Commit 27b8f667 authored Aug 02, 2017 by Mike Leach Committed by Greg Kroah-Hartman Aug 28, 2017

coresight: etm4x: Adds trace return stack option programming for ETMv4.



Adds handling to program the return stack option into ETMv4 hardware if
specified in the perf command line.

If option is not supported by the hardware then it will be ignored.
This allows capture to move between core/ETM combinations that have the
hardware support to those that do not.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 557587be

drivers/hwtracing/coresight/coresight-etm4x.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -224,6 +224,10 @@ static int etm4_parse_event_config(struct etmv4_drvdata *drvdata,
		if (attr->config & BIT(ETM_OPT_TS))
		/* bit[11], Global timestamp tracing bit */
		config->cfg \|= BIT(11);
		/* return stack - enable if selected and supported */
		if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack)
		/* bit[12], Return stack enable bit */
		config->cfg \|= BIT(12);

		out:
		return ret;

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