/*
 * 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 <net/busy_poll.h>
#include <linux/mlx4/cq.h>
#include <linux/slab.h>
#include <linux/mlx4/qp.h>
#include <linux/skbuff.h>
#include <linux/rculist.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/vmalloc.h>

#include "mlx4_en.h"

static int mlx4_alloc_pages(struct mlx4_en_priv *priv,
                            struct mlx4_en_rx_alloc *page_alloc,
                            const struct mlx4_en_frag_info *frag_info,
                            gfp_t _gfp)
{
        int order;
        struct page *page;
        dma_addr_t dma;

        for (order = MLX4_EN_ALLOC_PREFER_ORDER; ;) {
                gfp_t gfp = _gfp;

                if (order)
                        gfp |= __GFP_COMP | __GFP_NOWARN;
                page = alloc_pages(gfp, order);
                if (likely(page))
                        break;
                if (--order < 0 ||
                    ((PAGE_SIZE << order) < frag_info->frag_size))
                        return -ENOMEM;
        }
        dma = dma_map_page(priv->ddev, page, 0, PAGE_SIZE << order,
                           PCI_DMA_FROMDEVICE);
        if (dma_mapping_error(priv->ddev, dma)) {
                put_page(page);
                return -ENOMEM;
        }
        page_alloc->page_size = PAGE_SIZE << order;
        page_alloc->page = page;
        page_alloc->dma = dma;
        page_alloc->page_offset = frag_info->frag_align;
        /* Not doing get_page() for each frag is a big win
         * on asymetric workloads.
         */
        atomic_set(&page->_count,
                   page_alloc->page_size / frag_info->frag_stride);
        return 0;
}

static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv,
                               struct mlx4_en_rx_desc *rx_desc,
                               struct mlx4_en_rx_alloc *frags,
                               struct mlx4_en_rx_alloc *ring_alloc,
                               gfp_t gfp)
{
        struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS];
        const struct mlx4_en_frag_info *frag_info;
        struct page *page;
        dma_addr_t dma;
        int i;

        for (i = 0; i < priv->num_frags; i++) {
                frag_info = &priv->frag_info[i];
                page_alloc[i] = ring_alloc[i];
                page_alloc[i].page_offset += frag_info->frag_stride;

                if (page_alloc[i].page_offset + frag_info->frag_stride <=
                    ring_alloc[i].page_size)
                        continue;

                if (mlx4_alloc_pages(priv, &page_alloc[i], frag_info, gfp))
                        goto out;
        }

        for (i = 0; i < priv->num_frags; i++) {
                frags[i] = ring_alloc[i];
                dma = ring_alloc[i].dma + ring_alloc[i].page_offset;
                ring_alloc[i] = page_alloc[i];
                rx_desc->data[i].addr = cpu_to_be64(dma);
        }

        return 0;

out:
        while (i--) {
                frag_info = &priv->frag_info[i];
                if (page_alloc[i].page != ring_alloc[i].page) {
                        dma_unmap_page(priv->ddev, page_alloc[i].dma,
                                page_alloc[i].page_size, PCI_DMA_FROMDEVICE);
                        page = page_alloc[i].page;
                        atomic_set(&page->_count, 1);
                        put_page(page);
                }
        }
        return -ENOMEM;
}

static void mlx4_en_free_frag(struct mlx4_en_priv *priv,
                              struct mlx4_en_rx_alloc *frags,
                              int i)
{
        const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];
        u32 next_frag_end = frags[i].page_offset + 2 * frag_info->frag_stride;


        if (next_frag_end > frags[i].page_size)
                dma_unmap_page(priv->ddev, frags[i].dma, frags[i].page_size,
                               PCI_DMA_FROMDEVICE);

        if (frags[i].page)
                put_page(frags[i].page);
}

static int mlx4_en_init_allocator(struct mlx4_en_priv *priv,
                                  struct mlx4_en_rx_ring *ring)
{
        int i;
        struct mlx4_en_rx_alloc *page_alloc;

        for (i = 0; i < priv->num_frags; i++) {
                const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];

                if (mlx4_alloc_pages(priv, &ring->page_alloc[i],
                                     frag_info, GFP_KERNEL))
                        goto out;
        }
        return 0;

out:
        while (i--) {
                struct page *page;

