4c7c6e089e87b7b7d8ff374be512385c863f3cac
[linux-2.6.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c
1 /*
2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
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) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
7  *
8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or (at
13  *  your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful, but
16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  *  General Public License for more details.
19  *
20  *  You should have received a copy of the GNU General Public License along
21  *  with this program; if not, write to the Free Software Foundation, Inc.,
22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23  *
24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25  */
26
27 #include <linux/config.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/cpufreq.h>
32 #include <linux/proc_fs.h>
33 #include <linux/seq_file.h>
34 #include <linux/compiler.h>
35 #include <linux/sched.h>        /* current */
36 #include <asm/io.h>
37 #include <asm/delay.h>
38 #include <asm/uaccess.h>
39
40 #include <linux/acpi.h>
41 #include <acpi/processor.h>
42
43 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
44
45 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
46 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
47 MODULE_LICENSE("GPL");
48
49
50 struct cpufreq_acpi_io {
51         struct acpi_processor_performance       *acpi_data;
52         struct cpufreq_frequency_table          *freq_table;
53         unsigned int                            resume;
54 };
55
56 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
57 static struct acpi_processor_performance        *acpi_perf_data[NR_CPUS];
58
59 static struct cpufreq_driver acpi_cpufreq_driver;
60
61 static unsigned int acpi_pstate_strict;
62
63 static int
64 acpi_processor_write_port(
65         u16     port,
66         u8      bit_width,
67         u32     value)
68 {
69         if (bit_width <= 8) {
70                 outb(value, port);
71         } else if (bit_width <= 16) {
72                 outw(value, port);
73         } else if (bit_width <= 32) {
74                 outl(value, port);
75         } else {
76                 return -ENODEV;
77         }
78         return 0;
79 }
80
81 static int
82 acpi_processor_read_port(
83         u16     port,
84         u8      bit_width,
85         u32     *ret)
86 {
87         *ret = 0;
88         if (bit_width <= 8) {
89                 *ret = inb(port);
90         } else if (bit_width <= 16) {
91                 *ret = inw(port);
92         } else if (bit_width <= 32) {
93                 *ret = inl(port);
94         } else {
95                 return -ENODEV;
96         }
97         return 0;
98 }
99
100 static int
101 acpi_processor_set_performance (
102         struct cpufreq_acpi_io  *data,
103         unsigned int            cpu,
104         int                     state)
105 {
106         u16                     port = 0;
107         u8                      bit_width = 0;
108         int                     i = 0;
109         int                     ret = 0;
110         u32                     value = 0;
111         int                     retval;
112         struct acpi_processor_performance       *perf;
113
114         dprintk("acpi_processor_set_performance\n");
115
116         retval = 0;
117         perf = data->acpi_data; 
118         if (state == perf->state) {
119                 if (unlikely(data->resume)) {
120                         dprintk("Called after resume, resetting to P%d\n", state);
121                         data->resume = 0;
122                 } else {
123                         dprintk("Already at target state (P%d)\n", state);
124                         return (retval);
125                 }
126         }
127
128         dprintk("Transitioning from P%d to P%d\n", perf->state, state);
129
130         /*
131          * First we write the target state's 'control' value to the
132          * control_register.
133          */
134
135         port = perf->control_register.address;
136         bit_width = perf->control_register.bit_width;
137         value = (u32) perf->states[state].control;
138
139         dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
140
141         ret = acpi_processor_write_port(port, bit_width, value);
142         if (ret) {
143                 dprintk("Invalid port width 0x%04x\n", bit_width);
144                 return (ret);
145         }
146
147         /*
148          * Assume the write went through when acpi_pstate_strict is not used.
149          * As read status_register is an expensive operation and there 
150          * are no specific error cases where an IO port write will fail.
151          */
152         if (acpi_pstate_strict) {
153                 /* Then we read the 'status_register' and compare the value 
154                  * with the target state's 'status' to make sure the 
155                  * transition was successful.
156                  * Note that we'll poll for up to 1ms (100 cycles of 10us) 
157                  * before giving up.
