1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * acpi-cpufreq.c - ACPI Processor P-States Driver
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
8 * Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/sched.h>
18 #include <linux/cpufreq.h>
19 #include <linux/compiler.h>
20 #include <linux/dmi.h>
21 #include <linux/slab.h>
22 #include <linux/string_helpers.h>
23 #include <linux/platform_device.h>
25 #include <linux/acpi.h>
27 #include <linux/delay.h>
28 #include <linux/uaccess.h>
30 #include <acpi/processor.h>
31 #include <acpi/cppc_acpi.h>
34 #include <asm/processor.h>
35 #include <asm/cpufeature.h>
36 #include <asm/cpu_device_id.h>
38 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
39 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
40 MODULE_LICENSE("GPL");
43 UNDEFINED_CAPABLE
= 0,
44 SYSTEM_INTEL_MSR_CAPABLE
,
45 SYSTEM_AMD_MSR_CAPABLE
,
49 #define INTEL_MSR_RANGE (0xffff)
50 #define AMD_MSR_RANGE (0x7)
51 #define HYGON_MSR_RANGE (0x7)
53 struct acpi_cpufreq_data
{
55 unsigned int cpu_feature
;
56 unsigned int acpi_perf_cpu
;
57 cpumask_var_t freqdomain_cpus
;
58 void (*cpu_freq_write
)(struct acpi_pct_register
*reg
, u32 val
);
59 u32 (*cpu_freq_read
)(struct acpi_pct_register
*reg
);
62 /* acpi_perf_data is a pointer to percpu data. */
63 static struct acpi_processor_performance __percpu
*acpi_perf_data
;
65 static inline struct acpi_processor_performance
*to_perf_data(struct acpi_cpufreq_data
*data
)
67 return per_cpu_ptr(acpi_perf_data
, data
->acpi_perf_cpu
);
70 static struct cpufreq_driver acpi_cpufreq_driver
;
72 static unsigned int acpi_pstate_strict
;
74 static bool boost_state(unsigned int cpu
)
78 switch (boot_cpu_data
.x86_vendor
) {
79 case X86_VENDOR_INTEL
:
80 case X86_VENDOR_CENTAUR
:
81 case X86_VENDOR_ZHAOXIN
:
82 rdmsrl_on_cpu(cpu
, MSR_IA32_MISC_ENABLE
, &msr
);
83 return !(msr
& MSR_IA32_MISC_ENABLE_TURBO_DISABLE
);
84 case X86_VENDOR_HYGON
:
86 rdmsrl_on_cpu(cpu
, MSR_K7_HWCR
, &msr
);
87 return !(msr
& MSR_K7_HWCR_CPB_DIS
);
92 static int boost_set_msr(bool enable
)
97 switch (boot_cpu_data
.x86_vendor
) {
98 case X86_VENDOR_INTEL
:
99 case X86_VENDOR_CENTAUR
:
100 case X86_VENDOR_ZHAOXIN
:
101 msr_addr
= MSR_IA32_MISC_ENABLE
;
102 msr_mask
= MSR_IA32_MISC_ENABLE_TURBO_DISABLE
;
104 case X86_VENDOR_HYGON
:
106 msr_addr
= MSR_K7_HWCR
;
107 msr_mask
= MSR_K7_HWCR_CPB_DIS
;
113 rdmsrl(msr_addr
, val
);
120 wrmsrl(msr_addr
, val
);
124 static void boost_set_msr_each(void *p_en
)
126 bool enable
= (bool) p_en
;
128 boost_set_msr(enable
);
131 static int set_boost(struct cpufreq_policy
*policy
, int val
)
133 on_each_cpu_mask(policy
->cpus
, boost_set_msr_each
,
134 (void *)(long)val
, 1);
135 pr_debug("CPU %*pbl: Core Boosting %s.\n",
136 cpumask_pr_args(policy
->cpus
), str_enabled_disabled(val
));
141 static ssize_t
show_freqdomain_cpus(struct cpufreq_policy
*policy
, char *buf
)
143 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
148 return cpufreq_show_cpus(data
->freqdomain_cpus
, buf
);
151 cpufreq_freq_attr_ro(freqdomain_cpus
);
153 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
154 static ssize_t
store_cpb(struct cpufreq_policy
*policy
, const char *buf
,
158 unsigned int val
= 0;
160 if (!acpi_cpufreq_driver
.set_boost
)
163 ret
= kstrtouint(buf
, 10, &val
);
168 set_boost(policy
, val
);
174 static ssize_t
show_cpb(struct cpufreq_policy
