text: /*
   *
   * arch/xtensa/platforms/iss/network.c
   *
   * Platform specific initialization.
   *
   * Authors: Chris Zankel <chris@zankel.net>
   * Based on work form the UML team.
   *
   * Copyright 2005 Tensilica Inc.
   *
   * 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.
   *
   */
  
  #include <linux/list.h>
  #include <linux/irq.h>
  #include <linux/spinlock.h>
  #include <linux/slab.h>
  #include <linux/timer.h>
  #include <linux/if_ether.h>
  #include <linux/inetdevice.h>
  #include <linux/init.h>
  #include <linux/if_tun.h>
  #include <linux/etherdevice.h>
  #include <linux/interrupt.h>
  #include <linux/ioctl.h>
  #include <linux/bootmem.h>
  #include <linux/ethtool.h>
  #include <linux/rtnetlink.h>
  #include <linux/platform_device.h>
  
  #include <platform/simcall.h>
  
  #define DRIVER_NAME "iss-netdev"
  #define ETH_MAX_PACKET 1500
  #define ETH_HEADER_OTHER 14
  #define ISS_NET_TIMER_VALUE (HZ / 10)
  
  
  static DEFINE_SPINLOCK(opened_lock);
  static LIST_HEAD(opened);
  
  static DEFINE_SPINLOCK(devices_lock);
  static LIST_HEAD(devices);
  
  /* ------------------------------------------------------------------------- */
  
  /* We currently only support the TUNTAP transport protocol. */
  
  #define TRANSPORT_TUNTAP_NAME "tuntap"
  #define TRANSPORT_TUNTAP_MTU ETH_MAX_PACKET
  
  struct tuntap_info {
  	char dev_name[IFNAMSIZ];
  	int fd;
  };
  
  /* ------------------------------------------------------------------------- */
  
  
  /* This structure contains out private information for the driver. */
  
  struct iss_net_private {
  	struct list_head device_list;
  	struct list_head opened_list;
  
  	spinlock_t lock;
  	struct net_device *dev;
  	struct platform_device pdev;
  	struct timer_list tl;
  	struct net_device_stats stats;
  
  	struct timer_list timer;
  	unsigned int timer_val;
  
  	int index;
  	int mtu;
  
  	struct {
  		union {
  			struct tuntap_info tuntap;
  		} info;
  
  		int (*open)(struct iss_net_private *lp);
  		void (*close)(struct iss_net_private *lp);
  		int (*read)(struct iss_net_private *lp, struct sk_buff **skb);
  		int (*write)(struct iss_net_private *lp, struct sk_buff **skb);
  		unsigned short (*protocol)(struct sk_buff *skb);
  		int (*poll)(struct iss_net_private *lp);
  	} tp;
  
  };
  
  /* ================================ HELPERS ================================ */
  
  
  static char *split_if_spec(char *str, ...)
  {
  	char **arg, *end;
  	va_list ap;
  
  	va_start(ap, str);
  	while ((arg = va_arg(ap, char**)) != NULL) {
  		if (*str == '\0') {
  			va_end(ap);
  			return NULL;
  		}
  		end = strchr(str, ',');
  		if (end != str)
  			*arg = str;
  		if (end == NULL) {
  			va_end(ap);
  			return NULL;
  		}
  		*end++ = '\0';
  		str = end;
  	}
  	va_end(ap);
  	return str;
  }
  
  /* Set Ethernet address of the specified device. */
  
  static void setup_etheraddr(struct net_device *dev, char *str)
  {
  	unsigned char *addr = dev->dev_addr;
  
  	if (str == NULL)
  		goto random;
  
  	if (!mac_pton(str, addr)) {
  		pr_err("%s: failed to parse '%s' as an ethernet address\n",
  		       dev->name, str);
  		goto random;
  	}
  	if (is_multicast_ether_addr(addr)) {
  		pr_err("%s: attempt to assign a multicast ethernet address\n",
  		       dev->name);
  		goto random;
  	}
  	if (!is_valid_ether_addr(addr)) {
  		pr_err("%s: attempt to assign an invalid ethernet address\n",
  		       dev->name);
  		goto random;
  	}
  	if (!is_local_ether_addr(addr))
  		pr_warn("%s: assigning a globally valid ethernet address\n",
  			dev->name);
  	return;
  
  random:
  	pr_info("%s: choosing a random ethernet address\n",
  		dev->name);
  	eth_hw_addr_random(dev);
  }
  
