[PATCH v2] coresight: tmc-etr: Fix perf_data check.

[Yabin Cui]

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.

Fixes: 3147da92a8a8 ("coresight: tmc-etr: Allocate and free ETR memory buffers 
for CPU-wide scenarios")
Signed-off-by: Yabin Cui <yab...@google.com>
---

v1 -> v2: rename perf_data to perf_buf. Add fixes tag.

---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 +++---
 drivers/hwtracing/coresight/coresight-tmc.h     | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c 
b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 17006705287a..90d1548ad268 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;
@@ -1497,7 +1497,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
 
        CS_LOCK(drvdata->base);
        /* Reset perf specific data */
-       drvdata->perf_data = NULL;
+       drvdata->perf_buf = NULL;
        spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
        size = etr_buf->len;
@@ -1556,7 +1556,7 @@ 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;
+       drvdata->perf_buf = etr_perf->etr_buf;
 
        /*
         * No HW configuration is needed if the sink is already in
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