NAME       : HCPPPDBK
 DESCRIPTION: Paged PGMBK Data block
 DSECT      : PPDBK
 FUNCTION   : A PPDBK contains information required to find
              and process an STE corresponding to a paged
              PGMBK (PTRM page) which has been paged to DASD.
 LOCATED BY : The PPDBK address is saved in the invalid PTRM PTE
              for PTRM pages (paged PGMBKs) that reside on DASD.
              The address is saved in a hashed format so that the
              Invalid and Page Protect bits of the PTRM PTE are
              left undisturbed; HCPISTEA macro is used to insert
              the PPDBK address into the PTRM PTE, HCPGSTEA macro
              is used to extract the PPDBK address from the PTRM
              PTE.
 CREATED BY : HCPHRPOP when a PTRM page is invalidated,
              in preparation for the PTRM page (pageable PGMBK)
              potentially being paged to DASD.
              HCPPMPRB when a PTRM page (paged PGMBK) is
              migrated from expanded storage to DASD.
              HCPHRUSM when processing a segment table
              relocation, and a PTRM page (pageable PGMBK) on
              DASD, but without a PPDBK address in the PTRM PTE,
              is encountered.
 DELETED BY : HCPHTUPF when a PTRM page (paged PGMBK)
              is read in from DASD.
              HCPPTAQA when a PTRM page (pageable PGMBK) is paged
              to expanded storage instead of DASD.
 SERIALIZED :
              Serialized by PTRM PTE serialization, though to use
              or change the PPDSTE field, (at least) a share of
              VMDPTIL on the virtual configuration that owns
              the corresponding segment table entry is required,
              to serialize against concurrent destructive changes
              to the segment table (such as segment table relocate
              for resize during NSS/DCSS imbed/unimbed).
 COMMENTS   :

 PPDBK DSECT
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Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      PPDBK          Paged PGMBK Data block
0000    0 Address      8 PPDSTE         Address of STE corresponding to
                                        paged PGMBK
0008    8 Address      4 PPDVMDBK       Address of the owning vconfig's
                                        base VMDBK
          0000000C       PPDBKLEN       *-PPDBK Size of one PPDBK in
                                        bytes
          00000002       PPDBKSIZ       ((*-PPDBK)+7)/8 Size of one PPDBK
                                        in dws
      End of PPDBK definitions

          
*** PPDBK - Paged PGMBK Data block
*
*     +-------------------------------------------------------+
*   0 |                        PPDSTE                         |
*     +---------------------------+---------------------------+
*   8 |         PPDVMDBK          | C
*     +---------------------------+
*
*** PPDBK - Paged PGMBK Data block

 
Symbol         Dspl Value
-------------- ---- -----
PPDBKLEN       0008 0000000C
PPDBKSIZ       0008 00000002
PPDSTE         0000
PPDVMDBK       0008