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 *, acfreq_data);
73 static DEFINE_PER_CPU(struct aperfmperf, acfreq_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)
196 err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
197 WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */
200 static void drv_write(struct drv_cmd *cmd)
204 this_cpu = get_cpu();
205 if (cpumask_test_cpu(this_cpu, cmd->mask))
207 smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
211 static u32 get_cur_val(const struct cpumask *mask)
213 struct acpi_processor_performance *perf;
216 if (unlikely(cpumask_empty(mask)))
219 switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
220 case SYSTEM_INTEL_MSR_CAPABLE:
221 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
222 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
224 case SYSTEM_IO_CAPABLE:
225 cmd.type = SYSTEM_IO_CAPABLE;
226 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
227 cmd.addr.io.port = perf->control_register.address;
228 cmd.addr.io.bit_width = perf->control_register.bit_width;
237 dprintk("get_cur_val = %u\n", cmd.val);
242 /* Called via smp_call_function_single(), on the target CPU */
243 static void read_measured_perf_ctrs(void *_cur)
245 struct aperfmperf *am = _cur;
251 * Return the measured active (C0) frequency on this CPU since last call
254 * Return: Average CPU frequency in terms of max frequency (zero on error)
256 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
257 * over a period of time, while CPU is in C0 state.
258 * IA32_MPERF counts at the rate of max advertised frequency
259 * IA32_APERF counts at the rate of actual CPU frequency
260 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
261 * no meaning should be associated with absolute values of these MSRs.
263 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
266 struct aperfmperf perf;
270 if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
273 ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);
274 per_cpu(acfreq_old_perf, cpu) = perf;
276 retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
281 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
283 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
285 unsigned int cached_freq;
287 dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
289 if (unlikely(data == NULL ||
290 data->acpi_data == NULL || data->freq_table == NULL)) {
294 cached_freq = data->freq_table[data->acpi_data->state].frequency;
295 freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
296 if (freq != cached_freq) {
298 * The dreaded BIOS frequency change behind our back.
299 * Force set the frequency on next target call.
304 dprintk("cur freq = %u\n", freq);
309 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
310 struct acpi_cpufreq_data *data)
312 unsigned int cur_freq;
315 for (i = 0; i < 100; i++) {
316 cur_freq = extract_freq(get_cur_val(mask), data);
317 if (cur_freq == freq)
324 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
325 unsigned int target_freq, unsigned int relation)
327 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
328 struct acpi_processor_performance *perf;
329 struct cpufreq_freqs freqs;
331 unsigned int next_state = 0; /* Index into freq_table */
332 unsigned int next_perf_state = 0; /* Index into perf table */
336 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
338 if (unlikely(data == NULL ||
339 data->acpi_data == NULL || data->freq_table == NULL)) {
343 perf = data->acpi_data;
344 result = cpufreq_frequency_table_target(policy,
347 relation, &next_state);
348 if (unlikely(result)) {
353 next_perf_state = data->freq_table[next_state].index;
354 if (perf->state == next_perf_state) {
355 if (unlikely(data->resume)) {
356 dprintk("Called after resume, resetting to P%d\n",
360 dprintk("Already at target state (P%d)\n",
366 trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);
368 switch (data->cpu_feature) {
369 case SYSTEM_INTEL_MSR_CAPABLE:
370 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
371 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
372 cmd.val = (u32) perf->states[next_perf_state].control;
374 case SYSTEM_IO_CAPABLE:
375 cmd.type = SYSTEM_IO_CAPABLE;
376 cmd.addr.io.port = perf->control_register.address;
377 cmd.addr.io.bit_width = perf->control_register.bit_width;
378 cmd.val = (u32) perf->states[next_perf_state].control;
385 /* cpufreq holds the hotplug lock, so we are safe from here on */
386 if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
387 cmd.mask = policy->cpus;
389 cmd.mask = cpumask_of(policy->cpu);
391 freqs.old = perf->states[perf->state].core_frequency * 1000;
392 freqs.new = data->freq_table[next_state].frequency;
393 for_each_cpu(i, cmd.mask) {
395 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
400 if (acpi_pstate_strict) {
401 if (!check_freqs(cmd.mask, freqs.new, data)) {
402 dprintk("acpi_cpufreq_target failed (%d)\n",
409 for_each_cpu(i, cmd.mask) {
411 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
413 perf->state = next_perf_state;
419 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
421 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
423 dprintk("acpi_cpufreq_verify\n");
425 return cpufreq_frequency_table_verify(policy, data->freq_table);
429 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
431 struct acpi_processor_performance *perf = data->acpi_data;
434 /* search the closest match to cpu_khz */
437 unsigned long freqn = perf->states[0].core_frequency * 1000;
439 for (i = 0; i < (perf->state_count-1); i++) {
441 freqn = perf->states[i+1].core_frequency * 1000;
442 if ((2 * cpu_khz) > (freqn + freq)) {
447 perf->state = perf->state_count-1;
450 /* assume CPU is at P0... */
452 return perf->states[0].core_frequency * 1000;
456 static void free_acpi_perf_data(void)
460 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
461 for_each_possible_cpu(i)
462 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
464 free_percpu(acpi_perf_data);
468 * acpi_cpufreq_early_init - initialize ACPI P-States library
470 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
471 * in order to determine correct frequency and voltage pairings. We can
472 * do _PDC and _PSD and find out the processor dependency for the
473 * actual init that will happen later...
