Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/parisc/kernel/head.S b/arch/parisc/kernel/head.S
index fbb4e43..951a339 100644
--- a/arch/parisc/kernel/head.S
+++ b/arch/parisc/kernel/head.S
@@ -22,7 +22,7 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 
-	.level	LEVEL
+	.level	PA_ASM_LEVEL
 
 	__INITDATA
 ENTRY(boot_args)
@@ -258,7 +258,7 @@
 	ldo		R%PA(fault_vector_11)(%r10),%r10
 
 $is_pa20:
-	.level		LEVEL /* restore 1.1 || 2.0w */
+	.level		PA_ASM_LEVEL /* restore 1.1 || 2.0w */
 #endif /*!CONFIG_64BIT*/
 	load32		PA(fault_vector_20),%r10
 
@@ -329,6 +329,19 @@
 	mtsp	   %r0,%sr6
 	mtsp	   %r0,%sr7
 
+#ifdef CONFIG_64BIT
+	/*
+	 *  Enable Wide mode early, in case the task_struct for the idle
+	 *  task in smp_init_current_idle_task was allocated above 4GB.
+	 */
+1:	mfia            %rp             /* clear upper part of pcoq */
+	ldo             2f-1b(%rp),%rp
+	depdi           0,31,32,%rp
+	bv              (%rp)
+	ssm             PSW_SM_W,%r0
+2:
+#endif
+
 	/*  Initialize the SP - monarch sets up smp_init_current_idle_task */
 	load32		PA(smp_init_current_idle_task),%sp
 	LDREG		0(%sp),%sp	/* load task address */
@@ -363,7 +376,7 @@
 ENDPROC(parisc_kernel_start)
 
 #ifndef CONFIG_64BIT
-	.section .data..read_mostly
+	.section .data..ro_after_init
 
 	.align	4
 	.export	$global$,data