/*
 * XXX needed for backend support
 *
 */
static int
map_pte_fn(pte_t *pte, struct page *pmd_page,
           unsigned long addr, void *data)
{
    unsigned long **frames = (unsigned long **)data;

    set_pte_at(&init_mm, addr, pte, pfn_pte_ma((*frames)[0], PAGE_KERNEL));
    (*frames)++;
    return 0;
}
Beispiel #2
0
/*
 * Only sets the access flags (dirty, accessed), as well as write 
 * permission. Furthermore, we know it always gets set to a "more
 * permissive" setting, which allows most architectures to optimize
 * this. We return whether the PTE actually changed, which in turn
 * instructs the caller to do things like update__mmu_cache.  This
 * used to be done in the caller, but sparc needs minor faults to
 * force that call on sun4c so we changed this macro slightly
 */
int ptep_set_access_flags(struct vm_area_struct *vma,
			  unsigned long address, pte_t *ptep,
			  pte_t entry, int dirty)
{
	int changed = !pte_same(*ptep, entry);
	if (changed) {
		set_pte_at(vma->vm_mm, address, ptep, entry);
		flush_tlb_fix_spurious_fault(vma, address);
	}
	return changed;
}
Beispiel #3
0
/*
 * set a new huge pmd. We should not be called for updating
 * an existing pmd entry. That should go via pmd_hugepage_update.
 */
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
		pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
	WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
	assert_spin_locked(&mm->page_table_lock);
	WARN_ON(!pmd_trans_huge(pmd));
#endif
	trace_hugepage_set_pmd(addr, pmd_val(pmd));
	return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node)
{
	pte_t *pte = pte_offset_kernel(pmd, addr);
	if (pte_none(*pte)) {
		pte_t entry;
		void *p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
		if (!p)
			return NULL;
		entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
		set_pte_at(&init_mm, addr, pte, entry);
	}
Beispiel #5
0
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
		     pte_t *ptep, pte_t entry)
{
	int i;

	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
		set_pte_at(mm, addr, ptep, entry);
		ptep++;
		addr += PAGE_SIZE;
		pte_val(entry) += PAGE_SIZE;
	}
}
Beispiel #6
0
/*
 * The __w1data area holds data that is only written during initialization,
 * and is read-only and thus freely cacheable thereafter.  Fix the page
 * table entries that cover that region accordingly.
 */
static void mark_w1data_ro(void)
{
	/* Loop over page table entries */
	unsigned long addr = (unsigned long)__w1data_begin;
	BUG_ON((addr & (PAGE_SIZE-1)) != 0);
	for (; addr <= (unsigned long)__w1data_end - 1; addr += PAGE_SIZE) {
		unsigned long pfn = kaddr_to_pfn((void *)addr);
		pte_t *ptep = virt_to_pte(NULL, addr);
		BUG_ON(pte_huge(*ptep));   /* not relevant for kdata_huge */
		set_pte_at(&init_mm, addr, ptep, pfn_pte(pfn, PAGE_KERNEL_RO));
	}
}
Beispiel #7
0
/* Remap IO memory, the same way as remap_pfn_range(), but use
 * the obio memory space.
 *
 * They use a pgprot that sets PAGE_IO and does not check the
 * mem_map table as this is independent of normal memory.
 */
static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte,
				      unsigned long address,
				      unsigned long size,
				      unsigned long offset, pgprot_t prot,
				      int space)
{
	unsigned long end;

	/* clear hack bit that was used as a write_combine side-effect flag */
	offset &= ~0x1UL;
	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	do {
		pte_t entry;
		unsigned long curend = address + PAGE_SIZE;
		
		entry = mk_pte_io(offset, prot, space);
		if (!(address & 0xffff)) {
			if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
				entry = mk_pte_io(offset,
						  __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
						  space);
				curend = address + 0x400000;
				offset += 0x400000;
			} else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
				entry = mk_pte_io(offset,
						  __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
						  space);
				curend = address + 0x80000;
				offset += 0x80000;
			} else if (!(offset & 0xfffe) && end >= address + 0x10000) {
				entry = mk_pte_io(offset,
						  __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
						  space);
				curend = address + 0x10000;
				offset += 0x10000;
			} else
				offset += PAGE_SIZE;
		} else
			offset += PAGE_SIZE;

