2 * intel_pstate.c: Native P state management for Intel processors
4 * (C) Copyright 2012 Intel Corporation
5 * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2
13 #include <linux/kernel.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/module.h>
16 #include <linux/ktime.h>
17 #include <linux/hrtimer.h>
18 #include <linux/tick.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
21 #include <linux/list.h>
22 #include <linux/cpu.h>
23 #include <linux/cpufreq.h>
24 #include <linux/sysfs.h>
25 #include <linux/types.h>
27 #include <linux/debugfs.h>
28 #include <linux/acpi.h>
29 #include <linux/vmalloc.h>
30 #include <trace/events/power.h>
32 #include <asm/div64.h>
34 #include <asm/cpu_device_id.h>
35 #include <asm/cpufeature.h>
37 #define ATOM_RATIOS 0x66a
38 #define ATOM_VIDS 0x66b
39 #define ATOM_TURBO_RATIOS 0x66c
40 #define ATOM_TURBO_VIDS 0x66d
43 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
44 #define fp_toint(X) ((X) >> FRAC_BITS)
46 static inline int32_t mul_fp(int32_t x, int32_t y)
48 return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
51 static inline int32_t div_fp(s64 x, s64 y)
53 return div64_s64((int64_t)x << FRAC_BITS, y);
56 static inline int ceiling_fp(int32_t x)
61 mask = (1 << FRAC_BITS) - 1;
68 int32_t core_pct_busy;
81 int max_pstate_physical;
106 struct timer_list timer;
108 struct pstate_data pstate;
112 ktime_t last_sample_time;
116 u64 prev_cummulative_iowait;
117 struct sample sample;
120 static struct cpudata **all_cpu_data;
121 struct pstate_adjust_policy {
130 struct pstate_funcs {
131 int (*get_max)(void);
132 int (*get_max_physical)(void);
133 int (*get_min)(void);
134 int (*get_turbo)(void);
135 int (*get_scaling)(void);
136 void (*set)(struct cpudata*, int pstate);
137 void (*get_vid)(struct cpudata *);
138 int32_t (*get_target_pstate)(struct cpudata *);
141 struct cpu_defaults {
142 struct pstate_adjust_policy pid_policy;
143 struct pstate_funcs funcs;
146 static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu);
147 static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu);
149 static struct pstate_adjust_policy pid_params;
150 static struct pstate_funcs pstate_funcs;
151 static int hwp_active;
166 static struct perf_limits performance_limits = {
170 .max_perf = int_tofp(1),
172 .min_perf = int_tofp(1),
173 .max_policy_pct = 100,
174 .max_sysfs_pct = 100,
179 static struct perf_limits powersave_limits = {
183 .max_perf = int_tofp(1),
186 .max_policy_pct = 100,
187 .max_sysfs_pct = 100,
192 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
193 static struct perf_limits *limits = &performance_limits;
195 static struct perf_limits *limits = &powersave_limits;
198 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
199 int deadband, int integral) {
200 pid->setpoint = setpoint;
201 pid->deadband = deadband;
202 pid->integral = int_tofp(integral);
203 pid->last_err = int_tofp(setpoint) - int_tofp(busy);
206 static inline void pid_p_gain_set(struct _pid *pid, int percent)
208 pid->p_gain = div_fp(int_tofp(percent), int_tofp(100));
211 static inline void pid_i_gain_set(struct _pid *pid, int percent)
213 pid->i_gain = div_fp(int_tofp(percent), int_tofp(100));
216 static inline void pid_d_gain_set(struct _pid *pid, int percent)
218 pid->d_gain = div_fp(int_tofp(percent), int_tofp(100));
221 static signed int pid_calc(struct _pid *pid, int32_t busy)
224 int32_t pterm, dterm, fp_error;
225 int32_t integral_limit;
227 fp_error = int_tofp(pid->setpoint) - busy;
229 if (abs(fp_error) <= int_tofp(pid->deadband))
232 pterm = mul_fp(pid->p_gain, fp_error);
234 pid->integral += fp_error;
237 * We limit the integral here so that it will never
238 * get higher than 30. This prevents it from becoming
239 * too large an input over long periods of time and allows
240 * it to get factored out sooner.
242 * The value of 30 was chosen through experimentation.
