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 static struct acpi_processor_performance
*acpi_perf_data
[NR_CPUS
];
73 static struct cpufreq_driver acpi_cpufreq_driver
;
75 static unsigned int acpi_pstate_strict
;
77 static int check_est_cpu(unsigned int cpuid
)
79 struct cpuinfo_x86
*cpu
= &cpu_data
[cpuid
];
81 if (cpu
->x86_vendor
!= X86_VENDOR_INTEL
||
82 !cpu_has(cpu
, X86_FEATURE_EST
))
88 static unsigned extract_io(u32 value
, struct acpi_cpufreq_data
*data
)
90 struct acpi_processor_performance
*perf
;
93 perf
= data
->acpi_data
;
95 for (i
=0; i
<perf
->state_count
; i
++) {
96 if (value
== perf
->states
[i
].status
)
97 return data
->freq_table
[i
].frequency
;
102 static unsigned extract_msr(u32 msr
, struct acpi_cpufreq_data
*data
)
105 struct acpi_processor_performance
*perf
;
107 msr
&= INTEL_MSR_RANGE
;
108 perf
= data
->acpi_data
;
110 for (i
=0; data
->freq_table
[i
].frequency
!= CPUFREQ_TABLE_END
; i
++) {
111 if (msr
== perf
->states
[data
->freq_table
[i
].index
].status
)
112 return data
->freq_table
[i
].frequency
;
114 return data
->freq_table
[0].frequency
;
117 static unsigned extract_freq(u32 val
, struct acpi_cpufreq_data
*data
)
119 switch (data
->cpu_feature
) {
120 case SYSTEM_INTEL_MSR_CAPABLE
:
121 return extract_msr(val
, data
);
122 case SYSTEM_IO_CAPABLE
:
123 return extract_io(val
, data
);
129 static void wrport(u16 port
, u8 bit_width
, u32 value
)
133 else if (bit_width
<= 16)
135 else if (bit_width
<= 32)
139 static void rdport(u16 port
, u8 bit_width
, u32
* ret
)
144 else if (bit_width
<= 16)
146 else if (bit_width
<= 32)
171 static void do_drv_read(struct drv_cmd
*cmd
)
176 case SYSTEM_INTEL_MSR_CAPABLE
:
177 rdmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
179 case SYSTEM_IO_CAPABLE
:
180 rdport(cmd
->addr
.io
.port
, cmd
->addr
.io
.bit_width
, &cmd
->val
);
187 static void do_drv_write(struct drv_cmd
*cmd
)
192 case SYSTEM_INTEL_MSR_CAPABLE
:
193 wrmsr(cmd
->addr
.msr
.reg
, cmd
->val
, h
);
195 case SYSTEM_IO_CAPABLE
:
196 wrport(cmd
->addr
.io
.port
, cmd
->addr
.io
.bit_width
, cmd
->val
);
203 static void drv_read(struct drv_cmd
*cmd
)
205 cpumask_t saved_mask
= current
->cpus_allowed
;
208 set_cpus_allowed(current
, cmd
->mask
);
210 set_cpus_allowed(current
, saved_mask
);
213 static void drv_write(struct drv_cmd
*cmd
)
215 cpumask_t saved_mask
= current
->cpus_allowed
;
218 for_each_cpu_mask(i
, cmd
->mask
) {
219 set_cpus_allowed(current
, cpumask_of_cpu(i
));
223 set_cpus_allowed(current
, saved_mask
);
227 static u32
get_cur_val(cpumask_t mask
)
229 struct acpi_processor_performance
*perf
;
232 if (unlikely(cpus_empty(mask
)))
235 switch (drv_data
[first_cpu(mask
)]->cpu_feature
) {
236 case SYSTEM_INTEL_MSR_CAPABLE
:
237 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
238 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_STATUS
;
240 case SYSTEM_IO_CAPABLE
:
241 cmd
.type
= SYSTEM_IO_CAPABLE
;
242 perf
= drv_data
[first_cpu(mask
)]->acpi_data
;
243 cmd
.addr
.io
.port
= perf
->control_register
.address
;
244 cmd
.addr
.io
.bit_width
= perf
->control_register
.bit_width
;
254 dprintk("get_cur_val = %u\n", cmd
.val
);
260 * Return the measured active (C0) frequency on this CPU since last call
263 * Return: Average CPU frequency in terms of max frequency (zero on error)
265 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
266 * over a period of time, while CPU is in C0 state.
267 * IA32_MPERF counts at the rate of max advertised frequency
268 * IA32_APERF counts at the rate of actual CPU frequency
269 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
270 * no meaning should be associated with absolute values of these MSRs.
