diff options
Diffstat (limited to 'drivers/cpufreq/amd-pstate.c')
| -rw-r--r-- | drivers/cpufreq/amd-pstate.c | 1573 |
1 files changed, 1573 insertions, 0 deletions
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c new file mode 100644 index 000000000..1791d37fb --- /dev/null +++ b/drivers/cpufreq/amd-pstate.c @@ -0,0 +1,1573 @@ +// 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 <linux/amd-pstate.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 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_UNDEFINED; +static bool cppc_enabled; + +/* + * 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, + }; + +typedef int (*cppc_mode_transition_fn)(int); + +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) +{ + int ret, cpu; + unsigned long logical_proc_id_mask = 0; + + if (enable == cppc_enabled) + return 0; + + for_each_present_cpu(cpu) { + unsigned long logical_id = topology_logical_die_id(cpu); + + if (test_bit(logical_id, &logical_proc_id_mask)) + continue; + + set_bit(logical_id, &logical_proc_id_mask); + + ret = wrmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_ENABLE, + enable); + if (ret) + return ret; + } + + cppc_enabled = enable; + return 0; +} + +static int cppc_enable(bool enable) +{ + int cpu, ret = 0; + struct cppc_perf_ctrls perf_ctrls; + + if (enable == cppc_enabled) + return 0; + + 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; + } + } + + cppc_enabled = enable; + 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->max_limit_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)); + WRITE_ONCE(cpudata->min_limit_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->max_limit_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); + WRITE_ONCE(cpudata->min_limit_perf, cppc_perf.lowest_perf); + + if (cppc_state == AMD_PSTATE_ACTIVE) + return 0; + + ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf); + if (ret) { + pr_warn("failed to get auto_sel, ret: %d\n", ret); + return 0; + } + + ret = cppc_set_auto_sel(cpudata->cpu, + (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1); + + if (ret) + pr_warn("failed to set auto_sel, ret: %d\n", ret); + + return ret; +} + +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, int gov_flags) +{ + u64 prev = READ_ONCE(cpudata->cppc_req_cached); + u64 value = prev; + + min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf, + cpudata->max_limit_perf); + max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf, + cpudata->max_limit_perf); + des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf); + + if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) { + min_perf = des_perf; + des_perf = 0; + } + + 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_min_max_limit(struct cpufreq_policy *policy) +{ + u32 max_limit_perf, min_limit_perf; + struct amd_cpudata *cpudata = policy->driver_data; + + max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq); + min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq); + + WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf); + WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf); + WRITE_ONCE(cpudata->max_limit_freq, policy->max); + WRITE_ONCE(cpudata->min_limit_freq, policy->min); + + 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; + + if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq) + amd_pstate_update_min_max_limit(policy); + + 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, policy->governor->flags); + + 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) +{ + if (!amd_pstate_update_freq(policy, target_freq, true)) + return target_freq; + return policy->cur; +} + +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; + + if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq) + amd_pstate_update_min_max_limit(policy); + + + 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, + policy->governor->flags); + 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->max_limit_freq = max_freq; + cpudata->min_limit_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; + struct amd_cpudata *cpudata = policy->driver_data; + + if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) + return sysfs_emit_at(buf, offset, "%s\n", + energy_perf_strings[EPP_INDEX_PERFORMANCE]); + + while (energy_perf_strings[i] != NULL) + offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]); + + offset += 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 void amd_pstate_driver_cleanup(void) +{ + amd_pstate_enable(false); + cppc_state = AMD_PSTATE_DISABLE; + current_pstate_driver = NULL; +} + +static int amd_pstate_register_driver(int mode) +{ + int ret; + + if (mode == AMD_PSTATE_PASSIVE || mode == AMD_PSTATE_GUIDED) + current_pstate_driver = &amd_pstate_driver; + else if (mode == AMD_PSTATE_ACTIVE) + current_pstate_driver = &amd_pstate_epp_driver; + else + return -EINVAL; + + cppc_state = mode; + ret = cpufreq_register_driver(current_pstate_driver); + if (ret) { + amd_pstate_driver_cleanup(); + return ret; + } + return 0; +} + +static int amd_pstate_unregister_driver(int dummy) +{ + cpufreq_unregister_driver(current_pstate_driver); + amd_pstate_driver_cleanup(); + return 0; +} + +static int amd_pstate_change_mode_without_dvr_change(int mode) +{ + int cpu = 0; + + cppc_state = mode; + + if (boot_cpu_has(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE) + return 0; + + for_each_present_cpu(cpu) { + cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1); + } + + return 0; +} + +static int amd_pstate_change_driver_mode(int mode) +{ + int ret; + + ret = amd_pstate_unregister_driver(0); + if (ret) + return ret; + + ret = amd_pstate_register_driver(mode); + if (ret) + return ret; + + return 0; +} + +static