*policy
, char *buf
)
176 return sprintf(buf
, "%u\n", acpi_cpufreq_driver
.boost_enabled
);
179 cpufreq_freq_attr_rw(cpb
);
182 static int check_est_cpu(unsigned int cpuid
)
184 struct cpuinfo_x86
*cpu
= &cpu_data(cpuid
);
186 return cpu_has(cpu
, X86_FEATURE_EST
);
189 static int check_amd_hwpstate_cpu(unsigned int cpuid
)
191 struct cpuinfo_x86
*cpu
= &cpu_data(cpuid
);
193 return cpu_has(cpu
, X86_FEATURE_HW_PSTATE
);
196 static unsigned extract_io(struct cpufreq_policy
*policy
, u32 value
)
198 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
199 struct acpi_processor_performance
*perf
;
202 perf
= to_perf_data(data
);
204 for (i
= 0; i
< perf
->state_count
; i
++) {
205 if (value
== perf
->states
[i
].status
)
206 return policy
->freq_table
[i
].frequency
;
211 static unsigned extract_msr(struct cpufreq_policy
*policy
, u32 msr
)
213 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
214 struct cpufreq_frequency_table
*pos
;
215 struct acpi_processor_performance
*perf
;
217 if (boot_cpu_data
.x86_vendor
== X86_VENDOR_AMD
)
218 msr
&= AMD_MSR_RANGE
;
219 else if (boot_cpu_data
.x86_vendor
== X86_VENDOR_HYGON
)
220 msr
&= HYGON_MSR_RANGE
;
222 msr
&= INTEL_MSR_RANGE
;
224 perf
= to_perf_data(data
);
226 cpufreq_for_each_entry(pos
, policy
->freq_table
)
227 if (msr
== perf
->states
[pos
->driver_data
].status
)
228 return pos
->frequency
;
229 return policy
->freq_table
[0].frequency
;
232 static unsigned extract_freq(struct cpufreq_policy
*policy
, u32 val
)
234 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
236 switch (data
->cpu_feature
) {
237 case SYSTEM_INTEL_MSR_CAPABLE
:
238 case SYSTEM_AMD_MSR_CAPABLE
:
239 return extract_msr(policy
, val
);
240 case SYSTEM_IO_CAPABLE
:
241 return extract_io(policy
, val
);
247 static u32
cpu_freq_read_intel(struct acpi_pct_register
*not_used
)
249 u32 val
, dummy __always_unused
;
251 rdmsr(MSR_IA32_PERF_CTL
, val
, dummy
);
255 static void cpu_freq_write_intel(struct acpi_pct_register
*not_used
, u32 val
)
259 rdmsr(MSR_IA32_PERF_CTL
, lo
, hi
);
260 lo
= (lo
& ~INTEL_MSR_RANGE
) | (val
& INTEL_MSR_RANGE
);
261 wrmsr(MSR_IA32_PERF_CTL
, lo
, hi
);
264 static u32
cpu_freq_read_amd(struct acpi_pct_register
*not_used
)
266 u32 val
, dummy __always_unused
;
268 rdmsr(MSR_AMD_PERF_CTL
, val
, dummy
);
272 static void cpu_freq_write_amd(struct acpi_pct_register
*not_used
, u32 val
)
274 wrmsr(MSR_AMD_PERF_CTL
, val
, 0);
277 static u32
cpu_freq_read_io(struct acpi_pct_register
*reg
)
281 acpi_os_read_port(reg
->address
, &val
, reg
->bit_width
);
285 static void cpu_freq_write_io(struct acpi_pct_register
*reg
, u32 val
)
287 acpi_os_write_port(reg
->address
, val
, reg
->bit_width
);
291 struct acpi_pct_register
*reg
;
294 void (*write
)(struct acpi_pct_register
*reg
, u32 val
);
295 u32 (*read
)(struct acpi_pct_register
*reg
);
299 /* Called via smp_call_function_single(), on the target CPU */
300 static void do_drv_read(void *_cmd
)
302 struct drv_cmd
*cmd
= _cmd
;
304 cmd
->val
= cmd
->func
.read(cmd
->reg
);
307 static u32
drv_read(struct acpi_cpufreq_data
*data
, const struct cpumask
*mask
)
309 struct acpi_processor_performance
*perf
= to_perf_data(data
);
310 struct drv_cmd cmd
= {
311 .reg
= &perf
->control_register
,
312 .func
.read
= data
->cpu_freq_read
,
316 err
= smp_call_function_any(mask
, do_drv_read
, &cmd
, 1);