244 integral_limit = int_tofp(30);
245 if (pid->integral > integral_limit)
246 pid->integral = integral_limit;
247 if (pid->integral < -integral_limit)
248 pid->integral = -integral_limit;
250 dterm = mul_fp(pid->d_gain, fp_error - pid->last_err);
251 pid->last_err = fp_error;
253 result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
254 result = result + (1 << (FRAC_BITS-1));
255 return (signed int)fp_toint(result);
258 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
260 pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
261 pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
262 pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
264 pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
267 static inline void intel_pstate_reset_all_pid(void)
271 for_each_online_cpu(cpu) {
272 if (all_cpu_data[cpu])
273 intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
277 static inline void update_turbo_state(void)
282 cpu = all_cpu_data[0];
283 rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
284 limits->turbo_disabled =
285 (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
286 cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
289 static void intel_pstate_hwp_set(void)
291 int min, hw_min, max, hw_max, cpu, range, adj_range;
294 rdmsrl(MSR_HWP_CAPABILITIES, cap);
295 hw_min = HWP_LOWEST_PERF(cap);
296 hw_max = HWP_HIGHEST_PERF(cap);
297 range = hw_max - hw_min;
301 for_each_online_cpu(cpu) {
302 rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
303 adj_range = limits->min_perf_pct * range / 100;
304 min = hw_min + adj_range;
305 value &= ~HWP_MIN_PERF(~0L);
306 value |= HWP_MIN_PERF(min);
308 adj_range = limits->max_perf_pct * range / 100;
309 max = hw_min + adj_range;
310 if (limits->no_turbo) {
311 hw_max = HWP_GUARANTEED_PERF(cap);
316 value &= ~HWP_MAX_PERF(~0L);
317 value |= HWP_MAX_PERF(max);
318 wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
324 /************************** debugfs begin ************************/
325 static int pid_param_set(void *data, u64 val)
328 intel_pstate_reset_all_pid();
332 static int pid_param_get(void *data, u64 *val)
337 DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get, pid_param_set, "%llu\n");
344 static struct pid_param pid_files[] = {
345 {"sample_rate_ms", &pid_params.sample_rate_ms},
346 {"d_gain_pct", &pid_params.d_gain_pct},
347 {"i_gain_pct", &pid_params.i_gain_pct},
348 {"deadband", &pid_params.deadband},
349 {"setpoint", &pid_params.setpoint},
350 {"p_gain_pct", &pid_params.p_gain_pct},
354 static void __init intel_pstate_debug_expose_params(void)
356 struct dentry *debugfs_parent;
361 debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
362 if (IS_ERR_OR_NULL(debugfs_parent))
364 while (pid_files[i].name) {
365 debugfs_create_file(pid_files[i].name, 0660,
366 debugfs_parent, pid_files[i].value,
372 /************************** debugfs end ************************/
374 /************************** sysfs begin ************************/
375 #define show_one(file_name, object) \
376 static ssize_t show_##file_name \
377 (struct kobject *kobj, struct attribute *attr, char *buf) \
379 return sprintf(buf, "%u\n", limits->object); \
382 static ssize_t show_turbo_pct(struct kobject *kobj,
383 struct attribute *attr, char *buf)
386 int total, no_turbo, turbo_pct;
389 cpu = all_cpu_data[0];
391 total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
392 no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
393 turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
394 turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
395 return sprintf(buf, "%u\n", turbo_pct);
398 static ssize_t show_num_pstates(struct kobject *kobj,
399 struct attribute *attr, char *buf)
404 cpu = all_cpu_data[0];
405 total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
406 return sprintf(buf, "%u\n", total);
409 static ssize_t show_no_turbo(struct kobject *kobj,
410 struct attribute *attr, char *buf)
414 update_turbo_state();
415 if (limits->turbo_disabled)
