IB/ipath: misc infiniband code, part 2

Management datagram support, queue pairs, and reliable and unreliable
connections.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 913 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
new file mode 100644
index 000000000000..6058d70d7577
--- /dev/null
+++ b/drivers/infiniband/hw/ipath/ipath_qp.c
@@ -0,0 +1,913 @@
+/*
+ * 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 <linux/err.h>
+#include <linux/vmalloc.h>
+
+#include "ipath_verbs.h"
+#include "ips_common.h"
+
+#define BITS_PER_PAGE           (PAGE_SIZE*BITS_PER_BYTE)
+#define BITS_PER_PAGE_MASK      (BITS_PER_PAGE-1)
+#define mk_qpn(qpt, map, off)   (((map) - (qpt)->map) * BITS_PER_PAGE + \
+                                 (off))
+#define find_next_offset(map, off) find_next_zero_bit((map)->page, \
+                                                      BITS_PER_PAGE, off)
+
+#define TRANS_INVALID   0
+#define TRANS_ANY2RST   1
+#define TRANS_RST2INIT  2
+#define TRANS_INIT2INIT 3
+#define TRANS_INIT2RTR  4
+#define TRANS_RTR2RTS   5
+#define TRANS_RTS2RTS   6
+#define TRANS_SQERR2RTS 7
+#define TRANS_ANY2ERR   8
+#define TRANS_RTS2SQD   9  /* XXX Wait for expected ACKs & signal event */
+#define TRANS_SQD2SQD   10 /* error if not drained & parameter change */
+#define TRANS_SQD2RTS   11 /* error if not drained */
+
+/*
+ * Convert the AETH credit code into the number of credits.
+ */
+static u32 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 */
+};
+
+static u32 alloc_qpn(struct ipath_qp_table *qpt)
+{
+        u32 i, offset, max_scan, qpn;
+        struct qpn_map *map;
+        u32 ret;
+
+        qpn = qpt->last + 1;
+        if (qpn >= QPN_MAX)
+                qpn = 2;
+        offset = qpn & BITS_PER_PAGE_MASK;
+        map = &qpt->map[qpn / BITS_PER_PAGE];
+        max_scan = qpt->nmaps - !offset;
+        for (i = 0;;) {
+                if (unlikely(!map->page)) {
+                        unsigned long page = get_zeroed_page(GFP_KERNEL);
+                        unsigned long flags;
+
+                        /*
+                         * Free the page if someone raced with us
+                         * installing it:
+                         */
+                        spin_lock_irqsave(&qpt->lock, flags);
+                        if (map->page)
+                                free_page(page);
+                        else
+                                map->page = (void *)page;
+                        spin_unlock_irqrestore(&qpt->lock, flags);
+                        if (unlikely(!map->page))
+                                break;
+                }
+                if (likely(atomic_read(&map->n_free))) {
+                        do {
+                                if (!test_and_set_bit(offset, map->page)) {
+                                        atomic_dec(&map->n_free);
+                                        qpt->last = qpn;
+                                        ret = qpn;
+                                        goto bail;
+                                }
+                                offset = find_next_offset(map, offset);
+                                qpn = mk_qpn(qpt, map, offset);
+                                /*
+                                 * This test differs from alloc_pidmap().
+                                 * If find_next_offset() does find a zero
+                                 * bit, we don't need to check for QPN
+                                 * wrapping around past our starting QPN.
+                                 * We just need to be sure we don't loop
+                                 * forever.
+                                 */
+                        } while (offset < BITS_PER_PAGE && qpn < QPN_MAX);
+                }
+                /*
+                 * In order to keep the number of pages allocated to a
+                 * minimum, we scan the all existing pages before increasing
+                 * the size of the bitmap table.
