/*
 * Copyright (c) 2004 Topspin Communications.  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/gfp.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"

struct mthca_mgm {
        __be32 next_gid_index;
        u32    reserved[3];
        u8     gid[16];
        __be32 qp[MTHCA_QP_PER_MGM];
};

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

/*
 * 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_mgm(struct mthca_dev *dev,
                    u8 *gid, struct mthca_mailbox *mgm_mailbox,
                    u16 *hash, int *prev, int *index)
{
        struct mthca_mailbox *mailbox;
        struct mthca_mgm *mgm = mgm_mailbox->buf;
        u8 *mgid;
        int err;

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox))
                return -ENOMEM;
        mgid = mailbox->buf;

        memcpy(mgid, gid, 16);

        err = mthca_MGID_HASH(dev, mailbox, hash);
        if (err) {
                mthca_err(dev, "MGID_HASH failed (%d)\n", err);
                goto out;
        }

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

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

        do {
                err = mthca_READ_MGM(dev, *index, mgm_mailbox);
                if (err) {
                        mthca_err(dev, "READ_MGM failed (%d)\n", err);
                        goto out;
                }

                if (!memcmp(mgm->gid, zero_gid, 16)) {
                        if (*index != *hash) {
                                mthca_err(dev, "Found zero MGID in AMGM.\n");
                                err = -EINVAL;
                        }
                        goto out;
                }

                if (!memcmp(mgm->gid, gid, 16))
                        goto out;

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

        *index = -1;

 out:
        mthca_free_mailbox(dev, mailbox);
        return err;
}

int mthca_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
{
        struct mthca_dev *dev = to_mdev(ibqp->device);
        struct mthca_mailbox *mailbox;
        struct mthca_mgm *mgm;
        u16 hash;
        int index, prev;
        int link = 0;
        int i;
        int err;

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);
        mgm = mailbox->buf;

        mutex_lock(&dev->mcg_table.mutex);

        err = find_mgm(dev, gid->raw, mailbox, &hash, &prev, &index);
        if (err)
                goto out;

        if (index != -1) {
                if (!memcmp(mgm->gid, zero_gid, 16))
                        memcpy(mgm->gid, gid->raw, 16);
        } else {
                link = 1;

                index = mthca_alloc(&dev->mcg_table.alloc);
                if (index == -1) {
                        mthca_err(dev, "No AMGM entries left\n");
                        err = -ENOMEM;
                        goto out;
                }

                err = mthca_READ_MGM(dev, index, mailbox);
                if (err) {
                        mthca_err(dev, "READ_MGM failed (%d)\n", err);
                        goto out;
                }
                memset(mgm, 0, sizeof *mgm);
                memcpy(mgm->gid, gid->raw, 16);
        }

        for (i = 0; i < MTHCA_QP_PER_MGM; ++i)
                if (mgm->qp[i] == cpu_to_be32(ibqp->qp_num | (1 << 31))) {
                        mthca_dbg(dev, "QP %06x already a member of MGM\n",
                                  ibqp->qp_num);
                        err = 0;
                        goto out;
                } else if (!(mgm->qp[i] & cpu_to_be32(1 << 31))) {
                        mgm->qp[i] = cpu_to_be32(ibqp->qp_num | (1 << 31));
                        break;
                }

        if (i == MTHCA_QP_PER_MGM) {
                mthca_err(dev, "MGM at index %x is full.\n", index);
                err = -ENOMEM;
                goto out;
        }

        err = mthca_WRITE_MGM(dev, index, mailbox);
        if (err) {
                mthca_err(dev, "WRITE_MGM failed %d\n", err);
                err = -EINVAL;
                goto out;
        }

        if (!link)
                goto out;

        err = mthca_READ_MGM(dev, prev, mailbox);
        if (err) {
                mthca_err(dev, "READ_MGM failed %d\n", err);
                goto out;
        }

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

        err = mthca_WRITE_MGM(dev, prev, mailbox);
        if (err)
                mthca_err(dev, "WRITE_MGM returned %d\n", err);

 out:
        if (err && link && index != -1) {
                BUG_ON(index < dev->limits.num_mgms);
                mthca_free(&dev->mcg_table.alloc, index);
        }
        mutex_unlock(&dev->mcg_table.mutex);

        mthca_free_mailbox(dev, mailbox);
        return err;
}

int mthca_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
{
        struct mthca_dev *dev = to_mdev(ibqp->device);
        struct mthca_mailbox *mailbox;
        struct mthca_mgm *mgm;
        u16 hash;
        int prev, index;
        int i, loc;
        int err;

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);
        mgm = mailbox->buf;

        mutex_lock(&dev->mcg_table.mutex);

        err = find_mgm(dev, gid->raw, mailbox, &hash, &prev, &index);
        if (err)
                goto out;

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

        for (loc = -1, i = 0; i < MTHCA_QP_PER_MGM; ++i) {
                if (mgm->qp[i] == cpu_to_be32(ibqp->qp_num | (1 << 31)))
                        loc = i;
                if (!(mgm->qp[i] & cpu_to_be32(1 << 31)))
                        break;
        }

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

        mgm->qp[loc]   = mgm->qp[i - 1];
        mgm->qp[i - 1] = 0;

        err = mthca_WRITE_MGM(dev, index, mailbox);
        if (err) {
                mthca_err(dev, "WRITE_MGM returned %d\n", err);
                goto out;
        }

        if (i != 1)
                goto out;

        if (prev == -1) {
                /* Remove entry from MGM */
                int amgm_index_to_free = be32_to_cpu(mgm->next_gid_index) >> 6;
                if (amgm_index_to_free) {
                        err = mthca_READ_MGM(dev, amgm_index_to_free,
                                             mailbox);
                        if (err) {
                                mthca_err(dev, "READ_MGM returned %d\n", err);
                                goto out;
                        }
                } else
                        memset(mgm->gid, 0, 16);

                err = mthca_WRITE_MGM(dev, index, mailbox);
                if (err) {
                        mthca_err(dev, "WRITE_MGM returned %d\n", err);
                        goto out;
                }
                if (amgm_index_to_free) {
                        BUG_ON(amgm_index_to_free < dev->limits.num_mgms);
                        mthca_free(&dev->mcg_table.alloc, amgm_index_to_free);
                }
        } else {
                /* Remove entry from AMGM */
                int curr_next_index = be32_to_cpu(mgm->next_gid_index) >> 6;
                err = mthca_READ_MGM(dev, prev, mailbox);
                if (err) {
                        mthca_err(dev, "READ_MGM returned %d\n", err);
                        goto out;
                }

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

                err = mthca_WRITE_MGM(dev, prev, mailbox);
                if (err) {
                        mthca_err(dev, "WRITE_MGM returned %d\n", err);
                        goto out;
                }
                BUG_ON(index < dev->limits.num_mgms);
                mthca_free(&dev->mcg_table.alloc, index);
        }

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

        mthca_free_mailbox(dev, mailbox);
        return err;
}

int mthca_init_mcg_table(struct mthca_dev *dev)
{
        int err;
        int table_size = dev->limits.num_mgms + dev->limits.num_amgms;

        err = mthca_alloc_init(&dev->mcg_table.alloc,
                               table_size,
                               table_size - 1,
                               dev->limits.num_mgms);
        if (err)
                return err;

        mutex_init(&dev->mcg_table.mutex);

        return 0;
}

void mthca_cleanup_mcg_table(struct mthca_dev *dev)
{
        mthca_alloc_cleanup(&dev->mcg_table.alloc);
}