[PATCH net-next 0/5] net: lan966x: Extend xdp support

[PATCH net-next 0/5] net: lan966x: Extend xdp support

[Horatiu Vultur]

Extend the current support of XDP in lan966x with the action XDP_TX and
XDP_REDIRECT.
The first patch introduced a headroom for all the received frames. This
is needed when the XDP_TX and XDP_REDIRECT is added.
The next 2 patches, just introduced some helper functions that can be
reused when is needed to transmit back the frame.
The last 2 patches introduce the XDP actions XDP_TX and XDP_REDIRECT.

Horatiu Vultur (5):
  net: lan966x: Add XDP_PACKET_HEADROOM
  net: lan966x: Introduce helper functions
  net: lan966x: Add len field to lan966x_tx_dcb_buf
  net: lan966x: Add support for XDP_TX
  net: lan966x: Add support for XDP_REDIRECT

 .../ethernet/microchip/lan966x/lan966x_fdma.c | 183 ++++++++++++++----
 .../ethernet/microchip/lan966x/lan966x_main.c |   5 +-
 .../ethernet/microchip/lan966x/lan966x_main.h |  15 ++
 .../ethernet/microchip/lan966x/lan966x_xdp.c  |  41 +++-
 4 files changed, 200 insertions(+), 44 deletions(-)

-- 
2.38.0

[PATCH net-next 1/5] net: lan966x: Add XDP_PACKET_HEADROOM

[Horatiu Vultur]

Update the page_pool params to allocate XDP_PACKET_HEADROOM space as
headroom for all received frames.
This is needed for when the XDP_TX and XDP_REDIRECT are implemented.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../ethernet/microchip/lan966x/lan966x_fdma.c | 22 +++++++++++++------
 .../ethernet/microchip/lan966x/lan966x_xdp.c  |  5 +++--
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 5fbbd479cfb06..dc1ac340e1fb3 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 
+#include <linux/bpf.h>
+
 #include "lan966x_main.h"
 
 static int lan966x_fdma_channel_active(struct lan966x *lan966x)
@@ -16,7 +18,7 @@ static struct page *lan966x_fdma_rx_alloc_page(struct lan966x_rx *rx,
 	if (unlikely(!page))
 		return NULL;
 
-	db->dataptr = page_pool_get_dma_addr(page);
+	db->dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;
 
 	return page;
 }
@@ -72,7 +74,7 @@ static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx)
 		.nid = NUMA_NO_NODE,
 		.dev = lan966x->dev,
 		.dma_dir = DMA_FROM_DEVICE,
-		.offset = 0,
+		.offset = XDP_PACKET_HEADROOM,
 		.max_len = rx->max_mtu -
 			   SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
 	};
@@ -432,11 +434,13 @@ static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
 	if (unlikely(!page))
 		return FDMA_ERROR;
 
-	dma_sync_single_for_cpu(lan966x->dev, (dma_addr_t)db->dataptr,
+	dma_sync_single_for_cpu(lan966x->dev,
+				(dma_addr_t)db->dataptr + XDP_PACKET_HEADROOM,
 				FDMA_DCB_STATUS_BLOCKL(db->status),
 				DMA_FROM_DEVICE);
 
-	lan966x_ifh_get_src_port(page_address(page), src_port);
+	lan966x_ifh_get_src_port(page_address(page) + XDP_PACKET_HEADROOM,
+				 src_port);
 	if (WARN_ON(*src_port >= lan966x->num_phys_ports))
 		return FDMA_ERROR;
 
@@ -444,7 +448,9 @@ static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port)
 	if (!lan966x_xdp_port_present(port))
 		return FDMA_PASS;
 
-	return lan966x_xdp_run(port, page, FDMA_DCB_STATUS_BLOCKL(db->status));
+	return lan966x_xdp_run(port, page,
+			       FDMA_DCB_STATUS_BLOCKL(db->status) +
+			       XDP_PACKET_HEADROOM);
 }
 
 static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
@@ -466,7 +472,8 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
 
 	skb_mark_for_recycle(skb);
 
-	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
+	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status) + XDP_PACKET_HEADROOM);
+	skb_pull(skb, XDP_PACKET_HEADROOM);
 
 	lan966x_ifh_get_timestamp(skb->data, &timestamp);
 
