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7/23/26 15:12, K Prateek Nayak wrote: > Conver the global "dynamic_epp" toggle into a per-CPU Convert > "energy_performance_preference" mode "dynamic" that allows toggling the > functionality of "dynamic_epp" at a per-CPU level. > > Instead of being a system-wide toggle, users can opt into the > functionality of dynamic EPP on a per-CPU basis by switching to the > powersave governor and selecting the "dynamic" mode from the available > performance preferences. > > Unlike the previous implementation that had to check for driver mode > before toggling on the functionality, block writes to certain sysfs > files, potentially disallow policy change, etc. the per-CPU toggle fits > naturally into the intended design and provides more granular control to > the user. > > The dynamic_epp file is now redundant as the option to toggle it on is > controlled via energy_performance_preference, and the dynamic_epp file > will be removed in the subsequent commit. > > Signed-off-by: K Prateek Nayak Reviewed-by: Mario Limonciello (AMD) > --- > Changelog rfc v1..v2: > > o Removed "dynamic_epp" global control related changes since it will be > removed in the subsequent commit. > --- > drivers/cpufreq/amd-pstate.c | 57 +++++++++++++++++++++++++++++++----- > 1 file changed, 49 insertions(+), 8 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index 7d1feed0e11e..fc90e4108c22 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -106,6 +106,7 @@ static struct quirk_entry *quirks; > * 3 balance_power > * 4 power > * 5 custom (for raw EPP values) > + * 6 dynamic (platform profile driven selection) > */ > enum energy_perf_value_index { > EPP_INDEX_DEFAULT = 0, > @@ -114,6 +115,7 @@ enum energy_perf_value_index { > EPP_INDEX_BALANCE_POWERSAVE, > EPP_INDEX_POWERSAVE, > EPP_INDEX_CUSTOM, > + EPP_INDEX_DYNAMIC, > EPP_INDEX_MAX, > }; > > @@ -124,6 +126,7 @@ static const char * const energy_perf_strings[] = { > [EPP_INDEX_BALANCE_POWERSAVE] = "balance_power", > [EPP_INDEX_POWERSAVE] = "power", > [EPP_INDEX_CUSTOM] = "custom", > + [EPP_INDEX_DYNAMIC] = "dynamic", > }; > static_assert(ARRAY_SIZE(energy_perf_strings) == EPP_INDEX_MAX); > > @@ -134,7 +137,7 @@ static unsigned int epp_values[] = { > [EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE, > [EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE, > }; > -static_assert(ARRAY_SIZE(epp_values) == EPP_INDEX_MAX - 1); > +static_assert(ARRAY_SIZE(epp_values) == EPP_INDEX_MAX - 2); > > typedef int (*cppc_mode_transition_fn)(int); > > @@ -1274,6 +1277,7 @@ EXPORT_SYMBOL_GPL(amd_pstate_clear_dynamic_epp); > static int amd_pstate_set_dynamic_epp(struct cpufreq_policy *policy) > { > struct amd_cpudata *cpudata = policy->driver_data; > + u64 prev = READ_ONCE(cpudata->cppc_req_cached); > int ret; > u8 epp; > > @@ -1314,6 +1318,9 @@ static int amd_pstate_set_dynamic_epp(struct cpufreq_policy *policy) > cleanup: > amd_pstate_clear_dynamic_epp(policy); > > + epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, prev); > + /* Restore previous EPP if toggling Dynamic EPP failed. */ > + amd_pstate_set_epp(policy, epp); > return ret; > } > > @@ -1384,7 +1391,7 @@ static ssize_t show_amd_pstate_hw_prefcore(struct cpufreq_policy *policy, > static ssize_t show_energy_performance_available_preferences( > struct cpufreq_policy *policy, char *buf) > { > - int offset = 0, i; > + int i, offset = 0; > struct amd_cpudata *cpudata = policy->driver_data; > > if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) > @@ -1407,11 +1414,6 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, > bool raw_epp = false; > u8 epp; > > - if (cpudata->dynamic_epp) { > - pr_debug("EPP cannot be set when dynamic EPP is enabled\n"); > - return -EBUSY; > - } > - > /* > * if the value matches a number, use that, otherwise see if > * matches an index in the energy_perf_strings array > @@ -1422,6 +1424,23 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, > ret = sysfs_match_string(energy_perf_strings, buf); > if (ret < 0 || ret == EPP_INDEX_CUSTOM) > return -EINVAL; > + > + if (ret == EPP_INDEX_DYNAMIC) { > + /* > + * Dynamic EPP was already enabled for this CPU. > + * Nothing to do. > + */ > + if (cpudata->dynamic_epp) > + return count; > + > + cpudata->current_profile = PLATFORM_PROFILE_BALANCED; > + ret = amd_pstate_set_dynamic_epp(policy); > + if (ret) > + return ret; > + > + return count; > + } > + > if (ret) > epp = epp_values[ret]; > else > @@ -1433,6 +1452,13 @@ ssize_t store_energy_performance_preference(struct cpufreq_policy *policy, > return -EBUSY; > } > > + /* > + * Dynamic EPP was enabled previously! > + * Switch back to the static EPP mode. > + */ > + if (cpudata->dynamic_epp) > + amd_pstate_clear_dynamic_epp(policy); > + > ret = amd_pstate_set_epp(policy, epp); > if (ret) > return ret; > @@ -1450,7 +1476,7 @@ ssize_t show_energy_performance_preference(struct cpufreq_policy *policy, char * > > epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached); > > - if (cpudata->raw_epp) > + if (!cpudata->dynamic_epp && cpudata->raw_epp) > return sysfs_emit(buf, "%u\n", epp); > > switch (epp) { > @@ -1470,6 +1496,9 @@ ssize_t show_energy_performance_preference(struct cpufreq_policy *policy, char * > return -EINVAL; > } > > + if (cpudata->dynamic_epp) > + return sysfs_emit(buf, "dynamic(profile:%s)\n", energy_perf_strings[preference]); > + > return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); > } > EXPORT_SYMBOL_GPL(show_energy_performance_preference); > @@ -2030,6 +2059,18 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) > if (!policy->cpuinfo.max_freq) > return -ENODEV; > > + /* Must be a switch between PERFORMANCE and POWERSAVE */ > + if (cpudata->policy != policy->policy) { > + /* > + * Disable dynamic_epp when switching > + * out of CPUFREQ_POLICY_POWERSAVE. > + */ > + if (cpudata->dynamic_epp) { > + WARN_ON_ONCE(cpudata->policy != CPUFREQ_POLICY_POWERSAVE); > + amd_pstate_clear_dynamic_epp(policy); > + } > + } > + > cpudata->policy = policy->policy; > > ret = amd_pstate_epp_update_limit(policy, true);