Index: sys/arch/sparc/include/promlib.h
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/include/promlib.h,v
retrieving revision 1.24
diff -u -r1.24 promlib.h
--- sys/arch/sparc/include/promlib.h	21 Jan 2010 11:40:01 -0000	1.24
+++ sys/arch/sparc/include/promlib.h	8 Sep 2017 18:46:00 -0000
@@ -137,6 +137,7 @@
 /* Utility routines */
 int	prom_getprop(int, const char *, size_t, int *, void *);
 int	prom_getpropint(int, const char *, int);
+uint64_t prom_getpropuint64(int, const char *, uint64_t);
 char	*prom_getpropstring(int, const char *);
 char	*prom_getpropstringA(int, const char *, char *, size_t);
 void	prom_printf(const char *, ...);
Index: sys/arch/sparc/sparc/promlib.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/sparc/promlib.c,v
retrieving revision 1.45
diff -u -r1.45 promlib.c
--- sys/arch/sparc/sparc/promlib.c	1 Apr 2016 20:21:45 -0000	1.45
+++ sys/arch/sparc/sparc/promlib.c	8 Sep 2017 18:46:00 -0000
@@ -265,6 +265,22 @@
 }
 
 /*
+ * Fetch an unsigned 64-bit integer (or pointer) property.
+ * The return value is the property, or the default if there was none.
+ */
+uint64_t
+prom_getpropuint64(int node, const char *name, uint64_t deflt)
+{
+	uint64_t uint64buf, *uint64p = &uint64buf;
+	int len = 2;
+
+	if (prom_getprop(node, name, sizeof(uint64_t), &len, &uint64p) != 0)
+		return (deflt);
+
+	return (*uint64p);
+}
+
+/*
  * Node Name Matching per IEEE 1275, section 4.3.6.
  */
 static int
Index: sys/arch/sparc64/include/autoconf.h
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc64/include/autoconf.h,v
retrieving revision 1.32
diff -u -r1.32 autoconf.h
--- sys/arch/sparc64/include/autoconf.h	26 Oct 2013 18:47:27 -0000	1.32
+++ sys/arch/sparc64/include/autoconf.h	8 Sep 2017 18:46:00 -0000
@@ -133,7 +133,7 @@
  * `clockfreq' produces a printable representation of a clock frequency
  * (this is just a frill).
  */
-char	*clockfreq(long);
+char	*clockfreq(uint64_t);
 
 /* Kernel initialization routine. */
 void	bootstrap(void *, void *, void *, void *, void *);
Index: sys/arch/sparc64/sparc64/autoconf.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc64/sparc64/autoconf.c,v
retrieving revision 1.211
diff -u -r1.211 autoconf.c
--- sys/arch/sparc64/sparc64/autoconf.c	26 Mar 2017 12:59:29 -0000	1.211
+++ sys/arch/sparc64/sparc64/autoconf.c	8 Sep 2017 18:46:00 -0000
@@ -521,16 +521,16 @@
 }
 
 char *
-clockfreq(long freq)
+clockfreq(uint64_t freq)
 {
 	static char buf[10];
 	size_t len;
 
 	freq /= 1000;
-	len = snprintf(buf, sizeof(buf), "%ld", freq / 1000);
+	len = snprintf(buf, sizeof(buf), "%" PRIu64, freq / 1000);
 	freq %= 1000;
 	if (freq)
-		snprintf(buf + len, sizeof(buf) - len, ".%03ld", freq);
+		snprintf(buf + len, sizeof(buf) - len, ".%03" PRIu64, freq);
 	return buf;
 }
 
Index: sys/arch/sparc64/sparc64/cpu.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc64/sparc64/cpu.c,v
retrieving revision 1.131
diff -u -r1.131 cpu.c
--- sys/arch/sparc64/sparc64/cpu.c	27 Aug 2017 19:31:43 -0000	1.131
+++ sys/arch/sparc64/sparc64/cpu.c	8 Sep 2017 18:46:00 -0000
@@ -421,7 +421,7 @@
 cpu_attach(device_t parent, device_t dev, void *aux)
 {
 	int node;
-	unsigned int clk, sclk = 0;
+	uint64_t clk, sclk = 0;
 	struct mainbus_attach_args *ma = aux;
 	struct cpu_info *ci;
 	const char *sep;
@@ -465,7 +465,9 @@
 			     device_xname(dev), "timer");
 	mutex_init(&ci->ci_ctx_lock, MUTEX_SPIN, IPL_VM);
 
-	clk = prom_getpropint(node, "clock-frequency", 0);
+	clk = prom_getpropuint64(node, "clock-frequency64", 0);
+	if (clk == 0)
+	  clk = prom_getpropint(node, "clock-frequency", 0);
 	if (clk == 0) {
 		/*
 		 * Try to find it in the OpenPROM root...