srq.c

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/*
 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2007, 2008 Mellanox Technologies. 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/mlx4/qp.h>
#include <linux/mlx4/srq.h>
#include <linux/slab.h>

#include "mlx4_ib.h"
#include "user.h"

static void *get_wqe(struct mlx4_ib_srq *srq, int n)
{
    return mlx4_buf_offset(&srq->buf, n << srq->msrq.wqe_shift);
}

static void mlx4_ib_srq_event(struct mlx4_srq *srq, enum mlx4_event type)
{
    struct ib_event event;
    struct ib_srq *ibsrq = &to_mibsrq(srq)->ibsrq;

    if (ibsrq->event_handler) {
        event.device      = ibsrq->device;
        event.element.srq = ibsrq;
        switch (type) {
        case MLX4_EVENT_TYPE_SRQ_LIMIT:
            event.event = IB_EVENT_SRQ_LIMIT_REACHED;
            break;
        case MLX4_EVENT_TYPE_SRQ_CATAS_ERROR:
            event.event = IB_EVENT_SRQ_ERR;
            break;
        default:
            pr_warn("Unexpected event type %d "
                   "on SRQ %06x\n", type, srq->srqn);
            return;
        }

        ibsrq->event_handler(&event, ibsrq->srq_context);
    }
}

struct ib_srq *mlx4_ib_create_srq(struct ib_pd *pd,
                  struct ib_srq_init_attr *init_attr,
                  struct ib_udata *udata)
{
    struct mlx4_ib_dev *dev = to_mdev(pd->device);
    struct mlx4_ib_srq *srq;
    struct mlx4_wqe_srq_next_seg *next;
    struct mlx4_wqe_data_seg *scatter;
    u32 cqn;
    u16 xrcdn;
    int desc_size;
    int buf_size;
    int err;
    int i;

    /* Sanity check SRQ size before proceeding */
    if (init_attr->attr.max_wr  >= dev->dev->caps.max_srq_wqes ||
        init_attr->attr.max_sge >  dev->dev->caps.max_srq_sge)
        return ERR_PTR(-EINVAL);

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

    mutex_init(&srq->mutex);
    spin_lock_init(&srq->lock);
    srq->msrq.max    = roundup_pow_of_two(init_attr->attr.max_wr + 1);
    srq->msrq.max_gs = init_attr->attr.max_sge;

    desc_size = max(32UL,
            roundup_pow_of_two(sizeof (struct mlx4_wqe_srq_next_seg) +
                       srq->msrq.max_gs *
                       sizeof (struct mlx4_wqe_data_seg)));
    srq->msrq.wqe_shift = ilog2(desc_size);

    buf_size = srq->msrq.max * desc_size;

    if (pd->uobject) {
        struct mlx4_ib_create_srq ucmd;

        if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) {
            err = -EFAULT;
            goto err_srq;
        }

        srq->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr,
                    buf_size, 0, 0);
        if (IS_ERR(srq->umem)) {
            err = PTR_ERR(srq->umem);
            goto err_srq;
        }

        err = mlx4_mtt_init(dev->dev, ib_umem_page_count(srq->umem),
                    ilog2(srq->umem->page_size), &srq->mtt);
        if (err)
            goto err_buf;

        err = mlx4_ib_umem_write_mtt(dev, &srq->mtt, srq->umem);
        if (err)
            goto err_mtt;

        err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
                      ucmd.db_addr, &srq->db);
        if (err)
            goto err_mtt;
    } else {
        err = mlx4_db_alloc(dev->dev, &srq->db, 0);
        if (err)
            goto err_srq;

        *srq->db.db = 0;

        if (mlx4_buf_alloc(dev->dev, buf_size, PAGE_SIZE * 2, &srq->buf)) {
            err = -ENOMEM;
            goto err_db;
        }

        srq->head    = 0;
        srq->tail    = srq->msrq.max - 1;
        srq->wqe_ctr = 0;

        for (i = 0; i < srq->msrq.max; ++i) {
            next = get_wqe(srq, i);
            next->next_wqe_index =
                cpu_to_be16((i + 1) & (srq->msrq.max - 1));

            for (scatter = (void *) (next + 1);
                 (void *) scatter < (void *) next + desc_size;
                 ++scatter)
                scatter->lkey = cpu_to_be32(MLX4_INVALID_LKEY);
        }

        err = mlx4_mtt_init(dev->dev, srq->buf.npages, srq->buf.page_shift,
                    &srq->mtt);
        if (err)
            goto err_buf;

        err = mlx4_buf_write_mtt(dev->dev, &srq->mtt, &srq->buf);
        if (err)
            goto err_mtt;

        srq->wrid = kmalloc(srq->msrq.max * sizeof (u64), GFP_KERNEL);
        if (!srq->wrid) {
            err = -ENOMEM;
            goto err_mtt;
        }
    }

    cqn = (init_attr->srq_type == IB_SRQT_XRC) ?
        to_mcq(init_attr->ext.xrc.cq)->mcq.cqn : 0;
    xrcdn = (init_attr->srq_type == IB_SRQT_XRC) ?
        to_mxrcd(init_attr->ext.xrc.xrcd)->xrcdn :
        (u16) dev->dev->caps.reserved_xrcds;
    err = mlx4_srq_alloc(dev->dev, to_mpd(pd)->pdn, cqn, xrcdn, &srq->mtt,
                 srq->db.dma, &srq->msrq);
    if (err)
        goto err_wrid;

