[PATCH 9/9] coresight/ultrasoc: change cti_drvdata spinlock's type to raw_spinlock_t
From: Yeoreum Yun <hidden>
Date: 2024-11-25 09:48:44
Also in:
linux-rt-devel, lkml
Subsystem:
arm/coresight framework and drivers, hardware tracing facilities, the rest · Maintainers:
Suzuki K Poulose, Alexander Shishkin, Linus Torvalds
From: Levi Yun <redacted> 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. Signed-off-by: Yeoreum Yun <redacted> --- 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 ef7f560f0ffa..9ab4aec6955e 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}