/*
 * Copyright(c) 2015, 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * 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.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/err.h>
#include <linux/vmalloc.h>
#include <linux/hash.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <rdma/rdma_vt.h>
#include <rdma/rdmavt_qp.h>
#include <rdma/ib_verbs.h>

#include "hfi.h"
#include "qp.h"
#include "trace.h"
#include "verbs_txreq.h"

unsigned int hfi1_qp_table_size = 256;
module_param_named(qp_table_size, hfi1_qp_table_size, uint, S_IRUGO);
MODULE_PARM_DESC(qp_table_size, "QP table size");

static void flush_tx_list(struct rvt_qp *qp);
static int iowait_sleep(
        struct sdma_engine *sde,
        struct iowait *wait,
        struct sdma_txreq *stx,
        unsigned seq);
static void iowait_wakeup(struct iowait *wait, int reason);
static void iowait_sdma_drained(struct iowait *wait);
static void qp_pio_drain(struct rvt_qp *qp);

static inline unsigned mk_qpn(struct rvt_qpn_table *qpt,
                              struct rvt_qpn_map *map, unsigned off)
{
        return (map - qpt->map) * RVT_BITS_PER_PAGE + off;
}

/*
 * Convert the AETH credit code into the number of credits.
 */
static const u16 credit_table[31] = {
        0,                      /* 0 */
        1,                      /* 1 */
        2,                      /* 2 */
        3,                      /* 3 */
        4,                      /* 4 */
        6,                      /* 5 */
        8,                      /* 6 */
        12,                     /* 7 */
        16,                     /* 8 */
        24,                     /* 9 */
        32,                     /* A */
        48,                     /* B */
        64,                     /* C */
        96,                     /* D */
        128,                    /* E */
        192,                    /* F */
        256,                    /* 10 */
        384,                    /* 11 */
        512,                    /* 12 */
        768,                    /* 13 */
        1024,                   /* 14 */
        1536,                   /* 15 */
        2048,                   /* 16 */
        3072,                   /* 17 */
        4096,                   /* 18 */
        6144,                   /* 19 */
        8192,                   /* 1A */
        12288,                  /* 1B */
        16384,                  /* 1C */
        24576,                  /* 1D */
        32768                   /* 1E */
};

const struct rvt_operation_params hfi1_post_parms[RVT_OPERATION_MAX] = {
[IB_WR_RDMA_WRITE] = {
        .length = sizeof(struct ib_rdma_wr),
        .qpt_support = BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
},

[IB_WR_RDMA_READ] = {
        .length = sizeof(struct ib_rdma_wr),
        .qpt_support = BIT(IB_QPT_RC),
        .flags = RVT_OPERATION_ATOMIC,
},

[IB_WR_ATOMIC_CMP_AND_SWP] = {
        .length = sizeof(struct ib_atomic_wr),
        .qpt_support = BIT(IB_QPT_RC),
        .flags = RVT_OPERATION_ATOMIC | RVT_OPERATION_ATOMIC_SGE,
},

[IB_WR_ATOMIC_FETCH_AND_ADD] = {
        .length = sizeof(struct ib_atomic_wr),
        .qpt_support = BIT(IB_QPT_RC),
        .flags = RVT_OPERATION_ATOMIC | RVT_OPERATION_ATOMIC_SGE,
},

[IB_WR_RDMA_WRITE_WITH_IMM] = {
        .length = sizeof(struct ib_rdma_wr),
        .qpt_support = BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
},

[IB_WR_SEND] = {
        .length = sizeof(struct ib_send_wr),
        .qpt_support = BIT(IB_QPT_UD) | BIT(IB_QPT_SMI) | BIT(IB_QPT_GSI) |
                       BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
},

[IB_WR_SEND_WITH_IMM] = {
        .length = sizeof(struct ib_send_wr),
        .qpt_support = BIT(IB_QPT_UD) | BIT(IB_QPT_SMI) | BIT(IB_QPT_GSI) |
                       BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
},

[IB_WR_REG_MR] = {
        .length = sizeof(struct ib_reg_wr),
        .qpt_support = BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
        .flags = RVT_OPERATION_LOCAL,
},

