/*
 * Copyright (c) 2013-2015, 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/kernel.h>
#include <linux/hardirq.h>
#include <linux/mlx5/driver.h>
#include <rdma/ib_verbs.h>
#include <linux/mlx5/cq.h>
#include "mlx5_core.h"
#include "lib/eq.h"

#define TASKLET_MAX_TIME 2
#define TASKLET_MAX_TIME_JIFFIES msecs_to_jiffies(TASKLET_MAX_TIME)

void mlx5_cq_tasklet_cb(struct tasklet_struct *t)
{
        unsigned long flags;
        unsigned long end = jiffies + TASKLET_MAX_TIME_JIFFIES;
        struct mlx5_eq_tasklet *ctx = from_tasklet(ctx, t, task);
        struct mlx5_core_cq *mcq;
        struct mlx5_core_cq *temp;

        spin_lock_irqsave(&ctx->lock, flags);
        list_splice_tail_init(&ctx->list, &ctx->process_list);
        spin_unlock_irqrestore(&ctx->lock, flags);

        list_for_each_entry_safe(mcq, temp, &ctx->process_list,
                                 tasklet_ctx.list) {
                list_del_init(&mcq->tasklet_ctx.list);
                mcq->tasklet_ctx.comp(mcq, NULL);
                mlx5_cq_put(mcq);
                if (time_after(jiffies, end))
                        break;
        }

        if (!list_empty(&ctx->process_list))
                tasklet_schedule(&ctx->task);
}

void mlx5_add_cq_to_tasklet(struct mlx5_core_cq *cq,
                            struct mlx5_eqe *eqe)
{
        unsigned long flags;
        struct mlx5_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
        bool schedule_tasklet = false;

        spin_lock_irqsave(&tasklet_ctx->lock, flags);
        /* When migrating CQs between EQs will be implemented, please note
         * that you need to sync this point. It is possible that
         * while migrating a CQ, completions on the old EQs could
         * still arrive.
         */
        if (list_empty_careful(&cq->tasklet_ctx.list)) {
                mlx5_cq_hold(cq);
                /* If the tasklet CQ work list isn't empty, mlx5_cq_tasklet_cb()
                 * is scheduled/running and hasn't processed the list yet, so it
                 * will see this added CQ when it runs. If the list is empty,
                 * the tasklet needs to be scheduled to pick up the CQ. The
                 * spinlock avoids any race with the tasklet accessing the list.
                 */
                schedule_tasklet = list_empty(&tasklet_ctx->list);
                list_add_tail(&cq->tasklet_ctx.list, &tasklet_ctx->list);
        }
        spin_unlock_irqrestore(&tasklet_ctx->lock, flags);

        if (schedule_tasklet)
                tasklet_schedule(&tasklet_ctx->task);
}
EXPORT_SYMBOL(mlx5_add_cq_to_tasklet);

static void mlx5_core_cq_dummy_cb(struct mlx5_core_cq *cq, struct mlx5_eqe *eqe)
{
        mlx5_core_err(cq->eq->core.dev,
                      "CQ default completion callback, CQ #%u\n", cq->cqn);
}

#define MLX5_CQ_INIT_CMD_SN cpu_to_be32(2 << 28)
/* Callers must verify outbox status in case of err */
int mlx5_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
                   u32 *in, int inlen, u32 *out, int outlen)
{
        int eqn = MLX5_GET(cqc, MLX5_ADDR_OF(create_cq_in, in, cq_context),
                           c_eqn_or_apu_element);
        u32 din[MLX5_ST_SZ_DW(destroy_cq_in)] = {};
        struct mlx5_eq_comp *eq;
        int err;

        eq = mlx5_eqn2comp_eq(dev, eqn);
        if (IS_ERR(eq))
                return PTR_ERR(eq);

        memset(out, 0, outlen);
        MLX5_SET(create_cq_in, in, opcode, MLX5_CMD_OP_CREATE_CQ);
        err = mlx5_cmd_do(dev, in, inlen, out, outlen);
        if (err)
                return err;

        cq->cqn = MLX5_GET(create_cq_out, out, cqn);
        cq->cons_index = 0;
        cq->arm_sn     = 0;
        cq->eq         = eq;
        cq->uid = MLX5_GET(create_cq_in, in, uid);

        /* Kernel CQs must set the arm_db address prior to calling
         * this function, allowing for the proper value to be
         * initialized. User CQs are responsible for their own
         * initialization since they do not use the arm_db field.
         */
        if (cq->arm_db)
                *cq->arm_db = MLX5_CQ_INIT_CMD_SN;

        refcount_set(&cq->refcount, 1);
        init_completion(&cq->free);
        if (!cq->comp)
                cq->comp = mlx5_core_cq_dummy_cb;
        /* assuming CQ will be deleted before the EQ */
        cq->tasklet_ctx.priv = &eq->tasklet_ctx;
        INIT_LIST_HEAD(&cq->tasklet_ctx.list);

