Linux-2.6.12-rc2
[linux-3.10.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 <asm/io.h>
35 #include <asm/delay.h>
36 #include <asm/uaccess.h>
37
38 #include <linux/acpi.h>
39 #include <acpi/processor.h>
40
41 #include "speedstep-est-common.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
58 static struct cpufreq_driver acpi_cpufreq_driver;
59
60 static int
61 acpi_processor_write_port(
62         u16     port,
63         u8      bit_width,
64         u32     value)
65 {
66         if (bit_width <= 8) {
67                 outb(value, port);
68         } else if (bit_width <= 16) {
69                 outw(value, port);
70         } else if (bit_width <= 32) {
71                 outl(value, port);
72         } else {
73                 return -ENODEV;
74         }
75         return 0;
76 }
77
78 static int
79 acpi_processor_read_port(
80         u16     port,
81         u8      bit_width,
82         u32     *ret)
83 {
84         *ret = 0;
85         if (bit_width <= 8) {
86                 *ret = inb(port);
87         } else if (bit_width <= 16) {
88                 *ret = inw(port);
89         } else if (bit_width <= 32) {
90                 *ret = inl(port);
91         } else {
92                 return -ENODEV;
93         }
94         return 0;
95 }
96
97 static int
98 acpi_processor_set_performance (
99         struct cpufreq_acpi_io  *data,
100         unsigned int            cpu,
101         int                     state)
102 {
103         u16                     port = 0;
104         u8                      bit_width = 0;
105         int                     ret = 0;
106         u32                     value = 0;
107         int                     i = 0;
108         struct cpufreq_freqs    cpufreq_freqs;
109         cpumask_t               saved_mask;
110         int                     retval;
111
112         dprintk("acpi_processor_set_performance\n");
113
114         /*
115          * TBD: Use something other than set_cpus_allowed.
116          * As set_cpus_allowed is a bit racy, 
117          * with any other set_cpus_allowed for this process.
118          */
119         saved_mask = current->cpus_allowed;
120         set_cpus_allowed(current, cpumask_of_cpu(cpu));
121         if (smp_processor_id() != cpu) {
122                 return (-EAGAIN);
123         }
124         
125         if (state == data->acpi_data.state) {
126                 if (unlikely(data->resume)) {
127                         dprintk("Called after resume, resetting to P%d\n", state);
128                         data->resume = 0;
129                 } else {
130                         dprintk("Already at target state (P%d)\n", state);
131                         retval = 0;
132                         goto migrate_end;
133                 }
134         }
135
136         dprintk("Transitioning from P%d to P%d\n",
137                 data->acpi_data.state, state);
138
139         /* cpufreq frequency struct */
140         cpufreq_freqs.cpu = cpu;
141         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
142         cpufreq_freqs.new = data->freq_table[state].frequency;
143
144         /* notify cpufreq */
145         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
146
147         /*
148          * First we write the target state's 'control' value to the
149          * control_register.
150          */
151
152         port = data->acpi_data.control_register.address;
153         bit_width = data->acpi_data.control_register.bit_width;
154         value = (u32) data->acpi_data.states[state].control;
155
156         dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
157
158         ret = acpi_processor_write_port(port, bit_width, value);
159         if (ret) {
160                 dprintk("Invalid port width 0x%04x\n", bit_width);
161                 retval = ret;
162                 goto migrate_end;
163         }
164
165         /*
166          * Then we read the 'status_register' and compare the value with the
167          * target state's 'status' to make sure the transition was successful.
168          * Note that we'll poll for up to 1ms (100 cycles of 10us) before
169          * giving up.
