Files
android_kernel_xiaomi_sm8450/include/net/xdp_sock.h
Björn Töpel 2b43470add xsk: Introduce AF_XDP buffer allocation API
In order to simplify AF_XDP zero-copy enablement for NIC driver
developers, a new AF_XDP buffer allocation API is added. The
implementation is based on a single core (single producer/consumer)
buffer pool for the AF_XDP UMEM.

A buffer is allocated using the xsk_buff_alloc() function, and
returned using xsk_buff_free(). If a buffer is disassociated with the
pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is
said to be released. Currently, the release function is only used by
the AF_XDP internals and not visible to the driver.

Drivers using this API should register the XDP memory model with the
new MEM_TYPE_XSK_BUFF_POOL type.

The API is defined in net/xdp_sock_drv.h.

The buffer type is struct xdp_buff, and follows the lifetime of
regular xdp_buffs, i.e.  the lifetime of an xdp_buff is restricted to
a NAPI context. In other words, the API is not replacing xdp_frames.

In addition to introducing the API and implementations, the AF_XDP
core is migrated to use the new APIs.

rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test
         robot)
         Added headroom/chunk size getter. (Maxim/Björn)

v1->v2: Swapped SoBs. (Maxim)

v2->v3: Initialize struct xdp_buff member frame_sz. (Björn)
        Add API to query the DMA address of a frame. (Maxim)
        Do DMA sync for CPU till the end of the frame to handle
        possible growth (frame_sz). (Maxim)

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
2020-05-21 17:31:26 -07:00

167 lines
3.2 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/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_page {
void *addr;
dma_addr_t dma;
};
struct xdp_umem_fq_reuse {
u32 nentries;
u32 length;
u64 handles[];
};
struct xdp_umem {
struct xsk_queue *fq;
struct xsk_queue *cq;
struct xsk_buff_pool *pool;
struct xdp_umem_page *pages;
u64 chunk_mask;
u64 size;
u32 headroom;
u32 chunk_size_nohr;
u32 chunk_size;
struct user_struct *user;
refcount_t users;
struct work_struct work;
struct page **pgs;
u32 npgs;
u16 queue_id;
u8 need_wakeup;
u8 flags;
int id;
struct net_device *dev;
struct xdp_umem_fq_reuse *fq_reuse;
bool zc;
spinlock_t xsk_tx_list_lock;
struct list_head xsk_tx_list;
};
struct xsk_map {
struct bpf_map map;
spinlock_t lock; /* Synchronize map updates */
struct xdp_sock *xsk_map[];
};
struct xdp_sock {
/* struct sock must be the first member of struct xdp_sock */
struct sock sk;
struct xsk_queue *rx;
struct net_device *dev;
struct xdp_umem *umem;
struct list_head flush_node;
u16 queue_id;
bool zc;
enum {
XSK_READY = 0,
XSK_BOUND,
XSK_UNBOUND,
} state;
/* Protects multiple processes in the control path */
struct mutex mutex;
struct xsk_queue *tx ____cacheline_aligned_in_smp;
struct list_head list;
/* Mutual exclusion of NAPI TX thread and sendmsg error paths
* in the SKB destructor callback.
*/
spinlock_t tx_completion_lock;
/* Protects generic receive. */
spinlock_t rx_lock;
u64 rx_dropped;
struct list_head map_list;
/* Protects map_list */
spinlock_t map_list_lock;
};
#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);
static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
u32 key)
{
struct xsk_map *m = container_of(map, struct xsk_map, map);
struct xdp_sock *xs;
if (key >= map->max_entries)
return NULL;
xs = READ_ONCE(m->xsk_map[key]);
return xs;
}
static inline u64 xsk_umem_extract_addr(u64 addr)
{
return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
}
static inline u64 xsk_umem_extract_offset(u64 addr)
{
return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
}
static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
{
return xsk_umem_extract_addr(addr) + xsk_umem_extract_offset(addr);
}
#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)
{
}
static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
u32 key)
{
return NULL;
}
static inline u64 xsk_umem_extract_addr(u64 addr)
{
return 0;
}
static inline u64 xsk_umem_extract_offset(u64 addr)
{
return 0;
}
static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
{
return 0;
}
#endif /* CONFIG_XDP_SOCKETS */
#endif /* _LINUX_XDP_SOCK_H */