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 and trigger lgr freeing if applicable
 126  */
 127 static void smc_lgr_unregister_conn(struct smc_connection *conn)
 128 {
 129         struct smc_link_group *lgr = conn->lgr;
 130         int reduced = 0;
 131
 132         write_lock_bh(&lgr->conns_lock);
 133         if (conn->alert_token_local) {
 134                 reduced = 1;
 135                 __smc_lgr_unregister_conn(conn);
 136         }
 137         write_unlock_bh(&lgr->conns_lock);
 138         if (!reduced || lgr->conns_num)
 139                 return;
 140         smc_lgr_schedule_free_work(lgr);
 141 }
 142
 143 /* Send delete link, either as client to request the initiation
 144  * of the DELETE LINK sequence from server; or as server to
 145  * initiate the delete processing. See smc_llc_rx_delete_link().
 146  */
 147 static int smc_link_send_delete(struct smc_link *lnk)
 148 {
 149         if (lnk->state == SMC_LNK_ACTIVE &&
 150             !smc_llc_send_delete_link(lnk, SMC_LLC_REQ, true)) {
 151                 smc_llc_link_deleting(lnk);
 152                 return 0;
 153         }
 154         return -ENOTCONN;
 155 }
 156
 157 static void smc_lgr_free_work(struct work_struct *work)
 158 {
 159         struct smc_link_group *lgr = container_of(to_delayed_work(work),
 160                                                   struct smc_link_group,
 161                                                   free_work);
 162         bool conns;
 163
 164         spin_lock_bh(&smc_lgr_list.lock);
 165         if (list_empty(&lgr->list))
 166                 goto free;
 167         read_lock_bh(&lgr->conns_lock);
 168         conns = RB_EMPTY_ROOT(&lgr->conns_all);
 169         read_unlock_bh(&lgr->conns_lock);
 170         if (!conns) { /* number of lgr connections is no longer zero */
 171                 spin_unlock_bh(&smc_lgr_list.lock);
 172                 return;
 173         }
 174         list_del_init(&lgr->list); /* remove from smc_lgr_list */
 175 free:
 176         spin_unlock_bh(&smc_lgr_list.lock);
 177
 178         if (!lgr->is_smcd && !lgr->terminating) {
 179                 /* try to send del link msg, on error free lgr immediately */
 180                 if (!smc_link_send_delete(&lgr->lnk[SMC_SINGLE_LINK])) {
 181                         /* reschedule in case we never receive a response */
 182                         smc_lgr_schedule_free_work(lgr);
 183                         return;
 184                 }
 185         }
 186
 187         if (!delayed_work_pending(&lgr->free_work)) {
 188                 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 189
 190                 if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
 191                         smc_llc_link_inactive(lnk);
 192                 smc_lgr_free(lgr);
 193         }
 194 }
 195
 196 /* create a new SMC link group */
 197 static int smc_lgr_create(struct smc_sock *smc, bool is_smcd,
 198                           struct smc_ib_device *smcibdev, u8 ibport,
 199                           char *peer_systemid, unsigned short vlan_id,
 200                           struct smcd_dev *smcismdev, u64 peer_gid)
 201 {
 202         struct smc_link_group *lgr;
 203         struct smc_link *lnk;
 204         u8 rndvec[3];
 205         int rc = 0;
 206         int i;
 207
 208         if (is_smcd && vlan_id) {
 209                 rc = smc_ism_get_vlan(smcismdev, vlan_id);
 210                 if (rc)
 211                         goto out;
 212         }
 213
 214         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 215         if (!lgr) {
 216                 rc = -ENOMEM;
 217                 goto out;
 218         }
 219         lgr->is_smcd = is_smcd;
 220         lgr->sync_err = 0;
 221         lgr->vlan_id = vlan_id;
 222         rwlock_init(&lgr->sndbufs_lock);
 223         rwlock_init(&lgr->rmbs_lock);
 224         rwlock_init(&lgr->conns_lock);
 225         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 226                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 227                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 228         }