[IB_WR_LOCAL_INV] = {
        .length = sizeof(struct ib_send_wr),
        .qpt_support = BIT(IB_QPT_UC) | BIT(IB_QPT_RC),
        .flags = RVT_OPERATION_LOCAL,
},

[IB_WR_SEND_WITH_INV] = {
        .length = sizeof(struct ib_send_wr),
        .qpt_support = BIT(IB_QPT_RC),
},

};

static void flush_tx_list(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;

        while (!list_empty(&priv->s_iowait.tx_head)) {
                struct sdma_txreq *tx;

                tx = list_first_entry(
                        &priv->s_iowait.tx_head,
                        struct sdma_txreq,
                        list);
                list_del_init(&tx->list);
                hfi1_put_txreq(
                        container_of(tx, struct verbs_txreq, txreq));
        }
}

static void flush_iowait(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
        unsigned long flags;

        write_seqlock_irqsave(&dev->iowait_lock, flags);
        if (!list_empty(&priv->s_iowait.list)) {
                list_del_init(&priv->s_iowait.list);
                rvt_put_qp(qp);
        }
        write_sequnlock_irqrestore(&dev->iowait_lock, flags);
}

static inline int opa_mtu_enum_to_int(int mtu)
{
        switch (mtu) {
        case OPA_MTU_8192:  return 8192;
        case OPA_MTU_10240: return 10240;
        default:            return -1;
        }
}

/**
 * This function is what we would push to the core layer if we wanted to be a
 * "first class citizen".  Instead we hide this here and rely on Verbs ULPs
 * to blindly pass the MTU enum value from the PathRecord to us.
 */
static inline int verbs_mtu_enum_to_int(struct ib_device *dev, enum ib_mtu mtu)
{
        int val;

        /* Constraining 10KB packets to 8KB packets */
        if (mtu == (enum ib_mtu)OPA_MTU_10240)
                mtu = OPA_MTU_8192;
        val = opa_mtu_enum_to_int((int)mtu);
        if (val > 0)
                return val;
        return ib_mtu_enum_to_int(mtu);
}

int hfi1_check_modify_qp(struct rvt_qp *qp, struct ib_qp_attr *attr,
                         int attr_mask, struct ib_udata *udata)
{
        struct ib_qp *ibqp = &qp->ibqp;
        struct hfi1_ibdev *dev = to_idev(ibqp->device);
        struct hfi1_devdata *dd = dd_from_dev(dev);
        u8 sc;

        if (attr_mask & IB_QP_AV) {
                sc = ah_to_sc(ibqp->device, &attr->ah_attr);
                if (sc == 0xf)
                        return -EINVAL;

                if (!qp_to_sdma_engine(qp, sc) &&
                    dd->flags & HFI1_HAS_SEND_DMA)
                        return -EINVAL;

                if (!qp_to_send_context(qp, sc))
                        return -EINVAL;
        }

        if (attr_mask & IB_QP_ALT_PATH) {
                sc = ah_to_sc(ibqp->device, &attr->alt_ah_attr);
                if (sc == 0xf)
                        return -EINVAL;

                if (!qp_to_sdma_engine(qp, sc) &&
                    dd->flags & HFI1_HAS_SEND_DMA)
                        return -EINVAL;

                if (!qp_to_send_context(qp, sc))
                        return -EINVAL;
        }

        return 0;
}

void hfi1_modify_qp(struct rvt_qp *qp, struct ib_qp_attr *attr,
                    int attr_mask, struct ib_udata *udata)
{
        struct ib_qp *ibqp = &qp->ibqp;
        struct hfi1_qp_priv *priv = qp->priv;

        if (attr_mask & IB_QP_AV) {
                priv->s_sc = ah_to_sc(ibqp->device, &qp->remote_ah_attr);
                priv->s_sde = qp_to_sdma_engine(qp, priv->s_sc);
                priv->s_sendcontext = qp_to_send_context(qp, priv->s_sc);
        }

        if (attr_mask & IB_QP_PATH_MIG_STATE &&
            attr->path_mig_state == IB_MIG_MIGRATED &&
            qp->s_mig_state == IB_MIG_ARMED) {
                qp->s_flags |= RVT_S_AHG_CLEAR;
                priv->s_sc = ah_to_sc(ibqp->device, &qp->remote_ah_attr);
                priv->s_sde = qp_to_sdma_engine(qp, priv->s_sc);
                priv->s_sendcontext = qp_to_send_context(qp, priv->s_sc);
        }
}

