18daebcef1813eadd35f287eaa9c8e922ad98005
[sfrench/cifs-2.6.git] / net / smc / smc_core.c
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 <net/tcp.h>
17 #include <net/sock.h>
18 #include <rdma/ib_verbs.h>
19 #include <rdma/ib_cache.h>
20
21 #include "smc.h"
22 #include "smc_clc.h"
23 #include "smc_core.h"
24 #include "smc_ib.h"
25 #include "smc_wr.h"
26 #include "smc_llc.h"
27 #include "smc_cdc.h"
28 #include "smc_close.h"
29 #include "smc_ism.h"
30
31 #define SMC_LGR_NUM_INCR                256
32 #define SMC_LGR_FREE_DELAY_SERV         (600 * HZ)
33 #define SMC_LGR_FREE_DELAY_CLNT         (SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
34 #define SMC_LGR_FREE_DELAY_FAST         (8 * HZ)
35
36 static struct smc_lgr_list smc_lgr_list = {     /* established link groups */
37         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
38         .list = LIST_HEAD_INIT(smc_lgr_list.list),
39         .num = 0,
40 };
41
42 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
43                          struct smc_buf_desc *buf_desc);
44
45 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
46 {
47         /* client link group creation always follows the server link group
48          * creation. For client use a somewhat higher removal delay time,
49          * otherwise there is a risk of out-of-sync link groups.
50          */
51         mod_delayed_work(system_wq, &lgr->free_work,
52                          (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
53                          SMC_LGR_FREE_DELAY_CLNT : SMC_LGR_FREE_DELAY_SERV);
54 }
55
56 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)
57 {
58         mod_delayed_work(system_wq, &lgr->free_work, SMC_LGR_FREE_DELAY_FAST);
59 }
60
61 /* Register connection's alert token in our lookup structure.
62  * To use rbtrees we have to implement our own insert core.
63  * Requires @conns_lock
64  * @smc         connection to register
65  * Returns 0 on success, != otherwise.
66  */
67 static void smc_lgr_add_alert_token(struct smc_connection *conn)
68 {
69         struct rb_node **link, *parent = NULL;
70         u32 token = conn->alert_token_local;
71
72         link = &conn->lgr->conns_all.rb_node;
73         while (*link) {
74                 struct smc_connection *cur = rb_entry(*link,
75                                         struct smc_connection, alert_node);
76
77                 parent = *link;
78                 if (cur->alert_token_local > token)
79                         link = &parent->rb_left;
80                 else
81                         link = &parent->rb_right;
82         }
83         /* Put the new node there */
84         rb_link_node(&conn->alert_node, parent, link);
85         rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
86 }
87
88 /* Register connection in link group by assigning an alert token
89  * registered in a search tree.
90  * Requires @conns_lock
91  * Note that '0' is a reserved value and not assigned.
92  */
93 static void smc_lgr_register_conn(struct smc_connection *conn)
94 {
95         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
96         static atomic_t nexttoken = ATOMIC_INIT(0);
97
98         /* find a new alert_token_local value not yet used by some connection
99          * in this link group
100          */
101         sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
102         while (!conn->alert_token_local) {
103                 conn->alert_token_local = atomic_inc_return(&nexttoken);
104                 if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
105                         conn->alert_token_local = 0;
106         }
107         smc_lgr_add_alert_token(conn);
108         conn->lgr->conns_num++;
109 }
110
111 /* Unregister connection and reset the alert token of the given connection<
112  */
113 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
114 {
115         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
116         struct smc_link_group *lgr = conn->lgr;
117
118         rb_erase(&conn->alert_node, &lgr->conns_all);
119         lgr->conns_num--;
120         conn->alert_token_local = 0;
121         conn->lgr = NULL;
122         sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
123 }
124
125 /* Unregister connection from lgr
126  */
127 static void smc_lgr_unregister_conn(struct smc_connection *conn)
128 {
129         struct smc_link_group *lgr = conn->lgr;
130
131         write_lock_bh(&lgr->conns_lock);
132         if (conn->alert_token_local) {
133                 __smc_lgr_unregister_conn(conn);
134         }
135         write_unlock_bh(&lgr->conns_lock);
136 }
137
138 /* Send delete link, either as client to request the initiation
139  * of the DELETE LINK sequence from server; or as server to
140  * initiate the delete processing. See smc_llc_rx_delete_link().