@@ -786,7 +793,8 @@ static int lan966x_fdma_get_max_frame(struct lan966x *lan966x)
 	return lan966x_fdma_get_max_mtu(lan966x) +
 	       IFH_LEN_BYTES +
 	       SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
-	       VLAN_HLEN * 2;
+	       VLAN_HLEN * 2 +
+	       XDP_PACKET_HEADROOM;
 }
 
 int lan966x_fdma_change_mtu(struct lan966x *lan966x)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
index e77d9f2aad2b4..bab447e79273f 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -44,8 +44,9 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 
 	xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order,
 		      &port->xdp_rxq);
-	xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
-			 data_len - IFH_LEN_BYTES, false);
+	xdp_prepare_buff(&xdp, page_address(page),
+			 IFH_LEN_BYTES + XDP_PACKET_HEADROOM,
+			 data_len - IFH_LEN_BYTES - XDP_PACKET_HEADROOM, false);
 	act = bpf_prog_run_xdp(xdp_prog, &xdp);
 	switch (act) {
 	case XDP_PASS:
-- 
2.38.0

Re: [PATCH net-next 1/5] net: lan966x: Add XDP_PACKET_HEADROOM

[Alexander Lobakin]

From: Horatiu Vultur <horatiu.vultur@microchip.com>
Date: Sun, 13 Nov 2022 12:15:55 +0100

> Update the page_pool params to allocate XDP_PACKET_HEADROOM space as
> headroom for all received frames.
> This is needed for when the XDP_TX and XDP_REDIRECT are implemented.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> ---

[...]

> @@ -466,7 +472,8 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
>  
>  	skb_mark_for_recycle(skb);
>  
> -	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
> +	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status) + XDP_PACKET_HEADROOM);
> +	skb_pull(skb, XDP_PACKET_HEADROOM);

These two must be:

+	skb_reserve(skb, XDP_PACKET_HEADROOM);
 	skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));

i.e. you only need to add reserve, and that's it. It's not only
faster, but also moves ::tail, which is essential.

>  
>  	lan966x_ifh_get_timestamp(skb->data, &timestamp);
>  

[...]

> --- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
> +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
> @@ -44,8 +44,9 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
>  
>  	xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order,
>  		      &port->xdp_rxq);
> -	xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
> -			 data_len - IFH_LEN_BYTES, false);
> +	xdp_prepare_buff(&xdp, page_address(page),
> +			 IFH_LEN_BYTES + XDP_PACKET_HEADROOM,
> +			 data_len - IFH_LEN_BYTES - XDP_PACKET_HEADROOM, false);

Are you sure you need to substract %XDP_PACKET_HEADROOM from
@data_len? I think @data_len is the frame length, so headroom is not
included?

>  	act = bpf_prog_run_xdp(xdp_prog, &xdp);
>  	switch (act) {
>  	case XDP_PASS:
> -- 
> 2.38.0

Thanks,
Olek

Re: [PATCH net-next 1/5] net: lan966x: Add XDP_PACKET_HEADROOM

[Horatiu Vultur]

The 11/14/2022 15:16, Alexander Lobakin wrote:
> [Some people who received this message don't often get email from alexandr.lobakin@intel.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> 
> From: Horatiu Vultur <horatiu.vultur@microchip.com>
> Date: Sun, 13 Nov 2022 12:15:55 +0100

Hi Olek,

> 
> > Update the page_pool params to allocate XDP_PACKET_HEADROOM space as
> > headroom for all received frames.
> > This is needed for when the XDP_TX and XDP_REDIRECT are implemented.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> 
> [...]
> 
> > @@ -466,7 +472,8 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx,
> >
> >       skb_mark_for_recycle(skb);
> >
> > -     skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
> > +     skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status) + XDP_PACKET_HEADROOM);
> > +     skb_pull(skb, XDP_PACKET_HEADROOM);
> 
> These two must be:
> 
> +       skb_reserve(skb, XDP_PACKET_HEADROOM);
>         skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status));
> 
> i.e. you only need to add reserve, and that's it. It's not only
> faster, but also moves ::tail, which is essential.

Thanks for the suggestion. I will do that in the next version.

