ldmvsw: Split sunvnet driver into common code

  Split sunvnet.c into sunvnet.c and sunvnet_common.c.

  Details:

  Since the sunvnet and ldmvsw drivers will both use common sunvnet code,
  move the functions (and support functions) anticipated to be common code
  from sunvnet.c to sunvnet_common.c. Similarly, sunvnet.h was renamed to
  sunvnet_common.h. The sunvnet_common.c code will be compiled into the
  kernel and act as a library of functions that are linked by either
  (or both) drivers when loaded.

  Function names for external functions in sunvnet_common.c (to be
  called by both the sunvnet and ldmvsw drivers) were tagged with a "_common"
  suffix to clearly designate them as common functions.

  No functional changes as of yet... just moved code verbatim to the new
  sunvnet_common.c/h files.

  Makefile/Kconfig support added to build sunvnet_common.c file. The code
  is included in the kernel if SUN_LDOMS is defined/selected.

  NOTE - per the SubmittingPatches documentation, since the code was just
  moved from one file another, the code was NOT checkpatch'd in this commit
  to aid in review.

  Signed-off-by: Aaron Young <aaron.young@oracle.com>
  Signed-off-by: Rashmi Narasimhan <rashmi.narasimhan@oracle.com>
  Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
  Reviewed-by: Alexandre Chartre <Alexandre.Chartre@oracle.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 1730 deletions

diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 942a95db2061..5b9113524188 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -17,8 +17,6 @@
 #include <linux/mutex.h>
 #include <linux/highmem.h>
 #include <linux/if_vlan.h>
-#define CREATE_TRACE_POINTS
-#include <trace/events/sunvnet.h>
 
 #if IS_ENABLED(CONFIG_IPV6)
 #include <linux/icmpv6.h>
@@ -31,7 +29,12 @@
 #include <asm/vio.h>
 #include <asm/ldc.h>
 
-#include "sunvnet.h"
+#include "sunvnet_common.h"
+
+/* length of time before we decide the hardware is borked,
+ * and dev->tx_timeout() should be called to fix the problem
+ */
+#define VNET_TX_TIMEOUT			(5 * HZ)
 
 #define DRV_MODULE_NAME		"sunvnet"
 #define DRV_MODULE_VERSION	"1.0"
@@ -44,16 +47,6 @@ MODULE_DESCRIPTION("Sun LDOM virtual network driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_MODULE_VERSION);
 