141  */
142 static int smc_link_send_delete(struct smc_link *lnk)
143 {
144         if (lnk->state == SMC_LNK_ACTIVE &&
145             !smc_llc_send_delete_link(lnk, SMC_LLC_REQ, true)) {
146                 smc_llc_link_deleting(lnk);
147                 return 0;
148         }
149         return -ENOTCONN;
150 }
151
152 static void smc_lgr_free_work(struct work_struct *work)
153 {
154         struct smc_link_group *lgr = container_of(to_delayed_work(work),
155                                                   struct smc_link_group,
156                                                   free_work);
157         bool conns;
158
159         spin_lock_bh(&smc_lgr_list.lock);
160         if (list_empty(&lgr->list))
161                 goto free;
162         read_lock_bh(&lgr->conns_lock);
163         conns = RB_EMPTY_ROOT(&lgr->conns_all);
164         read_unlock_bh(&lgr->conns_lock);
165         if (!conns) { /* number of lgr connections is no longer zero */
166                 spin_unlock_bh(&smc_lgr_list.lock);
167                 return;
168         }
169         list_del_init(&lgr->list); /* remove from smc_lgr_list */
170 free:
171         spin_unlock_bh(&smc_lgr_list.lock);
172
173         if (!lgr->is_smcd && !lgr->terminating) {
174                 /* try to send del link msg, on error free lgr immediately */
175                 if (!smc_link_send_delete(&lgr->lnk[SMC_SINGLE_LINK])) {
176                         /* reschedule in case we never receive a response */
177                         smc_lgr_schedule_free_work(lgr);
178                         return;
179                 }
180         }
181
182         if (!delayed_work_pending(&lgr->free_work)) {
183                 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
184
185                 if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
186                         smc_llc_link_inactive(lnk);
187                 smc_lgr_free(lgr);
188         }
189 }
190
191 /* create a new SMC link group */
192 static int smc_lgr_create(struct smc_sock *smc, bool is_smcd,
193                           struct smc_ib_device *smcibdev, u8 ibport,
194                           char *peer_systemid, unsigned short vlan_id,
195                           struct smcd_dev *smcismdev, u64 peer_gid)
196 {
197         struct smc_link_group *lgr;
198         struct smc_link *lnk;
199         u8 rndvec[3];
200         int rc = 0;
201         int i;
202
203         if (is_smcd && vlan_id) {
204                 rc = smc_ism_get_vlan(smcismdev, vlan_id);
205                 if (rc)
206                         goto out;
207         }
208
209         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
210         if (!lgr) {
211                 rc = -ENOMEM;
212                 goto out;
213         }
214         lgr->is_smcd = is_smcd;
215         lgr->sync_err = 0;
216         lgr->vlan_id = vlan_id;
217         rwlock_init(&lgr->sndbufs_lock);
218         rwlock_init(&lgr->rmbs_lock);
219         rwlock_init(&lgr->conns_lock);
220         for (i = 0; i < SMC_RMBE_SIZES; i++) {
221                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
222                 INIT_LIST_HEAD(&lgr->rmbs[i]);
223         }
224         smc_lgr_list.num += SMC_LGR_NUM_INCR;
225         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
226         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
227         lgr->conns_all = RB_ROOT;
228         if (is_smcd) {
229                 /* SMC-D specific settings */
230                 lgr->peer_gid = peer_gid;
231                 lgr->smcd = smcismdev;
232         } else {
233                 /* SMC-R specific settings */
234                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
235                 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
236
237                 lnk = &lgr->lnk[SMC_SINGLE_LINK];
238                 /* initialize link */
239                 lnk->state = SMC_LNK_ACTIVATING;
240                 lnk->link_id = SMC_SINGLE_LINK;
241                 lnk->smcibdev = smcibdev;
242                 lnk->ibport = ibport;
243                 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
244                 if (!smcibdev->initialized)
245                         smc_ib_setup_per_ibdev(smcibdev);
246                 get_random_bytes(rndvec, sizeof(rndvec));
247                 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
248                         (rndvec[2] << 16);
249                 rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
250                                           vlan_id, lnk->gid, &lnk->sgid_index);
251                 if (rc)
252                         goto free_lgr;
253                 rc = smc_llc_link_init(lnk);
254                 if (rc)
255                         goto free_lgr;