158                  */
159
160                 port = perf->status_register.address;
161                 bit_width = perf->status_register.bit_width;
162
163                 dprintk("Looking for 0x%08x from port 0x%04x\n",
164                         (u32) perf->states[state].status, port);
165
166                 for (i = 0; i < 100; i++) {
167                         ret = acpi_processor_read_port(port, bit_width, &value);
168                         if (ret) {      
169                                 dprintk("Invalid port width 0x%04x\n", bit_width);
170                                 return (ret);
171                         }
172                         if (value == (u32) perf->states[state].status)
173                                 break;
174                         udelay(10);
175                 }
176         } else {
177                 i = 0;
178                 value = (u32) perf->states[state].status;
179         }
180
181         if (unlikely(value != (u32) perf->states[state].status)) {
182                 printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
183                 retval = -ENODEV;
184                 return (retval);
185         }
186
187         dprintk("Transition successful after %d microseconds\n", i * 10);
188
189         perf->state = state;
190         return (retval);
191 }
192
193
194 static int
195 acpi_cpufreq_target (
196         struct cpufreq_policy   *policy,
197         unsigned int target_freq,
198         unsigned int relation)
199 {
200         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
201         struct acpi_processor_performance *perf;
202         struct cpufreq_freqs freqs;
203         cpumask_t online_policy_cpus;
204         cpumask_t saved_mask;
205         cpumask_t set_mask;
206         cpumask_t covered_cpus;
207         unsigned int cur_state = 0;
208         unsigned int next_state = 0;
209         unsigned int result = 0;
210         unsigned int j;
211         unsigned int tmp;
212
213         dprintk("acpi_cpufreq_setpolicy\n");
214
215         result = cpufreq_frequency_table_target(policy,
216                         data->freq_table,
217                         target_freq,
218                         relation,
219                         &next_state);
220         if (unlikely(result))
221                 return (result);
222
223         perf = data->acpi_data;
224         cur_state = perf->state;
225         freqs.old = data->freq_table[cur_state].frequency;
226         freqs.new = data->freq_table[next_state].frequency;
227
228         /* cpufreq holds the hotplug lock, so we are safe from here on */
229         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
230
231         for_each_cpu_mask(j, online_policy_cpus) {
232                 freqs.cpu = j;
233                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
234         }
235
236         /*
237          * We need to call driver->target() on all or any CPU in
238          * policy->cpus, depending on policy->shared_type.
239          */
240         saved_mask = current->cpus_allowed;
241         cpus_clear(covered_cpus);
242         for_each_cpu_mask(j, online_policy_cpus) {
243                 /*
244                  * Support for SMP systems.
245                  * Make sure we are running on CPU that wants to change freq
246                  */
247                 cpus_clear(set_mask);
248                 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
249                         cpus_or(set_mask, set_mask, online_policy_cpus);
250                 else
251                         cpu_set(j, set_mask);
252
253                 set_cpus_allowed(current, set_mask);
254                 if (unlikely(!cpu_isset(smp_processor_id(), set_mask))) {
255                         dprintk("couldn't limit to CPUs in this domain\n");
256                         result = -EAGAIN;
257                         break;
258                 }
259
260                 result = acpi_processor_set_performance (data, j, next_state);
261                 if (result) {
262                         result = -EAGAIN;
263                         break;
264                 }
265
266                 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
267                         break;
268  
269                 cpu_set(j, covered_cpus);
270         }
271
272         for_each_cpu_mask(j, online_policy_cpus) {
273                 freqs.cpu = j;
274                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
275         }
276
277         if (unlikely(result)) {
278                 /*
279                  * We have failed halfway through the frequency change.
280                  * We have sent callbacks to online_policy_cpus and
281                  * acpi_processor_set_performance() has been called on 
282                  * coverd_cpus. Best effort undo..
