Commit bbedcb91 authored by Yabin Cui's avatar Yabin Cui Committed by Greg Kroah-Hartman
Browse files

coresight: tmc-etr: Fix perf_data check 



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: 3147da92 ("coresight: tmc-etr: Allocate and free ETR memory buffers for CPU-wide scenarios")
Signed-off-by: default avatarYabin Cui <yabinc@google.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190829202842.580-15-mathieu.poirier@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 13af88f3

drivers/hwtracing/coresight/coresight-tmc-etr.c

+4 −4
Original line number Diff line number Diff line
@@ -1488,7 +1488,7 @@ 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;
@@ -1500,8 +1500,6 @@ 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;
@@ -1564,7 +1562,6 @@ 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
@@ -1580,6 +1577,7 @@ 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);

	}
@@ -1625,6 +1623,8 @@ 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);

drivers/hwtracing/coresight/coresight-tmc.h

+3 −3
Original line number Diff line number Diff line
@@ -182,8 +182,8 @@ 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;
@@ -206,7 +206,7 @@ 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 {

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