LRDA Back to Index page
 
Prolog 
Control Block Contents 
   LRDA DSECT
   LRDXILRE DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  LRDA Prolog Top of page
  
 NAME       : HCPLRDA
 DESCRIPTION: Locate Record (Extended) data area
 DSECT      : LRDA
 FUNCTION   : Maps the contents of the Locate Record
              (Extended) data area.
 LOCATED BY :
              HCCWADDR - The Locate Record CCW data address field
              contains the address of the locate
              record data area.
 CREATED BY :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDA.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is allocated in modules HCPFMU/HCPFMP.
 DELETED BY :
              Storage for this control block cannot be
              specifically allocated/deallocated using
              HCPGETST/HCPRELST.
              Paging I/O manager -
              The data area resides in the HCPPIOBK which
              is allocated by HCPRDD.
              Track cache manager -
              Data area is part of a larger free storage
              area used to build ECKD channel programs
              which is deallocated in modules HCPFMU/HCPFMP.
 SERIALIZED :
              Paging I/O manager -
              EXPLCKFG - The paging I/O manager uses the exposure
              block lock to serialize this data area.
              Track cache manager -
              TCMTSLK  - Track cache lock
 RELOCATION CONSIDERATIONS : None
 COMMENTS   :
              Paging I/O manager -
              The Locate Record data area resides in the
              HCPPIOBK. Each Locate Record CCW address field
              contains the address of the Locate Record data
              area within that PIOBK.
              Track cache manager -
              None
 
 
  LRDA Control Block Content Top of page
  




 LRDA DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      LRDA           Locate Record (Extended) data area
0000    0 Bitstring   16 LRDAREA (0)    Locate record data area
             Byte 0 (Operation byte)
             Although defined as BITs, the contents of the
             operation byte are, architecturally, multiple
             codes.
0000    0 Bitstring    1 LRDOP          Operation byte
          11.. ....      LRDOR          X'C0' LRDOR Operation byte, bits
                                        0 and 1 ------- Codes for use
                                        with LRDOR
          .... ....      LRDORCA        X'00' LRDORCA Orient on count
                                        area
          .1.. ....      LRDORHA        X'40' LRDORHA Orient on home
                                        address
          1... ....      LRDORDA        X'80' LRDORDA Orient on data area
          11.. ....      LRDORIX        X'C0' LRDORIX Orient on index
                                        -------
          ..11 1111      LRDOOC         X'3F' Operation byte, bits 2
                                        through 7 ------- Codes for use
                                        with LRDOOC
          .... ....      LRDOCOR        X'00' Orient
          .... ...1      LRDOCWD        X'01' Write data
          .... ..11      LRDOCFW        X'03' Format write
          .... .11.      LRDOCRD        X'06' Read data
          .... 1.11      LRDOCWT        X'0B' Write track
          .... 11..      LRDOCRT        X'0C' Read tracks
          ...1 .11.      LRDOCR         X'16' Read -------
             Byte 1 (Auxiliary byte)
0001    1 Bitstring    1 LRDAUX         Auxiliary byte
          1... ....      LRDAVTLF       X'80' LRDAVTLF Validate transfer
                                        length factor
          .1.. ....      LRDATLFS       X'40' LRDATLFS (TM) Transfer
                                        Length Factor Scope
          ..1. ....      LRDICCWV       X'20' LRDICCWV (TM) Imbedded CCW
                                        Op Code Valid
          ...1 ....      LRDCBTMW       X'10' LRDCBTMW (TM) CRC on track
                                        boundary (WRITE)
          .... 1...      LRDCBTMR       X'08' LRDCBTMR (TM) CRC on TCW
                                        boundary (READ)
          .... .1..      LRDILRCV       X'04' LRDILRCV (TM) Imbedded Loc
                                        Record Count is valid
          .... ...1      LRDARCS        X'01' LRDARCS Read count suffix
             Byte 2 (Zeros -- Locate Record)
             Byte 2 (Imbedded CCW op code -- Loc Rec Extended)
0002    2 Bitstring    1 LRDZEROS       Must be zeros
          .... ..1.      LRDICCW        LRDZEROS LRDICCW (TM) Imbedded
                                        CCW Op Code (LRE only)
             Byte 3 (Record count)
0003    3 Bitstring    1 LRDRECCT       Record count
             Bytes 4 through 7 (Seek address)
0004    4 Bitstring    4 LRDSEEK (0)    Seek address (CCHH)
0004    4 Bitstring    2 LRDSCC         CC of CCHH
0006    6 Bitstring    2 LRDSHH         HH of CCHH
             Bytes 8 through 12 (Search argument)
0008    8 Bitstring    5 LRDSRCH (0)    Search argument (CCHHR)
0008    8 Bitstring    4 LRDRCCCH (0)   Cylinder and head (CCCCcccH)
0008    8 Bitstring    2 LRDRCC         CC of CCHHR
000A   10 Bitstring    2 LRDRHH         HH of CCHHR
000C   12 Bitstring    1 LRDRR          R of CCHHR
             Byte 13 (Sector number)
000D   13 Bitstring    1 LRDSECT        Sector number
             Bytes 14 and 15 (Transfer length factor)
000E   14 Bitstring    2 LRDTLF         Transfer length factor
             Length equates
          00000010       LRDBSIZE       *-LRDAREA Size of LRDA in bytes
          00000002       LRDSIZE        ((*-LRDAREA)+7)/8 Size of LRDA in
                                        DWs
             Bytes 16 through 19 (Locate Record Extended)
             For Transport Mode support
0010   16 Bitstring    1 LRDXILRC       (TM) Imbedded Locate Record Count
0011   17 Bitstring    1 LRDXOP         (TM) Extended Operation Byte
          ..1. ..11      LRDXUT         X'23' LRDXUT Update Tracks
0012   18 Bitstring    2 LRDXPLEN       (TM) Extended Parameter Length
             Bytes 20-nn (Locate Record Extended Parameters)
             For Transport Mode support
0014   20 Bitstring    1 LRDXPARM (0)   (TM) Extended Parameters
          00000014       LRDXBSZ        *-LRDAREA Size of Extended LRDA
                                        in bytes
          00000003       LRDXDSZ        (LRDXBSZ+7)/8 Size of Extended
                                        LRDA in DWs
             DSECT for mapping each Imbedded Locate Record entry
             For Transport Mode support