256                 rc = smc_wr_alloc_link_mem(lnk);
257                 if (rc)
258                         goto clear_llc_lnk;
259                 rc = smc_ib_create_protection_domain(lnk);
260                 if (rc)
261                         goto free_link_mem;
262                 rc = smc_ib_create_queue_pair(lnk);
263                 if (rc)
264                         goto dealloc_pd;
265                 rc = smc_wr_create_link(lnk);
266                 if (rc)
267                         goto destroy_qp;
268         }
269         smc->conn.lgr = lgr;
270         spin_lock_bh(&smc_lgr_list.lock);
271         list_add(&lgr->list, &smc_lgr_list.list);
272         spin_unlock_bh(&smc_lgr_list.lock);
273         return 0;
274
275 destroy_qp:
276         smc_ib_destroy_queue_pair(lnk);
277 dealloc_pd:
278         smc_ib_dealloc_protection_domain(lnk);
279 free_link_mem:
280         smc_wr_free_link_mem(lnk);
281 clear_llc_lnk:
282         smc_llc_link_clear(lnk);
283 free_lgr:
284         kfree(lgr);
285 out:
286         return rc;
287 }
288
289 static void smc_buf_unuse(struct smc_connection *conn,
290                           struct smc_link_group *lgr)
291 {
292         if (conn->sndbuf_desc)
293                 conn->sndbuf_desc->used = 0;
294         if (conn->rmb_desc) {
295                 if (!conn->rmb_desc->regerr) {
296                         conn->rmb_desc->reused = 1;
297                         conn->rmb_desc->used = 0;
298                 } else {
299                         /* buf registration failed, reuse not possible */
300                         write_lock_bh(&lgr->rmbs_lock);
301                         list_del(&conn->rmb_desc->list);
302                         write_unlock_bh(&lgr->rmbs_lock);
303
304                         smc_buf_free(lgr, true, conn->rmb_desc);
305                 }
306         }
307 }
308
309 /* remove a finished connection from its link group */
310 void smc_conn_free(struct smc_connection *conn)
311 {
312         struct smc_link_group *lgr = conn->lgr;
313
314         if (!lgr)
315                 return;
316         if (lgr->is_smcd) {
317                 smc_ism_unset_conn(conn);
318                 tasklet_kill(&conn->rx_tsklet);
319         } else {
320                 smc_cdc_tx_dismiss_slots(conn);
321         }
322         smc_lgr_unregister_conn(conn);          /* unsets conn->lgr */
323         smc_buf_unuse(conn, lgr);               /* allow buffer reuse */
324
325         if (!lgr->conns_num)
326                 smc_lgr_schedule_free_work(lgr);
327 }
328
329 static void smc_link_clear(struct smc_link *lnk)
330 {
331         lnk->peer_qpn = 0;
332         smc_llc_link_clear(lnk);
333         smc_ib_modify_qp_reset(lnk);
334         smc_wr_free_link(lnk);
335         smc_ib_destroy_queue_pair(lnk);
336         smc_ib_dealloc_protection_domain(lnk);
337         smc_wr_free_link_mem(lnk);
338 }
339
340 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
341                           struct smc_buf_desc *buf_desc)
342 {
343         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
344
345         if (is_rmb) {
346                 if (buf_desc->mr_rx[SMC_SINGLE_LINK])
347                         smc_ib_put_memory_region(
348                                         buf_desc->mr_rx[SMC_SINGLE_LINK]);
349                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
350                                     DMA_FROM_DEVICE);
351         } else {
352                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
353                                     DMA_TO_DEVICE);
354         }
355         sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
356         if (buf_desc->pages)
357                 __free_pages(buf_desc->pages, buf_desc->order);
358         kfree(buf_desc);
359 }
360
361 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
362                           struct smc_buf_desc *buf_desc)
363 {
364         if (is_dmb) {
365                 /* restore original buf len */
366                 buf_desc->len += sizeof(struct smcd_cdc_msg);
367                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
368         } else {
369                 kfree(buf_desc->cpu_addr);
370         }
371         kfree(buf_desc);
372 }
373
374 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
375                          struct smc_buf_desc *buf_desc)
376 {
377         if (lgr->is_smcd)
378                 smcd_buf_free(lgr, is_rmb, buf_desc);
379         else
380                 smcr_buf_free(lgr, is_rmb, buf_desc);
381 }
382
383 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
384 {
385         struct smc_buf_desc *buf_desc, *bf_desc;
386         struct list_head *buf_list;
387         int i;
388
389         for (i = 0; i < SMC_RMBE_SIZES; i++) {
