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Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
DRWBK
Cross Reference (Contains links to field and bit definitions)
DRWBK Prolog
NAME : HCPDRWBK
DESCRIPTION: DASD Read/Write Channel Program Block
DSECT : DRWBK
FUNCTION : This DSECT maps the channel program created
to process a *BLOCKIO or diagnose A4 I/O\request
LOCATED BY : DVICHPRG field in HCPDVIOP
CREATED BY : HCPDPSRW
DELETED BY : HCPDPSCU
SERIALIZED : Unique task execution
VMDBK dispatch lock.
The chain of DVIOPS is protected by the
BLKIO lock, in HCPBLKIO
DRWBK Control Block Content
DRWBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure DRWBK DASD Read/Write Channel Program Block 0000 0 Dbl-Word 8 DRWCHPRG (0) Channel program segment 0000 0 Dbl-Word 8 DRWSEEK SEEK CCW 0008 8 Dbl-Word 8 DRWSSECT SET SECTOR CCW 0010 16 Dbl-Word 8 DRWSRCH SEARCH ID CCW 0018 24 Dbl-Word 8 DRWTIC1 TIC CCW 0020 32 Dbl-Word 8 DRWRDWR READ/WRITE CCW 0028 40 Dbl-Word 8 DRWTIC2 TIC CCW 00000030 DRWCHPSZ *-DRWCHPRG 0030 48 Bitstring 12 DRWDATA (0) Data area portion of channel program Segment 0030 48 Bitstring 6 DRWSKARG (0) SEEK argument (BBCCHH) 0030 48 Bitstring 2 DRWSKBIN SEEK: bin (BB) number 0032 50 Bitstring 2 DRWSKCYL SEEK: cylinder (CC) number 0034 52 Bitstring 2 DRWSKHED SEEK: head/track (HH) number 0036 54 Bitstring 5 DRWSRCAR (0) SEARCH ID equal argument (CCHHR) 0036 54 Bitstring 2 DRWSRCYL SEARCH: cylinder (CC) number 0038 56 Bitstring 3 DRWSRHHR (0) SEARCH: head + record (HHR) 0038 56 Bitstring 2 DRWSRHED SEARCH: head/track (HH) number 003A 58 Bitstring 1 DRWSRREC SEARCH: record (R) number 003B 59 Bitstring 1 DRWSECTR SET SECTOR: sector number 003C 60 Signed 4 * Reserved for IBM use 00000040 DRWBSIZE *-DRWCHPRG Byte size of channel program (CCWs plus data area) 00000008 DRWSIZE (DRWBSIZE+7)/8 Doubleword size of channel program (CCWs plus data area) 0040 64 Dbl-Word 8 DRWNXTSG (0) Start of next channel program segment
DRWBK Storage Layout
*** DRWBK - DASD Read/Write Channel Program Block * * +-------------------------------------------------------+ * 0 | DRWSEEK | * +-------------------------------------------------------+ * 8 | DRWSSECT | * +-------------------------------------------------------+ * 10 | DRWSRCH | * +-------------------------------------------------------+ * 18 | DRWTIC1 | * +-------------------------------------------------------+ * 20 | DRWRDWR | * +-------------------------------------------------------+ * 28 | DRWTIC2 | * +-------------+-------------+-------------+-------------+ * 30 | DRWSKBIN | DRWSKCYL | DRWSKHED | DRWSRCYL | * +-------------+------+------+-------------+-------------+ * 38 | DRWSRHED |:SRREC|:SECTR|///////////////////////////| * +-------------+------+------+---------------------------+ * 40 | | * = DRWNXTSG = * | | * +-------------------------------------------------------+ * *** DRWBK - DASD Read/Write Channel Program Block
DRWBK Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----DRWBSIZE 003C 00000040
DRWCHPRG 0000
DRWCHPSZ 0028 00000030
DRWDATA 0030
DRWNXTSG 0040
DRWRDWR 0020
DRWSECTR 003B
DRWSEEK 0000
DRWSIZE 003C 00000008
DRWSKARG 0030
DRWSKBIN 0030
DRWSKCYL 0032
DRWSKHED 0034
DRWSRCAR 0036
DRWSRCH 0010
DRWSRCYL 0036
DRWSRHED 0038
DRWSRHHR 0038
DRWSRREC 003A
DRWSSECT 0008
DRWTIC1 0018
DRWTIC2 0028
Last updated on 3 Aug 1999 at 11:52:48 EDT.
Copyright IBM Corporation, 1990, 1999