BLKIO

Prolog  

Control Block Contents  
   BLKIO DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

BLKIO Prolog

 NAME       : HCPBLKIO
 DESCRIPTION: *BLOCKIO Device Connection Data
 DSECT      : BLKIO
 FUNCTION   : This DSECT maps data representing a successful
              connection to a device by a virtual machine
              using the *BLOCKIO system service
 LOCATED BY : VMDBLKIO field in VMDBK
              VDEVBIOA field in VDEV
 CREATED BY : HCPBIO
 DELETED BY : HCPBIO
 SERIALIZED : Unique task execution
              VMDBK dispatch lock.

BLKIO Control Block Content

BLKIO DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BLKIO          *BLOCKIO Device Connection Data
0000    0 Signed       4 BLKNEXT        Address of next BLKIO Block
0004    4 Bitstring    1 BLKRC          SEVER return code
0005    5 Bitstring    1 BLKSTAT        BLKIO status
          1... ....      BLKSVRD        X'80' SEVER is Pending
          .1.. ....      BLKRESET       X'40' RESET is Pending
0006    6 Bitstring    2 BLKPATH        IUCV path for this device
0008    8 Signed       4 BLKOFFCP       CP offset for CMS disk
     BLKDBCCT is used to indicate the number of outstanding processes in
     HCPDBC. It is used to indicate that i/o may be in progress for a
     particular request (by HCPFTUAD). Thus BLKDBCCT and BLKDBIAD both must
     be 0 for there to be no outstanding *BLOCKIO for this device.
000C   12 Signed       4 BLKDBCCT       Count of processes in HCPDBC
0010   16 Signed       4 BLKDBIAD       Chain of outstanding DBIRQs
0014   20 Signed       4 BLKDBCWK       Chain of outstanding sends to
                                        *BLOCKIO
0018   24 Bitstring   16 BLKCPARM (0)   User connect parameter list
0018   24 Signed       4 BLKSIZE        Block size of user's disk
001C   28 Signed       4 BLKOFFST       User's requested offset
0020   32 Signed       2 BLKVDEV        Virtual device address
0022   34 Bitstring    6 *              Reserved for future IBM use
0028   40 Bitstring   16 BLKPARMA (0)   ACCEPT parameter list
0028   40 Signed       4 BLKSTART       User's starting block
002C   44 Signed       4 BLKEND         User's ending block
0030   48 Bitstring    1 *              Reserved for Future IBM Use
0031   49 Bitstring    1 BLKFLAGS       Device status flags
          .... ...1      BLKDEVRD       X'01' Virtual device is read only
0032   50 Bitstring    2 *              Reserved for Future IBM Use
0034   52 Signed       4 BLKSPIRA       Special IRA for SEVER processing
0038   56 Signed       4 BLKVDEVA       Virtual device block address
003C   60 Signed       4 BLKDINFO       Address of device information
0040   64 Signed       4 BLKSAVBK       Caller's save block
0048   72 Dbl-Word     8 * (0)          Ensure Double Word Boundary
0048   72 Dbl-Word     8 BLKLOWN (3)    BLKIO lock
0060   96 Dbl-Word     8 * (0)          Ensure Double Word Boundary
0060   96 Bitstring   40 BLKPARML       IUCV parameter list
          00000011       BLKDSIZE       (*-BLKIO+7)/8 Size, in
                                        doublewords, of BLKIO

BLKIO Storage Layout

          
*** BLKIO - *BLOCKIO Device Connection Data
*
*     +---------------------------+------+------+-------------+
*   0 |         BLKNEXT           |BLKRC |:STAT |  BLKPATH    |
*     +---------------------------+------+------+-------------+
*   8 |         BLKOFFCP          |         BLKDBCCT          |
*     +---------------------------+---------------------------+
*  10 |         BLKDBIAD          |         BLKDBCWK          |
*     +---------------------------+---------------------------+
*  18 |         BLKSIZE           |         BLKOFFST          |
*     +-------------+-------------+---------------------------+
*  20 |  BLKVDEV    |/////////////////////////////////////////|
*     +-------------+-------------+---------------------------+
*  28 |         BLKSTART          |          BLKEND           |
*     +------+------+-------------+---------------------------+
*  30 |//////|:FLAGS|/////////////|         BLKSPIRA          |
*     +------+------+-------------+---------------------------+
*  38 |         BLKVDEVA          |         BLKDINFO          |
*     +---------------------------+---------------------------+
*  40 |         BLKSAVBK          |///////////////////////////|
*     +---------------------------+---------------------------+
*  48 |                                                       |
*     =                       BLKLOWN                         =
*     |                                                       |
*     +-------------------------------------------------------+
*  60 |                                                       |
*     =                       BLKPARML                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  88
*
*** BLKIO - *BLOCKIO Device Connection Data

BLKIO Cross Reference

Symbol         Dspl Value
-------------- ---- -----
BLKCPARM       0018
BLKDBCCT       000C
BLKDBCWK       0014
BLKDBIAD       0010
BLKDEVRD       0031 01
BLKDINFO       003C
BLKDSIZE       0060 00000011
BLKEND         002C
BLKFLAGS       0031
BLKLOWN        0048
BLKNEXT        0000
BLKOFFCP       0008
BLKOFFST       001C
BLKPARMA       0028
BLKPARML       0060
BLKPATH        0006
BLKRC          0004
BLKRESET       0005 40
BLKSAVBK       0040
BLKSIZE        0018
BLKSPIRA       0034
BLKSTART       0028
BLKSTAT        0005
BLKSVRD        0005 80
BLKVDEV        0020
BLKVDEVA       0038