| Message ID | 20241216115006.415861-10-yeoreum.yun@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: change some driver' spinlock type to raw_spinlock_t | expand |
Title of patch - this patch has nothing to do with cti_drvdata. Mike On Mon, 16 Dec 2024 at 11:50, Yeoreum Yun <yeoreum.yun@arm.com> wrote: > > 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 <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} > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
Hi Mike. > Title of patch - this patch has nothing to do with cti_drvdata. Sorry. I'll fix this. Thanks > > > On Mon, 16 Dec 2024 at 11:50, Yeoreum Yun <yeoreum.yun@arm.com> wrote: > > > > 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 <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} > > > > > -- > Mike Leach > Principal Engineer, ARM Ltd. > Manchester Design Centre. UK
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; };
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 <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(-)