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/events/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 static DEFINE_PER_CPU(struct aperfmperf, old_perf);
75 /* acpi_perf_data is a pointer to percpu data. */
76 static struct acpi_processor_performance *acpi_perf_data;
78 static struct cpufreq_driver acpi_cpufreq_driver;
80 static unsigned int acpi_pstate_strict;
82 static int check_est_cpu(unsigned int cpuid)
84 struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
86 return 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);
141 const struct cpumask *mask;
149 /* Called via smp_call_function_single(), on the target CPU */
150 static void do_drv_read(void *_cmd)
152 struct drv_cmd *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 /* Called via smp_call_function_many(), on the target CPUs */
170 static void do_drv_write(void *_cmd)
172 struct drv_cmd *cmd = _cmd;
176 case SYSTEM_INTEL_MSR_CAPABLE:
177 rdmsr(cmd->addr.msr.reg, lo, hi);
178 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
179 wrmsr(cmd->addr.msr.reg, lo, hi);
181 case SYSTEM_IO_CAPABLE:
182 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
184 (u32)cmd->addr.io.bit_width);
191 static void drv_read(struct drv_cmd *cmd)
195 smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
198 static void drv_write(struct drv_cmd *cmd)
202 this_cpu = get_cpu();
203 if (cpumask_test_cpu(this_cpu, cmd->mask))
205 smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
209 static u32 get_cur_val(const struct cpumask *mask)
211 struct acpi_processor_performance *perf;
214 if (unlikely(cpumask_empty(mask)))
217 switch (per_cpu(drv_data, cpumask_first(mask))->cpu_feature) {
218 case SYSTEM_INTEL_MSR_CAPABLE:
219 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
220 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
222 case SYSTEM_IO_CAPABLE:
223 cmd.type = SYSTEM_IO_CAPABLE;
224 perf = per_cpu(drv_data, cpumask_first(mask))->acpi_data;
225 cmd.addr.io.port = perf->control_register.address;
226 cmd.addr.io.bit_width = perf->control_register.bit_width;
235 dprintk("get_cur_val = %u\n", cmd.val);
240 /* Called via smp_call_function_single(), on the target CPU */
241 static void read_measured_perf_ctrs(void *_cur)
243 struct aperfmperf *am = _cur;
249 * Return the measured active (C0) frequency on this CPU since last call
252 * Return: Average CPU frequency in terms of max frequency (zero on error)
254 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
255 * over a period of time, while CPU is in C0 state.
256 * IA32_MPERF counts at the rate of max advertised frequency
257 * IA32_APERF counts at the rate of actual CPU frequency
258 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
259 * no meaning should be associated with absolute values of these MSRs.
261 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
264 struct aperfmperf perf;
268 if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
271 ratio = calc_aperfmperf_ratio(&per_cpu(old_perf, cpu), &perf);
272 per_cpu(old_perf, cpu) = perf;
274 retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
279 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
281 struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
283 unsigned int cached_freq;
285 dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
287 if (unlikely(data == NULL ||
288 data->acpi_data == NULL || data->freq_table == NULL)) {
292 cached_freq = data->freq_table[data->acpi_data->state].frequency;
293 freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
294 if (freq != cached_freq) {
296 * The dreaded BIOS frequency change behind our back.
297 * Force set the frequency on next target call.
302 dprintk("cur freq = %u\n", freq);
307 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
308 struct acpi_cpufreq_data *data)
310 unsigned int cur_freq;
313 for (i = 0; i < 100; i++) {
314 cur_freq = extract_freq(get_cur_val(mask), data);
315 if (cur_freq == freq)
322 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
323 unsigned int target_freq, unsigned int relation)
325 struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
326 struct acpi_processor_performance *perf;
327 struct cpufreq_freqs freqs;
329 unsigned int next_state = 0; /* Index into freq_table */
330 unsigned int next_perf_state = 0; /* Index into perf table */
334 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
336 if (unlikely(data == NULL ||
337 data->acpi_data == NULL || data->freq_table == NULL)) {
341 perf = data->acpi_data;
342 result = cpufreq_frequency_table_target(policy,
345 relation, &next_state);
346 if (unlikely(result)) {
351 next_perf_state = data->freq_table[next_state].index;
352 if (perf->state == next_perf_state) {
353 if (unlikely(data->resume)) {
354 dprintk("Called after resume, resetting to P%d\n",
358 dprintk("Already at target state (P%d)\n",
364 trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);
366 switch (data->cpu_feature) {
367 case SYSTEM_INTEL_MSR_CAPABLE:
368 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
369 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
