xref: /openbmc/linux/net/smc/smc_ib.c (revision 1b39e7607144337d752f36c2068ed79447462f99)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4   *
5   *  IB infrastructure:
6   *  Establish SMC-R as an Infiniband Client to be notified about added and
7   *  removed IB devices of type RDMA.
8   *  Determine device and port characteristics for these IB devices.
9   *
10   *  Copyright IBM Corp. 2016
11   *
12   *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
13   */
14  
15  #include <linux/etherdevice.h>
16  #include <linux/if_vlan.h>
17  #include <linux/random.h>
18  #include <linux/workqueue.h>
19  #include <linux/scatterlist.h>
20  #include <linux/wait.h>
21  #include <linux/mutex.h>
22  #include <linux/inetdevice.h>
23  #include <rdma/ib_verbs.h>
24  #include <rdma/ib_cache.h>
25  
26  #include "smc_pnet.h"
27  #include "smc_ib.h"
28  #include "smc_core.h"
29  #include "smc_wr.h"
30  #include "smc.h"
31  #include "smc_netlink.h"
32  
33  #define SMC_MAX_CQE 32766	/* max. # of completion queue elements */
34  
35  #define SMC_QP_MIN_RNR_TIMER		5
36  #define SMC_QP_TIMEOUT			15 /* 4096 * 2 ** timeout usec */
37  #define SMC_QP_RETRY_CNT			7 /* 7: infinite */
38  #define SMC_QP_RNR_RETRY			7 /* 7: infinite */
39  
40  struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
41  	.mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
42  	.list = LIST_HEAD_INIT(smc_ib_devices.list),
43  };
44  
45  u8 local_systemid[SMC_SYSTEMID_LEN];		/* unique system identifier */
46  
47  static int smc_ib_modify_qp_init(struct smc_link *lnk)
48  {
49  	struct ib_qp_attr qp_attr;
50  
51  	memset(&qp_attr, 0, sizeof(qp_attr));
52  	qp_attr.qp_state = IB_QPS_INIT;
53  	qp_attr.pkey_index = 0;
54  	qp_attr.port_num = lnk->ibport;
55  	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
56  				| IB_ACCESS_REMOTE_WRITE;
57  	return ib_modify_qp(lnk->roce_qp, &qp_attr,
58  			    IB_QP_STATE | IB_QP_PKEY_INDEX |
59  			    IB_QP_ACCESS_FLAGS | IB_QP_PORT);
60  }
61  
62  static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
63  {
64  	enum ib_qp_attr_mask qp_attr_mask =
65  		IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
66  		IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
67  	struct ib_qp_attr qp_attr;
68  	u8 hop_lim = 1;
69  
70  	memset(&qp_attr, 0, sizeof(qp_attr));
71  	qp_attr.qp_state = IB_QPS_RTR;
72  	qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
73  	qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
74  	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
75  	if (lnk->lgr->smc_version == SMC_V2 && lnk->lgr->uses_gateway)
76  		hop_lim = IPV6_DEFAULT_HOPLIMIT;
77  	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, hop_lim, 0);
78  	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
79  	if (lnk->lgr->smc_version == SMC_V2 && lnk->lgr->uses_gateway)
80  		memcpy(&qp_attr.ah_attr.roce.dmac, lnk->lgr->nexthop_mac,
81  		       sizeof(lnk->lgr->nexthop_mac));
82  	else
83  		memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
84  		       sizeof(lnk->peer_mac));
85  	qp_attr.dest_qp_num = lnk->peer_qpn;
86  	qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
87  	qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
88  					 * requests
89  					 */
90  	qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
91  
92  	return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
93  }
94  
95  int smc_ib_modify_qp_rts(struct smc_link *lnk)
96  {
97  	struct ib_qp_attr qp_attr;
98  
99  	memset(&qp_attr, 0, sizeof(qp_attr));
100  	qp_attr.qp_state = IB_QPS_RTS;
101  	qp_attr.timeout = SMC_QP_TIMEOUT;	/* local ack timeout */
102  	qp_attr.retry_cnt = SMC_QP_RETRY_CNT;	/* retry count */
103  	qp_attr.rnr_retry = SMC_QP_RNR_RETRY;	/* RNR retries, 7=infinite */
104  	qp_attr.sq_psn = lnk->psn_initial;	/* starting send packet seq # */
105  	qp_attr.max_rd_atomic = 1;	/* # of outstanding RDMA reads and
106  					 * atomic ops allowed
107  					 */
108  	return ib_modify_qp(lnk->roce_qp, &qp_attr,
109  			    IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