272 static unsigned int get_measured_perf(unsigned int cpu
)
280 } aperf_cur
, mperf_cur
;
282 cpumask_t saved_mask
;
283 unsigned int perf_percent
;
286 saved_mask
= current
->cpus_allowed
;
287 set_cpus_allowed(current
, cpumask_of_cpu(cpu
));
288 if (get_cpu() != cpu
) {
289 /* We were not able to run on requested processor */
294 rdmsr(MSR_IA32_APERF
, aperf_cur
.split
.lo
, aperf_cur
.split
.hi
);
295 rdmsr(MSR_IA32_MPERF
, mperf_cur
.split
.lo
, mperf_cur
.split
.hi
);
297 wrmsr(MSR_IA32_APERF
, 0,0);
298 wrmsr(MSR_IA32_MPERF
, 0,0);
302 * We dont want to do 64 bit divide with 32 bit kernel
303 * Get an approximate value. Return failure in case we cannot get
304 * an approximate value.
306 if (unlikely(aperf_cur
.split
.hi
|| mperf_cur
.split
.hi
)) {
310 h
= max_t(u32
, aperf_cur
.split
.hi
, mperf_cur
.split
.hi
);
311 shift_count
= fls(h
);
313 aperf_cur
.whole
>>= shift_count
;
314 mperf_cur
.whole
>>= shift_count
;
317 if (((unsigned long)(-1) / 100) < aperf_cur
.split
.lo
) {
319 aperf_cur
.split
.lo
>>= shift_count
;
320 mperf_cur
.split
.lo
>>= shift_count
;
323 if (aperf_cur
.split
.lo
&& mperf_cur
.split
.lo
)
324 perf_percent
= (aperf_cur
.split
.lo
* 100) / mperf_cur
.split
.lo
;
329 if (unlikely(((unsigned long)(-1) / 100) < aperf_cur
.whole
)) {
331 aperf_cur
.whole
>>= shift_count
;
332 mperf_cur
.whole
>>= shift_count
;
335 if (aperf_cur
.whole
&& mperf_cur
.whole
)
336 perf_percent
= (aperf_cur
.whole
* 100) / mperf_cur
.whole
;
342 retval
= drv_data
[cpu
]->max_freq
* perf_percent
/ 100;
345 set_cpus_allowed(current
, saved_mask
);
347 dprintk("cpu %d: performance percent %d\n", cpu
, perf_percent
);
351 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
353 struct acpi_cpufreq_data
*data
= drv_data
[cpu
];
356 dprintk("get_cur_freq_on_cpu (%d)\n", cpu
);
358 if (unlikely(data
== NULL
||
359 data
->acpi_data
== NULL
|| data
->freq_table
== NULL
)) {
363 freq
= extract_freq(get_cur_val(cpumask_of_cpu(cpu
)), data
);
364 dprintk("cur freq = %u\n", freq
);
369 static unsigned int check_freqs(cpumask_t mask
, unsigned int freq
,
370 struct acpi_cpufreq_data
*data
)
372 unsigned int cur_freq
;
375 for (i
=0; i
<100; i
++) {
376 cur_freq
= extract_freq(get_cur_val(mask
), data
);
377 if (cur_freq
== freq
)
384 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
385 unsigned int target_freq
, unsigned int relation
)
387 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
388 struct acpi_processor_performance
*perf
;
389 struct cpufreq_freqs freqs
;
390 cpumask_t online_policy_cpus
;
393 unsigned int next_state
= 0;
394 unsigned int next_perf_state
= 0;
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
))
413 #ifdef CONFIG_HOTPLUG_CPU
414 /* cpufreq holds the hotplug lock, so we are safe from here on */
415 cpus_and(online_policy_cpus
, cpu_online_map
, policy
->cpus
);
417 online_policy_cpus
= policy
->cpus
;
420 next_perf_state
= data
->freq_table
[next_state
].index
;
421 if (perf
->state
== next_perf_state
) {
422 if (unlikely(data
->resume
)) {
423 dprintk("Called after resume, resetting to P%d\n",
427 dprintk("Already at target state (P%d)\n",
433 switch (data
->cpu_feature
) {
434 case SYSTEM_INTEL_MSR_CAPABLE
:
435 cmd
.type
= SYSTEM_INTEL_MSR_CAPABLE
;
436 cmd
.addr
.msr
.reg
= MSR_IA32_PERF_CTL
;
438 (u32
) perf
->states
[next_perf_state
].