+                 */
+                if (++i > max_scan) {
+                        if (qpt->nmaps == QPNMAP_ENTRIES)
+                                break;
+                        map = &qpt->map[qpt->nmaps++];
+                        offset = 0;
+                } else if (map < &qpt->map[qpt->nmaps]) {
+                        ++map;
+                        offset = 0;
+                } else {
+                        map = &qpt->map[0];
+                        offset = 2;
+                }
+                qpn = mk_qpn(qpt, map, offset);
+        }
+
+        ret = 0;
+
+bail:
+        return ret;
+}
+
+static void free_qpn(struct ipath_qp_table *qpt, u32 qpn)
+{
+        struct qpn_map *map;
+
+        map = qpt->map + qpn / BITS_PER_PAGE;
+        if (map->page)
+                clear_bit(qpn & BITS_PER_PAGE_MASK, map->page);
+        atomic_inc(&map->n_free);
+}
+
+/**
+ * ipath_alloc_qpn - allocate a QP number
+ * @qpt: the QP table
+ * @qp: the QP
+ * @type: the QP type (IB_QPT_SMI and IB_QPT_GSI are special)
+ *
+ * Allocate the next available QPN and put the QP into the hash table.
+ * The hash table holds a reference to the QP.
+ */
+int ipath_alloc_qpn(struct ipath_qp_table *qpt, struct ipath_qp *qp,
+                    enum ib_qp_type type)
+{
+        unsigned long flags;
+        u32 qpn;
+        int ret;
+
+        if (type == IB_QPT_SMI)
+                qpn = 0;
+        else if (type == IB_QPT_GSI)
+                qpn = 1;
+        else {
+                /* Allocate the next available QPN */
+                qpn = alloc_qpn(qpt);
+                if (qpn == 0) {
+                        ret = -ENOMEM;
+                        goto bail;
+                }
+        }
+        qp->ibqp.qp_num = qpn;
+
+        /* Add the QP to the hash table. */
+        spin_lock_irqsave(&qpt->lock, flags);
+
+        qpn %= qpt->max;
+        qp->next = qpt->table[qpn];
+        qpt->table[qpn] = qp;
+        atomic_inc(&qp->refcount);
+
+        spin_unlock_irqrestore(&qpt->lock, flags);
+        ret = 0;
+
+bail:
+        return ret;
+}
+
+/**
+ * ipath_free_qp - remove a QP from the QP table
+ * @qpt: the QP table
+ * @qp: the QP to remove
+ *
+ * Remove the QP from the table so it can't be found asynchronously by
+ * the receive interrupt routine.
+ */
+void ipath_free_qp(struct ipath_qp_table *qpt, struct ipath_qp *qp)
+{
+        struct ipath_qp *q, **qpp;
+        unsigned long flags;
+        int fnd = 0;
+
+        spin_lock_irqsave(&qpt->lock, flags);
+
+        /* Remove QP from the hash table. */
+        qpp = &qpt->table[qp->ibqp.qp_num % qpt->max];
+        for (; (q = *qpp) != NULL; qpp = &q->next) {
+                if (q == qp) {
+                        *qpp = qp->next;
+                        qp->next = NULL;
+                        atomic_dec(&qp->refcount);
+                        fnd = 1;
+                        break;
+                }
+        }
+
+        spin_unlock_irqrestore(&qpt->lock, flags);
+
+        if (!fnd)
+                return;
+
+        /* If QPN is not reserved, mark QPN free in the bitmap. */
+        if (qp->ibqp.qp_num > 1)
+                free_qpn(qpt, qp->ibqp.qp_num);
+
+        wait_event(qp->wait, !atomic_read(&qp->refcount));
+}
+
+/**
+ * ipath_free_all_qps - remove all QPs from the table
+ * @qpt: the QP table to empty
+ */
+void ipath_free_all_qps(struct ipath_qp_table *qpt)
+{
+        unsigned long flags;
+        struct ipath_qp *qp, *nqp;
+        u32 n;
+
+        for (n = 0; n < qpt->max; n++) {
+                spin_lock_irqsave(&qpt->lock, flags);
+                qp = qpt->table[n];
+                qpt->table[n] = NULL;
+                spin_unlock_irqrestore(&qpt->lock, flags);
+
+                while (qp) {
+                        nqp = qp->next;
+                        if (qp->ibqp.qp_num > 1)
+                                free_qpn(qpt, qp->ibqp.qp_num);
+                        if (!atomic_dec_and_test(&qp->refcount) ||
+                            !ipath_destroy_qp(&qp->ibqp))
+                                _VERBS_INFO("QP memory leak!\n");
+                        qp = nqp;
+                }
+        }
+
+        for (n = 0; n < ARRAY_SIZE(qpt->map); n++) {
+                if (qpt->map[n].page)
+                        free_page((unsigned long)qpt->map[n].page);
+        }
+}
+
+/**
+ * ipath_lookup_qpn - return the QP with the given QPN
+ * @qpt: the QP table
+ * @qpn: the QP number to look up
+ *
+ * The caller is responsible for decrementing the QP reference count
+ * when done.