110  			    IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
111  			    IB_QP_MAX_QP_RD_ATOMIC);
112  }
113  
114  int smc_ib_modify_qp_error(struct smc_link *lnk)
115  {
116  	struct ib_qp_attr qp_attr;
117  
118  	memset(&qp_attr, 0, sizeof(qp_attr));
119  	qp_attr.qp_state = IB_QPS_ERR;
120  	return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
121  }
122  
123  int smc_ib_ready_link(struct smc_link *lnk)
124  {
125  	struct smc_link_group *lgr = smc_get_lgr(lnk);
126  	int rc = 0;
127  
128  	rc = smc_ib_modify_qp_init(lnk);
129  	if (rc)
130  		goto out;
131  
132  	rc = smc_ib_modify_qp_rtr(lnk);
133  	if (rc)
134  		goto out;
135  	smc_wr_remember_qp_attr(lnk);
136  	rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
137  			      IB_CQ_SOLICITED_MASK);
138  	if (rc)
139  		goto out;
140  	rc = smc_wr_rx_post_init(lnk);
141  	if (rc)
142  		goto out;
143  	smc_wr_remember_qp_attr(lnk);
144  
145  	if (lgr->role == SMC_SERV) {
146  		rc = smc_ib_modify_qp_rts(lnk);
147  		if (rc)
148  			goto out;
149  		smc_wr_remember_qp_attr(lnk);
150  	}
151  out:
152  	return rc;
153  }
154  
155  static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
156  {
157  	const struct ib_gid_attr *attr;
158  	int rc;
159  
160  	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
161  	if (IS_ERR(attr))
162  		return -ENODEV;
163  
164  	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
165  	rdma_put_gid_attr(attr);
166  	return rc;
167  }
168  
169  /* Create an identifier unique for this instance of SMC-R.
170   * The MAC-address of the first active registered IB device
171   * plus a random 2-byte number is used to create this identifier.
172   * This name is delivered to the peer during connection initialization.
173   */
174  static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
175  						u8 ibport)
176  {
177  	memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
178  	       sizeof(smcibdev->mac[ibport - 1]));
179  }
180  
181  bool smc_ib_is_valid_local_systemid(void)
182  {
183  	return !is_zero_ether_addr(&local_systemid[2]);
184  }
185  
186  static void smc_ib_init_local_systemid(void)
187  {
188  	get_random_bytes(&local_systemid[0], 2);
189  }
190  
191  bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
192  {
193  	return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
194  }
195  
196  int smc_ib_find_route(__be32 saddr, __be32 daddr,
197  		      u8 nexthop_mac[], u8 *uses_gateway)
198  {
199  	struct neighbour *neigh = NULL;
200  	struct rtable *rt = NULL;
201  	struct flowi4 fl4 = {
202  		.saddr = saddr,
203  		.daddr = daddr
204  	};
205  
206  	if (daddr == cpu_to_be32(INADDR_NONE))
207  		goto out;
208  	rt = ip_route_output_flow(&init_net, &fl4, NULL);
209  	if (IS_ERR(rt))
210  		goto out;
211  	if (rt->rt_uses_gateway && rt->rt_gw_family != AF_INET)
212  		goto out;
213  	neigh = rt->dst.ops->neigh_lookup(&rt->dst, NULL, &fl4.daddr);
214  	if (neigh) {
215  		memcpy(nexthop_mac, neigh->ha, ETH_ALEN);
216  		*uses_gateway = rt->rt_uses_gateway;
217  		return 0;
218  	}
219  out:
220  	return -ENOENT;
221  }
222  
223  static int smc_ib_determine_gid_rcu(const struct net_device *ndev,
224  				    const struct ib_gid_attr *attr,
225  				    u8 gid[], u8 *sgid_index,
226  				    struct smc_init_info_smcrv2 *smcrv2)
227  {
228  	if (!smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE) {
229  		if (gid)
230  			memcpy(gid, &attr->gid, SMC_GID_SIZE);
231  		if (sgid_index)
232  			*sgid_index = attr->index;
233  		return 0;
234  	}
235  	if (smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP &&
236  	    smc_ib_gid_to_ipv4((u8 *)&attr->gid) != cpu_to_be32(INADDR_NONE)) {
237  		struct in_device *in_dev = __in_dev_get_rcu(ndev);
238  		const struct in_ifaddr *ifa;
239  		bool subnet_match = false;
240  
241  		if (!in_dev)
242  			goto out;
243  		in_dev_for_each_ifa_rcu(ifa, in_dev) {
244  			if (!inet_ifa_match(smcrv2->saddr, ifa))
245  				continue;
246  			subnet_match = true;
247  			break;
248  		}
249  		if (!subnet_match)
250  			goto out;
251  		if (smcrv2->daddr && smc_ib_find_route(smcrv2->saddr,
