VMS Help System Services, $CRMPSC GPFILE 64 (Alpha Only)  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    On Alpha systems, allows a process to create a global page file
    section and to map a section of its address space to the global
    section.

    This service accepts 64-bit addresses.

    Format

      SYS$CRMPSC_GPFILE_64  gs_name_64 ,ident_64 ,prot ,length_64

                            ,region_id_64 ,section_offset_64 ,acmode

                            ,flags ,return_va_64 ,return_length_64

                            [,start_va_64 [,map_length_64]]

    C Prototype

      int sys$crmpsc_gpfile_64  (void *gs_nam_64, struct _secid

                                *ident_64, unsigned int prot,

                                unsigned __int64 length_64, struct

                                _generic_64 *region_id_64, unsigned

                                __int64 section_offset_64, unsigned

                                int acmode, unsigned int flags, void

                                *(*(return_va_64)), unsigned __int64

                                *return_length_64,...);

1 - Arguments

 gs_name_64

    OpenVMS usage:section_name
    type:         character-coded text string
    access:       read only
    mechanism:    by 32- or 64-bit descriptor-fixed-length string
                  descriptor
    Name of the global section. The gs_name_64 argument is the 32-
    or 64-bit virtual address of a naturally aligned 32- or 64-bit
    string descriptor pointing to this name string.

 ident_64

    OpenVMS usage:section_id
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by 32- or 64-bit reference
    Identification value specifying the version number of a global
    section. The ident_64 argument is a quadword containing three
    fields. The ident_64 argument is the 32- or 64-bit virtual
    address of a naturally aligned quadword that contains the
    identification value.

    The first longword specifies the matching criteria in its low-
    order 2 bits. The valid values, symbolic names by which they can
    be specified, and their meanings are as follows:

           Symbolic
    Value  Name           Match Criteria

    0      SEC$K_MATALL   Match all versions of the section.
    1      SEC$K_MATEQU   Match only if major and minor
                          identifications match.
    2      SEC$K_MATLEQ   Match if the major identifications are
                          equal and the minor identification of the
                          mapper is less than or equal to the minor
                          identification of the global section.

    When a section is mapped at creation time, the match control
    field is ignored. If you specify the ident_64 argument as 0, the
    version number and match control fields default to 0.

    The version number is in the second longword. The version number
    contains two fields: a minor identification in the low-order 24
    bits and a major identification in the high-order 8 bits. You
    can assign values for these fields by installation convention to
    differentiate versions of global sections. If no version number
    is specified when a section is created, processes that specify a
    version number when mapping cannot access the global section.

 prot

    OpenVMS usage:file_protection
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Protection to be applied to the global page file section. The
    mask contains four 4-bit fields. Bits are read from right to left
    in each field.

    Refer to the OpenVMS System Services Reference Manual to view the
    mask diagram.

    Cleared bits indicate that read, write, execute, and delete
    access, in that order, are granted to the particular category
    of user. Only read, write, and execute access are meaningful
    for section protection. Delete access bits are ignored. Read
    access also grants execute access for those situations where
    execute access applies. If zero is specified, read access and
    write access are granted to all users.

 length_64

    OpenVMS usage:byte count
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by value
    Length, in bytes, of the global page file section to be created.
    The length specified must be a multiple of CPU-specific pages. A
    length of 0 cannot be specified.

 region_id_64

    OpenVMS usage:region identifier
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by 32- or 64-bit reference
    The region ID associated with the region to map the global page
    file section.

    The file VADEF.H in SYS$STARLET_C.TLB and the $VADEF macro in
    STARLET.MLB define a symbolic name for each of the three default
    regions in P0, P1, and P2 space.

    The following region IDs are defined:

    Symbol     Region

    VA$C_P0    Program region
    VA$C_P1    Control region
    VA$C_P2    64-bit program region

    Other region IDs, as returned by the $CREATE_REGION_64 service,
    can be specified.

 section_offset_64

    OpenVMS usage:byte offset
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by value
    Offset into the global section to start mapping into the
    process's virtual address space. The offset specified must be
    a multiple of virtual disk blocks.

 acmode

    OpenVMS usage:access_mode
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Access mode that is to be the owner of the pages created during
    the mapping. The acmode argument is a longword containing the
    access mode.