 229         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 230         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 231         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 232         lgr->conns_all = RB_ROOT;
 233         if (is_smcd) {
 234                 /* SMC-D specific settings */
 235                 lgr->peer_gid = peer_gid;
 236                 lgr->smcd = smcismdev;
 237         } else {
 238                 /* SMC-R specific settings */
 239                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 240                 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
 241
 242                 lnk = &lgr->lnk[SMC_SINGLE_LINK];
 243                 /* initialize link */
 244                 lnk->state = SMC_LNK_ACTIVATING;
 245                 lnk->link_id = SMC_SINGLE_LINK;
 246                 lnk->smcibdev = smcibdev;
 247                 lnk->ibport = ibport;
 248                 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
 249                 if (!smcibdev->initialized)
 250                         smc_ib_setup_per_ibdev(smcibdev);
 251                 get_random_bytes(rndvec, sizeof(rndvec));
 252                 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 253                         (rndvec[2] << 16);
 254                 rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 255                                           vlan_id, lnk->gid, &lnk->sgid_index);
 256                 if (rc)
 257                         goto free_lgr;
 258                 rc = smc_llc_link_init(lnk);
 259                 if (rc)
 260                         goto free_lgr;
 261                 rc = smc_wr_alloc_link_mem(lnk);
 262                 if (rc)
 263                         goto clear_llc_lnk;
 264                 rc = smc_ib_create_protection_domain(lnk);
 265                 if (rc)
 266                         goto free_link_mem;
 267                 rc = smc_ib_create_queue_pair(lnk);
 268                 if (rc)
 269                         goto dealloc_pd;
 270                 rc = smc_wr_create_link(lnk);
 271                 if (rc)
 272                         goto destroy_qp;
 273         }
 274         smc->conn.lgr = lgr;
 275         spin_lock_bh(&smc_lgr_list.lock);
 276         list_add(&lgr->list, &smc_lgr_list.list);
 277         spin_unlock_bh(&smc_lgr_list.lock);
 278         return 0;
 279
 280 destroy_qp:
 281         smc_ib_destroy_queue_pair(lnk);
 282 dealloc_pd:
 283         smc_ib_dealloc_protection_domain(lnk);
 284 free_link_mem:
 285         smc_wr_free_link_mem(lnk);
 286 clear_llc_lnk:
 287         smc_llc_link_clear(lnk);
 288 free_lgr:
 289         kfree(lgr);
 290 out:
 291         return rc;
 292 }
 293
 294 static void smc_buf_unuse(struct smc_connection *conn)
 295 {
 296         if (conn->sndbuf_desc)
 297                 conn->sndbuf_desc->used = 0;
 298         if (conn->rmb_desc) {
 299                 if (!conn->rmb_desc->regerr) {
 300                         conn->rmb_desc->reused = 1;
 301                         conn->rmb_desc->used = 0;
 302                 } else {
 303                         /* buf registration failed, reuse not possible */
 304                         struct smc_link_group *lgr = conn->lgr;
 305
 306                         write_lock_bh(&lgr->rmbs_lock);
 307                         list_del(&conn->rmb_desc->list);
 308                         write_unlock_bh(&lgr->rmbs_lock);
 309
 310                         smc_buf_free(lgr, true, conn->rmb_desc);
 311                 }
 312         }
 313 }
 314
 315 /* remove a finished connection from its link group */
 316 void smc_conn_free(struct smc_connection *conn)
 317 {
 318         if (!conn->lgr)
 319                 return;
 320         if (conn->lgr->is_smcd) {
 321                 smc_ism_unset_conn(conn);
 322                 tasklet_kill(&conn->rx_tsklet);
 323         } else {
 324                 smc_cdc_tx_dismiss_slots(conn);
 325         }
 326         smc_lgr_unregister_conn(conn);
 327         smc_buf_unuse(conn);
 328 }
 329
 330 static void smc_link_clear(struct smc_link *lnk)
 331 {
 332         lnk->peer_qpn = 0;
 333         smc_llc_link_clear(lnk);
 334         smc_ib_modify_qp_reset(lnk);
 335         smc_wr_free_link(lnk);
 336         smc_ib_destroy_queue_pair(lnk);
