+#ifndef _X86_64_PGALLOC_H
+#define _X86_64_PGALLOC_H
+
+#include <asm/fixmap.h>
+#include <asm/pda.h>
+#include <linux/threads.h>
+#include <linux/mm.h>
+#include <asm/io.h> /* for phys_to_virt and page_to_pseudophys */
+
+#define arch_add_exec_range(mm, limit) \
+ do { (void)(mm), (void)(limit); } while (0)
+#define arch_flush_exec_range(mm) \
+ do { (void)(mm); } while (0)
+#define arch_remove_exec_range(mm, limit) \
+ do { (void)(mm), (void)(limit); } while (0)
+
+#include <xen/features.h>
+void make_page_readonly(void *va, unsigned int feature);
+void make_page_writable(void *va, unsigned int feature);
+void make_pages_readonly(void *va, unsigned int nr, unsigned int feature);
+void make_pages_writable(void *va, unsigned int nr, unsigned int feature);
+
+#define __user_pgd(pgd) ((pgd) + PTRS_PER_PGD)
+
+static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
+{
+ set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)));
+}
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
+{
+ if (unlikely((mm)->context.pinned)) {
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(page_to_pfn(pte) << PAGE_SHIFT),
+ pfn_pte(page_to_pfn(pte), PAGE_KERNEL_RO), 0));
+ set_pmd(pmd, __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)));
+ } else {
+ *(pmd) = __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT));
+ }
+}
+
+static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
+{
+ if (unlikely((mm)->context.pinned)) {
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)pmd,
+ pfn_pte(virt_to_phys(pmd)>>PAGE_SHIFT,
+ PAGE_KERNEL_RO), 0));
+ set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
+ } else {
+ *(pud) = __pud(_PAGE_TABLE | __pa(pmd));
+ }
+}
+
+/*
+ * We need to use the batch mode here, but pgd_pupulate() won't be
+ * be called frequently.
+ */
+static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
+{
+ if (unlikely((mm)->context.pinned)) {
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)pud,
+ pfn_pte(virt_to_phys(pud)>>PAGE_SHIFT,
+ PAGE_KERNEL_RO), 0));
+ set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pud)));
+ set_pgd(__user_pgd(pgd), __pgd(_PAGE_TABLE | __pa(pud)));
+ } else {
+ *(pgd) = __pgd(_PAGE_TABLE | __pa(pud));
+ *(__user_pgd(pgd)) = *(pgd);
+ }
+}
+
+static inline void pmd_free(pmd_t *pmd)
+{
+ pte_t *ptep = virt_to_ptep(pmd);
+
+ if (!pte_write(*ptep)) {
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)pmd,
+ pfn_pte(virt_to_phys(pmd)>>PAGE_SHIFT, PAGE_KERNEL),
+ 0));
+ }
+ free_page((unsigned long)pmd);
+}
+
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+ pmd_t *pmd = (pmd_t *) get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ return pmd;
+}
+
+static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
+{
+ pud_t *pud = (pud_t *) get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ return pud;
+}
+
+static inline void pud_free(pud_t *pud)
+{
+ pte_t *ptep = virt_to_ptep(pud);
+
+ if (!pte_write(*ptep)) {
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)pud,
+ pfn_pte(virt_to_phys(pud)>>PAGE_SHIFT, PAGE_KERNEL),
+ 0));
+ }
+ free_page((unsigned long)pud);
+}
+
+static inline void pgd_list_add(pgd_t *pgd)
+{
+ struct page *page = virt_to_page(pgd);
+
+ spin_lock(&pgd_lock);
+ page->index = (pgoff_t)pgd_list;
+ if (pgd_list)
+ pgd_list->private = (unsigned long)&page->index;
+ pgd_list = page;
+ page->private = (unsigned long)&pgd_list;
+ spin_unlock(&pgd_lock);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ struct page *next, **pprev, *page = virt_to_page(pgd);
+
+ spin_lock(&pgd_lock);
+ next = (struct page *)page->index;
+ pprev = (struct page **)page->private;
+ *pprev = next;
+ if (next)
+ next->private = (unsigned long)pprev;
+ spin_unlock(&pgd_lock);
+}
+
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ /*
+ * We allocate two contiguous pages for kernel and user.
+ */
+ unsigned boundary;
+ pgd_t *pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_REPEAT, 1);
+
+ if (!pgd)
+ return NULL;
+ pgd_list_add(pgd);
+ /*
+ * Copy kernel pointers in from init.
+ * Could keep a freelist or slab cache of those because the kernel
+ * part never changes.
+ */
+ boundary = pgd_index(__PAGE_OFFSET);
+ memset(pgd, 0, boundary * sizeof(pgd_t));
+ memcpy(pgd + boundary,
+ init_level4_pgt + boundary,
+ (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
+
+ memset(__user_pgd(pgd), 0, PAGE_SIZE); /* clean up user pgd */
+ /*
+ * Set level3_user_pgt for vsyscall area
+ */
+ set_pgd(__user_pgd(pgd) + pgd_index(VSYSCALL_START),
+ mk_kernel_pgd(__pa_symbol(level3_user_pgt)));
+ return pgd;
+}
+
+static inline void pgd_free(pgd_t *pgd)
+{
+ pte_t *ptep = virt_to_ptep(pgd);
+
+ if (!pte_write(*ptep)) {
+ xen_pgd_unpin(__pa(pgd));
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)pgd,
+ pfn_pte(virt_to_phys(pgd)>>PAGE_SHIFT, PAGE_KERNEL),
+ 0));
+ }
+
+ ptep = virt_to_ptep(__user_pgd(pgd));
+
+ if (!pte_write(*ptep)) {
+ xen_pgd_unpin(__pa(__user_pgd(pgd)));
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)__user_pgd(pgd),
+ pfn_pte(virt_to_phys(__user_pgd(pgd))>>PAGE_SHIFT,
+ PAGE_KERNEL),
+ 0));
+ }
+
+ pgd_list_del(pgd);
+ free_pages((unsigned long)pgd, 1);
+}
+
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
+{
+ pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ if (pte)
+ make_page_readonly(pte, XENFEAT_writable_page_tables);
+
+ return pte;
+}
+
+static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+ struct page *pte;
+
+ pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
+ return pte;
+}
+
+/* Should really implement gc for free page table pages. This could be
+ done with a reference count in struct page. */
+
+static inline void pte_free_kernel(pte_t *pte)
+{
+ BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
+ make_page_writable(pte, XENFEAT_writable_page_tables);
+ free_page((unsigned long)pte);
+}
+
+extern void pte_free(struct page *pte);
+
+//#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))
+//#define __pmd_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
+//#define __pud_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
+
+#define __pte_free_tlb(tlb,x) pte_free((x))
+#define __pmd_free_tlb(tlb,x) pmd_free((x))
+#define __pud_free_tlb(tlb,x) pud_free((x))
+
+#endif /* _X86_64_PGALLOC_H */