475 static int __init acpi_cpufreq_early_init(void)
478 dprintk("acpi_cpufreq_early_init\n");
480 acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
481 if (!acpi_perf_data) {
482 dprintk("Memory allocation error for acpi_perf_data.\n");
485 for_each_possible_cpu(i) {
486 if (!zalloc_cpumask_var_node(
487 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
488 GFP_KERNEL, cpu_to_node(i))) {
490 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
491 free_acpi_perf_data();
496 /* Do initialization in ACPI core */
497 acpi_processor_preregister_performance(acpi_perf_data);
503 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
504 * or do it in BIOS firmware and won't inform about it to OS. If not
505 * detected, this has a side effect of making CPU run at a different speed
506 * than OS intended it to run at. Detect it and handle it cleanly.
508 static int bios_with_sw_any_bug;
510 static int sw_any_bug_found(const struct dmi_system_id *d)
512 bios_with_sw_any_bug = 1;
516 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
518 .callback = sw_any_bug_found,
519 .ident = "Supermicro Server X6DLP",
521 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
522 DMI_MATCH(DMI_BIOS_VERSION, "080010"),
523 DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
529 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
531 /* Intel Xeon Processor 7100 Series Specification Update
532 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
533 * AL30: A Machine Check Exception (MCE) Occurring during an
534 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
535 * Both Processor Cores to Lock Up. */
536 if (c->x86_vendor == X86_VENDOR_INTEL) {
537 if ((c->x86 == 15) &&
538 (c->x86_model == 6) &&
539 (c->x86_mask == 8)) {
540 printk(KERN_INFO "acpi-cpufreq: Intel(R) "
541 "Xeon(R) 7100 Errata AL30, processors may "
542 "lock up on frequency changes: disabling "
551 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
554 unsigned int valid_states = 0;
555 unsigned int cpu = policy->cpu;
556 struct acpi_cpufreq_data *data;
557 unsigned int result = 0;
558 struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
559 struct acpi_processor_performance *perf;
561 static int blacklisted;
564 dprintk("acpi_cpufreq_cpu_init\n");
569 blacklisted = acpi_cpufreq_blacklist(c);
574 data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
578 data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
579 per_cpu(acfreq_data, cpu) = data;
581 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
582 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
584 result = acpi_processor_register_performance(data->acpi_data, cpu);
588 perf = data->acpi_data;
589 policy->shared_type = perf->shared_type;
592 * Will let policy->cpus know about dependency only when software
593 * coordination is required.