 337         smc_ib_dealloc_protection_domain(lnk);
 338         smc_wr_free_link_mem(lnk);
 339 }
 340
 341 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
 342                           struct smc_buf_desc *buf_desc)
 343 {
 344         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 345
 346         if (is_rmb) {
 347                 if (buf_desc->mr_rx[SMC_SINGLE_LINK])
 348                         smc_ib_put_memory_region(
 349                                         buf_desc->mr_rx[SMC_SINGLE_LINK]);
 350                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 351                                     DMA_FROM_DEVICE);
 352         } else {
 353                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 354                                     DMA_TO_DEVICE);
 355         }
 356         sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
 357         if (buf_desc->pages)
 358                 __free_pages(buf_desc->pages, buf_desc->order);
 359         kfree(buf_desc);
 360 }
 361
 362 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
 363                           struct smc_buf_desc *buf_desc)
 364 {
 365         if (is_dmb) {
 366                 /* restore original buf len */
 367                 buf_desc->len += sizeof(struct smcd_cdc_msg);
 368                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
 369         } else {
 370                 kfree(buf_desc->cpu_addr);
 371         }
 372         kfree(buf_desc);
 373 }
 374
 375 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
 376                          struct smc_buf_desc *buf_desc)
 377 {
 378         if (lgr->is_smcd)
 379                 smcd_buf_free(lgr, is_rmb, buf_desc);
 380         else
 381                 smcr_buf_free(lgr, is_rmb, buf_desc);
 382 }
 383
 384 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
 385 {
 386         struct smc_buf_desc *buf_desc, *bf_desc;
 387         struct list_head *buf_list;
 388         int i;
 389
 390         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 391                 if (is_rmb)
 392                         buf_list = &lgr->rmbs[i];
 393                 else
 394                         buf_list = &lgr->sndbufs[i];
 395                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
 396                                          list) {
 397                         list_del(&buf_desc->list);
 398                         smc_buf_free(lgr, is_rmb, buf_desc);
 399                 }
 400         }
 401 }
 402
 403 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
 404 {
 405         /* free send buffers */
 406         __smc_lgr_free_bufs(lgr, false);
 407         /* free rmbs */
 408         __smc_lgr_free_bufs(lgr, true);
 409 }
 410
 411 /* remove a link group */
 412 void smc_lgr_free(struct smc_link_group *lgr)
 413 {
 414         smc_lgr_free_bufs(lgr);
 415         if (lgr->is_smcd)
 416                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 417         else
 418                 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
 419         kfree(lgr);
 420 }
 421
 422 void smc_lgr_forget(struct smc_link_group *lgr)
 423 {
 424         spin_lock_bh(&smc_lgr_list.lock);
 425         /* do not use this link group for new connections */
 426         if (!list_empty(&lgr->list))
 427                 list_del_init(&lgr->list);
 428         spin_unlock_bh(&smc_lgr_list.lock);
 429 }
 430
 431 /* terminate linkgroup abnormally */
 432 static void __smc_lgr_terminate(struct smc_link_group *lgr)
 433 {
 434         struct smc_connection *conn;
 435         struct smc_sock *smc;
 436         struct rb_node *node;
 437
 438         if (lgr->terminating)
 439                 return; /* lgr already terminating */
 440         lgr->terminating = 1;
 441         if (!list_empty(&lgr->list)) /* forget lgr */
 442                 list_del_init(&lgr->list);
 443         if (!lgr->is_smcd)
 444                 smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
 445
 446         write_lock_bh(&lgr->conns_lock);
 447         node = rb_first(&lgr->conns_all);
 448         while (node) {
 449                 conn = rb_entry(node, struct smc_connection, alert_node);