317 WARN_ON_ONCE(err
); /* smp_call_function_any() was buggy? */
321 /* Called via smp_call_function_many(), on the target CPUs */
322 static void do_drv_write(void *_cmd
)
324 struct drv_cmd
*cmd
= _cmd
;
326 cmd
->func
.write(cmd
->reg
, cmd
->val
);
329 static void drv_write(struct acpi_cpufreq_data
*data
,
330 const struct cpumask
*mask
, u32 val
)
332 struct acpi_processor_performance
*perf
= to_perf_data(data
);
333 struct drv_cmd cmd
= {
334 .reg
= &perf
->control_register
,
336 .func
.write
= data
->cpu_freq_write
,
340 this_cpu
= get_cpu();
341 if (cpumask_test_cpu(this_cpu
, mask
))
344 smp_call_function_many(mask
, do_drv_write
, &cmd
, 1);
348 static u32
get_cur_val(const struct cpumask
*mask
, struct acpi_cpufreq_data
*data
)
352 if (unlikely(cpumask_empty(mask
)))
355 val
= drv_read(data
, mask
);
357 pr_debug("%s = %u\n", __func__
, val
);
362 static unsigned int get_cur_freq_on_cpu(unsigned int cpu
)
364 struct acpi_cpufreq_data
*data
;
365 struct cpufreq_policy
*policy
;
367 unsigned int cached_freq
;
369 pr_debug("%s (%d)\n", __func__
, cpu
);
371 policy
= cpufreq_cpu_get_raw(cpu
);
372 if (unlikely(!policy
))
375 data
= policy
->driver_data
;
376 if (unlikely(!data
|| !policy
->freq_table
))
379 cached_freq
= policy
->freq_table
[to_perf_data(data
)->state
].frequency
;
380 freq
= extract_freq(policy
, get_cur_val(cpumask_of(cpu
), data
));
381 if (freq
!= cached_freq
) {
383 * The dreaded BIOS frequency change behind our back.
384 * Force set the frequency on next target call.
389 pr_debug("cur freq = %u\n", freq
);
394 static unsigned int check_freqs(struct cpufreq_policy
*policy
,
395 const struct cpumask
*mask
, unsigned int freq
)
397 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
398 unsigned int cur_freq
;
401 for (i
= 0; i
< 100; i
++) {
402 cur_freq
= extract_freq(policy
, get_cur_val(mask
, data
));
403 if (cur_freq
== freq
)
410 static int acpi_cpufreq_target(struct cpufreq_policy
*policy
,
413 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
414 struct acpi_processor_performance
*perf
;
415 const struct cpumask
*mask
;
416 unsigned int next_perf_state
= 0; /* Index into perf table */
419 if (unlikely(!data
)) {
423 perf
= to_perf_data(data
);
424 next_perf_state
= policy
->freq_table
[index
].driver_data
;
425 if (perf
->state
== next_perf_state
) {
426 if (unlikely(data
->resume
)) {
427 pr_debug("Called after resume, resetting to P%d\n",
431 pr_debug("Already at target state (P%d)\n",
438 * The core won't allow CPUs to go away until the governor has been
439 * stopped, so we can rely on the stability of policy->cpus.
441 mask
= policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
?
442 cpumask_of(policy
->cpu
) : policy
->cpus
;
444 drv_write(data
, mask
, perf
->states
[next_perf_state
].control
);
446 if (acpi_pstate_strict
) {
447 if (!check_freqs(policy
, mask
,
448 policy
->freq_table
[index
].frequency
)) {
449 pr_debug("%s (%d)\n", __func__
, policy
->cpu
);
455 perf
->state
= next_perf_state
;
460 static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy
*policy
,
461 unsigned int target_freq
)
463 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
464 struct acpi_processor_performance
*perf
;
465 struct cpufreq_frequency_table
*entry
;
466 unsigned int next_perf_state
, next_freq
, index
;
469 * Find the closest frequency above target_freq.