252  						       smcrv2->daddr,
253  						       smcrv2->nexthop_mac,
254  						       &smcrv2->uses_gateway))
255  			goto out;
256  
257  		if (gid)
258  			memcpy(gid, &attr->gid, SMC_GID_SIZE);
259  		if (sgid_index)
260  			*sgid_index = attr->index;
261  		return 0;
262  	}
263  out:
264  	return -ENODEV;
265  }
266  
267  /* determine the gid for an ib-device port and vlan id */
268  int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
269  			 unsigned short vlan_id, u8 gid[], u8 *sgid_index,
270  			 struct smc_init_info_smcrv2 *smcrv2)
271  {
272  	const struct ib_gid_attr *attr;
273  	const struct net_device *ndev;
274  	int i;
275  
276  	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
277  		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
278  		if (IS_ERR(attr))
279  			continue;
280  
281  		rcu_read_lock();
282  		ndev = rdma_read_gid_attr_ndev_rcu(attr);
283  		if (!IS_ERR(ndev) &&
284  		    ((!vlan_id && !is_vlan_dev(ndev)) ||
285  		     (vlan_id && is_vlan_dev(ndev) &&
286  		      vlan_dev_vlan_id(ndev) == vlan_id))) {
287  			if (!smc_ib_determine_gid_rcu(ndev, attr, gid,
288  						      sgid_index, smcrv2)) {
289  				rcu_read_unlock();
290  				rdma_put_gid_attr(attr);
291  				return 0;
292  			}
293  		}
294  		rcu_read_unlock();
295  		rdma_put_gid_attr(attr);
296  	}
297  	return -ENODEV;
298  }
299  
300  /* check if gid is still defined on smcibdev */
301  static bool smc_ib_check_link_gid(u8 gid[SMC_GID_SIZE], bool smcrv2,
302  				  struct smc_ib_device *smcibdev, u8 ibport)
303  {
304  	const struct ib_gid_attr *attr;
305  	bool rc = false;
306  	int i;
307  
308  	for (i = 0; !rc && i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
309  		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
310  		if (IS_ERR(attr))
311  			continue;
312  
313  		rcu_read_lock();
314  		if ((!smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE) ||
315  		    (smcrv2 && attr->gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP &&
316  		     !(ipv6_addr_type((const struct in6_addr *)&attr->gid)
317  				     & IPV6_ADDR_LINKLOCAL)))
318  			if (!memcmp(gid, &attr->gid, SMC_GID_SIZE))
319  				rc = true;
320  		rcu_read_unlock();
321  		rdma_put_gid_attr(attr);
322  	}
323  	return rc;
324  }
325  
326  /* check all links if the gid is still defined on smcibdev */
327  static void smc_ib_gid_check(struct smc_ib_device *smcibdev, u8 ibport)
328  {
329  	struct smc_link_group *lgr;
330  	int i;
331  
332  	spin_lock_bh(&smc_lgr_list.lock);
333  	list_for_each_entry(lgr, &smc_lgr_list.list, list) {
334  		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
335  			    SMC_MAX_PNETID_LEN))
336  			continue; /* lgr is not affected */
337  		if (list_empty(&lgr->list))
338  			continue;
339  		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
340  			if (lgr->lnk[i].state == SMC_LNK_UNUSED ||
341  			    lgr->lnk[i].smcibdev != smcibdev)
342  				continue;
343  			if (!smc_ib_check_link_gid(lgr->lnk[i].gid,
344  						   lgr->smc_version == SMC_V2,
345  						   smcibdev, ibport))
346  				smcr_port_err(smcibdev, ibport);
347  		}
348  	}
349  	spin_unlock_bh(&smc_lgr_list.lock);
350  }
351  
352  static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
353  {
354  	int rc;
355  
356  	memset(&smcibdev->pattr[ibport - 1], 0,
357  	       sizeof(smcibdev->pattr[ibport - 1]));
358  	rc = ib_query_port(smcibdev->ibdev, ibport,
359  			   &smcibdev->pattr[ibport - 1]);
360  	if (rc)
361  		goto out;
362  	/* the SMC protocol requires specification of the RoCE MAC address */
363  	rc = smc_ib_fill_mac(smcibdev, ibport);
364  	if (rc)
365  		goto out;
366  	if (!smc_ib_is_valid_local_systemid() &&
367  	    smc_ib_port_active(smcibdev, ibport))
368  		/* create unique system identifier */
369  		smc_ib_define_local_systemid(smcibdev, ibport);
370  out:
371  	return rc;
372  }
373  
374  /* process context wrapper for might_sleep smc_ib_remember_port_attr */
375  static void smc_ib_port_event_work(struct work_struct *work)
376  {
377  	struct smc_ib_device *smcibdev = container_of(