                page_alloc = &ring->page_alloc[i];
                dma_unmap_page(priv->ddev, page_alloc->dma,
                               page_alloc->page_size, PCI_DMA_FROMDEVICE);
                page = page_alloc->page;
                atomic_set(&page->_count, 1);
                put_page(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++) {
                const struct mlx4_en_frag_info *frag_info = &priv->frag_info[i];

                page_alloc = &ring->page_alloc[i];
                en_dbg(DRV, priv, "Freeing allocator:%d count:%d\n",
                       i, page_count(page_alloc->page));

                dma_unmap_page(priv->ddev, page_alloc->dma,
                                page_alloc->page_size, PCI_DMA_FROMDEVICE);
                while (page_alloc->page_offset + frag_info->frag_stride <
                       page_alloc->page_size) {
                        put_page(page_alloc->page);
                        page_alloc->page_offset += frag_info->frag_stride;
                }
                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;
        int possible_frags;
        int i;

        /* Set size and memtype fields */
        for (i = 0; i < priv->num_frags; i++) {
                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,
                                   gfp_t gfp)
{
        struct mlx4_en_rx_desc *rx_desc = ring->buf + (index * ring->stride);
        struct mlx4_en_rx_alloc *frags = ring->rx_info +
                                        (index << priv->log_rx_info);

        return mlx4_en_alloc_frags(priv, rx_desc, frags, ring->page_alloc, gfp);
}

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 void mlx4_en_free_rx_desc(struct mlx4_en_priv *priv,
                                 struct mlx4_en_rx_ring *ring,
                                 int index)
{
        struct mlx4_en_rx_alloc *frags;
        int nr;

        frags = ring->rx_info + (index << priv->log_rx_info);
        for (nr = 0; nr < priv->num_frags; nr++) {
                en_dbg(DRV, priv, "Freeing fragment:%d\n", nr);
                mlx4_en_free_frag(priv, frags, nr);
        }
}

static int mlx4_en_fill_rx_buffers(struct mlx4_en_priv *priv)
{
        struct mlx4_en_rx_ring *ring;
        int ring_ind;
        int buf_ind;
        int new_size;

        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,
                                                    GFP_KERNEL)) {
                                if (ring->actual_size < MLX4_EN_MIN_RX_SIZE) {
                                        en_err(priv, "Failed to allocate "
                                                     "enough rx buffers\n");
                                        return -ENOMEM;
                                } else {
                                        new_size = rounddown_pow_of_two(ring->actual_size);
                                        en_warn(priv, "Only %d buffers allocated "
                                                      "reducing ring size to %d",
                                                ring->actual_size, new_size);
                                        goto reduce_rings;
                                }
                        }
                        ring->actual_size++;
                        ring->prod++;
                }
        }
        return 0;

reduce_rings:
        for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
                ring = &priv->rx_ring[ring_ind];
                while (ring->actual_size > new_size) {
                        ring->actual_size--;
                        ring->prod--;
                        mlx4_en_free_rx_desc(priv, ring, ring->actual_size);
                }
        }

        return 0;
}

static void mlx4_en_free_rx_buf(struct mlx4_en_priv *priv,
                                struct mlx4_en_rx_ring *ring)
{
        int index;

        en_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->actual_size);
        while (ring->cons != ring->prod) {
                index = ring->cons & ring->size_mask;
                en_dbg(DRV, priv, "Processing descriptor:%d\n", index);
                mlx4_en_free_rx_desc(priv, ring, index);
                ++ring->cons;
        }
}

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 = -ENOMEM;
        int tmp;

        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 + TXBB_SIZE;

        tmp = size * roundup_pow_of_two(MLX4_EN_MAX_RX_FRAGS *
                                        sizeof(struct mlx4_en_rx_alloc));
        ring->rx_info = vmalloc(tmp);
        if (!ring->rx_info)
                return -ENOMEM;

        en_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) {
                en_err(priv, "Failed to map RX buffer\n");
                goto err_hwq;
        }
        ring->buf = ring->wqres.buf.direct.buf;

        ring->hwtstamp_rx_filter = priv->hwtstamp_config.rx_filter;

        return 0;

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_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);

        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;
                if (ring->stride <= TXBB_SIZE)
                        ring->buf += TXBB_SIZE;

                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);

