1 files changed, 668 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
new file mode 100644
index 00000000000..c5a1d45e0ac
--- /dev/null
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -0,0 +1,668 @@
+/*
+ * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * $Id: ipoib_ib.c 1386 2004-12-27 16:23:17Z roland $
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+
+#include <ib_cache.h>
+
+#include "ipoib.h"
+
+#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG_DATA
+static int data_debug_level;
+
+module_param(data_debug_level, int, 0644);
+MODULE_PARM_DESC(data_debug_level,
+		 "Enable data path debug tracing if > 0");
+#endif
+
+#define	IPOIB_OP_RECV	(1ul << 31)
+
+static DECLARE_MUTEX(pkey_sem);
+
+struct ipoib_ah *ipoib_create_ah(struct net_device *dev,
+				 struct ib_pd *pd, struct ib_ah_attr *attr)
+{
+	struct ipoib_ah *ah;
+
+	ah = kmalloc(sizeof *ah, GFP_KERNEL);
+	if (!ah)
+		return NULL;
+
+	ah->dev       = dev;
+	ah->last_send = 0;
+	kref_init(&ah->ref);
+
+	ah->ah = ib_create_ah(pd, attr);
+	if (IS_ERR(ah->ah)) {
+		kfree(ah);
+		ah = NULL;
+	} else
+		ipoib_dbg(netdev_priv(dev), "Created ah %p\n", ah->ah);
+
+	return ah;
+}
+
+void ipoib_free_ah(struct kref *kref)
+{
+	struct ipoib_ah *ah = container_of(kref, struct ipoib_ah, ref);
+	struct ipoib_dev_priv *priv = netdev_priv(ah->dev);
+
+	unsigned long flags;
+
+	if (ah->last_send <= priv->tx_tail) {
+		ipoib_dbg(priv, "Freeing ah %p\n", ah->ah);
+		ib_destroy_ah(ah->ah);
+		kfree(ah);
+	} else {
+		spin_lock_irqsave(&priv->lock, flags);
+		list_add_tail(&ah->list, &priv->dead_ahs);
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+}
+
+static inline int ipoib_ib_receive(struct ipoib_dev_priv *priv,
+				   unsigned int wr_id,
+				   dma_addr_t addr)
+{
+	struct ib_sge list = {
+		.addr    = addr,
+		.length  = IPOIB_BUF_SIZE,
+		.lkey    = priv->mr->lkey,
+	};
+	struct ib_recv_wr param = {
+		.wr_id 	    = wr_id | IPOIB_OP_RECV,
+		.sg_list    = &list,
+		.num_sge    = 1,
+	};
+	struct ib_recv_wr *bad_wr;
+
+	return ib_post_recv(priv->qp, &param, &bad_wr);
+}
+
+static int ipoib_ib_post_receive(struct net_device *dev, int id)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	struct sk_buff *skb;
+	dma_addr_t addr;
+	int ret;
+
+	skb = dev_alloc_skb(IPOIB_BUF_SIZE + 4);
+	if (!skb) {
+		ipoib_warn(priv, "failed to allocate receive buffer\n");
+
+		priv->rx_ring[id].skb = NULL;
+		return -ENOMEM;
+	}
+	skb_reserve(skb, 4);	/* 16 byte align IP header */
+	priv->rx_ring[id].skb = skb;
+	addr = dma_map_single(priv->ca->dma_device,
+			      skb->data, IPOIB_BUF_SIZE,
+			      DMA_FROM_DEVICE);
+	pci_unmap_addr_set(&priv->rx_ring[id], mapping, addr);
+
+	ret = ipoib_ib_receive(priv, id, addr);
+	if (ret) {
+		ipoib_warn(priv, "ipoib_ib_receive failed for buf %d (%d)\n",
+			   id, ret);
+		dma_unmap_single(priv->ca->dma_device, addr,
+				 IPOIB_BUF_SIZE, DMA_FROM_DEVICE);
+		dev_kfree_skb_any(skb);
+		priv->rx_ring[id].skb = NULL;
+	}
+
+	return ret;
+}
+
