mlx4_en: Add driver for Mellanox ConnectX 10GbE NIC

The Mellanox ConnectX can operate as an InfiniBand adapter, as an
Ethernet NIC, or as a Fibre Channel (FC) HBA.  The kernel has a
low-level driver, mlx4_core, which handles multiplexing access to the
device, and there is also already an InfiniBad driver, mlx4_ib.

This patch adds a new driver, mlx4_en, which implements a standard
Ethernet NIC driver.

Signed-off-by: Liran Liss <liranl@mellanox.co.il>
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 1080 insertions, 0 deletions

diff --git a/drivers/net/mlx4/en_rx.c b/drivers/net/mlx4/en_rx.c
new file mode 100644
index 0000000..6232227
--- /dev/null
+++ b/drivers/net/mlx4/en_rx.c
@@ -0,0 +1,1080 @@
+/*
+ * Copyright (c) 2007 Mellanox Technologies. 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/mlx4/cq.h>
+#include <linux/mlx4/qp.h>
+#include <linux/skbuff.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/vmalloc.h>
+
+#include "mlx4_en.h"
+
+static void *get_wqe(struct mlx4_en_rx_ring *ring, int n)
+{
+	int offset = n << ring->srq.wqe_shift;
+	return ring->buf + offset;
+}
+
+static void mlx4_en_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
+{
+	return;
+}
+
+static int mlx4_en_get_frag_header(struct skb_frag_struct *frags, void **mac_hdr,
+				   void **ip_hdr, void **tcpudp_hdr,
+				   u64 *hdr_flags, void *priv)
+{
+	*mac_hdr = page_address(frags->page) + frags->page_offset;
+	*ip_hdr = *mac_hdr + ETH_HLEN;
+	*tcpudp_hdr = (struct tcphdr *)(*ip_hdr + sizeof(struct iphdr));
+	*hdr_flags = LRO_IPV4 | LRO_TCP;
+
+	return 0;
+}
+
+static int mlx4_en_alloc_frag(struct mlx4_en_priv *priv,
+			      struct mlx4_en_rx_desc *rx_desc,
+			      struct skb_frag_struct *skb_frags,
+			      struct mlx4_en_rx_alloc *ring_alloc,
+			      int i)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
+	struct mlx4_en_rx_alloc *page_alloc = &ring_alloc[i];
+	struct page *page;
+	dma_addr_t dma;
+
+	if (page_alloc->offset == frag_info->last_offset) {
+		/* Allocate new page */
+		page = alloc_pages(GFP_ATOMIC | __GFP_COMP, MLX4_EN_ALLOC_ORDER);
+		if (!page)
+			return -ENOMEM;
+
+		skb_frags[i].page = page_alloc->page;
+		skb_frags[i].page_offset = page_alloc->offset;
+		page_alloc->page = page;
+		page_alloc->offset = frag_info->frag_align;
+	} else {
+		page = page_alloc->page;
+		get_page(page);
+
+		skb_frags[i].page = page;
+		skb_frags[i].page_offset = page_alloc->offset;
+		page_alloc->offset += frag_info->frag_stride;
+	}
+	dma = pci_map_single(mdev->pdev, page_address(skb_frags[i].page) +
+			     skb_frags[i].page_offset, frag_info->frag_size,
+			     PCI_DMA_FROMDEVICE);
+	rx_desc->data[i].addr = cpu_to_be64(dma);
+	return 0;
+}
+
+static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
+				  struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_rx_alloc *page_alloc;
+	int i;
+
+	for (i = 0; i < priv->num_frags; i++) {
+		page_alloc = &ring->page_alloc[i];
+		page_alloc->page = alloc_pages(GFP_ATOMIC | __GFP_COMP,
+					       MLX4_EN_ALLOC_ORDER);
+		if (!page_alloc->page)
+			goto out;
+
+		page_alloc->offset = priv->frag_info[i].frag_align;
+		mlx4_dbg(DRV, priv, "Initialized allocator:%d with page:%p\n",
+			 i, page_alloc->page);
+	}
+	return 0;
+
+out:
+	while (i--) {
+		page_alloc = &ring->page_alloc[i];
+		put_page(page_alloc->page);
+		page_alloc->page = NULL;
+	}
+	return -ENOMEM;
+}
+
+static void mlx4_en_destroy_allocator(struct mlx4_en_priv *priv,
+				      struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_rx_alloc *page_alloc;
+	int i;
+
+	for (i = 0; i < priv->num_frags; i++) {
+		page_alloc = &ring->page_alloc[i];
+		mlx4_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
+			 i, page_count(page_alloc->page));
+
+		put_page(page_alloc->page);
+		page_alloc->page = NULL;
+	}
+}
+
+
+static void mlx4_en_init_rx_desc(struct mlx4_en_priv *priv,
+				 struct mlx4_en_rx_ring *ring, int index)
+{
+	struct mlx4_en_rx_desc *rx_desc = ring->buf + ring->stride * index;
