From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike.leach@linaro.org (Mike Leach) Date: Tue, 11 Jul 2017 12:25:50 +0100 Subject: [PATCH 2/3] coresight: ptm: Adds trace return stack option programming for PTM. In-Reply-To: <1499772351-2210-1-git-send-email-mike.leach@linaro.org> References: <1499772351-2210-1-git-send-email-mike.leach@linaro.org> Message-ID: <1499772351-2210-3-git-send-email-mike.leach@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Adds handling to program the return stack option into PTM 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 --- drivers/hwtracing/coresight/coresight-etm.h | 1 + drivers/hwtracing/coresight/coresight-etm3x.c | 18 +++++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h index ad063d7..70b0a24 100644 --- a/drivers/hwtracing/coresight/coresight-etm.h +++ b/drivers/hwtracing/coresight/coresight-etm.h @@ -106,6 +106,7 @@ #define ETMTECR1_START_STOP BIT(25) /* ETMCCER - 0x1E8 */ #define ETMCCER_TIMESTAMP BIT(22) +#define ETMCCER_RETSTACK BIT(23) #define ETM_MODE_EXCLUDE BIT(0) #define ETM_MODE_CYCACC BIT(1) diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index a51b6b6..a0973f6 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -308,7 +308,9 @@ void etm_config_trace_mode(struct etm_config *config) config->addr_type[1] = ETM_ADDR_TYPE_RANGE; } -#define ETM3X_SUPPORTED_OPTIONS (ETMCR_CYC_ACC | ETMCR_TIMESTAMP_EN) +#define ETM3X_SUPPORTED_OPTIONS (ETMCR_CYC_ACC | \ + ETMCR_TIMESTAMP_EN | \ + ETMCR_RETURN_STACK) static int etm_parse_event_config(struct etm_drvdata *drvdata, struct perf_event *event) @@ -339,14 +341,24 @@ static int etm_parse_event_config(struct etm_drvdata *drvdata, etm_config_trace_mode(config); /* - * At this time only cycle accurate and timestamp options are - * available. + * At this time only cycle accurate, return stack and timestamp + * options are available. */ if (attr->config & ~ETM3X_SUPPORTED_OPTIONS) return -EINVAL; config->ctrl = attr->config; + /* + * Possible to have cores with PTM (supports ret stack) and ETM + * (never has ret stack) on the same SoC. So if we have a request + * for return stack that can't be honoured on this core then + * clear the bit - trace will still continue normally + */ + if ((config->ctrl & ETMCR_RETURN_STACK) && + !(drvdata->etmccer & ETMCCER_RETSTACK)) + config->ctrl &= ~ETMCR_RETURN_STACK; + return 0; } -- 2.7.4