2 * acpi-cpufreq.c - ACPI Processor P-States Driver
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>
36 #include <trace/power.h>
38 #include <linux/acpi.h>
40 #include <linux/delay.h>
41 #include <linux/uaccess.h>
43 #include <acpi/processor.h>
46 #include <asm/processor.h>
47 #include <asm/cpufeature.h>
49 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
52 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
53 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
54 MODULE_LICENSE("GPL");
57 UNDEFINED_CAPABLE
= 0,
58 SYSTEM_INTEL_MSR_CAPABLE
,
62 #define INTEL_MSR_RANGE (0xffff)
64 struct acpi_cpufreq_data
{
65 struct acpi_processor_performance
*acpi_data
;
66 struct cpufreq_frequency_table
*freq_table
;
68 unsigned int cpu_feature
;
71 static DEFINE_PER_CPU(struct acpi_cpufreq_data
*, drv_data
);
73 struct acpi_msr_data
{
74 u64 saved_aperf
, saved_mperf
;
77 static DEFINE_PER_CPU(struct acpi_msr_data
, msr_data
);
79 DEFINE_TRACE(power_mark
);
81 /* acpi_perf_data is a pointer to percpu data. */
82 static struct acpi_processor_performance
*acpi_perf_data
;
84 static struct cpufreq_driver acpi_cpufreq_driver
;
86 static unsigned int acpi_pstate_strict
;
88 static int check_est_cpu(unsigned int cpuid
)
90 struct cpuinfo_x86
*cpu
= &cpu_data(cpuid
);
92 return cpu_has(cpu
, X86_FEATURE_EST
);
95 static unsigned extract_io(u32 value
, struct acpi_cpufreq_data
*data
)
97 struct acpi_processor_performance
*perf
;
100 perf
= data
->acpi_data
;
102 for (i
= 0; i
< perf
->state_count
; i
++) {
103 if (value
== perf
->states
[i
].status
)
104 return data
->freq_table
[i
].frequency
;
109 static unsigned extract_msr(u32 msr
, struct acpi_cpufreq_data
*data
)
112 struct acpi_processor_performance
*perf
;
114 msr
&= INTEL_MSR_RANGE
;
115 perf
= data
->acpi_data
;
117 for (i
= 0; data
->freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
118 if (msr
== perf
->states
[data
->freq_table
[i
].index
].status
)
119 return data
->freq_table
[i
].frequency
;
121 return data
->freq_table
[0].frequency
;
124 static unsigned extract_freq(u32 val
, struct acpi_cpufreq_data
*data
)
126 switch (data
->cpu_feature
) {
127 case SYSTEM_INTEL_MSR_CAPABLE
:
128 return extract_msr(val
, data
);
129 case SYSTEM_IO_CAPABLE
:
130 return extract_io(val
, data
);
147 const struct cpumask
*mask
;
155 /* Called via smp_call_function_single(), on the target CPU */
156 static void do_drv_read(void *_cmd
)
158 struct drv_cmd
*cmd
= _cmd
;
162 case SYSTEM_INTEL_MSR_CAPABLE
:
163 rdmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
165 case SYSTEM_IO_CAPABLE
:
166 acpi_os_read_port((acpi_io_address
)cmd
->addr
.io
.port
,
168 (u32
)cmd
->addr
.io
.bit_width
);
175 /* Called via smp_call_function_many(), on the target CPUs */
176 static void do_drv_write(void *_cmd
)
178 struct drv_cmd
*cmd
= _cmd
;
182 case SYSTEM_INTEL_MSR_CAPABLE
:
183 rdmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
184 lo
= (lo
& ~INTEL_MSR_RANGE
) | (cmd
->val
& INTEL_MSR_RANGE
);
185 wrmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
187 case SYSTEM_IO_CAPABLE
:
188 acpi_os_write_port((acpi_io_address
)cmd
->addr
.io
.port
,
190 (u32
)cmd
->addr
.io
.bit_width
);
197 static void drv_read(struct drv_cmd
*cmd
)
201 smp_call_function_single(cpumask_any(cmd
->mask
), do_drv_read
, cmd
, 1);
204 static void drv_write(struct drv_cmd
*cmd
)
208 this_cpu
= get_cpu();
209 if (cpumask_test_cpu(this_cpu
, cmd
->mask
))
211 smp_call_function_many(cmd
->mask
, do_drv_write
, cmd
, 1);
215 static u32
get_cur_val(const struct cpumask
