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(struct smc_link_group *lgr);
 153
 154 static void smc_lgr_free_work(struct work_struct *work)
 155 {
 156         struct smc_link_group *lgr = container_of(to_delayed_work(work),
 157                                                   struct smc_link_group,
 158                                                   free_work);
 159         bool conns;
 160
 161         spin_lock_bh(&smc_lgr_list.lock);
 162         if (list_empty(&lgr->list))
 163                 goto free;
 164         read_lock_bh(&lgr->conns_lock);
 165         conns = RB_EMPTY_ROOT(&lgr->conns_all);
 166         read_unlock_bh(&lgr->conns_lock);
 167         if (!conns) { /* number of lgr connections is no longer zero */
 168                 spin_unlock_bh(&smc_lgr_list.lock);
 169                 return;
 170         }
 171         list_del_init(&lgr->list); /* remove from smc_lgr_list */
 172 free:
 173         spin_unlock_bh(&smc_lgr_list.lock);
 174
 175         if (!lgr->is_smcd && !lgr->terminating) {
 176                 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 177
 178                 /* try to send del link msg, on error free lgr immediately */
 179                 if (lnk->state == SMC_LNK_ACTIVE &&
 180                     !smc_link_send_delete(lnk)) {
 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                 if (lgr->is_smcd)
 193                         smc_ism_signal_shutdown(lgr);
 194                 smc_lgr_free(lgr);
 195         }
 196 }
 197
 198 /* create a new SMC link group */
 199 static int smc_lgr_create(struct smc_sock *smc, bool is_smcd,
 200                           struct smc_ib_device *smcibdev, u8 ibport,
 201                           char *peer_systemid, unsigned short vlan_id,
 202                           struct smcd_dev *smcismdev, u64 peer_gid)
 203 {
 204         struct smc_link_group *lgr;
 205         struct smc_link *lnk;
 206         u8 rndvec[3];
 207         int rc = 0;
 208         int i;
 209
 210         if (is_smcd && vlan_id) {
 211                 rc = smc_ism_get_vlan(smcismdev, vlan_id);
 212                 if (rc)
 213                         goto out;
 214         }
 215
 216         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 217         if (!lgr) {
 218                 rc = -ENOMEM;
 219                 goto out;
 220         }
 221         lgr->is_smcd = is_smcd;
 222         lgr->sync_err = 0;
 223         lgr->vlan_id = vlan_id;
 224         rwlock_init(&lgr->sndbufs_lock);
 225         rwlock_init(&lgr->rmbs_lock);
 226         rwlock_init(&lgr->conns_lock);
 227         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 228                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 229                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 230         }
 231         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 232         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 233         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 234         lgr->conns_all = RB_ROOT;
 235         if (is_smcd) {
 236                 /* SMC-D specific settings */
 237                 lgr->peer_gid = peer_gid;
 238                 lgr->smcd = smcismdev;
 239         } else {
 240                 /* SMC-R specific settings */
 241                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 242                 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
 243
 244                 lnk = &lgr->lnk[SMC_SINGLE_LINK];
 245                 /* initialize link */
 246                 lnk->state = SMC_LNK_ACTIVATING;
 247                 lnk->link_id = SMC_SINGLE_LINK;
 248                 lnk->smcibdev = smcibdev;
 249                 lnk->ibport = ibport;
 250                 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
 251                 if (!smcibdev->initialized)
 252                         smc_ib_setup_per_ibdev(smcibdev);
 253                 get_random_bytes(rndvec, sizeof(rndvec));
 254                 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 255                         (rndvec[2] << 16);
 256                 rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 257                                           vlan_id, lnk->gid, &lnk->sgid_index);
 258                 if (rc)
 259                         goto free_lgr;
 260                 rc = smc_llc_link_init(lnk);
 261                 if (rc)
 262                         goto free_lgr;
 263                 rc = smc_wr_alloc_link_mem(lnk);
 264                 if (rc)
 265                         goto clear_llc_lnk;
 266                 rc = smc_ib_create_protection_domain(lnk);
 267                 if (rc)
 268                         goto free_link_mem;
 269                 rc = smc_ib_create_queue_pair(lnk);
 270                 if (rc)
 271                         goto dealloc_pd;
 272                 rc = smc_wr_create_link(lnk);
