[PATCH rfcv2 1/8] iommu/arm-smmu-v3: Clear cmds->num after arm_smmu_cmdq_batch_submit

[Nicolin Chen]

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 wrapper function, for
the new arm_smmu_invs structure.

Signed-off-by: Nicolin Chen <nicolinc at 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