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 (43)  Base IORBK region
     Lock for this IORBK and CHPBK work area
0158  344 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.
0170  368 Signed       2 CHPCMCLR (0)   Beginning of area to be cleared
                                        before reuse for trailer
0170  368 Address      4 CHPCURTK       Last ticket contained in current
                                        block
0174  372 Address      4 CHPCMSSQ       Last SSQBK
0178  376 Address      4 CHPCMCUR       Address of next Vpage slot in
                                        last SSQBK
017C  380 Signed       4 CHPCURHD       Displacement in header of cur hdr
0180  384 Signed       4 CHPCMXAB       Amt of XAB data associated with
                                        last tkt remaining to be written
0184  388 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
0188  392 Signed       4 CHPLLPTR       Last offset in page list +1 used
018C  396 Address      4 CHPLSTHD       Hdr addr for last completed file
0190  400 Signed       4 CHPLBLKZ       Save last block size at last
                                        complete file/tkt in this block.
     Counters, etc.
0194  404 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
0194  404 Address      4 CHPTKTSH       Head of CHPTKTS
0198  408 Address      4 CHPTKTST       Tail of CHPTKTS
019C  412 Signed       4 CHPTKTCT       Corresponding count of files on
                                        CHPTKTS
01A0  416 Signed       4 *              Reserved
01A4  420 Signed       4 CHPENTRY       Current entry in the header
01A8  424 Signed       4 CHPLIMIT       After the last entry in the hdr
01AC  428 Signed       4 CHPLINDX       Index into CCW list of buffers
01B0  432 Signed       4 CHPOFFST       Offset into block where data
                                        should be added
01B4  436 Signed       4 *
01B8  440 Signed       4 CHPPOOLC       Count of pool pages (data pages)
01BC  444 Address      4 CHPPLIST (14)  List of pages locked for this blk
          00000038       CHPPLLEN       *-CHPPLIST Length to clear
          0000000E       CHPPLMAX       14 Maximum number of entries
01F4  500 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
01F8  504 Address      4 CHPNEXT        Next work area in circular queue
     Save area across GOTO I/O request
01FC  508 Signed       4 CHPSAVE (7)    Save R3-R9 across call to IOS.QS
     Channel Program and Header Block copied from TAPBK
0218  536 Dbl-Word     8 CHPPGM (26)    Modeset + hdr + 3*8 (desc + xab +
                                        data)
02E8  744 Dbl-Word     8 CHPHEADR (37)  Block header
     End of CHPBK definition
0410 1040 Dbl-Word     8 CHPRESVD (12)  Round it off
          00000318       CHPLENBY       *-CHPLOCK Extra space (after
                                        IORBK)
          00000470       CHPIOBY        *-CHPBK Whole work area size in
                                        bytes
          0000008E       CHPIODW        CHPIOBY/8 Same in double words
          00000002       CHPBKCNT       2 Number of work areas per drive
     Redefinition for the channel program build area
0218  536 Dbl-Word     8 CHPMSCCW       Modeset, if applicable
0220  544 Address      4 CHPHDCCW       Read/write header CCW
0224  548 Address      4 CHPHCCWA       Address of the CHPHEADR
0228  552 Address      4 CHPCCW1        First general CCW
022C  556 Address      4 CHPCCW1A       Address section for deblocking
0230  560 Dbl-Word     8 CHPCCWS (20)   File write CCWs - desc, XAB, data
                                        Or read CCW's - up to 8 pages
          000000B8       CHPPGMLN       *-CHPPGM Must match size defined
                                        above
     Redefinition for the tape block header section
02E8  744 Character    4 CHPBLKID       Generally 'XHDR', could be 'TRLR'
02EC  748 Signed       4 CHPBLKSZ       Size of this block in bytes
02F0  752 Dbl-Word     8 CHPTIME        Time stamp
     Definition of an individual entry
02F8  760 Dbl-Word     8 CHPHDENT (0)   Start of the first entry
02F8  760 Character    8 CHPOWNER       File owner
0300  768 Signed       4 CHPFSEQ        File sequence number for drive
0304  772 Signed       4 CHPSYSID       System spool file ID when dumped
0308  776 Signed       2 CHPSPID        User spool file ID when dumped
030A  778 Bitstring    1 CHPHDFLG       Flags describing file section
030B  779 Bitstring    1 *
030C  780 Signed       4 CHPMAPCT       Count of map pages needed for
                                        file
0310  784 Signed       4 CHPPAGNO       Starting relative page number
0314  788 Signed       2 CHPPAGCT       Count of data pages in block
0316  790 Signed       2 CHPXABSZ       Size of XAB section in block
0318  792 Signed       2 CHPTKOFF       Offset to ticket - file
                                        descriptor
031A  794 Signed       2 CHPXAOFF       Offset to extended attributes buf
031C  796 Signed       2 CHPDPOFF       Offset to data pages
031E  798 Signed       2 *

 

