1/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2/*
3 * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
4 */
5
6#ifndef ENA_XDP_H
7#define ENA_XDP_H
8
9#include "ena_netdev.h"
10#include <linux/bpf_trace.h>
11
12/* The max MTU size is configured to be the ethernet frame size without
13 * the overhead of the ethernet header, which can have a VLAN header, and
14 * a frame check sequence (FCS).
15 * The buffer size we share with the device is defined to be ENA_PAGE_SIZE
16 */
17#define ENA_XDP_MAX_MTU (ENA_PAGE_SIZE - ETH_HLEN - ETH_FCS_LEN -	\
18			 VLAN_HLEN - XDP_PACKET_HEADROOM -		\
19			 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
20
21#define ENA_IS_XDP_INDEX(adapter, index) (((index) >= (adapter)->xdp_first_ring) && \
22	((index) < (adapter)->xdp_first_ring + (adapter)->xdp_num_queues))
23
24enum ENA_XDP_ACTIONS {
25	ENA_XDP_PASS		= 0,
26	ENA_XDP_TX		= BIT(0),
27	ENA_XDP_REDIRECT	= BIT(1),
28	ENA_XDP_DROP		= BIT(2)
29};
30
31#define ENA_XDP_FORWARDED (ENA_XDP_TX | ENA_XDP_REDIRECT)
32
33int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter);
34void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
35					  struct bpf_prog *prog,
36					  int first, int count);
37int ena_xdp_io_poll(struct napi_struct *napi, int budget);
38int ena_xdp_xmit_frame(struct ena_ring *tx_ring,
39		       struct ena_adapter *adapter,
40		       struct xdp_frame *xdpf,
41		       int flags);
42int ena_xdp_xmit(struct net_device *dev, int n,
43		 struct xdp_frame **frames, u32 flags);
44int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf);
45int ena_xdp_register_rxq_info(struct ena_ring *rx_ring);
46void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring);
47
48enum ena_xdp_errors_t {
49	ENA_XDP_ALLOWED = 0,
50	ENA_XDP_CURRENT_MTU_TOO_LARGE,
51	ENA_XDP_NO_ENOUGH_QUEUES,
52};
53
54static inline bool ena_xdp_present(struct ena_adapter *adapter)
55{
56	return !!adapter->xdp_bpf_prog;
57}
58
59static inline bool ena_xdp_present_ring(struct ena_ring *ring)
60{
61	return !!ring->xdp_bpf_prog;
62}
63
64static inline bool ena_xdp_legal_queue_count(struct ena_adapter *adapter,
65					     u32 queues)
66{
67	return 2 * queues <= adapter->max_num_io_queues;
68}
69
70static inline enum ena_xdp_errors_t ena_xdp_allowed(struct ena_adapter *adapter)
71{
72	enum ena_xdp_errors_t rc = ENA_XDP_ALLOWED;
73
74	if (adapter->netdev->mtu > ENA_XDP_MAX_MTU)
75		rc = ENA_XDP_CURRENT_MTU_TOO_LARGE;
76	else if (!ena_xdp_legal_queue_count(adapter, adapter->num_io_queues))
77		rc = ENA_XDP_NO_ENOUGH_QUEUES;
78
79	return rc;
80}
81
82static inline int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
83{
84	u32 verdict = ENA_XDP_PASS;
85	struct bpf_prog *xdp_prog;
86	struct ena_ring *xdp_ring;
87	struct xdp_frame *xdpf;
88	u64 *xdp_stat;
89
90	xdp_prog = READ_ONCE(rx_ring->xdp_bpf_prog);
91
92	verdict = bpf_prog_run_xdp(xdp_prog, xdp);
93
94	switch (verdict) {
95	case XDP_TX:
96		xdpf = xdp_convert_buff_to_frame(xdp);
97		if (unlikely(!xdpf)) {
98			trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
99			xdp_stat = &rx_ring->rx_stats.xdp_aborted;
100			verdict = ENA_XDP_DROP;
101			break;
102		}
103
104		/* Find xmit queue */
105		xdp_ring = rx_ring->xdp_ring;
106
107		/* The XDP queues are shared between XDP_TX and XDP_REDIRECT */
108		spin_lock(&xdp_ring->xdp_tx_lock);
109
110		if (ena_xdp_xmit_frame(xdp_ring, rx_ring->adapter, xdpf,
111				       XDP_XMIT_FLUSH))
112			xdp_return_frame(xdpf);
113
114		spin_unlock(&xdp_ring->xdp_tx_lock);
115		xdp_stat = &rx_ring->rx_stats.xdp_tx;
116		verdict = ENA_XDP_TX;
117		break;
118	case XDP_REDIRECT:
119		if (likely(!xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog))) {
120			xdp_stat = &rx_ring->rx_stats.xdp_redirect;
121			verdict = ENA_XDP_REDIRECT;
122			break;
123		}
124		trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
125		xdp_stat = &rx_ring->rx_stats.xdp_aborted;
126		verdict = ENA_XDP_DROP;
127		break;
128	case XDP_ABORTED:
129		trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict);
130		xdp_stat = &rx_ring->rx_stats.xdp_aborted;
131		verdict = ENA_XDP_DROP;
132		break;
133	case XDP_DROP:
134		xdp_stat = &rx_ring->rx_stats.xdp_drop;
135		verdict = ENA_XDP_DROP;
136		break;
137	case XDP_PASS:
138		xdp_stat = &rx_ring->rx_stats.xdp_pass;
139		verdict = ENA_XDP_PASS;
140		break;
141	default:
142		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, verdict);
143		xdp_stat = &rx_ring->rx_stats.xdp_invalid;
144		verdict = ENA_XDP_DROP;
145	}
146
147	ena_increase_stat(xdp_stat, 1, &rx_ring->syncp);
148
149	return verdict;
150}
151#endif /* ENA_XDP_H */
152