/*
 * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
 * Copyright (c) 2007, 2008 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/string.h>
#include <linux/etherdevice.h>

#include <linux/mlx4/cmd.h>

#include "mlx4.h"

#define MGM_QPN_MASK       0x00FFFFFF
#define MGM_BLCK_LB_BIT    30

static const u8 zero_gid[16];   /* automatically initialized to 0 */

static int mlx4_READ_ENTRY(struct mlx4_dev *dev, int index,
                           struct mlx4_cmd_mailbox *mailbox)
{
        return mlx4_cmd_box(dev, 0, mailbox->dma, index, 0, MLX4_CMD_READ_MCG,
                            MLX4_CMD_TIME_CLASS_A);
}

static int mlx4_WRITE_ENTRY(struct mlx4_dev *dev, int index,
                            struct mlx4_cmd_mailbox *mailbox)
{
        return mlx4_cmd(dev, mailbox->dma, index, 0, MLX4_CMD_WRITE_MCG,
                        MLX4_CMD_TIME_CLASS_A);
}

static int mlx4_WRITE_PROMISC(struct mlx4_dev *dev, u8 vep_num, u8 port, u8 steer,
                              struct mlx4_cmd_mailbox *mailbox)
{
        u32 in_mod;

        in_mod = (u32) vep_num << 24 | (u32) port << 16 | steer << 1;
        return mlx4_cmd(dev, mailbox->dma, in_mod, 0x1,
                        MLX4_CMD_WRITE_MCG, MLX4_CMD_TIME_CLASS_A);
}

static int mlx4_GID_HASH(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
                         u16 *hash, u8 op_mod)
{
        u64 imm;
        int err;

        err = mlx4_cmd_imm(dev, mailbox->dma, &imm, 0, op_mod,
                           MLX4_CMD_MGID_HASH, MLX4_CMD_TIME_CLASS_A);

        if (!err)
                *hash = imm;

        return err;
}

static struct mlx4_promisc_qp *get_promisc_qp(struct mlx4_dev *dev, u8 pf_num,
                                              enum mlx4_steer_type steer,
                                              u32 qpn)
{
        struct mlx4_steer *s_steer = &mlx4_priv(dev)->steer[pf_num];
        struct mlx4_promisc_qp *pqp;

        list_for_each_entry(pqp, &s_steer->promisc_qps[steer], list) {
                if (pqp->qpn == qpn)
                        return pqp;
        }
        /* not found */
        return NULL;
}

/*
 * Add new entry to steering data structure.
 * All promisc QPs should be added as well
 */
static int new_steering_entry(struct mlx4_dev *dev, u8 vep_num, u8 port,
                              enum mlx4_steer_type steer,
                              unsigned int index, u32 qpn)
{
        struct mlx4_steer *s_steer;
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        u32 members_count;
        struct mlx4_steer_index *new_entry;
        struct mlx4_promisc_qp *pqp;
        struct mlx4_promisc_qp *dqp = NULL;
        u32 prot;
        int err;
        u8 pf_num;

        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];
        new_entry = kzalloc(sizeof *new_entry, GFP_KERNEL);
        if (!new_entry)
                return -ENOMEM;

        INIT_LIST_HEAD(&new_entry->duplicates);
        new_entry->index = index;
        list_add_tail(&new_entry->list, &s_steer->steer_entries[steer]);

        /* If the given qpn is also a promisc qp,
         * it should be inserted to duplicates list
         */
        pqp = get_promisc_qp(dev, pf_num, steer, qpn);
        if (pqp) {
                dqp = kmalloc(sizeof *dqp, GFP_KERNEL);
                if (!dqp) {
                        err = -ENOMEM;
                        goto out_alloc;
                }
                dqp->qpn = qpn;
                list_add_tail(&dqp->list, &new_entry->duplicates);
        }

        /* if no promisc qps for this vep, we are done */
        if (list_empty(&s_steer->promisc_qps[steer]))
                return 0;

