/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
* James Leu (jleu@mindspring.net).
* Copyright (C) 2001 by various other people who didn't put their name here.
* Licensed under the GPL.
*/
#include <linux/bootmem.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/platform_device.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <init.h>
#include <irq_kern.h>
#include <irq_user.h>
#include "mconsole_kern.h"
#include <net_kern.h>
#include <net_user.h>
#define DRIVER_NAME "uml-netdev"
static DEFINE_SPINLOCK(opened_lock);
static LIST_HEAD(opened);
/*
* The drop_skb is used when we can't allocate an skb. The
* packet is read into drop_skb in order to get the data off the
* connection to the host.
* It is reallocated whenever a maximum packet size is seen which is
* larger than any seen before. update_drop_skb is called from
* eth_configure when a new interface is added.
*/
static DEFINE_SPINLOCK(drop_lock);
static struct sk_buff *drop_skb;
static int drop_max;
static int update_drop_skb(int max)
{
struct sk_buff *new;
unsigned long flags;
int err = 0;
spin_lock_irqsave(&drop_lock, flags);
if (max <= drop_max)
goto out;
err = -ENOMEM;
new = dev_alloc_skb(max);
if (new == NULL)
goto out;
skb_put(new, max);
kfree_skb(drop_skb);
drop_skb = new;
drop_max = max;
err = 0;
out:
spin_unlock_irqrestore(&drop_lock, flags);
return err;
}
static int uml_net_rx(struct net_device *dev)
{
struct uml_net_private *lp = netdev_priv(dev);
int pkt_len;
struct sk_buff *skb;
/* If we can't allocate memory, try again next round. */
skb = dev_alloc_skb(lp->max_packet);
if (skb == NULL) {
drop_skb->dev = dev;
/* Read a packet into drop_skb and don't do anything with it. */
(*lp->read)(lp->fd, drop_skb, lp);
dev->stats.rx_dropped++;
return 0;
}
skb->dev = dev;
skb_put(skb, lp->max_packet);
skb_reset_mac_header(skb);
pkt_len = (*lp->read)(lp->fd, skb, lp);
if (pkt_len > 0) {
skb_trim(skb, pkt_len);
skb->protocol = (*lp->protocol)(skb);
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;
netif_rx(skb);
return pkt_len;
}
kfree_skb(skb);
return pkt_len;
}
static void uml_dev_close(struct work_struct *work)
{
struct uml_net_private *lp =
container_of(work, struct uml_net_private, work);
dev_close(lp->dev);
}
static irqreturn_t uml_net_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct uml_net_private *lp = netdev_priv(dev);
int err;
if (!netif_running(dev))
return IRQ_NONE;
spin_lock(&lp->lock);
while ((err = uml_net_rx(dev)) > 0) ;
if (err < 0) {
printk(KERN_ERR
"Device '%s' read returned %d, shutting it down\n",
dev->name, err);
/* dev_close can't be called in interrupt context, and takes
* again lp->lock.
* And dev_close() can be safely called multiple times on the
* same device, since it tests for (dev->flags & IFF_UP). So
* there's no harm in delaying the device shutdown.
* Furthermore, the workqueue will not re-enqueue an already
* enqueued work item. */
schedule_work(&lp->work);
goto out;
}
reactivate_fd(lp->fd, UM_ETH_IRQ);
out:
spin_unlock(&lp->lock);
return IRQ_HANDLED;
}
static int uml_net_open(struct net_device *dev)
{
struct uml_net_private *lp = netdev_priv(dev);
int err;
if (lp->fd >= 0) {
err = -ENXIO;
goto out;
}
lp->fd = (*lp->open)(&lp->user);
if (lp->fd < 0) {
err = lp->fd;
goto out;
}
err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
IRQF_SHARED, dev->name, dev);
if (err != 0) {
printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
err = -ENETUNREACH;
goto out_close;
}
lp->tl.data = (unsigned long) &lp->user;
netif_start_queue(dev);
/* clear buffer - it can happen that the host side of the interface
* is full when we get here. In this case, new data is never queued,
* SIGIOs never arrive, and the net never works.
*/
while ((err = uml_net_rx(dev))