xref: /linux/net/smc/smc_core.c (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  Basic Transport Functions exploiting Infiniband API
6  *
7  *  Copyright IBM Corp. 2016
8  *
9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
10  */
11 
12 #include <linux/socket.h>
13 #include <linux/if_vlan.h>
14 #include <linux/random.h>
15 #include <linux/workqueue.h>
16 #include <linux/wait.h>
17 #include <linux/reboot.h>
18 #include <linux/mutex.h>
19 #include <linux/list.h>
20 #include <linux/smc.h>
21 #include <net/tcp.h>
22 #include <net/sock.h>
23 #include <rdma/ib_verbs.h>
24 #include <rdma/ib_cache.h>
25 
26 #include "smc.h"
27 #include "smc_clc.h"
28 #include "smc_core.h"
29 #include "smc_ib.h"
30 #include "smc_wr.h"
31 #include "smc_llc.h"
32 #include "smc_cdc.h"
33 #include "smc_close.h"
34 #include "smc_ism.h"
35 #include "smc_netlink.h"
36 #include "smc_stats.h"
37 #include "smc_tracepoint.h"
38 
39 #define SMC_LGR_NUM_INCR		256
40 #define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
41 #define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
42 
43 struct smc_lgr_list smc_lgr_list = {	/* established link groups */
44 	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
45 	.list = LIST_HEAD_INIT(smc_lgr_list.list),
46 	.num = 0,
47 };
48 
49 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
50 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
51 
52 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
53 			 struct smc_buf_desc *buf_desc);
54 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
55 
56 static void smc_link_down_work(struct work_struct *work);
57 
58 /* return head of link group list and its lock for a given link group */
smc_lgr_list_head(struct smc_link_group * lgr,spinlock_t ** lgr_lock)59 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
60 						  spinlock_t **lgr_lock)
61 {
62 	if (lgr->is_smcd) {
63 		*lgr_lock = &lgr->smcd->lgr_lock;
64 		return &lgr->smcd->lgr_list;
65 	}
66 
67 	*lgr_lock = &smc_lgr_list.lock;
68 	return &smc_lgr_list.list;
69 }
70 
smc_ibdev_cnt_inc(struct smc_link * lnk)71 static void smc_ibdev_cnt_inc(struct smc_link *lnk)
72 {
73 	atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
74 }
75 
smc_ibdev_cnt_dec(struct smc_link * lnk)76 static void smc_ibdev_cnt_dec(struct smc_link *lnk)
77 {
78 	atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
79 }
80 
smc_lgr_schedule_free_work(struct smc_link_group * lgr)81 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
82 {
83 	/* client link group creation always follows the server link group
84 	 * creation. For client use a somewhat higher removal delay time,
85 	 * otherwise there is a risk of out-of-sync link groups.
86 	 */
87 	if (!lgr->freeing) {
88 		mod_delayed_work(system_wq, &lgr->free_work,
89 				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
90 						SMC_LGR_FREE_DELAY_CLNT :
91 						SMC_LGR_FREE_DELAY_SERV);
92 	}
93 }
94 
95 /* Register connection's alert token in our lookup structure.
96  * To use rbtrees we have to implement our own insert core.
97  * Requires @conns_lock
98  * @smc		connection to register
99  * Returns 0 on success, != otherwise.
100  */
smc_lgr_add_alert_token(struct smc_connection * conn)101 static void smc_lgr_add_alert_token(struct smc_connection *conn)
102 {
103 	struct rb_node **link, *parent = NULL;
104 	u32 token = conn->alert_token_local;
105 
106 	link = &conn->lgr->conns_all.rb_node;
107 	while (*link) {
108 		struct smc_connection *cur = rb_entry(*link,
109 					struct smc_connection, alert_node);
110 
111 		parent = *link;
112 		if (cur->alert_token_local > token)
113 			link = &parent->rb_left;
114 		else
115 			link = &parent->rb_right;
116 	}
117 	/* Put the new node there */
118 	rb_link_node(&conn->alert_node, parent, link);
119 	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
120 }
121 
122 /* assign an SMC-R link to the connection */
smcr_lgr_conn_assign_link(struct smc_connection * conn,bool first)123 static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
124 {
125 	enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
126 				       SMC_LNK_ACTIVE;
127 	int i, j;
128 
129 	/* do link balancing */
130 	conn->lnk = NULL;	/* reset conn->lnk first */
131 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
132 		struct smc_link *lnk = &conn->lgr->lnk[i];
133 
134 		if (lnk->state != expected || lnk->link_is_asym)
135 			continue;
136 		if (conn->lgr->role == SMC_CLNT) {
137 			conn->lnk = lnk; /* temporary, SMC server assigns link*/
138 			break;
139 		}
140 		if (conn->lgr->conns_num % 2) {
141 			for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
142 				struct smc_link *lnk2;
143 
144 				lnk2 = &conn->lgr->lnk[j];
145 				if (lnk2->state == expected &&
146 				    !lnk2->link_is_asym) {
147 					conn->lnk = lnk2;
148 					break;
149 				}
150 			}
151 		}
152 		if (!conn->lnk)
153 			conn->lnk = lnk;
154 		break;
155 	}
156 	if (!conn->lnk)
157 		return SMC_CLC_DECL_NOACTLINK;
158 	atomic_inc(&conn->lnk->conn_cnt);
159 	return 0;
160 }
161 
162 /* Register connection in link group by assigning an alert token
163  * registered in a search tree.
164  * Requires @conns_lock
165  * Note that '0' is a reserved value and not assigned.
166  */
smc_lgr_register_conn(struct smc_connection * conn,bool first)167 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
168 {
169 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
170 	static atomic_t nexttoken = ATOMIC_INIT(0);
171 	int rc;
172 
173 	if (!conn->lgr->is_smcd) {
174 		rc = smcr_lgr_conn_assign_link(conn, first);
175 		if (rc) {
176 			conn->lgr = NULL;
177 			return rc;
178 		}
179 	}
180 	/* find a new alert_token_local value not yet used by some connection
181 	 * in this link group
182 	 */
183 	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
184 	while (!conn->alert_token_local) {
185 		conn->alert_token_local = atomic_inc_return(&nexttoken);
186 		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
187 			conn->alert_token_local = 0;
188 	}
189 	smc_lgr_add_alert_token(conn);
190 	conn->lgr->conns_num++;
191 	return 0;
192 }
193 
194 /* Unregister connection and reset the alert token of the given connection<
195  */
__smc_lgr_unregister_conn(struct smc_connection * conn)196 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
197 {
198 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
199 	struct smc_link_group *lgr = conn->lgr;
200 
201 	rb_erase(&conn->alert_node, &lgr->conns_all);
202 	if (conn->lnk)
203 		atomic_dec(&conn->lnk->conn_cnt);
204 	lgr->conns_num--;
205 	conn->alert_token_local = 0;
206 	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
207 }
208 
209 /* Unregister connection from lgr
210  */
smc_lgr_unregister_conn(struct smc_connection * conn)211 static void smc_lgr_unregister_conn(struct smc_connection *conn)
212 {
213 	struct smc_link_group *lgr = conn->lgr;
214 
215 	if (!smc_conn_lgr_valid(conn))
216 		return;
217 	write_lock_bh(&lgr->conns_lock);
218 	if (conn->alert_token_local) {
219 		__smc_lgr_unregister_conn(conn);
220 	}
221 	write_unlock_bh(&lgr->conns_lock);
222 }
223 
smc_lgr_buf_list_add(struct smc_link_group * lgr,bool is_rmb,struct list_head * buf_list,struct smc_buf_desc * buf_desc)224 static void smc_lgr_buf_list_add(struct smc_link_group *lgr,
225 				 bool is_rmb,
226 				 struct list_head *buf_list,
227 				 struct smc_buf_desc *buf_desc)
228 {
229 	list_add(&buf_desc->list, buf_list);
230 	if (is_rmb) {
231 		lgr->alloc_rmbs += buf_desc->len;
232 		lgr->alloc_rmbs +=
233 			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
234 	} else {
235 		lgr->alloc_sndbufs += buf_desc->len;
236 	}
237 }
238 
smc_lgr_buf_list_del(struct smc_link_group * lgr,bool is_rmb,struct smc_buf_desc * buf_desc)239 static void smc_lgr_buf_list_del(struct smc_link_group *lgr,
240 				 bool is_rmb,
241 				 struct smc_buf_desc *buf_desc)
242 {
243 	list_del(&buf_desc->list);
244 	if (is_rmb) {
245 		lgr->alloc_rmbs -= buf_desc->len;
246 		lgr->alloc_rmbs -=
247 			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
248 	} else {
249 		lgr->alloc_sndbufs -= buf_desc->len;
250 	}
251 }
252 
smc_nl_get_sys_info(struct sk_buff * skb,struct netlink_callback * cb)253 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
254 {
255 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
256 	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
257 	char smc_seid[SMC_MAX_EID_LEN + 1];
258 	struct nlattr *attrs;
259 	u8 *seid = NULL;
260 	u8 *host = NULL;
261 	void *nlh;
262 
263 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
264 			  &smc_gen_nl_family, NLM_F_MULTI,
265 			  SMC_NETLINK_GET_SYS_INFO);
266 	if (!nlh)
267 		goto errmsg;
268 	if (cb_ctx->pos[0])
269 		goto errout;
270 	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
271 	if (!attrs)
272 		goto errout;
273 	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
274 		goto errattr;
275 	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
276 		goto errattr;
277 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
278 		goto errattr;
279 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
280 		goto errattr;
281 	smc_clc_get_hostname(&host);
282 	if (host) {
283 		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
284 		hostname[SMC_MAX_HOSTNAME_LEN] = 0;
285 		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
286 			goto errattr;
287 	}
288 	if (smc_ism_is_v2_capable()) {
289 		smc_ism_get_system_eid(&seid);
290 		memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
291 		smc_seid[SMC_MAX_EID_LEN] = 0;
292 		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
293 			goto errattr;
294 	}
295 	nla_nest_end(skb, attrs);
296 	genlmsg_end(skb, nlh);
297 	cb_ctx->pos[0] = 1;
298 	return skb->len;
299 
300 errattr:
301 	nla_nest_cancel(skb, attrs);
302 errout:
303 	genlmsg_cancel(skb, nlh);
304 errmsg:
305 	return skb->len;
306 }
307 
308 /* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
smc_nl_fill_lgr_v2_common(struct smc_link_group * lgr,struct sk_buff * skb,struct netlink_callback * cb,struct nlattr * v2_attrs)309 static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
310 				     struct sk_buff *skb,
311 				     struct netlink_callback *cb,
312 				     struct nlattr *v2_attrs)
313 {
314 	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
315 	char smc_eid[SMC_MAX_EID_LEN + 1];
316 
317 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
318 		goto errv2attr;
319 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
320 		goto errv2attr;
321 	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
322 		goto errv2attr;
323 	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
324 	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
325 	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
326 		goto errv2attr;
327 	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
328 	smc_eid[SMC_MAX_EID_LEN] = 0;
329 	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
330 		goto errv2attr;
331 
332 	nla_nest_end(skb, v2_attrs);
333 	return 0;
334 
335 errv2attr:
336 	nla_nest_cancel(skb, v2_attrs);
337 	return -EMSGSIZE;
338 }
339 
smc_nl_fill_smcr_lgr_v2(struct smc_link_group * lgr,struct sk_buff * skb,struct netlink_callback * cb)340 static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
341 				   struct sk_buff *skb,
342 				   struct netlink_callback *cb)
343 {
344 	struct nlattr *v2_attrs;
345 
346 	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
347 	if (!v2_attrs)
348 		goto errattr;
349 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
350 		goto errv2attr;
351 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
352 		goto errv2attr;
353 	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
354 		goto errv2attr;
355 
356 	nla_nest_end(skb, v2_attrs);
357 	return 0;
358 
359 errv2attr:
360 	nla_nest_cancel(skb, v2_attrs);
361 errattr:
362 	return -EMSGSIZE;
363 }
364 
smc_nl_fill_lgr(struct smc_link_group * lgr,struct sk_buff * skb,struct netlink_callback * cb)365 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
366 			   struct sk_buff *skb,
367 			   struct netlink_callback *cb)
368 {
369 	char smc_target[SMC_MAX_PNETID_LEN + 1];
370 	struct nlattr *attrs, *v2_attrs;
371 
372 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
373 	if (!attrs)
374 		goto errout;
375 
376 	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
377 		goto errattr;
378 	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
379 		goto errattr;
380 	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
381 		goto errattr;
382 	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
383 		goto errattr;
384 	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
385 		goto errattr;
386 	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
387 		goto errattr;
388 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
389 			      lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
390 		goto errattr;
391 	memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
392 	smc_target[SMC_MAX_PNETID_LEN] = 0;
393 	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