390                 if (is_rmb)
391                         buf_list = &lgr->rmbs[i];
392                 else
393                         buf_list = &lgr->sndbufs[i];
394                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
395                                          list) {
396                         list_del(&buf_desc->list);
397                         smc_buf_free(lgr, is_rmb, buf_desc);
398                 }
399         }
400 }
401
402 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
403 {
404         /* free send buffers */
405         __smc_lgr_free_bufs(lgr, false);
406         /* free rmbs */
407         __smc_lgr_free_bufs(lgr, true);
408 }
409
410 /* remove a link group */
411 void smc_lgr_free(struct smc_link_group *lgr)
412 {
413         smc_lgr_free_bufs(lgr);
414         if (lgr->is_smcd)
415                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
416         else
417                 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
418         kfree(lgr);
419 }
420
421 void smc_lgr_forget(struct smc_link_group *lgr)
422 {
423         spin_lock_bh(&smc_lgr_list.lock);
424         /* do not use this link group for new connections */
425         if (!list_empty(&lgr->list))
426                 list_del_init(&lgr->list);
427         spin_unlock_bh(&smc_lgr_list.lock);
428 }
429
430 /* terminate linkgroup abnormally */
431 static void __smc_lgr_terminate(struct smc_link_group *lgr)
432 {
433         struct smc_connection *conn;
434         struct smc_sock *smc;
435         struct rb_node *node;
436
437         if (lgr->terminating)
438                 return; /* lgr already terminating */
439         lgr->terminating = 1;
440         if (!list_empty(&lgr->list)) /* forget lgr */
441                 list_del_init(&lgr->list);
442         if (!lgr->is_smcd)
443                 smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
444
445         write_lock_bh(&lgr->conns_lock);
446         node = rb_first(&lgr->conns_all);
447         while (node) {
448                 conn = rb_entry(node, struct smc_connection, alert_node);
449                 smc = container_of(conn, struct smc_sock, conn);
450                 sock_hold(&smc->sk); /* sock_put in close work */
451                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
452                 __smc_lgr_unregister_conn(conn);
453                 write_unlock_bh(&lgr->conns_lock);
454                 if (!schedule_work(&conn->close_work))
455                         sock_put(&smc->sk);
456                 write_lock_bh(&lgr->conns_lock);
457                 node = rb_first(&lgr->conns_all);
458         }
459         write_unlock_bh(&lgr->conns_lock);
460         if (!lgr->is_smcd)
461                 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
462         smc_lgr_schedule_free_work(lgr);
463 }
464
465 void smc_lgr_terminate(struct smc_link_group *lgr)
466 {
467         spin_lock_bh(&smc_lgr_list.lock);
468         __smc_lgr_terminate(lgr);
469         spin_unlock_bh(&smc_lgr_list.lock);
470 }
471
472 /* Called when IB port is terminated */
473 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
474 {
475         struct smc_link_group *lgr, *l;
476
477         spin_lock_bh(&smc_lgr_list.lock);
478         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
479                 if (!lgr->is_smcd &&
480                     lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
481                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
482                         __smc_lgr_terminate(lgr);
483         }
484         spin_unlock_bh(&smc_lgr_list.lock);
485 }
486
487 /* Called when SMC-D device is terminated or peer is lost */
488 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid)
489 {
490         struct smc_link_group *lgr, *l;
491         LIST_HEAD(lgr_free_list);
492
493         /* run common cleanup function and build free list */
494         spin_lock_bh(&smc_lgr_list.lock);
495         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
496                 if (lgr->is_smcd && lgr->smcd == dev &&
497                     (!peer_gid || lgr->peer_gid == peer_gid) &&
498                     !list_empty(&lgr->list)) {
499                         __smc_lgr_terminate(lgr);
500                         list_move(&lgr->list, &lgr_free_list);
501                 }
502         }
503         spin_unlock_bh(&smc_lgr_list.lock);
504
505         /* cancel the regular free workers and actually free lgrs */
506         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
507                 list_del_init(&lgr->list);
508                 cancel_delayed_work_sync(&lgr->free_work);
509                 smc_lgr_free(lgr);
510         }
511 }
512
513 /* Determine vlan of internal TCP socket.
