These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / staging / rdma / hfi1 / verbs_mcast.c
diff --git a/kernel/drivers/staging/rdma/hfi1/verbs_mcast.c b/kernel/drivers/staging/rdma/hfi1/verbs_mcast.c
new file mode 100644 (file)
index 0000000..afc6b4c
--- /dev/null
@@ -0,0 +1,385 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/rculist.h>
+
+#include "hfi.h"
+
+/**
+ * mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct
+ * @qp: the QP to link
+ */
+static struct hfi1_mcast_qp *mcast_qp_alloc(struct hfi1_qp *qp)
+{
+       struct hfi1_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 mcast_qp_free(struct hfi1_mcast_qp *mqp)
+{
+       struct hfi1_qp *qp = mqp->qp;
+
+       /* Notify hfi1_destroy_qp() if it is waiting. */
+       if (atomic_dec_and_test(&qp->refcount))
+               wake_up(&qp->wait);
+
+       kfree(mqp);
+}
+
+/**
+ * mcast_alloc - allocate the multicast GID structure
+ * @mgid: the multicast GID
+ *
+ * A list of QPs will be attached to this structure.
+ */
+static struct hfi1_mcast *mcast_alloc(union ib_gid *mgid)
+{
+       struct hfi1_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 mcast_free(struct hfi1_mcast *mcast)
+{
+       struct hfi1_mcast_qp *p, *tmp;
+
+       list_for_each_entry_safe(p, tmp, &mcast->qp_list, list)
+               mcast_qp_free(p);
+
+       kfree(mcast);
+}
+
+/**
+ * hfi1_mcast_find - search the global table for the given multicast GID
+ * @ibp: the IB port structure
+ * @mgid: the multicast GID to search for
+ *
+ * Returns NULL if not found.
+ *
+ * The caller is responsible for decrementing the reference count if found.
+ */
+struct hfi1_mcast *hfi1_mcast_find(struct hfi1_ibport *ibp, union ib_gid *mgid)
+{
+       struct rb_node *n;
+       unsigned long flags;
+       struct hfi1_mcast *mcast;
+
+       spin_lock_irqsave(&ibp->lock, flags);
+       n = ibp->mcast_tree.rb_node;
+       while (n) {
+               int ret;
+
+               mcast = rb_entry(n, struct hfi1_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(&ibp->lock, flags);
+                       goto bail;
+               }
+       }
+       spin_unlock_irqrestore(&ibp->lock, flags);
+
+       mcast = NULL;
+
+bail:
+       return mcast;
+}
+
+/**
+ * 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 mcast_add(struct hfi1_ibdev *dev, struct hfi1_ibport *ibp,
+                    struct hfi1_mcast *mcast, struct hfi1_mcast_qp *mqp)
+{
+       struct rb_node **n = &ibp->mcast_tree.rb_node;
+       struct rb_node *pn = NULL;
+       int ret;
+
+       spin_lock_irq(&ibp->lock);
+
+       while (*n) {
+               struct hfi1_mcast *tmcast;
+               struct hfi1_mcast_qp *p;
+
+               pn = *n;
+               tmcast = rb_entry(pn, struct hfi1_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 == hfi1_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 == hfi1_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, &ibp->mcast_tree);
+
+       ret = 0;
+
+bail:
+       spin_unlock_irq(&ibp->lock);
+
+       return ret;
+}
+
+int hfi1_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
+{
+       struct hfi1_qp *qp = to_iqp(ibqp);
+       struct hfi1_ibdev *dev = to_idev(ibqp->device);
+       struct hfi1_ibport *ibp;
+       struct hfi1_mcast *mcast;
+       struct hfi1_mcast_qp *mqp;
+       int ret;
+
+       if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) {
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       /*
+        * Allocate data structures since its better to do this outside of
+        * spin locks and it will most likely be needed.
+        */
+       mcast = mcast_alloc(gid);
+       if (mcast == NULL) {
+               ret = -ENOMEM;
+               goto bail;
+       }
+       mqp = mcast_qp_alloc(qp);
+       if (mqp == NULL) {
+               mcast_free(mcast);
+               ret = -ENOMEM;
+               goto bail;
+       }
+       ibp = to_iport(ibqp->device, qp->port_num);
+       switch (mcast_add(dev, ibp, mcast, mqp)) {
+       case ESRCH:
+               /* Neither was used: OK to attach the same QP twice. */
+               mcast_qp_free(mqp);
+               mcast_free(mcast);
+               break;
+
+       case EEXIST:            /* The mcast wasn't used */
+               mcast_free(mcast);
+               break;
+
+       case ENOMEM:
+               /* Exceeded the maximum number of mcast groups. */
+               mcast_qp_free(mqp);
+               mcast_free(mcast);
+               ret = -ENOMEM;
+               goto bail;
+
+       default:
+               break;
+       }
+
+       ret = 0;
+
+bail:
+       return ret;
+}
+
+int hfi1_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
+{
+       struct hfi1_qp *qp = to_iqp(ibqp);
+       struct hfi1_ibdev *dev = to_idev(ibqp->device);
+       struct hfi1_ibport *ibp = to_iport(ibqp->device, qp->port_num);
+       struct hfi1_mcast *mcast = NULL;
+       struct hfi1_mcast_qp *p, *tmp;
+       struct rb_node *n;
+       int last = 0;
+       int ret;
+
+       if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) {
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       spin_lock_irq(&ibp->lock);
+
+       /* Find the GID in the mcast table. */
+       n = ibp->mcast_tree.rb_node;
+       while (1) {
+               if (n == NULL) {
+                       spin_unlock_irq(&ibp->lock);
+                       ret = -EINVAL;
+                       goto bail;
+               }
+
+               mcast = rb_entry(n, struct hfi1_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, &ibp->mcast_tree);
+                       last = 1;
+               }
+               break;
+       }
+
+       spin_unlock_irq(&ibp->lock);
+
+       if (p) {
+               /*
+                * Wait for any list walkers to finish before freeing the
+                * list element.
+                */
+               wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1);
+               mcast_qp_free(p);
+       }
+       if (last) {
+               atomic_dec(&mcast->refcount);
+               wait_event(mcast->wait, !atomic_read(&mcast->refcount));
+               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 hfi1_mcast_tree_empty(struct hfi1_ibport *ibp)
+{
+       return ibp->mcast_tree.rb_node == NULL;
+}