/*
 * 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 <rdma/mlx4-abi.h>
#include <rdma/uverbs_ioctl.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);
        }
}

int mlx4_ib_create_srq(struct ib_srq *ib_srq,
                       struct ib_srq_init_attr *init_attr,
                       struct ib_udata *udata)
{
        struct mlx4_ib_dev *dev = to_mdev(ib_srq->device);
        struct mlx4_ib_ucontext *ucontext = rdma_udata_to_drv_context(
                udata, struct mlx4_ib_ucontext, ibucontext);
        struct mlx4_ib_srq *srq = to_msrq(ib_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;

        if (init_attr->srq_type != IB_SRQT_BASIC &&
            init_attr->srq_type != IB_SRQT_XRC)
                return -EOPNOTSUPP;

        /* 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 -EINVAL;

        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 (udata) {
                struct mlx4_ib_create_srq ucmd;

                if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd)))
                        return -EFAULT;

                srq->umem =
                        ib_umem_get(ib_srq->device, ucmd.buf_addr, buf_size, 0);
                if (IS_ERR(srq->umem))
                        return PTR_ERR(srq->umem);

                err = mlx4_mtt_init(
                        dev->dev, ib_umem_num_dma_blocks(srq->umem, PAGE_SIZE),
                        PAGE_SHIFT, &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(udata, ucmd.db_addr, &srq->db);
                if (err)
                        goto err_mtt;
        } else {
                err = mlx4_db_alloc(dev->dev, &srq->db, 0);
                if (err)
                        return err;

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

        cqn = ib_srq_has_cq(init_attr->srq_type) ?
                to_mcq(init_attr->ext.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(ib_srq->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 (udata)
                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 0;

err_wrid:
        if (udata)
                mlx4_ib_db_unmap_user(ucontext, &srq->db);
        else
                kvfree(srq->wrid);

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

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

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

        return 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 ib_udata *udata)
{
        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 (udata) {
                mlx4_ib_db_unmap_user(
                        rdma_udata_to_drv_context(
                                udata,
                                struct mlx4_ib_ucontext,
                                ibucontext),
                        &msrq->db);
        } else {
                kvfree(msrq->wrid);
                mlx4_buf_free(dev->dev, msrq->msrq.max << msrq->msrq.wqe_shift,
                              &msrq->buf);
                mlx4_db_free(dev->dev, &msrq->db);
        }
        ib_umem_release(msrq->umem);
        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, const struct ib_recv_wr *wr,
                          const 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;
        struct mlx4_ib_dev *mdev = to_mdev(ibsrq->device);

        spin_lock_irqsave(&srq->lock, flags);
        if (mdev->dev->persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR) {
                err = -EIO;
                *bad_wr = wr;
                goto out;
        }

        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);
        }
out:

        spin_unlock_irqrestore(&srq->lock, flags);

        return err;
}