394 		goto errattr;
395 	if (nla_put_uint(skb, SMC_NLA_LGR_R_SNDBUF_ALLOC, lgr->alloc_sndbufs))
396 		goto errattr;
397 	if (nla_put_uint(skb, SMC_NLA_LGR_R_RMB_ALLOC, lgr->alloc_rmbs))
398 		goto errattr;
399 	if (lgr->smc_version > SMC_V1) {
400 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
401 		if (!v2_attrs)
402 			goto errattr;
403 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
404 			goto errattr;
405 		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
406 			goto errattr;
407 	}
408 
409 	nla_nest_end(skb, attrs);
410 	return 0;
411 errattr:
412 	nla_nest_cancel(skb, attrs);
413 errout:
414 	return -EMSGSIZE;
415 }
416 
smc_nl_fill_lgr_link(struct smc_link_group * lgr,struct smc_link * link,struct sk_buff * skb,struct netlink_callback * cb)417 static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
418 				struct smc_link *link,
419 				struct sk_buff *skb,
420 				struct netlink_callback *cb)
421 {
422 	char smc_ibname[IB_DEVICE_NAME_MAX];
423 	u8 smc_gid_target[41];
424 	struct nlattr *attrs;
425 	u32 link_uid = 0;
426 	void *nlh;
427 
428 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
429 			  &smc_gen_nl_family, NLM_F_MULTI,
430 			  SMC_NETLINK_GET_LINK_SMCR);
431 	if (!nlh)
432 		goto errmsg;
433 
434 	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
435 	if (!attrs)
436 		goto errout;
437 
438 	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
439 		goto errattr;
440 	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
441 		goto errattr;
442 	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
443 			atomic_read(&link->conn_cnt)))
444 		goto errattr;
445 	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
446 		goto errattr;
447 	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
448 		goto errattr;
449 	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
450 	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
451 		goto errattr;
452 	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
453 	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
454 		goto errattr;
455 	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
456 	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
457 		goto errattr;
458 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
459 	smc_gid_be16_convert(smc_gid_target, link->gid);
460 	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
461 		goto errattr;
462 	memset(smc_gid_target, 0, sizeof(smc_gid_target));
463 	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
464 	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
465 		goto errattr;
466 
467 	nla_nest_end(skb, attrs);
468 	genlmsg_end(skb, nlh);
469 	return 0;
470 errattr:
471 	nla_nest_cancel(skb, attrs);
472 errout:
473 	genlmsg_cancel(skb, nlh);
474 errmsg:
475 	return -EMSGSIZE;
476 }
477 
smc_nl_handle_lgr(struct smc_link_group * lgr,struct sk_buff * skb,struct netlink_callback * cb,bool list_links)478 static int smc_nl_handle_lgr(struct smc_link_group *lgr,
479 			     struct sk_buff *skb,
480 			     struct netlink_callback *cb,
481 			     bool list_links)
482 {
483 	void *nlh;
484 	int i;
485 
486 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
487 			  &smc_gen_nl_family, NLM_F_MULTI,
488 			  SMC_NETLINK_GET_LGR_SMCR);
489 	if (!nlh)
490 		goto errmsg;
491 	if (smc_nl_fill_lgr(lgr, skb, cb))
492 		goto errout;
493 
494 	genlmsg_end(skb, nlh);
495 	if (!list_links)
496 		goto out;
497 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
498 		if (!smc_link_usable(&lgr->lnk[i]))
499 			continue;
500 		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
501 			goto errout;
502 	}
503 out:
504 	return 0;
505 
506 errout:
507 	genlmsg_cancel(skb, nlh);
508 errmsg:
509 	return -EMSGSIZE;
510 }
511 
smc_nl_fill_lgr_list(struct smc_lgr_list * smc_lgr,struct sk_buff * skb,struct netlink_callback * cb,bool list_links)512 static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
513 				 struct sk_buff *skb,
514 				 struct netlink_callback *cb,
515 				 bool list_links)
516 {
517 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
518 	struct smc_link_group *lgr;
519 	int snum = cb_ctx->pos[0];
520 	int num = 0;
521 
522 	spin_lock_bh(&smc_lgr->lock);
523 	list_for_each_entry(lgr, &smc_lgr->list, list) {
524 		if (num < snum)
525 			goto next;
526 		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
527 			goto errout;
528 next:
529 		num++;
530 	}
531 errout:
532 	spin_unlock_bh(&smc_lgr->lock);
533 	cb_ctx->pos[0] = num;
534 }
535 
smc_nl_fill_smcd_lgr(struct smc_link_group * lgr,struct sk_buff * skb,struct netlink_callback * cb)536 static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
537 				struct sk_buff *skb,
538 				struct netlink_callback *cb)
539 {
540 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
541 	struct smcd_dev *smcd = lgr->smcd;
542 	struct smcd_gid smcd_gid;
543 	struct nlattr *attrs;
544 	void *nlh;
545 
546 	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
547 			  &smc_gen_nl_family, NLM_F_MULTI,
548 			  SMC_NETLINK_GET_LGR_SMCD);
549 	if (!nlh)
550 		goto errmsg;
551 
552 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
553 	if (!attrs)
554 		goto errout;
555 
556 	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
557 		goto errattr;
558 	smcd->ops->get_local_gid(smcd, &smcd_gid);
559 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
560 			      smcd_gid.gid, SMC_NLA_LGR_D_PAD))
561 		goto errattr;
562 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_EXT_GID,
563 			      smcd_gid.gid_ext, SMC_NLA_LGR_D_PAD))
564 		goto errattr;
565 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid.gid,
566 			      SMC_NLA_LGR_D_PAD))
567 		goto errattr;
568 	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_EXT_GID,
569 			      lgr->peer_gid.gid_ext, SMC_NLA_LGR_D_PAD))
570 		goto errattr;
571 	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
572 		goto errattr;
573 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
574 		goto errattr;
575 	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
576 		goto errattr;
577 	if (nla_put_uint(skb, SMC_NLA_LGR_D_SNDBUF_ALLOC, lgr->alloc_sndbufs))
578 		goto errattr;
579 	if (nla_put_uint(skb, SMC_NLA_LGR_D_DMB_ALLOC, lgr->alloc_rmbs))
580 		goto errattr;
581 	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
582 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
583 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
584 		goto errattr;
585 	if (lgr->smc_version > SMC_V1) {
586 		struct nlattr *v2_attrs;
587 
588 		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
589 		if (!v2_attrs)
590 			goto errattr;
591 		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
592 			goto errattr;
593 	}
594 	nla_nest_end(skb, attrs);
595 	genlmsg_end(skb, nlh);
596 	return 0;
597 
598 errattr:
599 	nla_nest_cancel(skb, attrs);
600 errout:
601 	genlmsg_cancel(skb, nlh);
602 errmsg:
603 	return -EMSGSIZE;
604 }
605 
smc_nl_handle_smcd_lgr(struct smcd_dev * dev,struct sk_buff * skb,struct netlink_callback * cb)606 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
607 				  struct sk_buff *skb,
608 				  struct netlink_callback *cb)
609 {
610 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
611 	struct smc_link_group *lgr;
612 	int snum = cb_ctx->pos[1];
613 	int rc = 0, num = 0;
614 
615 	spin_lock_bh(&dev->lgr_lock);
616 	list_for_each_entry(lgr, &dev->lgr_list, list) {
617 		if (!lgr->is_smcd)
618 			continue;
619 		if (num < snum)
620 			goto next;
621 		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
622 		if (rc)
623 			goto errout;
624 next:
625 		num++;
626 	}
627 errout:
628 	spin_unlock_bh(&dev->lgr_lock);
629 	cb_ctx->pos[1] = num;
630 	return rc;
631 }
632 
smc_nl_fill_smcd_dev(struct smcd_dev_list * dev_list,struct sk_buff * skb,struct netlink_callback * cb)633 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
634 				struct sk_buff *skb,
635 				struct netlink_callback *cb)
636 {
637 	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
638 	struct smcd_dev *smcd_dev;
639 	int snum = cb_ctx->pos[0];
640 	int rc = 0, num = 0;
641 
642 	mutex_lock(&dev_list->mutex);
643 	list_for_each_entry(smcd_dev, &dev_list->list, list) {
644 		if (list_empty(&smcd_dev->lgr_list))
645 			continue;
646 		if (num < snum)
647 			goto next;
648 		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
649 		if (rc)
650 			goto errout;
651 next:
652 		num++;
653 	}
654 errout:
655 	mutex_unlock(&dev_list->mutex);
656 	cb_ctx->pos[0] = num;
657 	return rc;
658 }
659 
smcr_nl_get_lgr(struct sk_buff * skb,struct netlink_callback * cb)660 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
661 {
662 	bool list_links = false;
663 
664 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
665 	return skb->len;
666 }
667 
smcr_nl_get_link(struct sk_buff * skb,struct netlink_callback * cb)668 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
669 {
670 	bool list_links = true;
671 
672 	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
673 	return skb->len;
674 }
675 
smcd_nl_get_lgr(struct sk_buff * skb,struct netlink_callback * cb)676 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
677 {
678 	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
679 	return skb->len;
680 }
681 
smc_lgr_cleanup_early(struct smc_link_group * lgr)682 void smc_lgr_cleanup_early(struct smc_link_group *lgr)
683 {
684 	spinlock_t *lgr_lock;
685 
686 	if (!lgr)
687 		return;
688 
689 	smc_lgr_list_head(lgr, &lgr_lock);
690 	spin_lock_bh(lgr_lock);
691 	/* do not use this link group for new connections */
692 	if (!list_empty(&lgr->list))
693 		list_del_init(&lgr->list);
694 	spin_unlock_bh(lgr_lock);
695 	__smc_lgr_terminate(lgr, true);
696 }
697 
smcr_lgr_link_deactivate_all(struct smc_link_group * lgr)698 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
699 {
700 	int i;
701 
702 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
703 		struct smc_link *lnk = &lgr->lnk[i];
704 
705 		if (smc_link_sendable(lnk))
706 			lnk->state = SMC_LNK_INACTIVE;
707 	}
708 	wake_up_all(&lgr->llc_msg_waiter);
709 	wake_up_all(&lgr->llc_flow_waiter);
710 }
711 
712 static void smc_lgr_free(struct smc_link_group *lgr);
713 
smc_lgr_free_work(struct work_struct * work)714 static void smc_lgr_free_work(struct work_struct *work)
715 {
716 	struct smc_link_group *lgr = container_of(to_delayed_work(work),
717 						  struct smc_link_group,
718 						  free_work);
719 	spinlock_t *lgr_lock;
720 	bool conns;
721 
722 	smc_lgr_list_head(lgr, &lgr_lock);
723 	spin_lock_bh(lgr_lock);
724 	if (lgr->freeing) {
725 		spin_unlock_bh(lgr_lock);
726 		return;
727 	}
728 	read_lock_bh(&lgr->conns_lock);
729 	conns = RB_EMPTY_ROOT(&lgr->conns_all);
730 	read_unlock_bh(&lgr->conns_lock);
731 	if (!conns) { /* number of lgr connections is no longer zero */
732 		spin_unlock_bh(lgr_lock);
733 		return;
734 	}
735 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
736 	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
737 	spin_unlock_bh(lgr_lock);
738 	cancel_delayed_work(&lgr->free_work);
739 
740 	if (!lgr->is_smcd && !lgr->terminating)
741 		smc_llc_send_link_delete_all(lgr, true,
742 					     SMC_LLC_DEL_PROG_INIT_TERM);
743 	if (lgr->is_smcd && !lgr->terminating)
744 		smc_ism_signal_shutdown(lgr);
745 	if (!lgr->is_smcd)
746 		smcr_lgr_link_deactivate_all(lgr);
747 	smc_lgr_free(lgr);
748 }
749 
smc_lgr_terminate_work(struct work_struct * work)750 static void smc_lgr_terminate_work(struct work_struct *work)
751 {
752 	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
753 						  terminate_work);
754 
755 	__smc_lgr_terminate(lgr, true);
756 }
757 
758 /* return next unique link id for the lgr */
smcr_next_link_id(struct smc_link_group * lgr)759 static u8 smcr_next_link_id(struct smc_link_group *lgr)
760 {
761 	u8 link_id;
762 	int i;
763 
764 	while (1) {
765 again:
766 		link_id = ++lgr->next_link_id;
767 		if (!link_id)	/* skip zero as link_id */
768 			link_id = ++lgr->next_link_id;
769 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
770 			if (smc_link_usable(&lgr->lnk[i]) &&
771 			    lgr->lnk[i].link_id == link_id)
772 				goto again;
773 		}
774 		break;
775 	}
776 	return link_id;
777 }
778 
smcr_copy_dev_info_to_link(struct smc_link * link)779 static void smcr_copy_dev_info_to_link(struct smc_link *link)
780 {
781 	struct smc_ib_device *smcibdev = link->smcibdev;
782 
783 	snprintf(link->ibname, sizeof(link->ibname), "%s",
784 		 smcibdev->ibdev->name);
785 	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
786 }
787 
smcr_link_init(struct smc_link_group * lgr,struct smc_link * lnk,u8 link_idx,struct smc_init_info * ini)788 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
789 		   u8 link_idx, struct smc_init_info *ini)
790 {
791 	struct smc_ib_device *smcibdev;
792 	u8 rndvec[3];
793 	int rc;
794 
795 	if (lgr->smc_version == SMC_V2) {
796 		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
797 		lnk->ibport = ini->smcrv2.ib_port_v2;
798 		lnk->wr_rx_sge_cnt = lnk->smcibdev->ibdev->attrs.max_recv_sge < 2 ? 1 : 2;
799 		lnk->wr_rx_buflen = smc_link_shared_v2_rxbuf(lnk) ?
