text: /*
   * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
   * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
   * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
   * Copyright (c) 2004, 2005 Voltaire, Inc. 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.
   */
  
  #include <linux/delay.h>
  #include <linux/dma-mapping.h>
  #include <linux/slab.h>
  
  #include <linux/ip.h>
  #include <linux/tcp.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
  
  static DEFINE_MUTEX(pkey_mutex);
  
  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;
  
  	spin_lock_irqsave(&priv->lock, flags);
  	list_add_tail(&ah->list, &priv->dead_ahs);
  	spin_unlock_irqrestore(&priv->lock, flags);
  }
  
  static void ipoib_ud_dma_unmap_rx(struct ipoib_dev_priv *priv,
  				  u64 mapping[IPOIB_UD_RX_SG])
  {
  	if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
  		ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_UD_HEAD_SIZE,
  				    DMA_FROM_DEVICE);
  		ib_dma_unmap_page(priv->ca, mapping[1], PAGE_SIZE,
  				  DMA_FROM_DEVICE);
  	} else
  		ib_dma_unmap_single(priv->ca, mapping[0],
  				    IPOIB_UD_BUF_SIZE(priv->max_ib_mtu),
  				    DMA_FROM_DEVICE);
  }
  
  static void ipoib_ud_skb_put_frags(struct ipoib_dev_priv *priv,
  				   struct sk_buff *skb,
  				   unsigned int length)
  {
  	if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
  		skb_frag_t *frag = &skb_shinfo(skb)->frags[0];
  		unsigned int size;
  		/*
  		 * There is only two buffers needed for max_payload = 4K,
  		 * first buf size is IPOIB_UD_HEAD_SIZE
  		 */
  		skb->tail += IPOIB_UD_HEAD_SIZE;
  		skb->len  += length;
  
  		size = length - IPOIB_UD_HEAD_SIZE;
  
  		frag->size     = size;
  		skb->data_len += size;
  		skb->truesize += size;
  	} else
  		skb_put(skb, length);
  
  }
  
  static int ipoib_ib_post_receive(struct net_device *dev, int id)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	struct ib_recv_wr *bad_wr;
  	int ret;
  
  	priv->rx_wr.wr_id   = id | IPOIB_OP_RECV;
  	priv->rx_sge[0].addr = priv->rx_ring[id].mapping[0];
  	priv->rx_sge[1].addr = priv->rx_ring[id].mapping[1];
  
  
  	ret = ib_post_recv(priv->qp, &priv->rx_wr, &bad_wr);
  	if (unlikely(ret)) {
  		ipoib_warn(priv, "receive failed for buf %d (%d)\n", id, ret);
  		ipoib_ud_dma_unmap_rx(priv, priv->rx_ring[id].mapping);
  		dev_kfree_skb_any(priv->rx_ring[id].skb);
  		priv->rx_ring[id].skb = NULL;
  	}
  
  	return ret;
  }
  
  static struct sk_buff *ipoib_alloc_rx_skb(struct net_device *dev, int id)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	struct sk_buff *skb;
  	int buf_size;
  	u64 *mapping;
  
  	if (ipoib_ud_need_sg(priv->max_ib_mtu))
  		buf_size = IPOIB_UD_HEAD_SIZE;
  	else
  		buf_size = IPOIB_UD_BUF_SIZE(priv->max_ib_mtu);
  
  	skb = dev_alloc_skb(buf_size + 4);
  	if (unlikely(!skb))
  		return NULL;
  
  	/*
  	 * IB will leave a 40 byte gap for a GRH and IPoIB adds a 4 byte
  	 * header.  So we need 4 more bytes to get to 48 and align the
  	 * IP header to a multiple of 16.
  	 */
  	skb_reserve(skb, 4);
  
  	mapping = priv->rx_ring[id].mapping;
  	mapping[0] = ib_dma_map_single(priv->ca, skb->data, buf_size,
  				       DMA_FROM_DEVICE);
  	if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0])))
  		goto error;
  
  	if (ipoib_ud_need_sg(priv->max_ib_mtu)) {
  		struct page *page = alloc_page(GFP_ATOMIC);
  		if (!page)
  			goto partial_error;
  		skb_fill_page_desc(skb, 0, page, 0, PAGE_SIZE);
  		mapping[1] =
  			ib_dma_map_page(priv->ca, skb_shinfo(skb)->frags[0].page,
  					0, PAGE_SIZE, DMA_FROM_DEVICE);
  		if (unlikely(ib_dma_mapping_error(priv->ca, mapping[1])))
  			goto partial_error;
  	}
  
  	priv->rx_ring[id].skb = skb;
  	return skb;
  
  partial_error:
  	ib_dma_unmap_single(priv->ca, mapping[0], buf_size, DMA_FROM_DEVICE);
  error:
  	dev_kfree_skb_any(skb);
  	return NULL;
  }
  
