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From:   Horatiu Vultur <horatiu.vultur@microchip.com>
To:     <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <bpf@vger.kernel.org>
CC:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>, <ast@kernel.org>, <daniel@iogearbox.net>,
        <hawk@kernel.org>, <john.fastabend@gmail.com>,
        <alexandr.lobakin@intel.com>, <UNGLinuxDriver@microchip.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>
Subject: [PATCH net-next 5/5] net: lan966x: Add support for XDP_REDIRECT
Date:   Sun, 13 Nov 2022 12:15:59 +0100
Message-ID: <20221113111559.1028030-6-horatiu.vultur@microchip.com>
In-Reply-To: <20221113111559.1028030-1-horatiu.vultur@microchip.com>
References: <20221113111559.1028030-1-horatiu.vultur@microchip.com>
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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