Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
index 3f8189e..3d0d3ec 100644
--- a/arch/powerpc/kvm/e500_emulate.c
+++ b/arch/powerpc/kvm/e500_emulate.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2008-2011 Freescale Semiconductor, Inc. All rights reserved.
  *
@@ -6,10 +7,6 @@
  * Description:
  * This file is derived from arch/powerpc/kvm/44x_emulate.c,
  * by Hollis Blanchard <hollisb@us.ibm.com>.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2, as
- * published by the Free Software Foundation.
  */
 
 #include <asm/kvm_ppc.h>
@@ -277,6 +274,13 @@
 		vcpu->arch.pwrmgtcr0 = spr_val;
 		break;
 
+	case SPRN_BUCSR:
+		/*
+		 * If we are here, it means that we have already flushed the
+		 * branch predictor, so just return to guest.
+		 */
+		break;
+
 	/* extra exceptions */
 #ifdef CONFIG_SPE_POSSIBLE
 	case SPRN_IVOR32: