Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / hw / ipath / ipath_qp.c
diff --git a/kernel/drivers/infiniband/hw/ipath/ipath_qp.c b/kernel/drivers/infiniband/hw/ipath/ipath_qp.c
new file mode 100644 (file)
index 0000000..face876
--- /dev/null
@@ -0,0 +1,1080 @@
+/*
+ * 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 <linux/err.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "ipath_verbs.h"
+#include "ipath_kernel.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)
+
+/*
+ * 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 void get_map_page(struct ipath_qp_table *qpt, struct qpn_map *map)
+{
+       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);
+}
+
+
+static int alloc_qpn(struct ipath_qp_table *qpt, enum ib_qp_type type)
+{
+       u32 i, offset, max_scan, qpn;
+       struct qpn_map *map;
+       u32 ret = -1;
+
+       if (type == IB_QPT_SMI)
+               ret = 0;
+       else if (type == IB_QPT_GSI)
+               ret = 1;
+
+       if (ret != -1) {
+               map = &qpt->map[0];
+               if (unlikely(!map->page)) {
+                       get_map_page(qpt, map);
+                       if (unlikely(!map->page)) {
+                               ret = -ENOMEM;
+                               goto bail;
+                       }
+               }
+               if (!test_and_set_bit(ret, map->page))
+                       atomic_dec(&map->n_free);
+               else
+                       ret = -EBUSY;
+               goto bail;
+       }
+
+       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)) {
+                       get_map_page(qpt, map);
+                       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 = -ENOMEM;
+
+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.
+ */
+static int ipath_alloc_qpn(struct ipath_qp_table *qpt, struct ipath_qp *qp,
+                          enum ib_qp_type type)
+{
+       unsigned long flags;
+       int ret;
+
+       ret = alloc_qpn(qpt, type);
+       if (ret < 0)
+               goto bail;
+       qp->ibqp.qp_num = ret;
+
+       /* Add the QP to the hash table. */
+       spin_lock_irqsave(&qpt->lock, flags);
+
+       ret %= qpt->max;
+       qp->next = qpt->table[ret];
+       qpt->table[ret] = 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.
+ */
+static void ipath_free_qp(struct ipath_qp_table *qpt, struct ipath_qp *qp)
+{
+       struct ipath_qp *q, **qpp;
+       unsigned long flags;
+
+       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);
+                       break;
+               }
+       }
+
+       spin_unlock_irqrestore(&qpt->lock, flags);
+}
+
+/**
+ * ipath_free_all_qps - check for QPs still in use
+ * @qpt: the QP table to empty
+ *
+ * There should not be any QPs still in use.
+ * Free memory for table.
+ */
+unsigned ipath_free_all_qps(struct ipath_qp_table *qpt)
+{
+       unsigned long flags;
+       struct ipath_qp *qp;
+       u32 n, qp_inuse = 0;
+
+       spin_lock_irqsave(&qpt->lock, flags);
+       for (n = 0; n < qpt->max; n++) {
+               qp = qpt->table[n];
+               qpt->table[n] = NULL;
+
+               for (; qp; qp = qp->next)
+                       qp_inuse++;
+       }
+       spin_unlock_irqrestore(&qpt->lock, flags);
+
+       for (n = 0; n < ARRAY_SIZE(qpt->map); n++)
+               if (qpt->map[n].page)
+                       free_page((unsigned long) qpt->map[n].page);
+       return qp_inuse;
+}
+
+/**
+ * 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
+ * @type: the QP type
+ */
+static void ipath_reset_qp(struct ipath_qp *qp, enum ib_qp_type type)
+{
+       qp->remote_qpn = 0;
+       qp->qkey = 0;
+       qp->qp_access_flags = 0;
+       atomic_set(&qp->s_dma_busy, 0);
+       qp->s_flags &= IPATH_S_SIGNAL_REQ_WR;
+       qp->s_hdrwords = 0;
+       qp->s_wqe = NULL;
+       qp->s_pkt_delay = 0;
+       qp->s_draining = 0;
+       qp->s_psn = 0;
+       qp->r_psn = 0;
+       qp->r_msn = 0;
+       if (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->r_nak_state = 0;
+       qp->r_aflags = 0;
+       qp->r_flags = 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;
+       memset(qp->s_ack_queue, 0, sizeof(qp->s_ack_queue));
+       qp->r_head_ack_queue = 0;
+       qp->s_tail_ack_queue = 0;
+       qp->s_num_rd_atomic = 0;
+       if (qp->r_rq.wq) {
+               qp->r_rq.wq->head = 0;
+               qp->r_rq.wq->tail = 0;
+       }
+}
+
+/**
+ * ipath_error_qp - put a QP into the error state
+ * @qp: the QP to put into the error state
+ * @err: the receive completion error to signal if a RWQE is active
+ *
+ * Flushes both send and receive work queues.