514  * @vlan_id: address to store the determined vlan id into
515  */
516 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
517 {
518         struct dst_entry *dst = sk_dst_get(clcsock->sk);
519         struct net_device *ndev;
520         int i, nest_lvl, rc = 0;
521
522         *vlan_id = 0;
523         if (!dst) {
524                 rc = -ENOTCONN;
525                 goto out;
526         }
527         if (!dst->dev) {
528                 rc = -ENODEV;
529                 goto out_rel;
530         }
531
532         ndev = dst->dev;
533         if (is_vlan_dev(ndev)) {
534                 *vlan_id = vlan_dev_vlan_id(ndev);
535                 goto out_rel;
536         }
537
538         rtnl_lock();
539         nest_lvl = dev_get_nest_level(ndev);
540         for (i = 0; i < nest_lvl; i++) {
541                 struct list_head *lower = &ndev->adj_list.lower;
542
543                 if (list_empty(lower))
544                         break;
545                 lower = lower->next;
546                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
547                 if (is_vlan_dev(ndev)) {
548                         *vlan_id = vlan_dev_vlan_id(ndev);
549                         break;
550                 }
551         }
552         rtnl_unlock();
553
554 out_rel:
555         dst_release(dst);
556 out:
557         return rc;
558 }
559
560 static bool smcr_lgr_match(struct smc_link_group *lgr,
561                            struct smc_clc_msg_local *lcl,
562                            enum smc_lgr_role role)
563 {
564         return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
565                        SMC_SYSTEMID_LEN) &&
566                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
567                         SMC_GID_SIZE) &&
568                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
569                         sizeof(lcl->mac)) &&
570                 lgr->role == role;
571 }
572
573 static bool smcd_lgr_match(struct smc_link_group *lgr,
574                            struct smcd_dev *smcismdev, u64 peer_gid)
575 {
576         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
577 }
578
579 /* create a new SMC connection (and a new link group if necessary) */
580 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
581                     struct smc_ib_device *smcibdev, u8 ibport,
582                     struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
583                     u64 peer_gid)
584 {
585         struct smc_connection *conn = &smc->conn;
586         int local_contact = SMC_FIRST_CONTACT;
587         struct smc_link_group *lgr;
588         unsigned short vlan_id;
589         enum smc_lgr_role role;
590         int rc = 0;
591
592         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
593         rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
594         if (rc)
595                 return rc;
596
597         if ((role == SMC_CLNT) && srv_first_contact)
598                 /* create new link group as well */
599                 goto create;
600
601         /* determine if an existing link group can be reused */
602         spin_lock_bh(&smc_lgr_list.lock);
603         list_for_each_entry(lgr, &smc_lgr_list.list, list) {
604                 write_lock_bh(&lgr->conns_lock);
605                 if ((is_smcd ? smcd_lgr_match(lgr, smcd, peer_gid) :
606                      smcr_lgr_match(lgr, lcl, role)) &&
607                     !lgr->sync_err &&
608                     lgr->vlan_id == vlan_id &&
609                     (role == SMC_CLNT ||
610                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
611                         /* link group found */
612                         local_contact = SMC_REUSE_CONTACT;
613                         conn->lgr = lgr;
614                         smc_lgr_register_conn(conn); /* add smc conn to lgr */
615                         write_unlock_bh(&lgr->conns_lock);
616                         break;
617                 }
618                 write_unlock_bh(&lgr->conns_lock);
619         }
620         spin_unlock_bh(&smc_lgr_list.lock);
621
622         if (role == SMC_CLNT && !srv_first_contact &&
623             (local_contact == SMC_FIRST_CONTACT)) {
624                 /* Server reuses a link group, but Client wants to start
625                  * a new one
626                  * send out_of_sync decline, reason synchr. error
627                  */
628                 return -ENOLINK;
629         }
630
631 create:
632         if (local_contact == SMC_FIRST_CONTACT) {
633                 rc = smc_lgr_create(smc, is_smcd, smcibdev, ibport,
634                                     lcl->id_for_peer, vlan_id, smcd, peer_gid);
635                 if (rc)
636                         goto out;
637                 smc_lgr_register_conn(conn); /* add smc conn to lgr */
638         }
639         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
640         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
