text: /* sunvnet.c: Sun LDOM Virtual Network Driver.
   *
   * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/netdevice.h>
  #include <linux/ethtool.h>
  #include <linux/etherdevice.h>
  #include <linux/mutex.h>
  
  #include <asm/vio.h>
  #include <asm/ldc.h>
  
  #include "sunvnet.h"
  
  #define DRV_MODULE_NAME		"sunvnet"
  #define PFX DRV_MODULE_NAME	": "
  #define DRV_MODULE_VERSION	"1.0"
  #define DRV_MODULE_RELDATE	"June 25, 2007"
  
  static char version[] __devinitdata =
  	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
  MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
  MODULE_DESCRIPTION("Sun LDOM virtual network driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(DRV_MODULE_VERSION);
  
  /* Ordered from largest major to lowest */
  static struct vio_version vnet_versions[] = {
  	{ .major = 1, .minor = 0 },
  };
  
  static inline u32 vnet_tx_dring_avail(struct vio_dring_state *dr)
  {
  	return vio_dring_avail(dr, VNET_TX_RING_SIZE);
  }
  
  static int vnet_handle_unknown(struct vnet_port *port, void *arg)
  {
  	struct vio_msg_tag *pkt = arg;
  
  	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
  	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
  	printk(KERN_ERR PFX "Resetting connection.\n");
  
  	ldc_disconnect(port->vio.lp);
  
  	return -ECONNRESET;
  }
  
  static int vnet_send_attr(struct vio_driver_state *vio)
  {
  	struct vnet_port *port = to_vnet_port(vio);
  	struct net_device *dev = port->vp->dev;
  	struct vio_net_attr_info pkt;
  	int i;
  
  	memset(&pkt, 0, sizeof(pkt));
  	pkt.tag.type = VIO_TYPE_CTRL;
  	pkt.tag.stype = VIO_SUBTYPE_INFO;
  	pkt.tag.stype_env = VIO_ATTR_INFO;
  	pkt.tag.sid = vio_send_sid(vio);
  	pkt.xfer_mode = VIO_DRING_MODE;
  	pkt.addr_type = VNET_ADDR_ETHERMAC;
  	pkt.ack_freq = 0;
  	for (i = 0; i < 6; i++)
  		pkt.addr |= (u64)dev->dev_addr[i] << ((5 - i) * 8);
  	pkt.mtu = ETH_FRAME_LEN;
  
  	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
  	       "ackfreq[%u] mtu[%llu]\n",
  	       pkt.xfer_mode, pkt.addr_type,
  	       (unsigned long long) pkt.addr,
  	       pkt.ack_freq,
  	       (unsigned long long) pkt.mtu);
  
  	return vio_ldc_send(vio, &pkt, sizeof(pkt));
  }
  
  static int handle_attr_info(struct vio_driver_state *vio,
  			    struct vio_net_attr_info *pkt)
  {
  	viodbg(HS, "GOT NET ATTR INFO xmode[0x%x] atype[0x%x] addr[%llx] "
  	       "ackfreq[%u] mtu[%llu]\n",
  	       pkt->xfer_mode, pkt->addr_type,
  	       (unsigned long long) pkt->addr,
  	       pkt->ack_freq,
  	       (unsigned long long) pkt->mtu);
  
  	pkt->tag.sid = vio_send_sid(vio);
  
  	if (pkt->xfer_mode != VIO_DRING_MODE ||
  	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
  	    pkt->mtu != ETH_FRAME_LEN) {
  		viodbg(HS, "SEND NET ATTR NACK\n");
  
  		pkt->tag.stype = VIO_SUBTYPE_NACK;
  
  		(void) vio_ldc_send(vio, pkt, sizeof(*pkt));
  
  		return -ECONNRESET;
  	} else {
  		viodbg(HS, "SEND NET ATTR ACK\n");
  
  		pkt->tag.stype = VIO_SUBTYPE_ACK;
  
  		return vio_ldc_send(vio, pkt, sizeof(*pkt));
  	}
  
  }
  
  static int handle_attr_ack(struct vio_driver_state *vio,
  			   struct vio_net_attr_info *pkt)
  {
  	viodbg(HS, "GOT NET ATTR ACK\n");
  
  	return 0;
  }
  
  static int handle_attr_nack(struct vio_driver_state *vio,
  			    struct vio_net_attr_info *pkt)
  {
  	viodbg(HS, "GOT NET ATTR NACK\n");
  
  	return -ECONNRESET;
  }
  
  static int vnet_handle_attr(struct vio_driver_state *vio, void *arg)
  {
  	struct vio_net_attr_info *pkt = arg;
  
  	switch (pkt->tag.stype) {
  	case VIO_SUBTYPE_INFO:
  		return handle_attr_info(vio, pkt);
  
  	case VIO_SUBTYPE_ACK:
  		return handle_attr_ack(vio, pkt);
  
  	case VIO_SUBTYPE_NACK:
  		return handle_attr_nack(vio, pkt);
  
  	default:
  		return -ECONNRESET;
  	}
  }
  
  static void vnet_handshake_complete(struct vio_driver_state *vio)
  {
  	struct vio_dring_state *dr;
  
  	dr = &vio->drings[VIO_DRIVER_RX_RING];
  	dr->snd_nxt = dr->rcv_nxt = 1;
  
