[net-next v3 1/2] igc: Link IRQs to NAPI instances

[Joe Damato <jdamato@fastly.com>]

Link IRQs to NAPI instances via netdev-genl API so that users can query
this information with netlink.

Compare the output of /proc/interrupts (noting that IRQ 144 is the
"other" IRQ which does not appear to have a NAPI instance):

$ cat /proc/interrupts | grep enp86s0 | cut --delimiter=":" -f1
 128
 129
 130
 131
 132

The output from netlink shows the mapping of NAPI IDs to IRQs (again
noting that 144 is absent as it is the "other" IRQ):

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump napi-get --json='{"ifindex": 2}'

[{'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8196,
  'ifindex': 2,
  'irq': 132},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8195,
  'ifindex': 2,
  'irq': 131},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8194,
  'ifindex': 2,
  'irq': 130},
 {'defer-hard-irqs': 0,
  'gro-flush-timeout': 0,
  'id': 8193,
  'ifindex': 2,
  'irq': 129}]

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 v2:
   - Line wrap at 80 characters

 drivers/net/ethernet/intel/igc/igc_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 6e70bca15db1..7964bbedb16c 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -5576,6 +5576,9 @@ static int igc_request_msix(struct igc_adapter *adapter)
 				  q_vector);
 		if (err)
 			goto err_free;
+
+		netif_napi_set_irq(&q_vector->napi,
+				   adapter->msix_entries[vector].vector);
 	}
 
 	igc_configure_msix(adapter);
-- 
2.25.1