Received-SPF: pass (google.com: domain of linux-kernel+bounces-212693-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From: Perry Yuan <perry.yuan@amd.com>
To: <Mario.Limonciello@amd.com>, <gautham.shenoy@amd.com>,
	<Borislav.Petkov@amd.com>
CC: <rafael.j.wysocki@intel.com>, <viresh.kumar@linaro.org>,
	<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 v11 3/9] cpufreq: introduce init_boost callback to initialize boost state for pstate drivers
Date: Thu, 13 Jun 2024 15:25:15 +0800
Message-ID: <688d8e1ce875655c344ac3b29876da5dc0456739.1718262992.git.perry.yuan@amd.com>
In-Reply-To: <cover.1718262992.git.perry.yuan@amd.com>
References: <cover.1718262992.git.perry.yuan@amd.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jun 2024 07:25:50.1844
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 62bee58b-5e16-4026-b996-08dc8b7a0d3d
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource:
	MN1PEPF0000ECD9.namprd02.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB8215

Introduce a new init_boost callback in cpufreq to initialize the boost
state for specific pstate drivers. This initialization is required before
calling the set_boost interface for each CPU.

The init_boost callback will set up and synchronize each CPU's current
boost state before invoking the set_boost function. Without this step,
the boost state may be inconsistent across CPUs.

Signed-off-by: Perry Yuan <perry.yuan@amd.com>
---
 drivers/cpufreq/cpufreq.c | 12 ++++++++++--
 include/linux/cpufreq.h   |  2 ++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 1fdabb660231..e1a4730f4f8c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1429,8 +1429,16 @@ static int cpufreq_online(unsigned int cpu)
 			goto out_free_policy;
 		}
 
-		/* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
-		policy->boost_enabled = cpufreq_boost_enabled() && policy_has_boost_freq(policy);
+		/* init boost state to prepare set_boost callback for each CPU */
+		if (cpufreq_driver->init_boost) {
+			ret = cpufreq_driver->init_boost(policy);
+			if (ret)
+				pr_debug("%s: %d: initialization boost failed\n", __func__,
+					__LINE__);
+		} else {
+			/* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
+			policy->boost_enabled = cpufreq_boost_enabled() && policy_has_boost_freq(policy);
+		}
 
 		/*
 		 * The initialization has succeeded and the policy is online.
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 20f7e98ee8af..0698c0292d8f 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -409,6 +409,8 @@ struct cpufreq_driver {
 	bool		boost_enabled;
 	int		(*set_boost)(struct cpufreq_policy *policy, int state);
 
+	/* initialize boost state to be consistent before calling set_boost */
+	int		(*init_boost)(struct cpufreq_policy *policy);
 	/*
 	 * Set by drivers that want to register with the energy model after the
 	 * policy is properly initialized, but before the governor is started.
-- 
2.34.1