/*
 * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
 * Copyright (c) 2005 Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2004 Voltaire, Inc. All rights reserved.
 * Copyright (c) 2005 Open Grid Computing, 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/gfp.h>

#include "c2.h"
#include "c2_vq.h"
#include "c2_status.h"

#define C2_CQ_MSG_SIZE ((sizeof(struct c2wr_ce) + 32-1) & ~(32-1))

static struct c2_cq *c2_cq_get(struct c2_dev *c2dev, int cqn)
{
        struct c2_cq *cq;
        unsigned long flags;

        spin_lock_irqsave(&c2dev->lock, flags);
        cq = c2dev->qptr_array[cqn];
        if (!cq) {
                spin_unlock_irqrestore(&c2dev->lock, flags);
                return NULL;
        }
        atomic_inc(&cq->refcount);
        spin_unlock_irqrestore(&c2dev->lock, flags);
        return cq;
}

static void c2_cq_put(struct c2_cq *cq)
{
        if (atomic_dec_and_test(&cq->refcount))
                wake_up(&cq->wait);
}

void c2_cq_event(struct c2_dev *c2dev, u32 mq_index)
{
        struct c2_cq *cq;

        cq = c2_cq_get(c2dev, mq_index);
        if (!cq) {
                printk("discarding events on destroyed CQN=%d\n", mq_index);
                return;
        }

        (*cq->ibcq.comp_handler) (&cq->ibcq, cq->ibcq.cq_context);
        c2_cq_put(cq);
}

void c2_cq_clean(struct c2_dev *c2dev, struct c2_qp *qp, u32 mq_index)
{
        struct c2_cq *cq;
        struct c2_mq *q;

        cq = c2_cq_get(c2dev, mq_index);
        if (!cq)
                return;

        spin_lock_irq(&cq->lock);
        q = &cq->mq;
        if (q && !c2_mq_empty(q)) {
                u16 priv = q->priv;
                struct c2wr_ce *msg;

                while (priv != be16_to_cpu(*q->shared)) {
                        msg = (struct c2wr_ce *)
                                (q->msg_pool.host + priv * q->msg_size);
                        if (msg->qp_user_context == (u64) (unsigned long) qp) {
                                msg->qp_user_context = (u64) 0;
                        }
                        priv = (priv + 1) % q->q_size;
                }
        }
        spin_unlock_irq(&cq->lock);
        c2_cq_put(cq);
}

static inline enum ib_wc_status c2_cqe_status_to_openib(u8 status)
{
        switch (status) {
        case C2_OK:
                return IB_WC_SUCCESS;
        case CCERR_FLUSHED:
                return IB_WC_WR_FLUSH_ERR;
        case CCERR_BASE_AND_BOUNDS_VIOLATION:
                return IB_WC_LOC_PROT_ERR;
        case CCERR_ACCESS_VIOLATION:
                return IB_WC_LOC_ACCESS_ERR;
        case CCERR_TOTAL_LENGTH_TOO_BIG:
                return IB_WC_LOC_LEN_ERR;
        case CCERR_INVALID_WINDOW:
                return IB_WC_MW_BIND_ERR;
        default:
                return IB_WC_GENERAL_ERR;
        }
}


static inline int c2_poll_one(struct c2_dev *c2dev,
                              struct c2_cq *cq, struct ib_wc *entry)
{
        struct c2wr_ce *ce;
        struct c2_qp *qp;
        int is_recv = 0;

        ce = c2_mq_consume(&cq->mq);
        if (!ce) {
                return -EAGAIN;
        }

        /*
         * if the qp returned is null then this qp has already
         * been freed and we are unable process the completion.
         * try pulling the next message
         */
        while ((qp =
                (struct c2_qp *) (unsigned long) ce->qp_user_context) == NULL) {
                c2_mq_free(&cq->mq);
                ce = c2_mq_consume(&cq->mq);
                if (!ce)
                        return -EAGAIN;
        }

        entry->status = c2_cqe_status_to_openib(c2_wr_get_result(ce));
        entry->wr_id = ce->hdr.context;
        entry->qp = &qp->ibqp;
        entry->wc_flags = 0;
        entry->slid = 0;
        entry->sl = 0;
        entry->src_qp = 0;
        entry->dlid_path_bits = 0;
        entry->pkey_index = 0;

