ACPI / APEI: fix error return code in ghes_probe()
[linux-3.10.git] / drivers / acpi / processor_thermal.c
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;
222
223         if (!device)
224                 return -EINVAL;
225
226         pr = acpi_driver_data(device);
227         if (!pr)
228                 return -EINVAL;
229
230         *state = acpi_processor_max_state(pr);
231         return 0;
232 }
233
234 static int
235 processor_get_cur_state(struct thermal_cooling_device *cdev,
236                         unsigned long *cur_state)
237 {
238         struct acpi_device *device = cdev->devdata;
239         struct acpi_processor *pr;
240
241         if (!device)
242                 return -EINVAL;
243
244         pr = acpi_driver_data(device);
245         if (!pr)
246                 return -EINVAL;
247
248         *cur_state = cpufreq_get_cur_state(pr->id);
249         if (pr->flags.throttling)
250                 *cur_state += pr->throttling.state;
251         return 0;
252 }
253
254 static int
255 processor_set_cur_state(struct thermal_cooling_device *cdev,
256                         unsigned long state)
257 {
258         struct acpi_device *device = cdev->devdata;
259         struct acpi_processor *pr;
260         int result = 0;
261         int max_pstate;
262
263         if (!device)
264                 return -EINVAL;
265
266         pr = acpi_driver_data(device);
267         if (!pr)
268                 return -EINVAL;
269
270         max_pstate = cpufreq_get_max_state(pr->id);
271
272         if (state > acpi_processor_max_state(pr))
273                 return -EINVAL;
274
275         if (state <= max_pstate) {
276                 if (pr->flags.throttling && pr->throttling.state)
277                         result = acpi_processor_set_throttling(pr, 0, false);
278                 cpufreq_set_cur_state(pr->id, state);
279         } else {
280                 cpufreq_set_cur_state(pr->id, max_pstate);
281                 result = acpi_processor_set_throttling(pr,
282                                 state - max_pstate, false);
283         }
284         return result;
285 }
286
287 const struct thermal_cooling_device_ops processor_cooling_ops = {
288         .get_max_state = processor_get_max_state,
289         .get_cur_state = processor_get_cur_state,
290         .set_cur_state = processor_set_cur_state,
291 };