xref: /linux/tools/include/uapi/linux/if_xdp.h (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
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 _UAPI_LINUX_IF_XDP_H
11 #define _UAPI_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 #define XDP_MAX_TX_SKB_BUDGET		9
83 
84 struct xdp_umem_reg {
85 	__u64 addr; /* Start of packet data area */
86 	__u64 len; /* Length of packet data area */
87 	__u32 chunk_size;
88 	__u32 headroom;
89 	__u32 flags;
90 	__u32 tx_metadata_len;
91 };
92 
93 struct xdp_statistics {
94 	__u64 rx_dropped; /* Dropped for other reasons */
95 	__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
96 	__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
97 	__u64 rx_ring_full; /* Dropped due to rx ring being full */
98 	__u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
99 	__u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
100 };
101 
102 struct xdp_options {
103 	__u32 flags;
104 };
105 
106 /* Flags for the flags field of struct xdp_options */
107 #define XDP_OPTIONS_ZEROCOPY (1 << 0)
108 
109 /* Pgoff for mmaping the rings */
110 #define XDP_PGOFF_RX_RING			  0
111 #define XDP_PGOFF_TX_RING		 0x80000000
112 #define XDP_UMEM_PGOFF_FILL_RING	0x100000000ULL
113 #define XDP_UMEM_PGOFF_COMPLETION_RING	0x180000000ULL
114 
115 /* Masks for unaligned chunks mode */
116 #define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
117 #define XSK_UNALIGNED_BUF_ADDR_MASK \
118 	((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
119 
120 /* Request transmit timestamp. Upon completion, put it into tx_timestamp
121  * field of struct xsk_tx_metadata.
122  */
123 #define XDP_TXMD_FLAGS_TIMESTAMP		(1 << 0)
124 
125 /* Request transmit checksum offload. Checksum start position and offset
126  * are communicated via csum_start and csum_offset fields of struct
127  * xsk_tx_metadata.
128  */
129 #define XDP_TXMD_FLAGS_CHECKSUM			(1 << 1)
130 
131 /* Request launch time hardware offload. The device will schedule the packet for
132  * transmission at a pre-determined time called launch time. The value of
133  * launch time is communicated via launch_time field of struct xsk_tx_metadata.
134  */
135 #define XDP_TXMD_FLAGS_LAUNCH_TIME		(1 << 2)
136 
137 /* AF_XDP offloads request. 'request' union member is consumed by the driver
138  * when the packet is being transmitted. 'completion' union member is
139  * filled by the driver when the transmit completion arrives.
140  */
141 struct xsk_tx_metadata {
142 	__u64 flags;
143 
144 	union {
145 		struct {
146 			/* XDP_TXMD_FLAGS_CHECKSUM */
147 
148 			/* Offset from desc->addr where checksumming should start. */
149 			__u16 csum_start;
150 			/* Offset from csum_start where checksum should be stored. */
151 			__u16 csum_offset;
152 
153 			/* XDP_TXMD_FLAGS_LAUNCH_TIME */
154 			/* Launch time in nanosecond against the PTP HW Clock */
155 			__u64 launch_time;
156 		} request;
157 
158 		struct {
159 			/* XDP_TXMD_FLAGS_TIMESTAMP */
160 			__u64 tx_timestamp;
161 		} completion;
162 	};
163 };
164 
165 /* Rx/Tx descriptor */
166 struct xdp_desc {
167 	__u64 addr;
168 	__u32 len;
169 	__u32 options;
170 };
171 
172 /* UMEM descriptor is __u64 */
173 
174 /* Flag indicating that the packet continues with the buffer pointed out by the
175  * next frame in the ring. The end of the packet is signalled by setting this
176  * bit to zero. For single buffer packets, every descriptor has 'options' set
177  * to 0 and this maintains backward compatibility.
178  */
179 #define XDP_PKT_CONTD (1 << 0)
180 
181 /* TX packet carries valid metadata. */
182 #define XDP_TX_METADATA (1 << 1)
183 
184 #endif /* _UAPI_LINUX_IF_XDP_H */
185