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cpufreq/amd-pstate: Store the boost numerator as highest perf again

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commit ad4caad58d ("cpufreq: amd-pstate: Merge
amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
changed the semantics for highest perf and commit 18d9b52271
("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 <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: ad4caad58d ("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 <mario.limonciello@amd.com>
This commit is contained in:
Mario Limonciello 2024-12-09 12:52:34 -06:00
parent 919bfa9b2d
commit 50a062a762
2 changed files with 16 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/admin-guide/pm/amd-pstate.rst
View File

@ -251,9 +251,7 @@ performance supported in `AMD CPPC Performance Capability <perf_cap_>`_).
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``

25
drivers/cpufreq/amd-pstate.c
View File

@ -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);