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PMAP_ENTER(9) | Kernel Developer's Manual | PMAP_ENTER(9) |
NAME¶
pmap_enter
—
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 thepmap_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, thepmap_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¶
pmap(9)AUTHORS¶
This manual page was first written by Bruce M Simpson <bms@spc.org> and then rewritten byAlan Cox <alc@FreeBSD.org> and
Konstantin Belousov <kib@FreeBSD.org>.
February 16, 2018 | Linux 4.19.0-10-amd64 |