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-rw-r--r--drivers/hwtracing/coresight/coresight-etm.h1
-rw-r--r--drivers/hwtracing/coresight/coresight-etm3x.c18
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 9d8bd4e..9c010eb 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -310,7 +310,9 @@ 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)
@@ -341,14 +343,24 @@ 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;
}
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