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 (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
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