[PATCH v3 09/31] coresight: etm4x: Add flag to control single-shot restart

[Leo Yan]

Add a new argument restart_ss to etm4_enable_hw(). When passed as true,
it resets the TRCSSCSRn.STATUS bit to 0 to re-enable single-shot
control.

No functional change. This is a preparation for a subsequent change.

Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index fbcd0fcd1992cd600d2eb8c95ae9a5adf0c287da..f61c9924ad0496be2e41c84172c2bbe348df7b60 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -487,7 +487,7 @@ static int etm4_enable_trace_unit(struct etmv4_drvdata *drvdata)
 	return 0;
 }
 
-static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
+static int etm4_enable_hw(struct etmv4_drvdata *drvdata, bool restart_ss)
 {
 	int i, rc;
 	struct etmv4_config *config = &drvdata->config;
@@ -562,9 +562,11 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
 
 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
-		/* always clear status bit on restart if using single-shot */
-		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
-			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
+		if (restart_ss) {
+			/* always clear status bit on restart if using single-shot */
+			if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
+				config->ss_status[i] &= ~TRCSSCSRn_STATUS;
+		}
 		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
 		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
 		if (etm4x_sspcicrn_present(drvdata, i))
@@ -628,7 +630,7 @@ static void etm4_enable_hw_smp_call(void *info)
 		return;
 	}
 
-	arg->rc = etm4_enable_hw(arg->drvdata);
+	arg->rc = etm4_enable_hw(arg->drvdata, true);
 
 	/* The tracer didn't start */
 	if (arg->rc)
@@ -867,7 +869,7 @@ static int etm4_enable_perf(struct coresight_device *csdev,
 	drvdata->paused = !!READ_ONCE(event->hw.aux_paused);
 
 	/* And enable it */
-	ret = etm4_enable_hw(drvdata);
+	ret = etm4_enable_hw(drvdata, true);
 
 out:
 	/* The tracer didn't start */
@@ -1833,7 +1835,7 @@ static int etm4_starting_cpu(unsigned int cpu)
 		etm4_os_unlock(etmdrvdata[cpu]);
 
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
-		etm4_enable_hw(etmdrvdata[cpu]);
+		etm4_enable_hw(etmdrvdata[cpu], true);
 	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }

-- 
2.34.1