diff mbox

coresight: etm4x: Fix enabling of cycle accurate tracing in perf.

Message ID 1483397719-22235-1-git-send-email-mike.leach@linaro.org
State Superseded
Headers show

Commit Message

Mike Leach Jan. 2, 2017, 10:55 p.m. UTC
Using perf record 'cyclacc' option in cs_etm event was not setting up cycle
accurate trace correctly.

Corrects bit set in TRCCONFIGR to enable cycle accurate trace.
Programs TRCCCCTLR with a valid threshold value as required by ETMv4 spec.

Signed-off-by: Mike Leach <mike.leach@linaro.org>

---
 drivers/hwtracing/coresight/coresight-etm4x.c | 7 +++++--
 drivers/hwtracing/coresight/coresight-etm4x.h | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Comments

Mathieu Poirier Jan. 3, 2017, 4:57 p.m. UTC | #1
On Mon, Jan 02, 2017 at 10:55:19PM +0000, Mike Leach wrote:
> Using perf record 'cyclacc' option in cs_etm event was not setting up cycle

> accurate trace correctly.

> 

> Corrects bit set in TRCCONFIGR to enable cycle accurate trace.

> Programs TRCCCCTLR with a valid threshold value as required by ETMv4 spec.


This look good - just a tiny blip below.

> 

> Signed-off-by: Mike Leach <mike.leach@linaro.org>

> ---

>  drivers/hwtracing/coresight/coresight-etm4x.c | 7 +++++--

>  drivers/hwtracing/coresight/coresight-etm4x.h | 1 +

>  2 files changed, 6 insertions(+), 2 deletions(-)

> 

> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c

> index 4db8d6a..07be032 100644

> --- a/drivers/hwtracing/coresight/coresight-etm4x.c

> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c

> @@ -216,8 +216,11 @@ static int etm4_parse_event_config(struct etmv4_drvdata *drvdata,

>  		goto out;

>  

>  	/* Go from generic option to ETMv4 specifics */

> -	if (attr->config & BIT(ETM_OPT_CYCACC))

> -		config->cfg |= ETMv4_MODE_CYCACC;

> +	if (attr->config & BIT(ETM_OPT_CYCACC)) {

> +		config->cfg |= BIT(4);

> +		/* TRM: Must program this for cycacc to work */

> +		config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT;

> +	}

>  	if (attr->config & BIT(ETM_OPT_TS))

>  		config->cfg |= ETMv4_MODE_TIMESTAMP;

>  

> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h

> index ba8d3f8..8a62c6c 100644

> --- a/drivers/hwtracing/coresight/coresight-etm4x.h

> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h

> @@ -146,6 +146,7 @@

>  #define ETM_ARCH_V4			0x40

>  #define ETMv4_SYNC_MASK			0x1F

>  #define ETM_CYC_THRESHOLD_MASK		0xFFF

> +#define ETM_CYC_THRESHOLD_DEFAULT       256


If only to be consistent with the rest of the defines, please write this value
in base-16.

Thanks,
Mathieu

>  #define ETMv4_EVENT_MASK		0xFF

>  #define ETM_CNTR_MAX_VAL		0xFFFF

>  #define ETM_TRACEID_MASK		0x3f

> -- 

> 2.7.4

> 


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox

Patch

diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 4db8d6a..07be032 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -216,8 +216,11 @@  static int etm4_parse_event_config(struct etmv4_drvdata *drvdata,
 		goto out;
 
 	/* Go from generic option to ETMv4 specifics */
-	if (attr->config & BIT(ETM_OPT_CYCACC))
-		config->cfg |= ETMv4_MODE_CYCACC;
+	if (attr->config & BIT(ETM_OPT_CYCACC)) {
+		config->cfg |= BIT(4);
+		/* TRM: Must program this for cycacc to work */
+		config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT;
+	}
 	if (attr->config & BIT(ETM_OPT_TS))
 		config->cfg |= ETMv4_MODE_TIMESTAMP;
 
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index ba8d3f8..8a62c6c 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -146,6 +146,7 @@ 
 #define ETM_ARCH_V4			0x40
 #define ETMv4_SYNC_MASK			0x1F
 #define ETM_CYC_THRESHOLD_MASK		0xFFF
+#define ETM_CYC_THRESHOLD_DEFAULT       256
 #define ETMv4_EVENT_MASK		0xFF
 #define ETM_CNTR_MAX_VAL		0xFFFF
 #define ETM_TRACEID_MASK		0x3f