370 cmd.val = (u32) perf->states[next_perf_state].control;
372 case SYSTEM_IO_CAPABLE:
373 cmd.type = SYSTEM_IO_CAPABLE;
374 cmd.addr.io.port = perf->control_register.address;
375 cmd.addr.io.bit_width = perf->control_register.bit_width;
376 cmd.val = (u32) perf->states[next_perf_state].control;
383 /* cpufreq holds the hotplug lock, so we are safe from here on */
384 if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
385 cmd.mask = policy->cpus;
387 cmd.mask = cpumask_of(policy->cpu);
389 freqs.old = perf->states[perf->state].core_frequency * 1000;
390 freqs.new = data->freq_table[next_state].frequency;
391 for_each_cpu(i, cmd.mask) {
393 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
398 if (acpi_pstate_strict) {
399 if (!check_freqs(cmd.mask, freqs.new, data)) {
400 dprintk("acpi_cpufreq_target failed (%d)\n",
407 for_each_cpu(i, cmd.mask) {
409 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
411 perf->state = next_perf_state;
417 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
419 struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
421 dprintk("acpi_cpufreq_verify\n");
423 return cpufreq_frequency_table_verify(policy, data->freq_table);
427 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
429 struct acpi_processor_performance *perf = data->acpi_data;
432 /* search the closest match to cpu_khz */
435 unsigned long freqn = perf->states[0].core_frequency * 1000;
437 for (i = 0; i < (perf->state_count-1); i++) {
439 freqn = perf->states[i+1].core_frequency * 1000;
440 if ((2 * cpu_khz) > (freqn + freq)) {
445 perf->state = perf->state_count-1;
448 /* assume CPU is at P0... */
450 return perf->states[0].core_frequency * 1000;
454 static void free_acpi_perf_data(void)
458 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
459 for_each_possible_cpu(i)
460 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
462 free_percpu(acpi_perf_data);
466 * acpi_cpufreq_early_init - initialize ACPI P-States library
468 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
469 * in order to determine correct frequency and voltage pairings. We can
470 * do _PDC and _PSD and find out the processor dependency for the
471 * actual init that will happen later...
473 static int __init acpi_cpufreq_early_init(void)
476 dprintk("acpi_cpufreq_early_init\n");
478 acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
479 if (!acpi_perf_data) {
480 dprintk("Memory allocation error for acpi_perf_data.\n");
483 for_each_possible_cpu(i) {
484 if (!zalloc_cpumask_var_node(
485 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
486 GFP_KERNEL, cpu_to_node(i))) {
488 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
489 free_acpi_perf_data();
494 /* Do initialization in ACPI core */
495 acpi_processor_preregister_performance(acpi_perf_data);
501 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
502 * or do it in BIOS firmware and won't inform about it to OS. If not
503 * detected, this has a side effect of making CPU run at a different speed
504 * than OS intended it to run at. Detect it and handle it cleanly.
506 static int bios_with_sw_any_bug;
508 static int sw_any_bug_found(const struct dmi_system_id *d)
510 bios_with_sw_any_bug = 1;
514 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
516 .callback = sw_any_bug_found,
517 .ident = "Supermicro Server X6DLP",
519 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
520 DMI_MATCH(DMI_BIOS_VERSION, "080010"),
521 DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
527 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
529 /* Intel Xeon Processor 7100 Series Specification Update
530 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
531 * AL30: A Machine Check Exception (MCE) Occurring during an
532 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
533 * Both Processor Cores to Lock Up. */
534 if (c->x86_vendor == X86_VENDOR_INTEL) {
535 if ((c->x86 == 15) &&
536 (c->x86_model == 6) &&
537 (c->x86_mask == 8)) {
538 printk(KERN_INFO "acpi-cpufreq: Intel(R) "
539 "Xeon(R) 7100 Errata AL30, processors may "
540 "lock up on frequency changes: disabling "
549 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
552 unsigned int valid_states = 0;
553 unsigned int cpu = policy->cpu;
554 struct acpi_cpufreq_data *data;
555 unsigned int result = 0;
556 struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
557 struct acpi_processor_performance *perf;
559 static int blacklisted;
562 dprintk("acpi_cpufreq_cpu_init\n");
567 blacklisted = acpi_cpufreq_blacklist(c);
572 data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
576 data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
577 per_cpu(drv_data, cpu) = data;
579 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
580 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
582 result = acpi_processor_register_performance(data->acpi_data, cpu);
586 perf = data->acpi_data;
587 policy->shared_type = perf->shared_type;
590 * Will let policy->cpus know about dependency only when software
591 * coordination is required.
