Switch to using sg_dma_p2pdma_len() in places where sg_dma_len() is
used. Then replace the calls to pci_p2pdma_[un]map_sg() with calls
to dma_[un]map_sg() with DMA_ATTR_P2PDMA.

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

Using DMA_ATTR_P2PDMA is safe because the block layer restricts
requests to be much less than 2GB, thus there's no way for a
segment to be greater than 2GB.

Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
---
 drivers/nvme/host/pci.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ef7ce464a48d..26976bdf4af0 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -528,12 +528,8 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct 
request *req)
 
        WARN_ON_ONCE(!iod->nents);
 
-       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));
-
+       dma_unmap_sg_attrs(dev->dev, iod->sg, iod->nents, rq_dma_dir(req),
+                          DMA_ATTR_P2PDMA);
 
        if (iod->npages == 0)
                dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
@@ -570,7 +566,7 @@ static void nvme_print_sgl(struct scatterlist *sgl, int 
nents)
                pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
                        "dma_address:%pad dma_length:%d\n",
                        i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
-                       sg_dma_len(sg));
+                       sg_dma_p2pdma_len(sg));
        }
 }
 
@@ -581,7 +577,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev 
*dev,
        struct dma_pool *pool;
        int length = blk_rq_payload_bytes(req);
        struct scatterlist *sg = iod->sg;
-       int dma_len = sg_dma_len(sg);
+       int dma_len = sg_dma_p2pdma_len(sg);
        u64 dma_addr = sg_dma_address(sg);
        int offset = dma_addr & (NVME_CTRL_PAGE_SIZE - 1);
        __le64 *prp_list;
@@ -601,7 +597,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev 
*dev,
        } else {
                sg = sg_next(sg);
                dma_addr = sg_dma_address(sg);
-               dma_len = sg_dma_len(sg);
+               dma_len = sg_dma_p2pdma_len(sg);
        }
 
        if (length <= NVME_CTRL_PAGE_SIZE) {
@@ -650,7 +646,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev 
*dev,
                        goto bad_sgl;
                sg = sg_next(sg);
                dma_addr = sg_dma_address(sg);
-               dma_len = sg_dma_len(sg);
+               dma_len = sg_dma_p2pdma_len(sg);
        }
 
 done:
@@ -670,7 +666,7 @@ static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge,
                struct scatterlist *sg)
 {
        sge->addr = cpu_to_le64(sg_dma_address(sg));
-       sge->length = cpu_to_le32(sg_dma_len(sg));
+       sge->length = cpu_to_le32(sg_dma_p2pdma_len(sg));
        sge->type = NVME_SGL_FMT_DATA_DESC << 4;
 }
 
@@ -814,14 +810,12 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, 
struct request *req,
        if (!iod->nents)
                goto out;
 
-       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 | DMA_ATTR_P2PDMA);
+       if (!nr_mapped) {
+               ret = BLK_STS_IOERR;
                goto out;
+       }
 
        iod->use_sgl = nvme_pci_use_sgls(dev, req);
        if (iod->use_sgl)
-- 
2.20.1

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