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/*
* Copyright (C) 2006 Hollis Blanchard <hollisb@us.ibm.com>, IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/mm.h>
#include <linux/err.h>
static unsigned long kernel_virtual_offset;
static int is_xencomm_initialized;
/* for xen early printk. It uses console io hypercall which uses xencomm.
* However early printk may use it before xencomm initialization.
*/
int
xencomm_is_initialized(void)
{
return is_xencomm_initialized;
}
void
xencomm_initialize(void)
{
kernel_virtual_offset = KERNEL_START - ia64_tpa(KERNEL_START);
is_xencomm_initialized = 1;
}
/* Translate virtual address to physical address. */
unsigned long
xencomm_vtop(unsigned long vaddr)
{
struct page *page;
struct vm_area_struct *vma;
if (vaddr == 0)
return 0UL;
if (REGION_NUMBER(vaddr) == 5) {
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep;
/* On ia64, TASK_SIZE refers to current. It is not initialized
during boot.
Furthermore the kernel is relocatable and __pa() doesn't
work on addresses. */
if (vaddr >= KERNEL_START
&& vaddr < (KERNEL_START + KERNEL_TR_PAGE_SIZE))
return vaddr - kernel_virtual_offset;
/* In kernel area -- virtually mapped. */
pgd = pgd_offset_k(vaddr);
if (pgd_none(*pgd) || pgd_bad(*pgd))
return ~0UL;
pud = pud_offset(pgd, vaddr);
if (pud_none(*pud) || pud_bad(*pud))
return ~0UL;
pmd = pmd_offset(pud, vaddr);
if (pmd_none(*pmd) || pmd_bad(*pmd))
return ~0UL;
ptep = pte_offset_kernel(pmd, vaddr);
if (!ptep)
return ~0UL;
return (pte_val(*ptep) & _PFN_MASK) | (vaddr & ~PAGE_MASK);
}
if (vaddr > TASK_SIZE) {
/* percpu variables */
if (REGION_NUMBER(vaddr) == 7 &&
REGION_OFFSET(vaddr) >= (1ULL << IA64_MAX_PHYS_BITS))
ia64_tpa(vaddr);
/* kernel address */
return __pa(vaddr);
}
/* XXX double-check (lack of) locking */
vma = find_extend_vma(current->mm, vaddr);
if (!vma)
return ~0UL;
/* We assume the page is modified. */
page = follow_page(vma, vaddr, FOLL_WRITE | FOLL_TOUCH);
if (IS_ERR_OR_NULL(page))
return ~0UL;
return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK);
}
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