/*
   * 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)
  ", err);
  		goto out;
  	}
  
  	if (0)
  		mthca_dbg(dev, "Hash for %pI6 is %04x
  ", gid, *hash);
  
  	*index = *hash;
  	*prev  = -1;
  
  	do {
  		err = mthca_READ_MGM(dev, *index, mgm_mailbox);
  		if (err) {
  			mthca_err(dev, "READ_MGM failed (%d)
  ", err);
  			goto out;
  		}
  
  		if (!memcmp(mgm->gid, zero_gid, 16)) {
  			if (*index != *hash) {
  				mthca_err(dev, "Found zero MGID in AMGM.
  ");
  				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
  ");
  			err = -ENOMEM;
  			goto out;
  		}
  
  		err = mthca_READ_MGM(dev, index, mailbox);
  		if (err) {
  			mthca_err(dev, "READ_MGM failed (%d)
  ", 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
  ",
  				  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.
  ", index);
  		err = -ENOMEM;
  		goto out;
  	}
  
  	err = mthca_WRITE_MGM(dev, index, mailbox);
  	if (err) {
  		mthca_err(dev, "WRITE_MGM failed %d
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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
  ", 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);
  }