1 /*
2 *
3 * This file is provided under a dual BSD/GPLv2 license. When using or
4 * redistributing this file, you may do so under either license.
5 *
6 * GPL LICENSE SUMMARY
7 *
8 * Copyright(c) 2015 Intel Corporation.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * BSD LICENSE
20 *
21 * Copyright(c) 2015 Intel Corporation.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 *
27 * - Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * - Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in
31 * the documentation and/or other materials provided with the
32 * distribution.
33 * - Neither the name of Intel Corporation nor the names of its
34 * contributors may be used to endorse or promote products derived
35 * from this software without specific prior written permission.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
38 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
39 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
40 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
41 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
44 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
45 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
46 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48 *
49 */
50
51 #include <linux/rculist.h>
52
53 #include "hfi.h"
54
55 /**
56 * mcast_qp_alloc - alloc a struct to link a QP to mcast GID struct
57 * @qp: the QP to link
58 */
mcast_qp_alloc(struct hfi1_qp * qp)59 static struct hfi1_mcast_qp *mcast_qp_alloc(struct hfi1_qp *qp)
60 {
61 struct hfi1_mcast_qp *mqp;
62
63 mqp = kmalloc(sizeof(*mqp), GFP_KERNEL);
64 if (!mqp)
65 goto bail;
66
67 mqp->qp = qp;
68 atomic_inc(&qp->refcount);
69
70 bail:
71 return mqp;
72 }
73
mcast_qp_free(struct hfi1_mcast_qp * mqp)74 static void mcast_qp_free(struct hfi1_mcast_qp *mqp)
75 {
76 struct hfi1_qp *qp = mqp->qp;
77
78 /* Notify hfi1_destroy_qp() if it is waiting. */
79 if (atomic_dec_and_test(&qp->refcount))
80 wake_up(&qp->wait);
81
82 kfree(mqp);
83 }
84
85 /**
86 * mcast_alloc - allocate the multicast GID structure
87 * @mgid: the multicast GID
88 *
89 * A list of QPs will be attached to this structure.
90 */
mcast_alloc(union ib_gid * mgid)91 static struct hfi1_mcast *mcast_alloc(union ib_gid *mgid)
92 {
93 struct hfi1_mcast *mcast;
94
95 mcast = kmalloc(sizeof(*mcast), GFP_KERNEL);
96 if (!mcast)
97 goto bail;
98
99 mcast->mgid = *mgid;
100 INIT_LIST_HEAD(&mcast->qp_list);
101 init_waitqueue_head(&mcast->wait);
102 atomic_set(&mcast->refcount, 0);
103 mcast->n_attached = 0;
104
105 bail:
106 return mcast;
107 }
108
mcast_free(struct hfi1_mcast * mcast)109 static void mcast_free(struct hfi1_mcast *mcast)
110 {
111 struct hfi1_mcast_qp *p, *tmp;
112
113 list_for_each_entry_safe(p, tmp, &mcast->qp_list, list)
114 mcast_qp_free(p);
115
116 kfree(mcast);
117 }
118
119 /**
120 * hfi1_mcast_find - search the global table for the given multicast GID
121 * @ibp: the IB port structure
122 * @mgid: the multicast GID to search for
123 *
124 * Returns NULL if not found.
125 *
126 * The caller is responsible for decrementing the reference count if found.
127 */
hfi1_mcast_find(struct hfi1_ibport * ibp,union ib_gid * mgid)128 struct hfi1_mcast *hfi1_mcast_find(struct hfi1_ibport *ibp, union ib_gid *mgid)
129 {
130 struct rb_node *n;
131 unsigned long flags;
132 struct hfi1_mcast *mcast;
133
134 spin_lock_irqsave(&ibp->lock, flags);
135 n = ibp->mcast_tree.rb_node;
136 while (n) {
137 int ret;
138
139 mcast = rb_entry(n, struct hfi1_mcast, rb_node);
140
141 ret = memcmp(mgid->raw, mcast->mgid.raw,
142 sizeof(union ib_gid));
143 if (ret < 0)
144 n = n->rb_left;
145 else if (ret > 0)
146 n = n->rb_right;
147 else {
148 atomic_inc(&mcast->refcount);
149 spin_unlock_irqrestore(&ibp->lock, flags);
150 goto bail;
151 }
152 }
153 spin_unlock_irqrestore(&ibp->lock, flags);
154
155 mcast = NULL;
156
157 bail:
158 return mcast;
159 }
160
161 /**
162 * mcast_add - insert mcast GID into table and attach QP struct
163 * @mcast: the mcast GID table
164 * @mqp: the QP to attach
165 *
166 * Return zero if both were added. Return EEXIST if the GID was already in
167 * the table but the QP was added. Return ESRCH if the QP was already
168 * attached and neither structure was added.
