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Prolog Control Block Contents DVIOP DSECT DVIENTRY DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
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| DVIOP Prolog | Top of page |
NAME : HCPDVIOP
DESCRIPTION: DASD Virtual I/O Parameter List
DSECT : DVIOP
FUNCTION : Contains information specific to DASD virtual
I/O requests, including minidisk caching
interface parameters.
LOCATED BY : DVCOPPTR in the DVCPL control block.
The DVCPL control block is located
by DBCDVCPL located in the DBCWK
control block. All CMS block i/o
handlers (Diag X'18', Diag X'A4',
Diag X'250' and *BLOCKIO) have a register
pointing to the DBCWK block.
CREATED BY : HCPDPCUT macro (for diagnose X'A4', *BLOCKIO,
diagnose x'18', and diagnose x'250')
(created in module HCPDBC)
HCPZIW (for CP i/o to CMS files)
DELETED BY : When used as by *BLOCKIO, Diagnose x'A4',
Diagnose X'18', and Diagnose x'250',
it is deleted by HCPDPSCU.
RELOCATION CONSIDERATIONS : None
NOTES :
- This parameter list is used as a communication
block between virtual I/O (diagnoses and
*BLOCKIO), the channel program builder
(HCPDPSRW or HCPDCCWB) and the cache back
end processor (HCPBIUCB).
- It is used as the common descriptor for
an I/O request through *BLOCKIO, diagnose X'A4'
diagnose X'18', and diagnose x'250'.
It also is used as the common descriptor for
an I/O request to read records from a CMS file.
- The physical parameter list contains a DVIOP
header, which points to a variable sized linked
list of DVIENTRYs, one per DASD record.
- The DVIOP contains general information about
the request and information common to all blocks
associated with this DVIOP. A DVIOP represents
one i/o to be performed. A DVIENTRY represents
one block or record that is part of that i/o.
- The cache back end processor will process up to
one DVIOP at a time (or just a portion of that
DVIOP if requested) and relinquish access to
all tracks in the cache for a given DVIOP.
Any cache invalidation required is also
performed.
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| DVIOP Control Block Content | Top of page |
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| DVIOP Storage Layout | Top of page |
*** DVIOP - DASD Virtual I/O Parameter List
*
* +---------------------------+---------------------------+
* 0 | DVIOPNXT | DVIENPTR |
* +---------------------------+---------------------------+
* 8 | DVIENDEN | DVICYLNO |
* +-------------+------+------+------+--------------------+
* 10 | DVIDEVNO |:PLFLG|:OPRC |:HDROP|////////////////////|
* +-------------+------+------+------+------+-------------+
* 18 | DVICHPRG | DVICHSIZ | DVIBLKSZ |
* +---------------------------+-------------+-------------+
* 20 | DVITRIED | DVIBLKCT |
* +---------------------------+---------------------------+
* 28 | DVIECYL |///////////////////////////|
* +---------------------------+---------------------------+
* 30
*
*** DVIOP - DASD Virtual I/O Parameter List
*** DVIENTRY - DASD Virtual I/O Parameter List
*
* +---------------------------+---------------------------+
* 0 | DVINEXT | DVIPREV |
* +------+------+------+------+-------------+------+------+
* 8 |:IORC |:CCWFG|:STSEC|:RWFLG| DVICCFLD |:HED1 |:HED2 |
* +------+------+------+------+-------------+------+------+
* 10 |:RECNO|:PRVDD|/////////////| DVIHDARG | DVIBLKOV |
* +------+------+-------------+-------------+-------------+
* 18 | DVIIDAWA |
* +-------------------------------------------------------+
* 20 | DVIIDAWB |
* +---------------------------+---------------------------+
* 28 | DVIPLPTR | DVIRTRAK |
* +---------------------------+---------------------------+
* 30 | DVIFTKEY | DVIDVTRK |
* +---------------------------+---------------------------+
* 38 | DVIASITA |///////////////////////////|
* +---------------------------+---------------------------+
* 40
*
*** DVIENTRY - DASD Virtual I/O Parameter List
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| DVIOP Cross Reference | Top of page |
Symbol Dspl Value -------------- ---- ----- DVIADCPE 0008 0000002C DVIALSPE 0008 00000024 DVIALTRE 0008 00000020 DVIASITA 0038 DVIBDBLK 0008 00000004 DVIBDBUF 0008 00000008 DVIBDPLA 0008 00000038 DVIBDPLC 0008 0000003C DVIBDPLG 0008 00000040 DVIBDPLP 0008 00000034 DVIBDSVC 0008 00000010 DVIBLKCT 0024 DVIBLKID 000E DVIBLKOV 0016 DVIBLKSZ 001E DVIBLLEN 0040 00000040 DVICCCH 000C DVICCFLD 000C DVICCWFG 0009 DVICHPRG 0018 DVICHSIZ 001C DVICYLNO 000C DVIDEVNO 0010 DVIDIA18 0012 10 DVIDVTRK 0034 DVIDWLEN 0040 00000040 DVIDWSIZ 002C 00000006 DVID250 0012 02 DVIECYL 0028 DVIENDEN 0008 DVIENPTR 0004 DVIFAIL 0014 20 DVIFBABN 000C DVIFBALR 0012 01 DVIFTKEY 0030 DVIHDARG 0014 DVIHDROP 0014 DVIHEDNO 000E DVIHED1 000E DVIHED2 000F DVIHED2R 000F DVIIDAWA 0018 DVIIDAWB 0020 DVIIDLEN 0010 00000003 DVIIORC 0008 DVIISFBA 0012 04 DVIMXBLK 0012 08 DVINCLEN 0008 0000001C DVINEXT 0000 DVINOTPR 0008 00000030 DVIOPNXT 0000 DVIOPRC 0013 DVIOPSIZ 002C 00000030 DVIPAGER 0008 00000018 DVIPLFLG 0012 DVIPLPTR 0028 DVIPREV 0004 DVIPREXC 0008 00000014 DVIPRVDD 0011 DVIPRVSH 0011 20 DVIPRVSI 0011 40 DVIPRVSS 0011 80 DVIRBILD 0012 40 DVIRCOK 0008 00000000 DVIRDINS 0012 80 DVIRDONL 0008 0000000C DVIREAD 0014 40 DVIRECNO 0010 DVIRTRAK 002C DVIRWFLG 000B DVISEVER 0008 000000FF DVISILIB 0012 20 DVISPECE 0008 00000028 DVISRCID 000C DVISTSEC 000A DVITRIED 0020 DVIWRITE 0014 80 |
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