igb: don't read eicr when responding to legacy interrupts

[linux-2.6] / drivers / infiniband / hw / ipath / ipath_verbs.c

/*
 * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, 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 <rdma/ib_mad.h>
#include <rdma/ib_user_verbs.h>
#include <linux/io.h>
#include <linux/utsname.h>
#include <linux/rculist.h>

#include "ipath_kernel.h"
#include "ipath_verbs.h"
#include "ipath_common.h"

static unsigned int ib_ipath_qp_table_size = 251;
module_param_named(qp_table_size, ib_ipath_qp_table_size, uint, S_IRUGO);
MODULE_PARM_DESC(qp_table_size, "QP table size");

unsigned int ib_ipath_lkey_table_size = 12;
module_param_named(lkey_table_size, ib_ipath_lkey_table_size, uint,
                   S_IRUGO);
MODULE_PARM_DESC(lkey_table_size,
                 "LKEY table size in bits (2^n, 1 <= n <= 23)");

static unsigned int ib_ipath_max_pds = 0xFFFF;
module_param_named(max_pds, ib_ipath_max_pds, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_pds,
                 "Maximum number of protection domains to support");

static unsigned int ib_ipath_max_ahs = 0xFFFF;
module_param_named(max_ahs, ib_ipath_max_ahs, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_ahs, "Maximum number of address handles to support");

unsigned int ib_ipath_max_cqes = 0x2FFFF;
module_param_named(max_cqes, ib_ipath_max_cqes, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_cqes,
                 "Maximum number of completion queue entries to support");

unsigned int ib_ipath_max_cqs = 0x1FFFF;
module_param_named(max_cqs, ib_ipath_max_cqs, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_cqs, "Maximum number of completion queues to support");

unsigned int ib_ipath_max_qp_wrs = 0x3FFF;
module_param_named(max_qp_wrs, ib_ipath_max_qp_wrs, uint,
                   S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_qp_wrs, "Maximum number of QP WRs to support");

unsigned int ib_ipath_max_qps = 16384;
module_param_named(max_qps, ib_ipath_max_qps, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_qps, "Maximum number of QPs to support");

unsigned int ib_ipath_max_sges = 0x60;
module_param_named(max_sges, ib_ipath_max_sges, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_sges, "Maximum number of SGEs to support");

unsigned int ib_ipath_max_mcast_grps = 16384;
module_param_named(max_mcast_grps, ib_ipath_max_mcast_grps, uint,
                   S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_mcast_grps,
                 "Maximum number of multicast groups to support");

unsigned int ib_ipath_max_mcast_qp_attached = 16;
module_param_named(max_mcast_qp_attached, ib_ipath_max_mcast_qp_attached,
                   uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_mcast_qp_attached,
                 "Maximum number of attached QPs to support");

unsigned int ib_ipath_max_srqs = 1024;
module_param_named(max_srqs, ib_ipath_max_srqs, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_srqs, "Maximum number of SRQs to support");

unsigned int ib_ipath_max_srq_sges = 128;
module_param_named(max_srq_sges, ib_ipath_max_srq_sges,
                   uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_srq_sges, "Maximum number of SRQ SGEs to support");

unsigned int ib_ipath_max_srq_wrs = 0x1FFFF;
module_param_named(max_srq_wrs, ib_ipath_max_srq_wrs,
                   uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(max_srq_wrs, "Maximum number of SRQ WRs support");

static unsigned int ib_ipath_disable_sma;
module_param_named(disable_sma, ib_ipath_disable_sma, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(disable_sma, "Disable the SMA");

/*
 * Note that it is OK to post send work requests in the SQE and ERR
 * states; ipath_do_send() will process them and generate error
 * completions as per IB 1.2 C10-96.
 */
const int ib_ipath_state_ops[IB_QPS_ERR + 1] = {
        [IB_QPS_RESET] = 0,
        [IB_QPS_INIT] = IPATH_POST_RECV_OK,
        [IB_QPS_RTR] = IPATH_POST_RECV_OK | IPATH_PROCESS_RECV_OK,
        [IB_QPS_RTS] = IPATH_POST_RECV_OK | IPATH_PROCESS_RECV_OK |
            IPATH_POST_SEND_OK | IPATH_PROCESS_SEND_OK |
            IPATH_PROCESS_NEXT_SEND_OK,
        [IB_QPS_SQD] = IPATH_POST_RECV_OK | IPATH_PROCESS_RECV_OK |
            IPATH_POST_SEND_OK | IPATH_PROCESS_SEND_OK,
        [IB_QPS_SQE] = IPATH_POST_RECV_OK | IPATH_PROCESS_RECV_OK |
            IPATH_POST_SEND_OK | IPATH_FLUSH_SEND,
        [IB_QPS_ERR] = IPATH_POST_RECV_OK | IPATH_FLUSH_RECV |
            IPATH_POST_SEND_OK | IPATH_FLUSH_SEND,
};

struct ipath_ucontext {
        struct ib_ucontext ibucontext;
};

static inline struct ipath_ucontext *to_iucontext(struct ib_ucontext
                                                  *ibucontext)
{
        return container_of(ibucontext, struct ipath_ucontext, ibucontext);
}

/*
 * Translate ib_wr_opcode into ib_wc_opcode.
 */
const enum ib_wc_opcode ib_ipath_wc_opcode[] = {
        [IB_WR_RDMA_WRITE] = IB_WC_RDMA_WRITE,
        [IB_WR_RDMA_WRITE_WITH_IMM] = IB_WC_RDMA_WRITE,
        [IB_WR_SEND] = IB_WC_SEND,
        [IB_WR_SEND_WITH_IMM] = IB_WC_SEND,
        [IB_WR_RDMA_READ] = IB_WC_RDMA_READ,
        [IB_WR_ATOMIC_CMP_AND_SWP] = IB_WC_COMP_SWAP,
        [IB_WR_ATOMIC_FETCH_AND_ADD] = IB_WC_FETCH_ADD
};

/*
 * System image GUID.
 */
static __be64 sys_image_guid;

/**
 * ipath_copy_sge - copy data to SGE memory
 * @ss: the SGE state
 * @data: the data to copy
 * @length: the length of the data
 */
void ipath_copy_sge(struct ipath_sge_state *ss, void *data, u32 length)
{
        struct ipath_sge *sge = &ss->sge;

        while (length) {
                u32 len = sge->length;

                if (len > length)
                        len = length;
                if (len > sge->sge_length)
                        len = sge->sge_length;
                BUG_ON(len == 0);
                memcpy(sge->vaddr, data, len);
                sge->vaddr += len;
                sge->length -= len;
                sge->sge_length -= len;
                if (sge->sge_length == 0) {
                        if (--ss->num_sge)
                                *sge = *ss->sg_list++;
                } else if (sge->length == 0 && sge->mr != NULL) {
                        if (++sge->n >= IPATH_SEGSZ) {
                                if (++sge->m >= sge->mr->mapsz)
                                        break;
                                sge->n = 0;
                        }
                        sge->vaddr =
                                sge->mr->map[sge->m]->segs[sge->n].vaddr;
                        sge->length =
                                sge->mr->map[sge->m]->segs[sge->n].length;
                }
                data += len;
                length -= len;
        }
}

/**
 * ipath_skip_sge - skip over SGE memory - XXX almost dup of prev func
 * @ss: the SGE state
 * @length: the number of bytes to skip
 */
void ipath_skip_sge(struct ipath_sge_state *ss, u32 length)
{
        struct ipath_sge *sge = &ss->sge;

        while (length) {
                u32 len = sge->length;

                if (len > length)
                        len = length;
                if (len > sge->sge_length)
                        len = sge->sge_length;
                BUG_ON(len == 0);
                sge->vaddr += len;
                sge->length -= len;
                sge->sge_length -= len;
                if (sge->sge_length == 0) {
                        if (--ss->num_sge)
                                *sge = *ss->sg_list++;
                } else if (sge->length == 0 && sge->mr != NULL) {
                        if (++sge->n >= IPATH_SEGSZ) {
                                if (++sge->m >= sge->mr->mapsz)
                                        break;
                                sge->n = 0;
                        }
                        sge->vaddr =
                                sge->mr->map[sge->m]->segs[sge->n].vaddr;
                        sge->length =
                                sge->mr->map[sge->m]->segs[sge->n].length;
                }
                length -= len;
        }
}

/*
 * Count the number of DMA descriptors needed to send length bytes of data.
 * Don't modify the ipath_sge_state to get the count.
 * Return zero if any of the segments is not aligned.
 */
static u32 ipath_count_sge(struct ipath_sge_state *ss, u32 length)
{
        struct ipath_sge *sg_list = ss->sg_list;
        struct ipath_sge sge = ss->sge;
        u8 num_sge = ss->num_sge;
        u32 ndesc = 1;  /* count the header */

        while (length) {
                u32 len = sge.length;

                if (len > length)
                        len = length;
                if (len > sge.sge_length)
                        len = sge.sge_length;
                BUG_ON(len == 0);
                if (((long) sge.vaddr & (sizeof(u32) - 1)) ||
                    (len != length && (len & (sizeof(u32) - 1)))) {
                        ndesc = 0;
                        break;
                }
                ndesc++;
                sge.vaddr += len;
                sge.length -= len;
                sge.sge_length -= len;
                if (sge.sge_length == 0) {
                        if (--num_sge)
                                sge = *sg_list++;
                } else if (sge.length == 0 && sge.mr != NULL) {
                        if (++sge.n >= IPATH_SEGSZ) {
                                if (++sge.m >= sge.mr->mapsz)
                                        break;
                                sge.n = 0;
                        }
                        sge.vaddr =
                                sge.mr->map[sge.m]->segs[sge.n].vaddr;
                        sge.length =
                                sge.mr->map[sge.m]->segs[sge.n].length;
                }
                length -= len;
        }
        return ndesc;
}

/*
 * Copy from the SGEs to the data buffer.
 */
static void ipath_copy_from_sge(void *data, struct ipath_sge_state *ss,
                                u32 length)
{
        struct ipath_sge *sge = &ss->sge;

        while (length) {
                u32 len = sge->length;

                if (len > length)
                        len = length;
                if (len > sge->sge_length)
                        len = sge->sge_length;
                BUG_ON(len == 0);
                memcpy(data, sge->vaddr, len);
                sge->vaddr += len;
                sge->length -= len;
                sge->sge_length -= len;
                if (sge->sge_length == 0) {
                        if (--ss->num_sge)
                                *sge = *ss->sg_list++;
                } else if (sge->length == 0 && sge->mr != NULL) {
                        if (++sge->n >= IPATH_SEGSZ) {
                                if (++sge->m >= sge->mr->mapsz)
                                        break;
                                sge->n = 0;
                        }
                        sge->vaddr =
                                sge->mr->map[sge->m]->segs[sge->n].vaddr;
                        sge->length =
                                sge->mr->map[sge->m]->segs[sge->n].length;
                }
                data += len;
                length -= len;
        }
}

