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Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure HDPBK Host DAT table Programming area block
0000 0 Signed 8 HDPTD Table origin, table type, and
table length of DAT table
associated with this HDPBK, in
ASCE format (DT bits, not R*TE
format TT bits). Table offset
(TF) bits are assumed to be
unused.
0008 8 Signed 8 HDPVSTRT Starting virtual address of
virtual address range represented
by associated table. Must be zero
in highest level table designated
by the ASCE.
0010 16 Signed 8 HDPVEND Ending virtual address of virtual
address range represented by
associated table. This is the
highest virtual address ever made
addressable in the associated
table; addresses within this
range may have since been
nullified.
Back pointers to higher level control blocks and tables.
HDPASCBK and HDPASTEl are filled in for all associated
table types.
HDPHLRTE and HDPHLHDP are filled in if the associated
table is not the highest level table in this address
space's DAT structures; they point to the higher level
R*TE which designates the table associated with this
HDPBK, and the HDPBK which is associated with the table
containing that higher level R*TE, respectively.
0018 24 Signed 4 HDPASCBK ASCBK address
001C 28 Signed 4 HDPASTEl Copy of ASCASTEl
...1 11.. HDPASTE 00004 HDPASTEl,L'HDPASTEl
0020 32 Signed 4 * Reserved for IBM use
0024 36 Signed 4 HDPHLHDP HDPBK associated with the region
table containing the HDPHLRTE
R*TE
0028 40 Signed 8 HDPHLRTE Higher level R*TE which
designates this table (or 0 if
this is the highest level table
for the address space)
Masks useful for processing virtual addresses represented
by this table.
0030 48 Signed 8 HDPVMAXM Mask for generating highest
virtual address in area (region
or segment) represented by the
associated table. Also, for
highest level table designated by
ASCE, is the highest virtual
address representable by an ASCE
with matching DT bits.
for R1T: X'001FFFFFFFFFFFFF'
for R2T: X'000003FFFFFFFFFF'
for R3T: X'000000007FFFFFFF'
for ST: X'00000000000FFFFF'
0038 56 Signed 8 HDPISOXM Mask for isolating index portion
of virtual address in area
represented by the associated
table:
for R1T: x'FFE0000000000000' - isolate R1X
for R2T: x'001FFC0000000000' - isolate R2X
for R3T: x'000003FF80000000' - isolate R3X
for ST: x'000000007FF00000' - isolate SX
Pointers to the HDPBKs associated with existing tables at
this level which represent the next lower and next higher
virtual address range. (In sparse spaces, these HDPBKs
likely represent virtual address ranges which are not
contiguous with the address range represented by this
HDPBK.) Any code which validates or invalidates R*TEs
at any level must maintain these pointers. Allows quick
traversal to the next existing table at the given level,
regardless how big the virtual address gap between the
tables may be.
0040 64 Signed 8 HDPADLQA (0) Addressable HDPBK queue area -
Doubly linked queue of HDPBKs
anchored at ASCADHDQ.
0040 64 Signed 4 HDPADLNX Pointer to a next HDPBK (of
indeterminate level) representing
the next addressable virtual
storage byte address after the
end of the virtual address range
represented by the table
associated with this HDPBK. The
HDBK pointed to may or may not be
the lowest level HDPBK
representing the next addressable
virtual storage byte.
0044 68 Signed 4 HDPADLPR Pointer to a previous HDPBK (of
indeterminate level) representing
the last addressable virtual
storage byte address previous to
the start of the virtual address
range represented by the table
associated with this HDPBK. The
HDBK pointed to may or may not be
the lowest level HDPBK
representing the previous highest
addressable virtual storage byte.
0048 72 Signed 8 HDPLVLQA (0) HDPBK level queue area
0048 72 Signed 4 HDPLVLNX Pointer to next HDPBK at this
level (if any). If non-zero,
points to the HDPBK associated
with the existing table at this
level which represents the next
higher virtual address range.
004C 76 Signed 4 HDPLVLPR Pointer to previous HDPBK at this
level (if any). If non-zero,
points to the HDPBK associated
with the existing table at this
level which represents the next
lower virtual address range.
0050 80 Signed 4 HDP$END (0) End of control block
00000050 HDPLEN *-HDPBK Length of HDPBK in bytes
0000000A HDPSIZE (HDPLEN+7)/8 Size of HDPBK in
doublewords
DSECT to map individual HDPxxxQA queue pointer areas,
can also be used on individual ASCxxHDQ queue header
areas.
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure HDPQPTRA Host DAT table Programming area block
0000 0 Signed 4 HDPQPNXT First (next) HDPBK on queue
0004 4 Signed 4 HDPQPPRV Last (previous) HDPBK on queue
00000008 HDPQPLEN *-HDPQPTRA Length of one HDPBK
pointer area
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