                /* Initialize 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) {
                        en_err(priv, "Failed initializing ring allocator\n");
                        if (ring->stride <= TXBB_SIZE)
                                ring->buf -= TXBB_SIZE;
                        ring_ind--;
                        goto err_allocator;
                }
        }
        err = mlx4_en_fill_rx_buffers(priv);
        if (err)
                goto err_buffers;

        for (ring_ind = 0; ring_ind < priv->rx_ring_num; ring_ind++) {
                ring = &priv->rx_ring[ring_ind];

                ring->size_mask = ring->actual_size - 1;
                mlx4_en_update_rx_prod_db(ring);
        }

        return 0;

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) {
                if (priv->rx_ring[ring_ind].stride <= TXBB_SIZE)
                        priv->rx_ring[ring_ind].buf -= TXBB_SIZE;
                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, u32 size, u16 stride)
{
        struct mlx4_en_dev *mdev = priv->mdev;

        mlx4_en_unmap_buffer(&ring->wqres.buf);
        mlx4_free_hwq_res(mdev->dev, &ring->wqres, size * stride + TXBB_SIZE);
        vfree(ring->rx_info);
        ring->rx_info = NULL;
#ifdef CONFIG_RFS_ACCEL
        mlx4_en_cleanup_filters(priv, ring);
#endif
}

void mlx4_en_deactivate_rx_ring(struct mlx4_en_priv *priv,
                                struct mlx4_en_rx_ring *ring)
{
        mlx4_en_free_rx_buf(priv, ring);
        if (ring->stride <= TXBB_SIZE)
                ring->buf -= TXBB_SIZE;
        mlx4_en_destroy_allocator(priv, ring);
}


static int mlx4_en_complete_rx_desc(struct mlx4_en_priv *priv,
                                    struct mlx4_en_rx_desc *rx_desc,
                                    struct mlx4_en_rx_alloc *frags,
                                    struct sk_buff *skb,
                                    int length)
{
        struct skb_frag_struct *skb_frags_rx = skb_shinfo(skb)->frags;
        struct mlx4_en_frag_info *frag_info;
        int nr;
        dma_addr_t dma;

        /* Collect used fragments while replacing them in the HW descriptors */
        for (nr = 0; nr < priv->num_frags; nr++) {
                frag_info = &priv->frag_info[nr];
                if (length <= frag_info->frag_prefix_size)
                        break;
                if (!frags[nr].page)
                        goto fail;

                dma = be64_to_cpu(rx_desc->data[nr].addr);
                dma_sync_single_for_cpu(priv->ddev, dma, frag_info->frag_size,
                                        DMA_FROM_DEVICE);

                /* Save page reference in skb */
                __skb_frag_set_page(&skb_frags_rx[nr], frags[nr].page);
                skb_frag_size_set(&skb_frags_rx[nr], frag_info->frag_size);
                skb_frags_rx[nr].page_offset = frags[nr].page_offset;
                skb->truesize += frag_info->frag_stride;
                frags[nr].page = NULL;
        }
        /* Adjust size of last fragment to match actual length */
        if (nr > 0)
                skb_frag_size_set(&skb_frags_rx[nr - 1],
                        length - priv->frag_info[nr - 1].frag_prefix_size);
        return nr;

fail:
        while (nr > 0) {
                nr--;
                __skb_frag_unref(&skb_frags_rx[nr]);
        }
        return 0;
}


static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
                                      struct mlx4_en_rx_desc *rx_desc,
                                      struct mlx4_en_rx_alloc *frags,
                                      unsigned int length)
{
        struct sk_buff *skb;
        void *va;
        int used_frags;
        dma_addr_t dma;

        skb = netdev_alloc_skb(priv->dev, SMALL_PACKET_SIZE + NET_IP_ALIGN);
        if (!skb) {
                en_dbg(RX_ERR, priv, "Failed allocating skb\n");
                return NULL;
        }
        skb_reserve(skb, NET_IP_ALIGN);
        skb->len = length;

        /* Get pointer to first fragment so we could copy the headers into the
         * (linear part of the) skb */
        va = page_address(frags[0].page) + frags[0].page_offset;

        if (length <= SMALL_PACKET_SIZE) {
                /* We are copying all relevant data to the skb - temporarily
                 * sync buffers for the copy */
                dma = be64_to_cpu(rx_desc->data[0].addr);
                dma_sync_single_for_cpu(priv->ddev, dma, length,
                                        DMA_FROM_DEVICE);
                skb_copy_to_linear_data(skb, va, length);
                skb->tail += length;
        } else {
                /* Move relevant fragments to skb */
                used_frags = mlx4_en_complete_rx_desc(priv, rx_desc, frags,
                                                        skb, length);
                if (unlikely(!used_frags)) {
                        kfree_skb(skb);
                        return NULL;
                }
                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_frag_size_sub(&skb_shinfo(skb)->frags[0], HEADER_COPY_SIZE);
                skb->data_len = length - HEADER_COPY_SIZE;
        }
        return skb;
}

