zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/xenbus.c b/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/xenbus.c
new file mode 100644
index 0000000..bad4ee3
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/xenbus.c
@@ -0,0 +1,492 @@
+/*
+ * Xenbus code for netif backend
+ *
+ * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
+ * Copyright (C) 2005 XenSource Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#include "common.h"
+
+struct backend_info {
+	struct xenbus_device *dev;
+	struct xenvif *vif;
+	enum xenbus_state frontend_state;
+	struct xenbus_watch hotplug_status_watch;
+	u8 have_hotplug_status_watch:1;
+
+	const char *hotplug_script;
+};
+
+static int connect_rings(struct backend_info *);
+static void connect(struct backend_info *);
+static void backend_create_xenvif(struct backend_info *be);
+static void unregister_hotplug_status_watch(struct backend_info *be);
+
+static int netback_remove(struct xenbus_device *dev)
+{
+	struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+	unregister_hotplug_status_watch(be);
+	if (be->vif) {
+		kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+		xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
+		xenvif_disconnect(be->vif);
+		be->vif = NULL;
+	}
+	kfree(be->hotplug_script);
+	kfree(be);
+	dev_set_drvdata(&dev->dev, NULL);
+	return 0;
+}
+
+
+/**
+ * Entry point to this code when a new device is created.  Allocate the basic
+ * structures and switch to InitWait.
+ */
+static int netback_probe(struct xenbus_device *dev,
+			 const struct xenbus_device_id *id)
+{
+	const char *message;
+	struct xenbus_transaction xbt;
+	int err;
+	int sg;
+	const char *script;
+	struct backend_info *be = kzalloc(sizeof(struct backend_info),
+					  GFP_KERNEL);
+	if (!be) {
+		xenbus_dev_fatal(dev, -ENOMEM,
+				 "allocating backend structure");
+		return -ENOMEM;
+	}
+
+	be->dev = dev;
+	dev_set_drvdata(&dev->dev, be);
+
+	sg = 1;
+
+	do {
+		err = xenbus_transaction_start(&xbt);
+		if (err) {
+			xenbus_dev_fatal(dev, err, "starting transaction");
+			goto fail;
+		}
+
+		err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
+		if (err) {
+			message = "writing feature-sg";
+			goto abort_transaction;
+		}
+
+		err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
+				    "%d", sg);
+		if (err) {
+			message = "writing feature-gso-tcpv4";
+			goto abort_transaction;
+		}
+
+		/* We support rx-copy path. */
+		err = xenbus_printf(xbt, dev->nodename,
+				    "feature-rx-copy", "%d", 1);
+		if (err) {
+			message = "writing feature-rx-copy";
+			goto abort_transaction;
+		}
+
+		/*
+		 * We don't support rx-flip path (except old guests who don't
+		 * grok this feature flag).
+		 */
+		err = xenbus_printf(xbt, dev->nodename,
+				    "feature-rx-flip", "%d", 0);
+		if (err) {
+			message = "writing feature-rx-flip";
+			goto abort_transaction;
+		}
+
+		err = xenbus_transaction_end(xbt, 0);
+	} while (err == -EAGAIN);
+
+	if (err) {
+		xenbus_dev_fatal(dev, err, "completing transaction");
+		goto fail;
+	}
+
+	script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
+	if (IS_ERR(script)) {
+		err = PTR_ERR(script);
+		xenbus_dev_fatal(dev, err, "reading script");
+		goto fail;
+	}
+
+	be->hotplug_script = script;
+
+	err = xenbus_switch_state(dev, XenbusStateInitWait);
+	if (err)
+		goto fail;
+
+	/* This kicks hotplug scripts, so do it immediately. */
+	backend_create_xenvif(be);
+
+	return 0;
+
+abort_transaction:
+	xenbus_transaction_end(xbt, 1);
+	xenbus_dev_fatal(dev, err, "%s", message);
+fail:
+	pr_debug("failed");
+	netback_remove(dev);
+	return err;
+}
+
+
+/*
+ * Handle the creation of the hotplug script environment.  We add the script
+ * and vif variables to the environment, for the benefit of the vif-* hotplug
+ * scripts.
