freebsd5/sys/amd64/amd64/pmap.c
/*
 *	pmap_zero_page_area zeros the specified hardware page by mapping 
 *	the page into KVM and using bzero to clear its contents.
 *
 *	off and size may not cover an area beyond a single hardware page.
 */
pmap_zero_page_area zeros the specified hardware page by mapping
the page into KVM and using bzero to clear its contents.

off and size may not cover an area beyond a single hardware page.
pmap_zero_page_area zeros the specified hardware page by mapping the page into KVM and using bzero to clear its contents . off and size may not cover an area beyond a single hardware page .
void
pmap_zero_page_area(vm_page_t m, int off, int size)
{
	vm_offset_t va = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
	if (off == 0 && size == PAGE_SIZE)
		pagezero((void *)va);
	else
		bzero((char *)va + off, size);
}
void pmap_zero_page_area ( vm_page_t m , int off , int size ) { vm_offset_t va = PHYS_TO_DMAP ( VM_PAGE_TO_PHYS ( m ) ) ; if ( off == 0 && size == PAGE_SIZE ) pagezero ( ( void * ) va ) ; else bzero ( ( char * ) va + off , size ) ; }
pmap_zero_page_area zeros the specified hardware page by mapping
      the page into KVM and using bzero to clear its contents.
pmap_zero_page_area zeros the specified hardware page by mapping the page into KVM and using bzero to clear its contents .