Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index e465bb1..b072aeb 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -177,22 +177,28 @@
 			   struct pt_regs *regs);
 
 /**
+ *	kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU
+ *	@ignored: This parameter is only here to match the prototype.
+ *
+ *	If you're using the default implementation of kgdb_roundup_cpus()
+ *	this function will be called per CPU.  If you don't implement
+ *	kgdb_call_nmi_hook() a default will be used.
+ */
+
+extern void kgdb_call_nmi_hook(void *ignored);
+
+/**
  *	kgdb_roundup_cpus - Get other CPUs into a holding pattern
- *	@flags: Current IRQ state
  *
  *	On SMP systems, we need to get the attention of the other CPUs
  *	and get them into a known state.  This should do what is needed
  *	to get the other CPUs to call kgdb_wait(). Note that on some arches,
- *	the NMI approach is not used for rounding up all the CPUs. For example,
- *	in case of MIPS, smp_call_function() is used to roundup CPUs. In
- *	this case, we have to make sure that interrupts are enabled before
- *	calling smp_call_function(). The argument to this function is
- *	the flags that will be used when restoring the interrupts. There is
- *	local_irq_save() call before kgdb_roundup_cpus().
+ *	the NMI approach is not used for rounding up all the CPUs.  Normally
+ *	those architectures can just not implement this and get the default.
  *
  *	On non-SMP systems, this is not called.
  */
-extern void kgdb_roundup_cpus(unsigned long flags);
+extern void kgdb_roundup_cpus(void);
 
 /**
  *	kgdb_arch_set_pc - Generic call back to the program counter
@@ -281,7 +287,7 @@
 	int			is_console;
 };
 
-extern struct kgdb_arch		arch_kgdb_ops;
+extern const struct kgdb_arch		arch_kgdb_ops;
 
 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
 
@@ -320,8 +326,10 @@
 	(raw_smp_processor_id() == atomic_read(&kgdb_active))
 extern bool dbg_is_early;
 extern void __init dbg_late_init(void);
+extern void kgdb_panic(const char *msg);
 #else /* ! CONFIG_KGDB */
 #define in_dbg_master() (0)
 #define dbg_late_init()
+static inline void kgdb_panic(const char *msg) {}
 #endif /* ! CONFIG_KGDB */
 #endif /* _KGDB_H_ */