800 			SMC_WR_BUF_SIZE : SMC_WR_BUF_V2_SIZE;
801 	} else {
802 		lnk->smcibdev = ini->ib_dev;
803 		lnk->ibport = ini->ib_port;
804 		lnk->wr_rx_sge_cnt = 1;
805 		lnk->wr_rx_buflen = SMC_WR_BUF_SIZE;
806 	}
807 	get_device(&lnk->smcibdev->ibdev->dev);
808 	atomic_inc(&lnk->smcibdev->lnk_cnt);
809 	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
810 	lnk->clearing = 0;
811 	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
812 	lnk->link_id = smcr_next_link_id(lgr);
813 	lnk->lgr = lgr;
814 	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
815 	lnk->link_idx = link_idx;
816 	lnk->wr_rx_id_compl = 0;
817 	smc_ibdev_cnt_inc(lnk);
818 	smcr_copy_dev_info_to_link(lnk);
819 	atomic_set(&lnk->conn_cnt, 0);
820 	smc_llc_link_set_uid(lnk);
821 	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
822 	if (!lnk->smcibdev->initialized) {
823 		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
824 		if (rc)
825 			goto out;
826 	}
827 	get_random_bytes(rndvec, sizeof(rndvec));
828 	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
829 		(rndvec[2] << 16);
830 	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
831 				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
832 				  lgr->smc_version == SMC_V2 ?
833 						  &ini->smcrv2 : NULL);
834 	if (rc)
835 		goto out;
836 	rc = smc_llc_link_init(lnk);
837 	if (rc)
838 		goto out;
839 	rc = smc_wr_alloc_link_mem(lnk);
840 	if (rc)
841 		goto clear_llc_lnk;
842 	rc = smc_ib_create_protection_domain(lnk);
843 	if (rc)
844 		goto free_link_mem;
845 	rc = smc_ib_create_queue_pair(lnk);
846 	if (rc)
847 		goto dealloc_pd;
848 	rc = smc_wr_create_link(lnk);
849 	if (rc)
850 		goto destroy_qp;
851 	lnk->state = SMC_LNK_ACTIVATING;
852 	return 0;
853 
854 destroy_qp:
855 	smc_ib_destroy_queue_pair(lnk);
856 dealloc_pd:
857 	smc_ib_dealloc_protection_domain(lnk);
858 free_link_mem:
859 	smc_wr_free_link_mem(lnk);
860 clear_llc_lnk:
861 	smc_llc_link_clear(lnk, false);
862 out:
863 	smc_ibdev_cnt_dec(lnk);
864 	put_device(&lnk->smcibdev->ibdev->dev);
865 	smcibdev = lnk->smcibdev;
866 	memset(lnk, 0, sizeof(struct smc_link));
867 	lnk->state = SMC_LNK_UNUSED;
868 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
869 		wake_up(&smcibdev->lnks_deleted);
870 	smc_lgr_put(lgr); /* lgr_hold above */
871 	return rc;
872 }
873 
874 /* create a new SMC link group */
smc_lgr_create(struct smc_sock * smc,struct smc_init_info * ini)875 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
876 {
877 	struct smc_link_group *lgr;
878 	struct list_head *lgr_list;
879 	struct smcd_dev *smcd;
880 	struct smc_link *lnk;
881 	spinlock_t *lgr_lock;
882 	u8 link_idx;
883 	int rc = 0;
884 	int i;
885 
886 	if (ini->is_smcd && ini->vlan_id) {
887 		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
888 				     ini->vlan_id)) {
889 			rc = SMC_CLC_DECL_ISMVLANERR;
890 			goto out;
891 		}
892 	}
893 
894 	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
895 	if (!lgr) {
896 		rc = SMC_CLC_DECL_MEM;
897 		goto ism_put_vlan;
898 	}
899 	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
900 				     SMC_LGR_ID_SIZE, &lgr->id);
901 	if (!lgr->tx_wq) {
902 		rc = -ENOMEM;
903 		goto free_lgr;
904 	}
905 	lgr->is_smcd = ini->is_smcd;
906 	lgr->sync_err = 0;
907 	lgr->terminating = 0;
908 	lgr->freeing = 0;
909 	lgr->vlan_id = ini->vlan_id;
910 	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
911 	init_rwsem(&lgr->sndbufs_lock);
912 	init_rwsem(&lgr->rmbs_lock);
913 	rwlock_init(&lgr->conns_lock);
914 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
915 		INIT_LIST_HEAD(&lgr->sndbufs[i]);
916 		INIT_LIST_HEAD(&lgr->rmbs[i]);
917 	}
918 	lgr->next_link_id = 0;
919 	smc_lgr_list.num += SMC_LGR_NUM_INCR;
920 	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
921 	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
922 	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
923 	lgr->conns_all = RB_ROOT;
924 	if (ini->is_smcd) {
925 		/* SMC-D specific settings */
926 		smcd = ini->ism_dev[ini->ism_selected];
927 		get_device(smcd->ops->get_dev(smcd));
928 		lgr->peer_gid.gid =
929 			ini->ism_peer_gid[ini->ism_selected].gid;
930 		lgr->peer_gid.gid_ext =
931 			ini->ism_peer_gid[ini->ism_selected].gid_ext;
932 		lgr->smcd = ini->ism_dev[ini->ism_selected];
933 		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
934 		lgr_lock = &lgr->smcd->lgr_lock;
935 		lgr->smc_version = ini->smcd_version;
936 		lgr->peer_shutdown = 0;
937 		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
938 	} else {
939 		/* SMC-R specific settings */
940 		struct smc_ib_device *ibdev;
941 		int ibport;
942 
943 		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
944 		lgr->smc_version = ini->smcr_version;
945 		memcpy(lgr->peer_systemid, ini->peer_systemid,
946 		       SMC_SYSTEMID_LEN);
947 		if (lgr->smc_version == SMC_V2) {
948 			ibdev = ini->smcrv2.ib_dev_v2;
949 			ibport = ini->smcrv2.ib_port_v2;
950 			lgr->saddr = ini->smcrv2.saddr;
951 			lgr->uses_gateway = ini->smcrv2.uses_gateway;
952 			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
953 			       ETH_ALEN);
954 			lgr->max_conns = ini->max_conns;
955 			lgr->max_links = ini->max_links;
956 		} else {
957 			ibdev = ini->ib_dev;
958 			ibport = ini->ib_port;
959 			lgr->max_conns = SMC_CONN_PER_LGR_MAX;
960 			lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
961 		}
962 		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
963 		       SMC_MAX_PNETID_LEN);
964 		rc = smc_wr_alloc_lgr_mem(lgr);
965 		if (rc)
966 			goto free_wq;
967 		smc_llc_lgr_init(lgr, smc);
968 
969 		link_idx = SMC_SINGLE_LINK;
970 		lnk = &lgr->lnk[link_idx];
971 		rc = smcr_link_init(lgr, lnk, link_idx, ini);
972 		if (rc) {
973 			smc_wr_free_lgr_mem(lgr);
974 			goto free_wq;
975 		}
976 		lgr->net = smc_ib_net(lnk->smcibdev);
977 		lgr_list = &smc_lgr_list.list;
978 		lgr_lock = &smc_lgr_list.lock;
979 		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
980 		atomic_inc(&lgr_cnt);
981 	}
982 	smc->conn.lgr = lgr;
983 	spin_lock_bh(lgr_lock);
984 	list_add_tail(&lgr->list, lgr_list);
985 	spin_unlock_bh(lgr_lock);
986 	return 0;
987 
988 free_wq:
989 	destroy_workqueue(lgr->tx_wq);
990 free_lgr:
991 	kfree(lgr);
992 ism_put_vlan:
993 	if (ini->is_smcd && ini->vlan_id)
994 		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
995 out:
996 	if (rc < 0) {
997 		if (rc == -ENOMEM)
998 			rc = SMC_CLC_DECL_MEM;
999 		else
1000 			rc = SMC_CLC_DECL_INTERR;
1001 	}
1002 	return rc;
1003 }
1004 
smc_write_space(struct smc_connection * conn)1005 static int smc_write_space(struct smc_connection *conn)
1006 {
1007 	int buffer_len = conn->peer_rmbe_size;
1008 	union smc_host_cursor prod;
1009 	union smc_host_cursor cons;
1010 	int space;
1011 
1012 	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
1013 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1014 	/* determine rx_buf space */
1015 	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
1016 	return space;
1017 }
1018 
smc_switch_cursor(struct smc_sock * smc,struct smc_cdc_tx_pend * pend,struct smc_wr_buf * wr_buf)1019 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
1020 			     struct smc_wr_buf *wr_buf)
1021 {
1022 	struct smc_connection *conn = &smc->conn;
1023 	union smc_host_cursor cons, fin;
1024 	int rc = 0;
1025 	int diff;
1026 
1027 	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
1028 	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
1029 	/* set prod cursor to old state, enforce tx_rdma_writes() */
1030 	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
1031 	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1032 
1033 	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
1034 		/* cons cursor advanced more than fin, and prod was set
1035 		 * fin above, so now prod is smaller than cons. Fix that.
