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)
63 #define CPUID_6_ECX_APERFMPERF_CAPABILITY (0x1)
65 struct acpi_cpufreq_data
{
66 struct acpi_processor_performance
*acpi_data
;
67 struct cpufreq_frequency_table
*freq_table
;
68 unsigned int max_freq
;
70 unsigned int cpu_feature
;
73 static DEFINE_PER_CPU(struct acpi_cpufreq_data
*, drv_data
);
75 struct acpi_msr_data
{
76 u64 saved_aperf
, saved_mperf
;
79 static DEFINE_PER_CPU(struct acpi_msr_data
, msr_data
);
81 DEFINE_TRACE(power_mark
);
83 /* acpi_perf_data is a pointer to percpu data. */
84 static struct acpi_processor_performance
*acpi_perf_data
;
86 static struct cpufreq_driver acpi_cpufreq_driver
;
88 static unsigned int acpi_pstate_strict
;
90 static int check_est_cpu(unsigned int cpuid
)
92 struct cpuinfo_x86
*cpu
= &cpu_data(cpuid
);
94 if (cpu
->x86_vendor
!= X86_VENDOR_INTEL
||
95 !cpu_has(cpu
, X86_FEATURE_EST
))
101 static unsigned extract_io(u32 value
, struct acpi_cpufreq_data
*data
)
103 struct acpi_processor_performance
*perf
;
106 perf
= data
->acpi_data
;
108 for (i
= 0; i
< perf
->state_count
; i
++) {
109 if (value
== perf
->states
[i
].status
)
110 return data
->freq_table
[i
].frequency
;
115 static unsigned extract_msr(u32 msr
, struct acpi_cpufreq_data
*data
)
118 struct acpi_processor_performance
*perf
;
120 msr
&= INTEL_MSR_RANGE
;
121 perf
= data
->acpi_data
;
123 for (i
= 0; data
->freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
124 if (msr
== perf
->states
[data
->freq_table
[i
].index
].status
)
125 return data
->freq_table
[i
].frequency
;
127 return data
->freq_table
[0].frequency
;
130 static unsigned extract_freq(u32 val
, struct acpi_cpufreq_data
*data
)
132 switch (data
->cpu_feature
) {
133 case SYSTEM_INTEL_MSR_CAPABLE
:
134 return extract_msr(val
, data
);
135 case SYSTEM_IO_CAPABLE
:
136 return extract_io(val
, data
);
153 const struct cpumask
*mask
;
161 /* Called via smp_call_function_single(), on the target CPU */
162 static void do_drv_read(void *_cmd
)
164 struct drv_cmd
*cmd
= _cmd
;
168 case SYSTEM_INTEL_MSR_CAPABLE
:
169 rdmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
171 case SYSTEM_IO_CAPABLE
:
172 acpi_os_read_port((acpi_io_address
)cmd
->addr
.io
.port
,
174 (u32
)cmd
->addr
.io
.bit_width
);
181 /* Called via smp_call_function_many(), on the target CPUs */
182 static void do_drv_write(void *_cmd
)
184 struct drv_cmd
*cmd
= _cmd
;
188 case SYSTEM_INTEL_MSR_CAPABLE
:
189 rdmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
190 lo
= (lo
& ~INTEL_MSR_RANGE
) | (cmd
->val
& INTEL_MSR_RANGE
);
191 wrmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
193 case SYSTEM_IO_CAPABLE
:
194 acpi_os_write_port((acpi_io_address
)cmd
->addr
.io
.port
,
196 (u32
)cmd
->addr
.io
.bit_width
);
203 static void drv_read(struct drv_cmd
*cmd
)
207 smp_call_function_single(cpumask_any(cmd
->mask
), do_drv_read
, cmd
, 1);
210 static void drv_write(struct drv_cmd
*cmd
)
214 this_cpu
= get_cpu();
215 if (cpumask_test_cpu(this_cpu
, cmd
->mask
))
217 smp_call_function_many(cmd
->mask
, do_drv_write
, cmd
, 1);
221 static u32
get_cur_val(const struct cpumask
*mask
)
223 struct acpi_processor_performance
*perf
;
226 if (unlikely(cpumask_empty(mask
)))
229 switch (per_cpu(drv_data
, cpumask_first(mask
))->cpu_feature
) {
230 case SYSTEM_INTEL_MSR_CAPABLE
:
