BPLBK - 64-bit CP - V4R4.0

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

#### BPLBK

Prolog

Control Block Contents
BPLBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### BPLBK Prolog

     NAME       : HCPBPLBK
     DESCRIPTION: *BLOCKIO parameter list dsect
     DSECT      : BPLBK
     FUNCTION   : This DSECT maps the input parameter list sent
                  by the guest to CP when the guest requests a
                  multiple block I/O operation from *BLOCKIO
     LOCATED BY : SNDPLADR in SNDBK
     CREATED BY : HCPBIMMS (who copies the guest's parameter
                  list into host storage)
     DELETED BY : HCPBIMMS
     SERIALIZED : Unique task execution
                  VMDBK dispatch lock.
                  BLOCKIO lock
     Notes      : When the guest sends the address in guest storage
                  of this parameter list, it may not be word-aligned.
                  This DSECT assumes that before any fields are
                  referenced, the parameter list has been moved into
                  host storage and been word-aligned.  References
                  to address fields will cause an exception if this
                  is not the case.

#### BPLBK Control Block Content

#### BPLBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      BPLBK          *BLOCKIO parameter list dsect
    0000    0 Signed       4 * (0)
    0000    0 Bitstring    1 BPLRQCOD       Request code
              00000001       BPLWRITE       X'01' Write request
              00000002       BPLREAD        X'02' Read request
    0001    1 Bitstring    1 BPLRETCD       Return code for this operation
    0002    2 Bitstring    2 *              Reserved for IBM use
    0004    4 Address      4 BPLBUFAD       Guest real address of data buffer
    0008    8 Signed       4 BPLBKNUM       Block number
    000C   12 Signed       4 *              Reserved for IBM use
    0010   16 Signed       4 BPLNXENT (0)   Next entry in p-list starts here
              00000002       BPLSIZE        (*-BPLBK+7)/8 Size, in
                                            doublewords, of BPLBK

#### BPLBK Storage Layout

    *** BPLBK - *BLOCKIO parameter list dsect
    *
    *     +------+------+-------------+---------------------------+
    *   0 |:RQCOD|:RETCD|/////////////|         BPLBUFAD          |
    *     +------+------+-------------+---------------------------+
    *   8 |         BPLBKNUM          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *
    *** BPLBK - *BLOCKIO parameter list dsect

#### BPLBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    BPLBKNUM       0008
    BPLBUFAD       0004
    BPLNXENT       0010
    BPLREAD        0000 00000002
    BPLRETCD       0001
    BPLRQCOD       0000
    BPLSIZE        0010 00000002
    BPLWRITE       0000 00000001

This information is based on z/VM V4R4.0. Last updated on 30 Jul 2003 at 12:30:03 EDT.
Copyright IBM Corporation, 1990, 2003