xref: /openbmc/linux/net/rds/ib.c (revision 2c684d89)
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 unsigned int rds_ib_fmr_1m_pool_size = RDS_FMR_1M_POOL_SIZE;
47 unsigned int rds_ib_fmr_8k_pool_size = RDS_FMR_8K_POOL_SIZE;
48 unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
49 
50 module_param(rds_ib_fmr_1m_pool_size, int, 0444);
51 MODULE_PARM_DESC(rds_ib_fmr_1m_pool_size, " Max number of 1M fmr per HCA");
52 module_param(rds_ib_fmr_8k_pool_size, int, 0444);
53 MODULE_PARM_DESC(rds_ib_fmr_8k_pool_size, " Max number of 8K fmr per HCA");
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_8k_pool)
101 		rds_ib_destroy_mr_pool(rds_ibdev->mr_8k_pool);
102 	if (rds_ibdev->mr_1m_pool)
103 		rds_ib_destroy_mr_pool(rds_ibdev->mr_1m_pool);
104 	if (rds_ibdev->pd)
105 		ib_dealloc_pd(rds_ibdev->pd);
106 
107 	list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
108 		list_del(&i_ipaddr->list);
109 		kfree(i_ipaddr);
110 	}
111 
112 	kfree(rds_ibdev);
113 }
114 
115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
116 {
117 	BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
118 	if (atomic_dec_and_test(&rds_ibdev->refcount))
119 		queue_work(rds_wq, &rds_ibdev->free_work);
120 }
121 
122 static void rds_ib_add_one(struct ib_device *device)
123 {
124 	struct rds_ib_device *rds_ibdev;
125 	struct ib_device_attr *dev_attr;
126 
127 	/* Only handle IB (no iWARP) devices */
128 	if (device->node_type != RDMA_NODE_IB_CA)
129 		return;
130 
131 	dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
132 	if (!dev_attr)
133 		return;
134 
135 	if (ib_query_device(device, dev_attr)) {
136 		rdsdebug("Query device failed for %s\n", device->name);
137 		goto free_attr;
138 	}
139 
140 	rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
141 				 ibdev_to_node(device));
142 	if (!rds_ibdev)
143 		goto free_attr;
144 
145 	spin_lock_init(&rds_ibdev->spinlock);
146 	atomic_set(&rds_ibdev->refcount, 1);
147 	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
148 
149 	rds_ibdev->max_wrs = dev_attr->max_qp_wr;
150 	rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
151 
152 	rds_ibdev->fmr_max_remaps = dev_attr->max_map_per_fmr?: 32;
153 	rds_ibdev->max_1m_fmrs = dev_attr->max_mr ?
154 		min_t(unsigned int, (dev_attr->max_mr / 2),
155 		      rds_ib_fmr_1m_pool_size) : rds_ib_fmr_1m_pool_size;
156 
157 	rds_ibdev->max_8k_fmrs = dev_attr->max_mr ?
158 		min_t(unsigned int, ((dev_attr->max_mr / 2) * RDS_MR_8K_SCALE),
159 		      rds_ib_fmr_8k_pool_size) : rds_ib_fmr_8k_pool_size;
160 
161 	rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
162 	rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
163 
164 	rds_ibdev->dev = device;
165 	rds_ibdev->pd = ib_alloc_pd(device);
166 	if (IS_ERR(rds_ibdev->pd)) {
167 		rds_ibdev->pd = NULL;
168 		goto put_dev;
169 	}
170 
171 	rds_ibdev->mr_1m_pool =
172 		rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
173 	if (IS_ERR(rds_ibdev->mr_1m_pool)) {
174 		rds_ibdev->mr_1m_pool = NULL;
175 		goto put_dev;
176 	}
177 
178 	rds_ibdev->mr_8k_pool =
179 		rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
180 	if (IS_ERR(rds_ibdev->mr_8k_pool)) {
181 		rds_ibdev->mr_8k_pool = NULL;
182 		goto put_dev;
183 	}
184 
185 	rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, fmr_max_remaps = %d, max_1m_fmrs = %d, max_8k_fmrs = %d\n",
186 		 dev_attr->max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
187 		 rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_fmrs,
188 		 rds_ibdev->max_8k_fmrs);
189 
190 	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
191 	INIT_LIST_HEAD(&rds_ibdev->conn_list);
192 
193 	down_write(&rds_ib_devices_lock);
194 	list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
195 	up_write(&rds_ib_devices_lock);
196 	atomic_inc(&rds_ibdev->refcount);
197 
198 	ib_set_client_data(device, &rds_ib_client, rds_ibdev);
199 	atomic_inc(&rds_ibdev->refcount);
200 
201 	rds_ib_nodev_connect();
202 
203 put_dev:
204 	rds_ib_dev_put(rds_ibdev);
205 free_attr:
206 	kfree(dev_attr);
207 }
208 
209 /*
210  * New connections use this to find the device to associate with the
211  * connection.  It's not in the fast path so we're not concerned about the
212  * performance of the IB call.  (As of this writing, it uses an interrupt
213  * blocking spinlock to serialize walking a per-device list of all registered
214  * clients.)
