From 919bfa9b2dbf3bc0c478afd4e44445836381dacb Mon Sep 17 00:00:00 2001 From: K Prateek Nayak Date: Tue, 10 Dec 2024 03:25:57 +0000 Subject: [PATCH 1/3] cpufreq/amd-pstate: Detect preferred core support before driver registration Booting with amd-pstate on 3rd Generation EPYC system incorrectly enabled ITMT support despite the system not supporting Preferred Core ranking. amd_pstate_init_prefcore() called during amd_pstate*_cpu_init() requires "amd_pstate_prefcore" to be set correctly however the preferred core support is detected only after driver registration which is too late. Swap the function calls around to detect preferred core support before registring the driver via amd_pstate_register_driver(). This ensures amd_pstate*_cpu_init() sees the correct value of "amd_pstate_prefcore" considering the platform support. Fixes: 279f838a61f9 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") Fixes: ff2653ded4d9 ("cpufreq/amd-pstate: Move registration after static function call update") Signed-off-by: K Prateek Nayak Acked-by: Mario Limonciello Link: https://lore.kernel.org/r/20241210032557.754-1-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index d7630bab2516..8b36450bbdf6 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1869,18 +1869,18 @@ static int __init amd_pstate_init(void) static_call_update(amd_pstate_update_perf, shmem_update_perf); } - ret = amd_pstate_register_driver(cppc_state); - if (ret) { - pr_err("failed to register with return %d\n", ret); - return ret; - } - if (amd_pstate_prefcore) { ret = amd_detect_prefcore(&amd_pstate_prefcore); if (ret) return ret; } + ret = amd_pstate_register_driver(cppc_state); + if (ret) { + pr_err("failed to register with return %d\n", ret); + return ret; + } + dev_root = bus_get_dev_root(&cpu_subsys); if (dev_root) { ret = sysfs_create_group(&dev_root->kobj, &amd_pstate_global_attr_group); From 50a062a7620051c09adacd6d140ebd56881a333b Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Mon, 9 Dec 2024 12:52:34 -0600 Subject: [PATCH 2/3] cpufreq/amd-pstate: Store the boost numerator as highest perf again commit ad4caad58d91d ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()") changed the semantics for highest perf and commit 18d9b52271213 ("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled") worked around those semantic changes. This however is a confusing result and furthermore makes it awkward to change frequency limits and boost due to the scaling differences. Restore the boost numerator to highest perf again. Suggested-by: Dhananjay Ugwekar Reviewed-by: Gautham R. Shenoy Fixes: ad4caad58d91 ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()") Link: https://lore.kernel.org/r/20241209185248.16301-2-mario.limonciello@amd.com Signed-off-by: Mario Limonciello --- Documentation/admin-guide/pm/amd-pstate.rst | 4 +--- drivers/cpufreq/amd-pstate.c | 25 ++++++++++++--------- 2 files changed, 16 insertions(+), 13 deletions(-) diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 210a808b74ec..412423c54f25 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -251,9 +251,7 @@ performance supported in `AMD CPPC Performance Capability `_). In some ASICs, the highest CPPC performance is not the one in the ``_CPC`` table, so we need to expose it to sysfs. If boost is not active, but still supported, this maximum frequency will be larger than the one in -``cpuinfo``. On systems that support preferred core, the driver will have -different values for some cores than others and this will reflect the values -advertised by the platform at bootup. +``cpuinfo``. This attribute is read-only. ``amd_pstate_lowest_nonlinear_freq`` diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 8b36450bbdf6..ab6fe9c2150c 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -374,15 +374,19 @@ static inline int amd_pstate_cppc_enable(bool enable) static int msr_init_perf(struct amd_cpudata *cpudata) { - u64 cap1; + u64 cap1, numerator; int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &cap1); if (ret) return ret; - WRITE_ONCE(cpudata->highest_perf, AMD_CPPC_HIGHEST_PERF(cap1)); - WRITE_ONCE(cpudata->max_limit_perf, AMD_CPPC_HIGHEST_PERF(cap1)); + ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator); + if (ret) + return ret; + + WRITE_ONCE(cpudata->highest_perf, numerator); + WRITE_ONCE(cpudata->max_limit_perf, numerator); 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)); @@ -394,13 +398,18 @@ static int msr_init_perf(struct amd_cpudata *cpudata) static int shmem_init_perf(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; + u64 numerator; int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret; - WRITE_ONCE(cpudata->highest_perf, cppc_perf.highest_perf); - WRITE_ONCE(cpudata->max_limit_perf, cppc_perf.highest_perf); + ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator); + if (ret) + return ret; + + WRITE_ONCE(cpudata->highest_perf, numerator); + WRITE_ONCE(cpudata->max_limit_perf, numerator); WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf); WRITE_ONCE(cpudata->lowest_nonlinear_perf, cppc_perf.lowest_nonlinear_perf); @@ -889,7 +898,6 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata) { int ret; u32 min_freq, max_freq; - u64 numerator; u32 nominal_perf, nominal_freq; u32 lowest_nonlinear_perf, lowest_nonlinear_freq; u32 boost_ratio, lowest_nonlinear_ratio; @@ -911,10 +919,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata) nominal_perf = READ_ONCE(cpudata->nominal_perf); - ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator); - if (ret) - return ret; - boost_ratio = div_u64(numerator << SCHED_CAPACITY_SHIFT, nominal_perf); + boost_ratio = div_u64(cpudata->highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf); max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000; lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf); From 2993b29b2a98f2bc9d55dfd37ef39f56a2908748 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Mon, 9 Dec 2024 12:52:35 -0600 Subject: [PATCH 3/3] cpufreq/amd-pstate: Use boost numerator for upper bound of frequencies commit 18d9b5227121 ("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled") introduced different semantics for min/max limits based upon whether the user turned off boost from sysfs. This however is not necessary when the highest perf value is the boost numerator. Suggested-by: Dhananjay Ugwekar Reviewed-by: Gautham R. Shenoy Fixes: 18d9b5227121 ("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled") Link: https://lore.kernel.org/r/20241209185248.16301-3-mario.limonciello@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index ab6fe9c2150c..66e5dfc711c0 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -570,16 +570,13 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data) static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy) { - u32 max_limit_perf, min_limit_perf, lowest_perf, max_perf; + u32 max_limit_perf, min_limit_perf, lowest_perf, max_perf, max_freq; struct amd_cpudata *cpudata = policy->driver_data; - if (cpudata->boost_supported && !policy->boost_enabled) - max_perf = READ_ONCE(cpudata->nominal_perf); - else - max_perf = READ_ONCE(cpudata->highest_perf); - - max_limit_perf = div_u64(policy->max * max_perf, policy->cpuinfo.max_freq); - min_limit_perf = div_u64(policy->min * max_perf, policy->cpuinfo.max_freq); + max_perf = READ_ONCE(cpudata->highest_perf); + max_freq = READ_ONCE(cpudata->max_freq); + max_limit_perf = div_u64(policy->max * max_perf, max_freq); + min_limit_perf = div_u64(policy->min * max_perf, max_freq); lowest_perf = READ_ONCE(cpudata->lowest_perf); if (min_limit_perf < lowest_perf)