/*
 * Copyright(c) 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * 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.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/slab.h>
#include "ah.h"
#include "vt.h" /* for prints */

/**
 * rvt_check_ah - validate the attributes of AH
 * @ibdev: the ib device
 * @ah_attr: the attributes of the AH
 *
 * If driver supports a more detailed check_ah function call back to it
 * otherwise just check the basics.
 *
 * Return: 0 on success
 */
int rvt_check_ah(struct ib_device *ibdev,
		 struct rdma_ah_attr *ah_attr)
{
	int err;
	int port_num = rdma_ah_get_port_num(ah_attr);
	struct ib_port_attr port_attr;
	struct rvt_dev_info *rdi = ib_to_rvt(ibdev);
	enum rdma_link_layer link = rdma_port_get_link_layer(ibdev, port_num);
	u32 dlid = rdma_ah_get_dlid(ah_attr);
	u8 ah_flags = rdma_ah_get_ah_flags(ah_attr);
	u8 static_rate = rdma_ah_get_static_rate(ah_attr);

	err = ib_query_port(ibdev, port_num, &port_attr);
	if (err)
		return -EINVAL;
	if (port_num < 1 ||
	    port_num > ibdev->phys_port_cnt)
		return -EINVAL;
	if (static_rate != IB_RATE_PORT_CURRENT &&
	    ib_rate_to_mbps(static_rate) < 0)
		return -EINVAL;
	if ((ah_flags & IB_AH_GRH) &&
	    rdma_ah_read_grh(ah_attr)->sgid_index >= port_attr.gid_tbl_len)
		return -EINVAL;
	if (link != IB_LINK_LAYER_ETHERNET) {
		if (dlid == 0)
			return -EINVAL;
		if (dlid >= be16_to_cpu(IB_MULTICAST_LID_BASE) &&
		    dlid != be16_to_cpu(IB_LID_PERMISSIVE) &&
		    !(ah_flags & IB_AH_GRH))
			return -EINVAL;
	}
	if (rdi->driver_f.check_ah)
		return rdi->driver_f.check_ah(ibdev, ah_attr);
	return 0;
}
EXPORT_SYMBOL(rvt_check_ah);

/**
 * rvt_create_ah - create an address handle
 * @pd: the protection domain
 * @ah_attr: the attributes of the AH
 *
 * This may be called from interrupt context.
 *
 * Return: newly allocated ah
 */
struct ib_ah *rvt_create_ah(struct ib_pd *pd,
			    struct rdma_ah_attr *ah_attr)
{
	struct rvt_ah *ah;
	struct rvt_dev_info *dev = ib_to_rvt(pd->device);
	unsigned long flags;

	if (rvt_check_ah(pd->device, ah_attr))
		return ERR_PTR(-EINVAL);

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

	spin_lock_irqsave(&dev->n_ahs_lock, flags);
	if (dev->n_ahs_allocated == dev->dparms.props.max_ah) {
		spin_unlock_irqrestore(&dev->n_ahs_lock, flags);
		kfree(ah);
		return ERR_PTR(-ENOMEM);
	}

	dev->n_ahs_allocated++;
	spin_unlock_irqrestore(&dev->n_ahs_lock, flags);

	ah->attr = *ah_attr;
	atomic_set(&ah->refcount, 0);

	if (dev->driver_f.notify_new_ah)
		dev->driver_f.notify_new_ah(pd->device, ah_attr, ah);

	return &ah->ibah;
}

/**
 * rvt_destory_ah - Destory an address handle
 * @ibah: address handle
 *
 * Return: 0 on success
 */
int rvt_destroy_ah(struct ib_ah *ibah)
{
	struct rvt_dev_info *dev = ib_to_rvt(ibah->device);
	struct rvt_ah *ah = ibah_to_rvtah(ibah);
	unsigned long flags;

	if (atomic_read(&ah->refcount) != 0)
		return -EBUSY;

	spin_lock_irqsave(&dev->n_ahs_lock, flags);
	dev->n_ahs_allocated--;
	spin_unlock_irqrestore(&dev->n_ahs_lock, flags);

	kfree(ah);

	return 0;
}

/**
 * rvt_modify_ah - modify an ah with given attrs
 * @ibah: address handle to modify
 * @ah_attr: attrs to apply
 *
 * Return: 0 on success
 */
int rvt_modify_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
{
	struct rvt_ah *ah = ibah_to_rvtah(ibah);

	if (rvt_check_ah(ibah->device, ah_attr))
		return -EINVAL;

	ah->attr = *ah_attr;

	return 0;
}

/**
 * rvt_query_ah - return attrs for ah
 * @ibah: address handle to query
 * @ah_attr: return info in this
 *
 * Return: always 0
 */
int rvt_query_ah(struct ib_ah *ibah, struct rdma_ah_attr *ah_attr)
{
	struct rvt_ah *ah = ibah_to_rvtah(ibah);

	*ah_attr = ah->attr;

	return 0;
}