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Diffstat (limited to 'arch/ia64/xen/xencomm.c')
-rw-r--r--arch/ia64/xen/xencomm.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/ia64/xen/xencomm.c b/arch/ia64/xen/xencomm.c
new file mode 100644
index 00000000000..1f5d7ac82e9
--- /dev/null
+++ b/arch/ia64/xen/xencomm.c
@@ -0,0 +1,105 @@
+/*
+ * 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>
+
+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 (!page)
+ return ~0UL;
+
+ return (page_to_pfn(page) << PAGE_SHIFT) | (vaddr & ~PAGE_MASK);
+}