1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/net/ethernet/amazon/ena/ena_xdp.h b/drivers/net/ethernet/amazon/ena/ena_xdp.h
new file mode 100644
index 000000000000..cfd82728486a
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_xdp.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
+ */
+
+#ifndef ENA_XDP_H
+#define ENA_XDP_H
+
+#include "ena_netdev.h"
+#include <linux/bpf_trace.h>
+
+/* The max MTU size is configured to be the ethernet frame size without
+ * the overhead of the ethernet header, which can have a VLAN header, and
+ * a frame check sequence (FCS).
+ * The buffer size we share with the device is defined to be ENA_PAGE_SIZE
+ */
+#define ENA_XDP_MAX_MTU (ENA_PAGE_SIZE - ETH_HLEN - ETH_FCS_LEN -	\
+			 VLAN_HLEN - XDP_PACKET_HEADROOM -		\
+			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+
+#define ENA_IS_XDP_INDEX(adapter, index) (((index) >= (adapter)->xdp_first_ring) && \
+	((index) < (adapter)->xdp_first_ring + (adapter)->xdp_num_queues))
+
+enum ENA_XDP_ACTIONS {
+	ENA_XDP_PASS		= 0,
+	ENA_XDP_TX		= BIT(0),
+	ENA_XDP_REDIRECT	= BIT(1),
+	ENA_XDP_DROP		= BIT(2)
+};
+
+#define ENA_XDP_FORWARDED (ENA_XDP_TX | ENA_XDP_REDIRECT)
+
+int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter);
+void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
+					  struct bpf_prog *prog,
+					  int first, int count);
+int ena_xdp_io_poll(struct napi_struct *napi, int budget);
+int ena_xdp_xmit_frame(struct ena_ring *tx_ring,
+		       struct ena_adapter *adapter,
+		       struct xdp_frame *xdpf,
+		       int flags);
+int ena_xdp_xmit(struct net_device *dev, int n,
+		 struct xdp_frame **frames, u32 flags);
+int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf);
+int ena_xdp_register_rxq_info(struct ena_ring *rx_ring);
+void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring);
+
+enum ena_xdp_errors_t {
+	ENA_XDP_ALLOWED = 0,
+	ENA_XDP_CURRENT_MTU_TOO_LARGE,
+	ENA_XDP_NO_ENOUGH_QUEUES,
+};
+
+static inline bool ena_xdp_present(struct ena_adapter *adapter)
+{
+	return !!adapter->xdp_bpf_prog;
+}
+
+static inline bool ena_xdp_present_ring(struct ena_ring *ring)
+{
+	return !!ring->xdp_bpf_prog;
+}
+
+static inline bool ena_xdp_legal_queue_count(struct ena_adapter *adapter,
+					     u32 queues)
+{
+	return 2 * queues <= adapter->max_num_io_queues;
+}
+
+static inline enum ena_xdp_errors_t ena_xdp_allowed(struct ena_adapter *adapter)
+{
+	enum ena_xdp_errors_t rc = ENA_XDP_ALLOWED;
+
+	if (adapter->netdev->mtu > ENA_XDP_MAX_MTU)
+		rc = ENA_XDP_CURRENT_MTU_TOO_LARGE;
+	else if (!ena_xdp_legal_queue_count(adapter, adapter->num_io_queues))
+		rc = ENA_XDP_NO_ENOUGH_QUEUES;
+
+	return rc;
+}
+
+static inline int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
+{
+	u32 verdict = ENA_XDP_PASS;
+	struct bpf_prog *xdp_prog;
+	struct ena_ring *xdp_ring;
+	struct xdp_frame *xdpf;
+	u64 *xdp_stat;
+
+	xdp_prog = READ_ONCE(rx_ring->xdp_bpf_prog);
+
+	verdict = bpf_prog_run_xdp(xdp_prog, xdp);
+
+	switch (verdict) {
+	case XDP_TX:
+		xdpf = xdp_convert_buff_to_frame(xdp);
+		if (unlikely(!xdpf)) {
+			trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
+			xdp_stat = &rx_ring->rx_stats.xdp_aborted;
+			verdict = ENA_XDP_DROP;
+			break;
+		}
+
+		/* Find xmit queue */
+		xdp_ring = rx_ring->xdp_ring;
+
+		/* The XDP queues are shared between XDP_TX and XDP_REDIRECT */
+		spin_lock(&xdp_ring->xdp_tx_lock);
+
+		if (ena_xdp_xmit_frame(xdp_ring, rx_ring->adapter, xdpf,
+				       XDP_XMIT_FLUSH))
+			xdp_return_frame(xdpf);
+
+		spin_unlock(&xdp_ring->xdp_tx_lock);
+		xdp_stat = &rx_ring->rx_stats.xdp_tx;
+		verdict = ENA_XDP_TX;
+		break;
+	case XDP_REDIRECT:
+		if (likely(!xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog))) {
+			xdp_stat = &rx_ring->rx_stats.xdp_redirect;
+			verdict = ENA_XDP_REDIRECT;
+			break;
+		}
+		trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
+		xdp_stat = &rx_ring->rx_stats.xdp_aborted;
+		verdict = ENA_XDP_DROP;
+		break;
+	case XDP_ABORTED:
+		trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
+		xdp_stat = &rx_ring->rx_stats.xdp_aborted;
+		verdict = ENA_XDP_DROP;
+		break;
+	case XDP_DROP:
+		xdp_stat = &rx_ring->rx_stats.xdp_drop;
+		verdict = ENA_XDP_DROP;
+		break;
+	case XDP_PASS:
+		xdp_stat = &rx_ring->rx_stats.xdp_pass;
+		verdict = ENA_XDP_PASS;
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, verdict);
+		xdp_stat = &rx_ring->rx_stats.xdp_invalid;
+		verdict = ENA_XDP_DROP;
+	}
+
+	ena_increase_stat(xdp_stat, 1, &rx_ring->syncp);
+
+	return verdict;
+}
+#endif /* ENA_XDP_H */