/**
 * ipath_post_one_send - post one RC, UC, or UD send work request
 * @qp: the QP to post on
 * @wr: the work request to send
 */
static int ipath_post_one_send(struct ipath_qp *qp, struct ib_send_wr *wr)
{
        struct ipath_swqe *wqe;
        u32 next;
        int i;
        int j;
        int acc;
        int ret;
        unsigned long flags;
        struct ipath_devdata *dd = to_idev(qp->ibqp.device)->dd;

        spin_lock_irqsave(&qp->s_lock, flags);

        if (qp->ibqp.qp_type != IB_QPT_SMI &&
            !(dd->ipath_flags & IPATH_LINKACTIVE)) {
                ret = -ENETDOWN;
                goto bail;
        }

        /* Check that state is OK to post send. */
        if (unlikely(!(ib_ipath_state_ops[qp->state] & IPATH_POST_SEND_OK)))
                goto bail_inval;

        /* IB spec says that num_sge == 0 is OK. */
        if (wr->num_sge > qp->s_max_sge)
                goto bail_inval;

        /*
         * Don't allow RDMA reads or atomic operations on UC or
         * undefined operations.
         * Make sure buffer is large enough to hold the result for atomics.
         */
        if (qp->ibqp.qp_type == IB_QPT_UC) {
                if ((unsigned) wr->opcode >= IB_WR_RDMA_READ)
                        goto bail_inval;
        } else if (qp->ibqp.qp_type == IB_QPT_UD) {
                /* Check UD opcode */
                if (wr->opcode != IB_WR_SEND &&
                    wr->opcode != IB_WR_SEND_WITH_IMM)
                        goto bail_inval;
                /* Check UD destination address PD */
                if (qp->ibqp.pd != wr->wr.ud.ah->pd)
                        goto bail_inval;
        } else if ((unsigned) wr->opcode > IB_WR_ATOMIC_FETCH_AND_ADD)
                goto bail_inval;
        else if (wr->opcode >= IB_WR_ATOMIC_CMP_AND_SWP &&
                   (wr->num_sge == 0 ||
                    wr->sg_list[0].length < sizeof(u64) ||
                    wr->sg_list[0].addr & (sizeof(u64) - 1)))
                goto bail_inval;
        else if (wr->opcode >= IB_WR_RDMA_READ && !qp->s_max_rd_atomic)
                goto bail_inval;

        next = qp->s_head + 1;
        if (next >= qp->s_size)
                next = 0;
        if (next == qp->s_last) {
                ret = -ENOMEM;
                goto bail;
        }

        wqe = get_swqe_ptr(qp, qp->s_head);
        wqe->wr = *wr;
        wqe->length = 0;
        if (wr->num_sge) {
                acc = wr->opcode >= IB_WR_RDMA_READ ?
                        IB_ACCESS_LOCAL_WRITE : 0;
                for (i = 0, j = 0; i < wr->num_sge; i++) {
                        u32 length = wr->sg_list[i].length;
                        int ok;

                        if (length == 0)
                                continue;
                        ok = ipath_lkey_ok(qp, &wqe->sg_list[j],
                                           &wr->sg_list[i], acc);
                        if (!ok)
                                goto bail_inval;
                        wqe->length += length;
                        j++;
                }
                wqe->wr.num_sge = j;
        }
        if (qp->ibqp.qp_type == IB_QPT_UC ||
            qp->ibqp.qp_type == IB_QPT_RC) {
                if (wqe->length > 0x80000000U)
                        goto bail_inval;
        } else if (wqe->length > to_idev(qp->ibqp.device)->dd->ipath_ibmtu)
                goto bail_inval;
        wqe->ssn = qp->s_ssn++;
        qp->s_head = next;

        ret = 0;
        goto bail;

bail_inval:
        ret = -EINVAL;
bail:
        spin_unlock_irqrestore(&qp->s_lock, flags);
        return ret;
}

/**
 * ipath_post_send - post a send on a QP
 * @ibqp: the QP to post the send on
 * @wr: the list of work requests to post
 * @bad_wr: the first bad WR is put here
 *
 * This may be called from interrupt context.
 */
static int ipath_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
                           struct ib_send_wr **bad_wr)
{
        struct ipath_qp *qp = to_iqp(ibqp);
        int err = 0;

        for (; wr; wr = wr->next) {
                err = ipath_post_one_send(qp, wr);
                if (err) {
                        *bad_wr = wr;
                        goto bail;
                }
        }

        /* Try to do the send work in the caller's context. */
        ipath_do_send((unsigned long) qp);

bail:
        return err;
}

/**
 * ipath_post_receive - post a receive on a QP
 * @ibqp: the QP to post the receive on
 * @wr: the WR to post
 * @bad_wr: the first bad WR is put here
 *
 * This may be called from interrupt context.
 */
static int ipath_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
                              struct ib_recv_wr **bad_wr)
{
        struct ipath_qp *qp = to_iqp(ibqp);
        struct ipath_rwq *wq = qp->r_rq.wq;
        unsigned long flags;
        int ret;

        /* Check that state is OK to post receive. */
        if (!(ib_ipath_state_ops[qp->state] & IPATH_POST_RECV_OK) || !wq) {
                *bad_wr = wr;
                ret = -EINVAL;
                goto bail;
        }

        for (; wr; wr = wr->next) {
                struct ipath_rwqe *wqe;
                u32 next;
                int i;

                if ((unsigned) wr->num_sge > qp->r_rq.max_sge) {
                        *bad_wr = wr;
                        ret = -EINVAL;
                        goto bail;
                }

                spin_lock_irqsave(&qp->r_rq.lock, flags);
                next = wq->head + 1;
                if (next >= qp->r_rq.size)
                        next = 0;
                if (next == wq->tail) {
                        spin_unlock_irqrestore(&qp->r_rq.lock, flags);
                        *bad_wr = wr;
                        ret = -ENOMEM;
                        goto bail;
                }

                wqe = get_rwqe_ptr(&qp->r_rq, wq->head);
                wqe->wr_id = wr->wr_id;
                wqe->num_sge = wr->num_sge;
                for (i = 0; i < wr->num_sge; i++)
                        wqe->sg_list[i] = wr->sg_list[i];
                /* Make sure queue entry is written before the head index. */
                smp_wmb();
                wq->head = next;
                spin_unlock_irqrestore(&qp->r_rq.lock, flags);
        }
        ret = 0;

bail:
        return ret;
}

/**
 * ipath_qp_rcv - processing an incoming packet on a QP
 * @dev: the device the packet came on
 * @hdr: the packet header
 * @has_grh: true if the packet has a GRH
 * @data: the packet data
 * @tlen: the packet length
 * @qp: the QP the packet came on
 *
 * This is called from ipath_ib_rcv() to process an incoming packet
 * for the given QP.
 * Called at interrupt level.
 */
static void ipath_qp_rcv(struct ipath_ibdev *dev,
                         struct ipath_ib_header *hdr, int has_grh,
                         void *data, u32 tlen, struct ipath_qp *qp)
{
        /* Check for valid receive state. */
        if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_RECV_OK)) {
                dev->n_pkt_drops++;
                return;
        }

        switch (qp->ibqp.qp_type) {
        case IB_QPT_SMI:
        case IB_QPT_GSI:
                if (ib_ipath_disable_sma)
                        break;
                /* FALLTHROUGH */
        case IB_QPT_UD:
                ipath_ud_rcv(dev, hdr, has_grh, data, tlen, qp);
                break;

        case IB_QPT_RC:
                ipath_rc_rcv(dev, hdr, has_grh, data, tlen, qp);
                break;

        case IB_QPT_UC:
                ipath_uc_rcv(dev, hdr, has_grh, data, tlen, qp);
                break;

        default:
                break;
        }
}

/**
 * ipath_ib_rcv - process an incoming packet
 * @arg: the device pointer
 * @rhdr: the header of the packet
 * @data: the packet data
 * @tlen: the packet length
 *
 * This is called from ipath_kreceive() to process an incoming packet at
 * interrupt level. Tlen is the length of the header + data + CRC in bytes.
 */
void ipath_ib_rcv(struct ipath_ibdev *dev, void *rhdr, void *data,
                  u32 tlen)
{
        struct ipath_ib_header *hdr = rhdr;
        struct ipath_other_headers *ohdr;
        struct ipath_qp *qp;
        u32 qp_num;
        int lnh;
        u8 opcode;
        u16 lid;

        if (unlikely(dev == NULL))
                goto bail;

        if (unlikely(tlen < 24)) {      /* LRH+BTH+CRC */
                dev->rcv_errors++;
                goto bail;
        }

        /* Check for a valid destination LID (see ch. 7.11.1). */
        lid = be16_to_cpu(hdr->lrh[1]);
        if (lid < IPATH_MULTICAST_LID_BASE) {
                lid &= ~((1 << dev->dd->ipath_lmc) - 1);
                if (unlikely(lid != dev->dd->ipath_lid)) {
                        dev->rcv_errors++;
                        goto bail;
                }
        }

        /* Check for GRH */
        lnh = be16_to_cpu(hdr->lrh[0]) & 3;
        if (lnh == IPATH_LRH_BTH)
                ohdr = &hdr->u.oth;
        else if (lnh == IPATH_LRH_GRH)
                ohdr = &hdr->u.l.oth;
        else {
                dev->rcv_errors++;
                goto bail;
        }

        opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
        dev->opstats[opcode].n_bytes += tlen;
        dev->opstats[opcode].n_packets++;

