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11d43778 IY |
1 | /* |
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> | |
20 | ||
21 | static unsigned long kernel_virtual_offset; | |
f021c8b3 IY |
22 | static int is_xencomm_initialized; |
23 | ||
24 | /* for xen early printk. It uses console io hypercall which uses xencomm. | |
25 | * However early printk may use it before xencomm initialization. | |
26 | */ | |
27 | int | |
28 | xencomm_is_initialized(void) | |
29 | { | |
30 | return is_xencomm_initialized; | |
31 | } | |
11d43778 IY |
32 | |
33 | void | |
34 | xencomm_initialize(void) | |
35 | { | |
36 | kernel_virtual_offset = KERNEL_START - ia64_tpa(KERNEL_START); | |
f021c8b3 | 37 | is_xencomm_initialized = 1; |
11d43778 IY |
38 | } |
39 | ||
40 | /* Translate virtual address to physical address. */ | |
41 | unsigned long | |
42 | xencomm_vtop(unsigned long vaddr) | |
43 | { | |
44 | struct page *page; | |
45 | struct vm_area_struct *vma; | |
46 | ||
47 | if (vaddr == 0) | |
48 | return 0UL; | |
49 | ||
50 | if (REGION_NUMBER(vaddr) == 5) { | |
51 | pgd_t *pgd; | |
52 | pud_t *pud; | |
53 | pmd_t *pmd; | |
54 | pte_t *ptep; | |
55 | ||
56 | /* On ia64, TASK_SIZE refers to current. It is not initialized | |
57 | during boot. | |
58 | Furthermore the kernel is relocatable and __pa() doesn't | |
59 | work on addresses. */ | |
60 | if (vaddr >= KERNEL_START | |
61 | && vaddr < (KERNEL_START + KERNEL_TR_PAGE_SIZE)) | |
62 | return vaddr - kernel_virtual_offset; | |
63 | ||
64 | /* In kernel area -- virtually mapped. */ | |
65 | pgd = pgd_offset_k(vaddr); | |
66 | if (pgd_none(*pgd) || pgd_bad(*pgd)) | |
67 | return ~0UL; | |
68 | ||
69 | pud = pud_offset(pgd, vaddr); | |
70 | if (pud_none(*pud) || pud_bad(*pud)) | |
71 | return ~0UL; | |
72 | ||
73 | pmd = pmd_offset(pud, vaddr); | |
74 | if (pmd_none(*pmd) || pmd_bad(*pmd)) | |
75 | return ~0UL; | |
76 | ||
77 | ptep = pte_offset_kernel(pmd, vaddr); | |
78 | if (!ptep) | |
79 | return ~0UL; | |
80 | ||
81 | return (pte_val(*ptep) & _PFN_MASK) | (vaddr & ~PAGE_MASK); | |
82 | } | |
83 | ||
84 | if (vaddr > TASK_SIZE) { | |
85 | /* percpu variables */ | |
86 | if (REGION_NUMBER(vaddr) == 7 && | |
87 | REGION_OFFSET(vaddr) >= (1ULL << IA64_MAX_PHYS_BITS)) | |
88 | ia64_tpa(vaddr); | |
89 | ||
90 | /* kernel address */ | |
91 | return __pa(vaddr); | |
92 | } | |
93 | ||
94 | /* XXX double-check (lack of) locking */ | |
95 | vma = find_extend_vma(current->mm, vaddr); | |
96 | if (!vma) | |
97 | return ~0UL; | |
98 | ||
99 | /* We assume the page is modified. */ | |
100 | page = follow_page(vma, vaddr, FOLL_WRITE | FOLL_TOUCH); | |
101 | if (!page) | |
102 | return ~0UL; | |
103 | ||
104 | return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK); | |
105 | } |