215  *
216  * RCU is used to handle incoming connections racing with device teardown.
217  * Rather than use a lock to serialize removal from the client_data and
218  * getting a new reference, we use an RCU grace period.  The destruction
219  * path removes the device from client_data and then waits for all RCU
220  * readers to finish.
221  *
222  * A new connection can get NULL from this if its arriving on a
223  * device that is in the process of being removed.
224  */
225 struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
226 {
227 	struct rds_ib_device *rds_ibdev;
228 
229 	rcu_read_lock();
230 	rds_ibdev = ib_get_client_data(device, &rds_ib_client);
231 	if (rds_ibdev)
232 		atomic_inc(&rds_ibdev->refcount);
233 	rcu_read_unlock();
234 	return rds_ibdev;
235 }
236 
237 /*
238  * The IB stack is letting us know that a device is going away.  This can
239  * happen if the underlying HCA driver is removed or if PCI hotplug is removing
240  * the pci function, for example.
241  *
242  * This can be called at any time and can be racing with any other RDS path.
243  */
244 static void rds_ib_remove_one(struct ib_device *device, void *client_data)
245 {
246 	struct rds_ib_device *rds_ibdev = client_data;
247 
248 	if (!rds_ibdev)
249 		return;
250 
251 	rds_ib_dev_shutdown(rds_ibdev);
252 
253 	/* stop connection attempts from getting a reference to this device. */
254 	ib_set_client_data(device, &rds_ib_client, NULL);
255 
256 	down_write(&rds_ib_devices_lock);
257 	list_del_rcu(&rds_ibdev->list);
258 	up_write(&rds_ib_devices_lock);
259 
260 	/*
261 	 * This synchronize rcu is waiting for readers of both the ib
262 	 * client data and the devices list to finish before we drop
263 	 * both of those references.
264 	 */
265 	synchronize_rcu();
266 	rds_ib_dev_put(rds_ibdev);
267 	rds_ib_dev_put(rds_ibdev);
268 }
269 
270 struct ib_client rds_ib_client = {
271 	.name   = "rds_ib",
272 	.add    = rds_ib_add_one,
273 	.remove = rds_ib_remove_one
274 };
275 
276 static int rds_ib_conn_info_visitor(struct rds_connection *conn,
277 				    void *buffer)
278 {
279 	struct rds_info_rdma_connection *iinfo = buffer;
280 	struct rds_ib_connection *ic;
281 
282 	/* We will only ever look at IB transports */
283 	if (conn->c_trans != &rds_ib_transport)
284 		return 0;
285 
286 	iinfo->src_addr = conn->c_laddr;
287 	iinfo->dst_addr = conn->c_faddr;
288 
289 	memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
290 	memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
291 	if (rds_conn_state(conn) == RDS_CONN_UP) {
292 		struct rds_ib_device *rds_ibdev;
293 		struct rdma_dev_addr *dev_addr;
294 
295 		ic = conn->c_transport_data;
296 		dev_addr = &ic->i_cm_id->route.addr.dev_addr;
297 
298 		rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
299 		rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
300 
301 		rds_ibdev = ic->rds_ibdev;
302 		iinfo->max_send_wr = ic->i_send_ring.w_nr;
303 		iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
304 		iinfo->max_send_sge = rds_ibdev->max_sge;
305 		rds_ib_get_mr_info(rds_ibdev, iinfo);
306 	}
307 	return 1;
308 }
309 
310 static void rds_ib_ic_info(struct socket *sock, unsigned int len,
311 			   struct rds_info_iterator *iter,
312 			   struct rds_info_lengths *lens)
313 {
314 	rds_for_each_conn_info(sock, len, iter, lens,
315 				rds_ib_conn_info_visitor,
316 				sizeof(struct rds_info_rdma_connection));
317 }
318 
319 
320 /*
321  * Early RDS/IB was built to only bind to an address if there is an IPoIB
322  * device with that address set.
323  *
324  * If it were me, I'd advocate for something more flexible.  Sending and
325  * receiving should be device-agnostic.  Transports would try and maintain
326  * connections between peers who have messages queued.  Userspace would be
327  * allowed to influence which paths have priority.  We could call userspace
328  * asserting this policy "routing".
