C++ (Cpp) pte_mkspecial Examples

Example #1

File: userfaultfd.c Project: markus-oberhumer/linux

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;
	pgoff_t offset, max_off;
	struct inode *inode;

	_dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr),
					 dst_vma->vm_page_prot));
	dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
	if (dst_vma->vm_file) {
		/* the shmem MAP_PRIVATE case requires checking the i_size */
		inode = dst_vma->vm_file->f_inode;
		offset = linear_page_index(dst_vma, dst_addr);
		max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
		ret = -EFAULT;
		if (unlikely(offset >= max_off))
			goto out_unlock;
	}
	ret = -EEXIST;
	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;
}

Example #2

File: gnttab.c Project: Jinjian0609/UVP-Tools

static int __init
#else
int __devinit
#endif
gnttab_init(void)
{
	int i;
	unsigned int max_nr_glist_frames, nr_glist_frames;
	unsigned int nr_init_grefs;

	if (!is_running_on_xen())
		return -ENODEV;

	nr_grant_frames = 1;
	boot_max_nr_grant_frames = __max_nr_grant_frames();

	/* Determine the maximum number of frames required for the
	 * grant reference free list on the current hypervisor.
	 */
	max_nr_glist_frames = nr_freelist_frames(boot_max_nr_grant_frames);

	gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *),
			      GFP_KERNEL);
	if (gnttab_list == NULL)
		return -ENOMEM;

	nr_glist_frames = nr_freelist_frames(nr_grant_frames);
	for (i = 0; i < nr_glist_frames; i++) {
		gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL);
		if (gnttab_list[i] == NULL)
			goto ini_nomem;
	}

	if (gnttab_resume() < 0)
		return -ENODEV;

	nr_init_grefs = nr_grant_frames * ENTRIES_PER_GRANT_FRAME;

	for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
		gnttab_entry(i) = i + 1;

	gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
	gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
	gnttab_free_head  = NR_RESERVED_ENTRIES;

#if defined(CONFIG_XEN) && defined(__HAVE_ARCH_PTE_SPECIAL)
	if (!xen_feature(XENFEAT_auto_translated_physmap)
	    && xen_feature(XENFEAT_gnttab_map_avail_bits)) {
#ifdef CONFIG_X86
		GNTMAP_pte_special = (__pte_val(pte_mkspecial(__pte_ma(0)))
				      >> _PAGE_BIT_UNUSED1) << _GNTMAP_guest_avail0;
#else
#error Architecture not yet supported.
#endif
	}

Example #3

File: userfaultfd.c Project: shengwenhui/aufs4-linux

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;
}