+static int ipoib_ib_post_receives(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	int i;
+
+	for (i = 0; i < IPOIB_RX_RING_SIZE; ++i) {
+		if (ipoib_ib_post_receive(dev, i)) {
+			ipoib_warn(priv, "ipoib_ib_post_receive failed for buf %d\n", i);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static void ipoib_ib_handle_wc(struct net_device *dev,
+			       struct ib_wc *wc)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	unsigned int wr_id = wc->wr_id;
+
+	ipoib_dbg_data(priv, "called: id %d, op %d, status: %d\n",
+		       wr_id, wc->opcode, wc->status);
+
+	if (wr_id & IPOIB_OP_RECV) {
+		wr_id &= ~IPOIB_OP_RECV;
+
+		if (wr_id < IPOIB_RX_RING_SIZE) {
+			struct sk_buff *skb = priv->rx_ring[wr_id].skb;
+
+			priv->rx_ring[wr_id].skb = NULL;
+
+			dma_unmap_single(priv->ca->dma_device,
+					 pci_unmap_addr(&priv->rx_ring[wr_id],
+							mapping),
+					 IPOIB_BUF_SIZE,
+					 DMA_FROM_DEVICE);
+
+			if (wc->status != IB_WC_SUCCESS) {
+				if (wc->status != IB_WC_WR_FLUSH_ERR)
+					ipoib_warn(priv, "failed recv event "
+						   "(status=%d, wrid=%d vend_err %x)\n",
+						   wc->status, wr_id, wc->vendor_err);
+				dev_kfree_skb_any(skb);
+				return;
+			}
+
+			ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
+				       wc->byte_len, wc->slid);
+
+			skb_put(skb, wc->byte_len);
+			skb_pull(skb, IB_GRH_BYTES);
+
+			if (wc->slid != priv->local_lid ||
+			    wc->src_qp != priv->qp->qp_num) {
+				skb->protocol = ((struct ipoib_header *) skb->data)->proto;
+
+				skb_pull(skb, IPOIB_ENCAP_LEN);
+
+				dev->last_rx = jiffies;
+				++priv->stats.rx_packets;
+				priv->stats.rx_bytes += skb->len;
+
+				skb->dev = dev;
+				/* XXX get correct PACKET_ type here */
+				skb->pkt_type = PACKET_HOST;
+				netif_rx_ni(skb);
+			} else {
+				ipoib_dbg_data(priv, "dropping loopback packet\n");
+				dev_kfree_skb_any(skb);
+			}
+
+			/* repost receive */
+			if (ipoib_ib_post_receive(dev, wr_id))
+				ipoib_warn(priv, "ipoib_ib_post_receive failed "
+					   "for buf %d\n", wr_id);
+		} else
+			ipoib_warn(priv, "completion event with wrid %d\n",
+				   wr_id);
+
+	} else {
+		struct ipoib_buf *tx_req;
+		unsigned long flags;
+
+		if (wr_id >= IPOIB_TX_RING_SIZE) {
+			ipoib_warn(priv, "completion event with wrid %d (> %d)\n",
+				   wr_id, IPOIB_TX_RING_SIZE);
+			return;
+		}
+
+		ipoib_dbg_data(priv, "send complete, wrid %d\n", wr_id);
+
+		tx_req = &priv->tx_ring[wr_id];
+
+		dma_unmap_single(priv->ca->dma_device,
+				 pci_unmap_addr(tx_req, mapping),
+				 tx_req->skb->len,
+				 DMA_TO_DEVICE);
+
+		++priv->stats.tx_packets;
+		priv->stats.tx_bytes += tx_req->skb->len;
+
+		dev_kfree_skb_any(tx_req->skb);
+
+		spin_lock_irqsave(&priv->tx_lock, flags);
+		++priv->tx_tail;
+		if (netif_queue_stopped(dev) &&
+		    priv->tx_head - priv->tx_tail <= IPOIB_TX_RING_SIZE / 2)
+			netif_wake_queue(dev);
+		spin_unlock_irqrestore(&priv->tx_lock, flags);
+
+		if (wc->status != IB_WC_SUCCESS &&
+		    wc->status != IB_WC_WR_FLUSH_ERR)
+			ipoib_warn(priv, "failed send event "
+				   "(status=%d, wrid=%d vend_err %x)\n",