*mask
)
217 struct acpi_processor_performance
*perf
;
220 if (unlikely(cpumask_empty(mask
)))
223 switch (per_cpu(drv_data
, cpumask_first(mask
))->cpu_feature
) {
224 case SYSTEM_INTEL_MSR_CAPABLE
:
225 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
226 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_STATUS
;
228 case SYSTEM_IO_CAPABLE
:
229 cmd
.type
= SYSTEM_IO_CAPABLE
;
230 perf
= per_cpu(drv_data
, cpumask_first(mask
))->acpi_data
;
231 cmd
.addr
.io
.port
= perf
->control_register
.address
;
232 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
241 dprintk("get_cur_val = %u\n", cmd
.val
);
256 /* Called via smp_call_function_single(), on the target CPU */
257 static void read_measured_perf_ctrs(void *_cur
)
259 struct perf_pair
*cur
= _cur
;
261 rdmsr(MSR_IA32_APERF
, cur
->aperf
.split
.lo
, cur
->aperf
.split
.hi
);
262 rdmsr(MSR_IA32_MPERF
, cur
->mperf
.split
.lo
, cur
->mperf
.split
.hi
);
266 * Return the measured active (C0) frequency on this CPU since last call
269 * Return: Average CPU frequency in terms of max frequency (zero on error)
271 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
272 * over a period of time, while CPU is in C0 state.
273 * IA32_MPERF counts at the rate of max advertised frequency
274 * IA32_APERF counts at the rate of actual CPU frequency
275 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
276 * no meaning should be associated with absolute values of these MSRs.
278 static unsigned int get_measured_perf(struct cpufreq_policy
*policy
,
281 struct perf_pair readin
, cur
;
282 unsigned int perf_percent
;
285 if (smp_call_function_single(cpu
, read_measured_perf_ctrs
, &readin
, 1))
288 cur
.aperf
.whole
= readin
.aperf
.whole
-
289 per_cpu(msr_data
, cpu
).saved_aperf
;
290 cur
.mperf
.whole
= readin
.mperf
.whole
-
291 per_cpu(msr_data
, cpu
).saved_mperf
;
292 per_cpu(msr_data
, cpu
).saved_aperf
= readin
.aperf
.whole
;
293 per_cpu(msr_data
, cpu
).saved_mperf
= readin
.mperf
.whole
;
297 * We dont want to do 64 bit divide with 32 bit kernel
298 * Get an approximate value. Return failure in case we cannot get
299 * an approximate value.
301 if (unlikely(cur
.aperf
.split
.hi
|| cur
.mperf
.split
.hi
)) {
305 h
= max_t(u32
, cur
.aperf
.split
.hi
, cur
.mperf
.split
.hi
);
306 shift_count
= fls(h
);
308 cur
.aperf
.whole
>>= shift_count
;
309 cur
.mperf
.whole
>>= shift_count
;
312 if (((unsigned long)(-1) / 100) < cur
.aperf
.split
.lo
) {
314 cur
.aperf
.split
.lo
>>= shift_count
;
315 cur
.mperf
.split
.lo
>>= shift_count
;
318 if (cur
.aperf
.split
.lo
&& cur
.mperf
.split
.lo
)
319 perf_percent
= (cur
.aperf
.split
.lo
* 100) / cur
.mperf
.split
.lo
;
324 if (unlikely(((unsigned long)(-1) / 100) < cur
.aperf
.whole
)) {
326 cur
.aperf
.whole
>>= shift_count
;
327 cur
.mperf
.whole
>>= shift_count
;
330 if (cur
.aperf
.whole
&& cur
.mperf
.whole
)
331 perf_percent
= (cur
.aperf
.whole
* 100) / cur
.mperf
.whole
;
337 retval
= (policy
->cpuinfo
.max_freq
* perf_percent
) / 100;
342 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
344 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, cpu
);
346 unsigned int cached_freq
;
348 dprintk("get_cur_freq_on_cpu (%d)\n", cpu
);
350 if (unlikely(data
== NULL
||
351 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
355 cached_freq
= data
->freq_table
[data
->acpi_data
->state
].frequency
;
356 freq
= extract_freq(get_cur_val(cpumask_of(cpu
)), data
);
357 if (freq
!= cached_freq
) {
359 * The dreaded BIOS frequency change behind our back.
