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Linux-2.6.12-rc2
[linux-2.6/kvm.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c
blob963e17aa205d60ea91977887c622e6c4cb4c2701
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");
kernel-based virtual machine