xref: /openbmc/linux/net/rds/ib.c (revision 8b235f2f)
1  /*
2   * Copyright (c) 2006 Oracle.  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 <linux/kernel.h>
34  #include <linux/in.h>
35  #include <linux/if.h>
36  #include <linux/netdevice.h>
37  #include <linux/inetdevice.h>
38  #include <linux/if_arp.h>
39  #include <linux/delay.h>
40  #include <linux/slab.h>
41  #include <linux/module.h>
42  
43  #include "rds.h"
44  #include "ib.h"
45  
46  static unsigned int fmr_pool_size = RDS_FMR_POOL_SIZE;
47  unsigned int fmr_message_size = RDS_FMR_SIZE + 1; /* +1 allows for unaligned MRs */
48  unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
49  
50  module_param(fmr_pool_size, int, 0444);
51  MODULE_PARM_DESC(fmr_pool_size, " Max number of fmr per HCA");
52  module_param(fmr_message_size, int, 0444);
53  MODULE_PARM_DESC(fmr_message_size, " Max size of a RDMA transfer");
54  module_param(rds_ib_retry_count, int, 0444);
55  MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
56  
57  /*
58   * we have a clumsy combination of RCU and a rwsem protecting this list
59   * because it is used both in the get_mr fast path and while blocking in
60   * the FMR flushing path.
61   */
62  DECLARE_RWSEM(rds_ib_devices_lock);
63  struct list_head rds_ib_devices;
64  
65  /* NOTE: if also grabbing ibdev lock, grab this first */
66  DEFINE_SPINLOCK(ib_nodev_conns_lock);
67  LIST_HEAD(ib_nodev_conns);
68  
69  static void rds_ib_nodev_connect(void)
70  {
71  	struct rds_ib_connection *ic;
72  
73  	spin_lock(&ib_nodev_conns_lock);
74  	list_for_each_entry(ic, &ib_nodev_conns, ib_node)
75  		rds_conn_connect_if_down(ic->conn);
76  	spin_unlock(&ib_nodev_conns_lock);
77  }
78  
79  static void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
80  {
81  	struct rds_ib_connection *ic;
82  	unsigned long flags;
83  
84  	spin_lock_irqsave(&rds_ibdev->spinlock, flags);
85  	list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
86  		rds_conn_drop(ic->conn);
87  	spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
88  }
89  
90  /*
91   * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
92   * from interrupt context so we push freing off into a work struct in krdsd.
93   */
94  static void rds_ib_dev_free(struct work_struct *work)
95  {
96  	struct rds_ib_ipaddr *i_ipaddr, *i_next;
97  	struct rds_ib_device *rds_ibdev = container_of(work,
98  					struct rds_ib_device, free_work);
99  
100  	if (rds_ibdev->mr_pool)
101  		rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
102  	if (rds_ibdev->pd)
103  		ib_dealloc_pd(rds_ibdev->pd);
104  
105  	list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
106  		list_del(&i_ipaddr->list);
107  		kfree(i_ipaddr);
108  	}
109  
110  	kfree(rds_ibdev);
111  }
112  
113  void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
114  {
115  	BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
116  	if (atomic_dec_and_test(&rds_ibdev->refcount))
117  		queue_work(rds_wq, &rds_ibdev->free_work);
118  }
119  
120  static void rds_ib_add_one(struct ib_device *device)
121  {
122  	struct rds_ib_device *rds_ibdev;
123  	struct ib_device_attr *dev_attr;
124  
125  	/* Only handle IB (no iWARP) devices */
126  	if (device->node_type != RDMA_NODE_IB_CA)
127  		return;
128  
129  	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
130  	if (!dev_attr)
131  		return;
132  
133  	if (ib_query_device(device, dev_attr)) {
134  		rdsdebug("Query device failed for %s\n", device->name);
135  		goto free_attr;
136  	}
137  
138  	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
139  				 ibdev_to_node(device));
140  	if (!rds_ibdev)
141  		goto free_attr;
142  
143  	spin_lock_init(&rds_ibdev->spinlock);
144  	atomic_set(&rds_ibdev->refcount, 1);
145  	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
146  
147  	rds_ibdev->max_wrs = dev_attr->max_qp_wr;
148  	rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
149  
150  	rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
151  	rds_ibdev->max_fmrs = dev_attr->max_fmr ?
