1/*
2 * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
3 *
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:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
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.
22 *
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
30 * SOFTWARE.
31 */
32
33#include <rdma/ib_mad.h>
34
35#include <linux/mlx4/cmd.h>
36#include <linux/idr.h>
37#include <rdma/ib_cm.h>
38
39#include "mlx4_ib.h"
40
41#define CM_CLEANUP_CACHE_TIMEOUT  (5 * HZ)
42
43struct id_map_entry {
44	struct rb_node node;
45
46	u32 sl_cm_id;
47	u32 pv_cm_id;
48	int slave_id;
49	int scheduled_delete;
50	struct mlx4_ib_dev *dev;
51
52	struct list_head list;
53	struct delayed_work timeout;
54};
55
56struct cm_generic_msg {
57	struct ib_mad_hdr hdr;
58
59	__be32 local_comm_id;
60	__be32 remote_comm_id;
61};
62
63struct cm_req_msg {
64	unsigned char unused[0x60];
65	union ib_gid primary_path_sgid;
66};
67
68
69static void set_local_comm_id(struct ib_mad *mad, u32 cm_id)
70{
71	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
72	msg->local_comm_id = cpu_to_be32(cm_id);
73}
74
75static u32 get_local_comm_id(struct ib_mad *mad)
76{
77	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
78
79	return be32_to_cpu(msg->local_comm_id);
80}
81
82static void set_remote_comm_id(struct ib_mad *mad, u32 cm_id)
83{
84	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
85	msg->remote_comm_id = cpu_to_be32(cm_id);
86}
87
88static u32 get_remote_comm_id(struct ib_mad *mad)
89{
90	struct cm_generic_msg *msg = (struct cm_generic_msg *)mad;
91
92	return be32_to_cpu(msg->remote_comm_id);
93}
94
95static union ib_gid gid_from_req_msg(struct ib_device *ibdev, struct ib_mad *mad)
96{
97	struct cm_req_msg *msg = (struct cm_req_msg *)mad;
98
99	return msg->primary_path_sgid;
100}
101
102/* Lock should be taken before called */
103static struct id_map_entry *
104id_map_find_by_sl_id(struct ib_device *ibdev, u32 slave_id, u32 sl_cm_id)
105{
106	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
107	struct rb_node *node = sl_id_map->rb_node;
108
109	while (node) {
110		struct id_map_entry *id_map_entry =
111			rb_entry(node, struct id_map_entry, node);
112
113		if (id_map_entry->sl_cm_id > sl_cm_id)
114			node = node->rb_left;
115		else if (id_map_entry->sl_cm_id < sl_cm_id)
116			node = node->rb_right;
117		else if (id_map_entry->slave_id > slave_id)
118			node = node->rb_left;
119		else if (id_map_entry->slave_id < slave_id)
120			node = node->rb_right;
121		else
122			return id_map_entry;
123	}
124	return NULL;
125}
126
127static void id_map_ent_timeout(struct work_struct *work)
128{
129	struct delayed_work *delay = to_delayed_work(work);
130	struct id_map_entry *ent = container_of(delay, struct id_map_entry, timeout);
131	struct id_map_entry *db_ent, *found_ent;
132	struct mlx4_ib_dev *dev = ent->dev;
133	struct mlx4_ib_sriov *sriov = &dev->sriov;
134	struct rb_root *sl_id_map = &sriov->sl_id_map;
135	int pv_id = (int) ent->pv_cm_id;
136
137	spin_lock(&sriov->id_map_lock);
138	db_ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_id);