641         conn->urg_state = SMC_URG_READ;
642         if (is_smcd) {
643                 conn->rx_off = sizeof(struct smcd_cdc_msg);
644                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
645         }
646 #ifndef KERNEL_HAS_ATOMIC64
647         spin_lock_init(&conn->acurs_lock);
648 #endif
649
650 out:
651         return rc ? rc : local_contact;
652 }
653
654 /* convert the RMB size into the compressed notation - minimum 16K.
655  * In contrast to plain ilog2, this rounds towards the next power of 2,
656  * so the socket application gets at least its desired sndbuf / rcvbuf size.
657  */
658 static u8 smc_compress_bufsize(int size)
659 {
660         u8 compressed;
661
662         if (size <= SMC_BUF_MIN_SIZE)
663                 return 0;
664
665         size = (size - 1) >> 14;
666         compressed = ilog2(size) + 1;
667         if (compressed >= SMC_RMBE_SIZES)
668                 compressed = SMC_RMBE_SIZES - 1;
669         return compressed;
670 }
671
672 /* convert the RMB size from compressed notation into integer */
673 int smc_uncompress_bufsize(u8 compressed)
674 {
675         u32 size;
676
677         size = 0x00000001 << (((int)compressed) + 14);
678         return (int)size;
679 }
680
681 /* try to reuse a sndbuf or rmb description slot for a certain
682  * buffer size; if not available, return NULL
683  */
684 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
685                                              rwlock_t *lock,
686                                              struct list_head *buf_list)
687 {
688         struct smc_buf_desc *buf_slot;
689
690         read_lock_bh(lock);
691         list_for_each_entry(buf_slot, buf_list, list) {
692                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
693                         read_unlock_bh(lock);
694                         return buf_slot;
695                 }
696         }
697         read_unlock_bh(lock);
698         return NULL;
699 }
700
701 /* one of the conditions for announcing a receiver's current window size is
702  * that it "results in a minimum increase in the window size of 10% of the
703  * receive buffer space" [RFC7609]
704  */
705 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
706 {
707         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
708 }
709
710 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
711                                                 bool is_rmb, int bufsize)
712 {
713         struct smc_buf_desc *buf_desc;
714         struct smc_link *lnk;
715         int rc;
716
717         /* try to alloc a new buffer */
718         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
719         if (!buf_desc)
720                 return ERR_PTR(-ENOMEM);
721
722         buf_desc->order = get_order(bufsize);
723         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
724                                       __GFP_NOMEMALLOC | __GFP_COMP |
725                                       __GFP_NORETRY | __GFP_ZERO,
726                                       buf_desc->order);
727         if (!buf_desc->pages) {
728                 kfree(buf_desc);
729                 return ERR_PTR(-EAGAIN);
730         }
731         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
732
733         /* build the sg table from the pages */
734         lnk = &lgr->lnk[SMC_SINGLE_LINK];
735         rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
736                             GFP_KERNEL);
737         if (rc) {
738                 smc_buf_free(lgr, is_rmb, buf_desc);
739                 return ERR_PTR(rc);
740         }
741         sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
742                    buf_desc->cpu_addr, bufsize);
743
744         /* map sg table to DMA address */
745         rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
746                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
747         /* SMC protocol depends on mapping to one DMA address only */
748         if (rc != 1)  {
749                 smc_buf_free(lgr, is_rmb, buf_desc);
750                 return ERR_PTR(-EAGAIN);
751         }
752
753         /* create a new memory region for the RMB */
754         if (is_rmb) {
755                 rc = smc_ib_get_memory_region(lnk->roce_pd,
756                                               IB_ACCESS_REMOTE_WRITE |
757                                               IB_ACCESS_LOCAL_WRITE,
758                                               buf_desc);
759                 if (rc) {
760                         smc_buf_free(lgr, is_rmb, buf_desc);
761                         return ERR_PTR(rc);
762                 }
763         }
764
765         buf_desc->len = bufsize;
766         return buf_desc;
767 }
768
769 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
770
771 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
772                                                 bool is_dmb, int bufsize)
773 {