152  			min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
153  			fmr_pool_size;
154  
155  	rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
156  	rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
157  
158  	rds_ibdev->dev = device;
159  	rds_ibdev->pd = ib_alloc_pd(device);
160  	if (IS_ERR(rds_ibdev->pd)) {
161  		rds_ibdev->pd = NULL;
162  		goto put_dev;
163  	}
164  
165  	rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
166  	if (IS_ERR(rds_ibdev->mr_pool)) {
167  		rds_ibdev->mr_pool = NULL;
168  		goto put_dev;
169  	}
170  
171  	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
172  	INIT_LIST_HEAD(&rds_ibdev->conn_list);
173  
174  	down_write(&rds_ib_devices_lock);
175  	list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
176  	up_write(&rds_ib_devices_lock);
177  	atomic_inc(&rds_ibdev->refcount);
178  
179  	ib_set_client_data(device, &rds_ib_client, rds_ibdev);
180  	atomic_inc(&rds_ibdev->refcount);
181  
182  	rds_ib_nodev_connect();
183  
184  put_dev:
185  	rds_ib_dev_put(rds_ibdev);
186  free_attr:
187  	kfree(dev_attr);
188  }
189  
190  /*
191   * New connections use this to find the device to associate with the
192   * connection.  It's not in the fast path so we're not concerned about the
193   * performance of the IB call.  (As of this writing, it uses an interrupt
194   * blocking spinlock to serialize walking a per-device list of all registered
195   * clients.)
196   *
197   * RCU is used to handle incoming connections racing with device teardown.
198   * Rather than use a lock to serialize removal from the client_data and
199   * getting a new reference, we use an RCU grace period.  The destruction
200   * path removes the device from client_data and then waits for all RCU
201   * readers to finish.
202   *
203   * A new connection can get NULL from this if its arriving on a
204   * device that is in the process of being removed.
205   */
206  struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
207  {
208  	struct rds_ib_device *rds_ibdev;
209  
210  	rcu_read_lock();
211  	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
212  	if (rds_ibdev)
213  		atomic_inc(&rds_ibdev->refcount);
214  	rcu_read_unlock();
215  	return rds_ibdev;
216  }
217  
218  /*
219   * The IB stack is letting us know that a device is going away.  This can
220   * happen if the underlying HCA driver is removed or if PCI hotplug is removing
221   * the pci function, for example.
222   *
223   * This can be called at any time and can be racing with any other RDS path.
224   */
225  static void rds_ib_remove_one(struct ib_device *device, void *client_data)
226  {
227  	struct rds_ib_device *rds_ibdev = client_data;
228  
229  	if (!rds_ibdev)
230  		return;
231  
232  	rds_ib_dev_shutdown(rds_ibdev);
233  
234  	/* stop connection attempts from getting a reference to this device. */
235  	ib_set_client_data(device, &rds_ib_client, NULL);
236  
237  	down_write(&rds_ib_devices_lock);
238  	list_del_rcu(&rds_ibdev->list);
239  	up_write(&rds_ib_devices_lock);
240  
241  	/*
242  	 * This synchronize rcu is waiting for readers of both the ib
243  	 * client data and the devices list to finish before we drop
244  	 * both of those references.
245  	 */
246  	synchronize_rcu();
247  	rds_ib_dev_put(rds_ibdev);
248  	rds_ib_dev_put(rds_ibdev);
249  }
250  
251  struct ib_client rds_ib_client = {
252  	.name   = "rds_ib",
253  	.add    = rds_ib_add_one,
254  	.remove = rds_ib_remove_one
255  };
256  
257  static int rds_ib_conn_info_visitor(struct rds_connection *conn,
258  				    void *buffer)
259  {
260  	struct rds_info_rdma_connection *iinfo = buffer;
261  	struct rds_ib_connection *ic;
262  
263  	/* We will only ever look at IB transports */
264  	if (conn->c_trans != &rds_ib_transport)
265  		return 0;
266  
267  	iinfo->src_addr = conn->c_laddr;
268  	iinfo->dst_addr = conn->c_faddr;
269  
270  	memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
271  	memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
272  	if (rds_conn_state(conn) == RDS_CONN_UP) {
273  		struct rds_ib_device *rds_ibdev;
274  		struct rdma_dev_addr *dev_addr;
275  
276  		ic = conn->c_transport_data;
277  		dev_addr = &ic->i_cm_id->route.addr.dev_addr;
278  
279  		rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
280  		rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
281  
282  		rds_ibdev = ic->rds_ibdev;
283  		iinfo->max_send_wr = ic->i_send_ring.w_nr;
284  		iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
285  		iinfo->max_send_sge = rds_ibdev->max_sge;
286  		rds_ib_get_mr_info(rds_ibdev, iinfo);
287  	}
288  	return 1;
289  }
290  
291  static void rds_ib_ic_info(struct socket *sock, unsigned int len,
292  			   struct rds_info_iterator *iter,
293  			   struct rds_info_lengths *lens)
294  {
295  	rds_for_each_conn_info(sock, len, iter, lens,
296  				rds_ib_conn_info_visitor,
297  				sizeof(struct rds_info_rdma_connection));
298  }
299  
300  
301  /*
302   * Early RDS/IB was built to only bind to an address if there is an IPoIB
303   * device with that address set.
