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 <linux/slab.h>
37 #include <trace/events/power.h>
39 #include <linux/acpi.h>
41 #include <linux/delay.h>
42 #include <linux/uaccess.h>
44 #include <acpi/processor.h>
47 #include <asm/processor.h>
48 #include <asm/cpufeature.h>
50 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
53 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
54 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
55 MODULE_LICENSE("GPL");
58 UNDEFINED_CAPABLE = 0,
59 SYSTEM_INTEL_MSR_CAPABLE,
63 #define INTEL_MSR_RANGE (0xffff)
65 struct acpi_cpufreq_data {
66 struct acpi_processor_performance *acpi_data;
67 struct cpufreq_frequency_table *freq_table;
69 unsigned int cpu_feature;
72 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
74 static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);
76 /* acpi_perf_data is a pointer to percpu data. */
77 static struct acpi_processor_performance *acpi_perf_data;
79 static struct cpufreq_driver acpi_cpufreq_driver;
81 static unsigned int acpi_pstate_strict;
83 static int check_est_cpu(unsigned int cpuid)
85 struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
87 return cpu_has(cpu, X86_FEATURE_EST);
90 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
92 struct acpi_processor_performance *perf;
95 perf = data->acpi_data;
97 for (i = 0; i < perf->state_count; i++) {
98 if (value == perf->states[i].status)
99 return data->freq_table[i].frequency;
104 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
107 struct acpi_processor_performance *perf;
109 msr &= INTEL_MSR_RANGE;
110 perf = data->acpi_data;
112 for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
113 if (msr == perf->states[data->freq_table[i].index].status)
114 return data->freq_table[i].frequency;
116 return data->freq_table[0].frequency;
119 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
121 switch (data->cpu_feature) {
122 case SYSTEM_INTEL_MSR_CAPABLE:
123 return extract_msr(val, data);
124 case SYSTEM_IO_CAPABLE:
125 return extract_io(val, data);
142 const struct cpumask *mask;
150 /* Called via smp_call_function_single(), on the target CPU */
151 static void do_drv_read(void *_cmd)
153 struct drv_cmd *cmd = _cmd;
157 case SYSTEM_INTEL_MSR_CAPABLE:
158 rdmsr(cmd->addr.msr.reg, cmd->val, h);
160 case SYSTEM_IO_CAPABLE:
161 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
163 (u32)cmd->addr.io.bit_width);
170 /* Called via smp_call_function_many(), on the target CPUs */
171 static void do_drv_write(void *_cmd)
173 struct drv_cmd *cmd = _cmd;
177 case SYSTEM_INTEL_MSR_CAPABLE:
178 rdmsr(cmd->addr.msr.reg, lo, hi);
179 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
180 wrmsr(cmd->addr.msr.reg, lo, hi);
182 case SYSTEM_IO_CAPABLE:
183 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
185 (u32)cmd->addr.io.bit_width);
192 static void drv_read(struct drv_cmd *cmd)
197 err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
198 WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */
201 static void drv_write(struct drv_cmd *cmd)
205 this_cpu = get_cpu();
206 if (cpumask_test_cpu(this_cpu, cmd->mask))
208 smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
212 static u32 get_cur_val(const struct cpumask *mask)
214 struct acpi_processor_performance *perf;
217 if (unlikely(cpumask_empty(mask)))
220 switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
221 case SYSTEM_INTEL_MSR_CAPABLE:
222 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
223 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
225 case SYSTEM_IO_CAPABLE:
226 cmd.type = SYSTEM_IO_CAPABLE;
227 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
228 cmd.addr.io.port = perf->control_register.address;
229 cmd.addr.io.bit_width = perf->control_register.bit_width;
238 dprintk("get_cur_val = %u\n", cmd.val);
243 /* Called via smp_call_function_single(), on the target CPU */
244 static void read_measured_perf_ctrs(void *_cur)
246 struct aperfmperf *am = _cur;
252 * Return the measured active (C0) frequency on this CPU since last call
255 * Return: Average CPU frequency in terms of max frequency (zero on error)
257 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
258 * over a period of time, while CPU is in C0 state.
