STLTE | Back to Index page

| Prolog Control Block Contents STLTE DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

STLTE Prolog | Top of page

     NAME       : HCPSTLTE
     DESCRIPTION: Segment Table List Block Table Entry
     DSECT      : STLTE
     FUNCTION   : There is one Segment Table List Block Table
                  Entry (STLTE) for each megabyte in an STLBK.
                  The format of the STLTE matches the ESA/390
                  STE to the extent that there is a page table
                  origin (PTO) in the entry.
     LOCATED BY : STLSTEPT  field of HCPSTLBK
                  STLSTE2   field of HCPSTLBK
                  While these entries have a PTO like STEs, they
                  are only "templates" used during saved segment
                  processing.  They are never "attached" to the
                  hardware in the architectural sense.
     CREATED BY : HCPBSCSL  when an STLBK is built
                  HCPBSCBS  when an STLBK is built
     DELETED BY : HCPBSCBS  when an STLBK is released
                  HCPUIMSL  when an STLBK is released
     RELOCATION CONSIDERATIONS : None

STLTE Control Block Content | Top of page

     STLTE DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      STLTE          Segment Table List Block Table Entry
    0000    0 Address      8 STLENTRY       Pointer to page table in a PGMBK
                                            Masks to extract fields from the
                                            STE contents
              .... ....      STLNULLM       X'80000000' Isolate null entry
                                            flag
              0000F000       STLPGMM        X'F000' NILL mask to isolate the
                                            PGMBK HRA given the STE address
              0000F800       STLPTOM        X'F800' NILL mask to isolate the
                                            Page Table Origin HRA given the
                                            STE address
              00000020       STLEXCLM       STLEXCL Use NG Rx,=AD(STLEXCLM)
                                            to isolate the "exclusive" bit
              00000010       STLWRITM       STLWRITE Use NG Rx,=AD(STLWRITM)
                                            to isolate "shared writable" bit
              .... 1111      STLPTLM        X'000F' Use NG Rx,=AD(STLPLTM) to
                                            isolate the page-table length
              00000008       STLTElen       *-STLENTRY Length on one table
                                            entry
              00000003       STLTEsft       3 2**STLTEsft = L'STLTE
              00001000       STLTEsiz       4096 Size of each STLTE area.
              00000200       STLTEper       (STLTEsiz)/(STLTElen),(STLTEsiz)/
                                            (STLTElen) Number of STLTEs in
                                            each STLTE area. The second value
                                            is specified equal to the first
                                            value so that things like macros
                                            can use the L' attribute to get
                                            the actual value of STLTEper.
    0008    8 Dbl-Word     8 STLNEXT (0)    Next table entry
    0000    0 Bitstring    7 *              Bits 00-55 of PGMBK/PTO address
    0007    7 Bitstring    1 STLSTAT        Bits 56-63 of PGMBK/PTO address,
                                            which is the entry status
              ..1. ....      STLEXCL        X'20' STLEXCL Entry is exclusive
              ...1 ....      STLWRITE       X'10' STLWRITE Writeable storage
                                            in shared PGMBK

STLTE Storage Layout | Top of page

    *** STLTE - Segment Table List Block Table Entry
    *
    *     +-------------------------------------------------------+
    *   0 |                       STLENTRY                        |
    *     +-------------------------------------------------------+
    *
    *** STLTE - Segment Table List Block Table Entry

    *** Overlay for STLENTRY in STLTE
    *
    *     +------------------------------------------------+------+
    *   0 |////////////////////////////////////////////////|:STAT |
    *     +------------------------------------------------+------+
    *   8
    *
    *** Overlay for STLENTRY in STLTE

STLTE Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    STLENTRY       0000
    STLEXCL        0007 20
    STLEXCLM       0000 00000020
    STLNEXT        0008
    STLNULLM       0000 00
    STLPGMM        0000 0000F000
    STLPTLM        0000 0F
    STLPTOM        0000 0000F800
    STLSTAT        0007
    STLTElen       0000 00000008
    STLTEper       0000 00000200
    STLTEsft       0000 00000003
    STLTEsiz       0000 00001000
    STLWRITE       0007 10
    STLWRITM       0000 00000010

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:04 EDT.
Copyright IBM Corporation, 1990, 2020