Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 2cfbc53..7a0596f 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  arch/arm/include/asm/io.h
  *
  *  Copyright (C) 1996-2000 Russell King
  *
- * 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.
- *
  * Modifications:
  *  16-Sep-1996	RMK	Inlined the inx/outx functions & optimised for both
  *			constant addresses and variable addresses.
@@ -28,13 +25,11 @@
 #include <asm/byteorder.h>
 #include <asm/memory.h>
 #include <asm-generic/pci_iomap.h>
-#include <xen/xen.h>
 
 /*
  * ISA I/O bus memory addresses are 1:1 with the physical address.
  */
 #define isa_virt_to_bus virt_to_phys
-#define isa_page_to_bus page_to_phys
 #define isa_bus_to_virt phys_to_virt
 
 /*
@@ -282,8 +277,6 @@
 extern void _memcpy_toio(volatile void __iomem *, const void *, size_t);
 extern void _memset_io(volatile void __iomem *, int, size_t);
 
-#define mmiowb()
-
 /*
  *  Memory access primitives
  *  ------------------------
@@ -459,20 +452,6 @@
 
 #include <asm-generic/io.h>
 
-/*
- * can the hardware map this into one segment or not, given no other
- * constraints.
- */
-#define BIOVEC_MERGEABLE(vec1, vec2)	\
-	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
-
-struct bio_vec;
-extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
-				      const struct bio_vec *vec2);
-#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\
-	(__BIOVEC_PHYS_MERGEABLE(vec1, vec2) &&				\
-	 (!xen_domain() || xen_biovec_phys_mergeable(vec1, vec2)))
-
 #ifdef CONFIG_MMU
 #define ARCH_HAS_VALID_PHYS_ADDR_RANGE
 extern int valid_phys_addr_range(phys_addr_t addr, size_t size);