iommu/arm-smmu-v3: Support 52-bit virtual address

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.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index b73a5950eb65..1d647104bccc 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -92,6 +92,8 @@
 #define IDR5_OAS_44_BIT                 4
 #define IDR5_OAS_48_BIT                 5
 #define IDR5_OAS_52_BIT                 6
+#define IDR5_VAX                        GENMASK(11, 10)
+#define IDR5_VAX_52_BIT                 1
 
 #define ARM_SMMU_CR0                    0x20
 #define CR0_CMDQEN                      (1 << 3)
@@ -551,6 +553,7 @@ 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)
@@ -1591,7 +1594,8 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
 
         switch (smmu_domain->stage) {
         case ARM_SMMU_DOMAIN_S1:
-                ias = VA_BITS;
+                ias = (smmu->features & ARM_SMMU_FEAT_VAX) ? 52 : 48;
+                ias = min_t(unsigned long, ias, VA_BITS);
                 oas = smmu->ias;
                 fmt = ARM_64_LPAE_S1;
                 finalise_stage_fn = arm_smmu_domain_finalise_s1;
@@ -2645,6 +2649,10 @@ 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 (FIELD_GET(IDR5_VAX, reg) == IDR5_VAX_52_BIT)
+                smmu->features |= ARM_SMMU_FEAT_VAX;
+
         /* Output address size */
         switch (FIELD_GET(IDR5_OAS, reg)) {
         case IDR5_OAS_32_BIT: