xref: /linux/drivers/net/ethernet/intel/igc/igc_xdp.c (revision c3b999cad7ec39a5487b20e8b6e737d2ab0c5393)
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 	bool need_update;
17 	unsigned int i;
18 
19 	if (dev->mtu > ETH_DATA_LEN) {
20 		/* For now, the driver doesn't support XDP functionality with
21 		 * jumbo frames so we return error.
22 		 */
23 		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
24 		return -EOPNOTSUPP;
25 	}
26 
27 	need_update = !!adapter->xdp_prog != !!prog;
28 	if (if_running && need_update) {
29 		for (i = 0; i < adapter->num_rx_queues; i++) {
30 			igc_disable_rx_ring(adapter->rx_ring[i]);
31 			igc_disable_tx_ring(adapter->tx_ring[i]);
32 			napi_disable(&adapter->rx_ring[i]->q_vector->napi);
33 		}
34 	}
35 
36 	old_prog = xchg(&adapter->xdp_prog, prog);
37 	if (old_prog)
38 		bpf_prog_put(old_prog);
39 
40 	if (prog)
41 		xdp_features_set_redirect_target(dev, true);
42 	else
43 		xdp_features_clear_redirect_target(dev);
44 
45 	if (if_running && need_update) {
46 		for (i = 0; i < adapter->num_rx_queues; i++) {
47 			napi_enable(&adapter->rx_ring[i]->q_vector->napi);
48 			igc_enable_tx_ring(adapter->tx_ring[i]);
49 			igc_enable_rx_ring(adapter->rx_ring[i]);
50 		}
51 	}
52 
53 	return 0;
54 }
55 
56 static int igc_xdp_enable_pool(struct igc_adapter *adapter,
57 			       struct xsk_buff_pool *pool, u16 queue_id)
58 {
59 	struct net_device *ndev = adapter->netdev;
60 	struct device *dev = &adapter->pdev->dev;
61 	struct igc_ring *rx_ring, *tx_ring;
62 	struct napi_struct *napi;
63 	bool needs_reset;
64 	u32 frame_size;
65 	int err;
66 
67 	if (queue_id >= adapter->num_rx_queues ||
68 	    queue_id >= adapter->num_tx_queues)
69 		return -EINVAL;
70 
71 	frame_size = xsk_pool_get_rx_frame_size(pool);
72 	if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2) {
73 		/* When XDP is enabled, the driver doesn't support frames that
74 		 * span over multiple buffers. To avoid that, we check if xsk
75 		 * frame size is big enough to fit the max ethernet frame size
76 		 * + vlan double tagging.
77 		 */
78 		return -EOPNOTSUPP;
79 	}
80 
81 	err = xsk_pool_dma_map(pool, dev, IGC_RX_DMA_ATTR);
82 	if (err) {
83 		netdev_err(ndev, "Failed to map xsk pool\n");
84 		return err;
85 	}
86 
87 	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
88 
89 	rx_ring = adapter->rx_ring[queue_id];
90 	tx_ring = adapter->tx_ring[queue_id];
91 	/* Rx and Tx rings share the same napi context. */
92 	napi = &rx_ring->q_vector->napi;
93 
94 	if (needs_reset) {
95 		igc_disable_rx_ring(rx_ring);
96 		igc_disable_tx_ring(tx_ring);
97 		napi_disable(napi);
98 	}
99 
100 	igc_set_queue_napi(adapter, queue_id, NULL);
101 	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
102 	set_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
103 
104 	if (needs_reset) {
105 		napi_enable(napi);
106 		igc_enable_rx_ring(rx_ring);
107 		igc_enable_tx_ring(tx_ring);
108 
109 		err = igc_xsk_wakeup(ndev, queue_id, XDP_WAKEUP_RX);
110 		if (err) {
111 			xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
112 			return err;
113 		}
114 	}
115 
116 	return 0;
117 }
118 
119 static int igc_xdp_disable_pool(struct igc_adapter *adapter, u16 queue_id)
120 {
121 	struct igc_ring *rx_ring, *tx_ring;
122 	struct xsk_buff_pool *pool;
123 	struct napi_struct *napi;
124 	bool needs_reset;
125 
126 	if (queue_id >= adapter->num_rx_queues ||
127 	    queue_id >= adapter->num_tx_queues)
128 		return -EINVAL;
129 
130 	pool = xsk_get_pool_from_qid(adapter->netdev, queue_id);
131 	if (!pool)
132 		return -EINVAL;
133 
134 	needs_reset = netif_running(adapter->netdev) && igc_xdp_is_enabled(adapter);
135 
136 	rx_ring = adapter->rx_ring[queue_id];
137 	tx_ring = adapter->tx_ring[queue_id];
138 	/* Rx and Tx rings share the same napi context. */
139 	napi = &rx_ring->q_vector->napi;
140 
141 	if (needs_reset) {
142 		igc_disable_rx_ring(rx_ring);
143 		igc_disable_tx_ring(tx_ring);
144 		napi_disable(napi);
145 	}
146 
147 	xsk_pool_dma_unmap(pool, IGC_RX_DMA_ATTR);
148 	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &rx_ring->flags);
149 	clear_bit(IGC_RING_FLAG_AF_XDP_ZC, &tx_ring->flags);
150 	igc_set_queue_napi(adapter, queue_id, napi);
151 
152 	if (needs_reset) {
153 		napi_enable(napi);
154 		igc_enable_rx_ring(rx_ring);
155 		igc_enable_tx_ring(tx_ring);
156 	}
157 
158 	return 0;
159 }
160 
161 int igc_xdp_setup_pool(struct igc_adapter *adapter, struct xsk_buff_pool *pool,
162 		       u16 queue_id)
163 {
164 	return pool ? igc_xdp_enable_pool(adapter, pool, queue_id) :
165 		      igc_xdp_disable_pool(adapter, queue_id);
166 }
167