From: Perry Yuan Perry.Yuan@amd.com
[ Upstream commit bedadcfb011fef55273bd686e8893fdd8911dcdb ]
To avoid some new AMD processors use wrong highest perf when amd pstate driver loaded, this fix will query the highest perf from MSR register MSR_AMD_CPPC_CAP1 and cppc_acpi interface firstly, then compare with the highest perf value got by calling amd_get_highest_perf() function.
The lower value will be the correct highest perf we need to use. Otherwise the CPU max MHz will be incorrect if the amd_get_highest_perf() did not cover the new process family and model ID.
Like this lscpu info, the max frequency is incorrect.
Vendor ID: AuthenticAMD Socket(s): 1 Stepping: 2 CPU max MHz: 5410.0000 CPU min MHz: 400.0000 BogoMIPS: 5600.54
Fixes: 3743d55b289c2 (x86, sched: Fix the AMD CPPC maximum performance value on certain AMD Ryzen generations) Acked-by: Huang Rui ray.huang@amd.com Signed-off-by: Perry Yuan Perry.Yuan@amd.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpufreq/amd-pstate.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 9ac75c1cde9c..365f3ad166a7 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -152,6 +152,7 @@ static inline int amd_pstate_enable(bool enable) static int pstate_init_perf(struct amd_cpudata *cpudata) { u64 cap1; + u32 highest_perf;
int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &cap1); @@ -163,7 +164,11 @@ static int pstate_init_perf(struct amd_cpudata *cpudata) * * CPPC entry doesn't indicate the highest performance in some ASICs. */ - WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf()); + highest_perf = amd_get_highest_perf(); + if (highest_perf > AMD_CPPC_HIGHEST_PERF(cap1)) + highest_perf = AMD_CPPC_HIGHEST_PERF(cap1); + + WRITE_ONCE(cpudata->highest_perf, highest_perf);
WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1)); WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1)); @@ -175,12 +180,17 @@ static int pstate_init_perf(struct amd_cpudata *cpudata) static int cppc_init_perf(struct amd_cpudata *cpudata) { struct cppc_perf_caps cppc_perf; + u32 highest_perf;
int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf); if (ret) return ret;
- WRITE_ONCE(cpudata->highest_perf, amd_get_highest_perf()); + highest_perf = amd_get_highest_perf(); + if (highest_perf > cppc_perf.highest_perf) + highest_perf = cppc_perf.highest_perf; + + WRITE_ONCE(cpudata->highest_perf, highest_perf);
WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf); WRITE_ONCE(cpudata->lowest_nonlinear_perf,