304   *
305   * If it were me, I'd advocate for something more flexible.  Sending and
306   * receiving should be device-agnostic.  Transports would try and maintain
307   * connections between peers who have messages queued.  Userspace would be
308   * allowed to influence which paths have priority.  We could call userspace
309   * asserting this policy "routing".
310   */
311  static int rds_ib_laddr_check(struct net *net, __be32 addr)
312  {
313  	int ret;
314  	struct rdma_cm_id *cm_id;
315  	struct sockaddr_in sin;
316  
317  	/* Create a CMA ID and try to bind it. This catches both
318  	 * IB and iWARP capable NICs.
319  	 */
320  	cm_id = rdma_create_id(NULL, NULL, RDMA_PS_TCP, IB_QPT_RC);
321  	if (IS_ERR(cm_id))
322  		return PTR_ERR(cm_id);
323  
324  	memset(&sin, 0, sizeof(sin));
325  	sin.sin_family = AF_INET;
326  	sin.sin_addr.s_addr = addr;
327  
328  	/* rdma_bind_addr will only succeed for IB & iWARP devices */
329  	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
330  	/* due to this, we will claim to support iWARP devices unless we
331  	   check node_type. */
332  	if (ret || !cm_id->device ||
333  	    cm_id->device->node_type != RDMA_NODE_IB_CA)
334  		ret = -EADDRNOTAVAIL;
335  
336  	rdsdebug("addr %pI4 ret %d node type %d\n",
337  		&addr, ret,
338  		cm_id->device ? cm_id->device->node_type : -1);
339  
340  	rdma_destroy_id(cm_id);
341  
342  	return ret;
343  }
344  
345  static void rds_ib_unregister_client(void)
346  {
347  	ib_unregister_client(&rds_ib_client);
348  	/* wait for rds_ib_dev_free() to complete */
349  	flush_workqueue(rds_wq);
350  }
351  
352  void rds_ib_exit(void)
353  {
354  	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
355  	rds_ib_unregister_client();
356  	rds_ib_destroy_nodev_conns();
357  	rds_ib_sysctl_exit();
358  	rds_ib_recv_exit();
359  	rds_trans_unregister(&rds_ib_transport);
360  	rds_ib_fmr_exit();
361  }
362  
363  struct rds_transport rds_ib_transport = {
364  	.laddr_check		= rds_ib_laddr_check,
365  	.xmit_complete		= rds_ib_xmit_complete,
366  	.xmit			= rds_ib_xmit,
367  	.xmit_rdma		= rds_ib_xmit_rdma,
368  	.xmit_atomic		= rds_ib_xmit_atomic,
369  	.recv			= rds_ib_recv,
370  	.conn_alloc		= rds_ib_conn_alloc,
371  	.conn_free		= rds_ib_conn_free,
372  	.conn_connect		= rds_ib_conn_connect,
373  	.conn_shutdown		= rds_ib_conn_shutdown,
374  	.inc_copy_to_user	= rds_ib_inc_copy_to_user,
375  	.inc_free		= rds_ib_inc_free,
376  	.cm_initiate_connect	= rds_ib_cm_initiate_connect,
377  	.cm_handle_connect	= rds_ib_cm_handle_connect,
378  	.cm_connect_complete	= rds_ib_cm_connect_complete,
379  	.stats_info_copy	= rds_ib_stats_info_copy,
380  	.exit			= rds_ib_exit,
381  	.get_mr			= rds_ib_get_mr,
382  	.sync_mr		= rds_ib_sync_mr,
383  	.free_mr		= rds_ib_free_mr,
384  	.flush_mrs		= rds_ib_flush_mrs,
385  	.t_owner		= THIS_MODULE,
386  	.t_name			= "infiniband",
387  	.t_type			= RDS_TRANS_IB
388  };
389  
390  int rds_ib_init(void)
391  {
392  	int ret;
393  
394  	INIT_LIST_HEAD(&rds_ib_devices);
395  
396  	ret = rds_ib_fmr_init();
397  	if (ret)
398  		goto out;
399  
400  	ret = ib_register_client(&rds_ib_client);
401  	if (ret)
402  		goto out_fmr_exit;
403  
404  	ret = rds_ib_sysctl_init();
405  	if (ret)
406  		goto out_ibreg;
407  
408  	ret = rds_ib_recv_init();
409  	if (ret)
410  		goto out_sysctl;
411  
412  	ret = rds_trans_register(&rds_ib_transport);
413  	if (ret)
414  		goto out_recv;
415  
416  	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
417  
418  	goto out;
419  
420  out_recv:
421  	rds_ib_recv_exit();
422  out_sysctl:
423  	rds_ib_sysctl_exit();
424  out_ibreg:
425  	rds_ib_unregister_client();
426  out_fmr_exit:
427  	rds_ib_fmr_exit();
428  out:
429  	return ret;
430  }
431  
432  MODULE_LICENSE("GPL");
433  
434