139	if (!db_ent)
140		goto out;
141	found_ent = id_map_find_by_sl_id(&dev->ib_dev, ent->slave_id, ent->sl_cm_id);
142	if (found_ent && found_ent == ent)
143		rb_erase(&found_ent->node, sl_id_map);
144	idr_remove(&sriov->pv_id_table, pv_id);
145
146out:
147	list_del(&ent->list);
148	spin_unlock(&sriov->id_map_lock);
149	kfree(ent);
150}
151
152static void id_map_find_del(struct ib_device *ibdev, int pv_cm_id)
153{
154	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
155	struct rb_root *sl_id_map = &sriov->sl_id_map;
156	struct id_map_entry *ent, *found_ent;
157
158	spin_lock(&sriov->id_map_lock);
159	ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, pv_cm_id);
160	if (!ent)
161		goto out;
162	found_ent = id_map_find_by_sl_id(ibdev, ent->slave_id, ent->sl_cm_id);
163	if (found_ent && found_ent == ent)
164		rb_erase(&found_ent->node, sl_id_map);
165	idr_remove(&sriov->pv_id_table, pv_cm_id);
166out:
167	spin_unlock(&sriov->id_map_lock);
168}
169
170static void sl_id_map_add(struct ib_device *ibdev, struct id_map_entry *new)
171{
172	struct rb_root *sl_id_map = &to_mdev(ibdev)->sriov.sl_id_map;
173	struct rb_node **link = &sl_id_map->rb_node, *parent = NULL;
174	struct id_map_entry *ent;
175	int slave_id = new->slave_id;
176	int sl_cm_id = new->sl_cm_id;
177
178	ent = id_map_find_by_sl_id(ibdev, slave_id, sl_cm_id);
179	if (ent) {
180		pr_debug("overriding existing sl_id_map entry (cm_id = %x)\n",
181			 sl_cm_id);
182
183		rb_replace_node(&ent->node, &new->node, sl_id_map);
184		return;
185	}
186
187	/* Go to the bottom of the tree */
188	while (*link) {
189		parent = *link;
190		ent = rb_entry(parent, struct id_map_entry, node);
191
192		if (ent->sl_cm_id > sl_cm_id || (ent->sl_cm_id == sl_cm_id && ent->slave_id > slave_id))
193			link = &(*link)->rb_left;
194		else
195			link = &(*link)->rb_right;
196	}
197
198	rb_link_node(&new->node, parent, link);
199	rb_insert_color(&new->node, sl_id_map);
200}
201
202static struct id_map_entry *
203id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
204{
205	int ret, id;
206	static int next_id;
207	struct id_map_entry *ent;
208	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
209
210	ent = kmalloc(sizeof (struct id_map_entry), GFP_KERNEL);
211	if (!ent) {
212		mlx4_ib_warn(ibdev, "Couldn't allocate id cache entry - out of memory\n");
213		return ERR_PTR(-ENOMEM);
214	}
215
216	ent->sl_cm_id = sl_cm_id;
217	ent->slave_id = slave_id;
218	ent->scheduled_delete = 0;
219	ent->dev = to_mdev(ibdev);
220	INIT_DELAYED_WORK(&ent->timeout, id_map_ent_timeout);
221
222	do {
223		spin_lock(&to_mdev(ibdev)->sriov.id_map_lock);
224		ret = idr_get_new_above(&sriov->pv_id_table, ent,
225					next_id, &id);
226		if (!ret) {
227			next_id = ((unsigned) id + 1) & MAX_IDR_MASK;
228			ent->pv_cm_id = (u32)id;
229			sl_id_map_add(ibdev, ent);
230		}
231
232		spin_unlock(&sriov->id_map_lock);
233	} while (ret == -EAGAIN && idr_pre_get(&sriov->pv_id_table, GFP_KERNEL));
234	/*the function idr_get_new_above can return -ENOSPC, so don't insert in that case.*/
235	if (!ret) {
236		spin_lock(&sriov->id_map_lock);
