idpf: add TX splitq napi poll support

Add support to handle the interrupts for the TX completion queue and
process the various completion types.

In the flow scheduling mode, the driver processes primarily buffer
completions as well as descriptor completions occasionally. This mode
supports out of order TX completions. To do so, HW generates one buffer
completion per packet. Each of those completions contains the unique tag
provided during the TX encoding which is used to locate the packet either
on the TX buffer ring or in a hash table. The hash table is used to track
TX buffer information so the descriptor(s) for a given packet can be
reused while the driver is still waiting on the buffer completion(s).

Packets end up in the hash table in one of 2 ways: 1) a packet was
stashed during descriptor completion cleaning, or 2) because an out of
order buffer completion was processed. A descriptor completion arrives
only every so often and is primarily used to guarantee the TX descriptor
ring can be reused without having to wait on the individual buffer
completions. E.g. a descriptor completion for N+16 guarantees HW read all
of the descriptors for packets N through N+15, therefore all of the
buffers for packets N through N+15 are stashed into the hash table and the
descriptors can be reused for more TX packets. Similarly, a packet can be
stashed in the hash table because an out an order buffer completion was
processed. E.g. processing a buffer completion for packet N+3 implies that
HW read all of the descriptors for packets N through N+3 and they can be
reused. However, the HW did not do the DMA yet. The buffers for packets N
through N+2 cannot be freed, so they are stashed in the hash table.
In either case, the buffer completions will eventually be processed for
all of the stashed packets, and all of the buffers will be cleaned from
the hash table.

In queue based scheduling mode, the driver processes primarily descriptor
completions and cleans the TX ring the conventional way.

Finally, the driver triggers a TX queue drain after sending the disable
queues virtchnl message. When the HW completes the queue draining, it
sends the driver a queue marker packet completion. The driver determines
when all TX queues have been drained and proceeds with the disable flow.

With this, the driver can send TX packets and clean up the resources
properly.

Signed-off-by: Joshua Hay <joshua.a.hay@intel.com>
Co-developed-by: Alan Brady <alan.brady@intel.com>
Signed-off-by: Alan Brady <alan.brady@intel.com>
Co-developed-by: Madhu Chittim <madhu.chittim@intel.com>
Signed-off-by: Madhu Chittim <madhu.chittim@intel.com>
Co-developed-by: Phani Burra <phani.r.burra@intel.com>
Signed-off-by: Phani Burra <phani.r.burra@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Co-developed-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index c14dc49187cf..659f6eb68fa7 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -929,6 +929,7 @@ static struct idpf_vport *idpf_vport_alloc(struct idpf_adapter *adapter,
 
 	vport->idx = idx;
 	vport->adapter = adapter;
+	vport->compln_clean_budget = IDPF_TX_COMPLQ_CLEAN_BUDGET;
 	vport->default_vport = adapter->num_alloc_vports <
 			       idpf_get_default_vports(adapter);
 
@@ -1241,6 +1242,7 @@ void idpf_init_task(struct work_struct *work)
 	index = vport->idx;
 	vport_config = adapter->vport_config[index];
 
+	init_waitqueue_head(&vport->sw_marker_wq);
 	init_waitqueue_head(&vport->vchnl_wq);
 
 	mutex_init(&vport->vc_buf_lock);