        /* Get the destination QP number. */
        qp_num = be32_to_cpu(ohdr->bth[1]) & IPATH_QPN_MASK;
        if (qp_num == IPATH_MULTICAST_QPN) {
                struct ipath_mcast *mcast;
                struct ipath_mcast_qp *p;

                if (lnh != IPATH_LRH_GRH) {
                        dev->n_pkt_drops++;
                        goto bail;
                }
                mcast = ipath_mcast_find(&hdr->u.l.grh.dgid);
                if (mcast == NULL) {
                        dev->n_pkt_drops++;
                        goto bail;
                }
                dev->n_multicast_rcv++;
                list_for_each_entry_rcu(p, &mcast->qp_list, list)
                        ipath_qp_rcv(dev, hdr, 1, data, tlen, p->qp);
                /*
                 * Notify ipath_multicast_detach() if it is waiting for us
                 * to finish.
                 */
                if (atomic_dec_return(&mcast->refcount) <= 1)
                        wake_up(&mcast->wait);
        } else {
                qp = ipath_lookup_qpn(&dev->qp_table, qp_num);
                if (qp) {
                        dev->n_unicast_rcv++;
                        ipath_qp_rcv(dev, hdr, lnh == IPATH_LRH_GRH, data,
                                     tlen, qp);
                        /*
                         * Notify ipath_destroy_qp() if it is waiting
                         * for us to finish.
                         */
                        if (atomic_dec_and_test(&qp->refcount))
                                wake_up(&qp->wait);
                } else
                        dev->n_pkt_drops++;
        }

bail:;
}

/**
 * ipath_ib_timer - verbs timer
 * @arg: the device pointer
 *
 * This is called from ipath_do_rcv_timer() at interrupt level to check for
 * QPs which need retransmits and to collect performance numbers.
 */
static void ipath_ib_timer(struct ipath_ibdev *dev)
{
        struct ipath_qp *resend = NULL;
        struct ipath_qp *rnr = NULL;
        struct list_head *last;
        struct ipath_qp *qp;
        unsigned long flags;

        if (dev == NULL)
                return;

        spin_lock_irqsave(&dev->pending_lock, flags);
        /* Start filling the next pending queue. */
        if (++dev->pending_index >= ARRAY_SIZE(dev->pending))
                dev->pending_index = 0;
        /* Save any requests still in the new queue, they have timed out. */
        last = &dev->pending[dev->pending_index];
        while (!list_empty(last)) {
                qp = list_entry(last->next, struct ipath_qp, timerwait);
                list_del_init(&qp->timerwait);
                qp->timer_next = resend;
                resend = qp;
                atomic_inc(&qp->refcount);
        }
        last = &dev->rnrwait;
        if (!list_empty(last)) {
                qp = list_entry(last->next, struct ipath_qp, timerwait);
                if (--qp->s_rnr_timeout == 0) {
                        do {
                                list_del_init(&qp->timerwait);
                                qp->timer_next = rnr;
                                rnr = qp;
                                atomic_inc(&qp->refcount);
                                if (list_empty(last))
                                        break;
                                qp = list_entry(last->next, struct ipath_qp,
                                                timerwait);
                        } while (qp->s_rnr_timeout == 0);
                }
        }
        /*
         * We should only be in the started state if pma_sample_start != 0
         */
        if (dev->pma_sample_status == IB_PMA_SAMPLE_STATUS_STARTED &&
            --dev->pma_sample_start == 0) {
                dev->pma_sample_status = IB_PMA_SAMPLE_STATUS_RUNNING;
                ipath_snapshot_counters(dev->dd, &dev->ipath_sword,
                                        &dev->ipath_rword,
                                        &dev->ipath_spkts,
                                        &dev->ipath_rpkts,
                                        &dev->ipath_xmit_wait);
        }
        if (dev->pma_sample_status == IB_PMA_SAMPLE_STATUS_RUNNING) {
                if (dev->pma_sample_interval == 0) {
                        u64 ta, tb, tc, td, te;

                        dev->pma_sample_status = IB_PMA_SAMPLE_STATUS_DONE;
                        ipath_snapshot_counters(dev->dd, &ta, &tb,
                                                &tc, &td, &te);

                        dev->ipath_sword = ta - dev->ipath_sword;
                        dev->ipath_rword = tb - dev->ipath_rword;
                        dev->ipath_spkts = tc - dev->ipath_spkts;
                        dev->ipath_rpkts = td - dev->ipath_rpkts;
                        dev->ipath_xmit_wait = te - dev->ipath_xmit_wait;
                }
                else
                        dev->pma_sample_interval--;
        }
        spin_unlock_irqrestore(&dev->pending_lock, flags);

        /* XXX What if timer fires again while this is running? */
        while (resend != NULL) {
                qp = resend;
                resend = qp->timer_next;

                spin_lock_irqsave(&qp->s_lock, flags);
                if (qp->s_last != qp->s_tail &&
                    ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK) {
                        dev->n_timeouts++;
                        ipath_restart_rc(qp, qp->s_last_psn + 1);
                }
                spin_unlock_irqrestore(&qp->s_lock, flags);

                /* Notify ipath_destroy_qp() if it is waiting. */
                if (atomic_dec_and_test(&qp->refcount))
                        wake_up(&qp->wait);
        }
        while (rnr != NULL) {
                qp = rnr;
                rnr = qp->timer_next;

                spin_lock_irqsave(&qp->s_lock, flags);
                if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)
                        ipath_schedule_send(qp);
                spin_unlock_irqrestore(&qp->s_lock, flags);

                /* Notify ipath_destroy_qp() if it is waiting. */
                if (atomic_dec_and_test(&qp->refcount))
                        wake_up(&qp->wait);
        }
}

static void update_sge(struct ipath_sge_state *ss, u32 length)
{
        struct ipath_sge *sge = &ss->sge;

        sge->vaddr += length;
        sge->length -= length;
        sge->sge_length -= length;
        if (sge->sge_length == 0) {
                if (--ss->num_sge)
                        *sge = *ss->sg_list++;
        } else if (sge->length == 0 && sge->mr != NULL) {
                if (++sge->n >= IPATH_SEGSZ) {
                        if (++sge->m >= sge->mr->mapsz)
                                return;
                        sge->n = 0;
                }
                sge->vaddr = sge->mr->map[sge->m]->segs[sge->n].vaddr;
                sge->length = sge->mr->map[sge->m]->segs[sge->n].length;
        }
}

#ifdef __LITTLE_ENDIAN
static inline u32 get_upper_bits(u32 data, u32 shift)
{
        return data >> shift;
}

static inline u32 set_upper_bits(u32 data, u32 shift)
{
        return data << shift;
}

static inline u32 clear_upper_bytes(u32 data, u32 n, u32 off)
{
        data <<= ((sizeof(u32) - n) * BITS_PER_BYTE);
        data >>= ((sizeof(u32) - n - off) * BITS_PER_BYTE);
        return data;
}
#else
static inline u32 get_upper_bits(u32 data, u32 shift)
{
        return data << shift;
}

static inline u32 set_upper_bits(u32 data, u32 shift)
{
        return data >> shift;
}

static inline u32 clear_upper_bytes(u32 data, u32 n, u32 off)
{
        data >>= ((sizeof(u32) - n) * BITS_PER_BYTE);
        data <<= ((sizeof(u32) - n - off) * BITS_PER_BYTE);
        return data;
}
#endif

static void copy_io(u32 __iomem *piobuf, struct ipath_sge_state *ss,
                    u32 length, unsigned flush_wc)
{
        u32 extra = 0;
        u32 data = 0;
        u32 last;

        while (1) {
                u32 len = ss->sge.length;
                u32 off;

                if (len > length)
                        len = length;
                if (len > ss->sge.sge_length)
                        len = ss->sge.sge_length;
                BUG_ON(len == 0);
                /* If the source address is not aligned, try to align it. */
                off = (unsigned long)ss->sge.vaddr & (sizeof(u32) - 1);
                if (off) {
                        u32 *addr = (u32 *)((unsigned long)ss->sge.vaddr &
                                            ~(sizeof(u32) - 1));
                        u32 v = get_upper_bits(*addr, off * BITS_PER_BYTE);
                        u32 y;

                        y = sizeof(u32) - off;
                        if (len > y)
                                len = y;
                        if (len + extra >= sizeof(u32)) {
                                data |= set_upper_bits(v, extra *
                                                       BITS_PER_BYTE);
                                len = sizeof(u32) - extra;
                                if (len == length) {
                                        last = data;
                                        break;
                                }
                                __raw_writel(data, piobuf);
                                piobuf++;
                                extra = 0;
                                data = 0;
                        } else {
                                /* Clear unused upper bytes */
                                data |= clear_upper_bytes(v, len, extra);
                                if (len == length) {
                                        last = data;
                                        break;
                                }
                                extra += len;
                        }
                } else if (extra) {
                        /* Source address is aligned. */
                        u32 *addr = (u32 *) ss->sge.vaddr;
                        int shift = extra * BITS_PER_BYTE;
                        int ushift = 32 - shift;
                        u32 l = len;

                        while (l >= sizeof(u32)) {
                                u32 v = *addr;

                                data |= set_upper_bits(v, shift);
                                __raw_writel(data, piobuf);
                                data = get_upper_bits(v, ushift);
                                piobuf++;
                                addr++;
                                l -= sizeof(u32);
                        }
                        /*
                         * We still have 'extra' number of bytes leftover.
                         */
                        if (l) {
                                u32 v = *addr;

                                if (l + extra >= sizeof(u32)) {
                                        data |= set_upper_bits(v, shift);
                                        len -= l + extra - sizeof(u32);
                                        if (len == length) {
                                                last = data;
                                                break;
                                        }
                                        __raw_writel(data, piobuf);
                                        piobuf++;
                                        extra = 0;
                                        data = 0;
                                } else {
                                        /* Clear unused upper bytes */
                                        data |= clear_upper_bytes(v, l,
                                                                  extra);
                                        if (len == length) {
                                                last = data;
                                                break;
                                        }
                                        extra += l;
                                }
                        } else if (len == length) {
                                last = data;
                                break;
                        }
                } else if (len == length) {
                        u32 w;

                        /*
                         * Need to round up for the last dword in the
                         * packet.
                         */
                        w = (len + 3) >> 2;
                        __iowrite32_copy(piobuf, ss->sge.vaddr, w - 1);
                        piobuf += w - 1;
                        last = ((u32 *) ss->sge.vaddr)[w - 1];
                        break;
                } else {
                        u32 w = len >> 2;

                        __iowrite32_copy(piobuf, ss->sge.vaddr, w);
                        piobuf += w;

                        extra = len & (sizeof(u32) - 1);
                        if (extra) {
                                u32 v = ((u32 *) ss->sge.vaddr)[w];

                                /* Clear unused upper bytes */
                                data = clear_upper_bytes(v, extra, 0);
                        }
                }
                update_sge(ss, len);
                length -= len;
        }
        /* Update address before sending packet. */
        update_sge(ss, length);
        if (flush_wc) {
                /* must flush early everything before trigger word */
                ipath_flush_wc();
                __raw_writel(last, piobuf);
                /* be sure trigger word is written */
                ipath_flush_wc();
        } else
                __raw_writel(last, piobuf);
}