        /* now need to add all the promisc qps to the new
         * steering entry, as they should also receive the packets
         * destined to this address */
        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox)) {
                err = -ENOMEM;
                goto out_alloc;
        }
        mgm = mailbox->buf;

        err = mlx4_READ_ENTRY(dev, index, mailbox);
        if (err)
                goto out_mailbox;

        members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
        prot = be32_to_cpu(mgm->members_count) >> 30;
        list_for_each_entry(pqp, &s_steer->promisc_qps[steer], list) {
                /* don't add already existing qpn */
                if (pqp->qpn == qpn)
                        continue;
                if (members_count == MLX4_QP_PER_MGM) {
                        /* out of space */
                        err = -ENOMEM;
                        goto out_mailbox;
                }

                /* add the qpn */
                mgm->qp[members_count++] = cpu_to_be32(pqp->qpn & MGM_QPN_MASK);
        }
        /* update the qps count and update the entry with all the promisc qps*/
        mgm->members_count = cpu_to_be32(members_count | (prot << 30));
        err = mlx4_WRITE_ENTRY(dev, index, mailbox);

out_mailbox:
        mlx4_free_cmd_mailbox(dev, mailbox);
        if (!err)
                return 0;
out_alloc:
        if (dqp) {
                list_del(&dqp->list);
                kfree(dqp);
        }
        list_del(&new_entry->list);
        kfree(new_entry);
        return err;
}

/* update the data structures with existing steering entry */
static int existing_steering_entry(struct mlx4_dev *dev, u8 vep_num, u8 port,
                                   enum mlx4_steer_type steer,
                                   unsigned int index, u32 qpn)
{
        struct mlx4_steer *s_steer;
        struct mlx4_steer_index *tmp_entry, *entry = NULL;
        struct mlx4_promisc_qp *pqp;
        struct mlx4_promisc_qp *dqp;
        u8 pf_num;

        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];

        pqp = get_promisc_qp(dev, pf_num, steer, qpn);
        if (!pqp)
                return 0; /* nothing to do */

        list_for_each_entry(tmp_entry, &s_steer->steer_entries[steer], list) {
                if (tmp_entry->index == index) {
                        entry = tmp_entry;
                        break;
                }
        }
        if (unlikely(!entry)) {
                mlx4_warn(dev, "Steering entry at index %x is not registered\n", index);
                return -EINVAL;
        }

        /* the given qpn is listed as a promisc qpn
         * we need to add it as a duplicate to this entry
         * for future references */
        list_for_each_entry(dqp, &entry->duplicates, list) {
                if (qpn == dqp->qpn)
                        return 0; /* qp is already duplicated */
        }

        /* add the qp as a duplicate on this index */
        dqp = kmalloc(sizeof *dqp, GFP_KERNEL);
        if (!dqp)
                return -ENOMEM;
        dqp->qpn = qpn;
        list_add_tail(&dqp->list, &entry->duplicates);

        return 0;
}

/* Check whether a qpn is a duplicate on steering entry
 * If so, it should not be removed from mgm */
static bool check_duplicate_entry(struct mlx4_dev *dev, u8 vep_num, u8 port,
                                  enum mlx4_steer_type steer,
                                  unsigned int index, u32 qpn)
{
        struct mlx4_steer *s_steer;
        struct mlx4_steer_index *tmp_entry, *entry = NULL;
        struct mlx4_promisc_qp *dqp, *tmp_dqp;
        u8 pf_num;

        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];

        /* if qp is not promisc, it cannot be duplicated */
        if (!get_promisc_qp(dev, pf_num, steer, qpn))
                return false;

        /* The qp is promisc qp so it is a duplicate on this index
         * Find the index entry, and remove the duplicate */
        list_for_each_entry(tmp_entry, &s_steer->steer_entries[steer], list) {
                if (tmp_entry->index == index) {
                        entry = tmp_entry;
                        break;
                }
        }
        if (unlikely(!entry)) {
                mlx4_warn(dev, "Steering entry for index %x is not registered\n", index);
                return false;
        }
        list_for_each_entry_safe(dqp, tmp_dqp, &entry->duplicates, list) {
                if (dqp->qpn == qpn) {
                        list_del(&dqp->list);
                        kfree(dqp);
                }
        }
        return true;
}

