// SPDX-License-Identifier: GPL-2.0-or-later /* * amd-pstate.c - AMD Processor P-state Frequency Driver * * Copyright (C) 2021 Advanced Micro Devices, Inc. All Rights Reserved. * * Author: Huang Rui * * AMD P-State introduces a new CPU performance scaling design for AMD * processors using the ACPI Collaborative Performance and Power Control (CPPC) * feature which works with the AMD SMU firmware providing a finer grained * frequency control range. It is to replace the legacy ACPI P-States control, * allows a flexible, low-latency interface for the Linux kernel to directly * communicate the performance hints to hardware. * * AMD P-State is supported on recent AMD Zen base CPU series include some of * Zen2 and Zen3 processors. _CPC needs to be present in the ACPI tables of AMD * P-State supported system. And there are two types of hardware implementations * for AMD P-State: 1) Full MSR Solution and 2) Shared Memory Solution. * X86_FEATURE_CPPC CPU feature flag is used to distinguish the different types. */ #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 "amd-pstate-trace.h" #define AMD_PSTATE_TRANSITION_LATENCY 20000 #define AMD_PSTATE_TRANSITION_DELAY 1000 /* * TODO: We need more time to fine tune processors with shared memory solution * with community together. * * There are some performance drops on the CPU benchmarks which reports from * Suse. We are co-working with them to fine tune the shared memory solution. So * we disable it by default to go acpi-cpufreq on these processors and add a * module parameter to be able to enable it manually for debugging. */ static struct cpufreq_driver *current_pstate_driver; static struct cpufreq_driver amd_pstate_driver; static struct cpufreq_driver amd_pstate_epp_driver; static int cppc_state = AMD_PSTATE_DISABLE; struct kobject *amd_pstate_kobj; /* * AMD Energy Preference Performance (EPP) * The EPP is used in the CCLK DPM controller to drive * the frequency that a core is going to operate during * short periods of activity. EPP values will be utilized for * different OS profiles (balanced, performance, power savings) * 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 */ enum energy_perf_value_index { EPP_INDEX_DEFAULT = 0, EPP_INDEX_PERFORMANCE, EPP_INDEX_BALANCE_PERFORMANCE, EPP_INDEX_BALANCE_POWERSAVE, EPP_INDEX_POWERSAVE, }; static const char * const energy_perf_strings[] = { [EPP_INDEX_DEFAULT] = "default", [EPP_INDEX_PERFORMANCE] = "performance", [EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance", [EPP_INDEX_BALANCE_POWERSAVE] = "balance_power", [EPP_INDEX_POWERSAVE] = "power", NULL }; static unsigned int epp_values[] = { [EPP_INDEX_DEFAULT] = 0, [EPP_INDEX_PERFORMANCE] = AMD_CPPC_EPP_PERFORMANCE, [EPP_INDEX_BALANCE_PERFORMANCE] = AMD_CPPC_EPP_BALANCE_PERFORMANCE, [EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE, [EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE, }; static inline int get_mode_idx_from_str(const char *str, size_t size) { int i; for (i=0; i < AMD_PSTATE_MAX; i++) { if (!strncmp(str, amd_pstate_mode_string[i], size)) return i; } return -EINVAL; } static DEFINE_MUTEX(amd_pstate_limits_lock); static DEFINE_MUTEX(amd_pstate_driver_lock); static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached) { u64 epp; int ret; if (boot_cpu_has(X86_FEATURE_CPPC)) { if (!cppc_req_cached) { epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &cppc_req_cached); if (epp) return epp; } epp = (cppc_req_cached >> 24) & 0xFF; } else { ret = cppc_get_epp_perf(cpudata->cpu, &epp); if (ret < 0) { pr_debug("Could not retrieve energy perf value (%d)\n", ret); return -EIO; } } return (s16)(epp & 0xff); } static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata) { s16 epp; int index = -EINVAL; epp = amd_pstate_get_epp(cpudata, 0); if (epp < 0) return epp; switch (epp) { case AMD_CPPC_EPP_PERFORMANCE: index = EPP_INDEX_PERFORMANCE; break; case AMD_CPPC_EPP_BALANCE_PERFORMANCE: index = EPP_INDEX_BALANCE_PERFORMANCE; break; case AMD_CPPC_EPP_BALANCE_POWERSAVE: index = EPP_INDEX_BALANCE_POWERSAVE; break; case AMD_CPPC_EPP_POWERSAVE: index = EPP_INDEX_POWERSAVE; break; default: break; } return index; } static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp) { int ret; struct cppc_perf_ctrls perf_ctrls; if (boot_cpu_has(X86_FEATURE_CPPC)) { u64 value = READ_ONCE(cpudata->cppc_req_cached); value &= ~GENMASK_ULL(31, 24); value |= (u64)epp << 24; WRITE_ONCE(cpudata->cppc_req_cached, value); ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); if (!ret) cpudata->epp_cached = epp; } else { perf_ctrls.energy_perf = epp; ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1); if (ret) { pr_debug("failed to set energy perf value (%d)\n", ret); return ret; } cpudata->epp_cached = epp; } return ret; } static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata, int pref_index) { int epp = -EINVAL; int ret; if (!pref_index) { pr_debug("EPP pref_index is invalid\n"); return -EINVAL; } if (epp == -EINVAL) epp = epp_values[pref_index]; if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) { pr_debug("EPP cannot be set under performance policy\n"); return -EBUSY; } ret = amd_pstate_set_epp(cpudata, epp); return ret; } static inline int pstate_enable(bool enable) { return wrmsrl_safe(MSR_AMD_CPPC_ENABLE, enable); } static int cppc_enable(bool enable) { int cpu, ret = 0; struct cppc_perf_ctrls perf_ctrls; for_each_present_cpu(cpu) { ret = cppc_set_enable(cpu, enable); if (ret) return ret; /* Enable autonomous mode for EPP */ if (cppc_state == AMD_PSTATE_ACTIVE) { /* Set desired perf as zero to allow EPP firmware control */ perf_ctrls.desired_perf = 0; ret = cppc_set_perf(cpu, &perf_ctrls); if (ret) return ret; } } return ret; } DEFINE_STATIC_CALL(amd_pstate_enable, pstate_enable); static inline int amd_pstate_enable(bool enable) { return static_call(amd_pstate_enable)(enable); } static int pstate_init_perf(struct amd_cpudata *cpudata) { u64 cap1; u32 highest_perf; int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &cap1); if (ret) return ret; /* * TODO: Introduce AMD specific power feature. * * CPPC entry doesn't indicate the highest performance in some ASICs. */ highest_perf = amd_get_highest_perf(); if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1)) highest_perf = AMD_CPPC_HIGHEST_PERF(cap1); WRITE_ONCE(cpudata->highest_perf, highest_perf); WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1)); WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1)); WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1)); return 0; } static int cppc_init_perf(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; u32 highest_perf; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; highest_perf = amd_get_highest_perf(); if (highest_perf > cppc_perf.highest_perf) highest_perf = cppc_perf.highest_perf; WRITE_ONCE(cpudata->highest_perf, highest_perf); WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf); WRITE_ONCE(cpudata->lowest_nonlinear_perf, cppc_perf.lowest_nonlinear_perf); WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf); return 0; } DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf); static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata) { return static_call(amd_pstate_init_perf)(cpudata); } static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf, u32 des_perf, u32 max_perf, bool fast_switch) { if (fast_switch) wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached)); else wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached)); } static void cppc_update_perf(struct amd_cpudata *cpudata, u32 min_perf, u32 des_perf, u32 max_perf, bool fast_switch) { struct cppc_perf_ctrls perf_ctrls; perf_ctrls.max_perf = max_perf; perf_ctrls.min_perf = min_perf; perf_ctrls.desired_perf = des_perf; cppc_set_perf(cpudata->cpu, &perf_ctrls); } DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf); static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf, u32 