Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-06 05:13:18 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

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

Browse Source 
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: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210912125748.2816606-2-leo.yan@linaro.org
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
This commit is contained in:
Leo Yan 2021-09-12 20:57:47 +08:00 committed by Mathieu Poirier
parent bd8d06886d
commit f36dec8da1
1 changed files with 3 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/hwtracing/coresight/coresight-tmc-etr.c
View File

@ -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.