/*
 * Convert IB rate to delay multiplier.
 */
unsigned ipath_ib_rate_to_mult(enum ib_rate rate)
{
        switch (rate) {
        case IB_RATE_2_5_GBPS: return 8;
        case IB_RATE_5_GBPS:   return 4;
        case IB_RATE_10_GBPS:  return 2;
        case IB_RATE_20_GBPS:  return 1;
        default:               return 0;
        }
}

/*
 * Convert delay multiplier to IB rate
 */
static enum ib_rate ipath_mult_to_ib_rate(unsigned mult)
{
        switch (mult) {
        case 8:  return IB_RATE_2_5_GBPS;
        case 4:  return IB_RATE_5_GBPS;
        case 2:  return IB_RATE_10_GBPS;
        case 1:  return IB_RATE_20_GBPS;
        default: return IB_RATE_PORT_CURRENT;
        }
}

static inline struct ipath_verbs_txreq *get_txreq(struct ipath_ibdev *dev)
{
        struct ipath_verbs_txreq *tx = NULL;
        unsigned long flags;

        spin_lock_irqsave(&dev->pending_lock, flags);
        if (!list_empty(&dev->txreq_free)) {
                struct list_head *l = dev->txreq_free.next;

                list_del(l);
                tx = list_entry(l, struct ipath_verbs_txreq, txreq.list);
        }
        spin_unlock_irqrestore(&dev->pending_lock, flags);
        return tx;
}

static inline void put_txreq(struct ipath_ibdev *dev,
                             struct ipath_verbs_txreq *tx)
{
        unsigned long flags;

        spin_lock_irqsave(&dev->pending_lock, flags);
        list_add(&tx->txreq.list, &dev->txreq_free);
        spin_unlock_irqrestore(&dev->pending_lock, flags);
}

static void sdma_complete(void *cookie, int status)
{
        struct ipath_verbs_txreq *tx = cookie;
        struct ipath_qp *qp = tx->qp;
        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
        unsigned long flags;
        enum ib_wc_status ibs = status == IPATH_SDMA_TXREQ_S_OK ?
                IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR;

        if (atomic_dec_and_test(&qp->s_dma_busy)) {
                spin_lock_irqsave(&qp->s_lock, flags);
                if (tx->wqe)
                        ipath_send_complete(qp, tx->wqe, ibs);
                if ((ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND &&
                     qp->s_last != qp->s_head) ||
                    (qp->s_flags & IPATH_S_WAIT_DMA))
                        ipath_schedule_send(qp);
                spin_unlock_irqrestore(&qp->s_lock, flags);
                wake_up(&qp->wait_dma);
        } else if (tx->wqe) {
                spin_lock_irqsave(&qp->s_lock, flags);
                ipath_send_complete(qp, tx->wqe, ibs);
                spin_unlock_irqrestore(&qp->s_lock, flags);
        }

        if (tx->txreq.flags & IPATH_SDMA_TXREQ_F_FREEBUF)
                kfree(tx->txreq.map_addr);
        put_txreq(dev, tx);

        if (atomic_dec_and_test(&qp->refcount))
                wake_up(&qp->wait);
}

static void decrement_dma_busy(struct ipath_qp *qp)
{
        unsigned long flags;

        if (atomic_dec_and_test(&qp->s_dma_busy)) {
                spin_lock_irqsave(&qp->s_lock, flags);
                if ((ib_ipath_state_ops[qp->state] & IPATH_FLUSH_SEND &&
                     qp->s_last != qp->s_head) ||
                    (qp->s_flags & IPATH_S_WAIT_DMA))
                        ipath_schedule_send(qp);
                spin_unlock_irqrestore(&qp->s_lock, flags);
                wake_up(&qp->wait_dma);
        }
}

/*
 * Compute the number of clock cycles of delay before sending the next packet.
 * The multipliers reflect the number of clocks for the fastest rate so
 * one tick at 4xDDR is 8 ticks at 1xSDR.
 * If the destination port will take longer to receive a packet than
 * the outgoing link can send it, we need to delay sending the next packet
 * by the difference in time it takes the receiver to receive and the sender
 * to send this packet.
 * Note that this delay is always correct for UC and RC but not always
 * optimal for UD. For UD, the destination HCA can be different for each
 * packet, in which case, we could send packets to a different destination
 * while "waiting" for the delay. The overhead for doing this without
 * HW support is more than just paying the cost of delaying some packets
 * unnecessarily.
 */
static inline unsigned ipath_pkt_delay(u32 plen, u8 snd_mult, u8 rcv_mult)
{
        return (rcv_mult > snd_mult) ?
                (plen * (rcv_mult - snd_mult) + 1) >> 1 : 0;
}

static int ipath_verbs_send_dma(struct ipath_qp *qp,
                                struct ipath_ib_header *hdr, u32 hdrwords,
                                struct ipath_sge_state *ss, u32 len,
                                u32 plen, u32 dwords)
{
        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
        struct ipath_devdata *dd = dev->dd;
        struct ipath_verbs_txreq *tx;
        u32 *piobuf;
        u32 control;
        u32 ndesc;
        int ret;

        tx = qp->s_tx;
        if (tx) {
                qp->s_tx = NULL;
                /* resend previously constructed packet */
                atomic_inc(&qp->s_dma_busy);
                ret = ipath_sdma_verbs_send(dd, tx->ss, tx->len, tx);
                if (ret) {
                        qp->s_tx = tx;
                        decrement_dma_busy(qp);
                }
                goto bail;
        }

        tx = get_txreq(dev);
        if (!tx) {
                ret = -EBUSY;
                goto bail;
        }

        /*
         * Get the saved delay count we computed for the previous packet
         * and save the delay count for this packet to be used next time
         * we get here.
         */
        control = qp->s_pkt_delay;
        qp->s_pkt_delay = ipath_pkt_delay(plen, dd->delay_mult, qp->s_dmult);

        tx->qp = qp;
        atomic_inc(&qp->refcount);
        tx->wqe = qp->s_wqe;
        tx->txreq.callback = sdma_complete;
        tx->txreq.callback_cookie = tx;
        tx->txreq.flags = IPATH_SDMA_TXREQ_F_HEADTOHOST |
                IPATH_SDMA_TXREQ_F_INTREQ | IPATH_SDMA_TXREQ_F_FREEDESC;
        if (plen + 1 >= IPATH_SMALLBUF_DWORDS)
                tx->txreq.flags |= IPATH_SDMA_TXREQ_F_USELARGEBUF;

        /* VL15 packets bypass credit check */
        if ((be16_to_cpu(hdr->lrh[0]) >> 12) == 15) {
                control |= 1ULL << 31;
                tx->txreq.flags |= IPATH_SDMA_TXREQ_F_VL15;
        }

        if (len) {
                /*
                 * Don't try to DMA if it takes more descriptors than
                 * the queue holds.
                 */
                ndesc = ipath_count_sge(ss, len);
                if (ndesc >= dd->ipath_sdma_descq_cnt)
                        ndesc = 0;
        } else
                ndesc = 1;
        if (ndesc) {
                tx->hdr.pbc[0] = cpu_to_le32(plen);
                tx->hdr.pbc[1] = cpu_to_le32(control);
                memcpy(&tx->hdr.hdr, hdr, hdrwords << 2);
                tx->txreq.sg_count = ndesc;
                tx->map_len = (hdrwords + 2) << 2;
                tx->txreq.map_addr = &tx->hdr;
                atomic_inc(&qp->s_dma_busy);
                ret = ipath_sdma_verbs_send(dd, ss, dwords, tx);
                if (ret) {
                        /* save ss and length in dwords */
                        tx->ss = ss;
                        tx->len = dwords;
                        qp->s_tx = tx;
                        decrement_dma_busy(qp);
                }
                goto bail;
        }

        /* Allocate a buffer and copy the header and payload to it. */
        tx->map_len = (plen + 1) << 2;
        piobuf = kmalloc(tx->map_len, GFP_ATOMIC);
        if (unlikely(piobuf == NULL)) {
                ret = -EBUSY;
                goto err_tx;
        }
        tx->txreq.map_addr = piobuf;
        tx->txreq.flags |= IPATH_SDMA_TXREQ_F_FREEBUF;
        tx->txreq.sg_count = 1;

        *piobuf++ = (__force u32) cpu_to_le32(plen);
        *piobuf++ = (__force u32) cpu_to_le32(control);
        memcpy(piobuf, hdr, hdrwords << 2);
        ipath_copy_from_sge(piobuf + hdrwords, ss, len);

        atomic_inc(&qp->s_dma_busy);
        ret = ipath_sdma_verbs_send(dd, NULL, 0, tx);
        /*
         * 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.
         */
        if (ret) {
                tx->ss = NULL;
                tx->len = 0;
                qp->s_tx = tx;
                decrement_dma_busy(qp);
        }
        dev->n_unaligned++;
        goto bail;

err_tx:
        if (atomic_dec_and_test(&qp->refcount))
                wake_up(&qp->wait);
        put_txreq(dev, tx);
bail:
        return ret;
}

static int ipath_verbs_send_pio(struct ipath_qp *qp,
                                struct ipath_ib_header *ibhdr, u32 hdrwords,
                                struct ipath_sge_state *ss, u32 len,
                                u32 plen, u32 dwords)
{
        struct ipath_devdata *dd = to_idev(qp->ibqp.device)->dd;
        u32 *hdr = (u32 *) ibhdr;
        u32 __iomem *piobuf;
        unsigned flush_wc;
        u32 control;
        int ret;
        unsigned long flags;

        piobuf = ipath_getpiobuf(dd, plen, NULL);
        if (unlikely(piobuf == NULL)) {
                ret = -EBUSY;
                goto bail;
        }

        /*
         * Get the saved delay count we computed for the previous packet
         * and save the delay count for this packet to be used next time
         * we get here.
         */
        control = qp->s_pkt_delay;
        qp->s_pkt_delay = ipath_pkt_delay(plen, dd->delay_mult, qp->s_dmult);

        /* VL15 packets bypass credit check */
        if ((be16_to_cpu(ibhdr->lrh[0]) >> 12) == 15)
                control |= 1ULL << 31;

