1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * if_xdp: XDP socket user-space interface
4 * Copyright(c) 2018 Intel Corporation.
5 *
6 * Author(s): Bj��rn T��pel <bjorn.topel@intel.com>
7 *	      Magnus Karlsson <magnus.karlsson@intel.com>
8 */
9
10#ifndef _LINUX_IF_XDP_H
11#define _LINUX_IF_XDP_H
12
13#include <linux/types.h>
14
15/* Options for the sxdp_flags field */
16#define XDP_SHARED_UMEM	(1 << 0)
17#define XDP_COPY	(1 << 1) /* Force copy-mode */
18#define XDP_ZEROCOPY	(1 << 2) /* Force zero-copy mode */
19/* If this option is set, the driver might go sleep and in that case
20 * the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
21 * set. If it is set, the application need to explicitly wake up the
22 * driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
23 * running the driver and the application on the same core, you should
24 * use this option so that the kernel will yield to the user space
25 * application.
26 */
27#define XDP_USE_NEED_WAKEUP (1 << 3)
28/* By setting this option, userspace application indicates that it can
29 * handle multiple descriptors per packet thus enabling AF_XDP to split
30 * multi-buffer XDP frames into multiple Rx descriptors. Without this set
31 * such frames will be dropped.
32 */
33#define XDP_USE_SG	(1 << 4)
34
35/* Flags for xsk_umem_config flags */
36#define XDP_UMEM_UNALIGNED_CHUNK_FLAG	(1 << 0)
37
38/* Force checksum calculation in software. Can be used for testing or
39 * working around potential HW issues. This option causes performance
40 * degradation and only works in XDP_COPY mode.
41 */
42#define XDP_UMEM_TX_SW_CSUM		(1 << 1)
43
44struct sockaddr_xdp {
45	__u16 sxdp_family;
46	__u16 sxdp_flags;
47	__u32 sxdp_ifindex;
48	__u32 sxdp_queue_id;
49	__u32 sxdp_shared_umem_fd;
50};
51
52/* XDP_RING flags */
53#define XDP_RING_NEED_WAKEUP (1 << 0)
54
55struct xdp_ring_offset {
56	__u64 producer;
57	__u64 consumer;
58	__u64 desc;
59	__u64 flags;
60};
61
62struct xdp_mmap_offsets {
63	struct xdp_ring_offset rx;
64	struct xdp_ring_offset tx;
65	struct xdp_ring_offset fr; /* Fill */
66	struct xdp_ring_offset cr; /* Completion */
67};
68
69/* XDP socket options */
70#define XDP_MMAP_OFFSETS		1
71#define XDP_RX_RING			2
72#define XDP_TX_RING			3
73#define XDP_UMEM_REG			4
74#define XDP_UMEM_FILL_RING		5
75#define XDP_UMEM_COMPLETION_RING	6
76#define XDP_STATISTICS			7
77#define XDP_OPTIONS			8
78
79struct xdp_umem_reg {
80	__u64 addr; /* Start of packet data area */
81	__u64 len; /* Length of packet data area */
82	__u32 chunk_size;
83	__u32 headroom;
84	__u32 flags;
85	__u32 tx_metadata_len;
86};
87
88struct xdp_statistics {
89	__u64 rx_dropped; /* Dropped for other reasons */
90	__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
91	__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
92	__u64 rx_ring_full; /* Dropped due to rx ring being full */
93	__u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
94	__u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
95};
96
97struct xdp_options {
98	__u32 flags;
99};
100
101/* Flags for the flags field of struct xdp_options */
102#define XDP_OPTIONS_ZEROCOPY (1 << 0)
103
104/* Pgoff for mmaping the rings */
105#define XDP_PGOFF_RX_RING			  0
106#define XDP_PGOFF_TX_RING		 0x80000000
107#define XDP_UMEM_PGOFF_FILL_RING	0x100000000ULL
108#define XDP_UMEM_PGOFF_COMPLETION_RING	0x180000000ULL
109
110/* Masks for unaligned chunks mode */
111#define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
112#define XSK_UNALIGNED_BUF_ADDR_MASK \
113	((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
114
115/* Request transmit timestamp. Upon completion, put it into tx_timestamp
116 * field of union xsk_tx_metadata.
117 */
118#define XDP_TXMD_FLAGS_TIMESTAMP		(1 << 0)
119
120/* Request transmit checksum offload. Checksum start position and offset
121 * are communicated via csum_start and csum_offset fields of union
122 * xsk_tx_metadata.
123 */
124#define XDP_TXMD_FLAGS_CHECKSUM			(1 << 1)
125
126/* AF_XDP offloads request. 'request' union member is consumed by the driver
127 * when the packet is being transmitted. 'completion' union member is
128 * filled by the driver when the transmit completion arrives.
129 */
130struct xsk_tx_metadata {
131	__u64 flags;
132
133	union {
134		struct {
135			/* XDP_TXMD_FLAGS_CHECKSUM */
136
137			/* Offset from desc->addr where checksumming should start. */
138			__u16 csum_start;
139			/* Offset from csum_start where checksum should be stored. */
140			__u16 csum_offset;
141		} request;
142
143		struct {
144			/* XDP_TXMD_FLAGS_TIMESTAMP */
145			__u64 tx_timestamp;
146		} completion;
147	};
148};
149
150/* Rx/Tx descriptor */
151struct xdp_desc {
152	__u64 addr;
153	__u32 len;
154	__u32 options;
155};
156
157/* UMEM descriptor is __u64 */
158
159/* Flag indicating that the packet continues with the buffer pointed out by the
160 * next frame in the ring. The end of the packet is signalled by setting this
161 * bit to zero. For single buffer packets, every descriptor has 'options' set
162 * to 0 and this maintains backward compatibility.
163 */
164#define XDP_PKT_CONTD (1 << 0)
165
166/* TX packet carries valid metadata. */
167#define XDP_TX_METADATA (1 << 1)
168
169#endif /* _LINUX_IF_XDP_H */
170