des_perf, u32 max_perf, bool fast_switch) { static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf, max_perf, fast_switch); } static inline bool amd_pstate_sample(struct amd_cpudata *cpudata) { u64 aperf, mperf, tsc; unsigned long flags; local_irq_save(flags); rdmsrl(MSR_IA32_APERF, aperf); rdmsrl(MSR_IA32_MPERF, mperf); tsc = rdtsc(); if (cpudata->prev.mperf == mperf || cpudata->prev.tsc == tsc) { local_irq_restore(flags); return false; } local_irq_restore(flags); cpudata->cur.aperf = aperf; cpudata->cur.mperf = mperf; cpudata->cur.tsc = tsc; cpudata->cur.aperf -= cpudata->prev.aperf; cpudata->cur.mperf -= cpudata->prev.mperf; cpudata->cur.tsc -= cpudata->prev.tsc; cpudata->prev.aperf = aperf; cpudata->prev.mperf = mperf; cpudata->prev.tsc = tsc; cpudata->freq = div64_u64((cpudata->cur.aperf * cpu_khz), cpudata->cur.mperf); return true; } static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf, u32 des_perf, u32 max_perf, bool fast_switch) { u64 prev = READ_ONCE(cpudata->cppc_req_cached); u64 value = prev; des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); value &= ~AMD_CPPC_MIN_PERF(~0L); value |= AMD_CPPC_MIN_PERF(min_perf); value &= ~AMD_CPPC_DES_PERF(~0L); value |= AMD_CPPC_DES_PERF(des_perf); value &= ~AMD_CPPC_MAX_PERF(~0L); value |= AMD_CPPC_MAX_PERF(max_perf); if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) { trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq, cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc, cpudata->cpu, (value != prev), fast_switch); } if (value == prev) return; WRITE_ONCE(cpudata->cppc_req_cached, value); amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, fast_switch); } static int amd_pstate_verify(struct cpufreq_policy_data *policy) { cpufreq_verify_within_cpu_limits(policy); return 0; } static int amd_pstate_update_freq(struct cpufreq_policy *policy, unsigned int target_freq, bool fast_switch) { struct cpufreq_freqs freqs; struct amd_cpudata *cpudata = policy->driver_data; unsigned long max_perf, min_perf, des_perf, cap_perf; if (!cpudata->max_freq) return -ENODEV; cap_perf = READ_ONCE(cpudata->highest_perf); min_perf = READ_ONCE(cpudata->lowest_perf); max_perf = cap_perf; freqs.old = policy->cur; freqs.new = target_freq; des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf, cpudata->max_freq); WARN_ON(fast_switch && !policy->fast_switch_enabled); /* * If fast_switch is desired, then there aren't any registered * transition notifiers. See comment for * cpufreq_enable_fast_switch(). */ if (!fast_switch) cpufreq_freq_transition_begin(policy, &freqs); amd_pstate_update(cpudata, min_perf, des_perf, max_perf, fast_switch); if (!fast_switch) cpufreq_freq_transition_end(policy, &freqs, false); return 0; } static int amd_pstate_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { return amd_pstate_update_freq(policy, target_freq, false); } static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy, unsigned int target_freq) { return amd_pstate_update_freq(policy, target_freq, true); } static void amd_pstate_adjust_perf(unsigned int cpu, unsigned long _min_perf, unsigned long target_perf, unsigned long capacity) { unsigned long max_perf, min_perf, des_perf, cap_perf, lowest_nonlinear_perf, max_freq; struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); struct amd_cpudata *cpudata = policy->driver_data; unsigned int target_freq; cap_perf = READ_ONCE(cpudata->highest_perf); lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf); max_freq = READ_ONCE(cpudata->max_freq); des_perf = cap_perf; if (target_perf < capacity) des_perf = DIV_ROUND_UP(cap_perf * target_perf, capacity); min_perf = READ_ONCE(cpudata->highest_perf); if (_min_perf < capacity) min_perf = DIV_ROUND_UP(cap_perf * _min_perf, capacity); if (min_perf < lowest_nonlinear_perf) min_perf = lowest_nonlinear_perf; max_perf = cap_perf; if (max_perf < min_perf) max_perf = min_perf; des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); target_freq = div_u64(des_perf * max_freq, max_perf); policy->cur = target_freq; amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); cpufreq_cpu_put(policy); } static int amd_get_min_freq(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; /* Switch to khz */ return cppc_perf.lowest_freq * 1000; } static int amd_get_max_freq(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; u32 max_perf, max_freq, nominal_freq, nominal_perf; u64 boost_ratio; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; nominal_freq = cppc_perf.nominal_freq; nominal_perf = READ_ONCE(cpudata->nominal_perf); max_perf = READ_ONCE(cpudata->highest_perf); boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT, nominal_perf); max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT; /* Switch to khz */ return max_freq * 1000; } static int amd_get_nominal_freq(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; /* Switch to khz */ return cppc_perf.nominal_freq * 1000; } static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; u32 lowest_nonlinear_freq, lowest_nonlinear_perf, nominal_freq, nominal_perf; u64 lowest_nonlinear_ratio; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; nominal_freq = cppc_perf.nominal_freq; nominal_perf = READ_ONCE(cpudata->nominal_perf); lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf; lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT, nominal_perf); lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT; /* Switch to khz */ return lowest_nonlinear_freq * 1000; } static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state) { struct amd_cpudata *cpudata = policy->driver_data; int ret; if (!cpudata->boost_supported) { pr_err("Boost mode is not supported by this processor or SBIOS\n"); return -EINVAL; } if (state) policy->cpuinfo.max_freq = cpudata->max_freq; else policy->cpuinfo.max_freq = cpudata->nominal_freq; policy->max = policy->cpuinfo.max_freq; ret = freq_qos_update_request(&cpudata->req[1], policy->cpuinfo.max_freq); if (ret < 0) return ret; return 0; } static void amd_pstate_boost_init(struct amd_cpudata *cpudata) { u32 highest_perf, nominal_perf; highest_perf = READ_ONCE(cpudata->highest_perf); nominal_perf = READ_ONCE(cpudata->nominal_perf); if (highest_perf <= nominal_perf) return; cpudata->boost_supported = true; current_pstate_driver->boost_enabled = true; } static void amd_perf_ctl_reset(unsigned int cpu) { wrmsrl_on_cpu(cpu, MSR_AMD_PERF_CTL, 0); } static int amd_pstate_cpu_init(struct cpufreq_policy *policy) { int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; struct device *dev; struct amd_cpudata *cpudata; /* * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, * which is ideal for initialization process. */ amd_perf_ctl_reset(policy->cpu); dev = get_cpu_device(policy->cpu); if (!dev) return -ENODEV; cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); if (!cpudata) return -ENOMEM; cpudata->cpu = policy->cpu; ret = amd_pstate_init_perf(cpudata); if (ret) goto free_cpudata1; min_freq = amd_get_min_freq(cpudata); max_freq = amd_get_max_freq(cpudata); nominal_freq = amd_get_nominal_freq(cpudata); lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", min_freq, max_freq); ret = -EINVAL; goto free_cpudata1; } policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY; policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY; policy->min = min_freq; policy->max = max_freq; policy->cpuinfo.min_freq = min_freq; policy->cpuinfo.max_freq = max_freq; /* It will be updated by governor */ policy->cur = policy->cpuinfo.min_freq; if (boot_cpu_has(X86_FEATURE_CPPC)) policy->fast_switch_possible = true; ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0], FREQ_QOS_MIN, policy->cpuinfo.min_freq); if (ret < 0) { dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret); goto free_cpudata1; } ret = freq_qos_add_request(&policy->constraints, &cpudata->req[1], FREQ_QOS_MAX, policy->cpuinfo.max_freq); if (ret < 0) { dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret); goto free_cpudata2; } /* Initial processor data capability frequencies */ cpudata->max_freq = max_freq; cpudata->min_freq = min_freq; cpudata->nominal_freq = nominal_freq; cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; policy->driver_data = cpudata; amd_pstate_boost_init(cpudata); if (!current_pstate_driver->adjust_perf) current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; return 0; free_cpudata2: freq_qos_remove_request(&cpudata->req[0]); free_cpudata1: kfree(cpudata); return ret; } static int amd_pstate_cpu_exit(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; freq_qos_remove_request(&cpudata->req[1]); freq_qos_remove_request(&cpudata->req[0]); policy->fast_switch_possible = false; kfree(cpudata); return 0; } static int amd_pstate_cpu_resume(struct cpufreq_policy *policy) { int ret; ret = amd_pstate_enable(true); if (ret) pr_err("failed to enable amd-pstate during resume, return %d\n", ret); return ret; } static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy) { int ret; ret = amd_pstate_enable(false); if (ret) pr_err("failed to disable amd-pstate during suspend, return %d\n", ret); return ret; } /* Sysfs attributes */ /* * This frequency is to indicate the maximum hardware frequency. * If boost is not active but supported, the frequency will be larger than the * one in cpuinfo. */ static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy, char *buf) { int max_freq; struct amd_cpudata *cpudata = policy->driver_data; max_freq = amd_get_max_freq(cpudata); if (max_freq < 0) return max_freq; return sysfs_emit(buf, "%u\n", max_freq); } static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy, char *buf) { int freq; struct amd_cpudata *cpudata = policy->driver_data; freq = amd_get_lowest_nonlinear_freq(cpudata); if (freq < 0) return freq; return sysfs_emit(buf, "%u\n", freq); } /* * In some of ASICs, the highest_perf is not the one in the _CPC table, so we * need to expose it to sysfs. */ static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy, char *buf) { u32 perf; struct amd_cpudata *cpudata = policy->driver_data; perf = READ_ONCE(cpudata->highest_perf); return sysfs_emit(buf, "%u\n", perf); } static ssize_t show_energy_performance_available_preferences( struct cpufreq_policy *policy, char *buf) { int i = 0; int offset = 0; while (energy_perf_strings[i] != NULL) offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]); sysfs_emit_at(buf, offset, "\n"); return offset; } static ssize_t store_energy_performance_preference( struct cpufreq_policy *policy, const char *buf, size_t count) { struct amd_cpudata *cpudata = policy->driver_data; char str_preference[21]; ssize_t 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 -EINVAL; mutex_lock(&amd_pstate_limits_lock); ret = amd_pstate_set_energy_pref_index(cpudata, ret); mutex_unlock(&amd_pstate_limits_lock); return ret ?: count; } static ssize_t show_energy_performance_preference( struct cpufreq_policy *policy, char *buf) { struct amd_cpudata *cpudata = policy->driver_data; int preference; preference = amd_pstate_get_energy_pref_index(cpudata); if (preference < 0) return preference; return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); } static ssize_t amd_pstate_show_status(char *buf) { if (!current_pstate_driver) return sysfs_emit(buf, "disable\n"); return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]); } static void amd_pstate_driver_cleanup(void) { current_pstate_driver = NULL; } static int amd_pstate_update_status(const char *buf, size_t size) { int ret = 0; int mode_idx; if (size > 7 || size < 6) return -EINVAL; mode_idx = get_mode_idx_from_str(buf, size); switch(mode_idx) { case AMD_PSTATE_DISABLE: if (current_pstate_driver) { cpufreq_unregister_driver(current_pstate_driver); amd_pstate_driver_cleanup(); } break; case AMD_PSTATE_PASSIVE: if (current_pstate_driver) { if (current_pstate_driver == &amd_pstate_driver) return 0; cpufreq_unregister_driver(current_pstate_driver); } current_pstate_driver = &amd_pstate_driver; cppc_state = AMD_PSTATE_PASSIVE; ret = cpufreq_register_driver(current_pstate_driver); break; case AMD_PSTATE_ACTIVE: if (current_pstate_driver) { if (current_pstate_driver == &amd_pstate_epp_driver) return 0; cpufreq_unregister_driver(current_pstate_driver); } current_pstate_driver = &amd_pstate_epp_driver; cppc_state = AMD_PSTATE_ACTIVE; ret = cpufreq_register_driver(current_pstate_driver); break; default: ret = -EINVAL; break; } return ret; } static ssize_t show_status(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { ssize_t ret; mutex_lock(&amd_pstate_driver_lock); ret = amd_pstate_show_status(buf); mutex_unlock(&amd_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(&amd_pstate_driver_lock); ret = amd_pstate_update_status(buf, p ? p - buf : count); mutex_unlock(&amd_pstate_driver_lock); return ret < 0 ? ret : count; } cpufreq_freq_attr_ro(amd_pstate_max_freq); cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq); cpufreq_freq_attr_ro(amd_pstate_highest_perf); cpufreq_freq_attr_rw(energy_performance_preference); cpufreq_freq_attr_ro(energy_performance_available_preferences); define_one_global_rw(status); static struct freq_attr *amd_pstate_attr[] = { &amd_pstate_max_freq, &amd_pstate_lowest_nonlinear_freq, &amd_pstate_highest_perf, NULL, }; static struct freq_attr *amd_pstate_epp_attr[] = { &amd_pstate_max_freq, &amd_pstate_lowest_nonlinear_freq, &amd_pstate_highest_perf, &energy_performance_preference, &energy_performance_available_preferences, NULL, }; static struct attribute *pstate_global_attributes[] = { &status.attr, NULL }; static const struct attribute_group amd_pstate_global_attr_group = { .attrs = pstate_global_attributes, }; static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) { int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; struct amd_cpudata *cpudata; struct device *dev; u64 value; /* * Resetting PERF_CTL_MSR will put the CPU in P0 frequency, * which is ideal for initialization process. */ amd_perf_ctl_reset(policy->cpu); dev = get_cpu_device(policy->cpu); if (!dev) return -ENODEV; cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); if (!cpudata) return -ENOMEM; cpudata->cpu = policy->cpu; cpudata->epp_policy = 0; ret = amd_pstate_init_perf(cpudata); if (ret) goto free_cpudata1; min_freq = amd_get_min_freq(cpudata); max_freq = amd_get_max_freq(cpudata); nominal_freq = amd_get_nominal_freq(cpudata); lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata); if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) { dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n", min_freq, max_freq); ret = -EINVAL; goto free_cpudata1; } policy->cpuinfo.min_freq = min_freq; policy->cpuinfo.max_freq = max_freq; /* It will be updated by governor */ policy->cur = policy->cpuinfo.min_freq; /* Initial processor data capability frequencies */ cpudata->max_freq = max_freq; cpudata->min_freq = min_freq; cpudata->nominal_freq = nominal_freq; cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq; policy->driver_data = cpudata; cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0); policy->min = policy->cpuinfo.min_freq; policy->max = policy->cpuinfo.max_freq; /* * Set the policy to powersave to provide a valid fallback value in case * the default cpufreq governor is neither powersave nor performance. */ policy->policy = CPUFREQ_POLICY_POWERSAVE; if (boot_cpu_has(X86_FEATURE_CPPC)) { ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value); if (ret) return ret; WRITE_ONCE(cpudata->cppc_req_cached, value); ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value); if (ret) return ret; WRITE_ONCE(cpudata->cppc_cap1_cached, value); } amd_pstate_boost_init(cpudata); return 0; free_cpudata1: kfree(cpudata); return ret; } static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy) { pr_debug("CPU %d exiting\n", policy->cpu); return 