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Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM. |
CHPBK
Control Block Contents
CHPBK DSECT
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
Last updated on 6 Jun 2001 at 11:14:27 EDT.
Copyright IBM Corporation, 1990, 2001