		do {
			BUG_ON(!pte_none(*pte));
			set_pte_at(mm, address, pte, entry);
			address += PAGE_SIZE;
			pte_val(entry) += PAGE_SIZE;
			pte++;
		} while (address < curend);
	} while (address < end);
}
Beispiel #8
0
void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
	unsigned long addr;
	unsigned long i;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
			   __pte(0));
		addr += PAGE_SIZE;
	}
}
Beispiel #9
0
static void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
#ifdef CONFIG_HOMECACHE
    int home = initial_heap_home();
#endif
    unsigned long addr = (unsigned long) begin;

    if (kdata_huge && !initfree) {
        pr_warning("Warning: ignoring initfree=0:"
                   " incompatible with kdata=huge\n");
        initfree = 1;
    }
    end = (end + PAGE_SIZE - 1) & PAGE_MASK;
    local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
    for (addr = begin; addr < end; addr += PAGE_SIZE) {
        /*
         * Note we just reset the home here directly in the
         * page table.  We know this is safe because our caller
         * just flushed the caches on all the other cpus,
         * and they won't be touching any of these pages.
         */
        int pfn = kaddr_to_pfn((void *)addr);
        struct page *page = pfn_to_page(pfn);
        pte_t *ptep = virt_to_pte(NULL, addr);
        if (!initfree) {
            /*
             * If debugging page accesses then do not free
             * this memory but mark them not present - any
             * buggy init-section access will create a
             * kernel page fault:
             */
            pte_clear(&init_mm, addr, ptep);
            continue;
        }
#ifdef CONFIG_HOMECACHE
        set_page_home(page, home);
        __clear_bit(PG_homecache_nomigrate, &page->flags);
#endif
        __ClearPageReserved(page);
        init_page_count(page);
        if (pte_huge(*ptep))
            BUG_ON(!kdata_huge);
        else
            set_pte_at(&init_mm, addr, ptep,
                       pfn_pte(pfn, PAGE_KERNEL));
        memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
        free_page(addr);
        totalram_pages++;
    }
    pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}
Beispiel #10
0
/*
 * nid, region_start, and region_end are hints to try to place the page
 * table memory in the same node or region.
 */
static int __map_kernel_page(unsigned long ea, unsigned long pa,
			  pgprot_t flags,
			  unsigned int map_page_size,
			  int nid,
			  unsigned long region_start, unsigned long region_end)
{
	unsigned long pfn = pa >> PAGE_SHIFT;
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep;
	/*
	 * Make sure task size is correct as per the max adddr
	 */
	BUILD_BUG_ON(TASK_SIZE_USER64 > RADIX_PGTABLE_RANGE);

	if (unlikely(!slab_is_available()))
		return early_map_kernel_page(ea, pa, flags, map_page_size,
						nid, region_start, region_end);

	/*
	 * Should make page table allocation functions be able to take a
	 * node, so we can place kernel page tables on the right nodes after
	 * boot.
	 */
	pgdp = pgd_offset_k(ea);
	pudp = pud_alloc(&init_mm, pgdp, ea);
	if (!pudp)
		return -ENOMEM;
	if (map_page_size == PUD_SIZE) {
		ptep = (pte_t *)pudp;
		goto set_the_pte;
	}
	pmdp = pmd_alloc(&init_mm, pudp, ea);
	if (!pmdp)
		return -ENOMEM;
	if (map_page_size == PMD_SIZE) {
		ptep = pmdp_ptep(pmdp);
		goto set_the_pte;
	}
	ptep = pte_alloc_kernel(pmdp, ea);
	if (!ptep)
		return -ENOMEM;

set_the_pte:
	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
	smp_wmb();
	return 0;
}
Beispiel #11
0
static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
				unsigned long end)
{
	pte_t *pte = pte_offset_kernel(pmd, addr);
	pte_t zero_pte;

	zero_pte = pfn_pte(PFN_DOWN(__pa(kasan_zero_page)), PAGE_KERNEL);
	zero_pte = pte_wrprotect(zero_pte);

	while (addr + PAGE_SIZE <= end) {
		set_pte_at(&init_mm, addr, pte, zero_pte);
		addr += PAGE_SIZE;
		pte = pte_offset_kernel(pmd, addr);
	}
}
Beispiel #12
0
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
		     pte_t *ptep, pte_t entry)
{
	int i;

	if (!pte_present(*ptep) && pte_present(entry))
		mm->context.huge_pte_count++;