774         struct smc_buf_desc *buf_desc;
775         int rc;
776
777         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
778                 return ERR_PTR(-EAGAIN);
779
780         /* try to alloc a new DMB */
781         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
782         if (!buf_desc)
783                 return ERR_PTR(-ENOMEM);
784         if (is_dmb) {
785                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
786                 if (rc) {
787                         kfree(buf_desc);
788                         return ERR_PTR(-EAGAIN);
789                 }
790                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
791                 /* CDC header stored in buf. So, pretend it was smaller */
792                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
793         } else {
794                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
795                                              __GFP_NOWARN | __GFP_NORETRY |
796                                              __GFP_NOMEMALLOC);
797                 if (!buf_desc->cpu_addr) {
798                         kfree(buf_desc);
799                         return ERR_PTR(-EAGAIN);
800                 }
801                 buf_desc->len = bufsize;
802         }
803         return buf_desc;
804 }
805
806 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
807 {
808         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
809         struct smc_connection *conn = &smc->conn;
810         struct smc_link_group *lgr = conn->lgr;
811         struct list_head *buf_list;
812         int bufsize, bufsize_short;
813         int sk_buf_size;
814         rwlock_t *lock;
815
816         if (is_rmb)
817                 /* use socket recv buffer size (w/o overhead) as start value */
818                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
819         else
820                 /* use socket send buffer size (w/o overhead) as start value */
821                 sk_buf_size = smc->sk.sk_sndbuf / 2;
822
823         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
824              bufsize_short >= 0; bufsize_short--) {
825
826                 if (is_rmb) {
827                         lock = &lgr->rmbs_lock;
828                         buf_list = &lgr->rmbs[bufsize_short];
829                 } else {
830                         lock = &lgr->sndbufs_lock;
831                         buf_list = &lgr->sndbufs[bufsize_short];
832                 }
833                 bufsize = smc_uncompress_bufsize(bufsize_short);
834                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
835                         continue;
836
837                 /* check for reusable slot in the link group */
838                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
839                 if (buf_desc) {
840                         memset(buf_desc->cpu_addr, 0, bufsize);
841                         break; /* found reusable slot */
842                 }
843
844                 if (is_smcd)
845                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
846                 else
847                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
848
849                 if (PTR_ERR(buf_desc) == -ENOMEM)
850                         break;
851                 if (IS_ERR(buf_desc))
852                         continue;
853
854                 buf_desc->used = 1;
855                 write_lock_bh(lock);
856                 list_add(&buf_desc->list, buf_list);
857                 write_unlock_bh(lock);
858                 break; /* found */
859         }
860
861         if (IS_ERR(buf_desc))
862                 return -ENOMEM;
863
864         if (is_rmb) {
865                 conn->rmb_desc = buf_desc;
866                 conn->rmbe_size_short = bufsize_short;
867                 smc->sk.sk_rcvbuf = bufsize * 2;
868                 atomic_set(&conn->bytes_to_rcv, 0);
869                 conn->rmbe_update_limit =
870                         smc_rmb_wnd_update_limit(buf_desc->len);
871                 if (is_smcd)
872                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
873         } else {
874                 conn->sndbuf_desc = buf_desc;
875                 smc->sk.sk_sndbuf = bufsize * 2;
876                 atomic_set(&conn->sndbuf_space, bufsize);
877         }
878         return 0;
879 }
880
881 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
882 {
883         struct smc_link_group *lgr = conn->lgr;
884
885         if (!conn->lgr || conn->lgr->is_smcd)
886                 return;
887         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
888                                conn->sndbuf_desc, DMA_TO_DEVICE);
889 }
890
891 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
892 {
893         struct smc_link_group *lgr = conn->lgr;
894
895         if (!conn->lgr || conn->lgr->is_smcd)
896                 return;
897         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