 273                 if (rc)
 274                         goto destroy_qp;
 275         }
 276         smc->conn.lgr = lgr;
 277         spin_lock_bh(&smc_lgr_list.lock);
 278         list_add(&lgr->list, &smc_lgr_list.list);
 279         spin_unlock_bh(&smc_lgr_list.lock);
 280         return 0;
 281
 282 destroy_qp:
 283         smc_ib_destroy_queue_pair(lnk);
 284 dealloc_pd:
 285         smc_ib_dealloc_protection_domain(lnk);
 286 free_link_mem:
 287         smc_wr_free_link_mem(lnk);
 288 clear_llc_lnk:
 289         smc_llc_link_clear(lnk);
 290 free_lgr:
 291         kfree(lgr);
 292 out:
 293         return rc;
 294 }
 295
 296 static void smc_buf_unuse(struct smc_connection *conn,
 297                           struct smc_link_group *lgr)
 298 {
 299         if (conn->sndbuf_desc)
 300                 conn->sndbuf_desc->used = 0;
 301         if (conn->rmb_desc) {
 302                 if (!conn->rmb_desc->regerr) {
 303                         conn->rmb_desc->used = 0;
 304                         if (!lgr->is_smcd) {
 305                                 /* unregister rmb with peer */
 306                                 smc_llc_do_delete_rkey(
 307                                                 &lgr->lnk[SMC_SINGLE_LINK],
 308                                                 conn->rmb_desc);
 309                         }
 310                 } else {
 311                         /* buf registration failed, reuse not possible */
 312                         write_lock_bh(&lgr->rmbs_lock);
 313                         list_del(&conn->rmb_desc->list);
 314                         write_unlock_bh(&lgr->rmbs_lock);
 315
 316                         smc_buf_free(lgr, true, conn->rmb_desc);
 317                 }
 318         }
 319 }
 320
 321 /* remove a finished connection from its link group */
 322 void smc_conn_free(struct smc_connection *conn)
 323 {
 324         struct smc_link_group *lgr = conn->lgr;
 325
 326         if (!lgr)
 327                 return;
 328         if (lgr->is_smcd) {
 329                 smc_ism_unset_conn(conn);
 330                 tasklet_kill(&conn->rx_tsklet);
 331         } else {
 332                 smc_cdc_tx_dismiss_slots(conn);
 333         }
 334         smc_lgr_unregister_conn(conn);          /* unsets conn->lgr */
 335         smc_buf_unuse(conn, lgr);               /* allow buffer reuse */
 336
 337         if (!lgr->conns_num)
 338                 smc_lgr_schedule_free_work(lgr);
 339 }
 340
 341 static void smc_link_clear(struct smc_link *lnk)
 342 {
 343         lnk->peer_qpn = 0;
 344         smc_llc_link_clear(lnk);
 345         smc_ib_modify_qp_reset(lnk);
 346         smc_wr_free_link(lnk);
 347         smc_ib_destroy_queue_pair(lnk);
 348         smc_ib_dealloc_protection_domain(lnk);
 349         smc_wr_free_link_mem(lnk);
 350 }
 351
 352 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
 353                           struct smc_buf_desc *buf_desc)
 354 {
 355         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 356
 357         if (is_rmb) {
 358                 if (buf_desc->mr_rx[SMC_SINGLE_LINK])
 359                         smc_ib_put_memory_region(
 360                                         buf_desc->mr_rx[SMC_SINGLE_LINK]);
 361                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 362                                     DMA_FROM_DEVICE);
 363         } else {
 364                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 365                                     DMA_TO_DEVICE);
 366         }
 367         sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
 368         if (buf_desc->pages)
 369                 __free_pages(buf_desc->pages, buf_desc->order);
 370         kfree(buf_desc);
 371 }
 372
 373 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
 374                           struct smc_buf_desc *buf_desc)
 375 {
 376         if (is_dmb) {
 377                 /* restore original buf len */
 378                 buf_desc->len += sizeof(struct smcd_cdc_msg);
 379                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
 380         } else {
 381                 kfree(buf_desc->cpu_addr);
 382         }
 383         kfree(buf_desc);
 384 }
 385
 386 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
 387                          struct smc_buf_desc *buf_desc)
 388 {
 389         if (lgr->is_smcd)
 390                 smcd_buf_free(lgr, is_rmb, buf_desc);
 391         else
 392                 smcr_buf_free(lgr, is_rmb, buf_desc);
 393 }
 394
 395 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
 396 {
 397         struct smc_buf_desc *buf_desc, *bf_desc;
 398         struct list_head *buf_list;
 399         int i;
 400
 401         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 402                 if (is_rmb)
 403                         buf_list = &lgr->rmbs[i];
 404                 else