416 ret = sprintf(buf, "%u\n", limits->turbo_disabled);
418 ret = sprintf(buf, "%u\n", limits->no_turbo);
423 static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
424 const char *buf, size_t count)
429 ret = sscanf(buf, "%u", &input);
433 update_turbo_state();
434 if (limits->turbo_disabled) {
435 pr_warn("intel_pstate: Turbo disabled by BIOS or unavailable on processor\n");
439 limits->no_turbo = clamp_t(int, input, 0, 1);
442 intel_pstate_hwp_set();
447 static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
448 const char *buf, size_t count)
453 ret = sscanf(buf, "%u", &input);
457 limits->max_sysfs_pct = clamp_t(int, input, 0 , 100);
458 limits->max_perf_pct = min(limits->max_policy_pct,
459 limits->max_sysfs_pct);
460 limits->max_perf_pct = max(limits->min_policy_pct,
461 limits->max_perf_pct);
462 limits->max_perf_pct = max(limits->min_perf_pct,
463 limits->max_perf_pct);
464 limits->max_perf = div_fp(int_tofp(limits->max_perf_pct),
468 intel_pstate_hwp_set();
472 static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
473 const char *buf, size_t count)
478 ret = sscanf(buf, "%u", &input);
482 limits->min_sysfs_pct = clamp_t(int, input, 0 , 100);
483 limits->min_perf_pct = max(limits->min_policy_pct,
484 limits->min_sysfs_pct);
485 limits->min_perf_pct = min(limits->max_policy_pct,
486 limits->min_perf_pct);
487 limits->min_perf_pct = min(limits->max_perf_pct,
488 limits->min_perf_pct);
489 limits->min_perf = div_fp(int_tofp(limits->min_perf_pct),
493 intel_pstate_hwp_set();
497 show_one(max_perf_pct, max_perf_pct);
498 show_one(min_perf_pct, min_perf_pct);
500 define_one_global_rw(no_turbo);
501 define_one_global_rw(max_perf_pct);
502 define_one_global_rw(min_perf_pct);
503 define_one_global_ro(turbo_pct);
504 define_one_global_ro(num_pstates);
506 static struct attribute *intel_pstate_attributes[] = {
515 static struct attribute_group intel_pstate_attr_group = {
516 .attrs = intel_pstate_attributes,
519 static void __init intel_pstate_sysfs_expose_params(void)
521 struct kobject *intel_pstate_kobject;
524 intel_pstate_kobject = kobject_create_and_add("intel_pstate",
525 &cpu_subsys.dev_root->kobj);
526 BUG_ON(!intel_pstate_kobject);
527 rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
530 /************************** sysfs end ************************/
532 static void intel_pstate_hwp_enable(struct cpudata *cpudata)
534 wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
537 static int atom_get_min_pstate(void)
541 rdmsrl(ATOM_RATIOS, value);
542 return (value >> 8) & 0x7F;
545 static int atom_get_max_pstate(void)
549 rdmsrl(ATOM_RATIOS, value);
550 return (value >> 16) & 0x7F;
553 static int atom_get_turbo_pstate(void)
557 rdmsrl(ATOM_TURBO_RATIOS, value);
561 static void atom_set_pstate(struct cpudata *cpudata, int pstate)
567 val = (u64)pstate << 8;
568 if (limits->no_turbo && !limits->turbo_disabled)
571 vid_fp = cpudata->vid.min + mul_fp(
572 int_tofp(pstate - cpudata->pstate.min_pstate),
575 vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
576 vid = ceiling_fp(vid_fp);
578 if (pstate > cpudata->pstate.max_pstate)
579 vid = cpudata->vid.turbo;
583 wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
586 static int silvermont_get_scaling(void)
590 /* Defined in Table 35-6 from SDM (Sept 2015) */
591 static int silvermont_freq_table[] = {
592 83300, 100000, 133300, 116700, 80000};
594 rdmsrl(MSR_FSB_FREQ, value);
598 return silvermont_freq_table[i];
601 static int airmont_get_scaling(void)
605 /* Defined in Table 35-10 from SDM (Sept 2015) */
606 static int airmont_freq_table[] = {
607 83300, 100000, 133300, 116700, 80000,
608 93300, 90000, 88900, 87500};
610 rdmsrl(MSR_FSB_FREQ, value);
614 return airmont_freq_table[i];
617 static void atom_get_vid(struct cpudata *cpudata)
621 rdmsrl(ATOM_VIDS, value);
622 cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
623 cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
624 cpudata->vid.ratio = div_fp(
625 cpudata->vid.max - cpudata->vid.min,