/* I a steering entry contains only promisc QPs, it can be removed. */
static bool can_remove_steering_entry(struct mlx4_dev *dev, u8 vep_num, u8 port,
                                      enum mlx4_steer_type steer,
                                      unsigned int index, u32 tqpn)
{
        struct mlx4_steer *s_steer;
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        struct mlx4_steer_index *entry = NULL, *tmp_entry;
        u32 qpn;
        u32 members_count;
        bool ret = false;
        int i;
        u8 pf_num;

        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];

        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox))
                return false;
        mgm = mailbox->buf;

        if (mlx4_READ_ENTRY(dev, index, mailbox))
                goto out;
        members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
        for (i = 0;  i < members_count; i++) {
                qpn = be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK;
                if (!get_promisc_qp(dev, pf_num, steer, qpn) && qpn != tqpn) {
                        /* the qp is not promisc, the entry can't be removed */
                        goto out;
                }
        }
         /* All the qps currently registered for this entry are promiscuous,
          * Checking for duplicates */
        ret = true;
        list_for_each_entry_safe(entry, tmp_entry, &s_steer->steer_entries[steer], list) {
                if (entry->index == index) {
                        if (list_empty(&entry->duplicates)) {
                                list_del(&entry->list);
                                kfree(entry);
                        } else {
                                /* This entry contains duplicates so it shouldn't be removed */
                                ret = false;
                                goto out;
                        }
                }
        }

out:
        mlx4_free_cmd_mailbox(dev, mailbox);
        return ret;
}

static int add_promisc_qp(struct mlx4_dev *dev, u8 vep_num, u8 port,
                          enum mlx4_steer_type steer, u32 qpn)
{
        struct mlx4_steer *s_steer;
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        struct mlx4_steer_index *entry;
        struct mlx4_promisc_qp *pqp;
        struct mlx4_promisc_qp *dqp;
        u32 members_count;
        u32 prot;
        int i;
        bool found;
        int last_index;
        int err;
        u8 pf_num;
        struct mlx4_priv *priv = mlx4_priv(dev);
        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];

        mutex_lock(&priv->mcg_table.mutex);

        if (get_promisc_qp(dev, pf_num, steer, qpn)) {
                err = 0;  /* Noting to do, already exists */
                goto out_mutex;
        }

        pqp = kmalloc(sizeof *pqp, GFP_KERNEL);
        if (!pqp) {
                err = -ENOMEM;
                goto out_mutex;
        }
        pqp->qpn = qpn;

        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox)) {
                err = -ENOMEM;
                goto out_alloc;
        }
        mgm = mailbox->buf;

        /* the promisc qp needs to be added for each one of the steering
         * entries, if it already exists, needs to be added as a duplicate
         * for this entry */
        list_for_each_entry(entry, &s_steer->steer_entries[steer], list) {
                err = mlx4_READ_ENTRY(dev, entry->index, mailbox);
                if (err)
                        goto out_mailbox;

                members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
                prot = be32_to_cpu(mgm->members_count) >> 30;
                found = false;
                for (i = 0; i < members_count; i++) {
                        if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qpn) {
                                /* Entry already exists, add to duplicates */
                                dqp = kmalloc(sizeof *dqp, GFP_KERNEL);
                                if (!dqp)
                                        goto out_mailbox;
                                dqp->qpn = qpn;
                                list_add_tail(&dqp->list, &entry->duplicates);
                                found = true;
                        }
                }
                if (!found) {
                        /* Need to add the qpn to mgm */
                        if (members_count == MLX4_QP_PER_MGM) {
                                /* entry is full */
                                err = -ENOMEM;
                                goto out_mailbox;
                        }
                        mgm->qp[members_count++] = cpu_to_be32(qpn & MGM_QPN_MASK);
                        mgm->members_count = cpu_to_be32(members_count | (prot << 30));
                        err = mlx4_WRITE_ENTRY(dev, entry->index, mailbox);
                        if (err)
                                goto out_mailbox;
                }
                last_index = entry->index;
        }