169 */
mcast_add(struct hfi1_ibdev * dev,struct hfi1_ibport * ibp,struct hfi1_mcast * mcast,struct hfi1_mcast_qp * mqp)170 static int mcast_add(struct hfi1_ibdev *dev, struct hfi1_ibport *ibp,
171 struct hfi1_mcast *mcast, struct hfi1_mcast_qp *mqp)
172 {
173 struct rb_node **n = &ibp->mcast_tree.rb_node;
174 struct rb_node *pn = NULL;
175 int ret;
176
177 spin_lock_irq(&ibp->lock);
178
179 while (*n) {
180 struct hfi1_mcast *tmcast;
181 struct hfi1_mcast_qp *p;
182
183 pn = *n;
184 tmcast = rb_entry(pn, struct hfi1_mcast, rb_node);
185
186 ret = memcmp(mcast->mgid.raw, tmcast->mgid.raw,
187 sizeof(union ib_gid));
188 if (ret < 0) {
189 n = &pn->rb_left;
190 continue;
191 }
192 if (ret > 0) {
193 n = &pn->rb_right;
194 continue;
195 }
196
197 /* Search the QP list to see if this is already there. */
198 list_for_each_entry_rcu(p, &tmcast->qp_list, list) {
199 if (p->qp == mqp->qp) {
200 ret = ESRCH;
201 goto bail;
202 }
203 }
204 if (tmcast->n_attached == hfi1_max_mcast_qp_attached) {
205 ret = ENOMEM;
206 goto bail;
207 }
208
209 tmcast->n_attached++;
210
211 list_add_tail_rcu(&mqp->list, &tmcast->qp_list);
212 ret = EEXIST;
213 goto bail;
214 }
215
216 spin_lock(&dev->n_mcast_grps_lock);
217 if (dev->n_mcast_grps_allocated == hfi1_max_mcast_grps) {
218 spin_unlock(&dev->n_mcast_grps_lock);
219 ret = ENOMEM;
220 goto bail;
221 }
222
223 dev->n_mcast_grps_allocated++;
224 spin_unlock(&dev->n_mcast_grps_lock);
225
226 mcast->n_attached++;
227
228 list_add_tail_rcu(&mqp->list, &mcast->qp_list);
229
230 atomic_inc(&mcast->refcount);
231 rb_link_node(&mcast->rb_node, pn, n);
232 rb_insert_color(&mcast->rb_node, &ibp->mcast_tree);
233
234 ret = 0;
235
236 bail:
237 spin_unlock_irq(&ibp->lock);
238
239 return ret;
240 }
241
hfi1_multicast_attach(struct ib_qp * ibqp,union ib_gid * gid,u16 lid)242 int hfi1_multicast_attach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
243 {
244 struct hfi1_qp *qp = to_iqp(ibqp);
245 struct hfi1_ibdev *dev = to_idev(ibqp->device);
246 struct hfi1_ibport *ibp;
247 struct hfi1_mcast *mcast;
248 struct hfi1_mcast_qp *mqp;
249 int ret;
250
251 if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) {
252 ret = -EINVAL;
253 goto bail;
254 }
255
256 /*
257 * Allocate data structures since its better to do this outside of
258 * spin locks and it will most likely be needed.
