ACPI: delete tracing macros from drivers/acpi/*.c
[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 ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor Driver"
45 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
46 ACPI_MODULE_NAME("acpi_processor")
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 static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
98 static unsigned int acpi_thermal_cpufreq_is_init = 0;
99
100 static int cpu_has_cpufreq(unsigned int cpu)
101 {
102         struct cpufreq_policy policy;
103         if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
104                 return 0;
105         return 1;
106 }
107
108 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
109 {
110         if (!cpu_has_cpufreq(cpu))
111                 return -ENODEV;
112
113         if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
114                 cpufreq_thermal_reduction_pctg[cpu] += 20;
115                 cpufreq_update_policy(cpu);
116                 return 0;
117         }
118
119         return -ERANGE;
120 }
121
122 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
123 {
124         if (!cpu_has_cpufreq(cpu))
125                 return -ENODEV;
126
127         if (cpufreq_thermal_reduction_pctg[cpu] > 20)
128                 cpufreq_thermal_reduction_pctg[cpu] -= 20;
129         else
130                 cpufreq_thermal_reduction_pctg[cpu] = 0;
131         cpufreq_update_policy(cpu);
132         /* We reached max freq again and can leave passive mode */
133         return !cpufreq_thermal_reduction_pctg[cpu];
134 }
135
136 static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
137                                          unsigned long event, void *data)
138 {
139         struct cpufreq_policy *policy = data;
140         unsigned long max_freq = 0;
141
142         if (event != CPUFREQ_ADJUST)
143                 goto out;
144
145         max_freq =
146             (policy->cpuinfo.max_freq *
147              (100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;
148
149         cpufreq_verify_within_limits(policy, 0, max_freq);
150
151       out:
152         return 0;
153 }
154
155 static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
156         .notifier_call = acpi_thermal_cpufreq_notifier,
157 };
158
159 void acpi_thermal_cpufreq_init(void)
160 {
161         int i;
162
163         for (i = 0; i < NR_CPUS; i++)
164                 cpufreq_thermal_reduction_pctg[i] = 0;
165
166         i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
167                                       CPUFREQ_POLICY_NOTIFIER);
168         if (!i)
169                 acpi_thermal_cpufreq_is_init = 1;
170 }
171
172 void acpi_thermal_cpufreq_exit(void)
173 {
174         if (acpi_thermal_cpufreq_is_init)
175                 cpufreq_unregister_notifier
176                     (&acpi_thermal_cpufreq_notifier_block,
177                      CPUFREQ_POLICY_NOTIFIER);
178
179         acpi_thermal_cpufreq_is_init = 0;
180 }
181
182 #else                           /* ! CONFIG_CPU_FREQ */
183
184 static int acpi_thermal_cpufreq_increase(unsigned int cpu)
185 {
186         return -ENODEV;
187 }
188 static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
189 {
190         return -ENODEV;
191 }
192
193 #endif
194
195 int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
196 {
197         int result = 0;
198         struct acpi_processor *pr = NULL;
199         struct acpi_device *device = NULL;
200         int tx = 0, max_tx_px = 0;
201
202
203         if ((type < ACPI_PROCESSOR_LIMIT_NONE)
204             || (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
205                 return -EINVAL;
206
207         result = acpi_bus_get_device(handle, &device);
208         if (result)
209                 return result;
210
211         pr = (struct acpi_processor *)acpi_driver_data(device);
212         if (!pr)
213                 return -ENODEV;
214
215         /* Thermal limits are always relative to the current Px/Tx state. */
216         if (pr->flags.throttling)
217                 pr->limit.thermal.tx = pr->throttling.state;
218
219         /*
220          * Our default policy is to only use throttling at the lowest
221          * performance state.