> 
> >
> >       lan966x_ifh_get_timestamp(skb->data, &timestamp);
> >
> 
> [...]
> 
> > --- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
> > +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
> > @@ -44,8 +44,9 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
> >
> >       xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order,
> >                     &port->xdp_rxq);
> > -     xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
> > -                      data_len - IFH_LEN_BYTES, false);
> > +     xdp_prepare_buff(&xdp, page_address(page),
> > +                      IFH_LEN_BYTES + XDP_PACKET_HEADROOM,
> > +                      data_len - IFH_LEN_BYTES - XDP_PACKET_HEADROOM, false);
> 
> Are you sure you need to substract %XDP_PACKET_HEADROOM from
> @data_len? I think @data_len is the frame length, so headroom is not
> included?

Actually @data_len contains also the XDP_PACKET_HEADROOM. I am calling
lan966x_xdp_run like this:

---
return lan966x_xdp_run(port, page,
		       FDMA_DCB_STATUS_BLOCKL(db->status) + XDP_PACKET_HEADROOM);
---

But from what I can see, that doesn't make too much sense.
Because I am adding here the XDP_PACKET_HEADROOM and then remove it in
xdp_prepare_buff. So it would be better not to add it at all.

> 
> >       act = bpf_prog_run_xdp(xdp_prog, &xdp);
> >       switch (act) {
> >       case XDP_PASS:
> > --
> > 2.38.0
> 
> Thanks,
> Olek

-- 
/Horatiu

[PATCH net-next 2/5] net: lan966x: Introduce helper functions

[Horatiu Vultur]

Introduce lan966x_fdma_tx_setup_dcb and lan966x_fdma_tx_start functions
and use of them inside lan966x_fdma_xmit. There is no functional change
in here.
They are introduced to be used when XDP_TX/REDIRECT actions are
introduced.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../ethernet/microchip/lan966x/lan966x_fdma.c | 71 ++++++++++++-------
 1 file changed, 44 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index dc1ac340e1fb3..0dbe620d3093f 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -614,14 +614,53 @@ static int lan966x_fdma_get_next_dcb(struct lan966x_tx *tx)
 	return -1;
 }
 
+static void lan966x_fdma_tx_setup_dcb(struct lan966x_tx *tx,
+				      int next_to_use, int len,
+				      dma_addr_t dma_addr)
+{
+	struct lan966x_tx_dcb *next_dcb;
+	struct lan966x_db *next_db;
+
+	next_dcb = &tx->dcbs[next_to_use];
+	next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
+
+	next_db = &next_dcb->db[0];
+	next_db->dataptr = dma_addr;
+	next_db->status = FDMA_DCB_STATUS_SOF |
+			  FDMA_DCB_STATUS_EOF |
+			  FDMA_DCB_STATUS_INTR |
+			  FDMA_DCB_STATUS_BLOCKO(0) |
+			  FDMA_DCB_STATUS_BLOCKL(len);
+}
+
+static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use)
+{
+	struct lan966x *lan966x = tx->lan966x;
+	struct lan966x_tx_dcb *dcb;
+
+	if (likely(lan966x->tx.activated)) {
+		/* Connect current dcb to the next db */
+		dcb = &tx->dcbs[tx->last_in_use];
+		dcb->nextptr = tx->dma + (next_to_use *
+					  sizeof(struct lan966x_tx_dcb));
+
+		lan966x_fdma_tx_reload(tx);
+	} else {
+		/* Because it is first time, then just activate */
+		lan966x->tx.activated = true;
+		lan966x_fdma_tx_activate(tx);
+	}
+
+	/* Move to next dcb because this last in use */
+	tx->last_in_use = next_to_use;
+}
+
 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 {
 	struct lan966x_port *port = netdev_priv(dev);
 	struct lan966x *lan966x = port->lan966x;
 	struct lan966x_tx_dcb_buf *next_dcb_buf;
-	struct lan966x_tx_dcb *next_dcb, *dcb;
 	struct lan966x_tx *tx = &lan966x->tx;
-	struct lan966x_db *next_db;
 	int needed_headroom;
 	int needed_tailroom;
 	dma_addr_t dma_addr;
@@ -667,16 +706,7 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 	}
 
