[PATCH 21/58] microblaze_v5: heartbeat file

From: monstr
Date: Tue Jul 08 2008 - 08:41:37 EST


From: Michal Simek <monstr@xxxxxxxxx>

Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xxxxxxxxxx>
Signed-off-by: Michal Simek <monstr@xxxxxxxxx>
---
arch/microblaze/kernel/heartbeat.c | 35 +++++++++++++++++++++++++++++++++++
1 files changed, 35 insertions(+), 0 deletions(-)
create mode 100644 arch/microblaze/kernel/heartbeat.c

diff --git a/arch/microblaze/kernel/heartbeat.c b/arch/microblaze/kernel/heartbeat.c
new file mode 100644
index 0000000..5a21c1d
--- /dev/null
+++ b/arch/microblaze/kernel/heartbeat.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2007-2008 Michal Simek <monstr@xxxxxxxxx>
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/sched.h>
+#include <asm/page.h>
+#include <asm/io.h>
+#include <asm/setup.h>
+
+void heartbeat(void)
+{
+ static unsigned int cnt, period, dist;
+
+ if (cnt == 0 || cnt == dist)
+ iowrite32(1, CONFIG_HEART_BEAT_ADDRESS);
+ else if (cnt == 7 || cnt == dist + 7)
+ iowrite32(0, CONFIG_HEART_BEAT_ADDRESS);
+
+ if (++cnt > period) {
+ cnt = 0;
+ /*
+ * The hyperbolic function below modifies the heartbeat period
+ * length in dependency of the current (5min) load. It goes
+ * through the points f(0)=126, f(1)=86, f(5)=51, f(inf)->30.
+ */
+ period = ((672 << FSHIFT) / (5 * avenrun[0] +
+ (7 << FSHIFT))) + 30;
+ dist = period / 4;
+ }
+}
--
1.5.4.GIT

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/