1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020, Intel Corporation. */
3
4#include <linux/if_vlan.h>
5#include <net/xdp_sock_drv.h>
6
7#include "igc.h"
8#include "igc_xdp.h"
9
10int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
11		     struct netlink_ext_ack *extack)
12{
13	struct net_device *dev = adapter->netdev;
14	bool if_running = netif_running(dev);
15	struct bpf_prog *old_prog;
16
17	if (dev->mtu > ETH_DATA_LEN) {
18		/* For now, the driver doesn't support XDP functionality with
19		 * jumbo frames so we return error.
20		 */
21		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
22		return -EOPNOTSUPP;
23	}
24
25	if (if_running)
26		igc_close(dev);
27
28	old_prog = xchg(&adapter->xdp_prog, prog);
29	if (old_prog)
30		bpf_prog_put(old_prog);
31
32	if (prog)
33		xdp_features_set_redirect_target(dev, true);
34	else
35		xdp_features_clear_redirect_target(dev);
36
37	if (if_running)
38		igc_open(dev);
39
40	return 0;
41}
42
43static int igc_xdp_enable_pool(struct igc_adapter *adapter,
44			       struct xsk_buff_pool *pool, u16 queue_id)
45{
46	struct net_device *ndev = adapter->netdev;
47	struct device *dev = &adapter->pdev->dev;
48	struct igc_ring *rx_ring, *tx_ring;
49	struct napi_struct *napi;
50	bool needs_reset;
51	u32 frame_size;
52	int err;
53
54	if (queue_id >= adapter->num_rx_queues ||
55	    queue_id >= adapter->num_tx_queues)
56		return -EINVAL;
57
58	frame_size = xsk_pool_get_rx_frame_size(pool);
59	if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2) {
60		/* When XDP is enabled, the driver doesn't support frames that
61		 * span over multiple buffers. To avoid that, we check if xsk
62		 * frame size is big enough to fit the max ethernet frame size
63		 * + vlan double tagging.
64		 */
65		return -EOPNOTSUPP;
66	}
67
68	err = xsk_pool_dma_map(pool, dev, IGC_RX_DMA_ATTR);
69	if (err) {
70		netdev_err(ndev, "Failed to map xsk pool\n");
71		return err;
72	}
73
74	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
75
76	rx_ring = adapter->rx_ring[queue_id];
77	tx_ring = adapter->tx_ring[queue_id];
78	/* Rx and Tx rings share the same napi context. */
79	napi = &rx_ring->q_vector->napi;
80
81	if (needs_reset) {
82		igc_disable_rx_ring(rx_ring);
83		igc_disable_tx_ring(tx_ring);
84		napi_disable(napi);
85	}
86
87	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
88	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
89
90	if (needs_reset) {
91		napi_enable(napi);
92		igc_enable_rx_ring(rx_ring);
93		igc_enable_tx_ring(tx_ring);
94
95		err = igc_xsk_wakeup(ndev, queue_id, XDP_WAKEUP_RX);
96		if (err) {
97			xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
98			return err;
99		}
100	}
101
102	return 0;
103}
104
105static int igc_xdp_disable_pool(struct igc_adapter *adapter, u16 queue_id)
106{
107	struct igc_ring *rx_ring, *tx_ring;
108	struct xsk_buff_pool *pool;
109	struct napi_struct *napi;
110	bool needs_reset;
111
112	if (queue_id >= adapter->num_rx_queues ||
113	    queue_id >= adapter->num_tx_queues)
114		return -EINVAL;
115
116	pool = xsk_get_pool_from_qid(adapter->netdev, queue_id);
117	if (!pool)
118		return -EINVAL;
119
120	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
121
122	rx_ring = adapter->rx_ring[queue_id];
123	tx_ring = adapter->tx_ring[queue_id];
124	/* Rx and Tx rings share the same napi context. */
125	napi = &rx_ring->q_vector->napi;
126
127	if (needs_reset) {
128		igc_disable_rx_ring(rx_ring);
129		igc_disable_tx_ring(tx_ring);
130		napi_disable(napi);
131	}
132
133	xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
134	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
135	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
136
137	if (needs_reset) {
138		napi_enable(napi);
139		igc_enable_rx_ring(rx_ring);
140		igc_enable_tx_ring(tx_ring);
141	}
142
143	return 0;
144}
145
146int igc_xdp_setup_pool(struct igc_adapter *adapter, struct xsk_buff_pool *pool,
147		       u16 queue_id)
148{
149	return pool ? igc_xdp_enable_pool(adapter, pool, queue_id) :
150		      igc_xdp_disable_pool(adapter, queue_id);
151}
152