378  		work, struct smc_ib_device, port_event_work);
379  	u8 port_idx;
380  
381  	for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
382  		smc_ib_remember_port_attr(smcibdev, port_idx + 1);
383  		clear_bit(port_idx, &smcibdev->port_event_mask);
384  		if (!smc_ib_port_active(smcibdev, port_idx + 1)) {
385  			set_bit(port_idx, smcibdev->ports_going_away);
386  			smcr_port_err(smcibdev, port_idx + 1);
387  		} else {
388  			clear_bit(port_idx, smcibdev->ports_going_away);
389  			smcr_port_add(smcibdev, port_idx + 1);
390  			smc_ib_gid_check(smcibdev, port_idx + 1);
391  		}
392  	}
393  }
394  
395  /* can be called in IRQ context */
396  static void smc_ib_global_event_handler(struct ib_event_handler *handler,
397  					struct ib_event *ibevent)
398  {
399  	struct smc_ib_device *smcibdev;
400  	bool schedule = false;
401  	u8 port_idx;
402  
403  	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
404  
405  	switch (ibevent->event) {
406  	case IB_EVENT_DEVICE_FATAL:
407  		/* terminate all ports on device */
408  		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
409  			set_bit(port_idx, &smcibdev->port_event_mask);
410  			if (!test_and_set_bit(port_idx,
411  					      smcibdev->ports_going_away))
412  				schedule = true;
413  		}
414  		if (schedule)
415  			schedule_work(&smcibdev->port_event_work);
416  		break;
417  	case IB_EVENT_PORT_ACTIVE:
418  		port_idx = ibevent->element.port_num - 1;
419  		if (port_idx >= SMC_MAX_PORTS)
420  			break;
421  		set_bit(port_idx, &smcibdev->port_event_mask);
422  		if (test_and_clear_bit(port_idx, smcibdev->ports_going_away))
423  			schedule_work(&smcibdev->port_event_work);
424  		break;
425  	case IB_EVENT_PORT_ERR:
426  		port_idx = ibevent->element.port_num - 1;
427  		if (port_idx >= SMC_MAX_PORTS)
428  			break;
429  		set_bit(port_idx, &smcibdev->port_event_mask);
430  		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
431  			schedule_work(&smcibdev->port_event_work);
432  		break;
433  	case IB_EVENT_GID_CHANGE:
434  		port_idx = ibevent->element.port_num - 1;
435  		if (port_idx >= SMC_MAX_PORTS)
436  			break;
437  		set_bit(port_idx, &smcibdev->port_event_mask);
438  		schedule_work(&smcibdev->port_event_work);
439  		break;
440  	default:
441  		break;
442  	}
443  }
444  
445  void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
446  {
447  	if (lnk->roce_pd)
448  		ib_dealloc_pd(lnk->roce_pd);
449  	lnk->roce_pd = NULL;
450  }
451  
452  int smc_ib_create_protection_domain(struct smc_link *lnk)
453  {
454  	int rc;
455  
456  	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
457  	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
458  	if (IS_ERR(lnk->roce_pd))
459  		lnk->roce_pd = NULL;
460  	return rc;
461  }
462  
463  static bool smcr_diag_is_dev_critical(struct smc_lgr_list *smc_lgr,
464  				      struct smc_ib_device *smcibdev)
465  {
466  	struct smc_link_group *lgr;
467  	bool rc = false;
468  	int i;
469  
470  	spin_lock_bh(&smc_lgr->lock);
471  	list_for_each_entry(lgr, &smc_lgr->list, list) {
472  		if (lgr->is_smcd)
473  			continue;
474  		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
475  			if (lgr->lnk[i].state == SMC_LNK_UNUSED ||
476  			    lgr->lnk[i].smcibdev != smcibdev)
477  				continue;
478  			if (lgr->type == SMC_LGR_SINGLE ||
479  			    lgr->type == SMC_LGR_ASYMMETRIC_LOCAL) {
480  				rc = true;
481  				goto out;
482  			}
483  		}
484  	}
485  out:
486  	spin_unlock_bh(&smc_lgr->lock);
487  	return rc;
488  }
489  
490  static int smc_nl_handle_dev_port(struct sk_buff *skb,
491  				  struct ib_device *ibdev,
492  				  struct smc_ib_device *smcibdev,
493  				  int port)
494  {
495  	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
496  	struct nlattr *port_attrs;
497  	unsigned char port_state;
498  	int lnk_count = 0;
499  
500  	port_attrs = nla_nest_start(skb, SMC_NLA_DEV_PORT + port);
501  	if (!port_attrs)
502  		goto errout;
503  
504  	if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR,
505  		       smcibdev->pnetid_by_user[port]))
506  		goto errattr;
