VMS Help System Services, $CRMPSC GPFN 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 permanent global
    page frame section and to map a section of its address space to
    the global page frame section.

    This service accepts 64-bit addresses.

    Format

      SYS$CRMPSC_GPFN_64  gs_name_64 ,ident_64 ,prot ,start_pfn

                          ,page_count ,region_id_64 ,relative_page

                          ,acmode ,flags ,return_va_64

                          ,return_length_64 [,start_va_64

                          [,map_page_count]]

    C Prototype

      int sys$crmpsc_gpfn_64  (void *gs_nam_64, struct _secid

                              *ident_64, unsigned int prot, unsigned

                              int start_pfn, unsigned int page_count,

                              struct _generic_64 *region_id_64,

                              unsigned int relative_page, 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.

 start_pfn

    OpenVMS usage:page frame number
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    The CPU-specific page frame number where the section begins.

 page_count

    OpenVMS usage:CPU-specific page count
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Length of the page frame section in CPU-specific pages.

 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
    frame 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.

 relative_page

    OpenVMS usage:CPU-specific page number
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Relative CPU-specific page number within the global section to
    start mapping.

 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.

    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
    $CRMPSC_GPFN_64:

    Flag          Description

    SEC$M_EXPREG  Pages are mapped into the first available space at
                  the current end of the specified region.
    SEC$M_GBL     Pages form a global section. By default, this flag
                  is always present in this service and cannot be
                  disabled.
    SEC$M_PERM    Global section is permanent. By default, this flag
                  is always present in this service and cannot be
                  disabled.
    SEC$M_PFNMAP  Pages form a page frame 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_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, pages
                  form a read-only section.

    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
    illegal 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
    frame section was mapped. The return_va_64 argument is the 32-
    or 64-bit 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 frame
    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_page_count

    OpenVMS usage:CPU-specific page count
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Length of the global page frame section to be mapped in CPU-
    specific pages.