/* * intel_pstate.c: Native P state management for Intel processors * * (C) Copyright 2012 Intel Corporation * Author: Dirk Brandewie * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; version 2 * of the License. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define INTEL_PSTATE_SAMPLING_INTERVAL (10 * NSEC_PER_MSEC) #define INTEL_CPUFREQ_TRANSITION_LATENCY 20000 #define INTEL_CPUFREQ_TRANSITION_DELAY 500 #ifdef CONFIG_ACPI #include #include #endif #define FRAC_BITS 8 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS) #define fp_toint(X) ((X) >> FRAC_BITS) #define EXT_BITS 6 #define EXT_FRAC_BITS (EXT_BITS + FRAC_BITS) #define fp_ext_toint(X) ((X) >> EXT_FRAC_BITS) #define int_ext_tofp(X) ((int64_t)(X) << EXT_FRAC_BITS) static inline int32_t mul_fp(int32_t x, int32_t y) { return ((int64_t)x * (int64_t)y) >> FRAC_BITS; } static inline int32_t div_fp(s64 x, s64 y) { return div64_s64((int64_t)x << FRAC_BITS, y); } static inline int ceiling_fp(int32_t x) { int mask, ret; ret = fp_toint(x); mask = (1 << FRAC_BITS) - 1; if (x & mask) ret += 1; return ret; } static inline int32_t percent_fp(int percent) { return div_fp(percent, 100); } static inline u64 mul_ext_fp(u64 x, u64 y) { return (x * y) >> EXT_FRAC_BITS; } static inline u64 div_ext_fp(u64 x, u64 y) { return div64_u64(x << EXT_FRAC_BITS, y); } static inline int32_t percent_ext_fp(int percent) { return div_ext_fp(percent, 100); } /** * struct sample - Store performance sample * @core_avg_perf: Ratio of APERF/MPERF which is the actual average * performance during last sample period * @busy_scaled: Scaled busy value which is used to calculate next * P state. This can be different than core_avg_perf * to account for cpu idle period * @aperf: Difference of actual performance frequency clock count * read from APERF MSR between last and current sample * @mperf: Difference of maximum performance frequency clock count * read from MPERF MSR between last and current sample * @tsc: Difference of time stamp counter between last and * current sample * @time: Current time from scheduler * * This structure is used in the cpudata structure to store performance sample * data for choosing next P State. */ struct sample { int32_t core_avg_perf; int32_t busy_scaled; u64 aperf; u64 mperf; u64 tsc; u64 time; }; /** * struct pstate_data - Store P state data * @current_pstate: Current requested P state * @min_pstate: Min P state possible for this platform * @max_pstate: Max P state possible for this platform * @max_pstate_physical:This is physical Max P state for a processor * This can be higher than the max_pstate which can * be limited by platform thermal design power limits * @scaling: Scaling factor to convert frequency to cpufreq * frequency units * @turbo_pstate: Max Turbo P state possible for this platform * @max_freq: @max_pstate frequency in cpufreq units * @turbo_freq: @turbo_pstate frequency in cpufreq units * * Stores the per cpu model P state limits and current P state. */ struct pstate_data { int current_pstate; int min_pstate; int max_pstate; int max_pstate_physical; int scaling; int turbo_pstate; unsigned int max_freq; unsigned int turbo_freq; }; /** * struct vid_data - Stores voltage information data * @min: VID data for this platform corresponding to * the lowest P state * @max: VID data corresponding to the highest P State. * @turbo: VID data for turbo P state * @ratio: Ratio of (vid max - vid min) / * (max P state - Min P State) * * Stores the voltage data for DVFS (Dynamic Voltage and Frequency Scaling) * This data is used in Atom platforms, where in addition to target P state, * the voltage data needs to be specified to select next P State. */ struct vid_data { int min; int max; int turbo; int32_t ratio; }; /** * struct global_params - Global parameters, mostly tunable via sysfs. * @no_turbo: Whether or not to use turbo P-states. * @turbo_disabled: Whethet or not turbo P-states are available at all, * based on the MSR_IA32_MISC_ENABLE value and whether or * not the maximum reported turbo P-state is different from * the maximum reported non-turbo one. * @min_perf_pct: Minimum capacity limit in percent of the maximum turbo * P-state capacity. * @max_perf_pct: Maximum capacity limit in percent of the maximum turbo * P-state capacity. */ struct global_params { bool no_turbo; bool turbo_disabled; int max_perf_pct; int min_perf_pct; }; /** * struct cpudata - Per CPU instance data storage * @cpu: CPU number for this instance data * @policy: CPUFreq policy value * @update_util: CPUFreq utility callback information * @update_util_set: CPUFreq utility callback is set * @iowait_boost: iowait-related boost fraction * @last_update: Time of the last update. * @pstate: Stores P state limits for this CPU * @vid: Stores VID limits for this CPU * @last_sample_time: Last Sample time * @aperf_mperf_shift: Number of clock cycles after aperf, merf is incremented * This shift is a multiplier to mperf delta to * calculate CPU busy. * @prev_aperf: Last APERF value read from APERF MSR * @prev_mperf: Last MPERF value read from MPERF MSR * @prev_tsc: Last timestamp counter (TSC) value * @prev_cummulative_iowait: IO Wait time difference from last and * current sample * @sample: Storage for storing last Sample data * @min_perf_ratio: Minimum capacity in terms of PERF or HWP ratios * @max_perf_ratio: Maximum capacity in terms of PERF or HWP ratios * @acpi_perf_data: Stores ACPI perf information read from _PSS * @valid_pss_table: Set to true for valid ACPI _PSS entries found * @epp_powersave: Last saved HWP energy performance preference * (EPP) or energy performance bias (EPB), * when policy switched to performance * @epp_policy: Last saved policy used to set EPP/EPB * @epp_default: Power on default HWP energy performance * preference/bias * @epp_saved: Saved EPP/EPB during system suspend or CPU offline * operation * @hwp_req_cached: Cached value of the last HWP Request MSR * @hwp_cap_cached: Cached value of the last HWP Capabilities MSR * @last_io_update: Last time when IO wake flag was set * @sched_flags: Store scheduler flags for possible cross CPU update * @hwp_boost_min: Last HWP boosted min performance * * This structure stores per CPU instance data for all CPUs. */ struct cpudata { int cpu; unsigned int policy; struct update_util_data update_util; bool update_util_set; struct pstate_data pstate; struct vid_data vid; u64 last_update; u64 last_sample_time; u64 aperf_mperf_shift; u64 prev_aperf; u64 prev_mperf; u64 prev_tsc; u64 prev_cummulative_iowait; struct sample sample; int32_t min_perf_ratio; int32_t max_perf_ratio; #ifdef CONFIG_ACPI struct acpi_processor_performance acpi_perf_data; bool valid_pss_table; #endif unsigned int iowait_boost; s16 epp_powersave; s16 epp_policy; s16 epp_default; s16 epp_saved; u64 hwp_req_cached; u64 hwp_cap_cached; u64 last_io_update; unsigned int sched_flags; u32 hwp_boost_min; }; static struct cpudata **all_cpu_data; /** * struct pstate_funcs - Per CPU model specific callbacks * @get_max: Callback to get maximum non turbo effective P state * @get_max_physical: Callback to get maximum non turbo physical P state * @get_min: Callback to get minimum P state * @get_turbo: Callback to get turbo P state * @get_scaling: Callback to get frequency scaling factor * @get_val: Callback to convert P state to actual MSR write value * @get_vid: Callback to get VID data for Atom platforms * * Core and Atom CPU models have different way to get P State limits. This * structure is used to store those callbacks. */ struct pstate_funcs { int (*get_max)(void); int (*get_max_physical)(void); int (*get_min)(void); int (*get_turbo)(void); int (*get_scaling)(void); int (*get_aperf_mperf_shift)(void); u64 (*get_val)(struct cpudata*, int pstate); void (*get_vid)(struct cpudata *); }; static struct pstate_funcs pstate_funcs __read_mostly; static int hwp_active __read_mostly; static int hwp_mode_bdw __read_mostly; static bool per_cpu_limits __read_mostly; static bool hwp_boost __read_mostly; static struct cpufreq_driver *intel_pstate_driver __read_mostly; #ifdef CONFIG_ACPI static bool acpi_ppc; #endif static struct global_params global; static DEFINE_MUTEX(intel_pstate_driver_lock); static DEFINE_MUTEX(intel_pstate_limits_lock); #ifdef CONFIG_ACPI static bool intel_pstate_acpi_pm_profile_server(void) { if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER || acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER) return true; return false; } static bool intel_pstate_get_ppc_enable_status(void) { if (intel_pstate_acpi_pm_profile_server()) return true; return acpi_ppc; } #ifdef CONFIG_ACPI_CPPC_LIB /* The work item is needed to avoid CPU hotplug locking issues */ static void intel_pstste_sched_itmt_work_fn(struct work_struct *work) { sched_set_itmt_support(); } static DECLARE_WORK(sched_itmt_work, intel_pstste_sched_itmt_work_fn); static void intel_pstate_set_itmt_prio(int cpu) { struct cppc_perf_caps cppc_perf; static u32 max_highest_perf = 0, min_highest_perf = U32_MAX; int ret; ret = cppc_get_perf_caps(cpu, &cppc_perf); if (ret) return; /* * The priorities can be set regardless of whether or not * sched_set_itmt_support(true) has been called and it is valid to * update them at any time after it has been called. */ sched_set_itmt_core_prio(cppc_perf.highest_perf, cpu); if (max_highest_perf <= min_highest_perf) { if (cppc_perf.highest_perf > max_highest_perf) max_highest_perf = cppc_perf.highest_perf; if (cppc_perf.highest_perf < min_highest_perf) min_highest_perf = cppc_perf.highest_perf; if (max_highest_perf > min_highest_perf) { /* * This code can be run during CPU online under the * CPU hotplug locks, so sched_set_itmt_support() * cannot be called from here. Queue up a work item * to invoke it. */ schedule_work(&sched_itmt_work); } } } #else static void intel_pstate_set_itmt_prio(int cpu) { } #endif static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy) { struct cpudata *cpu; int ret; int i; if (hwp_active) { intel_pstate_set_itmt_prio(policy->cpu); return; } if (!intel_pstate_get_ppc_enable_status()) return; cpu = all_cpu_data[policy->cpu]; ret = acpi_processor_register_performance(&cpu->acpi_perf_data, policy->cpu); if (ret) return; /* * Check if the control value in _PSS is for PERF_CTL MSR, which should * guarantee that the states returned by it map to the states in our * list directly. */ if (cpu->acpi_perf_data.control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) goto err; /* * If there is only one entry _PSS, simply ignore _PSS and continue as * usual without taking _PSS into account */ if (cpu->acpi_perf_data.state_count < 2) goto err; pr_debug("CPU%u - ACPI _PSS perf data\n", policy->cpu); for (i = 0; i < cpu->acpi_perf_data.state_count; i++) { pr_debug(" %cP%d: %u MHz, %u mW, 0x%x\n", (i == cpu->acpi_perf_data.state ? '*' : ' '), i, (u32) cpu->acpi_perf_data.states[i].core_frequency, (u32) cpu->acpi_perf_data.states[i].power, (u32) cpu->acpi_perf_data.states[i].control); } /* * The _PSS table doesn't contain whole turbo frequency range. * This just contains +1 MHZ above the max non turbo frequency, * with control value corresponding to max turbo ratio. But * when cpufreq set policy is called, it will call with this * max frequency, which will cause a reduced performance as * this driver uses real max turbo frequency as the max * frequency. So correct this frequency in _PSS table to * correct max turbo frequency based on the turbo state. * Also need to convert to MHz as _PSS freq is in MHz. */ if (!global.turbo_disabled) cpu->acpi_perf_data.states[0].core_frequency = policy->cpuinfo.max_freq / 1000; cpu->valid_pss_table = true; pr_debug("_PPC limits will be enforced\n"); return; err: cpu->valid_pss_table = false; acpi_processor_unregister_performance(policy->cpu); } static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy) { struct cpudata *cpu; cpu = all_cpu_data[policy->cpu]; if (!cpu->valid_pss_table) return; acpi_processor_unregister_performance(policy->cpu); } #else static inline void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy) { } static inline void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy) { } static inline bool intel_pstate_acpi_pm_profile_server(void) { return false; } #endif static inline void update_turbo_state(void) { u64 misc_en; struct cpudata *cpu; cpu = all_cpu_data[0]; rdmsrl(MSR_IA32_MISC_ENABLE, misc_en); global.turbo_disabled = (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE || cpu->pstate.max_pstate == cpu->pstate.turbo_pstate); } static int min_perf_pct_min(void) { struct cpudata *cpu = all_cpu_data[0]; int turbo_pstate = cpu->pstate.turbo_pstate; return turbo_pstate ? (cpu->pstate.min_pstate * 100 / turbo_pstate) : 0; } static s16 intel_pstate_get_epb(struct cpudata *cpu_data) { u64 epb; int ret; if (!static_cpu_has(X86_FEATURE_EPB)) return -ENXIO; ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_IA32_ENERGY_PERF_BIAS, &epb); if (ret) return (s16)ret; return (s16)(epb & 0x0f); } static s16 intel_pstate_get_epp(struct cpudata *cpu_data, u64 hwp_req_data) { s16 epp; if (static_cpu_has(X86_FEATURE_HWP_EPP)) { /* * When hwp_req_data is 0, means that caller didn't read * MSR_HWP_REQUEST, so need to read and get EPP. */ if (!hwp_req_data) { epp = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &hwp_req_data); if (epp) return epp; } epp = (hwp_req_data >> 24) & 0xff; } else { /* When there is no EPP present, HWP uses EPB settings */ epp = intel_pstate_get_epb(cpu_data); } return epp; } static int intel_pstate_set_epb(int cpu, s16 pref) { u64 epb; int ret; if (!static_cpu_has(X86_FEATURE_EPB)) return -ENXIO; ret = rdmsrl_on_cpu(cpu, MSR_IA32_ENERGY_PERF_BIAS, &epb); if (ret) return ret; epb = (epb & ~0x0f) | pref; wrmsrl_on_cpu(cpu, MSR_IA32_ENERGY_PERF_BIAS, epb); return 0; } /* * EPP/EPB display strings corresponding to EPP index in the * energy_perf_strings[] * index String *------------------------------------- * 0 default * 1 performance * 2 balance_performance * 3 balance_power * 4 power */ static const char * const energy_perf_strings[] = { "default", "performance", "balance_performance", "balance_power", "power", NULL }; static const unsigned int epp_values[] = { HWP_EPP_PERFORMANCE, HWP_EPP_BALANCE_PERFORMANCE, HWP_EPP_BALANCE_POWERSAVE, HWP_EPP_POWERSAVE }; static int intel_pstate_get_energy_pref_index(struct cpudata *cpu_data) { s16 epp; int index = -EINVAL; epp = intel_pstate_get_epp(cpu_data, 0); if (epp < 0) return epp; if (static_cpu_has(X86_FEATURE_HWP_EPP)) { if (epp == HWP_EPP_PERFORMANCE) return 1; if (epp <= HWP_EPP_BALANCE_PERFORMANCE) return 2; if (epp <= HWP_EPP_BALANCE_POWERSAVE) return 3; else return 4; } else if (static_cpu_has(X86_FEATURE_EPB)) { /* * Range: * 0x00-0x03 : Performance * 0x04-0x07 : Balance performance * 0x08-0x0B : Balance power * 0x0C-0x0F : Power * The EPB is a 4 bit value, but our ranges restrict the * value which can be set. Here only using top two bits * effectively. */ index = (epp >> 2) + 1; } return index; } static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data, int pref_index) { int epp = -EINVAL; int ret; if (!pref_index) epp = cpu_data->epp_default; mutex_lock(&intel_pstate_limits_lock); if (static_cpu_has(X86_FEATURE_HWP_EPP)) { u64 value; ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &value); if (ret) goto return_pref; value &= ~GENMASK_ULL(31, 24); if (epp == -EINVAL) epp = epp_values[pref_index - 1]; value |= (u64)epp << 24; ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value); } else { if (epp == -EINVAL) epp = (pref_index - 1) << 2; ret = intel_pstate_set_epb(cpu_data->cpu, epp); } return_pref: mutex_unlock(&intel_pstate_limits_lock); return ret; } static ssize_t show_energy_performance_available_preferences( struct cpufreq_policy *policy, char *buf) { int i = 0; int ret = 0; while (energy_perf_strings[i] != NULL) ret += sprintf(&buf[ret], "%s ", energy_perf_strings[i++]); ret += sprintf(&buf[ret], "\n"); return ret; } cpufreq_freq_attr_ro(energy_performance_available_preferences); static ssize_t store_energy_performance_preference( struct cpufreq_policy *policy, const char *buf, size_t count) { struct cpudata *cpu_data = all_cpu_data[policy->cpu]; char str_preference[21]; int ret; ret = sscanf(buf, "%20s", str_preference); if (ret != 1) return -EINVAL; ret = match_string(energy_perf_strings, -1, str_preference); if (ret < 0) return ret; intel_pstate_set_energy_pref_index(cpu_data, ret); return count; } static ssize_t show_energy_performance_preference( struct cpufreq_policy *policy, char *buf) { struct cpudata *cpu_data = all_cpu_data[policy->cpu]; int preference; preference = intel_pstate_get_energy_pref_index(cpu_data); if (preference < 0) return preference; return sprintf(buf, "%s\n", energy_perf_strings[preference]); } cpufreq_freq_attr_rw(energy_performance_preference); static struct freq_attr *hwp_cpufreq_attrs[] = { &energy_performance_preference, &energy_performance_available_preferences, NULL, }; static void intel_pstate_get_hwp_max(unsigned int cpu, int *phy_max, int *current_max) { u64 cap; rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap); WRITE_ONCE(all_cpu_data[cpu]->hwp_cap_cached, cap); if (global.no_turbo) *current_max = HWP_GUARANTEED_PERF(cap); else *current_max = HWP_HIGHEST_PERF(cap); *phy_max = HWP_HIGHEST_PERF(cap); } static void intel_pstate_hwp_set(unsigned int cpu) { struct cpudata *cpu_data = all_cpu_data[cpu]; int max, min; u64 value; s16 epp; max = cpu_data->max_perf_ratio; min = cpu_data->min_perf_ratio; if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) min = max; rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value); value &= ~HWP_MIN_PERF(~0L); value |= HWP_MIN_PERF(min); value &= ~HWP_MAX_PERF(~0L); value |= HWP_MAX_PERF(max); if (cpu_data->epp_policy == cpu_data->policy) goto skip_epp; cpu_data->epp_policy = cpu_data->policy; if (cpu_data->epp_saved >= 0) { epp = cpu_data->epp_saved; cpu_data->epp_saved = -EINVAL; goto update_epp; } if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) { epp = intel_pstate_get_epp(cpu_data, value); cpu_data->epp_powersave = epp; /* If EPP read was failed, then don't try to write */ if (epp < 0) goto skip_epp; epp = 0; } else { /* skip setting EPP, when saved value is invalid */ if (cpu_data->epp_powersave < 0) goto skip_epp; /* * No need to restore EPP when it is not zero. This * means: * - Policy is not changed * - user has manually changed * - Error reading EPB */ epp = intel_pstate_get_epp(cpu_data, value); if (epp) goto skip_epp; epp = cpu_data->epp_powersave; } update_epp: if (static_cpu_has(X86_FEATURE_HWP_EPP)) { value &= ~GENMASK_ULL(31, 24); value |= (u64)epp << 24; } else { intel_pstate_set_epb(cpu, epp); } skip_epp: WRITE_ONCE(cpu_data->hwp_req_cached, value); wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value); } static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy) { struct cpudata *cpu_data = all_cpu_data[policy->cpu]; if (!hwp_active) return 0; cpu_data->epp_saved = intel_pstate_get_epp(cpu_data, 0); return 0; } static void intel_pstate_hwp_enable(struct cpudata *cpudata); static int intel_pstate_resume(struct cpufreq_policy *policy) { if (!hwp_active) return 0; mutex_lock(&intel_pstate_limits_lock); if (policy->cpu == 0) intel_pstate_hwp_enable(all_cpu_data[policy->cpu]); all_cpu_data[policy->cpu]->epp_policy = 0; intel_pstate_hwp_set(policy->cpu); mutex_unlock(&intel_pstate_limits_lock); return 0; } static void intel_pstate_update_policies(void) { int cpu; for_each_possible_cpu(cpu) cpufreq_update_policy(cpu); } /************************** sysfs begin ************************/ #define show_one(file_name, object) \ static ssize_t show_##file_name \ (struct kobject *kobj, struct kobj_attribute *attr, char *buf) \ { \ return sprintf(buf, "%u\n", global.object); \ } static ssize_t intel_pstate_show_status(char *buf); static int intel_pstate_update_status(const char *buf, size_t size); static ssize_t show_status(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { ssize_t ret; mutex_lock(&intel_pstate_driver_lock); ret = intel_pstate_show_status(buf); mutex_unlock(&intel_pstate_driver_lock); return ret; } static ssize_t store_status(struct kobject *a, struct kobj_attribute *b, const char *buf, size_t count) { char *p = memchr(buf, '\n', count); int ret; mutex_lock(&intel_pstate_driver_lock); ret = intel_pstate_update_status(buf, p ? p - buf : count); mutex_unlock(&intel_pstate_driver_lock); return ret < 0 ? ret : count; } static ssize_t show_turbo_pct(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { struct cpudata *cpu; int total, no_turbo, turbo_pct; uint32_t turbo_fp; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } cpu = all_cpu_data[0]; total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1; no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1; turbo_fp = div_fp(no_turbo, total); turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100))); mutex_unlock(&intel_pstate_driver_lock); return sprintf(buf, "%u\n", turbo_pct); } static ssize_t show_num_pstates(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { struct cpudata *cpu; int total; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } cpu = all_cpu_data[0]; total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1; mutex_unlock(&intel_pstate_driver_lock); return sprintf(buf, "%u\n", total); } static ssize_t show_no_turbo(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { ssize_t ret; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } update_turbo_state(); if (global.turbo_disabled) ret = sprintf(buf, "%u\n", global.turbo_disabled); else ret = sprintf(buf, "%u\n", global.no_turbo); mutex_unlock(&intel_pstate_driver_lock); return ret; } static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b, const char *buf, size_t count) { unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } mutex_lock(&intel_pstate_limits_lock); update_turbo_state(); if (global.turbo_disabled) { pr_warn("Turbo disabled by BIOS or unavailable on processor\n"); mutex_unlock(&intel_pstate_limits_lock); mutex_unlock(&intel_pstate_driver_lock); return -EPERM; } global.no_turbo = clamp_t(int, input, 0, 1); if (global.no_turbo) { struct cpudata *cpu = all_cpu_data[0]; int pct = cpu->pstate.max_pstate * 100 / cpu->pstate.turbo_pstate; /* Squash the global minimum into the permitted range. */ if (global.min_perf_pct > pct) global.min_perf_pct = pct; } mutex_unlock(&intel_pstate_limits_lock); intel_pstate_update_policies(); mutex_unlock(&intel_pstate_driver_lock); return count; } static ssize_t store_max_perf_pct(struct kobject *a, struct kobj_attribute *b, const char *buf, size_t count) { unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } mutex_lock(&intel_pstate_limits_lock); global.max_perf_pct = clamp_t(int, input, global.min_perf_pct, 100); mutex_unlock(&intel_pstate_limits_lock); intel_pstate_update_policies(); mutex_unlock(&intel_pstate_driver_lock); return count; } static ssize_t store_min_perf_pct(struct kobject *a, struct kobj_attribute *b, const char *buf, size_t count) { unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; mutex_lock(&intel_pstate_driver_lock); if (!intel_pstate_driver) { mutex_unlock(&intel_pstate_driver_lock); return -EAGAIN; } mutex_lock(&intel_pstate_limits_lock); global.min_perf_pct = clamp_t(int, input, min_perf_pct_min(), global.max_perf_pct); mutex_unlock(&intel_pstate_limits_lock); intel_pstate_update_policies(); mutex_unlock(&intel_pstate_driver_lock); return count; } static ssize_t show_hwp_dynamic_boost(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%u\n", hwp_boost); } static ssize_t store_hwp_dynamic_boost(struct kobject *a, struct kobj_attribute *b, const char *buf, size_t count) { unsigned int input; int ret; ret = kstrtouint(buf, 10, &input); if (ret) return ret; mutex_lock(&intel_pstate_driver_lock); hwp_boost = !!input; intel_pstate_update_policies(); mutex_unlock(&intel_pstate_driver_lock); return count; } show_one(max_perf_pct, max_perf_pct); show_one(min_perf_pct, min_perf_pct); define_one_global_rw(status); define_one_global_rw(no_turbo); define_one_global_rw(max_perf_pct); define_one_global_rw(min_perf_pct); define_one_global_ro(turbo_pct); define_one_global_ro(num_pstates); define_one_global_rw(hwp_dynamic_boost); static struct attribute *intel_pstate_attributes[] = { &status.attr, &no_turbo.attr, &turbo_pct.attr, &num_pstates.attr, NULL }; static const struct attribute_group intel_pstate_attr_group = { .attrs = intel_pstate_attributes, }; static void __init intel_pstate_sysfs_expose_params(void) { struct kobject *intel_pstate_kobject; int rc; intel_pstate_kobject = kobject_create_and_add("intel_pstate", &cpu_subsys.dev_root->kobj); if (WARN_ON(!intel_pstate_kobject)) return; rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group); if (WARN_ON(rc)) return; /* * If per cpu limits are enforced there are no global limits, so * return without creating max/min_perf_pct attributes */ if (per_cpu_limits) return; rc = sysfs_create_file(intel_pstate_kobject, &max_perf_pct.attr); WARN_ON(rc); rc = sysfs_create_file(intel_pstate_kobject, &min_perf_pct.attr); WARN_ON(rc); if (hwp_active) { rc = sysfs_create_file(intel_pstate_kobject, &hwp_dynamic_boost.attr); WARN_ON(rc); } } /************************** sysfs end ************************/ static void intel_pstate_hwp_enable(struct cpudata *cpudata) { /* First disable HWP notification interrupt as we don't process them */ if (static_cpu_has(X86_FEATURE_HWP_NOTIFY)) wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00); wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1); cpudata->epp_policy = 0; if (cpudata->epp_default == -EINVAL) cpudata->epp_default = intel_pstate_get_epp(cpudata, 0); } #define MSR_IA32_POWER_CTL_BIT_EE 19 /* Disable energy efficiency optimization */ static void intel_pstate_disable_ee(int cpu) { u64 power_ctl; int ret; ret = rdmsrl_on_cpu(cpu, MSR_IA32_POWER_CTL, &power_ctl); if (ret) return; if (!(power_ctl & BIT(MSR_IA32_POWER_CTL_BIT_EE))) { pr_info("Disabling energy efficiency optimization\n"); power_ctl |= BIT(MSR_IA32_POWER_CTL_BIT_EE); wrmsrl_on_cpu(cpu, MSR_IA32_POWER_CTL, power_ctl); } } static int atom_get_min_pstate(void) { u64 value; rdmsrl(MSR_ATOM_CORE_RATIOS, value); return (value >> 8) & 0x7F; } static int atom_get_max_pstate(void) { u64 value; rdmsrl(MSR_ATOM_CORE_RATIOS, value); return (value >> 16) & 0x7F; } static int atom_get_turbo_pstate(void) { u64 value; rdmsrl(MSR_ATOM_CORE_TURBO_RATIOS, value); return value & 0x7F; } static u64 atom_get_val(struct cpudata *cpudata, int pstate) { u64 val; int32_t vid_fp; u32 vid; val = (u64)pstate << 8; if (global.no_turbo && !global.turbo_disabled) val |= (u64)1 << 32; vid_fp = cpudata->vid.min + mul_fp( int_tofp(pstate - cpudata->pstate.min_pstate), cpudata->vid.ratio); vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max); vid = ceiling_fp(vid_fp); if (pstate > cpudata->pstate.max_pstate) vid = cpudata->vid.turbo; return val | vid; } static int silvermont_get_scaling(void) { u64 value; int i; /* Defined in Table 35-6 from SDM (Sept 2015) */ static int silvermont_freq_table[] = { 83300, 100000, 133300, 116700, 80000}; rdmsrl(MSR_FSB_FREQ, value); i = value & 0x7; WARN_ON(i > 4); return silvermont_freq_table[i]; } static int airmont_get_scaling(void) { u64 value; int i; /* Defined in Table 35-10 from SDM (Sept 2015) */ static int airmont_freq_table[] = { 83300, 100000, 133300, 116700, 80000, 93300, 90000, 88900, 87500}; rdmsrl(MSR_FSB_FREQ, value); i = value & 0xF; WARN_ON(i > 8); return airmont_freq_table[i]; } static void atom_get_vid(struct cpudata *cpudata) { u64 value; rdmsrl(MSR_ATOM_CORE_VIDS, value); cpudata->vid.min = int_tofp((value >> 8) & 0x7f); cpudata->vid.max = int_tofp((value >> 16) & 0x7f); cpudata->vid.ratio = div_fp( cpudata->vid.max - cpudata->vid.min, int_tofp(cpudata->pstate.max_pstate - cpudata->pstate.min_pstate)); rdmsrl(MSR_ATOM_CORE_TURBO_VIDS, value); cpudata->vid.turbo = value & 0x7f; } static int core_get_min_pstate(void) { u64 value; rdmsrl(MSR_PLATFORM_INFO, value); return (value >> 40) & 0xFF; } static int core_get_max_pstate_physical(void) { u64 value; rdmsrl(MSR_PLATFORM_INFO, value); return (value >> 8) & 0xFF; } static int core_get_tdp_ratio(u64 plat_info) { /* Check how many TDP levels present */ if (plat_info & 0x600000000) { u64 tdp_ctrl; u64 tdp_ratio; int tdp_msr; int err; /* Get the TDP level (0, 1, 2) to get ratios */ err = rdmsrl_safe(MSR_CONFIG_TDP_CONTROL, &tdp_ctrl); if (err) return err; /* TDP MSR are continuous starting at 0x648 */ tdp_msr = MSR_CONFIG_TDP_NOMINAL + (tdp_ctrl & 0x03); err = rdmsrl_safe(tdp_msr, &tdp_ratio); if (err) return err; /* For level 1 and 2, bits[23:16] contain the ratio */ if (tdp_ctrl & 0x03) tdp_ratio >>= 16; tdp_ratio &= 0xff; /* ratios are only 8 bits long */ pr_debug("tdp_ratio %x\n", (int)tdp_ratio); return (int)tdp_ratio; } return -ENXIO; } static int core_get_max_pstate(void) { u64 tar; u64 plat_info; int max_pstate; int tdp_ratio; int err; rdmsrl(MSR_PLATFORM_INFO, plat_info); max_pstate = (plat_info >> 8) & 0xFF; tdp_ratio = core_get_tdp_ratio(plat_info); if (tdp_ratio <= 0) return max_pstate; if (hwp_active) { /* Turbo activation ratio is not used on HWP platforms */ return tdp_ratio; } err = rdmsrl_safe(MSR_TURBO_ACTIVATION_RATIO, &tar); if (!err) { int tar_levels; /* Do some sanity checking for safety */ tar_levels = tar & 0xff; if (tdp_ratio - 1 == tar_levels) { max_pstate = tar_levels; pr_debug("max_pstate=TAC %x\n", max_pstate); } } return max_pstate; } static int core_get_turbo_pstate(void) { u64 value; int nont, ret; rdmsrl(MSR_TURBO_RATIO_LIMIT, value); nont = core_get_max_pstate(); ret = (value) & 255; if (ret <= nont) ret = nont; return ret; } static inline int core_get_scaling(void) { return 100000; } static u64 core_get_val(struct cpudata *cpudata, int pstate) { u64 val; val = (u64)pstate << 8; if (global.no_turbo && !global.turbo_disabled) val |= (u64)1 << 32; return val; } static int knl_get_aperf_mperf_shift(void) { return 10; } static int knl_get_turbo_pstate(void) { u64 value; int nont, ret; rdmsrl(MSR_TURBO_RATIO_LIMIT, value); nont = core_get_max_pstate(); ret = (((value) >> 8) & 0xFF); if (ret <= nont) ret = nont; return ret; } static int intel_pstate_get_base_pstate(struct cpudata *cpu) { return global.no_turbo || global.turbo_disabled ? cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; } static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate) { trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu); cpu->pstate.current_pstate = pstate; /* * Generally, there is no guarantee that this code will always run on * the CPU being updated, so force the register update to run on the * right CPU. */ wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate)); } static