drivers/infiniband/hw/ipath/ipath_verbs_mcast.c - kernel/skids - Git at Google

 /*
  * 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 <linux/sched.h>
 #include <linux/slab.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;
 }
	/*
	* 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 <linux/sched.h>
	#include <linux/slab.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;
	}