processor_perflib.c revision 4be44fcd3bf648b782f4460fd06dfae6c42ded4b 
1/*
2 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
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 *
13 *  This program is free software; you can redistribute it and/or modify
14 *  it under the terms of the GNU General Public License as published by
15 *  the Free Software Foundation; either version 2 of the License, or (at
16 *  your option) any later version.
17 *
18 *  This program is distributed in the hope that it will be useful, but
19 *  WITHOUT ANY WARRANTY; without even the implied warranty of
20 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21 *  General Public License for more details.
22 *
23 *  You should have received a copy of the GNU General Public License along
24 *  with this program; if not, write to the Free Software Foundation, Inc.,
25 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 *
27 */
28
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/init.h>
32#include <linux/cpufreq.h>
33
34#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
35#include <linux/proc_fs.h>
36#include <linux/seq_file.h>
37
38#include <asm/uaccess.h>
39#endif
40
41#include <acpi/acpi_bus.h>
42#include <acpi/processor.h>
43
44#define ACPI_PROCESSOR_COMPONENT	0x01000000
45#define ACPI_PROCESSOR_CLASS		"processor"
46#define ACPI_PROCESSOR_DRIVER_NAME	"ACPI Processor Driver"
47#define ACPI_PROCESSOR_FILE_PERFORMANCE	"performance"
48#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
49ACPI_MODULE_NAME("acpi_processor")
50
51static DECLARE_MUTEX(performance_sem);
52
53/*
54 * _PPC support is implemented as a CPUfreq policy notifier:
55 * This means each time a CPUfreq driver registered also with
56 * the ACPI core is asked to change the speed policy, the maximum
57 * value is adjusted so that it is within the platform limit.
58 *
59 * Also, when a new platform limit value is detected, the CPUfreq
60 * policy is adjusted accordingly.
61 */
62
63#define PPC_REGISTERED   1
64#define PPC_IN_USE       2
65
66static int acpi_processor_ppc_status = 0;
67
68static int acpi_processor_ppc_notifier(struct notifier_block *nb,
69				       unsigned long event, void *data)
70{
71	struct cpufreq_policy *policy = data;
72	struct acpi_processor *pr;
73	unsigned int ppc = 0;
74
75	down(&performance_sem);
76
77	if (event != CPUFREQ_INCOMPATIBLE)
78		goto out;
79
80	pr = processors[policy->cpu];
81	if (!pr || !pr->performance)
82		goto out;
83
84	ppc = (unsigned int)pr->performance_platform_limit;
85	if (!ppc)
86		goto out;
87
88	if (ppc > pr->performance->state_count)
89		goto out;
90
91	cpufreq_verify_within_limits(policy, 0,
92				     pr->performance->states[ppc].
93				     core_frequency * 1000);
94
95      out:
96	up(&performance_sem);
97
98	return 0;
99}
100
101static struct notifier_block acpi_ppc_notifier_block = {
102	.notifier_call = acpi_processor_ppc_notifier,
103};
104
105static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
106{
107	acpi_status status = 0;
108	unsigned long ppc = 0;
109
110	ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");
111
112	if (!pr)
113		return_VALUE(-EINVAL);
114
115	/*
116	 * _PPC indicates the maximum state currently supported by the platform
117	 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
118	 */
119	status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
120
121	if (status != AE_NOT_FOUND)
122		acpi_processor_ppc_status |= PPC_IN_USE;
123
124	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
125		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
126		return_VALUE(-ENODEV);
127	}
128
129	pr->performance_platform_limit = (int)ppc;
130
131	return_VALUE(0);
132}
133
134int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
135{
136	int ret = acpi_processor_get_platform_limit(pr);
137	if (ret < 0)
138		return (ret);
139	else
140		return cpufreq_update_policy(pr->id);
141}
142
143void acpi_processor_ppc_init(void)
144{
145	if (!cpufreq_register_notifier
146	    (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
147		acpi_processor_ppc_status |= PPC_REGISTERED;
148	else
149		printk(KERN_DEBUG
150		       "Warning: Processor Platform Limit not supported.\n");
151}
152
153void acpi_processor_ppc_exit(void)
154{
155	if (acpi_processor_ppc_status & PPC_REGISTERED)
156		cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
157					    CPUFREQ_POLICY_NOTIFIER);
158
159	acpi_processor_ppc_status &= ~PPC_REGISTERED;
160}
161
162static int acpi_processor_get_performance_control(struct acpi_processor *pr)
163{
164	int result = 0;
165	acpi_status status = 0;
166	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
167	union acpi_object *pct = NULL;
168	union acpi_object obj = { 0 };
169
170	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");
171
172	status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
173	if (ACPI_FAILURE(status)) {
174		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
175		return_VALUE(-ENODEV);
176	}
177
178	pct = (union acpi_object *)buffer.pointer;
179	if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
180	    || (pct->package.count != 2)) {
