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

CHPBK

Prolog  

Control Block Contents  
   CHPBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


CHPBK Prolog

 NAME       : HCPCHPBK
 DESCRIPTION: SPXTAPE Channel Program Block
 DSECT      : CHPBK
 FUNCTION   : Work area to hold a channel program and
              the resources needed (including an
              IORBK) to issue an SPXTAPE tape I/O
              request and handle the completion or
              recovery procedures.
 LOCATED BY :
              Routines:
              HCPSPYWT - to set up the I/O operation
              HCPSPYWI - interrupt processing
              HCPSPZRT - to set up the I/O operation
              HCPSPZRI - interrupt processing
              Control block fields:
              TAPCHPQ  - head of queue in the TAPBK
              CHPNEXT  - next in circular queue
 CREATED BY : HCPSPYWT - SPXTAPE DUMP commands
              HCPSPZRT - SPXTAPE LOAD and SCAN commands
 DELETED BY : HCPSPYWT - SPXTAPE DUMP commands
              HCPSPZRT - SPXTAPE LOAD and SCAN commands
 References : HCPCHPBK requires HCPIORBK COPY

 

CHPBK Control Block Content


CHPBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      CHPBK          SPXTAPE Channel Program Block
        Reserve space for the base IORBK
0000    0 Dbl-Word     8 CHPIORBK (59)  Base IORBK region
        Lock for this IORBK and CHPBK work area
01D8  472 Dbl-Word     8 CHPLOCK (3)    Lock to serialize this block
        Commit and recovery control data.
        Last items in the current block
        used to update commit cursors when
        successfully sent to tape.
01F0  496 Signed       2 CHPCMCLR (0)   Beginning of area to be cleared
                                        before reuse for trailer
01F0  496 Address      4 CHPCURTK       Last ticket contained in current
                                        block
01F4  500 Address      4 CHPCMSSQ       Last SSQBK
01F8  504 Address      4 CHPCMCUR       Address of next Vpage slot in
                                        last SSQBK
01FC  508 Signed       4 CHPCURHD       Displacement in header of cur hdr
0200  512 Signed       4 CHPCMXAB       Amt of XAB data associated with
                                        last tkt remaining to be written
0204  516 Address      4 CHPLSTCW       CCW address of the last piece of
                                        data for files that completed in
                                        the current block. If = 0 then
                                        block contains no complete files
0208  520 Signed       4 CHPLLPTR       Last offset in page list +1 used
020C  524 Address      4 CHPLSTHD       Hdr addr for last completed file
0210  528 Signed       4 CHPLBLKZ       Save last block size at last
                                        complete file/tkt in this block.
        Counters, etc.
0214  532 Character   16 CHPTKTS        Queue of files completed in this
                                        channel program. Moved to TAPTKTQ
                                        when I/O completes OK.
                                        Single-threaded double-headed
                                        FIFO queue terminated by zero
0214  532 Address      4 CHPTKTSH       Head of CHPTKTS
0218  536 Address      4 CHPTKTST       Tail of CHPTKTS
021C  540 Signed       4 CHPTKTCT       Corresponding count of files on
                                        CHPTKTS
0220  544 Signed       4 *              Reserved
0224  548 Signed       4 CHPENTRY       Current entry in the header
0228  552 Signed       4 CHPLIMIT       After the last entry in the hdr
022C  556 Signed       4 CHPLINDX       Index into CCW list of buffers
0230  560 Signed       4 CHPOFFST       Offset into block where data
                                        should be added