237		list_add_tail(&ent->list, &sriov->cm_list);
238		spin_unlock(&sriov->id_map_lock);
239		return ent;
240	}
241	/*error flow*/
242	kfree(ent);
243	mlx4_ib_warn(ibdev, "No more space in the idr (err:0x%x)\n", ret);
244	return ERR_PTR(-ENOMEM);
245}
246
247static struct id_map_entry *
248id_map_get(struct ib_device *ibdev, int *pv_cm_id, int sl_cm_id, int slave_id)
249{
250	struct id_map_entry *ent;
251	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
252
253	spin_lock(&sriov->id_map_lock);
254	if (*pv_cm_id == -1) {
255		ent = id_map_find_by_sl_id(ibdev, sl_cm_id, slave_id);
256		if (ent)
257			*pv_cm_id = (int) ent->pv_cm_id;
258	} else
259		ent = (struct id_map_entry *)idr_find(&sriov->pv_id_table, *pv_cm_id);
260	spin_unlock(&sriov->id_map_lock);
261
262	return ent;
263}
264
265static void schedule_delayed(struct ib_device *ibdev, struct id_map_entry *id)
266{
267	struct mlx4_ib_sriov *sriov = &to_mdev(ibdev)->sriov;
268	unsigned long flags;
269
270	spin_lock(&sriov->id_map_lock);
271	spin_lock_irqsave(&sriov->going_down_lock, flags);
272	/*make sure that there is no schedule inside the scheduled work.*/
273	if (!sriov->is_going_down) {
274		id->scheduled_delete = 1;
275		schedule_delayed_work(&id->timeout, CM_CLEANUP_CACHE_TIMEOUT);
276	}
277	spin_unlock_irqrestore(&sriov->going_down_lock, flags);
278	spin_unlock(&sriov->id_map_lock);
279}
280
281int mlx4_ib_multiplex_cm_handler(struct ib_device *ibdev, int port, int slave_id,
282		struct ib_mad *mad)
283{
284	struct id_map_entry *id;
285	u32 sl_cm_id;
286	int pv_cm_id = -1;
287
288	sl_cm_id = get_local_comm_id(mad);
289
290	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID ||
291			mad->mad_hdr.attr_id == CM_REP_ATTR_ID) {
292		id = id_map_alloc(ibdev, slave_id, sl_cm_id);
293		if (IS_ERR(id)) {
294			mlx4_ib_warn(ibdev, "%s: id{slave: %d, sl_cm_id: 0x%x} Failed to id_map_alloc\n",
295				__func__, slave_id, sl_cm_id);
296			return PTR_ERR(id);
297		}
298	} else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID) {
299		return 0;
300	} else {
301		id = id_map_get(ibdev, &pv_cm_id, slave_id, sl_cm_id);
302	}
303
304	if (!id) {
305		pr_debug("id{slave: %d, sl_cm_id: 0x%x} is NULL!\n",
306			 slave_id, sl_cm_id);
307		return -EINVAL;
308	}
309
310	set_local_comm_id(mad, id->pv_cm_id);
311
312	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
313		schedule_delayed(ibdev, id);
314	else if (mad->mad_hdr.attr_id == CM_DREP_ATTR_ID)
315		id_map_find_del(ibdev, pv_cm_id);
316
317	return 0;
318}
319
320int mlx4_ib_demux_cm_handler(struct ib_device *ibdev, int port, int *slave,
321			     struct ib_mad *mad, int is_eth)
322{
323	u32 pv_cm_id;
324	struct id_map_entry *id;
325
326	if (mad->mad_hdr.attr_id == CM_REQ_ATTR_ID) {
327		union ib_gid gid;
328
329		if (is_eth)
330			return 0;
331
332		gid = gid_from_req_msg(ibdev, mad);
333		*slave = mlx4_ib_find_real_gid(ibdev, port, gid.global.interface_id);
334		if (*slave < 0) {
335			mlx4_ib_warn(ibdev, "failed matching slave_id by gid (0x%llx)\n",
336					(long long)gid.global.interface_id);
337			return -ENOENT;
338		}
339		return 0;
340	}
341
