[PATCH v8 07/13] iommu: Explicitly skip bus address marked segments in __iommu_map_sg()

Logan Gunthorpe
2022-07-08T16:52:09Z

In order to support PCI P2PDMA mappings with dma-iommu, explicitly skip
any segments marked with sg_dma_mark_bus_address() in __iommu_map_sg().

These segments should not be mapped into the IOVA and will be handled
separately in as subsequent patch for dma-iommu.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
drivers/iommu/iommu.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 847ad47a2dfd..2844a3e02a89 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2457,6 +2457,9 @@ static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
len = 0;
}

+ if (sg_is_dma_bus_address(sg))
+ goto next;
+
if (len) {
len += sg->length;
} else {
@@ -2464,6 +2467,7 @@ static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
start = s_phys;
}

+next:
if (++i < nents)
sg = sg_next(sg);
}
--
2.30.2