+ * Returns true if last WQE event should be generated.
+ * The QP s_lock should be held and interrupts disabled.
+ * If we are already in error state, just return.
+ */
+
+int ipath_error_qp(struct ipath_qp *qp, enum ib_wc_status err)
+{
+       struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
+       struct ib_wc wc;
+       int ret = 0;
+
+       if (qp->state == IB_QPS_ERR)
+               goto bail;
+
+       qp->state = IB_QPS_ERR;
+
+       spin_lock(&dev->pending_lock);
+       if (!list_empty(&qp->timerwait))
+               list_del_init(&qp->timerwait);
+       if (!list_empty(&qp->piowait))
+               list_del_init(&qp->piowait);
+       spin_unlock(&dev->pending_lock);
+
+       /* Schedule the sending tasklet to drain the send work queue. */
+       if (qp->s_last != qp->s_head)
+               ipath_schedule_send(qp);
+
+       memset(&wc, 0, sizeof(wc));
+       wc.qp = &qp->ibqp;
+       wc.opcode = IB_WC_RECV;
+
+       if (test_and_clear_bit(IPATH_R_WRID_VALID, &qp->r_aflags)) {
+               wc.wr_id = qp->r_wr_id;
+               wc.status = err;
+               ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
+       }
+       wc.status = IB_WC_WR_FLUSH_ERR;
+
+       if (qp->r_rq.wq) {
+               struct ipath_rwq *wq;
+               u32 head;
+               u32 tail;
+
+               spin_lock(&qp->r_rq.lock);
+
+               /* sanity check pointers before trusting them */
+               wq = qp->r_rq.wq;
+               head = wq->head;
+               if (head >= qp->r_rq.size)
+                       head = 0;
+               tail = wq->tail;
+               if (tail >= qp->r_rq.size)
+                       tail = 0;
+               while (tail != head) {
+                       wc.wr_id = get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
+                       if (++tail >= qp->r_rq.size)
+                               tail = 0;
+                       ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
+               }
+               wq->tail = tail;
+
+               spin_unlock(&qp->r_rq.lock);
+       } else if (qp->ibqp.event_handler)
+               ret = 1;
+
+bail:
+       return ret;
+}
+
+/**
+ * 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
+ * @udata: user data for ipathverbs.so
+ *
+ * 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 ib_udata *udata)
+{
+       struct ipath_ibdev *dev = to_idev(ibqp->device);
+       struct ipath_qp *qp = to_iqp(ibqp);
+       enum ib_qp_state cur_state, new_state;
+       int lastwqe = 0;
+       int ret;
+
+       spin_lock_irq(&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, IB_LINK_LAYER_UNSPECIFIED))
+               goto inval;
+
+       if (attr_mask & IB_QP_AV) {
+               if (attr->ah_attr.dlid == 0 ||
+                   attr->ah_attr.dlid >= IPATH_MULTICAST_LID_BASE)
+                       goto inval;
+
+               if ((attr->ah_attr.ah_flags & IB_AH_GRH) &&
+                   (attr->ah_attr.grh.sgid_index > 1))
+                       goto inval;
+       }
+
+       if (attr_mask & IB_QP_PKEY_INDEX)
+               if (attr->pkey_index >= ipath_get_npkeys(dev->dd))
+                       goto inval;
+
+       if (attr_mask & IB_QP_MIN_RNR_TIMER)
+               if (attr->min_rnr_timer > 31)
+                       goto inval;
+
+       if (attr_mask & IB_QP_PORT)
+               if (attr->port_num == 0 ||
+                   attr->port_num > ibqp->device->phys_port_cnt)
+                       goto inval;
+
+       /*
+        * don't allow invalid Path MTU values or greater than 2048
+        * unless we are configured for a 4KB MTU
+        */
+       if ((attr_mask & IB_QP_PATH_MTU) &&
+               (ib_mtu_enum_to_int(attr->path_mtu) == -1 ||
+               (attr->path_mtu > IB_MTU_2048 && !ipath_mtu4096)))
+               goto inval;
+
+       if (attr_mask & IB_QP_PATH_MIG_STATE)
+               if (attr->path_mig_state != IB_MIG_MIGRATED &&
+                   attr->path_mig_state != IB_MIG_REARM)
+                       goto inval;
+
+       if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+               if (attr->max_dest_rd_atomic > IPATH_MAX_RDMA_ATOMIC)
+                       goto inval;
+
+       switch (new_state) {
+       case IB_QPS_RESET:
+               if (qp->state != IB_QPS_RESET) {
+                       qp->state = IB_QPS_RESET;
+                       spin_lock(&dev->pending_lock);
+                       if (!list_empty(&qp->timerwait))
+                               list_del_init(&qp->timerwait);