  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_recvq_size; ++i) {
  		if (!ipoib_alloc_rx_skb(dev, i)) {
  			ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
  			return -ENOMEM;
  		}
  		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_rx_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_OP_RECV;
  	struct sk_buff *skb;
  	u64 mapping[IPOIB_UD_RX_SG];
  
  	ipoib_dbg_data(priv, "recv completion: id %d, status: %d\n",
  		       wr_id, wc->status);
  
  	if (unlikely(wr_id >= ipoib_recvq_size)) {
  		ipoib_warn(priv, "recv completion event with wrid %d (> %d)\n",
  			   wr_id, ipoib_recvq_size);
  		return;
  	}
  
  	skb  = priv->rx_ring[wr_id].skb;
  
  	if (unlikely(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);
  		ipoib_ud_dma_unmap_rx(priv, priv->rx_ring[wr_id].mapping);
  		dev_kfree_skb_any(skb);
  		priv->rx_ring[wr_id].skb = NULL;
  		return;
  	}
  
  	/*
  	 * Drop packets that this interface sent, ie multicast packets
  	 * that the HCA has replicated.
  	 */
  	if (wc->slid == priv->local_lid && wc->src_qp == priv->qp->qp_num)
  		goto repost;
  
  	memcpy(mapping, priv->rx_ring[wr_id].mapping,
  	       IPOIB_UD_RX_SG * sizeof *mapping);
  
  	/*
  	 * If we can't allocate a new RX buffer, dump
  	 * this packet and reuse the old buffer.
  	 */
  	if (unlikely(!ipoib_alloc_rx_skb(dev, wr_id))) {
  		++dev->stats.rx_dropped;
  		goto repost;
  	}
  
  	ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
  		       wc->byte_len, wc->slid);
  
  	ipoib_ud_dma_unmap_rx(priv, mapping);
  	ipoib_ud_skb_put_frags(priv, skb, wc->byte_len);
  
  	skb_pull(skb, IB_GRH_BYTES);
  
  	skb->protocol = ((struct ipoib_header *) skb->data)->proto;
  	skb_reset_mac_header(skb);
  	skb_pull(skb, IPOIB_ENCAP_LEN);
  
  	++dev->stats.rx_packets;
  	dev->stats.rx_bytes += skb->len;
  
  	skb->dev = dev;
  	skb->pkt_type = PACKET_HOST;
  
  	if (test_bit(IPOIB_FLAG_CSUM, &priv->flags) && likely(wc->csum_ok))
  		skb->ip_summed = CHECKSUM_UNNECESSARY;
  
  	if (dev->features & NETIF_F_LRO)
  		lro_receive_skb(&priv->lro.lro_mgr, skb, NULL);
  	else
  		netif_receive_skb(skb);
  
  repost:
  	if (unlikely(ipoib_ib_post_receive(dev, wr_id)))
  		ipoib_warn(priv, "ipoib_ib_post_receive failed "
  			   "for buf %d\n", wr_id);
  }
  
  static int ipoib_dma_map_tx(struct ib_device *ca,
  			    struct ipoib_tx_buf *tx_req)
  {
  	struct sk_buff *skb = tx_req->skb;
  	u64 *mapping = tx_req->mapping;
  	int i;
  	int off;
  
  	if (skb_headlen(skb)) {
  		mapping[0] = ib_dma_map_single(ca, skb->data, skb_headlen(skb),
  					       DMA_TO_DEVICE);
  		if (unlikely(ib_dma_mapping_error(ca, mapping[0])))
  			return -EIO;
  
  		off = 1;
  	} else
  		off = 0;
  
  	for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) {
  		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
  		mapping[i + off] = ib_dma_map_page(ca, frag->page,
  						 frag->page_offset, frag->size,
  						 DMA_TO_DEVICE);
  		if (unlikely(ib_dma_mapping_error(ca, mapping[i + off])))
  			goto partial_error;
  	}
  	return 0;
  