        /* add the new qpn to list of promisc qps */
        list_add_tail(&pqp->list, &s_steer->promisc_qps[steer]);
        /* now need to add all the promisc qps to default entry */
        memset(mgm, 0, sizeof *mgm);
        members_count = 0;
        list_for_each_entry(dqp, &s_steer->promisc_qps[steer], list)
                mgm->qp[members_count++] = cpu_to_be32(dqp->qpn & MGM_QPN_MASK);
        mgm->members_count = cpu_to_be32(members_count | MLX4_PROT_ETH << 30);

        err = mlx4_WRITE_PROMISC(dev, vep_num, port, steer, mailbox);
        if (err)
                goto out_list;

        mlx4_free_cmd_mailbox(dev, mailbox);
        mutex_unlock(&priv->mcg_table.mutex);
        return 0;

out_list:
        list_del(&pqp->list);
out_mailbox:
        mlx4_free_cmd_mailbox(dev, mailbox);
out_alloc:
        kfree(pqp);
out_mutex:
        mutex_unlock(&priv->mcg_table.mutex);
        return err;
}

static int remove_promisc_qp(struct mlx4_dev *dev, u8 vep_num, u8 port,
                             enum mlx4_steer_type steer, u32 qpn)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_steer *s_steer;
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        struct mlx4_steer_index *entry;
        struct mlx4_promisc_qp *pqp;
        struct mlx4_promisc_qp *dqp;
        u32 members_count;
        bool found;
        bool back_to_list = false;
        int loc, i;
        int err;
        u8 pf_num;

        pf_num = (dev->caps.num_ports == 1) ? vep_num : (vep_num << 1) | (port - 1);
        s_steer = &mlx4_priv(dev)->steer[pf_num];
        mutex_lock(&priv->mcg_table.mutex);

        pqp = get_promisc_qp(dev, pf_num, steer, qpn);
        if (unlikely(!pqp)) {
                mlx4_warn(dev, "QP %x is not promiscuous QP\n", qpn);
                /* nothing to do */
                err = 0;
                goto out_mutex;
        }

        /*remove from list of promisc qps */
        list_del(&pqp->list);

        /* set the default entry not to include the removed one */
        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox)) {
                err = -ENOMEM;
                back_to_list = true;
                goto out_list;
        }
        mgm = mailbox->buf;
        members_count = 0;
        list_for_each_entry(dqp, &s_steer->promisc_qps[steer], list)
                mgm->qp[members_count++] = cpu_to_be32(dqp->qpn & MGM_QPN_MASK);
        mgm->members_count = cpu_to_be32(members_count | MLX4_PROT_ETH << 30);

        err = mlx4_WRITE_PROMISC(dev, vep_num, port, steer, mailbox);
        if (err)
                goto out_mailbox;

        /* remove the qp from all the steering entries*/
        list_for_each_entry(entry, &s_steer->steer_entries[steer], list) {
                found = false;
                list_for_each_entry(dqp, &entry->duplicates, list) {
                        if (dqp->qpn == qpn) {
                                found = true;
                                break;
                        }
                }
                if (found) {
                        /* a duplicate, no need to change the mgm,
                         * only update the duplicates list */
                        list_del(&dqp->list);
                        kfree(dqp);
                } else {
                        err = mlx4_READ_ENTRY(dev, entry->index, mailbox);
                                if (err)
                                        goto out_mailbox;
                        members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
                        for (loc = -1, i = 0; i < members_count; ++i)
                                if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qpn)
                                        loc = i;

                        mgm->members_count = cpu_to_be32(--members_count |
                                                         (MLX4_PROT_ETH << 30));
                        mgm->qp[loc] = mgm->qp[i - 1];
                        mgm->qp[i - 1] = 0;

                        err = mlx4_WRITE_ENTRY(dev, entry->index, mailbox);
                                if (err)
                                        goto out_mailbox;
                }

        }

out_mailbox:
        mlx4_free_cmd_mailbox(dev, mailbox);
out_list:
        if (back_to_list)
                list_add_tail(&pqp->list, &s_steer->promisc_qps[steer]);
        else
                kfree(pqp);
out_mutex:
        mutex_unlock(&priv->mcg_table.mutex);
        return err;
}