 	/* Setup next dcb */
-	next_dcb = &tx->dcbs[next_to_use];
-	next_dcb->nextptr = FDMA_DCB_INVALID_DATA;
-
-	next_db = &next_dcb->db[0];
-	next_db->dataptr = dma_addr;
-	next_db->status = FDMA_DCB_STATUS_SOF |
-			  FDMA_DCB_STATUS_EOF |
-			  FDMA_DCB_STATUS_INTR |
-			  FDMA_DCB_STATUS_BLOCKO(0) |
-			  FDMA_DCB_STATUS_BLOCKL(skb->len);
+	lan966x_fdma_tx_setup_dcb(tx, next_to_use, skb->len, dma_addr);
 
 	/* Fill up the buffer */
 	next_dcb_buf = &tx->dcbs_buf[next_to_use];
@@ -690,21 +720,8 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 	    LAN966X_SKB_CB(skb)->rew_op == IFH_REW_OP_TWO_STEP_PTP)
 		next_dcb_buf->ptp = true;
 
-	if (likely(lan966x->tx.activated)) {
-		/* Connect current dcb to the next db */
-		dcb = &tx->dcbs[tx->last_in_use];
-		dcb->nextptr = tx->dma + (next_to_use *
-					  sizeof(struct lan966x_tx_dcb));
-
-		lan966x_fdma_tx_reload(tx);
-	} else {
-		/* Because it is first time, then just activate */
-		lan966x->tx.activated = true;
-		lan966x_fdma_tx_activate(tx);
-	}
-
-	/* Move to next dcb because this last in use */
-	tx->last_in_use = next_to_use;
+	/* Start the transmission */
+	lan966x_fdma_tx_start(tx, next_to_use);
 
 	return NETDEV_TX_OK;
 
-- 
2.38.0

[PATCH net-next 3/5] net: lan966x: Add len field to lan966x_tx_dcb_buf

[Horatiu Vultur]

Currently when a frame was transmitted, it is required to unamp the
frame that was transmitted. The length of the frame was taken from the
transmitted skb. In the future we might not have an skb, therefore store
the length skb directly in the lan966x_tx_dcb_buf and use this one to
unamp the frame.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c | 5 +++--
 drivers/net/ethernet/microchip/lan966x/lan966x_main.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 0dbe620d3093f..833583f6bbfa6 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -391,12 +391,12 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
 			continue;
 
 		dcb_buf->dev->stats.tx_packets++;
-		dcb_buf->dev->stats.tx_bytes += dcb_buf->skb->len;
+		dcb_buf->dev->stats.tx_bytes += dcb_buf->len;
 
 		dcb_buf->used = false;
 		dma_unmap_single(lan966x->dev,
 				 dcb_buf->dma_addr,
-				 dcb_buf->skb->len,
+				 dcb_buf->len,
 				 DMA_TO_DEVICE);
 		if (!dcb_buf->ptp)
 			dev_kfree_skb_any(dcb_buf->skb);
@@ -711,6 +711,7 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 	/* Fill up the buffer */
 	next_dcb_buf = &tx->dcbs_buf[next_to_use];
 	next_dcb_buf->skb = skb;
+	next_dcb_buf->len = skb->len;
 	next_dcb_buf->dma_addr = dma_addr;
 	next_dcb_buf->used = true;
 	next_dcb_buf->ptp = false;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index bc93051aa0798..7bb9098496f60 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -175,6 +175,7 @@ struct lan966x_rx {
 struct lan966x_tx_dcb_buf {
 	struct net_device *dev;
 	struct sk_buff *skb;
+	int len;
 	dma_addr_t dma_addr;
 	bool used;
 	bool ptp;
-- 
2.38.0

[PATCH net-next 4/5] net: lan966x: Add support for XDP_TX

[Horatiu Vultur]

Extend lan966x XDP support with the action XDP_TX. In this case when the
received buffer needs to execute XDP_TX, the buffer will be moved to the
TX buffers. So a new RX buffer will be allocated.
When the TX finish with the frame, it would release completely this
buffer.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../ethernet/microchip/lan966x/lan966x_fdma.c | 78 +++++++++++++++++--
 .../ethernet/microchip/lan966x/lan966x_main.c |  4 +-
 .../ethernet/microchip/lan966x/lan966x_main.h |  8 ++
 .../ethernet/microchip/lan966x/lan966x_xdp.c  |  8 ++
 4 files changed, 91 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 833583f6bbfa6..a177ca499db4e 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -394,13 +394,21 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight)
 		dcb_buf->dev->stats.tx_bytes += dcb_buf->len;
 
 		dcb_buf->used = false;
-		dma_unmap_single(lan966x->dev,
-				 dcb_buf->dma_addr,
-				 dcb_buf->len,
-				 DMA_TO_DEVICE);
-		if (!dcb_buf->ptp)
+		if (dcb_buf->skb)
+			dma_unmap_single(lan966x->dev,
+					 dcb_buf->dma_addr,
+					 dcb_buf->len,
+					 DMA_TO_DEVICE);
+
+		if (dcb_buf->skb && !dcb_buf->ptp)
 			dev_kfree_skb_any(dcb_buf->skb);
 