+ */
+struct ipath_qp *ipath_lookup_qpn(struct ipath_qp_table *qpt, u32 qpn)
+{
+        unsigned long flags;
+        struct ipath_qp *qp;
+
+        spin_lock_irqsave(&qpt->lock, flags);
+
+        for (qp = qpt->table[qpn % qpt->max]; qp; qp = qp->next) {
+                if (qp->ibqp.qp_num == qpn) {
+                        atomic_inc(&qp->refcount);
+                        break;
+                }
+        }
+
+        spin_unlock_irqrestore(&qpt->lock, flags);
+        return qp;
+}
+
+/**
+ * ipath_reset_qp - initialize the QP state to the reset state
+ * @qp: the QP to reset
+ */
+static void ipath_reset_qp(struct ipath_qp *qp)
+{
+        qp->remote_qpn = 0;
+        qp->qkey = 0;
+        qp->qp_access_flags = 0;
+        qp->s_hdrwords = 0;
+        qp->s_psn = 0;
+        qp->r_psn = 0;
+        atomic_set(&qp->msn, 0);
+        if (qp->ibqp.qp_type == IB_QPT_RC) {
+                qp->s_state = IB_OPCODE_RC_SEND_LAST;
+                qp->r_state = IB_OPCODE_RC_SEND_LAST;
+        } else {
+                qp->s_state = IB_OPCODE_UC_SEND_LAST;
+                qp->r_state = IB_OPCODE_UC_SEND_LAST;
+        }
+        qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
+        qp->s_nak_state = 0;
+        qp->s_rnr_timeout = 0;
+        qp->s_head = 0;
+        qp->s_tail = 0;
+        qp->s_cur = 0;
+        qp->s_last = 0;
+        qp->s_ssn = 1;
+        qp->s_lsn = 0;
+        qp->r_rq.head = 0;
+        qp->r_rq.tail = 0;
+        qp->r_reuse_sge = 0;
+}
+
+/**
+ * ipath_modify_qp - modify the attributes of a queue pair
+ * @ibqp: the queue pair who's attributes we're modifying
+ * @attr: the new attributes
+ * @attr_mask: the mask of attributes to modify
+ *
+ * Returns 0 on success, otherwise returns an errno.
+ */
+int ipath_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+                    int attr_mask)
+{
+        struct ipath_qp *qp = to_iqp(ibqp);
+        enum ib_qp_state cur_state, new_state;
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&qp->r_rq.lock, flags);
+        spin_lock(&qp->s_lock);
+
+        cur_state = attr_mask & IB_QP_CUR_STATE ?