static void validate_loopback(struct mlx4_en_priv *priv, struct sk_buff *skb)
{
        int i;
        int offset = ETH_HLEN;

        for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++, offset++) {
                if (*(skb->data + offset) != (unsigned char) (i & 0xff))
                        goto out_loopback;
        }
        /* Loopback found */
        priv->loopback_ok = 1;

out_loopback:
        dev_kfree_skb_any(skb);
}

static void mlx4_en_refill_rx_buffers(struct mlx4_en_priv *priv,
                                     struct mlx4_en_rx_ring *ring)
{
        int index = ring->prod & ring->size_mask;

        while ((u32) (ring->prod - ring->cons) < ring->actual_size) {
                if (mlx4_en_prepare_rx_desc(priv, ring, index, GFP_ATOMIC))
                        break;
                ring->prod++;
                index = ring->prod & ring->size_mask;
        }
}

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 mlx4_en_rx_alloc *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;
        int factor = priv->cqe_factor;
        u64 timestamp;

        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 << factor) + factor];

        /* Process all completed CQEs */
        while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
                    cq->mcq.cons_index & cq->size)) {

                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)) {
                        en_err(priv, "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)) {
                        en_dbg(RX_ERR, priv, "Accepted frame with bad FCS\n");
                        goto next;
                }

                /* Check if we need to drop the packet if SRIOV is not enabled
                 * and not performing the selftest or flb disabled
                 */
                if (priv->flags & MLX4_EN_FLAG_RX_FILTER_NEEDED) {
                        struct ethhdr *ethh;
                        dma_addr_t dma;
                        /* Get pointer to first fragment since we haven't
                         * skb yet and cast it to ethhdr struct
                         */
                        dma = be64_to_cpu(rx_desc->data[0].addr);
                        dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh),
                                                DMA_FROM_DEVICE);
                        ethh = (struct ethhdr *)(page_address(frags[0].page) +
                                                 frags[0].page_offset);

                        if (is_multicast_ether_addr(ethh->h_dest)) {
                                struct mlx4_mac_entry *entry;
                                struct hlist_head *bucket;
                                unsigned int mac_hash;

                                /* Drop the packet, since HW loopback-ed it */
                                mac_hash = ethh->h_source[MLX4_EN_MAC_HASH_IDX];
                                bucket = &priv->mac_hash[mac_hash];
                                rcu_read_lock();
                                hlist_for_each_entry_rcu(entry, bucket, hlist) {
                                        if (ether_addr_equal_64bits(entry->mac,
                                                                    ethh->h_source)) {
                                                rcu_read_unlock();
                                                goto next;
                                        }
                                }
                                rcu_read_unlock();
                        }
                }

                /*
                 * Packet is OK - process it.
                 */
                length = be32_to_cpu(cqe->byte_cnt);
                length -= ring->fcs_del;
                ring->bytes += length;
                ring->packets++;

                if (likely(dev->features & NETIF_F_RXCSUM)) {
                        if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPOK)) &&
                            (cqe->checksum == cpu_to_be16(0xffff))) {
                                ring->csum_ok++;
                                /* This packet is eligible for GRO if it is:
                                 * - DIX Ethernet (type interpretation)
                                 * - TCP/IP (v4)
                                 * - without IP options
                                 * - not an IP fragment
                                 * - no LLS polling in progress
                                 */
                                if (!mlx4_en_cq_ll_polling(cq) &&
                                    (dev->features & NETIF_F_GRO)) {
                                        struct sk_buff *gro_skb = napi_get_frags(&cq->napi);
                                        if (!gro_skb)
                                                goto next;

                                        nr = mlx4_en_complete_rx_desc(priv,
                                                rx_desc, frags, gro_skb,
                                                length);
                                        if (!nr)
                                                goto next;

                                        skb_shinfo(gro_skb)->nr_frags = nr;
                                        gro_skb->len = length;
                                        gro_skb->data_len = length;
                                        gro_skb->ip_summed = CHECKSUM_UNNECESSARY;