259 * IA32_MPERF counts at the rate of max advertised frequency
260 * IA32_APERF counts at the rate of actual CPU frequency
261 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
262 * no meaning should be associated with absolute values of these MSRs.
264 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
267 struct aperfmperf perf;
271 if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
274 ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);
275 per_cpu(acfreq_old_perf, cpu) = perf;
277 retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
282 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
284 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
286 unsigned int cached_freq;
288 dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
290 if (unlikely(data == NULL ||
291 data->acpi_data == NULL || data->freq_table == NULL)) {
295 cached_freq = data->freq_table[data->acpi_data->state].frequency;
296 freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
297 if (freq != cached_freq) {
299 * The dreaded BIOS frequency change behind our back.
300 * Force set the frequency on next target call.
305 dprintk("cur freq = %u\n", freq);
310 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
311 struct acpi_cpufreq_data *data)
313 unsigned int cur_freq;
316 for (i = 0; i < 100; i++) {
317 cur_freq = extract_freq(get_cur_val(mask), data);
318 if (cur_freq == freq)
325 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
326 unsigned int target_freq, unsigned int relation)
328 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
329 struct acpi_processor_performance *perf;
330 struct cpufreq_freqs freqs;
332 unsigned int next_state = 0; /* Index into freq_table */
333 unsigned int next_perf_state = 0; /* Index into perf table */
337 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
339 if (unlikely(data == NULL ||
340 data->acpi_data == NULL || data->freq_table == NULL)) {
344 perf = data->acpi_data;
345 result = cpufreq_frequency_table_target(policy,
348 relation, &next_state);
349 if (unlikely(result)) {
354 next_perf_state = data->freq_table[next_state].index;
355 if (perf->state == next_perf_state) {
356 if (unlikely(data->resume)) {
357 dprintk("Called after resume, resetting to P%d\n",
361 dprintk("Already at target state (P%d)\n",
367 trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);
369 switch (data->cpu_feature) {
370 case SYSTEM_INTEL_MSR_CAPABLE:
371 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
372 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
373 cmd.val = (u32) perf->states[next_perf_state].control;
375 case SYSTEM_IO_CAPABLE:
376 cmd.type = SYSTEM_IO_CAPABLE;
377 cmd.addr.io.port = perf->control_register.address;
378 cmd.addr.io.bit_width = perf->control_register.bit_width;
379 cmd.val = (u32) perf->states[next_perf_state].control;
386 /* cpufreq holds the hotplug lock, so we are safe from here on */
387 if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
388 cmd.mask = policy->cpus;
390 cmd.mask = cpumask_of(policy->cpu);
392 freqs.old = perf->states[perf->state].core_frequency * 1000;
393 freqs.new = data->freq_table[next_state].frequency;
394 for_each_cpu(i, cmd.mask) {
396 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
401 if (acpi_pstate_strict) {
402 if (!check_freqs(cmd.mask, freqs.new, data)) {
403 dprintk("acpi_cpufreq_target failed (%d)\n",
410 for_each_cpu(i, cmd.mask) {
412 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
414 perf->state = next_perf_state;
420 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
422 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
424 dprintk("acpi_cpufreq_verify\n");
426 return cpufreq_frequency_table_verify(policy, data->freq_table);
430 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
432 struct acpi_processor_performance *perf = data->acpi_data;
435 /* search the closest match to cpu_khz */
438 unsigned long freqn = perf->states[0].core_frequency * 1000;
440 for (i = 0; i < (perf->state_count-1); i++) {
442 freqn = perf->states[i+1].core_frequency * 1000;
443 if ((2 * cpu_khz) > (freqn + freq)) {
448 perf->state = perf->state_count-1;
451 /* assume CPU is at P0... */
453 return perf->states[0].core_frequency * 1000;
457 static void free_acpi_perf_data(void)
461 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
462 for_each_possible_cpu(i)
463 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
465 free_percpu(acpi_perf_data);
469 * acpi_cpufreq_early_init - initialize ACPI P-States library
471 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
472 * in order to determine correct frequency and voltage pairings. We can
473 * do _PDC and _PSD and find out the processor dependency for the
474 * actual init that will happen later...
