1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /* Copyright (c) 2019 Mellanox Technologies. */
3
4 #include "tx.h"
5 #include "pool.h"
6 #include "en/xdp.h"
7 #include "en/params.h"
8 #include <net/xdp_sock_drv.h>
9
mlx5e_xsk_wakeup(struct net_device * dev,u32 qid,u32 flags)10 int mlx5e_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
11 {
12 struct mlx5e_priv *priv = netdev_priv(dev);
13 struct mlx5e_params *params = &priv->channels.params;
14 struct mlx5e_channel *c;
15
16 if (unlikely(!mlx5e_xdp_is_active(priv)))
17 return -ENETDOWN;
18
19 if (unlikely(qid >= params->num_channels))
20 return -EINVAL;
21
22 c = priv->channels.c[qid];
23
24 if (!napi_if_scheduled_mark_missed(&c->napi)) {
25 /* To avoid WQE overrun, don't post a NOP if async_icosq is not
26 * active and not polled by NAPI. Return 0, because the upcoming
27 * activate will trigger the IRQ for us.
28 */
29 if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &c->async_icosq.state)))
30 return 0;
31
32 if (test_and_set_bit(MLX5E_SQ_STATE_PENDING_XSK_TX, &c->async_icosq.state))
33 return 0;
34
35 mlx5e_trigger_napi_icosq(c);
36 }
37
38 return 0;
39 }
40
41 /* When TX fails (because of the size of the packet), we need to get completions
42 * in order, so post a NOP to get a CQE. Since AF_XDP doesn't distinguish
43 * between successful TX and errors, handling in mlx5e_poll_xdpsq_cq is the
44 * same.
45 */
mlx5e_xsk_tx_post_err(struct mlx5e_xdpsq * sq,struct mlx5e_xdp_info * xdpi)46 static void mlx5e_xsk_tx_post_err(struct mlx5e_xdpsq *sq,
47 struct mlx5e_xdp_info *xdpi)
48 {
49 u16 pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc);
50 struct mlx5e_xdp_wqe_info *wi = &sq->db.wqe_info[pi];
51 struct mlx5e_tx_wqe *nopwqe;
52
53 wi->num_wqebbs = 1;
54 wi->num_pkts = 1;
55
56 nopwqe = mlx5e_post_nop(&sq->wq, sq->sqn, &sq->pc);
57 mlx5e_xdpi_fifo_push(&sq->db.xdpi_fifo, xdpi);
58 sq->doorbell_cseg = &nopwqe->ctrl;
59 }
60
mlx5e_xsk_tx(struct mlx5e_xdpsq * sq,unsigned int budget)61 bool mlx5e_xsk_tx(struct mlx5e_xdpsq *sq, unsigned int budget)
62 {
63 struct xsk_buff_pool *pool = sq->xsk_pool;
64 struct mlx5e_xmit_data xdptxd;
65 struct mlx5e_xdp_info xdpi;
66 bool work_done = true;
67 bool flush = false;
68
69 xdpi.mode = MLX5E_XDP_XMIT_MODE_XSK;
70
71 for (; budget; budget--) {
72 int check_result = INDIRECT_CALL_2(sq->xmit_xdp_frame_check,
73 mlx5e_xmit_xdp_frame_check_mpwqe,
74 mlx5e_xmit_xdp_frame_check,
75 sq);
76 struct xdp_desc desc;
77 bool ret;
78
79 if (unlikely(check_result < 0)) {
80 work_done = false;
81 break;
82 }
83
84 if (!xsk_tx_peek_desc(pool, &desc)) {
85 /* TX will get stuck until something wakes it up by
86 * triggering NAPI. Currently it's expected that the
87 * application calls sendto() if there are consumed, but
88 * not completed frames.
89 */
90 break;
91 }
92
93 xdptxd.dma_addr = xsk_buff_raw_get_dma(pool, desc.addr);
94 xdptxd.data = xsk_buff_raw_get_data(pool, desc.addr);
95 xdptxd.len = desc.len;
96
97 xsk_buff_raw_dma_sync_for_device(pool, xdptxd.dma_addr, xdptxd.len);
98
99 ret = INDIRECT_CALL_2(sq->xmit_xdp_frame, mlx5e_xmit_xdp_frame_mpwqe,
100 mlx5e_xmit_xdp_frame, sq, &xdptxd, NULL,
101 check_result);
102 if (unlikely(!ret)) {
103 if (sq->mpwqe.wqe)
104 mlx5e_xdp_mpwqe_complete(sq);
105
106 mlx5e_xsk_tx_post_err(sq, &xdpi);
107 } else {
108 mlx5e_xdpi_fifo_push(&sq->db.xdpi_fifo, &xdpi);
109 }
110
111 flush = true;
112 }
113
114 if (flush) {
115 if (sq->mpwqe.wqe)
116 mlx5e_xdp_mpwqe_complete(sq);
117 mlx5e_xmit_xdp_doorbell(sq);
118
119 xsk_tx_release(pool);
120 }
121
122 return !(budget && work_done);
123 }
124