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         sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
 122 }
 123
 124 /* Unregister connection from lgr
 125  */
 126 static void smc_lgr_unregister_conn(struct smc_connection *conn)
 127 {
 128         struct smc_link_group *lgr = conn->lgr;
 129
 130         if (!lgr)
 131                 return;
 132         write_lock_bh(&lgr->conns_lock);
 133         if (conn->alert_token_local) {
 134                 __smc_lgr_unregister_conn(conn);
 135         }
 136         write_unlock_bh(&lgr->conns_lock);
 137 }
 138
 139 /* Send delete link, either as client to request the initiation
 140  * of the DELETE LINK sequence from server; or as server to
 141  * initiate the delete processing. See smc_llc_rx_delete_link().
 142  */
 143 static int smc_link_send_delete(struct smc_link *lnk)
 144 {
 145         if (lnk->state == SMC_LNK_ACTIVE &&
 146             !smc_llc_send_delete_link(lnk, SMC_LLC_REQ, true)) {
 147                 smc_llc_link_deleting(lnk);
 148                 return 0;
 149         }
 150         return -ENOTCONN;
 151 }
 152
 153 static void smc_lgr_free(struct smc_link_group *lgr);
 154
 155 static void smc_lgr_free_work(struct work_struct *work)
 156 {
 157         struct smc_link_group *lgr = container_of(to_delayed_work(work),
 158                                                   struct smc_link_group,
 159                                                   free_work);
 160         bool conns;
 161
 162         spin_lock_bh(&smc_lgr_list.lock);
 163         read_lock_bh(&lgr->conns_lock);
 164         conns = RB_EMPTY_ROOT(&lgr->conns_all);
 165         read_unlock_bh(&lgr->conns_lock);
 166         if (!conns) { /* number of lgr connections is no longer zero */
 167                 spin_unlock_bh(&smc_lgr_list.lock);
 168                 return;
 169         }
 170         if (!list_empty(&lgr->list))
 171                 list_del_init(&lgr->list); /* remove from smc_lgr_list */
 172         spin_unlock_bh(&smc_lgr_list.lock);
 173
 174         if (!lgr->is_smcd && !lgr->terminating) {
 175                 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 176
 177                 /* try to send del link msg, on error free lgr immediately */
 178                 if (lnk->state == SMC_LNK_ACTIVE &&
 179                     !smc_link_send_delete(lnk)) {
 180                         /* reschedule in case we never receive a response */
 181                         smc_lgr_schedule_free_work(lgr);
 182                         return;
 183                 }
 184         }
 185
 186         if (!delayed_work_pending(&lgr->free_work)) {
 187                 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 188
 189                 if (!lgr->is_smcd && lnk->state != SMC_LNK_INACTIVE)
 190                         smc_llc_link_inactive(lnk);
 191                 if (lgr->is_smcd)
 192                         smc_ism_signal_shutdown(lgr);
 193                 smc_lgr_free(lgr);
 194         }
 195 }
 196
 197 /* create a new SMC link group */
 198 static int smc_lgr_create(struct smc_sock *smc, bool is_smcd,
 199                           struct smc_ib_device *smcibdev, u8 ibport,
 200                           char *peer_systemid, unsigned short vlan_id,
 201                           struct smcd_dev *smcismdev, u64 peer_gid)
 202 {
 203         struct smc_link_group *lgr;
 204         struct smc_link *lnk;
 205         u8 rndvec[3];
 206         int rc = 0;
 207         int i;
 208
 209         if (is_smcd && vlan_id) {
 210                 rc = smc_ism_get_vlan(smcismdev, vlan_id);
 211                 if (rc)
 212                         goto out;
 213         }
 214
 215         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 216         if (!lgr) {
 217                 rc = -ENOMEM;
 218                 goto out;
 219         }
 220         lgr->is_smcd = is_smcd;
 221         lgr->sync_err = 0;
 222         lgr->vlan_id = vlan_id;
 223         rwlock_init(&lgr->sndbufs_lock);
 224         rwlock_init(&lgr->rmbs_lock);
 225         rwlock_init(&lgr->conns_lock);
 226         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 227                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 228                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 229         }
 230         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 231         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 232         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 233         lgr->conns_all = RB_ROOT;
 234         if (is_smcd) {
 235                 /* SMC-D specific settings */
 236                 lgr->peer_gid = peer_gid;
 237                 lgr->smcd = smcismdev;
 238         } else {
 239                 /* SMC-R specific settings */
 240                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 241                 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN);
 242
 243                 lnk = &lgr->lnk[SMC_SINGLE_LINK];
 244                 /* initialize link */
 245                 lnk->state = SMC_LNK_ACTIVATING;
 246                 lnk->link_id = SMC_SINGLE_LINK;
 247                 lnk->smcibdev = smcibdev;
 248                 lnk->ibport = ibport;
 249                 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
 250                 if (!smcibdev->initialized)
 251                         smc_ib_setup_per_ibdev(smcibdev);
 252                 get_random_bytes(rndvec, sizeof(rndvec));
 253                 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 254                         (rndvec[2] << 16);
 255                 rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 256                                           vlan_id, lnk->gid, &lnk->sgid_index);
