[PATCH 10/14] cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes

From: Mario Limonciello
Date: Thu Feb 06 2025 - 16:59:10 EST


From: Mario Limonciello <mario.limonciello@xxxxxxx>

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

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
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 e66ccfce5893f..754f2d606b371 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -338,6 +338,7 @@ 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;

lockdep_assert_held(&cpudata->lock);
@@ -366,6 +367,11 @@ 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