From: Yeoreum Yun yeoreum.yun@arm.com
[ Upstream commit 6b80c0abe475ed1017c5e862636049aa1cc17a1a ]
In coresight-etb10 drivers, etb_drvdata->spinlock can be held during __schedule() by perf_event_task_sched_out()/in().
Since etb_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 etb_drvdata->spinlock in coresight-etb10 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/20250306121110.1647948-6-yeoreum.yun@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-etb10.c | 26 +++++++++---------- 1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index aea9ac9c4bd06..7948597d483d2 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -84,7 +84,7 @@ struct etb_drvdata { struct clk *atclk; struct coresight_device *csdev; struct miscdevice miscdev; - spinlock_t spinlock; + raw_spinlock_t spinlock; local_t reading; pid_t pid; u8 *buf; @@ -145,7 +145,7 @@ static int etb_enable_sysfs(struct coresight_device *csdev) unsigned long flags; struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
- spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't messup with perf sessions. */ if (coresight_get_mode(csdev) == CS_MODE_PERF) { @@ -163,7 +163,7 @@ static int etb_enable_sysfs(struct coresight_device *csdev)
csdev->refcnt++; out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; }
@@ -176,7 +176,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data) struct perf_output_handle *handle = data; struct cs_buffers *buf = etm_perf_sink_config(handle);
- spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags);
/* No need to continue if the component is already in used by sysFS. */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { @@ -219,7 +219,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data) }
out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; }
@@ -352,11 +352,11 @@ static int etb_disable(struct coresight_device *csdev) struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); unsigned long flags;
- spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags);
csdev->refcnt--; if (csdev->refcnt) { - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; }
@@ -366,7 +366,7 @@ static int etb_disable(struct coresight_device *csdev) /* Dissociate from monitored process. */ drvdata->pid = -1; coresight_set_mode(csdev, CS_MODE_DISABLED); - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_dbg(&csdev->dev, "ETB disabled\n"); return 0; @@ -443,7 +443,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev,
capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
- spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't do anything if another tracer is using this sink */ if (csdev->refcnt != 1) @@ -566,7 +566,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev, __etb_enable_hw(drvdata); CS_LOCK(drvdata->base); out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
return to_read; } @@ -587,13 +587,13 @@ static void etb_dump(struct etb_drvdata *drvdata) { unsigned long flags;
- spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { __etb_disable_hw(drvdata); etb_dump_hw(drvdata); __etb_enable_hw(drvdata); } - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_dbg(&drvdata->csdev->dev, "ETB dumped\n"); } @@ -746,7 +746,7 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id) drvdata->base = base; desc.access = CSDEV_ACCESS_IOMEM(base);
- spin_lock_init(&drvdata->spinlock); + raw_spin_lock_init(&drvdata->spinlock);
drvdata->buffer_depth = etb_get_buffer_depth(drvdata);