        /* Add to comp EQ CQ tree to recv comp events */
        err = mlx5_eq_add_cq(&eq->core, cq);
        if (err)
                goto err_cmd;

        /* Add to async EQ CQ tree to recv async events */
        err = mlx5_eq_add_cq(mlx5_get_async_eq(dev), cq);
        if (err)
                goto err_cq_add;

        cq->pid = current->pid;
        err = mlx5_debug_cq_add(dev, cq);
        if (err)
                mlx5_core_dbg(dev, "failed adding CP 0x%x to debug file system\n",
                              cq->cqn);

        cq->irqn = eq->core.irqn;

        return 0;

err_cq_add:
        mlx5_eq_del_cq(&eq->core, cq);
err_cmd:
        MLX5_SET(destroy_cq_in, din, opcode, MLX5_CMD_OP_DESTROY_CQ);
        MLX5_SET(destroy_cq_in, din, cqn, cq->cqn);
        MLX5_SET(destroy_cq_in, din, uid, cq->uid);
        mlx5_cmd_exec_in(dev, destroy_cq, din);
        return err;
}
EXPORT_SYMBOL(mlx5_create_cq);

/* oubox is checked and err val is normalized */
int mlx5_core_create_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
                        u32 *in, int inlen, u32 *out, int outlen)
{
        int err = mlx5_create_cq(dev, cq, in, inlen, out, outlen);

        return mlx5_cmd_check(dev, err, in, out);
}
EXPORT_SYMBOL(mlx5_core_create_cq);

int mlx5_core_destroy_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq)
{
        u32 in[MLX5_ST_SZ_DW(destroy_cq_in)] = {};
        int err;

        mlx5_debug_cq_remove(dev, cq);

        mlx5_eq_del_cq(mlx5_get_async_eq(dev), cq);
        mlx5_eq_del_cq(&cq->eq->core, cq);

        MLX5_SET(destroy_cq_in, in, opcode, MLX5_CMD_OP_DESTROY_CQ);
        MLX5_SET(destroy_cq_in, in, cqn, cq->cqn);
        MLX5_SET(destroy_cq_in, in, uid, cq->uid);
        err = mlx5_cmd_exec_in(dev, destroy_cq, in);
        if (err)
                return err;

        synchronize_irq(cq->irqn);
        mlx5_cq_put(cq);
        wait_for_completion(&cq->free);

        return 0;
}
EXPORT_SYMBOL(mlx5_core_destroy_cq);

int mlx5_core_query_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
                       u32 *out)
{
        u32 in[MLX5_ST_SZ_DW(query_cq_in)] = {};

        MLX5_SET(query_cq_in, in, opcode, MLX5_CMD_OP_QUERY_CQ);
        MLX5_SET(query_cq_in, in, cqn, cq->cqn);
        return mlx5_cmd_exec_inout(dev, query_cq, in, out);
}
EXPORT_SYMBOL(mlx5_core_query_cq);

int mlx5_core_modify_cq(struct mlx5_core_dev *dev, struct mlx5_core_cq *cq,
                        u32 *in, int inlen)
{
        u32 out[MLX5_ST_SZ_DW(modify_cq_out)] = {};

        MLX5_SET(modify_cq_in, in, opcode, MLX5_CMD_OP_MODIFY_CQ);
        MLX5_SET(modify_cq_in, in, uid, cq->uid);
        return mlx5_cmd_exec(dev, in, inlen, out, sizeof(out));
}
EXPORT_SYMBOL(mlx5_core_modify_cq);

int mlx5_core_modify_cq_moderation(struct mlx5_core_dev *dev,
                                   struct mlx5_core_cq *cq,
                                   u16 cq_period,
                                   u16 cq_max_count)
{
        u32 in[MLX5_ST_SZ_DW(modify_cq_in)] = {};
        void *cqc;

        MLX5_SET(modify_cq_in, in, cqn, cq->cqn);
        cqc = MLX5_ADDR_OF(modify_cq_in, in, cq_context);
        MLX5_SET(cqc, cqc, cq_period, cq_period);
        MLX5_SET(cqc, cqc, cq_max_count, cq_max_count);
        MLX5_SET(modify_cq_in, in,
                 modify_field_select_resize_field_select.modify_field_select.modify_field_select,
                 MLX5_CQ_MODIFY_PERIOD | MLX5_CQ_MODIFY_COUNT);

        return mlx5_core_modify_cq(dev, cq, in, sizeof(in));
}
EXPORT_SYMBOL(mlx5_core_modify_cq_moderation);