        /*
         * Write the length to the control qword plus any needed flags.
         * We have to flush after the PBC for correctness on some cpus
         * or WC buffer can be written out of order.
         */
        writeq(((u64) control << 32) | plen, piobuf);
        piobuf += 2;

        flush_wc = dd->ipath_flags & IPATH_PIO_FLUSH_WC;
        if (len == 0) {
                /*
                 * If there is just the header portion, must flush before
                 * writing last word of header for correctness, and after
                 * the last header word (trigger word).
                 */
                if (flush_wc) {
                        ipath_flush_wc();
                        __iowrite32_copy(piobuf, hdr, hdrwords - 1);
                        ipath_flush_wc();
                        __raw_writel(hdr[hdrwords - 1], piobuf + hdrwords - 1);
                        ipath_flush_wc();
                } else
                        __iowrite32_copy(piobuf, hdr, hdrwords);
                goto done;
        }

        if (flush_wc)
                ipath_flush_wc();
        __iowrite32_copy(piobuf, hdr, hdrwords);
        piobuf += hdrwords;

        /* The common case is aligned and contained in one segment. */
        if (likely(ss->num_sge == 1 && len <= ss->sge.length &&
                   !((unsigned long)ss->sge.vaddr & (sizeof(u32) - 1)))) {
                u32 *addr = (u32 *) ss->sge.vaddr;

                /* Update address before sending packet. */
                update_sge(ss, len);
                if (flush_wc) {
                        __iowrite32_copy(piobuf, addr, dwords - 1);
                        /* must flush early everything before trigger word */
                        ipath_flush_wc();
                        __raw_writel(addr[dwords - 1], piobuf + dwords - 1);
                        /* be sure trigger word is written */
                        ipath_flush_wc();
                } else
                        __iowrite32_copy(piobuf, addr, dwords);
                goto done;
        }
        copy_io(piobuf, ss, len, flush_wc);
done:
        if (qp->s_wqe) {
                spin_lock_irqsave(&qp->s_lock, flags);
                ipath_send_complete(qp, qp->s_wqe, IB_WC_SUCCESS);
                spin_unlock_irqrestore(&qp->s_lock, flags);
        }
        ret = 0;
bail:
        return ret;
}

/**
 * ipath_verbs_send - send a packet
 * @qp: the QP to send on
 * @hdr: the packet header
 * @hdrwords: the number of 32-bit words in the header
 * @ss: the SGE to send
 * @len: the length of the packet in bytes
 */
int ipath_verbs_send(struct ipath_qp *qp, struct ipath_ib_header *hdr,
                     u32 hdrwords, struct ipath_sge_state *ss, u32 len)
{
        struct ipath_devdata *dd = to_idev(qp->ibqp.device)->dd;
        u32 plen;
        int ret;
        u32 dwords = (len + 3) >> 2;

        /*
         * Calculate the send buffer trigger address.
         * The +1 counts for the pbc control dword following the pbc length.
         */
        plen = hdrwords + dwords + 1;

        /*
         * VL15 packets (IB_QPT_SMI) will always use PIO, so we
         * can defer SDMA restart until link goes ACTIVE without
         * worrying about just how we got there.
         */
        if (qp->ibqp.qp_type == IB_QPT_SMI ||
            !(dd->ipath_flags & IPATH_HAS_SEND_DMA))
                ret = ipath_verbs_send_pio(qp, hdr, hdrwords, ss, len,
                                           plen, dwords);
        else
                ret = ipath_verbs_send_dma(qp, hdr, hdrwords, ss, len,
                                           plen, dwords);

        return ret;
}

int ipath_snapshot_counters(struct ipath_devdata *dd, u64 *swords,
                            u64 *rwords, u64 *spkts, u64 *rpkts,
                            u64 *xmit_wait)
{
        int ret;

        if (!(dd->ipath_flags & IPATH_INITTED)) {
                /* no hardware, freeze, etc. */
                ret = -EINVAL;
                goto bail;
        }
        *swords = ipath_snap_cntr(dd, dd->ipath_cregs->cr_wordsendcnt);
        *rwords = ipath_snap_cntr(dd, dd->ipath_cregs->cr_wordrcvcnt);
        *spkts = ipath_snap_cntr(dd, dd->ipath_cregs->cr_pktsendcnt);
        *rpkts = ipath_snap_cntr(dd, dd->ipath_cregs->cr_pktrcvcnt);
        *xmit_wait = ipath_snap_cntr(dd, dd->ipath_cregs->cr_sendstallcnt);

        ret = 0;

bail:
        return ret;
}

/**
 * ipath_get_counters - get various chip counters
 * @dd: the infinipath device
 * @cntrs: counters are placed here
 *
 * Return the counters needed by recv_pma_get_portcounters().
 */
int ipath_get_counters(struct ipath_devdata *dd,
                       struct ipath_verbs_counters *cntrs)
{
        struct ipath_cregs const *crp = dd->ipath_cregs;
        int ret;

        if (!(dd->ipath_flags & IPATH_INITTED)) {
                /* no hardware, freeze, etc. */
                ret = -EINVAL;
                goto bail;
        }
        cntrs->symbol_error_counter =
                ipath_snap_cntr(dd, crp->cr_ibsymbolerrcnt);
        cntrs->link_error_recovery_counter =
                ipath_snap_cntr(dd, crp->cr_iblinkerrrecovcnt);
        /*
         * The link downed counter counts when the other side downs the
         * connection.  We add in the number of times we downed the link
         * due to local link integrity errors to compensate.
         */
        cntrs->link_downed_counter =
                ipath_snap_cntr(dd, crp->cr_iblinkdowncnt);
        cntrs->port_rcv_errors =
                ipath_snap_cntr(dd, crp->cr_rxdroppktcnt) +
                ipath_snap_cntr(dd, crp->cr_rcvovflcnt) +
                ipath_snap_cntr(dd, crp->cr_portovflcnt) +
                ipath_snap_cntr(dd, crp->cr_err_rlencnt) +
                ipath_snap_cntr(dd, crp->cr_invalidrlencnt) +
                ipath_snap_cntr(dd, crp->cr_errlinkcnt) +
                ipath_snap_cntr(dd, crp->cr_erricrccnt) +
                ipath_snap_cntr(dd, crp->cr_errvcrccnt) +
                ipath_snap_cntr(dd, crp->cr_errlpcrccnt) +
                ipath_snap_cntr(dd, crp->cr_badformatcnt) +
                dd->ipath_rxfc_unsupvl_errs;
        if (crp->cr_rxotherlocalphyerrcnt)
                cntrs->port_rcv_errors +=
                        ipath_snap_cntr(dd, crp->cr_rxotherlocalphyerrcnt);
        if (crp->cr_rxvlerrcnt)
                cntrs->port_rcv_errors +=
                        ipath_snap_cntr(dd, crp->cr_rxvlerrcnt);
        cntrs->port_rcv_remphys_errors =
                ipath_snap_cntr(dd, crp->cr_rcvebpcnt);
        cntrs->port_xmit_discards = ipath_snap_cntr(dd, crp->cr_unsupvlcnt);
        cntrs->port_xmit_data = ipath_snap_cntr(dd, crp->cr_wordsendcnt);
        cntrs->port_rcv_data = ipath_snap_cntr(dd, crp->cr_wordrcvcnt);
        cntrs->port_xmit_packets = ipath_snap_cntr(dd, crp->cr_pktsendcnt);
        cntrs->port_rcv_packets = ipath_snap_cntr(dd, crp->cr_pktrcvcnt);
        cntrs->local_link_integrity_errors =
                crp->cr_locallinkintegrityerrcnt ?
                ipath_snap_cntr(dd, crp->cr_locallinkintegrityerrcnt) :
                ((dd->ipath_flags & IPATH_GPIO_ERRINTRS) ?
                 dd->ipath_lli_errs : dd->ipath_lli_errors);
        cntrs->excessive_buffer_overrun_errors =
                crp->cr_excessbufferovflcnt ?
                ipath_snap_cntr(dd, crp->cr_excessbufferovflcnt) :
                dd->ipath_overrun_thresh_errs;
        cntrs->vl15_dropped = crp->cr_vl15droppedpktcnt ?
                ipath_snap_cntr(dd, crp->cr_vl15droppedpktcnt) : 0;

        ret = 0;

bail:
        return ret;
}

/**
 * ipath_ib_piobufavail - callback when a PIO buffer is available
 * @arg: the device pointer
 *
 * This is called from ipath_intr() at interrupt level when a PIO buffer is
 * available after ipath_verbs_send() returned an error that no buffers were
 * available.  Return 1 if we consumed all the PIO buffers and we still have
 * QPs waiting for buffers (for now, just restart the send tasklet and
 * return zero).
 */
int ipath_ib_piobufavail(struct ipath_ibdev *dev)
{
        struct list_head *list;
        struct ipath_qp *qplist;
        struct ipath_qp *qp;
        unsigned long flags;

        if (dev == NULL)
                goto bail;

        list = &dev->piowait;
        qplist = NULL;

        spin_lock_irqsave(&dev->pending_lock, flags);
        while (!list_empty(list)) {
                qp = list_entry(list->next, struct ipath_qp, piowait);
                list_del_init(&qp->piowait);
                qp->pio_next = qplist;
                qplist = qp;
                atomic_inc(&qp->refcount);
        }
        spin_unlock_irqrestore(&dev->pending_lock, flags);

        while (qplist != NULL) {
                qp = qplist;
                qplist = qp->pio_next;

                spin_lock_irqsave(&qp->s_lock, flags);
                if (ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK)
                        ipath_schedule_send(qp);
                spin_unlock_irqrestore(&qp->s_lock, flags);

