From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.poirier@linaro.org (Mathieu Poirier) Date: Wed, 2 Aug 2017 10:22:03 -0600 Subject: [PATCH 09/26] coresight: etm4x: Adds trace return stack option programming for ETMv4. In-Reply-To: <1501690940-4137-1-git-send-email-mathieu.poirier@linaro.org> References: <1501690940-4137-1-git-send-email-mathieu.poirier@linaro.org> Message-ID: <1501690940-4137-10-git-send-email-mathieu.poirier@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Mike Leach 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 --- 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; -- 2.7.4