  partial_error:
  	for (; i > 0; --i) {
  		skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
  		ib_dma_unmap_page(ca, mapping[i - !off], frag->size, DMA_TO_DEVICE);
  	}
  
  	if (off)
  		ib_dma_unmap_single(ca, mapping[0], skb_headlen(skb), DMA_TO_DEVICE);
  
  	return -EIO;
  }
  
  static void ipoib_dma_unmap_tx(struct ib_device *ca,
  			       struct ipoib_tx_buf *tx_req)
  {
  	struct sk_buff *skb = tx_req->skb;
  	u64 *mapping = tx_req->mapping;
  	int i;
  	int off;
  
  	if (skb_headlen(skb)) {
  		ib_dma_unmap_single(ca, mapping[0], skb_headlen(skb), DMA_TO_DEVICE);
  		off = 1;
  	} else
  		off = 0;
  
  	for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) {
  		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
  		ib_dma_unmap_page(ca, mapping[i + off], frag->size,
  				  DMA_TO_DEVICE);
  	}
  }
  
  static void ipoib_ib_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	unsigned int wr_id = wc->wr_id;
  	struct ipoib_tx_buf *tx_req;
  
  	ipoib_dbg_data(priv, "send completion: id %d, status: %d\n",
  		       wr_id, wc->status);
  
  	if (unlikely(wr_id >= ipoib_sendq_size)) {
  		ipoib_warn(priv, "send completion event with wrid %d (> %d)\n",
  			   wr_id, ipoib_sendq_size);
  		return;
  	}
  
  	tx_req = &priv->tx_ring[wr_id];
  
  	ipoib_dma_unmap_tx(priv->ca, tx_req);
  
  	++dev->stats.tx_packets;
  	dev->stats.tx_bytes += tx_req->skb->len;
  
  	dev_kfree_skb_any(tx_req->skb);
  
  	++priv->tx_tail;
  	if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
  	    netif_queue_stopped(dev) &&
  	    test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
  		netif_wake_queue(dev);
  
  	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);
  }
  
  static int poll_tx(struct ipoib_dev_priv *priv)
  {
  	int n, i;
  
  	n = ib_poll_cq(priv->send_cq, MAX_SEND_CQE, priv->send_wc);
  	for (i = 0; i < n; ++i)
  		ipoib_ib_handle_tx_wc(priv->dev, priv->send_wc + i);
  
  	return n == MAX_SEND_CQE;
  }
  
  int ipoib_poll(struct napi_struct *napi, int budget)
  {
  	struct ipoib_dev_priv *priv = container_of(napi, struct ipoib_dev_priv, napi);
  	struct net_device *dev = priv->dev;
  	int done;
  	int t;
  	int n, i;
  
  	done  = 0;
  
  poll_more:
  	while (done < budget) {
  		int max = (budget - done);
  
  		t = min(IPOIB_NUM_WC, max);
  		n = ib_poll_cq(priv->recv_cq, t, priv->ibwc);
  
  		for (i = 0; i < n; i++) {
  			struct ib_wc *wc = priv->ibwc + i;
  
  			if (wc->wr_id & IPOIB_OP_RECV) {
  				++done;
  				if (wc->wr_id & IPOIB_OP_CM)
  					ipoib_cm_handle_rx_wc(dev, wc);
  				else
  					ipoib_ib_handle_rx_wc(dev, wc);
  			} else
  				ipoib_cm_handle_tx_wc(priv->dev, wc);
  		}
  
  		if (n != t)
  			break;
  	}
  
  	if (done < budget) {
  		if (dev->features & NETIF_F_LRO)
  			lro_flush_all(&priv->lro.lro_mgr);
  
  		napi_complete(napi);
  		if (unlikely(ib_req_notify_cq(priv->recv_cq,
  					      IB_CQ_NEXT_COMP |
  					      IB_CQ_REPORT_MISSED_EVENTS)) &&
  		    napi_reschedule(napi))
  			goto poll_more;
  	}
  
  	return done;
  }
  
  void ipoib_ib_completion(struct ib_cq *cq, void *dev_ptr)
  {
  	struct net_device *dev = dev_ptr;
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  
  	napi_schedule(&priv->napi);
  }
  
