2 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
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>
9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
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.
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.
25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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>
37 #include <linux/acpi.h>
38 #include <acpi/processor.h>
42 #include <asm/processor.h>
43 #include <asm/cpufeature.h>
44 #include <asm/delay.h>
45 #include <asm/uaccess.h>
47 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51 MODULE_LICENSE("GPL");
54 UNDEFINED_CAPABLE
= 0,
55 SYSTEM_INTEL_MSR_CAPABLE
,
59 #define INTEL_MSR_RANGE (0xffff)
60 #define CPUID_6_ECX_APERFMPERF_CAPABILITY (0x1)
62 struct acpi_cpufreq_data
{
63 struct acpi_processor_performance
*acpi_data
;
64 struct cpufreq_frequency_table
*freq_table
;
65 unsigned int max_freq
;
67 unsigned int cpu_feature
;
70 static DEFINE_PER_CPU(struct acpi_cpufreq_data
*, drv_data
);
72 /* acpi_perf_data is a pointer to percpu data. */
73 static struct acpi_processor_performance
*acpi_perf_data
;
75 static struct cpufreq_driver acpi_cpufreq_driver
;
77 static unsigned int acpi_pstate_strict
;
79 static int check_est_cpu(unsigned int cpuid
)
81 struct cpuinfo_x86
*cpu
= &cpu_data(cpuid
);
83 if (cpu
->x86_vendor
!= X86_VENDOR_INTEL
||
84 !cpu_has(cpu
, X86_FEATURE_EST
))
90 static unsigned extract_io(u32 value
, struct acpi_cpufreq_data
*data
)
92 struct acpi_processor_performance
*perf
;
95 perf
= data
->acpi_data
;
97 for (i
=0; i
<perf
->state_count
; i
++) {
98 if (value
== perf
->states
[i
].status
)
99 return data
->freq_table
[i
].frequency
;
104 static unsigned extract_msr(u32 msr
, struct acpi_cpufreq_data
*data
)
107 struct acpi_processor_performance
*perf
;
109 msr
&= INTEL_MSR_RANGE
;
110 perf
= data
->acpi_data
;
112 for (i
=0; data
->freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
113 if (msr
== perf
->states
[data
->freq_table
[i
].index
].status
)
114 return data
->freq_table
[i
].frequency
;
116 return data
->freq_table
[0].frequency
;
119 static unsigned extract_freq(u32 val
, struct acpi_cpufreq_data
*data
)
121 switch (data
->cpu_feature
) {
122 case SYSTEM_INTEL_MSR_CAPABLE
:
123 return extract_msr(val
, data
);
124 case SYSTEM_IO_CAPABLE
:
125 return extract_io(val
, data
);
152 static void do_drv_read(struct drv_cmd
*cmd
)
157 case SYSTEM_INTEL_MSR_CAPABLE
:
158 rdmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
160 case SYSTEM_IO_CAPABLE
:
161 acpi_os_read_port((acpi_io_address
)cmd
->addr
.io
.port
,
163 (u32
)cmd
->addr
.io
.bit_width
);
170 static void do_drv_write(struct drv_cmd
*cmd
)
175 case SYSTEM_INTEL_MSR_CAPABLE
:
176 rdmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
177 lo
= (lo
& ~INTEL_MSR_RANGE
) | (cmd
->val
& INTEL_MSR_RANGE
);
178 wrmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
180 case SYSTEM_IO_CAPABLE
:
181 acpi_os_write_port((acpi_io_address
)cmd
->addr
.io
.port
,
183 (u32
)cmd
->addr
.io
.bit_width
);
190 static void drv_read(struct drv_cmd
*cmd
)
192 cpumask_t saved_mask
= current
->cpus_allowed
;
195 set_cpus_allowed_ptr(current
, &cmd
->mask
);
197 set_cpus_allowed_ptr(current
, &saved_mask
);
200 static void drv_write(struct drv_cmd
*cmd
)
202 cpumask_t saved_mask
= current
->cpus_allowed
;
205 for_each_cpu_mask_nr(i
, cmd
->mask
) {
206 set_cpus_allowed_ptr(current
, &cpumask_of_cpu(i
