Root/
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> |
33 | |
34 | #include <asm/uaccess.h> |
35 | |
36 | #include <acpi/acpi_bus.h> |
37 | #include <acpi/processor.h> |
38 | #include <acpi/acpi_drivers.h> |
39 | |
40 | #define PREFIX "ACPI: " |
41 | |
42 | #define ACPI_PROCESSOR_CLASS "processor" |
43 | #define _COMPONENT ACPI_PROCESSOR_COMPONENT |
44 | ACPI_MODULE_NAME("processor_thermal"); |
45 | |
46 | #ifdef CONFIG_CPU_FREQ |
47 | |
48 | /* If a passive cooling situation is detected, primarily CPUfreq is used, as it |
49 | * offers (in most cases) voltage scaling in addition to frequency scaling, and |
50 | * thus a cubic (instead of linear) reduction of energy. Also, we allow for |
51 | * _any_ cpufreq driver and not only the acpi-cpufreq driver. |
52 | */ |
53 | |
54 | #define CPUFREQ_THERMAL_MIN_STEP 0 |
55 | #define CPUFREQ_THERMAL_MAX_STEP 3 |
56 | |
57 | static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg); |
58 | static unsigned int acpi_thermal_cpufreq_is_init = 0; |
59 | |
60 | #define reduction_pctg(cpu) \ |
61 | per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu)) |
62 | |
63 | /* |
64 | * Emulate "per package data" using per cpu data (which should really be |
65 | * provided elsewhere) |
66 | * |
67 | * Note we can lose a CPU on cpu hotunplug, in this case we forget the state |
68 | * temporarily. Fortunately that's not a big issue here (I hope) |
69 | */ |
70 | static int phys_package_first_cpu(int cpu) |
71 | { |
72 | int i; |
73 | int id = topology_physical_package_id(cpu); |
74 | |
75 | for_each_online_cpu(i) |
76 | if (topology_physical_package_id(i) == id) |
77 | return i; |
78 | return 0; |
79 | } |
80 | |
81 | static int cpu_has_cpufreq(unsigned int cpu) |
82 | { |
83 | struct cpufreq_policy policy; |
84 | if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu)) |
85 | return 0; |
86 | return 1; |
87 | } |
88 | |
89 | static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb, |
90 | unsigned long event, void *data) |
91 | { |
92 | struct cpufreq_policy *policy = data; |
93 | unsigned long max_freq = 0; |
94 | |
95 | if (event != CPUFREQ_ADJUST) |
96 | goto out; |
97 | |
98 | max_freq = ( |
99 | policy->cpuinfo.max_freq * |
100 | (100 - reduction_pctg(policy->cpu) * 20) |
101 | ) / 100; |
102 | |
103 | cpufreq_verify_within_limits(policy, 0, max_freq); |
104 | |
105 | out: |
106 | return 0; |
107 | } |
108 | |
109 | static struct notifier_block acpi_thermal_cpufreq_notifier_block = { |
110 | .notifier_call = acpi_thermal_cpufreq_notifier, |
111 | }; |
112 | |
113 | static int cpufreq_get_max_state(unsigned int cpu) |
114 | { |
115 | if (!cpu_has_cpufreq(cpu)) |
116 | return 0; |
117 | |
118 | return CPUFREQ_THERMAL_MAX_STEP; |
119 | } |
120 | |
121 | static int cpufreq_get_cur_state(unsigned int cpu) |
122 | { |
123 | if (!cpu_has_cpufreq(cpu)) |
124 | return 0; |
125 | |
126 | return reduction_pctg(cpu); |
127 | } |
128 | |
129 | static int cpufreq_set_cur_state(unsigned int cpu, int state) |
130 | { |
131 | int i; |
132 | |
133 | if (!cpu_has_cpufreq(cpu)) |
134 | return 0; |
135 | |
136 | reduction_pctg(cpu) = state; |
137 | |
138 | /* |
139 | * Update all the CPUs in the same package because they all |
140 | * contribute to the temperature and often share the same |
141 | * frequency. |
142 | */ |
143 | for_each_online_cpu(i) { |
144 | if (topology_physical_package_id(i) == |
145 | topology_physical_package_id(cpu)) |
146 | cpufreq_update_policy(i); |
147 | } |
148 | return 0; |
149 | } |
150 | |
151 | void acpi_thermal_cpufreq_init(void) |
152 | { |
153 | int i; |
154 | |