283                  */
284
285                 if (!cpus_empty(covered_cpus)) {
286                         for_each_cpu_mask(j, covered_cpus) {
287                                 policy->cpu = j;
288                                 acpi_processor_set_performance (data, 
289                                                 j, 
290                                                 cur_state);
291                         }
292                 }
293
294                 tmp = freqs.new;
295                 freqs.new = freqs.old;
296                 freqs.old = tmp;
297                 for_each_cpu_mask(j, online_policy_cpus) {
298                         freqs.cpu = j;
299                         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
300                         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
301                 }
302         }
303
304         set_cpus_allowed(current, saved_mask);
305         return (result);
306 }
307
308
309 static int
310 acpi_cpufreq_verify (
311         struct cpufreq_policy   *policy)
312 {
313         unsigned int result = 0;
314         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
315
316         dprintk("acpi_cpufreq_verify\n");
317
318         result = cpufreq_frequency_table_verify(policy, 
319                         data->freq_table);
320
321         return (result);
322 }
323
324
325 static unsigned long
326 acpi_cpufreq_guess_freq (
327         struct cpufreq_acpi_io  *data,
328         unsigned int            cpu)
329 {
330         struct acpi_processor_performance       *perf = data->acpi_data;
331
332         if (cpu_khz) {
333                 /* search the closest match to cpu_khz */
334                 unsigned int i;
335                 unsigned long freq;
336                 unsigned long freqn = perf->states[0].core_frequency * 1000;
337
338                 for (i = 0; i < (perf->state_count - 1); i++) {
339                         freq = freqn;
340                         freqn = perf->states[i+1].core_frequency * 1000;
341                         if ((2 * cpu_khz) > (freqn + freq)) {
342                                 perf->state = i;
343                                 return (freq);
344                         }
345                 }
346                 perf->state = perf->state_count - 1;
347                 return (freqn);
348         } else {
349                 /* assume CPU is at P0... */
350                 perf->state = 0;
351                 return perf->states[0].core_frequency * 1000;
352         }
353 }
354
355
356 /*
357  * acpi_cpufreq_early_init - initialize ACPI P-States library
358  *
359  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
360  * in order to determine correct frequency and voltage pairings. We can
361  * do _PDC and _PSD and find out the processor dependency for the
362  * actual init that will happen later...
363  */
364 static int acpi_cpufreq_early_init_acpi(void)
365 {
366         struct acpi_processor_performance       *data;
367         unsigned int                            i, j;
368
369         dprintk("acpi_cpufreq_early_init\n");
370
371         for_each_cpu(i) {
372                 data = kzalloc(sizeof(struct acpi_processor_performance), 
373                         GFP_KERNEL);
374                 if (!data) {
375                         for_each_cpu(j) {
376                                 kfree(acpi_perf_data[j]);
377                                 acpi_perf_data[j] = NULL;
378                         }
379                         return (-ENOMEM);
380                 }
381                 acpi_perf_data[i] = data;
382         }
383
384         /* Do initialization in ACPI core */
385         acpi_processor_preregister_performance(acpi_perf_data);
386         return 0;
387 }
388
389 static int
390 acpi_cpufreq_cpu_init (
391         struct cpufreq_policy   *policy)
392 {
393         unsigned int            i;
394         unsigned int            cpu = policy->cpu;
395         struct cpufreq_acpi_io  *data;
396         unsigned int            result = 0;
397         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
398         struct acpi_processor_performance       *perf;
399
400         dprintk("acpi_cpufreq_cpu_init\n");
401
402         if (!acpi_perf_data[cpu])
403                 return (-ENODEV);
404
405         data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
406         if (!data)
407                 return (-ENOMEM);
408
409         data->acpi_data = acpi_perf_data[cpu];
410         acpi_io_data[cpu] = data;
411
412         result = acpi_processor_register_performance(data->acpi_data, cpu);
413
414         if (result)
415                 goto err_free;
416
417         perf = data->acpi_data;
418         policy->cpus = perf->shared_cpu_map;
419         policy->shared_type = perf->shared_type;
420
421         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
422                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
423         }
424
425         /* capability check */
426         if (perf->state_count <= 1) {
427                 dprintk("No P-States\n");
428                 result = -ENODEV;
429                 goto err_unreg;
430         }
431
432         if ((perf->control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