181		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
182		result = -EFAULT;
183		goto end;
184	}
185
186	/*
187	 * control_register
188	 */
189
190	obj = pct->package.elements[0];
191
192	if ((obj.type != ACPI_TYPE_BUFFER)
193	    || (obj.buffer.length < sizeof(struct acpi_pct_register))
194	    || (obj.buffer.pointer == NULL)) {
195		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
196				  "Invalid _PCT data (control_register)\n"));
197		result = -EFAULT;
198		goto end;
199	}
200	memcpy(&pr->performance->control_register, obj.buffer.pointer,
201	       sizeof(struct acpi_pct_register));
202
203	/*
204	 * status_register
205	 */
206
207	obj = pct->package.elements[1];
208
209	if ((obj.type != ACPI_TYPE_BUFFER)
210	    || (obj.buffer.length < sizeof(struct acpi_pct_register))
211	    || (obj.buffer.pointer == NULL)) {
212		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
213				  "Invalid _PCT data (status_register)\n"));
214		result = -EFAULT;
215		goto end;
216	}
217
218	memcpy(&pr->performance->status_register, obj.buffer.pointer,
219	       sizeof(struct acpi_pct_register));
220
221      end:
222	acpi_os_free(buffer.pointer);
223
224	return_VALUE(result);
225}
226
227static int acpi_processor_get_performance_states(struct acpi_processor *pr)
228{
229	int result = 0;
230	acpi_status status = AE_OK;
231	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
232	struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
233	struct acpi_buffer state = { 0, NULL };
234	union acpi_object *pss = NULL;
235	int i;
236
237	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");
238
239	status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
240	if (ACPI_FAILURE(status)) {
241		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
242		return_VALUE(-ENODEV);
243	}
244
245	pss = (union acpi_object *)buffer.pointer;
246	if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
247		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
248		result = -EFAULT;
249		goto end;
250	}
251
252	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
253			  pss->package.count));
254
255	pr->performance->state_count = pss->package.count;
256	pr->performance->states =
257	    kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
258		    GFP_KERNEL);
259	if (!pr->performance->states) {
260		result = -ENOMEM;
261		goto end;
262	}
263
264	for (i = 0; i < pr->performance->state_count; i++) {
265
266		struct acpi_processor_px *px = &(pr->performance->states[i]);
267
268		state.length = sizeof(struct acpi_processor_px);
269		state.pointer = px;
270
271		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
272
273		status = acpi_extract_package(&(pss->package.elements[i]),
274					      &format, &state);
275		if (ACPI_FAILURE(status)) {
276			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
277					  "Invalid _PSS data\n"));
278			result = -EFAULT;
279			kfree(pr->performance->states);
280			goto end;
281		}
282
283		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
284				  "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
285				  i,
286				  (u32) px->core_frequency,
287				  (u32) px->power,
288				  (u32) px->transition_latency,
289				  (u32) px->bus_master_latency,
290				  (u32) px->control, (u32) px->status));
291
292		if (!px->core_frequency) {
293			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
294					  "Invalid _PSS data: freq is zero\n"));
295			result = -EFAULT;
296			kfree(pr->performance->states);
297			goto end;
298		}
299	}
300
301      end:
302	acpi_os_free(buffer.pointer);
303
304	return_VALUE(result);
305}
306
307static int acpi_processor_get_performance_info(struct acpi_processor *pr)
308{
309	int result = 0;
310	acpi_status status = AE_OK;
311	acpi_handle handle = NULL;
312
313	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");
314
315	if (!pr || !pr->performance || !pr->handle)
316		return_VALUE(-EINVAL);
317
318	acpi_processor_set_pdc(pr, pr->performance->pdc);
319
320	status = acpi_get_handle(pr->handle, "_PCT", &handle);
321	if (ACPI_FAILURE(status)) {
322		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
323				  "ACPI-based processor performance control unavailable\n"));
324		return_VALUE(-ENODEV);
325	}
326
327	result = acpi_processor_get_performance_control(pr);
328	if (result)
329		return_VALUE(result);
330
331	result = acpi_processor_get_performance_states(pr);
332	if (result)
333		return_VALUE(result);
334
335	result = acpi_processor_get_platform_limit(pr);
336	if (result)
337		return_VALUE(result);
338
339	return_VALUE(0);
340}
341
342int acpi_processor_notify_smm(struct module *calling_module)
343{
344	acpi_status status;
345	static int is_done = 0;
346
347	ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
348
349	if (!(acpi_processor_ppc_status & PPC_REGISTERED))
350		return_VALUE(-EBUSY);
351
352	if (!try_module_get(calling_module))
353		return_VALUE(-EINVAL);
354
355	/* is_done is set to negative if an error occured,
356	 * and to postitive if _no_ error occured, but SMM
357	 * was already notified. This avoids double notification
358	 * which might lead to unexpected results...