1036 		 */
1037 		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
1038 		smc_curs_add(conn->sndbuf_desc->len,
1039 			     &conn->tx_curs_sent, diff);
1040 		smc_curs_add(conn->sndbuf_desc->len,
1041 			     &conn->tx_curs_fin, diff);
1042 
1043 		smp_mb__before_atomic();
1044 		atomic_add(diff, &conn->sndbuf_space);
1045 		smp_mb__after_atomic();
1046 
1047 		smc_curs_add(conn->peer_rmbe_size,
1048 			     &conn->local_tx_ctrl.prod, diff);
1049 		smc_curs_add(conn->peer_rmbe_size,
1050 			     &conn->local_tx_ctrl_fin, diff);
1051 	}
1052 	/* recalculate, value is used by tx_rdma_writes() */
1053 	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
1054 
1055 	if (smc->sk.sk_state != SMC_INIT &&
1056 	    smc->sk.sk_state != SMC_CLOSED) {
1057 		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
1058 		if (!rc) {
1059 			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
1060 			smc->sk.sk_data_ready(&smc->sk);
1061 		}
1062 	} else {
1063 		smc_wr_tx_put_slot(conn->lnk,
1064 				   (struct smc_wr_tx_pend_priv *)pend);
1065 	}
1066 	return rc;
1067 }
1068 
smc_switch_link_and_count(struct smc_connection * conn,struct smc_link * to_lnk)1069 void smc_switch_link_and_count(struct smc_connection *conn,
1070 			       struct smc_link *to_lnk)
1071 {
1072 	atomic_dec(&conn->lnk->conn_cnt);
1073 	/* link_hold in smc_conn_create() */
1074 	smcr_link_put(conn->lnk);
1075 	conn->lnk = to_lnk;
1076 	atomic_inc(&conn->lnk->conn_cnt);
1077 	/* link_put in smc_conn_free() */
1078 	smcr_link_hold(conn->lnk);
1079 }
1080 
smc_switch_conns(struct smc_link_group * lgr,struct smc_link * from_lnk,bool is_dev_err)1081 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1082 				  struct smc_link *from_lnk, bool is_dev_err)
1083 {
1084 	struct smc_link *to_lnk = NULL;
1085 	struct smc_cdc_tx_pend *pend;
1086 	struct smc_connection *conn;
1087 	struct smc_wr_buf *wr_buf;
1088 	struct smc_sock *smc;
1089 	struct rb_node *node;
1090 	int i, rc = 0;
1091 
1092 	/* link is inactive, wake up tx waiters */
1093 	smc_wr_wakeup_tx_wait(from_lnk);
1094 
1095 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1096 		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1097 			continue;
1098 		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1099 		    from_lnk->ibport == lgr->lnk[i].ibport) {
1100 			continue;
1101 		}
1102 		to_lnk = &lgr->lnk[i];
1103 		break;
1104 	}
1105 	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1106 		smc_lgr_terminate_sched(lgr);
1107 		return NULL;
1108 	}
1109 again:
1110 	read_lock_bh(&lgr->conns_lock);
1111 	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1112 		conn = rb_entry(node, struct smc_connection, alert_node);
1113 		if (conn->lnk != from_lnk)
1114 			continue;
1115 		smc = container_of(conn, struct smc_sock, conn);
1116 		/* conn->lnk not yet set in SMC_INIT state */
1117 		if (smc->sk.sk_state == SMC_INIT)
1118 			continue;
1119 		if (smc->sk.sk_state == SMC_CLOSED ||
1120 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1121 		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1122 		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1123 		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1124 		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1125 		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1126 		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
1127 		    smc->sk.sk_state == SMC_PROCESSABORT) {
1128 			spin_lock_bh(&conn->send_lock);
1129 			smc_switch_link_and_count(conn, to_lnk);
1130 			spin_unlock_bh(&conn->send_lock);
1131 			continue;
1132 		}
1133 		sock_hold(&smc->sk);
1134 		read_unlock_bh(&lgr->conns_lock);
1135 		/* pre-fetch buffer outside of send_lock, might sleep */
1136 		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1137 		if (rc)
1138 			goto err_out;
1139 		/* avoid race with smcr_tx_sndbuf_nonempty() */
1140 		spin_lock_bh(&conn->send_lock);
1141 		smc_switch_link_and_count(conn, to_lnk);
1142 		rc = smc_switch_cursor(smc, pend, wr_buf);
1143 		spin_unlock_bh(&conn->send_lock);
1144 		sock_put(&smc->sk);
1145 		if (rc)
1146 			goto err_out;
1147 		goto again;
1148 	}
1149 	read_unlock_bh(&lgr->conns_lock);
1150 	smc_wr_tx_link_put(to_lnk);
1151 	return to_lnk;
1152 
1153 err_out:
1154 	smcr_link_down_cond_sched(to_lnk);
1155 	smc_wr_tx_link_put(to_lnk);
1156 	return NULL;
1157 }
1158 
smcr_buf_unuse(struct smc_buf_desc * buf_desc,bool is_rmb,struct smc_link_group * lgr)1159 static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1160 			   struct smc_link_group *lgr)
1161 {
1162 	struct rw_semaphore *lock;	/* lock buffer list */
1163 	int rc;
1164 
1165 	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1166 		/* unregister rmb with peer */
1167 		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1168 		if (!rc) {
1169 			/* protect against smc_llc_cli_rkey_exchange() */
1170 			down_read(&lgr->llc_conf_mutex);
1171 			smc_llc_do_delete_rkey(lgr, buf_desc);
1172 			buf_desc->is_conf_rkey = false;
1173 			up_read(&lgr->llc_conf_mutex);
1174 			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1175 		}
1176 	}
1177 
1178 	if (buf_desc->is_reg_err) {
1179 		/* buf registration failed, reuse not possible */
1180 		lock = is_rmb ? &lgr->rmbs_lock :
1181 				&lgr->sndbufs_lock;
1182 		down_write(lock);
1183 		smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1184 		up_write(lock);
1185 
1186 		smc_buf_free(lgr, is_rmb, buf_desc);
1187 	} else {
1188 		/* memzero_explicit provides potential memory barrier semantics */
1189 		memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
1190 		WRITE_ONCE(buf_desc->used, 0);
1191 	}
1192 }
1193 
smcd_buf_detach(struct smc_connection * conn)1194 static void smcd_buf_detach(struct smc_connection *conn)
1195 {
1196 	struct smcd_dev *smcd = conn->lgr->smcd;
1197 	u64 peer_token = conn->peer_token;
1198 
1199 	if (!conn->sndbuf_desc)
1200 		return;
1201 
1202 	smc_ism_detach_dmb(smcd, peer_token);
1203 
1204 	kfree(conn->sndbuf_desc);
1205 	conn->sndbuf_desc = NULL;
1206 }
1207 
smc_buf_unuse(struct smc_connection * conn,struct smc_link_group * lgr)1208 static void smc_buf_unuse(struct smc_connection *conn,
1209 			  struct smc_link_group *lgr)
1210 {
1211 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1212 	bool is_smcd = lgr->is_smcd;
1213 	int bufsize;
1214 
1215 	if (conn->sndbuf_desc) {
1216 		bufsize = conn->sndbuf_desc->len;
1217 		if (!is_smcd && conn->sndbuf_desc->is_vm) {
1218 			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1219 		} else {
1220 			memzero_explicit(conn->sndbuf_desc->cpu_addr, bufsize);
1221 			WRITE_ONCE(conn->sndbuf_desc->used, 0);
1222 		}
1223 		SMC_STAT_RMB_SIZE(smc, is_smcd, false, false, bufsize);
1224 	}
1225 	if (conn->rmb_desc) {
1226 		bufsize = conn->rmb_desc->len;
1227 		if (!is_smcd) {
1228 			smcr_buf_unuse(conn->rmb_desc, true, lgr);
1229 		} else {
1230 			bufsize += sizeof(struct smcd_cdc_msg);
1231 			memzero_explicit(conn->rmb_desc->cpu_addr, bufsize);
1232 			WRITE_ONCE(conn->rmb_desc->used, 0);
1233 		}
1234 		SMC_STAT_RMB_SIZE(smc, is_smcd, true, false, bufsize);
1235 	}
1236 }
1237 
1238 /* remove a finished connection from its link group */
smc_conn_free(struct smc_connection * conn)1239 void smc_conn_free(struct smc_connection *conn)
1240 {
1241 	struct smc_link_group *lgr = conn->lgr;
1242 
1243 	if (!lgr || conn->freed)
1244 		/* Connection has never been registered in a
1245 		 * link group, or has already been freed.
1246 		 */
1247 		return;
1248 
1249 	conn->freed = 1;
1250 	if (!smc_conn_lgr_valid(conn))
1251 		/* Connection has already unregistered from
1252 		 * link group.
1253 		 */
1254 		goto lgr_put;
1255 
1256 	if (lgr->is_smcd) {
1257 		if (!list_empty(&lgr->list))
1258 			smc_ism_unset_conn(conn);
1259 		if (smc_ism_support_dmb_nocopy(lgr->smcd))
1260 			smcd_buf_detach(conn);
1261 		tasklet_kill(&conn->rx_tsklet);
1262 	} else {
1263 		smc_cdc_wait_pend_tx_wr(conn);
1264 		if (current_work() != &conn->abort_work)
1265 			cancel_work_sync(&conn->abort_work);
1266 	}
1267 	if (!list_empty(&lgr->list)) {
1268 		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1269 		smc_lgr_unregister_conn(conn);
1270 	}
1271 
1272 	if (!lgr->conns_num)
1273 		smc_lgr_schedule_free_work(lgr);
1274 lgr_put:
1275 	if (!lgr->is_smcd)
1276 		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1277 	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1278 }
1279 
1280 /* unregister a link from a buf_desc */
smcr_buf_unmap_link(struct smc_buf_desc * buf_desc,bool is_rmb,struct smc_link * lnk)1281 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1282 				struct smc_link *lnk)
1283 {
1284 	if (is_rmb || buf_desc->is_vm)
1285 		buf_desc->is_reg_mr[lnk->link_idx] = false;
1286 	if (!buf_desc->is_map_ib[lnk->link_idx])
1287 		return;
1288 
1289 	if ((is_rmb || buf_desc->is_vm) &&
1290 	    buf_desc->mr[lnk->link_idx]) {
1291 		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1292 		buf_desc->mr[lnk->link_idx] = NULL;
1293 	}
1294 	if (is_rmb)
1295 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1296 	else
1297 		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1298 
1299 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1300 	buf_desc->is_map_ib[lnk->link_idx] = false;
1301 }
1302 
1303 /* unmap all buffers of lgr for a deleted link */
smcr_buf_unmap_lgr(struct smc_link * lnk)1304 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1305 {
1306 	struct smc_link_group *lgr = lnk->lgr;
1307 	struct smc_buf_desc *buf_desc, *bf;
1308 	int i;
1309 
1310 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1311 		down_write(&lgr->rmbs_lock);
1312 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1313 			smcr_buf_unmap_link(buf_desc, true, lnk);
1314 		up_write(&lgr->rmbs_lock);
1315 
1316 		down_write(&lgr->sndbufs_lock);
1317 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1318 					 list)
1319 			smcr_buf_unmap_link(buf_desc, false, lnk);
1320 		up_write(&lgr->sndbufs_lock);
1321 	}
1322 }
1323 
smcr_rtoken_clear_link(struct smc_link * lnk)1324 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1325 {
1326 	struct smc_link_group *lgr = lnk->lgr;
1327 	int i;
1328 
1329 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1330 		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1331 		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1332 	}
1333 }
1334 
__smcr_link_clear(struct smc_link * lnk)1335 static void __smcr_link_clear(struct smc_link *lnk)
1336 {
1337 	struct smc_link_group *lgr = lnk->lgr;
1338 	struct smc_ib_device *smcibdev;
1339 
1340 	smc_wr_free_link_mem(lnk);
1341 	smc_ibdev_cnt_dec(lnk);
