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Diffstat (limited to 'drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c')
-rw-r--r--drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c18
1 files changed, 16 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 034ed126e5c8..bfa953a07cf7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1524,6 +1524,20 @@ arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
size_t inval_grain_shift = 12;
unsigned long page_start, page_end;
+ /*
+ * ATS and PASID:
+ *
+ * If substream_valid is clear, the PCIe TLP is sent without a PASID
+ * prefix. In that case all ATC entries within the address range are
+ * invalidated, including those that were requested with a PASID! There
+ * is no way to invalidate only entries without PASID.
+ *
+ * When using STRTAB_STE_1_S1DSS_SSID0 (reserving CD 0 for non-PASID
+ * traffic), translation requests without PASID create ATC entries
+ * without PASID, which must be invalidated with substream_valid clear.
+ * This has the unpleasant side-effect of invalidating all PASID-tagged
+ * ATC entries within the address range.
+ */
*cmd = (struct arm_smmu_cmdq_ent) {
.opcode = CMDQ_OP_ATC_INV,
.substream_valid = !!ssid,
@@ -1582,8 +1596,8 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
return arm_smmu_cmdq_issue_sync(master->smmu);
}
-static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
- int ssid, unsigned long iova, size_t size)
+int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
+ unsigned long iova, size_t size)
{
int i;
unsigned long flags;