1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021, Intel Corporation. */
3 
4 #include <net/xdp_sock_drv.h>
5 
6 #include "stmmac.h"
7 #include "stmmac_xdp.h"
8 
9 static int stmmac_xdp_enable_pool(struct stmmac_priv *priv,
10 				  struct xsk_buff_pool *pool, u16 queue)
11 {
12 	struct stmmac_channel *ch = &priv->channel[queue];
13 	bool need_update;
14 	u32 frame_size;
15 	int err;
16 
17 	if (queue >= priv->plat->rx_queues_to_use ||
18 	    queue >= priv->plat->tx_queues_to_use)
19 		return -EINVAL;
20 
21 	frame_size = xsk_pool_get_rx_frame_size(pool);
22 	/* XDP ZC does not span multiple frame, make sure XSK pool buffer
23 	 * size can at least store Q-in-Q frame.
24 	 */
25 	if (frame_size < ETH_FRAME_LEN + VLAN_HLEN * 2)
26 		return -EOPNOTSUPP;
27 
28 	err = xsk_pool_dma_map(pool, priv->device, STMMAC_RX_DMA_ATTR);
29 	if (err) {
30 		netdev_err(priv->dev, "Failed to map xsk pool\n");
31 		return err;
32 	}
33 
34 	need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
35 
36 	if (need_update) {
37 		napi_disable(&ch->rx_napi);
38 		napi_disable(&ch->tx_napi);
39 		stmmac_disable_rx_queue(priv, queue);
40 		stmmac_disable_tx_queue(priv, queue);
41 	}
42 
43 	set_bit(queue, priv->af_xdp_zc_qps);
44 
45 	if (need_update) {
46 		stmmac_enable_rx_queue(priv, queue);
47 		stmmac_enable_tx_queue(priv, queue);
48 		napi_enable(&ch->rxtx_napi);
49 
50 		err = stmmac_xsk_wakeup(priv->dev, queue, XDP_WAKEUP_RX);
51 		if (err)
52 			return err;
53 	}
54 
55 	return 0;
56 }
57 
58 static int stmmac_xdp_disable_pool(struct stmmac_priv *priv, u16 queue)
59 {
60 	struct stmmac_channel *ch = &priv->channel[queue];
61 	struct xsk_buff_pool *pool;
62 	bool need_update;
63 
64 	if (queue >= priv->plat->rx_queues_to_use ||
65 	    queue >= priv->plat->tx_queues_to_use)
66 		return -EINVAL;
67 
68 	pool = xsk_get_pool_from_qid(priv->dev, queue);
69 	if (!pool)
70 		return -EINVAL;
71 
72 	need_update = netif_running(priv->dev) && stmmac_xdp_is_enabled(priv);
73 
74 	if (need_update) {
75 		napi_disable(&ch->rxtx_napi);
76 		stmmac_disable_rx_queue(priv, queue);
77 		stmmac_disable_tx_queue(priv, queue);
78 		synchronize_rcu();
79 	}
80 
81 	xsk_pool_dma_unmap(pool, STMMAC_RX_DMA_ATTR);
82 
83 	clear_bit(queue, priv->af_xdp_zc_qps);
84 
85 	if (need_update) {
86 		stmmac_enable_rx_queue(priv, queue);
87 		stmmac_enable_tx_queue(priv, queue);
88 		napi_enable(&ch->rx_napi);
89 		napi_enable(&ch->tx_napi);
90 	}
91 
92 	return 0;
93 }
94 
95 int stmmac_xdp_setup_pool(struct stmmac_priv *priv, struct xsk_buff_pool *pool,
96 			  u16 queue)
97 {
98 	return pool ? stmmac_xdp_enable_pool(priv, pool, queue) :
99 		      stmmac_xdp_disable_pool(priv, queue);
100 }
101 
102 int stmmac_xdp_set_prog(struct stmmac_priv *priv, struct bpf_prog *prog,
103 			struct netlink_ext_ack *extack)
104 {
105 	struct net_device *dev = priv->dev;
106 	struct bpf_prog *old_prog;
107 	bool need_update;
108 	bool if_running;
109 
110 	if_running = netif_running(dev);
111 
112 	if (prog && dev->mtu > ETH_DATA_LEN) {
113 		/* For now, the driver doesn't support XDP functionality with
114 		 * jumbo frames so we return error.
115 		 */
116 		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
117 		return -EOPNOTSUPP;
118 	}
119 
120 	need_update = !!priv->xdp_prog != !!prog;
121 	if (if_running && need_update)
122 		stmmac_xdp_release(dev);
123 
124 	old_prog = xchg(&priv->xdp_prog, prog);
125 	if (old_prog)
126 		bpf_prog_put(old_prog);
127 
128 	/* Disable RX SPH for XDP operation */
129 	priv->sph = priv->sph_cap && !stmmac_xdp_is_enabled(priv);
130 
131 	if (if_running && need_update)
132 		stmmac_xdp_open(dev);
133 
134 	return 0;
135 }
136