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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 BIT(3)
18
19struct net_device;
20struct xsk_queue;
21struct xdp_buff;
22
23struct 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
41struct 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
48struct 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 bool drain_cont;
84
85 struct list_head map_list;
86 /* Protects map_list */
87 spinlock_t map_list_lock;
88 u32 max_tx_budget;
89 /* Protects multiple processes in the control path */
90 struct mutex mutex;
91 struct xsk_queue *fq_tmp; /* Only as tmp storage before bind */
92 struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
93};
94
95/*
96 * AF_XDP TX metadata hooks for network devices.
97 * The following hooks can be defined; unless noted otherwise, they are
98 * optional and can be filled with a null pointer.
99 *
100 * void (*tmo_request_timestamp)(void *priv)
101 * Called when AF_XDP frame requested egress timestamp.
102 *
103 * u64 (*tmo_fill_timestamp)(void *priv)
104 * Called when AF_XDP frame, that had requested egress timestamp,
105 * received a completion. The hook needs to return the actual HW timestamp.
106 *
107 * void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv)
108 * Called when AF_XDP frame requested HW checksum offload. csum_start
109 * indicates position where checksumming should start.
110 * csum_offset indicates position where checksum should be stored.
111 *
112 * void (*tmo_request_launch_time)(u64 launch_time, void *priv)
113 * Called when AF_XDP frame requested launch time HW offload support.
114 * launch_time indicates the PTP time at which the device can schedule the
115 * packet for transmission.
116 */
117struct xsk_tx_metadata_ops {
118 void (*tmo_request_timestamp)(void *priv);
119 u64 (*tmo_fill_timestamp)(void *priv);
120 void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
121 void (*tmo_request_launch_time)(u64 launch_time, void *priv);
122};
123
124#ifdef CONFIG_XDP_SOCKETS
125
126int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
127int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
128void __xsk_map_flush(struct list_head *flush_list);
129INDIRECT_CALLABLE_DECLARE(void xsk_destruct_skb(struct sk_buff *));
130
131/**
132 * xsk_tx_metadata_to_compl - Save enough relevant metadata information
133 * to perform tx completion in the future.
134 * @meta: pointer to AF_XDP metadata area
135 * @compl: pointer to output struct xsk_tx_metadata_to_compl
136 *
137 * This function should be called by the networking device when
138 * it prepares AF_XDP egress packet. The value of @compl should be stored
139 * and passed to xsk_tx_metadata_complete upon TX completion.
140 */
141static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
142 struct xsk_tx_metadata_compl *compl)
143{
144 compl->tx_timestamp = NULL;
145
146 if (!meta)
147 return;
148
149 /* we can only arrive here if the completion timestamp has been
150 * requested via XDP_TXMD_FLAGS_TIMESTAMP, see xsk_tx_metadata_request
151 */
152
153 compl->tx_timestamp = &meta->completion.tx_timestamp;
154}
155
156/**
157 * xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion
158 * and call appropriate xsk_tx_metadata_ops operation.
159 * @compl: pointer to completion metadata produced from xsk_tx_metadata_to_compl
160 * @ops: pointer to struct xsk_tx_metadata_ops
161 * @priv: pointer to driver-private aread
162 *
163 * This function should be called by the networking device upon
164 * AF_XDP egress completion.
165 */
166static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
167 const struct xsk_tx_metadata_ops *ops,
168 void *priv)
169{
170 if (!compl)
171 return;
172 if (!compl->tx_timestamp)
173 return;
174
175 *compl->tx_timestamp = ops->tmo_fill_timestamp(priv);
176}
177
178#else
179
180static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
181{
182 return -ENOTSUPP;
183}
184
185static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
186{
187 return -EOPNOTSUPP;
188}
189
190static inline void __xsk_map_flush(struct list_head *flush_list)
191{
192}
193
194#ifdef CONFIG_MITIGATION_RETPOLINE
195static inline void xsk_destruct_skb(struct sk_buff *skb)
196{
197}
198#endif
199
200static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
201 struct xsk_tx_metadata_compl *compl)
202{
203}
204
205static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
206 const struct xsk_tx_metadata_ops *ops,
207 void *priv)
208{
209}
210
211#endif /* CONFIG_XDP_SOCKETS */
212#endif /* _LINUX_XDP_SOCK_H */