[RFC PATCH v1 2/2] iommu/arm-smmu-v3: Standardize granule size when support RIL

From: Kunkun Jiang
Date: Wed May 19 2021 - 05:44:37 EST


In __arm_smmu_tlb_inv_range(), the field 'ttl' of TLB invalidation
command is caculated based on granule size when the SMMU supports
RIL. There are some scenarious we need to avoid, which are pointed
out in the SMMUv3 spec(page 143-144, Version D.a). Adding a check
to ensure that the granule size is supported by the SMMU before set
the 'ttl' value.

Reported-by: Nianyao Tang <tangnianyao@xxxxxxxxxx>
Signed-off-by: Kunkun Jiang <jiangkunkun@xxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 +++++
1 file changed, 5 insertions(+)

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 8a2cacbb1ef8..77ff283ca329 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1711,6 +1711,11 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
cmd->tlbi.tg = (tg - 10) / 2;

/* Determine what level the granule is at */
+ if (!(granule & smmu_domain->domain.pgsize_bitmap) ||
+ (granule & (granule - 1))) {
+ granule = leaf_pgsize;
+ iova = ALIGN_DOWN(iova, leaf_pgsize);
+ }
cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3));

/* Align size with the leaf page size upwards */
--
2.23.0