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From: Yeoreum Yun <yeoreum.yun@arm.com>
To: suzuki.poulose@arm.com, james.clark@linaro.org,
	alexander.shishkin@linux.intel.com, bigeasy@linutronix.de,
	clrkwllms@kernel.org, rostedt@goodmis.org, mike.leach@linaro.org
Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev,
	Yeoreum Yun <yeoreum.yun@arm.com>
Subject: [PATCH v4 7/9] coresight-replicator: change replicator_drvdata spinlock's type to raw_spinlock_t
Date: Fri, 20 Dec 2024 10:45:19 +0000	[thread overview]
Message-ID: <20241220104521.809071-9-yeoreum.yun@arm.com> (raw)
In-Reply-To: <20241220104521.809071-1-yeoreum.yun@arm.com>

In coresight-replicator drivers, replicator_drvdata->spinlock can be held
during __schedule() by perf_event_task_sched_out()/in().

Since replicator_drvdata->spinlock type is spinlock_t and
perf_event_task_sched_out()/in() is called after acquiring rq_lock,
which is raw_spinlock_t (an unsleepable lock),
this poses an issue in PREEMPT_RT kernel where spinlock_t is sleepable.

To address this, change type replicator_drvdata->spinlock in
coresight-replicator drivers, which can be called
by perf_event_task_sched_out()/in(), from spinlock_t to raw_spinlock_t.

Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-replicator.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 0fba87de6d1a..7d36fe2176cc 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -41,7 +41,7 @@ struct replicator_drvdata {
 	struct clk		*atclk;
 	struct clk		*pclk;
 	struct coresight_device	*csdev;
-	spinlock_t		spinlock;
+	raw_spinlock_t		spinlock;
 	bool			check_idfilter_val;
 };
 
@@ -125,7 +125,7 @@ static int replicator_enable(struct coresight_device *csdev,
 	unsigned long flags;
 	bool first_enable = false;
 
-	spin_lock_irqsave(&drvdata->spinlock, flags);
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
 	if (atomic_read(&out->src_refcnt) == 0) {
 		if (drvdata->base)
 			rc = dynamic_replicator_enable(drvdata, in->dest_port,
@@ -135,7 +135,7 @@ static int replicator_enable(struct coresight_device *csdev,
 	}
 	if (!rc)
 		atomic_inc(&out->src_refcnt);
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	if (first_enable)
 		dev_dbg(&csdev->dev, "REPLICATOR enabled\n");
@@ -179,14 +179,14 @@ static void replicator_disable(struct coresight_device *csdev,
 	unsigned long flags;
 	bool last_disable = false;
 
-	spin_lock_irqsave(&drvdata->spinlock, flags);
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
 	if (atomic_dec_return(&out->src_refcnt) == 0) {
 		if (drvdata->base)
 			dynamic_replicator_disable(drvdata, in->dest_port,
 						   out->src_port);
 		last_disable = true;
 	}
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	if (last_disable)
 		dev_dbg(&csdev->dev, "REPLICATOR disabled\n");
@@ -277,7 +277,7 @@ static int replicator_probe(struct device *dev, struct resource *res)
 	}
 	dev->platform_data = pdata;
 
-	spin_lock_init(&drvdata->spinlock);
+	raw_spin_lock_init(&drvdata->spinlock);
 	desc.type = CORESIGHT_DEV_TYPE_LINK;
 	desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
 	desc.ops = &replicator_cs_ops;
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}


  parent reply	other threads:[~2024-12-20 10:45 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-20 10:45 [PATCH v4 0/9] coresight: change some driver' spinlock " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 1/9] coresight: change coresight_device lock " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 1/1] coresight/ultrasoc: change smb_drv_data spinlock's " Yeoreum Yun
2024-12-20 10:46   ` Yeo Reum Yun
2024-12-20 10:45 ` [PATCH v4 2/9] coresight-etm4x: change etmv4_drvdata spinlock " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 3/9] coresight: change coresight_trace_id_map's lock " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 4/9] coresight-cti: change cti_drvdata spinlock's " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 5/9] coresight-etb10: change etb_drvdata " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 6/9] coresight-funnel: change funnel_drvdata " Yeoreum Yun
2024-12-20 10:45 ` Yeoreum Yun [this message]
2024-12-20 10:45 ` [PATCH v4 8/9] coresight-tmc: change tmc_drvdata " Yeoreum Yun
2024-12-20 10:45 ` [PATCH v4 9/9] coresight/ultrasoc: change smb_drv_data " Yeoreum Yun
2024-12-31 14:44 ` [PATCH v4 0/9] coresight: change some driver' spinlock " Yeo Reum Yun
2025-02-25 10:23 ` Suzuki K Poulose
2025-02-25 13:53   ` Yeo Reum Yun

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