/*
 * Caller must hold MCG table semaphore.  gid and mgm parameters must
 * be properly aligned for command interface.
 *
 *  Returns 0 unless a firmware command error occurs.
 *
 * If GID is found in MGM or MGM is empty, *index = *hash, *prev = -1
 * and *mgm holds MGM entry.
 *
 * if GID is found in AMGM, *index = index in AMGM, *prev = index of
 * previous entry in hash chain and *mgm holds AMGM entry.
 *
 * If no AMGM exists for given gid, *index = -1, *prev = index of last
 * entry in hash chain and *mgm holds end of hash chain.
 */
static int find_entry(struct mlx4_dev *dev, u8 port,
                      u8 *gid, enum mlx4_protocol prot,
                      enum mlx4_steer_type steer,
                      struct mlx4_cmd_mailbox *mgm_mailbox,
                      u16 *hash, int *prev, int *index)
{
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm = mgm_mailbox->buf;
        u8 *mgid;
        int err;
        u8 op_mod = (prot == MLX4_PROT_ETH) ? !!(dev->caps.vep_mc_steering) : 0;

        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox))
                return -ENOMEM;
        mgid = mailbox->buf;

        memcpy(mgid, gid, 16);

        err = mlx4_GID_HASH(dev, mailbox, hash, op_mod);
        mlx4_free_cmd_mailbox(dev, mailbox);
        if (err)
                return err;

        if (0)
                mlx4_dbg(dev, "Hash for %pI6 is %04x\n", gid, *hash);

        *index = *hash;
        *prev  = -1;

        do {
                err = mlx4_READ_ENTRY(dev, *index, mgm_mailbox);
                if (err)
                        return err;

                if (!(be32_to_cpu(mgm->members_count) & 0xffffff)) {
                        if (*index != *hash) {
                                mlx4_err(dev, "Found zero MGID in AMGM.\n");
                                err = -EINVAL;
                        }
                        return err;
                }

                if (!memcmp(mgm->gid, gid, 16) &&
                    be32_to_cpu(mgm->members_count) >> 30 == prot)
                        return err;

                *prev = *index;
                *index = be32_to_cpu(mgm->next_gid_index) >> 6;
        } while (*index);

        *index = -1;
        return err;
}

int mlx4_qp_attach_common(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
                          int block_mcast_loopback, enum mlx4_protocol prot,
                          enum mlx4_steer_type steer)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        u32 members_count;
        u16 hash;
        int index, prev;
        int link = 0;
        int i;
        int err;
        u8 port = gid[5];
        u8 new_entry = 0;

        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);
        mgm = mailbox->buf;

        mutex_lock(&priv->mcg_table.mutex);
        err = find_entry(dev, port, gid, prot, steer,
                         mailbox, &hash, &prev, &index);
        if (err)
                goto out;

        if (index != -1) {
                if (!(be32_to_cpu(mgm->members_count) & 0xffffff)) {
                        new_entry = 1;
                        memcpy(mgm->gid, gid, 16);
                }
        } else {
                link = 1;

                index = mlx4_bitmap_alloc(&priv->mcg_table.bitmap);
                if (index == -1) {
                        mlx4_err(dev, "No AMGM entries left\n");
                        err = -ENOMEM;
                        goto out;
                }
                index += dev->caps.num_mgms;

                memset(mgm, 0, sizeof *mgm);
                memcpy(mgm->gid, gid, 16);
        }

        members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
        if (members_count == MLX4_QP_PER_MGM) {
                mlx4_err(dev, "MGM at index %x is full.\n", index);
                err = -ENOMEM;
                goto out;
        }

        for (i = 0; i < members_count; ++i)
                if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qp->qpn) {
                        mlx4_dbg(dev, "QP %06x already a member of MGM\n", qp->qpn);
                        err = 0;
                        goto out;
                }

        if (block_mcast_loopback)
                mgm->qp[members_count++] = cpu_to_be32((qp->qpn & MGM_QPN_MASK) |
                                                       (1U << MGM_BLCK_LB_BIT));
        else
                mgm->qp[members_count++] = cpu_to_be32(qp->qpn & MGM_QPN_MASK);

        mgm->members_count = cpu_to_be32(members_count | (u32) prot << 30);

        err = mlx4_WRITE_ENTRY(dev, index, mailbox);
        if (err)
                goto out;