+	struct skb_frag_struct *skb_frags = ring->rx_info +
+					    (index << priv->log_rx_info);
+	int possible_frags;
+	int i;
+
+	/* Pre-link descriptor */
+	rx_desc->next.next_wqe_index = cpu_to_be16((index + 1) & ring->size_mask);
+
+	/* Set size and memtype fields */
+	for (i = 0; i < priv->num_frags; i++) {
+		skb_frags[i].size = priv->frag_info[i].frag_size;
+		rx_desc->data[i].byte_count =
+			cpu_to_be32(priv->frag_info[i].frag_size);
+		rx_desc->data[i].lkey = cpu_to_be32(priv->mdev->mr.key);
+	}
+
+	/* If the number of used fragments does not fill up the ring stride,
+	 * remaining (unused) fragments must be padded with null address/size
+	 * and a special memory key */
+	possible_frags = (ring->stride - sizeof(struct mlx4_en_rx_desc)) / DS_SIZE;
+	for (i = priv->num_frags; i < possible_frags; i++) {
+		rx_desc->data[i].byte_count = 0;
+		rx_desc->data[i].lkey = cpu_to_be32(MLX4_EN_MEMTYPE_PAD);
+		rx_desc->data[i].addr = 0;
+	}
+}
+
+
+static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv,
+				   struct mlx4_en_rx_ring *ring, int index)
+{
+	struct mlx4_en_rx_desc *rx_desc = ring->buf + (index * ring->stride);
+	struct skb_frag_struct *skb_frags = ring->rx_info +
+					    (index << priv->log_rx_info);
+	int i;
+
+	for (i = 0; i < priv->num_frags; i++)
+		if (mlx4_en_alloc_frag(priv, rx_desc, skb_frags, ring->page_alloc, i))
+			goto err;
+
+	return 0;
+
+err:
+	while (i--)
+		put_page(skb_frags[i].page);
+	return -ENOMEM;
+}
+
+static inline void mlx4_en_update_rx_prod_db(struct mlx4_en_rx_ring *ring)
+{
+	*ring->wqres.db.db = cpu_to_be32(ring->prod & 0xffff);
+}
+
+static int mlx4_en_fill_rx_buffers(struct mlx4_en_priv *priv)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_rx_ring *ring;
+	int ring_ind;
+	int buf_ind;
+
+	for (buf_ind = 0; buf_ind < priv->prof->rx_ring_size; buf_ind++) {
+		for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
+			ring = &priv->rx_ring[ring_ind];
+
+			if (mlx4_en_prepare_rx_desc(priv, ring,
+						    ring->actual_size)) {
+				if (ring->actual_size < MLX4_EN_MIN_RX_SIZE) {
+					mlx4_err(mdev, "Failed to allocate "
+						       "enough rx buffers\n");
+					return -ENOMEM;
+				} else {
+					if (netif_msg_rx_err(priv))
+						mlx4_warn(mdev,
+							  "Only %d buffers allocated\n",
+							  ring->actual_size);
+					goto out;
+				}
+			}
+			ring->actual_size++;
+			ring->prod++;
+		}
+	}
+out:
+	return 0;
+}
+
+static int mlx4_en_fill_rx_buf(struct net_device *dev,
+			       struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int num = 0;
+	int err;
+
+	while ((u32) (ring->prod - ring->cons) < ring->actual_size) {
+		err = mlx4_en_prepare_rx_desc(priv, ring, ring->prod &
+					      ring->size_mask);
+		if (err) {
+			if (netif_msg_rx_err(priv))
+				mlx4_warn(priv->mdev,
+					  "Failed preparing rx descriptor\n");
+			priv->port_stats.rx_alloc_failed++;
+			break;
+		}
+		++num;
+		++ring->prod;
+	}
+	if ((u32) (ring->prod - ring->cons) == ring->size)
+		ring->full = 1;
+
+	return num;
+}
+
+static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
+				struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct skb_frag_struct *skb_frags;
+	struct mlx4_en_rx_desc *rx_desc;
+	dma_addr_t dma;
+	int index;
+	int nr;
+
+	mlx4_dbg(DRV, priv, "Freeing Rx buf - cons:%d prod:%d\n",
+			ring->cons, ring->prod);
+
+	/* Unmap and free Rx buffers */
+	BUG_ON((u32) (ring->prod - ring->cons) > ring->size);
+	while (ring->cons != ring->prod) {
+		index = ring->cons & ring->size_mask;
+		rx_desc = ring->buf + (index << ring->log_stride);
+		skb_frags = ring->rx_info + (index << priv->log_rx_info);
+		mlx4_dbg(DRV, priv, "Processing descriptor:%d\n", index);
+
+		for (nr = 0; nr < priv->num_frags; nr++) {
+			mlx4_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
+			dma = be64_to_cpu(rx_desc->data[nr].addr);
+
+			mlx4_dbg(DRV, priv, "Unmaping buffer at dma:0x%llx\n", (u64) dma);
+			pci_unmap_single(mdev->pdev, dma, skb_frags[nr].size,