                                        if ((cqe->vlan_my_qpn &
                                            cpu_to_be32(MLX4_CQE_VLAN_PRESENT_MASK)) &&
                                            (dev->features & NETIF_F_HW_VLAN_CTAG_RX)) {
                                                u16 vid = be16_to_cpu(cqe->sl_vid);

                                                __vlan_hwaccel_put_tag(gro_skb, htons(ETH_P_8021Q), vid);
                                        }

                                        if (dev->features & NETIF_F_RXHASH)
                                                gro_skb->rxhash = be32_to_cpu(cqe->immed_rss_invalid);

                                        skb_record_rx_queue(gro_skb, cq->ring);

                                        if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
                                                timestamp = mlx4_en_get_cqe_ts(cqe);
                                                mlx4_en_fill_hwtstamps(mdev,
                                                                       skb_hwtstamps(gro_skb),
                                                                       timestamp);
                                        }

                                        napi_gro_frags(&cq->napi);
                                        goto next;
                                }

                                /* GRO not possible, complete processing here */
                                ip_summed = CHECKSUM_UNNECESSARY;
                        } else {
                                ip_summed = CHECKSUM_NONE;
                                ring->csum_none++;
                        }
                } else {
                        ip_summed = CHECKSUM_NONE;
                        ring->csum_none++;
                }

                skb = mlx4_en_rx_skb(priv, rx_desc, frags, length);
                if (!skb) {
                        priv->stats.rx_dropped++;
                        goto next;
                }

                if (unlikely(priv->validate_loopback)) {
                        validate_loopback(priv, skb);
                        goto next;
                }

                skb->ip_summed = ip_summed;
                skb->protocol = eth_type_trans(skb, dev);
                skb_record_rx_queue(skb, cq->ring);

                if (dev->features & NETIF_F_RXHASH)
                        skb->rxhash = be32_to_cpu(cqe->immed_rss_invalid);

                if ((be32_to_cpu(cqe->vlan_my_qpn) &
                    MLX4_CQE_VLAN_PRESENT_MASK) &&
                    (dev->features & NETIF_F_HW_VLAN_CTAG_RX))
                        __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), be16_to_cpu(cqe->sl_vid));

                if (ring->hwtstamp_rx_filter == HWTSTAMP_FILTER_ALL) {
                        timestamp = mlx4_en_get_cqe_ts(cqe);
                        mlx4_en_fill_hwtstamps(mdev, skb_hwtstamps(skb),
                                               timestamp);
                }

                skb_mark_napi_id(skb, &cq->napi);

                /* Push it up the stack */
                netif_receive_skb(skb);

next:
                for (nr = 0; nr < priv->num_frags; nr++)
                        mlx4_en_free_frag(priv, frags, nr);

                ++cq->mcq.cons_index;
                index = (cq->mcq.cons_index) & ring->size_mask;
                cqe = &cq->buf[(index << factor) + factor];
                if (++polled == budget)
                        goto out;
        }

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;
        mlx4_en_refill_rx_buffers(priv, 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)
                napi_schedule(&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;

        if (!mlx4_en_cq_lock_napi(cq))
                return budget;

        done = mlx4_en_process_rx_cq(dev, cq, budget);

        mlx4_en_cq_unlock_napi(cq);

        /* 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 */
                napi_complete(napi);
                mlx4_en_arm_cq(priv, cq);
        }
        return done;
}

static const 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);
                }
                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 mlx4_en_rx_alloc));

        en_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++) {
                en_err(priv,
                       "  frag:%d - size:%d prefix:%d align:%d stride:%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);
        }
}

/* RSS related functions */

static int mlx4_en_config_rss_qp(struct mlx4_en_priv *priv, int qpn,
                                 struct mlx4_en_rx_ring *ring,
                                 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)
                return -ENOMEM;

        err = mlx4_qp_alloc(mdev->dev, qpn, qp);
        if (err) {
                en_err(priv, "Failed to allocate qp #%x\n", qpn);
                goto out;
        }
        qp->event = mlx4_en_sqp_event;

        memset(context, 0, sizeof *context);
        mlx4_en_fill_qp_context(priv, ring->actual_size, ring->stride, 0, 0,
                                qpn, ring->cqn, -1, context);
        context->db_rec_addr = cpu_to_be64(ring->wqres.db.dma);

