Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * processor_thermal.c - Passive cooling submodule of the ACPI processor driver | |
3 | * | |
4 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | |
5 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | |
6 | * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> | |
7 | * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> | |
8 | * - Added processor hotplug support | |
9 | * | |
10 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or (at | |
15 | * your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with this program; if not, write to the Free Software Foundation, Inc., | |
24 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
25 | * | |
26 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
27 | */ | |
28 | ||
29 | #include <linux/kernel.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/cpufreq.h> | |
8b48463f | 33 | #include <linux/acpi.h> |
1da177e4 | 34 | #include <acpi/processor.h> |
8b48463f | 35 | #include <asm/uaccess.h> |
1da177e4 | 36 | |
a192a958 LB |
37 | #define PREFIX "ACPI: " |
38 | ||
1da177e4 | 39 | #define ACPI_PROCESSOR_CLASS "processor" |
1da177e4 | 40 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT |
f52fd66d | 41 | ACPI_MODULE_NAME("processor_thermal"); |
1da177e4 | 42 | |
1da177e4 LT |
43 | #ifdef CONFIG_CPU_FREQ |
44 | ||
45 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it | |
46 | * offers (in most cases) voltage scaling in addition to frequency scaling, and | |
47 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for | |
48 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. | |
49 | */ | |
50 | ||
d9460fd2 ZR |
51 | #define CPUFREQ_THERMAL_MIN_STEP 0 |
52 | #define CPUFREQ_THERMAL_MAX_STEP 3 | |
53 | ||
c938ac21 | 54 | static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg); |
1da177e4 LT |
55 | static unsigned int acpi_thermal_cpufreq_is_init = 0; |
56 | ||
2815ab92 AK |
57 | #define reduction_pctg(cpu) \ |
58 | per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu)) | |
59 | ||
60 | /* | |
61 | * Emulate "per package data" using per cpu data (which should really be | |
62 | * provided elsewhere) | |
63 | * | |
64 | * Note we can lose a CPU on cpu hotunplug, in this case we forget the state | |
65 | * temporarily. Fortunately that's not a big issue here (I hope) | |
66 | */ | |
67 | static int phys_package_first_cpu(int cpu) | |
68 | { | |
69 | int i; | |
70 | int id = topology_physical_package_id(cpu); | |
71 | ||
72 | for_each_online_cpu(i) | |
73 | if (topology_physical_package_id(i) == id) | |
74 | return i; | |
75 | return 0; | |
76 | } | |
77 | ||
1da177e4 LT |
78 | static int cpu_has_cpufreq(unsigned int cpu) |
79 | { | |
80 | struct cpufreq_policy policy; | |
1cbf4c56 | 81 | if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu)) |
75b245b3 TR |
82 | return 0; |
83 | return 1; | |
1da177e4 LT |
84 | } |
85 | ||
4be44fcd LB |
86 | static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb, |
87 | unsigned long event, void *data) | |
1da177e4 LT |
88 | { |
89 | struct cpufreq_policy *policy = data; | |
90 | unsigned long max_freq = 0; | |
91 | ||
92 | if (event != CPUFREQ_ADJUST) | |
93 | goto out; | |
94 | ||
c938ac21 MT |
95 | max_freq = ( |
96 | policy->cpuinfo.max_freq * | |
2815ab92 | 97 | (100 - reduction_pctg(policy->cpu) * 20) |
c938ac21 | 98 | ) / 100; |
1da177e4 LT |
99 | |
100 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
101 | ||
4be44fcd | 102 | out: |
1da177e4 LT |
103 | return 0; |
104 | } | |
105 | ||
1da177e4 LT |
106 | static struct notifier_block acpi_thermal_cpufreq_notifier_block = { |
107 | .notifier_call = acpi_thermal_cpufreq_notifier, | |
108 | }; | |
109 | ||
d9460fd2 ZR |
110 | static int cpufreq_get_max_state(unsigned int cpu) |
111 | { | |
112 | if (!cpu_has_cpufreq(cpu)) | |
113 | return 0; | |
114 | ||
115 | return CPUFREQ_THERMAL_MAX_STEP; | |
116 | } | |
117 | ||
118 | static int cpufreq_get_cur_state(unsigned int cpu) | |
119 | { | |
120 | if (!cpu_has_cpufreq(cpu)) | |
121 | return 0; | |
122 | ||
2815ab92 | 123 | return reduction_pctg(cpu); |
d9460fd2 ZR |
124 | } |
125 | ||
126 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
127 | { | |
2815ab92 AK |
128 | int i; |
129 | ||
d9460fd2 ZR |
130 | if (!cpu_has_cpufreq(cpu)) |
131 | return 0; | |
132 | ||
2815ab92 AK |
133 | reduction_pctg(cpu) = state; |
134 | ||
135 | /* | |
136 | * Update all the CPUs in the same package because they all | |
137 | * contribute to the temperature and often share the same | |
