Merge branch 'lan966x-extend-xdp-support'

Horatiu Vultur says:

====================
net: lan966x: Extend xdp support

Extend the current support of XDP in lan966x with the action XDP_TX and
XDP_REDIRECT.
The first patches just prepare the things such that it would be easier
to add XDP_TX and XDP_REDIRECT actions. Like adding XDP_PACKET_HEADROOM,
introduce helper functions, use the correct dma_dir for the page pool
The last 2 patches introduce the XDP actions XDP_TX and XDP_REDIRECT.

v4->v5:
- add iterator declaration inside for loops
- move the scope of port inside the function lan966x_fdma_rx_alloc_page_pool
- create union for skb and xdpf inside struct lan966x_tx_dcb_buf

v3->v4:
- use napi_consume_skb instead of dev_kfree_skb_any
- arrange members in struct lan966x_tx_dcb_buf not to have holes
- fix when xdp program is added the check for determining if page pool
  needs to be recreated was wrong
- change type for len in lan966x_tx_dcb_buf to u32

v2->v3:
- make sure to update rxq memory model
- update the page pool direction if there is any xdp program
- in case of action XDP_TX give back to reuse the page
- in case of action XDP_REDIRECT, remap the frame and make sure to
  unmap it when is transmitted.

v1->v2:
- use skb_reserve of using skb_put and skb_pull
- make sure that data_len doesn't include XDP_PACKET_HEADROOM
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

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);
@@ -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)

drivers/net/ethernet/microchip/lan966x/lan966x_main.h

@@ -105,11 +105,15 @@ 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
+ * 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;
@@ -173,11 +177,17 @@ struct lan966x_rx {
 };
 
 struct lan966x_tx_dcb_buf {
+	dma_addr_t dma_addr;
 	struct net_device *dev;
+	union {
 		struct sk_buff *skb;
-	dma_addr_t dma_addr;
-	bool used;
-	bool ptp;
+		struct xdp_frame *xdpf;
+	} data;
+	u32 len;
+	u32 used : 1;
+	u32 ptp : 1;
+	u32 use_skb : 1;
+	u32 xdp_ndo : 1;
 };
 
 struct lan966x_tx {
@@ -359,6 +369,8 @@ 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);
@@ -459,12 +471,17 @@ 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,
+			   bool dma_map);
 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);
 int lan966x_fdma_init(struct lan966x *lan966x);
 void lan966x_fdma_deinit(struct lan966x *lan966x);
 irqreturn_t lan966x_fdma_irq_handler(int irq, void *args);
+int lan966x_fdma_reload_page_pool(struct lan966x *lan966x);
 
 int lan966x_lag_port_join(struct lan966x_port *port,
 			  struct net_device *brport_dev,
@@ -555,6 +572,11 @@ 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);
+bool lan966x_xdp_present(struct lan966x *lan966x);
 static inline bool lan966x_xdp_port_present(struct lan966x_port *port)
 {
 	return !!port->xdp_prog;

drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c

@@ -11,6 +11,8 @@ static int lan966x_xdp_setup(struct net_device *dev, struct netdev_bpf *xdp)
 	struct lan966x_port *port = netdev_priv(dev);
 	struct lan966x *lan966x = port->lan966x;
 	struct bpf_prog *old_prog;
+	bool old_xdp, new_xdp;
+	int err;
 
 	if (!lan966x->fdma) {
 		NL_SET_ERR_MSG_MOD(xdp->extack,
@@ -18,7 +20,20 @@ static int lan966x_xdp_setup(struct net_device *dev, struct netdev_bpf *xdp)
 		return -EOPNOTSUPP;
 	}
 
+	old_xdp = lan966x_xdp_present(lan966x);
 	old_prog = xchg(&port->xdp_prog, xdp->prog);
+	new_xdp = lan966x_xdp_present(lan966x);
+
+	if (old_xdp == new_xdp)
+		goto out;
+
+	err = lan966x_fdma_reload_page_pool(lan966x);
+	if (err) {
+		xchg(&port->xdp_prog, old_prog);
+		return err;
+	}
+
+out:
 	if (old_prog)
 		bpf_prog_put(old_prog);
 
@@ -35,21 +50,57 @@ 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 nxmit = 0;
+
+	for (int i = 0; i < n; ++i) {
+		struct xdp_frame *xdpf = frames[i];
+		int err;
+
+		err = lan966x_fdma_xmit_xdpf(port, xdpf, NULL, true);
+		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;
 	struct lan966x *lan966x = port->lan966x;
+	struct xdp_frame *xdpf;
 	struct xdp_buff xdp;
 	u32 act;
 
 	xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order,
 		      &port->xdp_rxq);
-	xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES,
+	xdp_prepare_buff(&xdp, page_address(page),
+			 IFH_LEN_BYTES + XDP_PACKET_HEADROOM,
 			 data_len - IFH_LEN_BYTES, false);
 	act = bpf_prog_run_xdp(xdp_prog, &xdp);
 	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, false) ?
+		       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;
@@ -61,6 +112,19 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len)
 	}
 }
 
+bool lan966x_xdp_present(struct lan966x *lan966x)
+{
+	for (int p = 0; p < lan966x->num_phys_ports; ++p) {
+		if (!lan966x->ports[p])
+			continue;
+
+		if (lan966x_xdp_port_present(lan966x->ports[p]))
+			return true;
+	}
+
+	return false;
+}
+
 int lan966x_xdp_port_init(struct lan966x_port *port)
 {
 	struct lan966x *lan966x = port->lan966x;