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): Björn Töpel <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
44 /* Request to reserve tx_metadata_len bytes of per-chunk metadata.
45 */
46 #define XDP_UMEM_TX_METADATA_LEN (1 << 2)
47
48 struct sockaddr_xdp {
49 __u16 sxdp_family;
50 __u16 sxdp_flags;
51 __u32 sxdp_ifindex;
52 __u32 sxdp_queue_id;
53 __u32 sxdp_shared_umem_fd;
54 };
55
56 /* XDP_RING flags */
57 #define XDP_RING_NEED_WAKEUP (1 << 0)
58
59 struct xdp_ring_offset {
60 __u64 producer;
61 __u64 consumer;
62 __u64 desc;
63 __u64 flags;
64 };
65
66 struct xdp_mmap_offsets {
67 struct xdp_ring_offset rx;
68 struct xdp_ring_offset tx;
69 struct xdp_ring_offset fr; /* Fill */
70 struct xdp_ring_offset cr; /* Completion */
71 };
72
73 /* XDP socket options */
74 #define XDP_MMAP_OFFSETS 1
75 #define XDP_RX_RING 2
76 #define XDP_TX_RING 3
77 #define XDP_UMEM_REG 4
78 #define XDP_UMEM_FILL_RING 5
79 #define XDP_UMEM_COMPLETION_RING 6
80 #define XDP_STATISTICS 7
81 #define XDP_OPTIONS 8
82
83 struct xdp_umem_reg {
84 __u64 addr; /* Start of packet data area */
85 __u64 len; /* Length of packet data area */
86 __u32 chunk_size;
87 __u32 headroom;
88 __u32 flags;
89 __u32 tx_metadata_len;
90 };
91
92 struct xdp_statistics {
93 __u64 rx_dropped; /* Dropped for other reasons */
94 __u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
95 __u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
96 __u64 rx_ring_full; /* Dropped due to rx ring being full */
97 __u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
98 __u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
99 };
100
101 struct xdp_options {
102 __u32 flags;
103 };
104
105 /* Flags for the flags field of struct xdp_options */
106 #define XDP_OPTIONS_ZEROCOPY (1 << 0)
107
108 /* Pgoff for mmaping the rings */
109 #define XDP_PGOFF_RX_RING 0
110 #define XDP_PGOFF_TX_RING 0x80000000
111 #define XDP_UMEM_PGOFF_FILL_RING 0x100000000ULL
112 #define XDP_UMEM_PGOFF_COMPLETION_RING 0x180000000ULL
113
114 /* Masks for unaligned chunks mode */
115 #define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
116 #define XSK_UNALIGNED_BUF_ADDR_MASK \
117 ((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
118
119 /* Request transmit timestamp. Upon completion, put it into tx_timestamp
120 * field of struct xsk_tx_metadata.
121 */
122 #define XDP_TXMD_FLAGS_TIMESTAMP (1 << 0)
123
124 /* Request transmit checksum offload. Checksum start position and offset
125 * are communicated via csum_start and csum_offset fields of struct
126 * xsk_tx_metadata.
127 */
128 #define XDP_TXMD_FLAGS_CHECKSUM (1 << 1)
129
130 /* AF_XDP offloads request. 'request' union member is consumed by the driver
131 * when the packet is being transmitted. 'completion' union member is
132 * filled by the driver when the transmit completion arrives.
133 */
134 struct xsk_tx_metadata {
135 __u64 flags;
136
137 union {
138 struct {
139 /* XDP_TXMD_FLAGS_CHECKSUM */
140
141 /* Offset from desc->addr where checksumming should start. */
142 __u16 csum_start;
143 /* Offset from csum_start where checksum should be stored. */
144 __u16 csum_offset;
145 } request;
146
147 struct {
148 /* XDP_TXMD_FLAGS_TIMESTAMP */
149 __u64 tx_timestamp;
150 } completion;
151 };
152 };
153
154 /* Rx/Tx descriptor */
155 struct xdp_desc {
156 __u64 addr;
157 __u32 len;
158 __u32 options;
159 };
160
161 /* UMEM descriptor is __u64 */
162
163 /* Flag indicating that the packet continues with the buffer pointed out by the
164 * next frame in the ring. The end of the packet is signalled by setting this
165 * bit to zero. For single buffer packets, every descriptor has 'options' set
166 * to 0 and this maintains backward compatibility.
167 */
168 #define XDP_PKT_CONTD (1 << 0)
169
170 /* TX packet carries valid metadata. */
171 #define XDP_TX_METADATA (1 << 1)
172
173 #endif /* _LINUX_IF_XDP_H */
174
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