+ */
+static int netback_uevent(struct xenbus_device *xdev,
+			  struct kobj_uevent_env *env)
+{
+	struct backend_info *be = dev_get_drvdata(&xdev->dev);
+
+	if (!be)
+		return 0;
+
+	if (add_uevent_var(env, "script=%s", be->hotplug_script))
+		return -ENOMEM;
+
+	if (!be->vif)
+		return 0;
+
+	return add_uevent_var(env, "vif=%s", be->vif->dev->name);
+}
+
+
+static void backend_create_xenvif(struct backend_info *be)
+{
+	int err;
+	long handle;
+	struct xenbus_device *dev = be->dev;
+
+	if (be->vif != NULL)
+		return;
+
+	err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
+	if (err != 1) {
+		xenbus_dev_fatal(dev, err, "reading handle");
+		return;
+	}
+
+	be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
+	if (IS_ERR(be->vif)) {
+		err = PTR_ERR(be->vif);
+		be->vif = NULL;
+		xenbus_dev_fatal(dev, err, "creating interface");
+		return;
+	}
+
+	kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
+}
+
+
+static void disconnect_backend(struct xenbus_device *dev)
+{
+	struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+	if (be->vif) {
+		xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
+		xenvif_disconnect(be->vif);
+		be->vif = NULL;
+	}
+}
+
+/**
+ * Callback received when the frontend's state changes.
+ */
+static void frontend_changed(struct xenbus_device *dev,
+			     enum xenbus_state frontend_state)
+{
+	struct backend_info *be = dev_get_drvdata(&dev->dev);
+
+	pr_debug("frontend state %s", xenbus_strstate(frontend_state));
+
+	be->frontend_state = frontend_state;
+
+	switch (frontend_state) {
+	case XenbusStateInitialising:
+		if (dev->state == XenbusStateClosed) {
+			printk(KERN_INFO "%s: %s: prepare for reconnect\n",
+			       __func__, dev->nodename);
+			xenbus_switch_state(dev, XenbusStateInitWait);
+		}
+		break;
+
+	case XenbusStateInitialised:
+		break;
+
+	case XenbusStateConnected:
+		if (dev->state == XenbusStateConnected)
+			break;
+		backend_create_xenvif(be);
+		if (be->vif)
+			connect(be);
+		break;
+
+	case XenbusStateClosing:
+		if (be->vif)
+			kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
+		disconnect_backend(dev);
+		xenbus_switch_state(dev, XenbusStateClosing);
+		break;
+
+	case XenbusStateClosed:
+		xenbus_switch_state(dev, XenbusStateClosed);
+		if (xenbus_dev_is_online(dev))
+			break;
+		/* fall through if not online */
+	case XenbusStateUnknown:
+		device_unregister(&dev->dev);
+		break;
+
+	default:
+		xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+				 frontend_state);
+		break;
+	}
+}
+
+
+static void xen_net_read_rate(struct xenbus_device *dev,
+			      unsigned long *bytes, unsigned long *usec)
+{
+	char *s, *e;
+	unsigned long b, u;
+	char *ratestr;
+
+	/* Default to unlimited bandwidth. */
+	*bytes = ~0UL;
+	*usec = 0;
+
+	ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
+	if (IS_ERR(ratestr))
+		return;
+
+	s = ratestr;
+	b = simple_strtoul(s, &e, 10);
+	if ((s == e) || (*e != ','))
+		goto fail;
+
+	s = e + 1;
+	u = simple_strtoul(s, &e, 10);
+	if ((s == e) || (*e != '\0'))
+		goto fail;
+
+	*bytes = b;
+	*usec = u;
+
+	kfree(ratestr);
+	return;
+
+ fail:
+	pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
+	kfree(ratestr);
+}
+
+static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
+{
+	char *s, *e, *macstr;
+	int i;
+
+	macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
+	if (IS_ERR(macstr))
+		return PTR_ERR(macstr);
+
+	for (i = 0; i < ETH_ALEN; i++) {
+		mac[i] = simple_strtoul(s, &e, 16);
+		if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
+			kfree(macstr);
+			return -ENOENT;
+		}
+		s = e+1;
+	}
+
+	kfree(macstr);
+	return 0;
+}
+
+static void unregister_hotplug_status_watch(struct backend_info *be)
+{
+	if (be->have_hotplug_status_watch) {
