Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### MMABK

Prolog

Control Block Contents
MMABK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### MMABK Prolog

     NAME       : HCPMMABK
     DESCRIPTION: ISFC Device Extension for MMC devices
     DSECT      : MMABK
     FUNCTION   : This DSECT maps information for one of the ISFC link
                  devices on a Microchannel to Mainframe Connection.
     LOCATED BY : LDVEXTBK  points to the MMABK for that device.
                  MMCWRDEV  points to the MMABK for the output device.
                  MMCRDDEV  points to the MMABK for the input device.
     CREATED BY : HCPMMC    when a new link is activated.
     DELETED BY : HCPMMC    when a link is deactivated.
     SERIALIZED : The ISFC Global Lock (HCPBDSGL).
                  The ISFC LNKBK lock (LNKLKWRD).
     COMMENTS   : None

#### MMABK Control Block Content

#### MMABK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      MMABK          ISFC Device Extension for MMC
                                            devices
          Higher-Level Objects (Link and device).
    0000    0 Address      4 MMAMMCBK       Address of MMC link block
    0004    4 Address      4 MMALDVBK       Address of ISFC device extension
          Device status.
    0008    8 Signed       4 MMADEVNO       Real device address
    000C   12 Signed       4 MMAMSNUM       Most recent msg number
    0010   16 Bitstring    1 MMASTAT        Latest operation attempted
              00000001       LNKIDLE        1 - Idle
              00000002       LNKBUSY        2 - Busy
              00000003       LNKWRITE       3 - Write in progress
              00000004       LNKREAD        4 - Read in progress
              00000005       LNKRESET       5 - Reset in progress
              00000006       LNKATTN        6 - Handling link attention
              00000007       LNKFATAL       7 - Fatal I/O on link
              00000008       LNKINIT        8 - Initialization in progress
              00000008       LNKDEACT       8 - Deactivation in progress
    0011   17 Bitstring    1 MMANEXT        Next operation to be started
              00000001       LNKIDLE        1 - Idle
              00000002       LNKBUSY        2 - Busy
              00000003       LNKWRITE       3 - Write in progress
              00000004       LNKREAD        4 - Read in progress
              00000005       LNKRESET       5 - Reset in progress
              00000006       LNKATTN        6 - Handling link attention
              00000007       LNKFATAL       7 - Fatal I/O on link
              00000008       LNKINIT        8 - Initialization in progress
              00000008       LNKDEACT       8 - Deactivation in progress
    0012   18 Bitstring    1 MMAPEND        I/O Pending Flags:
              1... ....      MMAIOACT       X'80' - I/O is active on this
                                            device
              .1.. ....      MMARQSEM       X'40' - SEM is required on this
                                            device
    0013   19 Bitstring    1 *              Reserved
    0014   20 Signed       4 MMARETRY       Retry counter
          ORB for this device.
    0018   24 Bitstring   12 MMAORB (0)     ORB for I/O requests
    0018   24 Signed       4 MMARET         ORB User Parm (I/O Return Addr)
    001C   28 Bitstring    4 MMAREQ         ORB Request Flags
    0020   32 Address      4 MMACPA         ORB Channel Program Address
          Interrupt information for this device.
    0024   36 Address      4 MMAIRB         Latest IRBLK address
    0028   40 Address      4 MMASNS         Latest SNSBK address
    002C   44 Signed       4 MMAIORC        Latest I/O Return Code
    0030   48 Address      4 MMACCWX        Last CCW expected
    0034   52 Address      4 MMACCWF        Failing CCW Address
          Work area for this device.
    0038   56 Dbl-Word     8 MMABUFF (8)    Space for a work buffer
              00000078       MMABKLEN       *-MMABK Size of MMABK in bytes
              0000000F       MMASIZE        (*-MMABK+7)/8 Size of MMABK in
                                            doublewords

#### MMABK Storage Layout

    *** MMABK - ISFC Device Extension for MMC devices
    *
    *     +---------------------------+---------------------------+
    *   0 |         MMAMMCBK          |         MMALDVBK          |
    *     +---------------------------+---------------------------+
    *   8 |         MMADEVNO          |         MMAMSNUM          |
    *     +------+------+------+------+---------------------------+
    *  10 |:STAT |:NEXT |:PEND |//////|         MMARETRY          |
    *     +------+------+------+------+---------------------------+
    *  18 |          MMARET           |          MMAREQ           |
    *     +---------------------------+---------------------------+
    *  20 |          MMACPA           |          MMAIRB           |
    *     +---------------------------+---------------------------+
    *  28 |          MMASNS           |         MMAIORC           |
    *     +---------------------------+---------------------------+
    *  30 |         MMACCWX           |         MMACCWF           |
    *     +---------------------------+---------------------------+
    *  38 |                                                       |
    *     =                       MMABUFF                         =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  78
    *
    *** MMABK - ISFC Device Extension for MMC devices

#### MMABK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    LNKATTN        0010 00000006
    LNKATTN        0011 00000006
    LNKBUSY        0010 00000002
    LNKBUSY        0011 00000002
    LNKDEACT       0010 00000008
    LNKDEACT       0011 00000008
    LNKFATAL       0010 00000007
    LNKFATAL       0011 00000007
    LNKIDLE        0010 00000001
    LNKIDLE        0011 00000001
    LNKINIT        0010 00000008
    LNKINIT        0011 00000008
    LNKREAD        0010 00000004
    LNKREAD        0011 00000004
    LNKRESET       0010 00000005
    LNKRESET       0011 00000005
    LNKWRITE       0010 00000003
    LNKWRITE       0011 00000003
    MMABKLEN       0038 00000078
    MMABUFF        0038
    MMACCWF        0034
    MMACCWX        0030
    MMACPA         0020
    MMADEVNO       0008
    MMAIOACT       0012 80
    MMAIORC        002C
    MMAIRB         0024
    MMALDVBK       0004
    MMAMMCBK       0000
    MMAMSNUM       000C
    MMANEXT        0011
    MMAORB         0018
    MMAPEND        0012
    MMAREQ         001C
    MMARET         0018
    MMARETRY       0014
    MMARQSEM       0012 40
    MMASIZE        0038 0000000F
    MMASNS         0028
    MMASTAT        0010

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 17:05:31 EDT.
Copyright IBM Corporation, 1990, 2005