ACPI: delete extra #defines in /drivers/acpi/ drivers
[linux-2.6.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 #include <linux/proc_fs.h>
34 #include <linux/seq_file.h>
35
36 #include <asm/uaccess.h>
37
38 #include <acpi/acpi_bus.h>
39 #include <acpi/processor.h>
40 #include <acpi/acpi_drivers.h>
41
42 #define ACPI_PROCESSOR_COMPONENT        0x01000000
43 #define ACPI_PROCESSOR_CLASS            "processor"
44 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
45 ACPI_MODULE_NAME("processor_thermal");
46
47 /* --------------------------------------------------------------------------
48                                  Limit Interface
49    -------------------------------------------------------------------------- */
50 static int acpi_processor_apply_limit(struct acpi_processor *pr)
51 {
52         int result = 0;
53         u16 px = 0;
54         u16 tx = 0;
55
56
57         if (!pr)
58                 return -EINVAL;
59
60         if (!pr->flags.limit)
61                 return -ENODEV;
62
63         if (pr->flags.throttling) {
64                 if (pr->limit.user.tx > tx)
65                         tx = pr->limit.user.tx;
66                 if (pr->limit.thermal.tx > tx)
67                         tx = pr->limit.thermal.tx;
68
69                 result = acpi_processor_set_throttling(pr, tx);
70                 if (result)
71                         goto end;
72         }
73
74         pr->limit.state.px = px;
75         pr->limit.state.tx = tx;
76
77         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
78                           "Processor [%d] limit set to (P%d:T%d)\n", pr->id,
79                           pr->limit.state.px, pr->limit.state.tx));
80
81       end:
82         if (result)
83                 printk(KERN_ERR PREFIX "Unable to set limit\n");
84
85         return result;
86 }
87
88 #ifdef CONFIG_CPU_FREQ
89
90 /* If a passive cooling situation is detected, primarily CPUfreq is used, as it
91  * offers (in most cases) voltage scaling in addition to frequency scaling, and
92  * thus a cubic (instead of linear) reduction of energy. Also, we allow for
93  * _any_ cpufreq driver and not only the acpi-cpufreq driver.
94  */
95
96 static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
97 static unsigned int acpi_thermal_cpufreq_is_init = 0;
98
99 static int cpu_has_cpufreq(unsigned int cpu)
100 {
101         struct cpufreq_policy policy;
102         if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
103                 return 0;
104         return 1;
105 }
106
107 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
108 {
109         if (!cpu_has_cpufreq(cpu))
110                 return -ENODEV;
111
112         if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
113                 cpufreq_thermal_reduction_pctg[cpu] += 20;
114                 cpufreq_update_policy(cpu);
115                 return 0;
116         }
117
118         return -ERANGE;
119 }
120
121 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
122 {
123         if (!cpu_has_cpufreq(cpu))
124                 return -ENODEV;
125
126         if (cpufreq_thermal_reduction_pctg[cpu] > 20)
127                 cpufreq_thermal_reduction_pctg[cpu] -= 20;
128         else
129                 cpufreq_thermal_reduction_pctg[cpu] = 0;
130         cpufreq_update_policy(cpu);
131         /* We reached max freq again and can leave passive mode */
132         return !cpufreq_thermal_reduction_pctg[cpu];
133 }
134
135 static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
136                                          unsigned long event, void *data)
137 {
138         struct cpufreq_policy *policy = data;
139         unsigned long max_freq = 0;
140
141         if (event != CPUFREQ_ADJUST)
142                 goto out;
143
144         max_freq =
145             (policy->cpuinfo.max_freq *
146              (100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;
147
148         cpufreq_verify_within_limits(policy, 0, max_freq);
149
150       out:
151         return 0;
152 }
153
154 static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
155         .notifier_call = acpi_thermal_cpufreq_notifier,
156 };
157
158 void acpi_thermal_cpufreq_init(void)
159 {
160         int i;
161
162         for (i = 0; i < NR_CPUS; i++)
163                 cpufreq_thermal_reduction_pctg[i] = 0;
164
165         i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
166                                       CPUFREQ_POLICY_NOTIFIER);
167         if (!i)
168                 acpi_thermal_cpufreq_is_init = 1;
169 }
170
171 void acpi_thermal_cpufreq_exit(void)
172 {
173         if (acpi_thermal_cpufreq_is_init)
174                 cpufreq_unregister_notifier
175                     (&acpi_thermal_cpufreq_notifier_block,
176                      CPUFREQ_POLICY_NOTIFIER);
177
178         acpi_thermal_cpufreq_is_init = 0;
179 }
180
181 #else                           /* ! CONFIG_CPU_FREQ */
182
183 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
184 {
185         return -ENODEV;
186 }
187 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
188 {
189         return -ENODEV;
190 }
191
192 #endif
193
194 int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
195 {
196         int result = 0;
197         struct acpi_processor *pr = NULL;
198         struct acpi_device *device = NULL;
199         int tx = 0, max_tx_px = 0;
200
201
202         if ((type < ACPI_PROCESSOR_LIMIT_NONE)
203             || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
204                 return -EINVAL;
205
206         result = acpi_bus_get_device(handle, &device);
207         if (result)
208                 return result;
209
210         pr = acpi_driver_data(device);
211         if (!pr)
212                 return -ENODEV;
213
214         /* Thermal limits are always relative to the current Px/Tx state. */
215         if (pr->flags.throttling)
216                 pr->limit.thermal.tx = pr->throttling.state;
217
218         /*
219          * Our default policy is to only use throttling at the lowest
220          * performance state.
