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 struct acpi_cpufreq_data
*drv_data
[NR_CPUS
];
71 /* acpi_perf_data is a pointer to percpu data. */
72 static struct acpi_processor_performance
*acpi_perf_data
;
74 static struct cpufreq_driver acpi_cpufreq_driver
;
76 static unsigned int acpi_pstate_strict
;
78 static int check_est_cpu(unsigned int cpuid
)
80 struct cpuinfo_x86
*cpu
= &cpu_data
[cpuid
];
82 if (cpu
->x86_vendor
!= X86_VENDOR_INTEL
||
83 !cpu_has(cpu
, X86_FEATURE_EST
))
89 static unsigned extract_io(u32 value
, struct acpi_cpufreq_data
*data
)
91 struct acpi_processor_performance
*perf
;
94 perf
= data
->acpi_data
;
96 for (i
=0; i
<perf
->state_count
; i
++) {
97 if (value
== perf
->states
[i
].status
)
98 return data
->freq_table
[i
].frequency
;
103 static unsigned extract_msr(u32 msr
, struct acpi_cpufreq_data
*data
)
106 struct acpi_processor_performance
*perf
;
108 msr
&= INTEL_MSR_RANGE
;
109 perf
= data
->acpi_data
;
111 for (i
=0; data
->freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
112 if (msr
== perf
->states
[data
->freq_table
[i
].index
].status
)
113 return data
->freq_table
[i
].frequency
;
115 return data
->freq_table
[0].frequency
;
118 static unsigned extract_freq(u32 val
, struct acpi_cpufreq_data
*data
)
120 switch (data
->cpu_feature
) {
121 case SYSTEM_INTEL_MSR_CAPABLE
:
122 return extract_msr(val
, data
);
123 case SYSTEM_IO_CAPABLE
:
124 return extract_io(val
, data
);
151 static void do_drv_read(struct drv_cmd
*cmd
)
156 case SYSTEM_INTEL_MSR_CAPABLE
:
157 rdmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
159 case SYSTEM_IO_CAPABLE
:
160 acpi_os_read_port((acpi_io_address
)cmd
->addr
.io
.port
,
162 (u32
)cmd
->addr
.io
.bit_width
);
169 static void do_drv_write(struct drv_cmd
*cmd
)
174 case SYSTEM_INTEL_MSR_CAPABLE
:
175 rdmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
176 lo
= (lo
& ~INTEL_MSR_RANGE
) | (cmd
->val
& INTEL_MSR_RANGE
);
177 wrmsr(cmd
->addr
.msr
.reg
, lo
, hi
);
179 case SYSTEM_IO_CAPABLE
:
180 acpi_os_write_port((acpi_io_address
)cmd
->addr
.io
.port
,
182 (u32
)cmd
->addr
.io
.bit_width
);
189 static void drv_read(struct drv_cmd
*cmd
)
191 cpumask_t saved_mask
= current
->cpus_allowed
;
194 set_cpus_allowed(current
, cmd
->mask
);
196 set_cpus_allowed(current
, saved_mask
);
199 static void drv_write(struct drv_cmd
*cmd
)
201 cpumask_t saved_mask
= current
->cpus_allowed
;
204 for_each_cpu_mask(i
, cmd
->mask
) {
205 set_cpus_allowed(current
, cpumask_of_cpu(i
));
209 set_cpus_allowed(current
, saved_mask
);
213 static u32
get_cur_val(cpumask_t mask
)
215 struct acpi_processor_performance
*perf
;
218 if (unlikely(cpus_empty(mask
)))
221 switch (drv_data
[first_cpu(mask
)]->cpu_feature
) {
222 case SYSTEM_INTEL_MSR_CAPABLE
:
223 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
224 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_STATUS
;
226 case SYSTEM_IO_CAPABLE
:
227 cmd
.type
= SYSTEM_IO_CAPABLE
;
228 perf
= drv_data
[first_cpu(mask
)]->acpi_data
;
229 cmd
.addr
.io
.port
= perf
->control_register
.address
;
230 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
240 dprintk("get_cur_val = %u\n", cmd
.val
);
246 * Return the measured active (C0) frequency on this CPU since last call
249 * Return: Average CPU frequency in terms of max frequency (zero on error)
251 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
252 * over a period of time, while CPU is in C0 state.
253 * IA32_MPERF counts at the rate of max advertised frequency
254 * IA32_APERF counts at the rate of actual CPU frequency
255 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
256 * no meaning should be associated with absolute values of these MSRs.