  	dr = &vio->drings[VIO_DRIVER_TX_RING];
  	dr->snd_nxt = dr->rcv_nxt = 1;
  }
  
  /* The hypervisor interface that implements copying to/from imported
   * memory from another domain requires that copies are done to 8-byte
   * aligned buffers, and that the lengths of such copies are also 8-byte
   * multiples.
   *
   * So we align skb->data to an 8-byte multiple and pad-out the data
   * area so we can round the copy length up to the next multiple of
   * 8 for the copy.
   *
   * The transmitter puts the actual start of the packet 6 bytes into
   * the buffer it sends over, so that the IP headers after the ethernet
   * header are aligned properly.  These 6 bytes are not in the descriptor
   * length, they are simply implied.  This offset is represented using
   * the VNET_PACKET_SKIP macro.
   */
  static struct sk_buff *alloc_and_align_skb(struct net_device *dev,
  					   unsigned int len)
  {
  	struct sk_buff *skb = netdev_alloc_skb(dev, len+VNET_PACKET_SKIP+8+8);
  	unsigned long addr, off;
  
  	if (unlikely(!skb))
  		return NULL;
  
  	addr = (unsigned long) skb->data;
  	off = ((addr + 7UL) & ~7UL) - addr;
  	if (off)
  		skb_reserve(skb, off);
  
  	return skb;
  }
  
  static int vnet_rx_one(struct vnet_port *port, unsigned int len,
  		       struct ldc_trans_cookie *cookies, int ncookies)
  {
  	struct net_device *dev = port->vp->dev;
  	unsigned int copy_len;
  	struct sk_buff *skb;
  	int err;
  
  	err = -EMSGSIZE;
  	if (unlikely(len < ETH_ZLEN || len > ETH_FRAME_LEN)) {
  		dev->stats.rx_length_errors++;
  		goto out_dropped;
  	}
  
  	skb = alloc_and_align_skb(dev, len);
  	err = -ENOMEM;
  	if (unlikely(!skb)) {
  		dev->stats.rx_missed_errors++;
  		goto out_dropped;
  	}
  
  	copy_len = (len + VNET_PACKET_SKIP + 7U) & ~7U;
  	skb_put(skb, copy_len);
  	err = ldc_copy(port->vio.lp, LDC_COPY_IN,
  		       skb->data, copy_len, 0,
  		       cookies, ncookies);
  	if (unlikely(err < 0)) {
  		dev->stats.rx_frame_errors++;
  		goto out_free_skb;
  	}
  
  	skb_pull(skb, VNET_PACKET_SKIP);
  	skb_trim(skb, len);
  	skb->protocol = eth_type_trans(skb, dev);
  
  	dev->stats.rx_packets++;
  	dev->stats.rx_bytes += len;
  
  	netif_rx(skb);
  
  	return 0;
  
  out_free_skb:
  	kfree_skb(skb);
  
  out_dropped:
  	dev->stats.rx_dropped++;
  	return err;
  }
  
  static int vnet_send_ack(struct vnet_port *port, struct vio_dring_state *dr,
  			 u32 start, u32 end, u8 vio_dring_state)
  {
  	struct vio_dring_data hdr = {
  		.tag = {
  			.type		= VIO_TYPE_DATA,
  			.stype		= VIO_SUBTYPE_ACK,
  			.stype_env	= VIO_DRING_DATA,
  			.sid		= vio_send_sid(&port->vio),
  		},
  		.dring_ident		= dr->ident,
  		.start_idx		= start,
  		.end_idx		= end,
  		.state			= vio_dring_state,
  	};
  	int err, delay;
  
  	hdr.seq = dr->snd_nxt;
  	delay = 1;
  	do {
  		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
  		if (err > 0) {
  			dr->snd_nxt++;
  			break;
  		}
  		udelay(delay);
  		if ((delay <<= 1) > 128)
  			delay = 128;
  	} while (err == -EAGAIN);
  
  	return err;
  }
  
  static u32 next_idx(u32 idx, struct vio_dring_state *dr)
  {
  	if (++idx == dr->num_entries)
  		idx = 0;
  	return idx;
  }
  
  static u32 prev_idx(u32 idx, struct vio_dring_state *dr)
  {
  	if (idx == 0)
  		idx = dr->num_entries - 1;
  	else
  		idx--;
  
  	return idx;
  }
  
  static struct vio_net_desc *get_rx_desc(struct vnet_port *port,
  					struct vio_dring_state *dr,
  					u32 index)
  {
  	struct vio_net_desc *desc = port->vio.desc_buf;
  	int err;
  
  	err = ldc_get_dring_entry(port->vio.lp, desc, dr->entry_size,
  				  (index * dr->entry_size),
  				  dr->cookies, dr->ncookies);
  	if (err < 0)
  		return ERR_PTR(err);
  
  	return desc;
  }
  
  static int put_rx_desc(struct vnet_port *port,
  		       struct vio_dring_state *dr,
  		       struct vio_net_desc *desc,
  		       u32 index)
  {
  	int err;
  
  	err = ldc_put_dring_entry(port->vio.lp, desc, dr->entry_size,
  				  (index * dr->entry_size),
  				  dr->cookies, dr->ncookies);
  	if (err < 0)
  		return err;
  