+                       if (!list_empty(&qp->piowait))
+                               list_del_init(&qp->piowait);
+                       spin_unlock(&dev->pending_lock);
+                       qp->s_flags &= ~IPATH_S_ANY_WAIT;
+                       spin_unlock_irq(&qp->s_lock);
+                       /* Stop the sending tasklet */
+                       tasklet_kill(&qp->s_task);
+                       wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
+                       spin_lock_irq(&qp->s_lock);
+               }
+               ipath_reset_qp(qp, ibqp->qp_type);
+               break;
+
+       case IB_QPS_SQD:
+               qp->s_draining = qp->s_last != qp->s_cur;
+               qp->state = new_state;
+               break;
+
+       case IB_QPS_SQE:
+               if (qp->ibqp.qp_type == IB_QPT_RC)
+                       goto inval;
+               qp->state = new_state;
+               break;
+
+       case IB_QPS_ERR:
+               lastwqe = ipath_error_qp(qp, IB_WC_WR_FLUSH_ERR);
+               break;
+
+       default:
+               qp->state = new_state;
+               break;
+       }
+
+       if (attr_mask & IB_QP_PKEY_INDEX)
+               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_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) {
+               qp->remote_ah_attr = attr->ah_attr;
+               qp->s_dmult = ipath_ib_rate_to_mult(attr->ah_attr.static_rate);
+       }
+
+       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)
+               qp->r_min_rnr_timer = attr->min_rnr_timer;
+
+       if (attr_mask & IB_QP_TIMEOUT)
+               qp->timeout = attr->timeout;
+
+       if (attr_mask & IB_QP_QKEY)
+               qp->qkey = attr->qkey;
+
+       if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+               qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
+
+       if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
+               qp->s_max_rd_atomic = attr->max_rd_atomic;
+
+       spin_unlock_irq(&qp->s_lock);
+
+       if (lastwqe) {
+               struct ib_event ev;
+
+               ev.device = qp->ibqp.device;
+               ev.element.qp = &qp->ibqp;
+               ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+               qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+       }
+       ret = 0;
+       goto bail;
+
+inval:
+       spin_unlock_irq(&qp->s_lock);
+       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->ibqp.srq ? 0 : 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 = qp->s_draining;
+       attr->max_rd_atomic = qp->s_max_rd_atomic;
+       attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
+       attr->min_rnr_timer = qp->r_min_rnr_timer;
+       attr->port_num = 1;
+       attr->timeout = qp->timeout;
+       attr->retry_cnt = qp->s_retry_cnt;
+       attr->rnr_retry = qp->s_rnr_retry_cnt;
+       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;
+       if (qp->s_flags & IPATH_S_SIGNAL_REQ_WR)
+               init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
+       else
+               init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
+       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.
+ */
+__be32 ipath_compute_aeth(struct ipath_qp *qp)
+{
+       u32 aeth = qp->r_msn & IPATH_MSN_MASK;
+
+       if (qp->ibqp.srq) {
+               /*
+                * Shared receive queues don't generate credits.
+                * Set the credit field to the invalid value.
+                */
+               aeth |= IPATH_AETH_CREDIT_INVAL << IPATH_AETH_CREDIT_SHIFT;
+       } else {
+               u32 min, max, x;
+               u32 credits;
+               struct ipath_rwq *wq = qp->r_rq.wq;
+               u32 head;
+               u32 tail;
+
+               /* sanity check pointers before trusting them */
+               head = wq->head;
+               if (head >= qp->r_rq.size)
+                       head = 0;
+               tail = wq->tail;
+               if (tail >= qp->r_rq.size)
+                       tail = 0;
+               /*
+                * Compute the number of credits available (RWQEs).
+                * XXX Not holding the r_rq.lock here so there is a small
+                * chance that the pair of reads are not atomic.
+                */
+               credits = head - tail;
+               if ((int)credits < 0)
+                       credits += qp->r_rq.size;
+               /*
+                * Binary search the credit table to find the code to
+                * use.
