Re: [PATCHv2] iommu/arm-smmu-qcom: Add debug support for TLB sync timeouts

From: Sai Prakash Ranjan
Date: Thu Jun 23 2022 - 02:02:31 EST


On 5/26/2022 9:44 AM, Sai Prakash Ranjan wrote:
TLB sync timeouts can be due to various reasons such as TBU power down
or pending TCU/TBU invalidation/sync and so on. Debugging these often
require dumping of some implementation defined registers to know the
status of TBU/TCU operations and some of these registers are not
accessible in non-secure world such as from kernel and requires SMC
calls to read them in the secure world. So, add this debug support
to dump implementation defined registers for TLB sync timeout issues.

Signed-off-by: Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx>
---

Changes in v2:
* Use scm call consistently so that it works on older chipsets where
some of these regs are secure registers.
* Add device specific data to get the implementation defined register
offsets.

---
drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 161 ++++++++++++++++++---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 2 +
drivers/iommu/arm/arm-smmu/arm-smmu.h | 1 +
3 files changed, 146 insertions(+), 18 deletions(-)

Any comments on this patch?

Thanks,
Sai