-#define	VNET_MAX_TXQS		16
-
-/* Heuristic for the number of times to exponentially backoff and
- * retry sending an LDC trigger when EAGAIN is encountered
- */
-#define	VNET_MAX_RETRIES	10
-
-static int __vnet_tx_trigger(struct vnet_port *port, u32 start);
-static void vnet_port_reset(struct vnet_port *port);
-
 /* Ordered from largest major to lowest */
 static struct vio_version vnet_versions[] = {
 	{ .major = 1, .minor = 8 },
@@ -62,1578 +55,6 @@ 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_port_alloc_tx_ring(struct vnet_port *port);
-
-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 framelen = ETH_FRAME_LEN;
-	int i, err;
-
-	err = vnet_port_alloc_tx_ring(to_vnet_port(vio));
-	if (err)
-		return err;
-
-	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);
-	if (vio_version_before(vio, 1, 2))
-		pkt.xfer_mode = VIO_DRING_MODE;
-	else
-		pkt.xfer_mode = VIO_NEW_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);
-	if (vio_version_after(vio, 1, 3)) {
-		if (port->rmtu) {
-			port->rmtu = min(VNET_MAXPACKET, port->rmtu);
-			pkt.mtu = port->rmtu;
-		} else {
-			port->rmtu = VNET_MAXPACKET;
-			pkt.mtu = port->rmtu;
-		}
-		if (vio_version_after_eq(vio, 1, 6))
-			pkt.options = VIO_TX_DRING;
-	} else if (vio_version_before(vio, 1, 3)) {
-		pkt.mtu = framelen;
-	} else { /* v1.3 */
-		pkt.mtu = framelen + VLAN_HLEN;
-	}
-
-	pkt.cflags = 0;
-	if (vio_version_after_eq(vio, 1, 7) && port->tso) {
-		pkt.cflags |= VNET_LSO_IPV4_CAPAB;
-		if (!port->tsolen)
-			port->tsolen = VNET_MAXTSO;
-		pkt.ipv4_lso_maxlen = port->tsolen;
-	}
-
-	pkt.plnk_updt = PHYSLINK_UPDATE_NONE;
-
-	viodbg(HS, "SEND NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
-	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
-	       "cflags[0x%04x] lso_max[%u]\n",
-	       pkt.xfer_mode, pkt.addr_type,
-	       (unsigned long long)pkt.addr,
-	       pkt.ack_freq, pkt.plnk_updt, pkt.options,
-	       (unsigned long long)pkt.mtu, pkt.cflags, pkt.ipv4_lso_maxlen);
-
-
-	return vio_ldc_send(vio, &pkt, sizeof(pkt));
-}
-
-static int handle_attr_info(struct vio_driver_state *vio,
-			    struct vio_net_attr_info *pkt)
-{
-	struct vnet_port *port = to_vnet_port(vio);
-	u64	localmtu;
-	u8	xfer_mode;
-
-	viodbg(HS, "GOT NET ATTR xmode[0x%x] atype[0x%x] addr[%llx] "
-	       "ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] mtu[%llu] "
-	       " (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
-	       pkt->xfer_mode, pkt->addr_type,
-	       (unsigned long long)pkt->addr,
-	       pkt->ack_freq, pkt->plnk_updt, pkt->options,
-	       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
-	       pkt->ipv4_lso_maxlen);
-
-	pkt->tag.sid = vio_send_sid(vio);
-
-	xfer_mode = pkt->xfer_mode;
-	/* for version < 1.2, VIO_DRING_MODE = 0x3 and no bitmask */
-	if (vio_version_before(vio, 1, 2) && xfer_mode == VIO_DRING_MODE)
-		xfer_mode = VIO_NEW_DRING_MODE;
-
-	/* MTU negotiation:
-	 *	< v1.3 - ETH_FRAME_LEN exactly
-	 *	> v1.3 - MIN(pkt.mtu, VNET_MAXPACKET, port->rmtu) and change
-	 *			pkt->mtu for ACK
-	 *	= v1.3 - ETH_FRAME_LEN + VLAN_HLEN exactly
-	 */
-	if (vio_version_before(vio, 1, 3)) {
-		localmtu = ETH_FRAME_LEN;
-	} else if (vio_version_after(vio, 1, 3)) {
-		localmtu = port->rmtu ? port->rmtu : VNET_MAXPACKET;
-		localmtu = min(pkt->mtu, localmtu);
-		pkt->mtu = localmtu;
-	} else { /* v1.3 */
-		localmtu = ETH_FRAME_LEN + VLAN_HLEN;
-	}
-	port->rmtu = localmtu;
-
-	/* LSO negotiation */
