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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
RELOCATION CONSIDERATIONS : None
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 (67) Base IORBK region
Lock for this IORBK and CHPBK work area
0218 536 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.
0230 560 Signed 2 CHPCMCLR (0) Beginning of area to be cleared
before reuse for trailer
0230 560 Address 4 CHPCURTK Last ticket contained in current
block
0234 564 Address 4 CHPCMSSQ Last SSQBK
0238 568 Address 4 CHPCMCUR Address of next Vpage slot in
last SSQBK
023C 572 Signed 4 CHPCURHD Displacement in header of cur hdr
0240 576 Signed 4 CHPCMXAB Amt of XAB data associated with
last tkt remaining to be written
0244 580 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
0248 584 Signed 4 CHPLLPTR Last offset in page list +1 used
024C 588 Address 4 CHPLSTHD Hdr addr for last completed file
0250 592 Signed 4 CHPLBLKZ Save last block size at last
complete file/tkt in this block.
Counters, etc.
0254 596 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
0254 596 Address 4 CHPTKTSH Head of CHPTKTS
0258 600 Address 4 CHPTKTST Tail of CHPTKTS
025C 604 Signed 4 CHPTKTCT Corresponding count of files on
CHPTKTS
0260 608 Signed 4 * Reserved
0264 612 Signed 4 CHPENTRY Current entry in the header
0268 616 Signed 4 CHPLIMIT After the last entry in the hdr
026C 620 Signed 4 CHPLINDX Index into CCW list of buffers
0270 624 Signed 4 CHPOFFST Offset into block where data
should be added
0274 628 Signed 4 *
0278 632 Signed 4 CHPPOOLC Count of pool pages (data pages)
027C 636 Address 4 CHPPLIST (14) List of pages locked for this blk
00000038 CHPPLLEN *-CHPPLIST Length to clear
0000000E CHPPLMAX 14 Maximum number of entries
02B4 692 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
02B8 696 Address 4 CHPNEXT Next work area in circular queue
Save area across GOTO I/O request
02BC 700 Signed 4 CHPSAVE (7) Save R3-R9 across call to IOS.QS
Channel Program and Header Block copied from TAPBK
02D8 728 Dbl-Word 8 CHPPGM (26) Modeset + hdr + 3*8 (desc + xab +
data)
03A8 936 Dbl-Word 8 CHPHEADR (37) Block header
Pointers
04D0 1232 Signed 4 CHPIDAWA IDAW list anchor
04D4 1236 Signed 4 CHPIDWNX Next available IDAW slot
04D8 1240 Signed 4 CHPBUFHL Host logical buffer addr anchor
04DC 1244 Signed 4 * Reserved
00000004 CHPHLLEN 4 Length of CHPBUFHL entries
End of CHPBK definition
04E0 1248 Dbl-Word 8 CHPRESVD (10) Round it off
00000318 CHPLENBY *-CHPLOCK Extra space (after
IORBK)
00000530 CHPIOBY *-CHPBK Whole work area size in
bytes
000000A6 CHPIODW CHPIOBY/8 Same in double words
00000002 CHPBKCNT 2 Number of work areas per drive
Redefinition for the channel program build area
02D8 728 Dbl-Word 8 CHPMSCCW Modeset, if applicable
02E0 736 Address 4 CHPHDCCW Read/write header CCW
02E4 740 Address 4 CHPHCCWA Address of the CHPHEADR
02E8 744 Address 4 CHPCCW1 First general CCW
02EC 748 Address 4 CHPCCW1A Address section for deblocking
02F0 752 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
03A8 936 Character 4 CHPBLKID Generally 'XHDR', could be 'TRLR'
03AC 940 Signed 4 CHPBLKSZ Size of this block in bytes
03B0 944 Dbl-Word 8 CHPTIME Time stamp
Definition of an individual entry
03B8 952 Dbl-Word 8 CHPHDENT (0) Start of the first entry
03B8 952 Character 8 CHPOWNER File owner
03C0 960 Signed 4 CHPFSEQ File sequence number for drive
03C4 964 Signed 4 CHPSYSID System spool file ID when dumped
03C8 968 Signed 2 CHPSPID User spool file ID when dumped
03CA 970 Bitstring 1 CHPHDFLG Flags describing file section
03CB 971 Bitstring 1 *
03CC 972 Signed 4 CHPMAPCT Count of map pages needed for
file
03D0 976 Signed 4 CHPPAGNO Starting relative page number
03D4 980 Signed 2 CHPPAGCT Count of data pages in block
03D6 982 Signed 2 CHPXABSZ Size of XAB section in block
03D8 984 Signed 2 CHPTKOFF Offset to ticket - file
descriptor
03DA 986 Signed 2 CHPXAOFF Offset to extended attributes buf
03DC 988 Signed 2 CHPDPOFF Offset to data pages
03DE 990 Signed 2 *
CHPBK Storage Layout
*** CHPBK - SPXTAPE Channel Program Block
*
* +-------------------------------------------------------+
* 0 | |
* = CHPIORBK =
* | |
* +-------------------------------------------------------+
* 218 | |
* = CHPLOCK =
* | |
* +---------------------------+---------------------------+
