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 1/1] coresight/ultrasoc: change smb_drv_data spinlock's type to raw_spinlock_t
Date: Fri, 20 Dec 2024 10:45:13 +0000 [thread overview]
Message-ID: <20241220104521.809071-3-yeoreum.yun@arm.com> (raw)
In-Reply-To: <20241220104521.809071-1-yeoreum.yun@arm.com>
In ultrasoc-smb drivers, smb_drv_data->spinlock can be held
during __schedule() by perf_event_task_sched_out()/in().
Since smb__drv_data->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 smb_drv_data->spinlock in ultrasoc-smb 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>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
drivers/hwtracing/coresight/ultrasoc-smb.c | 12 ++++++------
drivers/hwtracing/coresight/ultrasoc-smb.h | 2 +-
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index dc3c9504dd7c..26cfc939e5bd 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -98,7 +98,7 @@ static int smb_open(struct inode *inode, struct file *file)
struct smb_drv_data *drvdata = container_of(file->private_data,
struct smb_drv_data, miscdev);
- guard(spinlock)(&drvdata->spinlock);
+ guard(raw_spinlock)(&drvdata->spinlock);
if (drvdata->reading)
return -EBUSY;
@@ -152,7 +152,7 @@ static int smb_release(struct inode *inode, struct file *file)
struct smb_drv_data *drvdata = container_of(file->private_data,
struct smb_drv_data, miscdev);
- guard(spinlock)(&drvdata->spinlock);
+ guard(raw_spinlock)(&drvdata->spinlock);
drvdata->reading = false;
return 0;
@@ -245,7 +245,7 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret = 0;
- guard(spinlock)(&drvdata->spinlock);
+ guard(raw_spinlock)(&drvdata->spinlock);
/* Do nothing, the trace data is reading by other interface now */
if (drvdata->reading)
@@ -280,7 +280,7 @@ static int smb_disable(struct coresight_device *csdev)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
- guard(spinlock)(&drvdata->spinlock);
+ guard(raw_spinlock)(&drvdata->spinlock);
if (drvdata->reading)
return -EBUSY;
@@ -378,7 +378,7 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev,
if (!buf)
return 0;
- guard(spinlock)(&drvdata->spinlock);
+ guard(raw_spinlock)(&drvdata->spinlock);
/* Don't do anything if another tracer is using this sink. */
if (csdev->refcnt != 1)
@@ -563,7 +563,7 @@ static int smb_probe(struct platform_device *pdev)
smb_reset_buffer(drvdata);
platform_set_drvdata(pdev, drvdata);
- spin_lock_init(&drvdata->spinlock);
+ raw_spin_lock_init(&drvdata->spinlock);
drvdata->pid = -1;
ret = smb_register_sink(pdev, drvdata);
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h b/drivers/hwtracing/coresight/ultrasoc-smb.h
index a91d39cfccb8..c4c111275627 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.h
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.h
@@ -115,7 +115,7 @@ struct smb_drv_data {
struct coresight_device *csdev;
struct smb_data_buffer sdb;
struct miscdevice miscdev;
- spinlock_t spinlock;
+ raw_spinlock_t spinlock;
bool reading;
pid_t pid;
};
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
next prev 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 ` Yeoreum Yun [this message]
2024-12-20 10:46 ` [PATCH v4 1/1] coresight/ultrasoc: change smb_drv_data spinlock's " 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 ` [PATCH v4 7/9] coresight-replicator: change replicator_drvdata " Yeoreum Yun
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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