-	if (vio_version_after_eq(vio, 1, 7))
-		port->tso &= !!(pkt->cflags & VNET_LSO_IPV4_CAPAB);
-	else
-		port->tso = false;
-	if (port->tso) {
-		if (!port->tsolen)
-			port->tsolen = VNET_MAXTSO;
-		port->tsolen = min(port->tsolen, pkt->ipv4_lso_maxlen);
-		if (port->tsolen < VNET_MINTSO) {
-			port->tso = false;
-			port->tsolen = 0;
-			pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
-		}
-		pkt->ipv4_lso_maxlen = port->tsolen;
-	} else {
-		pkt->cflags &= ~VNET_LSO_IPV4_CAPAB;
-		pkt->ipv4_lso_maxlen = 0;
-	}
-
-	/* for version >= 1.6, ACK packet mode we support */
-	if (vio_version_after_eq(vio, 1, 6)) {
-		pkt->xfer_mode = VIO_NEW_DRING_MODE;
-		pkt->options = VIO_TX_DRING;
-	}
-
-	if (!(xfer_mode | VIO_NEW_DRING_MODE) ||
-	    pkt->addr_type != VNET_ADDR_ETHERMAC ||
-	    pkt->mtu != localmtu) {
-		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 xmode[0x%x] atype[0x%x] "
-		       "addr[%llx] ackfreq[%u] plnk_updt[0x%02x] opts[0x%02x] "
-		       "mtu[%llu] (rmtu[%llu]) cflags[0x%04x] lso_max[%u]\n",
-		       pkt->xfer_mode, pkt->addr_type,
-		       (unsigned long long)pkt->addr,
-		       pkt->ack_freq, pkt->plnk_updt, pkt->options,
-		       (unsigned long long)pkt->mtu, port->rmtu, pkt->cflags,
-		       pkt->ipv4_lso_maxlen);
-
-		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 inline void vnet_fullcsum(struct sk_buff *skb)
-{
-	struct iphdr *iph = ip_hdr(skb);
-	int offset = skb_transport_offset(skb);
-
-	if (skb->protocol != htons(ETH_P_IP))
-		return;
-	if (iph->protocol != IPPROTO_TCP &&
-	    iph->protocol != IPPROTO_UDP)
-		return;
-	skb->ip_summed = CHECKSUM_NONE;
-	skb->csum_level = 1;
-	skb->csum = 0;
-	if (iph->protocol == IPPROTO_TCP) {
-		struct tcphdr *ptcp = tcp_hdr(skb);
-
-		ptcp->check = 0;
-		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
-		ptcp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
-						skb->len - offset, IPPROTO_TCP,
-						skb->csum);
-	} else if (iph->protocol == IPPROTO_UDP) {
-		struct udphdr *pudp = udp_hdr(skb);
-
-		pudp->check = 0;
-		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
-		pudp->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
-						skb->len - offset, IPPROTO_UDP,
-						skb->csum);
-	}
-}
-
-static int vnet_rx_one(struct vnet_port *port, struct vio_net_desc *desc)
-{
-	struct net_device *dev = port->vp->dev;
-	unsigned int len = desc->size;
-	unsigned int copy_len;
-	struct sk_buff *skb;
-	int maxlen;
-	int err;
-
-	err = -EMSGSIZE;
-	if (port->tso && port->tsolen > port->rmtu)
-		maxlen = port->tsolen;
-	else
-		maxlen = port->rmtu;
-	if (unlikely(len < ETH_ZLEN || len > maxlen)) {
-		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,
-		       desc->cookies, desc->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);
-
-	if (vio_version_after_eq(&port->vio, 1, 8)) {
-		struct vio_net_dext *dext = vio_net_ext(desc);
-
-		skb_reset_network_header(skb);
-
-		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM) {
-			if (skb->protocol == ETH_P_IP) {
-				struct iphdr *iph = ip_hdr(skb);
-
-				iph->check = 0;
-				ip_send_check(iph);
-			}
-		}
-		if ((dext->flags & VNET_PKT_HCK_FULLCKSUM) &&
-		    skb->ip_summed == CHECKSUM_NONE) {
-			if (skb->protocol == htons(ETH_P_IP)) {
-				struct iphdr *iph = ip_hdr(skb);
-				int ihl = iph->ihl * 4;
-
-				skb_reset_transport_header(skb);
-				skb_set_transport_header(skb, ihl);
-				vnet_fullcsum(skb);
-			}
-		}
