[PATCH rfcv1 1/8] iommu/arm-smmu-v3: Clear cmds->num after arm_smmu_cmdq_batch_submit

Nicolin Chen
2025-08-14T01:26:22Z

None of the callers of arm_smmu_cmdq_batch_submit() cares about the batch
after a submission. So, it'll be certainly safe to nuke the cmds->num, at
least upon a successful one. This will ease a bit a new wrapper function.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 2a8b46b948f05..cccf8f52ee0d5 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -974,11 +974,17 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_device *smmu,
cmds->num++;
}

+/* Clears cmds->num after a successful submission */
static int arm_smmu_cmdq_batch_submit(struct arm_smmu_device *smmu,
struct arm_smmu_cmdq_batch *cmds)
{
- return arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
- cmds->num, true);
+ int ret;
+
+ ret = arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmdq, cmds->cmds,
+ cmds->num, true);
+ if (!ret)
+ cmds->num = 0;
+ return ret;
}

static void arm_smmu_page_response(struct device *dev, struct iopf_fault *unused,
--
2.43.0