/*
 * Copyright (c) 2016, 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 "mlx5_ib.h"

struct mlx5_ib_gsi_wr {
        struct ib_cqe cqe;
        struct ib_wc wc;
        int send_flags;
        bool completed:1;
};

struct mlx5_ib_gsi_qp {
        struct ib_qp ibqp;
        struct ib_qp *rx_qp;
        u8 port_num;
        struct ib_qp_cap cap;
        enum ib_sig_type sq_sig_type;
        /* Serialize qp state modifications */
        struct mutex mutex;
        struct ib_cq *cq;
        struct mlx5_ib_gsi_wr *outstanding_wrs;
        u32 outstanding_pi, outstanding_ci;
        int num_qps;
        /* Protects access to the tx_qps. Post send operations synchronize
         * with tx_qp creation in setup_qp(). Also protects the
         * outstanding_wrs array and indices.
         */
        spinlock_t lock;
        struct ib_qp **tx_qps;
};

static struct mlx5_ib_gsi_qp *gsi_qp(struct ib_qp *qp)
{
        return container_of(qp, struct mlx5_ib_gsi_qp, ibqp);
}

static bool mlx5_ib_deth_sqpn_cap(struct mlx5_ib_dev *dev)
{
        return MLX5_CAP_GEN(dev->mdev, set_deth_sqpn);
}

/* Call with gsi->lock locked */
static void generate_completions(struct mlx5_ib_gsi_qp *gsi)
{
        struct ib_cq *gsi_cq = gsi->ibqp.send_cq;
        struct mlx5_ib_gsi_wr *wr;
        u32 index;

        for (index = gsi->outstanding_ci; index != gsi->outstanding_pi;
             index++) {
                wr = &gsi->outstanding_wrs[index % gsi->cap.max_send_wr];

                if (!wr->completed)
                        break;

                if (gsi->sq_sig_type == IB_SIGNAL_ALL_WR ||
                    wr->send_flags & IB_SEND_SIGNALED)
                        WARN_ON_ONCE(mlx5_ib_generate_wc(gsi_cq, &wr->wc));

                wr->completed = false;
        }

        gsi->outstanding_ci = index;
}

static void handle_single_completion(struct ib_cq *cq, struct ib_wc *wc)
{
        struct mlx5_ib_gsi_qp *gsi = cq->cq_context;
        struct mlx5_ib_gsi_wr *wr =
                container_of(wc->wr_cqe, struct mlx5_ib_gsi_wr, cqe);
        u64 wr_id;
        unsigned long flags;

        spin_lock_irqsave(&gsi->lock, flags);
        wr->completed = true;
        wr_id = wr->wc.wr_id;
        wr->wc = *wc;
        wr->wc.wr_id = wr_id;
        wr->wc.qp = &gsi->ibqp;

        generate_completions(gsi);
        spin_unlock_irqrestore(&gsi->lock, flags);
}

struct ib_qp *mlx5_ib_gsi_create_qp(struct ib_pd *pd,
                                    struct ib_qp_init_attr *init_attr)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_ib_gsi_qp *gsi;
        struct ib_qp_init_attr hw_init_attr = *init_attr;
        const u8 port_num = init_attr->port_num;
        const int num_pkeys = pd->device->attrs.max_pkeys;
        const int num_qps = mlx5_ib_deth_sqpn_cap(dev) ? num_pkeys : 0;
        int ret;

        mlx5_ib_dbg(dev, "creating GSI QP\n");

        if (port_num > ARRAY_SIZE(dev->devr.ports) || port_num < 1) {
                mlx5_ib_warn(dev,
                             "invalid port number %d during GSI QP creation\n",
                             port_num);
                return ERR_PTR(-EINVAL);
        }

        gsi = kzalloc(sizeof(*gsi), GFP_KERNEL);
        if (!gsi)
                return ERR_PTR(-ENOMEM);

        gsi->tx_qps = kcalloc(num_qps, sizeof(*gsi->tx_qps), GFP_KERNEL);
        if (!gsi->tx_qps) {
                ret = -ENOMEM;
                goto err_free;
        }

        gsi->outstanding_wrs = kcalloc(init_attr->cap.max_send_wr,
                                       sizeof(*gsi->outstanding_wrs),
                                       GFP_KERNEL);
        if (!gsi->outstanding_wrs) {
                ret = -ENOMEM;
                goto err_free_tx;
        }

        mutex_init(&gsi->mutex);

        mutex_lock(&dev->devr.mutex);

