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 
10 int 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 (if_running)
33 		igc_open(dev);
34 
35 	return 0;
36 }
37 
38 static int igc_xdp_enable_pool(struct igc_adapter *adapter,
39 			       struct xsk_buff_pool *pool, u16 queue_id)
40 {
41 	struct net_device *ndev = adapter->netdev;
42 	struct device *dev = &adapter->pdev->dev;
43 	struct igc_ring *rx_ring, *tx_ring;
44 	struct napi_struct *napi;
45 	bool needs_reset;
46 	u32 frame_size;
47 	int err;
48 
49 	if (queue_id >= adapter->num_rx_queues ||
50 	    queue_id >= adapter->num_tx_queues)
51 		return -EINVAL;
52 
53 	frame_size = xsk_pool_get_rx_frame_size(pool);
54 	if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2) {
55 		/* When XDP is enabled, the driver doesn't support frames that
56 		 * span over multiple buffers. To avoid that, we check if xsk
57 		 * frame size is big enough to fit the max ethernet frame size
58 		 * + vlan double tagging.
59 		 */
60 		return -EOPNOTSUPP;
61 	}
62 
63 	err = xsk_pool_dma_map(pool, dev, IGC_RX_DMA_ATTR);
64 	if (err) {
65 		netdev_err(ndev, "Failed to map xsk pool\n");
66 		return err;
67 	}
68 
69 	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
70 
71 	rx_ring = adapter->rx_ring[queue_id];
72 	tx_ring = adapter->tx_ring[queue_id];
73 	/* Rx and Tx rings share the same napi context. */
74 	napi = &rx_ring->q_vector->napi;
75 
76 	if (needs_reset) {
77 		igc_disable_rx_ring(rx_ring);
78 		igc_disable_tx_ring(tx_ring);
79 		napi_disable(napi);
80 	}
81 
82 	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
83 	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
84 
85 	if (needs_reset) {
86 		napi_enable(napi);
87 		igc_enable_rx_ring(rx_ring);
88 		igc_enable_tx_ring(tx_ring);
89 
90 		err = igc_xsk_wakeup(ndev, queue_id, XDP_WAKEUP_RX);
91 		if (err) {
92 			xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
93 			return err;
94 		}
95 	}
96 
97 	return 0;
98 }
99 
100 static int igc_xdp_disable_pool(struct igc_adapter *adapter, u16 queue_id)
101 {
102 	struct igc_ring *rx_ring, *tx_ring;
103 	struct xsk_buff_pool *pool;
104 	struct napi_struct *napi;
105 	bool needs_reset;
106 
107 	if (queue_id >= adapter->num_rx_queues ||
108 	    queue_id >= adapter->num_tx_queues)
109 		return -EINVAL;
110 
111 	pool = xsk_get_pool_from_qid(adapter->netdev, queue_id);
112 	if (!pool)
113 		return -EINVAL;
114 
115 	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
116 
117 	rx_ring = adapter->rx_ring[queue_id];
118 	tx_ring = adapter->tx_ring[queue_id];
119 	/* Rx and Tx rings share the same napi context. */
120 	napi = &rx_ring->q_vector->napi;
121 
122 	if (needs_reset) {
123 		igc_disable_rx_ring(rx_ring);
124 		igc_disable_tx_ring(tx_ring);
125 		napi_disable(napi);
126 	}
127 
128 	xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
129 	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
130 	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
131 
132 	if (needs_reset) {
133 		napi_enable(napi);
134 		igc_enable_rx_ring(rx_ring);
135 		igc_enable_tx_ring(tx_ring);
136 	}
137 
138 	return 0;
139 }
140 
141 int igc_xdp_setup_pool(struct igc_adapter *adapter, struct xsk_buff_pool *pool,
142 		       u16 queue_id)
143 {
144 	return pool ? igc_xdp_enable_pool(adapter, pool, queue_id) :
145 		      igc_xdp_disable_pool(adapter, queue_id);
146 }
147