626 int_tofp(cpudata->pstate.max_pstate -
627 cpudata->pstate.min_pstate));
629 rdmsrl(ATOM_TURBO_VIDS, value);
630 cpudata->vid.turbo = value & 0x7f;
633 static int core_get_min_pstate(void)
637 rdmsrl(MSR_PLATFORM_INFO, value);
638 return (value >> 40) & 0xFF;
641 static int core_get_max_pstate_physical(void)
645 rdmsrl(MSR_PLATFORM_INFO, value);
646 return (value >> 8) & 0xFF;
649 static int core_get_max_pstate(void)
656 rdmsrl(MSR_PLATFORM_INFO, plat_info);
657 max_pstate = (plat_info >> 8) & 0xFF;
659 err = rdmsrl_safe(MSR_TURBO_ACTIVATION_RATIO, &tar);
661 /* Do some sanity checking for safety */
662 if (plat_info & 0x600000000) {
667 err = rdmsrl_safe(MSR_CONFIG_TDP_CONTROL, &tdp_ctrl);
671 tdp_msr = MSR_CONFIG_TDP_NOMINAL + tdp_ctrl;
672 err = rdmsrl_safe(tdp_msr, &tdp_ratio);
676 if (tdp_ratio - 1 == tar) {
678 pr_debug("max_pstate=TAC %x\n", max_pstate);
689 static int core_get_turbo_pstate(void)
694 rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
695 nont = core_get_max_pstate();
702 static inline int core_get_scaling(void)
707 static void core_set_pstate(struct cpudata *cpudata, int pstate)
711 val = (u64)pstate << 8;
712 if (limits->no_turbo && !limits->turbo_disabled)
715 wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
718 static int knl_get_turbo_pstate(void)
723 rdmsrl(MSR_NHM_TURBO_RATIO_LIMIT, value);
724 nont = core_get_max_pstate();
725 ret = (((value) >> 8) & 0xFF);
731 static struct cpu_defaults core_params = {
733 .sample_rate_ms = 10,
741 .get_max = core_get_max_pstate,
742 .get_max_physical = core_get_max_pstate_physical,
743 .get_min = core_get_min_pstate,
744 .get_turbo = core_get_turbo_pstate,
745 .get_scaling = core_get_scaling,
746 .set = core_set_pstate,
747 .get_target_pstate = get_target_pstate_use_performance,
751 static struct cpu_defaults silvermont_params = {
753 .sample_rate_ms = 10,
761 .get_max = atom_get_max_pstate,
762 .get_max_physical = atom_get_max_pstate,
763 .get_min = atom_get_min_pstate,
764 .get_turbo = atom_get_turbo_pstate,
765 .set = atom_set_pstate,
766 .get_scaling = silvermont_get_scaling,
767 .get_vid = atom_get_vid,
768 .get_target_pstate = get_target_pstate_use_cpu_load,
772 static struct cpu_defaults airmont_params = {
774 .sample_rate_ms = 10,
782 .get_max = atom_get_max_pstate,
783 .get_max_physical = atom_get_max_pstate,
784 .get_min = atom_get_min_pstate,
785 .get_turbo = atom_get_turbo_pstate,
786 .set = atom_set_pstate,
787 .get_scaling = airmont_get_scaling,
788 .get_vid = atom_get_vid,
789 .get_target_pstate = get_target_pstate_use_cpu_load,
793 static struct cpu_defaults knl_params = {
795 .sample_rate_ms = 10,
803 .get_max = core_get_max_pstate,
804 .get_max_physical = core_get_max_pstate_physical,
805 .get_min = core_get_min_pstate,
806 .get_turbo = knl_get_turbo_pstate,
807 .get_scaling = core_get_scaling,
808 .set = core_set_pstate,
809 .get_target_pstate = get_target_pstate_use_performance,
813 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
815 int max_perf = cpu->pstate.turbo_pstate;
819 if (limits->no_turbo || limits->turbo_disabled)
820 max_perf = cpu->pstate.max_pstate;
823 * performance can be limited by user through sysfs, by cpufreq
824 * policy, or by cpu specific default values determined through
827 max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits->max_perf));
828 *max = clamp_t(int, max_perf_adj,
829 cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
831 min_perf = fp_toint(mul_fp(int_tofp(max_perf), limits->min_perf));
832 *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
835 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate, bool force)
837 int max_perf, min_perf;
840 update_turbo_state();
842 intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
844 pstate = clamp_t(int, pstate, min_perf, max_perf);
846 if (pstate == cpu->pstate.current_pstate)
849 trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
851 cpu->pstate.current_pstate = pstate;
853 pstate_funcs.set(cpu, pstate);
856 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