        if (dev->devr.ports[port_num - 1].gsi) {
                mlx5_ib_warn(dev, "GSI QP already exists on port %d\n",
                             port_num);
                ret = -EBUSY;
                goto err_free_wrs;
        }
        gsi->num_qps = num_qps;
        spin_lock_init(&gsi->lock);

        gsi->cap = init_attr->cap;
        gsi->sq_sig_type = init_attr->sq_sig_type;
        gsi->ibqp.qp_num = 1;
        gsi->port_num = port_num;

        gsi->cq = ib_alloc_cq(pd->device, gsi, init_attr->cap.max_send_wr, 0,
                              IB_POLL_SOFTIRQ);
        if (IS_ERR(gsi->cq)) {
                mlx5_ib_warn(dev, "unable to create send CQ for GSI QP. error %ld\n",
                             PTR_ERR(gsi->cq));
                ret = PTR_ERR(gsi->cq);
                goto err_free_wrs;
        }

        hw_init_attr.qp_type = MLX5_IB_QPT_HW_GSI;
        hw_init_attr.send_cq = gsi->cq;
        if (num_qps) {
                hw_init_attr.cap.max_send_wr = 0;
                hw_init_attr.cap.max_send_sge = 0;
                hw_init_attr.cap.max_inline_data = 0;
        }
        gsi->rx_qp = ib_create_qp(pd, &hw_init_attr);
        if (IS_ERR(gsi->rx_qp)) {
                mlx5_ib_warn(dev, "unable to create hardware GSI QP. error %ld\n",
                             PTR_ERR(gsi->rx_qp));
                ret = PTR_ERR(gsi->rx_qp);
                goto err_destroy_cq;
        }

        dev->devr.ports[init_attr->port_num - 1].gsi = gsi;

        mutex_unlock(&dev->devr.mutex);

        return &gsi->ibqp;

err_destroy_cq:
        ib_free_cq(gsi->cq);
err_free_wrs:
        mutex_unlock(&dev->devr.mutex);
        kfree(gsi->outstanding_wrs);
err_free_tx:
        kfree(gsi->tx_qps);
err_free:
        kfree(gsi);
        return ERR_PTR(ret);
}

int mlx5_ib_gsi_destroy_qp(struct ib_qp *qp)
{
        struct mlx5_ib_dev *dev = to_mdev(qp->device);
        struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
        const int port_num = gsi->port_num;
        int qp_index;
        int ret;

        mlx5_ib_dbg(dev, "destroying GSI QP\n");

        mutex_lock(&dev->devr.mutex);
        ret = ib_destroy_qp(gsi->rx_qp);
        if (ret) {
                mlx5_ib_warn(dev, "unable to destroy hardware GSI QP. error %d\n",
                             ret);
                mutex_unlock(&dev->devr.mutex);
                return ret;
        }
        dev->devr.ports[port_num - 1].gsi = NULL;
        mutex_unlock(&dev->devr.mutex);
        gsi->rx_qp = NULL;

        for (qp_index = 0; qp_index < gsi->num_qps; ++qp_index) {
                if (!gsi->tx_qps[qp_index])
                        continue;
                WARN_ON_ONCE(ib_destroy_qp(gsi->tx_qps[qp_index]));
                gsi->tx_qps[qp_index] = NULL;
        }

        ib_free_cq(gsi->cq);

        kfree(gsi->outstanding_wrs);
        kfree(gsi->tx_qps);
        kfree(gsi);

        return 0;
}

static struct ib_qp *create_gsi_ud_qp(struct mlx5_ib_gsi_qp *gsi)
{
        struct ib_pd *pd = gsi->rx_qp->pd;
        struct ib_qp_init_attr init_attr = {
                .event_handler = gsi->rx_qp->event_handler,
                .qp_context = gsi->rx_qp->qp_context,
                .send_cq = gsi->cq,
                .recv_cq = gsi->rx_qp->recv_cq,
                .cap = {
                        .max_send_wr = gsi->cap.max_send_wr,
                        .max_send_sge = gsi->cap.max_send_sge,
                        .max_inline_data = gsi->cap.max_inline_data,
                },
                .sq_sig_type = gsi->sq_sig_type,
                .qp_type = IB_QPT_UD,
                .create_flags = mlx5_ib_create_qp_sqpn_qp1(),
        };

        return ib_create_qp(pd, &init_attr);
}

static int modify_to_rts(struct mlx5_ib_gsi_qp *gsi, struct ib_qp *qp,
                         u16 qp_index)
{
        struct mlx5_ib_dev *dev = to_mdev(qp->device);
        struct ib_qp_attr attr;
        int mask;
        int ret;