  /* ======================= TUNTAP TRANSPORT INTERFACE ====================== */
  
  static int tuntap_open(struct iss_net_private *lp)
  {
  	struct ifreq ifr;
  	char *dev_name = lp->tp.info.tuntap.dev_name;
  	int err = -EINVAL;
  	int fd;
  
  	fd = simc_open("/dev/net/tun", 02, 0); /* O_RDWR */
  	if (fd < 0) {
  		pr_err("%s: failed to open /dev/net/tun, returned %d (errno = %d)\n",
  		       lp->dev->name, fd, errno);
  		return fd;
  	}
  
  	memset(&ifr, 0, sizeof(ifr));
  	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  	strlcpy(ifr.ifr_name, dev_name, sizeof(ifr.ifr_name));
  
  	err = simc_ioctl(fd, TUNSETIFF, &ifr);
  	if (err < 0) {
  		pr_err("%s: failed to set interface %s, returned %d (errno = %d)\n",
  		       lp->dev->name, dev_name, err, errno);
  		simc_close(fd);
  		return err;
  	}
  
  	lp->tp.info.tuntap.fd = fd;
  	return err;
  }
  
  static void tuntap_close(struct iss_net_private *lp)
  {
  	simc_close(lp->tp.info.tuntap.fd);
  	lp->tp.info.tuntap.fd = -1;
  }
  
  static int tuntap_read(struct iss_net_private *lp, struct sk_buff **skb)
  {
  	return simc_read(lp->tp.info.tuntap.fd,
  			(*skb)->data, (*skb)->dev->mtu + ETH_HEADER_OTHER);
  }
  
  static int tuntap_write(struct iss_net_private *lp, struct sk_buff **skb)
  {
  	return simc_write(lp->tp.info.tuntap.fd, (*skb)->data, (*skb)->len);
  }
  
  unsigned short tuntap_protocol(struct sk_buff *skb)
  {
  	return eth_type_trans(skb, skb->dev);
  }
  
  static int tuntap_poll(struct iss_net_private *lp)
  {
  	return simc_poll(lp->tp.info.tuntap.fd);
  }
  
  /*
   * ethX=tuntap,[mac address],device name
   */
  
  static int tuntap_probe(struct iss_net_private *lp, int index, char *init)
  {
  	struct net_device *dev = lp->dev;
  	char *dev_name = NULL, *mac_str = NULL, *rem = NULL;
  
  	/* Transport should be 'tuntap': ethX=tuntap,mac,dev_name */
  
  	if (strncmp(init, TRANSPORT_TUNTAP_NAME,
  		    sizeof(TRANSPORT_TUNTAP_NAME) - 1))
  		return 0;
  
  	init += sizeof(TRANSPORT_TUNTAP_NAME) - 1;
  	if (*init == ',') {
  		rem = split_if_spec(init + 1, &mac_str, &dev_name);
  		if (rem != NULL) {
  			pr_err("%s: extra garbage on specification : '%s'\n",
  			       dev->name, rem);
  			return 0;
  		}
  	} else if (*init != '\0') {
  		pr_err("%s: invalid argument: %s. Skipping device!\n",
  		       dev->name, init);
  		return 0;
  	}
  
  	if (!dev_name) {
  		pr_err("%s: missing tuntap device name\n", dev->name);
  		return 0;
  	}
  
  	strlcpy(lp->tp.info.tuntap.dev_name, dev_name,
  		sizeof(lp->tp.info.tuntap.dev_name));
  
  	setup_etheraddr(dev, mac_str);
  