));
210 set_cpus_allowed_ptr(current
, &saved_mask
);
214 static u32
get_cur_val(const cpumask_t
*mask
)
216 struct acpi_processor_performance
*perf
;
219 if (unlikely(cpus_empty(*mask
)))
222 switch (per_cpu(drv_data
, first_cpu(*mask
))->cpu_feature
) {
223 case SYSTEM_INTEL_MSR_CAPABLE
:
224 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
225 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_STATUS
;
227 case SYSTEM_IO_CAPABLE
:
228 cmd
.type
= SYSTEM_IO_CAPABLE
;
229 perf
= per_cpu(drv_data
, first_cpu(*mask
))->acpi_data
;
230 cmd
.addr
.io
.port
= perf
->control_register
.address
;
231 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
241 dprintk("get_cur_val = %u\n", cmd
.val
);
247 * Return the measured active (C0) frequency on this CPU since last call
250 * Return: Average CPU frequency in terms of max frequency (zero on error)
252 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
253 * over a period of time, while CPU is in C0 state.
254 * IA32_MPERF counts at the rate of max advertised frequency
255 * IA32_APERF counts at the rate of actual CPU frequency
256 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
257 * no meaning should be associated with absolute values of these MSRs.
259 static unsigned int get_measured_perf(struct cpufreq_policy
*policy
,
268 } aperf_cur
, mperf_cur
;
270 cpumask_t saved_mask
;
271 unsigned int perf_percent
;
274 saved_mask
= current
->cpus_allowed
;
275 set_cpus_allowed_ptr(current
, &cpumask_of_cpu(cpu
));
276 if (get_cpu() != cpu
) {
277 /* We were not able to run on requested processor */
282 rdmsr(MSR_IA32_APERF
, aperf_cur
.split
.lo
, aperf_cur
.split
.hi
);
283 rdmsr(MSR_IA32_MPERF
, mperf_cur
.split
.lo
, mperf_cur
.split
.hi
);
285 wrmsr(MSR_IA32_APERF
, 0,0);
286 wrmsr(MSR_IA32_MPERF
, 0,0);
290 * We dont want to do 64 bit divide with 32 bit kernel
291 * Get an approximate value. Return failure in case we cannot get
292 * an approximate value.
294 if (unlikely(aperf_cur
.split
.hi
|| mperf_cur
.split
.hi
)) {
298 h
= max_t(u32
, aperf_cur
.split
.hi
, mperf_cur
.split
.hi
);
299 shift_count
= fls(h
);
301 aperf_cur
.whole
>>= shift_count
;
302 mperf_cur
.whole
>>= shift_count
;
305 if (((unsigned long)(-1) / 100) < aperf_cur
.split
.lo
) {
307 aperf_cur
.split
.lo
>>= shift_count
;
308 mperf_cur
.split
.lo
>>= shift_count
;
311 if (aperf_cur
.split
.lo
&& mperf_cur
.split
.lo
)
312 perf_percent
= (aperf_cur
.split
.lo
* 100) / mperf_cur
.split
.lo
;
317 if (unlikely(((unsigned long)(-1) / 100) < aperf_cur
.whole
)) {
319 aperf_cur
.whole
>>= shift_count
;
320 mperf_cur
.whole
>>= shift_count
;
323 if (aperf_cur
.whole
&& mperf_cur
.whole
)
324 perf_percent
= (aperf_cur
.whole
* 100) / mperf_cur
.whole
;
330 retval
= per_cpu(drv_data
, policy
->cpu
)->max_freq
* perf_percent
/ 100;
333 set_cpus_allowed_ptr(current
, &saved_mask
);
335 dprintk("cpu %d: performance percent %d\n", cpu
, perf_percent
);
339 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
341 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, cpu
);
343 unsigned int cached_freq
;
345 dprintk("get_cur_freq_on_cpu (%d)\n", cpu
);
347 if (unlikely(data
== NULL
||
348 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
352 cached_freq
= data
->freq_table
[data
->acpi_data
->state
].frequency
;
353 freq
= extract_freq(get_cur_val(&cpumask_of_cpu(cpu
)), data
);
354 if (freq
!= cached_freq
) {
356 * The dreaded BIOS frequency change behind our back.
