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Root/drivers/cpufreq/acpi-cpufreq.c

1	/*
2	* acpi-cpufreq.c - ACPI Processor P-States Driver
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	* Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
8	*
9	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10	*
11	* This program is free software; you can redistribute it and/or modify
12	* it under the terms of the GNU General Public License as published by
13	* the Free Software Foundation; either version 2 of the License, or (at
14	* your option) any later version.
15	*
16	* This program is distributed in the hope that it will be useful, but
17	* WITHOUT ANY WARRANTY; without even the implied warranty of
18	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19	* General Public License for more details.
20	*
21	* You should have received a copy of the GNU General Public License along
22	* with this program; if not, write to the Free Software Foundation, Inc.,
23	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24	*
25	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26	*/
27
28	#include <linux/kernel.h>
29	#include <linux/module.h>
30	#include <linux/init.h>
31	#include <linux/smp.h>
32	#include <linux/sched.h>
33	#include <linux/cpufreq.h>
34	#include <linux/compiler.h>
35	#include <linux/dmi.h>
36	#include <linux/slab.h>
37
38	#include <linux/acpi.h>
39	#include <linux/io.h>
40	#include <linux/delay.h>
41	#include <linux/uaccess.h>
42
43	#include <acpi/processor.h>
44
45	#include <asm/msr.h>
46	#include <asm/processor.h>
47	#include <asm/cpufeature.h>
48	#include "mperf.h"
49
50	MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
51	MODULE_DESCRIPTION("ACPI Processor P-States Driver");
52	MODULE_LICENSE("GPL");
53
54	enum {
55	UNDEFINED_CAPABLE = 0,
56	SYSTEM_INTEL_MSR_CAPABLE,
57	SYSTEM_IO_CAPABLE,
58	};
59
60	#define INTEL_MSR_RANGE (0xffff)
61
62	struct acpi_cpufreq_data {
63	struct acpi_processor_performance *acpi_data;
64	struct cpufreq_frequency_table *freq_table;
65	unsigned int resume;
66	unsigned int cpu_feature;
67	};
68
69	static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
70
71	/* acpi_perf_data is a pointer to percpu data. */
72	static struct acpi_processor_performance __percpu *acpi_perf_data;
73
74	static struct cpufreq_driver acpi_cpufreq_driver;
75
76	static unsigned int acpi_pstate_strict;
77
78	static int check_est_cpu(unsigned int cpuid)
79	{
80	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
81
82	return cpu_has(cpu, X86_FEATURE_EST);
83	}
84
85	static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
86	{
87	struct acpi_processor_performance *perf;
88	int i;
89
90	perf = data->acpi_data;
91
92	for (i = 0; i < perf->state_count; i++) {
93	if (value == perf->states[i].status)
94	return data->freq_table[i].frequency;
95	}
96	return 0;
97	}
98
99	static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
100	{
101	int i;
102	struct acpi_processor_performance *perf;
103
104	msr &= INTEL_MSR_RANGE;
105	perf = data->acpi_data;
106
107	for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
108	if (msr == perf->states[data->freq_table[i].index].status)
109	return data->freq_table[i].frequency;
110	}
111	return data->freq_table[0].frequency;
112	}
113
114	static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
115	{
116	switch (data->cpu_feature) {
117	case SYSTEM_INTEL_MSR_CAPABLE:
118	return extract_msr(val, data);
119	case SYSTEM_IO_CAPABLE:
120	return extract_io(val, data);
121	default:
122	return 0;
123	}
124	}
125
126	struct msr_addr {
127	u32 reg;
128	};
129
130	struct io_addr {
131	u16 port;
132	u8 bit_width;
133	};
134
135	struct drv_cmd {
136	unsigned int type;
137	const struct cpumask *mask;
138	union {
139	struct msr_addr msr;
140	struct io_addr io;
141	} addr;
142	u32 val;
143	};
144
145	/* Called via smp_call_function_single(), on the target CPU */
146	static void do_drv_read(void *_cmd)
147	{
148	struct drv_cmd *cmd = _cmd;
149	u32 h;
150
151	switch (cmd->type) {
152	case SYSTEM_INTEL_MSR_CAPABLE:
153	rdmsr(cmd->addr.msr.reg, cmd->val, h);
154	break;
155	case SYSTEM_IO_CAPABLE:
156	acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
