Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 4097764..10025e1 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * TLB Management (flush/create/diagnostics) for ARC700
  *
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.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.
- *
  * vineetg: Aug 2011
  *  -Reintroduce duplicate PD fixup - some customer chips still have the issue
  *
@@ -911,9 +908,11 @@
 			  struct pt_regs *regs)
 {
 	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
-	unsigned int pd0[mmu->ways];
 	unsigned long flags;
-	int set;
+	int set, n_ways = mmu->ways;
+
+	n_ways = min(n_ways, 4);
+	BUG_ON(mmu->ways > 4);
 
 	local_irq_save(flags);
 
@@ -921,9 +920,10 @@
 	for (set = 0; set < mmu->sets; set++) {
 
 		int is_valid, way;
+		unsigned int pd0[4];
 
 		/* read out all the ways of current set */
-		for (way = 0, is_valid = 0; way < mmu->ways; way++) {
+		for (way = 0, is_valid = 0; way < n_ways; way++) {
 			write_aux_reg(ARC_REG_TLBINDEX,
 					  SET_WAY_TO_IDX(mmu, set, way));
 			write_aux_reg(ARC_REG_TLBCOMMAND, TLBRead);
@@ -937,14 +937,14 @@
 			continue;
 
 		/* Scan the set for duplicate ways: needs a nested loop */
-		for (way = 0; way < mmu->ways - 1; way++) {
+		for (way = 0; way < n_ways - 1; way++) {
 
 			int n;
 
 			if (!pd0[way])
 				continue;
 
-			for (n = way + 1; n < mmu->ways; n++) {
+			for (n = way + 1; n < n_ways; n++) {
 				if (pd0[way] != pd0[n])
 					continue;