858 cpu->pstate.min_pstate = pstate_funcs.get_min();
859 cpu->pstate.max_pstate = pstate_funcs.get_max();
860 cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical();
861 cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
862 cpu->pstate.scaling = pstate_funcs.get_scaling();
864 if (pstate_funcs.get_vid)
865 pstate_funcs.get_vid(cpu);
866 intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
869 static inline void intel_pstate_calc_busy(struct cpudata *cpu)
871 struct sample *sample = &cpu->sample;
874 core_pct = int_tofp(sample->aperf) * int_tofp(100);
875 core_pct = div64_u64(core_pct, int_tofp(sample->mperf));
877 sample->freq = fp_toint(
879 cpu->pstate.max_pstate_physical *
880 cpu->pstate.scaling / 100),
883 sample->core_pct_busy = (int32_t)core_pct;
886 static inline void intel_pstate_sample(struct cpudata *cpu)
892 local_irq_save(flags);
893 rdmsrl(MSR_IA32_APERF, aperf);
894 rdmsrl(MSR_IA32_MPERF, mperf);
896 if ((cpu->prev_mperf == mperf) || (cpu->prev_tsc == tsc)) {
897 local_irq_restore(flags);
900 local_irq_restore(flags);
902 cpu->last_sample_time = cpu->sample.time;
903 cpu->sample.time = ktime_get();
904 cpu->sample.aperf = aperf;
905 cpu->sample.mperf = mperf;
906 cpu->sample.tsc = tsc;
907 cpu->sample.aperf -= cpu->prev_aperf;
908 cpu->sample.mperf -= cpu->prev_mperf;
909 cpu->sample.tsc -= cpu->prev_tsc;
911 intel_pstate_calc_busy(cpu);
913 cpu->prev_aperf = aperf;
914 cpu->prev_mperf = mperf;
918 static inline void intel_hwp_set_sample_time(struct cpudata *cpu)
922 delay = msecs_to_jiffies(50);
923 mod_timer_pinned(&cpu->timer, jiffies + delay);
926 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
930 delay = msecs_to_jiffies(pid_params.sample_rate_ms);
931 mod_timer_pinned(&cpu->timer, jiffies + delay);
934 static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
936 struct sample *sample = &cpu->sample;
937 u64 cummulative_iowait, delta_iowait_us;
938 u64 delta_iowait_mperf;
942 cummulative_iowait = get_cpu_iowait_time_us(cpu->cpu, &now);
945 * Convert iowait time into number of IO cycles spent at max_freq.
946 * IO is considered as busy only for the cpu_load algorithm. For
947 * performance this is not needed since we always try to reach the
948 * maximum P-State, so we are already boosting the IOs.
950 delta_iowait_us = cummulative_iowait - cpu->prev_cummulative_iowait;
951 delta_iowait_mperf = div64_u64(delta_iowait_us * cpu->pstate.scaling *
952 cpu->pstate.max_pstate, MSEC_PER_SEC);
954 mperf = cpu->sample.mperf + delta_iowait_mperf;
955 cpu->prev_cummulative_iowait = cummulative_iowait;
959 * The load can be estimated as the ratio of the mperf counter
960 * running at a constant frequency during active periods
961 * (C0) and the time stamp counter running at the same frequency
962 * also during C-states.
964 cpu_load = div64_u64(int_tofp(100) * mperf, sample->tsc);
965 cpu->sample.busy_scaled = cpu_load;
967 return cpu->pstate.current_pstate - pid_calc(&cpu->pid, cpu_load);
970 static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
972 int32_t core_busy, max_pstate, current_pstate, sample_ratio;
977 * core_busy is the ratio of actual performance to max
978 * max_pstate is the max non turbo pstate available
979 * current_pstate was the pstate that was requested during
980 * the last sample period.
982 * We normalize core_busy, which was our actual percent
983 * performance to what we requested during the last sample
984 * period. The result will be a percentage of busy at a
987 core_busy = cpu->sample.core_pct_busy;
988 max_pstate = int_tofp(cpu->pstate.max_pstate_physical);
989 current_pstate = int_tofp(cpu->pstate.current_pstate);
990 core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
993 * Since we have a deferred timer, it will not fire unless
994 * we are in C0. So, determine if the actual elapsed time
995 * is significantly greater (3x) than our sample interval. If it
996 * is, then we were idle for a long enough period of time
997 * to adjust our busyness.
