[CPUFREQ] change cpu freq tables to per_cpu variables
[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 #include <linux/sysdev.h>
36
37 #include <asm/uaccess.h>
38
39 #include <acpi/acpi_bus.h>
40 #include <acpi/processor.h>
41 #include <acpi/acpi_drivers.h>
42
43 #define ACPI_PROCESSOR_COMPONENT        0x01000000
44 #define ACPI_PROCESSOR_CLASS            "processor"
45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
46 ACPI_MODULE_NAME("processor_thermal");
47
48 /* --------------------------------------------------------------------------
49                                  Limit Interface
50    -------------------------------------------------------------------------- */
51 static int acpi_processor_apply_limit(struct acpi_processor *pr)
52 {
53         int result = 0;
54         u16 px = 0;
55         u16 tx = 0;
56
57
58         if (!pr)
59                 return -EINVAL;
60
61         if (!pr->flags.limit)
62                 return -ENODEV;
63
64         if (pr->flags.throttling) {
65                 if (pr->limit.user.tx > tx)
66                         tx = pr->limit.user.tx;
67                 if (pr->limit.thermal.tx > tx)
68                         tx = pr->limit.thermal.tx;
69
70                 result = acpi_processor_set_throttling(pr, tx);
71                 if (result)
72                         goto end;
73         }
74
75         pr->limit.state.px = px;
76         pr->limit.state.tx = tx;
77
78         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
79                           "Processor [%d] limit set to (P%d:T%d)\n", pr->id,
80                           pr->limit.state.px, pr->limit.state.tx));
81
82       end:
83         if (result)
84                 printk(KERN_ERR PREFIX "Unable to set limit\n");
85
86         return result;
87 }
88
89 #ifdef CONFIG_CPU_FREQ
90
91 /* If a passive cooling situation is detected, primarily CPUfreq is used, as it
92  * offers (in most cases) voltage scaling in addition to frequency scaling, and
93  * thus a cubic (instead of linear) reduction of energy. Also, we allow for
94  * _any_ cpufreq driver and not only the acpi-cpufreq driver.
95  */
96
97 #define CPUFREQ_THERMAL_MIN_STEP 0
98 #define CPUFREQ_THERMAL_MAX_STEP 3
99
100 static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
101 static unsigned int acpi_thermal_cpufreq_is_init = 0;
102
103 static int cpu_has_cpufreq(unsigned int cpu)
104 {
105         struct cpufreq_policy policy;
106         if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
107                 return 0;
108         return 1;
109 }
110
111 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
112 {
113         if (!cpu_has_cpufreq(cpu))
114                 return -ENODEV;
115
116         if (per_cpu(cpufreq_thermal_reduction_pctg, cpu) <
117                 CPUFREQ_THERMAL_MAX_STEP) {
118                 per_cpu(cpufreq_thermal_reduction_pctg, cpu)++;
119                 cpufreq_update_policy(cpu);
120                 return 0;
121         }
122
123         return -ERANGE;
124 }
125
126 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
127 {
128         if (!cpu_has_cpufreq(cpu))
129                 return -ENODEV;
130
131         if (per_cpu(cpufreq_thermal_reduction_pctg, cpu) >
132                 (CPUFREQ_THERMAL_MIN_STEP + 1))
133                 per_cpu(cpufreq_thermal_reduction_pctg, cpu)--;
134         else
135                 per_cpu(cpufreq_thermal_reduction_pctg, cpu) = 0;
136         cpufreq_update_policy(cpu);
137         /* We reached max freq again and can leave passive mode */
138         return !per_cpu(cpufreq_thermal_reduction_pctg, cpu);
139 }
140
141 static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
142                                          unsigned long event, void *data)
143 {
144         struct cpufreq_policy *policy = data;
145         unsigned long max_freq = 0;
146
147         if (event != CPUFREQ_ADJUST)
148                 goto out;
149
150         max_freq = (
151             policy->cpuinfo.max_freq *
152             (100 - per_cpu(cpufreq_thermal_reduction_pctg, policy->cpu) * 20)
153         ) / 100;
154
155         cpufreq_verify_within_limits(policy, 0, max_freq);
156
157       out:
158         return 0;
159 }
160
161 static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
162         .notifier_call = acpi_thermal_cpufreq_notifier,
163 };
164
165 static int cpufreq_get_max_state(unsigned int cpu)
166 {
167         if (!cpu_has_cpufreq(cpu))
168                 return 0;
169
170         return CPUFREQ_THERMAL_MAX_STEP;
171 }
172
173 static int cpufreq_get_cur_state(unsigned int cpu)
174 {
175         if (!cpu_has_cpufreq(cpu))
176                 return 0;
177
