[PATCH intel-next] ice: Add support for persistent NAPI config

[Joe Damato]

Use netif_napi_add_config to assign persistent per-NAPI config when
initializing NAPIs. This preserves NAPI config settings when queue
counts are adjusted.

Tested with an E810-2CQDA2 NIC.

Begin by setting the queue count to 4:

$ sudo ethtool -L eth4 combined 4

Check the queue settings:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 4}'
[{'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8452,
  'ifindex': 4,
  'irq': 2782},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8451,
  'ifindex': 4,
  'irq': 2781},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8450,
  'ifindex': 4,
  'irq': 2780},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8449,
  'ifindex': 4,
  'irq': 2779}]

Now, set the queue with NAPI ID 8451 to have a gro-flush-timeout of
1111:

$ sudo ./tools/net/ynl/cli.py \
            --spec Documentation/netlink/specs/netdev.yaml \
            --do napi-set --json='{"id": 8451, "gro-flush-timeout": 1111}'
None

Check that worked:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 4}'
[{'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8452,
  'ifindex': 4,
  'irq': 2782},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 1111,
  'id': 8451,
  'ifindex': 4,
  'irq': 2781},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8450,
  'ifindex': 4,
  'irq': 2780},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8449,
  'ifindex': 4,
  'irq': 2779}]

Now reduce the queue count to 2, which would destroy the queue with NAPI
ID 8451:

$ sudo ethtool -L eth4 combined 2

Check the queue settings, noting that NAPI ID 8451 is gone:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 4}'
[{'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8450,
  'ifindex': 4,
  'irq': 2780},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8449,
  'ifindex': 4,
  'irq': 2779}]

Now, increase the number of queues back to 4:

$ sudo ethtool -L eth4 combined 4

Dump the settings, expecting to see the same NAPI IDs as above and for
NAPI ID 8451 to have its gro-flush-timeout set to 1111:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 4}'
[{'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8452,
  'ifindex': 4,
  'irq': 2782},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 1111,
  'id': 8451,
  'ifindex': 4,
  'irq': 2781},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8450,
  'ifindex': 4,
  'irq': 2780},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8449,
  'ifindex': 4,
  'irq': 2779}]

Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/ice/ice_base.c | 3 ++-
 drivers/net/ethernet/intel/ice/ice_lib.c  | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c
index 3a8e156d7d86..82a9cd4ec7ae 100644
--- a/drivers/net/ethernet/intel/ice/ice_base.c
+++ b/drivers/net/ethernet/intel/ice/ice_base.c
@@ -156,7 +156,8 @@ static int ice_vsi_alloc_q_vector(struct ice_vsi *vsi, u16 v_idx)
 	 * handler here (i.e. resume, reset/rebuild, etc.)
 	 */
 	if (vsi->netdev)
-		netif_napi_add(vsi->netdev, &q_vector->napi, ice_napi_poll);
+		netif_napi_add_config(vsi->netdev, &q_vector->napi,
+				      ice_napi_poll, v_idx);
 
 out:
 	/* tie q_vector and VSI together */
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index d4e74f96a8ad..a7d45a8ce7ac 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -2777,8 +2777,10 @@ void ice_napi_add(struct ice_vsi *vsi)
 		return;
 
 	ice_for_each_q_vector(vsi, v_idx)
-		netif_napi_add(vsi->netdev, &vsi->q_vectors[v_idx]->napi,
-			       ice_napi_poll);
+		netif_napi_add_config(vsi->netdev,
+				      &vsi->q_vectors[v_idx]->napi,
+				      ice_napi_poll,
+				      v_idx);
 }
 
 /**

base-commit: 6f07cd8301706b661776074ddc97c991d107cc91
-- 
2.25.1