  	return 0;
  }
  
  static int vnet_walk_rx_one(struct vnet_port *port,
  			    struct vio_dring_state *dr,
  			    u32 index, int *needs_ack)
  {
  	struct vio_net_desc *desc = get_rx_desc(port, dr, index);
  	struct vio_driver_state *vio = &port->vio;
  	int err;
  
  	if (IS_ERR(desc))
  		return PTR_ERR(desc);
  
  	viodbg(DATA, "vio_walk_rx_one desc[%02x:%02x:%08x:%08x:%llx:%llx]\n",
  	       desc->hdr.state, desc->hdr.ack,
  	       desc->size, desc->ncookies,
  	       desc->cookies[0].cookie_addr,
  	       desc->cookies[0].cookie_size);
  
  	if (desc->hdr.state != VIO_DESC_READY)
  		return 1;
  	err = vnet_rx_one(port, desc->size, desc->cookies, desc->ncookies);
  	if (err == -ECONNRESET)
  		return err;
  	desc->hdr.state = VIO_DESC_DONE;
  	err = put_rx_desc(port, dr, desc, index);
  	if (err < 0)
  		return err;
  	*needs_ack = desc->hdr.ack;
  	return 0;
  }
  
  static int vnet_walk_rx(struct vnet_port *port, struct vio_dring_state *dr,
  			u32 start, u32 end)
  {
  	struct vio_driver_state *vio = &port->vio;
  	int ack_start = -1, ack_end = -1;
  
  	end = (end == (u32) -1) ? prev_idx(start, dr) : next_idx(end, dr);
  
  	viodbg(DATA, "vnet_walk_rx start[%08x] end[%08x]\n", start, end);
  
  	while (start != end) {
  		int ack = 0, err = vnet_walk_rx_one(port, dr, start, &ack);
  		if (err == -ECONNRESET)
  			return err;
  		if (err != 0)
  			break;
  		if (ack_start == -1)
  			ack_start = start;
  		ack_end = start;
  		start = next_idx(start, dr);
  		if (ack && start != end) {
  			err = vnet_send_ack(port, dr, ack_start, ack_end,
  					    VIO_DRING_ACTIVE);
  			if (err == -ECONNRESET)
  				return err;
  			ack_start = -1;
  		}
  	}
  	if (unlikely(ack_start == -1))
  		ack_start = ack_end = prev_idx(start, dr);
  	return vnet_send_ack(port, dr, ack_start, ack_end, VIO_DRING_STOPPED);
  }
  
  static int vnet_rx(struct vnet_port *port, void *msgbuf)
  {
  	struct vio_dring_data *pkt = msgbuf;
  	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_RX_RING];
  	struct vio_driver_state *vio = &port->vio;
  
  	viodbg(DATA, "vnet_rx stype_env[%04x] seq[%016llx] rcv_nxt[%016llx]\n",
  	       pkt->tag.stype_env, pkt->seq, dr->rcv_nxt);
  
  	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
  		return 0;
  	if (unlikely(pkt->seq != dr->rcv_nxt)) {
  		printk(KERN_ERR PFX "RX out of sequence seq[0x%llx] "
  		       "rcv_nxt[0x%llx]\n", pkt->seq, dr->rcv_nxt);
  		return 0;
  	}
  
  	dr->rcv_nxt++;
  
  	/* XXX Validate pkt->start_idx and pkt->end_idx XXX */
  
  	return vnet_walk_rx(port, dr, pkt->start_idx, pkt->end_idx);
  }
  
  static int idx_is_pending(struct vio_dring_state *dr, u32 end)
  {
  	u32 idx = dr->cons;
  	int found = 0;
  
  	while (idx != dr->prod) {
  		if (idx == end) {
  			found = 1;
  			break;
  		}
  		idx = next_idx(idx, dr);
  	}
  	return found;
  }
  
  static int vnet_ack(struct vnet_port *port, void *msgbuf)
  {
  	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  	struct vio_dring_data *pkt = msgbuf;
  	struct net_device *dev;
  	struct vnet *vp;
  	u32 end;
  
  	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
  		return 0;
  
  	end = pkt->end_idx;
  	if (unlikely(!idx_is_pending(dr, end)))
  		return 0;
  
  	dr->cons = next_idx(end, dr);
  
  	vp = port->vp;
  	dev = vp->dev;
  	if (unlikely(netif_queue_stopped(dev) &&
  		     vnet_tx_dring_avail(dr) >= VNET_TX_WAKEUP_THRESH(dr)))
  		return 1;
  
  	return 0;
  }
  
  static int vnet_nack(struct vnet_port *port, void *msgbuf)
  {
  	/* XXX just reset or similar XXX */
  	return 0;
  }
  
  static int handle_mcast(struct vnet_port *port, void *msgbuf)
  {
  	struct vio_net_mcast_info *pkt = msgbuf;
  
  	if (pkt->tag.stype != VIO_SUBTYPE_ACK)
  		printk(KERN_ERR PFX "%s: Got unexpected MCAST reply "
  		       "[%02x:%02x:%04x:%08x]\n",
  		       port->vp->dev->name,
  		       pkt->tag.type,
  		       pkt->tag.stype,
  		       pkt->tag.stype_env,
  		       pkt->tag.sid);
  
  	return 0;
  }
  
  static void maybe_tx_wakeup(struct vnet *vp)
  {
  	struct net_device *dev = vp->dev;
  