 405                         buf_list = &lgr->sndbufs[i];
 406                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
 407                                          list) {
 408                         list_del(&buf_desc->list);
 409                         smc_buf_free(lgr, is_rmb, buf_desc);
 410                 }
 411         }
 412 }
 413
 414 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
 415 {
 416         /* free send buffers */
 417         __smc_lgr_free_bufs(lgr, false);
 418         /* free rmbs */
 419         __smc_lgr_free_bufs(lgr, true);
 420 }
 421
 422 /* remove a link group */
 423 static void smc_lgr_free(struct smc_link_group *lgr)
 424 {
 425         smc_lgr_free_bufs(lgr);
 426         if (lgr->is_smcd)
 427                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 428         else
 429                 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
 430         kfree(lgr);
 431 }
 432
 433 void smc_lgr_forget(struct smc_link_group *lgr)
 434 {
 435         spin_lock_bh(&smc_lgr_list.lock);
 436         /* do not use this link group for new connections */
 437         if (!list_empty(&lgr->list))
 438                 list_del_init(&lgr->list);
 439         spin_unlock_bh(&smc_lgr_list.lock);
 440 }
 441
 442 /* terminate linkgroup abnormally */
 443 static void __smc_lgr_terminate(struct smc_link_group *lgr)
 444 {
 445         struct smc_connection *conn;
 446         struct smc_sock *smc;
 447         struct rb_node *node;
 448
 449         if (lgr->terminating)
 450                 return; /* lgr already terminating */
 451         lgr->terminating = 1;
 452         if (!list_empty(&lgr->list)) /* forget lgr */
 453                 list_del_init(&lgr->list);
 454         if (!lgr->is_smcd)
 455                 smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
 456
 457         write_lock_bh(&lgr->conns_lock);
 458         node = rb_first(&lgr->conns_all);
 459         while (node) {
 460                 conn = rb_entry(node, struct smc_connection, alert_node);
 461                 smc = container_of(conn, struct smc_sock, conn);
 462                 sock_hold(&smc->sk); /* sock_put in close work */
 463                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 464                 __smc_lgr_unregister_conn(conn);
 465                 write_unlock_bh(&lgr->conns_lock);
 466                 if (!schedule_work(&conn->close_work))
 467                         sock_put(&smc->sk);
 468                 write_lock_bh(&lgr->conns_lock);
 469                 node = rb_first(&lgr->conns_all);
 470         }
 471         write_unlock_bh(&lgr->conns_lock);
 472         if (!lgr->is_smcd)
 473                 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
 474         smc_lgr_schedule_free_work(lgr);
 475 }
 476
 477 void smc_lgr_terminate(struct smc_link_group *lgr)
 478 {
 479         spin_lock_bh(&smc_lgr_list.lock);
 480         __smc_lgr_terminate(lgr);
 481         spin_unlock_bh(&smc_lgr_list.lock);
 482 }
 483
 484 /* Called when IB port is terminated */
 485 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 486 {
 487         struct smc_link_group *lgr, *l;
 488
 489         spin_lock_bh(&smc_lgr_list.lock);
 490         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 491                 if (!lgr->is_smcd &&
 492                     lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 493                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 494                         __smc_lgr_terminate(lgr);
 495         }
 496         spin_unlock_bh(&smc_lgr_list.lock);
 497 }
 498
 499 /* Called when SMC-D device is terminated or peer is lost */
 500 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 501 {
 502         struct smc_link_group *lgr, *l;
 503         LIST_HEAD(lgr_free_list);
 504
 505         /* run common cleanup function and build free list */
 506         spin_lock_bh(&smc_lgr_list.lock);
 507         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 508                 if (lgr->is_smcd && lgr->smcd == dev &&
 509                     (!peer_gid || lgr->peer_gid == peer_gid) &&
 510                     (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
 511                         __smc_lgr_terminate(lgr);
 512                         list_move(&lgr->list, &lgr_free_list);
 513                 }
 514         }
 515         spin_unlock_bh(&smc_lgr_list.lock);
 516
 517         /* cancel the regular free workers and actually free lgrs */
 518         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 519                 list_del_init(&lgr->list);
 520                 cancel_delayed_work_sync(&lgr->free_work);
 521                 if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */
 522                         smc_ism_signal_shutdown(lgr);
 523                 smc_lgr_free(lgr);
 524         }
 525 }
 526
 527 /* Determine vlan of internal TCP socket.