/**
 * hfi1_check_send_wqe - validate wqe
 * @qp - The qp
 * @wqe - The built wqe
 *
 * validate wqe.  This is called
 * prior to inserting the wqe into
 * the ring but after the wqe has been
 * setup.
 *
 * Returns 0 on success, -EINVAL on failure
 *
 */
int hfi1_check_send_wqe(struct rvt_qp *qp,
                        struct rvt_swqe *wqe)
{
        struct hfi1_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num);
        struct rvt_ah *ah;

        switch (qp->ibqp.qp_type) {
        case IB_QPT_RC:
        case IB_QPT_UC:
                if (wqe->length > 0x80000000U)
                        return -EINVAL;
                break;
        case IB_QPT_SMI:
                ah = ibah_to_rvtah(wqe->ud_wr.ah);
                if (wqe->length > (1 << ah->log_pmtu))
                        return -EINVAL;
                break;
        case IB_QPT_GSI:
        case IB_QPT_UD:
                ah = ibah_to_rvtah(wqe->ud_wr.ah);
                if (wqe->length > (1 << ah->log_pmtu))
                        return -EINVAL;
                if (ibp->sl_to_sc[ah->attr.sl] == 0xf)
                        return -EINVAL;
        default:
                break;
        }
        return wqe->length <= piothreshold;
}

/**
 * hfi1_compute_aeth - compute the AETH (syndrome + MSN)
 * @qp: the queue pair to compute the AETH for
 *
 * Returns the AETH.
 */
__be32 hfi1_compute_aeth(struct rvt_qp *qp)
{
        u32 aeth = qp->r_msn & HFI1_MSN_MASK;

        if (qp->ibqp.srq) {
                /*
                 * Shared receive queues don't generate credits.
                 * Set the credit field to the invalid value.
                 */
                aeth |= HFI1_AETH_CREDIT_INVAL << HFI1_AETH_CREDIT_SHIFT;
        } else {
                u32 min, max, x;
                u32 credits;
                struct rvt_rwq *wq = qp->r_rq.wq;
                u32 head;
                u32 tail;

                /* sanity check pointers before trusting them */
                head = wq->head;
                if (head >= qp->r_rq.size)
                        head = 0;
                tail = wq->tail;
                if (tail >= qp->r_rq.size)
                        tail = 0;
                /*
                 * Compute the number of credits available (RWQEs).
                 * There is a small chance that the pair of reads are
                 * not atomic, which is OK, since the fuzziness is
                 * resolved as further ACKs go out.
                 */
                credits = head - tail;
                if ((int)credits < 0)
                        credits += qp->r_rq.size;
                /*
                 * Binary search the credit table to find the code to
                 * use.
                 */
                min = 0;
                max = 31;
                for (;;) {
                        x = (min + max) / 2;
                        if (credit_table[x] == credits)
                                break;
                        if (credit_table[x] > credits) {
                                max = x;
                        } else {
                                if (min == x)
                                        break;
                                min = x;
                        }
                }
                aeth |= x << HFI1_AETH_CREDIT_SHIFT;
        }
        return cpu_to_be32(aeth);
}

/**
 * _hfi1_schedule_send - schedule progress
 * @qp: the QP
 *
 * This schedules qp progress w/o regard to the s_flags.
 *
 * It is only used in the post send, which doesn't hold
 * the s_lock.
 */
void _hfi1_schedule_send(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct hfi1_ibport *ibp =
                to_iport(qp->ibqp.device, qp->port_num);
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
        struct hfi1_devdata *dd = dd_from_ibdev(qp->ibqp.device);

        iowait_schedule(&priv->s_iowait, ppd->hfi1_wq,
                        priv->s_sde ?
                        priv->s_sde->cpu :
                        cpumask_first(cpumask_of_node(dd->node)));
}

static void qp_pio_drain(struct rvt_qp *qp)
{
        struct hfi1_ibdev *dev;
        struct hfi1_qp_priv *priv = qp->priv;