 450                 smc = container_of(conn, struct smc_sock, conn);
 451                 sock_hold(&smc->sk); /* sock_put in close work */
 452                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 453                 __smc_lgr_unregister_conn(conn);
 454                 write_unlock_bh(&lgr->conns_lock);
 455                 if (!schedule_work(&conn->close_work))
 456                         sock_put(&smc->sk);
 457                 write_lock_bh(&lgr->conns_lock);
 458                 node = rb_first(&lgr->conns_all);
 459         }
 460         write_unlock_bh(&lgr->conns_lock);
 461         if (!lgr->is_smcd)
 462                 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
 463         smc_lgr_schedule_free_work(lgr);
 464 }
 465
 466 void smc_lgr_terminate(struct smc_link_group *lgr)
 467 {
 468         spin_lock_bh(&smc_lgr_list.lock);
 469         __smc_lgr_terminate(lgr);
 470         spin_unlock_bh(&smc_lgr_list.lock);
 471 }
 472
 473 /* Called when IB port is terminated */
 474 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 475 {
 476         struct smc_link_group *lgr, *l;
 477
 478         spin_lock_bh(&smc_lgr_list.lock);
 479         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 480                 if (!lgr->is_smcd &&
 481                     lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 482                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 483                         __smc_lgr_terminate(lgr);
 484         }
 485         spin_unlock_bh(&smc_lgr_list.lock);
 486 }
 487
 488 /* Called when SMC-D device is terminated or peer is lost */
 489 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid)
 490 {
 491         struct smc_link_group *lgr, *l;
 492         LIST_HEAD(lgr_free_list);
 493
 494         /* run common cleanup function and build free list */
 495         spin_lock_bh(&smc_lgr_list.lock);
 496         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 497                 if (lgr->is_smcd && lgr->smcd == dev &&
 498                     (!peer_gid || lgr->peer_gid == peer_gid) &&
 499                     !list_empty(&lgr->list)) {
 500                         __smc_lgr_terminate(lgr);
 501                         list_move(&lgr->list, &lgr_free_list);
 502                 }
 503         }
 504         spin_unlock_bh(&smc_lgr_list.lock);
 505
 506         /* cancel the regular free workers and actually free lgrs */
 507         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 508                 list_del_init(&lgr->list);
 509                 cancel_delayed_work_sync(&lgr->free_work);
 510                 smc_lgr_free(lgr);
 511         }
 512 }
 513
 514 /* Determine vlan of internal TCP socket.
 515  * @vlan_id: address to store the determined vlan id into
 516  */
 517 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
 518 {
 519         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 520         struct net_device *ndev;
 521         int i, nest_lvl, rc = 0;
 522
 523         *vlan_id = 0;
 524         if (!dst) {
 525                 rc = -ENOTCONN;
 526                 goto out;
 527         }
 528         if (!dst->dev) {
 529                 rc = -ENODEV;
 530                 goto out_rel;
 531         }
 532
 533         ndev = dst->dev;
 534         if (is_vlan_dev(ndev)) {
 535                 *vlan_id = vlan_dev_vlan_id(ndev);
 536                 goto out_rel;
 537         }
 538
 539         rtnl_lock();
 540         nest_lvl = dev_get_nest_level(ndev);
 541         for (i = 0; i < nest_lvl; i++) {
 542                 struct list_head *lower = &ndev->adj_list.lower;
 543
 544                 if (list_empty(lower))
 545                         break;
 546                 lower = lower->next;
 547                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
 548                 if (is_vlan_dev(ndev)) {
 549                         *vlan_id = vlan_dev_vlan_id(ndev);
 550                         break;
 551                 }
 552         }
 553         rtnl_unlock();
 554
 555 out_rel:
 556         dst_release(dst);
 557 out:
 558         return rc;
 559 }
 560
 561 static bool smcr_lgr_match(struct smc_link_group *lgr,
 562                            struct smc_clc_msg_local *lcl,