CHPBK Storage Layout

          
*** CHPBK - SPXTAPE Channel Program Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       CHPIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 158 |                                                       |
*     =                       CHPLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
* 170 |         CHPCURTK          |         CHPCMSSQ          |
*     +---------------------------+---------------------------+
* 178 |         CHPCMCUR          |         CHPCURHD          |
*     +---------------------------+---------------------------+
* 180 |         CHPCMXAB          |         CHPLSTCW          |
*     +---------------------------+---------------------------+
* 188 |         CHPLLPTR          |         CHPLSTHD          |
*     +---------------------------+---------------------------+
* 190 |         CHPLBLKZ          |                           |
*     +---------------------------+                           |
*     |                       CHPTKTS                         |
*     |                           +---------------------------+
*     |                           | 1A4
*     +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
          
*** Overlay for CHPTKTS in CHPBK
*
*                                 +---------------------------+
* 190 ...                     194 |         CHPTKTSH          |
*     +---------------------------+---------------------------+
* 198 |         CHPTKTST          |         CHPTKTCT          |
*     +---------------------------+---------------------------+
* 1A0 |///////////////////////////|         CHPENTRY          |
*     +---------------------------+---------------------------+
* 1A8 |         CHPLIMIT          |         CHPLINDX          |
*     +---------------------------+---------------------------+
* 1B0 |         CHPOFFST          |///////////////////////////|
*     +---------------------------+---------------------------+
* 1B8 |         CHPPOOLC          |                           |
*     +---------------------------+                           |
* 1C0 |                                                       |
*     =                       CHPPLIST                        =
*     |                           +---------------------------+
* 1F0 |                           |///////////////////////////|
*     +---------------------------+---------------------------+
* 1F8 |         CHPNEXT           |                           |
*     +---------------------------+                           |
* 200 |                                                       |
*     =                       CHPSAVE                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 218 |                                                       |
*     =                        CHPPGM                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 2E8 |                                                       |
*     =                       CHPHEADR                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 410 |                                                       |
*     =                       CHPRESVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 470
*
*** Overlay for CHPTKTS in CHPBK
          
*** Overlay for CHPPGM in CHPBK
*
*     +-------------------------------------------------------+
* 218 |                       CHPMSCCW                        |
*     +---------------------------+---------------------------+
* 220 |         CHPHDCCW          |         CHPHCCWA          |
*     +---------------------------+---------------------------+
* 228 |         CHPCCW1           |         CHPCCW1A          |
*     +---------------------------+---------------------------+
* 230 |                                                       |
*     =                       CHPCCWS                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 2D0
*
*** Overlay for CHPPGM in CHPBK
          
*** Overlay for CHPHEADR in CHPBK
*
*     +---------------------------+---------------------------+
* 2E8 |         CHPBLKID          |         CHPBLKSZ          |
*     +---------------------------+---------------------------+
* 2F0 |                       CHPTIME                         |
*     +-------------------------------------------------------+
* 2F8 |                       CHPOWNER                        |
*     +---------------------------+---------------------------+
* 300 |         CHPFSEQ           |         CHPSYSID          |
*     +-------------+------+------+---------------------------+
* 308 |  CHPSPID    |:HDFLG|//////|         CHPMAPCT          |
*     +-------------+------+------+-------------+-------------+
* 310 |         CHPPAGNO          |  CHPPAGCT   |  CHPXABSZ   |
*     +-------------+-------------+-------------+-------------+
* 318 |  CHPTKOFF   |  CHPXAOFF   |  CHPDPOFF   |/////////////|
*     +-------------+-------------+-------------+-------------+
* 320
*
*** Overlay for CHPHEADR in CHPBK

 

CHPBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
CHPBKCNT       0410 00000002
CHPBLKID       02E8
CHPBLKSZ       02EC
CHPCCWS        0230
CHPCCW1        0228
CHPCCW1A       022C
CHPCMCLR       0170
CHPCMCRL       01F4 00000088
CHPCMCUR       0178
CHPCMSSQ       0174
CHPCMXAB       0180
CHPCURHD       017C
CHPCURTK       0170
CHPDPOFF       031C
CHPENTRY       01A4
CHPFSEQ        0300
CHPHCCWA       0224
CHPHDCCW       0220
CHPHDENT       02F8
CHPHDFLG       030A
CHPHEADR       02E8
CHPIOBY        0410 00000470
CHPIODW        0410 0000008E
CHPIORBK       0000
CHPLBLKZ       0190
CHPLENBY       0410 00000318
CHPLIMIT       01A8
CHPLINDX       01AC
CHPLLPTR       0188
CHPLOCK        0158
CHPLSTCW       0184
CHPLSTHD       018C
CHPMAPCT       030C
CHPMSCCW       0218
CHPNEXT        01F8
CHPOFFST       01B0
CHPOWNER       02F8
CHPPAGCT       0314
CHPPAGNO       0310
CHPPGM         0218
CHPPGMLN       0230 000000B8
CHPPLIST       01BC
CHPPLLEN       01BC 00000038
CHPPLMAX       01BC 0000000E
CHPPOOLC       01B8
CHPRESVD       0410
CHPSAVE        01FC
CHPSPID        0308
CHPSYSID       0304
CHPTIME        02F0
CHPTKOFF       0318
CHPTKTCT       019C
CHPTKTS        0194
CHPTKTSH       0194
CHPTKTST       0198
CHPXABSZ       0316
CHPXAOFF       031A

This information is based on z/VM V4R2.0. Last updated on 17 Oct 2001 at 14:51:57 EDT.
Copyright IBM Corporation, 1990, 2001