        mask = IB_QP_STATE | IB_QP_PKEY_INDEX | IB_QP_QKEY | IB_QP_PORT;
        attr.qp_state = IB_QPS_INIT;
        attr.pkey_index = qp_index;
        attr.qkey = IB_QP1_QKEY;
        attr.port_num = gsi->port_num;
        ret = ib_modify_qp(qp, &attr, mask);
        if (ret) {
                mlx5_ib_err(dev, "could not change QP%d state to INIT: %d\n",
                            qp->qp_num, ret);
                return ret;
        }

        attr.qp_state = IB_QPS_RTR;
        ret = ib_modify_qp(qp, &attr, IB_QP_STATE);
        if (ret) {
                mlx5_ib_err(dev, "could not change QP%d state to RTR: %d\n",
                            qp->qp_num, ret);
                return ret;
        }

        attr.qp_state = IB_QPS_RTS;
        attr.sq_psn = 0;
        ret = ib_modify_qp(qp, &attr, IB_QP_STATE | IB_QP_SQ_PSN);
        if (ret) {
                mlx5_ib_err(dev, "could not change QP%d state to RTS: %d\n",
                            qp->qp_num, ret);
                return ret;
        }

        return 0;
}

static void setup_qp(struct mlx5_ib_gsi_qp *gsi, u16 qp_index)
{
        struct ib_device *device = gsi->rx_qp->device;
        struct mlx5_ib_dev *dev = to_mdev(device);
        struct ib_qp *qp;
        unsigned long flags;
        u16 pkey;
        int ret;

        ret = ib_query_pkey(device, gsi->port_num, qp_index, &pkey);
        if (ret) {
                mlx5_ib_warn(dev, "unable to read P_Key at port %d, index %d\n",
                             gsi->port_num, qp_index);
                return;
        }

        if (!pkey) {
                mlx5_ib_dbg(dev, "invalid P_Key at port %d, index %d.  Skipping.\n",
                            gsi->port_num, qp_index);
                return;
        }

        spin_lock_irqsave(&gsi->lock, flags);
        qp = gsi->tx_qps[qp_index];
        spin_unlock_irqrestore(&gsi->lock, flags);
        if (qp) {
                mlx5_ib_dbg(dev, "already existing GSI TX QP at port %d, index %d. Skipping\n",
                            gsi->port_num, qp_index);
                return;
        }

        qp = create_gsi_ud_qp(gsi);
        if (IS_ERR(qp)) {
                mlx5_ib_warn(dev, "unable to create hardware UD QP for GSI: %ld\n",
                             PTR_ERR(qp));
                return;
        }

        ret = modify_to_rts(gsi, qp, qp_index);
        if (ret)
                goto err_destroy_qp;

        spin_lock_irqsave(&gsi->lock, flags);
        WARN_ON_ONCE(gsi->tx_qps[qp_index]);
        gsi->tx_qps[qp_index] = qp;
        spin_unlock_irqrestore(&gsi->lock, flags);

        return;

err_destroy_qp:
        WARN_ON_ONCE(qp);
}

static void setup_qps(struct mlx5_ib_gsi_qp *gsi)
{
        u16 qp_index;

        for (qp_index = 0; qp_index < gsi->num_qps; ++qp_index)
                setup_qp(gsi, qp_index);
}

int mlx5_ib_gsi_modify_qp(struct ib_qp *qp, struct ib_qp_attr *attr,
                          int attr_mask)
{
        struct mlx5_ib_dev *dev = to_mdev(qp->device);
        struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
        int ret;

        mlx5_ib_dbg(dev, "modifying GSI QP to state %d\n", attr->qp_state);

        mutex_lock(&gsi->mutex);
        ret = ib_modify_qp(gsi->rx_qp, attr, attr_mask);
        if (ret) {
                mlx5_ib_warn(dev, "unable to modify GSI rx QP: %d\n", ret);
                goto unlock;
        }

        if (to_mqp(gsi->rx_qp)->state == IB_QPS_RTS)
                setup_qps(gsi);

unlock:
        mutex_unlock(&gsi->mutex);

        return ret;
}

int mlx5_ib_gsi_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
                         int qp_attr_mask,
                         struct ib_qp_init_attr *qp_init_attr)
{
        struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
        int ret;

        mutex_lock(&gsi->mutex);
        ret = ib_query_qp(gsi->rx_qp, qp_attr, qp_attr_mask, qp_init_attr);
        qp_init_attr->cap = gsi->cap;
        mutex_unlock(&gsi->mutex);