    The $PSLDEF macro in STARLET.MLB and the file PSLDEF.H in
    SYS$STARLET_C.TLB define the following symbols and their values
    for the four access modes:

    Value      Symbolic Name      Access Mode

    0          PSL$C_KERNEL       Kernel
    1          PSL$C_EXEC         Executive
    2          PSL$C_SUPER        Supervisor
    3          PSL$C_USER         User

    The most privileged access mode used is the access mode of the
    caller. The calling process can delete pages only if those pages
    are owned by an access mode equal to or less privileged than the
    access mode of the calling process.

    Address space cannot be created within a region that has a create
    mode associated with it that is more privileged than the caller's
    mode. The condition value SS$_IVACMODE is returned if the caller
    is less privileged than the create mode for the region.

 flags

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Flag mask specifying the characteristics of the global section
    to be created. The flags argument is a longword bit vector in
    which each bit corresponds to a flag. The $SECDEF macro and the
    SECDEF.H file define a symbolic name for each flag. You construct
    the flags argument by performing a logical OR operation on the
    symbol names for all desired flags.

    The following table describes each flag that is valid for the
    $CRMPSC_GPFILE_64 service:

    Flag          Description

    SEC$M_DZRO    Pages are demand-zero pages. By default, this flag
                  is always present in this service and cannot be
                  disabled.
    SEC$M_EXPREG  Pages are mapped into the first available space
                  at the current end of the specified region.
                  SEC$M_EXPREG cannot be specified with the
                  SEC$M_NO_OVERMAP flag.
    SEC$M_GBL     Pages form a global section. By default, this flag
                  is always present in this service and cannot be
                  disabled.
    SEC$M_NO_     Pages cannot overmap existing address space. By
    OVERMAP       default, pages can overmap existing address space.
                  SEC$M_NO_OVERMAP cannot be specified with the
                  SEC$M_EXPREG flag.
    SEC$M_PAGFIL  Pages form a global page file section. By default,
                  this flag is always present in this service and
                  cannot be disabled.
    SEC$M_PERM    Global section is permanent. By default, global
                  sections are temporary.
    SEC$M_SYSGBL  Pages form a system global section. By default,
                  pages form a group global section.
    SEC$M_WRT     Pages form a read/write section. By default, this
                  flag is always present in this service and cannot
                  be disabled.

    All other bits in the flags argument are reserved for future
    use by Compaq and should be specified as 0. The condition value
    SS$_IVSECFLG is returned if any undefined bits are set or if an
    invalid combination of flags is set.

 return_va_64

    OpenVMS usage:address
    type:         quadword address
    access:       write only
    mechanism:    by 32- or 64-bit reference
    The lowest process virtual address into which the global page
    file section was mapped. The return_va_64 argument is the 32- or
    64-bit virtual address of a naturally aligned quadword into which
    the service returns the virtual address.

 return_length_64

    OpenVMS usage:byte count
    type:         quadword (unsigned)
    access:       write only
    mechanism:    by 32- or 64-bit reference
    The 32- or 64-bit virtual address of a naturally aligned quadword
    into which the service returns the length of the virtual address
    range mapped in bytes.

 start_va_64

    OpenVMS usage:address
    type:         quadword address
    access:       read only
    mechanism:    by value
    The starting virtual address to map the global page file section.
    The specified virtual address must be a CPU-specific page aligned
    address. If the flag SEC$M_EXPREG is specified, the start_va_64
    argument must not be specified or must be specified as 0. If
    SEC$M_EXPREG is set and the start_va_64 argument is nonzero, the
    condition value SS$_IVSECFLG is returned.

    Always refer to the return_va_64 and return_length_64 arguments
    to determine the range of virtual addresses mapped.

 map_length_64

    OpenVMS usage:byte count
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by value
    Length of the global page file section to be mapped. The length
    specified must be a multiple of CPU-specific pages. If this
    argument is not specified or is specified as zero, the global
    file section is mapped up to and including the last page in that
    section.