+                */
+               min = 0;
+               max = 31;
+               for (;;) {
+                       x = (min + max) / 2;
+                       if (credit_table[x] == credits)
+                               break;
+                       if (credit_table[x] > credits)
+                               max = x;
+                       else if (min == x)
+                               break;
+                       else
+                               min = x;
+               }
+               aeth |= x << IPATH_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;
+       size_t sg_list_sz;
+       struct ib_qp *ret;
+
+       if (init_attr->create_flags) {
+               ret = ERR_PTR(-EINVAL);
+               goto bail;
+       }
+
+       if (init_attr->cap.max_send_sge > ib_ipath_max_sges ||
+           init_attr->cap.max_send_wr > ib_ipath_max_qp_wrs) {
+               ret = ERR_PTR(-EINVAL);
+               goto bail;
+       }
+
+       /* Check receive queue parameters if no SRQ is specified. */
+       if (!init_attr->srq) {
+               if (init_attr->cap.max_recv_sge > ib_ipath_max_sges ||
+                   init_attr->cap.max_recv_wr > ib_ipath_max_qp_wrs) {
+                       ret = ERR_PTR(-EINVAL);
+                       goto bail;
+               }
+               if (init_attr->cap.max_send_sge +
+                   init_attr->cap.max_send_wr +
+                   init_attr->cap.max_recv_sge +
+                   init_attr->cap.max_recv_wr == 0) {
+                       ret = ERR_PTR(-EINVAL);
+                       goto bail;
+               }
+       }
+
+       switch (init_attr->qp_type) {
+       case IB_QPT_UC:
+       case IB_QPT_RC:
+       case IB_QPT_UD:
+       case IB_QPT_SMI:
+       case IB_QPT_GSI:
+               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;
+               }
+               sz = sizeof(*qp);
+               sg_list_sz = 0;
+               if (init_attr->srq) {
+                       struct ipath_srq *srq = to_isrq(init_attr->srq);
+
+                       if (srq->rq.max_sge > 1)
+                               sg_list_sz = sizeof(*qp->r_sg_list) *
+                                       (srq->rq.max_sge - 1);
+               } else if (init_attr->cap.max_recv_sge > 1)
+                       sg_list_sz = sizeof(*qp->r_sg_list) *
+                               (init_attr->cap.max_recv_sge - 1);
+               qp = kmalloc(sz + sg_list_sz, GFP_KERNEL);
+               if (!qp) {
+                       ret = ERR_PTR(-ENOMEM);
+                       goto bail_swq;
+               }
+               if (sg_list_sz && (init_attr->qp_type == IB_QPT_UD ||
+                   init_attr->qp_type == IB_QPT_SMI ||
+                   init_attr->qp_type == IB_QPT_GSI)) {
+                       qp->r_ud_sg_list = kmalloc(sg_list_sz, GFP_KERNEL);
+                       if (!qp->r_ud_sg_list) {
+                               ret = ERR_PTR(-ENOMEM);
+                               goto bail_qp;
+                       }
+               } else
+                       qp->r_ud_sg_list = NULL;
+               if (init_attr->srq) {
+                       sz = 0;
+                       qp->r_rq.size = 0;
+                       qp->r_rq.max_sge = 0;
+                       qp->r_rq.wq = NULL;
+                       init_attr->cap.max_recv_wr = 0;
+                       init_attr->cap.max_recv_sge = 0;
+               } else {
+                       qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
+                       qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
+                       sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
+                               sizeof(struct ipath_rwqe);
+                       qp->r_rq.wq = vmalloc_user(sizeof(struct ipath_rwq) +
+                                             qp->r_rq.size * sz);
+                       if (!qp->r_rq.wq) {
+                               ret = ERR_PTR(-ENOMEM);
+                               goto bail_sg_list;
+                       }
+               }
+
+               /*
+                * 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);
+               init_waitqueue_head(&qp->wait_dma);
+               tasklet_init(&qp->s_task, ipath_do_send, (unsigned long)qp);
+               INIT_LIST_HEAD(&qp->piowait);
+               INIT_LIST_HEAD(&qp->timerwait);
+               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;
+               if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
+                       qp->s_flags = IPATH_S_SIGNAL_REQ_WR;
+               else
+                       qp->s_flags = 0;
+               dev = to_idev(ibpd->device);
+               err = ipath_alloc_qpn(&dev->qp_table, qp,
+                                     init_attr->qp_type);
+               if (err) {
+                       ret = ERR_PTR(err);
+                       vfree(qp->r_rq.wq);
+                       goto bail_sg_list;
+               }
+               qp->ip = NULL;
+               qp->s_tx = NULL;
+               ipath_reset_qp(qp, init_attr->qp_type);
+               break;
+
+       default:
+               /* Don't support raw QPs */
+               ret = ERR_PTR(-ENOSYS);
+               goto bail;
+       }
+
+       init_attr->cap.max_inline_data = 0;
+
+       /*
+        * Return the address of the RWQ as the offset to mmap.
