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