Hi Rob,
On Mon, Jan 13, 2020 at 08:39:06AM -0600, Rob Herring wrote:
> Similar to commit 2af2e72b18b4 ("iommu/arm-smmu-v3: Defer TLB
> invalidation until ->iotlb_sync()"), build up a list of ATC invalidation
> commands and submit them all at once to the command queue instead of
> one-by-one.
>
> Cc: Jean-Philippe Brucker <jean-phili...@linaro.org>
> Cc: Will Deacon <w...@kernel.org>
> Cc: Robin Murphy <robin.mur...@arm.com>
> Cc: Joerg Roedel <j...@8bytes.org>
> Signed-off-by: Rob Herring <r...@kernel.org>
> ---
> drivers/iommu/arm-smmu-v3.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index effe72eb89e7..e91b4a098215 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -1919,10 +1919,11 @@ static int arm_smmu_atc_inv_master(struct
> arm_smmu_master *master,
> static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
> int ssid, unsigned long iova, size_t size)
> {
> - int ret = 0;
> + int i, cmdn = 0;
> unsigned long flags;
> struct arm_smmu_cmdq_ent cmd;
> struct arm_smmu_master *master;
> + u64 cmds[CMDQ_BATCH_ENTRIES * CMDQ_ENT_DWORDS];
>
> if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS))
> return 0;
> @@ -1947,11 +1948,25 @@ static int arm_smmu_atc_inv_domain(struct
> arm_smmu_domain *smmu_domain,
> arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd);
>
> spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> - list_for_each_entry(master, &smmu_domain->devices, domain_head)
> - ret |= arm_smmu_atc_inv_master(master, &cmd);
It may be worth reworking arm_smmu_atc_inv_master() as well since it's now
only called by arm_smmu_disable_ats() to invalidate the whole ATC. I don't
think it requires batching (it's not on any fast path and num_sids will
almost always be 1), but it doesn't need the cmd argument anymore.
Thanks,
Jean
> + list_for_each_entry(master, &smmu_domain->devices, domain_head) {
> + if (!master->ats_enabled)
> + continue;
> +
> + for (i = 0; i < master->num_sids; i++) {
> + if (cmdn == CMDQ_BATCH_ENTRIES) {
> + arm_smmu_cmdq_issue_cmdlist(smmu_domain->smmu,
> + cmds, cmdn, false);
> + cmdn = 0;
> + }
> +
> + cmd.atc.sid = master->sids[i];
> + arm_smmu_cmdq_build_cmd(&cmds[cmdn * CMDQ_ENT_DWORDS],
> &cmd);
> + cmdn++;
> + }
> + }
> spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
>
> - return ret ? -ETIMEDOUT : 0;
> + return arm_smmu_cmdq_issue_cmdlist(smmu_domain->smmu, cmds, cmdn, true);
> }
>
> /* IO_PGTABLE API */
> --
> 2.20.1
>
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