/*
 * 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/err.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include "srq.h"
#include "vt.h"

/**
 * rvt_driver_srq_init - init srq resources on a per driver basis
 * @rdi: rvt dev structure
 *
 * Do any initialization needed when a driver registers with rdmavt.
 */
void rvt_driver_srq_init(struct rvt_dev_info *rdi)
{
        spin_lock_init(&rdi->n_srqs_lock);
        rdi->n_srqs_allocated = 0;
}

/**
 * rvt_create_srq - create a shared receive queue
 * @ibpd: the protection domain of the SRQ to create
 * @srq_init_attr: the attributes of the SRQ
 * @udata: data from libibverbs when creating a user SRQ
 *
 * Return: Allocated srq object
 */
struct ib_srq *rvt_create_srq(struct ib_pd *ibpd,
                              struct ib_srq_init_attr *srq_init_attr,
                              struct ib_udata *udata)
{
        struct rvt_dev_info *dev = ib_to_rvt(ibpd->device);
        struct rvt_srq *srq;
        u32 sz;
        struct ib_srq *ret;

        if (srq_init_attr->srq_type != IB_SRQT_BASIC)
                return ERR_PTR(-ENOSYS);

        if (srq_init_attr->attr.max_sge == 0 ||
            srq_init_attr->attr.max_sge > dev->dparms.props.max_srq_sge ||
            srq_init_attr->attr.max_wr == 0 ||
            srq_init_attr->attr.max_wr > dev->dparms.props.max_srq_wr)
                return ERR_PTR(-EINVAL);

        srq = kmalloc(sizeof(*srq), GFP_KERNEL);
        if (!srq)
                return ERR_PTR(-ENOMEM);

        /*
         * Need to use vmalloc() if we want to support large #s of entries.
         */
        srq->rq.size = srq_init_attr->attr.max_wr + 1;
        srq->rq.max_sge = srq_init_attr->attr.max_sge;
        sz = sizeof(struct ib_sge) * srq->rq.max_sge +
                sizeof(struct rvt_rwqe);
        srq->rq.wq = vmalloc_user(sizeof(struct rvt_rwq) + srq->rq.size * sz);
        if (!srq->rq.wq) {
                ret = ERR_PTR(-ENOMEM);
                goto bail_srq;
        }

        /*
         * Return the address of the RWQ as the offset to mmap.
         * See rvt_mmap() for details.
         */
        if (udata && udata->outlen >= sizeof(__u64)) {
                int err;
                u32 s = sizeof(struct rvt_rwq) + srq->rq.size * sz;

                srq->ip =
                    rvt_create_mmap_info(dev, s, ibpd->uobject->context,
                                         srq->rq.wq);
                if (!srq->ip) {
                        ret = ERR_PTR(-ENOMEM);
                        goto bail_wq;
                }

                err = ib_copy_to_udata(udata, &srq->ip->offset,
                                       sizeof(srq->ip->offset));
                if (err) {
                        ret = ERR_PTR(err);
                        goto bail_ip;
                }
        } else {
                srq->ip = NULL;
        }

        /*
         * ib_create_srq() will initialize srq->ibsrq.
         */
        spin_lock_init(&srq->rq.lock);
        srq->rq.wq->head = 0;
        srq->rq.wq->tail = 0;
        srq->limit = srq_init_attr->attr.srq_limit;

        spin_lock(&dev->n_srqs_lock);
        if (dev->n_srqs_allocated == dev->dparms.props.max_srq) {
                spin_unlock(&dev->n_srqs_lock);
                ret = ERR_PTR(-ENOMEM);
                goto bail_ip;
        }

        dev->n_srqs_allocated++;
        spin_unlock(&dev->n_srqs_lock);

        if (srq->ip) {
                spin_lock_irq(&dev->pending_lock);
                list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
                spin_unlock_irq(&dev->pending_lock);
        }

        return &srq->ibsrq;

bail_ip:
        kfree(srq->ip);
bail_wq:
        vfree(srq->rq.wq);
bail_srq:
        kfree(srq);
        return ret;
}

/**
 * rvt_modify_srq - modify a shared receive queue
 * @ibsrq: the SRQ to modify
 * @attr: the new attributes of the SRQ
 * @attr_mask: indicates which attributes to modify
 * @udata: user data for libibverbs.so
 *
 * Return: 0 on success
 */
int rvt_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
                   enum ib_srq_attr_mask attr_mask,
                   struct ib_udata *udata)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
        struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);
        struct rvt_rwq *wq;
        int ret = 0;

        if (attr_mask & IB_SRQ_MAX_WR) {
                struct rvt_rwq *owq;
                struct rvt_rwqe *p;
                u32 sz, size, n, head, tail;

