System Services, $MGBLSC GPFN 64 (Alpha Only)
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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VMS Help System Services, $MGBLSC GPFN 64 (Alpha Only) *Conan The Librarian (sorry for the slow response - running on an old VAX) |
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On Alpha systems, establishes a correspondence between pages in
the virtual address space of the process and the pages occupied
by a global page frame section.
This service accepts 64-bit addresses.
Format
SYS$MGBLSC_GPFN_64 gs_name_64 ,ident_64 ,region_id_64
,relative_page ,page_count ,acmode
,flags ,return_va_64 ,return_length_64
[,start_va_64]
C Prototype
int sys$mgblsc_gpfn_64 (void *gsdnam_64, struct _secid
*ident_64, struct _generic_64
*region_id_64, unsigned int
relative_page, unsigned int
page_count, unsigned int
acmode, unsigned int flags, void
*(*(return_va_64)), unsigned __int64
*return_length_64,...);
| 1 - Arguments |
gs_name_64
OpenVMS usage:section_name
type: character-coded text string
access: read only
mechanism: by 32- or 64-bit descriptor-fixed-length string
descriptor
Name of the global section. The gs_name argument is the 32- or
64-bit virtual address of a naturally aligned 32-bit or 64-bit
descriptor pointing to this name string.
You can specify any name from 1 to 43 characters. All processes
mapping to the same global section must specify the same name.
Note that the name is case sensitive.
Use of characters valid in logical names is strongly encouraged.
Valid values include alphanumeric characters, the dollar sign
($), and the underscore (_). If the name string begins with an
underscore (_), the underscore is stripped and the resultant
string is considered to be the actual name. Use of the colon (:)
is not permitted.
Names are first subject to a logical name translation, after
the application of the prefix GBL$ to the name. If the result
translates, it is used as the name of the section. If the
resulting name does not translate, the name specified by the
caller is used as the name of the section.
Additional information on logical name translations and on
section name processing is available in the OpenVMS Programming
Concepts Manual.
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 two 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$K_MATLEQ Match if the major identifications are
equal and the minor identification of the
mapper is less than or equal to the minor
identification of the global section.
If you specify the ident_64 argument as 0, the version number and
match control fields default to 0.
The version number is in the second longword. The version number
contains two fields: a minor identification in the low-order 24
bits and a major identification in the high-order 8 bits. You
can assign values for these fields by installation convention to
differentiate versions of global sections. If no version number
is specified when a section is created, processes that specify a
version number when mapping cannot access the global section.
region_id_64
OpenVMS usage:region identifier
type: quadword (unsigned)
access: read only
mechanism: by 32- or 64-bit reference
The region ID associated with the region to map the private page
frame section. The file VADEF.H in SYS$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 count
type: longword (unsigned)
access: read only
mechanism: by value
Relative CPU-specific page number within the global section to
start mapping.
page_count
OpenVMS usage:CPU-specific page count
type: longword (unsigned)
access: read only
mechanism: by value
Length of mapping in CPU-specific pages. If zero is specified,
the global page frame section is mapped to the end of the
section.
acmode
OpenVMS usage:access-mode
type: longword (unsigned)
access: read only
mechanism: by value
Access mode to be associated with the pages mapped into the
process virtual address space. The acmode argument is a longword
containing the access mode. The $PSLDEF macro defines symbols for
the four access modes.
The most privileged access mode used is the access mode of the
caller. Address space cannot be created within a region that has
a create mode associated with it that is more privileged than
the caller's mode. The condition value SS$_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 options for the operation. 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
$MGBLSC_GPFN_64 service:
Flag Description
SEC$M_GBL Pages form a global section. By default, this flag
is always present in this service and cannot be
disabled.
SEC$M_EXPREG Map the section into the first available space at
the current end of the specified region. If this
flag is specified, the start_va_64 argument is not
used.
SEC$M_PERM Pages are 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_PAGFIL Pages form a global page-file section. SEC$M_PAGFIL
also implies SEC$M_WRT and SEC$M_DZRO.
SEC$M_SYSGBL Map a system global section. By default, the
section is a group global section.
SEC$M_WRT Map the section with read/write access. By default,
the section is mapped with read-only access. If
SEC$M_WRT is specified, write access is required.
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 virtual address of a naturally aligned quadword that
contains 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 $MGBLSC_GPFN_64 service returns the length of the
virtual address range in bytes.
start_va_64
OpenVMS usage:address
type: quadword address
access: read only
mechanism: by value
The starting virtual address to map the global section. The
specified virtual address must be a CPU-specified page-aligned
address. If the flag SEC$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.
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