tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

coresight-etb10: change etb_drvdata spinlock's type to raw_spinlock_t

Browse Source 
[ 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>
This commit is contained in:
Yeoreum Yun
2025-03-06 12:11:06 +00:00
committed by Greg Kroah-Hartman
parent 75ae2a3553
commit 9032252905
1 changed files with 13 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/hwtracing/coresight/coresight-etb10.c
View File

@@ -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);