xref: /linux/drivers/acpi/processor_perflib.c (revision d8327c784b51b57dac2c26cfad87dce0d68dfd98) 
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
49 ACPI_MODULE_NAME("acpi_processor")
50 
51 static 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 
66 static int acpi_processor_ppc_status = 0;
67 
68 static 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 
101 static struct notifier_block acpi_ppc_notifier_block = {
102 	.notifier_call = acpi_processor_ppc_notifier,
103 };
104 
105 static 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 
134 int 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 
143 void 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 
153 void 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 
162 static 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 
227 static 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 
307 static 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 	status = acpi_get_handle(pr->handle, "_PCT", &handle);
319 	if (ACPI_FAILURE(status)) {
320 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
321 				  "ACPI-based processor performance control unavailable\n"));
322 		return_VALUE(-ENODEV);
323 	}
324 
325 	result = acpi_processor_get_performance_control(pr);
326 	if (result)
327 		return_VALUE(result);
328 
329 	result = acpi_processor_get_performance_states(pr);
330 	if (result)
331 		return_VALUE(result);
332 
333 	result = acpi_processor_get_platform_limit(pr);
334 	if (result)
335 		return_VALUE(result);
336 
337 	return_VALUE(0);
338 }
339 
340 int acpi_processor_notify_smm(struct module *calling_module)
341 {
342 	acpi_status status;
343 	static int is_done = 0;
344 
345 	ACPI_FUNCTION_TRACE("acpi_processor_notify_smm");
346 
347 	if (!(acpi_processor_ppc_status & PPC_REGISTERED))
348 		return_VALUE(-EBUSY);
349 
350 	if (!try_module_get(calling_module))
351 		return_VALUE(-EINVAL);
352 
353 	/* is_done is set to negative if an error occured,
354 	 * and to postitive if _no_ error occured, but SMM
355 	 * was already notified. This avoids double notification
356 	 * which might lead to unexpected results...
357 	 */
358 	if (is_done > 0) {
359 		module_put(calling_module);
360 		return_VALUE(0);
361 	} else if (is_done < 0) {
362 		module_put(calling_module);
363 		return_VALUE(is_done);
364 	}
365 
366 	is_done = -EIO;
367 
368 	/* Can't write pstate_cnt to smi_cmd if either value is zero */
369 	if ((!acpi_fadt.smi_cmd) || (!acpi_fadt.pstate_cnt)) {
370 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_cnt\n"));
371 		module_put(calling_module);
372 		return_VALUE(0);
373 	}
374 
375 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
376 			  "Writing pstate_cnt [0x%x] to smi_cmd [0x%x]\n",
377 			  acpi_fadt.pstate_cnt, acpi_fadt.smi_cmd));
378 
379 	/* FADT v1 doesn't support pstate_cnt, many BIOS vendors use
380 	 * it anyway, so we need to support it... */
381 	if (acpi_fadt_is_v1) {
382 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
383 				  "Using v1.0 FADT reserved value for pstate_cnt\n"));
384 	}
385 
386 	status = acpi_os_write_port(acpi_fadt.smi_cmd,
387 				    (u32) acpi_fadt.pstate_cnt, 8);
388 	if (ACPI_FAILURE(status)) {
389 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
390 				  "Failed to write pstate_cnt [0x%x] to "
391 				  "smi_cmd [0x%x]\n", acpi_fadt.pstate_cnt,
392 				  acpi_fadt.smi_cmd));
393 		module_put(calling_module);
394 		return_VALUE(status);
395 	}
396 
397 	/* Success. If there's no _PPC, we need to fear nothing, so
398 	 * we can allow the cpufreq driver to be rmmod'ed. */
399 	is_done = 1;
400 
401 	if (!(acpi_processor_ppc_status & PPC_IN_USE))
402 		module_put(calling_module);
403 
404 	return_VALUE(0);
405 }
406 
407 EXPORT_SYMBOL(acpi_processor_notify_smm);
408 
409 #ifdef CONFIG_X86_ACPI_CPUFREQ_PROC_INTF
410 /* /proc/acpi/processor/../performance interface (DEPRECATED) */
411 
412 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file);
413 static struct file_operations acpi_processor_perf_fops = {
414 	.open = acpi_processor_perf_open_fs,
415 	.read = seq_read,
416 	.llseek = seq_lseek,
417 	.release = single_release,
418 };
419 
420 static int acpi_processor_perf_seq_show(struct seq_file *seq, void *offset)
421 {
422 	struct acpi_processor *pr = (struct acpi_processor *)seq->private;
423 	int i;
424 
425 	ACPI_FUNCTION_TRACE("acpi_processor_perf_seq_show");
426 
427 	if (!pr)
428 		goto end;
429 
430 	if (!pr->performance) {
431 		seq_puts(seq, "<not supported>\n");
432 		goto end;
433 	}
434 
435 	seq_printf(seq, "state count:             %d\n"
436 		   "active state:            P%d\n",
437 		   pr->performance->state_count, pr->performance->state);
438 
439 	seq_puts(seq, "states:\n");
440 	for (i = 0; i < pr->performance->state_count; i++)
441 		seq_printf(seq,
442 			   "   %cP%d:                  %d MHz, %d mW, %d uS\n",
