This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / infiniband / ulp / ipoib / ipoib_ib.c
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
new file mode 100644 (file)
index 0000000..f89ac46
--- /dev/null
@@ -0,0 +1,666 @@
+/*
+ * 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
+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,
+               .recv_flags = IB_RECV_SIGNALED
+       };
+       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);
+               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;
+}