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 21static unsigned long kernel_virtual_offset; 22static 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 */ 27int 28xencomm_is_initialized(void) 29{ 30 return is_xencomm_initialized; 31} 32 33void 34xencomm_initialize(void) 35{ 36 kernel_virtual_offset = KERNEL_START - ia64_tpa(KERNEL_START); 37 is_xencomm_initialized = 1; 38} 39 40/* Translate virtual address to physical address. */ 41unsigned long 42xencomm_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 vma = find_extend_vma(current->mm, vaddr); 95 if (!vma) 96 return ~0UL; 97 98 /* We assume the page is modified. */ 99 page = follow_page(vma, vaddr, FOLL_WRITE | FOLL_TOUCH); 100 if (!page) 101 return ~0UL; 102 103 return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK); 104} 105