443 			   (i == pr->performance->state ? '*' : ' '), i,
444 			   (u32) pr->performance->states[i].core_frequency,
445 			   (u32) pr->performance->states[i].power,
446 			   (u32) pr->performance->states[i].transition_latency);
447 
448       end:
449 	return_VALUE(0);
450 }
451 
452 static int acpi_processor_perf_open_fs(struct inode *inode, struct file *file)
453 {
454 	return single_open(file, acpi_processor_perf_seq_show,
455 			   PDE(inode)->data);
456 }
457 
458 static ssize_t
459 acpi_processor_write_performance(struct file *file,
460 				 const char __user * buffer,
461 				 size_t count, loff_t * data)
462 {
463 	int result = 0;
464 	struct seq_file *m = (struct seq_file *)file->private_data;
465 	struct acpi_processor *pr = (struct acpi_processor *)m->private;
466 	struct acpi_processor_performance *perf;
467 	char state_string[12] = { '\0' };
468 	unsigned int new_state = 0;
469 	struct cpufreq_policy policy;
470 
471 	ACPI_FUNCTION_TRACE("acpi_processor_write_performance");
472 
473 	if (!pr || (count > sizeof(state_string) - 1))
474 		return_VALUE(-EINVAL);
475 
476 	perf = pr->performance;
477 	if (!perf)
478 		return_VALUE(-EINVAL);
479 
480 	if (copy_from_user(state_string, buffer, count))
481 		return_VALUE(-EFAULT);
482 
483 	state_string[count] = '\0';
484 	new_state = simple_strtoul(state_string, NULL, 0);
485 
486 	if (new_state >= perf->state_count)
487 		return_VALUE(-EINVAL);
488 
489 	cpufreq_get_policy(&policy, pr->id);
490 
491 	policy.cpu = pr->id;
492 	policy.min = perf->states[new_state].core_frequency * 1000;
493 	policy.max = perf->states[new_state].core_frequency * 1000;
494 
495 	result = cpufreq_set_policy(&policy);
496 	if (result)
497 		return_VALUE(result);
498 
499 	return_VALUE(count);
500 }
501 
502 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
503 {
504 	struct proc_dir_entry *entry = NULL;
505 	struct acpi_device *device = NULL;
506 
507 	ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
508 
509 	if (acpi_bus_get_device(pr->handle, &device))
510 		return_VOID;
511 
512 	/* add file 'performance' [R/W] */
513 	entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
514 				  S_IFREG | S_IRUGO | S_IWUSR,
515 				  acpi_device_dir(device));
516 	if (!entry)
517 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
518 				  "Unable to create '%s' fs entry\n",
519 				  ACPI_PROCESSOR_FILE_PERFORMANCE));
520 	else {
521 		acpi_processor_perf_fops.write = acpi_processor_write_performance;
522 		entry->proc_fops = &acpi_processor_perf_fops;
523 		entry->data = acpi_driver_data(device);
524 		entry->owner = THIS_MODULE;
525 	}
526 	return_VOID;
527 }
528 
529 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
530 {
531 	struct acpi_device *device = NULL;
532 
533 	ACPI_FUNCTION_TRACE("acpi_cpufreq_addfile");
534 
535 	if (acpi_bus_get_device(pr->handle, &device))
536 		return_VOID;
537 
538 	/* remove file 'performance' */
539 	remove_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
540 			  acpi_device_dir(device));
541 
542 	return_VOID;
543 }
544 
545 #else
546 static void acpi_cpufreq_add_file(struct acpi_processor *pr)
547 {
548 	return;
549 }
550 static void acpi_cpufreq_remove_file(struct acpi_processor *pr)
551 {
552 	return;
553 }
554 #endif				/* CONFIG_X86_ACPI_CPUFREQ_PROC_INTF */
555 
556 int
557 acpi_processor_register_performance(struct acpi_processor_performance
558 				    *performance, unsigned int cpu)
559 {
560 	struct acpi_processor *pr;
561 
562 	ACPI_FUNCTION_TRACE("acpi_processor_register_performance");
563 
564 	if (!(acpi_processor_ppc_status & PPC_REGISTERED))
565 		return_VALUE(-EINVAL);
566 
567 	down(&performance_sem);
568 
569 	pr = processors[cpu];
570 	if (!pr) {
571 		up(&performance_sem);
572 		return_VALUE(-ENODEV);
573 	}
574 
575 	if (pr->performance) {
576 		up(&performance_sem);
577 		return_VALUE(-EBUSY);
578 	}
579 
580 	pr->performance = performance;
581 
582 	if (acpi_processor_get_performance_info(pr)) {
583 		pr->performance = NULL;
584 		up(&performance_sem);
585 		return_VALUE(-EIO);
586 	}
587 
588 	acpi_cpufreq_add_file(pr);
589 
590 	up(&performance_sem);
591 	return_VALUE(0);
592 }
593 
594 EXPORT_SYMBOL(acpi_processor_register_performance);
595 
596 void
597 acpi_processor_unregister_performance(struct acpi_processor_performance
598 				      *performance, unsigned int cpu)
599 {
600 	struct acpi_processor *pr;
601 
602 	ACPI_FUNCTION_TRACE("acpi_processor_unregister_performance");
603 
604 	down(&performance_sem);
605 
606 	pr = processors[cpu];
607 	if (!pr) {
608 		up(&performance_sem);
609 		return_VOID;
610 	}
611 
612 	kfree(pr->performance->states);
613 	pr->performance = NULL;
614 
615 	acpi_cpufreq_remove_file(pr);
616 
617 	up(&performance_sem);
618 
619 	return_VOID;
620 }
621 
622 EXPORT_SYMBOL(acpi_processor_unregister_performance);
623