 LRDXILRE DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      LRDXILRE       Locate Record (Extended) data area
0000    0 Bitstring    5 LRDXSRCH (0)   Search argument (CCHHR)
0000    0 Bitstring    4 LRDXCCCH (0)   Cylinder and head (CCCCcccH)
0000    0 Bitstring    2 LRDXCC         CC
0002    2 Bitstring    2 LRDXHH         CC
0004    4 Bitstring    1 LRDXR          R
0005    5 Bitstring    1 LRDXCT         Count
0006    6 Bitstring    2 LRDXTLF        Transfer length factor
          00000008       LRDXILRB       *-LRDXILRE Byte size of Imbedded
                                        LR entry
 
 
  LRDA Storage Layout Top of page
  
          
*** LRDA - Locate Record (Extended) data area
*
*     +------+------+------+------+-------------+-------------+
*   0 |LRDOP |LRDAUX|:ZEROS|:RECCT|   LRDSCC    |   LRDSHH    |
*     +------+------+------+------+------+------+-------------+
*   8 |   LRDRCC    |   LRDRHH    |LRDRR |:SECT |   LRDTLF    |
*     +------+------+-------------+------+------+-------------+
*  10 |:XILRC|LRDXOP|  LRDXPLEN   |
*     +------+------+-------------+
*
*** LRDA - Locate Record (Extended) data area
          
*** LRDXILRE - Locate Record (Extended) data area
*
*     +-------------+-------------+------+------+-------------+
*   0 |   LRDXCC    |   LRDXHH    |LRDXR |LRDXCT|  LRDXTLF    |
*     +-------------+-------------+------+------+-------------+
*   8
*
*** LRDXILRE - Locate Record (Extended) data area
 
 
  LRDA Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
LRDARCS        0001 01
LRDAREA        0000
LRDATLFS       0001 40
LRDAUX         0001
LRDAVTLF       0001 80
LRDBSIZE       000E 00000010
LRDCBTMR       0001 08
LRDCBTMW       0001 10
LRDICCW        0002 02
LRDICCWV       0001 20
LRDILRCV       0001 04
LRDOCFW        0000 03
LRDOCOR        0000 00
LRDOCR         0000 16
LRDOCRD        0000 06
LRDOCRT        0000 0C
LRDOCWD        0000 01
LRDOCWT        0000 0B
LRDOOC         0000 3F
LRDOP          0000
LRDOR          0000 C0
LRDORCA        0000 00
LRDORDA        0000 80
LRDORHA        0000 40
LRDORIX        0000 C0
LRDRCC         0008
LRDRCCCH       0008
LRDRECCT       0003
LRDRHH         000A
LRDRR          000C
LRDSCC         0004
LRDSECT        000D
LRDSEEK        0004
LRDSHH         0006
LRDSIZE        000E 00000002
LRDSRCH        0008
LRDTLF         000E
LRDXBSZ        0014 00000014
LRDXCC         0000
LRDXCCCH       0000
LRDXCT         0005
LRDXDSZ        0014 00000003
LRDXHH         0002
LRDXILRB       0006 00000008
LRDXILRC       0010
LRDXOP         0011
LRDXPARM       0014
LRDXPLEN       0012
LRDXR          0004
LRDXSRCH       0000
LRDXTLF        0006
LRDXUT         0011 23
LRDZEROS       0002
 
This information is based on z/VM 7.4.0 Last updated on 24 Jun 2024 at 11:31:56 EDT.
Copyright IBM Corporation, 1990, 2024