1 /*
2  * Copyright (c) 2018, Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 #ifndef __MLX5_EN_XDP_H__
33 #define __MLX5_EN_XDP_H__
34 
35 #include <linux/indirect_call_wrapper.h>
36 #include <net/xdp_sock.h>
37 
38 #include "en.h"
39 #include "en/txrx.h"
40 
41 #define MLX5E_XDP_MIN_INLINE (ETH_HLEN + VLAN_HLEN)
42 
43 #define MLX5E_XDP_INLINE_WQE_MAX_DS_CNT 16
44 #define MLX5E_XDP_INLINE_WQE_SZ_THRSD \
45 	(MLX5E_XDP_INLINE_WQE_MAX_DS_CNT * MLX5_SEND_WQE_DS - \
46 	 sizeof(struct mlx5_wqe_inline_seg))
47 
48 /* XDP packets can be transmitted in different ways. On completion, we need to
49  * distinguish between them to clean up things in a proper way.
50  */
51 enum mlx5e_xdp_xmit_mode {
52 	/* An xdp_frame was transmitted due to either XDP_REDIRECT from another
53 	 * device or XDP_TX from an XSK RQ. The frame has to be unmapped and
54 	 * returned.
55 	 */
56 	MLX5E_XDP_XMIT_MODE_FRAME,
57 
58 	/* The xdp_frame was created in place as a result of XDP_TX from a
59 	 * regular RQ. No DMA remapping happened, and the page belongs to us.
60 	 */
61 	MLX5E_XDP_XMIT_MODE_PAGE,
62 
63 	/* No xdp_frame was created at all, the transmit happened from a UMEM
64 	 * page. The UMEM Completion Ring producer pointer has to be increased.
65 	 */
66 	MLX5E_XDP_XMIT_MODE_XSK,
67 };
68 
69 /* xmit_mode entry is pushed to the fifo per packet, followed by multiple
70  * entries, as follows:
71  *
72  * MLX5E_XDP_XMIT_MODE_FRAME:
73  *    xdpf, dma_addr_1, dma_addr_2, ... , dma_addr_num.
74  *    'num' is derived from xdpf.
75  *
76  * MLX5E_XDP_XMIT_MODE_PAGE:
77  *    num, page_1, page_2, ... , page_num.
78  *
79  * MLX5E_XDP_XMIT_MODE_XSK:
80  *    frame.xsk_meta.
81  */
82 #define MLX5E_XDP_FIFO_ENTRIES2DS_MAX_RATIO 4
83 
84 union mlx5e_xdp_info {
85 	enum mlx5e_xdp_xmit_mode mode;
86 	union {
87 		struct xdp_frame *xdpf;
88 		dma_addr_t dma_addr;
89 	} frame;
90 	union {
91 		struct mlx5e_rq *rq;
92 		u8 num;
93 		struct page *page;
94 	} page;
95 	struct xsk_tx_metadata_compl xsk_meta;
96 };
97 
98 struct mlx5e_xsk_param;
99 int mlx5e_xdp_max_mtu(struct mlx5e_params *params, struct mlx5e_xsk_param *xsk);
100 bool mlx5e_xdp_handle(struct mlx5e_rq *rq,
101 		      struct bpf_prog *prog, struct mlx5e_xdp_buff *mlctx);
102 void mlx5e_xdp_mpwqe_complete(struct mlx5e_xdpsq *sq);
103 bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq);
104 void mlx5e_free_xdpsq_descs(struct mlx5e_xdpsq *sq);
105 void mlx5e_set_xmit_fp(struct mlx5e_xdpsq *sq, bool is_mpw);
106 void mlx5e_xdp_rx_poll_complete(struct mlx5e_rq *rq);
107 int mlx5e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
108 		   u32 flags);
109 
110 extern const struct xdp_metadata_ops mlx5e_xdp_metadata_ops;
111 extern const struct xsk_tx_metadata_ops mlx5e_xsk_tx_metadata_ops;
112 
113 INDIRECT_CALLABLE_DECLARE(bool mlx5e_xmit_xdp_frame_mpwqe(struct mlx5e_xdpsq *sq,
114 							  struct mlx5e_xmit_data *xdptxd,
115 							  int check_result,
116 							  struct xsk_tx_metadata *meta));
117 INDIRECT_CALLABLE_DECLARE(bool mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq,
118 						    struct mlx5e_xmit_data *xdptxd,
119 						    int check_result,
120 						    struct xsk_tx_metadata *meta));
121 INDIRECT_CALLABLE_DECLARE(int mlx5e_xmit_xdp_frame_check_mpwqe(struct mlx5e_xdpsq *sq));
122 INDIRECT_CALLABLE_DECLARE(int mlx5e_xmit_xdp_frame_check(struct mlx5e_xdpsq *sq));
123 
mlx5e_xdp_tx_enable(struct mlx5e_priv * priv)124 static inline void mlx5e_xdp_tx_enable(struct mlx5e_priv *priv)
125 {
126 	set_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state);
127 
128 	if (priv->channels.params.xdp_prog)
129 		set_bit(MLX5E_STATE_XDP_ACTIVE, &priv->state);
130 }
131 
mlx5e_xdp_tx_disable(struct mlx5e_priv * priv)132 static inline void mlx5e_xdp_tx_disable(struct mlx5e_priv *priv)
133 {
134 	if (priv->channels.params.xdp_prog)
135 		clear_bit(MLX5E_STATE_XDP_ACTIVE, &priv->state);
136 
137 	clear_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state);
138 	/* Let other device's napi(s) and XSK wakeups see our new state. */
139 	synchronize_net();
140 }
141 
mlx5e_xdp_tx_is_enabled(struct mlx5e_priv * priv)142 static inline bool mlx5e_xdp_tx_is_enabled(struct mlx5e_priv *priv)
143 {
144 	return test_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state);
145 }
146 
mlx5e_xdp_is_active(struct mlx5e_priv * priv)147 static inline bool mlx5e_xdp_is_active(struct mlx5e_priv *priv)
148 {
149 	return test_bit(MLX5E_STATE_XDP_ACTIVE, &priv->state);
150 }
151 
mlx5e_xmit_xdp_doorbell(struct mlx5e_xdpsq * sq)152 static inline void mlx5e_xmit_xdp_doorbell(struct mlx5e_xdpsq *sq)
153 {
154 	if (sq->doorbell_cseg) {
155 		mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, sq->doorbell_cseg);
156 		sq->doorbell_cseg = NULL;
157 	}
158 }
159 
160 /* Enable inline WQEs to shift some load from a congested HCA (HW) to
161  * a less congested cpu (SW).