void intel_pstate_set_min_pstate(struct cpudata *cpu) { intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate); } static void intel_pstate_max_within_limits(struct cpudata *cpu) { int pstate; update_turbo_state(); pstate = intel_pstate_get_base_pstate(cpu); pstate = max(cpu->pstate.min_pstate, cpu->max_perf_ratio); intel_pstate_set_pstate(cpu, pstate); } static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) { cpu->pstate.min_pstate = pstate_funcs.get_min(); cpu->pstate.max_pstate = pstate_funcs.get_max(); cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical(); cpu->pstate.turbo_pstate = pstate_funcs.get_turbo(); cpu->pstate.scaling = pstate_funcs.get_scaling(); cpu->pstate.max_freq = cpu->pstate.max_pstate * cpu->pstate.scaling; if (hwp_active && !hwp_mode_bdw) { unsigned int phy_max, current_max; intel_pstate_get_hwp_max(cpu->cpu, &phy_max, ¤t_max); cpu->pstate.turbo_freq = phy_max * cpu->pstate.scaling; } else { cpu->pstate.turbo_freq = cpu->pstate.turbo_pstate * cpu->pstate.scaling; } if (pstate_funcs.get_aperf_mperf_shift) cpu->aperf_mperf_shift = pstate_funcs.get_aperf_mperf_shift(); if (pstate_funcs.get_vid) pstate_funcs.get_vid(cpu); intel_pstate_set_min_pstate(cpu); } /* * Long hold time will keep high perf limits for long time, * which negatively impacts perf/watt for some workloads, * like specpower. 3ms is based on experiements on some * workoads. */ static int hwp_boost_hold_time_ns = 3 * NSEC_PER_MSEC; static inline void intel_pstate_hwp_boost_up(struct cpudata *cpu) { u64 hwp_req = READ_ONCE(cpu->hwp_req_cached); u32 max_limit = (hwp_req & 0xff00) >> 8; u32 min_limit = (hwp_req & 0xff); u32 boost_level1; /* * Cases to consider (User changes via sysfs or boot time): * If, P0 (Turbo max) = P1 (Guaranteed max) = min: * No boost, return. * If, P0 (Turbo max) > P1 (Guaranteed max) = min: * Should result in one level boost only for P0. * If, P0 (Turbo max) = P1 (Guaranteed max) > min: * Should result in two level boost: * (min + p1)/2 and P1. * If, P0 (Turbo max) > P1 (Guaranteed max) > min: * Should result in three level boost: * (min + p1)/2, P1 and P0. */ /* If max and min are equal or already at max, nothing to boost */ if (max_limit == min_limit || cpu->hwp_boost_min >= max_limit) return; if (!cpu->hwp_boost_min) cpu->hwp_boost_min = min_limit; /* level at half way mark between min and guranteed */ boost_level1 = (HWP_GUARANTEED_PERF(cpu->hwp_cap_cached) + min_limit) >> 1; if (cpu->hwp_boost_min < boost_level1) cpu->hwp_boost_min = boost_level1; else if (cpu->hwp_boost_min < HWP_GUARANTEED_PERF(cpu->hwp_cap_cached)) cpu->hwp_boost_min = HWP_GUARANTEED_PERF(cpu->hwp_cap_cached); else if (cpu->hwp_boost_min == HWP_GUARANTEED_PERF(cpu->hwp_cap_cached) && max_limit != HWP_GUARANTEED_PERF(cpu->hwp_cap_cached)) cpu->hwp_boost_min = max_limit; else return; hwp_req = (hwp_req & ~GENMASK_ULL(7, 0)) | cpu->hwp_boost_min; wrmsrl(MSR_HWP_REQUEST, hwp_req); cpu->last_update = cpu->sample.time; } static inline void intel_pstate_hwp_boost_down(struct cpudata *cpu) { if (cpu->hwp_boost_min) { bool expired; /* Check if we are idle for hold time to boost down */ expired = time_after64(cpu->sample.time, cpu->last_update + hwp_boost_hold_time_ns); if (expired) { wrmsrl(MSR_HWP_REQUEST, cpu->hwp_req_cached); cpu->hwp_boost_min = 0; } } cpu->last_update = cpu->sample.time; } static inline void intel_pstate_update_util_hwp_local(struct cpudata *cpu, u64 time) { cpu->sample.time = time; if (cpu->sched_flags & SCHED_CPUFREQ_IOWAIT) { bool do_io = false; cpu->sched_flags = 0; /* * Set iowait_boost flag and update time. Since IO WAIT flag * is set all the time, we can't just conclude that there is * some IO bound activity is scheduled on this CPU with just * one occurrence. If we receive at least two in two * consecutive ticks, then we treat as boost candidate. */ if (time_before64(time, cpu->last_io_update + 2 * TICK_NSEC)) do_io = true; cpu->last_io_update = time; if (do_io) intel_pstate_hwp_boost_up(cpu); } else { intel_pstate_hwp_boost_down(cpu); } } static inline void intel_pstate_update_util_hwp(struct update_util_data *data, u64 time, unsigned int flags) { struct cpudata *cpu = container_of(data, struct cpudata, update_util); cpu->sched_flags |= flags; if (smp_processor_id() == cpu->cpu) intel_pstate_update_util_hwp_local(cpu, time); } static inline void intel_pstate_calc_avg_perf(struct cpudata *cpu) { struct sample *sample = &cpu->sample; sample->core_avg_perf = div_ext_fp(sample->aperf, sample->mperf); } static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time) { u64 aperf, mperf; unsigned long flags; u64 tsc; local_irq_save(flags); rdmsrl(MSR_IA32_APERF, aperf); rdmsrl(MSR_IA32_MPERF, mperf); tsc = rdtsc(); if (cpu->prev_mperf == mperf || cpu->prev_tsc == tsc) { local_irq_restore(flags); return false; } local_irq_restore(flags); cpu->last_sample_time = cpu->sample.time; cpu->sample.time = time; cpu->sample.aperf = aperf; cpu->sample.mperf = mperf; cpu->sample.tsc = tsc; cpu->sample.aperf -= cpu->prev_aperf; cpu->sample.mperf -= cpu->prev_mperf; cpu->sample.tsc -= cpu->prev_tsc; cpu->prev_aperf = aperf; cpu->prev_mperf = mperf; cpu->prev_tsc = tsc; /* * First time this function is invoked in a given cycle, all of the * previous sample data fields are equal to zero or stale and they must * be populated with meaningful numbers for things to work, so assume * that sample.time will always be reset before setting the utilization * update hook and make the caller skip the sample then. */ if (cpu->last_sample_time) { intel_pstate_calc_avg_perf(cpu); return true; } return false; } static inline int32_t get_avg_frequency(struct cpudata *cpu) { return mul_ext_fp(cpu->sample.core_avg_perf, cpu_khz); } static inline int32_t get_avg_pstate(struct cpudata *cpu) { return mul_ext_fp(cpu->pstate.max_pstate_physical, cpu->sample.core_avg_perf); } static inline int32_t get_target_pstate(struct cpudata *cpu) { struct sample *sample = &cpu->sample; int32_t busy_frac, boost; int target, avg_pstate; busy_frac = div_fp(sample->mperf << cpu->aperf_mperf_shift, sample->tsc); boost = cpu->iowait_boost; cpu->iowait_boost >>= 1; if (busy_frac < boost) busy_frac = boost; sample->busy_scaled = busy_frac * 100; target = global.no_turbo || global.turbo_disabled ? cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; target += target >> 2; target = mul_fp(target, busy_frac); if (target < cpu->pstate.min_pstate) target = cpu->pstate.min_pstate; /* * If the average P-state during the previous cycle was higher than the * current target, add 50% of the difference to the target to reduce * possible performance oscillations and offset possible performance * loss related to moving the workload from one CPU to another within * a package/module. */ avg_pstate = get_avg_pstate(cpu); if (avg_pstate > target) target += (avg_pstate - target) >> 1; return target; } static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate) { int max_pstate = intel_pstate_get_base_pstate(cpu); int min_pstate; min_pstate = max(cpu->pstate.min_pstate, cpu->min_perf_ratio); max_pstate = max(min_pstate, cpu->max_perf_ratio); return clamp_t(int, pstate, min_pstate, max_pstate); } static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate) { if (pstate == cpu->pstate.current_pstate) return; cpu->pstate.current_pstate = pstate; wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate)); } static void intel_pstate_adjust_pstate(struct cpudata *cpu) { int from = cpu->pstate.current_pstate; struct sample *sample; int target_pstate; update_turbo_state(); target_pstate = get_target_pstate(cpu); target_pstate = intel_pstate_prepare_request(cpu, target_pstate); trace_cpu_frequency(target_pstate * cpu->pstate.scaling, cpu->cpu); intel_pstate_update_pstate(cpu, target_pstate); sample = &cpu->sample; trace_pstate_sample(mul_ext_fp(100, sample->core_avg_perf), fp_toint(sample->busy_scaled), from, cpu->pstate.current_pstate, sample->mperf, sample->aperf, sample->tsc, get_avg_frequency(cpu), fp_toint(cpu->iowait_boost * 100)); } static void intel_pstate_update_util(struct update_util_data *data, u64 time, unsigned int flags) { struct cpudata *cpu = container_of(data, struct cpudata, update_util); u64 delta_ns; /* Don't allow remote callbacks */ if (smp_processor_id() != cpu->cpu) return; if (flags & SCHED_CPUFREQ_IOWAIT) { cpu->iowait_boost = int_tofp(1); cpu->last_update = time; /* * The last time the busy was 100% so P-state was max anyway * so avoid overhead of computation. */ if (fp_toint(cpu->sample.busy_scaled) == 100) return; goto set_pstate; } else if (cpu->iowait_boost) { /* Clear iowait_boost if the CPU may have been idle. */ delta_ns = time - cpu->last_update; if (delta_ns > TICK_NSEC) cpu->iowait_boost = 0; } cpu->last_update = time; delta_ns = time - cpu->sample.time; if ((s64)delta_ns < INTEL_PSTATE_SAMPLING_INTERVAL) return; set_pstate: if (intel_pstate_sample(cpu, time)) intel_pstate_adjust_pstate(cpu); } static struct pstate_funcs core_funcs = { .get_max = core_get_max_pstate, .get_max_physical = core_get_max_pstate_physical, .get_min = core_get_min_pstate, .get_turbo = core_get_turbo_pstate, .get_scaling = core_get_scaling, .get_val = core_get_val, }; static const struct pstate_funcs silvermont_funcs = { .get_max = atom_get_max_pstate, .get_max_physical = atom_get_max_pstate, .get_min = atom_get_min_pstate, .get_turbo = atom_get_turbo_pstate, .get_val = atom_get_val, .get_scaling = silvermont_get_scaling, .get_vid = atom_get_vid, }; static const struct pstate_funcs airmont_funcs = { .get_max = atom_get_max_pstate, .get_max_physical = atom_get_max_pstate, .get_min = atom_get_min_pstate, .get_turbo = atom_get_turbo_pstate, .get_val = atom_get_val, .get_scaling = airmont_get_scaling, .get_vid = atom_get_vid, }; static const struct pstate_funcs knl_funcs = { .get_max = core_get_max_pstate, .get_max_physical = core_get_max_pstate_physical, .get_min = core_get_min_pstate, .get_turbo = knl_get_turbo_pstate, .get_aperf_mperf_shift = knl_get_aperf_mperf_shift, .get_scaling = core_get_scaling, .get_val = core_get_val, }; #define ICPU(model, policy) \ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\ (unsigned long)&policy } static const struct x86_cpu_id intel_pstate_cpu_ids[] = { ICPU(INTEL_FAM6_SANDYBRIDGE, core_funcs), ICPU(INTEL_FAM6_SANDYBRIDGE_X, core_funcs), ICPU(INTEL_FAM6_ATOM_SILVERMONT, silvermont_funcs), ICPU(INTEL_FAM6_IVYBRIDGE, core_funcs), ICPU(INTEL_FAM6_HASWELL_CORE, core_funcs), ICPU(INTEL_FAM6_BROADWELL_CORE, core_funcs), ICPU(INTEL_FAM6_IVYBRIDGE_X, core_funcs), ICPU(INTEL_FAM6_HASWELL_X, core_funcs), ICPU(INTEL_FAM6_HASWELL_ULT, core_funcs), ICPU(INTEL_FAM6_HASWELL_GT3E, core_funcs), ICPU(INTEL_FAM6_BROADWELL_GT3E, core_funcs), ICPU(INTEL_FAM6_ATOM_AIRMONT, airmont_funcs), ICPU(INTEL_FAM6_SKYLAKE_MOBILE, core_funcs), ICPU(INTEL_FAM6_BROADWELL_X, core_funcs), ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, core_funcs), ICPU(INTEL_FAM6_BROADWELL_XEON_D, core_funcs), ICPU(INTEL_FAM6_XEON_PHI_KNL, knl_funcs), ICPU(INTEL_FAM6_XEON_PHI_KNM, knl_funcs), ICPU(INTEL_FAM6_ATOM_GOLDMONT, core_funcs), ICPU(INTEL_FAM6_ATOM_GOLDMONT_PLUS, core_funcs), ICPU(INTEL_FAM6_SKYLAKE_X, core_funcs), {} }; MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids); static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] __initconst = { ICPU(INTEL_FAM6_BROADWELL_XEON_D, core_funcs), ICPU(INTEL_FAM6_BROADWELL_X, core_funcs), ICPU(INTEL_FAM6_SKYLAKE_X, core_funcs), {} }; static const struct x86_cpu_id intel_pstate_cpu_ee_disable_ids[] = { ICPU(INTEL_FAM6_KABYLAKE_DESKTOP, core_funcs), {} }; static const struct x86_cpu_id intel_pstate_hwp_boost_ids[] = { ICPU(INTEL_FAM6_SKYLAKE_X, core_funcs), ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, core_funcs), {} }; static int intel_pstate_init_cpu(unsigned int cpunum) { struct cpudata *cpu; cpu = all_cpu_data[cpunum]; if (!cpu) { cpu = kzalloc(sizeof(*cpu), GFP_KERNEL); if (!cpu) return -ENOMEM; all_cpu_data[cpunum] = cpu; cpu->epp_default = -EINVAL; cpu->epp_powersave = -EINVAL; cpu->epp_saved = -EINVAL; } cpu = all_cpu_data[cpunum]; cpu->cpu = cpunum; if (hwp_active) { const struct x86_cpu_id *id; id = x86_match_cpu(intel_pstate_cpu_ee_disable_ids); if (id) intel_pstate_disable_ee(cpunum); intel_pstate_hwp_enable(cpu); id = x86_match_cpu(intel_pstate_hwp_boost_ids); if (id && intel_pstate_acpi_pm_profile_server()) hwp_boost = true; } intel_pstate_get_cpu_pstates(cpu); pr_debug("controlling: cpu %d\n", cpunum); return 0; } static void intel_pstate_set_update_util_hook(unsigned int cpu_num) { struct cpudata *cpu = all_cpu_data[cpu_num]; if (hwp_active && !hwp_boost) return; if (cpu->update_util_set) return; /* Prevent intel_pstate_update_util() from using stale data. */ cpu->sample.time = 0; cpufreq_add_update_util_hook(cpu_num, &cpu->update_util, (hwp_active ? intel_pstate_update_util_hwp : intel_pstate_update_util)); cpu->update_util_set = true; } static void intel_pstate_clear_update_util_hook(unsigned int cpu) { struct cpudata *cpu_data = all_cpu_data[cpu]; if (!cpu_data->update_util_set) return; cpufreq_remove_update_util_hook(cpu); cpu_data->update_util_set = false; synchronize_sched(); } static int intel_pstate_get_max_freq(struct cpudata *cpu) { return global.turbo_disabled || global.no_turbo ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; } static void intel_pstate_update_perf_limits(struct cpufreq_policy *policy, struct cpudata *cpu) { int max_freq = intel_pstate_get_max_freq(cpu); int32_t max_policy_perf, min_policy_perf; int max_state, turbo_max; /* * HWP needs some special consideration, because on BDX the * HWP_REQUEST uses abstract value to represent performance * rather than pure ratios. */ if (hwp_active) { intel_pstate_get_hwp_max(cpu->cpu, &turbo_max, &max_state); } else { max_state = intel_pstate_get_base_pstate(cpu); turbo_max = cpu->pstate.turbo_pstate; } max_policy_perf = max_state * policy->max / max_freq; if (policy->max == policy->min) { min_policy_perf = max_policy_perf; } else { min_policy_perf = max_state * policy->min / max_freq; min_policy_perf = clamp_t(int32_t, min_policy_perf, 0, max_policy_perf); } pr_debug("cpu:%d max_state %d min_policy_perf:%d max_policy_perf:%d\n", policy->cpu, max_state, min_policy_perf, max_policy_perf); /* Normalize user input to [min_perf, max_perf] */ if (per_cpu_limits) { cpu->min_perf_ratio = min_policy_perf; cpu->max_perf_ratio = max_policy_perf; } else { int32_t global_min, global_max; /* Global limits are in percent of the maximum turbo P-state. */ global_max = DIV_ROUND_UP(turbo_max * global.max_perf_pct, 100); global_min = DIV_ROUND_UP(turbo_max * global.min_perf_pct, 100); global_min = clamp_t(int32_t, global_min, 0, global_max); pr_debug("cpu:%d global_min:%d global_max:%d\n", policy->cpu, global_min, global_max); cpu->min_perf_ratio = max(min_policy_perf, global_min); cpu->min_perf_ratio = min(cpu->min_perf_ratio, max_policy_perf); cpu->max_perf_ratio = min(max_policy_perf, global_max); cpu->max_perf_ratio = max(min_policy_perf, cpu->max_perf_ratio); /* Make sure min_perf <= max_perf */ cpu->min_perf_ratio = min(cpu->min_perf_ratio, cpu->max_perf_ratio); } pr_debug("cpu:%d max_perf_ratio:%d min_perf_ratio:%d\n", policy->cpu, cpu->max_perf_ratio, cpu->min_perf_ratio); } static int intel_pstate_set_policy(struct cpufreq_policy *policy) { struct cpudata *cpu; if (!policy->cpuinfo.max_freq) return -ENODEV; pr_debug("set_policy cpuinfo.max %u policy->max %u\n", policy->cpuinfo.max_freq, policy->max); cpu = all_cpu_data[policy->cpu]; cpu->policy = policy->policy; mutex_lock(&intel_pstate_limits_lock); intel_pstate_update_perf_limits(policy, cpu); if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) { /* * NOHZ_FULL CPUs need this as the governor callback may not * be invoked on them. */ intel_pstate_clear_update_util_hook(policy->cpu); intel_pstate_max_within_limits(cpu); } else { intel_pstate_set_update_util_hook(policy->cpu); } if (hwp_active) { /* * When hwp_boost was active before and dynamically it * was turned off, in that case we need to clear the * update util hook. */ if (!hwp_boost) intel_pstate_clear_update_util_hook(policy->cpu); intel_pstate_hwp_set(policy->cpu); } mutex_unlock(&intel_pstate_limits_lock); return 0; } static void intel_pstate_adjust_policy_max(struct cpufreq_policy *policy, struct cpudata *cpu) { if (!hwp_active && cpu->pstate.max_pstate_physical > cpu->pstate.max_pstate && policy->max < policy->cpuinfo.max_freq && policy->max > cpu->pstate.max_freq) { pr_debug("policy->max > max non turbo frequency\n"); policy->max = policy->cpuinfo.max_freq; } } static int intel_pstate_verify_policy(struct cpufreq_policy *policy) { struct cpudata *cpu = all_cpu_data[policy->cpu]; update_turbo_state(); cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, intel_pstate_get_max_freq(cpu)); if (policy->policy != CPUFREQ_POLICY_POWERSAVE && policy->policy != CPUFREQ_POLICY_PERFORMANCE) return -EINVAL; intel_pstate_adjust_policy_max(policy, cpu); return 0; } static void intel_cpufreq_stop_cpu(struct cpufreq_policy *policy) { intel_pstate_set_min_pstate(all_cpu_data[policy->cpu]); } static void intel_pstate_stop_cpu(struct cpufreq_policy *policy) { pr_debug("CPU %d exiting\n", policy->cpu); intel_pstate_clear_update_util_hook(policy->cpu); if (hwp_active) intel_pstate_hwp_save_state(policy); else intel_cpufreq_stop_cpu(policy); } static int intel_pstate_cpu_exit(struct cpufreq_policy *policy) { intel_pstate_exit_perf_limits(policy); policy->fast_switch_possible = false; return 0; } static int __intel_pstate_cpu_init(struct cpufreq_policy *policy) { struct cpudata *cpu; int rc; rc = intel_pstate_init_cpu(policy->cpu); if (rc) return rc; cpu = all_cpu_data[policy->cpu]; cpu->max_perf_ratio = 0xFF; cpu->min_perf_ratio = 0; policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling; policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling; /* cpuinfo and default policy values */ policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling; update_turbo_state(); policy->cpuinfo.max_freq = global.turbo_disabled ? cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; policy->cpuinfo.max_freq *= cpu->pstate.scaling; if (hwp_active) { unsigned int max_freq; max_freq = global.turbo_disabled ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; if (max_freq < policy->cpuinfo.max_freq) policy->cpuinfo.max_freq = max_freq; } intel_pstate_init_acpi_perf_limits(policy); policy->fast_switch_possible = true; return 0; } static int intel_pstate_cpu_init(struct cpufreq_policy *policy) { int ret = __intel_pstate_cpu_init(policy); if (ret) return ret; if (IS_ENABLED(CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE)) policy->policy = CPUFREQ_POLICY_PERFORMANCE; else policy->policy = CPUFREQ_POLICY_POWERSAVE; return 0; } static struct cpufreq_driver intel_pstate = { .flags = CPUFREQ_CONST_LOOPS, .verify = intel_pstate_verify_policy, .setpolicy = intel_pstate_set_policy, .suspend = intel_pstate_hwp_save_state, .resume = intel_pstate_resume, .init = intel_pstate_cpu_init, .exit = intel_pstate_cpu_exit, .stop_cpu = intel_pstate_stop_cpu, .name = "intel_pstate", }; static int intel_cpufreq_verify_policy(struct cpufreq_policy *policy) { struct cpudata *cpu = all_cpu_data[policy->cpu]; update_turbo_state(); cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, intel_pstate_get_max_freq(cpu)); intel_pstate_adjust_policy_max(policy, cpu); intel_pstate_update_perf_limits(policy, cpu); return 0; } /* Use of trace in passive mode: * * In passive mode the trace core_busy field (also known as the * performance field, and lablelled as such on the graphs; also known as * core_avg_perf) is not needed and so is re-assigned to indicate if the * driver call was via the normal or fast switch path. Various graphs * output from the intel_pstate_tracer.py utility that include core_busy * (or performance or core_avg_perf) have a fixed y-axis from 0 to 100%, * so we use 10 to indicate the the normal path through the driver, and * 90 to indicate the fast switch path through the driver. * The scaled_busy field is not used, and is set to 0. */ #define INTEL_PSTATE_TRACE_TARGET 10 #define INTEL_PSTATE_TRACE_FAST_SWITCH 90 static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, int old_pstate) { struct sample *sample; if (!trace_pstate_sample_enabled()) return; if (!intel_pstate_sample(cpu, ktime_get())) return; sample = &cpu->sample; trace_pstate_sample(trace_type, 0, old_pstate, cpu->pstate.current_pstate, sample->mperf, sample->aperf, sample->tsc, get_avg_frequency(cpu), fp_toint(cpu->iowait_boost * 100)); } static int intel_cpufreq_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { struct cpudata *cpu = all_cpu_data[policy->cpu]; struct cpufreq_freqs freqs; int target_pstate, old_pstate; update_turbo_state(); freqs.old = policy->cur; freqs.new = target_freq; cpufreq_freq_transition_begin(policy, &freqs); switch (relation) { case CPUFREQ_RELATION_L: target_pstate = DIV_ROUND_UP(freqs.new, cpu->pstate.scaling); break; case CPUFREQ_RELATION_H: target_pstate = freqs.new / cpu->pstate.scaling; break; default: target_pstate = DIV_ROUND_CLOSEST(freqs.new, cpu->pstate.scaling); break; } target_pstate = intel_pstate_prepare_request(cpu, target_pstate); old_pstate = cpu->pstate.current_pstate; if (target_pstate != cpu->pstate.current_pstate) { cpu->pstate.current_pstate = target_pstate; wrmsrl_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, target_pstate)); } freqs.new = target_pstate * cpu->pstate.scaling; intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_TARGET, old_pstate); cpufreq_freq_transition_end(policy, &freqs, false); return 0; } static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy, unsigned int target_freq) { struct cpudata *cpu = all_cpu_data[policy->cpu]; int target_pstate, old_pstate; update_turbo_state(); target_pstate = DIV_ROUND_UP(target_freq, cpu->pstate.scaling); target_pstate = intel_pstate_prepare_request(cpu, target_pstate); old_pstate = cpu->pstate.current_pstate; intel_pstate_update_pstate(cpu, target_pstate); intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate); return target_pstate * cpu->pstate.scaling; } static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy) { int ret = __intel_pstate_cpu_init(policy); if (ret) return ret; policy->cpuinfo.transition_latency = INTEL_CPUFREQ_TRANSITION_LATENCY; policy->transition_delay_us = INTEL_CPUFREQ_TRANSITION_DELAY; /* This reflects the intel_pstate_get_cpu_pstates() setting. */ policy->cur = policy->cpuinfo.min_freq; return 0; } static struct cpufreq_driver intel_cpufreq = { .flags = CPUFREQ_CONST_LOOPS, .verify = intel_cpufreq_verify_policy, .target = intel_cpufreq_target, .fast_switch = intel_cpufreq_fast_switch, .init = intel_cpufreq_cpu_init, .exit = intel_pstate_cpu_exit, .stop_cpu = intel_cpufreq_stop_cpu, .name = "intel_cpufreq", }; static struct cpufreq_driver *default_driver = &intel_pstate; static void intel_pstate_driver_cleanup(void) { unsigned int cpu; get_online_cpus(); for_each_online_cpu(cpu) { if (all_cpu_data[cpu]) { if (intel_pstate_driver == &intel_pstate) intel_pstate_clear_update_util_hook(cpu); kfree(all_cpu_data[cpu]); all_cpu_data[cpu] = NULL; } } put_online_cpus(); intel_pstate_driver = NULL; } static int intel_pstate_register_driver(struct cpufreq_driver *driver) { int ret; memset(&global, 0, sizeof(global)); global.max_perf_pct = 100; intel_pstate_driver = driver; ret = cpufreq_register_driver(intel_pstate_driver); if (ret) { intel_pstate_driver_cleanup(); return ret; } global.min_perf_pct = min_perf_pct_min(); return 0; } static int intel_pstate_unregister_driver(void) { if (hwp_active) return -EBUSY; cpufreq_unregister_driver(intel_pstate_driver); intel_pstate_driver_cleanup(); return 0; } static ssize_t intel_pstate_show_status(char *buf) { if (!intel_pstate_driver) return sprintf(buf, "off\n"); return sprintf(buf, "%s\n", intel_pstate_driver == &intel_pstate ? "active" : "passive"); } static int intel_pstate_update_status(const char *buf, size_t size) { int ret; if (size == 3 && !strncmp(buf, "off", size)) return intel_pstate_driver ? intel_pstate_unregister_driver() : -EINVAL; if (size == 6 && !strncmp(buf, "active", size)) { if (intel_pstate_driver) { if (intel_pstate_driver == &intel_pstate) return 0; ret = intel_pstate_unregister_driver(); if (ret) return ret; } return intel_pstate_register_driver(&intel_pstate); } if (size == 7 && !strncmp(buf, "passive", size)) { if (intel_pstate_driver) { if (intel_pstate_driver == &intel_cpufreq) return 0; ret = intel_pstate_unregister_driver(); if (ret) return ret; } return intel_pstate_register_driver(&intel_cpufreq); } return -EINVAL; } static int no_load __initdata; static int no_hwp __initdata; static int hwp_only __initdata; static unsigned int force_load __initdata; static int __init intel_pstate_msrs_not_valid(void) { if (!pstate_funcs.get_max() || !pstate_funcs.get_min() || !pstate_funcs.get_turbo()) return -ENODEV; return 0; } static void __init copy_cpu_funcs(struct pstate_funcs *funcs) { pstate_funcs.get_max = funcs->get_max; pstate_funcs.get_max_physical = funcs->get_max_physical; pstate_funcs.get_min = funcs->get_min; pstate_funcs.get_turbo = funcs->get_turbo; pstate_funcs.get_scaling = funcs->get_scaling; pstate_funcs.get_val = funcs->get_val; pstate_funcs.get_vid = funcs->get_vid; pstate_funcs.get_aperf_mperf_shift = funcs->get_aperf_mperf_shift; } #ifdef CONFIG_ACPI static bool __init intel_pstate_no_acpi_pss(void) { int i; for_each_possible_cpu(i) { acpi_status status; union acpi_object *pss; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; struct acpi_processor *pr = per_cpu(processors, i); if (!pr) continue; status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); if (ACPI_FAILURE(status)) continue; pss = buffer.pointer; if (pss && pss->type == ACPI_TYPE_PACKAGE) { kfree(pss); return false; } kfree(pss); } return true; } static bool __init intel_pstate_no_acpi_pcch(void) { acpi_status status; acpi_handle handle; status = acpi_get_handle(NULL, "\\_SB", &handle); if (ACPI_FAILURE(status)) return true; return !acpi_has_method(handle, "PCCH"); } static bool __init intel_pstate_has_acpi_ppc(void) { int i; for_each_possible_cpu(i) { struct acpi_processor *pr = per_cpu(processors, i); if (!pr) continue; if (acpi_has_method(pr->handle, "_PPC")) return true; } return false; } enum { PSS, PPC, }; /* Hardware vendor-specific info that has its own power management modes */ static struct acpi_platform_list plat_info[] __initdata = { {"HP ", "ProLiant", 0, ACPI_SIG_FADT, all_versions, 0, PSS}, {"ORACLE", "X4-2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4-2L ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4-2B ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X3-2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X3-2L ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X3-2B ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4470M2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4270M3 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4270M2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4170M2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4170 M3", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X4275 M3", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "X6-2 ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, {"ORACLE", "Sudbury ", 0, ACPI_SIG_FADT, all_versions, 0, PPC}, { } /* End */ }; static bool __init intel_pstate_platform_pwr_mgmt_exists(void) { const struct x86_cpu_id *id; u64 misc_pwr; int idx; id = x86_match_cpu(intel_pstate_cpu_oob_ids); if (id) { rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr); if ( misc_pwr & (1 << 8)) return true; } idx = acpi_match_platform_list(plat_info); if (idx < 0) return false; switch (plat_info[idx].data) { case PSS: if (!intel_pstate_no_acpi_pss()) return false; return intel_pstate_no_acpi_pcch(); case PPC: return intel_pstate_has_acpi_ppc() && !force_load; } return false; } static void intel_pstate_request_control_from_smm(void) { /* * It may be unsafe to request P-states control from SMM if _PPC support * has not been enabled. */ if (acpi_ppc) acpi_processor_pstate_control(); } #else /* CONFIG_ACPI not enabled */ static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; } static inline bool intel_pstate_has_acpi_ppc(void) { return false; } static inline void intel_pstate_request_control_from_smm(void) {} #endif /* CONFIG_ACPI */ #define INTEL_PSTATE_HWP_BROADWELL 0x01 #define ICPU_HWP(model, hwp_mode) \ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_HWP, hwp_mode } static const struct x86_cpu_id hwp_support_ids[] __initconst = { ICPU_HWP(INTEL_FAM6_BROADWELL_X, INTEL_PSTATE_HWP_BROADWELL), ICPU_HWP(INTEL_FAM6_BROADWELL_XEON_D, INTEL_PSTATE_HWP_BROADWELL), ICPU_HWP(X86_MODEL_ANY, 0), {} }; static int __init intel_pstate_init(void) { const struct x86_cpu_id *id; int rc; if (no_load) return -ENODEV; id = x86_match_cpu(hwp_support_ids); if (id) { copy_cpu_funcs(&core_funcs); if (!no_hwp) { hwp_active++; hwp_mode_bdw = id->driver_data; intel_pstate.attr = hwp_cpufreq_attrs; goto hwp_cpu_matched; } } else { id = x86_match_cpu(intel_pstate_cpu_ids); if (!id) return -ENODEV; copy_cpu_funcs((struct pstate_funcs *)id->driver_data); } if (intel_pstate_msrs_not_valid()) return -ENODEV; hwp_cpu_matched: /* * The Intel pstate driver will be ignored if the platform * firmware has its own power management modes. */ if (intel_pstate_platform_pwr_mgmt_exists()) return -ENODEV; if (!hwp_active && hwp_only) return -ENOTSUPP; pr_info("Intel P-state driver initializing\n"); all_cpu_data = vzalloc(array_size(sizeof(void *), num_possible_cpus())); if (!all_cpu_data) return -ENOMEM; intel_pstate_request_control_from_smm(); intel_pstate_sysfs_expose_params(); mutex_lock(&intel_pstate_driver_lock); rc = intel_pstate_register_driver(default_driver); mutex_unlock(&intel_pstate_driver_lock); if (rc) return rc; if (hwp_active) pr_info("HWP enabled\n"); return 0; } device_initcall(intel_pstate_init); static int __init intel_pstate_setup(char *str) { if (!str) return -EINVAL; if (!strcmp(str, "disable")) { no_load = 1; } else if (!strcmp(str, "passive")) { pr_info("Passive mode enabled\n"); default_driver = &intel_cpufreq; no_hwp = 1; } if (!strcmp(str, "no_hwp")) { pr_info("HWP disabled\n"); no_hwp = 1; } if (!strcmp(str, "force")) force_load = 1; if (!strcmp(str, "hwp_only")) hwp_only = 1; if (!strcmp(str, "per_cpu_perf_limits")) per_cpu_limits = true; #ifdef CONFIG_ACPI if (!strcmp(str, "support_acpi_ppc")) acpi_ppc = true; #endif return 0; } early_param("intel_pstate", intel_pstate_setup); MODULE_AUTHOR("Dirk Brandewie "); MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors"); MODULE_LICENSE("GPL");