476 static int __init acpi_cpufreq_early_init(void)
479 dprintk("acpi_cpufreq_early_init\n");
481 acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
482 if (!acpi_perf_data) {
483 dprintk("Memory allocation error for acpi_perf_data.\n");
486 for_each_possible_cpu(i) {
487 if (!zalloc_cpumask_var_node(
488 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
489 GFP_KERNEL, cpu_to_node(i))) {
491 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
492 free_acpi_perf_data();
497 /* Do initialization in ACPI core */
498 acpi_processor_preregister_performance(acpi_perf_data);
504 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
505 * or do it in BIOS firmware and won't inform about it to OS. If not
506 * detected, this has a side effect of making CPU run at a different speed
507 * than OS intended it to run at. Detect it and handle it cleanly.
509 static int bios_with_sw_any_bug;
511 static int sw_any_bug_found(const struct dmi_system_id *d)
513 bios_with_sw_any_bug = 1;
517 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
519 .callback = sw_any_bug_found,
520 .ident = "Supermicro Server X6DLP",
522 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
523 DMI_MATCH(DMI_BIOS_VERSION, "080010"),
524 DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
530 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
532 /* Intel Xeon Processor 7100 Series Specification Update
533 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
534 * AL30: A Machine Check Exception (MCE) Occurring during an
535 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
536 * Both Processor Cores to Lock Up. */
537 if (c->x86_vendor == X86_VENDOR_INTEL) {
538 if ((c->x86 == 15) &&
539 (c->x86_model == 6) &&
540 (c->x86_mask == 8)) {
541 printk(KERN_INFO "acpi-cpufreq: Intel(R) "
542 "Xeon(R) 7100 Errata AL30, processors may "
543 "lock up on frequency changes: disabling "
552 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
555 unsigned int valid_states = 0;
556 unsigned int cpu = policy->cpu;
557 struct acpi_cpufreq_data *data;
558 unsigned int result = 0;
559 struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
560 struct acpi_processor_performance *perf;
562 static int blacklisted;
565 dprintk("acpi_cpufreq_cpu_init\n");
570 blacklisted = acpi_cpufreq_blacklist(c);
575 data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
579 data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
580 per_cpu(acfreq_data, cpu) = data;
582 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
583 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
585 result = acpi_processor_register_performance(data->acpi_data, cpu);
589 perf = data->acpi_data;
590 policy->shared_type = perf->shared_type;
593 * Will let policy->cpus know about dependency only when software
594 * coordination is required.