  	lp->mtu = TRANSPORT_TUNTAP_MTU;
  
  	lp->tp.info.tuntap.fd = -1;
  
  	lp->tp.open = tuntap_open;
  	lp->tp.close = tuntap_close;
  	lp->tp.read = tuntap_read;
  	lp->tp.write = tuntap_write;
  	lp->tp.protocol = tuntap_protocol;
  	lp->tp.poll = tuntap_poll;
  
  	return 1;
  }
  
  /* ================================ ISS NET ================================ */
  
  static int iss_net_rx(struct net_device *dev)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	int pkt_len;
  	struct sk_buff *skb;
  
  	/* Check if there is any new data. */
  
  	if (lp->tp.poll(lp) == 0)
  		return 0;
  
  	/* Try to allocate memory, if it fails, try again next round. */
  
  	skb = dev_alloc_skb(dev->mtu + 2 + ETH_HEADER_OTHER);
  	if (skb == NULL) {
  		lp->stats.rx_dropped++;
  		return 0;
  	}
  
  	skb_reserve(skb, 2);
  
  	/* Setup skb */
  
  	skb->dev = dev;
  	skb_reset_mac_header(skb);
  	pkt_len = lp->tp.read(lp, &skb);
  	skb_put(skb, pkt_len);
  
  	if (pkt_len > 0) {
  		skb_trim(skb, pkt_len);
  		skb->protocol = lp->tp.protocol(skb);
  
  		lp->stats.rx_bytes += skb->len;
  		lp->stats.rx_packets++;
  		netif_rx_ni(skb);
  		return pkt_len;
  	}
  	kfree_skb(skb);
  	return pkt_len;
  }
  
  static int iss_net_poll(void)
  {
  	struct list_head *ele;
  	int err, ret = 0;
  
  	spin_lock(&opened_lock);
  
  	list_for_each(ele, &opened) {
  		struct iss_net_private *lp;
  
  		lp = list_entry(ele, struct iss_net_private, opened_list);
  
  		if (!netif_running(lp->dev))
  			break;
  
  		spin_lock(&lp->lock);
  
  		while ((err = iss_net_rx(lp->dev)) > 0)
  			ret++;
  
  		spin_unlock(&lp->lock);
  
  		if (err < 0) {
  			pr_err("Device '%s' read returned %d, shutting it down\n",
  			       lp->dev->name, err);
  			dev_close(lp->dev);
  		} else {
  			/* FIXME reactivate_fd(lp->fd, ISS_ETH_IRQ); */
  		}
  	}
  
  	spin_unlock(&opened_lock);
  	return ret;
  }
  
  
  static void iss_net_timer(unsigned long priv)
  {
  	struct iss_net_private *lp = (struct iss_net_private *)priv;
  
  	iss_net_poll();
  	spin_lock(&lp->lock);
  	mod_timer(&lp->timer, jiffies + lp->timer_val);
  	spin_unlock(&lp->lock);
  }
  
  
  static int iss_net_open(struct net_device *dev)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	int err;
  
  	spin_lock_bh(&lp->lock);
  
  	err = lp->tp.open(lp);
  	if (err < 0)
  		goto out;
  
  	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 = iss_net_rx(dev)) > 0)
  		;
  
  	spin_unlock_bh(&lp->lock);
  	spin_lock_bh(&opened_lock);
  	list_add(&lp->opened_list, &opened);
  	spin_unlock_bh(&opened_lock);
  	spin_lock_bh(&lp->lock);
  
  	init_timer(&lp->timer);
  	lp->timer_val = ISS_NET_TIMER_VALUE;
  	lp->timer.data = (unsigned long) lp;
  	lp->timer.function = iss_net_timer;
  	mod_timer(&lp->timer, jiffies + lp->timer_val);
  
  out:
  	spin_unlock_bh(&lp->lock);
  	return err;
  }
  
  static int iss_net_close(struct net_device *dev)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	netif_stop_queue(dev);
  	spin_lock_bh(&lp->lock);
  