231 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
232 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_STATUS
;
234 case SYSTEM_IO_CAPABLE
:
235 cmd
.type
= SYSTEM_IO_CAPABLE
;
236 perf
= per_cpu(drv_data
, cpumask_first(mask
))->acpi_data
;
237 cmd
.addr
.io
.port
= perf
->control_register
.address
;
238 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
247 dprintk("get_cur_val = %u\n", cmd
.val
);
262 /* Called via smp_call_function_single(), on the target CPU */
263 static void read_measured_perf_ctrs(void *_cur
)
265 struct perf_pair
*cur
= _cur
;
267 rdmsr(MSR_IA32_APERF
, cur
->aperf
.split
.lo
, cur
->aperf
.split
.hi
);
268 rdmsr(MSR_IA32_MPERF
, cur
->mperf
.split
.lo
, cur
->mperf
.split
.hi
);
272 * Return the measured active (C0) frequency on this CPU since last call
275 * Return: Average CPU frequency in terms of max frequency (zero on error)
277 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
278 * over a period of time, while CPU is in C0 state.
279 * IA32_MPERF counts at the rate of max advertised frequency
280 * IA32_APERF counts at the rate of actual CPU frequency
281 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
282 * no meaning should be associated with absolute values of these MSRs.
284 static unsigned int get_measured_perf(struct cpufreq_policy
*policy
,
287 struct perf_pair readin
, cur
;
288 unsigned int perf_percent
;
291 if (smp_call_function_single(cpu
, read_measured_perf_ctrs
, &readin
, 1))
294 cur
.aperf
.whole
= readin
.aperf
.whole
-
295 per_cpu(msr_data
, cpu
).saved_aperf
;
296 cur
.mperf
.whole
= readin
.mperf
.whole
-
297 per_cpu(msr_data
, cpu
).saved_mperf
;
298 per_cpu(msr_data
, cpu
).saved_aperf
= readin
.aperf
.whole
;
299 per_cpu(msr_data
, cpu
).saved_mperf
= readin
.mperf
.whole
;
303 * We dont want to do 64 bit divide with 32 bit kernel
304 * Get an approximate value. Return failure in case we cannot get
305 * an approximate value.
307 if (unlikely(cur
.aperf
.split
.hi
|| cur
.mperf
.split
.hi
)) {
311 h
= max_t(u32
, cur
.aperf
.split
.hi
, cur
.mperf
.split
.hi
);
312 shift_count
= fls(h
);
314 cur
.aperf
.whole
>>= shift_count
;
315 cur
.mperf
.whole
>>= shift_count
;
318 if (((unsigned long)(-1) / 100) < cur
.aperf
.split
.lo
) {
320 cur
.aperf
.split
.lo
>>= shift_count
;
321 cur
.mperf
.split
.lo
>>= shift_count
;
324 if (cur
.aperf
.split
.lo
&& cur
.mperf
.split
.lo
)
325 perf_percent
= (cur
.aperf
.split
.lo
* 100) / cur
.mperf
.split
.lo
;
330 if (unlikely(((unsigned long)(-1) / 100) < cur
.aperf
.whole
)) {
332 cur
.aperf
.whole
>>= shift_count
;
333 cur
.mperf
.whole
>>= shift_count
;
336 if (cur
.aperf
.whole
&& cur
.mperf
.whole
)
337 perf_percent
= (cur
.aperf
.whole
* 100) / cur
.mperf
.whole
;
343 retval
= per_cpu(drv_data
, policy
->cpu
)->max_freq
* perf_percent
/ 100;
348 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
350 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, cpu
);
352 unsigned int cached_freq
;
354 dprintk("get_cur_freq_on_cpu (%d)\n", cpu
);
356 if (unlikely(data
== NULL
||
357 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
361 cached_freq
= data
->freq_table
[data
->acpi_data
->state
].frequency
;
362 freq
= extract_freq(get_cur_val(cpumask_of(cpu
)), data
);
363 if (freq
!= cached_freq
) {
365 * The dreaded BIOS frequency change behind our back.
