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