+					 PCI_DMA_FROMDEVICE);
+			put_page(skb_frags[nr].page);
+		}
+		++ring->cons;
+	}
+}
+
+
+void mlx4_en_rx_refill(struct work_struct *work)
+{
+	struct delayed_work *delay = container_of(work, struct delayed_work, work);
+	struct mlx4_en_priv *priv = container_of(delay, struct mlx4_en_priv,
+						 refill_task);
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct net_device *dev = priv->dev;
+	struct mlx4_en_rx_ring *ring;
+	int need_refill = 0;
+	int i;
+
+	mutex_lock(&mdev->state_lock);
+	if (!mdev->device_up || !priv->port_up)
+		goto out;
+
+	/* We only get here if there are no receive buffers, so we can't race
+	 * with Rx interrupts while filling buffers */
+	for (i = 0; i < priv->rx_ring_num; i++) {
+		ring = &priv->rx_ring[i];
+		if (ring->need_refill) {
+			if (mlx4_en_fill_rx_buf(dev, ring)) {
+				ring->need_refill = 0;
+				mlx4_en_update_rx_prod_db(ring);
+			} else
+				need_refill = 1;
+		}
+	}
+	if (need_refill)
+		queue_delayed_work(mdev->workqueue, &priv->refill_task, HZ);
+
+out:
+	mutex_unlock(&mdev->state_lock);
+}
+
+
+int mlx4_en_create_rx_ring(struct mlx4_en_priv *priv,
+			   struct mlx4_en_rx_ring *ring, u32 size, u16 stride)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	int err;
+	int tmp;
+
+	/* Sanity check SRQ size before proceeding */
+	if (size >= mdev->dev->caps.max_srq_wqes)
+		return -EINVAL;
+
+	ring->prod = 0;
+	ring->cons = 0;
+	ring->size = size;
+	ring->size_mask = size - 1;
+	ring->stride = stride;
+	ring->log_stride = ffs(ring->stride) - 1;
+	ring->buf_size = ring->size * ring->stride;
+
+	tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
+					sizeof(struct skb_frag_struct));
+	ring->rx_info = vmalloc(tmp);
+	if (!ring->rx_info) {
+		mlx4_err(mdev, "Failed allocating rx_info ring\n");
+		return -ENOMEM;
+	}
+	mlx4_dbg(DRV, priv, "Allocated rx_info ring at addr:%p size:%d\n",
+		 ring->rx_info, tmp);
+
+	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres,
+				 ring->buf_size, 2 * PAGE_SIZE);
+	if (err)
+		goto err_ring;
+
+	err = mlx4_en_map_buffer(&ring->wqres.buf);
+	if (err) {
+		mlx4_err(mdev, "Failed to map RX buffer\n");
+		goto err_hwq;
+	}
+	ring->buf = ring->wqres.buf.direct.buf;
+
+	/* Configure lro mngr */
+	memset(&ring->lro, 0, sizeof(struct net_lro_mgr));
+	ring->lro.dev = priv->dev;
+	ring->lro.features = LRO_F_NAPI;
+	ring->lro.frag_align_pad = NET_IP_ALIGN;
+	ring->lro.ip_summed = CHECKSUM_UNNECESSARY;
+	ring->lro.ip_summed_aggr = CHECKSUM_UNNECESSARY;
+	ring->lro.max_desc = mdev->profile.num_lro;
+	ring->lro.max_aggr = MAX_SKB_FRAGS;
+	ring->lro.lro_arr = kzalloc(mdev->profile.num_lro *
+				    sizeof(struct net_lro_desc),
+				    GFP_KERNEL);
+	if (!ring->lro.lro_arr) {
+		mlx4_err(mdev, "Failed to allocate lro array\n");
+		goto err_map;
+	}
+	ring->lro.get_frag_header = mlx4_en_get_frag_header;
+
+	return 0;
+
+err_map:
+	mlx4_en_unmap_buffer(&ring->wqres.buf);
+err_hwq:
+	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
+err_ring:
+	vfree(ring->rx_info);
+	ring->rx_info = NULL;
+	return err;
+}
+
+int mlx4_en_activate_rx_rings(struct mlx4_en_priv *priv)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_wqe_srq_next_seg *next;
+	struct mlx4_en_rx_ring *ring;
+	int i;
+	int ring_ind;
+	int err;
+	int stride = roundup_pow_of_two(sizeof(struct mlx4_en_rx_desc) +
+					DS_SIZE * priv->num_frags);
+	int max_gs = (stride - sizeof(struct mlx4_wqe_srq_next_seg)) / DS_SIZE;
+
+	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
+		ring = &priv->rx_ring[ring_ind];
+
+		ring->prod = 0;
+		ring->cons = 0;
+		ring->actual_size = 0;
+		ring->cqn = priv->rx_cq[ring_ind].mcq.cqn;
+
+		ring->stride = stride;
+		ring->log_stride = ffs(ring->stride) - 1;
+		ring->buf_size = ring->size * ring->stride;
+
+		memset(ring->buf, 0, ring->buf_size);
+		mlx4_en_update_rx_prod_db(ring);
+
+		/* Initailize all descriptors */
+		for (i = 0; i < ring->size; i++)
+			mlx4_en_init_rx_desc(priv, ring, i);
+