360 * Force set the frequency on next target call.
365 dprintk("cur freq = %u\n", freq
);
370 static unsigned int check_freqs(const struct cpumask
*mask
, unsigned int freq
,
371 struct acpi_cpufreq_data
*data
)
373 unsigned int cur_freq
;
376 for (i
= 0; i
< 100; i
++) {
377 cur_freq
= extract_freq(get_cur_val(mask
), data
);
378 if (cur_freq
== freq
)
385 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
386 unsigned int target_freq
, unsigned int relation
)
388 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
389 struct acpi_processor_performance
*perf
;
390 struct cpufreq_freqs freqs
;
392 unsigned int next_state
= 0; /* Index into freq_table */
393 unsigned int next_perf_state
= 0; /* Index into perf table */
396 struct power_trace it
;
398 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq
, policy
->cpu
);
400 if (unlikely(data
== NULL
||
401 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
405 perf
= data
->acpi_data
;
406 result
= cpufreq_frequency_table_target(policy
,
409 relation
, &next_state
);
410 if (unlikely(result
)) {
415 next_perf_state
= data
->freq_table
[next_state
].index
;
416 if (perf
->state
== next_perf_state
) {
417 if (unlikely(data
->resume
)) {
418 dprintk("Called after resume, resetting to P%d\n",
422 dprintk("Already at target state (P%d)\n",
428 trace_power_mark(&it
, POWER_PSTATE
, next_perf_state
);
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
;
447 /* cpufreq holds the hotplug lock, so we are safe from here on */
448 if (policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
)
449 cmd
.mask
= policy
->cpus
;
451 cmd
.mask
= cpumask_of(policy
->cpu
);
453 freqs
.old
= perf
->states
[perf
->state
].core_frequency
* 1000;
454 freqs
.new = data
->freq_table
[next_state
].frequency
;
455 for_each_cpu(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",
471 for_each_cpu(i
, cmd
.mask
) {
473 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
475 perf
->state
= next_perf_state
;
481 static int acpi_cpufreq_verify(struct cpufreq_policy
*policy
)
483 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
485 dprintk("acpi_cpufreq_verify\n");
487 return cpufreq_frequency_table_verify(policy
, data
->freq_table
);
491 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
493 struct acpi_processor_performance
*perf
= data
->acpi_data
;
496 /* search the closest match to cpu_khz */
499 unsigned long freqn
= perf
->states
[0].core_frequency
* 1000;
501 for (i
= 0; i
< (perf
->state_count
-1); i
++) {
503 freqn
= perf
->states
[i
+1].core_frequency
* 1000;
504 if ((2 * cpu_khz
) > (freqn
+ freq
)) {
509 perf
->state
= perf
->state_count
-1;
512 /* assume CPU is at P0... */
514 return perf
->states
[0].core_frequency
* 1000;
518 static void free_acpi_perf_data(void)
522 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
523 for_each_possible_cpu(i
)
524 free_cpumask_var(per_cpu_ptr(acpi_perf_data
, i
)
526 free_percpu(acpi_perf_data
);
530 * acpi_cpufreq_early_init - initialize ACPI P-States library
532 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
533 * in order to determine correct frequency and voltage pairings. We can
534 * do _PDC and _PSD and find out the processor dependency for the
535 * actual init that will happen later...
537 static int __init
acpi_cpufreq_early_init(void)
540 dprintk("acpi_cpufreq_early_init\n");
542 acpi_perf_data
= alloc_percpu(struct acpi_processor_performance
);
543 if (!acpi_perf_data
) {
544 dprintk("Memory allocation error for acpi_perf_data.\n");
547 for_each_possible_cpu(i
) {
548 if (!zalloc_cpumask_var_node(
549 &per_cpu_ptr(acpi_perf_data
, i
)->shared_cpu_map
,
550 GFP_KERNEL
, cpu_to_node(i
))) {
552 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
553 free_acpi_perf_data();
558 /* Do initialization in ACPI core */
559 acpi_processor_preregister_performance(acpi_perf_data
);
565 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
566 * or do it in BIOS firmware and won't inform about it to OS. If not
567 * detected, this has a side effect of making CPU run at a different speed
568 * than OS intended it to run at. Detect it and handle it cleanly.
570 static int bios_with_sw_any_bug
;
572 static int sw_any_bug_found(const struct dmi_system_id
*d
)
574 bios_with_sw_any_bug
= 1;
578 static const struct dmi_system_id sw_any_bug_dmi_table
[] = {
580 .callback
= sw_any_bug_found
,
581 .ident
= "Supermicro Server X6DLP",
583 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
584 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
585 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
592 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
595 unsigned int valid_states
= 0;
596 unsigned int cpu
= policy
->cpu
;
597 struct acpi_cpufreq_data
*data
;
598 unsigned int result
= 0;
599 struct cpuinfo_x86
*c
= &cpu_data(policy
->cpu
);
600 struct acpi_processor_performance
*perf
;
602 dprintk("acpi_cpufreq_cpu_init\n");
604 data
= kzalloc(sizeof(struct acpi_cpufreq_data
), GFP_KERNEL
);
608 data
->acpi_data
= per_cpu_ptr(acpi_perf_data
, cpu
);
609 per_cpu(drv_data
, cpu
) = data
;
611 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
612 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
614 result
= acpi_processor_register_performance(data
->acpi_data
, cpu
);
618 perf
= data
->acpi_data
;
619 policy
->shared_type
= perf
->shared_type
;
622 * Will let policy->cpus know about dependency only when software
623 * coordination is required.
625 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
626 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
627 cpumask_copy(policy
->cpus
, perf
->shared_cpu_map
);
629 cpumask_copy(policy
->related_cpus
, perf
->shared_cpu_map
);
632 dmi_check_system(sw_any_bug_dmi_table
);
633 if (bios_with_sw_any_bug
&& cpumask_weight(policy
->cpus
) == 1) {
634 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
635 cpumask_copy(policy
->cpus
, cpu_core_mask(cpu
));
639 /* capability check */
640 if (perf
->state_count
<= 1) {
641 dprintk("No P-States\n");
646 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
651 switch (perf
->control_register
.space_id
) {
652 case ACPI_ADR_SPACE_SYSTEM_IO
:
653 dprintk("SYSTEM IO addr space\n");
654 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
656 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
657 dprintk("HARDWARE addr space\n");
658 if (!check_est_cpu(cpu
)) {
662 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
665 dprintk("Unknown addr space %d\n",
666 (u32
) (perf
->control_register
.space_id
));
671 data
->freq_table
= kmalloc(sizeof(struct cpufreq_frequency_table
) *
672 (perf
->state_count
+1), GFP_KERNEL
);
673 if (!data
->freq_table
) {
678 /* detect transition latency */
679 policy
->cpuinfo
.transition_latency
= 0;
680 for (i
= 0; i
< perf
->state_count
; i
++) {
681 if ((perf
->states
[i
].transition_latency
* 1000) >
682 policy
->cpuinfo
.transition_latency
)
683 policy
->cpuinfo
.transition_latency
=
684 perf
->states
[i
].transition_latency
* 1000;
