Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * processor_thermal.c - Passive cooling submodule of the ACPI processor driver | |
4 | * | |
5 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | |
6 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | |
7 | * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> | |
8 | * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> | |
9 | * - Added processor hotplug support | |
1da177e4 LT |
10 | */ |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/cpufreq.h> | |
8b48463f | 16 | #include <linux/acpi.h> |
1da177e4 | 17 | #include <acpi/processor.h> |
7c0f6ba6 | 18 | #include <linux/uaccess.h> |
1da177e4 | 19 | |
a192a958 LB |
20 | #define PREFIX "ACPI: " |
21 | ||
1da177e4 | 22 | #define ACPI_PROCESSOR_CLASS "processor" |
1da177e4 | 23 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT |
f52fd66d | 24 | ACPI_MODULE_NAME("processor_thermal"); |
1da177e4 | 25 | |
1da177e4 LT |
26 | #ifdef CONFIG_CPU_FREQ |
27 | ||
28 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it | |
29 | * offers (in most cases) voltage scaling in addition to frequency scaling, and | |
30 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for | |
31 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. | |
32 | */ | |
33 | ||
d9460fd2 ZR |
34 | #define CPUFREQ_THERMAL_MIN_STEP 0 |
35 | #define CPUFREQ_THERMAL_MAX_STEP 3 | |
36 | ||
c938ac21 | 37 | static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg); |
1da177e4 LT |
38 | static unsigned int acpi_thermal_cpufreq_is_init = 0; |
39 | ||
2815ab92 AK |
40 | #define reduction_pctg(cpu) \ |
41 | per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu)) | |
42 | ||
43 | /* | |
44 | * Emulate "per package data" using per cpu data (which should really be | |
45 | * provided elsewhere) | |
46 | * | |
47 | * Note we can lose a CPU on cpu hotunplug, in this case we forget the state | |
48 | * temporarily. Fortunately that's not a big issue here (I hope) | |
49 | */ | |
50 | static int phys_package_first_cpu(int cpu) | |
51 | { | |
52 | int i; | |
53 | int id = topology_physical_package_id(cpu); | |
54 | ||
55 | for_each_online_cpu(i) | |
56 | if (topology_physical_package_id(i) == id) | |
57 | return i; | |
58 | return 0; | |
59 | } | |
60 | ||
1da177e4 LT |
61 | static int cpu_has_cpufreq(unsigned int cpu) |
62 | { | |
63 | struct cpufreq_policy policy; | |
1cbf4c56 | 64 | if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu)) |
75b245b3 TR |
65 | return 0; |
66 | return 1; | |
1da177e4 LT |
67 | } |
68 | ||
4be44fcd LB |
69 | static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb, |
70 | unsigned long event, void *data) | |
1da177e4 LT |
71 | { |
72 | struct cpufreq_policy *policy = data; | |
73 | unsigned long max_freq = 0; | |
74 | ||
75 | if (event != CPUFREQ_ADJUST) | |
76 | goto out; | |
77 | ||
c938ac21 MT |
78 | max_freq = ( |
79 | policy->cpuinfo.max_freq * | |
2815ab92 | 80 | (100 - reduction_pctg(policy->cpu) * 20) |
c938ac21 | 81 | ) / 100; |
1da177e4 LT |
82 | |
83 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
84 | ||
4be44fcd | 85 | out: |
1da177e4 LT |
86 | return 0; |
87 | } | |
88 | ||
1da177e4 LT |
89 | static struct notifier_block acpi_thermal_cpufreq_notifier_block = { |
90 | .notifier_call = acpi_thermal_cpufreq_notifier, | |
91 | }; | |
92 | ||
d9460fd2 ZR |
93 | static int cpufreq_get_max_state(unsigned int cpu) |
94 | { | |
95 | if (!cpu_has_cpufreq(cpu)) | |
96 | return 0; | |
97 | ||
98 | return CPUFREQ_THERMAL_MAX_STEP; | |
99 | } | |
100 | ||
101 | static int cpufreq_get_cur_state(unsigned int cpu) | |
102 | { | |
103 | if (!cpu_has_cpufreq(cpu)) | |
104 | return 0; | |
105 | ||
2815ab92 | 106 | return reduction_pctg(cpu); |
d9460fd2 ZR |
107 | } |
108 | ||
109 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
110 | { | |
2815ab92 AK |
111 | int i; |
112 | ||
d9460fd2 ZR |
113 | if (!cpu_has_cpufreq(cpu)) |
114 | return 0; | |
115 | ||
2815ab92 AK |
116 | reduction_pctg(cpu) = state; |
117 | ||
118 | /* | |
119 | * Update all the CPUs in the same package because they all | |
120 | * contribute to the temperature and often share the same | |
121 | * frequency. | |
122 | */ | |
123 | for_each_online_cpu(i) { | |
124 | if (topology_physical_package_id(i) == | |
125 | topology_physical_package_id(cpu)) | |
126 | cpufreq_update_policy(i); | |