1342 	put_device(&lnk->smcibdev->ibdev->dev);
1343 	smcibdev = lnk->smcibdev;
1344 	memset(lnk, 0, sizeof(struct smc_link));
1345 	lnk->state = SMC_LNK_UNUSED;
1346 	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1347 		wake_up(&smcibdev->lnks_deleted);
1348 	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1349 }
1350 
1351 /* must be called under lgr->llc_conf_mutex lock */
smcr_link_clear(struct smc_link * lnk,bool log)1352 void smcr_link_clear(struct smc_link *lnk, bool log)
1353 {
1354 	if (!lnk->lgr || lnk->clearing ||
1355 	    lnk->state == SMC_LNK_UNUSED)
1356 		return;
1357 	lnk->clearing = 1;
1358 	lnk->peer_qpn = 0;
1359 	smc_llc_link_clear(lnk, log);
1360 	smcr_buf_unmap_lgr(lnk);
1361 	smcr_rtoken_clear_link(lnk);
1362 	smc_ib_modify_qp_error(lnk);
1363 	smc_wr_free_link(lnk);
1364 	smc_ib_destroy_queue_pair(lnk);
1365 	smc_ib_dealloc_protection_domain(lnk);
1366 	smcr_link_put(lnk); /* theoretically last link_put */
1367 }
1368 
smcr_link_hold(struct smc_link * lnk)1369 void smcr_link_hold(struct smc_link *lnk)
1370 {
1371 	refcount_inc(&lnk->refcnt);
1372 }
1373 
smcr_link_put(struct smc_link * lnk)1374 void smcr_link_put(struct smc_link *lnk)
1375 {
1376 	if (refcount_dec_and_test(&lnk->refcnt))
1377 		__smcr_link_clear(lnk);
1378 }
1379 
smcr_buf_free(struct smc_link_group * lgr,bool is_rmb,struct smc_buf_desc * buf_desc)1380 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1381 			  struct smc_buf_desc *buf_desc)
1382 {
1383 	int i;
1384 
1385 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1386 		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1387 
1388 	if (!buf_desc->is_vm && buf_desc->pages)
1389 		__free_pages(buf_desc->pages, buf_desc->order);
1390 	else if (buf_desc->is_vm && buf_desc->cpu_addr)
1391 		vfree(buf_desc->cpu_addr);
1392 	kfree(buf_desc);
1393 }
1394 
smcd_buf_free(struct smc_link_group * lgr,bool is_dmb,struct smc_buf_desc * buf_desc)1395 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1396 			  struct smc_buf_desc *buf_desc)
1397 {
1398 	if (is_dmb) {
1399 		/* restore original buf len */
1400 		buf_desc->len += sizeof(struct smcd_cdc_msg);
1401 		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1402 	} else {
1403 		kfree(buf_desc->cpu_addr);
1404 	}
1405 	kfree(buf_desc);
1406 }
1407 
smc_buf_free(struct smc_link_group * lgr,bool is_rmb,struct smc_buf_desc * buf_desc)1408 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1409 			 struct smc_buf_desc *buf_desc)
1410 {
1411 	if (lgr->is_smcd)
1412 		smcd_buf_free(lgr, is_rmb, buf_desc);
1413 	else
1414 		smcr_buf_free(lgr, is_rmb, buf_desc);
1415 }
1416 
__smc_lgr_free_bufs(struct smc_link_group * lgr,bool is_rmb)1417 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1418 {
1419 	struct smc_buf_desc *buf_desc, *bf_desc;
1420 	struct list_head *buf_list;
1421 	int i;
1422 
1423 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1424 		if (is_rmb)
1425 			buf_list = &lgr->rmbs[i];
1426 		else
1427 			buf_list = &lgr->sndbufs[i];
1428 		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1429 					 list) {
1430 			smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1431 			smc_buf_free(lgr, is_rmb, buf_desc);
1432 		}
1433 	}
1434 }
1435 
smc_lgr_free_bufs(struct smc_link_group * lgr)1436 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1437 {
1438 	/* free send buffers */
1439 	__smc_lgr_free_bufs(lgr, false);
1440 	/* free rmbs */
1441 	__smc_lgr_free_bufs(lgr, true);
1442 }
1443 
1444 /* won't be freed until no one accesses to lgr anymore */
__smc_lgr_free(struct smc_link_group * lgr)1445 static void __smc_lgr_free(struct smc_link_group *lgr)
1446 {
1447 	smc_lgr_free_bufs(lgr);
1448 	if (lgr->is_smcd) {
1449 		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1450 			wake_up(&lgr->smcd->lgrs_deleted);
1451 	} else {
1452 		smc_wr_free_lgr_mem(lgr);
1453 		if (!atomic_dec_return(&lgr_cnt))
1454 			wake_up(&lgrs_deleted);
1455 	}
1456 	kfree(lgr);
1457 }
1458 
1459 /* remove a link group */
smc_lgr_free(struct smc_link_group * lgr)1460 static void smc_lgr_free(struct smc_link_group *lgr)
1461 {
1462 	int i;
1463 
1464 	if (!lgr->is_smcd) {
1465 		down_write(&lgr->llc_conf_mutex);
1466 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1467 			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1468 				smcr_link_clear(&lgr->lnk[i], false);
1469 		}
1470 		up_write(&lgr->llc_conf_mutex);
1471 		smc_llc_lgr_clear(lgr);
1472 	}
1473 
1474 	destroy_workqueue(lgr->tx_wq);
1475 	if (lgr->is_smcd) {
1476 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1477 		put_device(lgr->smcd->ops->get_dev(lgr->smcd));
1478 	}
1479 	smc_lgr_put(lgr); /* theoretically last lgr_put */
1480 }
1481 
smc_lgr_hold(struct smc_link_group * lgr)1482 void smc_lgr_hold(struct smc_link_group *lgr)
1483 {
1484 	refcount_inc(&lgr->refcnt);
1485 }
1486 
smc_lgr_put(struct smc_link_group * lgr)1487 void smc_lgr_put(struct smc_link_group *lgr)
1488 {
1489 	if (refcount_dec_and_test(&lgr->refcnt))
1490 		__smc_lgr_free(lgr);
1491 }
1492 
smc_sk_wake_ups(struct smc_sock * smc)1493 static void smc_sk_wake_ups(struct smc_sock *smc)
1494 {
1495 	smc->sk.sk_write_space(&smc->sk);
1496 	smc->sk.sk_data_ready(&smc->sk);
1497 	smc->sk.sk_state_change(&smc->sk);
1498 }
1499 
1500 /* kill a connection */
smc_conn_kill(struct smc_connection * conn,bool soft)1501 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1502 {
1503 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1504 
1505 	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1506 		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1507 	else
1508 		smc_close_abort(conn);
1509 	conn->killed = 1;
1510 	smc->sk.sk_err = ECONNABORTED;
1511 	smc_sk_wake_ups(smc);
1512 	if (conn->lgr->is_smcd) {
1513 		smc_ism_unset_conn(conn);
1514 		if (smc_ism_support_dmb_nocopy(conn->lgr->smcd))
1515 			smcd_buf_detach(conn);
1516 		if (soft)
1517 			tasklet_kill(&conn->rx_tsklet);
1518 		else
1519 			tasklet_unlock_wait(&conn->rx_tsklet);
1520 	} else {
1521 		smc_cdc_wait_pend_tx_wr(conn);
1522 	}
1523 	smc_lgr_unregister_conn(conn);
1524 	smc_close_active_abort(smc);
1525 }
1526 
smc_lgr_cleanup(struct smc_link_group * lgr)1527 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1528 {
1529 	if (lgr->is_smcd) {
1530 		smc_ism_signal_shutdown(lgr);
1531 	} else {
1532 		u32 rsn = lgr->llc_termination_rsn;
1533 
1534 		if (!rsn)
1535 			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1536 		smc_llc_send_link_delete_all(lgr, false, rsn);
1537 		smcr_lgr_link_deactivate_all(lgr);
1538 	}
1539 }
1540 
1541 /* terminate link group
1542  * @soft: true if link group shutdown can take its time
1543  *	  false if immediate link group shutdown is required
1544  */
__smc_lgr_terminate(struct smc_link_group * lgr,bool soft)1545 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1546 {
1547 	struct smc_connection *conn;
1548 	struct smc_sock *smc;
1549 	struct rb_node *node;
1550 
1551 	if (lgr->terminating)
1552 		return;	/* lgr already terminating */
1553 	/* cancel free_work sync, will terminate when lgr->freeing is set */
1554 	cancel_delayed_work(&lgr->free_work);
1555 	lgr->terminating = 1;
1556 
1557 	/* kill remaining link group connections */
1558 	read_lock_bh(&lgr->conns_lock);
1559 	node = rb_first(&lgr->conns_all);
1560 	while (node) {
1561 		read_unlock_bh(&lgr->conns_lock);
1562 		conn = rb_entry(node, struct smc_connection, alert_node);
1563 		smc = container_of(conn, struct smc_sock, conn);
1564 		sock_hold(&smc->sk); /* sock_put below */
1565 		lock_sock(&smc->sk);
1566 		smc_conn_kill(conn, soft);
1567 		release_sock(&smc->sk);
1568 		sock_put(&smc->sk); /* sock_hold above */
1569 		read_lock_bh(&lgr->conns_lock);
1570 		node = rb_first(&lgr->conns_all);
1571 	}
1572 	read_unlock_bh(&lgr->conns_lock);
1573 	smc_lgr_cleanup(lgr);
1574 	smc_lgr_free(lgr);
1575 }
1576 
1577 /* unlink link group and schedule termination */
smc_lgr_terminate_sched(struct smc_link_group * lgr)1578 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1579 {
1580 	spinlock_t *lgr_lock;
1581 
1582 	smc_lgr_list_head(lgr, &lgr_lock);
1583 	spin_lock_bh(lgr_lock);
1584 	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1585 		spin_unlock_bh(lgr_lock);
1586 		return;	/* lgr already terminating */
1587 	}
1588 	list_del_init(&lgr->list);
1589 	lgr->freeing = 1;
1590 	spin_unlock_bh(lgr_lock);
1591 	schedule_work(&lgr->terminate_work);
1592 }
1593 
1594 /* Called when peer lgr shutdown (regularly or abnormally) is received */
smc_smcd_terminate(struct smcd_dev * dev,struct smcd_gid * peer_gid,unsigned short vlan)1595 void smc_smcd_terminate(struct smcd_dev *dev, struct smcd_gid *peer_gid,
1596 			unsigned short vlan)
1597 {
1598 	struct smc_link_group *lgr, *l;
1599 	LIST_HEAD(lgr_free_list);
1600 
1601 	/* run common cleanup function and build free list */
1602 	spin_lock_bh(&dev->lgr_lock);
1603 	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1604 		if ((!peer_gid->gid ||
1605 		     (lgr->peer_gid.gid == peer_gid->gid &&
1606 		      !smc_ism_is_emulated(dev) ? 1 :
1607 		      lgr->peer_gid.gid_ext == peer_gid->gid_ext)) &&
1608 		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1609 			if (peer_gid->gid) /* peer triggered termination */
1610 				lgr->peer_shutdown = 1;
1611 			list_move(&lgr->list, &lgr_free_list);
1612 			lgr->freeing = 1;
1613 		}
1614 	}
1615 	spin_unlock_bh(&dev->lgr_lock);
1616 
1617 	/* cancel the regular free workers and actually free lgrs */
1618 	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1619 		list_del_init(&lgr->list);
1620 		schedule_work(&lgr->terminate_work);
1621 	}
1622 }
1623 
1624 /* Called when an SMCD device is removed or the smc module is unloaded */
smc_smcd_terminate_all(struct smcd_dev * smcd)1625 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1626 {
1627 	struct smc_link_group *lgr, *lg;
1628 	LIST_HEAD(lgr_free_list);
1629 
1630 	spin_lock_bh(&smcd->lgr_lock);
1631 	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1632 	list_for_each_entry(lgr, &lgr_free_list, list)
1633 		lgr->freeing = 1;
1634 	spin_unlock_bh(&smcd->lgr_lock);
1635 
1636 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1637 		list_del_init(&lgr->list);
1638 		__smc_lgr_terminate(lgr, false);
1639 	}
1640 
1641 	if (atomic_read(&smcd->lgr_cnt))
1642 		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1643 }
1644 
1645 /* Called when an SMCR device is removed or the smc module is unloaded.
1646  * If smcibdev is given, all SMCR link groups using this device are terminated.
1647  * If smcibdev is NULL, all SMCR link groups are terminated.
