IB/mlx5: Device memory mr registration support

Adding mlx5_ib driver implementation for reg_dm_mr callback
which allows registering device memory (DM) as an MR for
local and remote access.
Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/main.c

@@ -5226,6 +5226,7 @@ int mlx5_ib_stage_caps_init(struct mlx5_ib_dev *dev)
 	if (MLX5_CAP_DEV_MEM(mdev, memic)) {
 		dev->ib_dev.alloc_dm = mlx5_ib_alloc_dm;
 		dev->ib_dev.dealloc_dm = mlx5_ib_dealloc_dm;
+		dev->ib_dev.reg_dm_mr = mlx5_ib_reg_dm_mr;
 	}
 
 	dev->ib_dev.create_flow	= mlx5_ib_create_flow;

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -540,6 +540,12 @@ struct mlx5_ib_dm {
 
 #define MLX5_IB_MTT_PRESENT (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE)
 
+#define MLX5_IB_DM_ALLOWED_ACCESS (IB_ACCESS_LOCAL_WRITE   |\
+				   IB_ACCESS_REMOTE_WRITE  |\
+				   IB_ACCESS_REMOTE_READ   |\
+				   IB_ACCESS_REMOTE_ATOMIC |\
+				   IB_ZERO_BASED)
+
 struct mlx5_ib_mr {
 	struct ib_mr		ibmr;
 	void			*descs;
@@ -1075,6 +1081,9 @@ struct ib_dm *mlx5_ib_alloc_dm(struct ib_device *ibdev,
 			       struct ib_dm_alloc_attr *attr,
 			       struct uverbs_attr_bundle *attrs);
 int mlx5_ib_dealloc_dm(struct ib_dm *ibdm);
+struct ib_mr *mlx5_ib_reg_dm_mr(struct ib_pd *pd, struct ib_dm *dm,
+				struct ib_dm_mr_attr *attr,
+				struct uverbs_attr_bundle *attrs);
 
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev);

drivers/infiniband/hw/mlx5/mr.c

@@ -1229,6 +1229,80 @@ static void set_mr_fileds(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr,
 	mr->access_flags = access_flags;
 }
 
+static struct ib_mr *mlx5_ib_get_memic_mr(struct ib_pd *pd, u64 memic_addr,
+					  u64 length, int acc)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+	struct mlx5_core_dev *mdev = dev->mdev;
+	struct mlx5_ib_mr *mr;
+	void *mkc;
+	u32 *in;
+	int err;
+
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+	if (!mr)
+		return ERR_PTR(-ENOMEM);
+
+	in = kzalloc(inlen, GFP_KERNEL);
+	if (!in) {
+		err = -ENOMEM;
+		goto err_free;
+	}
+
+	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+
+	MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_MEMIC & 0x3);
+	MLX5_SET(mkc, mkc, access_mode_4_2,
+		 (MLX5_MKC_ACCESS_MODE_MEMIC >> 2) & 0x7);
+	MLX5_SET(mkc, mkc, a, !!(acc & IB_ACCESS_REMOTE_ATOMIC));
+	MLX5_SET(mkc, mkc, rw, !!(acc & IB_ACCESS_REMOTE_WRITE));
+	MLX5_SET(mkc, mkc, rr, !!(acc & IB_ACCESS_REMOTE_READ));
+	MLX5_SET(mkc, mkc, lw, !!(acc & IB_ACCESS_LOCAL_WRITE));
+	MLX5_SET(mkc, mkc, lr, 1);
+
+	MLX5_SET64(mkc, mkc, len, length);
+	MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
+	MLX5_SET(mkc, mkc, qpn, 0xffffff);
+	MLX5_SET64(mkc, mkc, start_addr,
+		   memic_addr - pci_resource_start(dev->mdev->pdev, 0));
+
+	err = mlx5_core_create_mkey(mdev, &mr->mmkey, in, inlen);
+	if (err)
+		goto err_in;
+
+	kfree(in);
+
+	mr->umem = NULL;
+	set_mr_fileds(dev, mr, 0, length, acc);
+
+	return &mr->ibmr;
+
+err_in:
+	kfree(in);
+
+err_free:
+	kfree(mr);
+
+	return ERR_PTR(err);
+}
+
+struct ib_mr *mlx5_ib_reg_dm_mr(struct ib_pd *pd, struct ib_dm *dm,
+				struct ib_dm_mr_attr *attr,
+				struct uverbs_attr_bundle *attrs)
+{
+	struct mlx5_ib_dm *mdm = to_mdm(dm);
+	u64 memic_addr;
+
+	if (attr->access_flags & ~MLX5_IB_DM_ALLOWED_ACCESS)
+		return ERR_PTR(-EINVAL);
+
+	memic_addr = mdm->dev_addr + attr->offset;
+
+	return mlx5_ib_get_memic_mr(pd, memic_addr, attr->length,
+				    attr->access_flags);
+}
+
 struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 				  u64 virt_addr, int access_flags,
 				  struct ib_udata *udata)