 563                            enum smc_lgr_role role)
 564 {
 565         return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
 566                        SMC_SYSTEMID_LEN) &&
 567                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
 568                         SMC_GID_SIZE) &&
 569                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
 570                         sizeof(lcl->mac)) &&
 571                 lgr->role == role;
 572 }
 573
 574 static bool smcd_lgr_match(struct smc_link_group *lgr,
 575                            struct smcd_dev *smcismdev, u64 peer_gid)
 576 {
 577         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
 578 }
 579
 580 /* create a new SMC connection (and a new link group if necessary) */
 581 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
 582                     struct smc_ib_device *smcibdev, u8 ibport,
 583                     struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
 584                     u64 peer_gid)
 585 {
 586         struct smc_connection *conn = &smc->conn;
 587         int local_contact = SMC_FIRST_CONTACT;
 588         struct smc_link_group *lgr;
 589         unsigned short vlan_id;
 590         enum smc_lgr_role role;
 591         int rc = 0;
 592
 593         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 594         rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
 595         if (rc)
 596                 return rc;
 597
 598         if ((role == SMC_CLNT) && srv_first_contact)
 599                 /* create new link group as well */
 600                 goto create;
 601
 602         /* determine if an existing link group can be reused */
 603         spin_lock_bh(&smc_lgr_list.lock);
 604         list_for_each_entry(lgr, &smc_lgr_list.list, list) {
 605                 write_lock_bh(&lgr->conns_lock);
 606                 if ((is_smcd ? smcd_lgr_match(lgr, smcd, peer_gid) :
 607                      smcr_lgr_match(lgr, lcl, role)) &&
 608                     !lgr->sync_err &&
 609                     lgr->vlan_id == vlan_id &&
 610                     (role == SMC_CLNT ||
 611                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
 612                         /* link group found */
 613                         local_contact = SMC_REUSE_CONTACT;
 614                         conn->lgr = lgr;
 615                         smc_lgr_register_conn(conn); /* add smc conn to lgr */
 616                         write_unlock_bh(&lgr->conns_lock);
 617                         break;
 618                 }
 619                 write_unlock_bh(&lgr->conns_lock);
 620         }
 621         spin_unlock_bh(&smc_lgr_list.lock);
 622
 623         if (role == SMC_CLNT && !srv_first_contact &&
 624             (local_contact == SMC_FIRST_CONTACT)) {
 625                 /* Server reuses a link group, but Client wants to start
 626                  * a new one
 627                  * send out_of_sync decline, reason synchr. error
 628                  */
 629                 return -ENOLINK;
 630         }
 631
 632 create:
 633         if (local_contact == SMC_FIRST_CONTACT) {
 634                 rc = smc_lgr_create(smc, is_smcd, smcibdev, ibport,
 635                                     lcl->id_for_peer, vlan_id, smcd, peer_gid);
 636                 if (rc)
 637                         goto out;
 638                 smc_lgr_register_conn(conn); /* add smc conn to lgr */
 639         }
 640         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
 641         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
 642         conn->urg_state = SMC_URG_READ;
 643         if (is_smcd) {
 644                 conn->rx_off = sizeof(struct smcd_cdc_msg);
 645                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
 646         }
 647 #ifndef KERNEL_HAS_ATOMIC64
 648         spin_lock_init(&conn->acurs_lock);
 649 #endif
 650
 651 out:
 652         return rc ? rc : local_contact;
 653 }
 654
 655 /* convert the RMB size into the compressed notation - minimum 16K.
 656  * In contrast to plain ilog2, this rounds towards the next power of 2,
 657  * so the socket application gets at least its desired sndbuf / rcvbuf size.
