[PATCH v2 04/15] iommu: Add iommu_group_get_max_opt_dma_size()

[John Garry]

Add a function to return the max optimised DMA size for an IOMMU group.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/iommu/iommu.c | 5 +++++
 include/linux/iommu.h | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 63cdfb11ebed..62e4491f32e0 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2296,6 +2296,11 @@ struct iommu_domain *iommu_get_dma_domain(struct device *dev)
 	return dev->iommu_group->default_domain;
 }
 
+size_t iommu_group_get_max_opt_dma_size(struct iommu_group *group)
+{
+	return group->max_opt_dma_size;
+}
+
 /*
  * IOMMU groups are really the natural working unit of the IOMMU, but
  * the IOMMU API works on domains and devices.  Bridge that gap by
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 32d448050bf7..e26abda94792 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -405,6 +405,7 @@ extern int iommu_sva_unbind_gpasid(struct iommu_domain *domain,
 				   struct device *dev, ioasid_t pasid);
 extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
 extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
+extern size_t iommu_group_get_max_opt_dma_size(struct iommu_group *group);
 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
 		     phys_addr_t paddr, size_t size, int prot);
 extern int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
@@ -653,6 +654,11 @@ static inline struct iommu_domain *iommu_get_domain_for_dev(struct device *dev)
 	return NULL;
 }
 
+static inline size_t iommu_group_get_max_opt_dma_size(struct iommu_group *group)
+{
+	return 0;
+}
+
 static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
 			    phys_addr_t paddr, size_t size, int prot)
 {
-- 
2.26.2