+		/* Initialize page allocators */
+		err = mlx4_en_init_allocator(priv, ring);
+		if (err) {
+			 mlx4_err(mdev, "Failed initializing ring allocator\n");
+			 goto err_allocator;
+		}
+
+		/* Fill Rx buffers */
+		ring->full = 0;
+	}
+	if (mlx4_en_fill_rx_buffers(priv))
+		goto err_buffers;
+
+	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
+		ring = &priv->rx_ring[ring_ind];
+
+		mlx4_en_update_rx_prod_db(ring);
+
+		/* Configure SRQ representing the ring */
+		ring->srq.max    = ring->size;
+		ring->srq.max_gs = max_gs;
+		ring->srq.wqe_shift = ilog2(ring->stride);
+
+		for (i = 0; i < ring->srq.max; ++i) {
+			next = get_wqe(ring, i);
+			next->next_wqe_index =
+			cpu_to_be16((i + 1) & (ring->srq.max - 1));
+		}
+
+		err = mlx4_srq_alloc(mdev->dev, mdev->priv_pdn, &ring->wqres.mtt,
+				     ring->wqres.db.dma, &ring->srq);
+		if (err){
+			mlx4_err(mdev, "Failed to allocate srq\n");
+			goto err_srq;
+		}
+		ring->srq.event = mlx4_en_srq_event;
+	}
+
+	return 0;
+
+err_srq:
+	while (ring_ind >= 0) {
+		ring = &priv->rx_ring[ring_ind];
+		mlx4_srq_free(mdev->dev, &ring->srq);
+		ring_ind--;
+	}
+
+err_buffers:
+	for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++)
+		mlx4_en_free_rx_buf(priv, &priv->rx_ring[ring_ind]);
+
+	ring_ind = priv->rx_ring_num - 1;
+err_allocator:
+	while (ring_ind >= 0) {
+		mlx4_en_destroy_allocator(priv, &priv->rx_ring[ring_ind]);
+		ring_ind--;
+	}
+	return err;
+}
+
+void mlx4_en_destroy_rx_ring(struct mlx4_en_priv *priv,
+			     struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+
+	kfree(ring->lro.lro_arr);
+	mlx4_en_unmap_buffer(&ring->wqres.buf);
+	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
+	vfree(ring->rx_info);
+	ring->rx_info = NULL;
+}
+
+void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
+				struct mlx4_en_rx_ring *ring)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+
+	mlx4_srq_free(mdev->dev, &ring->srq);
+	mlx4_en_free_rx_buf(priv, ring);
+	mlx4_en_destroy_allocator(priv, ring);
+}
+
+
+/* Unmap a completed descriptor and free unused pages */
+static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
+				    struct mlx4_en_rx_desc *rx_desc,
+				    struct skb_frag_struct *skb_frags,
+				    struct skb_frag_struct *skb_frags_rx,
+				    struct mlx4_en_rx_alloc *page_alloc,
+				    int length)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_frag_info *frag_info;
+	int nr;
+	dma_addr_t dma;
+
+	/* Collect used fragments while replacing them in the HW descirptors */
+	for (nr = 0; nr < priv->num_frags; nr++) {
+		frag_info = &priv->frag_info[nr];
+		if (length <= frag_info->frag_prefix_size)
+			break;
+
+		/* Save page reference in skb */
+		skb_frags_rx[nr].page = skb_frags[nr].page;
+		skb_frags_rx[nr].size = skb_frags[nr].size;
+		skb_frags_rx[nr].page_offset = skb_frags[nr].page_offset;
+		dma = be64_to_cpu(rx_desc->data[nr].addr);
+
+		/* Allocate a replacement page */
+		if (mlx4_en_alloc_frag(priv, rx_desc, skb_frags, page_alloc, nr))
+			goto fail;
+
+		/* Unmap buffer */
+		pci_unmap_single(mdev->pdev, dma, skb_frags[nr].size,
+				 PCI_DMA_FROMDEVICE);
+	}
+	/* Adjust size of last fragment to match actual length */
+	skb_frags_rx[nr - 1].size = length -
+		priv->frag_info[nr - 1].frag_prefix_size;
+	return nr;
+
+fail:
+	/* Drop all accumulated fragments (which have already been replaced in
+	 * the descriptor) of this packet; remaining fragments are reused... */
+	while (nr > 0) {
+		nr--;
+		put_page(skb_frags_rx[nr].page);
+	}
+	return 0;
+}
+
+
+static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
+				      struct mlx4_en_rx_desc *rx_desc,
+				      struct skb_frag_struct *skb_frags,
+				      struct mlx4_en_rx_alloc *page_alloc,
+				      unsigned int length)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct sk_buff *skb;
+	void *va;
+	int used_frags;
+	dma_addr_t dma;
+
+	skb = dev_alloc_skb(SMALL_PACKET_SIZE + NET_IP_ALIGN);
+	if (!skb) {