471 if (policy
->cached_target_freq
== target_freq
)
472 index
= policy
->cached_resolved_idx
;
474 index
= cpufreq_table_find_index_dl(policy
, target_freq
,
477 entry
= &policy
->freq_table
[index
];
478 next_freq
= entry
->frequency
;
479 next_perf_state
= entry
->driver_data
;
481 perf
= to_perf_data(data
);
482 if (perf
->state
== next_perf_state
) {
483 if (unlikely(data
->resume
))
489 data
->cpu_freq_write(&perf
->control_register
,
490 perf
->states
[next_perf_state
].control
);
491 perf
->state
= next_perf_state
;
496 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data
*data
, unsigned int cpu
)
498 struct acpi_processor_performance
*perf
;
500 perf
= to_perf_data(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
);
535 static int cpufreq_boost_down_prep(unsigned int cpu
)
538 * Clear the boost-disable bit on the CPU_DOWN path so that
539 * this cpu cannot block the remaining ones from boosting.
541 return boost_set_msr(1);
545 * acpi_cpufreq_early_init - initialize ACPI P-States library
547 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
548 * in order to determine correct frequency and voltage pairings. We can
549 * do _PDC and _PSD and find out the processor dependency for the
550 * actual init that will happen later...
552 static int __init
acpi_cpufreq_early_init(void)
555 pr_debug("%s\n", __func__
);
557 acpi_perf_data
= alloc_percpu(struct acpi_processor_performance
);
558 if (!acpi_perf_data
) {
559 pr_debug("Memory allocation error for acpi_perf_data.\n");
562 for_each_possible_cpu(i
) {
563 if (!zalloc_cpumask_var_node(
564 &per_cpu_ptr(acpi_perf_data
, i
)->shared_cpu_map
,
565 GFP_KERNEL
, cpu_to_node(i
))) {
567 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
568 free_acpi_perf_data();
573 /* Do initialization in ACPI core */
574 acpi_processor_preregister_performance(acpi_perf_data
);
580 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
581 * or do it in BIOS firmware and won't inform about it to OS. If not
582 * detected, this has a side effect of making CPU run at a different speed
583 * than OS intended it to run at. Detect it and handle it cleanly.
585 static int bios_with_sw_any_bug
;
587 static int sw_any_bug_found(const struct dmi_system_id
*d
)
589 bios_with_sw_any_bug
= 1;
593 static const struct dmi_system_id sw_any_bug_dmi_table
[] = {
595 .callback
= sw_any_bug_found
,
596 .ident
= "Supermicro Server X6DLP",
598 DMI_MATCH(DMI_SYS_VENDOR
, "Supermicro"),
599 DMI_MATCH(DMI_BIOS_VERSION
, "080010"),
600 DMI_MATCH(DMI_PRODUCT_NAME
, "X6DLP"),
606 static int acpi_cpufreq_blacklist(struct cpuinfo_x86
*c
)
608 /* Intel Xeon Processor 7100 Series Specification Update
609 * https://www.intel.com/Assets/PDF/specupdate/314554.pdf
610 * AL30: A Machine Check Exception (MCE) Occurring during an
611 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
612 * Both Processor Cores to Lock Up. */
613 if (c
->x86_vendor
== X86_VENDOR_INTEL
) {
614 if ((c
->x86
== 15) &&
615 (c
->x86_model
== 6) &&
616 (c
->x86_stepping
== 8)) {
617 pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
625 #ifdef CONFIG_ACPI_CPPC_LIB
626 static u64
get_max_boost_ratio(unsigned int cpu
)
628 struct cppc_perf_caps perf_caps
;
629 u64 highest_perf
, nominal_perf
;
632 if (acpi_pstate_strict
)
635 ret