-		if (dext->flags & VNET_PKT_HCK_IPV4_HDRCKSUM_OK) {
-			skb->ip_summed = CHECKSUM_PARTIAL;
-			skb->csum_level = 0;
-			if (dext->flags & VNET_PKT_HCK_FULLCKSUM_OK)
-				skb->csum_level = 1;
-		}
-	}
-
-	skb->ip_summed = port->switch_port ? CHECKSUM_NONE : CHECKSUM_PARTIAL;
-
-	dev->stats.rx_packets++;
-	dev->stats.rx_bytes += len;
-	napi_gro_receive(&port->napi, 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;
-	int retries = 0;
-
-	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;
-		if (retries++ > VNET_MAX_RETRIES) {
-			pr_info("ECONNRESET %x:%x:%x:%x:%x:%x\n",
-				port->raddr[0], port->raddr[1],
-				port->raddr[2], port->raddr[3],
-				port->raddr[4], port->raddr[5]);
-			break;
-		}
-	} while (err == -EAGAIN);
-
-	if (err <= 0 && vio_dring_state == VIO_DRING_STOPPED) {
-		port->stop_rx_idx = end;
-		port->stop_rx = true;
-	} else {
-		port->stop_rx_idx = 0;
-		port->stop_rx = false;
-	}
-
-	return err;
-}
-
-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;
-
-	BUG_ON(desc == NULL);
-	if (IS_ERR(desc))
-		return PTR_ERR(desc);
-
-	if (desc->hdr.state != VIO_DESC_READY)
-		return 1;
-
-	dma_rmb();
-
-	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);
-
-	err = vnet_rx_one(port, desc);
-	if (err == -ECONNRESET)
-		return err;
-	trace_vnet_rx_one(port->vio._local_sid, port->vio._peer_sid,
-			  index, desc->hdr.ack);
-	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, int *npkts, int budget)
-{
-	struct vio_driver_state *vio = &port->vio;
-	int ack_start = -1, ack_end = -1;
-	bool send_ack = true;
-
-	end = (end == (u32) -1) ? vio_dring_prev(dr, start)
-				: vio_dring_next(dr, end);
-
-	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;
-		(*npkts)++;
-		if (ack_start == -1)
-			ack_start = start;
-		ack_end = start;
-		start = vio_dring_next(dr, start);
-		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 ((*npkts) >= budget) {
-			send_ack = false;
-			break;
-		}
-	}
-	if (unlikely(ack_start == -1))
-		ack_start = ack_end = vio_dring_prev(dr, start);
-	if (send_ack) {
-		port->napi_resume = false;
-		trace_vnet_tx_send_stopped_ack(port->vio._local_sid,
-					       port->vio._peer_sid,
-					       ack_end, *npkts);
-		return vnet_send_ack(port, dr, ack_start, ack_end,
-				     VIO_DRING_STOPPED);
-	} else  {
-		trace_vnet_tx_defer_stopped_ack(port->vio._local_sid,
-						port->vio._peer_sid,
-						ack_end, *npkts);
-		port->napi_resume = true;
-		port->napi_stop_idx = ack_end;
-		return 1;
-	}
-}
-
-static int vnet_rx(struct vnet_port *port, void *msgbuf, int *npkts,
-		   int budget)
-{
-	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;
-	}
-
-	if (!port->napi_resume)
-		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,
-			    npkts, budget);
-}
-
-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 = vio_dring_next(dr, idx);
-	}
-	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;
-	struct vio_net_desc *desc;
-	struct netdev_queue *txq;
-
-	if (unlikely(pkt->tag.stype_env != VIO_DRING_DATA))
-		return 0;
-
-	end = pkt->end_idx;
-	vp = port->vp;
-	dev = vp->dev;
-	netif_tx_lock(dev);
-	if (unlikely(!idx_is_pending(dr, end))) {
-		netif_tx_unlock(dev);
-		return 0;
-	}
-
-	/* sync for race conditions with vnet_start_xmit() and tell xmit it
-	 * is time to send a trigger.
-	 */
-	trace_vnet_rx_stopped_ack(port->vio._local_sid,
-				  port->vio._peer_sid, end);
-	dr->cons = vio_dring_next(dr, end);
-	desc = vio_dring_entry(dr, dr->cons);
