[PATCH v2 14/17] cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes

Mario Limonciello
2025-02-15T00:53:10Z

On EPP only writes update the cached variable so that the min/max
performance controls don't need to be updated again.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
drivers/cpufreq/amd-pstate.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 1304bdc23e809..fd2b559f47c5c 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -336,6 +336,7 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
{
struct amd_cpudata *cpudata = policy->driver_data;
struct cppc_perf_ctrls perf_ctrls;
+ u64 value;
int ret;

if (trace_amd_pstate_epp_perf_enabled()) {
@@ -362,6 +363,11 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
}
WRITE_ONCE(cpudata->epp_cached, epp);

+ value = READ_ONCE(cpudata->cppc_req_cached);
+ value &= ~AMD_CPPC_EPP_PERF_MASK;
+ value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
+ WRITE_ONCE(cpudata->cppc_req_cached, value);
+
return ret;
}

--
2.43.0