170          */
171
172         port = data->acpi_data.status_register.address;
173         bit_width = data->acpi_data.status_register.bit_width;
174
175         dprintk("Looking for 0x%08x from port 0x%04x\n",
176                 (u32) data->acpi_data.states[state].status, port);
177
178         for (i=0; i<100; i++) {
179                 ret = acpi_processor_read_port(port, bit_width, &value);
180                 if (ret) {      
181                         dprintk("Invalid port width 0x%04x\n", bit_width);
182                         retval = ret;
183                         goto migrate_end;
184                 }
185                 if (value == (u32) data->acpi_data.states[state].status)
186                         break;
187                 udelay(10);
188         }
189
190         /* notify cpufreq */
191         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
192
193         if (value != (u32) data->acpi_data.states[state].status) {
194                 unsigned int tmp = cpufreq_freqs.new;
195                 cpufreq_freqs.new = cpufreq_freqs.old;
196                 cpufreq_freqs.old = tmp;
197                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
198                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
199                 printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
200                 retval = -ENODEV;
201                 goto migrate_end;
202         }
203
204         dprintk("Transition successful after %d microseconds\n", i * 10);
205
206         data->acpi_data.state = state;
207
208         retval = 0;
209 migrate_end:
210         set_cpus_allowed(current, saved_mask);
211         return (retval);
212 }
213
214
215 static int
216 acpi_cpufreq_target (
217         struct cpufreq_policy   *policy,
218         unsigned int target_freq,
219         unsigned int relation)
220 {
221         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
222         unsigned int next_state = 0;
223         unsigned int result = 0;
224
225         dprintk("acpi_cpufreq_setpolicy\n");
226
227         result = cpufreq_frequency_table_target(policy,
228                         data->freq_table,
229                         target_freq,
230                         relation,
231                         &next_state);
232         if (result)
233                 return (result);
234
235         result = acpi_processor_set_performance (data, policy->cpu, next_state);
236
237         return (result);
238 }
239
240
241 static int
242 acpi_cpufreq_verify (
243         struct cpufreq_policy   *policy)
244 {
245         unsigned int result = 0;
246         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
247
248         dprintk("acpi_cpufreq_verify\n");
249
250         result = cpufreq_frequency_table_verify(policy, 
251                         data->freq_table);
252
253         return (result);
254 }
255
256
257 static unsigned long
258 acpi_cpufreq_guess_freq (
259         struct cpufreq_acpi_io  *data,
260         unsigned int            cpu)
261 {
262         if (cpu_khz) {
263                 /* search the closest match to cpu_khz */
264                 unsigned int i;
265                 unsigned long freq;
266                 unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
267
268                 for (i=0; i < (data->acpi_data.state_count - 1); i++) {
269                         freq = freqn;
270                         freqn = data->acpi_data.states[i+1].core_frequency * 1000;
271                         if ((2 * cpu_khz) > (freqn + freq)) {
272                                 data->acpi_data.state = i;
273                                 return (freq);
274                         }
275                 }
276                 data->acpi_data.state = data->acpi_data.state_count - 1;
277                 return (freqn);
278         } else
279                 /* assume CPU is at P0... */
280                 data->acpi_data.state = 0;
281                 return data->acpi_data.states[0].core_frequency * 1000;
282         
283 }
284
285
286 /* 
287  * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
288  * of this driver
289  * @perf: processor-specific acpi_io_data struct
290  * @cpu: CPU being initialized
291  *
292  * To avoid issues with legacy OSes, some BIOSes require to be informed of
293  * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC 
294  * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
295  * driver/acpi/processor.c
296  */
297 static void 
298 acpi_processor_cpu_init_pdc_est(
299                 struct acpi_processor_performance *perf, 
300                 unsigned int cpu,
301                 struct acpi_object_list *obj_list
302                 )
303 {
304         union acpi_object *obj;
305         u32 *buf;
306         struct cpuinfo_x86 *c = cpu_data + cpu;
307         dprintk("acpi_processor_cpu_init_pdc_est\n");
308
309         if (!cpu_has(c, X86_FEATURE_EST))
310                 return;
311
312         /* Initialize pdc. It will be used later. */
313         if (!obj_list)
314                 return;
315                 
316         if (!(obj_list->count && obj_list->pointer))
317                 return;
318
319         obj = obj_list->pointer;
320         if ((obj->buffer.length == 12) && obj->buffer.pointer) {
321                 buf = (u32 *)obj->buffer.pointer;
322                 buf[0] = ACPI_PDC_REVISION_ID;
323                 buf[1] = 1;
324                 buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
325                 perf->pdc = obj_list;
326         }
327         return;
328 }
329  
330
331 /* CPU specific PDC initialization */
332 static void 
333 acpi_processor_cpu_init_pdc(
334                 struct acpi_processor_performance *perf, 
335                 unsigned int cpu,
336                 struct acpi_object_list *obj_list
337                 )
338 {
339         struct cpuinfo_x86 *c = cpu_data + cpu;
340         dprintk("acpi_processor_cpu_init_pdc\n");
341         perf->pdc = NULL;
342         if (cpu_has(c, X86_FEATURE_EST))
343                 acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
344         return;
345 }
346
347
348 static int
349 acpi_cpufreq_cpu_init (
350         struct cpufreq_policy   *policy)