  	spin_lock(&opened_lock);
  	list_del(&opened);
  	spin_unlock(&opened_lock);
  
  	del_timer_sync(&lp->timer);
  
  	lp->tp.close(lp);
  
  	spin_unlock_bh(&lp->lock);
  	return 0;
  }
  
  static int iss_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	int len;
  
  	netif_stop_queue(dev);
  	spin_lock_bh(&lp->lock);
  
  	len = lp->tp.write(lp, &skb);
  
  	if (len == skb->len) {
  		lp->stats.tx_packets++;
  		lp->stats.tx_bytes += skb->len;
  		netif_trans_update(dev);
  		netif_start_queue(dev);
  
  		/* this is normally done in the interrupt when tx finishes */
  		netif_wake_queue(dev);
  
  	} else if (len == 0) {
  		netif_start_queue(dev);
  		lp->stats.tx_dropped++;
  
  	} else {
  		netif_start_queue(dev);
  		pr_err("%s: %s failed(%d)\n", dev->name, __func__, len);
  	}
  
  	spin_unlock_bh(&lp->lock);
  
  	dev_kfree_skb(skb);
  	return NETDEV_TX_OK;
  }
  
  
  static struct net_device_stats *iss_net_get_stats(struct net_device *dev)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	return &lp->stats;
  }
  
  static void iss_net_set_multicast_list(struct net_device *dev)
  {
  }
  
  static void iss_net_tx_timeout(struct net_device *dev)
  {
  }
  
  static int iss_net_set_mac(struct net_device *dev, void *addr)
  {
  	struct iss_net_private *lp = netdev_priv(dev);
  	struct sockaddr *hwaddr = addr;
  
  	if (!is_valid_ether_addr(hwaddr->sa_data))
  		return -EADDRNOTAVAIL;
  	spin_lock_bh(&lp->lock);
  	memcpy(dev->dev_addr, hwaddr->sa_data, ETH_ALEN);
  	spin_unlock_bh(&lp->lock);
  	return 0;
  }
  
  static int iss_net_change_mtu(struct net_device *dev, int new_mtu)
  {
  	return -EINVAL;
  }
  
  void iss_net_user_timer_expire(unsigned long _conn)
  {
  }
  
  
  static struct platform_driver iss_net_driver = {
  	.driver = {
  		.name  = DRIVER_NAME,
  	},
  };
  
  static int driver_registered;
  
  static const struct net_device_ops iss_netdev_ops = {
  	.ndo_open		= iss_net_open,
  	.ndo_stop		= iss_net_close,
  	.ndo_get_stats		= iss_net_get_stats,
  	.ndo_start_xmit		= iss_net_start_xmit,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_change_mtu		= iss_net_change_mtu,
  	.ndo_set_mac_address	= iss_net_set_mac,
  	.ndo_tx_timeout		= iss_net_tx_timeout,
  	.ndo_set_rx_mode	= iss_net_set_multicast_list,
  };
  
  static int iss_net_configure(int index, char *init)
  {
  	struct net_device *dev;
  	struct iss_net_private *lp;
  	int err;
  
  	dev = alloc_etherdev(sizeof(*lp));
  	if (dev == NULL) {
  		pr_err("eth_configure: failed to allocate device\n");
  		return 1;
  	}
  
  	/* Initialize private element. */
  
  	lp = netdev_priv(dev);
  	*lp = (struct iss_net_private) {
  		.device_list		= LIST_HEAD_INIT(lp->device_list),
  		.opened_list		= LIST_HEAD_INIT(lp->opened_list),
  		.dev			= dev,
  		.index			= index,
  	};
  
  	spin_lock_init(&lp->lock);
  	/*
  	 * If this name ends up conflicting with an existing registered
  	 * netdevice, that is OK, register_netdev{,ice}() will notice this
  	 * and fail.
  	 */
  	snprintf(dev->name, sizeof(dev->name), "eth%d", index);
  