        if (!priv->s_sendcontext)
                return;
        dev = to_idev(qp->ibqp.device);
        while (iowait_pio_pending(&priv->s_iowait)) {
                write_seqlock_irq(&dev->iowait_lock);
                hfi1_sc_wantpiobuf_intr(priv->s_sendcontext, 1);
                write_sequnlock_irq(&dev->iowait_lock);
                iowait_pio_drain(&priv->s_iowait);
                write_seqlock_irq(&dev->iowait_lock);
                hfi1_sc_wantpiobuf_intr(priv->s_sendcontext, 0);
                write_sequnlock_irq(&dev->iowait_lock);
        }
}

/**
 * hfi1_schedule_send - schedule progress
 * @qp: the QP
 *
 * This schedules qp progress and caller should hold
 * the s_lock.
 */
void hfi1_schedule_send(struct rvt_qp *qp)
{
        lockdep_assert_held(&qp->s_lock);
        if (hfi1_send_ok(qp))
                _hfi1_schedule_send(qp);
}

/**
 * hfi1_get_credit - handle credit in aeth
 * @qp: the qp
 * @aeth: the Acknowledge Extended Transport Header
 *
 * The QP s_lock should be held.
 */
void hfi1_get_credit(struct rvt_qp *qp, u32 aeth)
{
        u32 credit = (aeth >> HFI1_AETH_CREDIT_SHIFT) & HFI1_AETH_CREDIT_MASK;

        lockdep_assert_held(&qp->s_lock);
        /*
         * If the credit is invalid, we can send
         * as many packets as we like.  Otherwise, we have to
         * honor the credit field.
         */
        if (credit == HFI1_AETH_CREDIT_INVAL) {
                if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
                        qp->s_flags |= RVT_S_UNLIMITED_CREDIT;
                        if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
                                qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
                                hfi1_schedule_send(qp);
                        }
                }
        } else if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
                /* Compute new LSN (i.e., MSN + credit) */
                credit = (aeth + credit_table[credit]) & HFI1_MSN_MASK;
                if (cmp_msn(credit, qp->s_lsn) > 0) {
                        qp->s_lsn = credit;
                        if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
                                qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
                                hfi1_schedule_send(qp);
                        }
                }
        }
}

void hfi1_qp_wakeup(struct rvt_qp *qp, u32 flag)
{
        unsigned long flags;

        spin_lock_irqsave(&qp->s_lock, flags);
        if (qp->s_flags & flag) {
                qp->s_flags &= ~flag;
                trace_hfi1_qpwakeup(qp, flag);
                hfi1_schedule_send(qp);
        }
        spin_unlock_irqrestore(&qp->s_lock, flags);
        /* Notify hfi1_destroy_qp() if it is waiting. */
        rvt_put_qp(qp);
}

static int iowait_sleep(
        struct sdma_engine *sde,
        struct iowait *wait,
        struct sdma_txreq *stx,
        unsigned seq)
{
        struct verbs_txreq *tx = container_of(stx, struct verbs_txreq, txreq);
        struct rvt_qp *qp;
        struct hfi1_qp_priv *priv;
        unsigned long flags;
        int ret = 0;
        struct hfi1_ibdev *dev;

        qp = tx->qp;
        priv = qp->priv;

        spin_lock_irqsave(&qp->s_lock, flags);
        if (ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) {
                /*
                 * If we couldn't queue the DMA request, save the info
                 * and try again later rather than destroying the
                 * buffer and undoing the side effects of the copy.
                 */
                /* Make a common routine? */
                dev = &sde->dd->verbs_dev;
                list_add_tail(&stx->list, &wait->tx_head);
                write_seqlock(&dev->iowait_lock);
                if (sdma_progress(sde, seq, stx))
                        goto eagain;
                if (list_empty(&priv->s_iowait.list)) {
                        struct hfi1_ibport *ibp =
                                to_iport(qp->ibqp.device, qp->port_num);

