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 (73) Base IORBK region Lock for this IORBK and CHPBK work area 0248 584 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. 0260 608 Signed 2 CHPCMCLR (0) Beginning of area to be cleared before reuse for trailer 0260 608 Address 4 CHPCURTK Last ticket contained in current block 0264 612 Address 4 CHPCMSSQ Last SSQBK 0268 616 Address 4 CHPCMCUR Address of next Vpage slot in last SSQBK 026C 620 Signed 4 CHPCURHD Displacement in header of cur hdr 0270 624 Signed 4 CHPCMXAB Amt of XAB data associated with last tkt remaining to be written 0274 628 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 0278 632 Signed 4 CHPLLPTR Last offset in page list +1 used 027C 636 Address 4 CHPLSTHD Hdr addr for last completed file 0280 640 Signed 4 CHPLBLKZ Save last block size at last complete file/tkt in this block. Counters, etc. 0284 644 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 0284 644 Address 4 CHPTKTSH Head of CHPTKTS 0288 648 Address 4 CHPTKTST Tail of CHPTKTS 028C 652 Signed 4 CHPTKTCT Corresponding count of files on CHPTKTS 0290 656 Signed 4 * Reserved 0294 660 Signed 4 CHPENTRY Current entry in the header 0298 664 Signed 4 CHPLIMIT After the last entry in the hdr 029C 668 Signed 4 CHPLINDX Index into CCW list of buffers 02A0 672 Signed 4 CHPOFFST Offset into block where data should be added 02A4 676 Signed 4 * 02A8 680 Signed 4 CHPPOOLC Count of pool pages (data pages) 02AC 684 Address 4 CHPPLIST (14) List of pages locked for this blk 00000038 CHPPLLEN *-CHPPLIST Length to clear 0000000E CHPPLMAX 14 Maximum number of entries 02E4 740 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 02E8 744 Address 4 CHPNEXT Next work area in circular queue Save area across GOTO I/O request 02EC 748 Signed 4 CHPSAVE (7) Save R3-R9 across call to IOS.QS Channel Program and Header Block copied from TAPBK 0308 776 Dbl-Word 8 CHPPGM (26) Modeset + hdr + 3*8 (desc + xab + data) 03D8 984 Dbl-Word 8 CHPHEADR (37) Block header Pointers 0500 1280 Signed 4 CHPIDAWA IDAW list anchor 0504 1284 Signed 4 CHPIDWNX Next available IDAW slot 0508 1288 Signed 4 CHPBUFHL Host logical buffer addr anchor 050C 1292 Signed 4 * Reserved 00000004 CHPHLLEN 4 Length of CHPBUFHL entries End of CHPBK definition 0510 1296 Dbl-Word 8 CHPRESVD (10) Round it off 00000318 CHPLENBY *-CHPLOCK Extra space (after IORBK) 00000560 CHPIOBY *-CHPBK Whole work area size in bytes 000000AC CHPIODW CHPIOBY/8 Same in double words 00000002 CHPBKCNT 2 Number of work areas per drive Redefinition for the channel program build area 0308 776 Dbl-Word 8 CHPMSCCW Modeset, if applicable 0310 784 Address 4 CHPHDCCW Read/write header CCW 0314 788 Address 4 CHPHCCWA Address of the CHPHEADR 0318 792 Address 4 CHPCCW1 First general CCW 031C 796 Address 4 CHPCCW1A Address section for deblocking 0320 800 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 03D8 984 Character 4 CHPBLKID Generally 'XHDR', could be 'TRLR' 03DC 988 Signed 4 CHPBLKSZ Size of this block in bytes 03E0 992 Dbl-Word 8 CHPTIME Time stamp Definition of an individual entry 03E8 1000 Dbl-Word 8 CHPHDENT (0) Start of the first entry 03E8 1000 Character 8 CHPOWNER File owner 03F0 1008 Signed 4 CHPFSEQ File sequence number for drive 03F4 1012 Signed 4 CHPSYSID System spool file ID when dumped 03F8 1016 Signed 2 CHPSPID User spool file ID when dumped 03FA 1018 Bitstring 1 CHPHDFLG Flags describing file section 03FB 1019 Bitstring 1 * 03FC 1020 Signed 4 CHPMAPCT Count of map pages needed for file 0400 1024 Signed 4 CHPPAGNO Starting relative page number 0404 1028 Signed 2 CHPPAGCT Count of data pages in block 0406 1030 Signed 2 CHPXABSZ Size of XAB section in block 0408 1032 Signed 2 CHPTKOFF Offset to ticket - file descriptor 040A 1034 Signed 2 CHPXAOFF Offset to extended attributes buf 040C 1036 Signed 2 CHPDPOFF Offset to data pages 040E 1038 Signed 2 *
 
 
  CHPBK Storage Layout Top of page
 
          
*** CHPBK - SPXTAPE Channel Program Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       CHPIORBK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 248 |                                                       |
*     =                       CHPLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
* 260 |         CHPCURTK          |         CHPCMSSQ          |
*     +---------------------------+---------------------------+
* 268 |         CHPCMCUR          |         CHPCURHD          |
*     +---------------------------+---------------------------+
* 270 |         CHPCMXAB          |         CHPLSTCW          |
*     +---------------------------+---------------------------+
* 278 |         CHPLLPTR          |         CHPLSTHD          |
*     +---------------------------+---------------------------+
* 280 |         CHPLBLKZ          |                           |
*     +---------------------------+                           |
*     |                       CHPTKTS                         |
*     |                           +---------------------------+
*     |                           | 294
*     +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
          
