HP OpenVMS Systems Documentation

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,...);

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:

Value	Symbolic 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. The following diagram depicts the mask:

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

page_count

region_id_64

The following region IDs are defined:

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

relative_page

acmode

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:

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

The following table describes each flag that is valid for $CRMPSC_GPFN_64:

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

return_length_64

start_va_64

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

map_page_count

Description

The Create and Map Global Page Frame Section service allows a process to create and map to a global page frame section. Creating a global page frame section involves defining certain physical page frame numbers (PFNs) as a section.

All global page frame sections are permanent. Pages mapped to a global page frame section are not included in or charged against the process's working set; they are always valid. Do not lock these pages in the working set by using $LKWSET; this can result in a machine check if they are in I/O space.

If the condition value SS$_ACCVIO is returned by this service, a value cannot be returned in the memory locations pointed to by the return_va_64 and return_length_64 arguments.

If a condition value other than SS$_ACCVIO is returned, the returned address and returned length indicate the pages that were successfully mapped before the error occurred. If no pages were mapped, the return_va_64 argument will contain the value --1, and a value cannot be returned in the memory location pointed to by the return_length_64 argument.

Required Privileges

To create a global page frame section, the process must have the following privileges:

• SYSGBL privilege to create a system global section (if flag SEC$M_SYSGBL is set)
• PRMGBL privilege to create a permanent global section (if flag SEC$M_PERM is set)
• PFNMAP privilege to create a page frame section

Required Quota

The working set quota (WSQUOTA) of the process must be sufficient to accommodate the increased length of the process page table required by the increase in virtual address space.

Related Services

$CREATE_GPFN, $CREATE_REGION_64, $CRMPSC, $CRMPSC_FILE_64, $CRMPSC_GFILE_64, $CRMPSC_GPFILE_64, $CRMPSC_PFN_64, $DELETE_REGION_64, $DELTVA_64, $DGBLSC, $MGBLSC_GPFN_64

Condition Values Returned

SS$_NORMAL	The service completed successfully. The specified global section already exists and has been mapped.
SS$_CREATED	The service completed successfully. The specified global section did not previously exist and has been created.
SS$_ACCVIO	The gs_name_64 argument cannot be read by the caller, or the return_va_64 or return_length_64 argument cannot be written by the caller.
SS$_EXBYTLM	The process has exceeded the byte count quota.
SS$_GBLSEC_MISMATCH	Global section type mismatch. The specified global section was found; however, it was not a global disk file section.
SS$_GPTFULL	There is no more room in the system global page table to set up page table entries for the section.
SS$_GSDFULL	There is no more room in the system space allocated to maintain control information for global sections.
SS$_ILLRELPAG	The specified relative page argument is either larger than the highest page number within the section or is not a valid 32-bit physical page frame number.
SS$_IVACMODE	The caller's mode is less privileged than the create mode associated with the region.
SS$_IVLOGNAM	The specified global section name has a length of 0 or has more than 43 characters.
SS$_IVREGID	Invalid region ID specified.
SS$_IVSECFLG	An invalid flag, a reserved flag, or an invalid combination of flags and arguments was specified.
SS$_IVSECIDCTL	The match control field of the global section identification is invalid.
SS$_NOPFNMAP	The process does not have the privilege to create or delete a section starting at a specific physical page frame number (PFNMAP).
SS$_NOPRMGBL	The process does not have the privileges to create or delete a permanent group global section (PRMGBL).
SS$_NOSHPTS	A virtual address within a shared page-table region was specified, or the region ID of a shared page-table region was specified.
SS$_NOSYSGBL	The process does not have the privileges to create or delete a system global section (SYSGBL).
SS$_NOWRTACC	The specified global section is not copy-on-reference and does not allow write access.
SS$_PAGNOTINREG	A page in the specified range is not within the specified region.
SS$_REGISFULL	The specified virtual region is full; no space is available in the region for the pages created to contain the mapped section.
SS$_TOOMANYLNAM	The logical name translation of the gs_name_64 argument exceeded the allowed depth of 10.
SS$_VA_IN_USE	A page in the specified input address range is already mapped and the flag SEC$M_NO_OVERMAP is set, or the existing underlying page cannot be deleted because it is associated with a buffer object.
SS$_VA_NOTPAGALGN	The start_va_64 argument is not CPU-specific page-aligned.

On Alpha systems, allows a process to map a section of its address space to a specified physical address range represented by page frame numbers. This service creates and maps a private page frame section.

This service accepts 64-bit addresses.

Format

SYS$CRMPSC_PFN_64 region_id_64 ,start_pfn ,page_count ,acmode ,flags ,return_va_64 ,return_length_64 [,start_va_64]

C Prototype

int sys$crmpsc_pfn_64 (struct _generic_64 *region_id_64, unsigned int start_pfn, unsigned int page_count, unsigned int acmode, unsigned int flags, void *(*(return_va_64)), unsigned __int64 *return_length_64,...);

Arguments

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.

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 in memory.

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.

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 private 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_PFN_64 service:

Flag	Description
SEC$M_EXPREG	Pages are mapped into the first available space at the current end of the specified region.
SEC$M_NO_OVERMAP	Pages cannot overmap existing address space. By default, pages can overmap existing address space.
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_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 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 private page frame 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 length of the virtual address range mapped. The return_length_64 argument is the 32- or 64-bit virtual address of a naturally aligned quadword into which the 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 private 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$_IVESCFLG is returned.

Description

The Create and Map Private Page Frame Section service allows a process to create a map to a private page frame section. Creating a private page frame section involves defining certain physical page numbers (PFNs) as a section. The section is mapped from a low address to a high address whether the section is mapped in a region that grows from low to high addresses or from high to low addresses.

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