NAME       : HCPBITMP
 DESCRIPTION: Bit Map Control Block
 DSECT      : BITMP
 FUNCTION   : The Bit Map Control Block contains fields that control
              access to the bits, pointers to the bits, and other
              useful stuff.
 LOCATED BY : R2 at entry to HCPBIT routines points to a full
              word that points to the BITMP.
 CREATED BY : HCPBIT
 DELETED BY : HCPBITRL
 REFERENCES : None
 SERIALIZED : Changes to the contents of bit maps need not be done
              under the control of the BITMP lock, because
              Compare-and-Swap is used to change the bits and the
              pointers to the bits.  However, if serialization is
              needed, the users of the bit maps should call the
              HCPBIT entry points AS, AX, RS, RX, SX, etc., which
              call the analogous HCPLCK entry points for control
              over the BITMP lock.
 RELOCATION CONSIDERATIONS : This control block is relocated as part of a live
              guest relocation (LGR).  The bits and fields that
              need to be relocated are defined in the
              corresponding LGRBITMP COPY file.  Whenever changes
              are made to this control block, consideration must
              be given to any effects these changes will have on
              a relocation.  If any new fields or bits are
              defined, they may need to be relocated.  If
              existing bits or fields are changed, corresponding
              modifications may be required in the LGR version of
              this control block.  Consider also the effects of
              these changes on a relocation involving a back-level
              release of CP.

 BITMP DSECT
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Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BITMP          Bit Map Control Block
      This portion of the BITMP is fixed length.  The final size
      of the BITMP depends on how many pointers are actually
      stored at BITMPPTR.
          00000000       BITMPFXD       * Fixed portion of the BITMP
0000    0 Dbl-Word     8 BITMPLCK (3)   The BITMP lock
0018   24 Signed       4 BITMPMAX       The max bit number allowed
001C   28 Signed       4 BITMPPGS       How many pointers at BITMPPTR
          00000020       BITMPFSZ       *-BITMP Size of fixed portion of
                                        BITMP expressed in bytes.
0020   32 Address      4 BITMPPTR (0)   Start of variable length data.
                                        Pointers to pages of bits. The
                                        upper bound of the subscript for
                                        this array is contained in
                                        BITMPPGS.

          
*** BITMP - Bit Map Control Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       BITMPLCK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         BITMPMAX          |         BITMPPGS          |
*     +---------------------------+---------------------------+
*
*** BITMP - Bit Map Control Block

 
Symbol         Dspl Value
-------------- ---- -----
BITMPFSZ       001C 00000020
BITMPFXD       0000 00000000
BITMPLCK       0000
BITMPMAX       0018
BITMPPGS       001C
BITMPPTR       0020