1648  */
smc_smcr_terminate_all(struct smc_ib_device * smcibdev)1649 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1650 {
1651 	struct smc_link_group *lgr, *lg;
1652 	LIST_HEAD(lgr_free_list);
1653 	int i;
1654 
1655 	spin_lock_bh(&smc_lgr_list.lock);
1656 	if (!smcibdev) {
1657 		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1658 		list_for_each_entry(lgr, &lgr_free_list, list)
1659 			lgr->freeing = 1;
1660 	} else {
1661 		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1662 			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1663 				if (lgr->lnk[i].smcibdev == smcibdev)
1664 					smcr_link_down_cond_sched(&lgr->lnk[i]);
1665 			}
1666 		}
1667 	}
1668 	spin_unlock_bh(&smc_lgr_list.lock);
1669 
1670 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1671 		list_del_init(&lgr->list);
1672 		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1673 		__smc_lgr_terminate(lgr, false);
1674 	}
1675 
1676 	if (smcibdev) {
1677 		if (atomic_read(&smcibdev->lnk_cnt))
1678 			wait_event(smcibdev->lnks_deleted,
1679 				   !atomic_read(&smcibdev->lnk_cnt));
1680 	} else {
1681 		if (atomic_read(&lgr_cnt))
1682 			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1683 	}
1684 }
1685 
1686 /* set new lgr type and clear all asymmetric link tagging */
smcr_lgr_set_type(struct smc_link_group * lgr,enum smc_lgr_type new_type)1687 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1688 {
1689 	char *lgr_type = "";
1690 	int i;
1691 
1692 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1693 		if (smc_link_usable(&lgr->lnk[i]))
1694 			lgr->lnk[i].link_is_asym = false;
1695 	if (lgr->type == new_type)
1696 		return;
1697 	lgr->type = new_type;
1698 
1699 	switch (lgr->type) {
1700 	case SMC_LGR_NONE:
1701 		lgr_type = "NONE";
1702 		break;
1703 	case SMC_LGR_SINGLE:
1704 		lgr_type = "SINGLE";
1705 		break;
1706 	case SMC_LGR_SYMMETRIC:
1707 		lgr_type = "SYMMETRIC";
1708 		break;
1709 	case SMC_LGR_ASYMMETRIC_PEER:
1710 		lgr_type = "ASYMMETRIC_PEER";
1711 		break;
1712 	case SMC_LGR_ASYMMETRIC_LOCAL:
1713 		lgr_type = "ASYMMETRIC_LOCAL";
1714 		break;
1715 	}
1716 	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1717 			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1718 			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1719 }
1720 
1721 /* set new lgr type and tag a link as asymmetric */
smcr_lgr_set_type_asym(struct smc_link_group * lgr,enum smc_lgr_type new_type,int asym_lnk_idx)1722 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1723 			    enum smc_lgr_type new_type, int asym_lnk_idx)
1724 {
1725 	smcr_lgr_set_type(lgr, new_type);
1726 	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1727 }
1728 
1729 /* abort connection, abort_work scheduled from tasklet context */
smc_conn_abort_work(struct work_struct * work)1730 static void smc_conn_abort_work(struct work_struct *work)
1731 {
1732 	struct smc_connection *conn = container_of(work,
1733 						   struct smc_connection,
1734 						   abort_work);
1735 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1736 
1737 	lock_sock(&smc->sk);
1738 	smc_conn_kill(conn, true);
1739 	release_sock(&smc->sk);
1740 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1741 }
1742 
smcr_port_add(struct smc_ib_device * smcibdev,u8 ibport)1743 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1744 {
1745 	struct smc_link_group *lgr, *n;
1746 
1747 	spin_lock_bh(&smc_lgr_list.lock);
1748 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1749 		struct smc_link *link;
1750 
1751 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1752 			    SMC_MAX_PNETID_LEN) ||
1753 		    lgr->type == SMC_LGR_SYMMETRIC ||
1754 		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1755 		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1756 			continue;
1757 
1758 		if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1759 			continue;
1760 
1761 		/* trigger local add link processing */
1762 		link = smc_llc_usable_link(lgr);
1763 		if (link)
1764 			smc_llc_add_link_local(link);
1765 	}
1766 	spin_unlock_bh(&smc_lgr_list.lock);
1767 }
1768 
1769 /* link is down - switch connections to alternate link,
1770  * must be called under lgr->llc_conf_mutex lock
1771  */
smcr_link_down(struct smc_link * lnk)1772 static void smcr_link_down(struct smc_link *lnk)
1773 {
1774 	struct smc_link_group *lgr = lnk->lgr;
1775 	struct smc_link *to_lnk;
1776 	int del_link_id;
1777 
1778 	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1779 		return;
1780 
1781 	to_lnk = smc_switch_conns(lgr, lnk, true);
1782 	if (!to_lnk) { /* no backup link available */
1783 		smcr_link_clear(lnk, true);
1784 		return;
1785 	}
1786 	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1787 	del_link_id = lnk->link_id;
1788 
1789 	if (lgr->role == SMC_SERV) {
1790 		/* trigger local delete link processing */
1791 		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1792 	} else {
1793 		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1794 			/* another llc task is ongoing */
1795 			up_write(&lgr->llc_conf_mutex);
1796 			wait_event_timeout(lgr->llc_flow_waiter,
1797 				(list_empty(&lgr->list) ||
1798 				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1799 				SMC_LLC_WAIT_TIME);
1800 			down_write(&lgr->llc_conf_mutex);
1801 		}
1802 		if (!list_empty(&lgr->list)) {
1803 			smc_llc_send_delete_link(to_lnk, del_link_id,
1804 						 SMC_LLC_REQ, true,
1805 						 SMC_LLC_DEL_LOST_PATH);
1806 			smcr_link_clear(lnk, true);
1807 		}
1808 		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1809 	}
1810 }
1811 
1812 /* must be called under lgr->llc_conf_mutex lock */
smcr_link_down_cond(struct smc_link * lnk)1813 void smcr_link_down_cond(struct smc_link *lnk)
1814 {
1815 	if (smc_link_downing(&lnk->state)) {
1816 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1817 		smcr_link_down(lnk);
1818 	}
1819 }
1820 
1821 /* will get the lgr->llc_conf_mutex lock */
smcr_link_down_cond_sched(struct smc_link * lnk)1822 void smcr_link_down_cond_sched(struct smc_link *lnk)
1823 {
1824 	if (smc_link_downing(&lnk->state)) {
1825 		trace_smcr_link_down(lnk, __builtin_return_address(0));
1826 		smcr_link_hold(lnk); /* smcr_link_put in link_down_wrk */
1827 		if (!schedule_work(&lnk->link_down_wrk))
1828 			smcr_link_put(lnk);
1829 	}
1830 }
1831 
smcr_port_err(struct smc_ib_device * smcibdev,u8 ibport)1832 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1833 {
1834 	struct smc_link_group *lgr, *n;
1835 	int i;
1836 
1837 	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1838 		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1839 			    SMC_MAX_PNETID_LEN))
1840 			continue; /* lgr is not affected */
1841 		if (list_empty(&lgr->list))
1842 			continue;
1843 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1844 			struct smc_link *lnk = &lgr->lnk[i];
1845 
1846 			if (smc_link_usable(lnk) &&
1847 			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1848 				smcr_link_down_cond_sched(lnk);
1849 		}
1850 	}
1851 }
1852 
smc_link_down_work(struct work_struct * work)1853 static void smc_link_down_work(struct work_struct *work)
1854 {
1855 	struct smc_link *link = container_of(work, struct smc_link,
1856 					     link_down_wrk);
1857 	struct smc_link_group *lgr = link->lgr;
1858 
1859 	if (list_empty(&lgr->list))
1860 		goto out;
1861 	wake_up_all(&lgr->llc_msg_waiter);
1862 	down_write(&lgr->llc_conf_mutex);
1863 	smcr_link_down(link);
1864 	up_write(&lgr->llc_conf_mutex);
1865 
1866 out:
1867 	smcr_link_put(link); /* smcr_link_hold by schedulers of link_down_work */
1868 }
1869 
smc_vlan_by_tcpsk_walk(struct net_device * lower_dev,struct netdev_nested_priv * priv)1870 static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1871 				  struct netdev_nested_priv *priv)
1872 {
1873 	unsigned short *vlan_id = (unsigned short *)priv->data;
1874 
1875 	if (is_vlan_dev(lower_dev)) {
1876 		*vlan_id = vlan_dev_vlan_id(lower_dev);
1877 		return 1;
1878 	}
1879 
1880 	return 0;
1881 }
1882 
1883 /* Determine vlan of internal TCP socket. */
smc_vlan_by_tcpsk(struct socket * clcsock,struct smc_init_info * ini)1884 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1885 {
1886 	struct dst_entry *dst = sk_dst_get(clcsock->sk);
1887 	struct netdev_nested_priv priv;
1888 	struct net_device *ndev;
1889 	int rc = 0;
1890 
1891 	ini->vlan_id = 0;
1892 	if (!dst) {
1893 		rc = -ENOTCONN;
1894 		goto out;
1895 	}
1896 	if (!dst->dev) {
1897 		rc = -ENODEV;
1898 		goto out_rel;
1899 	}
1900 
1901 	ndev = dst->dev;
1902 	if (is_vlan_dev(ndev)) {
1903 		ini->vlan_id = vlan_dev_vlan_id(ndev);
1904 		goto out_rel;
1905 	}
1906 
1907 	priv.data = (void *)&ini->vlan_id;
1908 	rtnl_lock();
1909 	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
1910 	rtnl_unlock();
1911 
1912 out_rel:
1913 	dst_release(dst);
1914 out:
1915 	return rc;
1916 }
1917 
smcr_lgr_match(struct smc_link_group * lgr,u8 smcr_version,u8 peer_systemid[],u8 peer_gid[],u8 peer_mac_v1[],enum smc_lgr_role role,u32 clcqpn,struct net * net)1918 static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1919 			   u8 peer_systemid[],
1920 			   u8 peer_gid[],
1921 			   u8 peer_mac_v1[],
1922 			   enum smc_lgr_role role, u32 clcqpn,
1923 			   struct net *net)
1924 {
1925 	struct smc_link *lnk;
1926 	int i;
1927 
1928 	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1929 	    lgr->role != role)
1930 		return false;
1931 
1932 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1933 		lnk = &lgr->lnk[i];
1934 
1935 		if (!smc_link_active(lnk))
1936 			continue;
1937 		/* use verbs API to check netns, instead of lgr->net */
1938 		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1939 			return false;
1940 		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1941 		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1942 		    (smcr_version == SMC_V2 ||
1943 		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1944 			return true;
1945 	}
1946 	return false;
1947 }
1948 
smcd_lgr_match(struct smc_link_group * lgr,struct smcd_dev * smcismdev,struct smcd_gid * peer_gid)1949 static bool smcd_lgr_match(struct smc_link_group *lgr,
1950 			   struct smcd_dev *smcismdev,
1951 			   struct smcd_gid *peer_gid)
1952 {
1953 	if (lgr->peer_gid.gid != peer_gid->gid ||
1954 	    lgr->smcd != smcismdev)
1955 		return false;
1956 
1957 	if (smc_ism_is_emulated(smcismdev) &&
1958 	    lgr->peer_gid.gid_ext != peer_gid->gid_ext)
1959 		return false;
1960 
1961 	return true;
1962 }
1963 
1964 /* create a new SMC connection (and a new link group if necessary) */
smc_conn_create(struct smc_sock * smc,struct smc_init_info * ini)1965 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1966 {
1967 	struct smc_connection *conn = &smc->conn;
1968 	struct net *net = sock_net(&smc->sk);
1969 	struct list_head *lgr_list;
1970 	struct smc_link_group *lgr;
1971 	enum smc_lgr_role role;
1972 	spinlock_t *lgr_lock;
1973 	int rc = 0;
1974 
1975 	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1976 				  &smc_lgr_list.list;
1977 	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1978 				  &smc_lgr_list.lock;
1979 	ini->first_contact_local = 1;
1980 	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1981 	if (role == SMC_CLNT && ini->first_contact_peer)
1982 		/* create new link group as well */
1983 		goto create;
1984 
1985 	/* determine if an existing link group can be reused */
1986 	spin_lock_bh(lgr_lock);
1987 	list_for_each_entry(lgr, lgr_list, list) {
1988 		write_lock_bh(&lgr->conns_lock);
1989 		if ((ini->is_smcd ?
1990 		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1991 				    &ini->ism_peer_gid[ini->ism_selected]) :
1992 		     smcr_lgr_match(lgr, ini->smcr_version,
1993 				    ini->peer_systemid,
1994 				    ini->peer_gid, ini->peer_mac, role,
1995 				    ini->ib_clcqpn, net)) &&
1996 		    !lgr->sync_err &&
1997 		    (ini->smcd_version == SMC_V2 ||
1998 		     lgr->vlan_id == ini->vlan_id) &&
1999 		    (role == SMC_CLNT || ini->is_smcd ||
2000 		    (lgr->conns_num < lgr->max_conns &&
2001 		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
2002 			/* link group found */
2003 			ini->first_contact_local = 0;
2004 			conn->lgr = lgr;
2005 			rc = smc_lgr_register_conn(conn, false);
2006 			write_unlock_bh(&lgr->conns_lock);
2007 			if (!rc && delayed_work_pending(&lgr->free_work))
2008 				cancel_delayed_work(&lgr->free_work);
2009 			break;
2010 		}
2011 		write_unlock_bh(&lgr->conns_lock);
2012 	}
2013 	spin_unlock_bh(lgr_lock);
2014 	if (rc)
2015 		return rc;
2016 
2017 	if (role == SMC_CLNT && !ini->first_contact_peer &&
2018 	    ini->first_contact_local) {
2019 		/* Server reuses a link group, but Client wants to start
2020 		 * a new one
2021 		 * send out_of_sync decline, reason synchr. error
2022 		 */
2023 		return SMC_CLC_DECL_SYNCERR;
2024 	}
2025 
2026 create:
2027 	if (ini->first_contact_local) {
2028 		rc = smc_lgr_create(smc, ini);
2029 		if (rc)
2030 			goto out;
2031 		lgr = conn->lgr;
2032 		write_lock_bh(&lgr->conns_lock);
2033 		rc = smc_lgr_register_conn(conn, true);
2034 		write_unlock_bh(&lgr->conns_lock);
2035 		if (rc) {
2036 			smc_lgr_cleanup_early(lgr);
2037 			goto out;
2038 		}
2039 	}
2040 	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
2041 	if (!conn->lgr->is_smcd)
2042 		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
2043 	conn->freed = 0;
2044 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
2045 	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
2046 	conn->urg_state = SMC_URG_READ;
2047 	init_waitqueue_head(&conn->cdc_pend_tx_wq);
2048 	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
2049 	if (ini->is_smcd) {
2050 		conn->rx_off = sizeof(struct smcd_cdc_msg);
2051 		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
2052 	} else {
2053 		conn->rx_off = 0;
2054 	}
2055 #ifndef KERNEL_HAS_ATOMIC64
2056 	spin_lock_init(&conn->acurs_lock);
2057 #endif
2058 
2059 out:
2060 	return rc;
2061 }
2062 
2063 #define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
2064 #define SMCR_RMBE_SIZES		15 /* 0 -> 16KB, 1 -> 32KB, .. 15 -> 512MB */
2065 
2066 /* convert the RMB size into the compressed notation (minimum 16K, see
2067  * SMCD/R_DMBE_SIZES.
