On Tue, Jun 22, 2021 at 03:45:56PM -0300, Jason Gunthorpe wrote:

On Mon, Jun 21, 2021 at 10:06:15AM +0300, Leon Romanovsky wrote:

quoted

From: Lior Nahmanson <redacted>

This patch isolates DCI QP creation logic to separate function, so this
change will reduce complexity when adding new features to DCI QP without
interfering with other QP types.

The code was copied from create_user_qp() while taking only DCI relevant bits.

Reviewed-by: Meir Lichtinger <redacted>
Signed-off-by: Lior Nahmanson <redacted>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
 drivers/infiniband/hw/mlx5/qp.c | 157 ++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index 7a5f1eba60e3..65a380543f5a 100644
+++ b/drivers/infiniband/hw/mlx5/qp.c

@@ -1974,6 +1974,160 @@ static int create_xrc_tgt_qp(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp,
 	return 0;
 }
 
+static int create_dci(struct mlx5_ib_dev *dev, struct ib_pd *pd,
+		      struct mlx5_ib_qp *qp,
+		      struct mlx5_create_qp_params *params)
+{

This is a huge amount of copying just to add 4 lines, why?

There must be a better way to do this qp stuff.

Why not put more stuff in _create_user_qp()?

Lior proposed it in original patch, but I didn't like it. It caused to
mix of various QP types and maze of "if () else ()" that are not applicable
one to another.

The huge _create_user_qp() is the reason why create_dci() is not small,
we simply had hard time to understand if specific HW bit is needed or
not in DCI flow.

My goal is to have small per-QP type specific functions that calls
to simple functions for very narrow scope.

Something like that:
static int create_dci(...)
{
  ...
  configure_send_cq(..)
  configure_recv_sq(..)
  configure_srq(...)
  ...
}

static int create_user_qp(...)
{
  ...
  configure_send_cq(..)
  configure_recv_sq(..)
  configure_srq(...)
  ...
}


Thanks

Jason