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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - tools/lib/bpf/xsk.h
1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
4 * AF_XDP user-space access library.
6 * Copyright(c) 2018 - 2019 Intel Corporation.
8 * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
11 #ifndef __LIBBPF_XSK_H
12 #define __LIBBPF_XSK_H
16 #include <linux/if_xdp.h>
19 #include "libbpf_util.h"
25 /* Do not access these members directly. Use the functions below. */
26 #define DEFINE_XSK_RING(name) \
37 DEFINE_XSK_RING(xsk_ring_prod
);
38 DEFINE_XSK_RING(xsk_ring_cons
);
40 /* For a detailed explanation on the memory barriers associated with the
41 * ring, please take a look at net/xdp/xsk_queue.h.
47 static inline __u64
*xsk_ring_prod__fill_addr(struct xsk_ring_prod
*fill
,
50 __u64
*addrs
= (__u64
*)fill
->ring
;
52 return &addrs
[idx
& fill
->mask
];
55 static inline const __u64
*
56 xsk_ring_cons__comp_addr(const struct xsk_ring_cons
*comp
, __u32 idx
)
58 const __u64
*addrs
= (const __u64
*)comp
->ring
;
60 return &addrs
[idx
& comp
->mask
];
63 static inline struct xdp_desc
*xsk_ring_prod__tx_desc(struct xsk_ring_prod
*tx
,
66 struct xdp_desc
*descs
= (struct xdp_desc
*)tx
->ring
;
68 return &descs
[idx
& tx
->mask
];
71 static inline const struct xdp_desc
*
72 xsk_ring_cons__rx_desc(const struct xsk_ring_cons
*rx
, __u32 idx
)
74 const struct xdp_desc
*descs
= (const struct xdp_desc
*)rx
->ring
;
76 return &descs
[idx
& rx
->mask
];
79 static inline __u32
xsk_prod_nb_free(struct xsk_ring_prod
*r
, __u32 nb
)
81 __u32 free_entries
= r
->cached_cons
- r
->cached_prod
;
83 if (free_entries
>= nb
)
86 /* Refresh the local tail pointer.
87 * cached_cons is r->size bigger than the real consumer pointer so
88 * that this addition can be avoided in the more frequently
89 * executed code that computs free_entries in the beginning of
90 * this function. Without this optimization it whould have been
91 * free_entries = r->cached_prod - r->cached_cons + r->size.
93 r
->cached_cons
= *r
->consumer
+ r
->size
;
95 return r
->cached_cons
- r
->cached_prod
;
98 static inline __u32
xsk_cons_nb_avail(struct xsk_ring_cons
*r
, __u32 nb
)
100 __u32 entries
= r
->cached_prod
- r
->cached_cons
;
103 r
->cached_prod
= *r
->producer
;
104 entries
= r
->cached_prod
- r
->cached_cons
;
107 return (entries
> nb
) ? nb
: entries
;
110 static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod
*prod
,
111 size_t nb
, __u32
*idx
)
113 if (xsk_prod_nb_free(prod
, nb
) < nb
)
116 *idx
= prod
->cached_prod
;
117 prod
->cached_prod
+= nb
;
122 static inline void xsk_ring_prod__submit(struct xsk_ring_prod
*prod
, size_t nb
)
124 /* Make sure everything has been written to the ring before indicating
125 * this to the kernel by writing the producer pointer.
129 *prod
->producer
+= nb
;
132 static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons
*cons
,
133 size_t nb
, __u32
*idx
)
135 size_t entries
= xsk_cons_nb_avail(cons
, nb
);
138 /* Make sure we do not speculatively read the data before
139 * we have received the packet buffers from the ring.
143 *idx
= cons
->cached_cons
;
144 cons
->cached_cons
+= entries
;
150 static inline void xsk_ring_cons__release(struct xsk_ring_cons
*cons
, size_t nb
)
152 /* Make sure data has been read before indicating we are done
153 * with the entries by updating the consumer pointer.
157 *cons
->consumer
+= nb
;
160 static inline void *xsk_umem__get_data(void *umem_area
, __u64 addr
)
162 return &((char *)umem_area
)[addr
];
165 LIBBPF_API
int xsk_umem__fd(const struct xsk_umem
*umem
);
166 LIBBPF_API
int xsk_socket__fd(const struct xsk_socket
*xsk
);
168 #define XSK_RING_CONS__DEFAULT_NUM_DESCS 2048
169 #define XSK_RING_PROD__DEFAULT_NUM_DESCS 2048
170 #define XSK_UMEM__DEFAULT_FRAME_SHIFT 12 /* 4096 bytes */
171 #define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT)
172 #define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0
174 struct xsk_umem_config
{
178 __u32 frame_headroom
;
181 /* Flags for the libbpf_flags field. */
182 #define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0)
184 struct xsk_socket_config
{
192 /* Set config to NULL to get the default configuration. */
193 LIBBPF_API
int xsk_umem__create(struct xsk_umem
**umem
,
194 void *umem_area
, __u64 size
,
195 struct xsk_ring_prod
*fill
,
196 struct xsk_ring_cons
*comp
,
197 const struct xsk_umem_config
*config
);
198 LIBBPF_API
int xsk_socket__create(struct xsk_socket
**xsk
,
199 const char *ifname
, __u32 queue_id
,
200 struct xsk_umem
*umem
,
201 struct xsk_ring_cons
*rx
,
202 struct xsk_ring_prod
*tx
,
203 const struct xsk_socket_config
*config
);
205 /* Returns 0 for success and -EBUSY if the umem is still in use. */
206 LIBBPF_API
int xsk_umem__delete(struct xsk_umem
*umem
);
207 LIBBPF_API
void xsk_socket__delete(struct xsk_socket
*xsk
);
213 #endif /* __LIBBPF_XSK_H */