433             (perf->status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
434                 dprintk("Unsupported address space [%d, %d]\n",
435                         (u32) (perf->control_register.space_id),
436                         (u32) (perf->status_register.space_id));
437                 result = -ENODEV;
438                 goto err_unreg;
439         }
440
441         /* alloc freq_table */
442         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (perf->state_count + 1), GFP_KERNEL);
443         if (!data->freq_table) {
444                 result = -ENOMEM;
445                 goto err_unreg;
446         }
447
448         /* detect transition latency */
449         policy->cpuinfo.transition_latency = 0;
450         for (i=0; i<perf->state_count; i++) {
451                 if ((perf->states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
452                         policy->cpuinfo.transition_latency = perf->states[i].transition_latency * 1000;
453         }
454         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
455
456         /* The current speed is unknown and not detectable by ACPI...  */
457         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
458
459         /* table init */
460         for (i=0; i<=perf->state_count; i++)
461         {
462                 data->freq_table[i].index = i;
463                 if (i<perf->state_count)
464                         data->freq_table[i].frequency = perf->states[i].core_frequency * 1000;
465                 else
466                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
467         }
468
469         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
470         if (result) {
471                 goto err_freqfree;
472         }
473
474         /* notify BIOS that we exist */
475         acpi_processor_notify_smm(THIS_MODULE);
476
477         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
478                cpu);
479         for (i = 0; i < perf->state_count; i++)
480                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
481                         (i == perf->state?'*':' '), i,
482                         (u32) perf->states[i].core_frequency,
483                         (u32) perf->states[i].power,
484                         (u32) perf->states[i].transition_latency);
485
486         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
487         
488         /*
489          * the first call to ->target() should result in us actually
490          * writing something to the appropriate registers.
491          */
492         data->resume = 1;
493         
494         return (result);
495
496  err_freqfree:
497         kfree(data->freq_table);
498  err_unreg:
499         acpi_processor_unregister_performance(perf, cpu);
500  err_free:
501         kfree(data);
502         acpi_io_data[cpu] = NULL;
503
504         return (result);
505 }
506
507
508 static int
509 acpi_cpufreq_cpu_exit (
510         struct cpufreq_policy   *policy)
511 {
512         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
513
514
515         dprintk("acpi_cpufreq_cpu_exit\n");
516
517         if (data) {
518                 cpufreq_frequency_table_put_attr(policy->cpu);
519                 acpi_io_data[policy->cpu] = NULL;
520                 acpi_processor_unregister_performance(data->acpi_data, policy->cpu);
521                 kfree(data);
522         }
523
524         return (0);
525 }
526
527 static int
528 acpi_cpufreq_resume (
529         struct cpufreq_policy   *policy)
530 {
531         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
532
533
534         dprintk("acpi_cpufreq_resume\n");
535
536         data->resume = 1;
537
538         return (0);
539 }
540
541
542 static struct freq_attr* acpi_cpufreq_attr[] = {
543         &cpufreq_freq_attr_scaling_available_freqs,
544         NULL,
545 };
546
547 static struct cpufreq_driver acpi_cpufreq_driver = {
548         .verify         = acpi_cpufreq_verify,
549         .target         = acpi_cpufreq_target,
550         .init           = acpi_cpufreq_cpu_init,
551         .exit           = acpi_cpufreq_cpu_exit,
552         .resume         = acpi_cpufreq_resume,
553         .name           = "acpi-cpufreq",
554         .owner          = THIS_MODULE,
555         .attr           = acpi_cpufreq_attr,
556 };
557
558
559 static int __init
560 acpi_cpufreq_init (void)
561 {
562         int                     result = 0;
563
564         dprintk("acpi_cpufreq_init\n");
565
566         result = acpi_cpufreq_early_init_acpi();
567
568         if (!result)
569                 result = cpufreq_register_driver(&acpi_cpufreq_driver);
570         
571         return (result);
572 }
573
574
575 static void __exit
576 acpi_cpufreq_exit (void)
577 {
578         unsigned int    i;
579         dprintk("acpi_cpufreq_exit\n");
580
581         cpufreq_unregister_driver(&acpi_cpufreq_driver);
582
583         for_each_cpu(i) {
584                 kfree(acpi_perf_data[i]);
585                 acpi_perf_data[i] = NULL;
586         }
587         return;
588 }
589
590 module_param(acpi_pstate_strict, uint, 0644);
591 MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
592
593 late_initcall(acpi_cpufreq_init);
594 module_exit(acpi_cpufreq_exit);
595
596 MODULE_ALIAS("acpi");