coresight-replicator: change replicator_drvdata spinlock's type to raw_spinlock_t

In coresight-replicator drivers, replicator_drvdata->spinlock can be held
during __schedule() by perf_event_task_sched_out()/in().

Since replicator_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 replicator_drvdata->spinlock in
coresight-replicator 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>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250306121110.1647948-8-yeoreum.yun@arm.com

diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index a1181c9048c08e580d6a14db5c4b72d0d924c49f..ee7ee79f6cf7750c41d5d53c5120c32e3c683066 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -41,7 +41,7 @@ struct replicator_drvdata {
        struct clk              *atclk;
        struct clk              *pclk;
        struct coresight_device *csdev;
-       spinlock_t              spinlock;
+       raw_spinlock_t          spinlock;
        bool                    check_idfilter_val;
 };
 
@@ -125,7 +125,7 @@ static int replicator_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 (out->src_refcnt == 0) {
                if (drvdata->base)
                        rc = dynamic_replicator_enable(drvdata, in->dest_port,
@@ -135,7 +135,7 @@ static int replicator_enable(struct coresight_device *csdev,
        }
        if (!rc)
                out->src_refcnt++;
-       spin_unlock_irqrestore(&drvdata->spinlock, flags);
+       raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        if (first_enable)
                dev_dbg(&csdev->dev, "REPLICATOR enabled\n");
@@ -179,14 +179,14 @@ static void replicator_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 (--out->src_refcnt == 0) {
                if (drvdata->base)
                        dynamic_replicator_disable(drvdata, in->dest_port,
                                                   out->src_port);
                last_disable = true;
        }
-       spin_unlock_irqrestore(&drvdata->spinlock, flags);
+       raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        if (last_disable)
                dev_dbg(&csdev->dev, "REPLICATOR disabled\n");
@@ -277,7 +277,7 @@ static int replicator_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_SPLIT;
        desc.ops = &replicator_cs_ops;