Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/kernel/Documentation/laptops/freefall.c b/kernel/Documentation/laptops/freefall.c
new file mode 100644
index 000000000..5e44b20b1
--- /dev/null
+++ b/kernel/Documentation/laptops/freefall.c
@@ -0,0 +1,174 @@
+/* Disk protection for HP/DELL machines.
+ *
+ * Copyright 2008 Eric Piel
+ * Copyright 2009 Pavel Machek <pavel@ucw.cz>
+ * Copyright 2012 Sonal Santan
+ * Copyright 2014 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * GPLv2.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include <sched.h>
+#include <syslog.h>
+
+static int noled;
+static char unload_heads_path[64];
+static char device_path[32];
+static const char app_name[] = "FREE FALL";
+
+static int set_unload_heads_path(char *device)
+{
+	if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
+		return -EINVAL;
+	strncpy(device_path, device, sizeof(device_path) - 1);
+
+	snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
+				"/sys/block/%s/device/unload_heads", device+5);
+	return 0;
+}
+
+static int valid_disk(void)
+{
+	int fd = open(unload_heads_path, O_RDONLY);
+
+	if (fd < 0) {
+		perror(unload_heads_path);
+		return 0;
+	}
+
+	close(fd);
+	return 1;
+}
+
+static void write_int(char *path, int i)
+{
+	char buf[1024];
+	int fd = open(path, O_RDWR);
+
+	if (fd < 0) {
+		perror("open");
+		exit(1);
+	}
+
+	sprintf(buf, "%d", i);
+
+	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
+		perror("write");
+		exit(1);
+	}
+
+	close(fd);
+}
+
+static void set_led(int on)
+{
+	if (noled)
+		return;
+	write_int("/sys/class/leds/hp::hddprotect/brightness", on);
+}
+
+static void protect(int seconds)
+{
+	const char *str = (seconds == 0) ? "Unparked" : "Parked";
+
+	write_int(unload_heads_path, seconds*1000);
+	syslog(LOG_INFO, "%s %s disk head\n", str, device_path);
+}
+
+static int on_ac(void)
+{
+	/* /sys/class/power_supply/AC0/online */
+	return 1;
+}
+
+static int lid_open(void)
+{
+	/* /proc/acpi/button/lid/LID/state */
+	return 1;
+}
+
+static void ignore_me(int signum)
+{
+	protect(0);
+	set_led(0);
+}
+
+int main(int argc, char **argv)
+{
+	int fd, ret;
+	struct stat st;
+	struct sched_param param;
+
+	if (argc == 1)
+		ret = set_unload_heads_path("/dev/sda");
+	else if (argc == 2)
+		ret = set_unload_heads_path(argv[1]);
+	else
+		ret = -EINVAL;
+
+	if (ret || !valid_disk()) {
+		fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
+				argv[0]);
+		exit(1);
+	}
+
+	fd = open("/dev/freefall", O_RDONLY);
+	if (fd < 0) {
+		perror("/dev/freefall");
+		return EXIT_FAILURE;
+	}
+
+	if (stat("/sys/class/leds/hp::hddprotect/brightness", &st))
+		noled = 1;
+
+	if (daemon(0, 0) != 0) {
+		perror("daemon");
+		return EXIT_FAILURE;
+	}
+
+	openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
+
+	param.sched_priority = sched_get_priority_max(SCHED_FIFO);
+	sched_setscheduler(0, SCHED_FIFO, &param);
+	mlockall(MCL_CURRENT|MCL_FUTURE);
+
+	signal(SIGALRM, ignore_me);
+
+	for (;;) {
+		unsigned char count;
+
+		ret = read(fd, &count, sizeof(count));
+		alarm(0);
+		if ((ret == -1) && (errno == EINTR)) {
+			/* Alarm expired, time to unpark the heads */
+			continue;
+		}
+
+		if (ret != sizeof(count)) {
+			perror("read");
+			break;
+		}
+
+		protect(21);
+		set_led(1);
+		if (1 || on_ac() || lid_open())
+			alarm(2);
+		else
+			alarm(20);
+	}
+
+	closelog();
+	close(fd);
+	return EXIT_SUCCESS;
+}