357 * Force set the frequency on next target call.
362 dprintk("cur freq = %u\n", freq
);
367 static unsigned int check_freqs(const cpumask_t
*mask
, unsigned int freq
,
368 struct acpi_cpufreq_data
*data
)
370 unsigned int cur_freq
;
373 for (i
=0; i
<100; i
++) {
374 cur_freq
= extract_freq(get_cur_val(mask
), data
);
375 if (cur_freq
== freq
)
382 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
383 unsigned int target_freq
, unsigned int relation
)
385 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
386 struct acpi_processor_performance
*perf
;
387 struct cpufreq_freqs freqs
;
388 cpumask_t online_policy_cpus
;
390 unsigned int next_state
= 0; /* Index into freq_table */
391 unsigned int next_perf_state
= 0; /* Index into perf table */
395 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq
, policy
->cpu
);
397 if (unlikely(data
== NULL
||
398 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
402 perf
= data
->acpi_data
;
403 result
= cpufreq_frequency_table_target(policy
,
406 relation
, &next_state
);
407 if (unlikely(result
))
410 #ifdef CONFIG_HOTPLUG_CPU
411 /* cpufreq holds the hotplug lock, so we are safe from here on */
412 cpus_and(online_policy_cpus
, cpu_online_map
, policy
->cpus
);
414 online_policy_cpus
= policy
->cpus
;
417 next_perf_state
= data
->freq_table
[next_state
].index
;
418 if (perf
->state
== next_perf_state
) {
419 if (unlikely(data
->resume
)) {
420 dprintk("Called after resume, resetting to P%d\n",
424 dprintk("Already at target state (P%d)\n",
430 switch (data
->cpu_feature
) {
431 case SYSTEM_INTEL_MSR_CAPABLE
:
432 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
433 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_CTL
;
434 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
436 case SYSTEM_IO_CAPABLE
:
437 cmd
.type
= SYSTEM_IO_CAPABLE
;
438 cmd
.addr
.io
.port
= perf
->control_register
.address
;
439 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
440 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
446 cpus_clear(cmd
.mask
);
448 if (policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
)
449 cmd
.mask
= online_policy_cpus
;
451 cpu_set(policy
->cpu
, cmd
.mask
);
453 freqs
.old
= perf
->states
[perf
->state
].core_frequency
* 1000;
454 freqs
.new = data
->freq_table
[next_state
].frequency
;
455 for_each_cpu_mask_nr(i
, cmd
.mask
) {
457 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
462 if (acpi_pstate_strict
) {
463 if (!check_freqs(&cmd
.mask
, freqs
.new, data
)) {
464 dprintk("acpi_cpufreq_target failed (%d)\n",
470 for_each_cpu_mask_nr(i
, cmd
.mask
) {
472 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
474 perf
->state
= next_perf_state
;
479 static int acpi_cpufreq_verify(struct cpufreq_policy
*policy
)
481 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
483 dprintk("acpi_cpufreq_verify\n");
485 return cpufreq_frequency_table_verify(policy
, data
->freq_table
);
489 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
491 struct acpi_processor_performance
*perf
= data
->acpi_data
;
494 /* search the closest match to cpu_khz */
497 unsigned long freqn
= perf
->states
[0].core_frequency
* 1000;
499 for (i
=0; i
<(perf
->state_count
-1); i
++) {
501 freqn
= perf
->states
[i
+1].core_frequency
* 1000;
502 if ((2 * cpu_khz
) > (freqn
+ freq
)) {
507 perf
->state
= perf
->state_count
-1;
510 /* assume CPU is at P0... */
512 return perf
->states
[0].core_frequency
* 1000;
517 * acpi_cpufreq_early_init - initialize ACPI P-States library
519 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
520 * in order to determine correct frequency and voltage pairings. We can
521 * do _PDC and _PSD and find out the processor dependency for the
522 * actual init that will happen later...
