drm: Add a function to get the ioctl flags

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

drivers/gpu/drm/drm_drv.c

@@ -450,3 +450,21 @@ long drm_ioctl(struct file *filp,
 	return retcode;
 }
 EXPORT_SYMBOL(drm_ioctl);
+
+/**
+ * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
+ *
+ * @nr: Ioctl number.
+ * @flags: Where to return the ioctl permission flags
+ */
+bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
+{
+	if ((nr >= DRM_COMMAND_END && nr < DRM_CORE_IOCTL_COUNT) ||
+	    (nr < DRM_COMMAND_BASE)) {
+		*flags = drm_ioctls[nr].flags;
+		return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(drm_ioctl_flags);

include/drm/drmP.h

@@ -1229,6 +1229,7 @@ extern long drm_ioctl(struct file *filp,
 extern long drm_compat_ioctl(struct file *filp,
 			     unsigned int cmd, unsigned long arg);
 extern int drm_lastclose(struct drm_device *dev);
+extern bool drm_ioctl_flags(unsigned int nr, unsigned int *flags);
 
 				/* Device support (drm_fops.h) */
 extern struct mutex drm_global_mutex;