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coresight-funnel: change funnel_drvdata spinlock's type to raw_spinlock_t

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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 <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250306121110.1647948-7-yeoreum.yun@arm.com
This commit is contained in:
Yeoreum Yun 2025-03-06 12:11:07 +00:00 committed by Suzuki K Poulose
parent 6b80c0abe4
commit 56eb02f0b0
1 changed files with 6 additions and 6 deletions
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12
drivers/hwtracing/coresight/coresight-funnel.c
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@ -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;