	for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
		set_pte_at(mm, addr, ptep, entry);
		ptep++;
		addr += PAGE_SIZE;
		pte_val(entry) += PAGE_SIZE;
	}
}
Beispiel #13
0
/*
 * No need to decide whether this PTE shares the swap entry with others,
 * just let do_wp_page work it out if a write is requested later - to
 * force COW, vm_page_prot omits write permission from any private vma.
 */
static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
		unsigned long addr, swp_entry_t entry, struct page *page)
{
	inc_mm_counter(vma->vm_mm, anon_rss);
	get_page(page);
	set_pte_at(vma->vm_mm, addr, pte,
		   pte_mkold(mk_pte(page, vma->vm_page_prot)));
	page_add_anon_rmap(page, vma, addr);
	swap_free(entry);
	/*
	 * Move the page to the active list so it is not
	 * immediately swapped out again after swapon.
	 */
	activate_page(page);
}
static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte, unsigned long address, unsigned long size,
	unsigned long offset, pgprot_t prot, int space)
{
	unsigned long end;

	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	do {
		set_pte_at(mm, address, pte, mk_pte_io(offset, prot, space));
		address += PAGE_SIZE;
		offset += PAGE_SIZE;
		pte++;
	} while (address < end);
}
Beispiel #15
0
/*
 * set a new huge pmd. We should not be called for updating
 * an existing pmd entry. That should go via pmd_hugepage_update.
 */
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
		pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
	/*
	 * Make sure hardware valid bit is not set. We don't do
	 * tlb flush for this update.
	 */

	WARN_ON(pte_hw_valid(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
	assert_spin_locked(pmd_lockptr(mm, pmdp));
	WARN_ON(!(pmd_large(pmd) || pmd_devmap(pmd)));
#endif
	trace_hugepage_set_pmd(addr, pmd_val(pmd));
	return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
static void ion_clean_and_init_allocated_pages(
		struct ion_system_heap *heap, struct scatterlist *sgl,
		int nents, bool memory_zero)
{
	int i;
	struct scatterlist *sg;
	size_t sum = 0;
	int page_idx;
	unsigned long vaddr;
	pte_t *ptep;

	down(&heap->vm_sem);

	page_idx = atomic_pop(&heap->page_idx, VM_PAGE_COUNT_WIDTH);
	BUG_ON((page_idx < 0) || (page_idx >= VM_PAGE_COUNT));

	ptep = heap->pte[page_idx * (SZ_1M / PAGE_SIZE)];
	vaddr = (unsigned long)heap->reserved_vm_area->addr +
				(SZ_1M * page_idx);

	for_each_sg(sgl, sg, nents, i) {
		int j;

		if (!PageHighMem(sg_page(sg))) {
			memset(page_address(sg_page(sg)), 0, sg_dma_len(sg));
			continue;
		}

		for (j = 0; j < (sg_dma_len(sg) / PAGE_SIZE); j++) {
			set_pte_at(&init_mm, vaddr, ptep,
					mk_pte(sg_page(sg) + j, PAGE_KERNEL));
			ptep++;
			vaddr += PAGE_SIZE;

		}

		sum += j * PAGE_SIZE;
		if (sum == SZ_1M) {
			ptep = heap->pte[page_idx * (SZ_1M / PAGE_SIZE)];
			vaddr = (unsigned long)heap->reserved_vm_area->addr +
						(SZ_1M * page_idx);

			ion_clean_and_unmap(vaddr, ptep, sum, memory_zero);

			sum = 0;
		}
	}
Beispiel #17
0
static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
		unsigned long end, unsigned long phys_addr, pgprot_t prot)
{
	pte_t *pte;
	unsigned long pfn;

	pfn = phys_addr >> PAGE_SHIFT;
	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;
	do {
		BUG_ON(!pte_none(*pte));
		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
		pfn++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}
Beispiel #18
0
static int early_map_kernel_page(unsigned long ea, unsigned long pa,
			  pgprot_t flags,
			  unsigned int map_page_size,
			  int nid,
			  unsigned long region_start, unsigned long region_end)
{
	unsigned long pfn = pa >> PAGE_SHIFT;
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep;