524 static int __init
acpi_cpufreq_early_init(void)
526 dprintk("acpi_cpufreq_early_init\n");
528 acpi_perf_data
= alloc_percpu(struct acpi_processor_performance
);
529 if (!acpi_perf_data
) {
530 dprintk("Memory allocation error for acpi_perf_data.\n");
534 /* Do initialization in ACPI core */
535 acpi_processor_preregister_performance(acpi_perf_data
);
541 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
542 * or do it in BIOS firmware and won't inform about it to OS. If not
543 * detected, this has a side effect of making CPU run at a different speed
544 * than OS intended it to run at. Detect it and handle it cleanly.
546 static int bios_with_sw_any_bug
;
548 static int sw_any_bug_found(const struct dmi_system_id
*d
)
550 bios_with_sw_any_bug
= 1;
554 static const struct dmi_system_id sw_any_bug_dmi_table
[] = {
556 .callback
= sw_any_bug_found
,
557 .ident
= "Supermicro Server X6DLP",
559 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
560 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
561 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
568 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
571 unsigned int valid_states
= 0;
572 unsigned int cpu
= policy
->cpu
;
573 struct acpi_cpufreq_data
*data
;
574 unsigned int result
= 0;
575 struct cpuinfo_x86
*c
= &cpu_data(policy
->cpu
);
576 struct acpi_processor_performance
*perf
;
578 dprintk("acpi_cpufreq_cpu_init\n");
580 data
= kzalloc(sizeof(struct acpi_cpufreq_data
), GFP_KERNEL
);
584 data
->acpi_data
= percpu_ptr(acpi_perf_data
, cpu
);
585 per_cpu(drv_data
, cpu
) = data
;
587 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
588 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
590 result
= acpi_processor_register_performance(data
->acpi_data
, cpu
);
594 perf
= data
->acpi_data
;
595 policy
->shared_type
= perf
->shared_type
;
598 * Will let policy->cpus know about dependency only when software
599 * coordination is required.
601 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
602 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
603 policy
->cpus
= perf
->shared_cpu_map
;
605 policy
->related_cpus
= perf
->shared_cpu_map
;
608 dmi_check_system(sw_any_bug_dmi_table
);
609 if (bios_with_sw_any_bug
&& cpus_weight(policy
->cpus
) == 1) {
610 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
611 policy
->cpus
= per_cpu(cpu_core_map
, cpu
);
615 /* capability check */
616 if (perf
->state_count
<= 1) {
617 dprintk("No P-States\n");
622 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
627 switch (perf
->control_register
.space_id
) {
628 case ACPI_ADR_SPACE_SYSTEM_IO
:
629 dprintk("SYSTEM IO addr space\n");
630 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
632 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
633 dprintk("HARDWARE addr space\n");
634 if (!check_est_cpu(cpu
)) {
638 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
641 dprintk("Unknown addr space %d\n",
642 (u32
) (perf
->control_register
.space_id
));
647 data
->freq_table
= kmalloc(sizeof(struct cpufreq_frequency_table
) *
648 (perf
->state_count
+1), GFP_KERNEL
);
649 if (!data
->freq_table
) {
654 /* detect transition latency */
655 policy
->cpuinfo
.transition_latency
= 0;
656 for (i
=0; i
<perf
->state_count
; i
++) {
657 if ((perf
->states
[i
].transition_latency
* 1000) >
658 policy
->cpuinfo
.transition_latency
)
659 policy
->cpuinfo
.transition_latency
=
660 perf
->states
[i
].transition_latency
