1 /* SPDX-License-Identifier: MIT */
2 /* Copyright (C) 2006-2017 Oracle Corporation */
3
4 #ifndef __HGSMI_DEFS_H__
5 #define __HGSMI_DEFS_H__
6
7 /* Buffer sequence type mask. */
8 #define HGSMI_BUFFER_HEADER_F_SEQ_MASK 0x03
9 /* Single buffer, not a part of a sequence. */
10 #define HGSMI_BUFFER_HEADER_F_SEQ_SINGLE 0x00
11 /* The first buffer in a sequence. */
12 #define HGSMI_BUFFER_HEADER_F_SEQ_START 0x01
13 /* A middle buffer in a sequence. */
14 #define HGSMI_BUFFER_HEADER_F_SEQ_CONTINUE 0x02
15 /* The last buffer in a sequence. */
16 #define HGSMI_BUFFER_HEADER_F_SEQ_END 0x03
17
18 /* 16 bytes buffer header. */
19 struct hgsmi_buffer_header {
20 u32 data_size; /* Size of data that follows the header. */
21 u8 flags; /* HGSMI_BUFFER_HEADER_F_* */
22 u8 channel; /* The channel the data must be routed to. */
23 u16 channel_info; /* Opaque to the HGSMI, used by the channel. */
24
25 union {
26 /* Opaque placeholder to make the union 8 bytes. */
27 u8 header_data[8];
28
29 /* HGSMI_BUFFER_HEADER_F_SEQ_SINGLE */
30 struct {
31 u32 reserved1; /* A reserved field, initialize to 0. */
32 u32 reserved2; /* A reserved field, initialize to 0. */
33 } buffer;
34
35 /* HGSMI_BUFFER_HEADER_F_SEQ_START */
36 struct {
37 /* Must be the same for all buffers in the sequence. */
38 u32 sequence_number;
39 /* The total size of the sequence. */
40 u32 sequence_size;
41 } sequence_start;
42
43 /*
44 * HGSMI_BUFFER_HEADER_F_SEQ_CONTINUE and
45 * HGSMI_BUFFER_HEADER_F_SEQ_END
46 */
47 struct {
48 /* Must be the same for all buffers in the sequence. */
49 u32 sequence_number;
50 /* Data offset in the entire sequence. */
51 u32 sequence_offset;
52 } sequence_continue;
53 } u;
54 } __packed;
55
56 /* 8 bytes buffer tail. */
57 struct hgsmi_buffer_tail {
58 /* Reserved, must be initialized to 0. */
59 u32 reserved;
60 /*
61 * One-at-a-Time Hash: http://www.burtleburtle.net/bob/hash/doobs.html
62 * Over the header, offset and for first 4 bytes of the tail.
63 */
64 u32 checksum;
65 } __packed;
66
67 /*
68 * The size of the array of channels. Array indexes are u8.
69 * Note: the value must not be changed.
70 */
71 #define HGSMI_NUMBER_OF_CHANNELS 0x100
72
73 #endif