157	&cmd->val,
158	(u32)cmd->addr.io.bit_width);
159	break;
160	default:
161	break;
162	}
163	}
164
165	/* Called via smp_call_function_many(), on the target CPUs */
166	static void do_drv_write(void *_cmd)
167	{
168	struct drv_cmd *cmd = _cmd;
169	u32 lo, hi;
170
171	switch (cmd->type) {
172	case SYSTEM_INTEL_MSR_CAPABLE:
173	rdmsr(cmd->addr.msr.reg, lo, hi);
174	lo = (lo & ~INTEL_MSR_RANGE) \| (cmd->val & INTEL_MSR_RANGE);
175	wrmsr(cmd->addr.msr.reg, lo, hi);
176	break;
177	case SYSTEM_IO_CAPABLE:
178	acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
179	cmd->val,
180	(u32)cmd->addr.io.bit_width);
181	break;
182	default:
183	break;
184	}
185	}
186
187	static void drv_read(struct drv_cmd *cmd)
188	{
189	int err;
190	cmd->val = 0;
191
192	err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
193	WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */
194	}
195
196	static void drv_write(struct drv_cmd *cmd)
197	{
198	int this_cpu;
199
200	this_cpu = get_cpu();
201	if (cpumask_test_cpu(this_cpu, cmd->mask))
202	do_drv_write(cmd);
203	smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
204	put_cpu();
205	}
206
207	static u32 get_cur_val(const struct cpumask *mask)
208	{
209	struct acpi_processor_performance *perf;
210	struct drv_cmd cmd;
211
212	if (unlikely(cpumask_empty(mask)))
213	return 0;
214
215	switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
216	case SYSTEM_INTEL_MSR_CAPABLE:
217	cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
218	cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
219	break;
220	case SYSTEM_IO_CAPABLE:
221	cmd.type = SYSTEM_IO_CAPABLE;
222	perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
223	cmd.addr.io.port = perf->control_register.address;
224	cmd.addr.io.bit_width = perf->control_register.bit_width;
225	break;
226	default:
227	return 0;
228	}
229
230	cmd.mask = mask;
231	drv_read(&cmd);
232
233	pr_debug("get_cur_val = %u\n", cmd.val);
234
235	return cmd.val;
236	}
237
238	static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
239	{
240	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
241	unsigned int freq;
242	unsigned int cached_freq;
243
244	pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
245
246	if (unlikely(data == NULL \|\|
247	data->acpi_data == NULL \|\| data->freq_table == NULL)) {
248	return 0;
249	}
250
251	cached_freq = data->freq_table[data->acpi_data->state].frequency;
252	freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
253	if (freq != cached_freq) {
254	/*
255	* The dreaded BIOS frequency change behind our back.
256	* Force set the frequency on next target call.
257	*/
258	data->resume = 1;
259	}
260
261	pr_debug("cur freq = %u\n", freq);
262
263	return freq;
264	}
265
266	static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
267	struct acpi_cpufreq_data *data)
268	{
269	unsigned int cur_freq;
270	unsigned int i;
271
272	for (i = 0; i < 100; i++) {
273	cur_freq = extract_freq(get_cur_val(mask), data);
274	if (cur_freq == freq)
275	return 1;
276	udelay(10);
277	}
278	return 0;
279	}
280
281	static int acpi_cpufreq_target(struct cpufreq_policy *policy,
282	unsigned int target_freq, unsigned int relation)
283	{
284	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
285	struct acpi_processor_performance *perf;
286	struct cpufreq_freqs freqs;
287	struct drv_cmd cmd;
288	unsigned int next_state = 0; /* Index into freq_table */
289	unsigned int next_perf_state = 0; /* Index into perf table */
290	unsigned int i;
291	int result = 0;
292
293	pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
294
295	if (unlikely(data == NULL \|\|
296	data->acpi_data == NULL \|\| data->freq_table == NULL)) {
297	return -ENODEV;
298	}
299
300	perf = data->acpi_data;
301	result = cpufreq_frequency_table_target(policy,
302	data->freq_table,
303	target_freq,
304	relation, &next_state);
305	if (unlikely(result)) {
306	result = -ENODEV;
307	goto out;
308	}
309
310	next_perf_state = data->freq_table[next_state].index;
311	if (perf->state == next_perf_state) {
312	if (unlikely(data->resume)) {
313	pr_debug("Called after resume, resetting to P%d\n",
314	next_perf_state);
315	data->resume = 0;
316	} else {