2068  * In contrast to plain ilog2, this rounds towards the next power of 2,
2069  * so the socket application gets at least its desired sndbuf / rcvbuf size.
2070  */
smc_compress_bufsize(int size,bool is_smcd,bool is_rmb)2071 static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
2072 {
2073 	u8 compressed;
2074 
2075 	if (size <= SMC_BUF_MIN_SIZE)
2076 		return 0;
2077 
2078 	size = (size - 1) >> 14;  /* convert to 16K multiple */
2079 	compressed = min_t(u8, ilog2(size) + 1,
2080 			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
2081 
2082 #ifdef CONFIG_ARCH_NO_SG_CHAIN
2083 	if (!is_smcd && is_rmb)
2084 		/* RMBs are backed by & limited to max size of scatterlists */
2085 		compressed = min_t(u8, compressed, ilog2((SG_MAX_SINGLE_ALLOC * PAGE_SIZE) >> 14));
2086 #endif
2087 
2088 	return compressed;
2089 }
2090 
2091 /* convert the RMB size from compressed notation into integer */
smc_uncompress_bufsize(u8 compressed)2092 int smc_uncompress_bufsize(u8 compressed)
2093 {
2094 	u32 size;
2095 
2096 	size = 0x00000001 << (((int)compressed) + 14);
2097 	return (int)size;
2098 }
2099 
2100 /* try to reuse a sndbuf or rmb description slot for a certain
2101  * buffer size; if not available, return NULL
2102  */
smc_buf_get_slot(int compressed_bufsize,struct rw_semaphore * lock,struct list_head * buf_list)2103 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
2104 					     struct rw_semaphore *lock,
2105 					     struct list_head *buf_list)
2106 {
2107 	struct smc_buf_desc *buf_slot;
2108 
2109 	down_read(lock);
2110 	list_for_each_entry(buf_slot, buf_list, list) {
2111 		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
2112 			up_read(lock);
2113 			return buf_slot;
2114 		}
2115 	}
2116 	up_read(lock);
2117 	return NULL;
2118 }
2119 
2120 /* one of the conditions for announcing a receiver's current window size is
2121  * that it "results in a minimum increase in the window size of 10% of the
2122  * receive buffer space" [RFC7609]
2123  */
smc_rmb_wnd_update_limit(int rmbe_size)2124 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2125 {
2126 	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2127 }
2128 
2129 /* map an buf to a link */
smcr_buf_map_link(struct smc_buf_desc * buf_desc,bool is_rmb,struct smc_link * lnk)2130 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2131 			     struct smc_link *lnk)
2132 {
2133 	int rc, i, nents, offset, buf_size, size, access_flags;
2134 	struct scatterlist *sg;
2135 	void *buf;
2136 
2137 	if (buf_desc->is_map_ib[lnk->link_idx])
2138 		return 0;
2139 
2140 	if (buf_desc->is_vm) {
2141 		buf = buf_desc->cpu_addr;
2142 		buf_size = buf_desc->len;
2143 		offset = offset_in_page(buf_desc->cpu_addr);
2144 		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2145 	} else {
2146 		nents = 1;
2147 	}
2148 
2149 	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2150 	if (rc)
2151 		return rc;
2152 
2153 	if (buf_desc->is_vm) {
2154 		/* virtually contiguous buffer */
2155 		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2156 			size = min_t(int, PAGE_SIZE - offset, buf_size);
2157 			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2158 			buf += size;
2159 			buf_size -= size;
2160 			offset = 0;
2161 		}
2162 	} else {
2163 		/* physically contiguous buffer */
2164 		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2165 			   buf_desc->cpu_addr, buf_desc->len);
2166 	}
2167 
2168 	/* map sg table to DMA address */
2169 	rc = smc_ib_buf_map_sg(lnk, buf_desc,
2170 			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2171 	/* SMC protocol depends on mapping to one DMA address only */
2172 	if (rc != nents) {
2173 		rc = -EAGAIN;
2174 		goto free_table;
2175 	}
2176 
2177 	buf_desc->is_dma_need_sync |=
2178 		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2179 
2180 	if (is_rmb || buf_desc->is_vm) {
2181 		/* create a new memory region for the RMB or vzalloced sndbuf */
2182 		access_flags = is_rmb ?
2183 			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2184 			       IB_ACCESS_LOCAL_WRITE;
2185 
2186 		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2187 					      buf_desc, lnk->link_idx);
2188 		if (rc)
2189 			goto buf_unmap;
2190 		smc_ib_sync_sg_for_device(lnk, buf_desc,
2191 					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2192 	}
2193 	buf_desc->is_map_ib[lnk->link_idx] = true;
2194 	return 0;
2195 
2196 buf_unmap:
2197 	smc_ib_buf_unmap_sg(lnk, buf_desc,
2198 			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2199 free_table:
2200 	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2201 	return rc;
2202 }
2203 
2204 /* register a new buf on IB device, rmb or vzalloced sndbuf
2205  * must be called under lgr->llc_conf_mutex lock
2206  */
smcr_link_reg_buf(struct smc_link * link,struct smc_buf_desc * buf_desc)2207 int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2208 {
2209 	if (list_empty(&link->lgr->list))
2210 		return -ENOLINK;
2211 	if (!buf_desc->is_reg_mr[link->link_idx]) {
2212 		/* register memory region for new buf */
2213 		if (buf_desc->is_vm)
2214 			buf_desc->mr[link->link_idx]->iova =
2215 				(uintptr_t)buf_desc->cpu_addr;
2216 		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2217 			buf_desc->is_reg_err = true;
2218 			return -EFAULT;
2219 		}
2220 		buf_desc->is_reg_mr[link->link_idx] = true;
2221 	}
2222 	return 0;
2223 }
2224 
_smcr_buf_map_lgr(struct smc_link * lnk,struct rw_semaphore * lock,struct list_head * lst,bool is_rmb)2225 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
2226 			     struct list_head *lst, bool is_rmb)
2227 {
2228 	struct smc_buf_desc *buf_desc, *bf;
2229 	int rc = 0;
2230 
2231 	down_write(lock);
2232 	list_for_each_entry_safe(buf_desc, bf, lst, list) {
2233 		if (!buf_desc->used)
2234 			continue;
2235 		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2236 		if (rc)
2237 			goto out;
2238 	}
2239 out:
2240 	up_write(lock);
2241 	return rc;
2242 }
2243 
2244 /* map all used buffers of lgr for a new link */
smcr_buf_map_lgr(struct smc_link * lnk)2245 int smcr_buf_map_lgr(struct smc_link *lnk)
2246 {
2247 	struct smc_link_group *lgr = lnk->lgr;
2248 	int i, rc = 0;
2249 
2250 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2251 		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2252 				       &lgr->rmbs[i], true);
2253 		if (rc)
2254 			return rc;
2255 		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2256 				       &lgr->sndbufs[i], false);
2257 		if (rc)
2258 			return rc;
2259 	}
2260 	return 0;
2261 }
2262 
2263 /* register all used buffers of lgr for a new link,
2264  * must be called under lgr->llc_conf_mutex lock
2265  */
smcr_buf_reg_lgr(struct smc_link * lnk)2266 int smcr_buf_reg_lgr(struct smc_link *lnk)
2267 {
2268 	struct smc_link_group *lgr = lnk->lgr;
2269 	struct smc_buf_desc *buf_desc, *bf;
2270 	int i, rc = 0;
2271 
2272 	/* reg all RMBs for a new link */
2273 	down_write(&lgr->rmbs_lock);
2274 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2275 		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2276 			if (!buf_desc->used)
2277 				continue;
2278 			rc = smcr_link_reg_buf(lnk, buf_desc);
2279 			if (rc) {
2280 				up_write(&lgr->rmbs_lock);
2281 				return rc;
2282 			}
2283 		}
2284 	}
2285 	up_write(&lgr->rmbs_lock);
2286 
2287 	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2288 		return rc;
2289 
2290 	/* reg all vzalloced sndbufs for a new link */
2291 	down_write(&lgr->sndbufs_lock);
2292 	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2293 		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2294 			if (!buf_desc->used || !buf_desc->is_vm)
2295 				continue;
2296 			rc = smcr_link_reg_buf(lnk, buf_desc);
2297 			if (rc) {
2298 				up_write(&lgr->sndbufs_lock);
2299 				return rc;
2300 			}
2301 		}
2302 	}
2303 	up_write(&lgr->sndbufs_lock);
2304 	return rc;
2305 }
2306 
smcr_new_buf_create(struct smc_link_group * lgr,int bufsize)2307 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2308 						int bufsize)
2309 {
2310 	struct smc_buf_desc *buf_desc;
2311 
2312 	/* try to alloc a new buffer */
2313 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2314 	if (!buf_desc)
2315 		return ERR_PTR(-ENOMEM);
2316 
2317 	switch (lgr->buf_type) {
2318 	case SMCR_PHYS_CONT_BUFS:
2319 	case SMCR_MIXED_BUFS:
2320 		buf_desc->order = get_order(bufsize);
2321 		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2322 					      __GFP_NOMEMALLOC | __GFP_COMP |
2323 					      __GFP_NORETRY | __GFP_ZERO,
2324 					      buf_desc->order);
2325 		if (buf_desc->pages) {
2326 			buf_desc->cpu_addr =
2327 				(void *)page_address(buf_desc->pages);
2328 			buf_desc->len = bufsize;
2329 			buf_desc->is_vm = false;
2330 			break;
2331 		}
2332 		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2333 			goto out;
2334 		fallthrough;	// try virtually contiguous buf
2335 	case SMCR_VIRT_CONT_BUFS:
2336 		buf_desc->order = get_order(bufsize);
2337 		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2338 		if (!buf_desc->cpu_addr)
2339 			goto out;
2340 		buf_desc->pages = NULL;
2341 		buf_desc->len = bufsize;
2342 		buf_desc->is_vm = true;
2343 		break;
2344 	}
2345 	return buf_desc;
2346 
2347 out:
2348 	kfree(buf_desc);
2349 	return ERR_PTR(-EAGAIN);
2350 }
2351 
2352 /* map buf_desc on all usable links,
2353  * unused buffers stay mapped as long as the link is up
2354  */
smcr_buf_map_usable_links(struct smc_link_group * lgr,struct smc_buf_desc * buf_desc,bool is_rmb)2355 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2356 				     struct smc_buf_desc *buf_desc, bool is_rmb)
2357 {
2358 	int i, rc = 0, cnt = 0;
2359 
2360 	/* protect against parallel link reconfiguration */
2361 	down_read(&lgr->llc_conf_mutex);
2362 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2363 		struct smc_link *lnk = &lgr->lnk[i];
2364 
2365 		if (!smc_link_usable(lnk))
2366 			continue;
2367 		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2368 			rc = -ENOMEM;
2369 			goto out;
2370 		}
2371 		cnt++;
2372 	}
2373 out:
2374 	up_read(&lgr->llc_conf_mutex);
2375 	if (!rc && !cnt)
2376 		rc = -EINVAL;
2377 	return rc;
2378 }
2379 
smcd_new_buf_create(struct smc_link_group * lgr,bool is_dmb,int bufsize)2380 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2381 						bool is_dmb, int bufsize)
2382 {
2383 	struct smc_buf_desc *buf_desc;
2384 	int rc;
2385 
2386 	/* try to alloc a new DMB */
2387 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2388 	if (!buf_desc)
2389 		return ERR_PTR(-ENOMEM);
2390 	if (is_dmb) {
2391 		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2392 		if (rc) {
2393 			kfree(buf_desc);
2394 			if (rc == -ENOMEM)
2395 				return ERR_PTR(-EAGAIN);
2396 			if (rc == -ENOSPC)
2397 				return ERR_PTR(-ENOSPC);
2398 			return ERR_PTR(-EIO);
2399 		}
2400 		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2401 		/* CDC header stored in buf. So, pretend it was smaller */
2402 		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2403 	} else {
2404 		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2405 					     __GFP_NOWARN | __GFP_NORETRY |
2406 					     __GFP_NOMEMALLOC);
2407 		if (!buf_desc->cpu_addr) {
2408 			kfree(buf_desc);
2409 			return ERR_PTR(-EAGAIN);
2410 		}
2411 		buf_desc->len = bufsize;
2412 	}
2413 	return buf_desc;
2414 }
2415 
__smc_buf_create(struct smc_sock * smc,bool is_smcd,bool is_rmb)2416 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2417 {
2418 	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2419 	struct smc_connection *conn = &smc->conn;
2420 	struct smc_link_group *lgr = conn->lgr;