 658  */
 659 static u8 smc_compress_bufsize(int size)
 660 {
 661         u8 compressed;
 662
 663         if (size <= SMC_BUF_MIN_SIZE)
 664                 return 0;
 665
 666         size = (size - 1) >> 14;
 667         compressed = ilog2(size) + 1;
 668         if (compressed >= SMC_RMBE_SIZES)
 669                 compressed = SMC_RMBE_SIZES - 1;
 670         return compressed;
 671 }
 672
 673 /* convert the RMB size from compressed notation into integer */
 674 int smc_uncompress_bufsize(u8 compressed)
 675 {
 676         u32 size;
 677
 678         size = 0x00000001 << (((int)compressed) + 14);
 679         return (int)size;
 680 }
 681
 682 /* try to reuse a sndbuf or rmb description slot for a certain
 683  * buffer size; if not available, return NULL
 684  */
 685 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
 686                                              rwlock_t *lock,
 687                                              struct list_head *buf_list)
 688 {
 689         struct smc_buf_desc *buf_slot;
 690
 691         read_lock_bh(lock);
 692         list_for_each_entry(buf_slot, buf_list, list) {
 693                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
 694                         read_unlock_bh(lock);
 695                         return buf_slot;
 696                 }
 697         }
 698         read_unlock_bh(lock);
 699         return NULL;
 700 }
 701
 702 /* one of the conditions for announcing a receiver's current window size is
 703  * that it "results in a minimum increase in the window size of 10% of the
 704  * receive buffer space" [RFC7609]
 705  */
 706 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
 707 {
 708         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
 709 }
 710
 711 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
 712                                                 bool is_rmb, int bufsize)
 713 {
 714         struct smc_buf_desc *buf_desc;
 715         struct smc_link *lnk;
 716         int rc;
 717
 718         /* try to alloc a new buffer */
 719         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 720         if (!buf_desc)
 721                 return ERR_PTR(-ENOMEM);
 722
 723         buf_desc->order = get_order(bufsize);
 724         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
 725                                       __GFP_NOMEMALLOC | __GFP_COMP |
 726                                       __GFP_NORETRY | __GFP_ZERO,
 727                                       buf_desc->order);
 728         if (!buf_desc->pages) {
 729                 kfree(buf_desc);
 730                 return ERR_PTR(-EAGAIN);
 731         }
 732         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
 733
 734         /* build the sg table from the pages */
 735         lnk = &lgr->lnk[SMC_SINGLE_LINK];
 736         rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
 737                             GFP_KERNEL);
 738         if (rc) {
 739                 smc_buf_free(lgr, is_rmb, buf_desc);
 740                 return ERR_PTR(rc);
 741         }
 742         sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
 743                    buf_desc->cpu_addr, bufsize);
 744
 745         /* map sg table to DMA address */
 746         rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
 747                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 748         /* SMC protocol depends on mapping to one DMA address only */
 749         if (rc != 1)  {
 750                 smc_buf_free(lgr, is_rmb, buf_desc);
 751                 return ERR_PTR(-EAGAIN);
 752         }
 753
 754         /* create a new memory region for the RMB */
 755         if (is_rmb) {
 756                 rc = smc_ib_get_memory_region(lnk->roce_pd,
 757                                               IB_ACCESS_REMOTE_WRITE |
 758                                               IB_ACCESS_LOCAL_WRITE,
 759                                               buf_desc);
 760                 if (rc) {
 761                         smc_buf_free(lgr, is_rmb, buf_desc);
 762                         return ERR_PTR(rc);
 763                 }
 764         }
 765
 766         buf_desc->len = bufsize;
 767         return buf_desc;
 768 }
 769
 770 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
 771
 772 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
 773                                                 bool is_dmb, int bufsize)
 774 {
 775         struct smc_buf_desc *buf_desc;
 776         int rc;
 777
 778         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
 779                 return ERR_PTR(-EAGAIN);
 780
 781         /* try to alloc a new DMB */
 782         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 783         if (!buf_desc)
 784                 return ERR_PTR(-ENOMEM);
 785         if (is_dmb) {