                        ibp->rvp.n_dmawait++;
                        qp->s_flags |= RVT_S_WAIT_DMA_DESC;
                        list_add_tail(&priv->s_iowait.list, &sde->dmawait);
                        trace_hfi1_qpsleep(qp, RVT_S_WAIT_DMA_DESC);
                        rvt_get_qp(qp);
                }
                write_sequnlock(&dev->iowait_lock);
                qp->s_flags &= ~RVT_S_BUSY;
                spin_unlock_irqrestore(&qp->s_lock, flags);
                ret = -EBUSY;
        } else {
                spin_unlock_irqrestore(&qp->s_lock, flags);
                hfi1_put_txreq(tx);
        }
        return ret;
eagain:
        write_sequnlock(&dev->iowait_lock);
        spin_unlock_irqrestore(&qp->s_lock, flags);
        list_del_init(&stx->list);
        return -EAGAIN;
}

static void iowait_wakeup(struct iowait *wait, int reason)
{
        struct rvt_qp *qp = iowait_to_qp(wait);

        WARN_ON(reason != SDMA_AVAIL_REASON);
        hfi1_qp_wakeup(qp, RVT_S_WAIT_DMA_DESC);
}

static void iowait_sdma_drained(struct iowait *wait)
{
        struct rvt_qp *qp = iowait_to_qp(wait);
        unsigned long flags;

        /*
         * This happens when the send engine notes
         * a QP in the error state and cannot
         * do the flush work until that QP's
         * sdma work has finished.
         */
        spin_lock_irqsave(&qp->s_lock, flags);
        if (qp->s_flags & RVT_S_WAIT_DMA) {
                qp->s_flags &= ~RVT_S_WAIT_DMA;
                hfi1_schedule_send(qp);
        }
        spin_unlock_irqrestore(&qp->s_lock, flags);
}

/**
 *
 * qp_to_sdma_engine - map a qp to a send engine
 * @qp: the QP
 * @sc5: the 5 bit sc
 *
 * Return:
 * A send engine for the qp or NULL for SMI type qp.
 */
struct sdma_engine *qp_to_sdma_engine(struct rvt_qp *qp, u8 sc5)
{
        struct hfi1_devdata *dd = dd_from_ibdev(qp->ibqp.device);
        struct sdma_engine *sde;

        if (!(dd->flags & HFI1_HAS_SEND_DMA))
                return NULL;
        switch (qp->ibqp.qp_type) {
        case IB_QPT_SMI:
                return NULL;
        default:
                break;
        }
        sde = sdma_select_engine_sc(dd, qp->ibqp.qp_num >> dd->qos_shift, sc5);
        return sde;
}

/*
 * qp_to_send_context - map a qp to a send context
 * @qp: the QP
 * @sc5: the 5 bit sc
 *
 * Return:
 * A send context for the qp
 */
struct send_context *qp_to_send_context(struct rvt_qp *qp, u8 sc5)
{
        struct hfi1_devdata *dd = dd_from_ibdev(qp->ibqp.device);

        switch (qp->ibqp.qp_type) {
        case IB_QPT_SMI:
                /* SMA packets to VL15 */
                return dd->vld[15].sc;
        default:
                break;
        }

        return pio_select_send_context_sc(dd, qp->ibqp.qp_num >> dd->qos_shift,
                                          sc5);
}

struct qp_iter {
        struct hfi1_ibdev *dev;
        struct rvt_qp *qp;
        int specials;
        int n;
};

struct qp_iter *qp_iter_init(struct hfi1_ibdev *dev)
{
        struct qp_iter *iter;

        iter = kzalloc(sizeof(*iter), GFP_KERNEL);
        if (!iter)
                return NULL;

        iter->dev = dev;
        iter->specials = dev->rdi.ibdev.phys_port_cnt * 2;

        return iter;
}

int qp_iter_next(struct qp_iter *iter)
{
        struct hfi1_ibdev *dev = iter->dev;
        int n = iter->n;
        int ret = 1;
        struct rvt_qp *pqp = iter->qp;
        struct rvt_qp *qp;