  	netif_tx_lock(dev);
  	if (likely(netif_queue_stopped(dev))) {
  		struct vnet_port *port;
  		int wake = 1;
  
  		list_for_each_entry(port, &vp->port_list, list) {
  			struct vio_dring_state *dr;
  
  			dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  			if (vnet_tx_dring_avail(dr) <
  			    VNET_TX_WAKEUP_THRESH(dr)) {
  				wake = 0;
  				break;
  			}
  		}
  		if (wake)
  			netif_wake_queue(dev);
  	}
  	netif_tx_unlock(dev);
  }
  
  static void vnet_event(void *arg, int event)
  {
  	struct vnet_port *port = arg;
  	struct vio_driver_state *vio = &port->vio;
  	unsigned long flags;
  	int tx_wakeup, err;
  
  	spin_lock_irqsave(&vio->lock, flags);
  
  	if (unlikely(event == LDC_EVENT_RESET ||
  		     event == LDC_EVENT_UP)) {
  		vio_link_state_change(vio, event);
  		spin_unlock_irqrestore(&vio->lock, flags);
  
  		if (event == LDC_EVENT_RESET)
  			vio_port_up(vio);
  		return;
  	}
  
  	if (unlikely(event != LDC_EVENT_DATA_READY)) {
  		printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
  		spin_unlock_irqrestore(&vio->lock, flags);
  		return;
  	}
  
  	tx_wakeup = err = 0;
  	while (1) {
  		union {
  			struct vio_msg_tag tag;
  			u64 raw[8];
  		} msgbuf;
  
  		err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
  		if (unlikely(err < 0)) {
  			if (err == -ECONNRESET)
  				vio_conn_reset(vio);
  			break;
  		}
  		if (err == 0)
  			break;
  		viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
  		       msgbuf.tag.type,
  		       msgbuf.tag.stype,
  		       msgbuf.tag.stype_env,
  		       msgbuf.tag.sid);
  		err = vio_validate_sid(vio, &msgbuf.tag);
  		if (err < 0)
  			break;
  
  		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
  			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
  				err = vnet_rx(port, &msgbuf);
  			} else if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) {
  				err = vnet_ack(port, &msgbuf);
  				if (err > 0)
  					tx_wakeup |= err;
  			} else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) {
  				err = vnet_nack(port, &msgbuf);
  			}
  		} else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
  			if (msgbuf.tag.stype_env == VNET_MCAST_INFO)
  				err = handle_mcast(port, &msgbuf);
  			else
  				err = vio_control_pkt_engine(vio, &msgbuf);
  			if (err)
  				break;
  		} else {
  			err = vnet_handle_unknown(port, &msgbuf);
  		}
  		if (err == -ECONNRESET)
  			break;
  	}
  	spin_unlock(&vio->lock);
  	if (unlikely(tx_wakeup && err != -ECONNRESET))
  		maybe_tx_wakeup(port->vp);
  	local_irq_restore(flags);
  }
  
  static int __vnet_tx_trigger(struct vnet_port *port)
  {
  	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  	struct vio_dring_data hdr = {
  		.tag = {
  			.type		= VIO_TYPE_DATA,
  			.stype		= VIO_SUBTYPE_INFO,
  			.stype_env	= VIO_DRING_DATA,
  			.sid		= vio_send_sid(&port->vio),
  		},
  		.dring_ident		= dr->ident,
  		.start_idx		= dr->prod,
  		.end_idx		= (u32) -1,
  	};
  	int err, delay;
  
  	hdr.seq = dr->snd_nxt;
  	delay = 1;
  	do {
  		err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
  		if (err > 0) {
  			dr->snd_nxt++;
  			break;
  		}
  		udelay(delay);
  		if ((delay <<= 1) > 128)
  			delay = 128;
  	} while (err == -EAGAIN);
  
  	return err;
  }
  
  struct vnet_port *__tx_port_find(struct vnet *vp, struct sk_buff *skb)
  {
  	unsigned int hash = vnet_hashfn(skb->data);
  	struct hlist_head *hp = &vp->port_hash[hash];
  	struct hlist_node *n;
  	struct vnet_port *port;
  
  	hlist_for_each_entry(port, n, hp, hash) {
  		if (!compare_ether_addr(port->raddr, skb->data))
  			return port;
  	}
  	port = NULL;
  	if (!list_empty(&vp->port_list))
  		port = list_entry(vp->port_list.next, struct vnet_port, list);
  
  	return port;
  }
  
  struct vnet_port *tx_port_find(struct vnet *vp, struct sk_buff *skb)
  {
  	struct vnet_port *ret;
  	unsigned long flags;
  
  	spin_lock_irqsave(&vp->lock, flags);
  	ret = __tx_port_find(vp, skb);
  	spin_unlock_irqrestore(&vp->lock, flags);
  
  	return ret;
  }
  
  static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
  {
  	struct vnet *vp = netdev_priv(dev);
  	struct vnet_port *port = tx_port_find(vp, skb);
  	struct vio_dring_state *dr;
  	struct vio_net_desc *d;
  	unsigned long flags;
  	unsigned int len;
  	void *tx_buf;
  	int i, err;
  
  	if (unlikely(!port))
  		goto out_dropped;
  
  	spin_lock_irqsave(&port->vio.lock, flags);
  
  	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  	if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
  		if (!netif_queue_stopped(dev)) {
  			netif_stop_queue(dev);
  