317	pr_debug("Already at target state (P%d)\n",
318	next_perf_state);
319	goto out;
320	}
321	}
322
323	switch (data->cpu_feature) {
324	case SYSTEM_INTEL_MSR_CAPABLE:
325	cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
326	cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
327	cmd.val = (u32) perf->states[next_perf_state].control;
328	break;
329	case SYSTEM_IO_CAPABLE:
330	cmd.type = SYSTEM_IO_CAPABLE;
331	cmd.addr.io.port = perf->control_register.address;
332	cmd.addr.io.bit_width = perf->control_register.bit_width;
333	cmd.val = (u32) perf->states[next_perf_state].control;
334	break;
335	default:
336	result = -ENODEV;
337	goto out;
338	}
339
340	/* cpufreq holds the hotplug lock, so we are safe from here on */
341	if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
342	cmd.mask = policy->cpus;
343	else
344	cmd.mask = cpumask_of(policy->cpu);
345
346	freqs.old = perf->states[perf->state].core_frequency * 1000;
347	freqs.new = data->freq_table[next_state].frequency;
348	for_each_cpu(i, policy->cpus) {
349	freqs.cpu = i;
350	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
351	}
352
353	drv_write(&cmd);
354
355	if (acpi_pstate_strict) {
356	if (!check_freqs(cmd.mask, freqs.new, data)) {
357	pr_debug("acpi_cpufreq_target failed (%d)\n",
358	policy->cpu);
359	result = -EAGAIN;
360	goto out;
361	}
362	}
363
364	for_each_cpu(i, policy->cpus) {
365	freqs.cpu = i;
366	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
367	}
368	perf->state = next_perf_state;
369
370	out:
371	return result;
372	}
373
374	static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
375	{
376	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
377
378	pr_debug("acpi_cpufreq_verify\n");
379
380	return cpufreq_frequency_table_verify(policy, data->freq_table);
381	}
382
383	static unsigned long
384	acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
385	{
386	struct acpi_processor_performance *perf = data->acpi_data;
387
388	if (cpu_khz) {
389	/* search the closest match to cpu_khz */
390	unsigned int i;
391	unsigned long freq;
392	unsigned long freqn = perf->states[0].core_frequency * 1000;
393
394	for (i = 0; i < (perf->state_count-1); i++) {
395	freq = freqn;
396	freqn = perf->states[i+1].core_frequency * 1000;
397	if ((2 * cpu_khz) > (freqn + freq)) {
398	perf->state = i;
399	return freq;
400	}
401	}
402	perf->state = perf->state_count-1;
403	return freqn;
404	} else {
405	/* assume CPU is at P0... */
406	perf->state = 0;
407	return perf->states[0].core_frequency * 1000;
408	}
409	}
410
411	static void free_acpi_perf_data(void)
412	{
413	unsigned int i;
414
415	/* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
416	for_each_possible_cpu(i)
417	free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
418	->shared_cpu_map);
419	free_percpu(acpi_perf_data);
420	}
421
422	/*
423	* acpi_cpufreq_early_init - initialize ACPI P-States library
424	*
425	* Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
426	* in order to determine correct frequency and voltage pairings. We can
427	* do _PDC and _PSD and find out the processor dependency for the
428	* actual init that will happen later...
429	*/
430	static int __init acpi_cpufreq_early_init(void)
431	{
432	unsigned int i;
433	pr_debug("acpi_cpufreq_early_init\n");
434
435	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
436	if (!acpi_perf_data) {
437	pr_debug("Memory allocation error for acpi_perf_data.\n");
438	return -ENOMEM;
439	}
440	for_each_possible_cpu(i) {
441	if (!zalloc_cpumask_var_node(
442	&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
443	GFP_KERNEL, cpu_to_node(i))) {
444
445	/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
446	free_acpi_perf_data();
447	return -ENOMEM;
448	}
449	}
450
451	/* Do initialization in ACPI core */
452	acpi_processor_preregister_performance(acpi_perf_data);
453	return 0;
454	}
455
456	#ifdef CONFIG_SMP
457	/*
458	* Some BIOSes do SW_ANY coordination internally, either set it up in hw
459	* or do it in BIOS firmware and won't inform about it to OS. If not
460	* detected, this has a side effect of making CPU run at a different speed
461	* than OS intended it to run at. Detect it and handle it cleanly.