  static void drain_tx_cq(struct net_device *dev)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  
  	netif_tx_lock(dev);
  	while (poll_tx(priv))
  		; /* nothing */
  
  	if (netif_queue_stopped(dev))
  		mod_timer(&priv->poll_timer, jiffies + 1);
  
  	netif_tx_unlock(dev);
  }
  
  void ipoib_send_comp_handler(struct ib_cq *cq, void *dev_ptr)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev_ptr);
  
  	mod_timer(&priv->poll_timer, jiffies);
  }
  
  static inline int post_send(struct ipoib_dev_priv *priv,
  			    unsigned int wr_id,
  			    struct ib_ah *address, u32 qpn,
  			    struct ipoib_tx_buf *tx_req,
  			    void *head, int hlen)
  {
  	struct ib_send_wr *bad_wr;
  	int i, off;
  	struct sk_buff *skb = tx_req->skb;
  	skb_frag_t *frags = skb_shinfo(skb)->frags;
  	int nr_frags = skb_shinfo(skb)->nr_frags;
  	u64 *mapping = tx_req->mapping;
  
  	if (skb_headlen(skb)) {
  		priv->tx_sge[0].addr         = mapping[0];
  		priv->tx_sge[0].length       = skb_headlen(skb);
  		off = 1;
  	} else
  		off = 0;
  
  	for (i = 0; i < nr_frags; ++i) {
  		priv->tx_sge[i + off].addr = mapping[i + off];
  		priv->tx_sge[i + off].length = frags[i].size;
  	}
  	priv->tx_wr.num_sge	     = nr_frags + off;
  	priv->tx_wr.wr_id 	     = wr_id;
  	priv->tx_wr.wr.ud.remote_qpn = qpn;
  	priv->tx_wr.wr.ud.ah 	     = address;
  
  	if (head) {
  		priv->tx_wr.wr.ud.mss	 = skb_shinfo(skb)->gso_size;
  		priv->tx_wr.wr.ud.header = head;
  		priv->tx_wr.wr.ud.hlen	 = hlen;
  		priv->tx_wr.opcode	 = IB_WR_LSO;
  	} else
  		priv->tx_wr.opcode	 = IB_WR_SEND;
  
  	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_tx_buf *tx_req;
  	int hlen, rc;
  	void *phead;
  
  	if (skb_is_gso(skb)) {
  		hlen = skb_transport_offset(skb) + tcp_hdrlen(skb);
  		phead = skb->data;
  		if (unlikely(!skb_pull(skb, hlen))) {
  			ipoib_warn(priv, "linear data too small\n");
  			++dev->stats.tx_dropped;
  			++dev->stats.tx_errors;
  			dev_kfree_skb_any(skb);
  			return;
  		}
  	} else {
  		if (unlikely(skb->len > priv->mcast_mtu + IPOIB_ENCAP_LEN)) {
  			ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n",
  				   skb->len, priv->mcast_mtu + IPOIB_ENCAP_LEN);
  			++dev->stats.tx_dropped;
  			++dev->stats.tx_errors;
  			ipoib_cm_skb_too_long(dev, skb, priv->mcast_mtu);
  			return;
  		}
  		phead = NULL;
  		hlen  = 0;
  	}
  
  	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_sendq_size - 1)];
  	tx_req->skb = skb;
  	if (unlikely(ipoib_dma_map_tx(priv->ca, tx_req))) {
  		++dev->stats.tx_errors;
  		dev_kfree_skb_any(skb);
  		return;
  	}
  
  	if (skb->ip_summed == CHECKSUM_PARTIAL)
  		priv->tx_wr.send_flags |= IB_SEND_IP_CSUM;
  	else
  		priv->tx_wr.send_flags &= ~IB_SEND_IP_CSUM;
  
  	if (++priv->tx_outstanding == ipoib_sendq_size) {
  		ipoib_dbg(priv, "TX ring full, stopping kernel net queue\n");
  		if (ib_req_notify_cq(priv->send_cq, IB_CQ_NEXT_COMP))
  			ipoib_warn(priv, "request notify on send CQ failed\n");
  		netif_stop_queue(dev);
  	}
  
  	rc = post_send(priv, priv->tx_head & (ipoib_sendq_size - 1),
  		       address->ah, qpn, tx_req, phead, hlen);
  	if (unlikely(rc)) {
  		ipoib_warn(priv, "post_send failed, error %d\n", rc);
  		++dev->stats.tx_errors;
  		--priv->tx_outstanding;
  		ipoib_dma_unmap_tx(priv->ca, tx_req);
  		dev_kfree_skb_any(skb);
  		if (netif_queue_stopped(dev))
  			netif_wake_queue(dev);
  	} else {
  		dev->trans_start = jiffies;
  
  		address->last_send = priv->tx_head;
  		++priv->tx_head;
  		skb_orphan(skb);
  