 528  * @vlan_id: address to store the determined vlan id into
 529  */
 530 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
 531 {
 532         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 533         struct net_device *ndev;
 534         int i, nest_lvl, rc = 0;
 535
 536         *vlan_id = 0;
 537         if (!dst) {
 538                 rc = -ENOTCONN;
 539                 goto out;
 540         }
 541         if (!dst->dev) {
 542                 rc = -ENODEV;
 543                 goto out_rel;
 544         }
 545
 546         ndev = dst->dev;
 547         if (is_vlan_dev(ndev)) {
 548                 *vlan_id = vlan_dev_vlan_id(ndev);
 549                 goto out_rel;
 550         }
 551
 552         rtnl_lock();
 553         nest_lvl = dev_get_nest_level(ndev);
 554         for (i = 0; i < nest_lvl; i++) {
 555                 struct list_head *lower = &ndev->adj_list.lower;
 556
 557                 if (list_empty(lower))
 558                         break;
 559                 lower = lower->next;
 560                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
 561                 if (is_vlan_dev(ndev)) {
 562                         *vlan_id = vlan_dev_vlan_id(ndev);
 563                         break;
 564                 }
 565         }
 566         rtnl_unlock();
 567
 568 out_rel:
 569         dst_release(dst);
 570 out:
 571         return rc;
 572 }
 573
 574 static bool smcr_lgr_match(struct smc_link_group *lgr,
 575                            struct smc_clc_msg_local *lcl,
 576                            enum smc_lgr_role role, u32 clcqpn)
 577 {
 578         return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
 579                        SMC_SYSTEMID_LEN) &&
 580                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
 581                         SMC_GID_SIZE) &&
 582                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
 583                         sizeof(lcl->mac)) &&
 584                 lgr->role == role &&
 585                 (lgr->role == SMC_SERV ||
 586                  lgr->lnk[SMC_SINGLE_LINK].peer_qpn == clcqpn);
 587 }
 588
 589 static bool smcd_lgr_match(struct smc_link_group *lgr,
 590                            struct smcd_dev *smcismdev, u64 peer_gid)
 591 {
 592         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
 593 }
 594
 595 /* create a new SMC connection (and a new link group if necessary) */
 596 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
 597                     struct smc_ib_device *smcibdev, u8 ibport, u32 clcqpn,
 598                     struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
 599                     u64 peer_gid)
 600 {
 601         struct smc_connection *conn = &smc->conn;
 602         int local_contact = SMC_FIRST_CONTACT;
 603         struct smc_link_group *lgr;
 604         unsigned short vlan_id;
 605         enum smc_lgr_role role;
 606         int rc = 0;
 607
 608         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 609         rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
 610         if (rc)
 611                 return rc;
 612
 613         if ((role == SMC_CLNT) && srv_first_contact)
 614                 /* create new link group as well */
 615                 goto create;
 616
 617         /* determine if an existing link group can be reused */
 618         spin_lock_bh(&smc_lgr_list.lock);
 619         list_for_each_entry(lgr, &smc_lgr_list.list, list) {
 620                 write_lock_bh(&lgr->conns_lock);
 621                 if ((is_smcd ? smcd_lgr_match(lgr, smcd, peer_gid) :
 622                      smcr_lgr_match(lgr, lcl, role, clcqpn)) &&
 623                     !lgr->sync_err &&
 624                     lgr->vlan_id == vlan_id &&
 625                     (role == SMC_CLNT ||
 626                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
 627                         /* link group found */
 628                         local_contact = SMC_REUSE_CONTACT;
 629                         conn->lgr = lgr;
 630                         smc_lgr_register_conn(conn); /* add smc conn to lgr */
 631                         write_unlock_bh(&lgr->conns_lock);
 632                         break;
 633                 }
 634                 write_unlock_bh(&lgr->conns_lock);
 635         }
 636         spin_unlock_bh(&smc_lgr_list.lock);
 637
 638         if (role == SMC_CLNT && !srv_first_contact &&
 639             (local_contact == SMC_FIRST_CONTACT)) {
 640                 /* Server reuses a link group, but Client wants to start
 641                  * a new one
 642                  * send out_of_sync decline, reason synchr. error
 643                  */
 644                 return -ENOLINK;
 645         }
 646
 647 create:
 648         if (local_contact == SMC_FIRST_CONTACT) {
 649                 rc = smc_lgr_create(smc, is_smcd, smcibdev, ibport,
 650                                     lcl->id_for_peer, vlan_id, smcd, peer_gid);
 651                 if (rc)
 652                         goto out;
 653                 smc_lgr_register_conn(conn); /* add smc conn to lgr */
 654         }
 655         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
 656         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
 657         conn->urg_state = SMC_URG_READ;
 658         if (is_smcd) {
 659                 conn->rx_off = sizeof(struct smcd_cdc_msg);
 660                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
 661         }
 662 #ifndef KERNEL_HAS_ATOMIC64
 663         spin_lock_init(&conn->acurs_lock);
 664 #endif
 665
 666 out:
 667         return rc ? rc : local_contact;
 668 }
 669
 670 /* convert the RMB size into the compressed notation - minimum 16K.
