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)
131 if (bit_width <= 8) {
133 } else if (bit_width <= 16) {
135 } else if (bit_width <= 32) {
140 static void rdport(u16 port, u8 bit_width, u32 * ret)
143 if (bit_width <= 8) {
145 } else if (bit_width <= 16) {
147 } else if (bit_width <= 32) {
173 static void do_drv_read(struct drv_cmd *cmd)
178 case SYSTEM_INTEL_MSR_CAPABLE:
179 rdmsr(cmd->addr.msr.reg, cmd->val, h);
181 case SYSTEM_IO_CAPABLE:
182 rdport(cmd->addr.io.port, cmd->addr.io.bit_width, &cmd->val);
189 static void do_drv_write(struct drv_cmd *cmd)
194 case SYSTEM_INTEL_MSR_CAPABLE:
195 wrmsr(cmd->addr.msr.reg, cmd->val, h);
197 case SYSTEM_IO_CAPABLE:
198 wrport(cmd->addr.io.port, cmd->addr.io.bit_width, cmd->val);
205 static inline void drv_read(struct drv_cmd *cmd)
207 cpumask_t saved_mask = current->cpus_allowed;
210 set_cpus_allowed(current, cmd->mask);
212 set_cpus_allowed(current, saved_mask);
216 static void drv_write(struct drv_cmd *cmd)
218 cpumask_t saved_mask = current->cpus_allowed;
221 for_each_cpu_mask(i, cmd->mask) {
222 set_cpus_allowed(current, cpumask_of_cpu(i));
226 set_cpus_allowed(current, saved_mask);
230 static u32 get_cur_val(cpumask_t mask)
232 struct acpi_processor_performance *perf;
235 if (unlikely(cpus_empty(mask)))
238 switch (drv_data[first_cpu(mask)]->cpu_feature) {
239 case SYSTEM_INTEL_MSR_CAPABLE:
240 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
241 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
243 case SYSTEM_IO_CAPABLE:
244 cmd.type = SYSTEM_IO_CAPABLE;
245 perf = drv_data[first_cpu(mask)]->acpi_data;
246 cmd.addr.io.port = perf->control_register.address;
247 cmd.addr.io.bit_width = perf->control_register.bit_width;
257 dprintk("get_cur_val = %u\n", cmd.val);
263 * Return the measured active (C0) frequency on this CPU since last call
266 * Return: Average CPU frequency in terms of max frequency (zero on error)
268 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
269 * over a period of time, while CPU is in C0 state.
270 * IA32_MPERF counts at the rate of max advertised frequency
271 * IA32_APERF counts at the rate of actual CPU frequency
272 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
273 * no meaning should be associated with absolute values of these MSRs.
275 static unsigned int get_measured_perf(unsigned int cpu)
283 } aperf_cur, mperf_cur;
285 cpumask_t saved_mask;
286 unsigned int perf_percent;
289 saved_mask = current->cpus_allowed;
290 set_cpus_allowed(current, cpumask_of_cpu(cpu));
291 if (get_cpu() != cpu) {
292 /* We were not able to run on requested processor */
297 rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
298 rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
300 wrmsr(MSR_IA32_APERF, 0,0);
301 wrmsr(MSR_IA32_MPERF, 0,0);
305 * We dont want to do 64 bit divide with 32 bit kernel
306 * Get an approximate value. Return failure in case we cannot get
307 * an approximate value.
309 if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
313 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
314 shift_count = fls(h);
316 aperf_cur.whole >>= shift_count;
317 mperf_cur.whole >>= shift_count;
320 if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
322 aperf_cur.split.lo >>= shift_count;
323 mperf_cur.split.lo >>= shift_count;
326 if (aperf_cur.split.lo && mperf_cur.split.lo) {
327 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
333 if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
335 aperf_cur.whole >>= shift_count;
336 mperf_cur.whole >>= shift_count;
339 if (aperf_cur.whole && mperf_cur.whole) {
340 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
347 retval = drv_data[cpu]->max_freq * perf_percent / 100;
350 set_cpus_allowed(current, saved_mask);
352 dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
356 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
358 struct acpi_cpufreq_data *data = drv_data[cpu];
361 dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
363 if (unlikely(data == NULL ||
364 data->acpi_data == NULL || data->freq_table == NULL)) {
368 freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
369 dprintk("cur freq = %u\n", freq);
374 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
375 struct acpi_cpufreq_data *data)
377 unsigned int cur_freq;
380 for (i = 0; i < 100; i++) {
381 cur_freq = extract_freq(get_cur_val(mask), data);
382 if (cur_freq == freq)
389 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
390 unsigned int target_freq, unsigned int relation)
392 struct acpi_cpufreq_data *data = drv_data[policy->cpu];
393 struct acpi_processor_performance *perf;
394 struct cpufreq_freqs freqs;
395 cpumask_t online_policy_cpus;
398 unsigned int next_state = 0;
399 unsigned int next_perf_state = 0;
403 dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
405 if (unlikely(data == NULL ||
406 data->acpi_data == NULL || data->freq_table == NULL)) {
410 perf = data->acpi_data;
411 result = cpufreq_frequency_table_target(policy,
414 relation, &next_state);
415 if (unlikely(result))
418 #ifdef CONFIG_HOTPLUG_CPU
419 /* cpufreq holds the hotplug lock, so we are safe from here on */
420 cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
422 online_policy_cpus = policy->cpus;
425 next_perf_state = data->freq_table[next_state].index;
426 if (perf->state == next_perf_state) {
427 if (unlikely(data->resume)) {
428 dprintk("Called after resume, resetting to P%d\n",
432 dprintk("Already at target state (P%d)\n",
438 switch (data->cpu_feature) {
439 case SYSTEM_INTEL_MSR_CAPABLE:
440 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
441 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
443 (u32) perf->states[next_perf_state].
