vm: convert fb_mmap to vm_iomap_memory() helper

This is my example conversion of a few existing mmap users.  The
fb_mmap() case is a good example because it is a bit more complicated
than some: fb_mmap() mmaps one of two different memory areas depending
on the page offset of the mmap (but happily there is never any mixing of
the two, so the helper function still works).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
static int do_register_framebuffer(struct fb_info *fb_info)
{
	int i;
	struct fb_event event;
	struct fb_videomode mode;

	if (fb_check_foreignness(fb_info))
		return -ENOSYS;

	do_remove_conflicting_framebuffers(fb_info->apertures, fb_info->fix.id,
					 fb_is_primary_device(fb_info));

	if (num_registered_fb == FB_MAX)
		return -ENXIO;

	num_registered_fb++;
	for (i = 0 ; i < FB_MAX; i++)
		if (!registered_fb[i])
			break;
	fb_info->node = i;
	atomic_set(&fb_info->count, 1);
	mutex_init(&fb_info->lock);
	mutex_init(&fb_info->mm_lock);

	fb_info->dev = device_create(fb_class, fb_info->device,
				     MKDEV(FB_MAJOR, i), NULL, "fb%d", i);
	if (IS_ERR(fb_info->dev)) {
		/* Not fatal */
		printk(KERN_WARNING "Unable to create device for framebuffer %d; errno = %ld\n", i, PTR_ERR(fb_info->dev));
		fb_info->dev = NULL;
	} else
		fb_init_device(fb_info);

	if (fb_info->pixmap.addr == NULL) {
		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
		if (fb_info->pixmap.addr) {
			fb_info->pixmap.size = FBPIXMAPSIZE;
			fb_info->pixmap.buf_align = 1;
			fb_info->pixmap.scan_align = 1;
			fb_info->pixmap.access_align = 32;
			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
		}
	}	
	fb_info->pixmap.offset = 0;

	if (!fb_info->pixmap.blit_x)
		fb_info->pixmap.blit_x = ~(u32)0;

	if (!fb_info->pixmap.blit_y)
		fb_info->pixmap.blit_y = ~(u32)0;

	if (!fb_info->modelist.prev || !fb_info->modelist.next)
		INIT_LIST_HEAD(&fb_info->modelist);

	fb_var_to_videomode(&mode, &fb_info->var);
	fb_add_videomode(&mode, &fb_info->modelist);
	registered_fb[i] = fb_info;

	event.info = fb_info;
	if (!lock_fb_info(fb_info))
		return -ENODEV;
	console_lock();
	fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
	console_unlock();
	unlock_fb_info(fb_info);
	return 0;
}

static int do_register_framebuffer(struct fb_info *fb_info)
{
	int i;
	struct fb_event event;
	struct fb_videomode mode;

	if (fb_check_foreignness(fb_info))
		return -ENOSYS;

	do_remove_conflicting_framebuffers(fb_info->apertures, fb_info->fix.id,
					 fb_is_primary_device(fb_info));

	if (num_registered_fb == FB_MAX)
		return -ENXIO;

	num_registered_fb++;
	for (i = 0 ; i < FB_MAX; i++)
		if (!registered_fb[i])
			break;
	fb_info->node = i;
	atomic_set(&fb_info->count, 1);
	mutex_init(&fb_info->lock);
	mutex_init(&fb_info->mm_lock);

	fb_info->dev = device_create(fb_class, fb_info->device,
				     MKDEV(FB_MAJOR, i), NULL, "fb%d", i);
	if (IS_ERR(fb_info->dev)) {
		/* Not fatal */
		printk(KERN_WARNING "Unable to create device for framebuffer %d; errno = %ld\n", i, PTR_ERR(fb_info->dev));
		fb_info->dev = NULL;
	} else
		fb_init_device(fb_info);

	if (fb_info->pixmap.addr == NULL) {
		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
		if (fb_info->pixmap.addr) {
			fb_info->pixmap.size = FBPIXMAPSIZE;
			fb_info->pixmap.buf_align = 1;
			fb_info->pixmap.scan_align = 1;
			fb_info->pixmap.access_align = 32;
			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
		}
	}	
	fb_info->pixmap.offset = 0;

	if (!fb_info->pixmap.blit_x)
		fb_info->pixmap.blit_x = ~(u32)0;

	if (!fb_info->pixmap.blit_y)
		fb_info->pixmap.blit_y = ~(u32)0;

	if (!fb_info->modelist.prev || !fb_info->modelist.next)
		INIT_LIST_HEAD(&fb_info->modelist);

	fb_var_to_videomode(&mode, &fb_info->var);
	fb_add_videomode(&mode, &fb_info->modelist);
	registered_fb[i] = fb_info;

	event.info = fb_info;
	if (!lock_fb_info(fb_info))
		return -ENODEV;
	console_lock();
	fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
	console_unlock();
	unlock_fb_info(fb_info);
	return 0;
}