        /*
         * The approach is to consider the special qps
         * as an additional table entries before the
         * real hash table.  Since the qp code sets
         * the qp->next hash link to NULL, this works just fine.
         *
         * iter->specials is 2 * # ports
         *
         * n = 0..iter->specials is the special qp indices
         *
         * n = iter->specials..dev->rdi.qp_dev->qp_table_size+iter->specials are
         * the potential hash bucket entries
         *
         */
        for (; n <  dev->rdi.qp_dev->qp_table_size + iter->specials; n++) {
                if (pqp) {
                        qp = rcu_dereference(pqp->next);
                } else {
                        if (n < iter->specials) {
                                struct hfi1_pportdata *ppd;
                                struct hfi1_ibport *ibp;
                                int pidx;

                                pidx = n % dev->rdi.ibdev.phys_port_cnt;
                                ppd = &dd_from_dev(dev)->pport[pidx];
                                ibp = &ppd->ibport_data;

                                if (!(n & 1))
                                        qp = rcu_dereference(ibp->rvp.qp[0]);
                                else
                                        qp = rcu_dereference(ibp->rvp.qp[1]);
                        } else {
                                qp = rcu_dereference(
                                        dev->rdi.qp_dev->qp_table[
                                                (n - iter->specials)]);
                        }
                }
                pqp = qp;
                if (qp) {
                        iter->qp = qp;
                        iter->n = n;
                        return 0;
                }
        }
        return ret;
}

static const char * const qp_type_str[] = {
        "SMI", "GSI", "RC", "UC", "UD",
};

static int qp_idle(struct rvt_qp *qp)
{
        return
                qp->s_last == qp->s_acked &&
                qp->s_acked == qp->s_cur &&
                qp->s_cur == qp->s_tail &&
                qp->s_tail == qp->s_head;
}

void qp_iter_print(struct seq_file *s, struct qp_iter *iter)
{
        struct rvt_swqe *wqe;
        struct rvt_qp *qp = iter->qp;
        struct hfi1_qp_priv *priv = qp->priv;
        struct sdma_engine *sde;
        struct send_context *send_context;

        sde = qp_to_sdma_engine(qp, priv->s_sc);
        wqe = rvt_get_swqe_ptr(qp, qp->s_last);
        send_context = qp_to_send_context(qp, priv->s_sc);
        seq_printf(s,
                   "N %d %s QP %x R %u %s %u %u %u f=%x %u %u %u %u %u %u PSN %x %x %x %x %x (%u %u %u %u %u %u %u) RQP %x LID %x SL %u MTU %u %u %u %u SDE %p,%u SC %p,%u SCQ %u %u PID %d\n",
                   iter->n,
                   qp_idle(qp) ? "I" : "B",
                   qp->ibqp.qp_num,
                   atomic_read(&qp->refcount),
                   qp_type_str[qp->ibqp.qp_type],
                   qp->state,
                   wqe ? wqe->wr.opcode : 0,
                   qp->s_hdrwords,
                   qp->s_flags,
                   iowait_sdma_pending(&priv->s_iowait),
                   iowait_pio_pending(&priv->s_iowait),
                   !list_empty(&priv->s_iowait.list),
                   qp->timeout,
                   wqe ? wqe->ssn : 0,
                   qp->s_lsn,
                   qp->s_last_psn,
                   qp->s_psn, qp->s_next_psn,
                   qp->s_sending_psn, qp->s_sending_hpsn,
                   qp->s_last, qp->s_acked, qp->s_cur,
                   qp->s_tail, qp->s_head, qp->s_size,
                   qp->s_avail,
                   qp->remote_qpn,
                   qp->remote_ah_attr.dlid,
                   qp->remote_ah_attr.sl,
                   qp->pmtu,
                   qp->s_retry,
                   qp->s_retry_cnt,
                   qp->s_rnr_retry_cnt,
                   sde,
                   sde ? sde->this_idx : 0,
                   send_context,
                   send_context ? send_context->sw_index : 0,
                   ibcq_to_rvtcq(qp->ibqp.send_cq)->queue->head,
                   ibcq_to_rvtcq(qp->ibqp.send_cq)->queue->tail,
                   qp->pid);
}

void qp_comm_est(struct rvt_qp *qp)
{
        qp->r_flags |= RVT_R_COMM_EST;
        if (qp->ibqp.event_handler) {
                struct ib_event ev;

                ev.device = qp->ibqp.device;
                ev.element.qp = &qp->ibqp;
                ev.event = IB_EVENT_COMM_EST;
                qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
        }
}