178         return per_cpu(cpufreq_thermal_reduction_pctg, cpu);
179 }
180
181 static int cpufreq_set_cur_state(unsigned int cpu, int state)
182 {
183         if (!cpu_has_cpufreq(cpu))
184                 return 0;
185
186         per_cpu(cpufreq_thermal_reduction_pctg, cpu) = state;
187         cpufreq_update_policy(cpu);
188         return 0;
189 }
190
191 void acpi_thermal_cpufreq_init(void)
192 {
193         int i;
194
195         for (i = 0; i < nr_cpu_ids; i++)
196                 if (cpu_present(i))
197                         per_cpu(cpufreq_thermal_reduction_pctg, i) = 0;
198
199         i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
200                                       CPUFREQ_POLICY_NOTIFIER);
201         if (!i)
202                 acpi_thermal_cpufreq_is_init = 1;
203 }
204
205 void acpi_thermal_cpufreq_exit(void)
206 {
207         if (acpi_thermal_cpufreq_is_init)
208                 cpufreq_unregister_notifier
209                     (&acpi_thermal_cpufreq_notifier_block,
210                      CPUFREQ_POLICY_NOTIFIER);
211
212         acpi_thermal_cpufreq_is_init = 0;
213 }
214
215 #else                           /* ! CONFIG_CPU_FREQ */
216 static int cpufreq_get_max_state(unsigned int cpu)
217 {
218         return 0;
219 }
220
221 static int cpufreq_get_cur_state(unsigned int cpu)
222 {
223         return 0;
224 }
225
226 static int cpufreq_set_cur_state(unsigned int cpu, int state)
227 {
228         return 0;
229 }
230
231 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
232 {
233         return -ENODEV;
234 }
235 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
236 {
237         return -ENODEV;
238 }
239
240 #endif
241
242 int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
243 {
244         int result = 0;
245         struct acpi_processor *pr = NULL;
246         struct acpi_device *device = NULL;
247         int tx = 0, max_tx_px = 0;
248
249
250         if ((type < ACPI_PROCESSOR_LIMIT_NONE)
251             || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
252                 return -EINVAL;
253
254         result = acpi_bus_get_device(handle, &device);
255         if (result)
256                 return result;
257
258         pr = acpi_driver_data(device);
259         if (!pr)
260                 return -ENODEV;
261
262         /* Thermal limits are always relative to the current Px/Tx state. */
263         if (pr->flags.throttling)
264                 pr->limit.thermal.tx = pr->throttling.state;
265
266         /*
267          * Our default policy is to only use throttling at the lowest
268          * performance state.
269          */
270
271         tx = pr->limit.thermal.tx;
272
273         switch (type) {
274
275         case ACPI_PROCESSOR_LIMIT_NONE:
276                 do {
277                         result = acpi_thermal_cpufreq_decrease(pr->id);
278                 } while (!result);
279                 tx = 0;
280                 break;
281
282         case ACPI_PROCESSOR_LIMIT_INCREMENT:
283                 /* if going up: P-states first, T-states later */
284
285                 result = acpi_thermal_cpufreq_increase(pr->id);
286                 if (!result)
287                         goto end;
288                 else if (result == -ERANGE)
289                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
290                                           "At maximum performance state\n"));
291
292                 if (pr->flags.throttling) {
293                         if (tx == (pr->throttling.state_count - 1))
294                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
295                                                   "At maximum throttling state\n"));
296                         else
297                                 tx++;
298                 }
299                 break;
300
301         case ACPI_PROCESSOR_LIMIT_DECREMENT:
302                 /* if going down: T-states first, P-states later */
303
304                 if (pr->flags.throttling) {
305                         if (tx == 0) {
306                                 max_tx_px = 1;
307                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
308                                                   "At minimum throttling state\n"));
309                         } else {
310                                 tx--;
311                                 goto end;
312                         }
313                 }
314
315                 result = acpi_thermal_cpufreq_decrease(pr->id);
316                 if (result) {
317                         /*
318                          * We only could get -ERANGE, 1 or 0.
319                          * In the first two cases we reached max freq again.