 257                 if (rc)
 258                         goto free_lgr;
 259                 rc = smc_llc_link_init(lnk);
 260                 if (rc)
 261                         goto free_lgr;
 262                 rc = smc_wr_alloc_link_mem(lnk);
 263                 if (rc)
 264                         goto clear_llc_lnk;
 265                 rc = smc_ib_create_protection_domain(lnk);
 266                 if (rc)
 267                         goto free_link_mem;
 268                 rc = smc_ib_create_queue_pair(lnk);
 269                 if (rc)
 270                         goto dealloc_pd;
 271                 rc = smc_wr_create_link(lnk);
 272                 if (rc)
 273                         goto destroy_qp;
 274         }
 275         smc->conn.lgr = lgr;
 276         spin_lock_bh(&smc_lgr_list.lock);
 277         list_add(&lgr->list, &smc_lgr_list.list);
 278         spin_unlock_bh(&smc_lgr_list.lock);
 279         return 0;
 280
 281 destroy_qp:
 282         smc_ib_destroy_queue_pair(lnk);
 283 dealloc_pd:
 284         smc_ib_dealloc_protection_domain(lnk);
 285 free_link_mem:
 286         smc_wr_free_link_mem(lnk);
 287 clear_llc_lnk:
 288         smc_llc_link_clear(lnk);
 289 free_lgr:
 290         kfree(lgr);
 291 out:
 292         return rc;
 293 }
 294
 295 static void smc_buf_unuse(struct smc_connection *conn,
 296                           struct smc_link_group *lgr)
 297 {
 298         if (conn->sndbuf_desc)
 299                 conn->sndbuf_desc->used = 0;
 300         if (conn->rmb_desc) {
 301                 if (!conn->rmb_desc->regerr) {
 302                         if (!lgr->is_smcd) {
 303                                 /* unregister rmb with peer */
 304                                 smc_llc_do_delete_rkey(
 305                                                 &lgr->lnk[SMC_SINGLE_LINK],
 306                                                 conn->rmb_desc);
 307                         }
 308                         conn->rmb_desc->used = 0;
 309                 } else {
 310                         /* buf registration failed, reuse not possible */
 311                         write_lock_bh(&lgr->rmbs_lock);
 312                         list_del(&conn->rmb_desc->list);
 313                         write_unlock_bh(&lgr->rmbs_lock);
 314
 315                         smc_buf_free(lgr, true, conn->rmb_desc);
 316                 }
 317         }
 318 }
 319
 320 /* remove a finished connection from its link group */
 321 void smc_conn_free(struct smc_connection *conn)
 322 {
 323         struct smc_link_group *lgr = conn->lgr;
 324
 325         if (!lgr)
 326                 return;
 327         if (lgr->is_smcd) {
 328                 smc_ism_unset_conn(conn);
 329                 tasklet_kill(&conn->rx_tsklet);
 330         } else {
 331                 smc_cdc_tx_dismiss_slots(conn);
 332         }
 333         smc_lgr_unregister_conn(conn);
 334         smc_buf_unuse(conn, lgr);               /* allow buffer reuse */
 335         conn->lgr = NULL;
 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                 conn->lgr = NULL;
 466                 write_unlock_bh(&lgr->conns_lock);
 467                 if (!schedule_work(&conn->close_work))
 468                         sock_put(&smc->sk);
 469                 write_lock_bh(&lgr->conns_lock);
 470                 node = rb_first(&lgr->conns_all);
 471         }
 472         write_unlock_bh(&lgr->conns_lock);
 473         if (!lgr->is_smcd)
 474                 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
 475         smc_lgr_schedule_free_work(lgr);
 476 }
 477
 478 void smc_lgr_terminate(struct smc_link_group *lgr)
 479 {
 480         spin_lock_bh(&smc_lgr_list.lock);
 481         __smc_lgr_terminate(lgr);
 482         spin_unlock_bh(&smc_lgr_list.lock);
 483 }
 484
 485 /* Called when IB port is terminated */
 486 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 487 {
 488         struct smc_link_group *lgr, *l;
 489
 490         spin_lock_bh(&smc_lgr_list.lock);
 491         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 492                 if (!lgr->is_smcd &&
 493                     lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 494                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 495                         __smc_lgr_terminate(lgr);
 496         }
 497         spin_unlock_bh(&smc_lgr_list.lock);
 498 }
 499
 500 /* Called when SMC-D device is terminated or peer is lost */
 501 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 502 {
 503         struct smc_link_group *lgr, *l;
 504         LIST_HEAD(lgr_free_list);
 505
 506         /* run common cleanup function and build free list */
 507         spin_lock_bh(&smc_lgr_list.lock);
 508         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 509                 if (lgr->is_smcd && lgr->smcd == dev &&
 510                     (!peer_gid || lgr->peer_gid == peer_gid) &&
 511                     (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
 512                         __smc_lgr_terminate(lgr);
 513                         list_move(&lgr->list, &lgr_free_list);
 514                 }
 515         }
 516         spin_unlock_bh(&smc_lgr_list.lock);
 517
 518         /* cancel the regular free workers and actually free lgrs */
 519         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 520                 list_del_init(&lgr->list);
 521                 cancel_delayed_work_sync(&lgr->free_work);
 522                 if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */
 523                         smc_ism_signal_shutdown(lgr);
 524                 smc_lgr_free(lgr);
 525         }
 526 }
 527
 528 /* Determine vlan of internal TCP socket.
