fbdev/fb-puv3: use vm_iomap_memory()

Use vm_iomap_memory() instead of [io_]remap_pfn_range().
vm_iomap_memory() gives us much simpler API to map memory to userspace,
and reduces possibilities for bugs.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>

drivers/video/fb-puv3.c

@@ -640,21 +640,9 @@ static int unifb_pan_display(struct fb_var_screeninfo *var,
 int unifb_mmap(struct fb_info *info,
 		    struct vm_area_struct *vma)
 {
-	unsigned long size = vma->vm_end - vma->vm_start;
-	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
-	unsigned long pos = info->fix.smem_start + offset;
-
-	if (offset + size > info->fix.smem_len)
-		return -EINVAL;
-
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
-	if (io_remap_pfn_range(vma, vma->vm_start, pos >> PAGE_SHIFT, size,
-				vma->vm_page_prot))
-		return -EAGAIN;
-
-	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
-	return 0;
+	return vm_iomap_memory(vma, info->fix.smem_start, info->fix.smem_len);
 }
 
 static struct fb_ops unifb_ops = {