-	if (desc->hdr.state == VIO_DESC_READY && !port->start_cons) {
-		/* vnet_start_xmit() just populated this dring but missed
-		 * sending the "start" LDC message to the consumer.
-		 * Send a "start" trigger on its behalf.
-		 */
-		if (__vnet_tx_trigger(port, dr->cons) > 0)
-			port->start_cons = false;
-		else
-			port->start_cons = true;
-	} else {
-		port->start_cons = true;
-	}
-	netif_tx_unlock(dev);
-
-	txq = netdev_get_tx_queue(dev, port->q_index);
-	if (unlikely(netif_tx_queue_stopped(txq) &&
-		     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;
-}
-
-/* Got back a STOPPED LDC message on port. If the queue is stopped,
- * wake it up so that we'll send out another START message at the
- * next TX.
- */
-static void maybe_tx_wakeup(struct vnet_port *port)
-{
-	struct netdev_queue *txq;
-
-	txq = netdev_get_tx_queue(port->vp->dev, port->q_index);
-	__netif_tx_lock(txq, smp_processor_id());
-	if (likely(netif_tx_queue_stopped(txq))) {
-		struct vio_dring_state *dr;
-
-		dr = &port->vio.drings[VIO_DRIVER_TX_RING];
-		netif_tx_wake_queue(txq);
-	}
-	__netif_tx_unlock(txq);
-}
-
-static inline bool port_is_up(struct vnet_port *vnet)
-{
-	struct vio_driver_state *vio = &vnet->vio;
-
-	return !!(vio->hs_state & VIO_HS_COMPLETE);
-}
-
-static int vnet_event_napi(struct vnet_port *port, int budget)
-{
-	struct vio_driver_state *vio = &port->vio;
-	int tx_wakeup, err;
-	int npkts = 0;
-	int event = (port->rx_event & LDC_EVENT_RESET);
-
-ldc_ctrl:
-	if (unlikely(event == LDC_EVENT_RESET ||
-		     event == LDC_EVENT_UP)) {
-		vio_link_state_change(vio, event);
-
-		if (event == LDC_EVENT_RESET) {
-			vnet_port_reset(port);
-			vio_port_up(vio);
-		}
-		port->rx_event = 0;
-		return 0;
-	}
-	/* We may have multiple LDC events in rx_event. Unroll send_events() */
-	event = (port->rx_event & LDC_EVENT_UP);
-	port->rx_event &= ~(LDC_EVENT_RESET|LDC_EVENT_UP);
-	if (event == LDC_EVENT_UP)
-		goto ldc_ctrl;
-	event = port->rx_event;
-	if (!(event & LDC_EVENT_DATA_READY))
-		return 0;
-
-	/* we dont expect any other bits than RESET, UP, DATA_READY */
-	BUG_ON(event != LDC_EVENT_DATA_READY);
-
-	tx_wakeup = err = 0;
-	while (1) {
-		union {
-			struct vio_msg_tag tag;
-			u64 raw[8];
-		} msgbuf;
-
-		if (port->napi_resume) {
-			struct vio_dring_data *pkt =
-				(struct vio_dring_data *)&msgbuf;
-			struct vio_dring_state *dr =
-				&port->vio.drings[VIO_DRIVER_RX_RING];
-
-			pkt->tag.type = VIO_TYPE_DATA;
-			pkt->tag.stype = VIO_SUBTYPE_INFO;
-			pkt->tag.stype_env = VIO_DRING_DATA;
-			pkt->seq = dr->rcv_nxt;
-			pkt->start_idx = vio_dring_next(dr, port->napi_stop_idx);
-			pkt->end_idx = -1;
-			goto napi_resume;
-		}
-		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;
-napi_resume:
-		if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
-			if (msgbuf.tag.stype == VIO_SUBTYPE_INFO) {
-				if (!port_is_up(port)) {
-					/* failures like handshake_failure()
-					 * may have cleaned up dring, but
-					 * NAPI polling may bring us here.
-					 */
-					err = -ECONNRESET;
-					break;
-				}
-				err = vnet_rx(port, &msgbuf, &npkts, budget);
-				if (npkts >= budget)
-					break;
-				if (npkts == 0)
-					break;
-			} 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;
-	}
-	if (unlikely(tx_wakeup && err != -ECONNRESET))
-		maybe_tx_wakeup(port);
-	return npkts;
-}
-
-static int vnet_poll(struct napi_struct *napi, int budget)
-{
-	struct vnet_port *port = container_of(napi, struct vnet_port, napi);