        /* Cancel FCS removal if FW allows */
        if (mdev->dev->caps.flags & MLX4_DEV_CAP_FLAG_FCS_KEEP) {
                context->param3 |= cpu_to_be32(1 << 29);
                ring->fcs_del = ETH_FCS_LEN;
        } else
                ring->fcs_del = 0;

        err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, context, qp, state);
        if (err) {
                mlx4_qp_remove(mdev->dev, qp);
                mlx4_qp_free(mdev->dev, qp);
        }
        mlx4_en_update_rx_prod_db(ring);
out:
        kfree(context);
        return err;
}

int mlx4_en_create_drop_qp(struct mlx4_en_priv *priv)
{
        int err;
        u32 qpn;

        err = mlx4_qp_reserve_range(priv->mdev->dev, 1, 1, &qpn);
        if (err) {
                en_err(priv, "Failed reserving drop qpn\n");
                return err;
        }
        err = mlx4_qp_alloc(priv->mdev->dev, qpn, &priv->drop_qp);
        if (err) {
                en_err(priv, "Failed allocating drop qp\n");
                mlx4_qp_release_range(priv->mdev->dev, qpn, 1);
                return err;
        }

        return 0;
}

void mlx4_en_destroy_drop_qp(struct mlx4_en_priv *priv)
{
        u32 qpn;

        qpn = priv->drop_qp.qpn;
        mlx4_qp_remove(priv->mdev->dev, &priv->drop_qp);
        mlx4_qp_free(priv->mdev->dev, &priv->drop_qp);
        mlx4_qp_release_range(priv->mdev->dev, qpn, 1);
}

/* 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_rss_context *rss_context;
        int rss_rings;
        void *ptr;
        u8 rss_mask = (MLX4_RSS_IPV4 | MLX4_RSS_TCP_IPV4 | MLX4_RSS_IPV6 |
                        MLX4_RSS_TCP_IPV6);
        int i, qpn;
        int err = 0;
        int good_qps = 0;
        static const u32 rsskey[10] = { 0xD181C62C, 0xF7F4DB5B, 0x1983A2FC,
                                0x943E1ADB, 0xD9389E6B, 0xD1039C2C, 0xA74499AD,
                                0x593D56D9, 0xF3253C06, 0x2ADC1FFC};

        en_dbg(DRV, priv, "Configuring rss steering\n");
        err = mlx4_qp_reserve_range(mdev->dev, priv->rx_ring_num,
                                    priv->rx_ring_num,
                                    &rss_map->base_qpn);
        if (err) {
                en_err(priv, "Failed reserving %d qps\n", priv->rx_ring_num);
                return err;
        }

        for (i = 0; i < priv->rx_ring_num; i++) {
                qpn = rss_map->base_qpn + i;
                err = mlx4_en_config_rss_qp(priv, qpn, &priv->rx_ring[i],
                                            &rss_map->state[i],
                                            &rss_map->qps[i]);
                if (err)
                        goto rss_err;

                ++good_qps;

        }

        /* Configure RSS indirection qp */
        err = mlx4_qp_alloc(mdev->dev, priv->base_qpn, &rss_map->indir_qp);
        if (err) {
                en_err(priv, "Failed to allocate RSS indirection QP\n");
                goto rss_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, -1, &context);

        if (!priv->prof->rss_rings || priv->prof->rss_rings > priv->rx_ring_num)
                rss_rings = priv->rx_ring_num;
        else
                rss_rings = priv->prof->rss_rings;

        ptr = ((void *) &context) + offsetof(struct mlx4_qp_context, pri_path)
                                        + MLX4_RSS_OFFSET_IN_QPC_PRI_PATH;
        rss_context = ptr;
        rss_context->base_qpn = cpu_to_be32(ilog2(rss_rings) << 24 |
                                            (rss_map->base_qpn));
        rss_context->default_qpn = cpu_to_be32(rss_map->base_qpn);
        if (priv->mdev->profile.udp_rss) {
                rss_mask |=  MLX4_RSS_UDP_IPV4 | MLX4_RSS_UDP_IPV6;
                rss_context->base_qpn_udp = rss_context->default_qpn;
        }
        rss_context->flags = rss_mask;
        rss_context->hash_fn = MLX4_RSS_HASH_TOP;
        for (i = 0; i < 10; i++)
                rss_context->rss_key[i] = cpu_to_be32(rsskey[i]);

        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);
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, priv->rx_ring_num);
        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);

        for (i = 0; i < priv->rx_ring_num; 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, priv->rx_ring_num);
}