Devmem ddi support

Documentation/netlink/specs/netdev.yaml

@@ -562,6 +562,13 @@ attribute-sets:
         type: u32
         checks:
           min: 1
+      -
+        name: ddi
+        doc: Use DDI (Data Direct Interface) for this dmabuf binding if the
+          dmabuf is backed by a device with a direct PCIe connection to the
+          NIC. When set, enables direct data transfer between the NIC and
+          the device, bypassing the CPU root complex.
+        type: u8
 
 operations:
   list:
@@ -769,6 +776,7 @@ operations:
             - ifindex
             - fd
             - queues
+            - ddi
         reply:
           attributes:
             - id
@@ -794,6 +802,7 @@ operations:
           attributes:
             - ifindex
             - fd
+            - ddi
         reply:
           attributes:
             - id

drivers/net/ethernet/mellanox/mlx5/core/en.h

@@ -447,6 +447,7 @@ struct mlx5e_txqsq {
 	u8                         min_inline_mode;
 	struct device             *pdev;
 	__be32                     mkey_be;
+	__be32                     crossing_mkey_be;
 	unsigned long              state;
 	unsigned int               hw_mtu;
 	struct mlx5_clock         *clock;
@@ -676,6 +677,8 @@ struct mlx5e_rq {
 			struct mlx5e_mpw_info *info;
 			mlx5e_fp_skb_from_cqe_mpwrq skb_from_cqe_mpwrq;
 			__be32                 umr_mkey_be;
+			__be32                 ksm_child_mkey_be;
+			u32                    crossing_mkey;
 			u16                    num_strides;
 			u16                    actual_wq_head;
 			u8                     log_stride_sz;
@@ -971,6 +974,8 @@ struct mlx5e_priv {
 	struct mlx5e_hv_vhca_stats_agent stats_agent;
 #endif
 	struct mlx5e_scratchpad    scratchpad;
+	u32                        ddi_mkey; /* DDI PA mkey with ethernet PD */
+	struct device             *ddi_dev; /* cached DDI PCI device */
 	struct mlx5e_htb          *htb;
 	struct mlx5e_mqprio_rl    *mqprio_rl;
 	struct dentry             *dfs_root;