687 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
688 if (perf
->control_register
.space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
&&
689 policy
->cpuinfo
.transition_latency
> 20 * 1000) {
690 policy
->cpuinfo
.transition_latency
= 20 * 1000;
691 printk_once(KERN_INFO
692 "P-state transition latency capped at 20 uS\n");
696 for (i
= 0; i
< perf
->state_count
; i
++) {
697 if (i
> 0 && perf
->states
[i
].core_frequency
>=
698 data
->freq_table
[valid_states
-1].frequency
/ 1000)
701 data
->freq_table
[valid_states
].index
= i
;
702 data
->freq_table
[valid_states
].frequency
=
703 perf
->states
[i
].core_frequency
* 1000;
706 data
->freq_table
[valid_states
].frequency
= CPUFREQ_TABLE_END
;
709 result
= cpufreq_frequency_table_cpuinfo(policy
, data
->freq_table
);
713 if (perf
->states
[0].core_frequency
* 1000 != policy
->cpuinfo
.max_freq
)
714 printk(KERN_WARNING FW_WARN
"P-state 0 is not max freq\n");
716 switch (perf
->control_register
.space_id
) {
717 case ACPI_ADR_SPACE_SYSTEM_IO
:
718 /* Current speed is unknown and not detectable by IO port */
719 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
721 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
722 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
723 policy
->cur
= get_cur_freq_on_cpu(cpu
);
729 /* notify BIOS that we exist */
730 acpi_processor_notify_smm(THIS_MODULE
);
732 /* Check for APERF/MPERF support in hardware */
733 if (cpu_has(c
, X86_FEATURE_APERFMPERF
))
734 acpi_cpufreq_driver
.getavg
= get_measured_perf
;
736 dprintk("CPU%u - ACPI performance management activated.\n", cpu
);
737 for (i
= 0; i
< perf
->state_count
; i
++)
738 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
739 (i
== perf
->state
? '*' : ' '), i
,
740 (u32
) perf
->states
[i
].core_frequency
,
741 (u32
) perf
->states
[i
].power
,
742 (u32
) perf
->states
[i
].transition_latency
);
744 cpufreq_frequency_table_get_attr(data
->freq_table
, policy
->cpu
);
747 * the first call to ->target() should result in us actually
748 * writing something to the appropriate registers.
755 kfree(data
->freq_table
);
757 acpi_processor_unregister_performance(perf
, cpu
);
760 per_cpu(drv_data
, cpu
) = NULL
;
765 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
767 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
769 dprintk("acpi_cpufreq_cpu_exit\n");
772 cpufreq_frequency_table_put_attr(policy
->cpu
);
773 per_cpu(drv_data
, policy
->cpu
) = NULL
;
774 acpi_processor_unregister_performance(data
->acpi_data
,
782 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
784 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
786 dprintk("acpi_cpufreq_resume\n");
793 static struct freq_attr
*acpi_cpufreq_attr
[] = {
794 &cpufreq_freq_attr_scaling_available_freqs
,
798 static struct cpufreq_driver acpi_cpufreq_driver
= {
799 .verify
= acpi_cpufreq_verify
,
800 .target
= acpi_cpufreq_target
,
801 .init
= acpi_cpufreq_cpu_init
,
802 .exit
= acpi_cpufreq_cpu_exit
,
803 .resume
= acpi_cpufreq_resume
,
804 .name
= "acpi-cpufreq",
805 .owner
= THIS_MODULE
,
806 .attr
= acpi_cpufreq_attr
,
809 static int __init
acpi_cpufreq_init(void)
816 dprintk("acpi_cpufreq_init\n");
818 ret
= acpi_cpufreq_early_init();
822 ret
= cpufreq_register_driver(&acpi_cpufreq_driver
);
824 free_acpi_perf_data();
829 static void __exit
acpi_cpufreq_exit(void)
831 dprintk("acpi_cpufreq_exit\n");
833 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
835 free_percpu(acpi_perf_data
);
838 module_param(acpi_pstate_strict
, uint
, 0644);
839 MODULE_PARM_DESC(acpi_pstate_strict
,
840 "value 0 or non-zero. non-zero -> strict ACPI checks are "
841 "performed during frequency changes.");
843 late_initcall(acpi_cpufreq_init
);
844 module_exit(acpi_cpufreq_exit
);
846 MODULE_ALIAS("acpi");