* 230 | CHPCURTK | CHPCMSSQ |
* +---------------------------+---------------------------+
* 238 | CHPCMCUR | CHPCURHD |
* +---------------------------+---------------------------+
* 240 | CHPCMXAB | CHPLSTCW |
* +---------------------------+---------------------------+
* 248 | CHPLLPTR | CHPLSTHD |
* +---------------------------+---------------------------+
* 250 | CHPLBLKZ | |
* +---------------------------+ |
* | CHPTKTS |
* | +---------------------------+
* | | 264
* +---------------------------+
*
*** CHPBK - SPXTAPE Channel Program Block
*** Overlay for CHPTKTS in CHPBK
*
* +---------------------------+
* 250 ... 254 | CHPTKTSH |
* +---------------------------+---------------------------+
* 258 | CHPTKTST | CHPTKTCT |
* +---------------------------+---------------------------+
* 260 |///////////////////////////| CHPENTRY |
* +---------------------------+---------------------------+
* 268 | CHPLIMIT | CHPLINDX |
* +---------------------------+---------------------------+
* 270 | CHPOFFST |///////////////////////////|
* +---------------------------+---------------------------+
* 278 | CHPPOOLC | |
* +---------------------------+ |
* 280 | |
* = CHPPLIST =
* | +---------------------------+
* 2B0 | |///////////////////////////|
* +---------------------------+---------------------------+
* 2B8 | CHPNEXT | |
* +---------------------------+ |
* 2C0 | |
* = CHPSAVE =
* | |
* +-------------------------------------------------------+
* 2D8 | |
* = CHPPGM =
* | |
* +-------------------------------------------------------+
* 3A8 | |
* = CHPHEADR =
* | |
* +---------------------------+---------------------------+
* 4D0 | CHPIDAWA | CHPIDWNX |
* +---------------------------+---------------------------+
* 4D8 | CHPBUFHL |///////////////////////////|
* +---------------------------+---------------------------+
* 4E0 | |
* = CHPRESVD =
* | |
* +-------------------------------------------------------+
* 530
*
*** Overlay for CHPTKTS in CHPBK
*** Overlay for CHPPGM in CHPBK
*
* +-------------------------------------------------------+
* 2D8 | CHPMSCCW |
* +---------------------------+---------------------------+
* 2E0 | CHPHDCCW | CHPHCCWA |
* +---------------------------+---------------------------+
* 2E8 | CHPCCW1 | CHPCCW1A |
* +---------------------------+---------------------------+
* 2F0 | |
* = CHPCCWS =
* | |
* +-------------------------------------------------------+
* 390
*
*** Overlay for CHPPGM in CHPBK
*** Overlay for CHPHEADR in CHPBK
*
* +---------------------------+---------------------------+
* 3A8 | CHPBLKID | CHPBLKSZ |
* +---------------------------+---------------------------+
* 3B0 | CHPTIME |
* +-------------------------------------------------------+
* 3B8 | CHPOWNER |
* +---------------------------+---------------------------+
* 3C0 | CHPFSEQ | CHPSYSID |
* +-------------+------+------+---------------------------+
* 3C8 | CHPSPID |:HDFLG|//////| CHPMAPCT |
* +-------------+------+------+-------------+-------------+
* 3D0 | CHPPAGNO | CHPPAGCT | CHPXABSZ |
* +-------------+-------------+-------------+-------------+
* 3D8 | CHPTKOFF | CHPXAOFF | CHPDPOFF |/////////////|
* +-------------+-------------+-------------+-------------+
* 3E0
*
*** Overlay for CHPHEADR in CHPBK
CHPBK Cross Reference
Symbol Dspl Value -------------- ---- ----- CHPBKCNT 04E0 00000002 CHPBLKID 03A8 CHPBLKSZ 03AC CHPBUFHL 04D8 CHPCCWCT 02F0 00000015 CHPCCWS 02F0 CHPCCW1 02E8 CHPCCW1A 02EC CHPCMCLR 0230 CHPCMCRL 02B4 00000088 CHPCMCUR 0238 CHPCMSSQ 0234 CHPCMXAB 0240 CHPCURHD 023C CHPCURTK 0230 CHPDPOFF 03DC CHPENTRY 0264 CHPFSEQ 03C0 CHPHCCWA 02E4 CHPHDCCW 02E0 CHPHDENT 03B8 CHPHDFLG 03CA CHPHEADR 03A8 CHPHLLEN 04DC 00000004 CHPIDAWA 04D0 CHPIDWNX 04D4 CHPIOBY 04E0 00000530 CHPIODW 04E0 000000A6 CHPIORBK 0000 CHPLBLKZ 0250 CHPLENBY 04E0 00000318 CHPLIMIT 0268 CHPLINDX 026C CHPLLPTR 0248 CHPLOCK 0218 CHPLSTCW 0244 CHPLSTHD 024C CHPMAPCT 03CC CHPMSCCW 02D8 CHPNEXT 02B8 CHPOFFST 0270 CHPOWNER 03B8 CHPPAGCT 03D4 CHPPAGNO 03D0 CHPPGM 02D8 CHPPGMLN 02F0 000000B8 CHPPLIST 027C CHPPLLEN 027C 00000038 CHPPLMAX 027C 0000000E CHPPOOLC 0278 CHPRESVD 04E0 CHPSAVE 02BC CHPSPID 03C8 CHPSYSID 03C4 CHPTIME 03B0 CHPTKOFF 03D8 CHPTKTCT 025C CHPTKTS 0254 CHPTKTSH 0254 CHPTKTST 0258 CHPXABSZ 03D6 CHPXAOFF 03DA
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