+                attr->cur_qp_state : qp->state;
+        new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
+
+        if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
+                                attr_mask))
+                goto inval;
+
+        switch (new_state) {
+        case IB_QPS_RESET:
+                ipath_reset_qp(qp);
+                break;
+
+        case IB_QPS_ERR:
+                ipath_error_qp(qp);
+                break;
+
+        default:
+                break;
+
+        }
+
+        if (attr_mask & IB_QP_PKEY_INDEX) {
+                struct ipath_ibdev *dev = to_idev(ibqp->device);
+
+                if (attr->pkey_index >= ipath_layer_get_npkeys(dev->dd))
+                        goto inval;
+                qp->s_pkey_index = attr->pkey_index;
+        }
+
+        if (attr_mask & IB_QP_DEST_QPN)
+                qp->remote_qpn = attr->dest_qp_num;
+
+        if (attr_mask & IB_QP_SQ_PSN) {
+                qp->s_next_psn = attr->sq_psn;
+                qp->s_last_psn = qp->s_next_psn - 1;
+        }
+
+        if (attr_mask & IB_QP_RQ_PSN)
+                qp->r_psn = attr->rq_psn;
+
+        if (attr_mask & IB_QP_ACCESS_FLAGS)
+                qp->qp_access_flags = attr->qp_access_flags;
+
+        if (attr_mask & IB_QP_AV) {
+                if (attr->ah_attr.dlid == 0 ||
+                    attr->ah_attr.dlid >= IPS_MULTICAST_LID_BASE)
+                        goto inval;
+                qp->remote_ah_attr = attr->ah_attr;
+        }
+
+        if (attr_mask & IB_QP_PATH_MTU)
+                qp->path_mtu = attr->path_mtu;
+
+        if (attr_mask & IB_QP_RETRY_CNT)
+                qp->s_retry = qp->s_retry_cnt = attr->retry_cnt;
+
+        if (attr_mask & IB_QP_RNR_RETRY) {
+                qp->s_rnr_retry = attr->rnr_retry;
+                if (qp->s_rnr_retry > 7)
+                        qp->s_rnr_retry = 7;
+                qp->s_rnr_retry_cnt = qp->s_rnr_retry;
+        }
+
+        if (attr_mask & IB_QP_MIN_RNR_TIMER) {
+                if (attr->min_rnr_timer > 31)
+                        goto inval;
+                qp->s_min_rnr_timer = attr->min_rnr_timer;
+        }
+
+        if (attr_mask & IB_QP_QKEY)
+                qp->qkey = attr->qkey;
+
+        if (attr_mask & IB_QP_PKEY_INDEX)
+                qp->s_pkey_index = attr->pkey_index;
+
+        qp->state = new_state;
+        spin_unlock(&qp->s_lock);
+        spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+
+        /*
+         * If QP1 changed to the RTS state, try to move to the link to INIT
+         * even if it was ACTIVE so the SM will reinitialize the SMA's
+         * state.
+         */
+        if (qp->ibqp.qp_num == 1 && new_state == IB_QPS_RTS) {
+                struct ipath_ibdev *dev = to_idev(ibqp->device);
+
+                ipath_layer_set_linkstate(dev->dd, IPATH_IB_LINKDOWN);
+        }
+        ret = 0;
+        goto bail;
+
+inval:
+        spin_unlock(&qp->s_lock);
+        spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+        ret = -EINVAL;
+
+bail:
+        return ret;
+}
+
+int ipath_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+                   int attr_mask, struct ib_qp_init_attr *init_attr)
+{
+        struct ipath_qp *qp = to_iqp(ibqp);
+
+        attr->qp_state = qp->state;