258 static unsigned int get_measured_perf(unsigned int cpu
)
266 } aperf_cur
, mperf_cur
;
268 cpumask_t saved_mask
;
269 unsigned int perf_percent
;
272 saved_mask
= current
->cpus_allowed
;
273 set_cpus_allowed(current
, cpumask_of_cpu(cpu
));
274 if (get_cpu() != cpu
) {
275 /* We were not able to run on requested processor */
280 rdmsr(MSR_IA32_APERF
, aperf_cur
.split
.lo
, aperf_cur
.split
.hi
);
281 rdmsr(MSR_IA32_MPERF
, mperf_cur
.split
.lo
, mperf_cur
.split
.hi
);
283 wrmsr(MSR_IA32_APERF
, 0,0);
284 wrmsr(MSR_IA32_MPERF
, 0,0);
288 * We dont want to do 64 bit divide with 32 bit kernel
289 * Get an approximate value. Return failure in case we cannot get
290 * an approximate value.
292 if (unlikely(aperf_cur
.split
.hi
|| mperf_cur
.split
.hi
)) {
296 h
= max_t(u32
, aperf_cur
.split
.hi
, mperf_cur
.split
.hi
);
297 shift_count
= fls(h
);
299 aperf_cur
.whole
>>= shift_count
;
300 mperf_cur
.whole
>>= shift_count
;
303 if (((unsigned long)(-1) / 100) < aperf_cur
.split
.lo
) {
305 aperf_cur
.split
.lo
>>= shift_count
;
306 mperf_cur
.split
.lo
>>= shift_count
;
309 if (aperf_cur
.split
.lo
&& mperf_cur
.split
.lo
)
310 perf_percent
= (aperf_cur
.split
.lo
* 100) / mperf_cur
.split
.lo
;
315 if (unlikely(((unsigned long)(-1) / 100) < aperf_cur
.whole
)) {
317 aperf_cur
.whole
>>= shift_count
;
318 mperf_cur
.whole
>>= shift_count
;
321 if (aperf_cur
.whole
&& mperf_cur
.whole
)
322 perf_percent
= (aperf_cur
.whole
* 100) / mperf_cur
.whole
;
328 retval
= drv_data
[cpu
]->max_freq
* perf_percent
/ 100;
331 set_cpus_allowed(current
, saved_mask
);
333 dprintk("cpu %d: performance percent %d\n", cpu
, perf_percent
);
337 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
339 struct acpi_cpufreq_data
*data
= drv_data
[cpu
];
342 dprintk("get_cur_freq_on_cpu (%d)\n", cpu
);
344 if (unlikely(data
== NULL
||
345 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
349 freq
= extract_freq(get_cur_val(cpumask_of_cpu(cpu
)), data
);
350 dprintk("cur freq = %u\n", freq
);
355 static unsigned int check_freqs(cpumask_t mask
, unsigned int freq
,
356 struct acpi_cpufreq_data
*data
)
358 unsigned int cur_freq
;
361 for (i
=0; i
<100; i
++) {
362 cur_freq
= extract_freq(get_cur_val(mask
), data
);
363 if (cur_freq
== freq
)
370 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
371 unsigned int target_freq
, unsigned int relation
)
373 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
374 struct acpi_processor_performance
*perf
;
375 struct cpufreq_freqs freqs
;
376 cpumask_t online_policy_cpus
;
378 unsigned int next_state
= 0; /* Index into freq_table */
379 unsigned int next_perf_state
= 0; /* Index into perf table */
383 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq
, policy
->cpu
);
385 if (unlikely(data
== NULL
||
386 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
390 perf
= data
->acpi_data
;
391 result
= cpufreq_frequency_table_target(policy
,
394 relation
, &next_state
);
395 if (unlikely(result
))
398 #ifdef CONFIG_HOTPLUG_CPU
399 /* cpufreq holds the hotplug lock, so we are safe from here on */
400 cpus_and(online_policy_cpus
, cpu_online_map
, policy
->cpus
);
402 online_policy_cpus
= policy
->cpus
;
405 next_perf_state
= data
->freq_table
[next_state
].index
;
406 if (perf
->state
== next_perf_state
) {
407 if (unlikely(data
->resume
)) {
408 dprintk("Called after resume, resetting to P%d\n",
412 dprintk("Already at target state (P%d)\n",
418 switch (data
->cpu_feature
) {
419 case SYSTEM_INTEL_MSR_CAPABLE
:
420 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
421 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_CTL
;
422 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
424 case SYSTEM_IO_CAPABLE
:
425 cmd
.type
= SYSTEM_IO_CAPABLE
;
426 cmd
.addr
.io
.port
= perf
->control_register
.address