	pgdp = pgd_offset_k(ea);
	if (pgd_none(*pgdp)) {
		pudp = early_alloc_pgtable(PUD_TABLE_SIZE, nid,
						region_start, region_end);
		pgd_populate(&init_mm, pgdp, pudp);
	}
	pudp = pud_offset(pgdp, ea);
	if (map_page_size == PUD_SIZE) {
		ptep = (pte_t *)pudp;
		goto set_the_pte;
	}
	if (pud_none(*pudp)) {
		pmdp = early_alloc_pgtable(PMD_TABLE_SIZE, nid,
						region_start, region_end);
		pud_populate(&init_mm, pudp, pmdp);
	}
	pmdp = pmd_offset(pudp, ea);
	if (map_page_size == PMD_SIZE) {
		ptep = pmdp_ptep(pmdp);
		goto set_the_pte;
	}
	if (!pmd_present(*pmdp)) {
		ptep = early_alloc_pgtable(PAGE_SIZE, nid,
						region_start, region_end);
		pmd_populate_kernel(&init_mm, pmdp, ptep);
	}
	ptep = pte_offset_kernel(pmdp, ea);

set_the_pte:
	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
	smp_wmb();
	return 0;
}
Beispiel #19
0
void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
	pte_t **ptes;
	unsigned long addr;
	unsigned long i;

	if (shared == gnttab_status_vm_area.area->addr)
		ptes = gnttab_status_vm_area.ptes;
	else
		ptes = gnttab_shared_vm_area.ptes;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, ptes[i], __pte(0));
		addr += PAGE_SIZE;
	}
}
Beispiel #20
0
void *kmap_atomic(struct page *page)
{
	int idx, cpu_idx;
	unsigned long vaddr;

	preempt_disable();
	pagefault_disable();
	if (!PageHighMem(page))
		return page_address(page);

	cpu_idx = kmap_atomic_idx_push();
	idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
	vaddr = FIXMAP_ADDR(idx);

	set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
	mk_pte(page, kmap_prot));

	return (void *)vaddr;
}
Beispiel #21
0
/*
 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
 * no global lock is needed and because the kmap code must perform a global TLB
 * invalidation when the kmap pool wraps.
 *
 * However when holding an atomic kmap it is not legal to sleep, so atomic
 * kmaps are appropriate for short, tight code paths only.
 */
void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
{
	enum fixed_addresses idx;
	unsigned long vaddr;

	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
	pagefault_disable();

	if (!PageHighMem(page))
		return page_address(page);

	debug_kmap_atomic(type);

	idx = type + KM_TYPE_NR*smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
	BUG_ON(!pte_none(*(kmap_pte-idx)));
	set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));

	return (void *)vaddr;
}
Beispiel #22
0
static inline void clear_soft_dirty(struct vm_area_struct *vma,
		unsigned long addr, pte_t *pte)
{
	/*
	 * The soft-dirty tracker uses #PF-s to catch writes
	 * to pages, so write-protect the pte as well. See the
	 * Documentation/vm/soft-dirty.txt for full description
	 * of how soft-dirty works.
	 */
	pte_t ptent = *pte;

	if (pte_present(ptent)) {
		ptent = pte_wrprotect(ptent);
		ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY);
	} else if (is_swap_pte(ptent)) {
		ptent = pte_swp_clear_soft_dirty(ptent);
	}

	set_pte_at(vma->vm_mm, addr, pte, ptent);
}
Beispiel #23
0
static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
{
	pte_t *pte;


	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;
	do {
		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
		(*nr)++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}
Beispiel #24
0
int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
			   unsigned long max_nr_gframes,
			   grant_status_t **__shared)
{
	grant_status_t *shared = *__shared;
	unsigned long addr;
	unsigned long i;

	if (shared == NULL)
		*__shared = shared = gnttab_status_vm_area.area->addr;

	addr = (unsigned long)shared;

	for (i = 0; i < nr_gframes; i++) {
		set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
			   mfn_pte(frames[i], PAGE_KERNEL));
		addr += PAGE_SIZE;
	}

	return 0;
}
Beispiel #25
0
static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
			  pgprot_t prot)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	pgd = pgd_offset(&tboot_mm, vaddr);
	pud = pud_alloc(&tboot_mm, pgd, vaddr);
	if (!pud)
		return -1;
	pmd = pmd_alloc(&tboot_mm, pud, vaddr);
	if (!pmd)
		return -1;
	pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
	if (!pte)
		return -1;
	set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
	pte_unmap(pte);
	return 0;
}
Beispiel #26
0
int arch_prepare_hugepage(struct page *page)
{
	unsigned long addr = page_to_phys(page);
	pte_t pte;
	pte_t *ptep;
	int i;