507  	memcpy(smc_pnet, &smcibdev->pnetid[port], SMC_MAX_PNETID_LEN);
508  	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
509  	if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet))
510  		goto errattr;
511  	if (nla_put_u32(skb, SMC_NLA_DEV_PORT_NETDEV,
512  			smcibdev->ndev_ifidx[port]))
513  		goto errattr;
514  	if (nla_put_u8(skb, SMC_NLA_DEV_PORT_VALID, 1))
515  		goto errattr;
516  	port_state = smc_ib_port_active(smcibdev, port + 1);
517  	if (nla_put_u8(skb, SMC_NLA_DEV_PORT_STATE, port_state))
518  		goto errattr;
519  	lnk_count = atomic_read(&smcibdev->lnk_cnt_by_port[port]);
520  	if (nla_put_u32(skb, SMC_NLA_DEV_PORT_LNK_CNT, lnk_count))
521  		goto errattr;
522  	nla_nest_end(skb, port_attrs);
523  	return 0;
524  errattr:
525  	nla_nest_cancel(skb, port_attrs);
526  errout:
527  	return -EMSGSIZE;
528  }
529  
530  static bool smc_nl_handle_pci_values(const struct smc_pci_dev *smc_pci_dev,
531  				     struct sk_buff *skb)
532  {
533  	if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev->pci_fid))
534  		return false;
535  	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev->pci_pchid))
536  		return false;
537  	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_VENDOR, smc_pci_dev->pci_vendor))
538  		return false;
539  	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_DEVICE, smc_pci_dev->pci_device))
540  		return false;
541  	if (nla_put_string(skb, SMC_NLA_DEV_PCI_ID, smc_pci_dev->pci_id))
542  		return false;
543  	return true;
544  }
545  
546  static int smc_nl_handle_smcr_dev(struct smc_ib_device *smcibdev,
547  				  struct sk_buff *skb,
548  				  struct netlink_callback *cb)
549  {
550  	char smc_ibname[IB_DEVICE_NAME_MAX];
551  	struct smc_pci_dev smc_pci_dev;
552  	struct pci_dev *pci_dev;
553  	unsigned char is_crit;
554  	struct nlattr *attrs;
555  	void *nlh;
556  	int i;
557  
558  	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
559  			  &smc_gen_nl_family, NLM_F_MULTI,
560  			  SMC_NETLINK_GET_DEV_SMCR);
561  	if (!nlh)
562  		goto errmsg;
563  	attrs = nla_nest_start(skb, SMC_GEN_DEV_SMCR);
564  	if (!attrs)
565  		goto errout;
566  	is_crit = smcr_diag_is_dev_critical(&smc_lgr_list, smcibdev);
567  	if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, is_crit))
568  		goto errattr;
569  	if (smcibdev->ibdev->dev.parent) {
570  		memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
571  		pci_dev = to_pci_dev(smcibdev->ibdev->dev.parent);
572  		smc_set_pci_values(pci_dev, &smc_pci_dev);
573  		if (!smc_nl_handle_pci_values(&smc_pci_dev, skb))
574  			goto errattr;
575  	}
576  	snprintf(smc_ibname, sizeof(smc_ibname), "%s", smcibdev->ibdev->name);
577  	if (nla_put_string(skb, SMC_NLA_DEV_IB_NAME, smc_ibname))
578  		goto errattr;
579  	for (i = 1; i <= SMC_MAX_PORTS; i++) {
580  		if (!rdma_is_port_valid(smcibdev->ibdev, i))
581  			continue;
582  		if (smc_nl_handle_dev_port(skb, smcibdev->ibdev,
583  					   smcibdev, i - 1))
584  			goto errattr;
585  	}
586  
587  	nla_nest_end(skb, attrs);
588  	genlmsg_end(skb, nlh);
589  	return 0;
590  
591  errattr:
592  	nla_nest_cancel(skb, attrs);
593  errout:
594  	genlmsg_cancel(skb, nlh);
595  errmsg:
596  	return -EMSGSIZE;
597  }
598  
599  static void smc_nl_prep_smcr_dev(struct smc_ib_devices *dev_list,
600  				 struct sk_buff *skb,
601  				 struct netlink_callback *cb)
602  {
603  	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
604  	struct smc_ib_device *smcibdev;
605  	int snum = cb_ctx->pos[0];
606  	int num = 0;
607  
608  	mutex_lock(&dev_list->mutex);
609  	list_for_each_entry(smcibdev, &dev_list->list, list) {
610  		if (num < snum)
611  			goto next;
612  		if (smc_nl_handle_smcr_dev(smcibdev, skb, cb))
613  			goto errout;
614  next:
615  		num++;
616  	}
617  errout:
618  	mutex_unlock(&dev_list->mutex);
619  	cb_ctx->pos[0] = num;
620  }
621  
622  int smcr_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb)
623  {
624  	smc_nl_prep_smcr_dev(&smc_ib_devices, skb, cb);
625  	return skb->len;
626  }
627  
628  static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
629  {
