When tracing etm data of multiple threads on multiple cpus through
perf interface, each cpu has a unique etr_perf_buffer while sharing
the same etr device. There is no guarantee that the last cpu starts
etm tracing also stops last. This makes perf_data check fail.
Fix it by checking etr_buf instead of etr_perf_buffer.
Also move the code setting and clearing perf_buf to more suitable
places.
Fixes: 3147da92a8a8 ("coresight: tmc-etr: Allocate and free ETR memory buffers
for CPU-wide scenarios")
Signed-off-by: Yabin Cui <yab...@google.com>
---
v2 -> v3:
moved place of setting drvdata->perf_buf based on review comment.
Also moved place of clearing drvdata->perf_buf from
tmc_update_etr_buffer() to tmc_disable_etr_sink() for below
situation:
cpu 0 enable etr device (set perf_buf)
cpu 0 update etr buffer (clear perf_buf)
cpu 1 enable etr device (perf_buf isn't set because pid set by cpu 0)
cpu 0 disable etr device
cpu 1 update etr buffer (perf_buf == NULL, check fails)
To fix it, we need to move clearing perf_buf to the disable function.
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 8 ++++----
drivers/hwtracing/coresight/coresight-tmc.h | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 17006705287a..80af313f55d7 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1484,7 +1484,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
goto out;
}
- if (WARN_ON(drvdata->perf_data != etr_perf)) {
+ if (WARN_ON(drvdata->perf_buf != etr_buf)) {
lost = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
goto out;
@@ -1496,8 +1496,6 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
tmc_sync_etr_buf(drvdata);
CS_LOCK(drvdata->base);
- /* Reset perf specific data */
- drvdata->perf_data = NULL;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
size = etr_buf->len;
@@ -1556,7 +1554,6 @@ static int tmc_enable_etr_sink_perf(struct
coresight_device *csdev, void *data)
}
etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf);
- drvdata->perf_data = etr_perf;
/*
* No HW configuration is needed if the sink is already in
@@ -1572,6 +1569,7 @@ static int tmc_enable_etr_sink_perf(struct
coresight_device *csdev, void *data)
/* Associate with monitored process. */
drvdata->pid = pid;
drvdata->mode = CS_MODE_PERF;
+ drvdata->perf_buf = etr_perf->etr_buf;
atomic_inc(csdev->refcnt);
}
@@ -1617,6 +1615,8 @@ static int tmc_disable_etr_sink(struct coresight_device
*csdev)
/* Dissociate from monitored process. */
drvdata->pid = -1;
drvdata->mode = CS_MODE_DISABLED;
+ /* Reset perf specific data */
+ drvdata->perf_buf = NULL;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h
b/drivers/hwtracing/coresight/coresight-tmc.h
index 1ed50411cc3c..f9a0c95e9ba2 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -178,8 +178,8 @@ struct etr_buf {
* device configuration register (DEVID)
* @idr: Holds etr_bufs allocated for this ETR.
* @idr_mutex: Access serialisation for idr.
- * @perf_data: PERF buffer for ETR.
- * @sysfs_data: SYSFS buffer for ETR.
+ * @sysfs_buf: SYSFS buffer for ETR.
+ * @perf_buf: PERF buffer for ETR.
*/
struct tmc_drvdata {
void __iomem *base;
@@ -202,7 +202,7 @@ struct tmc_drvdata {
struct idr idr;
struct mutex idr_mutex;
struct etr_buf *sysfs_buf;
- void *perf_data;
+ struct etr_buf *perf_buf;
};
struct etr_buf_operations {
--
2.23.0.rc1.153.gdeed80330f-goog