  			/* This is a hard error, log it. */
  			printk(KERN_ERR PFX "%s: BUG! Tx Ring full when "
  			       "queue awake!\n", dev->name);
  			dev->stats.tx_errors++;
  		}
  		spin_unlock_irqrestore(&port->vio.lock, flags);
  		return NETDEV_TX_BUSY;
  	}
  
  	d = vio_dring_cur(dr);
  
  	tx_buf = port->tx_bufs[dr->prod].buf;
  	skb_copy_from_linear_data(skb, tx_buf + VNET_PACKET_SKIP, skb->len);
  
  	len = skb->len;
  	if (len < ETH_ZLEN) {
  		len = ETH_ZLEN;
  		memset(tx_buf+VNET_PACKET_SKIP+skb->len, 0, len - skb->len);
  	}
  
  	d->hdr.ack = VIO_ACK_ENABLE;
  	d->size = len;
  	d->ncookies = port->tx_bufs[dr->prod].ncookies;
  	for (i = 0; i < d->ncookies; i++)
  		d->cookies[i] = port->tx_bufs[dr->prod].cookies[i];
  
  	/* This has to be a non-SMP write barrier because we are writing
  	 * to memory which is shared with the peer LDOM.
  	 */
  	wmb();
  
  	d->hdr.state = VIO_DESC_READY;
  
  	err = __vnet_tx_trigger(port);
  	if (unlikely(err < 0)) {
  		printk(KERN_INFO PFX "%s: TX trigger error %d\n",
  		       dev->name, err);
  		d->hdr.state = VIO_DESC_FREE;
  		dev->stats.tx_carrier_errors++;
  		goto out_dropped_unlock;
  	}
  
  	dev->stats.tx_packets++;
  	dev->stats.tx_bytes += skb->len;
  
  	dr->prod = (dr->prod + 1) & (VNET_TX_RING_SIZE - 1);
  	if (unlikely(vnet_tx_dring_avail(dr) < 2)) {
  		netif_stop_queue(dev);
  		if (vnet_tx_dring_avail(dr) > VNET_TX_WAKEUP_THRESH(dr))
  			netif_wake_queue(dev);
  	}
  
  	spin_unlock_irqrestore(&port->vio.lock, flags);
  
  	dev_kfree_skb(skb);
  
  	dev->trans_start = jiffies;
  	return NETDEV_TX_OK;
  
  out_dropped_unlock:
  	spin_unlock_irqrestore(&port->vio.lock, flags);
  
  out_dropped:
  	dev_kfree_skb(skb);
  	dev->stats.tx_dropped++;
  	return NETDEV_TX_OK;
  }
  
  static void vnet_tx_timeout(struct net_device *dev)
  {
  	/* XXX Implement me XXX */
  }
  
  static int vnet_open(struct net_device *dev)
  {
  	netif_carrier_on(dev);
  	netif_start_queue(dev);
  
  	return 0;
  }
  
  static int vnet_close(struct net_device *dev)
  {
  	netif_stop_queue(dev);
  	netif_carrier_off(dev);
  
  	return 0;
  }
  
  static struct vnet_mcast_entry *__vnet_mc_find(struct vnet *vp, u8 *addr)
  {
  	struct vnet_mcast_entry *m;
  
  	for (m = vp->mcast_list; m; m = m->next) {
  		if (!memcmp(m->addr, addr, ETH_ALEN))
  			return m;
  	}
  	return NULL;
  }
  
  static void __update_mc_list(struct vnet *vp, struct net_device *dev)
  {
  	struct dev_addr_list *p;
  
  	for (p = dev->mc_list; p; p = p->next) {
  		struct vnet_mcast_entry *m;
  
  		m = __vnet_mc_find(vp, p->dmi_addr);
  		if (m) {
  			m->hit = 1;
  			continue;
  		}
  
  		if (!m) {
  			m = kzalloc(sizeof(*m), GFP_ATOMIC);
  			if (!m)
  				continue;
  			memcpy(m->addr, p->dmi_addr, ETH_ALEN);
  			m->hit = 1;
  
  			m->next = vp->mcast_list;
  			vp->mcast_list = m;
  		}
  	}
  }
  
  static void __send_mc_list(struct vnet *vp, struct vnet_port *port)
  {
  	struct vio_net_mcast_info info;
  	struct vnet_mcast_entry *m, **pp;
  	int n_addrs;
  
  	memset(&info, 0, sizeof(info));
  
  	info.tag.type = VIO_TYPE_CTRL;
  	info.tag.stype = VIO_SUBTYPE_INFO;
  	info.tag.stype_env = VNET_MCAST_INFO;
  	info.tag.sid = vio_send_sid(&port->vio);
  	info.set = 1;
  
  	n_addrs = 0;
  	for (m = vp->mcast_list; m; m = m->next) {
  		if (m->sent)
  			continue;
  		m->sent = 1;
  		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
  		       m->addr, ETH_ALEN);
  		if (++n_addrs == VNET_NUM_MCAST) {
  			info.count = n_addrs;
  