                /* Notify ipath_destroy_qp() if it is waiting. */
                if (atomic_dec_and_test(&qp->refcount))
                        wake_up(&qp->wait);
        }

bail:
        return 0;
}

static int ipath_query_device(struct ib_device *ibdev,
                              struct ib_device_attr *props)
{
        struct ipath_ibdev *dev = to_idev(ibdev);

        memset(props, 0, sizeof(*props));

        props->device_cap_flags = IB_DEVICE_BAD_PKEY_CNTR |
                IB_DEVICE_BAD_QKEY_CNTR | IB_DEVICE_SHUTDOWN_PORT |
                IB_DEVICE_SYS_IMAGE_GUID | IB_DEVICE_RC_RNR_NAK_GEN |
                IB_DEVICE_PORT_ACTIVE_EVENT | IB_DEVICE_SRQ_RESIZE;
        props->page_size_cap = PAGE_SIZE;
        props->vendor_id =
                IPATH_SRC_OUI_1 << 16 | IPATH_SRC_OUI_2 << 8 | IPATH_SRC_OUI_3;
        props->vendor_part_id = dev->dd->ipath_deviceid;
        props->hw_ver = dev->dd->ipath_pcirev;

        props->sys_image_guid = dev->sys_image_guid;

        props->max_mr_size = ~0ull;
        props->max_qp = ib_ipath_max_qps;
        props->max_qp_wr = ib_ipath_max_qp_wrs;
        props->max_sge = ib_ipath_max_sges;
        props->max_cq = ib_ipath_max_cqs;
        props->max_ah = ib_ipath_max_ahs;
        props->max_cqe = ib_ipath_max_cqes;
        props->max_mr = dev->lk_table.max;
        props->max_fmr = dev->lk_table.max;
        props->max_map_per_fmr = 32767;
        props->max_pd = ib_ipath_max_pds;
        props->max_qp_rd_atom = IPATH_MAX_RDMA_ATOMIC;
        props->max_qp_init_rd_atom = 255;
        /* props->max_res_rd_atom */
        props->max_srq = ib_ipath_max_srqs;
        props->max_srq_wr = ib_ipath_max_srq_wrs;
        props->max_srq_sge = ib_ipath_max_srq_sges;
        /* props->local_ca_ack_delay */
        props->atomic_cap = IB_ATOMIC_GLOB;
        props->max_pkeys = ipath_get_npkeys(dev->dd);
        props->max_mcast_grp = ib_ipath_max_mcast_grps;
        props->max_mcast_qp_attach = ib_ipath_max_mcast_qp_attached;
        props->max_total_mcast_qp_attach = props->max_mcast_qp_attach *
                props->max_mcast_grp;

        return 0;
}

const u8 ipath_cvt_physportstate[32] = {
        [INFINIPATH_IBCS_LT_STATE_DISABLED] = IB_PHYSPORTSTATE_DISABLED,
        [INFINIPATH_IBCS_LT_STATE_LINKUP] = IB_PHYSPORTSTATE_LINKUP,
        [INFINIPATH_IBCS_LT_STATE_POLLACTIVE] = IB_PHYSPORTSTATE_POLL,
        [INFINIPATH_IBCS_LT_STATE_POLLQUIET] = IB_PHYSPORTSTATE_POLL,
        [INFINIPATH_IBCS_LT_STATE_SLEEPDELAY] = IB_PHYSPORTSTATE_SLEEP,
        [INFINIPATH_IBCS_LT_STATE_SLEEPQUIET] = IB_PHYSPORTSTATE_SLEEP,
        [INFINIPATH_IBCS_LT_STATE_CFGDEBOUNCE] =
                IB_PHYSPORTSTATE_CFG_TRAIN,
        [INFINIPATH_IBCS_LT_STATE_CFGRCVFCFG] =
                IB_PHYSPORTSTATE_CFG_TRAIN,
        [INFINIPATH_IBCS_LT_STATE_CFGWAITRMT] =
                IB_PHYSPORTSTATE_CFG_TRAIN,
        [INFINIPATH_IBCS_LT_STATE_CFGIDLE] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [INFINIPATH_IBCS_LT_STATE_RECOVERRETRAIN] =
                IB_PHYSPORTSTATE_LINK_ERR_RECOVER,
        [INFINIPATH_IBCS_LT_STATE_RECOVERWAITRMT] =
                IB_PHYSPORTSTATE_LINK_ERR_RECOVER,
        [INFINIPATH_IBCS_LT_STATE_RECOVERIDLE] =
                IB_PHYSPORTSTATE_LINK_ERR_RECOVER,
        [0x10] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x11] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x12] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x13] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x14] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x15] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x16] = IB_PHYSPORTSTATE_CFG_TRAIN,
        [0x17] = IB_PHYSPORTSTATE_CFG_TRAIN
};

u32 ipath_get_cr_errpkey(struct ipath_devdata *dd)
{
        return ipath_read_creg32(dd, dd->ipath_cregs->cr_errpkey);
}

static int ipath_query_port(struct ib_device *ibdev,
                            u8 port, struct ib_port_attr *props)
{
        struct ipath_ibdev *dev = to_idev(ibdev);
        struct ipath_devdata *dd = dev->dd;
        enum ib_mtu mtu;
        u16 lid = dd->ipath_lid;
        u64 ibcstat;

        memset(props, 0, sizeof(*props));
        props->lid = lid ? lid : __constant_be16_to_cpu(IB_LID_PERMISSIVE);
        props->lmc = dd->ipath_lmc;
        props->sm_lid = dev->sm_lid;
        props->sm_sl = dev->sm_sl;
        ibcstat = dd->ipath_lastibcstat;
        /* map LinkState to IB portinfo values.  */
        props->state = ipath_ib_linkstate(dd, ibcstat) + 1;

        /* See phys_state_show() */
        props->phys_state = /* MEA: assumes shift == 0 */
                ipath_cvt_physportstate[dd->ipath_lastibcstat &
                dd->ibcs_lts_mask];
        props->port_cap_flags = dev->port_cap_flags;
        props->gid_tbl_len = 1;
        props->max_msg_sz = 0x80000000;
        props->pkey_tbl_len = ipath_get_npkeys(dd);
        props->bad_pkey_cntr = ipath_get_cr_errpkey(dd) -
                dev->z_pkey_violations;
        props->qkey_viol_cntr = dev->qkey_violations;
        props->active_width = dd->ipath_link_width_active;
        /* See rate_show() */
        props->active_speed = dd->ipath_link_speed_active;
        props->max_vl_num = 1;          /* VLCap = VL0 */
        props->init_type_reply = 0;

        props->max_mtu = ipath_mtu4096 ? IB_MTU_4096 : IB_MTU_2048;
        switch (dd->ipath_ibmtu) {
        case 4096:
                mtu = IB_MTU_4096;
                break;
        case 2048:
                mtu = IB_MTU_2048;
                break;
        case 1024:
                mtu = IB_MTU_1024;
                break;
        case 512:
                mtu = IB_MTU_512;
                break;
        case 256:
                mtu = IB_MTU_256;
                break;
        default:
                mtu = IB_MTU_2048;
        }
        props->active_mtu = mtu;
        props->subnet_timeout = dev->subnet_timeout;

        return 0;
}

static int ipath_modify_device(struct ib_device *device,
                               int device_modify_mask,
                               struct ib_device_modify *device_modify)
{
        int ret;

        if (device_modify_mask & ~(IB_DEVICE_MODIFY_SYS_IMAGE_GUID |
                                   IB_DEVICE_MODIFY_NODE_DESC)) {
                ret = -EOPNOTSUPP;
                goto bail;
        }

        if (device_modify_mask & IB_DEVICE_MODIFY_NODE_DESC)
                memcpy(device->node_desc, device_modify->node_desc, 64);

        if (device_modify_mask & IB_DEVICE_MODIFY_SYS_IMAGE_GUID)
                to_idev(device)->sys_image_guid =
                        cpu_to_be64(device_modify->sys_image_guid);

        ret = 0;

bail:
        return ret;
}

static int ipath_modify_port(struct ib_device *ibdev,
                             u8 port, int port_modify_mask,
                             struct ib_port_modify *props)
{
        struct ipath_ibdev *dev = to_idev(ibdev);

        dev->port_cap_flags |= props->set_port_cap_mask;
        dev->port_cap_flags &= ~props->clr_port_cap_mask;
        if (port_modify_mask & IB_PORT_SHUTDOWN)
                ipath_set_linkstate(dev->dd, IPATH_IB_LINKDOWN);
        if (port_modify_mask & IB_PORT_RESET_QKEY_CNTR)
                dev->qkey_violations = 0;
        return 0;
}

static int ipath_query_gid(struct ib_device *ibdev, u8 port,
                           int index, union ib_gid *gid)
{
        struct ipath_ibdev *dev = to_idev(ibdev);
        int ret;

        if (index >= 1) {
                ret = -EINVAL;
                goto bail;
        }
        gid->global.subnet_prefix = dev->gid_prefix;
        gid->global.interface_id = dev->dd->ipath_guid;

        ret = 0;

bail:
        return ret;
}

static struct ib_pd *ipath_alloc_pd(struct ib_device *ibdev,
                                    struct ib_ucontext *context,
                                    struct ib_udata *udata)
{
        struct ipath_ibdev *dev = to_idev(ibdev);
        struct ipath_pd *pd;
        struct ib_pd *ret;

        /*
         * This is actually totally arbitrary.  Some correctness tests
         * assume there's a maximum number of PDs that can be allocated.
         * We don't actually have this limit, but we fail the test if
         * we allow allocations of more than we report for this value.
         */

        pd = kmalloc(sizeof *pd, GFP_KERNEL);
        if (!pd) {
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        spin_lock(&dev->n_pds_lock);
        if (dev->n_pds_allocated == ib_ipath_max_pds) {
                spin_unlock(&dev->n_pds_lock);
                kfree(pd);
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        dev->n_pds_allocated++;
        spin_unlock(&dev->n_pds_lock);

        /* ib_alloc_pd() will initialize pd->ibpd. */
        pd->user = udata != NULL;

        ret = &pd->ibpd;

bail:
        return ret;
}

static int ipath_dealloc_pd(struct ib_pd *ibpd)
{
        struct ipath_pd *pd = to_ipd(ibpd);
        struct ipath_ibdev *dev = to_idev(ibpd->device);

        spin_lock(&dev->n_pds_lock);
        dev->n_pds_allocated--;
        spin_unlock(&dev->n_pds_lock);

        kfree(pd);

        return 0;
}

/**
 * ipath_create_ah - create an address handle
 * @pd: the protection domain
 * @ah_attr: the attributes of the AH
 *
 * This may be called from interrupt context.
 */
static struct ib_ah *ipath_create_ah(struct ib_pd *pd,
                                     struct ib_ah_attr *ah_attr)
{
        struct ipath_ah *ah;
        struct ib_ah *ret;
        struct ipath_ibdev *dev = to_idev(pd->device);
        unsigned long flags;

        /* A multicast address requires a GRH (see ch. 8.4.1). */
        if (ah_attr->dlid >= IPATH_MULTICAST_LID_BASE &&
            ah_attr->dlid != IPATH_PERMISSIVE_LID &&
            !(ah_attr->ah_flags & IB_AH_GRH)) {
                ret = ERR_PTR(-EINVAL);
                goto bail;
        }

        if (ah_attr->dlid == 0) {
                ret = ERR_PTR(-EINVAL);
                goto bail;
        }

        if (ah_attr->port_num < 1 ||
            ah_attr->port_num > pd->device->phys_port_cnt) {
                ret = ERR_PTR(-EINVAL);
                goto bail;
        }

        ah = kmalloc(sizeof *ah, GFP_ATOMIC);
        if (!ah) {
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        spin_lock_irqsave(&dev->n_ahs_lock, flags);
        if (dev->n_ahs_allocated == ib_ipath_max_ahs) {
                spin_unlock_irqrestore(&dev->n_ahs_lock, flags);
                kfree(ah);
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        dev->n_ahs_allocated++;
        spin_unlock_irqrestore(&dev->n_ahs_lock, flags);