 786                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
 787                 if (rc) {
 788                         kfree(buf_desc);
 789                         return ERR_PTR(-EAGAIN);
 790                 }
 791                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
 792                 /* CDC header stored in buf. So, pretend it was smaller */
 793                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
 794         } else {
 795                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
 796                                              __GFP_NOWARN | __GFP_NORETRY |
 797                                              __GFP_NOMEMALLOC);
 798                 if (!buf_desc->cpu_addr) {
 799                         kfree(buf_desc);
 800                         return ERR_PTR(-EAGAIN);
 801                 }
 802                 buf_desc->len = bufsize;
 803         }
 804         return buf_desc;
 805 }
 806
 807 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 808 {
 809         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
 810         struct smc_connection *conn = &smc->conn;
 811         struct smc_link_group *lgr = conn->lgr;
 812         struct list_head *buf_list;
 813         int bufsize, bufsize_short;
 814         int sk_buf_size;
 815         rwlock_t *lock;
 816
 817         if (is_rmb)
 818                 /* use socket recv buffer size (w/o overhead) as start value */
 819                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
 820         else
 821                 /* use socket send buffer size (w/o overhead) as start value */
 822                 sk_buf_size = smc->sk.sk_sndbuf / 2;
 823
 824         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
 825              bufsize_short >= 0; bufsize_short--) {
 826
 827                 if (is_rmb) {
 828                         lock = &lgr->rmbs_lock;
 829                         buf_list = &lgr->rmbs[bufsize_short];
 830                 } else {
 831                         lock = &lgr->sndbufs_lock;
 832                         buf_list = &lgr->sndbufs[bufsize_short];
 833                 }
 834                 bufsize = smc_uncompress_bufsize(bufsize_short);
 835                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
 836                         continue;
 837
 838                 /* check for reusable slot in the link group */
 839                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
 840                 if (buf_desc) {
 841                         memset(buf_desc->cpu_addr, 0, bufsize);
 842                         break; /* found reusable slot */
 843                 }
 844
 845                 if (is_smcd)
 846                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
 847                 else
 848                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
 849
 850                 if (PTR_ERR(buf_desc) == -ENOMEM)
 851                         break;
 852                 if (IS_ERR(buf_desc))
 853                         continue;
 854
 855                 buf_desc->used = 1;
 856                 write_lock_bh(lock);
 857                 list_add(&buf_desc->list, buf_list);
 858                 write_unlock_bh(lock);
 859                 break; /* found */
 860         }
 861
 862         if (IS_ERR(buf_desc))
 863                 return -ENOMEM;
 864
 865         if (is_rmb) {
 866                 conn->rmb_desc = buf_desc;
 867                 conn->rmbe_size_short = bufsize_short;
 868                 smc->sk.sk_rcvbuf = bufsize * 2;
 869                 atomic_set(&conn->bytes_to_rcv, 0);
 870                 conn->rmbe_update_limit =
 871                         smc_rmb_wnd_update_limit(buf_desc->len);
 872                 if (is_smcd)
 873                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
 874         } else {
 875                 conn->sndbuf_desc = buf_desc;
 876                 smc->sk.sk_sndbuf = bufsize * 2;
 877                 atomic_set(&conn->sndbuf_space, bufsize);
 878         }
 879         return 0;
 880 }
 881
 882 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
 883 {
 884         struct smc_link_group *lgr = conn->lgr;
 885
 886         if (!conn->lgr || conn->lgr->is_smcd)
 887                 return;
 888         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 889                                conn->sndbuf_desc, DMA_TO_DEVICE);
 890 }
 891
 892 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
 893 {
 894         struct smc_link_group *lgr = conn->lgr;
 895
 896         if (!conn->lgr || conn->lgr->is_smcd)
 897                 return;
 898         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 899                                   conn->sndbuf_desc, DMA_TO_DEVICE);
 900 }
 901
 902 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
 903 {
 904         struct smc_link_group *lgr = conn->lgr;
