[RFC PATCH v2 10/10] iommu:riscv: support nested iommu for get_msi_mapping_domain operation

[Zong Li]

Return the iommu_domain that should hold the MSI cookie.

Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
---
 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 d08eb0a2939e..969a0ba32c9e 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1689,10 +1689,22 @@ static int riscv_iommu_cache_invalidate_user(struct iommu_domain *domain,
 	return ret;
 }
 
+static struct iommu_domain *
+riscv_iommu_get_msi_mapping_domain(struct iommu_domain *domain)
+{
+	struct riscv_iommu_domain *riscv_domain = iommu_domain_to_riscv(domain);
+
+	if (riscv_domain->s2)
+		return &riscv_domain->s2->domain;
+
+	return domain;
+}
+
 static const struct iommu_domain_ops riscv_iommu_nested_domain_ops = {
 	.attach_dev	= riscv_iommu_attach_dev_nested,
 	.free		= riscv_iommu_domain_free_nested,
 	.cache_invalidate_user = riscv_iommu_cache_invalidate_user,
+	.get_msi_mapping_domain = riscv_iommu_get_msi_mapping_domain,
 };
 
 static int
-- 
2.17.1