/*

* 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"

/* mlr-begin : added include */

/*

#include <string.h>

#include <stdlib.h>

*/

/* mlr-end */

/* mlr-begin : added variable */

static unsigned long total_credit = 625000UL;

/* mlr-end */

struct backend_info {

};

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);

/* mlr-begin : xen_read_bandwidth, domain_number */

/*

static void xen_read_bandwidth(struct xenbus_device *dev)

{

char *s, *e;

unsigned long b;

char *bandwidthstr;

//read bandwidth from config

bandwidthstr = xenbus_read(XBT_NIL, dev->nodename, "bandwidth", NULL);

if (IS_ERR(bandwidthstr))

return;

//convert bandwidth to credit

s = bandwidthstr;

b = simple_strtoul(s, &e, 10);

if ((s == e) || (*e != ','))

goto fail;

total_credit = b;

kfree(bandwidthstr);

return;

fail:

pr_warn("Failed to parse network bandwidth.\n");

kfree(bandwidthstr);

}

*/

/*

static int domain_number()

{

struct domain_device **pd;

int count = 0;

pd = &dev_list_node;

for (pd = &ddev_list_node; *pd != NULL; pd = &(*pd)->next_in_list)

count++;

return count;

}

*/

/*

static int atoi(char *array){

printk("mlr: atoi parse %s\n", array);

int result = 0;

while(*array != '\0'){

result += 10 * result + (*array - '0');

array ++;

}

printk("mlr: result of atoi(%s) is %d\n", array, result);

return result;

}

static int xen_read_priority(struct xenbus_device *dev, int *priority)

{

printk("mlr: enter xen_read_priority\n");

unsigned int b;

char *prioritystr;

//read priority from config

prioritystr = xenbus_read(XBT_NIL, dev->nodename, "priority", NULL);

if (IS_ERR(prioritystr))

return -ENOENT;

b = atoi(prioritystr);

printk("mlr: priority of vm %s is %d\n", dev->nodename, b);

*priority = b;

kfree(prioritystr);

printk("mlr: exit xen_read_priority\n");

return 0;

}

*/

/* mlr-end */

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);

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;

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;

}

/*

* Split event channels support, this is optional so it is not

* put inside the above loop.

*/

err = xenbus_printf(XBT_NIL, dev->nodename,

"feature-split-event-channels",

"%u", separate_tx_rx_irq);

if (err)

pr_debug("Error writing feature-split-event-channels\n");

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\n");

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);

char *val;

val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);

if (IS_ERR(val)) {

int err = PTR_ERR(val);

xenbus_dev_fatal(xdev, err, "reading script");

return err;

} else {

if (add_uevent_var(env, "script=%s", val)) {

kfree(val);

return -ENOMEM;

}

kfree(val);

}

if (!be || !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\n", xenbus_strstate(frontend_state));

be->frontend_state = frontend_state;

switch (frontend_state) {

case XenbusStateInitialising:

if (dev->state == XenbusStateClosed) {

pr_info("%s: prepare for reconnect\n", 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;

}

}

/* mlr-begin : check whether average allocation is set */

/*

static bool xen_net_read_average(struct xenbus_device *dev)

{

char *averagestr;

averagestr = xenbus_read(XBT_NIL, dev->nodename, "average", NULL);

if (IS_ERR(averagestr))

return false;

char *averageset = "true";

if (_stricmp(averagestr, averageset) == 0)

return true;

else

return false;

}

*/

/* mlr-end */

/* mlr-begin : changed, add para unsigned long *initial */

static void xen_net_read_rate(struct xenbus_device *dev,

unsigned long *bytes, unsigned long *usec, unsigned long *initial)

/* mlr-end */

{

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;

/* mlr-begin : check for average */

/**

if (xen_net_read_average)

{

int dn = domain_number();

xen_read_bandwidth(dev);

*bytes = (long) total_credit/dn;

}

else

*/

*bytes = b;

*initial = *bytes;

/* mlr-end */ /* original: *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;

}

/* mlr-begin : read the priority the vif*/

/*

err = xen_read_priority(dev, &(be->vif->priority));

if (err) {

xenbus_dev_fatal(dev, err, "parsing %s/priority", dev->nodename);

return;

}

*/

/* mlr-end */

/* mlr-begin : changed, add para '&be->vif->credit_initial' */

xen_net_read_rate(dev, &be->vif->credit_bytes,

&be->vif->credit_usec, &be->vif->credit_initial);

printk("mlr: vif-%s credit initial is %ld\n", be->vif->dev->name, be->vif->credit_initial);

/* mlr-end */

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 tx_evtchn, rx_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, NULL);

if (err) {

xenbus_dev_fatal(dev, err,

"reading %s/ring-ref",

dev->otherend);

return err;

}

/* Try split event channels first, then single event channel. */

err = xenbus_gather(XBT_NIL, dev->otherend,

"event-channel-tx", "%u", &tx_evtchn,

"event-channel-rx", "%u", &rx_evtchn, NULL);

if (err < 0) {

err = xenbus_scanf(XBT_NIL, dev->otherend,

"event-channel", "%u", &tx_evtchn);

if (err < 0) {

xenbus_dev_fatal(dev, err,

"reading %s/event-channel(-tx/rx)",

dev->otherend);

return err;

}

rx_evtchn = tx_evtchn;

}

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,

tx_evtchn, rx_evtchn);

if (err) {

xenbus_dev_fatal(dev, err,

"mapping shared-frames %lu/%lu port tx %u rx %u",

tx_ring_ref, rx_ring_ref,

tx_evtchn, rx_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);

}

void xenvif_xenbus_fini(void)

{

return xenbus_unregister_driver(&netback_driver);

}