359	 */
360	if (is_done > 0) {
361		module_put(calling_module);
362		return_VALUE(0);
363	} else if (is_done < 0) {
364		module_put(calling_module);
365		return_VALUE(is_done);
366	}
367
368	is_done = -EIO;
369
370	/* Can't write pstate_cnt to smi_cmd if either value is zero */
371	if ((!acpi_fadt.smi_cmd) || (!acpi_fadt.pstate_cnt)) {
372		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_cnt\n"));
373		module_put(calling_module);
374		return_VALUE(0);
375	}
376
377	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
378			  "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n",
379			  acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
380
381	/* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
382	 * it anyway, so we need to support it... */
383	if (acpi_fadt_is_v1) {
384		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
385				  "Using v1.0 FADT reserved value for pstate_cnt\n"));
386	}
387
388	status = acpi_os_write_port(acpi_fadt.smi_cmd,
389				    (u32) acpi_fadt.pstate_cnt, 8);
390	if (ACPI_FAILURE(status)) {
391		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
392				  "Failed to write pstate_cnt [0x%x] to "
393				  "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt,
394				  acpi_fadt.smi_cmd));
395		module_put(calling_module);
396		return_VALUE(status);
397	}
398
399	/* Success. If there's no _PPC, we need to fear nothing, so
400	 * we can allow the cpufreq driver to be rmmod'ed. */
401	is_done = 1;
402
403	if (!(acpi_processor_ppc_status & PPC_IN_USE))
404		module_put(calling_module);
405
406	return_VALUE(0);
407}
408
409EXPORT_SYMBOL(acpi_processor_notify_smm);
410
411#ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
412/* /proc/acpi/processor/../performance interface (DEPRECATED) */
413
414static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
415static struct file_operations acpi_processor_perf_fops = {
416	.open = acpi_processor_perf_open_fs,
417	.read = seq_read,
418	.llseek = seq_lseek,
419	.release = single_release,
420};
421
422static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
423{
424	struct acpi_processor *pr = (struct acpi_processor *)seq->private;
425	int i;
426
427	ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
428
429	if (!pr)
430		goto end;
431
432	if (!pr->performance) {
433		seq_puts(seq, "<not supported>\n");
434		goto end;
435	}
436
437	seq_printf(seq, "state count:             %d\n"
438		   "active state:            P%d\n",
439		   pr->performance->state_count, pr->performance->state);
440
441	seq_puts(seq, "states:\n");
442	for (i = 0; i < pr->performance->state_count; i++)
443		seq_printf(seq,
444			   "   %cP%d:                  %d MHz, %d mW, %d uS\n",
445			   (i == pr->performance->state ? '*' : ' '), i,
446			   (u32) pr->performance->states[i].core_frequency,
447			   (u32) pr->performance->states[i].power,
448			   (u32) pr->performance->states[i].transition_latency);
449
450      end:
451	return_VALUE(0);
452}
453
454static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
455{
456	return single_open(file, acpi_processor_perf_seq_show,
457			   PDE(inode)->data);
458}
459
460static ssize_t
461acpi_processor_write_performance(struct file *file,
462				 const char __user * buffer,
463				 size_t count, loff_t * data)
464{
465	int result = 0;
466	struct seq_file *m = (struct seq_file *)file->private_data;
467	struct acpi_processor *pr = (struct acpi_processor *)m->private;
468	struct acpi_processor_performance *perf;
469	char state_string[12] = { '\0' };
470	unsigned int new_state = 0;
471	struct cpufreq_policy policy;
472
473	ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
474
