lkml.org 
[lkml]   [2021]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 1/3] coresight: tmc-etr: Use perf_output_handle::head for AUX ring buffer
Date
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 perf_output_handle::head.

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

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etr.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index acdb59e0e661..b22823d67680 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -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;
};
@@ -1437,16 +1435,16 @@ 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;
@@ -1553,7 +1551,7 @@ 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
@@ -1605,8 +1603,6 @@ 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.
--
2.25.1
\
 
 \ /
  Last update: 2021-07-01 11:36    [W:0.086 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site