Commit 7c2cc5e2 authored Oct 19, 2021 by Suzuki K Poulose Committed by Mathieu Poirier Oct 27, 2021

coresight: trbe: Add a helper to determine the minimum buffer size

For the TRBE to operate, we need a minimum space available to collect
meaningful trace session. This is currently a few bytes, but we may need
to extend this for working around errata. So, abstract this into a helper
function.

Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20211019163153.3692640-12-suzuki.poulose@arm.com

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

parent 5cb75f18

drivers/hwtracing/coresight/coresight-trbe.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -303,6 +303,11 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle)
		return buf->nr_pages * PAGE_SIZE;
		}

		static u64 trbe_min_trace_buf_size(struct perf_output_handle *handle)
		{
		return TRBE_TRACE_MIN_BUF_SIZE;
		}

		/*
		* TRBE Limit Calculation
		*
		@@ -473,7 +478,7 @@ static unsigned long trbe_normal_offset(struct perf_output_handle *handle)
		* have space for a meaningful run, we rather pad it
		* and start fresh.
		*/
		if (limit && (limit - head < TRBE_TRACE_MIN_BUF_SIZE)) {
		if (limit && ((limit - head) < trbe_min_trace_buf_size(handle))) {
		trbe_pad_buf(handle, limit - head);
		limit = __trbe_normal_offset(handle);
		}