462	*/
463	static int bios_with_sw_any_bug;
464
465	static int sw_any_bug_found(const struct dmi_system_id *d)
466	{
467	bios_with_sw_any_bug = 1;
468	return 0;
469	}
470
471	static const struct dmi_system_id sw_any_bug_dmi_table[] = {
472	{
473	.callback = sw_any_bug_found,
474	.ident = "Supermicro Server X6DLP",
475	.matches = {
476	DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
477	DMI_MATCH(DMI_BIOS_VERSION, "080010"),
478	DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
479	},
480	},
481	{ }
482	};
483
484	static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
485	{
486	/* Intel Xeon Processor 7100 Series Specification Update
487	* http://www.intel.com/Assets/PDF/specupdate/314554.pdf
488	* AL30: A Machine Check Exception (MCE) Occurring during an
489	* Enhanced Intel SpeedStep Technology Ratio Change May Cause
490	* Both Processor Cores to Lock Up. */
491	if (c->x86_vendor == X86_VENDOR_INTEL) {
492	if ((c->x86 == 15) &&
493	(c->x86_model == 6) &&
494	(c->x86_mask == 8)) {
495	printk(KERN_INFO "acpi-cpufreq: Intel(R) "
496	"Xeon(R) 7100 Errata AL30, processors may "
497	"lock up on frequency changes: disabling "
498	"acpi-cpufreq.\n");
499	return -ENODEV;
500	}
501	}
502	return 0;
503	}
504	#endif
505
506	static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
507	{
508	unsigned int i;
509	unsigned int valid_states = 0;
510	unsigned int cpu = policy->cpu;
511	struct acpi_cpufreq_data *data;
512	unsigned int result = 0;
513	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
514	struct acpi_processor_performance *perf;
515	#ifdef CONFIG_SMP
516	static int blacklisted;
517	#endif
518
519	pr_debug("acpi_cpufreq_cpu_init\n");
520
521	#ifdef CONFIG_SMP
522	if (blacklisted)
523	return blacklisted;
524	blacklisted = acpi_cpufreq_blacklist(c);
525	if (blacklisted)
526	return blacklisted;
527	#endif
528
529	data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
530	if (!data)
531	return -ENOMEM;
532
533	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
534	per_cpu(acfreq_data, cpu) = data;
535
536	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
537	acpi_cpufreq_driver.flags \|= CPUFREQ_CONST_LOOPS;
538
539	result = acpi_processor_register_performance(data->acpi_data, cpu);
540	if (result)
541	goto err_free;
542
543	perf = data->acpi_data;
544	policy->shared_type = perf->shared_type;
545
546	/*
547	* Will let policy->cpus know about dependency only when software
548	* coordination is required.
549	*/
550	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL \|\|
551	policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
552	cpumask_copy(policy->cpus, perf->shared_cpu_map);
553	}
554	cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
555
556	#ifdef CONFIG_SMP
557	dmi_check_system(sw_any_bug_dmi_table);
558	if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
559	policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
560	cpumask_copy(policy->cpus, cpu_core_mask(cpu));
561	}
562	#endif
563
564	/* capability check */
565	if (perf->state_count <= 1) {
566	pr_debug("No P-States\n");
567	result = -ENODEV;
568	goto err_unreg;
569	}
570
571	if (perf->control_register.space_id != perf->status_register.space_id) {
572	result = -ENODEV;
573	goto err_unreg;
574	}
575
576	switch (perf->control_register.space_id) {
577	case ACPI_ADR_SPACE_SYSTEM_IO:
578	pr_debug("SYSTEM IO addr space\n");
579	data->cpu_feature = SYSTEM_IO_CAPABLE;
580	break;
581	case ACPI_ADR_SPACE_FIXED_HARDWARE:
582	pr_debug("HARDWARE addr space\n");
583	if (!check_est_cpu(cpu)) {
584	result = -ENODEV;
585	goto err_unreg;
586	}
587	data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
588	break;
589	default:
590	pr_debug("Unknown addr space %d\n",
591	(u32) (perf->control_register.space_id));
592	result = -ENODEV;
593	goto err_unreg;
594	}
595
596	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
597	(perf->state_count+1), GFP_KERNEL);
598	if (!data->freq_table) {
599	result = -ENOMEM;
600	goto err_unreg;
601	}
602
603	/* detect transition latency */
604	policy->cpuinfo.transition_latency = 0;
605	for (i = 0; i < perf->state_count; i++) {
606	if ((perf->states[i].transition_latency * 1000) >
607	policy->cpuinfo.transition_latency)
608	policy->cpuinfo.transition_latency =
609	perf->states[i].transition_latency * 1000;
610	}
611
612	/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
613	if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
