linux-kernel - [PATCH 10/14] cpufreq/amd-pstate: Update cppc_req

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Message-ID: <20250206215659.3350066-11-superm1@kernel.org>
Date: Thu,  6 Feb 2025 15:56:55 -0600
From: Mario Limonciello <superm1@...nel.org>
To: "Gautham R . Shenoy" <gautham.shenoy@....com>,
	Perry Yuan <perry.yuan@....com>
Cc: Dhananjay Ugwekar <Dhananjay.Ugwekar@....com>,
	linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	linux-pm@...r.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK),
	Mario Limonciello <mario.limonciello@....com>
Subject: [PATCH 10/14] cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes

From: Mario Limonciello <mario.limonciello@....com>

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@....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 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