        return ret;
}

/* Call with gsi->lock locked */
static int mlx5_ib_add_outstanding_wr(struct mlx5_ib_gsi_qp *gsi,
                                      struct ib_ud_wr *wr, struct ib_wc *wc)
{
        struct mlx5_ib_dev *dev = to_mdev(gsi->rx_qp->device);
        struct mlx5_ib_gsi_wr *gsi_wr;

        if (gsi->outstanding_pi == gsi->outstanding_ci + gsi->cap.max_send_wr) {
                mlx5_ib_warn(dev, "no available GSI work request.\n");
                return -ENOMEM;
        }

        gsi_wr = &gsi->outstanding_wrs[gsi->outstanding_pi %
                                       gsi->cap.max_send_wr];
        gsi->outstanding_pi++;

        if (!wc) {
                memset(&gsi_wr->wc, 0, sizeof(gsi_wr->wc));
                gsi_wr->wc.pkey_index = wr->pkey_index;
                gsi_wr->wc.wr_id = wr->wr.wr_id;
        } else {
                gsi_wr->wc = *wc;
                gsi_wr->completed = true;
        }

        gsi_wr->cqe.done = &handle_single_completion;
        wr->wr.wr_cqe = &gsi_wr->cqe;

        return 0;
}

/* Call with gsi->lock locked */
static int mlx5_ib_gsi_silent_drop(struct mlx5_ib_gsi_qp *gsi,
                                    struct ib_ud_wr *wr)
{
        struct ib_wc wc = {
                { .wr_id = wr->wr.wr_id },
                .status = IB_WC_SUCCESS,
                .opcode = IB_WC_SEND,
                .qp = &gsi->ibqp,
        };
        int ret;

        ret = mlx5_ib_add_outstanding_wr(gsi, wr, &wc);
        if (ret)
                return ret;

        generate_completions(gsi);

        return 0;
}

/* Call with gsi->lock locked */
static struct ib_qp *get_tx_qp(struct mlx5_ib_gsi_qp *gsi, struct ib_ud_wr *wr)
{
        struct mlx5_ib_dev *dev = to_mdev(gsi->rx_qp->device);
        int qp_index = wr->pkey_index;

        if (!mlx5_ib_deth_sqpn_cap(dev))
                return gsi->rx_qp;

        if (qp_index >= gsi->num_qps)
                return NULL;

        return gsi->tx_qps[qp_index];
}

int mlx5_ib_gsi_post_send(struct ib_qp *qp, const struct ib_send_wr *wr,
                          const struct ib_send_wr **bad_wr)
{
        struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);
        struct ib_qp *tx_qp;
        unsigned long flags;
        int ret;

        for (; wr; wr = wr->next) {
                struct ib_ud_wr cur_wr = *ud_wr(wr);

                cur_wr.wr.next = NULL;

                spin_lock_irqsave(&gsi->lock, flags);
                tx_qp = get_tx_qp(gsi, &cur_wr);
                if (!tx_qp) {
                        ret = mlx5_ib_gsi_silent_drop(gsi, &cur_wr);
                        if (ret)
                                goto err;
                        spin_unlock_irqrestore(&gsi->lock, flags);
                        continue;
                }

                ret = mlx5_ib_add_outstanding_wr(gsi, &cur_wr, NULL);
                if (ret)
                        goto err;

                ret = ib_post_send(tx_qp, &cur_wr.wr, bad_wr);
                if (ret) {
                        /* Undo the effect of adding the outstanding wr */
                        gsi->outstanding_pi = (gsi->outstanding_pi - 1) %
                                              gsi->cap.max_send_wr;
                        goto err;
                }
                spin_unlock_irqrestore(&gsi->lock, flags);
        }

        return 0;

err:
        spin_unlock_irqrestore(&gsi->lock, flags);
        *bad_wr = wr;
        return ret;
}

int mlx5_ib_gsi_post_recv(struct ib_qp *qp, const struct ib_recv_wr *wr,
                          const struct ib_recv_wr **bad_wr)
{
        struct mlx5_ib_gsi_qp *gsi = gsi_qp(qp);

        return ib_post_recv(gsi->rx_qp, wr, bad_wr);
}

void mlx5_ib_gsi_pkey_change(struct mlx5_ib_gsi_qp *gsi)
{
        if (!gsi)
                return;

        mutex_lock(&gsi->mutex);
        setup_qps(gsi);
        mutex_unlock(&gsi->mutex);
}