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Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
EXPBK
Control Block Contents
EXPBK DSECT
EXPQUENT DSECT
Cross Reference (Contains links to field and bit definitions)
EXPBK Prolog
NAME : HCPEXPBK
DESCRIPTION: EXPOSURE BLOCK
DSECT : EXPBK
FUNCTION : The exposure block contains necessary information
about a CP volume for paging information.
LOCATED BY : CPVEXPBK - Points to the exposure block.
CREATED BY : HCPRDAAT - When the CP owned volume is brought on
line at IPL time and during the ATTACH
command processing.
DELETED BY : HCPRDADT - When the CP owned volume is DETACHed from
the system.
SERIALIZED : EXPLCKFG - A Test and Set instruction is used to set
the lock flag on to serialize this control
block and the IORBK control block for the
exposure.
COMMENTS :
EXPBK Control Block Content
EXPBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure EXPBK EXPOSURE BLOCK
Flags for the exposure block.
0000 0 Signed 4 EXPFLAGS (0) Flags for the exposure block
0000 0 Bitstring 1 EXPLCKFG Exposure lock byte. X'FF' -
Indicates this exposure is
locked. X'00' - Indicates this
exposure is available for use
.... .... EXPLCKRL X'00' Used to release the
exposure lock
This flag is to keep the status information for this
exposure.
0001 1 Bitstring 1 EXPSTATF Exposure status flag
00000000 EXPNOP X'00' Indicates that neither a
RSCH or a SSCH is required.
00000001 EXPDQINP X'01' Indicates a DEQUEUE in
progress
00000002 EXPRSCH X'02' Indicates that a RSCH is
required
00000004 EXPSSCH X'04' Indicates that a SSCH is
required
0002 2 Bitstring 1 EXPTYPEF Exposure type flag
..1. .... EXPSCSI X'20' Native SCSI (FBA on SCSI)
.... ..1. EXPFBA X'02' This is an FBA device
.... ...1 EXPECKD X'01' Indicates this is an ECKD
paging device
0003 3 Bitstring 1 * Reserved for future IBM use
Maximum number of outstanding DASD I/O for multiple
read or writes.
0004 4 Signed 2 EXPMAXMW Maximum number of multiple writes
that can be added into the
channel program. This value is 4
* number of records per track.
0006 6 Signed 2 EXPQCNEG Number of times EXPCURQC went
neg.
The PIOBKs for this exposure
0008 8 Address 4 EXPFACPA Host absolute address of the
first active PIOBK.
000C 12 Address 4 EXPSCCWP Suspended CCW package. This is
the host absolute address of the
PIOBK in the current channel
program that contains the
suspended NOP.
0010 16 Address 4 EXPPIOHL Host logical address of the
contiguous block of PIOBKs.
These are deferred saveareas when all CCW packages
are used for this exposure. The queues are described
in the general comments section of HCPPAGRV.
0014 20 Address 4 EXPSFDSV First deferred savearea for
single reads and writes. (A
PPIBK)
0018 24 Address 4 EXPSLDSV Last deferred savearea for single
reads and writes. (A PPIBK)
001C 28 Address 4 EXPMRDFQ Host logical address of the PPIBK
that contains the queue of
deferred FRMTEs (PPIFRMQG) to be
read for a multiple read request.
0020 32 Address 4 EXPMWDFQ Host logical address of the PPIBK
that contains the queue of
deferred FRMTEs (PPIFRMQG) to be
written for a multiple write
request.
0024 36 Bitstring 8 * Reserved for future IBM use.
Monitor counters.
002C 44 Signed 4 EXPCTPRD Total count of page read
operations for this device. Note
that page read operations may be
directed to devices without any
cylinders specifically defined as
type PAGE.
0030 48 Signed 4 EXPCTPWR Total count of page write
operations for this device. Note
that page write operations may be
directed to devices without any
cylinders specifically defined as
type PAGE.
0034 52 Signed 4 EXPCTSRD Total count of spooling reads for
this device.
0038 56 Signed 4 EXPCTSWR Total count of spooling writes
for this device.
003C 60 Signed 4 EXPCTACP Total count of paging/spooling
reads and writes added to an
existing channel program without
executing a SSCH or RSCH.
0040 64 Signed 4 EXPCURQC Cardinal count of all outstanding
paging/spooling reads/writes for
this device.
0044 68 Signed 4 EXP2BQED Count of slots that have been
assigned on this CPVOL but have
not yet been added to EXPCURQC,
updated using CS logic
0048 72 Address 4 EXPIORBK IORBK for this exposure. The
IORBK is always at the beginning
of each PAGBK so this field
doubles as the PAGBK address
00000048 EXPPAGBK EXPIORBK,4 PAGBK for this
exposure
004C 76 Signed 4 EXPCTUSI Total count of the number of
times the channel program had to
be terminated to allow user I/O.