999 sample_time = pid_params.sample_rate_ms * USEC_PER_MSEC;
1000 duration_us = ktime_us_delta(cpu->sample.time,
1001 cpu->last_sample_time);
1002 if (duration_us > sample_time * 3) {
1003 sample_ratio = div_fp(int_tofp(sample_time),
1004 int_tofp(duration_us));
1005 core_busy = mul_fp(core_busy, sample_ratio);
1008 cpu->sample.busy_scaled = core_busy;
1009 return cpu->pstate.current_pstate - pid_calc(&cpu->pid, core_busy);
1012 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
1014 int from, target_pstate;
1015 struct sample *sample;
1017 from = cpu->pstate.current_pstate;
1019 target_pstate = pstate_funcs.get_target_pstate(cpu);
1021 intel_pstate_set_pstate(cpu, target_pstate, true);
1023 sample = &cpu->sample;
1024 trace_pstate_sample(fp_toint(sample->core_pct_busy),
1025 fp_toint(sample->busy_scaled),
1027 cpu->pstate.current_pstate,
1034 static void intel_hwp_timer_func(unsigned long __data)
1036 struct cpudata *cpu = (struct cpudata *) __data;
1038 intel_pstate_sample(cpu);
1039 intel_hwp_set_sample_time(cpu);
1042 static void intel_pstate_timer_func(unsigned long __data)
1044 struct cpudata *cpu = (struct cpudata *) __data;
1046 intel_pstate_sample(cpu);
1048 intel_pstate_adjust_busy_pstate(cpu);
1050 intel_pstate_set_sample_time(cpu);
1053 #define ICPU(model, policy) \
1054 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
1055 (unsigned long)&policy }
1057 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
1058 ICPU(0x2a, core_params),
1059 ICPU(0x2d, core_params),
1060 ICPU(0x37, silvermont_params),
1061 ICPU(0x3a, core_params),
1062 ICPU(0x3c, core_params),
1063 ICPU(0x3d, core_params),
1064 ICPU(0x3e, core_params),
1065 ICPU(0x3f, core_params),
1066 ICPU(0x45, core_params),
1067 ICPU(0x46, core_params),
1068 ICPU(0x47, core_params),
1069 ICPU(0x4c, airmont_params),
1070 ICPU(0x4e, core_params),
1071 ICPU(0x4f, core_params),
1072 ICPU(0x5e, core_params),
1073 ICPU(0x56, core_params),
1074 ICPU(0x57, knl_params),
1077 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
1079 static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] = {
1080 ICPU(0x56, core_params),
1084 static int intel_pstate_init_cpu(unsigned int cpunum)
1086 struct cpudata *cpu;
1088 if (!all_cpu_data[cpunum])
1089 all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata),
1091 if (!all_cpu_data[cpunum])
1094 cpu = all_cpu_data[cpunum];
1099 intel_pstate_hwp_enable(cpu);
1101 intel_pstate_get_cpu_pstates(cpu);
1103 init_timer_deferrable(&cpu->timer);
1104 cpu->timer.data = (unsigned long)cpu;
1105 cpu->timer.expires = jiffies + HZ/100;
1108 cpu->timer.function = intel_pstate_timer_func;
1110 cpu->timer.function = intel_hwp_timer_func;
1112 intel_pstate_busy_pid_reset(cpu);
1113 intel_pstate_sample(cpu);
1115 add_timer_on(&cpu->timer, cpunum);
1117 pr_debug("intel_pstate: controlling: cpu %d\n", cpunum);
1122 static unsigned int intel_pstate_get(unsigned int cpu_num)
1124 struct sample *sample;
1125 struct cpudata *cpu;
1127 cpu = all_cpu_data[cpu_num];
1130 sample = &cpu->sample;
1131 return sample->freq;
1134 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
1136 if (!policy->cpuinfo.max_freq)
1139 if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
1140 policy->max >= policy->cpuinfo.max_freq) {
1141 pr_debug("intel_pstate: set performance\n");
1142 limits = &performance_limits;
1144 intel_pstate_hwp_set();
1148 pr_debug("intel_pstate: set powersave\n");
1149 limits = &powersave_limits;
1150 limits->min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
1151 limits->min_policy_pct = clamp_t(int, limits->min_policy_pct, 0 , 100);
1152 limits->max_policy_pct = DIV_ROUND_UP(policy->max * 100,
1153 policy->cpuinfo.max_freq);