+		mlx4_dbg(RX_ERR, priv, "Failed allocating skb\n");
+		return NULL;
+	}
+	skb->dev = priv->dev;
+	skb_reserve(skb, NET_IP_ALIGN);
+	skb->len = length;
+	skb->truesize = length + sizeof(struct sk_buff);
+
+	/* Get pointer to first fragment so we could copy the headers into the
+	 * (linear part of the) skb */
+	va = page_address(skb_frags[0].page) + skb_frags[0].page_offset;
+
+	if (length <= SMALL_PACKET_SIZE) {
+		/* We are copying all relevant data to the skb - temporarily
+		 * synch buffers for the copy */
+		dma = be64_to_cpu(rx_desc->data[0].addr);
+		dma_sync_single_range_for_cpu(&mdev->pdev->dev, dma, 0,
+					      length, DMA_FROM_DEVICE);
+		skb_copy_to_linear_data(skb, va, length);
+		dma_sync_single_range_for_device(&mdev->pdev->dev, dma, 0,
+						 length, DMA_FROM_DEVICE);
+		skb->tail += length;
+	} else {
+
+		/* Move relevant fragments to skb */
+		used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, skb_frags,
+						      skb_shinfo(skb)->frags,
+						      page_alloc, length);
+		skb_shinfo(skb)->nr_frags = used_frags;
+
+		/* Copy headers into the skb linear buffer */
+		memcpy(skb->data, va, HEADER_COPY_SIZE);
+		skb->tail += HEADER_COPY_SIZE;
+
+		/* Skip headers in first fragment */
+		skb_shinfo(skb)->frags[0].page_offset += HEADER_COPY_SIZE;
+
+		/* Adjust size of first fragment */
+		skb_shinfo(skb)->frags[0].size -= HEADER_COPY_SIZE;
+		skb->data_len = length - HEADER_COPY_SIZE;
+	}
+	return skb;
+}
+
+static void mlx4_en_copy_desc(struct mlx4_en_priv *priv,
+			      struct mlx4_en_rx_ring *ring,
+			      int from, int to, int num)
+{
+	struct skb_frag_struct *skb_frags_from;
+	struct skb_frag_struct *skb_frags_to;
+	struct mlx4_en_rx_desc *rx_desc_from;
+	struct mlx4_en_rx_desc *rx_desc_to;
+	int from_index, to_index;
+	int nr, i;
+
+	for (i = 0; i < num; i++) {
+		from_index = (from + i) & ring->size_mask;
+		to_index = (to + i) & ring->size_mask;
+		skb_frags_from = ring->rx_info + (from_index << priv->log_rx_info);
+		skb_frags_to = ring->rx_info + (to_index << priv->log_rx_info);
+		rx_desc_from = ring->buf + (from_index << ring->log_stride);
+		rx_desc_to = ring->buf + (to_index << ring->log_stride);
+
+		for (nr = 0; nr < priv->num_frags; nr++) {
+			skb_frags_to[nr].page = skb_frags_from[nr].page;
+			skb_frags_to[nr].page_offset = skb_frags_from[nr].page_offset;
+			rx_desc_to->data[nr].addr = rx_desc_from->data[nr].addr;
+		}
+	}
+}
+
+
+int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int budget)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_cqe *cqe;
+	struct mlx4_en_rx_ring *ring = &priv->rx_ring[cq->ring];
+	struct skb_frag_struct *skb_frags;
+	struct skb_frag_struct lro_frags[MLX4_EN_MAX_RX_FRAGS];
+	struct mlx4_en_rx_desc *rx_desc;
+	struct sk_buff *skb;
+	int index;
+	int nr;
+	unsigned int length;
+	int polled = 0;
+	int ip_summed;
+
+	if (!priv->port_up)
+		return 0;
+
+	/* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx
+	 * descriptor offset can be deduced from the CQE index instead of
+	 * reading 'cqe->index' */
+	index = cq->mcq.cons_index & ring->size_mask;
+	cqe = &cq->buf[index];
+
+	/* Process all completed CQEs */
+	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
+		    cq->mcq.cons_index & cq->size)) {
+
+		skb_frags = ring->rx_info + (index << priv->log_rx_info);
+		rx_desc = ring->buf + (index << ring->log_stride);
+
+		/*
+		 * make sure we read the CQE after we read the ownership bit
+		 */
+		rmb();
+
+		/* Drop packet on bad receive or bad checksum */
+		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
+						MLX4_CQE_OPCODE_ERROR)) {
+			mlx4_err(mdev, "CQE completed in error - vendor "
+				  "syndrom:%d syndrom:%d\n",
+				  ((struct mlx4_err_cqe *) cqe)->vendor_err_syndrome,
+				  ((struct mlx4_err_cqe *) cqe)->syndrome);
+			goto next;
+		}
+		if (unlikely(cqe->badfcs_enc & MLX4_CQE_BAD_FCS)) {
+			mlx4_dbg(RX_ERR, priv, "Accepted frame with bad FCS\n");
+			goto next;
+		}
+
+		/*
+		 * Packet is OK - process it.