475	if (!pr || (count > sizeof(state_string) - 1))
476		return_VALUE(-EINVAL);
477
478	perf = pr->performance;
479	if (!perf)
480		return_VALUE(-EINVAL);
481
482	if (copy_from_user(state_string, buffer, count))
483		return_VALUE(-EFAULT);
484
485	state_string[count] = '\0';
486	new_state = simple_strtoul(state_string, NULL, 0);
487
488	if (new_state >= perf->state_count)
489		return_VALUE(-EINVAL);
490
491	cpufreq_get_policy(&policy, pr->id);
492
493	policy.cpu = pr->id;
494	policy.min = perf->states[new_state].core_frequency * 1000;
495	policy.max = perf->states[new_state].core_frequency * 1000;
496
497	result = cpufreq_set_policy(&policy);
498	if (result)
499		return_VALUE(result);
500
501	return_VALUE(count);
502}
503
504static void acpi_cpufreq_add_file(struct acpi_processor *pr)
505{
506	struct proc_dir_entry *entry = NULL;
507	struct acpi_device *device = NULL;
508
509	ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
510
511	if (acpi_bus_get_device(pr->handle, &device))
512		return_VOID;
513
514	/* add file 'performance' [R/W] */
515	entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
516				  S_IFREG | S_IRUGO | S_IWUSR,
517				  acpi_device_dir(device));
518	if (!entry)
519		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
520				  "Unable to create '%s' fs entry\n",
521				  ACPI_PROCESSOR_FILE_PERFORMANCE));
522	else {
523		entry->proc_fops = &acpi_processor_perf_fops;
524		entry->proc_fops->write = acpi_processor_write_performance;
525		entry->data = acpi_driver_data(device);
526		entry->owner = THIS_MODULE;
527	}
528	return_VOID;
529}
530
531static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
532{
533	struct acpi_device *device = NULL;
534
535	ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
536
537	if (acpi_bus_get_device(pr->handle, &device))
538		return_VOID;
539
540	/* remove file 'performance' */
541	remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
542			  acpi_device_dir(device));
543
544	return_VOID;
545}
546
547#else
548static void acpi_cpufreq_add_file(struct acpi_processor *pr)
549{
550	return;
551}
552static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
553{
554	return;
555}
556#endif				/* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
557
558int
559acpi_processor_register_performance(struct acpi_processor_performance
560				    *performance, unsigned int cpu)
561{
562	struct acpi_processor *pr;
563
564	ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
565
566	if (!(acpi_processor_ppc_status & PPC_REGISTERED))
567		return_VALUE(-EINVAL);
568
569	down(&performance_sem);
570
571	pr = processors[cpu];
572	if (!pr) {
573		up(&performance_sem);
574		return_VALUE(-ENODEV);
575	}
576
577	if (pr->performance) {
578		up(&performance_sem);
579		return_VALUE(-EBUSY);
580	}
581
582	pr->performance = performance;
583
584	if (acpi_processor_get_performance_info(pr)) {
585		pr->performance = NULL;
586		up(&performance_sem);
587		return_VALUE(-EIO);
588	}
589
590	acpi_cpufreq_add_file(pr);
591
592	up(&performance_sem);
593	return_VALUE(0);
594}
595
596EXPORT_SYMBOL(acpi_processor_register_performance);
597
598void
599acpi_processor_unregister_performance(struct acpi_processor_performance
600				      *performance, unsigned int cpu)
601{
602	struct acpi_processor *pr;
603
604	ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
605
606	down(&performance_sem);
607
608	pr = processors[cpu];
609	if (!pr) {
610		up(&performance_sem);
611		return_VOID;
612	}
613
614	kfree(pr->performance->states);
615	pr->performance = NULL;
616
617	acpi_cpufreq_remove_file(pr);
618
619	up(&performance_sem);
620
621	return_VOID;
622}
623
624EXPORT_SYMBOL(acpi_processor_unregister_performance);
625