630  	struct smc_link *lnk = (struct smc_link *)priv;
631  	struct smc_ib_device *smcibdev = lnk->smcibdev;
632  	u8 port_idx;
633  
634  	switch (ibevent->event) {
635  	case IB_EVENT_QP_FATAL:
636  	case IB_EVENT_QP_ACCESS_ERR:
637  		port_idx = ibevent->element.qp->port - 1;
638  		if (port_idx >= SMC_MAX_PORTS)
639  			break;
640  		set_bit(port_idx, &smcibdev->port_event_mask);
641  		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
642  			schedule_work(&smcibdev->port_event_work);
643  		break;
644  	default:
645  		break;
646  	}
647  }
648  
649  void smc_ib_destroy_queue_pair(struct smc_link *lnk)
650  {
651  	if (lnk->roce_qp)
652  		ib_destroy_qp(lnk->roce_qp);
653  	lnk->roce_qp = NULL;
654  }
655  
656  /* create a queue pair within the protection domain for a link */
657  int smc_ib_create_queue_pair(struct smc_link *lnk)
658  {
659  	int sges_per_buf = (lnk->lgr->smc_version == SMC_V2) ? 2 : 1;
660  	struct ib_qp_init_attr qp_attr = {
661  		.event_handler = smc_ib_qp_event_handler,
662  		.qp_context = lnk,
663  		.send_cq = lnk->smcibdev->roce_cq_send,
664  		.recv_cq = lnk->smcibdev->roce_cq_recv,
665  		.srq = NULL,
666  		.cap = {
667  				/* include unsolicited rdma_writes as well,
668  				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
669  				 */
670  			.max_send_wr = SMC_WR_BUF_CNT * 3,
671  			.max_recv_wr = SMC_WR_BUF_CNT * 3,
672  			.max_send_sge = SMC_IB_MAX_SEND_SGE,
673  			.max_recv_sge = sges_per_buf,
674  			.max_inline_data = 0,
675  		},
676  		.sq_sig_type = IB_SIGNAL_REQ_WR,
677  		.qp_type = IB_QPT_RC,
678  	};
679  	int rc;
680  
681  	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
682  	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
683  	if (IS_ERR(lnk->roce_qp))
684  		lnk->roce_qp = NULL;
685  	else
686  		smc_wr_remember_qp_attr(lnk);
687  	return rc;
688  }
689  
690  void smc_ib_put_memory_region(struct ib_mr *mr)
691  {
692  	ib_dereg_mr(mr);
693  }
694  
695  static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot, u8 link_idx)
696  {
697  	unsigned int offset = 0;
698  	int sg_num;
699  
700  	/* map the largest prefix of a dma mapped SG list */
701  	sg_num = ib_map_mr_sg(buf_slot->mr[link_idx],
702  			      buf_slot->sgt[link_idx].sgl,
703  			      buf_slot->sgt[link_idx].orig_nents,
704  			      &offset, PAGE_SIZE);
705  
706  	return sg_num;
707  }
708  
709  /* Allocate a memory region and map the dma mapped SG list of buf_slot */
710  int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
711  			     struct smc_buf_desc *buf_slot, u8 link_idx)
712  {
713  	if (buf_slot->mr[link_idx])
714  		return 0; /* already done */
715  
716  	buf_slot->mr[link_idx] =
717  		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
718  	if (IS_ERR(buf_slot->mr[link_idx])) {
719  		int rc;
720  
721  		rc = PTR_ERR(buf_slot->mr[link_idx]);
722  		buf_slot->mr[link_idx] = NULL;
723  		return rc;
724  	}
725  
726  	if (smc_ib_map_mr_sg(buf_slot, link_idx) !=
727  			     buf_slot->sgt[link_idx].orig_nents)
728  		return -EINVAL;
729  
730  	return 0;
731  }
732  
733  bool smc_ib_is_sg_need_sync(struct smc_link *lnk,
734  			    struct smc_buf_desc *buf_slot)
735  {
736  	struct scatterlist *sg;
737  	unsigned int i;
738  	bool ret = false;
739  
740  	/* for now there is just one DMA address */
741  	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
742  		    buf_slot->sgt[lnk->link_idx].nents, i) {
743  		if (!sg_dma_len(sg))
744  			break;
745  		if (dma_need_sync(lnk->smcibdev->ibdev->dma_device,
746  				  sg_dma_address(sg))) {
747  			ret = true;
748  			goto out;
749  		}
750  	}
751  
752  out:
753  	return ret;
754  }
755  
756  /* synchronize buffer usage for cpu access */
757  void smc_ib_sync_sg_for_cpu(struct smc_link *lnk,
758  			    struct smc_buf_desc *buf_slot,
759  			    enum dma_data_direction data_direction)
760  {
761  	struct scatterlist *sg;
762  	unsigned int i;
763  
764  	if (!(buf_slot->is_dma_need_sync & (1U << lnk->link_idx)))
765  		return;
766  
767  	/* for now there is just one DMA address */