+		 */
+		length = be32_to_cpu(cqe->byte_cnt);
+		ring->bytes += length;
+		ring->packets++;
+
+		if (likely(priv->rx_csum)) {
+			if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
+			    (cqe->checksum == cpu_to_be16(0xffff))) {
+				priv->port_stats.rx_chksum_good++;
+				/* This packet is eligible for LRO if it is:
+				 * - DIX Ethernet (type interpretation)
+				 * - TCP/IP (v4)
+				 * - without IP options
+				 * - not an IP fragment */
+				if (mlx4_en_can_lro(cqe->status) &&
+				    dev->features & NETIF_F_LRO) {
+
+					nr = mlx4_en_complete_rx_desc(
+						priv, rx_desc,
+						skb_frags, lro_frags,
+						ring->page_alloc, length);
+					if (!nr)
+						goto next;
+
+					if (priv->vlgrp && (cqe->vlan_my_qpn &
+							    cpu_to_be32(MLX4_CQE_VLAN_PRESENT_MASK))) {
+						lro_vlan_hwaccel_receive_frags(
+						       &ring->lro, lro_frags,
+						       length, length,
+						       priv->vlgrp,
+						       be16_to_cpu(cqe->sl_vid),
+						       NULL, 0);
+					} else
+						lro_receive_frags(&ring->lro,
+								  lro_frags,
+								  length,
+								  length,
+								  NULL, 0);
+
+					goto next;
+				}
+
+				/* LRO not possible, complete processing here */
+				ip_summed = CHECKSUM_UNNECESSARY;
+				INC_PERF_COUNTER(priv->pstats.lro_misses);
+			} else {
+				ip_summed = CHECKSUM_NONE;
+				priv->port_stats.rx_chksum_none++;
+			}
+		} else {
+			ip_summed = CHECKSUM_NONE;
+			priv->port_stats.rx_chksum_none++;
+		}
+
+		skb = mlx4_en_rx_skb(priv, rx_desc, skb_frags,
+				     ring->page_alloc, length);
+		if (!skb) {
+			priv->stats.rx_dropped++;
+			goto next;
+		}
+
+		skb->ip_summed = ip_summed;
+		skb->protocol = eth_type_trans(skb, dev);
+
+		/* Push it up the stack */
+		if (priv->vlgrp && (be32_to_cpu(cqe->vlan_my_qpn) &
+				    MLX4_CQE_VLAN_PRESENT_MASK)) {
+			vlan_hwaccel_receive_skb(skb, priv->vlgrp,
+						be16_to_cpu(cqe->sl_vid));
+		} else
+			netif_receive_skb(skb);
+
+		dev->last_rx = jiffies;
+
+next:
+		++cq->mcq.cons_index;
+		index = (cq->mcq.cons_index) & ring->size_mask;
+		cqe = &cq->buf[index];
+		if (++polled == budget) {
+			/* We are here because we reached the NAPI budget -
+			 * flush only pending LRO sessions */
+			lro_flush_all(&ring->lro);
+			goto out;
+		}
+	}
+
+	/* If CQ is empty flush all LRO sessions unconditionally */
+	lro_flush_all(&ring->lro);
+
+out:
+	AVG_PERF_COUNTER(priv->pstats.rx_coal_avg, polled);
+	mlx4_cq_set_ci(&cq->mcq);
+	wmb(); /* ensure HW sees CQ consumer before we post new buffers */
+	ring->cons = cq->mcq.cons_index;
+	ring->prod += polled; /* Polled descriptors were realocated in place */
+	if (unlikely(!ring->full)) {
+		mlx4_en_copy_desc(priv, ring, ring->cons - polled,
+				  ring->prod - polled, polled);
+		mlx4_en_fill_rx_buf(dev, ring);
+	}
+	mlx4_en_update_rx_prod_db(ring);
+	return polled;
+}
+
+
+void mlx4_en_rx_irq(struct mlx4_cq *mcq)
+{
+	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
+	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
+
+	if (priv->port_up)
+		netif_rx_schedule(cq->dev, &cq->napi);
+	else
+		mlx4_en_arm_cq(priv, cq);
+}
+
+/* Rx CQ polling - called by NAPI */
+int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
+{
+	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
+	struct net_device *dev = cq->dev;
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int done;
+
+	done = mlx4_en_process_rx_cq(dev, cq, budget);
+
+	/* If we used up all the quota - we're probably not done yet... */
+	if (done == budget)
+		INC_PERF_COUNTER(priv->pstats.napi_quota);
+	else {
+		/* Done for now */
+		netif_rx_complete(dev, napi);
+		mlx4_en_arm_cq(priv, cq);
+	}
+	return done;
+}
+
+
+/* Calculate the last offset position that accomodates a full fragment
+ * (assuming fagment size = stride-align) */
+static int mlx4_en_last_alloc_offset(struct mlx4_en_priv *priv, u16 stride, u16 align)
+{
+	u16 res = MLX4_EN_ALLOC_SIZE % stride;
+	u16 offset = MLX4_EN_ALLOC_SIZE - stride - res + align;
+
+	mlx4_dbg(DRV, priv, "Calculated last offset for stride:%d align:%d "
+			    "res:%d offset:%d\n", stride, align, res, offset);
+	return offset;
+}
+
+
+static int frag_sizes[] = {
+	FRAG_SZ0,
+	FRAG_SZ1,
+	FRAG_SZ2,
+	FRAG_SZ3
+};
+
+void mlx4_en_calc_rx_buf(struct net_device *dev)
+{
+	struct mlx4_en_priv *priv = netdev_priv(dev);
+	int eff_mtu = dev->mtu + ETH_HLEN + VLAN_HLEN + ETH_LLC_SNAP_SIZE;
+	int buf_size = 0;
+	int i = 0;
+
+	while (buf_size < eff_mtu) {
+		priv->frag_info[i].frag_size =
+			(eff_mtu > buf_size + frag_sizes[i]) ?