+		unregister_xenbus_watch(&be->hotplug_status_watch);
+		kfree(be->hotplug_status_watch.node);
+	}
+	be->have_hotplug_status_watch = 0;
+}
+
+static void hotplug_status_changed(struct xenbus_watch *watch,
+				   const char **vec,
+				   unsigned int vec_size)
+{
+	struct backend_info *be = container_of(watch,
+					       struct backend_info,
+					       hotplug_status_watch);
+	char *str;
+	unsigned int len;
+
+	str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
+	if (IS_ERR(str))
+		return;
+	if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
+		xenbus_switch_state(be->dev, XenbusStateConnected);
+		/* Not interested in this watch anymore. */
+		unregister_hotplug_status_watch(be);
+	}
+	kfree(str);
+}
+
+static void connect(struct backend_info *be)
+{
+	int err;
+	struct xenbus_device *dev = be->dev;
+
+	err = connect_rings(be);
+	if (err)
+		return;
+
+	err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
+	if (err) {
+		xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
+		return;
+	}
+
+	xen_net_read_rate(dev, &be->vif->credit_bytes,
+			  &be->vif->credit_usec);
+	be->vif->remaining_credit = be->vif->credit_bytes;
+
+	unregister_hotplug_status_watch(be);
+	err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
+				   hotplug_status_changed,
+				   "%s/%s", dev->nodename, "hotplug-status");
+	if (err) {
+		/* Switch now, since we can't do a watch. */
+		xenbus_switch_state(dev, XenbusStateConnected);
+	} else {
+		be->have_hotplug_status_watch = 1;
+	}
+
+	netif_wake_queue(be->vif->dev);
+}
+
+
+static int connect_rings(struct backend_info *be)
+{
+	struct xenvif *vif = be->vif;
+	struct xenbus_device *dev = be->dev;
+	unsigned long tx_ring_ref, rx_ring_ref;
+	unsigned int evtchn, rx_copy;
+	int err;
+	int val;
+
+	err = xenbus_gather(XBT_NIL, dev->otherend,
+			    "tx-ring-ref", "%lu", &tx_ring_ref,
+			    "rx-ring-ref", "%lu", &rx_ring_ref,
+			    "event-channel", "%u", &evtchn, NULL);
+	if (err) {
+		xenbus_dev_fatal(dev, err,
+				 "reading %s/ring-ref and event-channel",
+				 dev->otherend);
+		return err;
+	}
+
+	err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
+			   &rx_copy);
+	if (err == -ENOENT) {
+		err = 0;
+		rx_copy = 0;
+	}
+	if (err < 0) {
+		xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
+				 dev->otherend);
+		return err;
+	}
+	if (!rx_copy)
+		return -EOPNOTSUPP;
+
+	if (vif->dev->tx_queue_len != 0) {
+		if (xenbus_scanf(XBT_NIL, dev->otherend,
+				 "feature-rx-notify", "%d", &val) < 0)
+			val = 0;
+		if (val)
+			vif->can_queue = 1;
+		else
+			/* Must be non-zero for pfifo_fast to work. */
+			vif->dev->tx_queue_len = 1;
+	}
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
+			 "%d", &val) < 0)
+		val = 0;
+	vif->can_sg = !!val;
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
+			 "%d", &val) < 0)
+		val = 0;
+	vif->gso = !!val;
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
+			 "%d", &val) < 0)
+		val = 0;
+	vif->gso_prefix = !!val;
+
+	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
+			 "%d", &val) < 0)
+		val = 0;
+	vif->csum = !val;
+
+	/* Map the shared frame, irq etc. */
+	err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref, evtchn);
+	if (err) {
+		xenbus_dev_fatal(dev, err,
+				 "mapping shared-frames %lu/%lu port %u",
+				 tx_ring_ref, rx_ring_ref, evtchn);
+		return err;
+	}
+	return 0;
+}
+
+
+/* ** Driver Registration ** */
+
+
+static const struct xenbus_device_id netback_ids[] = {
+	{ "vif" },
+	{ "" }
+};
+
+
+static DEFINE_XENBUS_DRIVER(netback, ,
+	.probe = netback_probe,
+	.remove = netback_remove,
+	.uevent = netback_uevent,
+	.otherend_changed = frontend_changed,
+);
+
+int xenvif_xenbus_init(void)
+{
+	return xenbus_register_backend(&netback_driver);
+}