[RFC PATCH v2 11/11] nvme-pci: Convert to using dma_map_sg for p2pdma pages

[Logan Gunthorpe]

Convert to using dma_[un]map_sg() for PCI p2pdma pages.

This should be equivalent, though support will be somewhat less
(only dma-direct and dma-iommu are currently supported).

Signed-off-by: Logan Gunthorpe <logang at deltatee.com>
---
 drivers/nvme/host/pci.c | 27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 7d40c6a9e58e..89ca5acf7a62 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -577,17 +577,6 @@ static void nvme_free_sgls(struct nvme_dev *dev, struct request *req)
 
 }
 
-static void nvme_unmap_sg(struct nvme_dev *dev, struct request *req)
-{
-	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
-
-	if (is_pci_p2pdma_page(sg_page(iod->sg)))
-		pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents,
-				    rq_dma_dir(req));
-	else
-		dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
-}
-
 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
@@ -600,7 +589,7 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
 
 	WARN_ON_ONCE(!iod->nents);
 
-	nvme_unmap_sg(dev, req);
+	dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
 	if (iod->npages == 0)
 		dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
 			      iod->first_dma);
@@ -868,13 +857,11 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
 	if (!iod->nents)
 		goto out_free_sg;
 
-	if (is_pci_p2pdma_page(sg_page(iod->sg)))
-		nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg,
-				iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN);
-	else
-		nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
-					     rq_dma_dir(req), DMA_ATTR_NO_WARN);
-	if (!nr_mapped)
+	nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
+				     rq_dma_dir(req), DMA_ATTR_NO_WARN);
+	if (nr_mapped < 0)
+		ret = BLK_STS_P2PDMA;
+	if (nr_mapped <= 0)
 		goto out_free_sg;
 
 	iod->use_sgl = nvme_pci_use_sgls(dev, req);
@@ -887,7 +874,7 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
 	return BLK_STS_OK;
 
 out_unmap_sg:
-	nvme_unmap_sg(dev, req);
+	dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
 out_free_sg:
 	mempool_free(iod->sg, dev->iod_mempool);
 	return ret;
-- 
2.20.1