From: Logan Gunthorpe <logang@deltatee.com>
Date: Fri, 8 Jul 2022 10:50:58 -0600
Subject: iommu: Explicitly skip bus address marked segments in
 __iommu_map_sg()
Git-commit: c96321834b2f7aa442cf4c076f73d8273e622725
Patch-mainline: v6.0-rc1
References: bsc#1205701

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>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 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);
 	}