[PATCH v2 1/2] RDMA/rw: fix error flow during RDMA context initialization

[Max Gurtovoy <maxg@xxxxxxxxxxxx>]

In case the SGL was mapped for P2P DMA operation, we must unmap it using
pci_p2pdma_unmap_sg.

Fixes: 7f73eac3a713 ("PCI/P2PDMA: Introduce pci_p2pdma_unmap_sg()")
Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
---
 drivers/infiniband/core/rw.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
index 4fad732f9b3c..69513b484507 100644
--- a/drivers/infiniband/core/rw.c
+++ b/drivers/infiniband/core/rw.c
@@ -273,6 +273,24 @@ static int rdma_rw_init_single_wr(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
 	return 1;
 }
 
+static void rdma_rw_unmap_sg(struct ib_device *dev, struct scatterlist *sg,
+		u32 sg_cnt, enum dma_data_direction dir)
+{
+	if (is_pci_p2pdma_page(sg_page(sg)))
+		pci_p2pdma_unmap_sg(dev->dma_device, sg, sg_cnt, dir);
+	else
+		ib_dma_unmap_sg(dev, sg, sg_cnt, dir);
+}
+
+static int rdma_rw_map_sg(struct ib_device *dev, struct scatterlist *sg,
+		u32 sg_cnt, enum dma_data_direction dir)
+{
+	if (is_pci_p2pdma_page(sg_page(sg)))
+		return pci_p2pdma_map_sg(dev->dma_device, sg, sg_cnt, dir);
+	else
+		return ib_dma_map_sg(dev, sg, sg_cnt, dir);
+}
+
 /**
  * rdma_rw_ctx_init - initialize a RDMA READ/WRITE context
  * @ctx:	context to initialize
@@ -295,11 +313,7 @@ int rdma_rw_ctx_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
 	struct ib_device *dev = qp->pd->device;
 	int ret;
 
-	if (is_pci_p2pdma_page(sg_page(sg)))
-		ret = pci_p2pdma_map_sg(dev->dma_device, sg, sg_cnt, dir);
-	else
-		ret = ib_dma_map_sg(dev, sg, sg_cnt, dir);
-
+	ret = rdma_rw_map_sg(dev, sg, sg_cnt, dir);
 	if (!ret)
 		return -ENOMEM;
 	sg_cnt = ret;
@@ -338,7 +352,7 @@ int rdma_rw_ctx_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
 	return ret;
 
 out_unmap_sg:
-	ib_dma_unmap_sg(dev, sg, sg_cnt, dir);
+	rdma_rw_unmap_sg(dev, sg, sg_cnt, dir);
 	return ret;
 }
 EXPORT_SYMBOL(rdma_rw_ctx_init);
@@ -588,11 +602,7 @@ void rdma_rw_ctx_destroy(struct rdma_rw_ctx *ctx, struct ib_qp *qp, u8 port_num,
 		break;
 	}
 
-	if (is_pci_p2pdma_page(sg_page(sg)))
-		pci_p2pdma_unmap_sg(qp->pd->device->dma_device, sg,
-				    sg_cnt, dir);
-	else
-		ib_dma_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
+	rdma_rw_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
 }
 EXPORT_SYMBOL(rdma_rw_ctx_destroy);
 
-- 
2.20.1