[PATCH v4 1/6] iommu: Add a per domain PASID for DMA API

[Jacob Pan]

DMA requests tagged with PASID can target individual IOMMU domains.
Introduce a domain-wide PASID for DMA API, it will be used on the same
mapping as legacy DMA without PASID. Let it be IOVA or PA in case of
identity domain.

Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
 include/linux/iommu.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9405034e3013..36ad007084cc 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -106,6 +106,8 @@ struct iommu_domain {
 	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
 						      void *data);
 	void *fault_data;
+	ioasid_t dma_pasid;		/* Used for DMA requests with PASID */
+	atomic_t dma_pasid_users;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
-- 
2.25.1