LXR linux/include/scsi/fc/fc

   1/*
   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_ */
 139