CHPBK Back to Index page
 
Prolog 
Control Block Contents 
   CHPBK 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.


  CHPBK Prolog Top of page
 
 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
 RELOCATION CONSIDERATIONS : None
 
 
  CHPBK Control Block Content Top of page
 

 CHPBK DSECT Top of page
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 (83) Base IORBK region Lock for this IORBK and CHPBK work area 0298 664 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. 02B0 688 Signed 2 CHPCMCLR (0) Beginning of area to be cleared before reuse for trailer 02B0 688 Address 4 CHPCURTK Last ticket contained in current block 02B4 692 Address 4 CHPCMSSQ Last SSQBK 02B8 696 Address 4 CHPCMCUR Address of next Vpage slot in last SSQBK 02BC 700 Signed 4 CHPCURHD Displacement in header of cur hdr 02C0 704 Signed 4 CHPCMXAB Amt of XAB data associated with last tkt remaining to be written 02C4 708 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 02C8 712 Signed 4 CHPLLPTR Last offset in page list +1 used 02CC 716 Address 4 CHPLSTHD Hdr addr for last completed file 02D0 720 Signed 4 CHPLBLKZ Save last block size at last complete file/tkt in this block. Counters, etc. 02D4 724 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 02D4 724 Address 4 CHPTKTSH Head of CHPTKTS 02D8 728 Address 4 CHPTKTST Tail of CHPTKTS 02DC 732 Signed 4 CHPTKTCT Corresponding count of files on CHPTKTS 02E0 736 Signed 4 * Reserved 02E4 740 Signed 4 CHPENTRY Current entry in the header 02E8 744 Signed 4 CHPLIMIT After the last entry in the hdr 02EC 748 Signed 4 CHPLINDX Index into CCW list of buffers 02F0 752 Signed 4 CHPOFFST Offset into block where data should be added 02F4 756 Signed 4 * 02F8 760 Signed 4 CHPPOOLC Count of pool pages (data pages) 02FC 764 Address 4 CHPPLIST (14) List of pages locked for this blk 00000038 CHPPLLEN *-CHPPLIST Length to clear 0000000E CHPPLMAX 14 Maximum number of entries 0334 820 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 0338 824 Address 4 CHPNEXT Next work area in circular queue Save area across GOTO I/O request 033C 828 Signed 4 CHPSAVE (7) Save R3-R9 across call to IOS.QS Channel Program and Header Block copied from TAPBK 0358 856 Dbl-Word 8 CHPPGM (26) Modeset + hdr + 3*8 (desc + xab + data) 0428 1064 Dbl-Word 8 CHPHEADR (37) Block header Pointers 0550 1360 Signed 4 CHPIDAWA IDAW list anchor 0554 1364 Signed 4 CHPIDWNX Next available IDAW slot 0558 1368 Signed 4 CHPBUFHL Host logical buffer addr anchor 055C 1372 Signed 4 * Reserved 00000004 CHPHLLEN 4 Length of CHPBUFHL entries End of CHPBK definition 0560 1376 Dbl-Word 8 CHPRESVD (10) Round it off 00000318 CHPLENBY *-CHPLOCK Extra space (after IORBK) 000005B0 CHPIOBY *-CHPBK Whole work area size in bytes 000000B6 CHPIODW CHPIOBY/8 Same in double words 00000002 CHPBKCNT 2 Number of work areas per drive Redefinition for the channel program build area 0358 856 Dbl-Word 8 CHPMSCCW Modeset, if applicable 0360 864 Address 4 CHPHDCCW Read/write header CCW 0364 868 Address 4 CHPHCCWA Address of the CHPHEADR 0368 872 Address 4 CHPCCW1 First general CCW 036C 876 Address 4 CHPCCW1A Address section for deblocking 0370 880 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 0428 1064 Character 4 CHPBLKID Generally 'XHDR', could be 'TRLR' 042C 1068 Signed 4 CHPBLKSZ Size of this block in bytes 0430 1072 Dbl-Word 8 CHPTIME Time stamp Definition of an individual entry 0438 1080 Dbl-Word 8 CHPHDENT (0) Start of the first entry 0438 1080 Character 8 CHPOWNER File owner 0440 1088 Signed 4 CHPFSEQ File sequence number for drive 0444 1092 Signed 4 CHPSYSID System spool file ID when dumped 0448 1096 Signed 2 CHPSPID User spool file ID when dumped 044A 1098 Bitstring 1 CHPHDFLG Flags describing file section 044B 1099 Bitstring 1 * 044C 1100 Signed 4 CHPMAPCT Count of map pages needed for file 0450 1104 Signed 4 CHPPAGNO Starting relative page number 0454 1108 Signed 2 CHPPAGCT Count of data pages in block 0456 1110 Signed 2 CHPXABSZ Size of XAB section in block 0458 1112 Signed 2 CHPTKOFF Offset to ticket - file descriptor 045A 1114 Signed 2 CHPXAOFF Offset to extended attributes buf 045C 1116 Signed 2 CHPDPOFF Offset to data pages 045E 1118 Signed 2 *
 
 
  CHPBK Storage Layout Top of page
 
          
*** CHPBK - SPXTAPE Channel Program Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       CHPIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 298 |                                                       |
*     =                       CHPLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
* 2B0 |         CHPCURTK          |         CHPCMSSQ          |
*     +---------------------------+---------------------------+
* 2B8 |         CHPCMCUR          |         CHPCURHD          |
*     +---------------------------+---------------------------+
* 2C0 |         CHPCMXAB          |         CHPLSTCW          |
*     +---------------------------+---------------------------+
* 2C8 |         CHPLLPTR          |         CHPLSTHD          |
*     +---------------------------+---------------------------+
* 2D0 |         CHPLBLKZ          |                           |
*     +---------------------------+                           |
*     |                       CHPTKTS                         |
*     |                           +---------------------------+
*     |                           | 2E4
*     +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
          
*** Overlay for CHPTKTS in CHPBK
*
*                                 +---------------------------+
* 2D0 ...                     2D4 |         CHPTKTSH          |
*     +---------------------------+---------------------------+
* 2D8 |         CHPTKTST          |         CHPTKTCT          |
*     +---------------------------+---------------------------+
* 2E0 |///////////////////////////|         CHPENTRY          |
*     +---------------------------+---------------------------+
* 2E8 |         CHPLIMIT          |         CHPLINDX          |
*     +---------------------------+---------------------------+
* 2F0 |         CHPOFFST          |///////////////////////////|
*     +---------------------------+---------------------------+
* 2F8 |         CHPPOOLC          |                           |
*     +---------------------------+                           |
* 300 |                                                       |
*     =                       CHPPLIST                        =
*     |                           +---------------------------+
* 330 |                           |///////////////////////////|
*     +---------------------------+---------------------------+
* 338 |         CHPNEXT           |                           |
*     +---------------------------+                           |
* 340 |                                                       |
*     =                       CHPSAVE                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 358 |                                                       |
*     =                        CHPPGM                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 428 |                                                       |
*     =                       CHPHEADR                        =
*     |                                                       |
*     +---------------------------+---------------------------+
* 550 |         CHPIDAWA          |         CHPIDWNX          |
*     +---------------------------+---------------------------+
* 558 |         CHPBUFHL          |///////////////////////////|
*     +---------------------------+---------------------------+
* 560 |                                                       |
*     =                       CHPRESVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 5B0
*
*** Overlay for CHPTKTS in CHPBK
          
*** Overlay for CHPPGM in CHPBK
*
*     +-------------------------------------------------------+
* 358 |                       CHPMSCCW                        |
*     +---------------------------+---------------------------+
* 360 |         CHPHDCCW          |         CHPHCCWA          |
*     +---------------------------+---------------------------+
* 368 |         CHPCCW1           |         CHPCCW1A          |
*     +---------------------------+---------------------------+
* 370 |                                                       |
*     =                       CHPCCWS                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 410
*
*** Overlay for CHPPGM in CHPBK
          
*** Overlay for CHPHEADR in CHPBK
*
*     +---------------------------+---------------------------+
* 428 |         CHPBLKID          |         CHPBLKSZ          |
*     +---------------------------+---------------------------+
* 430 |                       CHPTIME                         |
*     +-------------------------------------------------------+
* 438 |                       CHPOWNER                        |
*     +---------------------------+---------------------------+
* 440 |         CHPFSEQ           |         CHPSYSID          |
*     +-------------+------+------+---------------------------+
* 448 |  CHPSPID    |:HDFLG|//////|         CHPMAPCT          |
*     +-------------+------+------+-------------+-------------+
* 450 |         CHPPAGNO          |  CHPPAGCT   |  CHPXABSZ   |
*     +-------------+-------------+-------------+-------------+
* 458 |  CHPTKOFF   |  CHPXAOFF   |  CHPDPOFF   |/////////////|
*     +-------------+-------------+-------------+-------------+
* 460
*
*** Overlay for CHPHEADR in CHPBK
 
 
  CHPBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
CHPBKCNT       0560 00000002
CHPBLKID       0428
CHPBLKSZ       042C
CHPBUFHL       0558
CHPCCWCT       0370 00000015
CHPCCWS        0370
CHPCCW1        0368
CHPCCW1A       036C
CHPCMCLR       02B0
CHPCMCRL       0334 00000088
CHPCMCUR       02B8
CHPCMSSQ       02B4
CHPCMXAB       02C0
CHPCURHD       02BC
CHPCURTK       02B0
CHPDPOFF       045C
CHPENTRY       02E4
CHPFSEQ        0440
CHPHCCWA       0364
CHPHDCCW       0360
CHPHDENT       0438
CHPHDFLG       044A
CHPHEADR       0428
CHPHLLEN       055C 00000004
CHPIDAWA       0550
CHPIDWNX       0554
CHPIOBY        0560 000005B0
CHPIODW        0560 000000B6
CHPIORBK       0000
CHPLBLKZ       02D0
CHPLENBY       0560 00000318
CHPLIMIT       02E8
CHPLINDX       02EC
CHPLLPTR       02C8
CHPLOCK        0298
CHPLSTCW       02C4
CHPLSTHD       02CC
CHPMAPCT       044C
CHPMSCCW       0358
CHPNEXT        0338
CHPOFFST       02F0
CHPOWNER       0438
CHPPAGCT       0454
CHPPAGNO       0450
CHPPGM         0358
CHPPGMLN       0370 000000B8
CHPPLIST       02FC
CHPPLLEN       02FC 00000038
CHPPLMAX       02FC 0000000E
CHPPOOLC       02F8
CHPRESVD       0560
CHPSAVE        033C
CHPSPID        0448
CHPSYSID       0444
CHPTIME        0430
CHPTKOFF       0458
CHPTKTCT       02DC
CHPTKTS        02D4
CHPTKTSH       02D4
CHPTKTST       02D8
CHPXABSZ       0456
CHPXAOFF       045A
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:48:03 EDT.
Copyright IBM Corporation, 1990, 2022