2421 	struct list_head *buf_list;
2422 	int bufsize, bufsize_comp;
2423 	struct rw_semaphore *lock;	/* lock buffer list */
2424 	bool is_dgraded = false;
2425 
2426 	if (is_rmb)
2427 		/* use socket recv buffer size (w/o overhead) as start value */
2428 		bufsize = smc->sk.sk_rcvbuf / 2;
2429 	else
2430 		/* use socket send buffer size (w/o overhead) as start value */
2431 		bufsize = smc->sk.sk_sndbuf / 2;
2432 
2433 	for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb);
2434 	     bufsize_comp >= 0; bufsize_comp--) {
2435 		if (is_rmb) {
2436 			lock = &lgr->rmbs_lock;
2437 			buf_list = &lgr->rmbs[bufsize_comp];
2438 		} else {
2439 			lock = &lgr->sndbufs_lock;
2440 			buf_list = &lgr->sndbufs[bufsize_comp];
2441 		}
2442 		bufsize = smc_uncompress_bufsize(bufsize_comp);
2443 
2444 		/* check for reusable slot in the link group */
2445 		buf_desc = smc_buf_get_slot(bufsize_comp, lock, buf_list);
2446 		if (buf_desc) {
2447 			buf_desc->is_dma_need_sync = 0;
2448 			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2449 			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2450 			break; /* found reusable slot */
2451 		}
2452 
2453 		if (is_smcd)
2454 			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2455 		else
2456 			buf_desc = smcr_new_buf_create(lgr, bufsize);
2457 
2458 		if (PTR_ERR(buf_desc) == -ENOMEM)
2459 			break;
2460 		if (IS_ERR(buf_desc)) {
2461 			if (!is_dgraded) {
2462 				is_dgraded = true;
2463 				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2464 			}
2465 			continue;
2466 		}
2467 
2468 		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2469 		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2470 		buf_desc->used = 1;
2471 		down_write(lock);
2472 		smc_lgr_buf_list_add(lgr, is_rmb, buf_list, buf_desc);
2473 		up_write(lock);
2474 		break; /* found */
2475 	}
2476 
2477 	if (IS_ERR(buf_desc))
2478 		return PTR_ERR(buf_desc);
2479 
2480 	if (!is_smcd) {
2481 		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2482 			smcr_buf_unuse(buf_desc, is_rmb, lgr);
2483 			return -ENOMEM;
2484 		}
2485 	}
2486 
2487 	if (is_rmb) {
2488 		conn->rmb_desc = buf_desc;
2489 		conn->rmbe_size_comp = bufsize_comp;
2490 		smc->sk.sk_rcvbuf = bufsize * 2;
2491 		atomic_set(&conn->bytes_to_rcv, 0);
2492 		conn->rmbe_update_limit =
2493 			smc_rmb_wnd_update_limit(buf_desc->len);
2494 		if (is_smcd)
2495 			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2496 	} else {
2497 		conn->sndbuf_desc = buf_desc;
2498 		smc->sk.sk_sndbuf = bufsize * 2;
2499 		atomic_set(&conn->sndbuf_space, bufsize);
2500 	}
2501 	return 0;
2502 }
2503 
smc_sndbuf_sync_sg_for_device(struct smc_connection * conn)2504 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2505 {
2506 	if (!conn->sndbuf_desc->is_dma_need_sync)
2507 		return;
2508 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2509 	    !smc_link_active(conn->lnk))
2510 		return;
2511 	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2512 }
2513 
smc_rmb_sync_sg_for_cpu(struct smc_connection * conn)2514 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2515 {
2516 	int i;
2517 
2518 	if (!conn->rmb_desc->is_dma_need_sync)
2519 		return;
2520 	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2521 		return;
2522 	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2523 		if (!smc_link_active(&conn->lgr->lnk[i]))
2524 			continue;
2525 		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2526 				       DMA_FROM_DEVICE);
2527 	}
2528 }
2529 
2530 /* create the send and receive buffer for an SMC socket;
2531  * receive buffers are called RMBs;
2532  * (even though the SMC protocol allows more than one RMB-element per RMB,
2533  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2534  * extra RMB for every connection in a link group
2535  */
smc_buf_create(struct smc_sock * smc,bool is_smcd)2536 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2537 {
2538 	int rc;
2539 
2540 	/* create send buffer */
2541 	if (is_smcd &&
2542 	    smc_ism_support_dmb_nocopy(smc->conn.lgr->smcd))
2543 		goto create_rmb;
2544 
2545 	rc = __smc_buf_create(smc, is_smcd, false);
2546 	if (rc)
2547 		return rc;
2548 
2549 create_rmb:
2550 	/* create rmb */
2551 	rc = __smc_buf_create(smc, is_smcd, true);
2552 	if (rc && smc->conn.sndbuf_desc) {
2553 		down_write(&smc->conn.lgr->sndbufs_lock);
2554 		smc_lgr_buf_list_del(smc->conn.lgr, false,
2555 				     smc->conn.sndbuf_desc);
2556 		up_write(&smc->conn.lgr->sndbufs_lock);
2557 		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2558 		smc->conn.sndbuf_desc = NULL;
2559 	}
2560 	return rc;
2561 }
2562 
smcd_buf_attach(struct smc_sock * smc)2563 int smcd_buf_attach(struct smc_sock *smc)
2564 {
2565 	struct smc_connection *conn = &smc->conn;
2566 	struct smcd_dev *smcd = conn->lgr->smcd;
2567 	u64 peer_token = conn->peer_token;
2568 	struct smc_buf_desc *buf_desc;
2569 	int rc;
2570 
2571 	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2572 	if (!buf_desc)
2573 		return -ENOMEM;
2574 
2575 	/* The ghost sndbuf_desc describes the same memory region as
2576 	 * peer RMB. Its lifecycle is consistent with the connection's
2577 	 * and it will be freed with the connections instead of the
2578 	 * link group.
2579 	 */
2580 	rc = smc_ism_attach_dmb(smcd, peer_token, buf_desc);
2581 	if (rc)
2582 		goto free;
2583 
2584 	smc->sk.sk_sndbuf = buf_desc->len;
2585 	buf_desc->cpu_addr =
2586 		(u8 *)buf_desc->cpu_addr + sizeof(struct smcd_cdc_msg);
2587 	buf_desc->len -= sizeof(struct smcd_cdc_msg);
2588 	conn->sndbuf_desc = buf_desc;
2589 	conn->sndbuf_desc->used = 1;
2590 	atomic_set(&conn->sndbuf_space, conn->sndbuf_desc->len);
2591 	return 0;
2592 
2593 free:
2594 	kfree(buf_desc);
2595 	return rc;
2596 }
2597 
smc_rmb_reserve_rtoken_idx(struct smc_link_group * lgr)2598 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2599 {
2600 	int i;
2601 
2602 	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2603 		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2604 			return i;
2605 	}
2606 	return -ENOSPC;
2607 }
2608 
smc_rtoken_find_by_link(struct smc_link_group * lgr,int lnk_idx,u32 rkey)2609 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2610 				   u32 rkey)
2611 {
2612 	int i;
2613 
2614 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2615 		if (test_bit(i, lgr->rtokens_used_mask) &&
2616 		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2617 			return i;
2618 	}
2619 	return -ENOENT;
2620 }
2621 
2622 /* set rtoken for a new link to an existing rmb */
smc_rtoken_set(struct smc_link_group * lgr,int link_idx,int link_idx_new,__be32 nw_rkey_known,__be64 nw_vaddr,__be32 nw_rkey)2623 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2624 		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2625 {
2626 	int rtok_idx;
2627 
2628 	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2629 	if (rtok_idx == -ENOENT)
2630 		return;
2631 	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2632 	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2633 }
2634 
2635 /* set rtoken for a new link whose link_id is given */
smc_rtoken_set2(struct smc_link_group * lgr,int rtok_idx,int link_id,__be64 nw_vaddr,__be32 nw_rkey)2636 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2637 		     __be64 nw_vaddr, __be32 nw_rkey)
2638 {
2639 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2640 	u32 rkey = ntohl(nw_rkey);
2641 	bool found = false;
2642 	int link_idx;
2643 
2644 	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2645 		if (lgr->lnk[link_idx].link_id == link_id) {
2646 			found = true;
2647 			break;
2648 		}
2649 	}
2650 	if (!found)
2651 		return;
2652 	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2653 	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2654 }
2655 
2656 /* add a new rtoken from peer */
smc_rtoken_add(struct smc_link * lnk,__be64 nw_vaddr,__be32 nw_rkey)2657 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2658 {
2659 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2660 	u64 dma_addr = be64_to_cpu(nw_vaddr);
2661 	u32 rkey = ntohl(nw_rkey);
2662 	int i;
2663 
2664 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2665 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2666 		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2667 		    test_bit(i, lgr->rtokens_used_mask)) {
2668 			/* already in list */
2669 			return i;
2670 		}
2671 	}
2672 	i = smc_rmb_reserve_rtoken_idx(lgr);
2673 	if (i < 0)
2674 		return i;
2675 	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2676 	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2677 	return i;
2678 }
2679 
2680 /* delete an rtoken from all links */
smc_rtoken_delete(struct smc_link * lnk,__be32 nw_rkey)2681 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2682 {
2683 	struct smc_link_group *lgr = smc_get_lgr(lnk);
2684 	u32 rkey = ntohl(nw_rkey);
2685 	int i, j;
2686 
2687 	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2688 		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2689 		    test_bit(i, lgr->rtokens_used_mask)) {
2690 			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2691 				lgr->rtokens[i][j].rkey = 0;
2692 				lgr->rtokens[i][j].dma_addr = 0;
2693 			}
2694 			clear_bit(i, lgr->rtokens_used_mask);
2695 			return 0;
2696 		}
2697 	}
2698 	return -ENOENT;
2699 }
2700 
2701 /* save rkey and dma_addr received from peer during clc handshake */
smc_rmb_rtoken_handling(struct smc_connection * conn,struct smc_link * lnk,struct smc_clc_msg_accept_confirm * clc)2702 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2703 			    struct smc_link *lnk,
2704 			    struct smc_clc_msg_accept_confirm *clc)
2705 {
2706 	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2707 					  clc->r0.rmb_rkey);
2708 	if (conn->rtoken_idx < 0)
2709 		return conn->rtoken_idx;
2710 	return 0;
2711 }
2712 
smc_core_going_away(void)2713 static void smc_core_going_away(void)
2714 {
2715 	struct smc_ib_device *smcibdev;
2716 	struct smcd_dev *smcd;
2717 
2718 	mutex_lock(&smc_ib_devices.mutex);
2719 	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2720 		int i;
2721 
2722 		for (i = 0; i < SMC_MAX_PORTS; i++)
2723 			set_bit(i, smcibdev->ports_going_away);
2724 	}
2725 	mutex_unlock(&smc_ib_devices.mutex);
2726 
2727 	mutex_lock(&smcd_dev_list.mutex);
2728 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2729 		smcd->going_away = 1;
2730 	}
2731 	mutex_unlock(&smcd_dev_list.mutex);
2732 }
2733 
2734 /* Clean up all SMC link groups */
smc_lgrs_shutdown(void)2735 static void smc_lgrs_shutdown(void)
2736 {
2737 	struct smcd_dev *smcd;
2738 
2739 	smc_core_going_away();
2740 
2741 	smc_smcr_terminate_all(NULL);
2742 
2743 	mutex_lock(&smcd_dev_list.mutex);
2744 	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2745 		smc_smcd_terminate_all(smcd);
2746 	mutex_unlock(&smcd_dev_list.mutex);
2747 }
2748 
smc_core_reboot_event(struct notifier_block * this,unsigned long event,void * ptr)2749 static int smc_core_reboot_event(struct notifier_block *this,
2750 				 unsigned long event, void *ptr)
2751 {
2752 	smc_lgrs_shutdown();
2753 	smc_ib_unregister_client();
2754 	smc_ism_exit();
2755 	return 0;
2756 }
2757 
2758 static struct notifier_block smc_reboot_notifier = {
2759 	.notifier_call = smc_core_reboot_event,
2760 };
2761 
smc_core_init(void)2762 int __init smc_core_init(void)
2763 {
2764 	return register_reboot_notifier(&smc_reboot_notifier);
2765 }
2766 
2767 /* Called (from smc_exit) when module is removed */
smc_core_exit(void)2768 void smc_core_exit(void)
2769 {
2770 	unregister_reboot_notifier(&smc_reboot_notifier);
2771 	smc_lgrs_shutdown();
2772 }
2773