blob: 73d903ca2d64ceef40602a619ad00167006e367d [file] [log] [blame]
Isaku Yamahata11d43772008-10-17 11:17:53 +09001/*
2 * Copyright (C) 2006 Hollis Blanchard <hollisb@us.ibm.com>, IBM Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19#include <linux/mm.h>
Wei Yongjun39c9a4a2012-09-27 12:30:18 -070020#include <linux/err.h>
Isaku Yamahata11d43772008-10-17 11:17:53 +090021
22static unsigned long kernel_virtual_offset;
Isaku Yamahataf021c8b2008-10-17 11:17:54 +090023static int is_xencomm_initialized;
24
25/* for xen early printk. It uses console io hypercall which uses xencomm.
26 * However early printk may use it before xencomm initialization.
27 */
28int
29xencomm_is_initialized(void)
30{
31 return is_xencomm_initialized;
32}
Isaku Yamahata11d43772008-10-17 11:17:53 +090033
34void
35xencomm_initialize(void)
36{
37 kernel_virtual_offset = KERNEL_START - ia64_tpa(KERNEL_START);
Isaku Yamahataf021c8b2008-10-17 11:17:54 +090038 is_xencomm_initialized = 1;
Isaku Yamahata11d43772008-10-17 11:17:53 +090039}
40
41/* Translate virtual address to physical address. */
42unsigned long
43xencomm_vtop(unsigned long vaddr)
44{
45 struct page *page;
46 struct vm_area_struct *vma;
47
48 if (vaddr == 0)
49 return 0UL;
50
51 if (REGION_NUMBER(vaddr) == 5) {
52 pgd_t *pgd;
53 pud_t *pud;
54 pmd_t *pmd;
55 pte_t *ptep;
56
57 /* On ia64, TASK_SIZE refers to current. It is not initialized
58 during boot.
59 Furthermore the kernel is relocatable and __pa() doesn't
60 work on addresses. */
61 if (vaddr >= KERNEL_START
62 && vaddr < (KERNEL_START + KERNEL_TR_PAGE_SIZE))
63 return vaddr - kernel_virtual_offset;
64
65 /* In kernel area -- virtually mapped. */
66 pgd = pgd_offset_k(vaddr);
67 if (pgd_none(*pgd) || pgd_bad(*pgd))
68 return ~0UL;
69
70 pud = pud_offset(pgd, vaddr);
71 if (pud_none(*pud) || pud_bad(*pud))
72 return ~0UL;
73
74 pmd = pmd_offset(pud, vaddr);
75 if (pmd_none(*pmd) || pmd_bad(*pmd))
76 return ~0UL;
77
78 ptep = pte_offset_kernel(pmd, vaddr);
79 if (!ptep)
80 return ~0UL;
81
82 return (pte_val(*ptep) & _PFN_MASK) | (vaddr & ~PAGE_MASK);
83 }
84
85 if (vaddr > TASK_SIZE) {
86 /* percpu variables */
87 if (REGION_NUMBER(vaddr) == 7 &&
88 REGION_OFFSET(vaddr) >= (1ULL << IA64_MAX_PHYS_BITS))
89 ia64_tpa(vaddr);
90
91 /* kernel address */
92 return __pa(vaddr);
93 }
94
95 /* XXX double-check (lack of) locking */
96 vma = find_extend_vma(current->mm, vaddr);
97 if (!vma)
98 return ~0UL;
99
100 /* We assume the page is modified. */
101 page = follow_page(vma, vaddr, FOLL_WRITE | FOLL_TOUCH);
Wei Yongjun39c9a4a2012-09-27 12:30:18 -0700102 if (IS_ERR_OR_NULL(page))
Isaku Yamahata11d43772008-10-17 11:17:53 +0900103 return ~0UL;
104
105 return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK);
106}