->cpu]; | |
87 | ||
88 | cpu->cpu = cpu_num; | |
89 | ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps); | |
90 | ||
91 | if (ret) { | |
92 | pr_debug("Err reading CPU%d perf capabilities. ret:%d\n", | |
93 | cpu_num, ret); | |
94 | return ret; | |
95 | } | |
96 | ||
97 | policy->min = cpu->perf_caps.lowest_perf; | |
98 | policy->max = cpu->perf_caps.highest_perf; | |
99 | policy->cpuinfo.min_freq = policy->min; | |
100 | policy->cpuinfo.max_freq = policy->max; | |
9dc17917 | 101 | policy->shared_type = cpu->shared_type; |
5477fb3b AC |
102 | |
103 | if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) | |
104 | cpumask_copy(policy->cpus, cpu->shared_cpu_map); | |
9dc17917 | 105 | else if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL) { |
5477fb3b AC |
106 | /* Support only SW_ANY for now. */ |
107 | pr_debug("Unsupported CPU co-ord type\n"); | |
108 | return -EFAULT; | |
109 | } | |
110 | ||
111 | cpumask_set_cpu(policy->cpu, policy->cpus); | |
112 | cpu->cur_policy = policy; | |
113 | ||
114 | /* Set policy->cur to max now. The governors will adjust later. */ | |
115 | policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf; | |
116 | ||
117 | ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls); | |
118 | if (ret) | |
119 | pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n", | |
120 | cpu->perf_caps.highest_perf, cpu_num, ret); | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
125 | static struct cpufreq_driver cppc_cpufreq_driver = { | |
126 | .flags = CPUFREQ_CONST_LOOPS, | |
127 | .verify = cppc_verify_policy, | |
128 | .target = cppc_cpufreq_set_target, | |
129 | .init = cppc_cpufreq_cpu_init, | |
130 | .stop_cpu = cppc_cpufreq_stop_cpu, | |
131 | .name = "cppc_cpufreq", | |
132 | }; | |
133 | ||
134 | static int __init cppc_cpufreq_init(void) | |
135 | { | |
136 | int i, ret = 0; | |
137 | struct cpudata *cpu; | |
138 | ||
139 | if (acpi_disabled) | |
140 | return -ENODEV; | |
141 | ||
142 | all_cpu_data = kzalloc(sizeof(void *) * num_possible_cpus(), GFP_KERNEL); | |
143 | if (!all_cpu_data) | |
144 | return -ENOMEM; | |
145 | ||
146 | for_each_possible_cpu(i) { | |
147 | all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL); | |
148 | if (!all_cpu_data[i]) | |
149 | goto out; | |
150 | ||
151 | cpu = all_cpu_data[i]; | |
152 | if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL)) | |
153 | goto out; | |
154 | } | |
155 | ||
156 | ret = acpi_get_psd_map(all_cpu_data); | |
157 | if (ret) { | |
158 | pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n"); | |
159 | goto out; | |
160 | } | |
161 | ||
162 | ret = cpufreq_register_driver(&cppc_cpufreq_driver); | |
163 | if (ret) | |
164 | goto out; | |
165 | ||
166 | return ret; | |
167 | ||
168 | out: | |
169 | for_each_possible_cpu(i) | |
efb2d3be | 170 | kfree(all_cpu_data[i]); |
5477fb3b AC |
171 | |
172 | kfree(all_cpu_data); | |
173 | return -ENODEV; | |
174 | } | |
175 | ||
a29a1e76 AC |
176 | static void __exit cppc_cpufreq_exit(void) |
177 | { | |
178 | struct cpudata *cpu; | |
179 | int i; | |
180 | ||
181 | cpufreq_unregister_driver(&cppc_cpufreq_driver); | |
182 | ||
183 | for_each_possible_cpu(i) { | |
184 | cpu = all_cpu_data[i]; | |
185 | free_cpumask_var(cpu->shared_cpu_map); | |
186 | kfree(cpu); | |
187 | } | |
188 | ||
189 | kfree(all_cpu_data); | |
190 | } | |
191 | ||
192 | module_exit(cppc_cpufreq_exit); | |
193 | MODULE_AUTHOR("Ashwin Chaugule"); | |
194 | MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec"); | |
195 | MODULE_LICENSE("GPL"); | |
196 | ||
5477fb3b | 197 | late_initcall(cppc_cpufreq_init); |