-	struct vio_driver_state *vio = &port->vio;
-	int processed = vnet_event_napi(port, budget);
-
-	if (processed < budget) {
-		napi_complete(napi);
-		port->rx_event &= ~LDC_EVENT_DATA_READY;
-		vio_set_intr(vio->vdev->rx_ino, HV_INTR_ENABLED);
-	}
-	return processed;
-}
-
-static void vnet_event(void *arg, int event)
-{
-	struct vnet_port *port = arg;
-	struct vio_driver_state *vio = &port->vio;
-
-	port->rx_event |= event;
-	vio_set_intr(vio->vdev->rx_ino, HV_INTR_DISABLED);
-	napi_schedule(&port->napi);
-
-}
-
-static int __vnet_tx_trigger(struct vnet_port *port, u32 start)
-{
-	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		= start,
-		.end_idx		= (u32) -1,
-	};
-	int err, delay;
-	int retries = 0;
-
-	if (port->stop_rx) {
-		trace_vnet_tx_pending_stopped_ack(port->vio._local_sid,
-						  port->vio._peer_sid,
-						  port->stop_rx_idx, -1);
-		err = vnet_send_ack(port,
-				    &port->vio.drings[VIO_DRIVER_RX_RING],
-				    port->stop_rx_idx, -1,
-				    VIO_DRING_STOPPED);
-		if (err <= 0)
-			return err;
-	}
-
-	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;
-		if (retries++ > VNET_MAX_RETRIES)
-			break;
-	} while (err == -EAGAIN);
-	trace_vnet_tx_trigger(port->vio._local_sid,
-			      port->vio._peer_sid, start, err);
-
-	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 vnet_port *port;
-
-	hlist_for_each_entry_rcu(port, hp, hash) {
-		if (!port_is_up(port))
-			continue;
-		if (ether_addr_equal(port->raddr, skb->data))
-			return port;
-	}
-	list_for_each_entry_rcu(port, &vp->port_list, list) {
-		if (!port->switch_port)
-			continue;
-		if (!port_is_up(port))
-			continue;
-		return port;
-	}
-	return NULL;
-}
-
-static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port,
-					  unsigned *pending)
-{
-	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
-	struct sk_buff *skb = NULL;
-	int i, txi;
-
-	*pending = 0;
-
-	txi = dr->prod;
-	for (i = 0; i < VNET_TX_RING_SIZE; ++i) {
-		struct vio_net_desc *d;
-
-		--txi;
-		if (txi < 0)
-			txi = VNET_TX_RING_SIZE-1;
-
-		d = vio_dring_entry(dr, txi);
-
-		if (d->hdr.state == VIO_DESC_READY) {
-			(*pending)++;
-			continue;
-		}
-		if (port->tx_bufs[txi].skb) {
-			if (d->hdr.state != VIO_DESC_DONE)
-				pr_notice("invalid ring buffer state %d\n",
-					  d->hdr.state);
-			BUG_ON(port->tx_bufs[txi].skb->next);
-
-			port->tx_bufs[txi].skb->next = skb;
-			skb = port->tx_bufs[txi].skb;
-			port->tx_bufs[txi].skb = NULL;
-
-			ldc_unmap(port->vio.lp,
-				  port->tx_bufs[txi].cookies,
-				  port->tx_bufs[txi].ncookies);
-		} else if (d->hdr.state == VIO_DESC_FREE)
-			break;
-		d->hdr.state = VIO_DESC_FREE;
-	}
-	return skb;
-}
-
-static inline void vnet_free_skbs(struct sk_buff *skb)
-{
-	struct sk_buff *next;
-
-	while (skb) {
-		next = skb->next;
-		skb->next = NULL;
-		dev_kfree_skb(skb);
-		skb = next;
-	}
-}
-
-static void vnet_clean_timer_expire(unsigned long port0)
-{
-	struct vnet_port *port = (struct vnet_port *)port0;
-	struct sk_buff *freeskbs;
-	unsigned pending;
-
-	netif_tx_lock(port->vp->dev);
-	freeskbs = vnet_clean_tx_ring(port, &pending);
-	netif_tx_unlock(port->vp->dev);
-
-	vnet_free_skbs(freeskbs);
-
-	if (pending)
-		(void)mod_timer(&port->clean_timer,
-				jiffies + VNET_CLEAN_TIMEOUT);
-	 else
-		del_timer(&port->clean_timer);
-}
-
-static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb,
-			       struct ldc_trans_cookie *cookies, int ncookies,