        if (!link)
                goto out;

        err = mlx4_READ_ENTRY(dev, prev, mailbox);
        if (err)
                goto out;

        mgm->next_gid_index = cpu_to_be32(index << 6);

        err = mlx4_WRITE_ENTRY(dev, prev, mailbox);
        if (err)
                goto out;

out:
        if (prot == MLX4_PROT_ETH) {
                /* manage the steering entry for promisc mode */
                if (new_entry)
                        new_steering_entry(dev, 0, port, steer, index, qp->qpn);
                else
                        existing_steering_entry(dev, 0, port, steer,
                                                index, qp->qpn);
        }
        if (err && link && index != -1) {
                if (index < dev->caps.num_mgms)
                        mlx4_warn(dev, "Got AMGM index %d < %d",
                                  index, dev->caps.num_mgms);
                else
                        mlx4_bitmap_free(&priv->mcg_table.bitmap,
                                         index - dev->caps.num_mgms);
        }
        mutex_unlock(&priv->mcg_table.mutex);

        mlx4_free_cmd_mailbox(dev, mailbox);
        return err;
}

int mlx4_qp_detach_common(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
                          enum mlx4_protocol prot, enum mlx4_steer_type steer)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_cmd_mailbox *mailbox;
        struct mlx4_mgm *mgm;
        u32 members_count;
        u16 hash;
        int prev, index;
        int i, loc;
        int err;
        u8 port = gid[5];
        bool removed_entry = false;

        mailbox = mlx4_alloc_cmd_mailbox(dev);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);
        mgm = mailbox->buf;

        mutex_lock(&priv->mcg_table.mutex);

        err = find_entry(dev, port, gid, prot, steer,
                         mailbox, &hash, &prev, &index);
        if (err)
                goto out;

        if (index == -1) {
                mlx4_err(dev, "MGID %pI6 not found\n", gid);
                err = -EINVAL;
                goto out;
        }

        /* if this pq is also a promisc qp, it shouldn't be removed */
        if (prot == MLX4_PROT_ETH &&
            check_duplicate_entry(dev, 0, port, steer, index, qp->qpn))
                goto out;

        members_count = be32_to_cpu(mgm->members_count) & 0xffffff;
        for (loc = -1, i = 0; i < members_count; ++i)
                if ((be32_to_cpu(mgm->qp[i]) & MGM_QPN_MASK) == qp->qpn)
                        loc = i;

        if (loc == -1) {
                mlx4_err(dev, "QP %06x not found in MGM\n", qp->qpn);
                err = -EINVAL;
                goto out;
        }


        mgm->members_count = cpu_to_be32(--members_count | (u32) prot << 30);
        mgm->qp[loc]       = mgm->qp[i - 1];
        mgm->qp[i - 1]     = 0;

        if (prot == MLX4_PROT_ETH)
                removed_entry = can_remove_steering_entry(dev, 0, port, steer, index, qp->qpn);
        if (i != 1 && (prot != MLX4_PROT_ETH || !removed_entry)) {
                err = mlx4_WRITE_ENTRY(dev, index, mailbox);
                goto out;
        }

        /* We are going to delete the entry, members count should be 0 */
        mgm->members_count = cpu_to_be32((u32) prot << 30);

        if (prev == -1) {
                /* Remove entry from MGM */
                int amgm_index = be32_to_cpu(mgm->next_gid_index) >> 6;
                if (amgm_index) {
                        err = mlx4_READ_ENTRY(dev, amgm_index, mailbox);
                        if (err)
                                goto out;
                } else
                        memset(mgm->gid, 0, 16);

                err = mlx4_WRITE_ENTRY(dev, index, mailbox);
                if (err)
                        goto out;

                if (amgm_index) {
                        if (amgm_index < dev->caps.num_mgms)
                                mlx4_warn(dev, "MGM entry %d had AMGM index %d < %d",
                                          index, amgm_index, dev->caps.num_mgms);
                        else
                                mlx4_bitmap_free(&priv->mcg_table.bitmap,
                                                 amgm_index - dev->caps.num_mgms);
                }
        } else {
                /* Remove entry from AMGM */
                int cur_next_index = be32_to_cpu(mgm->next_gid_index) >> 6;
                err = mlx4_READ_ENTRY(dev, prev, mailbox);
                if (err)
                        goto out;

