| Isaku Yamahata | 11d4377 | 2008-10-17 11:17:53 +0900 | [diff] [blame^] | 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; |
| 22 | |
| 23 | void |
| 24 | xencomm_initialize(void) |
| 25 | { |
| 26 | kernel_virtual_offset = KERNEL_START - ia64_tpa(KERNEL_START); |
| 27 | } |
| 28 | |
| 29 | /* Translate virtual address to physical address. */ |
| 30 | unsigned long |
| 31 | xencomm_vtop(unsigned long vaddr) |
| 32 | { |
| 33 | struct page *page; |
| 34 | struct vm_area_struct *vma; |
| 35 | |
| 36 | if (vaddr == 0) |
| 37 | return 0UL; |
| 38 | |
| 39 | if (REGION_NUMBER(vaddr) == 5) { |
| 40 | pgd_t *pgd; |
| 41 | pud_t *pud; |
| 42 | pmd_t *pmd; |
| 43 | pte_t *ptep; |
| 44 | |
| 45 | /* On ia64, TASK_SIZE refers to current. It is not initialized |
| 46 | during boot. |
| 47 | Furthermore the kernel is relocatable and __pa() doesn't |
| 48 | work on addresses. */ |
| 49 | if (vaddr >= KERNEL_START |
| 50 | && vaddr < (KERNEL_START + KERNEL_TR_PAGE_SIZE)) |
| 51 | return vaddr - kernel_virtual_offset; |
| 52 | |
| 53 | /* In kernel area -- virtually mapped. */ |
| 54 | pgd = pgd_offset_k(vaddr); |
| 55 | if (pgd_none(*pgd) || pgd_bad(*pgd)) |
| 56 | return ~0UL; |
| 57 | |
| 58 | pud = pud_offset(pgd, vaddr); |
| 59 | if (pud_none(*pud) || pud_bad(*pud)) |
| 60 | return ~0UL; |
| 61 | |
| 62 | pmd = pmd_offset(pud, vaddr); |
| 63 | if (pmd_none(*pmd) || pmd_bad(*pmd)) |
| 64 | return ~0UL; |
| 65 | |
| 66 | ptep = pte_offset_kernel(pmd, vaddr); |
| 67 | if (!ptep) |
| 68 | return ~0UL; |
| 69 | |
| 70 | return (pte_val(*ptep) & _PFN_MASK) | (vaddr & ~PAGE_MASK); |
| 71 | } |
| 72 | |
| 73 | if (vaddr > TASK_SIZE) { |
| 74 | /* percpu variables */ |
| 75 | if (REGION_NUMBER(vaddr) == 7 && |
| 76 | REGION_OFFSET(vaddr) >= (1ULL << IA64_MAX_PHYS_BITS)) |
| 77 | ia64_tpa(vaddr); |
| 78 | |
| 79 | /* kernel address */ |
| 80 | return __pa(vaddr); |
| 81 | } |
| 82 | |
| 83 | /* XXX double-check (lack of) locking */ |
| 84 | vma = find_extend_vma(current->mm, vaddr); |
| 85 | if (!vma) |
| 86 | return ~0UL; |
| 87 | |
| 88 | /* We assume the page is modified. */ |
| 89 | page = follow_page(vma, vaddr, FOLL_WRITE | FOLL_TOUCH); |
| 90 | if (!page) |
| 91 | return ~0UL; |
| 92 | |
| 93 | return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK); |
| 94 | } |