+/**
+ * Wait until GR goes idle. GR is considered idle if it is disabled by the
+ * MC (0x200) register, or GR is not busy and a context switch is not in
+ * progress.
+ */
+int
+gf100_gr_wait_idle(struct gf100_gr_priv *priv)
+{
+ unsigned long end_jiffies = jiffies + msecs_to_jiffies(2000);
+ bool gr_enabled, ctxsw_active, gr_busy;
+
+ do {
+ /*
+ * required to make sure FIFO_ENGINE_STATUS (0x2640) is
+ * up-to-date
+ */
+ nv_rd32(priv, 0x400700);
+
+ gr_enabled = nv_rd32(priv, 0x200) & 0x1000;
+ ctxsw_active = nv_rd32(priv, 0x2640) & 0x8000;
+ gr_busy = nv_rd32(priv, 0x40060c) & 0x1;
+
+ if (!gr_enabled || (!gr_busy && !ctxsw_active))
+ return 0;
+ } while (time_before(jiffies, end_jiffies));
+
+ nv_error(priv, "wait for idle timeout (en: %d, ctxsw: %d, busy: %d)\n",
+ gr_enabled, ctxsw_active, gr_busy);
+ return -EAGAIN;
+}
+