                mgm->next_gid_index = cpu_to_be32(cur_next_index << 6);

                err = mlx4_WRITE_ENTRY(dev, prev, mailbox);
                if (err)
                        goto out;

                if (index < dev->caps.num_mgms)
                        mlx4_warn(dev, "entry %d had next AMGM index %d < %d",
                                  prev, index, dev->caps.num_mgms);
                else
                        mlx4_bitmap_free(&priv->mcg_table.bitmap,
                                         index - dev->caps.num_mgms);
        }

out:
        mutex_unlock(&priv->mcg_table.mutex);

        mlx4_free_cmd_mailbox(dev, mailbox);
        return err;
}


int mlx4_multicast_attach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
                          int block_mcast_loopback, enum mlx4_protocol prot)
{
        enum mlx4_steer_type steer;

        steer = (is_valid_ether_addr(&gid[10])) ? MLX4_UC_STEER : MLX4_MC_STEER;

        if (prot == MLX4_PROT_ETH && !dev->caps.vep_mc_steering)
                return 0;

        if (prot == MLX4_PROT_ETH)
                gid[7] |= (steer << 1);

        return mlx4_qp_attach_common(dev, qp, gid,
                                     block_mcast_loopback, prot,
                                     steer);
}
EXPORT_SYMBOL_GPL(mlx4_multicast_attach);

int mlx4_multicast_detach(struct mlx4_dev *dev, struct mlx4_qp *qp, u8 gid[16],
                          enum mlx4_protocol prot)
{
        enum mlx4_steer_type steer;

        steer = (is_valid_ether_addr(&gid[10])) ? MLX4_UC_STEER : MLX4_MC_STEER;

        if (prot == MLX4_PROT_ETH && !dev->caps.vep_mc_steering)
                return 0;

        if (prot == MLX4_PROT_ETH) {
                gid[7] |= (steer << 1);
        }

        return mlx4_qp_detach_common(dev, qp, gid, prot, steer);
}
EXPORT_SYMBOL_GPL(mlx4_multicast_detach);


int mlx4_multicast_promisc_add(struct mlx4_dev *dev, u32 qpn, u8 port)
{
        if (!dev->caps.vep_mc_steering)
                return 0;


        return add_promisc_qp(dev, 0, port, MLX4_MC_STEER, qpn);
}
EXPORT_SYMBOL_GPL(mlx4_multicast_promisc_add);

int mlx4_multicast_promisc_remove(struct mlx4_dev *dev, u32 qpn, u8 port)
{
        if (!dev->caps.vep_mc_steering)
                return 0;


        return remove_promisc_qp(dev, 0, port, MLX4_MC_STEER, qpn);
}
EXPORT_SYMBOL_GPL(mlx4_multicast_promisc_remove);

int mlx4_unicast_promisc_add(struct mlx4_dev *dev, u32 qpn, u8 port)
{
        if (!dev->caps.vep_mc_steering)
                return 0;


        return add_promisc_qp(dev, 0, port, MLX4_UC_STEER, qpn);
}
EXPORT_SYMBOL_GPL(mlx4_unicast_promisc_add);

int mlx4_unicast_promisc_remove(struct mlx4_dev *dev, u32 qpn, u8 port)
{
        if (!dev->caps.vep_mc_steering)
                return 0;

        return remove_promisc_qp(dev, 0, port, MLX4_UC_STEER, qpn);
}
EXPORT_SYMBOL_GPL(mlx4_unicast_promisc_remove);

int mlx4_init_mcg_table(struct mlx4_dev *dev)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        int err;

        err = mlx4_bitmap_init(&priv->mcg_table.bitmap, dev->caps.num_amgms,
                               dev->caps.num_amgms - 1, 0, 0);
        if (err)
                return err;

        mutex_init(&priv->mcg_table.mutex);

        return 0;
}

void mlx4_cleanup_mcg_table(struct mlx4_dev *dev)
{
        mlx4_bitmap_cleanup(&mlx4_priv(dev)->mcg_table.bitmap);
}