593 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
594 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
595 cpumask_copy(policy->cpus, perf->shared_cpu_map);
597 cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
600 dmi_check_system(sw_any_bug_dmi_table);
601 if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
602 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
603 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
607 /* capability check */
608 if (perf->state_count <= 1) {
609 dprintk("No P-States\n");
614 if (perf->control_register.space_id != perf->status_register.space_id) {
619 switch (perf->control_register.space_id) {
620 case ACPI_ADR_SPACE_SYSTEM_IO:
621 dprintk("SYSTEM IO addr space\n");
622 data->cpu_feature = SYSTEM_IO_CAPABLE;
624 case ACPI_ADR_SPACE_FIXED_HARDWARE:
625 dprintk("HARDWARE addr space\n");
626 if (!check_est_cpu(cpu)) {
630 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
633 dprintk("Unknown addr space %d\n",
634 (u32) (perf->control_register.space_id));
639 data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
640 (perf->state_count+1), GFP_KERNEL);
641 if (!data->freq_table) {
646 /* detect transition latency */
647 policy->cpuinfo.transition_latency = 0;
648 for (i = 0; i < perf->state_count; i++) {
649 if ((perf->states[i].transition_latency * 1000) >
650 policy->cpuinfo.transition_latency)
651 policy->cpuinfo.transition_latency =
652 perf->states[i].transition_latency * 1000;
655 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
656 if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
657 policy->cpuinfo.transition_latency > 20 * 1000) {
658 policy->cpuinfo.transition_latency = 20 * 1000;
659 printk_once(KERN_INFO
660 "P-state transition latency capped at 20 uS\n");
664 for (i = 0; i < perf->state_count; i++) {
665 if (i > 0 && perf->states[i].core_frequency >=
666 data->freq_table[valid_states-1].frequency / 1000)
669 data->freq_table[valid_states].index = i;
670 data->freq_table[valid_states].frequency =
671 perf->states[i].core_frequency * 1000;
674 data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
677 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
681 if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
682 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
684 switch (perf->control_register.space_id) {
685 case ACPI_ADR_SPACE_SYSTEM_IO:
686 /* Current speed is unknown and not detectable by IO port */
687 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
689 case ACPI_ADR_SPACE_FIXED_HARDWARE:
690 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
691 policy->cur = get_cur_freq_on_cpu(cpu);
697 /* notify BIOS that we exist */
698 acpi_processor_notify_smm(THIS_MODULE);
700 /* Check for APERF/MPERF support in hardware */
701 if (cpu_has(c, X86_FEATURE_APERFMPERF))
702 acpi_cpufreq_driver.getavg = get_measured_perf;
704 dprintk("CPU%u - ACPI performance management activated.\n", cpu);
705 for (i = 0; i < perf->state_count; i++)
706 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
707 (i == perf->state ? '*' : ' '), i,
708 (u32) perf->states[i].core_frequency,
709 (u32) perf->states[i].power,
710 (u32) perf->states[i].transition_latency);
712 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
715 * the first call to ->target() should result in us actually
716 * writing something to the appropriate registers.
723 kfree(data->freq_table);
725 acpi_processor_unregister_performance(perf, cpu);
728 per_cpu(drv_data, cpu) = NULL;
733 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
735 struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
737 dprintk("acpi_cpufreq_cpu_exit\n");
740 cpufreq_frequency_table_put_attr(policy->cpu);
741 per_cpu(drv_data, policy->cpu) = NULL;
742 acpi_processor_unregister_performance(data->acpi_data,
750 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
752 struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
754 dprintk("acpi_cpufreq_resume\n");
761 static struct freq_attr *acpi_cpufreq_attr[] = {
762 &cpufreq_freq_attr_scaling_available_freqs,
766 static struct cpufreq_driver acpi_cpufreq_driver = {
767 .verify = acpi_cpufreq_verify,
768 .target = acpi_cpufreq_target,
769 .bios_limit = acpi_processor_get_bios_limit,
770 .init = acpi_cpufreq_cpu_init,
771 .exit = acpi_cpufreq_cpu_exit,
772 .resume = acpi_cpufreq_resume,
773 .name = "acpi-cpufreq",
774 .owner = THIS_MODULE,
775 .attr = acpi_cpufreq_attr,
778 static int __init acpi_cpufreq_init(void)
785 dprintk("acpi_cpufreq_init\n");
787 ret = acpi_cpufreq_early_init();
791 ret = cpufreq_register_driver(&acpi_cpufreq_driver);
793 free_acpi_perf_data();
798 static void __exit acpi_cpufreq_exit(void)
800 dprintk("acpi_cpufreq_exit\n");
802 cpufreq_unregister_driver(&acpi_cpufreq_driver);
804 free_percpu(acpi_perf_data);
807 module_param(acpi_pstate_strict, uint, 0644);
808 MODULE_PARM_DESC(acpi_pstate_strict,
809 "value 0 or non-zero. non-zero -> strict ACPI checks are "
810 "performed during frequency changes.");
812 late_initcall(acpi_cpufreq_init);
813 module_exit(acpi_cpufreq_exit);
815 MODULE_ALIAS("acpi");