Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h
index f34d729..ca42161 100644
--- a/arch/s390/include/asm/io.h
+++ b/arch/s390/include/asm/io.h
@@ -30,14 +30,8 @@
 #define ioremap_wc			ioremap_nocache
 #define ioremap_wt			ioremap_nocache
 
-static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
-{
-	return (void __iomem *) offset;
-}
-
-static inline void iounmap(volatile void __iomem *addr)
-{
-}
+void __iomem *ioremap(unsigned long offset, unsigned long size);
+void iounmap(volatile void __iomem *addr);
 
 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
 {
@@ -57,14 +51,17 @@
  * the corresponding device and create the mapping cookie.
  */
 #define pci_iomap pci_iomap
+#define pci_iomap_range pci_iomap_range
 #define pci_iounmap pci_iounmap
-#define pci_iomap_wc pci_iomap
-#define pci_iomap_wc_range pci_iomap_range
+#define pci_iomap_wc pci_iomap_wc
+#define pci_iomap_wc_range pci_iomap_wc_range
 
 #define memcpy_fromio(dst, src, count)	zpci_memcpy_fromio(dst, src, count)
 #define memcpy_toio(dst, src, count)	zpci_memcpy_toio(dst, src, count)
 #define memset_io(dst, val, count)	zpci_memset_io(dst, val, count)
 
+#define mmiowb()	zpci_barrier()
+
 #define __raw_readb	zpci_read_u8
 #define __raw_readw	zpci_read_u16
 #define __raw_readl	zpci_read_u32