VIRT_TO_PHYS(9) Public Functions Provided VIRT_TO_PHYS(9)NAME
virt_to_phys - map virtual addresses to physical
SYNOPSIS
phys_addr_t virt_to_phys(volatile void * address);
ARGUMENTS
address
address to remap
DESCRIPTION
The returned physical address is the physical (CPU) mapping for the memory address given. It is only valid to use this function on
addresses directly mapped or allocated via kmalloc.
This function does not give bus mappings for DMA transfers. In almost all conceivable cases a device driver should not be using this
function
AUTHORS
Matthew Wilcox <matthew@wil.cx>
Author.
Alan Cox <alan@lxorguk.ukuu.org.uk>
Author.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 VIRT_TO_PHYS(9)
Check Out this Related Man Page
PMAP_EXTRACT(9) BSD Kernel Developer's Manual PMAP_EXTRACT(9)NAME
pmap_extract, pmap_extract_and_hold -- map a virtual address to a physical page
SYNOPSIS
#include <sys/param.h>
#include <vm/vm.h>
#include <vm/pmap.h>
vm_paddr_t
pmap_extract(pmap_t pmap, vm_offset_t va);
vm_paddr_t
pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot);
DESCRIPTION
The pmap_extract() function maps a virtual address to a physical page. In certain situations, callers may use pmap_extract_and_hold()
instead, to ensure that the returned page is held.
The pmap_extract_and_hold() function maps a virtual address to a physical page, and atomically holds the returned page for use by the caller,
only if the mapping permits the given page protection.
IMPLEMENTATION NOTES
Currently, the page protection requested by the caller is not verified.
RETURN VALUES
The pmap_extract() function will return the physical page address associated with the virtual address va inside the physical map pmap. If
the mapping does not exist, or if the pmap parameter is NULL, then NULL will be returned.
The pmap_extract_and_hold() function will return the physical page address associated with the virtual address va inside the physical map
pmap. If the mapping does not exist, the result is a no-op, and NULL will be returned.
SEE ALSO mutex(9), pmap(9)AUTHORS
The pmap_extract_and_hold() function was implemented by Alan L. Cox <alc@imimic.com>. This manual page was written by Bruce M Simpson
<bms@spc.org>.
BSD July 21, 2003 BSD