1 files changed, 26 insertions, 19 deletions

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 61d849b11c26..0549249f4b39 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -32,39 +32,28 @@ static void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
 
 static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
 {
-	bool lost = false;
 	char *bufp;
-	const u32 *barrier;
-	u32 read_data, status;
+	u32 read_data, lost;
 	int i;
 
-	/*
-	 * Get a hold of the status register and see if a wrap around
-	 * has occurred.
-	 */
-	status = readl_relaxed(drvdata->base + TMC_STS);
-	if (status & TMC_STS_FULL)
-		lost = true;
-
+	/* Check if the buffer wrapped around. */
+	lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL;
 	bufp = drvdata->buf;
 	drvdata->len = 0;
-	barrier = barrier_pkt;
 	while (1) {
 		for (i = 0; i < drvdata->memwidth; i++) {
 			read_data = readl_relaxed(drvdata->base + TMC_RRD);
 			if (read_data == 0xFFFFFFFF)
-				return;
-
-			if (lost && *barrier) {
-				read_data = *barrier;
-				barrier++;
-			}
-
+				goto done;
 			memcpy(bufp, &read_data, 4);
 			bufp += 4;
 			drvdata->len += 4;
 		}
 	}
+done:
+	if (lost)
+		coresight_insert_barrier_packet(drvdata->buf);
+	return;
 }
 
 static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
@@ -109,6 +98,24 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
 	CS_LOCK(drvdata->base);
 }
 
+/*
+ * Return the available trace data in the buffer from @pos, with
+ * a maximum limit of @len, updating the @bufpp on where to
+ * find it.
+ */
+ssize_t tmc_etb_get_sysfs_trace(struct tmc_drvdata *drvdata,
+				loff_t pos, size_t len, char **bufpp)
+{
+	ssize_t actual = len;
+
+	/* Adjust the len to available size @pos */
+	if (pos + actual > drvdata->len)
+		actual = drvdata->len - pos;
+	if (actual > 0)
+		*bufpp = drvdata->buf + pos;
+	return actual;
+}
+
 static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
 {
 	int ret = 0;