768  	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
769  		    buf_slot->sgt[lnk->link_idx].nents, i) {
770  		if (!sg_dma_len(sg))
771  			break;
772  		ib_dma_sync_single_for_cpu(lnk->smcibdev->ibdev,
773  					   sg_dma_address(sg),
774  					   sg_dma_len(sg),
775  					   data_direction);
776  	}
777  }
778  
779  /* synchronize buffer usage for device access */
780  void smc_ib_sync_sg_for_device(struct smc_link *lnk,
781  			       struct smc_buf_desc *buf_slot,
782  			       enum dma_data_direction data_direction)
783  {
784  	struct scatterlist *sg;
785  	unsigned int i;
786  
787  	if (!(buf_slot->is_dma_need_sync & (1U << lnk->link_idx)))
788  		return;
789  
790  	/* for now there is just one DMA address */
791  	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
792  		    buf_slot->sgt[lnk->link_idx].nents, i) {
793  		if (!sg_dma_len(sg))
794  			break;
795  		ib_dma_sync_single_for_device(lnk->smcibdev->ibdev,
796  					      sg_dma_address(sg),
797  					      sg_dma_len(sg),
798  					      data_direction);
799  	}
800  }
801  
802  /* Map a new TX or RX buffer SG-table to DMA */
803  int smc_ib_buf_map_sg(struct smc_link *lnk,
804  		      struct smc_buf_desc *buf_slot,
805  		      enum dma_data_direction data_direction)
806  {
807  	int mapped_nents;
808  
809  	mapped_nents = ib_dma_map_sg(lnk->smcibdev->ibdev,
810  				     buf_slot->sgt[lnk->link_idx].sgl,
811  				     buf_slot->sgt[lnk->link_idx].orig_nents,
812  				     data_direction);
813  	if (!mapped_nents)
814  		return -ENOMEM;
815  
816  	return mapped_nents;
817  }
818  
819  void smc_ib_buf_unmap_sg(struct smc_link *lnk,
820  			 struct smc_buf_desc *buf_slot,
821  			 enum dma_data_direction data_direction)
822  {
823  	if (!buf_slot->sgt[lnk->link_idx].sgl->dma_address)
824  		return; /* already unmapped */
825  
826  	ib_dma_unmap_sg(lnk->smcibdev->ibdev,
827  			buf_slot->sgt[lnk->link_idx].sgl,
828  			buf_slot->sgt[lnk->link_idx].orig_nents,
829  			data_direction);
830  	buf_slot->sgt[lnk->link_idx].sgl->dma_address = 0;
831  }
832  
833  long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
834  {
835  	struct ib_cq_init_attr cqattr =	{
836  		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
837  	int cqe_size_order, smc_order;
838  	long rc;
839  
840  	mutex_lock(&smcibdev->mutex);
841  	rc = 0;
842  	if (smcibdev->initialized)
843  		goto out;
844  	/* the calculated number of cq entries fits to mlx5 cq allocation */
845  	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
846  	smc_order = MAX_ORDER - cqe_size_order;
847  	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
848  		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
849  	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
850  					      smc_wr_tx_cq_handler, NULL,
851  					      smcibdev, &cqattr);
852  	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
853  	if (IS_ERR(smcibdev->roce_cq_send)) {
854  		smcibdev->roce_cq_send = NULL;
855  		goto out;
856  	}
857  	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
858  					      smc_wr_rx_cq_handler, NULL,
859  					      smcibdev, &cqattr);
860  	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
861  	if (IS_ERR(smcibdev->roce_cq_recv)) {
862  		smcibdev->roce_cq_recv = NULL;
863  		goto err;
864  	}
865  	smc_wr_add_dev(smcibdev);
866  	smcibdev->initialized = 1;
867  	goto out;
868  
869  err:
870  	ib_destroy_cq(smcibdev->roce_cq_send);
871  out:
872  	mutex_unlock(&smcibdev->mutex);
873  	return rc;
874  }
875  
876  static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
877  {
878  	mutex_lock(&smcibdev->mutex);
879  	if (!smcibdev->initialized)
880  		goto out;
881  	smcibdev->initialized = 0;
882  	ib_destroy_cq(smcibdev->roce_cq_recv);
883  	ib_destroy_cq(smcibdev->roce_cq_send);
884  	smc_wr_remove_dev(smcibdev);
885  out:
886  	mutex_unlock(&smcibdev->mutex);
887  }
888  
889  static struct ib_client smc_ib_client;
890  
891  static void smc_copy_netdev_ifindex(struct smc_ib_device *smcibdev, int port)
892  {
893  	struct ib_device *ibdev = smcibdev->ibdev;
894  	struct net_device *ndev;
895  