void *qp_priv_alloc(struct rvt_dev_info *rdi, struct rvt_qp *qp,
                    gfp_t gfp)
{
        struct hfi1_qp_priv *priv;

        priv = kzalloc_node(sizeof(*priv), gfp, rdi->dparms.node);
        if (!priv)
                return ERR_PTR(-ENOMEM);

        priv->owner = qp;

        priv->s_ahg = kzalloc_node(sizeof(*priv->s_ahg), gfp,
                                   rdi->dparms.node);
        if (!priv->s_ahg) {
                kfree(priv);
                return ERR_PTR(-ENOMEM);
        }
        iowait_init(
                &priv->s_iowait,
                1,
                _hfi1_do_send,
                iowait_sleep,
                iowait_wakeup,
                iowait_sdma_drained);
        setup_timer(&priv->s_rnr_timer, hfi1_rc_rnr_retry, (unsigned long)qp);
        qp->s_timer.function = hfi1_rc_timeout;
        return priv;
}

void qp_priv_free(struct rvt_dev_info *rdi, struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;

        kfree(priv->s_ahg);
        kfree(priv);
}

unsigned free_all_qps(struct rvt_dev_info *rdi)
{
        struct hfi1_ibdev *verbs_dev = container_of(rdi,
                                                    struct hfi1_ibdev,
                                                    rdi);
        struct hfi1_devdata *dd = container_of(verbs_dev,
                                               struct hfi1_devdata,
                                               verbs_dev);
        int n;
        unsigned qp_inuse = 0;

        for (n = 0; n < dd->num_pports; n++) {
                struct hfi1_ibport *ibp = &dd->pport[n].ibport_data;

                rcu_read_lock();
                if (rcu_dereference(ibp->rvp.qp[0]))
                        qp_inuse++;
                if (rcu_dereference(ibp->rvp.qp[1]))
                        qp_inuse++;
                rcu_read_unlock();
        }

        return qp_inuse;
}

void flush_qp_waiters(struct rvt_qp *qp)
{
        lockdep_assert_held(&qp->s_lock);
        flush_iowait(qp);
        hfi1_stop_rc_timers(qp);
}

void stop_send_queue(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;

        cancel_work_sync(&priv->s_iowait.iowork);
        hfi1_del_timers_sync(qp);
}

void quiesce_qp(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;

        iowait_sdma_drain(&priv->s_iowait);
        qp_pio_drain(qp);
        flush_tx_list(qp);
}

void notify_qp_reset(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;

        priv->r_adefered = 0;
        clear_ahg(qp);
}

/*
 * Switch to alternate path.
 * The QP s_lock should be held and interrupts disabled.
 */
void hfi1_migrate_qp(struct rvt_qp *qp)
{
        struct hfi1_qp_priv *priv = qp->priv;
        struct ib_event ev;

        qp->s_mig_state = IB_MIG_MIGRATED;
        qp->remote_ah_attr = qp->alt_ah_attr;
        qp->port_num = qp->alt_ah_attr.port_num;
        qp->s_pkey_index = qp->s_alt_pkey_index;
        qp->s_flags |= RVT_S_AHG_CLEAR;
        priv->s_sc = ah_to_sc(qp->ibqp.device, &qp->remote_ah_attr);
        priv->s_sde = qp_to_sdma_engine(qp, priv->s_sc);

        ev.device = qp->ibqp.device;
        ev.element.qp = &qp->ibqp;
        ev.event = IB_EVENT_PATH_MIG;
        qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
}

int mtu_to_path_mtu(u32 mtu)
{
        return mtu_to_enum(mtu, OPA_MTU_8192);
}

u32 mtu_from_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp, u32 pmtu)
{
        u32 mtu;
        struct hfi1_ibdev *verbs_dev = container_of(rdi,
                                                    struct hfi1_ibdev,
                                                    rdi);
        struct hfi1_devdata *dd = container_of(verbs_dev,
                                               struct hfi1_devdata,
                                               verbs_dev);
        struct hfi1_ibport *ibp;
        u8 sc, vl;

        ibp = &dd->pport[qp->port_num - 1].ibport_data;
        sc = ibp->sl_to_sc[qp->remote_ah_attr.sl];
        vl = sc_to_vlt(dd, sc);