  			(void) vio_ldc_send(&port->vio, &info,
  					    sizeof(info));
  			n_addrs = 0;
  		}
  	}
  	if (n_addrs) {
  		info.count = n_addrs;
  		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
  	}
  
  	info.set = 0;
  
  	n_addrs = 0;
  	pp = &vp->mcast_list;
  	while ((m = *pp) != NULL) {
  		if (m->hit) {
  			m->hit = 0;
  			pp = &m->next;
  			continue;
  		}
  
  		memcpy(&info.mcast_addr[n_addrs * ETH_ALEN],
  		       m->addr, ETH_ALEN);
  		if (++n_addrs == VNET_NUM_MCAST) {
  			info.count = n_addrs;
  			(void) vio_ldc_send(&port->vio, &info,
  					    sizeof(info));
  			n_addrs = 0;
  		}
  
  		*pp = m->next;
  		kfree(m);
  	}
  	if (n_addrs) {
  		info.count = n_addrs;
  		(void) vio_ldc_send(&port->vio, &info, sizeof(info));
  	}
  }
  
  static void vnet_set_rx_mode(struct net_device *dev)
  {
  	struct vnet *vp = netdev_priv(dev);
  	struct vnet_port *port;
  	unsigned long flags;
  
  	spin_lock_irqsave(&vp->lock, flags);
  	if (!list_empty(&vp->port_list)) {
  		port = list_entry(vp->port_list.next, struct vnet_port, list);
  
  		if (port->switch_port) {
  			__update_mc_list(vp, dev);
  			__send_mc_list(vp, port);
  		}
  	}
  	spin_unlock_irqrestore(&vp->lock, flags);
  }
  
  static int vnet_change_mtu(struct net_device *dev, int new_mtu)
  {
  	if (new_mtu != ETH_DATA_LEN)
  		return -EINVAL;
  
  	dev->mtu = new_mtu;
  	return 0;
  }
  
  static int vnet_set_mac_addr(struct net_device *dev, void *p)
  {
  	return -EINVAL;
  }
  
  static void vnet_get_drvinfo(struct net_device *dev,
  			     struct ethtool_drvinfo *info)
  {
  	strcpy(info->driver, DRV_MODULE_NAME);
  	strcpy(info->version, DRV_MODULE_VERSION);
  }
  
  static u32 vnet_get_msglevel(struct net_device *dev)
  {
  	struct vnet *vp = netdev_priv(dev);
  	return vp->msg_enable;
  }
  
  static void vnet_set_msglevel(struct net_device *dev, u32 value)
  {
  	struct vnet *vp = netdev_priv(dev);
  	vp->msg_enable = value;
  }
  
  static const struct ethtool_ops vnet_ethtool_ops = {
  	.get_drvinfo		= vnet_get_drvinfo,
  	.get_msglevel		= vnet_get_msglevel,
  	.set_msglevel		= vnet_set_msglevel,
  	.get_link		= ethtool_op_get_link,
  };
  
  static void vnet_port_free_tx_bufs(struct vnet_port *port)
  {
  	struct vio_dring_state *dr;
  	int i;
  
  	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  	if (dr->base) {
  		ldc_free_exp_dring(port->vio.lp, dr->base,
  				   (dr->entry_size * dr->num_entries),
  				   dr->cookies, dr->ncookies);
  		dr->base = NULL;
  		dr->entry_size = 0;
  		dr->num_entries = 0;
  		dr->pending = 0;
  		dr->ncookies = 0;
  	}
  
  	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
  		void *buf = port->tx_bufs[i].buf;
  
  		if (!buf)
  			continue;
  
  		ldc_unmap(port->vio.lp,
  			  port->tx_bufs[i].cookies,
  			  port->tx_bufs[i].ncookies);
  
  		kfree(buf);
  		port->tx_bufs[i].buf = NULL;
  	}
  }
  
  static int __devinit vnet_port_alloc_tx_bufs(struct vnet_port *port)
  {
  	struct vio_dring_state *dr;
  	unsigned long len;
  	int i, err, ncookies;
  	void *dring;
  
  	for (i = 0; i < VNET_TX_RING_SIZE; i++) {
  		void *buf = kzalloc(ETH_FRAME_LEN + 8, GFP_KERNEL);
  		int map_len = (ETH_FRAME_LEN + 7) & ~7;
  
  		err = -ENOMEM;
  		if (!buf) {
  			printk(KERN_ERR "TX buffer allocation failure\n");
  			goto err_out;
  		}
  		err = -EFAULT;
  		if ((unsigned long)buf & (8UL - 1)) {
  			printk(KERN_ERR "TX buffer misaligned\n");
  			kfree(buf);
  			goto err_out;
  		}
  
  		err = ldc_map_single(port->vio.lp, buf, map_len,
  				     port->tx_bufs[i].cookies, 2,
  				     (LDC_MAP_SHADOW |
  				      LDC_MAP_DIRECT |
  				      LDC_MAP_RW));
  		if (err < 0) {
  			kfree(buf);
  			goto err_out;
  		}
  		port->tx_bufs[i].buf = buf;
  		port->tx_bufs[i].ncookies = err;
  	}
  
  	dr = &port->vio.drings[VIO_DRIVER_TX_RING];
  
  	len = (VNET_TX_RING_SIZE *
  	       (sizeof(struct vio_net_desc) +
  		(sizeof(struct ldc_trans_cookie) * 2)));
  
  	ncookies = VIO_MAX_RING_COOKIES;
  	dring = ldc_alloc_exp_dring(port->vio.lp, len,
  				    dr->cookies, &ncookies,
  				    (LDC_MAP_SHADOW |
  				     LDC_MAP_DIRECT |
  				     LDC_MAP_RW));
  	if (IS_ERR(dring)) {
  		err = PTR_ERR(dring);
  		goto err_out;
  	}
  