+        attr->cur_qp_state = attr->qp_state;
+        attr->path_mtu = qp->path_mtu;
+        attr->path_mig_state = 0;
+        attr->qkey = qp->qkey;
+        attr->rq_psn = qp->r_psn;
+        attr->sq_psn = qp->s_next_psn;
+        attr->dest_qp_num = qp->remote_qpn;
+        attr->qp_access_flags = qp->qp_access_flags;
+        attr->cap.max_send_wr = qp->s_size - 1;
+        attr->cap.max_recv_wr = qp->r_rq.size - 1;
+        attr->cap.max_send_sge = qp->s_max_sge;
+        attr->cap.max_recv_sge = qp->r_rq.max_sge;
+        attr->cap.max_inline_data = 0;
+        attr->ah_attr = qp->remote_ah_attr;
+        memset(&attr->alt_ah_attr, 0, sizeof(attr->alt_ah_attr));
+        attr->pkey_index = qp->s_pkey_index;
+        attr->alt_pkey_index = 0;
+        attr->en_sqd_async_notify = 0;
+        attr->sq_draining = 0;
+        attr->max_rd_atomic = 1;
+        attr->max_dest_rd_atomic = 1;
+        attr->min_rnr_timer = qp->s_min_rnr_timer;
+        attr->port_num = 1;
+        attr->timeout = 0;
+        attr->retry_cnt = qp->s_retry_cnt;
+        attr->rnr_retry = qp->s_rnr_retry;
+        attr->alt_port_num = 0;
+        attr->alt_timeout = 0;
+
+        init_attr->event_handler = qp->ibqp.event_handler;
+        init_attr->qp_context = qp->ibqp.qp_context;
+        init_attr->send_cq = qp->ibqp.send_cq;
+        init_attr->recv_cq = qp->ibqp.recv_cq;
+        init_attr->srq = qp->ibqp.srq;
+        init_attr->cap = attr->cap;
+        init_attr->sq_sig_type =
+                (qp->s_flags & (1 << IPATH_S_SIGNAL_REQ_WR))
+                ? IB_SIGNAL_REQ_WR : 0;
+        init_attr->qp_type = qp->ibqp.qp_type;
+        init_attr->port_num = 1;
+        return 0;
+}
+
+/**
+ * ipath_compute_aeth - compute the AETH (syndrome + MSN)
+ * @qp: the queue pair to compute the AETH for
+ *
+ * Returns the AETH.
+ *
+ * The QP s_lock should be held.
+ */
+__be32 ipath_compute_aeth(struct ipath_qp *qp)
+{
+        u32 aeth = atomic_read(&qp->msn) & IPS_MSN_MASK;
+
+        if (qp->s_nak_state) {
+                aeth |= qp->s_nak_state << IPS_AETH_CREDIT_SHIFT;
+        } else if (qp->ibqp.srq) {
+                /*
+                 * Shared receive queues don't generate credits.
+                 * Set the credit field to the invalid value.
+                 */
+                aeth |= IPS_AETH_CREDIT_INVAL << IPS_AETH_CREDIT_SHIFT;
+        } else {
+                u32 min, max, x;
+                u32 credits;
+
+                /*
+                 * Compute the number of credits available (RWQEs).
+                 * XXX Not holding the r_rq.lock here so there is a small
+                 * chance that the pair of reads are not atomic.
+                 */
+                credits = qp->r_rq.head - qp->r_rq.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;
+                        else
+                                min = x;
+                }
+                aeth |= x << IPS_AETH_CREDIT_SHIFT;
+        }
+        return cpu_to_be32(aeth);
+}
+
+/**
+ * ipath_create_qp - create a queue pair for a device
+ * @ibpd: the protection domain who's device we create the queue pair for
+ * @init_attr: the attributes of the queue pair
+ * @udata: unused by InfiniPath
+ *
+ * Returns the queue pair on success, otherwise returns an errno.
+ *
+ * Called by the ib_create_qp() core verbs function.