        /* ib_create_ah() will initialize ah->ibah. */
        ah->attr = *ah_attr;
        ah->attr.static_rate = ipath_ib_rate_to_mult(ah_attr->static_rate);

        ret = &ah->ibah;

bail:
        return ret;
}

/**
 * ipath_destroy_ah - destroy an address handle
 * @ibah: the AH to destroy
 *
 * This may be called from interrupt context.
 */
static int ipath_destroy_ah(struct ib_ah *ibah)
{
        struct ipath_ibdev *dev = to_idev(ibah->device);
        struct ipath_ah *ah = to_iah(ibah);
        unsigned long flags;

        spin_lock_irqsave(&dev->n_ahs_lock, flags);
        dev->n_ahs_allocated--;
        spin_unlock_irqrestore(&dev->n_ahs_lock, flags);

        kfree(ah);

        return 0;
}

static int ipath_query_ah(struct ib_ah *ibah, struct ib_ah_attr *ah_attr)
{
        struct ipath_ah *ah = to_iah(ibah);

        *ah_attr = ah->attr;
        ah_attr->static_rate = ipath_mult_to_ib_rate(ah->attr.static_rate);

        return 0;
}

/**
 * ipath_get_npkeys - return the size of the PKEY table for port 0
 * @dd: the infinipath device
 */
unsigned ipath_get_npkeys(struct ipath_devdata *dd)
{
        return ARRAY_SIZE(dd->ipath_pd[0]->port_pkeys);
}

/**
 * ipath_get_pkey - return the indexed PKEY from the port PKEY table
 * @dd: the infinipath device
 * @index: the PKEY index
 */
unsigned ipath_get_pkey(struct ipath_devdata *dd, unsigned index)
{
        unsigned ret;

        /* always a kernel port, no locking needed */
        if (index >= ARRAY_SIZE(dd->ipath_pd[0]->port_pkeys))
                ret = 0;
        else
                ret = dd->ipath_pd[0]->port_pkeys[index];

        return ret;
}

static int ipath_query_pkey(struct ib_device *ibdev, u8 port, u16 index,
                            u16 *pkey)
{
        struct ipath_ibdev *dev = to_idev(ibdev);
        int ret;

        if (index >= ipath_get_npkeys(dev->dd)) {
                ret = -EINVAL;
                goto bail;
        }

        *pkey = ipath_get_pkey(dev->dd, index);
        ret = 0;

bail:
        return ret;
}

/**
 * ipath_alloc_ucontext - allocate a ucontest
 * @ibdev: the infiniband device
 * @udata: not used by the InfiniPath driver
 */

static struct ib_ucontext *ipath_alloc_ucontext(struct ib_device *ibdev,
                                                struct ib_udata *udata)
{
        struct ipath_ucontext *context;
        struct ib_ucontext *ret;

        context = kmalloc(sizeof *context, GFP_KERNEL);
        if (!context) {
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        ret = &context->ibucontext;

bail:
        return ret;
}

static int ipath_dealloc_ucontext(struct ib_ucontext *context)
{
        kfree(to_iucontext(context));
        return 0;
}

static int ipath_verbs_register_sysfs(struct ib_device *dev);

static void __verbs_timer(unsigned long arg)
{
        struct ipath_devdata *dd = (struct ipath_devdata *) arg;

        /* Handle verbs layer timeouts. */
        ipath_ib_timer(dd->verbs_dev);

        mod_timer(&dd->verbs_timer, jiffies + 1);
}

static int enable_timer(struct ipath_devdata *dd)
{
        /*
         * Early chips had a design flaw where the chip and kernel idea
         * of the tail register don't always agree, and therefore we won't
         * get an interrupt on the next packet received.
         * If the board supports per packet receive interrupts, use it.
         * Otherwise, the timer function periodically checks for packets
         * to cover this case.
         * Either way, the timer is needed for verbs layer related
         * processing.
         */
        if (dd->ipath_flags & IPATH_GPIO_INTR) {
                ipath_write_kreg(dd, dd->ipath_kregs->kr_debugportselect,
                                 0x2074076542310ULL);
                /* Enable GPIO bit 2 interrupt */
                dd->ipath_gpio_mask |= (u64) (1 << IPATH_GPIO_PORT0_BIT);
                ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_mask,
                                 dd->ipath_gpio_mask);
        }

        init_timer(&dd->verbs_timer);
        dd->verbs_timer.function = __verbs_timer;
        dd->verbs_timer.data = (unsigned long)dd;
        dd->verbs_timer.expires = jiffies + 1;
        add_timer(&dd->verbs_timer);

        return 0;
}

static int disable_timer(struct ipath_devdata *dd)
{
        /* Disable GPIO bit 2 interrupt */
        if (dd->ipath_flags & IPATH_GPIO_INTR) {
                /* Disable GPIO bit 2 interrupt */
                dd->ipath_gpio_mask &= ~((u64) (1 << IPATH_GPIO_PORT0_BIT));
                ipath_write_kreg(dd, dd->ipath_kregs->kr_gpio_mask,
                                 dd->ipath_gpio_mask);
                /*
                 * We might want to undo changes to debugportselect,
                 * but how?
                 */
        }

        del_timer_sync(&dd->verbs_timer);

        return 0;
}

/**
 * ipath_register_ib_device - register our device with the infiniband core
 * @dd: the device data structure
 * Return the allocated ipath_ibdev pointer or NULL on error.
 */
int ipath_register_ib_device(struct ipath_devdata *dd)
{
        struct ipath_verbs_counters cntrs;
        struct ipath_ibdev *idev;
        struct ib_device *dev;
        struct ipath_verbs_txreq *tx;
        unsigned i;
        int ret;

        idev = (struct ipath_ibdev *)ib_alloc_device(sizeof *idev);
        if (idev == NULL) {
                ret = -ENOMEM;
                goto bail;
        }

        dev = &idev->ibdev;

        if (dd->ipath_sdma_descq_cnt) {
                tx = kmalloc(dd->ipath_sdma_descq_cnt * sizeof *tx,
                             GFP_KERNEL);
                if (tx == NULL) {
                        ret = -ENOMEM;
                        goto err_tx;
                }
        } else
                tx = NULL;
        idev->txreq_bufs = tx;

        /* Only need to initialize non-zero fields. */
        spin_lock_init(&idev->n_pds_lock);
        spin_lock_init(&idev->n_ahs_lock);
        spin_lock_init(&idev->n_cqs_lock);
        spin_lock_init(&idev->n_qps_lock);
        spin_lock_init(&idev->n_srqs_lock);
        spin_lock_init(&idev->n_mcast_grps_lock);

        spin_lock_init(&idev->qp_table.lock);
        spin_lock_init(&idev->lk_table.lock);
        idev->sm_lid = __constant_be16_to_cpu(IB_LID_PERMISSIVE);
        /* Set the prefix to the default value (see ch. 4.1.1) */
        idev->gid_prefix = __constant_cpu_to_be64(0xfe80000000000000ULL);

        ret = ipath_init_qp_table(idev, ib_ipath_qp_table_size);
        if (ret)
                goto err_qp;

        /*
         * The top ib_ipath_lkey_table_size bits are used to index the
         * table.  The lower 8 bits can be owned by the user (copied from
         * the LKEY).  The remaining bits act as a generation number or tag.
         */
        idev->lk_table.max = 1 << ib_ipath_lkey_table_size;
        idev->lk_table.table = kzalloc(idev->lk_table.max *
                                       sizeof(*idev->lk_table.table),
                                       GFP_KERNEL);
        if (idev->lk_table.table == NULL) {
                ret = -ENOMEM;
                goto err_lk;
        }
        INIT_LIST_HEAD(&idev->pending_mmaps);
        spin_lock_init(&idev->pending_lock);
        idev->mmap_offset = PAGE_SIZE;
        spin_lock_init(&idev->mmap_offset_lock);
        INIT_LIST_HEAD(&idev->pending[0]);
        INIT_LIST_HEAD(&idev->pending[1]);
        INIT_LIST_HEAD(&idev->pending[2]);
        INIT_LIST_HEAD(&idev->piowait);
        INIT_LIST_HEAD(&idev->rnrwait);
        INIT_LIST_HEAD(&idev->txreq_free);
        idev->pending_index = 0;
        idev->port_cap_flags =
                IB_PORT_SYS_IMAGE_GUID_SUP | IB_PORT_CLIENT_REG_SUP;
        if (dd->ipath_flags & IPATH_HAS_LINK_LATENCY)
                idev->port_cap_flags |= IB_PORT_LINK_LATENCY_SUP;
        idev->pma_counter_select[0] = IB_PMA_PORT_XMIT_DATA;
        idev->pma_counter_select[1] = IB_PMA_PORT_RCV_DATA;
        idev->pma_counter_select[2] = IB_PMA_PORT_XMIT_PKTS;
        idev->pma_counter_select[3] = IB_PMA_PORT_RCV_PKTS;
        idev->pma_counter_select[4] = IB_PMA_PORT_XMIT_WAIT;

        /* Snapshot current HW counters to "clear" them. */
        ipath_get_counters(dd, &cntrs);
        idev->z_symbol_error_counter = cntrs.symbol_error_counter;
        idev->z_link_error_recovery_counter =
                cntrs.link_error_recovery_counter;
        idev->z_link_downed_counter = cntrs.link_downed_counter;
        idev->z_port_rcv_errors = cntrs.port_rcv_errors;
        idev->z_port_rcv_remphys_errors =
                cntrs.port_rcv_remphys_errors;
        idev->z_port_xmit_discards = cntrs.port_xmit_discards;
        idev->z_port_xmit_data = cntrs.port_xmit_data;
        idev->z_port_rcv_data = cntrs.port_rcv_data;
        idev->z_port_xmit_packets = cntrs.port_xmit_packets;
        idev->z_port_rcv_packets = cntrs.port_rcv_packets;
        idev->z_local_link_integrity_errors =
                cntrs.local_link_integrity_errors;
        idev->z_excessive_buffer_overrun_errors =
                cntrs.excessive_buffer_overrun_errors;
        idev->z_vl15_dropped = cntrs.vl15_dropped;

        for (i = 0; i < dd->ipath_sdma_descq_cnt; i++, tx++)
                list_add(&tx->txreq.list, &idev->txreq_free);