221          */
222
223         tx = pr->limit.thermal.tx;
224
225         switch (type) {
226
227         case ACPI_PROCESSOR_LIMIT_NONE:
228                 do {
229                         result = acpi_thermal_cpufreq_decrease(pr->id);
230                 } while (!result);
231                 tx = 0;
232                 break;
233
234         case ACPI_PROCESSOR_LIMIT_INCREMENT:
235                 /* if going up: P-states first, T-states later */
236
237                 result = acpi_thermal_cpufreq_increase(pr->id);
238                 if (!result)
239                         goto end;
240                 else if (result == -ERANGE)
241                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
242                                           "At maximum performance state\n"));
243
244                 if (pr->flags.throttling) {
245                         if (tx == (pr->throttling.state_count - 1))
246                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
247                                                   "At maximum throttling state\n"));
248                         else
249                                 tx++;
250                 }
251                 break;
252
253         case ACPI_PROCESSOR_LIMIT_DECREMENT:
254                 /* if going down: T-states first, P-states later */
255
256                 if (pr->flags.throttling) {
257                         if (tx == 0) {
258                                 max_tx_px = 1;
259                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
260                                                   "At minimum throttling state\n"));
261                         } else {
262                                 tx--;
263                                 goto end;
264                         }
265                 }
266
267                 result = acpi_thermal_cpufreq_decrease(pr->id);
268                 if (result) {
269                         /*
270                          * We only could get -ERANGE, 1 or 0.
271                          * In the first two cases we reached max freq again.
272                          */
273                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
274                                           "At minimum performance state\n"));
275                         max_tx_px = 1;
276                 } else
277                         max_tx_px = 0;
278
279                 break;
280         }
281
282       end:
283         if (pr->flags.throttling) {
284                 pr->limit.thermal.px = 0;
285                 pr->limit.thermal.tx = tx;
286
287                 result = acpi_processor_apply_limit(pr);
288                 if (result)
289                         printk(KERN_ERR PREFIX "Unable to set thermal limit\n");
290
291                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
292                                   pr->limit.thermal.px, pr->limit.thermal.tx));
293         } else
294                 result = 0;
295         if (max_tx_px)
296                 return 1;
297         else
298                 return result;
299 }
300
301 int acpi_processor_get_limit_info(struct acpi_processor *pr)
302 {
303
304         if (!pr)
305                 return -EINVAL;
306
307         if (pr->flags.throttling)
308                 pr->flags.limit = 1;
309
310         return 0;
311 }
312
313 /* /proc interface */
314
315 static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
316 {
317         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
318
319
320         if (!pr)
321                 goto end;
322
323         if (!pr->flags.limit) {
324                 seq_puts(seq, "<not supported>\n");
325                 goto end;
326         }
327
328         seq_printf(seq, "active limit:            P%d:T%d\n"
329                    "user limit:              P%d:T%d\n"
330                    "thermal limit:           P%d:T%d\n",
331                    pr->limit.state.px, pr->limit.state.tx,
332                    pr->limit.user.px, pr->limit.user.tx,
333                    pr->limit.thermal.px, pr->limit.thermal.tx);
334
335       end:
336         return 0;
337 }
338
339 static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
340 {
341         return single_open(file, acpi_processor_limit_seq_show,
342                            PDE(inode)->data);
343 }
344
345 static ssize_t acpi_processor_write_limit(struct file * file,
346                                           const char __user * buffer,
347                                           size_t count, loff_t * data)
348 {
349         int result = 0;
350         struct seq_file *m = file->private_data;
351         struct acpi_processor *pr = m->private;
352         char limit_string[25] = { '\0' };
353         int px = 0;
354         int tx = 0;
355
356
357         if (!pr || (count > sizeof(limit_string) - 1)) {
358                 return -EINVAL;
359         }
360
361         if (copy_from_user(limit_string, buffer, count)) {
362                 return -EFAULT;
363         }
364
365         limit_string[count] = '\0';
366
367         if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
368                 printk(KERN_ERR PREFIX "Invalid data format\n");
369                 return -EINVAL;
370         }
371
372         if (pr->flags.throttling) {
373                 if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
374                         printk(KERN_ERR PREFIX "Invalid tx\n");
375                         return -EINVAL;
376                 }
377                 pr->limit.user.tx = tx;
378         }
379
380         result = acpi_processor_apply_limit(pr);
381
382         return count;
383 }
384
385 struct file_operations acpi_processor_limit_fops = {
386         .open = acpi_processor_limit_open_fs,
387         .read = seq_read,
388         .write = acpi_processor_write_limit,
389         .llseek = seq_lseek,
390         .release = single_release,
391 };