+		if (dcb_buf->page) {
+			page_pool_release_page(lan966x->rx.page_pool,
+					       dcb_buf->page);
+			put_page(dcb_buf->page);
+		}
+
 		clear = true;
 	}
 
@@ -534,6 +542,9 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 			lan966x_fdma_rx_free_page(rx);
 			lan966x_fdma_rx_advance_dcb(rx);
 			goto allocate_new;
+		case FDMA_TX:
+			lan966x_fdma_rx_advance_dcb(rx);
+			continue;
 		case FDMA_DROP:
 			lan966x_fdma_rx_free_page(rx);
 			lan966x_fdma_rx_advance_dcb(rx);
@@ -655,6 +666,62 @@ static void lan966x_fdma_tx_start(struct lan966x_tx *tx, int next_to_use)
 	tx->last_in_use = next_to_use;
 }
 
+int lan966x_fdma_xmit_xdpf(struct lan966x_port *port,
+			   struct xdp_frame *xdpf,
+			   struct page *page)
+{
+	struct lan966x *lan966x = port->lan966x;
+	struct lan966x_tx_dcb_buf *next_dcb_buf;
+	struct lan966x_tx *tx = &lan966x->tx;
+	dma_addr_t dma_addr;
+	int next_to_use;
+	__be32 *ifh;
+	int ret = 0;
+
+	spin_lock(&lan966x->tx_lock);
+
+	/* Get next index */
+	next_to_use = lan966x_fdma_get_next_dcb(tx);
+	if (next_to_use < 0) {
+		netif_stop_queue(port->dev);
+		ret = NETDEV_TX_BUSY;
+		goto out;
+	}
+
+	/* Generate new IFH */
+	ifh = page_address(page) + XDP_PACKET_HEADROOM;
+	memset(ifh, 0x0, sizeof(__be32) * IFH_LEN);
+	lan966x_ifh_set_bypass(ifh, 1);
+	lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port));
+
+	dma_addr = page_pool_get_dma_addr(page);
+	dma_sync_single_for_device(lan966x->dev, dma_addr + XDP_PACKET_HEADROOM,
+				   xdpf->len + IFH_LEN_BYTES,
+				   DMA_TO_DEVICE);
+
+	/* Setup next dcb */
+	lan966x_fdma_tx_setup_dcb(tx, next_to_use, xdpf->len + IFH_LEN_BYTES,
+				  dma_addr + XDP_PACKET_HEADROOM);
+
+	/* Fill up the buffer */
+	next_dcb_buf = &tx->dcbs_buf[next_to_use];
+	next_dcb_buf->skb = NULL;
+	next_dcb_buf->page = page;
+	next_dcb_buf->len = xdpf->len + IFH_LEN_BYTES;
+	next_dcb_buf->dma_addr = dma_addr;
+	next_dcb_buf->used = true;
+	next_dcb_buf->ptp = false;
+	next_dcb_buf->dev = port->dev;
+
+	/* Start the transmission */
+	lan966x_fdma_tx_start(tx, next_to_use);
+
+out:
+	spin_unlock(&lan966x->tx_lock);
+
+	return ret;
+}
+
 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 {
 	struct lan966x_port *port = netdev_priv(dev);
@@ -711,6 +778,7 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev)
 	/* Fill up the buffer */
 	next_dcb_buf = &tx->dcbs_buf[next_to_use];
 	next_dcb_buf->skb = skb;
+	next_dcb_buf->page = NULL;
 	next_dcb_buf->len = skb->len;
 	next_dcb_buf->dma_addr = dma_addr;
 	next_dcb_buf->used = true;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 42be5d0f1f015..0b7707306da26 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -302,13 +302,13 @@ static int lan966x_port_ifh_xmit(struct sk_buff *skb,
 	return NETDEV_TX_BUSY;
 }
 