 671  * In contrast to plain ilog2, this rounds towards the next power of 2,
 672  * so the socket application gets at least its desired sndbuf / rcvbuf size.
 673  */
 674 static u8 smc_compress_bufsize(int size)
 675 {
 676         u8 compressed;
 677
 678         if (size <= SMC_BUF_MIN_SIZE)
 679                 return 0;
 680
 681         size = (size - 1) >> 14;
 682         compressed = ilog2(size) + 1;
 683         if (compressed >= SMC_RMBE_SIZES)
 684                 compressed = SMC_RMBE_SIZES - 1;
 685         return compressed;
 686 }
 687
 688 /* convert the RMB size from compressed notation into integer */
 689 int smc_uncompress_bufsize(u8 compressed)
 690 {
 691         u32 size;
 692
 693         size = 0x00000001 << (((int)compressed) + 14);
 694         return (int)size;
 695 }
 696
 697 /* try to reuse a sndbuf or rmb description slot for a certain
 698  * buffer size; if not available, return NULL
 699  */
 700 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
 701                                              rwlock_t *lock,
 702                                              struct list_head *buf_list)
 703 {
 704         struct smc_buf_desc *buf_slot;
 705
 706         read_lock_bh(lock);
 707         list_for_each_entry(buf_slot, buf_list, list) {
 708                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
 709                         read_unlock_bh(lock);
 710                         return buf_slot;
 711                 }
 712         }
 713         read_unlock_bh(lock);
 714         return NULL;
 715 }
 716
 717 /* one of the conditions for announcing a receiver's current window size is
 718  * that it "results in a minimum increase in the window size of 10% of the
 719  * receive buffer space" [RFC7609]
 720  */
 721 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
 722 {
 723         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
 724 }
 725
 726 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
 727                                                 bool is_rmb, int bufsize)
 728 {
 729         struct smc_buf_desc *buf_desc;
 730         struct smc_link *lnk;
 731         int rc;
 732
 733         /* try to alloc a new buffer */
 734         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 735         if (!buf_desc)
 736                 return ERR_PTR(-ENOMEM);
 737
 738         buf_desc->order = get_order(bufsize);
 739         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
 740                                       __GFP_NOMEMALLOC | __GFP_COMP |
 741                                       __GFP_NORETRY | __GFP_ZERO,
 742                                       buf_desc->order);
 743         if (!buf_desc->pages) {
 744                 kfree(buf_desc);
 745                 return ERR_PTR(-EAGAIN);
 746         }
 747         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
 748
 749         /* build the sg table from the pages */
 750         lnk = &lgr->lnk[SMC_SINGLE_LINK];
 751         rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
 752                             GFP_KERNEL);
 753         if (rc) {
 754                 smc_buf_free(lgr, is_rmb, buf_desc);
 755                 return ERR_PTR(rc);
 756         }
 757         sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
 758                    buf_desc->cpu_addr, bufsize);
 759
 760         /* map sg table to DMA address */
 761         rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
 762                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 763         /* SMC protocol depends on mapping to one DMA address only */
 764         if (rc != 1)  {
 765                 smc_buf_free(lgr, is_rmb, buf_desc);
 766                 return ERR_PTR(-EAGAIN);
 767         }
 768
 769         /* create a new memory region for the RMB */
 770         if (is_rmb) {
 771                 rc = smc_ib_get_memory_region(lnk->roce_pd,
 772                                               IB_ACCESS_REMOTE_WRITE |
 773                                               IB_ACCESS_LOCAL_WRITE,
 774                                               buf_desc);
 775                 if (rc) {
 776                         smc_buf_free(lgr, is_rmb, buf_desc);
 777                         return ERR_PTR(rc);
 778                 }
 779         }
 780
 781         buf_desc->len = bufsize;
 782         return buf_desc;
 783 }
 784
 785 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
 786
 787 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
 788                                                 bool is_dmb, int bufsize)
 789 {
 790         struct smc_buf_desc *buf_desc;
 791         int rc;
 792
 793         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
 794                 return ERR_PTR(-EAGAIN);
 795
 796         /* try to alloc a new DMB */
 797         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 798         if (!buf_desc)
 799                 return ERR_PTR(-ENOMEM);
