include/net/xdp_sock.h

   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         /* Protects generic receive. */
  75         spinlock_t rx_lock;
  76
  77         /* Statistics */
  78         u64 rx_dropped;
  79         u64 rx_queue_full;
  80
  81         /* When __xsk_generic_xmit() must return before it sees the EOP descriptor for the current
  82          * packet, the partially built skb is saved here so that packet building can resume in next
  83          * call of __xsk_generic_xmit().
  84          */
  85         struct sk_buff *skb;
  86
  87         struct list_head map_list;
  88         /* Protects map_list */
  89         spinlock_t map_list_lock;
  90         /* Protects multiple processes in the control path */
  91         struct mutex mutex;
  92         struct xsk_queue *fq_tmp; /* Only as tmp storage before bind */
  93         struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
  94 };
  95
  96 /*
  97  * AF_XDP TX metadata hooks for network devices.
  98  * The following hooks can be defined; unless noted otherwise, they are
  99  * optional and can be filled with a null pointer.
 100  *
 101  * void (*tmo_request_timestamp)(void *priv)
 102  *     Called when AF_XDP frame requested egress timestamp.
 103  *
 104  * u64 (*tmo_fill_timestamp)(void *priv)
 105  *     Called when AF_XDP frame, that had requested egress timestamp,
 106  *     received a completion. The hook needs to return the actual HW timestamp.
 107  *
 108  * void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv)
 109  *     Called when AF_XDP frame requested HW checksum offload. csum_start
 110  *     indicates position where checksumming should start.
 111  *     csum_offset indicates position where checksum should be stored.
 112  *
 113  */
 114 struct xsk_tx_metadata_ops {
 115         void    (*tmo_request_timestamp)(void *priv);
 116         u64     (*tmo_fill_timestamp)(void *priv);
 117         void    (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
 118 };
 119
 120 #ifdef CONFIG_XDP_SOCKETS
 121
 122 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
 123 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
 124 void __xsk_map_flush(struct list_head *flush_list);
 125
 126 /**
 127  *  xsk_tx_metadata_to_compl - Save enough relevant metadata information
 128  *  to perform tx completion in the future.
 129  *  @meta: pointer to AF_XDP metadata area
 130  *  @compl: pointer to output struct xsk_tx_metadata_to_compl
 131  *
 132  *  This function should be called by the networking device when
 133  *  it prepares AF_XDP egress packet. The value of @compl should be stored
 134  *  and passed to xsk_tx_metadata_complete upon TX completion.
 135  */
 136 static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
 137                                             struct xsk_tx_metadata_compl *compl)
 138 {
 139         if (!meta)
 140                 return;
 141
 142         if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
 143                 compl->tx_timestamp = &meta->completion.tx_timestamp;
 144         else
 145                 compl->tx_timestamp = NULL;
 146 }
 147
 148 /**
 149  *  xsk_tx_metadata_request - Evaluate AF_XDP TX metadata at submission
 150  *  and call appropriate xsk_tx_metadata_ops operation.
 151  *  @meta: pointer to AF_XDP metadata area
 152  *  @ops: pointer to struct xsk_tx_metadata_ops
 153  *  @priv: pointer to driver-private aread
 154  *
 155  *  This function should be called by the networking device when
 156  *  it prepares AF_XDP egress packet.
 157  */
 158 static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
 159                                            const struct xsk_tx_metadata_ops *ops,
 160                                            void *priv)
 161 {
 162         if (!meta)
 163                 return;
 164
 165         if (ops->tmo_request_timestamp)
 166                 if (meta->flags & XDP_TXMD_FLAGS_TIMESTAMP)
 167                         ops->tmo_request_timestamp(priv);
 168
 169         if (ops->tmo_request_checksum)
 170                 if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
 171                         ops->tmo_request_checksum(meta->request.csum_start,
 172                                                   meta->request.csum_offset, priv);
 173 }
 174
 175 /**
 176  *  xsk_tx_metadata_complete - Evaluate AF_XDP TX metadata at completion
 177  *  and call appropriate xsk_tx_metadata_ops operation.
 178  *  @compl: pointer to completion metadata produced from xsk_tx_metadata_to_compl
 179  *  @ops: pointer to struct xsk_tx_metadata_ops
 180  *  @priv: pointer to driver-private aread
 181  *
 182  *  This function should be called by the networking device upon
 183  *  AF_XDP egress completion.
 184  */
 185 static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
 186                                             const struct xsk_tx_metadata_ops *ops,
 187                                             void *priv)
 188 {
 189         if (!compl)
 190                 return;
 191         if (!compl->tx_timestamp)
 192                 return;
 193
 194         *compl->tx_timestamp = ops->tmo_fill_timestamp(priv);
 195 }
 196
 197 #else
 198
 199 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 200 {
 201         return -ENOTSUPP;
 202 }
 203
 204 static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
 205 {
 206         return -EOPNOTSUPP;
 207 }
 208
 209 static inline void __xsk_map_flush(struct list_head *flush_list)
 210 {
 211 }
 212
 213 static inline void xsk_tx_metadata_to_compl(struct xsk_tx_metadata *meta,
 214                                             struct xsk_tx_metadata_compl *compl)
 215 {
 216 }
 217
 218 static inline void xsk_tx_metadata_request(struct xsk_tx_metadata *meta,
 219                                            const struct xsk_tx_metadata_ops *ops,
 220                                            void *priv)
 221 {
 222 }
 223
 224 static inline void xsk_tx_metadata_complete(struct xsk_tx_metadata_compl *compl,
 225                                             const struct xsk_tx_metadata_ops *ops,
 226                                             void *priv)
 227 {
 228 }
 229
 230 #endif /* CONFIG_XDP_SOCKETS */
 231 #endif /* _LINUX_XDP_SOCK_H */