        switch (c2_wr_get_id(ce)) {
        case C2_WR_TYPE_SEND:
                entry->opcode = IB_WC_SEND;
                break;
        case C2_WR_TYPE_RDMA_WRITE:
                entry->opcode = IB_WC_RDMA_WRITE;
                break;
        case C2_WR_TYPE_RDMA_READ:
                entry->opcode = IB_WC_RDMA_READ;
                break;
        case C2_WR_TYPE_BIND_MW:
                entry->opcode = IB_WC_BIND_MW;
                break;
        case C2_WR_TYPE_RECV:
                entry->byte_len = be32_to_cpu(ce->bytes_rcvd);
                entry->opcode = IB_WC_RECV;
                is_recv = 1;
                break;
        default:
                break;
        }

        /* consume the WQEs */
        if (is_recv)
                c2_mq_lconsume(&qp->rq_mq, 1);
        else
                c2_mq_lconsume(&qp->sq_mq,
                               be32_to_cpu(c2_wr_get_wqe_count(ce)) + 1);

        /* free the message */
        c2_mq_free(&cq->mq);

        return 0;
}

int c2_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
{
        struct c2_dev *c2dev = to_c2dev(ibcq->device);
        struct c2_cq *cq = to_c2cq(ibcq);
        unsigned long flags;
        int npolled, err;

        spin_lock_irqsave(&cq->lock, flags);

        for (npolled = 0; npolled < num_entries; ++npolled) {

                err = c2_poll_one(c2dev, cq, entry + npolled);
                if (err)
                        break;
        }

        spin_unlock_irqrestore(&cq->lock, flags);

        return npolled;
}

int c2_arm_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
{
        struct c2_mq_shared __iomem *shared;
        struct c2_cq *cq;
        unsigned long flags;
        int ret = 0;

        cq = to_c2cq(ibcq);
        shared = cq->mq.peer;

        if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_NEXT_COMP)
                writeb(C2_CQ_NOTIFICATION_TYPE_NEXT, &shared->notification_type);
        else if ((notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED)
                writeb(C2_CQ_NOTIFICATION_TYPE_NEXT_SE, &shared->notification_type);
        else
                return -EINVAL;

        writeb(CQ_WAIT_FOR_DMA | CQ_ARMED, &shared->armed);

        /*
         * Now read back shared->armed to make the PCI
         * write synchronous.  This is necessary for
         * correct cq notification semantics.
         */
        readb(&shared->armed);

        if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
                spin_lock_irqsave(&cq->lock, flags);
                ret = !c2_mq_empty(&cq->mq);
                spin_unlock_irqrestore(&cq->lock, flags);
        }

        return ret;
}

static void c2_free_cq_buf(struct c2_dev *c2dev, struct c2_mq *mq)
{
        dma_free_coherent(&c2dev->pcidev->dev, mq->q_size * mq->msg_size,
                          mq->msg_pool.host, dma_unmap_addr(mq, mapping));
}

static int c2_alloc_cq_buf(struct c2_dev *c2dev, struct c2_mq *mq, int q_size,
                           int msg_size)
{
        u8 *pool_start;

        pool_start = dma_alloc_coherent(&c2dev->pcidev->dev, q_size * msg_size,
                                        &mq->host_dma, GFP_KERNEL);
        if (!pool_start)
                return -ENOMEM;

        c2_mq_rep_init(mq,
                       0,               /* index (currently unknown) */
                       q_size,
                       msg_size,
                       pool_start,
                       NULL,    /* peer (currently unknown) */
                       C2_MQ_HOST_TARGET);

        dma_unmap_addr_set(mq, mapping, mq->host_dma);

        return 0;
}

int c2_init_cq(struct c2_dev *c2dev, int entries,
               struct c2_ucontext *ctx, struct c2_cq *cq)
{
        struct c2wr_cq_create_req wr;
        struct c2wr_cq_create_rep *reply;
        unsigned long peer_pa;
        struct c2_vq_req *vq_req;
        int err;

        might_sleep();

        cq->ibcq.cqe = entries - 1;
        cq->is_kernel = !ctx;

        /* Allocate a shared pointer */
        cq->mq.shared = c2_alloc_mqsp(c2dev, c2dev->kern_mqsp_pool,
                                      &cq->mq.shared_dma, GFP_KERNEL);
        if (!cq->mq.shared)
                return -ENOMEM;