        mtu = verbs_mtu_enum_to_int(qp->ibqp.device, pmtu);
        if (vl < PER_VL_SEND_CONTEXTS)
                mtu = min_t(u32, mtu, dd->vld[vl].mtu);
        return mtu;
}

int get_pmtu_from_attr(struct rvt_dev_info *rdi, struct rvt_qp *qp,
                       struct ib_qp_attr *attr)
{
        int mtu, pidx = qp->port_num - 1;
        struct hfi1_ibdev *verbs_dev = container_of(rdi,
                                                    struct hfi1_ibdev,
                                                    rdi);
        struct hfi1_devdata *dd = container_of(verbs_dev,
                                               struct hfi1_devdata,
                                               verbs_dev);
        mtu = verbs_mtu_enum_to_int(qp->ibqp.device, attr->path_mtu);
        if (mtu == -1)
                return -1; /* values less than 0 are error */

        if (mtu > dd->pport[pidx].ibmtu)
                return mtu_to_enum(dd->pport[pidx].ibmtu, IB_MTU_2048);
        else
                return attr->path_mtu;
}

void notify_error_qp(struct rvt_qp *qp)
{
        struct hfi1_ibdev *dev = to_idev(qp->ibqp.device);
        struct hfi1_qp_priv *priv = qp->priv;

        write_seqlock(&dev->iowait_lock);
        if (!list_empty(&priv->s_iowait.list) && !(qp->s_flags & RVT_S_BUSY)) {
                qp->s_flags &= ~RVT_S_ANY_WAIT_IO;
                list_del_init(&priv->s_iowait.list);
                rvt_put_qp(qp);
        }
        write_sequnlock(&dev->iowait_lock);

        if (!(qp->s_flags & RVT_S_BUSY)) {
                qp->s_hdrwords = 0;
                if (qp->s_rdma_mr) {
                        rvt_put_mr(qp->s_rdma_mr);
                        qp->s_rdma_mr = NULL;
                }
                flush_tx_list(qp);
        }
}

/**
 * hfi1_error_port_qps - put a port's RC/UC qps into error state
 * @ibp: the ibport.
 * @sl: the service level.
 *
 * This function places all RC/UC qps with a given service level into error
 * state. It is generally called to force upper lay apps to abandon stale qps
 * after an sl->sc mapping change.
 */
void hfi1_error_port_qps(struct hfi1_ibport *ibp, u8 sl)
{
        struct rvt_qp *qp = NULL;
        struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
        struct hfi1_ibdev *dev = &ppd->dd->verbs_dev;
        int n;
        int lastwqe;
        struct ib_event ev;

        rcu_read_lock();

        /* Deal only with RC/UC qps that use the given SL. */
        for (n = 0; n < dev->rdi.qp_dev->qp_table_size; n++) {
                for (qp = rcu_dereference(dev->rdi.qp_dev->qp_table[n]); qp;
                        qp = rcu_dereference(qp->next)) {
                        if (qp->port_num == ppd->port &&
                            (qp->ibqp.qp_type == IB_QPT_UC ||
                             qp->ibqp.qp_type == IB_QPT_RC) &&
                            qp->remote_ah_attr.sl == sl &&
                            (ib_rvt_state_ops[qp->state] &
                             RVT_POST_SEND_OK)) {
                                spin_lock_irq(&qp->r_lock);
                                spin_lock(&qp->s_hlock);
                                spin_lock(&qp->s_lock);
                                lastwqe = rvt_error_qp(qp,
                                                       IB_WC_WR_FLUSH_ERR);
                                spin_unlock(&qp->s_lock);
                                spin_unlock(&qp->s_hlock);
                                spin_unlock_irq(&qp->r_lock);
                                if (lastwqe) {
                                        ev.device = qp->ibqp.device;
                                        ev.element.qp = &qp->ibqp;
                                        ev.event =
                                                IB_EVENT_QP_LAST_WQE_REACHED;
                                        qp->ibqp.event_handler(&ev,
                                                qp->ibqp.qp_context);
                                }
                        }
                }
        }

        rcu_read_unlock();
}