Re: [RFC net-next v2 2/2] tg3: Link queues to NAPIs

[Joe Damato <jdamato@fastly.com>]

On Wed, Sep 25, 2024 at 04:20:48PM +0000, Joe Damato wrote:
> Link queues to NAPIs using the netdev-genl API so this information is
> queryable.
> 
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                          --dump queue-get --json='{"ifindex": 2}'
> 
> [{'id': 0, 'ifindex': 2, 'type': 'rx'},
>  {'id': 1, 'ifindex': 2, 'napi-id': 146, 'type': 'rx'},
>  {'id': 2, 'ifindex': 2, 'napi-id': 147, 'type': 'rx'},
>  {'id': 3, 'ifindex': 2, 'napi-id': 148, 'type': 'rx'},
>  {'id': 0, 'ifindex': 2, 'napi-id': 145, 'type': 'tx'}]
> 
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>  drivers/net/ethernet/broadcom/tg3.c | 24 ++++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
> index ddf0bb65c929..f78d7e8c40b2 100644
> --- a/drivers/net/ethernet/broadcom/tg3.c
> +++ b/drivers/net/ethernet/broadcom/tg3.c
> @@ -7395,18 +7395,34 @@ static int tg3_poll(struct napi_struct *napi, int budget)
>  
>  static void tg3_napi_disable(struct tg3 *tp)
>  {
> +	struct tg3_napi *tnapi;
>  	int i;
>  
> -	for (i = tp->irq_cnt - 1; i >= 0; i--)
> -		napi_disable(&tp->napi[i].napi);
> +	ASSERT_RTNL();
> +	for (i = tp->irq_cnt - 1; i >= 0; i--) {
> +		tnapi = &tp->napi[i];
> +		if (tnapi->tx_buffers)
> +			netif_queue_set_napi(tp->dev, i, NETDEV_QUEUE_TYPE_TX, NULL);

It looks like the ASSERT_RTNL is unnecessary; netif_queue_set_napi
will call it internally, so I'll remove it before sending this to
the list (barring any other feedback).

>  static void tg3_napi_enable(struct tg3 *tp)
>  {
> +	struct tg3_napi *tnapi;
>  	int i;
>  
> -	for (i = 0; i < tp->irq_cnt; i++)
> -		napi_enable(&tp->napi[i].napi);
> +	ASSERT_RTNL();
> +	for (i = 0; i < tp->irq_cnt; i++) {
> +		tnapi = &tp->napi[i];
> +		napi_enable(&tnapi->napi);
> +		if (tnapi->tx_buffers)
> +			netif_queue_set_napi(tp->dev, i, NETDEV_QUEUE_TYPE_TX, &tnapi->napi);

Same as above.