+				frag_sizes[i] : eff_mtu - buf_size;
+		priv->frag_info[i].frag_prefix_size = buf_size;
+		if (!i)	{
+			priv->frag_info[i].frag_align = NET_IP_ALIGN;
+			priv->frag_info[i].frag_stride =
+				ALIGN(frag_sizes[i] + NET_IP_ALIGN, SMP_CACHE_BYTES);
+		} else {
+			priv->frag_info[i].frag_align = 0;
+			priv->frag_info[i].frag_stride =
+				ALIGN(frag_sizes[i], SMP_CACHE_BYTES);
+		}
+		priv->frag_info[i].last_offset = mlx4_en_last_alloc_offset(
+						priv, priv->frag_info[i].frag_stride,
+						priv->frag_info[i].frag_align);
+		buf_size += priv->frag_info[i].frag_size;
+		i++;
+	}
+
+	priv->num_frags = i;
+	priv->rx_skb_size = eff_mtu;
+	priv->log_rx_info = ROUNDUP_LOG2(i * sizeof(struct skb_frag_struct));
+
+	mlx4_dbg(DRV, priv, "Rx buffer scatter-list (effective-mtu:%d "
+		  "num_frags:%d):\n", eff_mtu, priv->num_frags);
+	for (i = 0; i < priv->num_frags; i++) {
+		mlx4_dbg(DRV, priv, "  frag:%d - size:%d prefix:%d align:%d "
+				"stride:%d last_offset:%d\n", i,
+				priv->frag_info[i].frag_size,
+				priv->frag_info[i].frag_prefix_size,
+				priv->frag_info[i].frag_align,
+				priv->frag_info[i].frag_stride,
+				priv->frag_info[i].last_offset);
+	}
+}
+
+/* RSS related functions */
+
+/* Calculate rss size and map each entry in rss table to rx ring */
+void mlx4_en_set_default_rss_map(struct mlx4_en_priv *priv,
+				 struct mlx4_en_rss_map *rss_map,
+				 int num_entries, int num_rings)
+{
+	int i;
+
+	rss_map->size = roundup_pow_of_two(num_entries);
+	mlx4_dbg(DRV, priv, "Setting default RSS map of %d entires\n",
+		 rss_map->size);
+
+	for (i = 0; i < rss_map->size; i++) {
+		rss_map->map[i] = i % num_rings;
+		mlx4_dbg(DRV, priv, "Entry %d ---> ring %d\n", i, rss_map->map[i]);
+	}
+}
+
+static void mlx4_en_sqp_event(struct mlx4_qp *qp, enum mlx4_event event)
+{
+    return;
+}
+
+
+static int mlx4_en_config_rss_qp(struct mlx4_en_priv *priv,
+				 int qpn, int srqn, int cqn,
+				 enum mlx4_qp_state *state,
+				 struct mlx4_qp *qp)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_qp_context *context;
+	int err = 0;
+
+	context = kmalloc(sizeof *context , GFP_KERNEL);
+	if (!context) {
+		mlx4_err(mdev, "Failed to allocate qp context\n");
+		return -ENOMEM;
+	}
+
+	err = mlx4_qp_alloc(mdev->dev, qpn, qp);
+	if (err) {
+		mlx4_err(mdev, "Failed to allocate qp #%d\n", qpn);
+		goto out;
+		return err;
+	}
+	qp->event = mlx4_en_sqp_event;
+
+	memset(context, 0, sizeof *context);
+	mlx4_en_fill_qp_context(priv, 0, 0, 0, 0, qpn, cqn, srqn, context);
+
+	err = mlx4_qp_to_ready(mdev->dev, &priv->res.mtt, context, qp, state);
+	if (err) {
+		mlx4_qp_remove(mdev->dev, qp);
+		mlx4_qp_free(mdev->dev, qp);
+	}
+out:
+	kfree(context);
+	return err;
+}
+
+/* Allocate rx qp's and configure them according to rss map */
+int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_rss_map *rss_map = &priv->rss_map;
+	struct mlx4_qp_context context;
+	struct mlx4_en_rss_context *rss_context;
+	void *ptr;
+	int rss_xor = mdev->profile.rss_xor;
+	u8 rss_mask = mdev->profile.rss_mask;
+	int i, srqn, qpn, cqn;
+	int err = 0;
+	int good_qps = 0;
+