+ */
+struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
+                              struct ib_qp_init_attr *init_attr,
+                              struct ib_udata *udata)
+{
+        struct ipath_qp *qp;
+        int err;
+        struct ipath_swqe *swq = NULL;
+        struct ipath_ibdev *dev;
+        size_t sz;
+        struct ib_qp *ret;
+
+        if (init_attr->cap.max_send_sge > 255 ||
+            init_attr->cap.max_recv_sge > 255) {
+                ret = ERR_PTR(-ENOMEM);
+                goto bail;
+        }
+
+        switch (init_attr->qp_type) {
+        case IB_QPT_UC:
+        case IB_QPT_RC:
+                sz = sizeof(struct ipath_sge) *
+                        init_attr->cap.max_send_sge +
+                        sizeof(struct ipath_swqe);
+                swq = vmalloc((init_attr->cap.max_send_wr + 1) * sz);
+                if (swq == NULL) {
+                        ret = ERR_PTR(-ENOMEM);
+                        goto bail;
+                }
+                /* FALLTHROUGH */
+        case IB_QPT_UD:
+        case IB_QPT_SMI:
+        case IB_QPT_GSI:
+                qp = kmalloc(sizeof(*qp), GFP_KERNEL);
+                if (!qp) {
+                        ret = ERR_PTR(-ENOMEM);
+                        goto bail;
+                }
+                qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
+                sz = sizeof(struct ipath_sge) *
+                        init_attr->cap.max_recv_sge +
+                        sizeof(struct ipath_rwqe);
+                qp->r_rq.wq = vmalloc(qp->r_rq.size * sz);
+                if (!qp->r_rq.wq) {
+                        kfree(qp);
+                        ret = ERR_PTR(-ENOMEM);
+                        goto bail;
+                }
+
+                /*
+                 * ib_create_qp() will initialize qp->ibqp
+                 * except for qp->ibqp.qp_num.
+                 */
+                spin_lock_init(&qp->s_lock);
+                spin_lock_init(&qp->r_rq.lock);
+                atomic_set(&qp->refcount, 0);
+                init_waitqueue_head(&qp->wait);
+                tasklet_init(&qp->s_task,
+                             init_attr->qp_type == IB_QPT_RC ?
+                             ipath_do_rc_send : ipath_do_uc_send,
+                             (unsigned long)qp);
+                qp->piowait.next = LIST_POISON1;
+                qp->piowait.prev = LIST_POISON2;
+                qp->timerwait.next = LIST_POISON1;
+                qp->timerwait.prev = LIST_POISON2;
+                qp->state = IB_QPS_RESET;
+                qp->s_wq = swq;
+                qp->s_size = init_attr->cap.max_send_wr + 1;
+                qp->s_max_sge = init_attr->cap.max_send_sge;
+                qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
+                qp->s_flags = init_attr->sq_sig_type == IB_SIGNAL_REQ_WR ?
+                        1 << IPATH_S_SIGNAL_REQ_WR : 0;
+                dev = to_idev(ibpd->device);
+                err = ipath_alloc_qpn(&dev->qp_table, qp,
+                                      init_attr->qp_type);
+                if (err) {
+                        vfree(swq);
+                        vfree(qp->r_rq.wq);
+                        kfree(qp);
+                        ret = ERR_PTR(err);
+                        goto bail;
+                }
+                ipath_reset_qp(qp);
+
+                /* Tell the core driver that the kernel SMA is present. */
+                if (qp->ibqp.qp_type == IB_QPT_SMI)
+                        ipath_layer_set_verbs_flags(dev->dd,
+                                                    IPATH_VERBS_KERNEL_SMA);
+                break;
+
+        default:
+                /* Don't support raw QPs */
+                ret = ERR_PTR(-ENOSYS);
+                goto bail;
+        }
+
+        init_attr->cap.max_inline_data = 0;
+
+        ret = &qp->ibqp;
+
+bail:
+        return ret;
+}
+
+/**
+ * ipath_destroy_qp - destroy a queue pair
+ * @ibqp: the queue pair to destroy
+ *
+ * Returns 0 on success.
+ *
+ * Note that this can be called while the QP is actively sending or
+ * receiving!