-			       unsigned int map_perm)
-{
-	int i, nc, err, blen;
-
-	/* header */
-	blen = skb_headlen(skb);
-	if (blen < ETH_ZLEN)
-		blen = ETH_ZLEN;
-	blen += VNET_PACKET_SKIP;
-	blen += 8 - (blen & 7);
-
-	err = ldc_map_single(lp, skb->data-VNET_PACKET_SKIP, blen, cookies,
-			     ncookies, map_perm);
-	if (err < 0)
-		return err;
-	nc = err;
-
-	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-		u8 *vaddr;
-
-		if (nc < ncookies) {
-			vaddr = kmap_atomic(skb_frag_page(f));
-			blen = skb_frag_size(f);
-			blen += 8 - (blen & 7);
-			err = ldc_map_single(lp, vaddr + f->page_offset,
-					     blen, cookies + nc, ncookies - nc,
-					     map_perm);
-			kunmap_atomic(vaddr);
-		} else {
-			err = -EMSGSIZE;
-		}
-
-		if (err < 0) {
-			ldc_unmap(lp, cookies, nc);
-			return err;
-		}
-		nc += err;
-	}
-	return nc;
-}
-
-static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, int ncookies)
-{
-	struct sk_buff *nskb;
-	int i, len, pad, docopy;
-
-	len = skb->len;
-	pad = 0;
-	if (len < ETH_ZLEN) {
-		pad += ETH_ZLEN - skb->len;
-		len += pad;
-	}
-	len += VNET_PACKET_SKIP;
-	pad += 8 - (len & 7);
-
-	/* make sure we have enough cookies and alignment in every frag */
-	docopy = skb_shinfo(skb)->nr_frags >= ncookies;
-	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-
-		docopy |= f->page_offset & 7;
-	}
-	if (((unsigned long)skb->data & 7) != VNET_PACKET_SKIP ||
-	    skb_tailroom(skb) < pad ||
-	    skb_headroom(skb) < VNET_PACKET_SKIP || docopy) {
-		int start = 0, offset;
-		__wsum csum;
-
-		len = skb->len > ETH_ZLEN ? skb->len : ETH_ZLEN;
-		nskb = alloc_and_align_skb(skb->dev, len);
-		if (nskb == NULL) {
-			dev_kfree_skb(skb);
-			return NULL;
-		}
-		skb_reserve(nskb, VNET_PACKET_SKIP);
-
-		nskb->protocol = skb->protocol;
-		offset = skb_mac_header(skb) - skb->data;
-		skb_set_mac_header(nskb, offset);
-		offset = skb_network_header(skb) - skb->data;
-		skb_set_network_header(nskb, offset);
-		offset = skb_transport_header(skb) - skb->data;
-		skb_set_transport_header(nskb, offset);
-
-		offset = 0;
-		nskb->csum_offset = skb->csum_offset;
-		nskb->ip_summed = skb->ip_summed;
-
-		if (skb->ip_summed == CHECKSUM_PARTIAL)
-			start = skb_checksum_start_offset(skb);
-		if (start) {
-			struct iphdr *iph = ip_hdr(nskb);
-			int offset = start + nskb->csum_offset;
-
-			if (skb_copy_bits(skb, 0, nskb->data, start)) {
-				dev_kfree_skb(nskb);
-				dev_kfree_skb(skb);
-				return NULL;
-			}
-			*(__sum16 *)(skb->data + offset) = 0;
-			csum = skb_copy_and_csum_bits(skb, start,
-						      nskb->data + start,
-						      skb->len - start, 0);
-			if (iph->protocol == IPPROTO_TCP ||
-			    iph->protocol == IPPROTO_UDP) {
-				csum = csum_tcpudp_magic(iph->saddr, iph->daddr,
-							 skb->len - start,
-							 iph->protocol, csum);
-			}
-			*(__sum16 *)(nskb->data + offset) = csum;
-
-			nskb->ip_summed = CHECKSUM_NONE;
-		} else if (skb_copy_bits(skb, 0, nskb->data, skb->len)) {
-			dev_kfree_skb(nskb);
-			dev_kfree_skb(skb);
-			return NULL;
-		}
-		(void)skb_put(nskb, skb->len);
-		if (skb_is_gso(skb)) {
-			skb_shinfo(nskb)->gso_size = skb_shinfo(skb)->gso_size;
-			skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
-		}
-		nskb->queue_mapping = skb->queue_mapping;
-		dev_kfree_skb(skb);
-		skb = nskb;
-	}
-	return skb;
-}
-
-static u16
-vnet_select_queue(struct net_device *dev, struct sk_buff *skb,
-		  void *accel_priv, select_queue_fallback_t fallback)