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 (59) Base IORBK region Lock for this IORBK and CHPBK work area 01D8 472 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. 01F0 496 Signed 2 CHPCMCLR (0) Beginning of area to be cleared before reuse for trailer 01F0 496 Address 4 CHPCURTK Last ticket contained in current block 01F4 500 Address 4 CHPCMSSQ Last SSQBK 01F8 504 Address 4 CHPCMCUR Address of next Vpage slot in last SSQBK 01FC 508 Signed 4 CHPCURHD Displacement in header of cur hdr 0200 512 Signed 4 CHPCMXAB Amt of XAB data associated with last tkt remaining to be written 0204 516 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 0208 520 Signed 4 CHPLLPTR Last offset in page list +1 used 020C 524 Address 4 CHPLSTHD Hdr addr for last completed file 0210 528 Signed 4 CHPLBLKZ Save last block size at last complete file/tkt in this block. Counters, etc. 0214 532 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 0214 532 Address 4 CHPTKTSH Head of CHPTKTS 0218 536 Address 4 CHPTKTST Tail of CHPTKTS 021C 540 Signed 4 CHPTKTCT Corresponding count of files on CHPTKTS 0220 544 Signed 4 * Reserved 0224 548 Signed 4 CHPENTRY Current entry in the header 0228 552 Signed 4 CHPLIMIT After the last entry in the hdr 022C 556 Signed 4 CHPLINDX Index into CCW list of buffers 0230 560 Signed 4 CHPOFFST Offset into block where data should be added 0234 564 Signed 4 * 0238 568 Signed 4 CHPPOOLC Count of pool pages (data pages) 023C 572 Address 4 CHPPLIST (14) List of pages locked for this blk 00000038 CHPPLLEN *-CHPPLIST Length to clear 0000000E CHPPLMAX 14 Maximum number of entries 0274 628 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 0278 632 Address 4 CHPNEXT Next work area in circular queue Save area across GOTO I/O request 027C 636 Signed 4 CHPSAVE (7) Save R3-R9 across call to IOS.QS Channel Program and Header Block copied from TAPBK 0298 664 Dbl-Word 8 CHPPGM (26) Modeset + hdr + 3*8 (desc + xab + data) 0368 872 Dbl-Word 8 CHPHEADR (37) Block header Pointers 0490 1168 Signed 4 CHPIDAWA IDAW list anchor 0494 1172 Signed 4 CHPIDWNX Next available IDAW slot 0498 1176 Signed 4 CHPBUFHL Host logical buffer addr anchor 049C 1180 Signed 4 * Reserved 00000004 CHPHLLEN 4 Length of CHPBUFHL entries End of CHPBK definition 04A0 1184 Dbl-Word 8 CHPRESVD (10) Round it off 00000318 CHPLENBY *-CHPLOCK Extra space (after IORBK) 000004F0 CHPIOBY *-CHPBK Whole work area size in bytes 0000009E CHPIODW CHPIOBY/8 Same in double words 00000002 CHPBKCNT 2 Number of work areas per drive Redefinition for the channel program build area 0298 664 Dbl-Word 8 CHPMSCCW Modeset, if applicable 02A0 672 Address 4 CHPHDCCW Read/write header CCW 02A4 676 Address 4 CHPHCCWA Address of the CHPHEADR 02A8 680 Address 4 CHPCCW1 First general CCW 02AC 684 Address 4 CHPCCW1A Address section for deblocking 02B0 688 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 0368 872 Character 4 CHPBLKID Generally 'XHDR', could be 'TRLR' 036C 876 Signed 4 CHPBLKSZ Size of this block in bytes 0370 880 Dbl-Word 8 CHPTIME Time stamp Definition of an individual entry 0378 888 Dbl-Word 8 CHPHDENT (0) Start of the first entry 0378 888 Character 8 CHPOWNER File owner 0380 896 Signed 4 CHPFSEQ File sequence number for drive 0384 900 Signed 4 CHPSYSID System spool file ID when dumped 0388 904 Signed 2 CHPSPID User spool file ID when dumped 038A 906 Bitstring 1 CHPHDFLG Flags describing file section 038B 907 Bitstring 1 * 038C 908 Signed 4 CHPMAPCT Count of map pages needed for file 0390 912 Signed 4 CHPPAGNO Starting relative page number 0394 916 Signed 2 CHPPAGCT Count of data pages in block 0396 918 Signed 2 CHPXABSZ Size of XAB section in block 0398 920 Signed 2 CHPTKOFF Offset to ticket - file descriptor 039A 922 Signed 2 CHPXAOFF Offset to extended attributes buf 039C 924 Signed 2 CHPDPOFF Offset to data pages 039E 926 Signed 2 *
CHPBK Storage Layout
