diff options
Diffstat (limited to 'drivers/infiniband/hw/ipath/ipath_verbs_mcast.c')
| -rw-r--r-- | drivers/infiniband/hw/ipath/ipath_verbs_mcast.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c b/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c new file mode 100644 index 0000000..d73e322 --- /dev/null +++ b/drivers/infiniband/hw/ipath/ipath_verbs_mcast.c @@ -0,0 +1,362 @@ +/* + * Copyright (c) 2006, 2007 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/rculist.h> + +#include "ipath_verbs.h" + +/* + * Global table of GID to attached QPs. + * The table is global to all ipath devices since a send from one QP/device + * needs to be locally routed to any locally attached QPs on the same + * or different device. + */ +static struct rb_root mcast_tree; +static DEFINE_SPINLOCK(mcast_lock); + +/** + * ipath_mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct + * @qp: the QP to link + */ +static struct ipath_mcast_qp *ipath_mcast_qp_alloc(struct ipath_qp *qp) +{ + struct ipath_mcast_qp *mqp; + + mqp = kmalloc(sizeof *mqp, GFP_KERNEL); + if (!mqp) + goto bail; + + mqp->qp = qp; + atomic_inc(&qp->refcount); + +bail: + return mqp; +} + +static void ipath_mcast_qp_free(struct ipath_mcast_qp *mqp) +{ + struct ipath_qp *qp = mqp->qp; + + /* Notify ipath_destroy_qp() if it is waiting. */ + if (atomic_dec_and_test(&qp->refcount)) + wake_up(&qp->wait); + + kfree(mqp); +} + +/** + * ipath_mcast_alloc - allocate the multicast GID structure + * @mgid: the multicast GID + * + * A list of QPs will be attached to this structure. + */ +static struct ipath_mcast *ipath_mcast_alloc(union ib_gid *mgid) +{ + struct ipath_mcast *mcast; + + mcast = kmalloc(sizeof *mcast, GFP_KERNEL); + if (!mcast) + goto bail; + + mcast->mgid = *mgid; + INIT_LIST_HEAD(&mcast->qp_list); + init_waitqueue_head(&mcast->wait); + atomic_set(&mcast->refcount, 0); + mcast->n_attached = 0; + +bail: + return mcast; +} + +static void ipath_mcast_free(struct ipath_mcast *mcast) +{ + struct ipath_mcast_qp *p, *tmp; + + list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) + ipath_mcast_qp_free(p); + + kfree(mcast); +} + +/** + * ipath_mcast_find - search the global table for the given multicast GID + * @mgid: the multicast GID to search for + * + * Returns NULL if not found. + * + * The caller is responsible for decrementing the reference count if found. + */ +struct ipath_mcast *ipath_mcast_find(union ib_gid *mgid) +{ + struct rb_node *n; + unsigned long flags; + struct ipath_mcast *mcast; + + spin_lock_irqsave(&mcast_lock, flags); + n = mcast_tree.rb_node; + while (n) { + int ret; + + mcast = rb_entry(n, struct ipath_mcast, rb_node); + + ret = memcmp(mgid->raw, mcast->mgid.raw, + sizeof(union ib_gid)); + if (ret < 0) + n = n->rb_left; + else if (ret > 0) + n = n->rb_right; + else { + atomic_inc(&mcast->refcount); + spin_unlock_irqrestore(&mcast_lock, flags); + goto bail; + } + } + spin_unlock_irqrestore(&mcast_lock, flags); + + mcast = NULL; + +bail: + return mcast; +} + +/** + * ipath_mcast_add - insert mcast GID into table and attach QP struct + * @mcast: the mcast GID table + * @mqp: the QP to attach + * + * Return zero if both were added. Return EEXIST if the GID was already in + * the table but the QP was added. Return ESRCH if the QP was already + * attached and neither structure was added. + */ +static int ipath_mcast_add(struct ipath_ibdev *dev, + struct ipath_mcast *mcast, + struct ipath_mcast_qp *mqp) +{ + struct rb_node **n = &mcast_tree.rb_node; + struct rb_node *pn = NULL; + int ret; + + spin_lock_irq(&mcast_lock); + + while (*n) { + struct ipath_mcast *tmcast; + struct ipath_mcast_qp *p; + + pn = *n; + tmcast = rb_entry(pn, struct ipath_mcast, rb_node); + + ret = memcmp(mcast->mgid.raw, tmcast->mgid.raw, + sizeof(union ib_gid)); + if (ret < 0) { + n = &pn->rb_left; + continue; + } + if (ret > 0) { + n = &pn->rb_right; + continue; + } + + /* Search the QP list to see if this is already there. */ + list_for_each_entry_rcu(p, &tmcast->qp_list, list) { + if (p->qp == mqp->qp) { + ret = ESRCH; + goto bail; + } + } + if (tmcast->n_attached == ib_ipath_max_mcast_qp_attached) { + ret = ENOMEM; + goto bail; + } + + tmcast->n_attached++; + + list_add_tail_rcu(&mqp->list, &tmcast->qp_list); + ret = EEXIST; + goto bail; + } + + spin_lock(&dev->n_mcast_grps_lock); + if (dev->n_mcast_grps_allocated == ib_ipath_max_mcast_grps) { + spin_unlock(&dev->n_mcast_grps_lock); + ret = ENOMEM; + goto bail; + } + + dev->n_mcast_grps_allocated++; + spin_unlock(&dev->n_mcast_grps_lock); + + mcast->n_attached++; + + list_add_tail_rcu(&mqp->list, &mcast->qp_list); + + atomic_inc(&mcast->refcount); + rb_link_node(&mcast->rb_node, pn, n); + rb_insert_color(&mcast->rb_node, &mcast_tree); + + ret = 0; + +bail: + spin_unlock_irq(&mcast_lock); + + return ret; +} + +int ipath_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) +{ + struct ipath_qp *qp = to_iqp(ibqp); + struct ipath_ibdev *dev = to_idev(ibqp->device); + struct ipath_mcast *mcast; + struct ipath_mcast_qp *mqp; + int ret; + + /* + * Allocate data structures since its better to do this outside of + * spin locks and it will most likely be needed. + */ + mcast = ipath_mcast_alloc(gid); + if (mcast == NULL) { + ret = -ENOMEM; + goto bail; + } + mqp = ipath_mcast_qp_alloc(qp); + if (mqp == NULL) { + ipath_mcast_free(mcast); + ret = -ENOMEM; + goto bail; + } + switch (ipath_mcast_add(dev, mcast, mqp)) { + case ESRCH: + /* Neither was used: can't attach the same QP twice. */ + ipath_mcast_qp_free(mqp); + ipath_mcast_free(mcast); + ret = -EINVAL; + goto bail; + case EEXIST: /* The mcast wasn't used */ + ipath_mcast_free(mcast); + break; + case ENOMEM: + /* Exceeded the maximum number of mcast groups. */ + ipath_mcast_qp_free(mqp); + ipath_mcast_free(mcast); + ret = -ENOMEM; + goto bail; + default: + break; + } + + ret = 0; + +bail: + return ret; +} + +int ipath_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid) +{ + struct ipath_qp *qp = to_iqp(ibqp); + struct ipath_ibdev *dev = to_idev(ibqp->device); + struct ipath_mcast *mcast = NULL; + struct ipath_mcast_qp *p, *tmp; + struct rb_node *n; + int last = 0; + int ret; + + spin_lock_irq(&mcast_lock); + + /* Find the GID in the mcast table. */ + n = mcast_tree.rb_node; + while (1) { + if (n == NULL) { + spin_unlock_irq(&mcast_lock); + ret = -EINVAL; + goto bail; + } + + mcast = rb_entry(n, struct ipath_mcast, rb_node); + ret = memcmp(gid->raw, mcast->mgid.raw, + sizeof(union ib_gid)); + if (ret < 0) + n = n->rb_left; + else if (ret > 0) + n = n->rb_right; + else + break; + } + + /* Search the QP list. */ + list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) { + if (p->qp != qp) + continue; + /* + * We found it, so remove it, but don't poison the forward + * link until we are sure there are no list walkers. + */ + list_del_rcu(&p->list); + mcast->n_attached--; + + /* If this was the last attached QP, remove the GID too. */ + if (list_empty(&mcast->qp_list)) { + rb_erase(&mcast->rb_node, &mcast_tree); + last = 1; + } + break; + } + + spin_unlock_irq(&mcast_lock); + + if (p) { + /* + * Wait for any list walkers to finish before freeing the + * list element. + */ + wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1); + ipath_mcast_qp_free(p); + } + if (last) { + atomic_dec(&mcast->refcount); + wait_event(mcast->wait, !atomic_read(&mcast->refcount)); + ipath_mcast_free(mcast); + spin_lock_irq(&dev->n_mcast_grps_lock); + dev->n_mcast_grps_allocated--; + spin_unlock_irq(&dev->n_mcast_grps_lock); + } + + ret = 0; + +bail: + return ret; +} + +int ipath_mcast_tree_empty(void) +{ + return mcast_tree.rb_node == NULL; +} |