  	}
  
  	if (unlikely(priv->tx_outstanding > MAX_SEND_CQE))
  		while (poll_tx(priv))
  			; /* nothing */
  }
  
  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);
  	unsigned long flags;
  
  	netif_tx_lock_bh(dev);
  	spin_lock_irqsave(&priv->lock, flags);
  
  	list_for_each_entry_safe(ah, tah, &priv->dead_ahs, list)
  		if ((int) priv->tx_tail - (int) ah->last_send >= 0) {
  			list_del(&ah->list);
  			ib_destroy_ah(ah->ah);
  			kfree(ah);
  		}
  
  	spin_unlock_irqrestore(&priv->lock, flags);
  	netif_tx_unlock_bh(dev);
  }
  
  void ipoib_reap_ah(struct work_struct *work)
  {
  	struct ipoib_dev_priv *priv =
  		container_of(work, struct ipoib_dev_priv, ah_reap_task.work);
  	struct net_device *dev = priv->dev;
  
  	__ipoib_reap_ah(dev);
  
  	if (!test_bit(IPOIB_STOP_REAPER, &priv->flags))
  		queue_delayed_work(ipoib_workqueue, &priv->ah_reap_task,
  				   round_jiffies_relative(HZ));
  }
  
  static void ipoib_ib_tx_timer_func(unsigned long ctx)
  {
  	drain_tx_cq((struct net_device *)ctx);
  }
  
  int ipoib_ib_dev_open(struct net_device *dev)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	int ret;
  
  	if (ib_find_pkey(priv->ca, priv->port, priv->pkey, &priv->pkey_index)) {
  		ipoib_warn(priv, "P_Key 0x%04x not found\n", priv->pkey);
  		clear_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
  		return -1;
  	}
  	set_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
  
  	ret = ipoib_init_qp(dev);
  	if (ret) {
  		ipoib_warn(priv, "ipoib_init_qp 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);
  		ipoib_ib_dev_stop(dev, 1);
  		return -1;
  	}
  
  	ret = ipoib_cm_dev_open(dev);
  	if (ret) {
  		ipoib_warn(priv, "ipoib_cm_dev_open returned %d\n", ret);
  		ipoib_ib_dev_stop(dev, 1);
  		return -1;
  	}
  
  	clear_bit(IPOIB_STOP_REAPER, &priv->flags);
  	queue_delayed_work(ipoib_workqueue, &priv->ah_reap_task,
  			   round_jiffies_relative(HZ));
  
  	if (!test_and_set_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
  		napi_enable(&priv->napi);
  
  	return 0;
  }
  
  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_pkey(priv->ca, priv->port, priv->pkey, &pkey_index))
  		clear_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
  	else
  		set_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
  }
  
  int ipoib_ib_dev_up(struct net_device *dev)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  
  	ipoib_pkey_dev_check_presence(dev);
  
  	if (!test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags)) {
  		ipoib_dbg(priv, "PKEY is not assigned.\n");
  		return 0;
  	}
  
  	set_bit(IPOIB_FLAG_OPER_UP, &priv->flags);
  
  	return ipoib_mcast_start_thread(dev);
  }
  
  int ipoib_ib_dev_down(struct net_device *dev, int flush)
  {
  	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)) {
  		mutex_lock(&pkey_mutex);
  		set_bit(IPOIB_PKEY_STOP, &priv->flags);
  		cancel_delayed_work(&priv->pkey_poll_task);
  		mutex_unlock(&pkey_mutex);
  		if (flush)
  			flush_workqueue(ipoib_workqueue);
  	}
  
  	ipoib_mcast_stop_thread(dev, flush);
  	ipoib_mcast_dev_flush(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_recvq_size; ++i)
  		if (priv->rx_ring[i].skb)
  			++pending;
  
  	return pending;
  }
  
  void ipoib_drain_cq(struct net_device *dev)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	int i, n;
  
