/*
 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, Inc. 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/err.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include "qib_verbs.h"

/**
 * qib_post_srq_receive - post a receive on a shared receive queue
 * @ibsrq: the SRQ to post the receive on
 * @wr: the list of work requests to post
 * @bad_wr: A pointer to the first WR to cause a problem is put here
 *
 * This may be called from interrupt context.
 */
int qib_post_srq_receive(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
                         struct ib_recv_wr **bad_wr)
{
        struct qib_srq *srq = to_isrq(ibsrq);
        struct qib_rwq *wq;
        unsigned long flags;
        int ret;

        for (; wr; wr = wr->next) {
                struct qib_rwqe *wqe;
                u32 next;
                int i;

                if ((unsigned) wr->num_sge > srq->rq.max_sge) {
                        *bad_wr = wr;
                        ret = -EINVAL;
                        goto bail;
                }

                spin_lock_irqsave(&srq->rq.lock, flags);
                wq = srq->rq.wq;
                next = wq->head + 1;
                if (next >= srq->rq.size)
                        next = 0;
                if (next == wq->tail) {
                        spin_unlock_irqrestore(&srq->rq.lock, flags);
                        *bad_wr = wr;
                        ret = -ENOMEM;
                        goto bail;
                }

                wqe = get_rwqe_ptr(&srq->rq, wq->head);
                wqe->wr_id = wr->wr_id;
                wqe->num_sge = wr->num_sge;
                for (i = 0; i < wr->num_sge; i++)
                        wqe->sg_list[i] = wr->sg_list[i];
                /* Make sure queue entry is written before the head index. */
                smp_wmb();
                wq->head = next;
                spin_unlock_irqrestore(&srq->rq.lock, flags);
        }
        ret = 0;

bail:
        return ret;
}

/**
 * qib_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
 */
struct ib_srq *qib_create_srq(struct ib_pd *ibpd,
                              struct ib_srq_init_attr *srq_init_attr,
                              struct ib_udata *udata)
{
        struct qib_ibdev *dev = to_idev(ibpd->device);
        struct qib_srq *srq;
        u32 sz;
        struct ib_srq *ret;

        if (srq_init_attr->srq_type != IB_SRQT_BASIC) {
                ret = ERR_PTR(-ENOSYS);
                goto done;
        }

        if (srq_init_attr->attr.max_sge == 0 ||
            srq_init_attr->attr.max_sge > ib_qib_max_srq_sges ||
            srq_init_attr->attr.max_wr == 0 ||
            srq_init_attr->attr.max_wr > ib_qib_max_srq_wrs) {
                ret = ERR_PTR(-EINVAL);
                goto done;
        }

        srq = kmalloc(sizeof(*srq), GFP_KERNEL);
        if (!srq) {
                ret = ERR_PTR(-ENOMEM);
                goto done;
        }

        /*
         * 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 qib_rwqe);
        srq->rq.wq = vmalloc_user(sizeof(struct qib_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 qib_mmap() for details.
         */
        if (udata && udata->outlen >= sizeof(__u64)) {
                int err;
                u32 s = sizeof(struct qib_rwq) + srq->rq.size * sz;

                srq->ip =
                    qib_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 == ib_qib_max_srqs) {
                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);
        }

        ret = &srq->ibsrq;
        goto done;

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

/**
 * qib_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
 */
int qib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
                   enum ib_srq_attr_mask attr_mask,
                   struct ib_udata *udata)
{
        struct qib_srq *srq = to_isrq(ibsrq);
        struct qib_rwq *wq;
        int ret = 0;

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

                /* Check that the requested sizes are below the limits. */
                if ((attr->max_wr > ib_qib_max_srq_wrs) ||
                    ((attr_mask & IB_SRQ_LIMIT) ?
                     attr->srq_limit : srq->limit) > attr->max_wr) {
                        ret = -EINVAL;
                        goto bail;
                }

                sz = sizeof(struct qib_rwqe) +
                        srq->rq.max_sge * sizeof(struct ib_sge);
                size = attr->max_wr + 1;
                wq = vmalloc_user(sizeof(struct qib_rwq) + size * sz);
                if (!wq) {
                        ret = -ENOMEM;
                        goto bail;
                }

                /* 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 qib_rwqe *wqe;
                        int i;

                        wqe = 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 qib_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 qib_mmap_info *ip = srq->ip;
                        struct qib_ibdev *dev = to_idev(srq->ibsrq.device);
                        u32 s = sizeof(struct qib_rwq) + size * sz;

                        qib_update_mmap_info(dev, ip, s, wq);

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

                        /*
                         * 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);
        }
        goto bail;

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

int qib_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
{
        struct qib_srq *srq = to_isrq(ibsrq);

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

/**
 * qib_destroy_srq - destroy a shared receive queue
 * @ibsrq: the SRQ to destroy
 */
int qib_destroy_srq(struct ib_srq *ibsrq)
{
        struct qib_srq *srq = to_isrq(ibsrq);
        struct qib_ibdev *dev = to_idev(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, qib_release_mmap_info);
        else
                vfree(srq->rq.wq);
        kfree(srq);

        return 0;
}