[PATCH v2 net-next] eth: bnxt: add netmem TX support

[PATCH v2 net-next] eth: bnxt: add netmem TX support

[Taehee Yoo]

Use netmem_dma_*() helpers and declare netmem_tx to support netmem TX.
By this change, all bnxt devices will support the netmem TX.

Unreadable skbs are not going to be handled by the TX push logic.
So, it checks whether a skb is readable or not before the TX push logic.

netmem TX can be tested with ncdevmem.c

Acked-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---

v2:
 - Fix commit message.
 - Add Ack tags from Mina and Stanislav.

 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 28 ++++++++++++++---------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 00a60b2b90c4..cd9d1b75738a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -477,6 +477,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct bnxt_tx_ring_info *txr;
 	struct bnxt_sw_tx_bd *tx_buf;
 	__le32 lflags = 0;
+	skb_frag_t *frag;
 
 	i = skb_get_queue_mapping(skb);
 	if (unlikely(i >= bp->tx_nr_rings)) {
@@ -563,7 +564,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		lflags |= cpu_to_le32(TX_BD_FLAGS_NO_CRC);
 
 	if (free_size == bp->tx_ring_size && length <= bp->tx_push_thresh &&
-	    !lflags) {
+	    skb_frags_readable(skb) && !lflags) {
 		struct tx_push_buffer *tx_push_buf = txr->tx_push;
 		struct tx_push_bd *tx_push = &tx_push_buf->push_bd;
 		struct tx_bd_ext *tx_push1 = &tx_push->txbd2;
@@ -598,9 +599,9 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		skb_copy_from_linear_data(skb, pdata, len);
 		pdata += len;
 		for (j = 0; j < last_frag; j++) {
-			skb_frag_t *frag = &skb_shinfo(skb)->frags[j];
 			void *fptr;
 
+			frag = &skb_shinfo(skb)->frags[j];
 			fptr = skb_frag_address_safe(frag);
 			if (!fptr)
 				goto normal_tx;
@@ -708,8 +709,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			cpu_to_le32(cfa_action << TX_BD_CFA_ACTION_SHIFT);
 	txbd0 = txbd;
 	for (i = 0; i < last_frag; i++) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
-
+		frag = &skb_shinfo(skb)->frags[i];
 		prod = NEXT_TX(prod);
 		txbd = &txr->tx_desc_ring[TX_RING(bp, prod)][TX_IDX(prod)];
 
@@ -721,7 +721,8 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			goto tx_dma_error;
 
 		tx_buf = &txr->tx_buf_ring[RING_TX(bp, prod)];
-		dma_unmap_addr_set(tx_buf, mapping, mapping);
+		netmem_dma_unmap_addr_set(skb_frag_netmem(frag), tx_buf,
+					  mapping, mapping);
 
 		txbd->tx_bd_haddr = cpu_to_le64(mapping);
 
@@ -778,9 +779,11 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	for (i = 0; i < last_frag; i++) {
 		prod = NEXT_TX(prod);
 		tx_buf = &txr->tx_buf_ring[RING_TX(bp, prod)];
-		dma_unmap_page(&pdev->dev, dma_unmap_addr(tx_buf, mapping),
-			       skb_frag_size(&skb_shinfo(skb)->frags[i]),
-			       DMA_TO_DEVICE);
+		frag = &skb_shinfo(skb)->frags[i];
+		netmem_dma_unmap_page_attrs(&pdev->dev,
+					    dma_unmap_addr(tx_buf, mapping),
+					    skb_frag_size(frag),
+					    DMA_TO_DEVICE, 0);
 	}
 
 tx_free:
@@ -3422,9 +3425,11 @@ static void bnxt_free_one_tx_ring_skbs(struct bnxt *bp,
 			skb_frag_t *frag = &skb_shinfo(skb)->frags[j];
 
 			tx_buf = &txr->tx_buf_ring[ring_idx];
-			dma_unmap_page(&pdev->dev,
-				       dma_unmap_addr(tx_buf, mapping),
-				       skb_frag_size(frag), DMA_TO_DEVICE);
+			netmem_dma_unmap_page_attrs(&pdev->dev,
+						    dma_unmap_addr(tx_buf,
+								   mapping),
+						    skb_frag_size(frag),
+						    DMA_TO_DEVICE, 0);
 		}
 		dev_kfree_skb(skb);
 	}
@@ -16713,6 +16718,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (BNXT_SUPPORTS_QUEUE_API(bp))
 		dev->queue_mgmt_ops = &bnxt_queue_mgmt_ops;
 	dev->request_ops_lock = true;
+	dev->netmem_tx = true;
 
 	rc = register_netdev(dev);
 	if (rc)
-- 
2.34.1

Re: [PATCH v2 net-next] eth: bnxt: add netmem TX support

[Michael Chan]

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On Wed, Jun 18, 2025 at 6:54 AM Taehee Yoo <ap420073@gmail.com> wrote:
>
> Use netmem_dma_*() helpers and declare netmem_tx to support netmem TX.
> By this change, all bnxt devices will support the netmem TX.
>
> Unreadable skbs are not going to be handled by the TX push logic.
> So, it checks whether a skb is readable or not before the TX push logic.
>
> netmem TX can be tested with ncdevmem.c
>
> Acked-by: Mina Almasry <almasrymina@google.com>
> Acked-by: Stanislav Fomichev <sdf@fomichev.me>
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> ---
>
> v2:
>  - Fix commit message.
>  - Add Ack tags from Mina and Stanislav.
>

Thanks for the patch.  At a quick glance, it seems that the netmem dma
unmap is missing in __bnxt_tx_int().

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Re: [PATCH v2 net-next] eth: bnxt: add netmem TX support

[Taehee Yoo]

On Thu, Jun 19, 2025 at 2:21 AM Michael Chan <michael.chan@broadcom.com> wrote:
>

Hi Michael,
Thanks a lot for the review :)

> On Wed, Jun 18, 2025 at 6:54 AM Taehee Yoo <ap420073@gmail.com> wrote:
> >
> > Use netmem_dma_*() helpers and declare netmem_tx to support netmem TX.
> > By this change, all bnxt devices will support the netmem TX.
> >
> > Unreadable skbs are not going to be handled by the TX push logic.
> > So, it checks whether a skb is readable or not before the TX push logic.
> >
> > netmem TX can be tested with ncdevmem.c
> >
> > Acked-by: Mina Almasry <almasrymina@google.com>
> > Acked-by: Stanislav Fomichev <sdf@fomichev.me>
> > Signed-off-by: Taehee Yoo <ap420073@gmail.com>
> > ---
> >
> > v2:
> >  - Fix commit message.
> >  - Add Ack tags from Mina and Stanislav.
> >
>
> Thanks for the patch.  At a quick glance, it seems that the netmem dma
> unmap is missing in __bnxt_tx_int().

Thanks! I will change unmaps in __bnxt_in_int() in the v3.

Thanks a lot!
Taehee Yoo