cppc_mode_transition_fn mode_state_machine[AMD_PSTATE_MAX][AMD_PSTATE_MAX] = { + [AMD_PSTATE_DISABLE] = { + [AMD_PSTATE_DISABLE] = NULL, + [AMD_PSTATE_PASSIVE] = amd_pstate_register_driver, + [AMD_PSTATE_ACTIVE] = amd_pstate_register_driver, + [AMD_PSTATE_GUIDED] = amd_pstate_register_driver, + }, + [AMD_PSTATE_PASSIVE] = { + [AMD_PSTATE_DISABLE] = amd_pstate_unregister_driver, + [AMD_PSTATE_PASSIVE] = NULL, + [AMD_PSTATE_ACTIVE] = amd_pstate_change_driver_mode, + [AMD_PSTATE_GUIDED] = amd_pstate_change_mode_without_dvr_change, + }, + [AMD_PSTATE_ACTIVE] = { + [AMD_PSTATE_DISABLE] = amd_pstate_unregister_driver, + [AMD_PSTATE_PASSIVE] = amd_pstate_change_driver_mode, + [AMD_PSTATE_ACTIVE] = NULL, + [AMD_PSTATE_GUIDED] = amd_pstate_change_driver_mode, + }, + [AMD_PSTATE_GUIDED] = { + [AMD_PSTATE_DISABLE] = amd_pstate_unregister_driver, + [AMD_PSTATE_PASSIVE] = amd_pstate_change_mode_without_dvr_change, + [AMD_PSTATE_ACTIVE] = amd_pstate_change_driver_mode, + [AMD_PSTATE_GUIDED] = NULL, + }, +}; + +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 int amd_pstate_update_status(const char *buf, size_t size) +{ + int mode_idx; + + if (size > strlen("passive") || size < strlen("active")) + return -EINVAL; + + mode_idx = get_mode_idx_from_str(buf, size); + + if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX) + return -EINVAL; + + if (mode_state_machine[cppc_state][mode_idx]) + return mode_state_machine[cppc_state][mode_idx](mode_idx); + + return 0; +} + +static ssize_t status_show(struct device *dev, + struct device_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 status_store(struct device *a, struct device_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); +static DEVICE_ATTR_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[] = { + &dev_attr_status.attr, + NULL +}; + +static const struct attribute_group amd_pstate_global_attr_group = { + .name = "amd_pstate", + .attrs = pstate_global_attributes, +}; + +static bool amd_pstate_acpi_pm_profile_server(void) +{ + switch (acpi_gbl_FADT.preferred_profile) { + case PM_ENTERPRISE_SERVER: + case PM_SOHO_SERVER: + case PM_PERFORMANCE_SERVER: + return true; + } + return false; +} + +static bool amd_pstate_acpi_pm_profile_undefined(void) +{ + if (acpi_gbl_FADT.preferred_profile == PM_UNSPECIFIED) + return true; + if (acpi_gbl_FADT.preferred_profile >= NR_PM_PROFILES) + return true; + return false; +} + +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 provide a valid fallback value in case + * the default cpufreq governor is neither powersave nor performance. + */ + if (amd_pstate_acpi_pm_profile_server() || + amd_pstate_acpi_pm_profile_undefined()) + policy->policy = CPUFREQ_POLICY_PERFORMANCE; + else + 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_update_limit(struct cpufreq_policy *policy) +{ + struct amd_cpudata *cpudata = policy->driver_data; + u32 max_perf, min_perf, min_limit_perf, max_limit_perf; + u64 value; + s16 epp; + + max_perf = READ_ONCE(cpudata->highest_perf); + min_perf = READ_ONCE(cpudata->lowest_perf); + max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq); + min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq); + + WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf); + WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf); + + max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf, + cpudata->max_limit_perf); + min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf, + cpudata->max_limit_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); + + 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. + */ + return; + } + + 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); +} + +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_update_limit(policy); + + 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_set_driver(int mode_idx) +{ + 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 || cppc_state == AMD_PSTATE_GUIDED) + current_pstate_driver = &amd_pstate_driver; + + return 0; + } + + return -EINVAL; +} + +static int __init amd_pstate_init(void) +{ + struct device *dev_root; + int ret; + + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) + 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; + + switch (cppc_state) { + case AMD_PSTATE_UNDEFINED: + /* Disable on the following configs by default: + * 1. Undefined platforms + * 2. Server platforms + * 3. Shared memory designs + */ + if (amd_pstate_acpi_pm_profile_undefined() || + amd_pstate_acpi_pm_profile_server() || + !boot_cpu_has(X86_FEATURE_CPPC)) { + pr_info("driver load is disabled, boot with specific mode to enable this\n"); + return -ENODEV; + } + ret = amd_pstate_set_driver(CONFIG_X86_AMD_PSTATE_DEFAULT_MODE); + if (ret) + return ret; + break; + case AMD_PSTATE_DISABLE: + return -ENODEV; + case AMD_PSTATE_PASSIVE: + case AMD_PSTATE_ACTIVE: + case AMD_PSTATE_GUIDED: + break; + default: + return -EINVAL; + } + + /* capability check */ + if (boot_cpu_has(X86_FEATURE_CPPC)) { + pr_debug("AMD CPPC MSR based functionality is supported\n"); + if (cppc_state != AMD_PSTATE_ACTIVE) + 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); + + dev_root = bus_get_dev_root(&cpu_subsys); + if (dev_root) { + ret = sysfs_create_group(&dev_root->kobj, &amd_pstate_global_attr_group); + put_device(dev_root); + if (ret) { + pr_err("sysfs attribute export failed with error %d.\n", ret); + goto global_attr_free; + } + } + + return ret; + +global_attr_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); + + return amd_pstate_set_driver(mode_idx); +} +early_param("amd_pstate", amd_pstate_param); + +MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>"); +MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); |