# HG changeset patch
# User Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
# Date 1565103965 14400
#      Tue Aug 06 11:06:05 2019 -0400
# Node ID 4e892db025b5502135336f69dae2f4e9de31f269
# Parent  9ef53b94bd0a9b01b52673d513fd007eebe2c28c
include: add a sigp_halt() helper to stop the cpu

Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>

diff --git a/include/arch.h b/include/arch.h
--- a/include/arch.h
+++ b/include/arch.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007-2011 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
+ * Copyright (c) 2007-2019 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -64,6 +64,29 @@
 }
 
 /*
+ * Stop the cpu
+ *
+ * NOTE: We don't care about not clobbering registers as when this
+ * code executes, the CPU will be stopped.
+ *
+ * TODO: mark this with a no-return attribute
+ */
+static inline void sigp_stop(void)
+{
+	asm volatile(
+		"SR	%r1, %r1	# not used, but should be zero\n"
+		"SR	%r3, %r3 	# CPU Address\n"
+		"SIGP	%r1, %r3, 0x05	# order 0x05 = stop\n"
+	);
+
+	/*
+	 * Just in case SIGP fails
+	 */
+	for (;;)
+		;
+}
+
+/*
  * Control Register handling
  */
 #define set_cr(cr, val)						\