[PATCH RFC 02/11] iommu: Add iommu_domain type for SVA

Lu Baolu
2022-03-20T06:42:49Z

Add a new iommu domain type IOMMU_DOMAIN_SVA to represent an I/O page
table which is shared from CPU host VA. Add a sva_cookie field in the
iommu_domain structure to save the mm_struct which represent the CPU
memory page table.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
include/linux/iommu.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 36f43af0af53..3e179b853380 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -64,6 +64,9 @@ struct iommu_domain_geometry {
#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
#define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */

+#define __IOMMU_DOMAIN_SHARED (1U << 4) /* Page table shared from CPU */
+#define __IOMMU_DOMAIN_HOST_VA (1U << 5) /* Host CPU virtual address */
+
/*
* This are the possible domain-types
*
@@ -86,6 +89,8 @@ struct iommu_domain_geometry {
#define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \
__IOMMU_DOMAIN_DMA_API | \
__IOMMU_DOMAIN_DMA_FQ)
+#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SHARED | \
+ __IOMMU_DOMAIN_HOST_VA)

struct iommu_domain {
unsigned type;
@@ -95,6 +100,7 @@ struct iommu_domain {
void *handler_token;
struct iommu_domain_geometry geometry;
struct iommu_dma_cookie *iova_cookie;
+ struct mm_struct *sva_cookie;
};

static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
--
2.25.1