896  	if (!ibdev->ops.get_netdev)
897  		return;
898  	ndev = ibdev->ops.get_netdev(ibdev, port + 1);
899  	if (ndev) {
900  		smcibdev->ndev_ifidx[port] = ndev->ifindex;
901  		dev_put(ndev);
902  	}
903  }
904  
905  void smc_ib_ndev_change(struct net_device *ndev, unsigned long event)
906  {
907  	struct smc_ib_device *smcibdev;
908  	struct ib_device *libdev;
909  	struct net_device *lndev;
910  	u8 port_cnt;
911  	int i;
912  
913  	mutex_lock(&smc_ib_devices.mutex);
914  	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
915  		port_cnt = smcibdev->ibdev->phys_port_cnt;
916  		for (i = 0; i < min_t(size_t, port_cnt, SMC_MAX_PORTS); i++) {
917  			libdev = smcibdev->ibdev;
918  			if (!libdev->ops.get_netdev)
919  				continue;
920  			lndev = libdev->ops.get_netdev(libdev, i + 1);
921  			dev_put(lndev);
922  			if (lndev != ndev)
923  				continue;
924  			if (event == NETDEV_REGISTER)
925  				smcibdev->ndev_ifidx[i] = ndev->ifindex;
926  			if (event == NETDEV_UNREGISTER)
927  				smcibdev->ndev_ifidx[i] = 0;
928  		}
929  	}
930  	mutex_unlock(&smc_ib_devices.mutex);
931  }
932  
933  /* callback function for ib_register_client() */
934  static int smc_ib_add_dev(struct ib_device *ibdev)
935  {
936  	struct smc_ib_device *smcibdev;
937  	u8 port_cnt;
938  	int i;
939  
940  	if (ibdev->node_type != RDMA_NODE_IB_CA)
941  		return -EOPNOTSUPP;
942  
943  	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
944  	if (!smcibdev)
945  		return -ENOMEM;
946  
947  	smcibdev->ibdev = ibdev;
948  	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
949  	atomic_set(&smcibdev->lnk_cnt, 0);
950  	init_waitqueue_head(&smcibdev->lnks_deleted);
951  	mutex_init(&smcibdev->mutex);
952  	mutex_lock(&smc_ib_devices.mutex);
953  	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
954  	mutex_unlock(&smc_ib_devices.mutex);
955  	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
956  	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
957  			      smc_ib_global_event_handler);
958  	ib_register_event_handler(&smcibdev->event_handler);
959  
960  	/* trigger reading of the port attributes */
961  	port_cnt = smcibdev->ibdev->phys_port_cnt;
962  	pr_warn_ratelimited("smc: adding ib device %s with port count %d\n",
963  			    smcibdev->ibdev->name, port_cnt);
964  	for (i = 0;
965  	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
966  	     i++) {
967  		set_bit(i, &smcibdev->port_event_mask);
968  		/* determine pnetids of the port */
969  		if (smc_pnetid_by_dev_port(ibdev->dev.parent, i,
970  					   smcibdev->pnetid[i]))
971  			smc_pnetid_by_table_ib(smcibdev, i + 1);
972  		smc_copy_netdev_ifindex(smcibdev, i);
973  		pr_warn_ratelimited("smc:    ib device %s port %d has pnetid "
974  				    "%.16s%s\n",
975  				    smcibdev->ibdev->name, i + 1,
976  				    smcibdev->pnetid[i],
977  				    smcibdev->pnetid_by_user[i] ?
978  				     " (user defined)" :
979  				     "");
980  	}
981  	schedule_work(&smcibdev->port_event_work);
982  	return 0;
983  }
984  
985  /* callback function for ib_unregister_client() */
986  static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
987  {
988  	struct smc_ib_device *smcibdev = client_data;
989  
990  	mutex_lock(&smc_ib_devices.mutex);
991  	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
992  	mutex_unlock(&smc_ib_devices.mutex);
993  	pr_warn_ratelimited("smc: removing ib device %s\n",
994  			    smcibdev->ibdev->name);
995  	smc_smcr_terminate_all(smcibdev);
996  	smc_ib_cleanup_per_ibdev(smcibdev);
997  	ib_unregister_event_handler(&smcibdev->event_handler);
998  	cancel_work_sync(&smcibdev->port_event_work);
999  	kfree(smcibdev);
1000  }
1001  
1002  static struct ib_client smc_ib_client = {
1003  	.name	= "smc_ib",
1004  	.add	= smc_ib_add_dev,
1005  	.remove = smc_ib_remove_dev,
1006  };
1007  
1008  int __init smc_ib_register_client(void)
1009  {
1010  	smc_ib_init_local_systemid();
1011  	return ib_register_client(&smc_ib_client);
1012  }
1013  
1014  void smc_ib_unregister_client(void)
1015  {
1016  	ib_unregister_client(&smc_ib_client);
1017  }
1018