Programming Interface Information:
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BELBK
Control Block Contents
BELBK DSECT
Cross Reference (Contains links to field and bit definitions)
BELBK Prolog
NAME : HCPBELBK DESCRIPTION: Block I/O entry list DSECT : BELBK FUNCTION : This DSECT maps the input parameter list sent by the guest to CP when the guest requests an I/O operation via DIAGNOSE X'250'. LOCATED BY : BRQBELBK in the BRQBK CREATED BY : HCPBIDRW (who copies the guest's parameter list into host storage) DELETED BY : HCPBIDRW, for synchronous requests HCPBIDRW. for asynchronous requests satisfied synchronously HCPBIRIN, for asynchronous requests satisfied asynchronously SERIALIZED : Instruction stream serialization RELOCATION CONSIDERATIONS : None COMMENTS : This parameter list may not be word-aligned in guest storage. However, this DSECT assumes that before any fields are referenced, the parameter list has been moved into host storage and word-aligned. References to fields in this block will cause an exception if this is not the case. There is one entry within the block I/O entry list for each read/write request. This control block is a GPI, and should not be changed incompatibly.
BELBK Control Block Content
BELBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure BELBK Block I/O entry list 0000 0 Signed 4 * (0) 0000 0 Bitstring 1 BELRQTYP Type of operation being requested. 00000001 BELWRITE X'01' BELWRITE Write operation requested 00000002 BELREAD X'02' BELREAD Read operation requested 0001 1 Bitstring 1 BELSTAT Status code for this operation 00000000 BELOK X'00' BELOK The read or write operation was successful 00000001 BELINVBK X'01' BELINVBK Invalid block number specified 00000002 BELADDRE X'02' BELADDRE Addressing exception condition 00000003 BELRODEV X'03' BELRODEV A write operation was requested to a read-only device 00000004 BELINVSZ X'04' BELINVSZ Block size does not match that of the virtual device 00000005 BELIOERR X'05' BELIOERR Unrecoverable I/O error 00000006 BELBADRQ X'06' BELBADRQ Request type is not read or write 00000007 BELPROTE X'07' BELPROTE Protection exception condition 00000008 BELADCPE X'08' BELADCPE Addressing-capability exception condition 00000009 BELALTRE X'09' BELALTRE ALEN-translation exception condition 0000000A BELALSPE X'0A' BELALSPE ALET-specification exception condition 0000000B BELSPECE X'0B' BELSPECE Specification exception condition 0000000C BELNOTPR X'0C' BELNOTPR This block I/O entry was not processed 0002 2 Bitstring 2 BELRSD01 Reserved for IBM use Format of remainder of block when BIO64BIT = 0 in the BIOPL. 0004 4 Signed 4 BELBKNUM 32 bit block number 0008 8 Address 4 BELBALET ALET of guest data buffer 000C 12 Address 4 BELBUFAD 31 bit guest absolute address of the data buffer. 0010 16 Signed 4 BELNEXT (0) Start of next entry in p-list 00000002 BELSIZE (*-BELBK+7)/8 Size of one entry of the BELBK in doublewords Format of remainder of block when BIO64BIT = 1 in the BIOPL. 0004 4 Address 4 BELBALETF1 ALET of guest data buffer 0008 8 Dbl-Word 8 BELBKNUM64 64 bit block number 0010 16 Address 8 BELBUFAD64 64 bit guest absolute address of the data buffer. 0018 24 Signed 4 BELNEXTF1 (0) Start of next entry in p-list 00000003 BELSIZEF1 (*-BELBK+7)/8 Size of one entry of the BELBK in doublewords
BELBK Storage Layout
*** BELBK - Block I/O entry list * * +------+------+-------------+---------------------------+ * 0 |:RQTYP|:STAT | BELRSD01 | BELBKNUM | * +------+------+-------------+---------------------------+ * 8 | BELBALET | BELBUFAD | * +---------------------------+---------------------------+ * *** BELBK - Block I/O entry list *** Overlay for BELBKNUM in BELBK * * +---------------------------+ * 0 ... 4 | BELBALETF1 | * +---------------------------+---------------------------+ * 8 | BELBKNUM64 | * +-------------------------------------------------------+ * 10 | BELBUFAD64 | * +-------------------------------------------------------+ * *** Overlay for BELBKNUM in BELBK
BELBK Cross Reference
Symbol Dspl Value -------------- ---- ----- BELADCPE 0001 00000008 BELADDRE 0001 00000002 BELALSPE 0001 0000000A BELALTRE 0001 00000009 BELBADRQ 0001 00000006 BELBALET 0008 BELBALETF1 0004 BELBKNUM 0004 BELBKNUM64 0008 BELBUFAD 000C BELBUFAD64 0010 BELINVBK 0001 00000001 BELINVSZ 0001 00000004 BELIOERR 0001 00000005 BELNEXT 0010 BELNEXTF1 0018 BELNOTPR 0001 0000000C BELOK 0001 00000000 BELPROTE 0001 00000007 BELREAD 0000 00000002 BELRODEV 0001 00000003 BELRQTYP 0000 BELRSD01 0002 BELSIZE 0010 00000002 BELSIZEF1 0018 00000003 BELSPECE 0001 0000000B BELSTAT 0001 BELWRITE 0000 00000001
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