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

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 <[email protected]> Signed-off-by: Mathieu Poirier <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
imcsk8 · Jan 25, 2017 · ae3fabc · ae3fabc
1 parent f094446
commit ae3fabc
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git 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
@@ -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       0x100
 #define ETMv4_EVENT_MASK		0xFF
 #define ETM_CNTR_MAX_VAL		0xFFFF
 #define ETM_TRACEID_MASK		0x3f