  	/*
  	 * We call completion handling routines that expect to be
  	 * called from the BH-disabled NAPI poll context, so disable
  	 * BHs here too.
  	 */
  	local_bh_disable();
  
  	do {
  		n = ib_poll_cq(priv->recv_cq, IPOIB_NUM_WC, priv->ibwc);
  		for (i = 0; i < n; ++i) {
  			/*
  			 * Convert any successful completions to flush
  			 * errors to avoid passing packets up the
  			 * stack after bringing the device down.
  			 */
  			if (priv->ibwc[i].status == IB_WC_SUCCESS)
  				priv->ibwc[i].status = IB_WC_WR_FLUSH_ERR;
  
  			if (priv->ibwc[i].wr_id & IPOIB_OP_RECV) {
  				if (priv->ibwc[i].wr_id & IPOIB_OP_CM)
  					ipoib_cm_handle_rx_wc(dev, priv->ibwc + i);
  				else
  					ipoib_ib_handle_rx_wc(dev, priv->ibwc + i);
  			} else
  				ipoib_cm_handle_tx_wc(dev, priv->ibwc + i);
  		}
  	} while (n == IPOIB_NUM_WC);
  
  	while (poll_tx(priv))
  		; /* nothing */
  
  	local_bh_enable();
  }
  
  int ipoib_ib_dev_stop(struct net_device *dev, int flush)
  {
  	struct ipoib_dev_priv *priv = netdev_priv(dev);
  	struct ib_qp_attr qp_attr;
  	unsigned long begin;
  	struct ipoib_tx_buf *tx_req;
  	int i;
  
  	if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
  		napi_disable(&priv->napi);
  
  	ipoib_cm_dev_stop(dev);
  
  	/*
  	 * Move our QP to the error state and then reinitialize in
  	 * when all work requests have completed or have been flushed.
  	 */
  	qp_attr.qp_state = IB_QPS_ERR;
  	if (ib_modify_qp(priv->qp, &qp_attr, IB_QP_STATE))
  		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 ((int) priv->tx_tail - (int) priv->tx_head < 0) {
  				tx_req = &priv->tx_ring[priv->tx_tail &
  							(ipoib_sendq_size - 1)];
  				ipoib_dma_unmap_tx(priv->ca, tx_req);
  				dev_kfree_skb_any(tx_req->skb);
  				++priv->tx_tail;
  				--priv->tx_outstanding;
  			}
  
  			for (i = 0; i < ipoib_recvq_size; ++i) {
  				struct ipoib_rx_buf *rx_req;
  
  				rx_req = &priv->rx_ring[i];
  				if (!rx_req->skb)
  					continue;
  				ipoib_ud_dma_unmap_rx(priv,
  						      priv->rx_ring[i].mapping);
  				dev_kfree_skb_any(rx_req->skb);
  				rx_req->skb = NULL;
  			}
  
  			goto timeout;
  		}
  
  		ipoib_drain_cq(dev);
  
  		msleep(1);
  	}
  
  	ipoib_dbg(priv, "All sends and receives done.\n");
  
  timeout:
  	del_timer_sync(&priv->poll_timer);
  	qp_attr.qp_state = IB_QPS_RESET;
  	if (ib_modify_qp(priv->qp, &qp_attr, IB_QP_STATE))
  		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);
  	if (flush)
  		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);
  	}
  
  	ib_req_notify_cq(priv->recv_cq, IB_CQ_NEXT_COMP);
  
  	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;
  	}
  
  	setup_timer(&priv->poll_timer, ipoib_ib_tx_timer_func,
  		    (unsigned long) dev);
  
  	if (dev->flags & IFF_UP) {
  		if (ipoib_ib_dev_open(dev)) {
  			ipoib_transport_dev_cleanup(dev);
  			return -ENODEV;
  		}
  	}
  
  	return 0;
  }
  
  static void __ipoib_ib_dev_flush(struct ipoib_dev_priv *priv,
  				enum ipoib_flush_level level)
  {
  	struct ipoib_dev_priv *cpriv;
  	struct net_device *dev = priv->dev;
  	u16 new_index;
  
  	mutex_lock(&priv->vlan_mutex);
  