= cppc_get_perf_caps(cpu
, &perf_caps
);
637 pr_debug("CPU%d: Unable to get performance capabilities (%d)\n",
642 if (boot_cpu_data
.x86_vendor
== X86_VENDOR_AMD
) {
643 ret
= amd_get_boost_ratio_numerator(cpu
, &highest_perf
);
645 pr_debug("CPU%d: Unable to get boost ratio numerator (%d)\n",
650 highest_perf
= perf_caps
.highest_perf
;
653 nominal_perf
= perf_caps
.nominal_perf
;
655 if (!highest_perf
|| !nominal_perf
) {
656 pr_debug("CPU%d: highest or nominal performance missing\n", cpu
);
660 if (highest_perf
< nominal_perf
) {
661 pr_debug("CPU%d: nominal performance above highest\n", cpu
);
665 return div_u64(highest_perf
<< SCHED_CAPACITY_SHIFT
, nominal_perf
);
668 static inline u64
get_max_boost_ratio(unsigned int cpu
) { return 0; }
671 static int acpi_cpufreq_cpu_init(struct cpufreq_policy
*policy
)
673 struct cpufreq_frequency_table
*freq_table
;
674 struct acpi_processor_performance
*perf
;
675 struct acpi_cpufreq_data
*data
;
676 unsigned int cpu
= policy
->cpu
;
677 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
678 unsigned int valid_states
= 0;
679 unsigned int result
= 0;
683 static int blacklisted
;
686 pr_debug("%s\n", __func__
);
691 blacklisted
= acpi_cpufreq_blacklist(c
);
696 data
= kzalloc(sizeof(*data
), GFP_KERNEL
);
700 if (!zalloc_cpumask_var(&data
->freqdomain_cpus
, GFP_KERNEL
)) {
705 perf
= per_cpu_ptr(acpi_perf_data
, cpu
);
706 data
->acpi_perf_cpu
= cpu
;
707 policy
->driver_data
= data
;
709 if (cpu_has(c
, X86_FEATURE_CONSTANT_TSC
))
710 acpi_cpufreq_driver
.flags
|= CPUFREQ_CONST_LOOPS
;
712 result
= acpi_processor_register_performance(perf
, cpu
);
716 policy
->shared_type
= perf
->shared_type
;
719 * Will let policy->cpus know about dependency only when software
720 * coordination is required.
722 if (policy
->shared_type
== CPUFREQ_SHARED_TYPE_ALL
||
723 policy
->shared_type
== CPUFREQ_SHARED_TYPE_ANY
) {
724 cpumask_copy(policy
->cpus
, perf
->shared_cpu_map
);
726 cpumask_copy(data
->freqdomain_cpus
, perf
->shared_cpu_map
);
729 dmi_check_system(sw_any_bug_dmi_table
);
730 if (bios_with_sw_any_bug
&& !policy_is_shared(policy
)) {
731 policy
->shared_type
= CPUFREQ_SHARED_TYPE_ALL
;
732 cpumask_copy(policy
->cpus
, topology_core_cpumask(cpu
));
735 if (check_amd_hwpstate_cpu(cpu
) && boot_cpu_data
.x86
< 0x19 &&
736 !acpi_pstate_strict
) {
737 cpumask_clear(policy
->cpus
);
738 cpumask_set_cpu(cpu
, policy
->cpus
);
739 cpumask_copy(data
->freqdomain_cpus
,
740 topology_sibling_cpumask(cpu
));
741 policy
->shared_type
= CPUFREQ_SHARED_TYPE_HW
;
742 pr_info_once("overriding BIOS provided _PSD data\n");
746 /* capability check */
747 if (perf
->state_count
<= 1) {
748 pr_debug("No P-States\n");
753 if (perf
->control_register
.space_id
!= perf
->status_register
.space_id
) {
758 switch (perf
->control_register
.space_id
) {
759 case ACPI_ADR_SPACE_SYSTEM_IO
:
760 if (boot_cpu_data
.x86_vendor
== X86_VENDOR_AMD
&&
761 boot_cpu_data
.x86
== 0xf) {
762 pr_debug("AMD K8 systems must use native drivers.\n");
766 pr_debug("SYSTEM IO addr space\n");
767 data
->cpu_feature
= SYSTEM_IO_CAPABLE
;
768 data
->cpu_freq_read
= cpu_freq_read_io
;
769 data
->cpu_freq_write
= cpu_freq_write_io
;
771 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
772 pr_debug("HARDWARE addr space\n");
773 if (check_est_cpu(cpu
