Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h
index e25f439..c82f7a2 100644
--- a/arch/arm/include/asm/proc-fns.h
+++ b/arch/arm/include/asm/proc-fns.h
@@ -1,12 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  *  arch/arm/include/asm/proc-fns.h
  *
  *  Copyright (C) 1997-1999 Russell King
  *  Copyright (C) 2000 Deep Blue Solutions Ltd
- *
- * 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.
  */
 #ifndef __ASM_PROCFNS_H
 #define __ASM_PROCFNS_H
@@ -23,7 +20,7 @@
 /*
  * Don't change this structure - ASM code relies on it.
  */
-extern struct processor {
+struct processor {
 	/* MISC
 	 * get data abort address/flags
 	 */
@@ -79,9 +76,13 @@
 	unsigned int suspend_size;
 	void (*do_suspend)(void *);
 	void (*do_resume)(void *);
-} processor;
+};
 
 #ifndef MULTI_CPU
+static inline void init_proc_vtable(const struct processor *p)
+{
+}
+
 extern void cpu_proc_init(void);
 extern void cpu_proc_fin(void);
 extern int cpu_do_idle(void);
@@ -98,17 +99,50 @@
 extern void cpu_do_suspend(void *);
 extern void cpu_do_resume(void *);
 #else
-#define cpu_proc_init			processor._proc_init
-#define cpu_proc_fin			processor._proc_fin
-#define cpu_reset			processor.reset
-#define cpu_do_idle			processor._do_idle
-#define cpu_dcache_clean_area		processor.dcache_clean_area
-#define cpu_set_pte_ext			processor.set_pte_ext
-#define cpu_do_switch_mm		processor.switch_mm
 
-/* These three are private to arch/arm/kernel/suspend.c */
-#define cpu_do_suspend			processor.do_suspend
-#define cpu_do_resume			processor.do_resume
+extern struct processor processor;
+#if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+#include <linux/smp.h>
+/*
+ * This can't be a per-cpu variable because we need to access it before
+ * per-cpu has been initialised.  We have a couple of functions that are
+ * called in a pre-emptible context, and so can't use smp_processor_id()
+ * there, hence PROC_TABLE().  We insist in init_proc_vtable() that the
+ * function pointers for these are identical across all CPUs.
+ */
+extern struct processor *cpu_vtable[];
+#define PROC_VTABLE(f)			cpu_vtable[smp_processor_id()]->f
+#define PROC_TABLE(f)			cpu_vtable[0]->f
+static inline void init_proc_vtable(const struct processor *p)
+{
+	unsigned int cpu = smp_processor_id();
+	*cpu_vtable[cpu] = *p;
+	WARN_ON_ONCE(cpu_vtable[cpu]->dcache_clean_area !=
+		     cpu_vtable[0]->dcache_clean_area);
+	WARN_ON_ONCE(cpu_vtable[cpu]->set_pte_ext !=
+		     cpu_vtable[0]->set_pte_ext);
+}
+#else
+#define PROC_VTABLE(f)			processor.f
+#define PROC_TABLE(f)			processor.f
+static inline void init_proc_vtable(const struct processor *p)
+{
+	processor = *p;
+}
+#endif
+
+#define cpu_proc_init			PROC_VTABLE(_proc_init)
+#define cpu_check_bugs			PROC_VTABLE(check_bugs)
+#define cpu_proc_fin			PROC_VTABLE(_proc_fin)
+#define cpu_reset			PROC_VTABLE(reset)
+#define cpu_do_idle			PROC_VTABLE(_do_idle)
+#define cpu_dcache_clean_area		PROC_TABLE(dcache_clean_area)
+#define cpu_set_pte_ext			PROC_TABLE(set_pte_ext)
+#define cpu_do_switch_mm		PROC_VTABLE(switch_mm)
+
+/* These two are private to arch/arm/kernel/suspend.c */
+#define cpu_do_suspend			PROC_VTABLE(do_suspend)
+#define cpu_do_resume			PROC_VTABLE(do_resume)
 #endif
 
 extern void cpu_resume(void);