  	/*
  	 * Try all transport protocols.
  	 * Note: more protocols can be added by adding '&& !X_init(lp, eth)'.
  	 */
  
  	if (!tuntap_probe(lp, index, init)) {
  		pr_err("%s: invalid arguments. Skipping device!\n",
  		       dev->name);
  		goto errout;
  	}
  
  	pr_info("Netdevice %d (%pM)\n", index, dev->dev_addr);
  
  	/* sysfs register */
  
  	if (!driver_registered) {
  		platform_driver_register(&iss_net_driver);
  		driver_registered = 1;
  	}
  
  	spin_lock(&devices_lock);
  	list_add(&lp->device_list, &devices);
  	spin_unlock(&devices_lock);
  
  	lp->pdev.id = index;
  	lp->pdev.name = DRIVER_NAME;
  	platform_device_register(&lp->pdev);
  	SET_NETDEV_DEV(dev, &lp->pdev.dev);
  
  	dev->netdev_ops = &iss_netdev_ops;
  	dev->mtu = lp->mtu;
  	dev->watchdog_timeo = (HZ >> 1);
  	dev->irq = -1;
  
  	rtnl_lock();
  	err = register_netdevice(dev);
  	rtnl_unlock();
  
  	if (err) {
  		pr_err("%s: error registering net device!\n", dev->name);
  		/* XXX: should we call ->remove() here? */
  		free_netdev(dev);
  		return 1;
  	}
  
  	init_timer(&lp->tl);
  	lp->tl.function = iss_net_user_timer_expire;
  
  	return 0;
  
  errout:
  	/* FIXME: unregister; free, etc.. */
  	return -EIO;
  }
  
  /* ------------------------------------------------------------------------- */
  
  /* Filled in during early boot */
  
  struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
  
  struct iss_net_init {
  	struct list_head list;
  	char *init;		/* init string */
  	int index;
  };
  
  /*
   * Parse the command line and look for 'ethX=...' fields, and register all
   * those fields. They will be later initialized in iss_net_init.
   */
  
  #define ERR KERN_ERR "iss_net_setup: "
  
  static int __init iss_net_setup(char *str)
  {
  	struct iss_net_private *device = NULL;
  	struct iss_net_init *new;
  	struct list_head *ele;
  	char *end;
  	int rc;
  	unsigned n;
  
  	end = strchr(str, '=');
  	if (!end) {
  		printk(ERR "Expected '=' after device number\n");
  		return 1;
  	}
  	*end = 0;
  	rc = kstrtouint(str, 0, &n);
  	*end = '=';
  	if (rc < 0) {
  		printk(ERR "Failed to parse '%s'\n", str);
  		return 1;
  	}
  	str = end;
  
  	spin_lock(&devices_lock);
  
  	list_for_each(ele, &devices) {
  		device = list_entry(ele, struct iss_net_private, device_list);
  		if (device->index == n)
  			break;
  	}
  
  	spin_unlock(&devices_lock);
  
  	if (device && device->index == n) {
  		printk(ERR "Device %u already configured\n", n);
  		return 1;
  	}
  
  	new = alloc_bootmem(sizeof(*new));
  	if (new == NULL) {
  		printk(ERR "Alloc_bootmem failed\n");
  		return 1;
  	}
  
  	INIT_LIST_HEAD(&new->list);
  	new->index = n;
  	new->init = str + 1;
  
  	list_add_tail(&new->list, &eth_cmd_line);
  	return 1;
  }
  
  #undef ERR
  
  __setup("eth", iss_net_setup);
  
  /*
   * Initialize all ISS Ethernet devices previously registered in iss_net_setup.
   */
  
  static int iss_net_init(void)
  {
  	struct list_head *ele, *next;
  
  	/* Walk through all Ethernet devices specified in the command line. */
  
  	list_for_each_safe(ele, next, &eth_cmd_line) {
  		struct iss_net_init *eth;
  		eth = list_entry(ele, struct iss_net_init, list);
  		iss_net_configure(eth->index, eth->init);
  	}
  
  	return 1;
  }
  device_initcall(iss_net_init);
  