 905
 906         if (!conn->lgr || conn->lgr->is_smcd)
 907                 return;
 908         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 909                                conn->rmb_desc, DMA_FROM_DEVICE);
 910 }
 911
 912 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
 913 {
 914         struct smc_link_group *lgr = conn->lgr;
 915
 916         if (!conn->lgr || conn->lgr->is_smcd)
 917                 return;
 918         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 919                                   conn->rmb_desc, DMA_FROM_DEVICE);
 920 }
 921
 922 /* create the send and receive buffer for an SMC socket;
 923  * receive buffers are called RMBs;
 924  * (even though the SMC protocol allows more than one RMB-element per RMB,
 925  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
 926  * extra RMB for every connection in a link group
 927  */
 928 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
 929 {
 930         int rc;
 931
 932         /* create send buffer */
 933         rc = __smc_buf_create(smc, is_smcd, false);
 934         if (rc)
 935                 return rc;
 936         /* create rmb */
 937         rc = __smc_buf_create(smc, is_smcd, true);
 938         if (rc)
 939                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
 940         return rc;
 941 }
 942
 943 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
 944 {
 945         int i;
 946
 947         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
 948                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
 949                         return i;
 950         }
 951         return -ENOSPC;
 952 }
 953
 954 /* add a new rtoken from peer */
 955 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
 956 {
 957         u64 dma_addr = be64_to_cpu(nw_vaddr);
 958         u32 rkey = ntohl(nw_rkey);
 959         int i;
 960
 961         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 962                 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
 963                     (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
 964                     test_bit(i, lgr->rtokens_used_mask)) {
 965                         /* already in list */
 966                         return i;
 967                 }
 968         }
 969         i = smc_rmb_reserve_rtoken_idx(lgr);
 970         if (i < 0)
 971                 return i;
 972         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
 973         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
 974         return i;
 975 }
 976
 977 /* delete an rtoken */
 978 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
 979 {
 980         u32 rkey = ntohl(nw_rkey);
 981         int i;
 982
 983         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 984                 if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
 985                     test_bit(i, lgr->rtokens_used_mask)) {
 986                         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
 987                         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
 988
 989                         clear_bit(i, lgr->rtokens_used_mask);
 990                         return 0;
 991                 }
 992         }
 993         return -ENOENT;
 994 }
 995
 996 /* save rkey and dma_addr received from peer during clc handshake */
 997 int smc_rmb_rtoken_handling(struct smc_connection *conn,
 998                             struct smc_clc_msg_accept_confirm *clc)
 999 {
1000         conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1001                                           clc->rmb_rkey);
1002         if (conn->rtoken_idx < 0)
1003                 return conn->rtoken_idx;
1004         return 0;
1005 }
1006
1007 /* Called (from smc_exit) when module is removed */
1008 void smc_core_exit(void)
1009 {
1010         struct smc_link_group *lgr, *lg;
1011         LIST_HEAD(lgr_freeing_list);
1012
1013         spin_lock_bh(&smc_lgr_list.lock);
1014         if (!list_empty(&smc_lgr_list.list))
1015                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1016         spin_unlock_bh(&smc_lgr_list.lock);
1017         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1018                 list_del_init(&lgr->list);
1019                 if (!lgr->is_smcd) {
1020                         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
1021
1022                         if (lnk->state == SMC_LNK_ACTIVE)
1023                                 smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
1024                                                          false);
1025                         smc_llc_link_inactive(lnk);
1026                 }
1027                 cancel_delayed_work_sync(&lgr->free_work);
1028                 smc_lgr_free(lgr); /* free link group */
1029         }
1030 }