ipath_srq.c

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/*
 * Copyright (c) 2006, 2007, 2008 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 "ipath_verbs.h"

int ipath_post_srq_receive(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
               struct ib_recv_wr **bad_wr)
{
    struct ipath_srq *srq = to_isrq(ibsrq);
    struct ipath_rwq *wq;
    unsigned long flags;
    int ret;

    for (; wr; wr = wr->next) {
        struct ipath_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;
}

struct ib_srq *ipath_create_srq(struct ib_pd *ibpd,
                struct ib_srq_init_attr *srq_init_attr,
                struct ib_udata *udata)
{
    struct ipath_ibdev *dev = to_idev(ibpd->device);
    struct ipath_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_wr == 0) {
        ret = ERR_PTR(-EINVAL);
        goto done;
    }

    if ((srq_init_attr->attr.max_sge > ib_ipath_max_srq_sges) ||
        (srq_init_attr->attr.max_wr > ib_ipath_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 ipath_rwqe);
    srq->rq.wq = vmalloc_user(sizeof(struct ipath_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 ipath_mmap() for details.
     */
    if (udata && udata->outlen >= sizeof(__u64)) {
        int err;
        u32 s = sizeof(struct ipath_rwq) + srq->rq.size * sz;

        srq->ip =
            ipath_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_ipath_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;
}

int ipath_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
             enum ib_srq_attr_mask attr_mask,
             struct ib_udata *udata)
{
    struct ipath_srq *srq = to_isrq(ibsrq);
    struct ipath_rwq *wq;
    int ret = 0;

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

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

        sz = sizeof(struct ipath_rwqe) +
            srq->rq.max_sge * sizeof(struct ib_sge);
        size = attr->max_wr + 1;
        wq = vmalloc_user(sizeof(struct ipath_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 pointer value and compute
         * the number of remaining WQEs.
         */
        owq = srq->rq.wq;
        head = owq->head;
        if (head >= srq->rq.size)
            head = 0;
        tail = owq->tail;
        if (tail >= srq->rq.size)
            tail = 0;
        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 ipath_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 ipath_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 ipath_mmap_info *ip = srq->ip;
            struct ipath_ibdev *dev = to_idev(srq->ibsrq.device);
            u32 s = sizeof(struct ipath_rwq) + size * sz;

            ipath_update_mmap_info(dev, ip, s, wq);

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

            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 ipath_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
{
    struct ipath_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;
}

int ipath_destroy_srq(struct ib_srq *ibsrq)
{
    struct ipath_srq *srq = to_isrq(ibsrq);
    struct ipath_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, ipath_release_mmap_info);
    else
        vfree(srq->rq.wq);
    kfree(srq);

    return 0;
}