        /*
         * The system image GUID is supposed to be the same for all
         * IB HCAs in a single system but since there can be other
         * device types in the system, we can't be sure this is unique.
         */
        if (!sys_image_guid)
                sys_image_guid = dd->ipath_guid;
        idev->sys_image_guid = sys_image_guid;
        idev->ib_unit = dd->ipath_unit;
        idev->dd = dd;

        strlcpy(dev->name, "ipath%d", IB_DEVICE_NAME_MAX);
        dev->owner = THIS_MODULE;
        dev->node_guid = dd->ipath_guid;
        dev->uverbs_abi_ver = IPATH_UVERBS_ABI_VERSION;
        dev->uverbs_cmd_mask =
                (1ull << IB_USER_VERBS_CMD_GET_CONTEXT)         |
                (1ull << IB_USER_VERBS_CMD_QUERY_DEVICE)        |
                (1ull << IB_USER_VERBS_CMD_QUERY_PORT)          |
                (1ull << IB_USER_VERBS_CMD_ALLOC_PD)            |
                (1ull << IB_USER_VERBS_CMD_DEALLOC_PD)          |
                (1ull << IB_USER_VERBS_CMD_CREATE_AH)           |
                (1ull << IB_USER_VERBS_CMD_DESTROY_AH)          |
                (1ull << IB_USER_VERBS_CMD_QUERY_AH)            |
                (1ull << IB_USER_VERBS_CMD_REG_MR)              |
                (1ull << IB_USER_VERBS_CMD_DEREG_MR)            |
                (1ull << IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL) |
                (1ull << IB_USER_VERBS_CMD_CREATE_CQ)           |
                (1ull << IB_USER_VERBS_CMD_RESIZE_CQ)           |
                (1ull << IB_USER_VERBS_CMD_DESTROY_CQ)          |
                (1ull << IB_USER_VERBS_CMD_POLL_CQ)             |
                (1ull << IB_USER_VERBS_CMD_REQ_NOTIFY_CQ)       |
                (1ull << IB_USER_VERBS_CMD_CREATE_QP)           |
                (1ull << IB_USER_VERBS_CMD_QUERY_QP)            |
                (1ull << IB_USER_VERBS_CMD_MODIFY_QP)           |
                (1ull << IB_USER_VERBS_CMD_DESTROY_QP)          |
                (1ull << IB_USER_VERBS_CMD_POST_SEND)           |
                (1ull << IB_USER_VERBS_CMD_POST_RECV)           |
                (1ull << IB_USER_VERBS_CMD_ATTACH_MCAST)        |
                (1ull << IB_USER_VERBS_CMD_DETACH_MCAST)        |
                (1ull << IB_USER_VERBS_CMD_CREATE_SRQ)          |
                (1ull << IB_USER_VERBS_CMD_MODIFY_SRQ)          |
                (1ull << IB_USER_VERBS_CMD_QUERY_SRQ)           |
                (1ull << IB_USER_VERBS_CMD_DESTROY_SRQ)         |
                (1ull << IB_USER_VERBS_CMD_POST_SRQ_RECV);
        dev->node_type = RDMA_NODE_IB_CA;
        dev->phys_port_cnt = 1;
        dev->num_comp_vectors = 1;
        dev->dma_device = &dd->pcidev->dev;
        dev->query_device = ipath_query_device;
        dev->modify_device = ipath_modify_device;
        dev->query_port = ipath_query_port;
        dev->modify_port = ipath_modify_port;
        dev->query_pkey = ipath_query_pkey;
        dev->query_gid = ipath_query_gid;
        dev->alloc_ucontext = ipath_alloc_ucontext;
        dev->dealloc_ucontext = ipath_dealloc_ucontext;
        dev->alloc_pd = ipath_alloc_pd;
        dev->dealloc_pd = ipath_dealloc_pd;
        dev->create_ah = ipath_create_ah;
        dev->destroy_ah = ipath_destroy_ah;
        dev->query_ah = ipath_query_ah;
        dev->create_srq = ipath_create_srq;
        dev->modify_srq = ipath_modify_srq;
        dev->query_srq = ipath_query_srq;
        dev->destroy_srq = ipath_destroy_srq;
        dev->create_qp = ipath_create_qp;
        dev->modify_qp = ipath_modify_qp;
        dev->query_qp = ipath_query_qp;
        dev->destroy_qp = ipath_destroy_qp;
        dev->post_send = ipath_post_send;
        dev->post_recv = ipath_post_receive;
        dev->post_srq_recv = ipath_post_srq_receive;
        dev->create_cq = ipath_create_cq;
        dev->destroy_cq = ipath_destroy_cq;
        dev->resize_cq = ipath_resize_cq;
        dev->poll_cq = ipath_poll_cq;
        dev->req_notify_cq = ipath_req_notify_cq;
        dev->get_dma_mr = ipath_get_dma_mr;
        dev->reg_phys_mr = ipath_reg_phys_mr;
        dev->reg_user_mr = ipath_reg_user_mr;
        dev->dereg_mr = ipath_dereg_mr;
        dev->alloc_fmr = ipath_alloc_fmr;
        dev->map_phys_fmr = ipath_map_phys_fmr;
        dev->unmap_fmr = ipath_unmap_fmr;
        dev->dealloc_fmr = ipath_dealloc_fmr;
        dev->attach_mcast = ipath_multicast_attach;
        dev->detach_mcast = ipath_multicast_detach;
        dev->process_mad = ipath_process_mad;
        dev->mmap = ipath_mmap;
        dev->dma_ops = &ipath_dma_mapping_ops;

        snprintf(dev->node_desc, sizeof(dev->node_desc),
                 IPATH_IDSTR " %s", init_utsname()->nodename);

        ret = ib_register_device(dev);
        if (ret)
                goto err_reg;

        if (ipath_verbs_register_sysfs(dev))
                goto err_class;

        enable_timer(dd);

        goto bail;

err_class:
        ib_unregister_device(dev);
err_reg:
        kfree(idev->lk_table.table);
err_lk:
        kfree(idev->qp_table.table);
err_qp:
        kfree(idev->txreq_bufs);
err_tx:
        ib_dealloc_device(dev);
        ipath_dev_err(dd, "cannot register verbs: %d!\n", -ret);
        idev = NULL;

bail:
        dd->verbs_dev = idev;
        return ret;
}

void ipath_unregister_ib_device(struct ipath_ibdev *dev)
{
        struct ib_device *ibdev = &dev->ibdev;
        u32 qps_inuse;

        ib_unregister_device(ibdev);

        disable_timer(dev->dd);

        if (!list_empty(&dev->pending[0]) ||
            !list_empty(&dev->pending[1]) ||
            !list_empty(&dev->pending[2]))
                ipath_dev_err(dev->dd, "pending list not empty!\n");
        if (!list_empty(&dev->piowait))
                ipath_dev_err(dev->dd, "piowait list not empty!\n");
        if (!list_empty(&dev->rnrwait))
                ipath_dev_err(dev->dd, "rnrwait list not empty!\n");
        if (!ipath_mcast_tree_empty())
                ipath_dev_err(dev->dd, "multicast table memory leak!\n");
        /*
         * Note that ipath_unregister_ib_device() can be called before all
         * the QPs are destroyed!
         */
        qps_inuse = ipath_free_all_qps(&dev->qp_table);
        if (qps_inuse)
                ipath_dev_err(dev->dd, "QP memory leak! %u still in use\n",
                        qps_inuse);
        kfree(dev->qp_table.table);
        kfree(dev->lk_table.table);
        kfree(dev->txreq_bufs);
        ib_dealloc_device(ibdev);
}

static ssize_t show_rev(struct device *device, struct device_attribute *attr,
                        char *buf)
{
        struct ipath_ibdev *dev =
                container_of(device, struct ipath_ibdev, ibdev.dev);

        return sprintf(buf, "%x\n", dev->dd->ipath_pcirev);
}

static ssize_t show_hca(struct device *device, struct device_attribute *attr,
                        char *buf)
{
        struct ipath_ibdev *dev =
                container_of(device, struct ipath_ibdev, ibdev.dev);
        int ret;

        ret = dev->dd->ipath_f_get_boardname(dev->dd, buf, 128);
        if (ret < 0)
                goto bail;
        strcat(buf, "\n");
        ret = strlen(buf);

bail:
        return ret;
}

static ssize_t show_stats(struct device *device, struct device_attribute *attr,
                          char *buf)
{
        struct ipath_ibdev *dev =
                container_of(device, struct ipath_ibdev, ibdev.dev);
        int i;
        int len;

        len = sprintf(buf,
                      "RC resends  %d\n"
                      "RC no QACK  %d\n"
                      "RC ACKs     %d\n"
                      "RC SEQ NAKs %d\n"
                      "RC RDMA seq %d\n"
                      "RC RNR NAKs %d\n"
                      "RC OTH NAKs %d\n"
                      "RC timeouts %d\n"
                      "RC RDMA dup %d\n"
                      "piobuf wait %d\n"
                      "unaligned   %d\n"
                      "PKT drops   %d\n"
                      "WQE errs    %d\n",
                      dev->n_rc_resends, dev->n_rc_qacks, dev->n_rc_acks,
                      dev->n_seq_naks, dev->n_rdma_seq, dev->n_rnr_naks,
                      dev->n_other_naks, dev->n_timeouts,
                      dev->n_rdma_dup_busy, dev->n_piowait, dev->n_unaligned,
                      dev->n_pkt_drops, dev->n_wqe_errs);
        for (i = 0; i < ARRAY_SIZE(dev->opstats); i++) {
                const struct ipath_opcode_stats *si = &dev->opstats[i];

                if (!si->n_packets && !si->n_bytes)
                        continue;
                len += sprintf(buf + len, "%02x %llu/%llu\n", i,
                               (unsigned long long) si->n_packets,
                               (unsigned long long) si->n_bytes);
        }
        return len;
}

static DEVICE_ATTR(hw_rev, S_IRUGO, show_rev, NULL);
static DEVICE_ATTR(hca_type, S_IRUGO, show_hca, NULL);
static DEVICE_ATTR(board_id, S_IRUGO, show_hca, NULL);
static DEVICE_ATTR(stats, S_IRUGO, show_stats, NULL);

static struct device_attribute *ipath_class_attributes[] = {
        &dev_attr_hw_rev,
        &dev_attr_hca_type,
        &dev_attr_board_id,
        &dev_attr_stats
};

static int ipath_verbs_register_sysfs(struct ib_device *dev)
{
        int i;
        int ret;

        for (i = 0; i < ARRAY_SIZE(ipath_class_attributes); ++i)
                if (device_create_file(&dev->dev,
                                       ipath_class_attributes[i])) {
                        ret = 1;
                        goto bail;
                }

        ret = 0;

bail:
        return ret;
}