127 | } | |
d9460fd2 ZR |
128 | return 0; |
129 | } | |
130 | ||
4be44fcd LB |
131 | void acpi_thermal_cpufreq_init(void) |
132 | { | |
1da177e4 LT |
133 | int i; |
134 | ||
4be44fcd LB |
135 | i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block, |
136 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
137 | if (!i) |
138 | acpi_thermal_cpufreq_is_init = 1; | |
139 | } | |
140 | ||
4be44fcd LB |
141 | void acpi_thermal_cpufreq_exit(void) |
142 | { | |
1da177e4 | 143 | if (acpi_thermal_cpufreq_is_init) |
4be44fcd LB |
144 | cpufreq_unregister_notifier |
145 | (&acpi_thermal_cpufreq_notifier_block, | |
146 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
147 | |
148 | acpi_thermal_cpufreq_is_init = 0; | |
149 | } | |
150 | ||
4be44fcd | 151 | #else /* ! CONFIG_CPU_FREQ */ |
d9460fd2 ZR |
152 | static int cpufreq_get_max_state(unsigned int cpu) |
153 | { | |
154 | return 0; | |
155 | } | |
156 | ||
157 | static int cpufreq_get_cur_state(unsigned int cpu) | |
158 | { | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
163 | { | |
164 | return 0; | |
165 | } | |
1da177e4 | 166 | |
1da177e4 LT |
167 | #endif |
168 | ||
6dd7aca8 | 169 | /* thermal cooling device callbacks */ |
d9460fd2 ZR |
170 | static int acpi_processor_max_state(struct acpi_processor *pr) |
171 | { | |
172 | int max_state = 0; | |
173 | ||
174 | /* | |
175 | * There exists four states according to | |
6dd7aca8 | 176 | * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3 |
d9460fd2 ZR |
177 | */ |
178 | max_state += cpufreq_get_max_state(pr->id); | |
179 | if (pr->flags.throttling) | |
180 | max_state += (pr->throttling.state_count -1); | |
181 | ||
182 | return max_state; | |
183 | } | |
184 | static int | |
6503e5df MG |
185 | processor_get_max_state(struct thermal_cooling_device *cdev, |
186 | unsigned long *state) | |
d9460fd2 ZR |
187 | { |
188 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 189 | struct acpi_processor *pr; |
d9460fd2 | 190 | |
99aa3638 CIK |
191 | if (!device) |
192 | return -EINVAL; | |
193 | ||
194 | pr = acpi_driver_data(device); | |
195 | if (!pr) | |
d9460fd2 ZR |
196 | return -EINVAL; |
197 | ||
6503e5df MG |
198 | *state = acpi_processor_max_state(pr); |
199 | return 0; | |
d9460fd2 ZR |
200 | } |
201 | ||
202 | static int | |
6503e5df MG |
203 | processor_get_cur_state(struct thermal_cooling_device *cdev, |
204 | unsigned long *cur_state) | |
d9460fd2 ZR |
205 | { |
206 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 207 | struct acpi_processor *pr; |
d9460fd2 | 208 | |
99aa3638 CIK |
209 | if (!device) |
210 | return -EINVAL; | |
211 | ||
212 | pr = acpi_driver_data(device); | |
213 | if (!pr) | |
d9460fd2 ZR |
214 | return -EINVAL; |
215 | ||
6503e5df | 216 | *cur_state = cpufreq_get_cur_state(pr->id); |
d9460fd2 | 217 | if (pr->flags.throttling) |
6503e5df MG |
218 | *cur_state += pr->throttling.state; |
219 | return 0; | |
d9460fd2 ZR |
220 | } |
221 | ||
222 | static int | |
6503e5df MG |
223 | processor_set_cur_state(struct thermal_cooling_device *cdev, |
224 | unsigned long state) | |
d9460fd2 ZR |
225 | { |
226 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 227 | struct acpi_processor *pr; |
d9460fd2 ZR |
228 | int result = 0; |
229 | int max_pstate; | |
230 | ||
99aa3638 CIK |
231 | if (!device) |
232 | return -EINVAL; | |
233 | ||
234 | pr = acpi_driver_data(device); | |
235 | if (!pr) | |
d9460fd2 ZR |
236 | return -EINVAL; |
237 | ||
238 | max_pstate = cpufreq_get_max_state(pr->id); | |
239 | ||
240 | if (state > acpi_processor_max_state(pr)) | |
241 | return -EINVAL; | |
242 | ||
243 | if (state <= max_pstate) { | |
244 | if (pr->flags.throttling && pr->throttling.state) | |
2a908002 | 245 | result = acpi_processor_set_throttling(pr, 0, false); |
d9460fd2 ZR |
246 | cpufreq_set_cur_state(pr->id, state); |
247 | } else { | |
248 | cpufreq_set_cur_state(pr->id, max_pstate); | |
249 | result = acpi_processor_set_throttling(pr, | |
2a908002 | 250 | state - max_pstate, false); |
d9460fd2 ZR |
251 | } |
252 | return result; | |
253 | } | |
254 | ||
9c8b04be | 255 | const struct thermal_cooling_device_ops processor_cooling_ops = { |
d9460fd2 ZR |
256 | .get_max_state = processor_get_max_state, |
257 | .get_cur_state = processor_get_cur_state, | |
258 | .set_cur_state = processor_set_cur_state, | |
259 | }; |