-static void lan966x_ifh_set_bypass(void *ifh, u64 bypass)
+void lan966x_ifh_set_bypass(void *ifh, u64 bypass)
 {
 	packing(ifh, &bypass, IFH_POS_BYPASS + IFH_WID_BYPASS - 1,
 		IFH_POS_BYPASS, IFH_LEN * 4, PACK, 0);
 }
 
-static void lan966x_ifh_set_port(void *ifh, u64 bypass)
+void lan966x_ifh_set_port(void *ifh, u64 bypass)
 {
 	packing(ifh, &bypass, IFH_POS_DSTS + IFH_WID_DSTS - 1,
 		IFH_POS_DSTS, IFH_LEN * 4, PACK, 0);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index 7bb9098496f60..df7fec361962b 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -105,11 +105,13 @@ enum macaccess_entry_type {
  * FDMA_PASS, frame is valid and can be used
  * FDMA_ERROR, something went wrong, stop getting more frames
  * FDMA_DROP, frame is dropped, but continue to get more frames
+ * FDMA_TX, frame is given to TX, but continue to get more frames
  */
 enum lan966x_fdma_action {
 	FDMA_PASS = 0,
 	FDMA_ERROR,
 	FDMA_DROP,
+	FDMA_TX,
 };
 
 struct lan966x_port;
@@ -175,6 +177,7 @@ struct lan966x_rx {
 struct lan966x_tx_dcb_buf {
 	struct net_device *dev;
 	struct sk_buff *skb;
+	struct page *page;
 	int len;
 	dma_addr_t dma_addr;
 	bool used;
@@ -360,6 +363,8 @@ bool lan966x_hw_offload(struct lan966x *lan966x, u32 port, struct sk_buff *skb);
 
 void lan966x_ifh_get_src_port(void *ifh, u64 *src_port);
 void lan966x_ifh_get_timestamp(void *ifh, u64 *timestamp);
+void lan966x_ifh_set_bypass(void *ifh, u64 bypass);
+void lan966x_ifh_set_port(void *ifh, u64 bypass);
 
 void lan966x_stats_get(struct net_device *dev,
 		       struct rtnl_link_stats64 *stats);
@@ -460,6 +465,9 @@ u32 lan966x_ptp_get_period_ps(void);
 int lan966x_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts);
 
 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
+int lan966x_fdma_xmit_xdpf(struct lan966x_port *port,
+			   struct xdp_frame *frame,
+			   struct page *page);
 int lan966x_fdma_change_mtu(struct lan966x *lan966x);
 void lan966x_fdma_netdev_init(struct lan966x *lan966x, struct net_device *dev);
 void lan966x_fdma_netdev_deinit(struct lan966x *lan966x, struct net_device *dev);
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
index bab447e79273f..c7dcb9d443ffa 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -39,6 +39,7 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 {
 	struct bpf_prog *xdp_prog = port->xdp_prog;
 	struct lan966x *lan966x = port->lan966x;
+	struct xdp_frame *xdpf;
 	struct xdp_buff xdp;
 	u32 act;
 
@@ -51,6 +52,13 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 	switch (act) {
 	case XDP_PASS:
 		return FDMA_PASS;
+	case XDP_TX:
+		xdpf = xdp_convert_buff_to_frame(&xdp);
+		if (!xdpf)
+			return FDMA_DROP;
+
+		return lan966x_fdma_xmit_xdpf(port, xdpf, page) ?
+		       FDMA_DROP : FDMA_TX;
 	default:
 		bpf_warn_invalid_xdp_action(port->dev, xdp_prog, act);
 		fallthrough;
-- 
2.38.0

[PATCH net-next 5/5] net: lan966x: Add support for XDP_REDIRECT

[Horatiu Vultur]

Extend lan966x XDP support with the action XDP_REDIRECT. This is similar
with the XDP_TX, so a lot of functionality can be reused.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../ethernet/microchip/lan966x/lan966x_fdma.c |  9 ++++++
 .../ethernet/microchip/lan966x/lan966x_main.c |  1 +
 .../ethernet/microchip/lan966x/lan966x_main.h |  6 ++++
 .../ethernet/microchip/lan966x/lan966x_xdp.c  | 28 +++++++++++++++++++
 4 files changed, 44 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index a177ca499db4e..18de2880e202c 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 
 #include <linux/bpf.h>
+#include <linux/filter.h>
 
