Link IRQs to NAPI instances with netif_napi_set_irq. This information
can be queried with the netdev-genl API. Note that the ENA device
appears to allocate an IRQ for management purposes which does not have a
NAPI associated with it; this commit takes this into consideration to
accurately construct a map between IRQs and NAPI instances.

Compare the output of /proc/interrupts for my ena device with the output of
netdev-genl after applying this patch:

$ cat /proc/interrupts | grep enp55s0 | cut -f1 --delimiter=':'
 94
 95
 96
 97
 98
 99
100
101

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

[{'id': 8208, 'ifindex': 2, 'irq': 101},
 {'id': 8207, 'ifindex': 2, 'irq': 100},
 {'id': 8206, 'ifindex': 2, 'irq': 99},
 {'id': 8205, 'ifindex': 2, 'irq': 98},
 {'id': 8204, 'ifindex': 2, 'irq': 97},
 {'id': 8203, 'ifindex': 2, 'irq': 96},
 {'id': 8202, 'ifindex': 2, 'irq': 95},
 {'id': 8201, 'ifindex': 2, 'irq': 94}]

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index c5b50cfa935a..e88de5e426ef 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1679,7 +1679,7 @@ static int ena_request_io_irq(struct ena_adapter *adapter)
 	u32 io_queue_count = adapter->num_io_queues + adapter->xdp_num_queues;
 	unsigned long flags = 0;
 	struct ena_irq *irq;
-	int rc = 0, i, k;
+	int rc = 0, i, k, irq_idx;
 
 	if (!test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
 		netif_err(adapter, ifup, adapter->netdev,
@@ -1705,6 +1705,16 @@ static int ena_request_io_irq(struct ena_adapter *adapter)
 		irq_set_affinity_hint(irq->vector, &irq->affinity_hint_mask);
 	}
 
+	/* Now that IO IRQs have been successfully allocated map them to the
+	 * corresponding IO NAPI instance. Note that the mgmnt IRQ does not
+	 * have a NAPI, so care must be taken to correctly map IRQs to NAPIs.
+	 */
+	for (i = 0; i < io_queue_count; i++) {
+		irq_idx = ENA_IO_IRQ_IDX(i);
+		irq = &adapter->irq_tbl[irq_idx];
+		netif_napi_set_irq(&adapter->ena_napi[i].napi, irq->vector);
+	}
+
 	return rc;
 
 err:
-- 
2.43.0

> Link IRQs to NAPI instances with netif_napi_set_irq. This information can be
> queried with the netdev-genl API. Note that the ENA device appears to
> allocate an IRQ for management purposes which does not have a NAPI
> associated with it; this commit takes this into consideration to accurately
> construct a map between IRQs and NAPI instances.
> 
> Compare the output of /proc/interrupts for my ena device with the output
> of netdev-genl after applying this patch:
> 
> $ cat /proc/interrupts | grep enp55s0 | cut -f1 --delimiter=':'
>  94
>  95
>  96
>  97
>  98
>  99
> 100
> 101
> 
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                          --dump napi-get --json='{"ifindex": 2}'
> 
> [{'id': 8208, 'ifindex': 2, 'irq': 101},
>  {'id': 8207, 'ifindex': 2, 'irq': 100},
>  {'id': 8206, 'ifindex': 2, 'irq': 99},
>  {'id': 8205, 'ifindex': 2, 'irq': 98},
>  {'id': 8204, 'ifindex': 2, 'irq': 97},
>  {'id': 8203, 'ifindex': 2, 'irq': 96},
>  {'id': 8202, 'ifindex': 2, 'irq': 95},
>  {'id': 8201, 'ifindex': 2, 'irq': 94}]
> 
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>  drivers/net/ethernet/amazon/ena/ena_netdev.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> index c5b50cfa935a..e88de5e426ef 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> @@ -1679,7 +1679,7 @@ static int ena_request_io_irq(struct ena_adapter
> *adapter)
>         u32 io_queue_count = adapter->num_io_queues + adapter-
> >xdp_num_queues;
>         unsigned long flags = 0;
>         struct ena_irq *irq;
> -       int rc = 0, i, k;
> +       int rc = 0, i, k, irq_idx;

nit: This breaks RCT guidelines, can you please move it to be below io_queue_count?

> 
>         if (!test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
>                 netif_err(adapter, ifup, adapter->netdev, @@ -1705,6 +1705,16 @@
> static int ena_request_io_irq(struct ena_adapter *adapter)
>                 irq_set_affinity_hint(irq->vector, &irq->affinity_hint_mask);
>         }
> 
> +       /* Now that IO IRQs have been successfully allocated map them to the
> +        * corresponding IO NAPI instance. Note that the mgmnt IRQ does not
> +        * have a NAPI, so care must be taken to correctly map IRQs to NAPIs.
> +        */
> +       for (i = 0; i < io_queue_count; i++) {
> +               irq_idx = ENA_IO_IRQ_IDX(i);
> +               irq = &adapter->irq_tbl[irq_idx];
> +               netif_napi_set_irq(&adapter->ena_napi[i].napi, irq->vector);
> +       }
> +
>         return rc;
> 
>  err:
> --
> 2.43.0

Thank you for uploading this patch.

On Tue, Oct 01, 2024 at 08:57:47AM +0000, Arinzon, David wrote:
> > Link IRQs to NAPI instances with netif_napi_set_irq. This information can be
> > queried with the netdev-genl API. Note that the ENA device appears to
> > allocate an IRQ for management purposes which does not have a NAPI
> > associated with it; this commit takes this into consideration to accurately
> > construct a map between IRQs and NAPI instances.
> > 
> > Compare the output of /proc/interrupts for my ena device with the output
> > of netdev-genl after applying this patch:
> > 
> > $ cat /proc/interrupts | grep enp55s0 | cut -f1 --delimiter=':'
> >  94
> >  95
> >  96
> >  97
> >  98
> >  99
> > 100
> > 101
> > 
> > $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
> >                          --dump napi-get --json='{"ifindex": 2}'
> > 
> > [{'id': 8208, 'ifindex': 2, 'irq': 101},
> >  {'id': 8207, 'ifindex': 2, 'irq': 100},
> >  {'id': 8206, 'ifindex': 2, 'irq': 99},
> >  {'id': 8205, 'ifindex': 2, 'irq': 98},
> >  {'id': 8204, 'ifindex': 2, 'irq': 97},
> >  {'id': 8203, 'ifindex': 2, 'irq': 96},
> >  {'id': 8202, 'ifindex': 2, 'irq': 95},
> >  {'id': 8201, 'ifindex': 2, 'irq': 94}]
> > 
> > Signed-off-by: Joe Damato <jdamato@fastly.com>
> > ---
> >  drivers/net/ethernet/amazon/ena/ena_netdev.c | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> > b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> > index c5b50cfa935a..e88de5e426ef 100644
> > --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> > +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> > @@ -1679,7 +1679,7 @@ static int ena_request_io_irq(struct ena_adapter
> > *adapter)
> >         u32 io_queue_count = adapter->num_io_queues + adapter-
> > >xdp_num_queues;
> >         unsigned long flags = 0;
> >         struct ena_irq *irq;
> > -       int rc = 0, i, k;
> > +       int rc = 0, i, k, irq_idx;
> 
> nit: This breaks RCT guidelines, can you please move it to be below io_queue_count?

You are right; sorry I missed that. Will fix in the next revision.