IBM: BKIBK

Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

BKIBK

Prolog

Control Block Contents

BKIBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

BKIBK Prolog

 NAME       : HCPBKIBK
 DESCRIPTION: Block I/O Block for DIAGNOSE X'250'
 DSECT      : BKIBK
 FUNCTION   : Main control block for the DIAGNOSE X'250'
              function; all other information can be found
              from this block.
 LOCATED BY : VDEVBKIA
 CREATED BY : HCPBICIN, during the initialization of the
              DIAGNOSE X'250' block I/O environment
 DELETED BY : HCPBICRE, during the removal of the
              DIAGNOSE X'250' block I/O environment
 SERIALIZED : The block I/O block lock, BKILOCK.
 COMMENTS   : Refer to the description of the VDEVBKIA
              field for information on the serialization
              for pointing to this block from the
              appropriate VDEV. There is one BKIBK for
              each VDEV for which a DIAGNOSE X'250'
              environment is initialized.

BKIBK Control Block Content


BKIBK DSECT
Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BKIBK          Block I/O Block for DIAGNOSE
                                        X'250'
0000    0 Bitstring    1 BKISTAT        Block I/O function status
          .1.. ....      BKIRESET       X'40' A reset operation is
                                        pending. Note: this flag is set
                                        for serviceability - it is not
                                        checked, since BKIRMPD is always
                                        set as well by the time
                                        reset/remove status needs to be
                                        recognized.
0001    1 Bitstring    1 BKIFLAGS       Device status flags
          .... .1..      BKIRMPD        X'04' A REMOVE request is pending
          .... ...1      BKIDEVRD       X'01' Virtual device is read only
0002    2 Bitstring    2 *              Reserved for IBM use
0004    4 Signed       4 BKIOFFCP       CP offset for CMS disk
     BKIDBCCT indicates processes in HCPDBC. It is used to indicate that
     outstanding i/o is being done maybe by the minidisk cache i/o handler
     (HCPFTUAD). Thus BKIDBIRQ and BKIDBCCT BOTH must be 0 to indicate there
     is no outstanding Diag 250 for this device.
0008    8 Signed       4 BKIDBCCT       Count of processes in HCPDBC
000C   12 Signed       4 BKIDBIRQ       Chain of outstanding DBIRQs
0010   16 Signed       4 BKIDBCWK       Chain of outstanding i/o requests
0014   20 Signed       4 BKIBLKSZ       Block size of user's disk
0018   24 Signed       4 BKIOFFST       User's requested offset
001C   28 Signed       2 BKIVDEVN       Virtual device number
001E   30 Bitstring    2 *              Reserved for future IBM use
0020   32 Signed       4 BKISTART       User's starting block
0024   36 Signed       4 BKIEND         User's ending block
0028   40 Signed       4 BKIVDEVA       Virtual device block address
002C   44 Signed       4 BKIDINFO       Address of device information
0030   48 Signed       4 BKISAVBK       Caller's save block
0034   52 Signed       4 BKIRMVMD       Address of the VMDBK on which
                                        .the RESET or REMOVE was .issued.
0038   56 Signed       4 *              Reserved for IBM use
0040   64 Dbl-Word     8 BKILOCK (3)    BKIBK lock
0058   88 Signed       4 *              Reserved for IBM use
005C   92 Signed       4 *              Reserved for IBM use
0060   96 Signed       4 *              Reserved for IBM Use
0064  100 Signed       4 *              Reserved for IBM use
          0000000D       BKISIZE        (*-BKIBK+7)/8 Length of BKIBK in
                                        DWs

BKIBK Storage Layout

*** BKIBK - Block I/O Block for DIAGNOSE X'250'
*
*     +------+------+-------------+---------------------------+
*   0 |:STAT |:FLAGS|/////////////|         BKIOFFCP          |
*     +------+------+-------------+---------------------------+
*   8 |         BKIDBCCT          |         BKIDBIRQ          |
*     +---------------------------+---------------------------+
*  10 |         BKIDBCWK          |         BKIBLKSZ          |
*     +---------------------------+-------------+-------------+
*  18 |         BKIOFFST          |  BKIVDEVN   |/////////////|
*     +---------------------------+-------------+-------------+
*  20 |         BKISTART          |          BKIEND           |
*     +---------------------------+---------------------------+
*  28 |         BKIVDEVA          |         BKIDINFO          |
*     +---------------------------+---------------------------+
*  30 |         BKISAVBK          |         BKIRMVMD          |
*     +---------------------------+---------------------------+
*  38 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  40 |                                                       |
*     =                       BKILOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  58 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  60 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  68
*
*** BKIBK - Block I/O Block for DIAGNOSE X'250'