366 * Force set the frequency on next target call.
371 dprintk("cur freq = %u\n", freq
);
376 static unsigned int check_freqs(const struct cpumask
*mask
, unsigned int freq
,
377 struct acpi_cpufreq_data
*data
)
379 unsigned int cur_freq
;
382 for (i
= 0; i
< 100; i
++) {
383 cur_freq
= extract_freq(get_cur_val(mask
), data
);
384 if (cur_freq
== freq
)
391 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
392 unsigned int target_freq
, unsigned int relation
)
394 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
395 struct acpi_processor_performance
*perf
;
396 struct cpufreq_freqs freqs
;
398 unsigned int next_state
= 0; /* Index into freq_table */
399 unsigned int next_perf_state
= 0; /* Index into perf table */
402 struct power_trace it
;
404 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq
, policy
->cpu
);
406 if (unlikely(data
== NULL
||
407 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
411 perf
= data
->acpi_data
;
412 result
= cpufreq_frequency_table_target(policy
,
415 relation
, &next_state
);
416 if (unlikely(result
)) {
421 next_perf_state
= data
->freq_table
[next_state
].index
;
422 if (perf
->state
== next_perf_state
) {
423 if (unlikely(data
->resume
)) {
424 dprintk("Called after resume, resetting to P%d\n",
428 dprintk("Already at target state (P%d)\n",
434 trace_power_mark(&it
, POWER_PSTATE
, next_perf_state
);
436 switch (data
->cpu_feature
) {
437 case SYSTEM_INTEL_MSR_CAPABLE
:
438 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
439 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_CTL
;
440 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
442 case SYSTEM_IO_CAPABLE
:
443 cmd
.type
= SYSTEM_IO_CAPABLE
;
444 cmd
.addr
.io
.port
= perf
->control_register
.address
;
445 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
446 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
453 /* cpufreq holds the hotplug lock, so we are safe from here on */
454 if (policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
)
455 cmd
.mask
= policy
->cpus
;
457 cmd
.mask
= cpumask_of(policy
->cpu
);
459 freqs
.old
= perf
->states
[perf
->state
].core_frequency
* 1000;
460 freqs
.new = data
->freq_table
[next_state
].frequency
;
461 for_each_cpu(i
, cmd
.mask
) {
463 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
468 if (acpi_pstate_strict
) {
469 if (!check_freqs(cmd
.mask
, freqs
.new, data
)) {
470 dprintk("acpi_cpufreq_target failed (%d)\n",
477 for_each_cpu(i
, cmd
.mask
) {
479 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
481 perf
->state
= next_perf_state
;
487 static int acpi_cpufreq_verify(struct cpufreq_policy
*policy
)
489 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
491 dprintk("acpi_cpufreq_verify\n");
493 return cpufreq_frequency_table_verify(policy
, data
->freq_table
);
497 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
499 struct acpi_processor_performance
*perf
= data
->acpi_data
;
502 /* search the closest match to cpu_khz */
505 unsigned long freqn
= perf
->states
[0].core_frequency
* 1000;
507 for (i
= 0; i
< (perf
->state_count
-1); i
++) {
509 freqn
= perf
->states
[i
+1].core_frequency
* 1000;
510 if ((2 * cpu_khz
) > (freqn
+ freq
)) {
515 perf
->state
= perf
->state_count
-1;
518 /* assume CPU is at P0... */
520 return perf
->states
[0].core_frequency
* 1000;
524 static void free_acpi_perf_data(void)
528 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
529 for_each_possible_cpu(i
)
530 free_cpumask_var(per_cpu_ptr(acpi_perf_data
, i
)
532 free_percpu(acpi_perf_data
);
536 * acpi_cpufreq_early_init - initialize ACPI P-States library
538 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
539 * in order to determine correct frequency and voltage pairings. We can
540 * do _PDC and _PSD and find out the processor dependency for the
541 * actual init that will happen later...