*** CHPBK - SPXTAPE Channel Program Block * * +-------------------------------------------------------+ * 0 | | * = CHPIORBK = * | | * +-------------------------------------------------------+ * 1D8 | | * = CHPLOCK = * | | * +---------------------------+---------------------------+ * 1F0 | CHPCURTK | CHPCMSSQ | * +---------------------------+---------------------------+ * 1F8 | CHPCMCUR | CHPCURHD | * +---------------------------+---------------------------+ * 200 | CHPCMXAB | CHPLSTCW | * +---------------------------+---------------------------+ * 208 | CHPLLPTR | CHPLSTHD | * +---------------------------+---------------------------+ * 210 | CHPLBLKZ | | * +---------------------------+ | * | CHPTKTS | * | +---------------------------+ * | | 224 * +---------------------------+ * *** CHPBK - SPXTAPE Channel Program Block *** Overlay for CHPTKTS in CHPBK * * +---------------------------+ * 210 ... 214 | CHPTKTSH | * +---------------------------+---------------------------+ * 218 | CHPTKTST | CHPTKTCT | * +---------------------------+---------------------------+ * 220 |///////////////////////////| CHPENTRY | * +---------------------------+---------------------------+ * 228 | CHPLIMIT | CHPLINDX | * +---------------------------+---------------------------+ * 230 | CHPOFFST |///////////////////////////| * +---------------------------+---------------------------+ * 238 | CHPPOOLC | | * +---------------------------+ | * 240 | | * = CHPPLIST = * | +---------------------------+ * 270 | |///////////////////////////| * +---------------------------+---------------------------+ * 278 | CHPNEXT | | * +---------------------------+ | * 280 | | * = CHPSAVE = * | | * +-------------------------------------------------------+ * 298 | | * = CHPPGM = * | | * +-------------------------------------------------------+ * 368 | | * = CHPHEADR = * | | * +---------------------------+---------------------------+ * 490 | CHPIDAWA | CHPIDWNX | * +---------------------------+---------------------------+ * 498 | CHPBUFHL |///////////////////////////| * +---------------------------+---------------------------+ * 4A0 | | * = CHPRESVD = * | | * +-------------------------------------------------------+ * 4F0 * *** Overlay for CHPTKTS in CHPBK *** Overlay for CHPPGM in CHPBK * * +-------------------------------------------------------+ * 298 | CHPMSCCW | * +---------------------------+---------------------------+ * 2A0 | CHPHDCCW | CHPHCCWA | * +---------------------------+---------------------------+ * 2A8 | CHPCCW1 | CHPCCW1A | * +---------------------------+---------------------------+ * 2B0 | | * = CHPCCWS = * | | * +-------------------------------------------------------+ * 350 * *** Overlay for CHPPGM in CHPBK *** Overlay for CHPHEADR in CHPBK * * +---------------------------+---------------------------+ * 368 | CHPBLKID | CHPBLKSZ | * +---------------------------+---------------------------+ * 370 | CHPTIME | * +-------------------------------------------------------+ * 378 | CHPOWNER | * +---------------------------+---------------------------+ * 380 | CHPFSEQ | CHPSYSID | * +-------------+------+------+---------------------------+ * 388 | CHPSPID |:HDFLG|//////| CHPMAPCT | * +-------------+------+------+-------------+-------------+ * 390 | CHPPAGNO | CHPPAGCT | CHPXABSZ | * +-------------+-------------+-------------+-------------+ * 398 | CHPTKOFF | CHPXAOFF | CHPDPOFF |/////////////| * +-------------+-------------+-------------+-------------+ * 3A0 * *** Overlay for CHPHEADR in CHPBK
CHPBK Cross Reference
Symbol Dspl Value -------------- ---- ----- CHPBKCNT 04A0 00000002 CHPBLKID 0368 CHPBLKSZ 036C CHPBUFHL 0498 CHPCCWCT 02B0 00000015 CHPCCWS 02B0 CHPCCW1 02A8 CHPCCW1A 02AC CHPCMCLR 01F0 CHPCMCRL 0274 00000088 CHPCMCUR 01F8 CHPCMSSQ 01F4 CHPCMXAB 0200 CHPCURHD 01FC CHPCURTK 01F0 CHPDPOFF 039C CHPENTRY 0224 CHPFSEQ 0380 CHPHCCWA 02A4 CHPHDCCW 02A0 CHPHDENT 0378 CHPHDFLG 038A CHPHEADR 0368 CHPHLLEN 049C 00000004 CHPIDAWA 0490 CHPIDWNX 0494 CHPIOBY 04A0 000004F0 CHPIODW 04A0 0000009E CHPIORBK 0000 CHPLBLKZ 0210 CHPLENBY 04A0 00000318 CHPLIMIT 0228 CHPLINDX 022C CHPLLPTR 0208 CHPLOCK 01D8 CHPLSTCW 0204 CHPLSTHD 020C CHPMAPCT 038C CHPMSCCW 0298 CHPNEXT 0278 CHPOFFST 0230 CHPOWNER 0378 CHPPAGCT 0394 CHPPAGNO 0390 CHPPGM 0298 CHPPGMLN 02B0 000000B8 CHPPLIST 023C CHPPLLEN 023C 00000038 CHPPLMAX 023C 0000000E CHPPOOLC 0238 CHPRESVD 04A0 CHPSAVE 027C CHPSPID 0388 CHPSYSID 0384 CHPTIME 0370 CHPTKOFF 0398 CHPTKTCT 021C CHPTKTS 0214 CHPTKTSH 0214 CHPTKTST 0218 CHPXABSZ 0396 CHPXAOFF 039A
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