444 control & INTEL_MSR_RANGE;
445 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
447 case SYSTEM_IO_CAPABLE:
448 cmd.type = SYSTEM_IO_CAPABLE;
449 cmd.addr.io.port = perf->control_register.address;
450 cmd.addr.io.bit_width = perf->control_register.bit_width;
451 cmd.val = (u32) perf->states[next_perf_state].control;
457 cpus_clear(cmd.mask);
459 if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
460 cmd.mask = online_policy_cpus;
462 cpu_set(policy->cpu, cmd.mask);
464 freqs.old = data->freq_table[perf->state].frequency;
465 freqs.new = data->freq_table[next_perf_state].frequency;
466 for_each_cpu_mask(i, cmd.mask) {
468 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
473 if (acpi_pstate_strict) {
474 if (!check_freqs(cmd.mask, freqs.new, data)) {
475 dprintk("acpi_cpufreq_target failed (%d)\n",
481 for_each_cpu_mask(i, cmd.mask) {
483 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
485 perf->state = next_perf_state;
490 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
492 struct acpi_cpufreq_data *data = drv_data[policy->cpu];
494 dprintk("acpi_cpufreq_verify\n");
496 return cpufreq_frequency_table_verify(policy, data->freq_table);
500 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
502 struct acpi_processor_performance *perf = data->acpi_data;
505 /* search the closest match to cpu_khz */
508 unsigned long freqn = perf->states[0].core_frequency * 1000;
510 for (i = 0; i < (perf->state_count - 1); i++) {
512 freqn = perf->states[i + 1].core_frequency * 1000;
513 if ((2 * cpu_khz) > (freqn + freq)) {
518 perf->state = perf->state_count - 1;
521 /* assume CPU is at P0... */
523 return perf->states[0].core_frequency * 1000;
528 * acpi_cpufreq_early_init - initialize ACPI P-States library
530 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
531 * in order to determine correct frequency and voltage pairings. We can
532 * do _PDC and _PSD and find out the processor dependency for the
533 * actual init that will happen later...
535 static int acpi_cpufreq_early_init(void)
537 struct acpi_processor_performance *data;
541 dprintk("acpi_cpufreq_early_init\n");
543 for_each_possible_cpu(i) {
544 data = kzalloc(sizeof(struct acpi_processor_performance),
547 for_each_cpu_mask(j, covered) {
548 kfree(acpi_perf_data[j]);
549 acpi_perf_data[j] = NULL;
553 acpi_perf_data[i] = data;
557 /* Do initialization in ACPI core */
558 acpi_processor_preregister_performance(acpi_perf_data);
563 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
564 * or do it in BIOS firmware and won't inform about it to OS. If not
565 * detected, this has a side effect of making CPU run at a different speed
566 * than OS intended it to run at. Detect it and handle it cleanly.
568 static int bios_with_sw_any_bug;
570 static int sw_any_bug_found(struct dmi_system_id *d)
572 bios_with_sw_any_bug = 1;
576 static struct dmi_system_id sw_any_bug_dmi_table[] = {
578 .callback = sw_any_bug_found,
579 .ident = "Supermicro Server X6DLP",
581 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
582 DMI_MATCH(DMI_BIOS_VERSION, "080010"),
583 DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
589 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
592 unsigned int valid_states = 0;
593 unsigned int cpu = policy->cpu;
594 struct acpi_cpufreq_data *data;
595 unsigned int result = 0;
596 struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
597 struct acpi_processor_performance *perf;
599 dprintk("acpi_cpufreq_cpu_init\n");
601 if (!acpi_perf_data[cpu])
604 data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
608 data->acpi_data = acpi_perf_data[cpu];
609 drv_data[cpu] = data;
611 if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
612 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
615 result = acpi_processor_register_performance(data->acpi_data, cpu);
619 perf = data->acpi_data;
620 policy->shared_type = perf->shared_type;
622 * Will let policy->cpus know about dependency only when software
623 * coordination is required.