 #include "lan966x_main.h"
 
@@ -520,6 +521,7 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 	int dcb_reload = rx->dcb_index;
 	struct lan966x_rx_dcb *old_dcb;
 	struct lan966x_db *db;
+	bool redirect = false;
 	struct sk_buff *skb;
 	struct page *page;
 	int counter = 0;
@@ -545,6 +547,10 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 		case FDMA_TX:
 			lan966x_fdma_rx_advance_dcb(rx);
 			continue;
+		case FDMA_REDIRECT:
+			lan966x_fdma_rx_advance_dcb(rx);
+			redirect = true;
+			continue;
 		case FDMA_DROP:
 			lan966x_fdma_rx_free_page(rx);
 			lan966x_fdma_rx_advance_dcb(rx);
@@ -581,6 +587,9 @@ static int lan966x_fdma_napi_poll(struct napi_struct *napi, int weight)
 	if (counter < weight && napi_complete_done(napi, counter))
 		lan_wr(0xff, lan966x, FDMA_INTR_DB_ENA);
 
+	if (redirect)
+		xdp_do_flush();
+
 	return counter;
 }
 
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index 0b7707306da26..0aed244826d39 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -469,6 +469,7 @@ static const struct net_device_ops lan966x_port_netdev_ops = {
 	.ndo_eth_ioctl			= lan966x_port_ioctl,
 	.ndo_setup_tc			= lan966x_tc_setup,
 	.ndo_bpf			= lan966x_xdp,
+	.ndo_xdp_xmit			= lan966x_xdp_xmit,
 };
 
 bool lan966x_netdevice_check(const struct net_device *dev)
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index df7fec361962b..b73c5a6cc0beb 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -106,12 +106,14 @@ enum macaccess_entry_type {
  * FDMA_ERROR, something went wrong, stop getting more frames
  * FDMA_DROP, frame is dropped, but continue to get more frames
  * FDMA_TX, frame is given to TX, but continue to get more frames
+ * FDMA_REDIRECT, frame is given to TX, but continue to get more frames
  */
 enum lan966x_fdma_action {
 	FDMA_PASS = 0,
 	FDMA_ERROR,
 	FDMA_DROP,
 	FDMA_TX,
+	FDMA_REDIRECT,
 };
 
 struct lan966x_port;
@@ -564,6 +566,10 @@ int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp);
 int lan966x_xdp_run(struct lan966x_port *port,
 		    struct page *page,
 		    u32 data_len);
+int lan966x_xdp_xmit(struct net_device *dev,
+		     int n,
+		     struct xdp_frame **frames,
+		     u32 flags);
 static inline bool lan966x_xdp_port_present(struct lan966x_port *port)
 {
 	return !!port->xdp_prog;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
index c7dcb9d443ffa..fbf04a82ef994 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c
@@ -35,6 +35,29 @@ int lan966x_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 	}
 }
 
+int lan966x_xdp_xmit(struct net_device *dev,
+		     int n,
+		     struct xdp_frame **frames,
+		     u32 flags)
+{
+	struct lan966x_port *port = netdev_priv(dev);
+	int i, nxmit = 0;
+
+	for (i = 0; i < n; ++i) {
+		struct xdp_frame *xdpf = frames[i];
+		int err;
+
+		err = lan966x_fdma_xmit_xdpf(port, xdpf,
+					     virt_to_head_page(xdpf->data));
+		if (err)
+			break;
+
+		nxmit++;
+	}
+
+	return nxmit;
+}
+
 int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 {
 	struct bpf_prog *xdp_prog = port->xdp_prog;
@@ -59,6 +82,11 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 
 		return lan966x_fdma_xmit_xdpf(port, xdpf, page) ?
 		       FDMA_DROP : FDMA_TX;
+	case XDP_REDIRECT:
+		if (xdp_do_redirect(port->dev, &xdp, xdp_prog))
+			return FDMA_DROP;
+
+		return FDMA_REDIRECT;
 	default:
 		bpf_warn_invalid_xdp_action(port->dev, xdp_prog, act);
 		fallthrough;
-- 
2.38.0