linux/include/net/xdp_sock.h
Tirthendu Sarkar b7f72a30e9 xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path
In Tx path, xsk core reserves space for each desc to be transmitted in
the completion queue and it's address contained in it is stored in the
skb destructor arg. After successful transmission the skb destructor
submits the addr marking completion.

To handle multiple descriptors per packet, now along with reserving
space for each descriptor, the corresponding address is also stored in
completion queue. The number of pending descriptors are stored in skb
destructor arg and is used by the skb destructor to update completions.

Introduce 'skb' in xdp_sock to store a partially built packet when
__xsk_generic_xmit() must return before it sees the EOP descriptor for
the current packet so that packet building can resume in next call of
__xsk_generic_xmit().

Helper functions are introduced to set and get the pending descriptors
in the skb destructor arg. Also, wrappers are introduced for storing
descriptor addresses, submitting and cancelling (for unsuccessful
transmissions) the number of completions.

Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-7-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 09:56:49 -07:00

111 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* AF_XDP internal functions
* Copyright(c) 2018 Intel Corporation.
*/
#ifndef _LINUX_XDP_SOCK_H
#define _LINUX_XDP_SOCK_H
#include <linux/bpf.h>
#include <linux/workqueue.h>
#include <linux/if_xdp.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <net/sock.h>
struct net_device;
struct xsk_queue;
struct xdp_buff;
struct xdp_umem {
void *addrs;
u64 size;
u32 headroom;
u32 chunk_size;
u32 chunks;
u32 npgs;
struct user_struct *user;
refcount_t users;
u8 flags;
bool zc;
struct page **pgs;
int id;
struct list_head xsk_dma_list;
struct work_struct work;
};
struct xsk_map {
struct bpf_map map;
spinlock_t lock; /* Synchronize map updates */
atomic_t count;
struct xdp_sock __rcu *xsk_map[];
};
struct xdp_sock {
/* struct sock must be the first member of struct xdp_sock */
struct sock sk;
struct xsk_queue *rx ____cacheline_aligned_in_smp;
struct net_device *dev;
struct xdp_umem *umem;
struct list_head flush_node;
struct xsk_buff_pool *pool;
u16 queue_id;
bool zc;
bool sg;
enum {
XSK_READY = 0,
XSK_BOUND,
XSK_UNBOUND,
} state;
struct xsk_queue *tx ____cacheline_aligned_in_smp;
struct list_head tx_list;
/* Protects generic receive. */
spinlock_t rx_lock;
/* Statistics */
u64 rx_dropped;
u64 rx_queue_full;
/* When __xsk_generic_xmit() must return before it sees the EOP descriptor for the current
* packet, the partially built skb is saved here so that packet building can resume in next
* call of __xsk_generic_xmit().
*/
struct sk_buff *skb;
struct list_head map_list;
/* Protects map_list */
spinlock_t map_list_lock;
/* Protects multiple processes in the control path */
struct mutex mutex;
struct xsk_queue *fq_tmp; /* Only as tmp storage before bind */
struct xsk_queue *cq_tmp; /* Only as tmp storage before bind */
};
#ifdef CONFIG_XDP_SOCKETS
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
void __xsk_map_flush(void);
#else
static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
return -ENOTSUPP;
}
static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
{
return -EOPNOTSUPP;
}
static inline void __xsk_map_flush(void)
{
}
#endif /* CONFIG_XDP_SOCKETS */
#endif /* _LINUX_XDP_SOCK_H */