320                          */
321                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
322                                           "At minimum performance state\n"));
323                         max_tx_px = 1;
324                 } else
325                         max_tx_px = 0;
326
327                 break;
328         }
329
330       end:
331         if (pr->flags.throttling) {
332                 pr->limit.thermal.px = 0;
333                 pr->limit.thermal.tx = tx;
334
335                 result = acpi_processor_apply_limit(pr);
336                 if (result)
337                         printk(KERN_ERR PREFIX "Unable to set thermal limit\n");
338
339                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
340                                   pr->limit.thermal.px, pr->limit.thermal.tx));
341         } else
342                 result = 0;
343         if (max_tx_px)
344                 return 1;
345         else
346                 return result;
347 }
348
349 int acpi_processor_get_limit_info(struct acpi_processor *pr)
350 {
351
352         if (!pr)
353                 return -EINVAL;
354
355         if (pr->flags.throttling)
356                 pr->flags.limit = 1;
357
358         return 0;
359 }
360
361 /* thermal coolign device callbacks */
362 static int acpi_processor_max_state(struct acpi_processor *pr)
363 {
364         int max_state = 0;
365
366         /*
367          * There exists four states according to
368          * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3
369          */
370         max_state += cpufreq_get_max_state(pr->id);
371         if (pr->flags.throttling)
372                 max_state += (pr->throttling.state_count -1);
373
374         return max_state;
375 }
376 static int
377 processor_get_max_state(struct thermal_cooling_device *cdev, char *buf)
378 {
379         struct acpi_device *device = cdev->devdata;
380         struct acpi_processor *pr = acpi_driver_data(device);
381
382         if (!device || !pr)
383                 return -EINVAL;
384
385         return sprintf(buf, "%d\n", acpi_processor_max_state(pr));
386 }
387
388 static int
389 processor_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
390 {
391         struct acpi_device *device = cdev->devdata;
392         struct acpi_processor *pr = acpi_driver_data(device);
393         int cur_state;
394
395         if (!device || !pr)
396                 return -EINVAL;
397
398         cur_state = cpufreq_get_cur_state(pr->id);
399         if (pr->flags.throttling)
400                 cur_state += pr->throttling.state;
401
402         return sprintf(buf, "%d\n", cur_state);
403 }
404
405 static int
406 processor_set_cur_state(struct thermal_cooling_device *cdev, unsigned int state)
407 {
408         struct acpi_device *device = cdev->devdata;
409         struct acpi_processor *pr = acpi_driver_data(device);
410         int result = 0;
411         int max_pstate;
412
413         if (!device || !pr)
414                 return -EINVAL;
415
416         max_pstate = cpufreq_get_max_state(pr->id);
417
418         if (state > acpi_processor_max_state(pr))
419                 return -EINVAL;
420
421         if (state <= max_pstate) {
422                 if (pr->flags.throttling && pr->throttling.state)
423                         result = acpi_processor_set_throttling(pr, 0);
424                 cpufreq_set_cur_state(pr->id, state);
425         } else {
426                 cpufreq_set_cur_state(pr->id, max_pstate);
427                 result = acpi_processor_set_throttling(pr,
428                                 state - max_pstate);
429         }
430         return result;
431 }
432
433 struct thermal_cooling_device_ops processor_cooling_ops = {
434         .get_max_state = processor_get_max_state,
435         .get_cur_state = processor_get_cur_state,
436         .set_cur_state = processor_set_cur_state,
437 };
438
439 /* /proc interface */
440
441 static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
442 {
443         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
444
445
446         if (!pr)
447                 goto end;
448
449         if (!pr->flags.limit) {
450                 seq_puts(seq, "<not supported>\n");
451                 goto end;
452         }
453
454         seq_printf(seq, "active limit:            P%d:T%d\n"
455                    "user limit:              P%d:T%d\n"
456                    "thermal limit:           P%d:T%d\n",
457                    pr->limit.state.px, pr->limit.state.tx,
458                    pr->limit.user.px, pr->limit.user.tx,
459                    pr->limit.thermal.px, pr->limit.thermal.tx);
460
461       end:
462         return 0;
463 }
464
465 static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
466 {
467         return single_open(file, acpi_processor_limit_seq_show,
468                            PDE(inode)->data);
469 }
470
471 static ssize_t acpi_processor_write_limit(struct file * file,
472                                           const char __user * buffer,
473                                           size_t count, loff_t * data)
474 {
475         int result = 0;
476         struct seq_file *m = file->private_data;
477         struct acpi_processor *pr = m->private;
478         char limit_string[25] = { '\0' };
479         int px = 0;
480         int tx = 0;
481
482
483         if (!pr || (count > sizeof(limit_string) - 1)) {
484                 return -EINVAL;
485         }
486
487         if (copy_from_user(limit_string, buffer, count)) {
488                 return -EFAULT;
489         }
490
491         limit_string[count] = '\0';
492
493         if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
494                 printk(KERN_ERR PREFIX "Invalid data format\n");
495                 return -EINVAL;
496         }
497
498         if (pr->flags.throttling) {
499                 if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
500                         printk(KERN_ERR PREFIX "Invalid tx\n");
501                         return -EINVAL;
502                 }
503                 pr->limit.user.tx = tx;
504         }
505
506         result = acpi_processor_apply_limit(pr);
507
508         return count;
509 }
510
511 struct file_operations acpi_processor_limit_fops = {
512         .open = acpi_processor_limit_open_fs,
513         .read = seq_read,
514         .write = acpi_processor_write_limit,
515         .llseek = seq_lseek,
516         .release = single_release,
517 };