162  */
mlx5e_xdp_get_inline_state(struct mlx5e_xdpsq * sq,bool cur)163 static inline bool mlx5e_xdp_get_inline_state(struct mlx5e_xdpsq *sq, bool cur)
164 {
165 	u16 outstanding = sq->xdpi_fifo_pc - sq->xdpi_fifo_cc;
166 
167 #define MLX5E_XDP_INLINE_WATERMARK_LOW	10
168 #define MLX5E_XDP_INLINE_WATERMARK_HIGH 128
169 
170 	if (cur && outstanding <= MLX5E_XDP_INLINE_WATERMARK_LOW)
171 		return false;
172 
173 	if (!cur && outstanding >= MLX5E_XDP_INLINE_WATERMARK_HIGH)
174 		return true;
175 
176 	return cur;
177 }
178 
mlx5e_xdp_mpwqe_is_full(struct mlx5e_tx_mpwqe * session)179 static inline bool mlx5e_xdp_mpwqe_is_full(struct mlx5e_tx_mpwqe *session)
180 {
181 	if (session->inline_on)
182 		return session->ds_count + MLX5E_XDP_INLINE_WQE_MAX_DS_CNT >
183 		       session->ds_count_max;
184 
185 	return mlx5e_tx_mpwqe_is_full(session);
186 }
187 
188 struct mlx5e_xdp_wqe_info {
189 	u8 num_wqebbs;
190 	u8 num_pkts;
191 };
192 
193 static inline void
mlx5e_xdp_mpwqe_add_dseg(struct mlx5e_xdpsq * sq,struct mlx5e_xmit_data * xdptxd,struct mlx5e_xdpsq_stats * stats)194 mlx5e_xdp_mpwqe_add_dseg(struct mlx5e_xdpsq *sq,
195 			 struct mlx5e_xmit_data *xdptxd,
196 			 struct mlx5e_xdpsq_stats *stats)
197 {
198 	struct mlx5e_tx_mpwqe *session = &sq->mpwqe;
199 	struct mlx5_wqe_data_seg *dseg =
200 		(struct mlx5_wqe_data_seg *)session->wqe + session->ds_count;
201 	u32 dma_len = xdptxd->len;
202 
203 	session->pkt_count++;
204 	session->bytes_count += dma_len;
205 
206 	if (session->inline_on && dma_len <= MLX5E_XDP_INLINE_WQE_SZ_THRSD) {
207 		struct mlx5_wqe_inline_seg *inline_dseg =
208 			(struct mlx5_wqe_inline_seg *)dseg;
209 		u16 ds_len = sizeof(*inline_dseg) + dma_len;
210 		u16 ds_cnt = DIV_ROUND_UP(ds_len, MLX5_SEND_WQE_DS);
211 
212 		inline_dseg->byte_count = cpu_to_be32(dma_len | MLX5_INLINE_SEG);
213 		memcpy(inline_dseg->data, xdptxd->data, dma_len);
214 
215 		session->ds_count += ds_cnt;
216 		stats->inlnw++;
217 		return;
218 	}
219 
220 	dseg->addr       = cpu_to_be64(xdptxd->dma_addr);
221 	dseg->byte_count = cpu_to_be32(dma_len);
222 	dseg->lkey       = sq->mkey_be;
223 	session->ds_count++;
224 }
225 
226 static inline void
mlx5e_xdpi_fifo_push(struct mlx5e_xdp_info_fifo * fifo,union mlx5e_xdp_info xi)227 mlx5e_xdpi_fifo_push(struct mlx5e_xdp_info_fifo *fifo,
228 		     union mlx5e_xdp_info xi)
229 {
230 	u32 i = (*fifo->pc)++ & fifo->mask;
231 
232 	fifo->xi[i] = xi;
233 }
234 
235 static inline union mlx5e_xdp_info
mlx5e_xdpi_fifo_pop(struct mlx5e_xdp_info_fifo * fifo)236 mlx5e_xdpi_fifo_pop(struct mlx5e_xdp_info_fifo *fifo)
237 {
238 	return fifo->xi[(*fifo->cc)++ & fifo->mask];
239 }
240 #endif
241