543 static int __init
acpi_cpufreq_early_init(void)
546 dprintk("acpi_cpufreq_early_init\n");
548 acpi_perf_data
= alloc_percpu(struct acpi_processor_performance
);
549 if (!acpi_perf_data
) {
550 dprintk("Memory allocation error for acpi_perf_data.\n");
553 for_each_possible_cpu(i
) {
554 if (!alloc_cpumask_var_node(
555 &per_cpu_ptr(acpi_perf_data
, i
)->shared_cpu_map
,
556 GFP_KERNEL
, cpu_to_node(i
))) {
558 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
559 free_acpi_perf_data();
564 /* Do initialization in ACPI core */
565 acpi_processor_preregister_performance(acpi_perf_data
);
571 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
572 * or do it in BIOS firmware and won't inform about it to OS. If not
573 * detected, this has a side effect of making CPU run at a different speed
574 * than OS intended it to run at. Detect it and handle it cleanly.
576 static int bios_with_sw_any_bug
;
578 static int sw_any_bug_found(const struct dmi_system_id
*d
)
580 bios_with_sw_any_bug
= 1;
584 static const struct dmi_system_id sw_any_bug_dmi_table
[] = {
586 .callback
= sw_any_bug_found
,
587 .ident
= "Supermicro Server X6DLP",
589 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
590 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
591 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
598 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
601 unsigned int valid_states
= 0;
602 unsigned int cpu
= policy
->cpu
;
603 struct acpi_cpufreq_data
*data
;
604 unsigned int result
= 0;
605 struct cpuinfo_x86
*c
= &cpu_data(policy
->cpu
);
606 struct acpi_processor_performance
*perf
;
608 dprintk("acpi_cpufreq_cpu_init\n");
610 data
= kzalloc(sizeof(struct acpi_cpufreq_data
), GFP_KERNEL
);
614 data
->acpi_data
= per_cpu_ptr(acpi_perf_data
, cpu
);
615 per_cpu(drv_data
, cpu
) = data
;
617 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
618 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
620 result
= acpi_processor_register_performance(data
->acpi_data
, cpu
);
624 perf
= data
->acpi_data
;
625 policy
->shared_type
= perf
->shared_type
;
628 * Will let policy->cpus know about dependency only when software
629 * coordination is required.
631 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
632 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
633 cpumask_copy(policy
->cpus
, perf
->shared_cpu_map
);
635 cpumask_copy(policy
->related_cpus
, perf
->shared_cpu_map
);
638 dmi_check_system(sw_any_bug_dmi_table
);
639 if (bios_with_sw_any_bug
&& cpumask_weight(policy
->cpus
) == 1) {
640 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
641 cpumask_copy(policy
->cpus
, cpu_core_mask(cpu
));
645 /* capability check */
646 if (perf
->state_count
<= 1) {
647 dprintk("No P-States\n");
652 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
657 switch (perf
->control_register
.space_id
) {
658 case ACPI_ADR_SPACE_SYSTEM_IO
:
659 dprintk("SYSTEM IO addr space\n");
660 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
662 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
663 dprintk("HARDWARE addr space\n");
664 if (!check_est_cpu(cpu
)) {
668 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
671 dprintk("Unknown addr space %d\n",
672 (u32
) (perf
->control_register
.space_id
));
677 data
->freq_table
= kmalloc(sizeof(struct cpufreq_frequency_table
) *
678 (perf
->state_count
+1), GFP_KERNEL
);
679 if (!data
->freq_table
) {
684 /* detect transition latency */
685 policy
->cpuinfo
.transition_latency
= 0;
686 for (i
= 0; i
< perf
->state_count
; i
++) {
687 if ((perf
->states
[i
].transition_latency
* 1000) >
688 policy
->cpuinfo
.transition_latency
)
689 policy
->cpuinfo
.transition_latency
=
690 perf
->states
[i
].transition_latency
* 1000;
693 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
