From: Joe Damato <jdamato@fastly.com>
Date: Wed, 9 Oct 2024 17:55:09 +0000 (+0000)
Subject: tg3: Link queues to NAPIs
X-Git-Tag: v6.13-rc1~135^2~353^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aec5514d739fad575069a43832cb11c066992057;p=thirdparty%2Flinux.git

tg3: Link queues to NAPIs

Link queues to NAPIs using the netdev-genl API so this information is
queryable.

First, test with the default setting on my tg3 NIC at boot with 1 TX
queue:

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

[{'id': 0, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
 {'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'}]

Now, adjust the number of TX queues to be 4 via ethtool:

$ sudo ethtool -L eth0 tx 4
$ sudo ethtool -l eth0 | tail -5
Current hardware settings:
RX:		4
TX:		4
Other:		n/a
Combined:	n/a

Despite "Combined: n/a" in the ethtool output, /proc/interrupts shows
the tg3 has renamed the IRQs to be combined:

343: [...] eth0-0
344: [...] eth0-txrx-1
345: [...] eth0-txrx-2
346: [...] eth0-txrx-3
347: [...] eth0-txrx-4

Now query this via netlink to ensure the queues are linked properly to
their NAPIs:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8960, 'type': 'rx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8961, 'type': 'rx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8962, 'type': 'rx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8963, 'type': 'rx'},
 {'id': 0, 'ifindex': 2, 'napi-id': 8960, 'type': 'tx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8961, 'type': 'tx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8962, 'type': 'tx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8963, 'type': 'tx'}]

As you can see above, id 0 for both TX and RX share a NAPI, NAPI ID
8960, and so on for each queue index up to 3.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20241009175509.31753-3-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 6564072b47ba2..c4bce6493afa8 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -7395,18 +7395,49 @@ tx_recovery:
 
 static void tg3_napi_disable(struct tg3 *tp)
 {
+	int txq_idx = tp->txq_cnt - 1;
+	int rxq_idx = tp->rxq_cnt - 1;
+	struct tg3_napi *tnapi;
 	int i;
 
-	for (i = tp->irq_cnt - 1; i >= 0; i--)
-		napi_disable(&tp->napi[i].napi);
+	for (i = tp->irq_cnt - 1; i >= 0; i--) {
+		tnapi = &tp->napi[i];
+		if (tnapi->tx_buffers) {
+			netif_queue_set_napi(tp->dev, txq_idx,
+					     NETDEV_QUEUE_TYPE_TX, NULL);
+			txq_idx--;
+		}
+		if (tnapi->rx_rcb) {
+			netif_queue_set_napi(tp->dev, rxq_idx,
+					     NETDEV_QUEUE_TYPE_RX, NULL);
+			rxq_idx--;
+		}
+		napi_disable(&tnapi->napi);
+	}
 }
 
 static void tg3_napi_enable(struct tg3 *tp)
 {
+	int txq_idx = 0, rxq_idx = 0;
+	struct tg3_napi *tnapi;
 	int i;
 
-	for (i = 0; i < tp->irq_cnt; i++)
-		napi_enable(&tp->napi[i].napi);
+	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, txq_idx,
+					     NETDEV_QUEUE_TYPE_TX,
+					     &tnapi->napi);
+			txq_idx++;
+		}
+		if (tnapi->rx_rcb) {
+			netif_queue_set_napi(tp->dev, rxq_idx,
+					     NETDEV_QUEUE_TYPE_RX,
+					     &tnapi->napi);
+			rxq_idx++;
+		}
+	}
 }
 
 static void tg3_napi_init(struct tg3 *tp)