1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* AF_XDP internal functions
3 * Copyright(c) 2018 Intel Corporation.
4 */
5
6 #ifndef _LINUX_XDP_SOCK_H
7 #define _LINUX_XDP_SOCK_H
8
9 #include <linux/bpf.h>
10 #include <linux/workqueue.h>
11 #include <linux/if_xdp.h>
12 #include <linux/mutex.h>
13 #include <linux/spinlock.h>
14 #include <linux/mm.h>
15 #include <net/sock.h>
16
17 #define XDP_UMEM_SG_FLAG (1 << 1)
18
19 struct net_device;
20 struct xsk_queue;
21 struct xdp_buff;
22
23 struct xdp_umem {
24 void *addrs;
25 u64 size;
26 u32 headroom;
27 u32 chunk_size;
28 u32 chunks;
29 u32 npgs;
30 struct user_struct *user;
31 refcount_t users;
32 u8 flags;
33 u8 tx_metadata_len;
34 bool zc;
35 struct page **pgs;
36 int id;
37 struct list_head xsk_dma_list;
38 struct work_struct work;
39 };
40
41 struct xsk_map {
42 struct bpf_map map;
43 spinlock_t lock; /* Synchronize map updates */
44 atomic_t count;
45 struct xdp_sock __rcu *xsk_map[];
46 };
47
48 struct xdp_sock {
49 /* struct sock must be the first member of struct xdp_sock */
50 struct sock sk;
51 struct xsk_queue *rx ____cacheline_aligned_in_smp;
52 struct net_device *dev;
53 struct xdp_umem *umem;
54 struct list_head flush_node;
55 struct xsk_buff_pool *pool;
56 u16 queue_id;
57 bool zc;
58 bool sg;
59 enum {
60 XSK_READY = 0,
61 XSK_BOUND,
62 XSK_UNBOUND,
63 } state;
64
65 struct xsk_queue *tx ____cacheline_aligned_in_smp;
66 struct list_head tx_list;
67 /* record the number of tx descriptors sent by this xsk and
68 * when it exceeds MAX_PER_SOCKET_BUDGET, an opportunity needs
69 * to be given to other xsks for sending tx descriptors, thereby
70 * preventing other XSKs from being starved.
71 */
72 u32 tx_budget_spent;
73
74 /* Statistics */
75 u64 rx_dropped;
76 u64 rx_queue_full;
77
78 /* When __xsk_generic_xmit() must return before it sees the EOP descriptor for the current
79 * packet, the partially built skb is saved here so that packet building can resume in next
80 * call of __xsk_generic_xmit().
81 */
82 struct sk_buff *skb;
83
84 struct list_head map_list;
85 /* Protects map_list */
86 spinlock_t map_list_lock;
87 /* Protects multiple processes in the control path */
88 struct mutex mutex;
89 struct xsk_queue *fq_tmp; /* Only as tmp storage before bind */
90 struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
91 };
92
93 /*
94 * AF_XDP TX metadata hooks for network devices.
95 * The following hooks can be defined; unless noted otherwise, they are
96 * optional and can be filled with a null pointer.
97 *
98 * void (*tmo_request_timestamp)(void *priv)
99 * Called when AF_XDP frame requested egress timestamp.
100 *
101 * u64 (*tmo_fill_timestamp)(void *priv)
102 * Called when AF_XDP frame, that had requested egress timestamp,
103 * received a completion. The hook needs to return the actual HW timestamp.
104 *
105 * void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv)
106 * Called when AF_XDP frame requested HW checksum offload. csum_start
107 * indicates position where checksumming should start.
108 * csum_offset indicates position where checksum should be stored.
109 *
110 * void (*tmo_request_launch_time)(u64 launch_time, void *priv)
111 * Called when AF_XDP frame requested launch time HW offload support.
112 * launch_time indicates the PTP time at which the device can schedule the
113 * packet for transmission.
114 */
115 struct xsk_tx_metadata_ops {
116 void (*tmo_request_timestamp)(void *priv);
117 u64 (*tmo_fill_timestamp)(void *priv);
118 void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
119 void (*tmo_request_launch_time)(u64 launch_time, void *priv);
120 };
121
122 #ifdef CONFIG_XDP_SOCKETS
123
124 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
125 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
126 void __xsk_map_flush(struct list_head *flush_list);
127
128 /**
129 * xsk_tx_metadata_to_compl - Save enough relevant metadata information
130 * to perform tx completion in the future.