694 if (perf
->control_register
.space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
&&
695 policy
->cpuinfo
.transition_latency
> 20 * 1000) {
696 policy
->cpuinfo
.transition_latency
= 20 * 1000;
697 printk_once(KERN_INFO
"Capping off P-state tranision"
698 " latency at 20 uS\n");
701 data
->max_freq
= perf
->states
[0].core_frequency
* 1000;
703 for (i
= 0; i
< perf
->state_count
; i
++) {
704 if (i
> 0 && perf
->states
[i
].core_frequency
>=
705 data
->freq_table
[valid_states
-1].frequency
/ 1000)
708 data
->freq_table
[valid_states
].index
= i
;
709 data
->freq_table
[valid_states
].frequency
=
710 perf
->states
[i
].core_frequency
* 1000;
713 data
->freq_table
[valid_states
].frequency
= CPUFREQ_TABLE_END
;
716 result
= cpufreq_frequency_table_cpuinfo(policy
, data
->freq_table
);
720 switch (perf
->control_register
.space_id
) {
721 case ACPI_ADR_SPACE_SYSTEM_IO
:
722 /* Current speed is unknown and not detectable by IO port */
723 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
725 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
726 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
727 policy
->cur
= get_cur_freq_on_cpu(cpu
);
733 /* notify BIOS that we exist */
734 acpi_processor_notify_smm(THIS_MODULE
);
736 /* Check for APERF/MPERF support in hardware */
737 if (c
->x86_vendor
== X86_VENDOR_INTEL
&& c
->cpuid_level
>= 6) {
740 if (ecx
& CPUID_6_ECX_APERFMPERF_CAPABILITY
)
741 acpi_cpufreq_driver
.getavg
= get_measured_perf
;
744 dprintk("CPU%u - ACPI performance management activated.\n", cpu
);
745 for (i
= 0; i
< perf
->state_count
; i
++)
746 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
747 (i
== perf
->state
? '*' : ' '), i
,
748 (u32
) perf
->states
[i
].core_frequency
,
749 (u32
) perf
->states
[i
].power
,
750 (u32
) perf
->states
[i
].transition_latency
);
752 cpufreq_frequency_table_get_attr(data
->freq_table
, policy
->cpu
);
755 * the first call to ->target() should result in us actually
756 * writing something to the appropriate registers.
763 kfree(data
->freq_table
);
765 acpi_processor_unregister_performance(perf
, cpu
);
768 per_cpu(drv_data
, cpu
) = NULL
;
773 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
775 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
777 dprintk("acpi_cpufreq_cpu_exit\n");
780 cpufreq_frequency_table_put_attr(policy
->cpu
);
781 per_cpu(drv_data
, policy
->cpu
) = NULL
;
782 acpi_processor_unregister_performance(data
->acpi_data
,
790 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
792 struct acpi_cpufreq_data
*data
= per_cpu(drv_data
, policy
->cpu
);
794 dprintk("acpi_cpufreq_resume\n");
801 static struct freq_attr
*acpi_cpufreq_attr
[] = {
802 &cpufreq_freq_attr_scaling_available_freqs
,
806 static struct cpufreq_driver acpi_cpufreq_driver
= {
807 .verify
= acpi_cpufreq_verify
,
808 .target
= acpi_cpufreq_target
,
809 .init
= acpi_cpufreq_cpu_init
,
810 .exit
= acpi_cpufreq_cpu_exit
,
811 .resume
= acpi_cpufreq_resume
,
812 .name
= "acpi-cpufreq",
813 .owner
= THIS_MODULE
,
814 .attr
= acpi_cpufreq_attr
,
817 static int __init
acpi_cpufreq_init(void)
824 dprintk("acpi_cpufreq_init\n");
826 ret
= acpi_cpufreq_early_init();
830 ret
= cpufreq_register_driver(&acpi_cpufreq_driver
);
832 free_acpi_perf_data();
837 static void __exit
acpi_cpufreq_exit(void)
839 dprintk("acpi_cpufreq_exit\n");
841 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
843 free_percpu(acpi_perf_data
);
846 module_param(acpi_pstate_strict
, uint
, 0644);
847 MODULE_PARM_DESC(acpi_pstate_strict
,
848 "value 0 or non-zero. non-zero -> strict ACPI checks are "
849 "performed during frequency changes.");
851 late_initcall(acpi_cpufreq_init
);
852 module_exit(acpi_cpufreq_exit
);
854 MODULE_ALIAS("acpi");