| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Huang Rui | 2374 | 87.76% | 7 | 77.78% |
| Jinzhou.Su | 331 | 12.24% | 2 | 22.22% |
| Total | 2705 | 9 |
// 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 <ray.huang@amd.com> * * 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 <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/smp.h> #include <linux/sched.h> #include <linux/cpufreq.h> #include <linux/compiler.h> #include <linux/dmi.h> #include <linux/slab.h> #include <linux/acpi.h> #include <linux/io.h> #include <linux/delay.h> #include <linux/uaccess.h> #include <linux/static_call.h> #include <acpi/processor.h> #include <acpi/cppc_acpi.h> #include <asm/msr.h> #include <asm/processor.h> #include <asm/cpufeature.h> #include <asm/cpu_device_id.h> #include "amd-pstate-trace.h" #define AMD_PSTATE_TRANSITION_LATENCY 0x20000 #define AMD_PSTATE_TRANSITION_DELAY 500 /* * 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 bool shared_mem = false; module_param(shared_mem, bool, 0444); MODULE_PARM_DESC(shared_mem, "enable amd-pstate on processors with shared memory solution (false = disabled (default), true = enabled)"); static struct cpufreq_driver amd_pstate_driver; /** * struct amd_aperf_mperf * @aperf: actual performance frequency clock count * @mperf: maximum performance frequency clock count * @tsc: time stamp counter */ struct amd_aperf_mperf { u64 aperf; u64 mperf; u64 tsc; }; /** * struct amd_cpudata - private CPU data for AMD P-State * @cpu: CPU number * @req: constraint request to apply * @cppc_req_cached: cached performance request hints * @highest_perf: the maximum performance an individual processor may reach, * assuming ideal conditions * @nominal_perf: the maximum sustained performance level of the processor, * assuming ideal operating conditions * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power * savings are achieved * @lowest_perf: the absolute lowest performance level of the processor * @max_freq: the frequency that mapped to highest_perf * @min_freq: the frequency that mapped to lowest_perf * @nominal_freq: the frequency that mapped to nominal_perf * @lowest_nonlinear_freq: the frequency that mapped to lowest_nonlinear_perf * @cur: Difference of Aperf/Mperf/tsc count between last and current sample * @prev: Last Aperf/Mperf/tsc count value read from register * @freq: current cpu frequency value * @boost_supported: check whether the Processor or SBIOS supports boost mode * * The amd_cpudata is key private data for each CPU thread in AMD P-State, and * represents all the attributes and goals that AMD P-State requests at runtime. */ struct amd_cpudata { int cpu; struct freq_qos_request req[2]; u64 cppc_req_cached; u32 highest_perf; u32 nominal_perf; u32 lowest_nonlinear_perf; u32 lowest_perf; u32 max_freq; u32 min_freq; u32 nominal_freq; u32 lowest_nonlinear_freq; struct amd_aperf_mperf cur; struct amd_aperf_mperf prev; u64 freq; bool boost_supported; }; 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; for_each_present_cpu(cpu) { ret = cppc_set_enable(cpu, enable); 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; 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. */ WRITE_ONCE(cpudata->highest_perf, amd_get_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; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; WRITE_ONCE(cpudata->highest_perf, amd_get_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; 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_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) { 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_nonlinear_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); cpufreq_freq_transition_begin(policy, &freqs); amd_pstate_update(cpudata, min_perf, des_perf, max_perf, false); cpufreq_freq_transition_end(policy, &freqs, false); return 0; } 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; struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); struct amd_cpudata *cpudata = policy->driver_data; cap_perf = READ_ONCE(cpudata->highest_perf); lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf); 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); amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true); } 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; amd_pstate_driver.boost_enabled = true; } 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; 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); 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; cpudata = policy->driver_data; freq_qos_remove_request(&cpudata->req[1]); freq_qos_remove_request(&cpudata->req[0]); 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; cpudata = policy->driver_data; max_freq = amd_get_max_freq(cpudata); if (max_freq < 0) return max_freq; return sprintf(&buf[0], "%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; cpudata = policy->driver_data; freq = amd_get_lowest_nonlinear_freq(cpudata); if (freq < 0) return freq; return sprintf(&buf[0], "%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 sprintf(&buf[0], "%u\n", perf); } 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); static struct freq_attr *amd_pstate_attr[] = { &amd_pstate_max_freq, &amd_pstate_lowest_nonlinear_freq, &amd_pstate_highest_perf, NULL, }; static struct cpufreq_driver amd_pstate_driver = { .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify = amd_pstate_verify, .target = amd_pstate_target, .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 int __init amd_pstate_init(void) { int ret; if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) return -ENODEV; if (!acpi_cpc_valid()) { pr_debug("the _CPC object is not present in SBIOS\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"); amd_pstate_driver.adjust_perf = amd_pstate_adjust_perf; } else if (shared_mem) { 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); } else { pr_info("This processor supports shared memory solution, you can enable it with amd_pstate.shared_mem=1\n"); return -ENODEV; } /* enable amd pstate feature */ ret = amd_pstate_enable(true); if (ret) { pr_err("failed to enable amd-pstate with return %d\n", ret); return ret; } ret = cpufreq_register_driver(&amd_pstate_driver); if (ret) pr_err("failed to register amd_pstate_driver with return %d\n", ret); return ret; } static void __exit amd_pstate_exit(void) { cpufreq_unregister_driver(&amd_pstate_driver); amd_pstate_enable(false); } module_init(amd_pstate_init); module_exit(amd_pstate_exit); MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>"); MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); MODULE_LICENSE("GPL");
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