                /* Check that the requested sizes are below the limits. */
                if ((attr->max_wr > dev->dparms.props.max_srq_wr) ||
                    ((attr_mask & IB_SRQ_LIMIT) ?
                     attr->srq_limit : srq->limit) > attr->max_wr)
                        return -EINVAL;

                sz = sizeof(struct rvt_rwqe) +
                        srq->rq.max_sge * sizeof(struct ib_sge);
                size = attr->max_wr + 1;
                wq = vmalloc_user(sizeof(struct rvt_rwq) + size * sz);
                if (!wq)
                        return -ENOMEM;

                /* Check that we can write the offset to mmap. */
                if (udata && udata->inlen >= sizeof(__u64)) {
                        __u64 offset_addr;
                        __u64 offset = 0;

                        ret = ib_copy_from_udata(&offset_addr, udata,
                                                 sizeof(offset_addr));
                        if (ret)
                                goto bail_free;
                        udata->outbuf = (void __user *)
                                        (unsigned long)offset_addr;
                        ret = ib_copy_to_udata(udata, &offset,
                                               sizeof(offset));
                        if (ret)
                                goto bail_free;
                }

                spin_lock_irq(&srq->rq.lock);
                /*
                 * validate head and tail pointer values and compute
                 * the number of remaining WQEs.
                 */
                owq = srq->rq.wq;
                head = owq->head;
                tail = owq->tail;
                if (head >= srq->rq.size || tail >= srq->rq.size) {
                        ret = -EINVAL;
                        goto bail_unlock;
                }
                n = head;
                if (n < tail)
                        n += srq->rq.size - tail;
                else
                        n -= tail;
                if (size <= n) {
                        ret = -EINVAL;
                        goto bail_unlock;
                }
                n = 0;
                p = wq->wq;
                while (tail != head) {
                        struct rvt_rwqe *wqe;
                        int i;

                        wqe = rvt_get_rwqe_ptr(&srq->rq, tail);
                        p->wr_id = wqe->wr_id;
                        p->num_sge = wqe->num_sge;
                        for (i = 0; i < wqe->num_sge; i++)
                                p->sg_list[i] = wqe->sg_list[i];
                        n++;
                        p = (struct rvt_rwqe *)((char *)p + sz);
                        if (++tail >= srq->rq.size)
                                tail = 0;
                }
                srq->rq.wq = wq;
                srq->rq.size = size;
                wq->head = n;
                wq->tail = 0;
                if (attr_mask & IB_SRQ_LIMIT)
                        srq->limit = attr->srq_limit;
                spin_unlock_irq(&srq->rq.lock);

                vfree(owq);

                if (srq->ip) {
                        struct rvt_mmap_info *ip = srq->ip;
                        struct rvt_dev_info *dev = ib_to_rvt(srq->ibsrq.device);
                        u32 s = sizeof(struct rvt_rwq) + size * sz;

                        rvt_update_mmap_info(dev, ip, s, wq);

                        /*
                         * Return the offset to mmap.
                         * See rvt_mmap() for details.
                         */
                        if (udata && udata->inlen >= sizeof(__u64)) {
                                ret = ib_copy_to_udata(udata, &ip->offset,
                                                       sizeof(ip->offset));
                                if (ret)
                                        return ret;
                        }

                        /*
                         * Put user mapping info onto the pending list
                         * unless it already is on the list.
                         */
                        spin_lock_irq(&dev->pending_lock);
                        if (list_empty(&ip->pending_mmaps))
                                list_add(&ip->pending_mmaps,
                                         &dev->pending_mmaps);
                        spin_unlock_irq(&dev->pending_lock);
                }
        } else if (attr_mask & IB_SRQ_LIMIT) {
                spin_lock_irq(&srq->rq.lock);
                if (attr->srq_limit >= srq->rq.size)
                        ret = -EINVAL;
                else
                        srq->limit = attr->srq_limit;
                spin_unlock_irq(&srq->rq.lock);
        }
        return ret;

bail_unlock:
        spin_unlock_irq(&srq->rq.lock);
bail_free:
        vfree(wq);
        return ret;
}

/** rvt_query_srq - query srq data
 * @ibsrq: srq to query
 * @attr: return info in attr
 *
 * Return: always 0
 */
int rvt_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);

        attr->max_wr = srq->rq.size - 1;
        attr->max_sge = srq->rq.max_sge;
        attr->srq_limit = srq->limit;
        return 0;
}

/**
 * rvt_destroy_srq - destory an srq
 * @ibsrq: srq object to destroy
 *
 * Return always 0
 */
int rvt_destroy_srq(struct ib_srq *ibsrq)
{
        struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
        struct rvt_dev_info *dev = ib_to_rvt(ibsrq->device);

        spin_lock(&dev->n_srqs_lock);
        dev->n_srqs_allocated--;
        spin_unlock(&dev->n_srqs_lock);
        if (srq->ip)
                kref_put(&srq->ip->ref, rvt_release_mmap_info);
        else
                vfree(srq->rq.wq);
        kfree(srq);

        return 0;
}