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From: Perry Yuan <perry.yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <Mario.Limonciello@amd.com>,
	<viresh.kumar@linaro.org>, <Ray.Huang@amd.com>,
	<gautham.shenoy@amd.com>, <Borislav.Petkov@amd.com>
Cc: <Alexander.Deucher@amd.com>, <Xinmei.Huang@amd.com>,
	<Xiaojian.Du@amd.com>, <Li.Meng@amd.com>,
	<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 3/6] cpufreq:amd-pstate: initialize nominal_freq of each cpudata
Date: Fri, 2 Feb 2024 16:55:35 +0800	[thread overview]
Message-ID: <b4fcf3b4c2b5abcf79bbaf9780fe67b4ec697dee.1706863981.git.perry.yuan@amd.com> (raw)
In-Reply-To: <cover.1706863981.git.perry.yuan@amd.com>

Optimizes the process of retrieving the nominal frequency by utilizing
'cpudata->nominal_freq' instead of repeatedly accessing the cppc_acpi interface.

To enhance efficiency and reduce the CPU load, shifted to using
'cpudata->nominal_freq'. It allows for the nominal frequency to be accessed
directly from the cached data in 'cpudata' of each CPU.
It will also slightly reduce the frequency change latency while using pstate
driver passive mode.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index ac7faa98a450..ea8681ea3bad 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -619,7 +619,7 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	nominal_freq = cppc_perf.nominal_freq;
+	nominal_freq = READ_ONCE(cpudata->nominal_freq);
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	max_perf = READ_ONCE(cpudata->highest_perf);
 
@@ -654,7 +654,7 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	nominal_freq = cppc_perf.nominal_freq;
+	nominal_freq = READ_ONCE(cpudata->nominal_freq);
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
 	lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
@@ -848,13 +848,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 
 	min_freq = amd_get_min_freq(cpudata);
-	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
+	cpudata->nominal_freq = nominal_freq;
+	max_freq = amd_get_max_freq(cpudata);
 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
 
-	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-			min_freq, max_freq);
+	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
+		dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n",
+			min_freq, max_freq, nominal_freq);
 		ret = -EINVAL;
 		goto free_cpudata1;
 	}
@@ -893,7 +894,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	cpudata->min_freq = min_freq;
 	cpudata->max_limit_freq = max_freq;
 	cpudata->min_limit_freq = min_freq;
-	cpudata->nominal_freq = nominal_freq;
 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
 
 	policy->driver_data = cpudata;
@@ -1310,12 +1310,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 
 	min_freq = amd_get_min_freq(cpudata);
-	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
+	cpudata->nominal_freq = nominal_freq;
+	max_freq = amd_get_max_freq(cpudata);
 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
-	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-				min_freq, max_freq);
+	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
+		dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n",
+				min_freq, max_freq, nominal_freq);
 		ret = -EINVAL;
 		goto free_cpudata1;
 	}
@@ -1328,7 +1329,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	/* Initial processor data capability frequencies */
 	cpudata->max_freq = max_freq;
 	cpudata->min_freq = min_freq;
-	cpudata->nominal_freq = nominal_freq;
 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
 
 	policy->driver_data = cpudata;
-- 
2.34.1


  parent reply	other threads:[~2024-02-02  8:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-02  8:55 [PATCH v2 0/6] AMD Pstate Fixes And Enhancements Perry Yuan
2024-02-02  8:55 ` [PATCH v2 1/6] ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors Perry Yuan
2024-02-02  8:55 ` [PATCH v2 2/6] cpufreq:amd-pstate: fix the nominal freq value set Perry Yuan
2024-02-02  8:55 ` Perry Yuan [this message]
2024-02-02  8:55 ` [PATCH v2 4/6] cpufreq:amd-pstate: get pstate transition delay and latency value from ACPI tables Perry Yuan
2024-02-02  8:55 ` [PATCH v2 5/6] cppc_acpi: print error message if CPPC is unsupported Perry Yuan
2024-02-02 15:17   ` Mario Limonciello
2024-02-02  8:55 ` [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing Perry Yuan
2024-02-02 15:16   ` Mario Limonciello
2024-02-02 15:35     ` Yuan, Perry
2024-02-02 15:55       ` Mario Limonciello
2024-02-02 16:27         ` Yuan, Perry

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