898                                   conn->sndbuf_desc, DMA_TO_DEVICE);
899 }
900
901 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
902 {
903         struct smc_link_group *lgr = conn->lgr;
904
905         if (!conn->lgr || conn->lgr->is_smcd)
906                 return;
907         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
908                                conn->rmb_desc, DMA_FROM_DEVICE);
909 }
910
911 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
912 {
913         struct smc_link_group *lgr = conn->lgr;
914
915         if (!conn->lgr || conn->lgr->is_smcd)
916                 return;
917         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
918                                   conn->rmb_desc, DMA_FROM_DEVICE);
919 }
920
921 /* create the send and receive buffer for an SMC socket;
922  * receive buffers are called RMBs;
923  * (even though the SMC protocol allows more than one RMB-element per RMB,
924  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
925  * extra RMB for every connection in a link group
926  */
927 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
928 {
929         int rc;
930
931         /* create send buffer */
932         rc = __smc_buf_create(smc, is_smcd, false);
933         if (rc)
934                 return rc;
935         /* create rmb */
936         rc = __smc_buf_create(smc, is_smcd, true);
937         if (rc)
938                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
939         return rc;
940 }
941
942 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
943 {
944         int i;
945
946         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
947                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
948                         return i;
949         }
950         return -ENOSPC;
951 }
952
953 /* add a new rtoken from peer */
954 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
955 {
956         u64 dma_addr = be64_to_cpu(nw_vaddr);
957         u32 rkey = ntohl(nw_rkey);
958         int i;
959
960         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
961                 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
962                     (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
963                     test_bit(i, lgr->rtokens_used_mask)) {
964                         /* already in list */
965                         return i;
966                 }
967         }
968         i = smc_rmb_reserve_rtoken_idx(lgr);
969         if (i < 0)
970                 return i;
971         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
972         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
973         return i;
974 }
975
976 /* delete an rtoken */
977 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
978 {
979         u32 rkey = ntohl(nw_rkey);
980         int i;
981
982         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
983                 if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
984                     test_bit(i, lgr->rtokens_used_mask)) {
985                         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
986                         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
987
988                         clear_bit(i, lgr->rtokens_used_mask);
989                         return 0;
990                 }
991         }
992         return -ENOENT;
993 }
994
995 /* save rkey and dma_addr received from peer during clc handshake */
996 int smc_rmb_rtoken_handling(struct smc_connection *conn,
997                             struct smc_clc_msg_accept_confirm *clc)
998 {
999         conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1000                                           clc->rmb_rkey);
1001         if (conn->rtoken_idx < 0)
1002                 return conn->rtoken_idx;
1003         return 0;
1004 }
1005
1006 /* Called (from smc_exit) when module is removed */
1007 void smc_core_exit(void)
1008 {
1009         struct smc_link_group *lgr, *lg;
1010         LIST_HEAD(lgr_freeing_list);
1011
1012         spin_lock_bh(&smc_lgr_list.lock);
1013         if (!list_empty(&smc_lgr_list.list))
1014                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1015         spin_unlock_bh(&smc_lgr_list.lock);
1016         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1017                 list_del_init(&lgr->list);
1018                 if (!lgr->is_smcd) {
1019                         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
1020
1021                         if (lnk->state == SMC_LNK_ACTIVE)
1022                                 smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
1023                                                          false);
1024                         smc_llc_link_inactive(lnk);
1025                 }
1026                 cancel_delayed_work_sync(&lgr->free_work);
1027                 smc_lgr_free(lgr); /* free link group */
1028         }
1029 }