  	dr->base = dring;
  	dr->entry_size = (sizeof(struct vio_net_desc) +
  			  (sizeof(struct ldc_trans_cookie) * 2));
  	dr->num_entries = VNET_TX_RING_SIZE;
  	dr->prod = dr->cons = 0;
  	dr->pending = VNET_TX_RING_SIZE;
  	dr->ncookies = ncookies;
  
  	return 0;
  
  err_out:
  	vnet_port_free_tx_bufs(port);
  
  	return err;
  }
  
  static LIST_HEAD(vnet_list);
  static DEFINE_MUTEX(vnet_list_mutex);
  
  static const struct net_device_ops vnet_ops = {
  	.ndo_open		= vnet_open,
  	.ndo_stop		= vnet_close,
  	.ndo_set_multicast_list	= vnet_set_rx_mode,
  	.ndo_set_mac_address	= vnet_set_mac_addr,
  	.ndo_validate_addr	= eth_validate_addr,
  	.ndo_tx_timeout		= vnet_tx_timeout,
  	.ndo_change_mtu		= vnet_change_mtu,
  	.ndo_start_xmit		= vnet_start_xmit,
  };
  
  static struct vnet * __devinit vnet_new(const u64 *local_mac)
  {
  	struct net_device *dev;
  	struct vnet *vp;
  	int err, i;
  
  	dev = alloc_etherdev(sizeof(*vp));
  	if (!dev) {
  		printk(KERN_ERR PFX "Etherdev alloc failed, aborting.\n");
  		return ERR_PTR(-ENOMEM);
  	}
  
  	for (i = 0; i < ETH_ALEN; i++)
  		dev->dev_addr[i] = (*local_mac >> (5 - i) * 8) & 0xff;
  
  	memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
  
  	vp = netdev_priv(dev);
  
  	spin_lock_init(&vp->lock);
  	vp->dev = dev;
  
  	INIT_LIST_HEAD(&vp->port_list);
  	for (i = 0; i < VNET_PORT_HASH_SIZE; i++)
  		INIT_HLIST_HEAD(&vp->port_hash[i]);
  	INIT_LIST_HEAD(&vp->list);
  	vp->local_mac = *local_mac;
  
  	dev->netdev_ops = &vnet_ops;
  	dev->ethtool_ops = &vnet_ethtool_ops;
  	dev->watchdog_timeo = VNET_TX_TIMEOUT;
  
  	err = register_netdev(dev);
  	if (err) {
  		printk(KERN_ERR PFX "Cannot register net device, "
  		       "aborting.\n");
  		goto err_out_free_dev;
  	}
  
  	printk(KERN_INFO "%s: Sun LDOM vnet ", dev->name);
  
  	for (i = 0; i < 6; i++)
  		printk("%2.2x%c", dev->dev_addr[i], i == 5 ? '\n' : ':');
  
  	list_add(&vp->list, &vnet_list);
  
  	return vp;
  
  err_out_free_dev:
  	free_netdev(dev);
  
  	return ERR_PTR(err);
  }
  
  static struct vnet * __devinit vnet_find_or_create(const u64 *local_mac)
  {
  	struct vnet *iter, *vp;
  
  	mutex_lock(&vnet_list_mutex);
  	vp = NULL;
  	list_for_each_entry(iter, &vnet_list, list) {
  		if (iter->local_mac == *local_mac) {
  			vp = iter;
  			break;
  		}
  	}
  	if (!vp)
  		vp = vnet_new(local_mac);
  	mutex_unlock(&vnet_list_mutex);
  
  	return vp;
  }
  
  static void vnet_cleanup(void)
  {
  	struct vnet *vp;
  	struct net_device *dev;
  
  	mutex_lock(&vnet_list_mutex);
  	while (!list_empty(&vnet_list)) {
  		vp = list_first_entry(&vnet_list, struct vnet, list);
  		list_del(&vp->list);
  		dev = vp->dev;
  		/* vio_unregister_driver() should have cleaned up port_list */
  		BUG_ON(!list_empty(&vp->port_list));
  		unregister_netdev(dev);
  		free_netdev(dev);
  	}
  	mutex_unlock(&vnet_list_mutex);
  }
  
  static const char *local_mac_prop = "local-mac-address";
  
  static struct vnet * __devinit vnet_find_parent(struct mdesc_handle *hp,
  						u64 port_node)
  {
  	const u64 *local_mac = NULL;
  	u64 a;
  
  	mdesc_for_each_arc(a, hp, port_node, MDESC_ARC_TYPE_BACK) {
  		u64 target = mdesc_arc_target(hp, a);
  		const char *name;
  
  		name = mdesc_get_property(hp, target, "name", NULL);
  		if (!name || strcmp(name, "network"))
  			continue;
  
  		local_mac = mdesc_get_property(hp, target,
  					       local_mac_prop, NULL);
  		if (local_mac)
  			break;
  	}
  	if (!local_mac)
  		return ERR_PTR(-ENODEV);
  
  	return vnet_find_or_create(local_mac);
  }
  
  static struct ldc_channel_config vnet_ldc_cfg = {
  	.event		= vnet_event,
  	.mtu		= 64,
  	.mode		= LDC_MODE_UNRELIABLE,
  };
  