439 control
& INTEL_MSR_RANGE
;
440 cmd
.val
= (cmd
.val
& ~INTEL_MSR_RANGE
) | msr
;
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
;
452 cpus_clear(cmd
.mask
);
454 if (policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
)
455 cmd
.mask
= online_policy_cpus
;
457 cpu_set(policy
->cpu
, cmd
.mask
);
459 freqs
.old
= data
->freq_table
[perf
->state
].frequency
;
460 freqs
.new = data
->freq_table
[next_perf_state
].frequency
;
461 for_each_cpu_mask(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",
476 for_each_cpu_mask(i
, cmd
.mask
) {
478 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
480 perf
->state
= next_perf_state
;
485 static int acpi_cpufreq_verify(struct cpufreq_policy
*policy
)
487 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
489 dprintk("acpi_cpufreq_verify\n");
491 return cpufreq_frequency_table_verify(policy
, data
->freq_table
);
495 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
497 struct acpi_processor_performance
*perf
= data
->acpi_data
;
500 /* search the closest match to cpu_khz */
503 unsigned long freqn
= perf
->states
[0].core_frequency
* 1000;
505 for (i
=0; i
<(perf
->state_count
-1); i
++) {
507 freqn
= perf
->states
[i
+1].core_frequency
* 1000;
508 if ((2 * cpu_khz
) > (freqn
+ freq
)) {
513 perf
->state
= perf
->state_count
-1;
516 /* assume CPU is at P0... */
518 return perf
->states
[0].core_frequency
* 1000;
523 * acpi_cpufreq_early_init - initialize ACPI P-States library
525 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
526 * in order to determine correct frequency and voltage pairings. We can
527 * do _PDC and _PSD and find out the processor dependency for the
528 * actual init that will happen later...
530 static int acpi_cpufreq_early_init(void)
532 struct acpi_processor_performance
*data
;
536 dprintk("acpi_cpufreq_early_init\n");
538 for_each_possible_cpu(i
) {
539 data
= kzalloc(sizeof(struct acpi_processor_performance
),
542 for_each_cpu_mask(j
, covered
) {
543 kfree(acpi_perf_data
[j
]);
544 acpi_perf_data
[j
] = NULL
;
548 acpi_perf_data
[i
] = data
;
552 /* Do initialization in ACPI core */
553 acpi_processor_preregister_performance(acpi_perf_data
);
558 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
559 * or do it in BIOS firmware and won't inform about it to OS. If not
560 * detected, this has a side effect of making CPU run at a different speed
561 * than OS intended it to run at. Detect it and handle it cleanly.
563 static int bios_with_sw_any_bug
;
565 static int sw_any_bug_found(struct dmi_system_id
*d
)
567 bios_with_sw_any_bug
= 1;
571 static struct dmi_system_id sw_any_bug_dmi_table
[] = {
573 .callback
= sw_any_bug_found
,
574 .ident
= "Supermicro Server X6DLP",
576 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
577 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
578 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
584 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
587 unsigned int valid_states
= 0;
588 unsigned int cpu
= policy
->cpu
;
589 struct acpi_cpufreq_data
*data
;
590 unsigned int result
= 0;
591 struct cpuinfo_x86
*c
= &cpu_data
[policy
->cpu
];
592 struct acpi_processor_performance
*perf
;
594 dprintk("acpi_cpufreq_cpu_init\n");
596 if (!acpi_perf_data
[cpu
])
599 data
= kzalloc(sizeof(struct acpi_cpufreq_data
), GFP_KERNEL
);
603 data
->acpi_data
= acpi_perf_data
[cpu
];
604 drv_data
[cpu
] = data
;
606 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
607 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
609 result
= acpi_processor_register_performance(data
->acpi_data
, cpu
);
613 perf
= data
->acpi_data
;
614 policy
->shared_type
= perf
->shared_type
;
617 * Will let policy->cpus know about dependency only when software
618 * coordination is required.