+				   wc->status, wr_id, wc->vendor_err);
+	}
+}
+
+void ipoib_ib_completion(struct ib_cq *cq, void *dev_ptr)
+{
+	struct net_device *dev = (struct net_device *) dev_ptr;
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	int n, i;
+
+	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
+	do {
+		n = ib_poll_cq(cq, IPOIB_NUM_WC, priv->ibwc);
+		for (i = 0; i < n; ++i)
+			ipoib_ib_handle_wc(dev, priv->ibwc + i);
+	} while (n == IPOIB_NUM_WC);
+}
+
+static inline int post_send(struct ipoib_dev_priv *priv,
+			    unsigned int wr_id,
+			    struct ib_ah *address, u32 qpn,
+			    dma_addr_t addr, int len)
+{
+	struct ib_send_wr *bad_wr;
+
+	priv->tx_sge.addr             = addr;
+	priv->tx_sge.length           = len;
+
+	priv->tx_wr.wr_id 	      = wr_id;
+	priv->tx_wr.wr.ud.remote_qpn  = qpn;
+	priv->tx_wr.wr.ud.ah 	      = address;
+
+	return ib_post_send(priv->qp, &priv->tx_wr, &bad_wr);
+}
+
+void ipoib_send(struct net_device *dev, struct sk_buff *skb,
+		struct ipoib_ah *address, u32 qpn)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	struct ipoib_buf *tx_req;
+	dma_addr_t addr;
+
+	if (skb->len > dev->mtu + INFINIBAND_ALEN) {
+		ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
+			   skb->len, dev->mtu + INFINIBAND_ALEN);
+		++priv->stats.tx_dropped;
+		++priv->stats.tx_errors;
+		dev_kfree_skb_any(skb);
+		return;
+	}
+
+	ipoib_dbg_data(priv, "sending packet, length=%d address=%p qpn=0x%06x\n",
+		       skb->len, address, qpn);
+
+	/*
+	 * We put the skb into the tx_ring _before_ we call post_send()
+	 * because it's entirely possible that the completion handler will
+	 * run before we execute anything after the post_send().  That
+	 * means we have to make sure everything is properly recorded and
+	 * our state is consistent before we call post_send().
+	 */
+	tx_req = &priv->tx_ring[priv->tx_head & (IPOIB_TX_RING_SIZE - 1)];
+	tx_req->skb = skb;
+	addr = dma_map_single(priv->ca->dma_device, skb->data, skb->len,
+			      DMA_TO_DEVICE);
+	pci_unmap_addr_set(tx_req, mapping, addr);
+
+	if (unlikely(post_send(priv, priv->tx_head & (IPOIB_TX_RING_SIZE - 1),
+			       address->ah, qpn, addr, skb->len))) {
+		ipoib_warn(priv, "post_send failed\n");
+		++priv->stats.tx_errors;
+		dma_unmap_single(priv->ca->dma_device, addr, skb->len,
+				 DMA_TO_DEVICE);
+		dev_kfree_skb_any(skb);
+	} else {
+		dev->trans_start = jiffies;
+
+		address->last_send = priv->tx_head;
+		++priv->tx_head;
+
+		if (priv->tx_head - priv->tx_tail == IPOIB_TX_RING_SIZE) {
+			ipoib_dbg(priv, "TX ring full, stopping kernel net queue\n");
+			netif_stop_queue(dev);
+		}
+	}
+}
+
+static void __ipoib_reap_ah(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	struct ipoib_ah *ah, *tah;
+	LIST_HEAD(remove_list);
+
+	spin_lock_irq(&priv->lock);
+	list_for_each_entry_safe(ah, tah, &priv->dead_ahs, list)
+		if (ah->last_send <= priv->tx_tail) {
+			list_del(&ah->list);
+			list_add_tail(&ah->list, &remove_list);
+		}
+	spin_unlock_irq(&priv->lock);
+
