linux-kernel - [PATCH V8 7/9] drm/amd/pm: add flood detection for wbrf events

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Message-ID: <20230810073803.1643451-8-evan.quan@amd.com>
Date:   Thu, 10 Aug 2023 15:38:01 +0800
From:   Evan Quan <evan.quan@....com>
To:     <rafael@...nel.org>, <lenb@...nel.org>,
        <Alexander.Deucher@....com>, <Christian.Koenig@....com>,
        <Xinhui.Pan@....com>, <airlied@...il.com>, <daniel@...ll.ch>,
        <johannes@...solutions.net>, <davem@...emloft.net>,
        <edumazet@...gle.com>, <kuba@...nel.org>, <pabeni@...hat.com>,
        <Mario.Limonciello@....com>, <mdaenzer@...hat.com>,
        <maarten.lankhorst@...ux.intel.com>, <tzimmermann@...e.de>,
        <hdegoede@...hat.com>, <jingyuwang_vip@....com>,
        <Lijo.Lazar@....com>, <jim.cromie@...il.com>,
        <bellosilicio@...il.com>, <andrealmeid@...lia.com>,
        <trix@...hat.com>, <jsg@....id.au>, <arnd@...db.de>,
        <andrew@...n.ch>
CC:     <linux-kernel@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
        <amd-gfx@...ts.freedesktop.org>, <dri-devel@...ts.freedesktop.org>,
        <linux-wireless@...r.kernel.org>, <netdev@...r.kernel.org>,
        Evan Quan <evan.quan@....com>,
        Mario Limonciello <mario.limonciello@....com>
Subject: [PATCH V8 7/9] drm/amd/pm: add flood detection for wbrf events

To protect PMFW from being overloaded.

Signed-off-by: Evan Quan <evan.quan@....com>
Reviewed-by: Mario Limonciello <mario.limonciello@....com>
---
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     | 31 +++++++++++++++----
 drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  7 +++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
index 163037bd6d16..aa5e1123ac0a 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
@@ -1318,7 +1318,8 @@ static int smu_wbrf_event_handler(struct notifier_block *nb,
 
 	switch (action) {
 	case WBRF_CHANGED:
-		smu_wbrf_handle_exclusion_ranges(smu);
+		schedule_delayed_work(&smu->wbrf_delayed_work,
+				      msecs_to_jiffies(SMU_WBRF_EVENT_HANDLING_PACE));
 		break;
 	default:
 		return NOTIFY_DONE;
@@ -1327,6 +1328,21 @@ static int smu_wbrf_event_handler(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
+/**
+ * smu_wbrf_delayed_work_handler - callback on delayed work timer expired
+ *
+ * @work: struct work_struct pointer
+ *
+ * Flood is over and driver will consume the latest exclusion ranges.
+ */
+static void smu_wbrf_delayed_work_handler(struct work_struct *work)
+{
+	struct smu_context *smu =
+		container_of(work, struct smu_context, wbrf_delayed_work.work);
+
+	smu_wbrf_handle_exclusion_ranges(smu);
+}
+
 /**
  * smu_wbrf_support_check - check wbrf support
  *
@@ -1357,12 +1373,14 @@ static void smu_wbrf_support_check(struct smu_context *smu)
  */
 static int smu_wbrf_init(struct smu_context *smu)
 {
-	struct amdgpu_device *adev = smu->adev;
 	int ret;
 
 	if (!smu->wbrf_supported)
 		return 0;
 
+	INIT_DELAYED_WORK(&smu->wbrf_delayed_work,
+			  smu_wbrf_delayed_work_handler);
+
 	smu->wbrf_notifier.notifier_call = smu_wbrf_event_handler;
 	ret = wbrf_register_notifier(&smu->wbrf_notifier);
 	if (ret)
@@ -1373,11 +1391,10 @@ static int smu_wbrf_init(struct smu_context *smu)
 	 * before our driver loaded. To make sure our driver
 	 * is awared of those exclusion ranges.
 	 */
-	ret = smu_wbrf_handle_exclusion_ranges(smu);
-	if (ret)
-		dev_err(adev->dev, "Failed to handle wbrf exclusion ranges\n");
+	schedule_delayed_work(&smu->wbrf_delayed_work,
+			      msecs_to_jiffies(SMU_WBRF_EVENT_HANDLING_PACE));
 
-	return ret;
+	return 0;
 }
 
 /**
@@ -1393,6 +1410,8 @@ static void smu_wbrf_fini(struct smu_context *smu)
 		return;
 
 	wbrf_unregister_notifier(&smu->wbrf_notifier);
+
+	cancel_delayed_work_sync(&smu->wbrf_delayed_work);
 }
 
 static int smu_smc_hw_setup(struct smu_context *smu)
diff --git a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
index 244297979f92..4d5cb1b511e5 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
+++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
@@ -480,6 +480,12 @@ struct stb_context {
 
 #define WORKLOAD_POLICY_MAX 7
 
+/*
+ * Configure wbrf event handling pace as there can be only one
+ * event processed every SMU_WBRF_EVENT_HANDLING_PACE ms.
+ */
+#define SMU_WBRF_EVENT_HANDLING_PACE	10
+
 struct smu_context
 {
 	struct amdgpu_device            *adev;
@@ -581,6 +587,7 @@ struct smu_context
 	/* data structures for wbrf feature support */
 	bool				wbrf_supported;
 	struct notifier_block		wbrf_notifier;
+	struct delayed_work		wbrf_delayed_work;
 };
 
 struct i2c_adapter;
-- 
2.34.1