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 (65)  Base IORBK region
        Lock for this IORBK and CHPBK work area
0208  520 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.
0220  544 Signed       2 CHPCMCLR (0)   Beginning of area to be cleared
                                        before reuse for trailer
0220  544 Address      4 CHPCURTK       Last ticket contained in current
                                        block
0224  548 Address      4 CHPCMSSQ       Last SSQBK
0228  552 Address      4 CHPCMCUR       Address of next Vpage slot in
                                        last SSQBK
022C  556 Signed       4 CHPCURHD       Displacement in header of cur hdr
0230  560 Signed       4 CHPCMXAB       Amt of XAB data associated with
                                        last tkt remaining to be written
0234  564 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
0238  568 Signed       4 CHPLLPTR       Last offset in page list +1 used
023C  572 Address      4 CHPLSTHD       Hdr addr for last completed file
0240  576 Signed       4 CHPLBLKZ       Save last block size at last
                                        complete file/tkt in this block.
        Counters, etc.
0244  580 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
0244  580 Address      4 CHPTKTSH       Head of CHPTKTS
0248  584 Address      4 CHPTKTST       Tail of CHPTKTS
024C  588 Signed       4 CHPTKTCT       Corresponding count of files on
                                        CHPTKTS
0250  592 Signed       4 *              Reserved
0254  596 Signed       4 CHPENTRY       Current entry in the header
0258  600 Signed       4 CHPLIMIT       After the last entry in the hdr
025C  604 Signed       4 CHPLINDX       Index into CCW list of buffers
0260  608 Signed       4 CHPOFFST       Offset into block where data
                                        should be added
0264  612 Signed       4 *
0268  616 Signed       4 CHPPOOLC       Count of pool pages (data pages)
026C  620 Address      4 CHPPLIST (14)  List of pages locked for this blk
          00000038       CHPPLLEN       *-CHPPLIST Length to clear
          0000000E       CHPPLMAX       14 Maximum number of entries
02A4  676 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
02A8  680 Address      4 CHPNEXT        Next work area in circular queue
        Save area across GOTO I/O request
02AC  684 Signed       4 CHPSAVE (7)    Save R3-R9 across call to IOS.QS
        Channel Program and Header Block copied from TAPBK
02C8  712 Dbl-Word     8 CHPPGM (26)    Modeset + hdr + 3*8 (desc + xab +
                                        data)
0398  920 Dbl-Word     8 CHPHEADR (37)  Block header
        Pointers
04C0 1216 Signed       4 CHPIDAWA       IDAW list anchor
04C4 1220 Signed       4 CHPIDWNX       Next available IDAW slot
04C8 1224 Signed       4 CHPBUFHL       Host logical buffer addr anchor
04CC 1228 Signed       4 *              Reserved
          00000004       CHPHLLEN       4 Length of CHPBUFHL entries
        End of CHPBK definition
04D0 1232 Dbl-Word     8 CHPRESVD (10)  Round it off
          00000318       CHPLENBY       *-CHPLOCK Extra space (after
                                        IORBK)
          00000520       CHPIOBY        *-CHPBK Whole work area size in
                                        bytes
          000000A4       CHPIODW        CHPIOBY/8 Same in double words
          00000002       CHPBKCNT       2 Number of work areas per drive
        Redefinition for the channel program build area
02C8  712 Dbl-Word     8 CHPMSCCW       Modeset, if applicable
02D0  720 Address      4 CHPHDCCW       Read/write header CCW
02D4  724 Address      4 CHPHCCWA       Address of the CHPHEADR
02D8  728 Address      4 CHPCCW1        First general CCW
02DC  732 Address      4 CHPCCW1A       Address section for deblocking
02E0  736 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
0398  920 Character    4 CHPBLKID       Generally 'XHDR', could be 'TRLR'
039C  924 Signed       4 CHPBLKSZ       Size of this block in bytes
03A0  928 Dbl-Word     8 CHPTIME        Time stamp
        Definition of an individual entry
03A8  936 Dbl-Word     8 CHPHDENT (0)   Start of the first entry
03A8  936 Character    8 CHPOWNER       File owner
03B0  944 Signed       4 CHPFSEQ        File sequence number for drive
03B4  948 Signed       4 CHPSYSID       System spool file ID when dumped
03B8  952 Signed       2 CHPSPID        User spool file ID when dumped
03BA  954 Bitstring    1 CHPHDFLG       Flags describing file section
03BB  955 Bitstring    1 *
03BC  956 Signed       4 CHPMAPCT       Count of map pages needed for
                                        file
03C0  960 Signed       4 CHPPAGNO       Starting relative page number
03C4  964 Signed       2 CHPPAGCT       Count of data pages in block
03C6  966 Signed       2 CHPXABSZ       Size of XAB section in block
03C8  968 Signed       2 CHPTKOFF       Offset to ticket - file
                                        descriptor
03CA  970 Signed       2 CHPXAOFF       Offset to extended attributes buf
03CC  972 Signed       2 CHPDPOFF       Offset to data pages
03CE  974 Signed       2 *

 

CHPBK Storage Layout

          
*** CHPBK - SPXTAPE Channel Program Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       CHPIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 208 |                                                       |
*     =                       CHPLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
* 220 |         CHPCURTK          |         CHPCMSSQ          |
*     +---------------------------+---------------------------+
* 228 |         CHPCMCUR          |         CHPCURHD          |
*     +---------------------------+---------------------------+
* 230 |         CHPCMXAB          |         CHPLSTCW          |
*     +---------------------------+---------------------------+
* 238 |         CHPLLPTR          |         CHPLSTHD          |
*     +---------------------------+---------------------------+
* 240 |         CHPLBLKZ          |                           |
*     +---------------------------+                           |
*     |                       CHPTKTS                         |
*     |                           +---------------------------+
*     |                           | 254
*     +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
          