351 {
352         unsigned int            i;
353         unsigned int            cpu = policy->cpu;
354         struct cpufreq_acpi_io  *data;
355         unsigned int            result = 0;
356
357         union acpi_object               arg0 = {ACPI_TYPE_BUFFER};
358         u32                             arg0_buf[3];
359         struct acpi_object_list         arg_list = {1, &arg0};
360
361         dprintk("acpi_cpufreq_cpu_init\n");
362         /* setup arg_list for _PDC settings */
363         arg0.buffer.length = 12;
364         arg0.buffer.pointer = (u8 *) arg0_buf;
365
366         data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
367         if (!data)
368                 return (-ENOMEM);
369         memset(data, 0, sizeof(struct cpufreq_acpi_io));
370
371         acpi_io_data[cpu] = data;
372
373         acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
374         result = acpi_processor_register_performance(&data->acpi_data, cpu);
375         data->acpi_data.pdc = NULL;
376
377         if (result)
378                 goto err_free;
379
380         if (is_const_loops_cpu(cpu)) {
381                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
382         }
383
384         /* capability check */
385         if (data->acpi_data.state_count <= 1) {
386                 dprintk("No P-States\n");
387                 result = -ENODEV;
388                 goto err_unreg;
389         }
390         if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
391             (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
392                 dprintk("Unsupported address space [%d, %d]\n",
393                         (u32) (data->acpi_data.control_register.space_id),
394                         (u32) (data->acpi_data.status_register.space_id));
395                 result = -ENODEV;
396                 goto err_unreg;
397         }
398
399         /* alloc freq_table */
400         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
401         if (!data->freq_table) {
402                 result = -ENOMEM;
403                 goto err_unreg;
404         }
405
406         /* detect transition latency */
407         policy->cpuinfo.transition_latency = 0;
408         for (i=0; i<data->acpi_data.state_count; i++) {
409                 if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
410                         policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
411         }
412         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
413
414         /* The current speed is unknown and not detectable by ACPI...  */
415         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
416
417         /* table init */
418         for (i=0; i<=data->acpi_data.state_count; i++)
419         {
420                 data->freq_table[i].index = i;
421                 if (i<data->acpi_data.state_count)
422                         data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
423                 else
424                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
425         }
426
427         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
428         if (result) {
429                 goto err_freqfree;
430         }
431
432         /* notify BIOS that we exist */
433         acpi_processor_notify_smm(THIS_MODULE);
434
435         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
436                cpu);
437         for (i = 0; i < data->acpi_data.state_count; i++)
438                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
439                         (i == data->acpi_data.state?'*':' '), i,
440                         (u32) data->acpi_data.states[i].core_frequency,
441                         (u32) data->acpi_data.states[i].power,
442                         (u32) data->acpi_data.states[i].transition_latency);
443
444         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
445         return (result);
446
447  err_freqfree:
448         kfree(data->freq_table);
449  err_unreg:
450         acpi_processor_unregister_performance(&data->acpi_data, cpu);
451  err_free:
452         kfree(data);
453         acpi_io_data[cpu] = NULL;
454
455         return (result);
456 }
457
458
459 static int
460 acpi_cpufreq_cpu_exit (
461         struct cpufreq_policy   *policy)
462 {
463         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
464
465
466         dprintk("acpi_cpufreq_cpu_exit\n");
467
468         if (data) {
469                 cpufreq_frequency_table_put_attr(policy->cpu);
470                 acpi_io_data[policy->cpu] = NULL;
471                 acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
472                 kfree(data);
473         }
474
475         return (0);
476 }
477
478 static int
479 acpi_cpufreq_resume (
480         struct cpufreq_policy   *policy)
481 {
482         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
483
484
485         dprintk("acpi_cpufreq_resume\n");
486
487         data->resume = 1;
488
489         return (0);
490 }
491
492
493 static struct freq_attr* acpi_cpufreq_attr[] = {
494         &cpufreq_freq_attr_scaling_available_freqs,
495         NULL,
496 };
497
498 static struct cpufreq_driver acpi_cpufreq_driver = {
499         .verify         = acpi_cpufreq_verify,
500         .target         = acpi_cpufreq_target,
501         .init           = acpi_cpufreq_cpu_init,
502         .exit           = acpi_cpufreq_cpu_exit,
503         .resume         = acpi_cpufreq_resume,
504         .name           = "acpi-cpufreq",
505         .owner          = THIS_MODULE,
506         .attr           = acpi_cpufreq_attr,
507 };
508
509
510 static int __init
511 acpi_cpufreq_init (void)
512 {
513         int                     result = 0;
514
515         dprintk("acpi_cpufreq_init\n");
516
517         result = cpufreq_register_driver(&acpi_cpufreq_driver);
518         
519         return (result);
520 }
521
522
523 static void __exit
524 acpi_cpufreq_exit (void)
525 {
526         dprintk("acpi_cpufreq_exit\n");
527
528         cpufreq_unregister_driver(&acpi_cpufreq_driver);
529
530         return;
531 }
532
533
534 late_initcall(acpi_cpufreq_init);
535 module_exit(acpi_cpufreq_exit);
536
537 MODULE_ALIAS("acpi");