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> | |
d9460fd2 | 33 | #include <linux/sysdev.h> |
1da177e4 LT |
34 | |
35 | #include <asm/uaccess.h> | |
36 | ||
37 | #include <acpi/acpi_bus.h> | |
38 | #include <acpi/processor.h> | |
39 | #include <acpi/acpi_drivers.h> | |
40 | ||
a192a958 LB |
41 | #define PREFIX "ACPI: " |
42 | ||
1da177e4 | 43 | #define ACPI_PROCESSOR_CLASS "processor" |
1da177e4 | 44 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT |
f52fd66d | 45 | ACPI_MODULE_NAME("processor_thermal"); |
1da177e4 | 46 | |
1da177e4 LT |
47 | #ifdef CONFIG_CPU_FREQ |
48 | ||
49 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it | |
50 | * offers (in most cases) voltage scaling in addition to frequency scaling, and | |
51 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for | |
52 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. | |
53 | */ | |
54 | ||
d9460fd2 ZR |
55 | #define CPUFREQ_THERMAL_MIN_STEP 0 |
56 | #define CPUFREQ_THERMAL_MAX_STEP 3 | |
57 | ||
c938ac21 | 58 | static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg); |
1da177e4 LT |
59 | static unsigned int acpi_thermal_cpufreq_is_init = 0; |
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 * | |
80 | (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20) | |
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 | ||
c938ac21 | 106 | return per_cpu(cpufreq_thermal_reduction_pctg, cpu); |
d9460fd2 ZR |
107 | } |
108 | ||
109 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
110 | { | |
111 | if (!cpu_has_cpufreq(cpu)) | |
112 | return 0; | |
113 | ||
c938ac21 | 114 | per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state; |
d9460fd2 ZR |
115 | cpufreq_update_policy(cpu); |
116 | return 0; | |
117 | } | |
118 | ||
4be44fcd LB |
119 | void acpi_thermal_cpufreq_init(void) |
120 | { | |
1da177e4 LT |
121 | int i; |
122 | ||
c938ac21 MT |
123 | for (i = 0; i < nr_cpu_ids; i++) |
124 | if (cpu_present(i)) | |
125 | per_cpu(cpufreq_thermal_reduction_pctg, i) = 0; | |
1da177e4 | 126 | |
4be44fcd LB |
127 | i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block, |
128 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
129 | if (!i) |
130 | acpi_thermal_cpufreq_is_init = 1; | |
131 | } | |
132 | ||
4be44fcd LB |
133 | void acpi_thermal_cpufreq_exit(void) |
134 | { | |
1da177e4 | 135 | if (acpi_thermal_cpufreq_is_init) |
4be44fcd LB |
136 | cpufreq_unregister_notifier |
137 | (&acpi_thermal_cpufreq_notifier_block, | |
138 | CPUFREQ_POLICY_NOTIFIER); | |
1da177e4 LT |
139 | |
140 | acpi_thermal_cpufreq_is_init = 0; | |
141 | } | |
142 | ||
4be44fcd | 143 | #else /* ! CONFIG_CPU_FREQ */ |
d9460fd2 ZR |
144 | static int cpufreq_get_max_state(unsigned int cpu) |
145 | { | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static int cpufreq_get_cur_state(unsigned int cpu) | |
150 | { | |
151 | return 0; | |
152 | } | |
153 | ||
154 | static int cpufreq_set_cur_state(unsigned int cpu, int state) | |
155 | { | |
156 | return 0; | |
157 | } | |
1da177e4 | 158 | |
1da177e4 LT |
159 | #endif |
160 | ||
4be44fcd | 161 | int acpi_processor_get_limit_info(struct acpi_processor *pr) |
1da177e4 | 162 | { |
1da177e4 LT |
163 | |
164 | if (!pr) | |
d550d98d | 165 | return -EINVAL; |
1da177e4 LT |
166 | |
167 | if (pr->flags.throttling) | |
168 | pr->flags.limit = 1; | |
169 | ||
d550d98d | 170 | return 0; |
1da177e4 LT |
171 | } |
172 | ||
d9460fd2 ZR |
173 | /* thermal coolign device callbacks */ |
174 | static int acpi_processor_max_state(struct acpi_processor *pr) | |
175 | { | |
176 | int max_state = 0; | |
177 | ||
178 | /* | |
179 | * There exists four states according to | |
180 | * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3 | |
181 | */ | |
182 | max_state += cpufreq_get_max_state(pr->id); | |
183 | if (pr->flags.throttling) | |
184 | max_state += (pr->throttling.state_count -1); | |
185 | ||
186 | return max_state; | |
187 | } | |
188 | static int | |
6503e5df MG |
189 | processor_get_max_state(struct thermal_cooling_device *cdev, |
190 | unsigned long *state) | |
d9460fd2 ZR |
191 | { |
192 | struct acpi_device *device = cdev->devdata; | |
193 | struct acpi_processor *pr = acpi_driver_data(device); | |
194 | ||
195 | if (!device || !pr) | |
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; | |
207 | struct acpi_processor *pr = acpi_driver_data(device); | |
d9460fd2 ZR |
208 | |
209 | if (!device || !pr) | |
210 | return -EINVAL; | |
211 | ||
6503e5df | 212 | *cur_state = cpufreq_get_cur_state(pr->id); |
d9460fd2 | 213 | if (pr->flags.throttling) |
6503e5df MG |
214 | *cur_state += pr->throttling.state; |
215 | return 0; | |
d9460fd2 ZR |
216 | } |
217 | ||
218 | static int | |
6503e5df MG |
219 | processor_set_cur_state(struct thermal_cooling_device *cdev, |
220 | unsigned long state) | |
d9460fd2 ZR |
221 | { |
222 | struct acpi_device *device = cdev->devdata; | |
223 | struct acpi_processor *pr = acpi_driver_data(device); | |
224 | int result = 0; | |
225 | int max_pstate; | |
226 | ||
227 | if (!device || !pr) | |
228 | return -EINVAL; | |
229 | ||
230 | max_pstate = cpufreq_get_max_state(pr->id); | |
231 | ||
232 | if (state > acpi_processor_max_state(pr)) | |
233 | return -EINVAL; | |
234 | ||
235 | if (state <= max_pstate) { | |
236 | if (pr->flags.throttling && pr->throttling.state) | |
2a908002 | 237 | result = acpi_processor_set_throttling(pr, 0, false); |
d9460fd2 ZR |
238 | cpufreq_set_cur_state(pr->id, state); |
239 | } else { | |
240 | cpufreq_set_cur_state(pr->id, max_pstate); | |
241 | result = acpi_processor_set_throttling(pr, | |
2a908002 | 242 | state - max_pstate, false); |
d9460fd2 ZR |
243 | } |
244 | return result; | |
245 | } | |
246 | ||
9c8b04be | 247 | const struct thermal_cooling_device_ops processor_cooling_ops = { |
d9460fd2 ZR |
248 | .get_max_state = processor_get_max_state, |
249 | .get_cur_state = processor_get_cur_state, | |
250 | .set_cur_state = processor_set_cur_state, | |
251 | }; |