*** Overlay for CHPTKTS in CHPBK
*
*                                 +---------------------------+
* 240 ...                     244 |         CHPTKTSH          |
*     +---------------------------+---------------------------+
* 248 |         CHPTKTST          |         CHPTKTCT          |
*     +---------------------------+---------------------------+
* 250 |///////////////////////////|         CHPENTRY          |
*     +---------------------------+---------------------------+
* 258 |         CHPLIMIT          |         CHPLINDX          |
*     +---------------------------+---------------------------+
* 260 |         CHPOFFST          |///////////////////////////|
*     +---------------------------+---------------------------+
* 268 |         CHPPOOLC          |                           |
*     +---------------------------+                           |
* 270 |                                                       |
*     =                       CHPPLIST                        =
*     |                           +---------------------------+
* 2A0 |                           |///////////////////////////|
*     +---------------------------+---------------------------+
* 2A8 |         CHPNEXT           |                           |
*     +---------------------------+                           |
* 2B0 |                                                       |
*     =                       CHPSAVE                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 2C8 |                                                       |
*     =                        CHPPGM                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 398 |                                                       |
*     =                       CHPHEADR                        =
*     |                                                       |
*     +---------------------------+---------------------------+
* 4C0 |         CHPIDAWA          |         CHPIDWNX          |
*     +---------------------------+---------------------------+
* 4C8 |         CHPBUFHL          |///////////////////////////|
*     +---------------------------+---------------------------+
* 4D0 |                                                       |
*     =                       CHPRESVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 520
*
*** Overlay for CHPTKTS in CHPBK
          
*** Overlay for CHPPGM in CHPBK
*
*     +-------------------------------------------------------+
* 2C8 |                       CHPMSCCW                        |
*     +---------------------------+---------------------------+
* 2D0 |         CHPHDCCW          |         CHPHCCWA          |
*     +---------------------------+---------------------------+
* 2D8 |         CHPCCW1           |         CHPCCW1A          |
*     +---------------------------+---------------------------+
* 2E0 |                                                       |
*     =                       CHPCCWS                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 380
*
*** Overlay for CHPPGM in CHPBK
          
*** Overlay for CHPHEADR in CHPBK
*
*     +---------------------------+---------------------------+
* 398 |         CHPBLKID          |         CHPBLKSZ          |
*     +---------------------------+---------------------------+
* 3A0 |                       CHPTIME                         |
*     +-------------------------------------------------------+
* 3A8 |                       CHPOWNER                        |
*     +---------------------------+---------------------------+
* 3B0 |         CHPFSEQ           |         CHPSYSID          |
*     +-------------+------+------+---------------------------+
* 3B8 |  CHPSPID    |:HDFLG|//////|         CHPMAPCT          |
*     +-------------+------+------+-------------+-------------+
* 3C0 |         CHPPAGNO          |  CHPPAGCT   |  CHPXABSZ   |
*     +-------------+-------------+-------------+-------------+
* 3C8 |  CHPTKOFF   |  CHPXAOFF   |  CHPDPOFF   |/////////////|
*     +-------------+-------------+-------------+-------------+
* 3D0
*
*** Overlay for CHPHEADR in CHPBK

 

CHPBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
CHPBKCNT       04D0 00000002
CHPBLKID       0398
CHPBLKSZ       039C
CHPBUFHL       04C8
CHPCCWCT       02E0 00000015
CHPCCWS        02E0
CHPCCW1        02D8
CHPCCW1A       02DC
CHPCMCLR       0220
CHPCMCRL       02A4 00000088
CHPCMCUR       0228
CHPCMSSQ       0224
CHPCMXAB       0230
CHPCURHD       022C
CHPCURTK       0220
CHPDPOFF       03CC
CHPENTRY       0254
CHPFSEQ        03B0
CHPHCCWA       02D4
CHPHDCCW       02D0
CHPHDENT       03A8
CHPHDFLG       03BA
CHPHEADR       0398
CHPHLLEN       04CC 00000004
CHPIDAWA       04C0
CHPIDWNX       04C4
CHPIOBY        04D0 00000520
CHPIODW        04D0 000000A4
CHPIORBK       0000
CHPLBLKZ       0240
CHPLENBY       04D0 00000318
CHPLIMIT       0258
CHPLINDX       025C
CHPLLPTR       0238
CHPLOCK        0208
CHPLSTCW       0234
CHPLSTHD       023C
CHPMAPCT       03BC
CHPMSCCW       02C8
CHPNEXT        02A8
CHPOFFST       0260
CHPOWNER       03A8
CHPPAGCT       03C4
CHPPAGNO       03C0
CHPPGM         02C8
CHPPGMLN       02E0 000000B8
CHPPLIST       026C
CHPPLLEN       026C 00000038
CHPPLMAX       026C 0000000E
CHPPOOLC       0268
CHPRESVD       04D0
CHPSAVE        02AC
CHPSPID        03B8
CHPSYSID       03B4
CHPTIME        03A0
CHPTKOFF       03C8
CHPTKTCT       024C
CHPTKTS        0244
CHPTKTSH       0244
CHPTKTST       0248
CHPXABSZ       03C6
CHPXAOFF       03CA

This information is based on z/VM V5R4.0. Last updated on 18 Feb 2010 at 03:30:07 EDT.
Copyright IBM Corporation, 1990, 2009