131 * @meta: pointer to AF_XDP metadata area
132 * @compl: pointer to output struct xsk_tx_metadata_to_compl
133 *
134 * This function should be called by the networking device when
135 * it prepares AF_XDP egress packet. The value of @compl should be stored
136 * and passed to xsk_tx_metadata_complete upon TX completion.
137 */
xsk_tx_metadata_to_compl(struct xsk_tx_metadata * meta,struct xsk_tx_metadata_compl * compl)138 static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
139 struct xsk_tx_metadata_compl *compl)
140 {
141 if (!meta)
142 return;
143
144 if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
145 compl->tx_timestamp = &meta->completion.tx_timestamp;
146 else
147 compl->tx_timestamp = NULL;
148 }
149
150 /**
151 * xsk_tx_metadata_request - Evaluate AF_XDP TX metadata at submission
152 * and call appropriate xsk_tx_metadata_ops operation.
153 * @meta: pointer to AF_XDP metadata area
154 * @ops: pointer to struct xsk_tx_metadata_ops
155 * @priv: pointer to driver-private aread
156 *
157 * This function should be called by the networking device when
158 * it prepares AF_XDP egress packet.
159 */
xsk_tx_metadata_request(const struct xsk_tx_metadata * meta,const struct xsk_tx_metadata_ops * ops,void * priv)160 static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
161 const struct xsk_tx_metadata_ops *ops,
162 void *priv)
163 {
164 if (!meta)
165 return;
166
167 if (ops->tmo_request_launch_time)
168 if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME)
169 ops->tmo_request_launch_time(meta->request.launch_time,
170 priv);
171
172 if (ops->tmo_request_timestamp)
173 if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
174 ops->tmo_request_timestamp(priv);
175
176 if (ops->tmo_request_checksum)
177 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
178 ops->tmo_request_checksum(meta->request.csum_start,
179 meta->request.csum_offset, priv);
180 }
181
182 /**
183 * xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion
184 * and call appropriate xsk_tx_metadata_ops operation.
185 * @compl: pointer to completion metadata produced from xsk_tx_metadata_to_compl
186 * @ops: pointer to struct xsk_tx_metadata_ops
187 * @priv: pointer to driver-private aread
188 *
189 * This function should be called by the networking device upon
190 * AF_XDP egress completion.
191 */
xsk_tx_metadata_complete(struct xsk_tx_metadata_compl * compl,const struct xsk_tx_metadata_ops * ops,void * priv)192 static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
193 const struct xsk_tx_metadata_ops *ops,
194 void *priv)
195 {
196 if (!compl)
197 return;
198 if (!compl->tx_timestamp)
199 return;
200
201 *compl->tx_timestamp = ops->tmo_fill_timestamp(priv);
202 }
203
204 #else
205
xsk_generic_rcv(struct xdp_sock * xs,struct xdp_buff * xdp)206 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
207 {
208 return -ENOTSUPP;
209 }
210
__xsk_map_redirect(struct xdp_sock * xs,struct xdp_buff * xdp)211 static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
212 {
213 return -EOPNOTSUPP;
214 }
215
__xsk_map_flush(struct list_head * flush_list)216 static inline void __xsk_map_flush(struct list_head *flush_list)
217 {
218 }
219
xsk_tx_metadata_to_compl(struct xsk_tx_metadata * meta,struct xsk_tx_metadata_compl * compl)220 static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
221 struct xsk_tx_metadata_compl *compl)
222 {
223 }
224
xsk_tx_metadata_request(struct xsk_tx_metadata * meta,const struct xsk_tx_metadata_ops * ops,void * priv)225 static inline void xsk_tx_metadata_request(struct xsk_tx_metadata *meta,
226 const struct xsk_tx_metadata_ops *ops,
227 void *priv)
228 {
229 }
230
xsk_tx_metadata_complete(struct xsk_tx_metadata_compl * compl,const struct xsk_tx_metadata_ops * ops,void * priv)231 static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
232 const struct xsk_tx_metadata_ops *ops,
233 void *priv)
234 {
235 }
236
237 #endif /* CONFIG_XDP_SOCKETS */
238 #endif /* _LINUX_XDP_SOCK_H */
239