dpaa_eth: add XDP_REDIRECT support

After transmission, the frame is returned on confirmation queues for
cleanup. For this, store a backpointer to the xdp_frame in the private
reserved area at the start of the TX buffer.

No TX batching support is implemented at this time.

Acked-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa/dpaa_eth.c

@@ -2305,8 +2305,11 @@ static int dpaa_eth_poll(struct napi_struct *napi, int budget)
 {
 	struct dpaa_napi_portal *np =
 			container_of(napi, struct dpaa_napi_portal, napi);
+	int cleaned;
 
-	int cleaned = qman_p_poll_dqrr(np->p, budget);
+	np->xdp_act = 0;
+
+	cleaned = qman_p_poll_dqrr(np->p, budget);
 
 	if (cleaned < budget) {
 		napi_complete_done(napi, cleaned);
@@ -2315,6 +2318,9 @@ static int dpaa_eth_poll(struct napi_struct *napi, int budget)
 		qman_p_irqsource_add(np->p, QM_PIRQ_DQRI);
 	}
 
+	if (np->xdp_act & XDP_REDIRECT)
+		xdp_do_flush();
+
 	return cleaned;
 }
 
@@ -2457,6 +2463,7 @@ static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd, void *vaddr,
 	struct xdp_frame *xdpf;
 	struct xdp_buff xdp;
 	u32 xdp_act;
+	int err;
 
 	rcu_read_lock();
 
@@ -2497,6 +2504,17 @@ static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd, void *vaddr,
 		if (dpaa_xdp_xmit_frame(priv->net_dev, xdpf))
 			xdp_return_frame_rx_napi(xdpf);
 
+		break;
+	case XDP_REDIRECT:
+		/* Allow redirect to use the full headroom */
+		xdp.data_hard_start = vaddr;
+		xdp.frame_sz = DPAA_BP_RAW_SIZE;
+
+		err = xdp_do_redirect(priv->net_dev, &xdp, xdp_prog);
+		if (err) {
+			trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);
+			free_pages((unsigned long)vaddr, 0);
+		}
 		break;
 	default:
 		bpf_warn_invalid_xdp_action(xdp_act);
@@ -2527,6 +2545,7 @@ static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal *portal,
 	struct dpaa_percpu_priv *percpu_priv;
 	const struct qm_fd *fd = &dq->fd;
 	dma_addr_t addr = qm_fd_addr(fd);
+	struct dpaa_napi_portal *np;
 	enum qm_fd_format fd_format;
 	struct net_device *net_dev;
 	u32 fd_status, hash_offset;
@@ -2541,6 +2560,7 @@ static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal *portal,
 	u32 hash;
 	u64 ns;
 
+	np = container_of(&portal, struct dpaa_napi_portal, p);
 	dpaa_fq = container_of(fq, struct dpaa_fq, fq_base);
 	fd_status = be32_to_cpu(fd->status);
 	fd_format = qm_fd_get_format(fd);
@@ -2614,6 +2634,7 @@ static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal *portal,
 	if (likely(fd_format == qm_fd_contig)) {
 		xdp_act = dpaa_run_xdp(priv, (struct qm_fd *)fd, vaddr,
 				       dpaa_fq, &xdp_meta_len);
+		np->xdp_act |= xdp_act;
 		if (xdp_act != XDP_PASS) {
 			percpu_stats->rx_packets++;
 			percpu_stats->rx_bytes += qm_fd_get_length(fd);
@@ -2946,6 +2967,30 @@ static int dpaa_xdp(struct net_device *net_dev, struct netdev_bpf *xdp)
 	}
 }
 
+static int dpaa_xdp_xmit(struct net_device *net_dev, int n,
+			 struct xdp_frame **frames, u32 flags)
+{
+	struct xdp_frame *xdpf;
+	int i, err, drops = 0;
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+		return -EINVAL;
+
+	if (!netif_running(net_dev))
+		return -ENETDOWN;
+
+	for (i = 0; i < n; i++) {
+		xdpf = frames[i];
+		err = dpaa_xdp_xmit_frame(net_dev, xdpf);
+		if (err) {
+			xdp_return_frame_rx_napi(xdpf);
+			drops++;
+		}
+	}
+
+	return n - drops;
+}
+
 static int dpaa_ts_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 {
 	struct dpaa_priv *priv = netdev_priv(dev);
@@ -3014,6 +3059,7 @@ static const struct net_device_ops dpaa_ops = {
 	.ndo_setup_tc = dpaa_setup_tc,
 	.ndo_change_mtu = dpaa_change_mtu,
 	.ndo_bpf = dpaa_xdp,
+	.ndo_xdp_xmit = dpaa_xdp_xmit,
 };
 
 static int dpaa_napi_add(struct net_device *net_dev)

drivers/net/ethernet/freescale/dpaa/dpaa_eth.h

@@ -127,6 +127,7 @@ struct dpaa_napi_portal {
 	struct napi_struct napi;
 	struct qman_portal *p;
 	bool down;
+	int xdp_act;
 };
 
 struct dpaa_percpu_priv {