| Message ID | 20250415102118.694999-1-dhananjay.ugwekar@amd.com |
|---|---|
| Headers | show |
| Series | Add support for "Requested CPU Min Frequency" BIOS option | expand |
On 4/15/2025 5:21 AM, Dhananjay Ugwekar wrote: > Rename and use the existing amd_pstate_epp callbacks for amd_pstate driver > as well. Remove the debug print in online callback while at it. > > These callbacks will be needed to support the "Requested CPU Min Frequency" > BIOS option. > > Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> > --- > drivers/cpufreq/amd-pstate.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index c29840ba3b30..02de51001eba 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -1568,19 +1568,17 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) > return 0; > } > > -static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy) > +static int amd_pstate_cpu_online(struct cpufreq_policy *policy) > { > - pr_debug("AMD CPU Core %d going online\n", policy->cpu); > - > return amd_pstate_cppc_enable(policy); > } > > -static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy) > +static int amd_pstate_cpu_offline(struct cpufreq_policy *policy) > { > return 0; > } > > -static int amd_pstate_epp_suspend(struct cpufreq_policy *policy) > +static int amd_pstate_suspend(struct cpufreq_policy *policy) > { > struct amd_cpudata *cpudata = policy->driver_data; > > @@ -1618,6 +1616,9 @@ static struct cpufreq_driver amd_pstate_driver = { > .fast_switch = amd_pstate_fast_switch, > .init = amd_pstate_cpu_init, > .exit = amd_pstate_cpu_exit, > + .online = amd_pstate_cpu_online, > + .offline = amd_pstate_cpu_offline, > + .suspend = amd_pstate_suspend, > .set_boost = amd_pstate_set_boost, > .update_limits = amd_pstate_update_limits, > .name = "amd-pstate", > @@ -1630,9 +1631,9 @@ static struct cpufreq_driver amd_pstate_epp_driver = { > .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, > + .offline = amd_pstate_cpu_offline, > + .online = amd_pstate_cpu_online, > + .suspend = amd_pstate_suspend, > .resume = amd_pstate_epp_resume, > .update_limits = amd_pstate_update_limits, > .set_boost = amd_pstate_set_boost,
Zen 4 AMD EPYC systems and above have a "Requested CPU Min Frequency" BIOS option which allows the user to set an initial lower frequency limit. This limit can later be overridden by the user by writing to the sysfs file "scaling_min_freq". Initialize lower frequency limit to the "Requested CPU Min frequency" BIOS option (if it is set) value as part of the driver->init() callback. The BIOS specified value is passed as min_perf in the CPPC_REQ MSR. To ensure that we don't mistake a stale min_perf value in CPPC_REQ value as the "Requested CPU Min frequency" during a kexec wakeup, reset the CPPC_REQ.min_perf value back to the BIOS specified one in the offline, exit and suspend callbacks. amd_pstate_target() and amd_pstate_epp_update_limit() which are invoked as part of the resume() and online() callbacks will take care of restoring the CPPC_REQ back to the last sane values. Dhananjay Ugwekar (2): cpufreq/amd-pstate: Add offline, online and suspend callbacks for amd_pstate_driver cpufreq/amd-pstate: Add support for the "Requested CPU Min frequency" BIOS option drivers/cpufreq/amd-pstate.c | 79 ++++++++++++++++++++++++++---------- drivers/cpufreq/amd-pstate.h | 2 + 2 files changed, 60 insertions(+), 21 deletions(-)