+ */
+int ipath_destroy_qp(struct ib_qp *ibqp)
+{
+        struct ipath_qp *qp = to_iqp(ibqp);
+        struct ipath_ibdev *dev = to_idev(ibqp->device);
+        unsigned long flags;
+
+        /* Tell the core driver that the kernel SMA is gone. */
+        if (qp->ibqp.qp_type == IB_QPT_SMI)
+                ipath_layer_set_verbs_flags(dev->dd, 0);
+
+        spin_lock_irqsave(&qp->r_rq.lock, flags);
+        spin_lock(&qp->s_lock);
+        qp->state = IB_QPS_ERR;
+        spin_unlock(&qp->s_lock);
+        spin_unlock_irqrestore(&qp->r_rq.lock, flags);
+
+        /* Stop the sending tasklet. */
+        tasklet_kill(&qp->s_task);
+
+        /* Make sure the QP isn't on the timeout list. */
+        spin_lock_irqsave(&dev->pending_lock, flags);
+        if (qp->timerwait.next != LIST_POISON1)
+                list_del(&qp->timerwait);
+        if (qp->piowait.next != LIST_POISON1)
+                list_del(&qp->piowait);
+        spin_unlock_irqrestore(&dev->pending_lock, flags);
+
+        /*
+         * Make sure that the QP is not in the QPN table so receive
+         * interrupts will discard packets for this QP.  XXX Also remove QP
+         * from multicast table.
+         */
+        if (atomic_read(&qp->refcount) != 0)
+                ipath_free_qp(&dev->qp_table, qp);
+
+        vfree(qp->s_wq);
+        vfree(qp->r_rq.wq);
+        kfree(qp);
+        return 0;
+}
+
+/**
+ * ipath_init_qp_table - initialize the QP table for a device
+ * @idev: the device who's QP table we're initializing
+ * @size: the size of the QP table
+ *
+ * Returns 0 on success, otherwise returns an errno.
+ */
+int ipath_init_qp_table(struct ipath_ibdev *idev, int size)
+{
+        int i;
+        int ret;
+
+        idev->qp_table.last = 1;        /* QPN 0 and 1 are special. */
+        idev->qp_table.max = size;
+        idev->qp_table.nmaps = 1;
+        idev->qp_table.table = kzalloc(size * sizeof(*idev->qp_table.table),
+                                       GFP_KERNEL);
+        if (idev->qp_table.table == NULL) {
+                ret = -ENOMEM;
+                goto bail;
+        }
+
+        for (i = 0; i < ARRAY_SIZE(idev->qp_table.map); i++) {
+                atomic_set(&idev->qp_table.map[i].n_free, BITS_PER_PAGE);
+                idev->qp_table.map[i].page = NULL;
+        }
+
+        ret = 0;
+
+bail:
+        return ret;
+}
+
+/**
+ * ipath_sqerror_qp - put a QP's send queue into an error state
+ * @qp: QP who's send queue will be put into an error state
+ * @wc: the WC responsible for putting the QP in this state
+ *
+ * Flushes the send work queue.
+ * The QP s_lock should be held.
+ */
+
+void ipath_sqerror_qp(struct ipath_qp *qp, struct ib_wc *wc)
+{
+        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
+        struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
+
+        _VERBS_INFO("Send queue error on QP%d/%d: err: %d\n",
+                    qp->ibqp.qp_num, qp->remote_qpn, wc->status);
+
+        spin_lock(&dev->pending_lock);
+        /* XXX What if its already removed by the timeout code? */
+        if (qp->timerwait.next != LIST_POISON1)
+                list_del(&qp->timerwait);
+        if (qp->piowait.next != LIST_POISON1)
+                list_del(&qp->piowait);
+        spin_unlock(&dev->pending_lock);
+
+        ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 1);
+        if (++qp->s_last >= qp->s_size)
+                qp->s_last = 0;
+
+        wc->status = IB_WC_WR_FLUSH_ERR;
+
+        while (qp->s_last != qp->s_head) {
+                wc->wr_id = wqe->wr.wr_id;
+                wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
+                ipath_cq_enter(to_icq(qp->ibqp.send_cq), wc, 1);
+                if (++qp->s_last >= qp->s_size)
+                        qp->s_last = 0;
+                wqe = get_swqe_ptr(qp, qp->s_last);
+        }
+        qp->s_cur = qp->s_tail = qp->s_head;
+        qp->state = IB_QPS_SQE;
+}
+
+/**
+ * ipath_error_qp - put a QP into an error state
+ * @qp: the QP to put into an error state
+ *
+ * Flushes both send and receive work queues.
