2 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 #include <linux/list.h>
34 #include <linux/rcupdate.h>
36 #include "ipath_verbs.h"
39 * Global table of GID to attached QPs.
40 * The table is global to all ipath devices since a send from one QP/device
41 * needs to be locally routed to any locally attached QPs on the same
42 * or different device.
44 static struct rb_root mcast_tree
;
45 static DEFINE_SPINLOCK(mcast_lock
);
48 * ipath_mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct
51 static struct ipath_mcast_qp
*ipath_mcast_qp_alloc(struct ipath_qp
*qp
)
53 struct ipath_mcast_qp
*mqp
;
55 mqp
= kmalloc(sizeof *mqp
, GFP_KERNEL
);
60 atomic_inc(&qp
->refcount
);
66 static void ipath_mcast_qp_free(struct ipath_mcast_qp
*mqp
)
68 struct ipath_qp
*qp
= mqp
->qp
;
70 /* Notify ipath_destroy_qp() if it is waiting. */
71 if (atomic_dec_and_test(&qp
->refcount
))
78 * ipath_mcast_alloc - allocate the multicast GID structure
79 * @mgid: the multicast GID
81 * A list of QPs will be attached to this structure.
83 static struct ipath_mcast
*ipath_mcast_alloc(union ib_gid
*mgid
)
85 struct ipath_mcast
*mcast
;
87 mcast
= kmalloc(sizeof *mcast
, GFP_KERNEL
);
92 INIT_LIST_HEAD(&mcast
->qp_list
);
93 init_waitqueue_head(&mcast
->wait
);
94 atomic_set(&mcast
->refcount
, 0);
100 static void ipath_mcast_free(struct ipath_mcast
*mcast
)
102 struct ipath_mcast_qp
*p
, *tmp
;
104 list_for_each_entry_safe(p
, tmp
, &mcast
->qp_list
, list
)
105 ipath_mcast_qp_free(p
);
111 * ipath_mcast_find - search the global table for the given multicast GID
112 * @mgid: the multicast GID to search for
114 * Returns NULL if not found.
116 * The caller is responsible for decrementing the reference count if found.
118 struct ipath_mcast
*ipath_mcast_find(union ib_gid
*mgid
)
122 struct ipath_mcast
*mcast
;
124 spin_lock_irqsave(&mcast_lock
, flags
);
125 n
= mcast_tree
.rb_node
;
129 mcast
= rb_entry(n
, struct ipath_mcast
, rb_node
);
131 ret
= memcmp(mgid
->raw
, mcast
->mgid
.raw
,
132 sizeof(union ib_gid
));
138 atomic_inc(&mcast
->refcount
);
139 spin_unlock_irqrestore(&mcast_lock
, flags
);
143 spin_unlock_irqrestore(&mcast_lock
, flags
);
152 * ipath_mcast_add - insert mcast GID into table and attach QP struct
153 * @mcast: the mcast GID table
154 * @mqp: the QP to attach
156 * Return zero if both were added. Return EEXIST if the GID was already in
157 * the table but the QP was added. Return ESRCH if the QP was already
158 * attached and neither structure was added.
160 static int ipath_mcast_add(struct ipath_mcast
*mcast
,
161 struct ipath_mcast_qp
*mqp
)
163 struct rb_node
**n
= &mcast_tree
.rb_node
;
164 struct rb_node
*pn
= NULL
;
168 spin_lock_irqsave(&mcast_lock
, flags
);
171 struct ipath_mcast
*tmcast
;
172 struct ipath_mcast_qp
*p
;
175 tmcast
= rb_entry(pn
, struct ipath_mcast
, rb_node
);
177 ret
= memcmp(mcast
->mgid
.raw
, tmcast
->mgid
.raw
,
178 sizeof(union ib_gid
));
188 /* Search the QP list to see if this is already there. */
189 list_for_each_entry_rcu(p
, &tmcast
->qp_list
, list
) {
190 if (p
->qp
== mqp
->qp
) {
191 spin_unlock_irqrestore(&mcast_lock
, flags
);
196 list_add_tail_rcu(&mqp
->list
, &tmcast
->qp_list
);
197 spin_unlock_irqrestore(&mcast_lock
, flags
);
202 list_add_tail_rcu(&mqp
->list
, &mcast
->qp_list
);
204 atomic_inc(&mcast
->refcount
);
205 rb_link_node(&mcast
->rb_node
, pn
, n
);
206 rb_insert_color(&mcast
->rb_node
, &mcast_tree
);
208 spin_unlock_irqrestore(&mcast_lock
, flags
);
216 int ipath_multicast_attach(struct ib_qp
*ibqp
, union ib_gid
*gid
, u16 lid
)
218 struct ipath_qp
*qp
= to_iqp(ibqp
);
219 struct ipath_mcast
*mcast
;
220 struct ipath_mcast_qp
*mqp
;
224 * Allocate data structures since its better to do this outside of
225 * spin locks and it will most likely be needed.
227 mcast
= ipath_mcast_alloc(gid
);
232 mqp
= ipath_mcast_qp_alloc(qp
);
234 ipath_mcast_free(mcast
);
238 switch (ipath_mcast_add(mcast
, mqp
)) {
240 /* Neither was used: can't attach the same QP twice. */
241 ipath_mcast_qp_free(mqp
);
242 ipath_mcast_free(mcast
);
245 case EEXIST
: /* The mcast wasn't used */
246 ipath_mcast_free(mcast
);
258 int ipath_multicast_detach(struct ib_qp
*ibqp
, union ib_gid
*gid
, u16 lid
)
260 struct ipath_qp
*qp
= to_iqp(ibqp
);
261 struct ipath_mcast
*mcast
= NULL
;
262 struct ipath_mcast_qp
*p
, *tmp
;
268 spin_lock_irqsave(&mcast_lock
, flags
);
270 /* Find the GID in the mcast table. */
271 n
= mcast_tree
.rb_node
;
274 spin_unlock_irqrestore(&mcast_lock
, flags
);
279 mcast
= rb_entry(n
, struct ipath_mcast
, rb_node
);
280 ret
= memcmp(gid
->raw
, mcast
->mgid
.raw
,
281 sizeof(union ib_gid
));
290 /* Search the QP list. */
291 list_for_each_entry_safe(p
, tmp
, &mcast
->qp_list
, list
) {
295 * We found it, so remove it, but don't poison the forward
296 * link until we are sure there are no list walkers.
298 list_del_rcu(&p
->list
);
300 /* If this was the last attached QP, remove the GID too. */
301 if (list_empty(&mcast
->qp_list
)) {
302 rb_erase(&mcast
->rb_node
, &mcast_tree
);
308 spin_unlock_irqrestore(&mcast_lock
, flags
);
312 * Wait for any list walkers to finish before freeing the
315 wait_event(mcast
->wait
, atomic_read(&mcast
->refcount
) <= 1);
316 ipath_mcast_qp_free(p
);
319 atomic_dec(&mcast
->refcount
);
320 wait_event(mcast
->wait
, !atomic_read(&mcast
->refcount
));
321 ipath_mcast_free(mcast
);
330 int ipath_mcast_tree_empty(void)
332 return mcast_tree
.rb_node
== NULL
;