Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/include/asm/tlb.h b/arch/csky/include/asm/tlb.h
new file mode 100644
index 0000000..fdff9b8
--- /dev/null
+++ b/arch/csky/include/asm/tlb.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_TLB_H
+#define __ASM_CSKY_TLB_H
+
+#include <asm/cacheflush.h>
+
+#define tlb_start_vma(tlb, vma) \
+	do { \
+		if (!(tlb)->fullmm) \
+			flush_cache_range(vma, (vma)->vm_start, (vma)->vm_end); \
+	}  while (0)
+
+#define tlb_end_vma(tlb, vma) \
+	do { \
+		if (!(tlb)->fullmm) \
+			flush_tlb_range(vma, (vma)->vm_start, (vma)->vm_end); \
+	}  while (0)
+
+#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
+
+#include <asm-generic/tlb.h>
+
+#endif /* __ASM_CSKY_TLB_H */