*** Overlay for CHPTKTS in CHPBK
*
*                                 +---------------------------+
* 280 ...                     284 |         CHPTKTSH          |
*     +---------------------------+---------------------------+
* 288 |         CHPTKTST          |         CHPTKTCT          |
*     +---------------------------+---------------------------+
* 290 |///////////////////////////|         CHPENTRY          |
*     +---------------------------+---------------------------+
* 298 |         CHPLIMIT          |         CHPLINDX          |
*     +---------------------------+---------------------------+
* 2A0 |         CHPOFFST          |///////////////////////////|
*     +---------------------------+---------------------------+
* 2A8 |         CHPPOOLC          |                           |
*     +---------------------------+                           |
* 2B0 |                                                       |
*     =                       CHPPLIST                        =
*     |                           +---------------------------+
* 2E0 |                           |///////////////////////////|
*     +---------------------------+---------------------------+
* 2E8 |         CHPNEXT           |                           |
*     +---------------------------+                           |
* 2F0 |                                                       |
*     =                       CHPSAVE                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 308 |                                                       |
*     =                        CHPPGM                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 3D8 |                                                       |
*     =                       CHPHEADR                        =
*     |                                                       |
*     +---------------------------+---------------------------+
* 500 |         CHPIDAWA          |         CHPIDWNX          |
*     +---------------------------+---------------------------+
* 508 |         CHPBUFHL          |///////////////////////////|
*     +---------------------------+---------------------------+
* 510 |                                                       |
*     =                       CHPRESVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 560
*
*** Overlay for CHPTKTS in CHPBK
          
*** Overlay for CHPPGM in CHPBK
*
*     +-------------------------------------------------------+
* 308 |                       CHPMSCCW                        |
*     +---------------------------+---------------------------+
* 310 |         CHPHDCCW          |         CHPHCCWA          |
*     +---------------------------+---------------------------+
* 318 |         CHPCCW1           |         CHPCCW1A          |
*     +---------------------------+---------------------------+
* 320 |                                                       |
*     =                       CHPCCWS                         =
*     |                                                       |
*     +-------------------------------------------------------+
* 3C0
*
*** Overlay for CHPPGM in CHPBK
          
*** Overlay for CHPHEADR in CHPBK
*
*     +---------------------------+---------------------------+
* 3D8 |         CHPBLKID          |         CHPBLKSZ          |
*     +---------------------------+---------------------------+
* 3E0 |                       CHPTIME                         |
*     +-------------------------------------------------------+
* 3E8 |                       CHPOWNER                        |
*     +---------------------------+---------------------------+
* 3F0 |         CHPFSEQ           |         CHPSYSID          |
*     +-------------+------+------+---------------------------+
* 3F8 |  CHPSPID    |:HDFLG|//////|         CHPMAPCT          |
*     +-------------+------+------+-------------+-------------+
* 400 |         CHPPAGNO          |  CHPPAGCT   |  CHPXABSZ   |
*     +-------------+-------------+-------------+-------------+
* 408 |  CHPTKOFF   |  CHPXAOFF   |  CHPDPOFF   |/////////////|
*     +-------------+-------------+-------------+-------------+
* 410
*
*** Overlay for CHPHEADR in CHPBK
 
 
  CHPBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
CHPBKCNT       0510 00000002
CHPBLKID       03D8
CHPBLKSZ       03DC
CHPBUFHL       0508
CHPCCWCT       0320 00000015
CHPCCWS        0320
CHPCCW1        0318
CHPCCW1A       031C
CHPCMCLR       0260
CHPCMCRL       02E4 00000088
CHPCMCUR       0268
CHPCMSSQ       0264
CHPCMXAB       0270
CHPCURHD       026C
CHPCURTK       0260
CHPDPOFF       040C
CHPENTRY       0294
CHPFSEQ        03F0
CHPHCCWA       0314
CHPHDCCW       0310
CHPHDENT       03E8
CHPHDFLG       03FA
CHPHEADR       03D8
CHPHLLEN       050C 00000004
CHPIDAWA       0500
CHPIDWNX       0504
CHPIOBY        0510 00000560
CHPIODW        0510 000000AC
CHPIORBK       0000
CHPLBLKZ       0280
CHPLENBY       0510 00000318
CHPLIMIT       0298
CHPLINDX       029C
CHPLLPTR       0278
CHPLOCK        0248
CHPLSTCW       0274
CHPLSTHD       027C
CHPMAPCT       03FC
CHPMSCCW       0308
CHPNEXT        02E8
CHPOFFST       02A0
CHPOWNER       03E8
CHPPAGCT       0404
CHPPAGNO       0400
CHPPGM         0308
CHPPGMLN       0320 000000B8
CHPPLIST       02AC
CHPPLLEN       02AC 00000038
CHPPLMAX       02AC 0000000E
CHPPOOLC       02A8
CHPRESVD       0510
CHPSAVE        02EC
CHPSPID        03F8
CHPSYSID       03F4
CHPTIME        03E0
CHPTKOFF       0408
CHPTKTCT       028C
CHPTKTS        0284
CHPTKTSH       0284
CHPTKTST       0288
CHPXABSZ       0406
CHPXAOFF       040A
 
This information is based on z/VM 6.3.0 Last updated on 22 May 2013 at 13:54:00 EDT.
Copyright IBM Corporation, 1990, 2013