Stage 1 input addresses are effectively 64-bit in SMMUv3 anyway, so
really all that's involved is letting io-pgtable know the appropriate
upper bound for T0SZ.

Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
 drivers/iommu/arm-smmu-v3.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index e251762663c6..a209a02388af 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -102,6 +102,7 @@
 #define IDR5_OAS_44_BIT                        (4 << IDR5_OAS_SHIFT)
 #define IDR5_OAS_48_BIT                        (5 << IDR5_OAS_SHIFT)
 #define IDR5_OAS_52_BIT                        (6 << IDR5_OAS_SHIFT)
+#define IDR5_VAX                       (1 << 10)
 
 #define ARM_SMMU_CR0                   0x20
 #define CR0_CMDQEN                     (1 << 3)
@@ -604,6 +605,7 @@ struct arm_smmu_device {
 #define ARM_SMMU_FEAT_STALLS           (1 << 11)
 #define ARM_SMMU_FEAT_HYP              (1 << 12)
 #define ARM_SMMU_FEAT_STALL_FORCE      (1 << 13)
+#define ARM_SMMU_FEAT_VAX              (1 << 14)
        u32                             features;
 
 #define ARM_SMMU_OPT_SKIP_PREFETCH     (1 << 0)
@@ -1657,6 +1659,8 @@ static int arm_smmu_domain_finalise(struct iommu_domain 
*domain)
        switch (smmu_domain->stage) {
        case ARM_SMMU_DOMAIN_S1:
                ias = VA_BITS;
+               if (VA_BITS > 48 && !(smmu->features & ARM_SMMU_FEAT_VAX))
+                       ias = 48;
                oas = smmu->ias;
                fmt = ARM_64_LPAE_S1;
                finalise_stage_fn = arm_smmu_domain_finalise_s1;
@@ -2695,6 +2699,10 @@ static int arm_smmu_device_hw_probe(struct 
arm_smmu_device *smmu)
        if (reg & IDR5_GRAN4K)
                smmu->pgsize_bitmap |= SZ_4K | SZ_2M | SZ_1G;
 
+       /* Input address size */
+       if (reg & IDR5_VAX)
+               smmu->features |= ARM_SMMU_FEAT_VAX;
+
        /* Output address size */
        switch (reg & IDR5_OAS_MASK << IDR5_OAS_SHIFT) {
        case IDR5_OAS_32_BIT:
-- 
2.13.4.dirty

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