222          */
223
224         tx = pr->limit.thermal.tx;
225
226         switch (type) {
227
228         case ACPI_PROCESSOR_LIMIT_NONE:
229                 do {
230                         result = acpi_thermal_cpufreq_decrease(pr->id);
231                 } while (!result);
232                 tx = 0;
233                 break;
234
235         case ACPI_PROCESSOR_LIMIT_INCREMENT:
236                 /* if going up: P-states first, T-states later */
237
238                 result = acpi_thermal_cpufreq_increase(pr->id);
239                 if (!result)
240                         goto end;
241                 else if (result == -ERANGE)
242                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
243                                           "At maximum performance state\n"));
244
245                 if (pr->flags.throttling) {
246                         if (tx == (pr->throttling.state_count - 1))
247                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
248                                                   "At maximum throttling state\n"));
249                         else
250                                 tx++;
251                 }
252                 break;
253
254         case ACPI_PROCESSOR_LIMIT_DECREMENT:
255                 /* if going down: T-states first, P-states later */
256
257                 if (pr->flags.throttling) {
258                         if (tx == 0) {
259                                 max_tx_px = 1;
260                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
261                                                   "At minimum throttling state\n"));
262                         } else {
263                                 tx--;
264                                 goto end;
265                         }
266                 }
267
268                 result = acpi_thermal_cpufreq_decrease(pr->id);
269                 if (result) {
270                         /*
271                          * We only could get -ERANGE, 1 or 0.
272                          * In the first two cases we reached max freq again.
273                          */
274                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
275                                           "At minimum performance state\n"));
276                         max_tx_px = 1;
277                 } else
278                         max_tx_px = 0;
279
280                 break;
281         }
282
283       end:
284         if (pr->flags.throttling) {
285                 pr->limit.thermal.px = 0;
286                 pr->limit.thermal.tx = tx;
287
288                 result = acpi_processor_apply_limit(pr);
289                 if (result)
290                         printk(KERN_ERR PREFIX "Unable to set thermal limit\n");
291
292                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
293                                   pr->limit.thermal.px, pr->limit.thermal.tx));
294         } else
295                 result = 0;
296         if (max_tx_px)
297                 return 1;
298         else
299                 return result;
300 }
301
302 int acpi_processor_get_limit_info(struct acpi_processor *pr)
303 {
304
305         if (!pr)
306                 return -EINVAL;
307
308         if (pr->flags.throttling)
309                 pr->flags.limit = 1;
310
311         return 0;
312 }
313
314 /* /proc interface */
315
316 static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
317 {
318         struct acpi_processor *pr = (struct acpi_processor *)seq->private;
319
320
321         if (!pr)
322                 goto end;
323
324         if (!pr->flags.limit) {
325                 seq_puts(seq, "<not supported>\n");
326                 goto end;
327         }
328
329         seq_printf(seq, "active limit:            P%d:T%d\n"
330                    "user limit:              P%d:T%d\n"
331                    "thermal limit:           P%d:T%d\n",
332                    pr->limit.state.px, pr->limit.state.tx,
333                    pr->limit.user.px, pr->limit.user.tx,
334                    pr->limit.thermal.px, pr->limit.thermal.tx);
335
336       end:
337         return 0;
338 }
339
340 static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
341 {
342         return single_open(file, acpi_processor_limit_seq_show,
343                            PDE(inode)->data);
344 }
345
346 static ssize_t acpi_processor_write_limit(struct file * file,
347                                           const char __user * buffer,
348                                           size_t count, loff_t * data)
349 {
350         int result = 0;
351         struct seq_file *m = (struct seq_file *)file->private_data;
352         struct acpi_processor *pr = (struct acpi_processor *)m->private;
353         char limit_string[25] = { '\0' };
354         int px = 0;
355         int tx = 0;
356
357
358         if (!pr || (count > sizeof(limit_string) - 1)) {
359                 return -EINVAL;
360         }
361
362         if (copy_from_user(limit_string, buffer, count)) {
363                 return -EFAULT;
364         }
365
366         limit_string[count] = '\0';
367
368         if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
369                 printk(KERN_ERR PREFIX "Invalid data format\n");
370                 return -EINVAL;
371         }
372
373         if (pr->flags.throttling) {
374                 if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
375                         printk(KERN_ERR PREFIX "Invalid tx\n");
376                         return -EINVAL;
377                 }
378                 pr->limit.user.tx = tx;
379         }
380
381         result = acpi_processor_apply_limit(pr);
382
383         return count;
384 }
385
386 struct file_operations acpi_processor_limit_fops = {
387         .open = acpi_processor_limit_open_fs,
388         .read = seq_read,
389         .write = acpi_processor_write_limit,
390         .llseek = seq_lseek,
391         .release = single_release,
392 };