  	/*
  	 * Flush any child interfaces too -- they might be up even if
  	 * the parent is down.
  	 */
  	list_for_each_entry(cpriv, &priv->child_intfs, list)
  		__ipoib_ib_dev_flush(cpriv, level);
  
  	mutex_unlock(&priv->vlan_mutex);
  
  	if (!test_bit(IPOIB_FLAG_INITIALIZED, &priv->flags)) {
  		ipoib_dbg(priv, "Not flushing - IPOIB_FLAG_INITIALIZED not set.\n");
  		return;
  	}
  
  	if (!test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags)) {
  		ipoib_dbg(priv, "Not flushing - IPOIB_FLAG_ADMIN_UP not set.\n");
  		return;
  	}
  
  	if (level == IPOIB_FLUSH_HEAVY) {
  		if (ib_find_pkey(priv->ca, priv->port, priv->pkey, &new_index)) {
  			clear_bit(IPOIB_PKEY_ASSIGNED, &priv->flags);
  			ipoib_ib_dev_down(dev, 0);
  			ipoib_ib_dev_stop(dev, 0);
  			if (ipoib_pkey_dev_delay_open(dev))
  				return;
  		}
  
  		/* restart QP only if P_Key index is changed */
  		if (test_and_set_bit(IPOIB_PKEY_ASSIGNED, &priv->flags) &&
  		    new_index == priv->pkey_index) {
  			ipoib_dbg(priv, "Not flushing - P_Key index not changed.\n");
  			return;
  		}
  		priv->pkey_index = new_index;
  	}
  
  	if (level == IPOIB_FLUSH_LIGHT) {
  		ipoib_mark_paths_invalid(dev);
  		ipoib_mcast_dev_flush(dev);
  	}
  
  	if (level >= IPOIB_FLUSH_NORMAL)
  		ipoib_ib_dev_down(dev, 0);
  
  	if (level == IPOIB_FLUSH_HEAVY) {
  		ipoib_ib_dev_stop(dev, 0);
  		ipoib_ib_dev_open(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)) {
  		if (level >= IPOIB_FLUSH_NORMAL)
  			ipoib_ib_dev_up(dev);
  		ipoib_mcast_restart_task(&priv->restart_task);
  	}
  }
  
  void ipoib_ib_dev_flush_light(struct work_struct *work)
  {
  	struct ipoib_dev_priv *priv =
  		container_of(work, struct ipoib_dev_priv, flush_light);
  
  	__ipoib_ib_dev_flush(priv, IPOIB_FLUSH_LIGHT);
  }
  
  void ipoib_ib_dev_flush_normal(struct work_struct *work)
  {
  	struct ipoib_dev_priv *priv =
  		container_of(work, struct ipoib_dev_priv, flush_normal);
  
  	__ipoib_ib_dev_flush(priv, IPOIB_FLUSH_NORMAL);
  }
  
  void ipoib_ib_dev_flush_heavy(struct work_struct *work)
  {
  	struct ipoib_dev_priv *priv =
  		container_of(work, struct ipoib_dev_priv, flush_heavy);
  
  	__ipoib_ib_dev_flush(priv, IPOIB_FLUSH_HEAVY);
  }
  
  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, 1);
  	ipoib_mcast_dev_flush(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.
   */
  
  void ipoib_pkey_poll(struct work_struct *work)
  {
  	struct ipoib_dev_priv *priv =
  		container_of(work, struct ipoib_dev_priv, pkey_poll_task.work);
  	struct net_device *dev = priv->dev;
  
  	ipoib_pkey_dev_check_presence(dev);
  
  	if (test_bit(IPOIB_PKEY_ASSIGNED, &priv->flags))
  		ipoib_open(dev);
  	else {
  		mutex_lock(&pkey_mutex);
  		if (!test_bit(IPOIB_PKEY_STOP, &priv->flags))
  			queue_delayed_work(ipoib_workqueue,
  					   &priv->pkey_poll_task,
  					   HZ);
  		mutex_unlock(&pkey_mutex);
  	}
  }
  
  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)) {
  		mutex_lock(&pkey_mutex);
  		clear_bit(IPOIB_PKEY_STOP, &priv->flags);
  		queue_delayed_work(ipoib_workqueue,
  				   &priv->pkey_poll_task,
  				   HZ);
  		mutex_unlock(&pkey_mutex);
  		return 1;
  	}
  
  	return 0;
  }
  