Messages in this thread | | | Date | Thu, 19 Jan 2023 10:47:11 +0530 | Subject | Re: [PATCH v11 04/11] cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors | From | Wyes Karny <> |
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On 1/18/2023 1:22 PM, Perry Yuan wrote: > From: Perry Yuan <Perry.Yuan@amd.com> > > Add EPP driver support for AMD SoCs which support a dedicated MSR for > CPPC. EPP is used by the DPM controller to configure the frequency that > a core operates at during short periods of activity. > > The SoC EPP targets are configured on a scale from 0 to 255 where 0 > represents maximum performance and 255 represents maximum efficiency. > > The amd-pstate driver exports profile string names to userspace that are > tied to specific EPP values. > > The balance_performance string (0x80) provides the best balance for > efficiency versus power on most systems, but users can choose other > strings to meet their needs as well. > > $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences > default performance balance_performance balance_power power > > $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference > balance_performance > > To enable the driver,it needs to add `amd_pstate=active` to kernel > command line and kernel will load the active mode epp driver > > Acked-by: Huang Rui <ray.huang@amd.com> > Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com> > Tested-by: Wyes Karny <wyes.karny@amd.com> > Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
> --- > drivers/cpufreq/amd-pstate.c | 379 ++++++++++++++++++++++++++++++++++- > include/linux/amd-pstate.h | 55 +++++ > 2 files changed, 428 insertions(+), 6 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index 1a8b31277620..2109ad3fdd42 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -59,7 +59,9 @@ > * 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; > > static inline int get_mode_idx_from_str(const char *str, size_t size) > @@ -73,6 +75,114 @@ static inline int get_mode_idx_from_str(const char *str, size_t size) > 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); > @@ -81,11 +191,21 @@ static inline int pstate_enable(bool 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; > @@ -428,7 +548,7 @@ static void amd_pstate_boost_init(struct amd_cpudata *cpudata) > return; > > cpudata->boost_supported = true; > - amd_pstate_driver.boost_enabled = true; > + current_pstate_driver->boost_enabled = true; > } > > static void amd_perf_ctl_reset(unsigned int cpu) > @@ -602,10 +722,61 @@ static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy, > return sprintf(&buf[0], "%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]); > +} > + > 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 struct freq_attr *amd_pstate_attr[] = { > &amd_pstate_max_freq, > @@ -614,6 +785,186 @@ static struct freq_attr *amd_pstate_attr[] = { > 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 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; > + int rc; > + 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) > + goto free_cpudata1; > + > + cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL); > + if (!cpudata) > + return -ENOMEM; > + > + cpudata->cpu = policy->cpu; > + cpudata->epp_policy = 0; > + > + rc = amd_pstate_init_perf(cpudata); > + if (rc) > + 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)) { > + policy->fast_switch_possible = true; > + 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); > + policy->fast_switch_possible = false; > + 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; > + > + if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) { > + epp = amd_pstate_get_epp(cpudata, value); > + if (epp < 0) > + goto skip_epp; > + /* force the epp value to be zero for performance policy */ > + epp = 0; > + } else { > + /* Get BIOS pre-defined epp value */ > + epp = amd_pstate_get_epp(cpudata, value); > + if (epp) > + goto skip_epp; > + } > + /* Set initial EPP value */ > + if (boot_cpu_has(X86_FEATURE_CPPC)) { > + value &= ~GENMASK_ULL(31, 24); > + value |= (u64)epp << 24; > + } > + > +skip_epp: > + WRITE_ONCE(cpudata->cppc_req_cached, value); > + amd_pstate_set_epp(cpudata, 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 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 struct cpufreq_driver amd_pstate_driver = { > .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, > .verify = amd_pstate_verify, > @@ -627,6 +978,16 @@ static struct cpufreq_driver amd_pstate_driver = { > .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, > + .name = "amd_pstate_epp", > + .attr = amd_pstate_epp_attr, > +}; > + > static int __init amd_pstate_init(void) > { > int ret; > @@ -655,7 +1016,8 @@ static int __init amd_pstate_init(void) > /* 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; > + 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); > @@ -666,14 +1028,13 @@ static int __init amd_pstate_init(void) > /* enable amd pstate feature */ > ret = amd_pstate_enable(true); > if (ret) { > - pr_err("failed to enable amd-pstate with return %d\n", ret); > + pr_err("failed to enable with return %d\n", ret); > return ret; > } > > - ret = cpufreq_register_driver(&amd_pstate_driver); > + ret = cpufreq_register_driver(current_pstate_driver); > if (ret) > - pr_err("failed to register amd_pstate_driver with return %d\n", > - ret); > + pr_err("failed to register with return %d\n", ret); > > return ret; > } > @@ -695,6 +1056,12 @@ static int __init amd_pstate_param(char *str) > 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; > } > > diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h > index dae2ce0f6735..9bfdabd9d930 100644 > --- a/include/linux/amd-pstate.h > +++ b/include/linux/amd-pstate.h > @@ -47,6 +47,10 @@ struct amd_aperf_mperf { > * @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 > + * @epp_policy: Last saved policy used to set energy-performance preference > + * @epp_cached: Cached CPPC energy-performance preference value > + * @policy: Cpufreq policy value > + * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value > * > * 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. > @@ -72,6 +76,12 @@ struct amd_cpudata { > > u64 freq; > bool boost_supported; > + > + /* EPP feature related attributes*/ > + s16 epp_policy; > + s16 epp_cached; > + u32 policy; > + u64 cppc_cap1_cached; > }; > > /* > @@ -91,4 +101,49 @@ static const char * const amd_pstate_mode_string[] = { > NULL, > }; > > +#define AMD_CPPC_EPP_PERFORMANCE 0x00 > +#define AMD_CPPC_EPP_BALANCE_PERFORMANCE 0x80 > +#define AMD_CPPC_EPP_BALANCE_POWERSAVE 0xBF > +#define AMD_CPPC_EPP_POWERSAVE 0xFF > + > +/* > + * 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, > + }; > #endif /* _LINUX_AMD_PSTATE_H */
-- Thanks & Regards, Wyes
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