 800         if (is_dmb) {
 801                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
 802                 if (rc) {
 803                         kfree(buf_desc);
 804                         return ERR_PTR(-EAGAIN);
 805                 }
 806                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
 807                 /* CDC header stored in buf. So, pretend it was smaller */
 808                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
 809         } else {
 810                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
 811                                              __GFP_NOWARN | __GFP_NORETRY |
 812                                              __GFP_NOMEMALLOC);
 813                 if (!buf_desc->cpu_addr) {
 814                         kfree(buf_desc);
 815                         return ERR_PTR(-EAGAIN);
 816                 }
 817                 buf_desc->len = bufsize;
 818         }
 819         return buf_desc;
 820 }
 821
 822 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 823 {
 824         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
 825         struct smc_connection *conn = &smc->conn;
 826         struct smc_link_group *lgr = conn->lgr;
 827         struct list_head *buf_list;
 828         int bufsize, bufsize_short;
 829         int sk_buf_size;
 830         rwlock_t *lock;
 831
 832         if (is_rmb)
 833                 /* use socket recv buffer size (w/o overhead) as start value */
 834                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
 835         else
 836                 /* use socket send buffer size (w/o overhead) as start value */
 837                 sk_buf_size = smc->sk.sk_sndbuf / 2;
 838
 839         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
 840              bufsize_short >= 0; bufsize_short--) {
 841
 842                 if (is_rmb) {
 843                         lock = &lgr->rmbs_lock;
 844                         buf_list = &lgr->rmbs[bufsize_short];
 845                 } else {
 846                         lock = &lgr->sndbufs_lock;
 847                         buf_list = &lgr->sndbufs[bufsize_short];
 848                 }
 849                 bufsize = smc_uncompress_bufsize(bufsize_short);
 850                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
 851                         continue;
 852
 853                 /* check for reusable slot in the link group */
 854                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
 855                 if (buf_desc) {
 856                         memset(buf_desc->cpu_addr, 0, bufsize);
 857                         break; /* found reusable slot */
 858                 }
 859
 860                 if (is_smcd)
 861                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
 862                 else
 863                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
 864
 865                 if (PTR_ERR(buf_desc) == -ENOMEM)
 866                         break;
 867                 if (IS_ERR(buf_desc))
 868                         continue;
 869
 870                 buf_desc->used = 1;
 871                 write_lock_bh(lock);
 872                 list_add(&buf_desc->list, buf_list);
 873                 write_unlock_bh(lock);
 874                 break; /* found */
 875         }
 876
 877         if (IS_ERR(buf_desc))
 878                 return -ENOMEM;
 879
 880         if (is_rmb) {
 881                 conn->rmb_desc = buf_desc;
 882                 conn->rmbe_size_short = bufsize_short;
 883                 smc->sk.sk_rcvbuf = bufsize * 2;
 884                 atomic_set(&conn->bytes_to_rcv, 0);
 885                 conn->rmbe_update_limit =
 886                         smc_rmb_wnd_update_limit(buf_desc->len);
 887                 if (is_smcd)
 888                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
 889         } else {
 890                 conn->sndbuf_desc = buf_desc;
 891                 smc->sk.sk_sndbuf = bufsize * 2;
 892                 atomic_set(&conn->sndbuf_space, bufsize);
 893         }
 894         return 0;
 895 }
 896
 897 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
 898 {
 899         struct smc_link_group *lgr = conn->lgr;
 900
 901         if (!conn->lgr || conn->lgr->is_smcd)
 902                 return;
 903         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 904                                conn->sndbuf_desc, DMA_TO_DEVICE);
 905 }
 906
 907 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
 908 {
 909         struct smc_link_group *lgr = conn->lgr;
 910
 911         if (!conn->lgr || conn->lgr->is_smcd)
 912                 return;
 913         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 914                                   conn->sndbuf_desc, DMA_TO_DEVICE);
 915 }
 916
 917 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
 918 {
 919         struct smc_link_group *lgr = conn->lgr;