259 */
260 mcast = mcast_alloc(gid);
261 if (mcast == NULL) {
262 ret = -ENOMEM;
263 goto bail;
264 }
265 mqp = mcast_qp_alloc(qp);
266 if (mqp == NULL) {
267 mcast_free(mcast);
268 ret = -ENOMEM;
269 goto bail;
270 }
271 ibp = to_iport(ibqp->device, qp->port_num);
272 switch (mcast_add(dev, ibp, mcast, mqp)) {
273 case ESRCH:
274 /* Neither was used: OK to attach the same QP twice. */
275 mcast_qp_free(mqp);
276 mcast_free(mcast);
277 break;
278
279 case EEXIST: /* The mcast wasn't used */
280 mcast_free(mcast);
281 break;
282
283 case ENOMEM:
284 /* Exceeded the maximum number of mcast groups. */
285 mcast_qp_free(mqp);
286 mcast_free(mcast);
287 ret = -ENOMEM;
288 goto bail;
289
290 default:
291 break;
292 }
293
294 ret = 0;
295
296 bail:
297 return ret;
298 }
299
hfi1_multicast_detach(struct ib_qp * ibqp,union ib_gid * gid,u16 lid)300 int hfi1_multicast_detach(struct ib_qp *ibqp, union ib_gid *gid, u16 lid)
301 {
302 struct hfi1_qp *qp = to_iqp(ibqp);
303 struct hfi1_ibdev *dev = to_idev(ibqp->device);
304 struct hfi1_ibport *ibp = to_iport(ibqp->device, qp->port_num);
305 struct hfi1_mcast *mcast = NULL;
306 struct hfi1_mcast_qp *p, *tmp;
307 struct rb_node *n;
308 int last = 0;
309 int ret;
310
311 if (ibqp->qp_num <= 1 || qp->state == IB_QPS_RESET) {
312 ret = -EINVAL;
313 goto bail;
314 }
315
316 spin_lock_irq(&ibp->lock);
317
318 /* Find the GID in the mcast table. */
319 n = ibp->mcast_tree.rb_node;
320 while (1) {
321 if (n == NULL) {
322 spin_unlock_irq(&ibp->lock);
323 ret = -EINVAL;
324 goto bail;
325 }
326
327 mcast = rb_entry(n, struct hfi1_mcast, rb_node);
328 ret = memcmp(gid->raw, mcast->mgid.raw,
329 sizeof(union ib_gid));
330 if (ret < 0)
331 n = n->rb_left;
332 else if (ret > 0)
333 n = n->rb_right;
334 else
335 break;
336 }
337
338 /* Search the QP list. */
339 list_for_each_entry_safe(p, tmp, &mcast->qp_list, list) {
340 if (p->qp != qp)
341 continue;
342 /*
343 * We found it, so remove it, but don't poison the forward
344 * link until we are sure there are no list walkers.
345 */
346 list_del_rcu(&p->list);
347 mcast->n_attached--;
348
349 /* If this was the last attached QP, remove the GID too. */
350 if (list_empty(&mcast->qp_list)) {
351 rb_erase(&mcast->rb_node, &ibp->mcast_tree);
352 last = 1;
353 }
354 break;
355 }
356
357 spin_unlock_irq(&ibp->lock);
358
359 if (p) {
360 /*
361 * Wait for any list walkers to finish before freeing the
362 * list element.
363 */
364 wait_event(mcast->wait, atomic_read(&mcast->refcount) <= 1);
365 mcast_qp_free(p);
366 }
367 if (last) {
368 atomic_dec(&mcast->refcount);
369 wait_event(mcast->wait, !atomic_read(&mcast->refcount));
370 mcast_free(mcast);
371 spin_lock_irq(&dev->n_mcast_grps_lock);
372 dev->n_mcast_grps_allocated--;
373 spin_unlock_irq(&dev->n_mcast_grps_lock);
374 }
375
376 ret = 0;
377
378 bail:
379 return ret;
380 }
381
hfi1_mcast_tree_empty(struct hfi1_ibport * ibp)382 int hfi1_mcast_tree_empty(struct hfi1_ibport *ibp)
383 {
384 return ibp->mcast_tree.rb_node == NULL;
385 }
386