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Robert Lovef032c2f2008-12-09 15:10:11 -08001/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Maintained at www.Open-FCoE.org
18 */
19#ifndef _FC_ENCAPS_H_
20#define _FC_ENCAPS_H_
21
22/*
23 * Protocol definitions from RFC 3643 - Fibre Channel Frame Encapsulation.
24 *
25 * Note: The frame length field is the number of 32-bit words in
26 * the encapsulation including the fcip_encaps_header, CRC and EOF words.
27 * The minimum frame length value in bytes is (32 + 24 + 4 + 4) * 4 = 64.
28 * The maximum frame length value in bytes is (32 + 24 + 2112 + 4 + 4) = 2172.
29 */
30#define FC_ENCAPS_MIN_FRAME_LEN 64 /* min frame len (bytes) (see above) */
31#define FC_ENCAPS_MAX_FRAME_LEN (FC_ENCAPS_MIN_FRAME_LEN + FC_MAX_PAYLOAD)
32
33#define FC_ENCAPS_VER 1 /* current version number */
34
35struct fc_encaps_hdr {
36 __u8 fc_proto; /* protocol number */
37 __u8 fc_ver; /* version of encapsulation */
38 __u8 fc_proto_n; /* ones complement of protocol */
39 __u8 fc_ver_n; /* ones complement of version */
40
41 unsigned char fc_proto_data[8]; /* protocol specific data */
42
43 __be16 fc_len_flags; /* 10-bit length/4 w/ 6 flag bits */
44 __be16 fc_len_flags_n; /* ones complement of length / flags */
45
46 /*
47 * Offset 0x10
48 */
49 __be32 fc_time[2]; /* time stamp: seconds and fraction */
50 __be32 fc_crc; /* CRC */
51 __be32 fc_sof; /* start of frame (see FC_SOF below) */
52
53 /* 0x20 - FC frame content followed by EOF word */
54};
55
56#define FCIP_ENCAPS_HDR_LEN 0x20 /* expected length for asserts */
57
58/*
59 * Macro's for making redundant copies of EOF and SOF.
60 */
61#define FC_XY(x, y) ((((x) & 0xff) << 8) | ((y) & 0xff))
62#define FC_XYXY(x, y) ((FCIP_XY(x, y) << 16) | FCIP_XY(x, y))
63#define FC_XYNN(x, y) (FCIP_XYXY(x, y) ^ 0xffff)
64
65#define FC_SOF_ENCODE(n) FC_XYNN(n, n)
66#define FC_EOF_ENCODE(n) FC_XYNN(n, n)
67
68/*
69 * SOF / EOF bytes.
70 */
71enum fc_sof {
72 FC_SOF_F = 0x28, /* fabric */
73 FC_SOF_I4 = 0x29, /* initiate class 4 */
74 FC_SOF_I2 = 0x2d, /* initiate class 2 */
75 FC_SOF_I3 = 0x2e, /* initiate class 3 */
76 FC_SOF_N4 = 0x31, /* normal class 4 */
77 FC_SOF_N2 = 0x35, /* normal class 2 */
78 FC_SOF_N3 = 0x36, /* normal class 3 */
79 FC_SOF_C4 = 0x39, /* activate class 4 */
80} __attribute__((packed));
81
82enum fc_eof {
83 FC_EOF_N = 0x41, /* normal (not last frame of seq) */
84 FC_EOF_T = 0x42, /* terminate (last frame of sequence) */
85 FC_EOF_RT = 0x44,
86 FC_EOF_DT = 0x46, /* disconnect-terminate class-1 */
87 FC_EOF_NI = 0x49, /* normal-invalid */
88 FC_EOF_DTI = 0x4e, /* disconnect-terminate-invalid */
89 FC_EOF_RTI = 0x4f,
90 FC_EOF_A = 0x50, /* abort */
91} __attribute__((packed));
92
93#define FC_SOF_CLASS_MASK 0x06 /* mask for class of service in SOF */
94
95/*
96 * Define classes in terms of the SOF code (initial).
97 */
98enum fc_class {
99 FC_CLASS_NONE = 0, /* software value indicating no class */
100 FC_CLASS_2 = FC_SOF_I2,
101 FC_CLASS_3 = FC_SOF_I3,
102 FC_CLASS_4 = FC_SOF_I4,
103 FC_CLASS_F = FC_SOF_F,
104};
105
106/*
107 * Determine whether SOF code indicates the need for a BLS ACK.
108 */
109static inline int fc_sof_needs_ack(enum fc_sof sof)
110{
111 return (~sof) & 0x02; /* true for class 1, 2, 4, 6, or F */
112}
113
114/*
115 * Given an fc_class, return the normal (non-initial) SOF value.
116 */
117static inline enum fc_sof fc_sof_normal(enum fc_class class)
118{
119 return class + FC_SOF_N3 - FC_SOF_I3; /* diff is always 8 */
120}
121
122/*
123 * Compute class from SOF value.
124 */
125static inline enum fc_class fc_sof_class(enum fc_sof sof)
126{
127 return (sof & 0x7) | FC_SOF_F;
128}
129
130/*
131 * Determine whether SOF is for the initial frame of a sequence.
132 */
133static inline int fc_sof_is_init(enum fc_sof sof)
134{
135 return sof < 0x30;
136}
137
138#endif /* _FC_ENCAPS_H_ */