From 27b8f6673a53a63531922bd4c96623c2b8299cc2 Mon Sep 17 00:00:00 2001 From: Mike Leach Date: Wed, 2 Aug 2017 10:22:03 -0600 Subject: [PATCH] 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 Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm4x.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 532adc9dd32a..ac77b4c973d8 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -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;