614	policy->cpuinfo.transition_latency > 20 * 1000) {
615	policy->cpuinfo.transition_latency = 20 * 1000;
616	printk_once(KERN_INFO
617	"P-state transition latency capped at 20 uS\n");
618	}
619
620	/* table init */
621	for (i = 0; i < perf->state_count; i++) {
622	if (i > 0 && perf->states[i].core_frequency >=
623	data->freq_table[valid_states-1].frequency / 1000)
624	continue;
625
626	data->freq_table[valid_states].index = i;
627	data->freq_table[valid_states].frequency =
628	perf->states[i].core_frequency * 1000;
629	valid_states++;
630	}
631	data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
632	perf->state = 0;
633
634	result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
635	if (result)
636	goto err_freqfree;
637
638	if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
639	printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
640
641	switch (perf->control_register.space_id) {
642	case ACPI_ADR_SPACE_SYSTEM_IO:
643	/* Current speed is unknown and not detectable by IO port */
644	policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
645	break;
646	case ACPI_ADR_SPACE_FIXED_HARDWARE:
647	acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
648	policy->cur = get_cur_freq_on_cpu(cpu);
649	break;
650	default:
651	break;
652	}
653
654	/* notify BIOS that we exist */
655	acpi_processor_notify_smm(THIS_MODULE);
656
657	/* Check for APERF/MPERF support in hardware */
658	if (boot_cpu_has(X86_FEATURE_APERFMPERF))
659	acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
660
661	pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
662	for (i = 0; i < perf->state_count; i++)
663	pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
664	(i == perf->state ? '*' : ' '), i,
665	(u32) perf->states[i].core_frequency,
666	(u32) perf->states[i].power,
667	(u32) perf->states[i].transition_latency);
668
669	cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
670
671	/*
672	* the first call to ->target() should result in us actually
673	* writing something to the appropriate registers.
674	*/
675	data->resume = 1;
676
677	return result;
678
679	err_freqfree:
680	kfree(data->freq_table);
681	err_unreg:
682	acpi_processor_unregister_performance(perf, cpu);
683	err_free:
684	kfree(data);
685	per_cpu(acfreq_data, cpu) = NULL;
686
687	return result;
688	}
689
690	static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
691	{
692	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
693
694	pr_debug("acpi_cpufreq_cpu_exit\n");
695
696	if (data) {
697	cpufreq_frequency_table_put_attr(policy->cpu);
698	per_cpu(acfreq_data, policy->cpu) = NULL;
699	acpi_processor_unregister_performance(data->acpi_data,
700	policy->cpu);
701	kfree(data->freq_table);
702	kfree(data);
703	}
704
705	return 0;
706	}
707
708	static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
709	{
710	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
711
712	pr_debug("acpi_cpufreq_resume\n");
713
714	data->resume = 1;
715
716	return 0;
717	}
718
719	static struct freq_attr *acpi_cpufreq_attr[] = {
720	&cpufreq_freq_attr_scaling_available_freqs,
721	NULL,
722	};
723
724	static struct cpufreq_driver acpi_cpufreq_driver = {
725	.verify = acpi_cpufreq_verify,
726	.target = acpi_cpufreq_target,
727	.bios_limit = acpi_processor_get_bios_limit,
728	.init = acpi_cpufreq_cpu_init,
729	.exit = acpi_cpufreq_cpu_exit,
730	.resume = acpi_cpufreq_resume,
731	.name = "acpi-cpufreq",
732	.owner = THIS_MODULE,
733	.attr = acpi_cpufreq_attr,
734	};
735
736	static int __init acpi_cpufreq_init(void)
737	{
738	int ret;
739
740	if (acpi_disabled)
741	return 0;
742
743	pr_debug("acpi_cpufreq_init\n");
744
745	ret = acpi_cpufreq_early_init();
746	if (ret)
747	return ret;
748
749	ret = cpufreq_register_driver(&acpi_cpufreq_driver);
750	if (ret)
751	free_acpi_perf_data();
752
753	return ret;
754	}
755
756	static void __exit acpi_cpufreq_exit(void)
757	{
758	pr_debug("acpi_cpufreq_exit\n");
759
760	cpufreq_unregister_driver(&acpi_cpufreq_driver);
761
762	free_acpi_perf_data();
763	}
764
765	module_param(acpi_pstate_strict, uint, 0644);
766	MODULE_PARM_DESC(acpi_pstate_strict,
767	"value 0 or non-zero. non-zero -> strict ACPI checks are "
768	"performed during frequency changes.");
769
770	late_initcall(acpi_cpufreq_init);
771	module_exit(acpi_cpufreq_exit);
772
773	MODULE_ALIAS("acpi");
774

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