1 files changed, 46 insertions, 19 deletions

diff --git a/sys/boot/alpha/libalpha/getsecs.c b/sys/boot/alpha/libalpha/getsecs.c
index 18c87702738b..e4e175c49331 100644
--- a/sys/boot/alpha/libalpha/getsecs.c
+++ b/sys/boot/alpha/libalpha/getsecs.c
@@ -1,5 +1,27 @@
-/*
- * $NetBSD: getsecs.c,v 1.5 1998/01/05 07:02:49 perry Exp $	
+/*-
+ * Copyright (c) 2005 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
@@ -9,31 +31,36 @@ __FBSDID("$FreeBSD$");
 #include <machine/prom.h>
 #include <machine/rpb.h>
 
+static unsigned long lastpcc;
+static int tnsec;
+
+/*
+ * Count the number of elapsed seconds since this function was called first.
+ * The algorithm uses the processor's cycle counter, which means that it'd
+ * better be called frequently (on a 433Mhz machine this means at least once
+ * every 9 seconds or so).
+ */
 int
 getsecs()
 {
-	static long tnsec;
-	static long lastpcc, wrapsecs;
-	long curpcc;
+	struct rpb *hwrpb = (struct rpb *)HWRPB_ADDR;
+	unsigned long curpcc;
+	int delta;
 
 	if (tnsec == 0) {
 		tnsec = 1;
-		lastpcc = alpha_rpcc() & 0xffffffff;
-		wrapsecs = (0xffffffff /
-		    ((struct rpb *)HWRPB_ADDR)->rpb_cc_freq) + 1;
-
-#if 0
-		printf("getsecs: cc freq = %d, time to wrap = %d\n",
-		    ((struct rpb *)HWRPB_ADDR)->rpb_cc_freq, wrapsecs);
-#endif
+		lastpcc = alpha_rpcc() & 0xfffffffful;
+		return (tnsec);
 	}
 
-	curpcc = alpha_rpcc() & 0xffffffff;
+	curpcc = alpha_rpcc() & 0xfffffffful;
 	if (curpcc < lastpcc)
-		curpcc += 0x100000000;
-
-	tnsec += ((curpcc - lastpcc) * 1000000000) / ((struct rpb *)HWRPB_ADDR)->rpb_cc_freq;
-	lastpcc = curpcc;
+		curpcc += 0x100000000ul;
 
-	return (tnsec / 1000000000);
+	delta = (curpcc - lastpcc) / hwrpb->rpb_cc_freq;
+	if (delta) {
+		tnsec += delta;
+		lastpcc = curpcc & 0xfffffffful;
+	}
+	return (tnsec);
 }