[PATCH 6.1 316/473] coresight: etm4x: Do not hardcode IOMEM access for register restore

Greg Kroah-Hartman
2024-06-06T14:17:10Z

From: Suzuki K Poulose <suzuki.poulose@arm.com>

[ Upstream commit 1e7ba33fa591de1cf60afffcabb45600b3607025 ]

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@google.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Yabin Cui <yabinc@google.com>
Link: https://lore.kernel.org/r/20240412142702.2882478-2-suzuki.poulose@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 63fe506a60314..e8adee6017714 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1726,8 +1726,10 @@ 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);
--
2.43.0