596 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
597 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
598 cpumask_copy(policy->cpus, perf->shared_cpu_map);
600 cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
603 dmi_check_system(sw_any_bug_dmi_table);
604 if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
605 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
606 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
610 /* capability check */
611 if (perf->state_count <= 1) {
612 dprintk("No P-States\n");
617 if (perf->control_register.space_id != perf->status_register.space_id) {
622 switch (perf->control_register.space_id) {
623 case ACPI_ADR_SPACE_SYSTEM_IO:
624 dprintk("SYSTEM IO addr space\n");
625 data->cpu_feature = SYSTEM_IO_CAPABLE;
627 case ACPI_ADR_SPACE_FIXED_HARDWARE:
628 dprintk("HARDWARE addr space\n");
629 if (!check_est_cpu(cpu)) {
633 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
636 dprintk("Unknown addr space %d\n",
637 (u32) (perf->control_register.space_id));
642 data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
643 (perf->state_count+1), GFP_KERNEL);
644 if (!data->freq_table) {
649 /* detect transition latency */
650 policy->cpuinfo.transition_latency = 0;
651 for (i = 0; i < perf->state_count; i++) {
652 if ((perf->states[i].transition_latency * 1000) >
653 policy->cpuinfo.transition_latency)
654 policy->cpuinfo.transition_latency =
655 perf->states[i].transition_latency * 1000;
658 /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
659 if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
660 policy->cpuinfo.transition_latency > 20 * 1000) {
661 policy->cpuinfo.transition_latency = 20 * 1000;
662 printk_once(KERN_INFO
663 "P-state transition latency capped at 20 uS\n");
667 for (i = 0; i < perf->state_count; i++) {
668 if (i > 0 && perf->states[i].core_frequency >=
669 data->freq_table[valid_states-1].frequency / 1000)
672 data->freq_table[valid_states].index = i;
673 data->freq_table[valid_states].frequency =
674 perf->states[i].core_frequency * 1000;
677 data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
680 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
684 if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
685 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
687 switch (perf->control_register.space_id) {
688 case ACPI_ADR_SPACE_SYSTEM_IO:
689 /* Current speed is unknown and not detectable by IO port */
690 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
692 case ACPI_ADR_SPACE_FIXED_HARDWARE:
693 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
694 policy->cur = get_cur_freq_on_cpu(cpu);
700 /* notify BIOS that we exist */
701 acpi_processor_notify_smm(THIS_MODULE);
703 /* Check for APERF/MPERF support in hardware */
704 if (cpu_has(c, X86_FEATURE_APERFMPERF))
705 acpi_cpufreq_driver.getavg = get_measured_perf;
707 dprintk("CPU%u - ACPI performance management activated.\n", cpu);
708 for (i = 0; i < perf->state_count; i++)
709 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
710 (i == perf->state ? '*' : ' '), i,
711 (u32) perf->states[i].core_frequency,
712 (u32) perf->states[i].power,
713 (u32) perf->states[i].transition_latency);
715 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
718 * the first call to ->target() should result in us actually
719 * writing something to the appropriate registers.
726 kfree(data->freq_table);
728 acpi_processor_unregister_performance(perf, cpu);
731 per_cpu(acfreq_data, cpu) = NULL;
736 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
738 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
740 dprintk("acpi_cpufreq_cpu_exit\n");
743 cpufreq_frequency_table_put_attr(policy->cpu);
744 per_cpu(acfreq_data, policy->cpu) = NULL;
745 acpi_processor_unregister_performance(data->acpi_data,
753 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
755 struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
757 dprintk("acpi_cpufreq_resume\n");
764 static struct freq_attr *acpi_cpufreq_attr[] = {
765 &cpufreq_freq_attr_scaling_available_freqs,
769 static struct cpufreq_driver acpi_cpufreq_driver = {
770 .verify = acpi_cpufreq_verify,
771 .target = acpi_cpufreq_target,
772 .bios_limit = acpi_processor_get_bios_limit,
773 .init = acpi_cpufreq_cpu_init,
774 .exit = acpi_cpufreq_cpu_exit,
775 .resume = acpi_cpufreq_resume,
776 .name = "acpi-cpufreq",
777 .owner = THIS_MODULE,
778 .attr = acpi_cpufreq_attr,
781 static int __init acpi_cpufreq_init(void)
788 dprintk("acpi_cpufreq_init\n");
790 ret = acpi_cpufreq_early_init();
794 ret = cpufreq_register_driver(&acpi_cpufreq_driver);
796 free_acpi_perf_data();
801 static void __exit acpi_cpufreq_exit(void)
803 dprintk("acpi_cpufreq_exit\n");
805 cpufreq_unregister_driver(&acpi_cpufreq_driver);
807 free_percpu(acpi_perf_data);
810 module_param(acpi_pstate_strict, uint, 0644);
811 MODULE_PARM_DESC(acpi_pstate_strict,
812 "value 0 or non-zero. non-zero -> strict ACPI checks are "
813 "performed during frequency changes.");
815 late_initcall(acpi_cpufreq_init);
816 module_exit(acpi_cpufreq_exit);
818 MODULE_ALIAS("acpi");