* 1000;
663 data
->max_freq
= perf
->states
[0].core_frequency
* 1000;
665 for (i
=0; i
<perf
->state_count
; i
++) {
666 if (i
>0 && perf
->states
[i
].core_frequency
>=
667 data
->freq_table
[valid_states
-1].frequency
/ 1000)
670 data
->freq_table
[valid_states
].index
= i
;
671 data
->freq_table
[valid_states
].frequency
=
672 perf
->states
[i
].core_frequency
* 1000;
675 data
->freq_table
[valid_states
].frequency
= CPUFREQ_TABLE_END
;
678 result
= cpufreq_frequency_table_cpuinfo(policy
, data
->freq_table
);
682 switch (perf
->control_register
.space_id
) {
683 case ACPI_ADR_SPACE_SYSTEM_IO
:
684 /* Current speed is unknown and not detectable by IO port */
685 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
687 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
688 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
689 policy
->cur
= get_cur_freq_on_cpu(cpu
);
695 /* notify BIOS that we exist */
696 acpi_processor_notify_smm(THIS_MODULE
);
698 /* Check for APERF/MPERF support in hardware */
699 if (c
->x86_vendor
== X86_VENDOR_INTEL
&& c
->cpuid_level
>= 6) {
702 if (ecx
& CPUID_6_ECX_APERFMPERF_CAPABILITY
)
703 acpi_cpufreq_driver
.getavg
= get_measured_perf
;
706 dprintk("CPU%u - ACPI performance management activated.\n", cpu
);
707 for (i
= 0; i
< perf
->state_count
; i
++)
708 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
709 (i
== perf
->state
? '*' : ' '), i
,
710 (u32
) perf
->states
[i
].core_frequency
,
711 (u32
) perf
->states
[i
].power
,
712 (u32
) perf
->states
[i
].transition_latency
);
714 cpufreq_frequency_table_get_attr(data
->freq_table
, policy
->cpu
);
717 * the first call to ->target() should result in us actually
718 * writing something to the appropriate registers.
725 kfree(data
->freq_table
);
727 acpi_processor_unregister_performance(perf
, cpu
);
730 per_cpu(drv_data
, cpu
) = NULL
;
735 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
737 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
739 dprintk("acpi_cpufreq_cpu_exit\n");
742 cpufreq_frequency_table_put_attr(policy
->cpu
);
743 per_cpu(drv_data
, policy
->cpu
) = NULL
;
744 acpi_processor_unregister_performance(data
->acpi_data
,
752 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
754 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
756 dprintk("acpi_cpufreq_resume\n");
763 static struct freq_attr
*acpi_cpufreq_attr
[] = {
764 &cpufreq_freq_attr_scaling_available_freqs
,
768 static struct cpufreq_driver acpi_cpufreq_driver
= {
769 .verify
= acpi_cpufreq_verify
,
770 .target
= acpi_cpufreq_target
,
771 .init
= acpi_cpufreq_cpu_init
,
772 .exit
= acpi_cpufreq_cpu_exit
,
773 .resume
= acpi_cpufreq_resume
,
774 .name
= "acpi-cpufreq",
775 .owner
= THIS_MODULE
,
776 .attr
= acpi_cpufreq_attr
,
779 static int __init
acpi_cpufreq_init(void)
786 dprintk("acpi_cpufreq_init\n");
788 ret
= acpi_cpufreq_early_init();
792 ret
= cpufreq_register_driver(&acpi_cpufreq_driver
);
794 free_percpu(acpi_perf_data
);
799 static void __exit
acpi_cpufreq_exit(void)
801 dprintk("acpi_cpufreq_exit\n");
803 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
805 free_percpu(acpi_perf_data
);
808 module_param(acpi_pstate_strict
, uint
, 0644);
809 MODULE_PARM_DESC(acpi_pstate_strict
,
810 "value 0 or non-zero. non-zero -> strict ACPI checks are "
811 "performed during frequency changes.");
813 late_initcall(acpi_cpufreq_init
);
814 module_exit(acpi_cpufreq_exit
);
816 MODULE_ALIAS("acpi");