+ * QP r_rq.lock and s_lock should be held.
+ */
+
+void ipath_error_qp(struct ipath_qp *qp)
+{
+        struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
+        struct ib_wc wc;
+
+        _VERBS_INFO("QP%d/%d in error state\n",
+                    qp->ibqp.qp_num, qp->remote_qpn);
+
+        spin_lock(&dev->pending_lock);
+        /* XXX What if its already removed by the timeout code? */
+        if (qp->timerwait.next != LIST_POISON1)
+                list_del(&qp->timerwait);
+        if (qp->piowait.next != LIST_POISON1)
+                list_del(&qp->piowait);
+        spin_unlock(&dev->pending_lock);
+
+        wc.status = IB_WC_WR_FLUSH_ERR;
+        wc.vendor_err = 0;
+        wc.byte_len = 0;
+        wc.imm_data = 0;
+        wc.qp_num = qp->ibqp.qp_num;
+        wc.src_qp = 0;
+        wc.wc_flags = 0;
+        wc.pkey_index = 0;
+        wc.slid = 0;
+        wc.sl = 0;
+        wc.dlid_path_bits = 0;
+        wc.port_num = 0;
+
+        while (qp->s_last != qp->s_head) {
+                struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
+
+                wc.wr_id = wqe->wr.wr_id;
+                wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
+                if (++qp->s_last >= qp->s_size)
+                        qp->s_last = 0;
+                ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 1);
+        }
+        qp->s_cur = qp->s_tail = qp->s_head;
+        qp->s_hdrwords = 0;
+        qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
+
+        wc.opcode = IB_WC_RECV;
+        while (qp->r_rq.tail != qp->r_rq.head) {
+                wc.wr_id = get_rwqe_ptr(&qp->r_rq, qp->r_rq.tail)->wr_id;
+                if (++qp->r_rq.tail >= qp->r_rq.size)
+                        qp->r_rq.tail = 0;
+                ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
+        }
+}
+
+/**
+ * ipath_get_credit - flush the send work queue of a QP
+ * @qp: the qp who's send work queue to flush
+ * @aeth: the Acknowledge Extended Transport Header
+ *
+ * The QP s_lock should be held.
+ */
+void ipath_get_credit(struct ipath_qp *qp, u32 aeth)
+{
+        u32 credit = (aeth >> IPS_AETH_CREDIT_SHIFT) & IPS_AETH_CREDIT_MASK;
+
+        /*
+         * If the credit is invalid, we can send
+         * as many packets as we like.  Otherwise, we have to
+         * honor the credit field.
+         */
+        if (credit == IPS_AETH_CREDIT_INVAL) {
+                qp->s_lsn = (u32) -1;
+        } else if (qp->s_lsn != (u32) -1) {
+                /* Compute new LSN (i.e., MSN + credit) */
+                credit = (aeth + credit_table[credit]) & IPS_MSN_MASK;
+                if (ipath_cmp24(credit, qp->s_lsn) > 0)
+                        qp->s_lsn = credit;
+        }
+
+        /* Restart sending if it was blocked due to lack of credits. */
+        if (qp->s_cur != qp->s_head &&
+            (qp->s_lsn == (u32) -1 ||
+             ipath_cmp24(get_swqe_ptr(qp, qp->s_cur)->ssn,
+                         qp->s_lsn + 1) <= 0))
+                tasklet_hi_schedule(&qp->s_task);
+}