0234  564 Signed       4 *
0238  568 Signed       4 CHPPOOLC       Count of pool pages (data pages)
023C  572 Address      4 CHPPLIST (14)  List of pages locked for this blk
          00000038       CHPPLLEN       *-CHPPLIST Length to clear
          0000000E       CHPPLMAX       14 Maximum number of entries
0274  628 Signed       4 *              End flag for PLIST - zero = end
          00000088       CHPCMCRL       *-CHPCMCLR Length of area to be
                                        cleared before reuse for trailer
        Queue of CHPbks link field
0278  632 Address      4 CHPNEXT        Next work area in circular queue
        Save area across GOTO I/O request
027C  636 Signed       4 CHPSAVE (7)    Save R3-R9 across call to IOS.QS
        Channel Program and Header Block copied from TAPBK
0298  664 Dbl-Word     8 CHPPGM (26)    Modeset + hdr + 3*8 (desc + xab +
                                        data)
0368  872 Dbl-Word     8 CHPHEADR (37)  Block header
        Pointers
0490 1168 Signed       4 CHPIDAWA       IDAW list anchor
0494 1172 Signed       4 CHPIDWNX       Next available IDAW slot
0498 1176 Signed       4 CHPBUFHL       Host logical buffer addr anchor
049C 1180 Signed       4 *              Reserved
          00000004       CHPHLLEN       4 Length of CHPBUFHL entries
        End of CHPBK definition
04A0 1184 Dbl-Word     8 CHPRESVD (10)  Round it off
          00000318       CHPLENBY       *-CHPLOCK Extra space (after
                                        IORBK)
          000004F0       CHPIOBY        *-CHPBK Whole work area size in
                                        bytes
          0000009E       CHPIODW        CHPIOBY/8 Same in double words
          00000002       CHPBKCNT       2 Number of work areas per drive
        Redefinition for the channel program build area
0298  664 Dbl-Word     8 CHPMSCCW       Modeset, if applicable
02A0  672 Address      4 CHPHDCCW       Read/write header CCW
02A4  676 Address      4 CHPHCCWA       Address of the CHPHEADR
02A8  680 Address      4 CHPCCW1        First general CCW
02AC  684 Address      4 CHPCCW1A       Address section for deblocking
02B0  688 Dbl-Word     8 CHPCCWS (20)   File write CCWs - desc, XAB, data
                                        Or read CCW's - up to 8 pages
          00000015       CHPCCWCT       (*-CHPCCW1)/8 Number of CCWs
                                        (doublewords)
          000000B8       CHPPGMLN       *-CHPPGM Must match size defined
                                        above
        Redefinition for the tape block header section
0368  872 Character    4 CHPBLKID       Generally 'XHDR', could be 'TRLR'
036C  876 Signed       4 CHPBLKSZ       Size of this block in bytes
0370  880 Dbl-Word     8 CHPTIME        Time stamp
        Definition of an individual entry
0378  888 Dbl-Word     8 CHPHDENT (0)   Start of the first entry
0378  888 Character    8 CHPOWNER       File owner
0380  896 Signed       4 CHPFSEQ        File sequence number for drive
0384  900 Signed       4 CHPSYSID       System spool file ID when dumped
0388  904 Signed       2 CHPSPID        User spool file ID when dumped
038A  906 Bitstring    1 CHPHDFLG       Flags describing file section
038B  907 Bitstring    1 *
038C  908 Signed       4 CHPMAPCT       Count of map pages needed for
                                        file
0390  912 Signed       4 CHPPAGNO       Starting relative page number
0394  916 Signed       2 CHPPAGCT       Count of data pages in block
0396  918 Signed       2 CHPXABSZ       Size of XAB section in block
0398  920 Signed       2 CHPTKOFF       Offset to ticket - file
                                        descriptor
039A  922 Signed       2 CHPXAOFF       Offset to extended attributes buf
039C  924 Signed       2 CHPDPOFF       Offset to data pages
039E  926 Signed       2 *

