Commit eff19474 authored by Zhen Lei's avatar Zhen Lei Committed by Will Deacon
Browse files

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



The obvious key to the performance optimization of commit 587e6c10
("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: default avatarZhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210811114852.2429-2-thunder.leizhen@huawei.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent ef75702d

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

+3 −2
Original line number Diff line number Diff line
@@ -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,