138 | * frequency. | |
139 | */ | |
140 | for_each_online_cpu(i) { | |
141 | if (topology_physical_package_id(i) == | |
142 | topology_physical_package_id(cpu)) | |
143 | cpufreq_update_policy(i); | |
144 | } | |
d9460fd2 ZR |
145 | return 0; |
146 | } | |
147 | ||
4be44fcd LB |
148 | void acpi_thermal_cpufreq_init(void) |
149 | { | |
1da177e4 LT |
150 | int i; |
151 | ||
4be44fcd LB |
152 | i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block, |
153 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
154 | if (!i) |
155 | acpi_thermal_cpufreq_is_init = 1; | |
156 | } | |
157 | ||
4be44fcd LB |
158 | void acpi_thermal_cpufreq_exit(void) |
159 | { | |
1da177e4 | 160 | if (acpi_thermal_cpufreq_is_init) |
4be44fcd LB |
161 | cpufreq_unregister_notifier |
162 | (&acpi_thermal_cpufreq_notifier_block, | |
163 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
164 | |
165 | acpi_thermal_cpufreq_is_init = 0; | |
166 | } | |
167 | ||
4be44fcd | 168 | #else /* ! CONFIG_CPU_FREQ */ |
d9460fd2 ZR |
169 | static int cpufreq_get_max_state(unsigned int cpu) |
170 | { | |
171 | return 0; | |
172 | } | |
173 | ||
174 | static int cpufreq_get_cur_state(unsigned int cpu) | |
175 | { | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
180 | { | |
181 | return 0; | |
182 | } | |
1da177e4 | 183 | |
1da177e4 LT |
184 | #endif |
185 | ||
6dd7aca8 | 186 | /* thermal cooling device callbacks */ |
d9460fd2 ZR |
187 | static int acpi_processor_max_state(struct acpi_processor *pr) |
188 | { | |
189 | int max_state = 0; | |
190 | ||
191 | /* | |
192 | * There exists four states according to | |
6dd7aca8 | 193 | * cpufreq_thermal_reduction_pctg. 0, 1, 2, 3 |
d9460fd2 ZR |
194 | */ |
195 | max_state += cpufreq_get_max_state(pr->id); | |
196 | if (pr->flags.throttling) | |
197 | max_state += (pr->throttling.state_count -1); | |
198 | ||
199 | return max_state; | |
200 | } | |
201 | static int | |
6503e5df MG |
202 | processor_get_max_state(struct thermal_cooling_device *cdev, |
203 | unsigned long *state) | |
d9460fd2 ZR |
204 | { |
205 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 206 | struct acpi_processor *pr; |
d9460fd2 | 207 | |
99aa3638 CIK |
208 | if (!device) |
209 | return -EINVAL; | |
210 | ||
211 | pr = acpi_driver_data(device); | |
212 | if (!pr) | |
d9460fd2 ZR |
213 | return -EINVAL; |
214 | ||
6503e5df MG |
215 | *state = acpi_processor_max_state(pr); |
216 | return 0; | |
d9460fd2 ZR |
217 | } |
218 | ||
219 | static int | |
6503e5df MG |
220 | processor_get_cur_state(struct thermal_cooling_device *cdev, |
221 | unsigned long *cur_state) | |
d9460fd2 ZR |
222 | { |
223 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 224 | struct acpi_processor *pr; |
d9460fd2 | 225 | |
99aa3638 CIK |
226 | if (!device) |
227 | return -EINVAL; | |
228 | ||
229 | pr = acpi_driver_data(device); | |
230 | if (!pr) | |
d9460fd2 ZR |
231 | return -EINVAL; |
232 | ||
6503e5df | 233 | *cur_state = cpufreq_get_cur_state(pr->id); |
d9460fd2 | 234 | if (pr->flags.throttling) |
6503e5df MG |
235 | *cur_state += pr->throttling.state; |
236 | return 0; | |
d9460fd2 ZR |
237 | } |
238 | ||
239 | static int | |
6503e5df MG |
240 | processor_set_cur_state(struct thermal_cooling_device *cdev, |
241 | unsigned long state) | |
d9460fd2 ZR |
242 | { |
243 | struct acpi_device *device = cdev->devdata; | |
99aa3638 | 244 | struct acpi_processor *pr; |
d9460fd2 ZR |
245 | int result = 0; |
246 | int max_pstate; | |
247 | ||
99aa3638 CIK |
248 | if (!device) |
249 | return -EINVAL; | |
250 | ||
251 | pr = acpi_driver_data(device); | |
252 | if (!pr) | |
d9460fd2 ZR |
253 | return -EINVAL; |
254 | ||
255 | max_pstate = cpufreq_get_max_state(pr->id); | |
256 | ||
257 | if (state > acpi_processor_max_state(pr)) | |
258 | return -EINVAL; | |
259 | ||
260 | if (state <= max_pstate) { | |
261 | if (pr->flags.throttling && pr->throttling.state) | |
2a908002 | 262 | result = acpi_processor_set_throttling(pr, 0, false); |
d9460fd2 ZR |
263 | cpufreq_set_cur_state(pr->id, state); |
264 | } else { | |
265 | cpufreq_set_cur_state(pr->id, max_pstate); | |
266 | result = acpi_processor_set_throttling(pr, | |
2a908002 | 267 | state - max_pstate, false); |
d9460fd2 ZR |
268 | } |
269 | return result; | |
270 | } | |
271 | ||
9c8b04be | 272 | const struct thermal_cooling_device_ops processor_cooling_ops = { |
d9460fd2 ZR |
273 | .get_max_state = processor_get_max_state, |
274 | .get_cur_state = processor_get_cur_state, | |
275 | .set_cur_state = processor_set_cur_state, | |
276 | }; |