	if (MACHINE_HAS_HPAGE)
		return 0;

	ptep = (pte_t *) pte_alloc_one(&init_mm, addr);
	if (!ptep)
		return -ENOMEM;

	pte_val(pte) = addr;
	for (i = 0; i < PTRS_PER_PTE; i++) {
		set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
		pte_val(pte) += PAGE_SIZE;
	}
	page[1].index = (unsigned long) ptep;
	return 0;
}
Beispiel #27
0
static int mfill_zeropage_pte(struct mm_struct *dst_mm,
			      pmd_t *dst_pmd,
			      struct vm_area_struct *dst_vma,
			      unsigned long dst_addr)
{
	pte_t _dst_pte, *dst_pte;
	spinlock_t *ptl;
	int ret;

	_dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr),
					 dst_vma->vm_page_prot));
	ret = -EEXIST;
	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
	if (!pte_none(*dst_pte))
		goto out_unlock;
	set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
	/* No need to invalidate - it was non-present before */
	update_mmu_cache(dst_vma, dst_addr, dst_pte);
	ret = 0;
out_unlock:
	pte_unmap_unlock(dst_pte, ptl);
	return ret;
}
Beispiel #28
0
static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address,
		pte_t *pte, unsigned int flags)
{
	/* No page to get reference */
	if (flags & FOLL_GET)
		return -EFAULT;

	if (flags & FOLL_TOUCH) {
		pte_t entry = *pte;

		if (flags & FOLL_WRITE)
			entry = pte_mkdirty(entry);
		entry = pte_mkyoung(entry);

		if (!pte_same(*pte, entry)) {
			set_pte_at(vma->vm_mm, address, pte, entry);
			update_mmu_cache(vma, address, pte);
		}
	}

	/* Proper page table entry exists, but no corresponding struct page */
	return -EEXIST;
}
Beispiel #29
0
void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{

	unsigned long vaddr;
	int idx, type;

	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
	pagefault_disable();
	if (!PageHighMem(page))
		return page_address(page);


	type = kmap_atomic_idx_push();
	idx = type + KM_TYPE_NR*smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
	BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
	set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot));
	local_flush_tlb_page(NULL, vaddr);

	return (void *) vaddr;
}
/* map fgmfn of domid to lpfn in the current domain */
static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
			    unsigned int domid)
{
	int rc;
	struct xen_add_to_physmap_range xatp = {
		.domid = DOMID_SELF,
		.foreign_domid = domid,
		.size = 1,
		.space = XENMAPSPACE_gmfn_foreign,
	};
	xen_ulong_t idx = fgmfn;
	xen_pfn_t gpfn = lpfn;
	int err = 0;

	set_xen_guest_handle(xatp.idxs, &idx);
	set_xen_guest_handle(xatp.gpfns, &gpfn);
	set_xen_guest_handle(xatp.errs, &err);

	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
	if (rc || err) {
		pr_warn("Failed to map pfn to mfn rc:%d:%d pfn:%lx mfn:%lx\n",
			rc, err, lpfn, fgmfn);
		return 1;
	}
	return 0;
}

struct remap_data {
	xen_pfn_t fgmfn; /* foreign domain's gmfn */
	pgprot_t prot;
	domid_t  domid;
	struct vm_area_struct *vma;
	int index;
	struct page **pages;
	struct xen_remap_mfn_info *info;
};

static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
			void *data)
{
	struct remap_data *info = data;
	struct page *page = info->pages[info->index++];
	unsigned long pfn = page_to_pfn(page);
	pte_t pte = pfn_pte(pfn, info->prot);

	if (map_foreign_page(pfn, info->fgmfn, info->domid))
		return -EFAULT;
	set_pte_at(info->vma->vm_mm, addr, ptep, pte);

	return 0;
}

int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
			       unsigned long addr,
			       xen_pfn_t mfn, int nr,
			       pgprot_t prot, unsigned domid,
			       struct page **pages)
{
	int err;
	struct remap_data data;

	/* TBD: Batching, current sole caller only does page at a time */
	if (nr > 1)
		return -EINVAL;

	data.fgmfn = mfn;
	data.prot = prot;
	data.domid = domid;
	data.vma = vma;
	data.index = 0;
	data.pages = pages;
	err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
				  remap_pte_fn, &data);
	return err;
}