625 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
626 policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
627 policy->cpus = perf->shared_cpu_map;
631 dmi_check_system(sw_any_bug_dmi_table);
632 if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
633 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
634 policy->cpus = cpu_core_map[cpu];
638 /* capability check */
639 if (perf->state_count <= 1) {
640 dprintk("No P-States\n");
645 if (perf->control_register.space_id != perf->status_register.space_id) {
650 switch (perf->control_register.space_id) {
651 case ACPI_ADR_SPACE_SYSTEM_IO:
652 dprintk("SYSTEM IO addr space\n");
653 data->cpu_feature = SYSTEM_IO_CAPABLE;
655 case ACPI_ADR_SPACE_FIXED_HARDWARE:
656 dprintk("HARDWARE addr space\n");
657 if (!check_est_cpu(cpu)) {
661 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
664 dprintk("Unknown addr space %d\n",
665 (u32) (perf->control_register.space_id));
671 kmalloc(sizeof(struct cpufreq_frequency_table) *
672 (perf->state_count + 1), GFP_KERNEL);
673 if (!data->freq_table) {
678 /* detect transition latency */
679 policy->cpuinfo.transition_latency = 0;
680 for (i = 0; i < perf->state_count; i++) {
681 if ((perf->states[i].transition_latency * 1000) >
682 policy->cpuinfo.transition_latency)
683 policy->cpuinfo.transition_latency =
684 perf->states[i].transition_latency * 1000;
686 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
688 data->max_freq = perf->states[0].core_frequency * 1000;
690 for (i = 0; i < perf->state_count; i++) {
691 if (i > 0 && perf->states[i].core_frequency ==
692 perf->states[i - 1].core_frequency)
695 data->freq_table[valid_states].index = i;
696 data->freq_table[valid_states].frequency =
697 perf->states[i].core_frequency * 1000;
700 data->freq_table[perf->state_count].frequency = CPUFREQ_TABLE_END;
702 result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
707 switch (data->cpu_feature) {
708 case ACPI_ADR_SPACE_SYSTEM_IO:
709 /* Current speed is unknown and not detectable by IO port */
710 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
712 case ACPI_ADR_SPACE_FIXED_HARDWARE:
713 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
714 get_cur_freq_on_cpu(cpu);
720 /* notify BIOS that we exist */
721 acpi_processor_notify_smm(THIS_MODULE);
723 /* Check for APERF/MPERF support in hardware */
724 if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
727 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY) {
728 acpi_cpufreq_driver.getavg = get_measured_perf;
732 dprintk("CPU%u - ACPI performance management activated.\n", cpu);
733 for (i = 0; i < perf->state_count; i++)
734 dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
735 (i == perf->state ? '*' : ' '), i,
736 (u32) perf->states[i].core_frequency,
737 (u32) perf->states[i].power,
738 (u32) perf->states[i].transition_latency);
740 cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
743 * the first call to ->target() should result in us actually
744 * writing something to the appropriate registers.
751 kfree(data->freq_table);
753 acpi_processor_unregister_performance(perf, cpu);
756 drv_data[cpu] = NULL;
761 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
763 struct acpi_cpufreq_data *data = drv_data[policy->cpu];
765 dprintk("acpi_cpufreq_cpu_exit\n");
768 cpufreq_frequency_table_put_attr(policy->cpu);
769 drv_data[policy->cpu] = NULL;
770 acpi_processor_unregister_performance(data->acpi_data,
778 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
780 struct acpi_cpufreq_data *data = drv_data[policy->cpu];
782 dprintk("acpi_cpufreq_resume\n");
789 static struct freq_attr *acpi_cpufreq_attr[] = {
790 &cpufreq_freq_attr_scaling_available_freqs,
794 static struct cpufreq_driver acpi_cpufreq_driver = {
795 .verify = acpi_cpufreq_verify,
796 .target = acpi_cpufreq_target,
797 .init = acpi_cpufreq_cpu_init,
798 .exit = acpi_cpufreq_cpu_exit,
799 .resume = acpi_cpufreq_resume,
800 .name = "acpi-cpufreq",
801 .owner = THIS_MODULE,
802 .attr = acpi_cpufreq_attr,
805 static int __init acpi_cpufreq_init(void)
807 dprintk("acpi_cpufreq_init\n");
809 acpi_cpufreq_early_init();
811 return cpufreq_register_driver(&acpi_cpufreq_driver);
814 static void __exit acpi_cpufreq_exit(void)
817 dprintk("acpi_cpufreq_exit\n");
819 cpufreq_unregister_driver(&acpi_cpufreq_driver);
821 for_each_possible_cpu(i) {
822 kfree(acpi_perf_data[i]);
823 acpi_perf_data[i] = NULL;
828 module_param(acpi_pstate_strict, uint, 0644);
829 MODULE_PARM_DESC(acpi_pstate_strict,
830 "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
832 late_initcall(acpi_cpufreq_init);
833 module_exit(acpi_cpufreq_exit);
835 MODULE_ALIAS("acpi");