342	pv_cm_id = get_remote_comm_id(mad);
343	id = id_map_get(ibdev, (int *)&pv_cm_id, -1, -1);
344
345	if (!id) {
346		pr_debug("Couldn't find an entry for pv_cm_id 0x%x\n", pv_cm_id);
347		return -ENOENT;
348	}
349
350	if (!is_eth)
351		*slave = id->slave_id;
352	set_remote_comm_id(mad, id->sl_cm_id);
353
354	if (mad->mad_hdr.attr_id == CM_DREQ_ATTR_ID)
355		schedule_delayed(ibdev, id);
356	else if (mad->mad_hdr.attr_id == CM_REJ_ATTR_ID ||
357			mad->mad_hdr.attr_id == CM_DREP_ATTR_ID) {
358		id_map_find_del(ibdev, (int) pv_cm_id);
359	}
360
361	return 0;
362}
363
364void mlx4_ib_cm_paravirt_init(struct mlx4_ib_dev *dev)
365{
366	spin_lock_init(&dev->sriov.id_map_lock);
367	INIT_LIST_HEAD(&dev->sriov.cm_list);
368	dev->sriov.sl_id_map = RB_ROOT;
369	idr_init(&dev->sriov.pv_id_table);
370	idr_pre_get(&dev->sriov.pv_id_table, GFP_KERNEL);
371}
372
373/* slave = -1 ==> all slaves */
374/* TBD -- call paravirt clean for single slave.  Need for slave RESET event */
375void mlx4_ib_cm_paravirt_clean(struct mlx4_ib_dev *dev, int slave)
376{
377	struct mlx4_ib_sriov *sriov = &dev->sriov;
378	struct rb_root *sl_id_map = &sriov->sl_id_map;
379	struct list_head lh;
380	struct rb_node *nd;
381	int need_flush = 1;
382	struct id_map_entry *map, *tmp_map;
383	/* cancel all delayed work queue entries */
384	INIT_LIST_HEAD(&lh);
385	spin_lock(&sriov->id_map_lock);
386	list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
387		if (slave < 0 || slave == map->slave_id) {
388			if (map->scheduled_delete)
389				need_flush &= !!cancel_delayed_work(&map->timeout);
390		}
391	}
392
393	spin_unlock(&sriov->id_map_lock);
394
395	if (!need_flush)
396		flush_scheduled_work(); /* make sure all timers were flushed */
397
398	/* now, remove all leftover entries from databases*/
399	spin_lock(&sriov->id_map_lock);
400	if (slave < 0) {
401		while (rb_first(sl_id_map)) {
402			struct id_map_entry *ent =
403				rb_entry(rb_first(sl_id_map),
404					 struct id_map_entry, node);
405
406			rb_erase(&ent->node, sl_id_map);
407			idr_remove(&sriov->pv_id_table, (int) ent->pv_cm_id);
408		}
409		list_splice_init(&dev->sriov.cm_list, &lh);
410	} else {
411		/* first, move nodes belonging to slave to db remove list */
412		nd = rb_first(sl_id_map);
413		while (nd) {
414			struct id_map_entry *ent =
415				rb_entry(nd, struct id_map_entry, node);
416			nd = rb_next(nd);
417			if (ent->slave_id == slave)
418				list_move_tail(&ent->list, &lh);
419		}
420		/* remove those nodes from databases */
421		list_for_each_entry_safe(map, tmp_map, &lh, list) {
422			rb_erase(&map->node, sl_id_map);
423			idr_remove(&sriov->pv_id_table, (int) map->pv_cm_id);
424		}
425
426		/* add remaining nodes from cm_list */
427		list_for_each_entry_safe(map, tmp_map, &dev->sriov.cm_list, list) {
428			if (slave == map->slave_id)
429				list_move_tail(&map->list, &lh);
430		}
431	}
432
433	spin_unlock(&sriov->id_map_lock);
434
435	/* free any map entries left behind due to cancel_delayed_work above */
436	list_for_each_entry_safe(map, tmp_map, &lh, list) {
437		list_del(&map->list);
438		kfree(map);
439	}
440}
441