595 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
596 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
597 cpumask_copy(policy->cpus, perf->shared_cpu_map);
599 cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
602 dmi_check_system(sw_any_bug_dmi_table);
603 if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
604 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
605 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
609 /* capability check */
610 if (perf->state_count <= 1) {
611 dprintk("No P-States\n");
616 if (perf->control_register.space_id != perf->status_register.space_id) {
621 switch (perf->control_register.space_id) {
622 case ACPI_ADR_SPACE_SYSTEM_IO:
623 dprintk("SYSTEM IO addr space\n");
624 data->cpu_feature = SYSTEM_IO_CAPABLE;
626 case ACPI_ADR_SPACE_FIXED_HARDWARE:
627 dprintk("HARDWARE addr space\n");
628 if (!check_est_cpu(cpu)) {
632 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
635 dprintk("Unknown addr space %d\n",
636 (u32) (perf->control_register.space_id));
641 data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
642 (perf->state_count+1), GFP_KERNEL);
643 if (!data->freq_table) {
648 /* detect transition latency */
649 policy->cpuinfo.transition_latency = 0;
650 for (i = 0; i < perf->state_count; i++) {
651 if ((perf->states[i].transition_latency * 1000) >
652 policy->cpuinfo.transition_latency)
653 policy->cpuinfo.transition_latency =
654 perf->states[i].transition_latency * 1000;
657 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
658 if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
659 policy->cpuinfo.transition_latency > 20 * 1000) {
660 policy->cpuinfo.transition_latency = 20 * 1000;
661 printk_once(KERN_INFO
662 "P-state transition latency capped at 20 uS\n");
666 for (i = 0; i < perf->state_count; i++) {
667 if (i > 0 && perf->states[i].core_frequency >=
668 data->freq_table[valid_states-1].frequency / 1000)
671 data->freq_table[valid_states].index = i;
672 data->freq_table[valid_states].frequency =
673 perf->states[i].core_frequency * 1000;
676 data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
679 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
683 if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
684 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
686 switch (perf->control_register.space_id) {
687 case ACPI_ADR_SPACE_SYSTEM_IO:
688 /* Current speed is unknown and not detectable by IO port */
689 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
691 case ACPI_ADR_SPACE_FIXED_HARDWARE:
692 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
693 policy->cur = get_cur_freq_on_cpu(cpu);
699 /* notify BIOS that we exist */
700 acpi_processor_notify_smm(THIS_MODULE);
702 /* Check for APERF/MPERF support in hardware */
703 if (cpu_has(c, X86_FEATURE_APERFMPERF))
704 acpi_cpufreq_driver.getavg = get_measured_perf;
706 dprintk("CPU%u - ACPI performance management activated.\n", cpu);
707 for (i = 0; i < perf->state_count; i++)
708 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
709 (i == perf->state ? '*' : ' '), i,
710 (u32) perf->states[i].core_frequency,
711 (u32) perf->states[i].power,
712 (u32) perf->states[i].transition_latency);
714 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
717 * the first call to ->target() should result in us actually
718 * writing something to the appropriate registers.
725 kfree(data->freq_table);
727 acpi_processor_unregister_performance(perf, cpu);
730 per_cpu(acfreq_data, cpu) = NULL;
735 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
737 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
739 dprintk("acpi_cpufreq_cpu_exit\n");
742 cpufreq_frequency_table_put_attr(policy->cpu);
743 per_cpu(acfreq_data, policy->cpu) = NULL;
744 acpi_processor_unregister_performance(data->acpi_data,
752 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
754 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
756 dprintk("acpi_cpufreq_resume\n");
763 static struct freq_attr *acpi_cpufreq_attr[] = {
764 &cpufreq_freq_attr_scaling_available_freqs,
768 static struct cpufreq_driver acpi_cpufreq_driver = {
769 .verify = acpi_cpufreq_verify,
770 .target = acpi_cpufreq_target,
771 .bios_limit = acpi_processor_get_bios_limit,
772 .init = acpi_cpufreq_cpu_init,
773 .exit = acpi_cpufreq_cpu_exit,
774 .resume = acpi_cpufreq_resume,
775 .name = "acpi-cpufreq",
776 .owner = THIS_MODULE,
777 .attr = acpi_cpufreq_attr,
780 static int __init acpi_cpufreq_init(void)
787 dprintk("acpi_cpufreq_init\n");
789 ret = acpi_cpufreq_early_init();
793 ret = cpufreq_register_driver(&acpi_cpufreq_driver);
795 free_acpi_perf_data();
800 static void __exit acpi_cpufreq_exit(void)
802 dprintk("acpi_cpufreq_exit\n");
804 cpufreq_unregister_driver(&acpi_cpufreq_driver);
806 free_percpu(acpi_perf_data);
809 module_param(acpi_pstate_strict, uint, 0644);
810 MODULE_PARM_DESC(acpi_pstate_strict,
811 "value 0 or non-zero. non-zero -> strict ACPI checks are "
812 "performed during frequency changes.");
814 late_initcall(acpi_cpufreq_init);
815 module_exit(acpi_cpufreq_exit);
817 MODULE_ALIAS("acpi");