+	list_for_each_entry_safe(ah, tah, &remove_list, list) {
+		ipoib_dbg(priv, "Reaping ah %p\n", ah->ah);
+		ib_destroy_ah(ah->ah);
+		kfree(ah);
+	}
+}
+
+void ipoib_reap_ah(void *dev_ptr)
+{
+	struct net_device *dev = dev_ptr;
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	__ipoib_reap_ah(dev);
+
+	if (!test_bit(IPOIB_STOP_REAPER, &priv->flags))
+		queue_delayed_work(ipoib_workqueue, &priv->ah_reap_task, HZ);
+}
+
+int ipoib_ib_dev_open(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	int ret;
+
+	ret = ipoib_qp_create(dev);
+	if (ret) {
+		ipoib_warn(priv, "ipoib_qp_create returned %d\n", ret);
+		return -1;
+	}
+
+	ret = ipoib_ib_post_receives(dev);
+	if (ret) {
+		ipoib_warn(priv, "ipoib_ib_post_receives returned %d\n", ret);
+		return -1;
+	}
+
+	clear_bit(IPOIB_STOP_REAPER, &priv->flags);
+	queue_delayed_work(ipoib_workqueue, &priv->ah_reap_task, HZ);
+
+	return 0;
+}
+
+int ipoib_ib_dev_up(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	set_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
+
+	return ipoib_mcast_start_thread(dev);
+}
+
+int ipoib_ib_dev_down(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	ipoib_dbg(priv, "downing ib_dev\n");
+
+	clear_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
+	netif_carrier_off(dev);
+
+	/* Shutdown the P_Key thread if still active */
+	if (!test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags)) {
+		down(&pkey_sem);
+		set_bit(IPOIB_PKEY_STOP, &priv->flags);
+		cancel_delayed_work(&priv->pkey_task);
+		up(&pkey_sem);
+		flush_workqueue(ipoib_workqueue);
+	}
+
+	ipoib_mcast_stop_thread(dev);
+
+	/*
+	 * Flush the multicast groups first so we stop any multicast joins. The
+	 * completion thread may have already died and we may deadlock waiting
+	 * for the completion thread to finish some multicast joins.
+	 */
+	ipoib_mcast_dev_flush(dev);
+
+	/* Delete broadcast and local addresses since they will be recreated */
+	ipoib_mcast_dev_down(dev);
+
+	ipoib_flush_paths(dev);
+
+	return 0;
+}
+
+static int recvs_pending(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	int pending = 0;
+	int i;
+
+	for (i = 0; i < IPOIB_RX_RING_SIZE; ++i)
+		if (priv->rx_ring[i].skb)
+			++pending;
+
+	return pending;
+}
+
+int ipoib_ib_dev_stop(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	struct ib_qp_attr qp_attr;
+	int attr_mask;
+	unsigned long begin;
+	struct ipoib_buf *tx_req;
+	int i;
+
+	/* Kill the existing QP and allocate a new one */
+	qp_attr.qp_state = IB_QPS_ERR;
+	attr_mask        = IB_QP_STATE;
+	if (ib_modify_qp(priv->qp, &qp_attr, attr_mask))
+		ipoib_warn(priv, "Failed to modify QP to ERROR state\n");
+
+	/* Wait for all sends and receives to complete */
+	begin = jiffies;
+
+	while (priv->tx_head != priv->tx_tail || recvs_pending(dev)) {
+		if (time_after(jiffies, begin + 5 * HZ)) {
+			ipoib_warn(priv, "timing out; %d sends %d receives not completed\n",
+				   priv->tx_head - priv->tx_tail, recvs_pending(dev));
+
+			/*
+			 * assume the HW is wedged and just free up
+			 * all our pending work requests.