  static struct vio_driver_ops vnet_vio_ops = {
  	.send_attr		= vnet_send_attr,
  	.handle_attr		= vnet_handle_attr,
  	.handshake_complete	= vnet_handshake_complete,
  };
  
  static void __devinit print_version(void)
  {
  	static int version_printed;
  
  	if (version_printed++ == 0)
  		printk(KERN_INFO "%s", version);
  }
  
  const char *remote_macaddr_prop = "remote-mac-address";
  
  static int __devinit vnet_port_probe(struct vio_dev *vdev,
  				     const struct vio_device_id *id)
  {
  	struct mdesc_handle *hp;
  	struct vnet_port *port;
  	unsigned long flags;
  	struct vnet *vp;
  	const u64 *rmac;
  	int len, i, err, switch_port;
  
  	print_version();
  
  	hp = mdesc_grab();
  
  	vp = vnet_find_parent(hp, vdev->mp);
  	if (IS_ERR(vp)) {
  		printk(KERN_ERR PFX "Cannot find port parent vnet.\n");
  		err = PTR_ERR(vp);
  		goto err_out_put_mdesc;
  	}
  
  	rmac = mdesc_get_property(hp, vdev->mp, remote_macaddr_prop, &len);
  	err = -ENODEV;
  	if (!rmac) {
  		printk(KERN_ERR PFX "Port lacks %s property.\n",
  		       remote_macaddr_prop);
  		goto err_out_put_mdesc;
  	}
  
  	port = kzalloc(sizeof(*port), GFP_KERNEL);
  	err = -ENOMEM;
  	if (!port) {
  		printk(KERN_ERR PFX "Cannot allocate vnet_port.\n");
  		goto err_out_put_mdesc;
  	}
  
  	for (i = 0; i < ETH_ALEN; i++)
  		port->raddr[i] = (*rmac >> (5 - i) * 8) & 0xff;
  
  	port->vp = vp;
  
  	err = vio_driver_init(&port->vio, vdev, VDEV_NETWORK,
  			      vnet_versions, ARRAY_SIZE(vnet_versions),
  			      &vnet_vio_ops, vp->dev->name);
  	if (err)
  		goto err_out_free_port;
  
  	err = vio_ldc_alloc(&port->vio, &vnet_ldc_cfg, port);
  	if (err)
  		goto err_out_free_port;
  
  	err = vnet_port_alloc_tx_bufs(port);
  	if (err)
  		goto err_out_free_ldc;
  
  	INIT_HLIST_NODE(&port->hash);
  	INIT_LIST_HEAD(&port->list);
  
  	switch_port = 0;
  	if (mdesc_get_property(hp, vdev->mp, "switch-port", NULL) != NULL)
  		switch_port = 1;
  	port->switch_port = switch_port;
  
  	spin_lock_irqsave(&vp->lock, flags);
  	if (switch_port)
  		list_add(&port->list, &vp->port_list);
  	else
  		list_add_tail(&port->list, &vp->port_list);
  	hlist_add_head(&port->hash, &vp->port_hash[vnet_hashfn(port->raddr)]);
  	spin_unlock_irqrestore(&vp->lock, flags);
  
  	dev_set_drvdata(&vdev->dev, port);
  
  	printk(KERN_INFO "%s: PORT ( remote-mac %pM%s )\n",
  	       vp->dev->name, port->raddr,
  	       switch_port ? " switch-port" : "");
  
  	vio_port_up(&port->vio);
  
  	mdesc_release(hp);
  
  	return 0;
  
  err_out_free_ldc:
  	vio_ldc_free(&port->vio);
  
  err_out_free_port:
  	kfree(port);
  
  err_out_put_mdesc:
  	mdesc_release(hp);
  	return err;
  }
  
  static int vnet_port_remove(struct vio_dev *vdev)
  {
  	struct vnet_port *port = dev_get_drvdata(&vdev->dev);
  
  	if (port) {
  		struct vnet *vp = port->vp;
  		unsigned long flags;
  
  		del_timer_sync(&port->vio.timer);
  
  		spin_lock_irqsave(&vp->lock, flags);
  		list_del(&port->list);
  		hlist_del(&port->hash);
  		spin_unlock_irqrestore(&vp->lock, flags);
  
  		vnet_port_free_tx_bufs(port);
  		vio_ldc_free(&port->vio);
  
  		dev_set_drvdata(&vdev->dev, NULL);
  
  		kfree(port);
  
  	}
  	return 0;
  }
  
  static const struct vio_device_id vnet_port_match[] = {
  	{
  		.type = "vnet-port",
  	},
  	{},
  };
  MODULE_DEVICE_TABLE(vio, vnet_port_match);
  
  static struct vio_driver vnet_port_driver = {
  	.id_table	= vnet_port_match,
  	.probe		= vnet_port_probe,
  	.remove		= vnet_port_remove,
  	.driver		= {
  		.name	= "vnet_port",
  		.owner	= THIS_MODULE,
  	}
  };
  
  static int __init vnet_init(void)
  {
  	return vio_register_driver(&vnet_port_driver);
  }
  
  static void __exit vnet_exit(void)
  {
  	vio_unregister_driver(&vnet_port_driver);
  	vnet_cleanup();
  }
  
  module_init(vnet_init);
  module_exit(vnet_exit);
  