ah.c

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/*
 * Copyright (c) 2007 Cisco Systems, 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 <rdma/ib_addr.h>
#include <rdma/ib_cache.h>

#include <linux/slab.h>
#include <linux/inet.h>
#include <linux/string.h>

#include "mlx4_ib.h"

int mlx4_ib_resolve_grh(struct mlx4_ib_dev *dev, const struct ib_ah_attr *ah_attr,
            u8 *mac, int *is_mcast, u8 port)
{
    struct in6_addr in6;

    *is_mcast = 0;

    memcpy(&in6, ah_attr->grh.dgid.raw, sizeof in6);
    if (rdma_link_local_addr(&in6))
        rdma_get_ll_mac(&in6, mac);
    else if (rdma_is_multicast_addr(&in6)) {
        rdma_get_mcast_mac(&in6, mac);
        *is_mcast = 1;
    } else
        return -EINVAL;

    return 0;
}

static struct ib_ah *create_ib_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr,
                  struct mlx4_ib_ah *ah)
{
    struct mlx4_dev *dev = to_mdev(pd->device)->dev;

    ah->av.ib.port_pd = cpu_to_be32(to_mpd(pd)->pdn | (ah_attr->port_num << 24));
    ah->av.ib.g_slid  = ah_attr->src_path_bits;
    if (ah_attr->ah_flags & IB_AH_GRH) {
        ah->av.ib.g_slid   |= 0x80;
        ah->av.ib.gid_index = ah_attr->grh.sgid_index;
        ah->av.ib.hop_limit = ah_attr->grh.hop_limit;
        ah->av.ib.sl_tclass_flowlabel |=
            cpu_to_be32((ah_attr->grh.traffic_class << 20) |
                    ah_attr->grh.flow_label);
        memcpy(ah->av.ib.dgid, ah_attr->grh.dgid.raw, 16);
    }

    ah->av.ib.dlid    = cpu_to_be16(ah_attr->dlid);
    if (ah_attr->static_rate) {
        ah->av.ib.stat_rate = ah_attr->static_rate + MLX4_STAT_RATE_OFFSET;
        while (ah->av.ib.stat_rate > IB_RATE_2_5_GBPS + MLX4_STAT_RATE_OFFSET &&
               !(1 << ah->av.ib.stat_rate & dev->caps.stat_rate_support))
            --ah->av.ib.stat_rate;
    }
    ah->av.ib.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 28);

    return &ah->ibah;
}

static struct ib_ah *create_iboe_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr,
                    struct mlx4_ib_ah *ah)
{
    struct mlx4_ib_dev *ibdev = to_mdev(pd->device);
    struct mlx4_dev *dev = ibdev->dev;
    union ib_gid sgid;
    u8 mac[6];
    int err;
    int is_mcast;
    u16 vlan_tag;

    err = mlx4_ib_resolve_grh(ibdev, ah_attr, mac, &is_mcast, ah_attr->port_num);
    if (err)
        return ERR_PTR(err);

    memcpy(ah->av.eth.mac, mac, 6);
    err = ib_get_cached_gid(pd->device, ah_attr->port_num, ah_attr->grh.sgid_index, &sgid);
    if (err)
        return ERR_PTR(err);
    vlan_tag = rdma_get_vlan_id(&sgid);
    if (vlan_tag < 0x1000)
        vlan_tag |= (ah_attr->sl & 7) << 13;
    ah->av.eth.port_pd = cpu_to_be32(to_mpd(pd)->pdn | (ah_attr->port_num << 24));
    ah->av.eth.gid_index = ah_attr->grh.sgid_index;
    ah->av.eth.vlan = cpu_to_be16(vlan_tag);
    if (ah_attr->static_rate) {
        ah->av.eth.stat_rate = ah_attr->static_rate + MLX4_STAT_RATE_OFFSET;
        while (ah->av.eth.stat_rate > IB_RATE_2_5_GBPS + MLX4_STAT_RATE_OFFSET &&
               !(1 << ah->av.eth.stat_rate & dev->caps.stat_rate_support))
            --ah->av.eth.stat_rate;
    }

    /*
     * HW requires multicast LID so we just choose one.
     */
    if (is_mcast)
        ah->av.ib.dlid = cpu_to_be16(0xc000);

    memcpy(ah->av.eth.dgid, ah_attr->grh.dgid.raw, 16);
    ah->av.eth.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 29);

    return &ah->ibah;
}

struct ib_ah *mlx4_ib_create_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr)
{
    struct mlx4_ib_ah *ah;
    struct ib_ah *ret;

    ah = kzalloc(sizeof *ah, GFP_ATOMIC);
    if (!ah)
        return ERR_PTR(-ENOMEM);

    if (rdma_port_get_link_layer(pd->device, ah_attr->port_num) == IB_LINK_LAYER_ETHERNET) {
        if (!(ah_attr->ah_flags & IB_AH_GRH)) {
            ret = ERR_PTR(-EINVAL);
        } else {
            /*
             * TBD: need to handle the case when we get
             * called in an atomic context and there we
             * might sleep.  We don't expect this
             * currently since we're working with link
             * local addresses which we can translate
             * without going to sleep.
             */
            ret = create_iboe_ah(pd, ah_attr, ah);
        }

        if (IS_ERR(ret))
            kfree(ah);

        return ret;
    } else
        return create_ib_ah(pd, ah_attr, ah); /* never fails */
}

int mlx4_ib_query_ah(struct ib_ah *ibah, struct ib_ah_attr *ah_attr)
{
    struct mlx4_ib_ah *ah = to_mah(ibah);
    enum rdma_link_layer ll;

    memset(ah_attr, 0, sizeof *ah_attr);
    ah_attr->sl = be32_to_cpu(ah->av.ib.sl_tclass_flowlabel) >> 28;
    ah_attr->port_num = be32_to_cpu(ah->av.ib.port_pd) >> 24;
    ll = rdma_port_get_link_layer(ibah->device, ah_attr->port_num);
    ah_attr->dlid = ll == IB_LINK_LAYER_INFINIBAND ? be16_to_cpu(ah->av.ib.dlid) : 0;
    if (ah->av.ib.stat_rate)
        ah_attr->static_rate = ah->av.ib.stat_rate - MLX4_STAT_RATE_OFFSET;
    ah_attr->src_path_bits = ah->av.ib.g_slid & 0x7F;

    if (mlx4_ib_ah_grh_present(ah)) {
        ah_attr->ah_flags = IB_AH_GRH;

        ah_attr->grh.traffic_class =
            be32_to_cpu(ah->av.ib.sl_tclass_flowlabel) >> 20;
        ah_attr->grh.flow_label =
            be32_to_cpu(ah->av.ib.sl_tclass_flowlabel) & 0xfffff;
        ah_attr->grh.hop_limit  = ah->av.ib.hop_limit;
        ah_attr->grh.sgid_index = ah->av.ib.gid_index;
        memcpy(ah_attr->grh.dgid.raw, ah->av.ib.dgid, 16);
    }

    return 0;
}

int mlx4_ib_destroy_ah(struct ib_ah *ah)
{
    kfree(to_mah(ah));
    return 0;
}