155 | i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block, |
156 | CPUFREQ_POLICY_NOTIFIER); |
157 | if (!i) |
158 | acpi_thermal_cpufreq_is_init = 1; |
159 | } |
160 | |
161 | void acpi_thermal_cpufreq_exit(void) |
162 | { |
163 | if (acpi_thermal_cpufreq_is_init) |
164 | cpufreq_unregister_notifier |
165 | (&acpi_thermal_cpufreq_notifier_block, |
166 | CPUFREQ_POLICY_NOTIFIER); |
167 | |
168 | acpi_thermal_cpufreq_is_init = 0; |
169 | } |
170 | |
171 | #else /* ! CONFIG_CPU_FREQ */ |
172 | static int cpufreq_get_max_state(unsigned int cpu) |
173 | { |
174 | return 0; |
175 | } |
176 | |
177 | static int cpufreq_get_cur_state(unsigned int cpu) |
178 | { |
179 | return 0; |
180 | } |
181 | |
182 | static int cpufreq_set_cur_state(unsigned int cpu, int state) |
183 | { |
184 | return 0; |
185 | } |
186 | |
187 | #endif |
188 | |
189 | int acpi_processor_get_limit_info(struct acpi_processor *pr) |
190 | { |
191 | |
192 | if (!pr) |
193 | return -EINVAL; |
194 | |
195 | if (pr->flags.throttling) |
196 | pr->flags.limit = 1; |
197 | |
198 | return 0; |
199 | } |
200 | |
201 | /* thermal coolign device callbacks */ |
202 | static int acpi_processor_max_state(struct acpi_processor *pr) |
203 | { |
204 | int max_state = 0; |
205 | |
206 | /* |
207 | * There exists four states according to |
208 | * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3 |
209 | */ |
210 | max_state += cpufreq_get_max_state(pr->id); |
211 | if (pr->flags.throttling) |
212 | max_state += (pr->throttling.state_count -1); |
213 | |
214 | return max_state; |
215 | } |
216 | static int |
217 | processor_get_max_state(struct thermal_cooling_device *cdev, |
218 | unsigned long *state) |
219 | { |
220 | struct acpi_device *device = cdev->devdata; |
221 | struct acpi_processor *pr = acpi_driver_data(device); |
222 | |
223 | if (!device || !pr) |
224 | return -EINVAL; |
225 | |
226 | *state = acpi_processor_max_state(pr); |
227 | return 0; |
228 | } |
229 | |
230 | static int |
231 | processor_get_cur_state(struct thermal_cooling_device *cdev, |
232 | unsigned long *cur_state) |
233 | { |
234 | struct acpi_device *device = cdev->devdata; |
235 | struct acpi_processor *pr = acpi_driver_data(device); |
236 | |
237 | if (!device || !pr) |
238 | return -EINVAL; |
239 | |
240 | *cur_state = cpufreq_get_cur_state(pr->id); |
241 | if (pr->flags.throttling) |
242 | *cur_state += pr->throttling.state; |
243 | return 0; |
244 | } |
245 | |
246 | static int |
247 | processor_set_cur_state(struct thermal_cooling_device *cdev, |
248 | unsigned long state) |
249 | { |
250 | struct acpi_device *device = cdev->devdata; |
251 | struct acpi_processor *pr = acpi_driver_data(device); |
252 | int result = 0; |
253 | int max_pstate; |
254 | |
255 | if (!device || !pr) |
256 | return -EINVAL; |
257 | |
258 | max_pstate = cpufreq_get_max_state(pr->id); |
259 | |
260 | if (state > acpi_processor_max_state(pr)) |
261 | return -EINVAL; |
262 | |
263 | if (state <= max_pstate) { |
264 | if (pr->flags.throttling && pr->throttling.state) |
265 | result = acpi_processor_set_throttling(pr, 0, false); |
266 | cpufreq_set_cur_state(pr->id, state); |
267 | } else { |
268 | cpufreq_set_cur_state(pr->id, max_pstate); |
269 | result = acpi_processor_set_throttling(pr, |
270 | state - max_pstate, false); |
271 | } |
272 | return result; |
273 | } |
274 | |
275 | const struct thermal_cooling_device_ops processor_cooling_ops = { |
276 | .get_max_state = processor_get_max_state, |
277 | .get_cur_state = processor_get_cur_state, |
278 | .set_cur_state = processor_set_cur_state, |
279 | }; |
280 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9