;
427 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
428 cmd
.val
= (u32
) perf
->states
[next_perf_state
].control
;
434 cpus_clear(cmd
.mask
);
436 if (policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
)
437 cmd
.mask
= online_policy_cpus
;
439 cpu_set(policy
->cpu
, cmd
.mask
);
441 freqs
.old
= perf
->states
[perf
->state
].core_frequency
* 1000;
442 freqs
.new = data
->freq_table
[next_state
].frequency
;
443 for_each_cpu_mask(i
, cmd
.mask
) {
445 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
450 if (acpi_pstate_strict
) {
451 if (!check_freqs(cmd
.mask
, freqs
.new, data
)) {
452 dprintk("acpi_cpufreq_target failed (%d)\n",
458 for_each_cpu_mask(i
, cmd
.mask
) {
460 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
462 perf
->state
= next_perf_state
;
467 static int acpi_cpufreq_verify(struct cpufreq_policy
*policy
)
469 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
471 dprintk("acpi_cpufreq_verify\n");
473 return cpufreq_frequency_table_verify(policy
, data
->freq_table
);
477 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
479 struct acpi_processor_performance
*perf
= data
->acpi_data
;
482 /* search the closest match to cpu_khz */
485 unsigned long freqn
= perf
->states
[0].core_frequency
* 1000;
487 for (i
=0; i
<(perf
->state_count
-1); i
++) {
489 freqn
= perf
->states
[i
+1].core_frequency
* 1000;
490 if ((2 * cpu_khz
) > (freqn
+ freq
)) {
495 perf
->state
= perf
->state_count
-1;
498 /* assume CPU is at P0... */
500 return perf
->states
[0].core_frequency
* 1000;
505 * acpi_cpufreq_early_init - initialize ACPI P-States library
507 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
508 * in order to determine correct frequency and voltage pairings. We can
509 * do _PDC and _PSD and find out the processor dependency for the
510 * actual init that will happen later...
512 static int __init
acpi_cpufreq_early_init(void)
514 dprintk("acpi_cpufreq_early_init\n");
516 acpi_perf_data
= alloc_percpu(struct acpi_processor_performance
);
517 if (!acpi_perf_data
) {
518 dprintk("Memory allocation error for acpi_perf_data.\n");
522 /* Do initialization in ACPI core */
523 acpi_processor_preregister_performance(acpi_perf_data
);
529 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
530 * or do it in BIOS firmware and won't inform about it to OS. If not
531 * detected, this has a side effect of making CPU run at a different speed
532 * than OS intended it to run at. Detect it and handle it cleanly.
534 static int bios_with_sw_any_bug
;
536 static int sw_any_bug_found(const struct dmi_system_id
*d
)
538 bios_with_sw_any_bug
= 1;
542 static const struct dmi_system_id sw_any_bug_dmi_table
[] = {
544 .callback
= sw_any_bug_found
,
545 .ident
= "Supermicro Server X6DLP",
547 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
548 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
549 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
556 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
559 unsigned int valid_states
= 0;
560 unsigned int cpu
= policy
->cpu
;
561 struct acpi_cpufreq_data
*data
;
562 unsigned int result
= 0;
563 struct cpuinfo_x86
*c
= &cpu_data
[policy
->cpu
];
564 struct acpi_processor_performance
*perf
;
566 dprintk("acpi_cpufreq_cpu_init\n");
568 data
= kzalloc(sizeof(struct acpi_cpufreq_data
), GFP_KERNEL
);
572 data
->acpi_data
= percpu_ptr(acpi_perf_data
, cpu
);
573 drv_data
[cpu
] = data
;
575 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
576 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
578 result
= acpi_processor_register_performance(data
->acpi_data
, cpu
);
582 perf
= data
->acpi_data
;
583 policy
->shared_type
= perf
->shared_type
;
586 * Will let policy->cpus know about dependency only when software
587 * coordination is required.
589 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
590 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
591 policy
->cpus
= perf
->shared_cpu_map
;
595 dmi_check_system(sw_any_bug_dmi_table
);
596 if (bios_with_sw_any_bug
&& cpus_weight(policy
->cpus
) == 1) {
597 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
598 policy
->cpus
= cpu_core_map
[cpu
];
602 /* capability check */
603 if (perf
->state_count
<= 1) {
604 dprintk("No P-States\n");
609 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
614 switch (perf
->control_register
.space_id
) {
615 case ACPI_ADR_SPACE_SYSTEM_IO
:
616 dprintk("SYSTEM IO addr space\n");
617 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
619 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
620 dprintk("HARDWARE addr space\n");
621 if (!check_est_cpu(cpu
)) {
625 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
628 dprintk("Unknown addr space %d\n",
629 (u32
) (perf
->control_register
.space_id
));
634 data
->freq_table
= kmalloc(sizeof(struct cpufreq_frequency_table
) *
635 (perf
->state_count
+1), GFP_KERNEL
);
636 if (!data
->freq_table
) {
641 /* detect transition latency */
642 policy
->cpuinfo
.transition_latency
= 0;
643 for (i
=0; i
<perf
->state_count
; i
++) {
644 if ((perf
->states
[i
].transition_latency
* 1000) >
645 policy
->cpuinfo
.transition_latency
)
646 policy
->cpuinfo
.transition_latency
=
647 perf
->states
[i
].transition_latency
* 1000;
649 policy
->governor
= CPUFREQ_DEFAULT_GOVERNOR
;
651 data
->max_freq
= perf
->states
[0].core_frequency
* 1000;
653 for (i
=0; i
<perf
->state_count
; i
++) {
654 if (i
>0 && perf
->states
[i
].core_frequency
>=
655 data
->freq_table
[valid_states
-1].frequency
/ 1000)
658 data
->freq_table
[valid_states
].index
= i
;
659 data
->freq_table
[valid_states
].frequency
=
660 perf
->states
[i
].core_frequency
* 1000;
663 data
->freq_table
[valid_states
].frequency
= CPUFREQ_TABLE_END
;
666 result
= cpufreq_frequency_table_cpuinfo(policy
, data
->freq_table
);
670 switch (perf
->control_register
.space_id
) {
671 case ACPI_ADR_SPACE_SYSTEM_IO
:
672 /* Current speed is unknown and not detectable by IO port */
673 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
675 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
676 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
677 policy
->cur
= get_cur_freq_on_cpu(cpu
);
683 /* notify BIOS that we exist */
684 acpi_processor_notify_smm(THIS_MODULE
);
686 /* Check for APERF/MPERF support in hardware */
687 if (c
->x86_vendor
== X86_VENDOR_INTEL
&& c
->cpuid_level
>= 6) {
690 if (ecx
& CPUID_6_ECX_APERFMPERF_CAPABILITY
)
691 acpi_cpufreq_driver
.getavg
= get_measured_perf
;
694 dprintk("CPU%u - ACPI performance management activated.\n", cpu
);
695 for (i
= 0; i
< perf
->state_count
; i
++)
696 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
697 (i
== perf
->state
? '*' : ' '), i
,
698 (u32
) perf
->states
[i
].core_frequency
,
699 (u32
) perf
->states
[i
].power
,
700 (u32
) perf
->states
[i
].transition_latency
);
702 cpufreq_frequency_table_get_attr(data
->freq_table
, policy
->cpu
);
705 * the first call to ->target() should result in us actually
706 * writing something to the appropriate registers.
713 kfree(data
->freq_table
);
715 acpi_processor_unregister_performance(perf
, cpu
);
718 drv_data
[cpu
] = NULL
;
723 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
725 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
727 dprintk("acpi_cpufreq_cpu_exit\n");
730 cpufreq_frequency_table_put_attr(policy
->cpu
);
731 drv_data
[policy
->cpu
] = NULL
;
732 acpi_processor_unregister_performance(data
->acpi_data
,
740 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
742 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
744 dprintk("acpi_cpufreq_resume\n");
751 static struct freq_attr
*acpi_cpufreq_attr
[] = {
752 &cpufreq_freq_attr_scaling_available_freqs
,
756 static struct cpufreq_driver acpi_cpufreq_driver
= {
757 .verify
= acpi_cpufreq_verify
,
758 .target
= acpi_cpufreq_target
,
759 .init
= acpi_cpufreq_cpu_init
,
760 .exit
= acpi_cpufreq_cpu_exit
,
761 .resume
= acpi_cpufreq_resume
,
762 .name
= "acpi-cpufreq",
763 .owner
= THIS_MODULE
,
764 .attr
= acpi_cpufreq_attr
,
767 static int __init
acpi_cpufreq_init(void)
771 dprintk("acpi_cpufreq_init\n");
773 ret
= acpi_cpufreq_early_init();
777 return cpufreq_register_driver(&acpi_cpufreq_driver
);
780 static void __exit
acpi_cpufreq_exit(void)
782 dprintk("acpi_cpufreq_exit\n");
784 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
786 free_percpu(acpi_perf_data
);
791 module_param(acpi_pstate_strict
, uint
, 0644);
792 MODULE_PARM_DESC(acpi_pstate_strict
,
793 "value 0 or non-zero. non-zero -> strict ACPI checks are "
794 "performed during frequency changes.");
796 late_initcall(acpi_cpufreq_init
);
797 module_exit(acpi_cpufreq_exit
);
799 MODULE_ALIAS("acpi");