+	mlx4_dbg(DRV, priv, "Configuring rss steering for port %u\n", priv->port);
+	err = mlx4_qp_reserve_range(mdev->dev, rss_map->size,
+				    rss_map->size, &rss_map->base_qpn);
+	if (err) {
+		mlx4_err(mdev, "Failed reserving %d qps for port %u\n",
+			 rss_map->size, priv->port);
+		return err;
+	}
+
+	for (i = 0; i < rss_map->size; i++) {
+		cqn = priv->rx_ring[rss_map->map[i]].cqn;
+		srqn = priv->rx_ring[rss_map->map[i]].srq.srqn;
+		qpn = rss_map->base_qpn + i;
+		err = mlx4_en_config_rss_qp(priv, qpn, srqn, cqn,
+					    &rss_map->state[i],
+					    &rss_map->qps[i]);
+		if (err)
+			goto rss_err;
+
+		++good_qps;
+	}
+
+	/* Configure RSS indirection qp */
+	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &priv->base_qpn);
+	if (err) {
+		mlx4_err(mdev, "Failed to reserve range for RSS "
+			       "indirection qp\n");
+		goto rss_err;
+	}
+	err = mlx4_qp_alloc(mdev->dev, priv->base_qpn, &rss_map->indir_qp);
+	if (err) {
+		mlx4_err(mdev, "Failed to allocate RSS indirection QP\n");
+		goto reserve_err;
+	}
+	rss_map->indir_qp.event = mlx4_en_sqp_event;
+	mlx4_en_fill_qp_context(priv, 0, 0, 0, 1, priv->base_qpn,
+				priv->rx_ring[0].cqn, 0, &context);
+
+	ptr = ((void *) &context) + 0x3c;
+	rss_context = (struct mlx4_en_rss_context *) ptr;
+	rss_context->base_qpn = cpu_to_be32(ilog2(rss_map->size) << 24 |
+					    (rss_map->base_qpn));
+	rss_context->default_qpn = cpu_to_be32(rss_map->base_qpn);
+	rss_context->hash_fn = rss_xor & 0x3;
+	rss_context->flags = rss_mask << 2;
+
+	err = mlx4_qp_to_ready(mdev->dev, &priv->res.mtt, &context,
+			       &rss_map->indir_qp, &rss_map->indir_state);
+	if (err)
+		goto indir_err;
+
+	return 0;
+
+indir_err:
+	mlx4_qp_modify(mdev->dev, NULL, rss_map->indir_state,
+		       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->indir_qp);
+	mlx4_qp_remove(mdev->dev, &rss_map->indir_qp);
+	mlx4_qp_free(mdev->dev, &rss_map->indir_qp);
+reserve_err:
+	mlx4_qp_release_range(mdev->dev, priv->base_qpn, 1);
+rss_err:
+	for (i = 0; i < good_qps; i++) {
+		mlx4_qp_modify(mdev->dev, NULL, rss_map->state[i],
+			       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->qps[i]);
+		mlx4_qp_remove(mdev->dev, &rss_map->qps[i]);
+		mlx4_qp_free(mdev->dev, &rss_map->qps[i]);
+	}
+	mlx4_qp_release_range(mdev->dev, rss_map->base_qpn, rss_map->size);
+	return err;
+}
+
+void mlx4_en_release_rss_steer(struct mlx4_en_priv *priv)
+{
+	struct mlx4_en_dev *mdev = priv->mdev;
+	struct mlx4_en_rss_map *rss_map = &priv->rss_map;
+	int i;
+
+	mlx4_qp_modify(mdev->dev, NULL, rss_map->indir_state,
+		       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->indir_qp);
+	mlx4_qp_remove(mdev->dev, &rss_map->indir_qp);
+	mlx4_qp_free(mdev->dev, &rss_map->indir_qp);
+	mlx4_qp_release_range(mdev->dev, priv->base_qpn, 1);
+
+	for (i = 0; i < rss_map->size; i++) {
+		mlx4_qp_modify(mdev->dev, NULL, rss_map->state[i],
+			       MLX4_QP_STATE_RST, NULL, 0, 0, &rss_map->qps[i]);
+		mlx4_qp_remove(mdev->dev, &rss_map->qps[i]);
+		mlx4_qp_free(mdev->dev, &rss_map->qps[i]);
+	}
+	mlx4_qp_release_range(mdev->dev, rss_map->base_qpn, rss_map->size);
+}
+
+
+
+
+