1 files changed, 1284 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
new file mode 100644
index 000000000000..bf3c762de620
--- /dev/null
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -0,0 +1,1284 @@
+/* sunvnet.c: Sun LDOM Virtual Network Driver.
+ *
+ * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 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;
+
+	pr_err("Received unknown msg [%02x:%02x:%04x:%08x]\n",
+	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
+	pr_err("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)) {
+		pr_err("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)
+		pr_err("%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)) {
+		pr_warning("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. */
+			netdev_err(dev, "BUG! Tx Ring full when queue awake!\n");
+			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)) {
+		netdev_info(dev, "TX trigger error %d\n", 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);
+
+	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 netdev_hw_addr *ha;
+
+	netdev_for_each_mc_addr(ha, dev) {
+		struct vnet_mcast_entry *m;
+
+		m = __vnet_mc_find(vp, ha->addr);
+		if (m) {
+			m->hit = 1;
+			continue;
+		}
+
+		if (!m) {
+			m = kzalloc(sizeof(*m), GFP_ATOMIC);
+			if (!m)
+				continue;
+			memcpy(m->addr, ha->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) {
+			pr_err("TX buffer allocation failure\n");
+			goto err_out;
+		}
+		err = -EFAULT;
+		if ((unsigned long)buf & (8UL - 1)) {
+			pr_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) {
+		pr_err("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) {
+		pr_err("Cannot register net device, aborting\n");
+		goto err_out_free_dev;
+	}
+
+	netdev_info(dev, "Sun LDOM vnet %pM\n", dev->dev_addr);
+
+	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 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)
+{
+	printk_once(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)) {
+		pr_err("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) {
+		pr_err("Port lacks %s property\n", remote_macaddr_prop);
+		goto err_out_put_mdesc;
+	}
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	err = -ENOMEM;
+	if (!port) {
+		pr_err("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);
+
+	pr_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);
+}
+
+module_init(vnet_init);
+module_exit(vnet_exit);