[PATCH 16/26] RDMA/uverbs: Use the SGT_P2P mapping type

[Alistair Popple <apopple@nvidia.com>]

From: Jason Gunthorpe <jgg@nvidia.com>

Very similar to habana, except the rejection of unsupported
pci_p2p_dma_distance() is done inside map not attach via
dma_buf_phys_vec_to_sgt().

Convert this directly to a SGT_P2P match which will prevent matching if
dma_buf_phys_vec_to_sgt() would fail.

Remove the now empty attach function.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[ rebase context change, upstream added MODULE_IMPORT_NS("DMA_BUF") - apopple ]
Signed-off-by: Alistair Popple <apopple@nvidia.com>
---
 .../infiniband/core/uverbs_std_types_dmabuf.c | 30 ++++++++++++-------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_std_types_dmabuf.c b/drivers/infiniband/core/uverbs_std_types_dmabuf.c
index 2411ebee69e2..3c5c3ea2cf55 100644
--- a/drivers/infiniband/core/uverbs_std_types_dmabuf.c
+++ b/drivers/infiniband/core/uverbs_std_types_dmabuf.c
@@ -12,15 +12,6 @@
 
 MODULE_IMPORT_NS("DMA_BUF");
 
-static int uverbs_dmabuf_attach(struct dma_buf *dmabuf,
-				struct dma_buf_attachment *attachment)
-{
-	if (!attachment->peer2peer)
-		return -EOPNOTSUPP;
-
-	return 0;
-}
-
 static struct sg_table *
 uverbs_dmabuf_map(struct dma_buf_attachment *attachment,
 		  enum dma_data_direction dir)
@@ -76,13 +67,30 @@ static void uverbs_dmabuf_release(struct dma_buf *dmabuf)
 	uverbs_uobject_release(&priv->uobj);
 }
 
-static const struct dma_buf_ops uverbs_dmabuf_ops = {
-	.attach = uverbs_dmabuf_attach,
+static const struct dma_buf_mapping_sgt_exp_ops uverbs_dma_buf_sgt_ops = {
 	.map_dma_buf = uverbs_dmabuf_map,
 	.unmap_dma_buf = uverbs_dmabuf_unmap,
+};
+
+static int uverbs_dmabuf_match_mapping(struct dma_buf_match_args *args)
+{
+	struct ib_uverbs_dmabuf_file *priv = args->dmabuf->priv;
+	struct dma_buf_mapping_match sgt_match[1];
+
+	if (WARN_ON(!dev_is_pci(priv->provider->owner)))
+		return -EINVAL;
+
+	sgt_match[0] = DMA_BUF_EMAPPING_SGT_P2P(
+		&uverbs_dma_buf_sgt_ops, to_pci_dev(priv->provider->owner));
+
+	return dma_buf_match_mapping(args, sgt_match, ARRAY_SIZE(sgt_match));
+}
+
+static const struct dma_buf_ops uverbs_dmabuf_ops = {
 	.pin = uverbs_dmabuf_pin,
 	.unpin = uverbs_dmabuf_unpin,
 	.release = uverbs_dmabuf_release,
+	.match_mapping = uverbs_dmabuf_match_mapping,
 };
 
 static int UVERBS_HANDLER(UVERBS_METHOD_DMABUF_ALLOC)(
-- 
2.54.0