Commit f36dec8d authored by Leo Yan's avatar Leo Yan Committed by Mathieu Poirier
Browse files

coresight: tmc-etr: Use perf_output_handle::head for AUX ring buffer 



When enable the Arm CoreSight PMU event, the context for AUX ring buffer
is prepared in the structure perf_output_handle, and its field "head"
points the head of the AUX ring buffer and it is updated after filling
AUX trace data into buffer.

Current code uses an extra field etr_perf_buffer::head to maintain the
header for the AUX ring buffer which is not necessary; alternatively,
it's better to directly use perf_output_handle::head.

This patch removes the field etr_perf_buffer::head and directly uses
perf_output_handle::head for the head of AUX ring buffer.

Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210912125748.2816606-2-leo.yan@linaro.org


Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
parent bd8d0688

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

+3 −7
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ struct etr_flat_buf { 
 * @etr_buf		- Actual buffer used by the ETR

 * @pid			- The PID this etr_perf_buffer belongs to.

 * @snaphost		- Perf session mode

 * @head		- handle->head at the beginning of the session.

 * @nr_pages		- Number of pages in the ring buffer.

 * @pages		- Array of Pages in the ring buffer.

 */
@@ -41,7 +40,6 @@ struct etr_perf_buffer { 
	struct etr_buf		*etr_buf;

	pid_t			pid;

	bool			snapshot;

	unsigned long		head;

	int			nr_pages;

	void			**pages;

};
@@ -1438,16 +1436,16 @@ static void tmc_free_etr_buffer(void *config) 
 * buffer to the perf ring buffer.

 */

static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,

				     unsigned long head,

				     unsigned long src_offset,

				     unsigned long to_copy)

{

	long bytes;

	long pg_idx, pg_offset;

	unsigned long head = etr_perf->head;

	char **dst_pages, *src_buf;

	struct etr_buf *etr_buf = etr_perf->etr_buf;



	head = etr_perf->head;

	head = PERF_IDX2OFF(head, etr_perf);

	pg_idx = head >> PAGE_SHIFT;

	pg_offset = head & (PAGE_SIZE - 1);

	dst_pages = (char **)etr_perf->pages;
@@ -1554,7 +1552,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev, 
	/* Insert barrier packets at the beginning, if there was an overflow */

	if (lost)

		tmc_etr_buf_insert_barrier_packet(etr_buf, offset);

	tmc_etr_sync_perf_buffer(etr_perf, offset, size);

	tmc_etr_sync_perf_buffer(etr_perf, handle->head, offset, size);



	/*

	 * In snapshot mode we simply increment the head by the number of byte
@@ -1614,8 +1612,6 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data) 
		goto unlock_out;

	}



	etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf);



	/*

	 * No HW configuration is needed if the sink is already in

	 * use for this session.