+        * See ipath_mmap() for details.
+        */
+       if (udata && udata->outlen >= sizeof(__u64)) {
+               if (!qp->r_rq.wq) {
+                       __u64 offset = 0;
+
+                       err = ib_copy_to_udata(udata, &offset,
+                                              sizeof(offset));
+                       if (err) {
+                               ret = ERR_PTR(err);
+                               goto bail_ip;
+                       }
+               } else {
+                       u32 s = sizeof(struct ipath_rwq) +
+                               qp->r_rq.size * sz;
+
+                       qp->ip =
+                           ipath_create_mmap_info(dev, s,
+                                                  ibpd->uobject->context,
+                                                  qp->r_rq.wq);
+                       if (!qp->ip) {
+                               ret = ERR_PTR(-ENOMEM);
+                               goto bail_ip;
+                       }
+
+                       err = ib_copy_to_udata(udata, &(qp->ip->offset),
+                                              sizeof(qp->ip->offset));
+                       if (err) {
+                               ret = ERR_PTR(err);
+                               goto bail_ip;
+                       }
+               }
+       }
+
+       spin_lock(&dev->n_qps_lock);
+       if (dev->n_qps_allocated == ib_ipath_max_qps) {
+               spin_unlock(&dev->n_qps_lock);
+               ret = ERR_PTR(-ENOMEM);
+               goto bail_ip;
+       }
+
+       dev->n_qps_allocated++;
+       spin_unlock(&dev->n_qps_lock);
+
+       if (qp->ip) {
+               spin_lock_irq(&dev->pending_lock);
+               list_add(&qp->ip->pending_mmaps, &dev->pending_mmaps);
+               spin_unlock_irq(&dev->pending_lock);
+       }
+
+       ret = &qp->ibqp;
+       goto bail;
+
+bail_ip:
+       if (qp->ip)
+               kref_put(&qp->ip->ref, ipath_release_mmap_info);
+       else
+               vfree(qp->r_rq.wq);
+       ipath_free_qp(&dev->qp_table, qp);
+       free_qpn(&dev->qp_table, qp->ibqp.qp_num);
+bail_sg_list:
+       kfree(qp->r_ud_sg_list);
+bail_qp:
+       kfree(qp);
+bail_swq:
+       vfree(swq);
+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);
+
+       /* Make sure HW and driver activity is stopped. */
+       spin_lock_irq(&qp->s_lock);
+       if (qp->state != IB_QPS_RESET) {
+               qp->state = IB_QPS_RESET;
+               spin_lock(&dev->pending_lock);
+               if (!list_empty(&qp->timerwait))
+                       list_del_init(&qp->timerwait);
+               if (!list_empty(&qp->piowait))
+                       list_del_init(&qp->piowait);
+               spin_unlock(&dev->pending_lock);
+               qp->s_flags &= ~IPATH_S_ANY_WAIT;
+               spin_unlock_irq(&qp->s_lock);
+               /* Stop the sending tasklet */
+               tasklet_kill(&qp->s_task);
+               wait_event(qp->wait_dma, !atomic_read(&qp->s_dma_busy));
+       } else
+               spin_unlock_irq(&qp->s_lock);
+
+       ipath_free_qp(&dev->qp_table, qp);
+
+       if (qp->s_tx) {
+               atomic_dec(&qp->refcount);
+               if (qp->s_tx->txreq.flags & IPATH_SDMA_TXREQ_F_FREEBUF)
+                       kfree(qp->s_tx->txreq.map_addr);
+               spin_lock_irq(&dev->pending_lock);
+               list_add(&qp->s_tx->txreq.list, &dev->txreq_free);
+               spin_unlock_irq(&dev->pending_lock);
+               qp->s_tx = NULL;
+       }
+
+       wait_event(qp->wait, !atomic_read(&qp->refcount));
+
+       /* all user's cleaned up, mark it available */
+       free_qpn(&dev->qp_table, qp->ibqp.qp_num);
+       spin_lock(&dev->n_qps_lock);
+       dev->n_qps_allocated--;
+       spin_unlock(&dev->n_qps_lock);
+
+       if (qp->ip)
+               kref_put(&qp->ip->ref, ipath_release_mmap_info);
+       else
+               vfree(qp->r_rq.wq);
+       kfree(qp->r_ud_sg_list);
+       vfree(qp->s_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_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 >> IPATH_AETH_CREDIT_SHIFT) & IPATH_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 == IPATH_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]) & IPATH_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_flags & IPATH_S_WAIT_SSN_CREDIT) &&
+           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))
+               ipath_schedule_send(qp);
+}