mlxsw: pci: Store CQ pointer as part of RDQ structure

Next patches will add support for page pool in mlxsw driver. Page pool will
be used to allocate buffers for RDQ and will use NAPI instance of the
appropriate CQ (RDQ is mapped 1:1 to CQ).

To allow pool initialization as part of CQ init, when NAPI is initialized,
page_pool structure will be as part of CQ structure. Later, the allocations
for RDQ will be done from the pool in the appropriate CQ. To allow access
to the appropriate pool, set CQ pointer as part of RDQ initialization.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/d60918ca1e142a554af1df9c1152cdac83854a3b.1718709196.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlxsw/pci.c

@@ -92,6 +92,9 @@ struct mlxsw_pci_queue {
 		struct {
 			struct tasklet_struct tasklet;
 		} eq;
+		struct {
+			struct mlxsw_pci_queue *cq;
+		} rdq;
 	} u;
 };
 
@@ -434,6 +437,7 @@ static int mlxsw_pci_rdq_init(struct mlxsw_pci *mlxsw_pci, char *mbox,
 
 	cq = mlxsw_pci_cq_get(mlxsw_pci, cq_num);
 	cq->u.cq.dq = q;
+	q->u.rdq.cq = cq;
 
 	mlxsw_pci_queue_doorbell_producer_ring(mlxsw_pci, q);
 
@@ -455,6 +459,7 @@ static int mlxsw_pci_rdq_init(struct mlxsw_pci *mlxsw_pci, char *mbox,
 		elem_info = mlxsw_pci_queue_elem_info_get(q, i);
 		mlxsw_pci_rdq_skb_free(mlxsw_pci, elem_info);
 	}
+	q->u.rdq.cq = NULL;
 	cq->u.cq.dq = NULL;
 	mlxsw_cmd_hw2sw_rdq(mlxsw_pci->core, q->num);