[RFC PATCH 04/15] iommu/riscv: report iommu capabilities

[Andrew Jones]

From: Tomasz Jeznach <tjeznach at rivosinc.com>

Report RISC-V IOMMU capabilities required by VFIO subsystem
to enable PCIe device assignment.

Signed-off-by: Tomasz Jeznach <tjeznach at rivosinc.com>
Signed-off-by: Andrew Jones <ajones at ventanamicro.com>
---
 drivers/iommu/riscv/iommu.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 8a05def774bd..3fe4ceba8dd3 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1462,6 +1462,17 @@ static struct iommu_group *riscv_iommu_device_group(struct device *dev)
 	return generic_device_group(dev);
 }
 
+static bool riscv_iommu_capable(struct device *dev, enum iommu_cap cap)
+{
+	switch (cap) {
+	case IOMMU_CAP_CACHE_COHERENCY:
+	case IOMMU_CAP_DEFERRED_FLUSH:
+		return true;
+	default:
+		return false;
+	}
+}
+
 static int riscv_iommu_of_xlate(struct device *dev, const struct of_phandle_args *args)
 {
 	return iommu_fwspec_add_ids(dev, args->args, 1);
@@ -1526,6 +1537,7 @@ static void riscv_iommu_release_device(struct device *dev)
 static const struct iommu_ops riscv_iommu_ops = {
 	.pgsize_bitmap = SZ_4K,
 	.of_xlate = riscv_iommu_of_xlate,
+	.capable = riscv_iommu_capable,
 	.identity_domain = &riscv_iommu_identity_domain,
 	.blocked_domain = &riscv_iommu_blocking_domain,
 	.release_domain = &riscv_iommu_blocking_domain,
-- 
2.47.0