 

CHPBK Storage Layout

          
*** CHPBK - SPXTAPE Channel Program Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       CHPIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 1D8 |                                                       |
*     =                       CHPLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
* 1F0 |         CHPCURTK          |         CHPCMSSQ          |
*     +---------------------------+---------------------------+
* 1F8 |         CHPCMCUR          |         CHPCURHD          |
*     +---------------------------+---------------------------+
* 200 |         CHPCMXAB          |         CHPLSTCW          |
*     +---------------------------+---------------------------+
* 208 |         CHPLLPTR          |         CHPLSTHD          |
*     +---------------------------+---------------------------+
* 210 |         CHPLBLKZ          |                           |
*     +---------------------------+                           |
*     |                       CHPTKTS                         |
*     |                           +---------------------------+
*     |                           | 224
*     +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
          
*** Overlay for CHPTKTS in CHPBK
*
*                                 +---------------------------+
* 210 ...                     214 |         CHPTKTSH          |
*     +---------------------------+---------------------------+
* 218 |         CHPTKTST          |         CHPTKTCT          |
*     +---------------------------+---------------------------+
* 220 |///////////////////////////|         CHPENTRY          |
*     +---------------------------+---------------------------+
* 228 |         CHPLIMIT          |         CHPLINDX          |
*     +---------------------------+---------------------------+
* 230 |         CHPOFFST          |///////////////////////////|
*     +---------------------------+---------------------------+
* 238 |         CHPPOOLC          |                           |
*     +---------------------------+                           |
* 240 |                                                       |
*     =                       CHPPLIST                        =
*     |                           +---------------------------+
* 270 |                           |///////////////////////////|
*     +---------------------------+---------------------------+
* 278 |         CHPNEXT           |                           |
*     +---------------------------+                           |
* 280 |                                                       |
*     =                       CHPSAVE                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 298 |                                                       |
*     =                        CHPPGM                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 368 |                                                       |
*     =                       CHPHEADR                        =
*     |                                                       |
*     +---------------------------+---------------------------+
* 490 |         CHPIDAWA          |         CHPIDWNX          |
*     +---------------------------+---------------------------+
* 498 |         CHPBUFHL          |///////////////////////////|
*     +---------------------------+---------------------------+
* 4A0 |                                                       |
*     =                       CHPRESVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 4F0
*
*** Overlay for CHPTKTS in CHPBK
          
*** Overlay for CHPPGM in CHPBK
*
*     +-------------------------------------------------------+
* 298 |                       CHPMSCCW                        |
*     +---------------------------+---------------------------+
* 2A0 |         CHPHDCCW          |         CHPHCCWA          |
*     +---------------------------+---------------------------+
* 2A8 |         CHPCCW1           |         CHPCCW1A          |
*     +---------------------------+---------------------------+
* 2B0 |                                                       |
*     =                       CHPCCWS                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 350
*
*** Overlay for CHPPGM in CHPBK
          
*** Overlay for CHPHEADR in CHPBK
*
*     +---------------------------+---------------------------+
* 368 |         CHPBLKID          |         CHPBLKSZ          |
*     +---------------------------+---------------------------+
* 370 |                       CHPTIME                         |
*     +-------------------------------------------------------+
* 378 |                       CHPOWNER                        |
*     +---------------------------+---------------------------+
* 380 |         CHPFSEQ           |         CHPSYSID          |
*     +-------------+------+------+---------------------------+
* 388 |  CHPSPID    |:HDFLG|//////|         CHPMAPCT          |
*     +-------------+------+------+-------------+-------------+
* 390 |         CHPPAGNO          |  CHPPAGCT   |  CHPXABSZ   |
*     +-------------+-------------+-------------+-------------+
* 398 |  CHPTKOFF   |  CHPXAOFF   |  CHPDPOFF   |/////////////|
*     +-------------+-------------+-------------+-------------+
* 3A0
*
*** Overlay for CHPHEADR in CHPBK

 

CHPBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
CHPBKCNT       04A0 00000002
CHPBLKID       0368
CHPBLKSZ       036C
CHPBUFHL       0498
CHPCCWCT       02B0 00000015
CHPCCWS        02B0
CHPCCW1        02A8
CHPCCW1A       02AC
CHPCMCLR       01F0
CHPCMCRL       0274 00000088
CHPCMCUR       01F8
CHPCMSSQ       01F4
CHPCMXAB       0200
CHPCURHD       01FC
CHPCURTK       01F0
CHPDPOFF       039C
CHPENTRY       0224
CHPFSEQ        0380
CHPHCCWA       02A4
CHPHDCCW       02A0
CHPHDENT       0378
CHPHDFLG       038A
CHPHEADR       0368
CHPHLLEN       049C 00000004
CHPIDAWA       0490
CHPIDWNX       0494
CHPIOBY        04A0 000004F0
CHPIODW        04A0 0000009E
CHPIORBK       0000
CHPLBLKZ       0210
CHPLENBY       04A0 00000318
CHPLIMIT       0228
CHPLINDX       022C
CHPLLPTR       0208
CHPLOCK        01D8
CHPLSTCW       0204
CHPLSTHD       020C
CHPMAPCT       038C
CHPMSCCW       0298
CHPNEXT        0278
CHPOFFST       0230
CHPOWNER       0378
CHPPAGCT       0394
CHPPAGNO       0390
CHPPGM         0298
CHPPGMLN       02B0 000000B8
CHPPLIST       023C
CHPPLLEN       023C 00000038
CHPPLMAX       023C 0000000E
CHPPOOLC       0238
CHPRESVD       04A0
CHPSAVE        027C
CHPSPID        0388
CHPSYSID       0384
CHPTIME        0370
CHPTKOFF       0398
CHPTKTCT       021C
CHPTKTS        0214
CHPTKTSH       0214
CHPTKTST       0218
CHPXABSZ       0396
CHPXAOFF       039A

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 16:43:41 EDT.
Copyright IBM Corporation, 1990, 2005