For supporting BBM Level 2 for userspace mappings, we want to ensure
that the smmu also supports its own version of BBM Level 2. Luckily, the
smmu spec (IHI 0070G 3.21.1.3) is stricter than the aarch64 spec (DDI
0487K.a D8.16.2), so already guarantees that no aborts are raised when
BBM level 2 is claimed.
Add the feature and testing for it under arm_smmu_sva_supported().
Signed-off-by: Mikołaj Lenczewski <miko.lenczewski@xxxxxxx>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 3 +++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 +++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 ++++
3 files changed, 10 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 9ba596430e7c..6ba182572788 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -222,6 +222,9 @@ bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
feat_mask |= ARM_SMMU_FEAT_VAX;
}
+ if (system_supports_bbml2_noabort())
+ feat_mask |= ARM_SMMU_FEAT_BBML2;
+
if ((smmu->features & feat_mask) != feat_mask)
return false;
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 358072b4e293..dcee0bdec924 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -4406,6 +4406,9 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
if (FIELD_GET(IDR3_RIL, reg))
smmu->features |= ARM_SMMU_FEAT_RANGE_INV;
+ if (FIELD_GET(IDR3_BBML, reg) == IDR3_BBML2)
+ smmu->features |= ARM_SMMU_FEAT_BBML2;
+
/* IDR5 */
reg = readl_relaxed(smmu->base + ARM_SMMU_IDR5);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index bd9d7c85576a..85eaf3ab88c2 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -60,6 +60,9 @@ struct arm_smmu_device;
#define ARM_SMMU_IDR3 0xc
#define IDR3_FWB (1 << 8)
#define IDR3_RIL (1 << 10)
+#define IDR3_BBML GENMASK(12, 11)
+#define IDR3_BBML1 (1 << 11)
+#define IDR3_BBML2 (2 << 11)
#define ARM_SMMU_IDR5 0x14
#define IDR5_STALL_MAX GENMASK(31, 16)
@@ -754,6 +757,7 @@ struct arm_smmu_device {
#define ARM_SMMU_FEAT_HA (1 << 21)
#define ARM_SMMU_FEAT_HD (1 << 22)
#define ARM_SMMU_FEAT_S2FWB (1 << 23)
+#define ARM_SMMU_FEAT_BBML2 (1 << 24)
u32 features;
#define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0)
--
2.48.1