620 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
621 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
622 policy
->cpus
= perf
->shared_cpu_map
;
626 dmi_check_system(sw_any_bug_dmi_table
);
627 if (bios_with_sw_any_bug
&& cpus_weight(policy
->cpus
) == 1) {
628 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
629 policy
->cpus
= cpu_core_map
[cpu
];
633 /* capability check */
634 if (perf
->state_count
<= 1) {
635 dprintk("No P-States\n");
640 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
645 switch (perf
->control_register
.space_id
) {
646 case ACPI_ADR_SPACE_SYSTEM_IO
:
647 dprintk("SYSTEM IO addr space\n");
648 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
650 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
651 dprintk("HARDWARE addr space\n");
652 if (!check_est_cpu(cpu
)) {
656 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
659 dprintk("Unknown addr space %d\n",
660 (u32
) (perf
->control_register
.space_id
));
665 data
->freq_table
= kmalloc(sizeof(struct cpufreq_frequency_table
) *
666 (perf
->state_count
+1), GFP_KERNEL
);
667 if (!data
->freq_table
) {
672 /* detect transition latency */
673 policy
->cpuinfo
.transition_latency
= 0;
674 for (i
=0; i
<perf
->state_count
; i
++) {
675 if ((perf
->states
[i
].transition_latency
* 1000) >
676 policy
->cpuinfo
.transition_latency
)
677 policy
->cpuinfo
.transition_latency
=
678 perf
->states
[i
].transition_latency
* 1000;
680 policy
->governor
= CPUFREQ_DEFAULT_GOVERNOR
;
682 data
->max_freq
= perf
->states
[0].core_frequency
* 1000;
684 for (i
=0; i
<perf
->state_count
; i
++) {
685 if (i
>0 && perf
->states
[i
].core_frequency
==
686 perf
->states
[i
-1].core_frequency
)
689 data
->freq_table
[valid_states
].index
= i
;
690 data
->freq_table
[valid_states
].frequency
=
691 perf
->states
[i
].core_frequency
* 1000;
694 data
->freq_table
[perf
->state_count
].frequency
= CPUFREQ_TABLE_END
;
696 result
= cpufreq_frequency_table_cpuinfo(policy
, data
->freq_table
);
700 switch (data
->cpu_feature
) {
701 case ACPI_ADR_SPACE_SYSTEM_IO
:
702 /* Current speed is unknown and not detectable by IO port */
703 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
705 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
706 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
707 get_cur_freq_on_cpu(cpu
);
713 /* notify BIOS that we exist */
714 acpi_processor_notify_smm(THIS_MODULE
);
716 /* Check for APERF/MPERF support in hardware */
717 if (c
->x86_vendor
== X86_VENDOR_INTEL
&& c
->cpuid_level
>= 6) {
720 if (ecx
& CPUID_6_ECX_APERFMPERF_CAPABILITY
)
721 acpi_cpufreq_driver
.getavg
= get_measured_perf
;
724 dprintk("CPU%u - ACPI performance management activated.\n", cpu
);
725 for (i
= 0; i
< perf
->state_count
; i
++)
726 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
727 (i
== perf
->state
? '*' : ' '), i
,
728 (u32
) perf
->states
[i
].core_frequency
,
729 (u32
) perf
->states
[i
].power
,
730 (u32
) perf
->states
[i
].transition_latency
);
732 cpufreq_frequency_table_get_attr(data
->freq_table
, policy
->cpu
);
735 * the first call to ->target() should result in us actually
736 * writing something to the appropriate registers.
743 kfree(data
->freq_table
);
745 acpi_processor_unregister_performance(perf
, cpu
);
748 drv_data
[cpu
] = NULL
;
753 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
755 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
757 dprintk("acpi_cpufreq_cpu_exit\n");
760 cpufreq_frequency_table_put_attr(policy
->cpu
);
761 drv_data
[policy
->cpu
] = NULL
;
762 acpi_processor_unregister_performance(data
->acpi_data
,
770 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
772 struct acpi_cpufreq_data
*data
= drv_data
[policy
->cpu
];
774 dprintk("acpi_cpufreq_resume\n");
781 static struct freq_attr
*acpi_cpufreq_attr
[] = {
782 &cpufreq_freq_attr_scaling_available_freqs
,
786 static struct cpufreq_driver acpi_cpufreq_driver
= {
787 .verify
= acpi_cpufreq_verify
,
788 .target
= acpi_cpufreq_target
,
789 .init
= acpi_cpufreq_cpu_init
,
790 .exit
= acpi_cpufreq_cpu_exit
,
791 .resume
= acpi_cpufreq_resume
,
792 .name
= "acpi-cpufreq",
793 .owner
= THIS_MODULE
,
794 .attr
= acpi_cpufreq_attr
,
797 static int __init
acpi_cpufreq_init(void)
799 dprintk("acpi_cpufreq_init\n");
801 acpi_cpufreq_early_init();
803 return cpufreq_register_driver(&acpi_cpufreq_driver
);
806 static void __exit
acpi_cpufreq_exit(void)
809 dprintk("acpi_cpufreq_exit\n");
811 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
813 for_each_possible_cpu(i
) {
814 kfree(acpi_perf_data
[i
]);
815 acpi_perf_data
[i
] = NULL
;
820 module_param(acpi_pstate_strict
, uint
, 0644);
821 MODULE_PARM_DESC(acpi_pstate_strict
,
822 "value 0 or non-zero. non-zero -> strict ACPI checks are "
823 "performed during frequency changes.");
825 late_initcall(acpi_cpufreq_init
);
826 module_exit(acpi_cpufreq_exit
);
828 MODULE_ALIAS("acpi");