)) {
774 data
->cpu_feature
= SYSTEM_INTEL_MSR_CAPABLE
;
775 data
->cpu_freq_read
= cpu_freq_read_intel
;
776 data
->cpu_freq_write
= cpu_freq_write_intel
;
779 if (check_amd_hwpstate_cpu(cpu
)) {
780 data
->cpu_feature
= SYSTEM_AMD_MSR_CAPABLE
;
781 data
->cpu_freq_read
= cpu_freq_read_amd
;
782 data
->cpu_freq_write
= cpu_freq_write_amd
;
788 pr_debug("Unknown addr space %d\n",
789 (u32
) (perf
->control_register
.space_id
));
794 freq_table
= kcalloc(perf
->state_count
+ 1, sizeof(*freq_table
),
801 /* detect transition latency */
802 policy
->cpuinfo
.transition_latency
= 0;
803 for (i
= 0; i
< perf
->state_count
; i
++) {
804 if ((perf
->states
[i
].transition_latency
* 1000) >
805 policy
->cpuinfo
.transition_latency
)
806 policy
->cpuinfo
.transition_latency
=
807 perf
->states
[i
].transition_latency
* 1000;
810 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
811 if (perf
->control_register
.space_id
== ACPI_ADR_SPACE_FIXED_HARDWARE
&&
812 policy
->cpuinfo
.transition_latency
> 20 * 1000) {
813 policy
->cpuinfo
.transition_latency
= 20 * 1000;
814 pr_info_once("P-state transition latency capped at 20 uS\n");
818 for (i
= 0; i
< perf
->state_count
; i
++) {
819 if (i
> 0 && perf
->states
[i
].core_frequency
>=
820 freq_table
[valid_states
-1].frequency
/ 1000)
823 freq_table
[valid_states
].driver_data
= i
;
824 freq_table
[valid_states
].frequency
=
825 perf
->states
[i
].core_frequency
* 1000;
828 freq_table
[valid_states
].frequency
= CPUFREQ_TABLE_END
;
830 max_boost_ratio
= get_max_boost_ratio(cpu
);
831 if (max_boost_ratio
) {
832 unsigned int freq
= freq_table
[0].frequency
;
835 * Because the loop above sorts the freq_table entries in the
836 * descending order, freq is the maximum frequency in the table.
837 * Assume that it corresponds to the CPPC nominal frequency and
838 * use it to set cpuinfo.max_freq.
840 policy
->cpuinfo
.max_freq
= freq
* max_boost_ratio
>> SCHED_CAPACITY_SHIFT
;
843 * If the maximum "boost" frequency is unknown, ask the arch
844 * scale-invariance code to use the "nominal" performance for
845 * CPU utilization scaling so as to prevent the schedutil
846 * governor from selecting inadequate CPU frequencies.
848 arch_set_max_freq_ratio(true);
851 policy
->freq_table
= freq_table
;
854 switch (perf
->control_register
.space_id
) {
855 case ACPI_ADR_SPACE_SYSTEM_IO
:
857 * The core will not set policy->cur, because
858 * cpufreq_driver->get is NULL, so we need to set it here.
859 * However, we have to guess it, because the current speed is
860 * unknown and not detectable via IO ports.
862 policy
->cur
= acpi_cpufreq_guess_freq(data
, policy
->cpu
);
864 case ACPI_ADR_SPACE_FIXED_HARDWARE
:
865 acpi_cpufreq_driver
.get
= get_cur_freq_on_cpu
;
871 /* notify BIOS that we exist */
872 acpi_processor_notify_smm(THIS_MODULE
);
874 pr_debug("CPU%u - ACPI performance management activated.\n", cpu
);
875 for (i
= 0; i
< perf
->state_count
; i
++)
876 pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
877 (i
== perf
->state
? '*' : ' '), i
,
878 (u32
) perf
->states
[i
].core_frequency
,
879 (u32
) perf
->states
[i
].power
,
880 (u32
) perf
->states
[i
].transition_latency
);
883 * the first call to ->target() should result in us actually
884 * writing something to the appropriate registers.