1154 limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0 , 100);
1156 /* Normalize user input to [min_policy_pct, max_policy_pct] */
1157 limits->min_perf_pct = max(limits->min_policy_pct,
1158 limits->min_sysfs_pct);
1159 limits->min_perf_pct = min(limits->max_policy_pct,
1160 limits->min_perf_pct);
1161 limits->max_perf_pct = min(limits->max_policy_pct,
1162 limits->max_sysfs_pct);
1163 limits->max_perf_pct = max(limits->min_policy_pct,
1164 limits->max_perf_pct);
1165 limits->max_perf = round_up(limits->max_perf, FRAC_BITS);
1167 /* Make sure min_perf_pct <= max_perf_pct */
1168 limits->min_perf_pct = min(limits->max_perf_pct, limits->min_perf_pct);
1170 limits->min_perf = div_fp(int_tofp(limits->min_perf_pct),
1172 limits->max_perf = div_fp(int_tofp(limits->max_perf_pct),
1176 intel_pstate_hwp_set();
1181 static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
1183 cpufreq_verify_within_cpu_limits(policy);
1185 if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
1186 policy->policy != CPUFREQ_POLICY_PERFORMANCE)
1192 static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
1194 int cpu_num = policy->cpu;
1195 struct cpudata *cpu = all_cpu_data[cpu_num];
1197 pr_debug("intel_pstate: CPU %d exiting\n", cpu_num);
1199 del_timer_sync(&all_cpu_data[cpu_num]->timer);
1203 intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate, false);
1206 static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
1208 struct cpudata *cpu;
1211 rc = intel_pstate_init_cpu(policy->cpu);
1215 cpu = all_cpu_data[policy->cpu];
1217 if (limits->min_perf_pct == 100 && limits->max_perf_pct == 100)
1218 policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1220 policy->policy = CPUFREQ_POLICY_POWERSAVE;
1222 policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
1223 policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1225 /* cpuinfo and default policy values */
1226 policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
1227 policy->cpuinfo.max_freq =
1228 cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1229 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
1230 cpumask_set_cpu(policy->cpu, policy->cpus);
1235 static struct cpufreq_driver intel_pstate_driver = {
1236 .flags = CPUFREQ_CONST_LOOPS,
1237 .verify = intel_pstate_verify_policy,
1238 .setpolicy = intel_pstate_set_policy,
1239 .get = intel_pstate_get,
1240 .init = intel_pstate_cpu_init,
1241 .stop_cpu = intel_pstate_stop_cpu,
1242 .name = "intel_pstate",
1245 static int __initdata no_load;
1246 static int __initdata no_hwp;
1247 static int __initdata hwp_only;
1248 static unsigned int force_load;
1250 static int intel_pstate_msrs_not_valid(void)
1252 if (!pstate_funcs.get_max() ||
1253 !pstate_funcs.get_min() ||
1254 !pstate_funcs.get_turbo())
1260 static void copy_pid_params(struct pstate_adjust_policy *policy)
1262 pid_params.sample_rate_ms = policy->sample_rate_ms;
1263 pid_params.p_gain_pct = policy->p_gain_pct;
1264 pid_params.i_gain_pct = policy->i_gain_pct;
1265 pid_params.d_gain_pct = policy->d_gain_pct;
1266 pid_params.deadband = policy->deadband;
1267 pid_params.setpoint = policy->setpoint;
1270 static void copy_cpu_funcs(struct pstate_funcs *funcs)
1272 pstate_funcs.get_max = funcs->get_max;
1273 pstate_funcs.get_max_physical = funcs->get_max_physical;
1274 pstate_funcs.get_min = funcs->get_min;
1275 pstate_funcs.get_turbo = funcs->get_turbo;
1276 pstate_funcs.get_scaling = funcs->get_scaling;
1277 pstate_funcs.set = funcs->set;
1278 pstate_funcs.get_vid = funcs->get_vid;
1279 pstate_funcs.get_target_pstate = funcs->get_target_pstate;
1283 #if IS_ENABLED(CONFIG_ACPI)
1284 #include <acpi/processor.h>
1286 static bool intel_pstate_no_acpi_pss(void)
1290 for_each_possible_cpu(i) {
1292 union acpi_object *pss;
