NAME
pmap_enter —
insert a virtual page into a physical
map
SYNOPSIS
#include
<sys/param.h>
#include <vm/vm.h>
#include <vm/pmap.h>
int
pmap_enter(pmap_t pmap,
vm_offset_t va, vm_page_t m,
vm_prot_t prot, u_int flags,
int8_t psind);
DESCRIPTION
Thepmap_enter()
function creates a mapping in the physical map pmap from
the virtual address va to the physical page
m with the protection prot. Any
previous mapping at the virtual address va is destroyed.
The flags argument may have the following values:
VM_PROT_READ- A read access to the given virtual address triggered the call.
VM_PROT_WRITE- A write access to the given virtual address triggered the call.
VM_PROT_EXECUTE- An execute access to the given virtual address triggered the call.
PMAP_ENTER_WIRED- The mapping should be marked as wired.
PMAP_ENTER_NOSLEEP- This function may not sleep during creation of the mapping. If the mapping cannot be created without sleeping, an appropriate Mach VM error is returned.
PMAP_ENTER_NOSLEEP flag is not specified, this
function must create the requested mapping before returning. It may not fail.
In order to create the requested mapping, this function may destroy any
non-wired mapping in any pmap.
The psind parameter specifies the page size
that should be used by the mapping. The supported page sizes are described
by the global array pagesizes[]. The desired page
size is specified by passing the index of the array element that equals the
desired page size.
When the
pmap_enter()
function destroys or updates a managed mapping, including an existing
mapping at virtual address va, it updates the
vm_page structure corresponding to the previously
mapped physical page. If the physical page was accessed through the managed
mapping, then the vm_page structure's
PGA_REFERENCED aflag is set. If the physical page
was modified through the managed mapping, then the
vm_page_dirty()
function is called on the vm_page structure.
The PGA_WRITEABLE aflag must be set for
the page m if the new mapping is managed and
writeable. It is advised to clear PGA_WRITEABLE for
destroyed mappings if the implementation can ensure that no other writeable
managed mappings for the previously mapped pages exist.
If the page m is managed, the page must be
busied by the caller or the owning object must be locked. In the later case,
the PMAP_ENTER_NOSLEEP must be specified by the
caller.
The
pmap_enter()
function must handle the multiprocessor TLB consistency for the given
address.
NOTES
On arm and i386 architectures the existing implementation of the
pmap_enter function is incomplete, only value 0 for
psind is supported. Other supported architectures,
except amd64, have pagesizes[] array of size 1.
RETURN VALUES
If successful, the pmap_enter() function
returns KERN_SUCCESS. If the
PMAP_ENTER_NOSLEEP flag was specified and the
resources required for the mapping cannot be acquired without sleeping,
KERN_RESOURCE_SHORTAGE is returned.
SEE ALSO
AUTHORS
This manual page was first written by Bruce M
Simpson
<bms@spc.org> and then
rewritten by
Alan Cox
<alc@FreeBSD.org> and
Konstantin Belousov
<kib@FreeBSD.org>.