    srq->msrq.event = mlx4_ib_srq_event;
    srq->ibsrq.ext.xrc.srq_num = srq->msrq.srqn;

    if (pd->uobject)
        if (ib_copy_to_udata(udata, &srq->msrq.srqn, sizeof (__u32))) {
            err = -EFAULT;
            goto err_wrid;
        }

    init_attr->attr.max_wr = srq->msrq.max - 1;

    return &srq->ibsrq;

err_wrid:
    if (pd->uobject)
        mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &srq->db);
    else
        kfree(srq->wrid);

err_mtt:
    mlx4_mtt_cleanup(dev->dev, &srq->mtt);

err_buf:
    if (pd->uobject)
        ib_umem_release(srq->umem);
    else
        mlx4_buf_free(dev->dev, buf_size, &srq->buf);

err_db:
    if (!pd->uobject)
        mlx4_db_free(dev->dev, &srq->db);

err_srq:
    kfree(srq);

    return ERR_PTR(err);
}

int mlx4_ib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
               enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
{
    struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
    struct mlx4_ib_srq *srq = to_msrq(ibsrq);
    int ret;

    /* We don't support resizing SRQs (yet?) */
    if (attr_mask & IB_SRQ_MAX_WR)
        return -EINVAL;

    if (attr_mask & IB_SRQ_LIMIT) {
        if (attr->srq_limit >= srq->msrq.max)
            return -EINVAL;

        mutex_lock(&srq->mutex);
        ret = mlx4_srq_arm(dev->dev, &srq->msrq, attr->srq_limit);
        mutex_unlock(&srq->mutex);

        if (ret)
            return ret;
    }

    return 0;
}

int mlx4_ib_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
{
    struct mlx4_ib_dev *dev = to_mdev(ibsrq->device);
    struct mlx4_ib_srq *srq = to_msrq(ibsrq);
    int ret;
    int limit_watermark;

    ret = mlx4_srq_query(dev->dev, &srq->msrq, &limit_watermark);
    if (ret)
        return ret;

    srq_attr->srq_limit = limit_watermark;
    srq_attr->max_wr    = srq->msrq.max - 1;
    srq_attr->max_sge   = srq->msrq.max_gs;

    return 0;
}

int mlx4_ib_destroy_srq(struct ib_srq *srq)
{
    struct mlx4_ib_dev *dev = to_mdev(srq->device);
    struct mlx4_ib_srq *msrq = to_msrq(srq);

    mlx4_srq_free(dev->dev, &msrq->msrq);
    mlx4_mtt_cleanup(dev->dev, &msrq->mtt);

    if (srq->uobject) {
        mlx4_ib_db_unmap_user(to_mucontext(srq->uobject->context), &msrq->db);
        ib_umem_release(msrq->umem);
    } else {
        kfree(msrq->wrid);
        mlx4_buf_free(dev->dev, msrq->msrq.max << msrq->msrq.wqe_shift,
                  &msrq->buf);
        mlx4_db_free(dev->dev, &msrq->db);
    }

    kfree(msrq);

    return 0;
}

void mlx4_ib_free_srq_wqe(struct mlx4_ib_srq *srq, int wqe_index)
{
    struct mlx4_wqe_srq_next_seg *next;

    /* always called with interrupts disabled. */
    spin_lock(&srq->lock);

    next = get_wqe(srq, srq->tail);
    next->next_wqe_index = cpu_to_be16(wqe_index);
    srq->tail = wqe_index;

    spin_unlock(&srq->lock);
}

int mlx4_ib_post_srq_recv(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
              struct ib_recv_wr **bad_wr)
{
    struct mlx4_ib_srq *srq = to_msrq(ibsrq);
    struct mlx4_wqe_srq_next_seg *next;
    struct mlx4_wqe_data_seg *scat;
    unsigned long flags;
    int err = 0;
    int nreq;
    int i;

    spin_lock_irqsave(&srq->lock, flags);

    for (nreq = 0; wr; ++nreq, wr = wr->next) {
        if (unlikely(wr->num_sge > srq->msrq.max_gs)) {
            err = -EINVAL;
            *bad_wr = wr;
            break;
        }

        if (unlikely(srq->head == srq->tail)) {
            err = -ENOMEM;
            *bad_wr = wr;
            break;
        }

        srq->wrid[srq->head] = wr->wr_id;

        next      = get_wqe(srq, srq->head);
        srq->head = be16_to_cpu(next->next_wqe_index);
        scat      = (struct mlx4_wqe_data_seg *) (next + 1);

        for (i = 0; i < wr->num_sge; ++i) {
            scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length);
            scat[i].lkey       = cpu_to_be32(wr->sg_list[i].lkey);
            scat[i].addr       = cpu_to_be64(wr->sg_list[i].addr);
        }

        if (i < srq->msrq.max_gs) {
            scat[i].byte_count = 0;
            scat[i].lkey       = cpu_to_be32(MLX4_INVALID_LKEY);
            scat[i].addr       = 0;
        }
    }

    if (likely(nreq)) {
        srq->wqe_ctr += nreq;

        /*
         * Make sure that descriptors are written before
         * doorbell record.
         */
        wmb();

        *srq->db.db = cpu_to_be32(srq->wqe_ctr);
    }

    spin_unlock_irqrestore(&srq->lock, flags);

    return err;
}