        /* Allocate pages for the message pool */
        err = c2_alloc_cq_buf(c2dev, &cq->mq, entries + 1, C2_CQ_MSG_SIZE);
        if (err)
                goto bail0;

        vq_req = vq_req_alloc(c2dev);
        if (!vq_req) {
                err = -ENOMEM;
                goto bail1;
        }

        memset(&wr, 0, sizeof(wr));
        c2_wr_set_id(&wr, CCWR_CQ_CREATE);
        wr.hdr.context = (unsigned long) vq_req;
        wr.rnic_handle = c2dev->adapter_handle;
        wr.msg_size = cpu_to_be32(cq->mq.msg_size);
        wr.depth = cpu_to_be32(cq->mq.q_size);
        wr.shared_ht = cpu_to_be64(cq->mq.shared_dma);
        wr.msg_pool = cpu_to_be64(cq->mq.host_dma);
        wr.user_context = (u64) (unsigned long) (cq);

        vq_req_get(c2dev, vq_req);

        err = vq_send_wr(c2dev, (union c2wr *) & wr);
        if (err) {
                vq_req_put(c2dev, vq_req);
                goto bail2;
        }

        err = vq_wait_for_reply(c2dev, vq_req);
        if (err)
                goto bail2;

        reply = (struct c2wr_cq_create_rep *) (unsigned long) (vq_req->reply_msg);
        if (!reply) {
                err = -ENOMEM;
                goto bail2;
        }

        if ((err = c2_errno(reply)) != 0)
                goto bail3;

        cq->adapter_handle = reply->cq_handle;
        cq->mq.index = be32_to_cpu(reply->mq_index);

        peer_pa = c2dev->pa + be32_to_cpu(reply->adapter_shared);
        cq->mq.peer = ioremap_nocache(peer_pa, PAGE_SIZE);
        if (!cq->mq.peer) {
                err = -ENOMEM;
                goto bail3;
        }

        vq_repbuf_free(c2dev, reply);
        vq_req_free(c2dev, vq_req);

        spin_lock_init(&cq->lock);
        atomic_set(&cq->refcount, 1);
        init_waitqueue_head(&cq->wait);

        /*
         * Use the MQ index allocated by the adapter to
         * store the CQ in the qptr_array
         */
        cq->cqn = cq->mq.index;
        c2dev->qptr_array[cq->cqn] = cq;

        return 0;

      bail3:
        vq_repbuf_free(c2dev, reply);
      bail2:
        vq_req_free(c2dev, vq_req);
      bail1:
        c2_free_cq_buf(c2dev, &cq->mq);
      bail0:
        c2_free_mqsp(cq->mq.shared);

        return err;
}

void c2_free_cq(struct c2_dev *c2dev, struct c2_cq *cq)
{
        int err;
        struct c2_vq_req *vq_req;
        struct c2wr_cq_destroy_req wr;
        struct c2wr_cq_destroy_rep *reply;

        might_sleep();

        /* Clear CQ from the qptr array */
        spin_lock_irq(&c2dev->lock);
        c2dev->qptr_array[cq->mq.index] = NULL;
        atomic_dec(&cq->refcount);
        spin_unlock_irq(&c2dev->lock);

        wait_event(cq->wait, !atomic_read(&cq->refcount));

        vq_req = vq_req_alloc(c2dev);
        if (!vq_req) {
                goto bail0;
        }

        memset(&wr, 0, sizeof(wr));
        c2_wr_set_id(&wr, CCWR_CQ_DESTROY);
        wr.hdr.context = (unsigned long) vq_req;
        wr.rnic_handle = c2dev->adapter_handle;
        wr.cq_handle = cq->adapter_handle;

        vq_req_get(c2dev, vq_req);

        err = vq_send_wr(c2dev, (union c2wr *) & wr);
        if (err) {
                vq_req_put(c2dev, vq_req);
                goto bail1;
        }

        err = vq_wait_for_reply(c2dev, vq_req);
        if (err)
                goto bail1;

        reply = (struct c2wr_cq_destroy_rep *) (unsigned long) (vq_req->reply_msg);
        if (reply)
                vq_repbuf_free(c2dev, reply);
      bail1:
        vq_req_free(c2dev, vq_req);
      bail0:
        if (cq->is_kernel) {
                c2_free_cq_buf(c2dev, &cq->mq);
        }

        return;
}