 920
 921         if (!conn->lgr || conn->lgr->is_smcd)
 922                 return;
 923         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 924                                conn->rmb_desc, DMA_FROM_DEVICE);
 925 }
 926
 927 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
 928 {
 929         struct smc_link_group *lgr = conn->lgr;
 930
 931         if (!conn->lgr || conn->lgr->is_smcd)
 932                 return;
 933         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 934                                   conn->rmb_desc, DMA_FROM_DEVICE);
 935 }
 936
 937 /* create the send and receive buffer for an SMC socket;
 938  * receive buffers are called RMBs;
 939  * (even though the SMC protocol allows more than one RMB-element per RMB,
 940  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
 941  * extra RMB for every connection in a link group
 942  */
 943 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
 944 {
 945         int rc;
 946
 947         /* create send buffer */
 948         rc = __smc_buf_create(smc, is_smcd, false);
 949         if (rc)
 950                 return rc;
 951         /* create rmb */
 952         rc = __smc_buf_create(smc, is_smcd, true);
 953         if (rc)
 954                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
 955         return rc;
 956 }
 957
 958 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
 959 {
 960         int i;
 961
 962         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
 963                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
 964                         return i;
 965         }
 966         return -ENOSPC;
 967 }
 968
 969 /* add a new rtoken from peer */
 970 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
 971 {
 972         u64 dma_addr = be64_to_cpu(nw_vaddr);
 973         u32 rkey = ntohl(nw_rkey);
 974         int i;
 975
 976         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 977                 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
 978                     (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
 979                     test_bit(i, lgr->rtokens_used_mask)) {
 980                         /* already in list */
 981                         return i;
 982                 }
 983         }
 984         i = smc_rmb_reserve_rtoken_idx(lgr);
 985         if (i < 0)
 986                 return i;
 987         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
 988         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
 989         return i;
 990 }
 991
 992 /* delete an rtoken */
 993 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
 994 {
 995         u32 rkey = ntohl(nw_rkey);
 996         int i;
 997
 998         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 999                 if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
1000                     test_bit(i, lgr->rtokens_used_mask)) {
1001                         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
1002                         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
1003
1004                         clear_bit(i, lgr->rtokens_used_mask);
1005                         return 0;
1006                 }
1007         }
1008         return -ENOENT;
1009 }
1010
1011 /* save rkey and dma_addr received from peer during clc handshake */
1012 int smc_rmb_rtoken_handling(struct smc_connection *conn,
1013                             struct smc_clc_msg_accept_confirm *clc)
1014 {
1015         conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1016                                           clc->rmb_rkey);
1017         if (conn->rtoken_idx < 0)
1018                 return conn->rtoken_idx;
1019         return 0;
1020 }
1021
1022 /* Called (from smc_exit) when module is removed */
1023 void smc_core_exit(void)
1024 {
1025         struct smc_link_group *lgr, *lg;
1026         LIST_HEAD(lgr_freeing_list);
1027
1028         spin_lock_bh(&smc_lgr_list.lock);
1029         if (!list_empty(&smc_lgr_list.list))
1030                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1031         spin_unlock_bh(&smc_lgr_list.lock);
1032         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1033                 list_del_init(&lgr->list);
1034                 if (!lgr->is_smcd) {
1035                         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
1036
1037                         if (lnk->state == SMC_LNK_ACTIVE)
1038                                 smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
1039                                                          false);
1040                         smc_llc_link_inactive(lnk);
1041                 }
1042                 cancel_delayed_work_sync(&lgr->free_work);
1043                 if (lgr->is_smcd)
1044                         smc_ism_signal_shutdown(lgr);
1045                 smc_lgr_free(lgr); /* free link group */
1046         }
1047 }