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, 120 insertions, 0 deletions

diff --git a/kernel/arch/um/drivers/slirp_kern.c b/kernel/arch/um/drivers/slirp_kern.c
new file mode 100644
index 000000000..4ef11ca7c
--- /dev/null
+++ b/kernel/arch/um/drivers/slirp_kern.c
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL.
+ */
+
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <net_kern.h>
+#include <net_user.h>
+#include "slirp.h"
+
+struct slirp_init {
+	struct arg_list_dummy_wrapper argw;  /* XXX should be simpler... */
+};
+
+void slirp_init(struct net_device *dev, void *data)
+{
+	struct uml_net_private *private;
+	struct slirp_data *spri;
+	struct slirp_init *init = data;
+	int i;
+
+	private = netdev_priv(dev);
+	spri = (struct slirp_data *) private->user;
+
+	spri->argw = init->argw;
+	spri->pid = -1;
+	spri->slave = -1;
+	spri->dev = dev;
+
+	slip_proto_init(&spri->slip);
+
+	dev->hard_header_len = 0;
+	dev->header_ops = NULL;
+	dev->addr_len = 0;
+	dev->type = ARPHRD_SLIP;
+	dev->tx_queue_len = 256;
+	dev->flags = IFF_NOARP;
+	printk("SLIRP backend - command line:");
+	for (i = 0; spri->argw.argv[i] != NULL; i++)
+		printk(" '%s'",spri->argw.argv[i]);
+	printk("\n");
+}
+
+static unsigned short slirp_protocol(struct sk_buff *skbuff)
+{
+	return htons(ETH_P_IP);
+}
+
+static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
+			       (struct slirp_data *) &lp->user);
+}
+
+static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	return slirp_user_write(fd, skb->data, skb->len,
+				(struct slirp_data *) &lp->user);
+}
+
+const struct net_kern_info slirp_kern_info = {
+	.init			= slirp_init,
+	.protocol		= slirp_protocol,
+	.read			= slirp_read,
+	.write			= slirp_write,
+};
+
+static int slirp_setup(char *str, char **mac_out, void *data)
+{
+	struct slirp_init *init = data;
+	int i=0;
+
+	*init = ((struct slirp_init) { .argw = { { "slirp", NULL  } } });
+
+	str = split_if_spec(str, mac_out, NULL);
+
+	if (str == NULL) /* no command line given after MAC addr */
+		return 1;
+
+	do {
+		if (i >= SLIRP_MAX_ARGS - 1) {
+			printk(KERN_WARNING "slirp_setup: truncating slirp "
+			       "arguments\n");
+			break;
+		}
+		init->argw.argv[i++] = str;
+		while(*str && *str!=',') {
+			if (*str == '_')
+				*str=' ';
+			str++;
+		}
+		if (*str != ',')
+			break;
+		*str++ = '\0';
+	} while (1);
+
+	init->argw.argv[i] = NULL;
+	return 1;
+}
+
+static struct transport slirp_transport = {
+	.list 		= LIST_HEAD_INIT(slirp_transport.list),
+	.name 		= "slirp",
+	.setup  	= slirp_setup,
+	.user 		= &slirp_user_info,
+	.kern 		= &slirp_kern_info,
+	.private_size 	= sizeof(struct slirp_data),
+	.setup_size 	= sizeof(struct slirp_init),
+};
+
+static int register_slirp(void)
+{
+	register_transport(&slirp_transport);
+	return 0;
+}
+
+late_initcall(register_slirp);