888 policy
->fast_switch_possible
= !acpi_pstate_strict
&&
889 !(policy_is_shared(policy
) && policy
->shared_type
!= CPUFREQ_SHARED_TYPE_ANY
);
891 if (perf
->states
[0].core_frequency
* 1000 != freq_table
[0].frequency
)
892 pr_warn(FW_WARN
"P-state 0 is not max freq\n");
894 if (acpi_cpufreq_driver
.set_boost
) {
895 set_boost(policy
, acpi_cpufreq_driver
.boost_enabled
);
896 policy
->boost_enabled
= acpi_cpufreq_driver
.boost_enabled
;
902 acpi_processor_unregister_performance(cpu
);
904 free_cpumask_var(data
->freqdomain_cpus
);
907 policy
->driver_data
= NULL
;
912 static void acpi_cpufreq_cpu_exit(struct cpufreq_policy
*policy
)
914 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
916 pr_debug("%s\n", __func__
);
918 cpufreq_boost_down_prep(policy
->cpu
);
919 policy
->fast_switch_possible
= false;
920 policy
->driver_data
= NULL
;
921 acpi_processor_unregister_performance(data
->acpi_perf_cpu
);
922 free_cpumask_var(data
->freqdomain_cpus
);
923 kfree(policy
->freq_table
);
927 static int acpi_cpufreq_resume(struct cpufreq_policy
*policy
)
929 struct acpi_cpufreq_data
*data
= policy
->driver_data
;
931 pr_debug("%s\n", __func__
);
938 static struct freq_attr
*acpi_cpufreq_attr
[] = {
939 &cpufreq_freq_attr_scaling_available_freqs
,
941 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
947 static struct cpufreq_driver acpi_cpufreq_driver
= {
948 .verify
= cpufreq_generic_frequency_table_verify
,
949 .target_index
= acpi_cpufreq_target
,
950 .fast_switch
= acpi_cpufreq_fast_switch
,
951 .bios_limit
= acpi_processor_get_bios_limit
,
952 .init
= acpi_cpufreq_cpu_init
,
953 .exit
= acpi_cpufreq_cpu_exit
,
954 .resume
= acpi_cpufreq_resume
,
955 .name
= "acpi-cpufreq",
956 .attr
= acpi_cpufreq_attr
,
959 static void __init
acpi_cpufreq_boost_init(void)
961 if (!(boot_cpu_has(X86_FEATURE_CPB
) || boot_cpu_has(X86_FEATURE_IDA
))) {
962 pr_debug("Boost capabilities not present in the processor\n");
966 acpi_cpufreq_driver
.set_boost
= set_boost
;
967 acpi_cpufreq_driver
.boost_enabled
= boost_state(0);
970 static int __init
acpi_cpufreq_probe(struct platform_device
*pdev
)
977 /* don't keep reloading if cpufreq_driver exists */
978 if (cpufreq_get_current_driver())
981 pr_debug("%s\n", __func__
);
983 ret
= acpi_cpufreq_early_init();
987 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
988 /* this is a sysfs file with a strange name and an even stranger
989 * semantic - per CPU instantiation, but system global effect.
990 * Lets enable it only on AMD CPUs for compatibility reasons and
991 * only if configured. This is considered legacy code, which
992 * will probably be removed at some point in the future.
994 if (!check_amd_hwpstate_cpu(0)) {
995 struct freq_attr
**attr
;
997 pr_debug("CPB unsupported, do not expose it\n");
999 for (attr
= acpi_cpufreq_attr
; *attr
; attr
++)
1000 if (*attr
== &cpb
) {
1006 acpi_cpufreq_boost_init();
1008 ret
= cpufreq_register_driver(&acpi_cpufreq_driver
);
1010 free_acpi_perf_data();
1015 static void acpi_cpufreq_remove(struct platform_device
*pdev
)
1017 pr_debug("%s\n", __func__
);
1019 cpufreq_unregister_driver(&acpi_cpufreq_driver
);
1021 free_acpi_perf_data();
1024 static struct platform_driver acpi_cpufreq_platdrv
= {
1026 .name
= "acpi-cpufreq",
1028 .remove
= acpi_cpufreq_remove
,
1031 static int __init
acpi_cpufreq_init(void)
1033 return platform_driver_probe(&acpi_cpufreq_platdrv
, acpi_cpufreq_probe
);
1036 static void __exit
acpi_cpufreq_exit(void)
1038 platform_driver_unregister(&acpi_cpufreq_platdrv
);
1041 module_param(acpi_pstate_strict
, uint
, 0644);
1042 MODULE_PARM_DESC(acpi_pstate_strict
,
1043 "value 0 or non-zero. non-zero -> strict ACPI checks are "
1044 "performed during frequency changes.");
1046 late_initcall(acpi_cpufreq_init
);
1047 module_exit(acpi_cpufreq_exit
);
1049 MODULE_ALIAS("platform:acpi-cpufreq");