329  */
330 static int rds_ib_laddr_check(struct net *net, __be32 addr)
331 {
332 	int ret;
333 	struct rdma_cm_id *cm_id;
334 	struct sockaddr_in sin;
335 
336 	/* Create a CMA ID and try to bind it. This catches both
337 	 * IB and iWARP capable NICs.
338 	 */
339 	cm_id = rdma_create_id(&init_net, NULL, NULL, RDMA_PS_TCP, IB_QPT_RC);
340 	if (IS_ERR(cm_id))
341 		return PTR_ERR(cm_id);
342 
343 	memset(&sin, 0, sizeof(sin));
344 	sin.sin_family = AF_INET;
345 	sin.sin_addr.s_addr = addr;
346 
347 	/* rdma_bind_addr will only succeed for IB & iWARP devices */
348 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
349 	/* due to this, we will claim to support iWARP devices unless we
350 	   check node_type. */
351 	if (ret || !cm_id->device ||
352 	    cm_id->device->node_type != RDMA_NODE_IB_CA)
353 		ret = -EADDRNOTAVAIL;
354 
355 	rdsdebug("addr %pI4 ret %d node type %d\n",
356 		&addr, ret,
357 		cm_id->device ? cm_id->device->node_type : -1);
358 
359 	rdma_destroy_id(cm_id);
360 
361 	return ret;
362 }
363 
364 static void rds_ib_unregister_client(void)
365 {
366 	ib_unregister_client(&rds_ib_client);
367 	/* wait for rds_ib_dev_free() to complete */
368 	flush_workqueue(rds_wq);
369 }
370 
371 void rds_ib_exit(void)
372 {
373 	rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
374 	rds_ib_unregister_client();
375 	rds_ib_destroy_nodev_conns();
376 	rds_ib_sysctl_exit();
377 	rds_ib_recv_exit();
378 	rds_trans_unregister(&rds_ib_transport);
379 	rds_ib_fmr_exit();
380 }
381 
382 struct rds_transport rds_ib_transport = {
383 	.laddr_check		= rds_ib_laddr_check,
384 	.xmit_complete		= rds_ib_xmit_complete,
385 	.xmit			= rds_ib_xmit,
386 	.xmit_rdma		= rds_ib_xmit_rdma,
387 	.xmit_atomic		= rds_ib_xmit_atomic,
388 	.recv			= rds_ib_recv,
389 	.conn_alloc		= rds_ib_conn_alloc,
390 	.conn_free		= rds_ib_conn_free,
391 	.conn_connect		= rds_ib_conn_connect,
392 	.conn_shutdown		= rds_ib_conn_shutdown,
393 	.inc_copy_to_user	= rds_ib_inc_copy_to_user,
394 	.inc_free		= rds_ib_inc_free,
395 	.cm_initiate_connect	= rds_ib_cm_initiate_connect,
396 	.cm_handle_connect	= rds_ib_cm_handle_connect,
397 	.cm_connect_complete	= rds_ib_cm_connect_complete,
398 	.stats_info_copy	= rds_ib_stats_info_copy,
399 	.exit			= rds_ib_exit,
400 	.get_mr			= rds_ib_get_mr,
401 	.sync_mr		= rds_ib_sync_mr,
402 	.free_mr		= rds_ib_free_mr,
403 	.flush_mrs		= rds_ib_flush_mrs,
404 	.t_owner		= THIS_MODULE,
405 	.t_name			= "infiniband",
406 	.t_type			= RDS_TRANS_IB
407 };
408 
409 int rds_ib_init(void)
410 {
411 	int ret;
412 
413 	INIT_LIST_HEAD(&rds_ib_devices);
414 
415 	ret = rds_ib_fmr_init();
416 	if (ret)
417 		goto out;
418 
419 	ret = ib_register_client(&rds_ib_client);
420 	if (ret)
421 		goto out_fmr_exit;
422 
423 	ret = rds_ib_sysctl_init();
424 	if (ret)
425 		goto out_ibreg;
426 
427 	ret = rds_ib_recv_init();
428 	if (ret)
429 		goto out_sysctl;
430 
431 	ret = rds_trans_register(&rds_ib_transport);
432 	if (ret)
433 		goto out_recv;
434 
435 	rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
436 
437 	goto out;
438 
439 out_recv:
440 	rds_ib_recv_exit();
441 out_sysctl:
442 	rds_ib_sysctl_exit();
443 out_ibreg:
444 	rds_ib_unregister_client();
445 out_fmr_exit:
446 	rds_ib_fmr_exit();
447 out:
448 	return ret;
449 }
450 
451 MODULE_LICENSE("GPL");
452 
453