[PATCH v5 6/9] coresight-funnel: change funnel_drvdata spinlock's type to raw_spinlock_t
From: Yeoreum Yun <hidden>
Date: 2025-02-25 13:53:40
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
In coresight-funnel drivers, cti_drvdata->spinlock can be held during __schedule() by perf_event_task_sched_out()/in(). Since funnel_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 funnel_drvdata->spinlock in coresight-funnel 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> Reviewed-by: James Clark <james.clark@linaro.org> Reviewed-by: Mike Leach <redacted> --- drivers/hwtracing/coresight/coresight-funnel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index 8faf51469bb8..0541712b2bcb 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c@@ -47,7 +47,7 @@ struct funnel_drvdata { struct clk *pclk; struct coresight_device *csdev; unsigned long priority; - spinlock_t spinlock; + raw_spinlock_t spinlock; }; static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
@@ -85,7 +85,7 @@ static int funnel_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 (in->dest_refcnt == 0) { if (drvdata->base) rc = dynamic_funnel_enable_hw(drvdata, in->dest_port);
@@ -94,7 +94,7 @@ static int funnel_enable(struct coresight_device *csdev, } if (!rc) in->dest_refcnt++; - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (first_enable) dev_dbg(&csdev->dev, "FUNNEL inport %d enabled\n",
@@ -129,13 +129,13 @@ static void funnel_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 (--in->dest_refcnt == 0) { if (drvdata->base) dynamic_funnel_disable_hw(drvdata, in->dest_port); last_disable = true; } - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (last_disable) dev_dbg(&csdev->dev, "FUNNEL inport %d disabled\n",
@@ -266,7 +266,7 @@ static int funnel_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_MERG; desc.ops = &funnel_cs_ops;
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}