0; } static void amd_pstate_epp_init(unsigned int cpu) { struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); struct amd_cpudata *cpudata = policy->driver_data; u32 max_perf, min_perf; u64 value; s16 epp; max_perf = READ_ONCE(cpudata->highest_perf); min_perf = READ_ONCE(cpudata->lowest_perf); value = READ_ONCE(cpudata->cppc_req_cached); if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) min_perf = max_perf; /* Initial min/max values for CPPC Performance Controls Register */ value &= ~AMD_CPPC_MIN_PERF(~0L); value |= AMD_CPPC_MIN_PERF(min_perf); value &= ~AMD_CPPC_MAX_PERF(~0L); value |= AMD_CPPC_MAX_PERF(max_perf); /* CPPC EPP feature require to set zero to the desire perf bit */ value &= ~AMD_CPPC_DES_PERF(~0L); value |= AMD_CPPC_DES_PERF(0); if (cpudata->epp_policy == cpudata->policy) goto skip_epp; cpudata->epp_policy = cpudata->policy; /* Get BIOS pre-defined epp value */ epp = amd_pstate_get_epp(cpudata, value); if (epp < 0) { /** * This return value can only be negative for shared_memory * systems where EPP register read/write not supported. */ goto skip_epp; } if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) epp = 0; /* Set initial EPP value */ if (boot_cpu_has(X86_FEATURE_CPPC)) { value &= ~GENMASK_ULL(31, 24); value |= (u64)epp << 24; } WRITE_ONCE(cpudata->cppc_req_cached, value); amd_pstate_set_epp(cpudata, epp); skip_epp: cpufreq_cpu_put(policy); } static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; if (!policy->cpuinfo.max_freq) return -ENODEV; pr_debug("set_policy: cpuinfo.max %u policy->max %u\n", policy->cpuinfo.max_freq, policy->max); cpudata->policy = policy->policy; amd_pstate_epp_init(policy->cpu); return 0; } static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata) { struct cppc_perf_ctrls perf_ctrls; u64 value, max_perf; int ret; ret = amd_pstate_enable(true); if (ret) pr_err("failed to enable amd pstate during resume, return %d\n", ret); value = READ_ONCE(cpudata->cppc_req_cached); max_perf = READ_ONCE(cpudata->highest_perf); if (boot_cpu_has(X86_FEATURE_CPPC)) { wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); } else { perf_ctrls.max_perf = max_perf; perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(cpudata->epp_cached); cppc_set_perf(cpudata->cpu, &perf_ctrls); } } static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; pr_debug("AMD CPU Core %d going online\n", cpudata->cpu); if (cppc_state == AMD_PSTATE_ACTIVE) { amd_pstate_epp_reenable(cpudata); cpudata->suspended = false; } return 0; } static void amd_pstate_epp_offline(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; struct cppc_perf_ctrls perf_ctrls; int min_perf; u64 value; min_perf = READ_ONCE(cpudata->lowest_perf); value = READ_ONCE(cpudata->cppc_req_cached); mutex_lock(&amd_pstate_limits_lock); if (boot_cpu_has(X86_FEATURE_CPPC)) { cpudata->epp_policy = CPUFREQ_POLICY_UNKNOWN; /* Set max perf same as min perf */ value &= ~AMD_CPPC_MAX_PERF(~0L); value |= AMD_CPPC_MAX_PERF(min_perf); value &= ~AMD_CPPC_MIN_PERF(~0L); value |= AMD_CPPC_MIN_PERF(min_perf); wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value); } else { perf_ctrls.desired_perf = 0; perf_ctrls.max_perf = min_perf; perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(HWP_EPP_BALANCE_POWERSAVE); cppc_set_perf(cpudata->cpu, &perf_ctrls); } mutex_unlock(&amd_pstate_limits_lock); } static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; pr_debug("AMD CPU Core %d going offline\n", cpudata->cpu); if (cpudata->suspended) return 0; if (cppc_state == AMD_PSTATE_ACTIVE) amd_pstate_epp_offline(policy); return 0; } static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy) { cpufreq_verify_within_cpu_limits(policy); pr_debug("policy_max =%d, policy_min=%d\n", policy->max, policy->min); return 0; } static int amd_pstate_epp_suspend(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; int ret; /* avoid suspending when EPP is not enabled */ if (cppc_state != AMD_PSTATE_ACTIVE) return 0; /* set this flag to avoid setting core offline*/ cpudata->suspended = true; /* disable CPPC in lowlevel firmware */ ret = amd_pstate_enable(false); if (ret) pr_err("failed to suspend, return %d\n", ret); return 0; } static int amd_pstate_epp_resume(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; if (cpudata->suspended) { mutex_lock(&amd_pstate_limits_lock); /* enable amd pstate from suspend state*/ amd_pstate_epp_reenable(cpudata); mutex_unlock(&amd_pstate_limits_lock); cpudata->suspended = false; } return 0; } static struct cpufreq_driver amd_pstate_driver = { .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify = amd_pstate_verify, .target = amd_pstate_target, .fast_switch = amd_pstate_fast_switch, .init = amd_pstate_cpu_init, .exit = amd_pstate_cpu_exit, .suspend = amd_pstate_cpu_suspend, .resume = amd_pstate_cpu_resume, .set_boost = amd_pstate_set_boost, .name = "amd-pstate", .attr = amd_pstate_attr, }; static struct cpufreq_driver amd_pstate_epp_driver = { .flags = CPUFREQ_CONST_LOOPS, .verify = amd_pstate_epp_verify_policy, .setpolicy = amd_pstate_epp_set_policy, .init = amd_pstate_epp_cpu_init, .exit = amd_pstate_epp_cpu_exit, .offline = amd_pstate_epp_cpu_offline, .online = amd_pstate_epp_cpu_online, .suspend = amd_pstate_epp_suspend, .resume = amd_pstate_epp_resume, .name = "amd_pstate_epp", .attr = amd_pstate_epp_attr, }; static int __init amd_pstate_init(void) { int ret; if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) return -ENODEV; /* * by default the pstate driver is disabled to load * enable the amd_pstate passive mode driver explicitly * with amd_pstate=passive or other modes in kernel command line */ if (cppc_state == AMD_PSTATE_DISABLE) { pr_info("driver load is disabled, boot with specific mode to enable this\n"); return -ENODEV; } if (!acpi_cpc_valid()) { pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n"); return -ENODEV; } /* don't keep reloading if cpufreq_driver exists */ if (cpufreq_get_current_driver()) return -EEXIST; /* capability check */ if (boot_cpu_has(X86_FEATURE_CPPC)) { pr_debug("AMD CPPC MSR based functionality is supported\n"); if (cppc_state == AMD_PSTATE_PASSIVE) current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; } else { pr_debug("AMD CPPC shared memory based functionality is supported\n"); static_call_update(amd_pstate_enable, cppc_enable); static_call_update(amd_pstate_init_perf, cppc_init_perf); static_call_update(amd_pstate_update_perf, cppc_update_perf); } /* enable amd pstate feature */ ret = amd_pstate_enable(true); if (ret) { pr_err("failed to enable with return %d\n", ret); return ret; } ret = cpufreq_register_driver(current_pstate_driver); if (ret) pr_err("failed to register with return %d\n", ret); amd_pstate_kobj = kobject_create_and_add("amd_pstate", &cpu_subsys.dev_root->kobj); if (!amd_pstate_kobj) { ret = -EINVAL; pr_err("global sysfs registration failed.\n"); goto kobject_free; } ret = sysfs_create_group(amd_pstate_kobj, &amd_pstate_global_attr_group); if (ret) { pr_err("sysfs attribute export failed with error %d.\n", ret); goto global_attr_free; } return ret; global_attr_free: kobject_put(amd_pstate_kobj); kobject_free: cpufreq_unregister_driver(current_pstate_driver); return ret; } device_initcall(amd_pstate_init); static int __init amd_pstate_param(char *str) { size_t size; int mode_idx; if (!str) return -EINVAL; size = strlen(str); mode_idx = get_mode_idx_from_str(str, size); if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { cppc_state = mode_idx; if (cppc_state == AMD_PSTATE_DISABLE) pr_info("driver is explicitly disabled\n"); if (cppc_state == AMD_PSTATE_ACTIVE) current_pstate_driver = &amd_pstate_epp_driver; if (cppc_state == AMD_PSTATE_PASSIVE) current_pstate_driver = &amd_pstate_driver; return 0; } return -EINVAL; } early_param("amd_pstate", amd_pstate_param); MODULE_AUTHOR("Huang Rui "); MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");