1293 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1294 struct acpi_processor *pr = per_cpu(processors, i);
1299 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
1300 if (ACPI_FAILURE(status))
1303 pss = buffer.pointer;
1304 if (pss && pss->type == ACPI_TYPE_PACKAGE) {
1315 static bool intel_pstate_has_acpi_ppc(void)
1319 for_each_possible_cpu(i) {
1320 struct acpi_processor *pr = per_cpu(processors, i);
1324 if (acpi_has_method(pr->handle, "_PPC"))
1335 struct hw_vendor_info {
1337 char oem_id[ACPI_OEM_ID_SIZE];
1338 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
1342 /* Hardware vendor-specific info that has its own power management modes */
1343 static struct hw_vendor_info vendor_info[] = {
1344 {1, "HP ", "ProLiant", PSS},
1345 {1, "ORACLE", "X4-2 ", PPC},
1346 {1, "ORACLE", "X4-2L ", PPC},
1347 {1, "ORACLE", "X4-2B ", PPC},
1348 {1, "ORACLE", "X3-2 ", PPC},
1349 {1, "ORACLE", "X3-2L ", PPC},
1350 {1, "ORACLE", "X3-2B ", PPC},
1351 {1, "ORACLE", "X4470M2 ", PPC},
1352 {1, "ORACLE", "X4270M3 ", PPC},
1353 {1, "ORACLE", "X4270M2 ", PPC},
1354 {1, "ORACLE", "X4170M2 ", PPC},
1355 {1, "ORACLE", "X4170 M3", PPC},
1356 {1, "ORACLE", "X4275 M3", PPC},
1357 {1, "ORACLE", "X6-2 ", PPC},
1358 {1, "ORACLE", "Sudbury ", PPC},
1362 static bool intel_pstate_platform_pwr_mgmt_exists(void)
1364 struct acpi_table_header hdr;
1365 struct hw_vendor_info *v_info;
1366 const struct x86_cpu_id *id;
1369 id = x86_match_cpu(intel_pstate_cpu_oob_ids);
1371 rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
1372 if ( misc_pwr & (1 << 8))
1376 if (acpi_disabled ||
1377 ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
1380 for (v_info = vendor_info; v_info->valid; v_info++) {
1381 if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
1382 !strncmp(hdr.oem_table_id, v_info->oem_table_id,
1383 ACPI_OEM_TABLE_ID_SIZE))
1384 switch (v_info->oem_pwr_table) {
1386 return intel_pstate_no_acpi_pss();
1388 return intel_pstate_has_acpi_ppc() &&
1395 #else /* CONFIG_ACPI not enabled */
1396 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
1397 static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
1398 #endif /* CONFIG_ACPI */
1400 static int __init intel_pstate_init(void)
1403 const struct x86_cpu_id *id;
1404 struct cpu_defaults *cpu_def;
1409 id = x86_match_cpu(intel_pstate_cpu_ids);
1414 * The Intel pstate driver will be ignored if the platform
1415 * firmware has its own power management modes.
1417 if (intel_pstate_platform_pwr_mgmt_exists())
1420 cpu_def = (struct cpu_defaults *)id->driver_data;
1422 copy_pid_params(&cpu_def->pid_policy);
1423 copy_cpu_funcs(&cpu_def->funcs);
1425 if (intel_pstate_msrs_not_valid())
1428 pr_info("Intel P-state driver initializing.\n");
1430 all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
1434 if (static_cpu_has_safe(X86_FEATURE_HWP) && !no_hwp) {
1435 pr_info("intel_pstate: HWP enabled\n");
1439 if (!hwp_active && hwp_only)
1442 rc = cpufreq_register_driver(&intel_pstate_driver);
1446 intel_pstate_debug_expose_params();
1447 intel_pstate_sysfs_expose_params();
1452 for_each_online_cpu(cpu) {
1453 if (all_cpu_data[cpu]) {
1454 del_timer_sync(&all_cpu_data[cpu]->timer);
1455 kfree(all_cpu_data[cpu]);
1460 vfree(all_cpu_data);
1463 device_initcall(intel_pstate_init);
1465 static int __init intel_pstate_setup(char *str)
1470 if (!strcmp(str, "disable"))
1472 if (!strcmp(str, "no_hwp")) {
1473 pr_info("intel_pstate: HWP disabled\n");
1476 if (!strcmp(str, "force"))
1478 if (!strcmp(str, "hwp_only"))
1482 early_param("intel_pstate", intel_pstate_setup);
1484 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
1485 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
1486 MODULE_LICENSE("GPL");