iommu/arm-smmu-v3: Use command queue batching helpers to improve performance

The obvious key to the performance optimization of commit 587e6c1
("iommu/arm-smmu-v3: Reduce contention during command-queue insertion") is
to allow multiple cores to insert commands in parallel after a brief mutex
contention.

Obviously, inserting as many commands at a time as possible can reduce the
number of times the mutex contention participates, thereby improving the
overall performance. At least it reduces the number of calls to function
arm_smmu_cmdq_issue_cmdlist().

Therefore, use command queue batching helpers to insert multiple commands
at a time.

Signed-off-by: Zhen Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: Zhen Lei

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

@@ -1747,15 +1747,16 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
 {
 	int i;
 	struct arm_smmu_cmdq_ent cmd;
+	struct arm_smmu_cmdq_batch cmds = {};
 
 	arm_smmu_atc_inv_to_cmd(0, 0, 0, &cmd);
 
 	for (i = 0; i < master->num_streams; i++) {
 		cmd.atc.sid = master->streams[i].id;
-		arm_smmu_cmdq_issue_cmd(master->smmu, &cmd);
+		arm_smmu_cmdq_batch_add(master->smmu, &cmds, &cmd);
 	}
 
-	return arm_smmu_cmdq_issue_sync(master->smmu);
+	return arm_smmu_cmdq_batch_submit(master->smmu, &cmds);
 }
 
 int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,