+static struct vmw_master *vmw_master_check(struct drm_device *dev,
+ struct drm_file *file_priv,
+ unsigned int flags)
+{
+ int ret;
+ struct vmw_fpriv *vmw_fp = vmw_fpriv(file_priv);
+ struct vmw_master *vmaster;
+
+ if (file_priv->minor->type != DRM_MINOR_LEGACY ||
+ !(flags & DRM_AUTH))
+ return NULL;
+
+ ret = mutex_lock_interruptible(&dev->master_mutex);
+ if (unlikely(ret != 0))
+ return ERR_PTR(-ERESTARTSYS);
+
+ if (file_priv->is_master) {
+ mutex_unlock(&dev->master_mutex);
+ return NULL;
+ }
+
+ /*
+ * Check if we were previously master, but now dropped.
+ */
+ if (vmw_fp->locked_master) {
+ mutex_unlock(&dev->master_mutex);
+ DRM_ERROR("Dropped master trying to access ioctl that "
+ "requires authentication.\n");
+ return ERR_PTR(-EACCES);
+ }
+ mutex_unlock(&dev->master_mutex);
+
+ /*
+ * Taking the drm_global_mutex after the TTM lock might deadlock
+ */
+ if (!(flags & DRM_UNLOCKED)) {
+ DRM_ERROR("Refusing locked ioctl access.\n");
+ return ERR_PTR(-EDEADLK);
+ }
+
+ /*
+ * Take the TTM lock. Possibly sleep waiting for the authenticating
+ * master to become master again, or for a SIGTERM if the
+ * authenticating master exits.
+ */
+ vmaster = vmw_master(file_priv->master);
+ ret = ttm_read_lock(&vmaster->lock, true);
+ if (unlikely(ret != 0))
+ vmaster = ERR_PTR(ret);
+
+ return vmaster;
+}
+
+static long vmw_generic_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg,
+ long (*ioctl_func)(struct file *, unsigned int,
+ unsigned long))