[PATCH v2 1/4] coresight: etm4x: Do not hardcode IOMEM access for register restore

Suzuki K Poulose suzuki.poulose at arm.com
Fri Apr 12 07:26:59 PDT 2024


When we restore the register state for ETM4x, while coming back
from CPU idle, we hardcode IOMEM access. This is wrong and could
blow up for an ETM with system instructions access (and for ETE).

Fixes: f5bd523690d2 ("coresight: etm4x: Convert all register accesses")
Reported-by: Yabin Cui <yabinc at google.com>
Reviewed-by: Mike Leach <mike.leach at linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index c2ca4a02dfce..7bd849e28953 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1843,8 +1843,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 {
 	int i;
 	struct etmv4_save_state *state = drvdata->save_state;
-	struct csdev_access tmp_csa = CSDEV_ACCESS_IOMEM(drvdata->base);
-	struct csdev_access *csa = &tmp_csa;
+	struct csdev_access *csa = &drvdata->csdev->access;
+
+	if (WARN_ON(!drvdata->csdev))
+		return;
 
 	etm4_cs_unlock(drvdata, csa);
 	etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET);
-- 
2.34.1




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