This is an indicator of
interference between user and
paging/spooling I/O.
0050 80 Signed 4 EXPDEVST Exposure service time.
0054 84 Signed 4 EXPMLOAD Exposure MLOAD.
0058 88 Signed 4 EXPTIMER Exposure timestamp for SSCH/RSCH.
005C 92 Signed 4 EXPINTIM Exposure timestamp at I/O
interrupt time.
0060 96 Signed 4 EXPNMPIO Number of active PIOBKS at I/O
interrupt time used to calc
service time.
0064 100 Address 4 EXPRDCBK Address of the RDCBK.
0068 104 Signed 4 EXPCONT (20) Count of 20 contiguous free
spaces allocated from 1 to 20
plus.
00B8 184 Signed 4 EXPBKEND (0) End of EXPBK.
000000B8 EXPBSIZE *-EXPBK Size of this DSECT in
Bytes
00000017 EXPSIZE (((*-EXPBK)+7)/8) Size in
double-words
The next two statements EXPQUENT, and EXPQANCH
are used to map the multiple read and
write queue fields EXPMRDFQ and EXPMWDFQ.
EXPQUENT DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure EXPQUENT EXPOSURE BLOCK
0000 0 Address 4 EXPQANCH Anchor for multiple defer queues.
EXPBK Storage Layout
*** EXPBK - EXPOSURE BLOCK
*
* +------+------+------+------+-------------+-------------+
* 0 |:LCKFG|:STATF|:TYPEF|//////| EXPMAXMW | EXPQCNEG |
* +------+------+------+------+-------------+-------------+
* 8 | EXPFACPA | EXPSCCWP |
* +---------------------------+---------------------------+
* 10 | EXPPIOHL | EXPSFDSV |
* +---------------------------+---------------------------+
* 18 | EXPSLDSV | EXPMRDFQ |
* +---------------------------+---------------------------+
* 20 | EXPMWDFQ |///////////////////////////|
* +---------------------------+---------------------------+
* 28 |///////////////////////////| EXPCTPRD |
* +---------------------------+---------------------------+
* 30 | EXPCTPWR | EXPCTSRD |
* +---------------------------+---------------------------+
* 38 | EXPCTSWR | EXPCTACP |
* +---------------------------+---------------------------+
* 40 | EXPCURQC | EXP2BQED |
* +---------------------------+---------------------------+
* 48 | EXPIORBK | EXPCTUSI |
* +---------------------------+---------------------------+
* 50 | EXPDEVST | EXPMLOAD |
* +---------------------------+---------------------------+
* 58 | EXPTIMER | EXPINTIM |
* +---------------------------+---------------------------+
* 60 | EXPNMPIO | EXPRDCBK |
* +---------------------------+---------------------------+
* 68 | |
* = EXPCONT =
* | |
* +-------------------------------------------------------+
*
*** EXPBK - EXPOSURE BLOCK
*** EXPQUENT - EXPOSURE BLOCK
*
* +---------------------------+
* 0 | EXPQANCH | 4
* +---------------------------+
*
*** EXPQUENT - EXPOSURE BLOCK
EXPBK Cross Reference
Symbol Dspl Value
-------------- ---- -----
EXPBKEND 00B8
EXPBSIZE 00B8 000000B8
EXPCONT 0068
EXPCTACP 003C
EXPCTPRD 002C
EXPCTPWR 0030
EXPCTSRD 0034
EXPCTSWR 0038
EXPCTUSI 004C
EXPCURQC 0040
EXPDEVST 0050
EXPDQINP 0001 00000001
EXPECKD 0002 01
EXPFACPA 0008
EXPFBA 0002 02
EXPFLAGS 0000
EXPINTIM 005C
EXPIORBK 0048
EXPLCKFG 0000
EXPLCKRL 0000 00
EXPMAXMW 0004
EXPMLOAD 0054
EXPMRDFQ 001C
EXPMWDFQ 0020
EXPNMPIO 0060
EXPNOP 0001 00000000
EXPPAGBK 0048 00000048
EXPPIOHL 0010
EXPQANCH 0000
EXPQCNEG 0006
EXPRDCBK 0064
EXPRSCH 0001 00000002
EXPSCCWP 000C
EXPSCSI 0002 20
EXPSFDSV 0014
EXPSIZE 00B8 00000017
EXPSLDSV 0018
EXPSSCH 0001 00000004
EXPSTATF 0001
EXPTIMER 0058
EXPTYPEF 0002
EXP2BQED 0044
This information is
based on z/VM V5R2.0.
Last updated on 12 Apr 2006 at 17:13:57 EDT.
Copyright IBM Corporation, 1990, 2005