+			 */
+			while (priv->tx_tail < priv->tx_head) {
+				tx_req = &priv->tx_ring[priv->tx_tail &
+							(IPOIB_TX_RING_SIZE - 1)];
+				dma_unmap_single(priv->ca->dma_device,
+						 pci_unmap_addr(tx_req, mapping),
+						 tx_req->skb->len,
+						 DMA_TO_DEVICE);
+				dev_kfree_skb_any(tx_req->skb);
+				++priv->tx_tail;
+			}
+
+			for (i = 0; i < IPOIB_RX_RING_SIZE; ++i)
+				if (priv->rx_ring[i].skb) {
+					dma_unmap_single(priv->ca->dma_device,
+							 pci_unmap_addr(&priv->rx_ring[i],
+									mapping),
+							 IPOIB_BUF_SIZE,
+							 DMA_FROM_DEVICE);
+					dev_kfree_skb_any(priv->rx_ring[i].skb);
+					priv->rx_ring[i].skb = NULL;
+				}
+
+			goto timeout;
+		}
+
+		msleep(1);
+	}
+
+	ipoib_dbg(priv, "All sends and receives done.\n");
+
+timeout:
+	qp_attr.qp_state = IB_QPS_RESET;
+	attr_mask        = IB_QP_STATE;
+	if (ib_modify_qp(priv->qp, &qp_attr, attr_mask))
+		ipoib_warn(priv, "Failed to modify QP to RESET state\n");
+
+	/* Wait for all AHs to be reaped */
+	set_bit(IPOIB_STOP_REAPER, &priv->flags);
+	cancel_delayed_work(&priv->ah_reap_task);
+	flush_workqueue(ipoib_workqueue);
+
+	begin = jiffies;
+
+	while (!list_empty(&priv->dead_ahs)) {
+		__ipoib_reap_ah(dev);
+
+		if (time_after(jiffies, begin + HZ)) {
+			ipoib_warn(priv, "timing out; will leak address handles\n");
+			break;
+		}
+
+		msleep(1);
+	}
+
+	return 0;
+}
+
+int ipoib_ib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	priv->ca = ca;
+	priv->port = port;
+	priv->qp = NULL;
+
+	if (ipoib_transport_dev_init(dev, ca)) {
+		printk(KERN_WARNING "%s: ipoib_transport_dev_init failed\n", ca->name);
+		return -ENODEV;
+	}
+
+	if (dev->flags & IFF_UP) {
+		if (ipoib_ib_dev_open(dev)) {
+			ipoib_transport_dev_cleanup(dev);
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+void ipoib_ib_dev_flush(void *_dev)
+{
+	struct net_device *dev = (struct net_device *)_dev;
+	struct ipoib_dev_priv *priv = netdev_priv(dev), *cpriv;
+
+	if (!test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
+		return;
+
+	ipoib_dbg(priv, "flushing\n");
+
+	ipoib_ib_dev_down(dev);
+
+	/*
+	 * The device could have been brought down between the start and when
+	 * we get here, don't bring it back up if it's not configured up
+	 */
+	if (test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
+		ipoib_ib_dev_up(dev);
+
+	/* Flush any child interfaces too */
+	list_for_each_entry(cpriv, &priv->child_intfs, list)
+		ipoib_ib_dev_flush(&cpriv->dev);
+}
+
+void ipoib_ib_dev_cleanup(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	ipoib_dbg(priv, "cleaning up ib_dev\n");
+
+	ipoib_mcast_stop_thread(dev);
+
+	/* Delete the broadcast address and the local address */
+	ipoib_mcast_dev_down(dev);
+
+	ipoib_transport_dev_cleanup(dev);
+}
+
+/*
+ * Delayed P_Key Assigment Interim Support
+ *
+ * The following is initial implementation of delayed P_Key assigment
+ * mechanism. It is using the same approach implemented for the multicast
+ * group join. The single goal of this implementation is to quickly address
+ * Bug #2507. This implementation will probably be removed when the P_Key
+ * change async notification is available.
+ */
+int ipoib_open(struct net_device *dev);
+
+static void ipoib_pkey_dev_check_presence(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+	u16 pkey_index = 0;
+
+	if (ib_find_cached_pkey(priv->ca, priv->port, priv->pkey, &pkey_index))
+		clear_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
+	else
+		set_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
+}
+
+void ipoib_pkey_poll(void *dev_ptr)
+{
+	struct net_device *dev = dev_ptr;
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	ipoib_pkey_dev_check_presence(dev);
+
+	if (test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags))
+		ipoib_open(dev);
+	else {
+		down(&pkey_sem);
+		if (!test_bit(IPOIB_PKEY_STOP, &priv->flags))
+			queue_delayed_work(ipoib_workqueue,
+					   &priv->pkey_task,
+					   HZ);
+		up(&pkey_sem);
+	}
+}
+
+int ipoib_pkey_dev_delay_open(struct net_device *dev)
+{
+	struct ipoib_dev_priv *priv = netdev_priv(dev);
+
+	/* Look for the interface pkey value in the IB Port P_Key table and */
+	/* set the interface pkey assigment flag                            */
+	ipoib_pkey_dev_check_presence(dev);
+
+	/* P_Key value not assigned yet - start polling */
+	if (!test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags)) {
+		down(&pkey_sem);
+		clear_bit(IPOIB_PKEY_STOP, &priv->flags);
+		queue_delayed_work(ipoib_workqueue,
+				   &priv->pkey_task,
+				   HZ);
+		up(&pkey_sem);
+		return 1;
+	}
+
+	return 0;
+}