 529  * @vlan_id: address to store the determined vlan id into
 530  */
 531 int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id)
 532 {
 533         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 534         struct net_device *ndev;
 535         int i, nest_lvl, rc = 0;
 536
 537         *vlan_id = 0;
 538         if (!dst) {
 539                 rc = -ENOTCONN;
 540                 goto out;
 541         }
 542         if (!dst->dev) {
 543                 rc = -ENODEV;
 544                 goto out_rel;
 545         }
 546
 547         ndev = dst->dev;
 548         if (is_vlan_dev(ndev)) {
 549                 *vlan_id = vlan_dev_vlan_id(ndev);
 550                 goto out_rel;
 551         }
 552
 553         rtnl_lock();
 554         nest_lvl = dev_get_nest_level(ndev);
 555         for (i = 0; i < nest_lvl; i++) {
 556                 struct list_head *lower = &ndev->adj_list.lower;
 557
 558                 if (list_empty(lower))
 559                         break;
 560                 lower = lower->next;
 561                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
 562                 if (is_vlan_dev(ndev)) {
 563                         *vlan_id = vlan_dev_vlan_id(ndev);
 564                         break;
 565                 }
 566         }
 567         rtnl_unlock();
 568
 569 out_rel:
 570         dst_release(dst);
 571 out:
 572         return rc;
 573 }
 574
 575 static bool smcr_lgr_match(struct smc_link_group *lgr,
 576                            struct smc_clc_msg_local *lcl,
 577                            enum smc_lgr_role role, u32 clcqpn)
 578 {
 579         return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
 580                        SMC_SYSTEMID_LEN) &&
 581                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
 582                         SMC_GID_SIZE) &&
 583                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
 584                         sizeof(lcl->mac)) &&
 585                 lgr->role == role &&
 586                 (lgr->role == SMC_SERV ||
 587                  lgr->lnk[SMC_SINGLE_LINK].peer_qpn == clcqpn);
 588 }
 589
 590 static bool smcd_lgr_match(struct smc_link_group *lgr,
 591                            struct smcd_dev *smcismdev, u64 peer_gid)
 592 {
 593         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
 594 }
 595
 596 /* create a new SMC connection (and a new link group if necessary) */
 597 int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact,
 598                     struct smc_ib_device *smcibdev, u8 ibport, u32 clcqpn,
 599                     struct smc_clc_msg_local *lcl, struct smcd_dev *smcd,
 600                     u64 peer_gid)
 601 {
 602         struct smc_connection *conn = &smc->conn;
 603         int local_contact = SMC_FIRST_CONTACT;
 604         struct smc_link_group *lgr;
 605         unsigned short vlan_id;
 606         enum smc_lgr_role role;
 607         int rc = 0;
 608
 609         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 610         rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id);
 611         if (rc)
 612                 return rc;
 613
 614         if ((role == SMC_CLNT) && srv_first_contact)
 615                 /* create new link group as well */
 616                 goto create;
 617
 618         /* determine if an existing link group can be reused */
 619         spin_lock_bh(&smc_lgr_list.lock);
 620         list_for_each_entry(lgr, &smc_lgr_list.list, list) {
 621                 write_lock_bh(&lgr->conns_lock);
 622                 if ((is_smcd ? smcd_lgr_match(lgr, smcd, peer_gid) :
 623                      smcr_lgr_match(lgr, lcl, role, clcqpn)) &&
 624                     !lgr->sync_err &&
 625                     lgr->vlan_id == vlan_id &&
 626                     (role == SMC_CLNT ||
 627                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
 628                         /* link group found */
 629                         local_contact = SMC_REUSE_CONTACT;
 630                         conn->lgr = lgr;
 631                         smc_lgr_register_conn(conn); /* add smc conn to lgr */
 632                         if (delayed_work_pending(&lgr->free_work))
 633                                 cancel_delayed_work(&lgr->free_work);
 634                         write_unlock_bh(&lgr->conns_lock);
 635                         break;
 636                 }
 637                 write_unlock_bh(&lgr->conns_lock);
 638         }
 639         spin_unlock_bh(&smc_lgr_list.lock);
 640
 641         if (role == SMC_CLNT && !srv_first_contact &&
 642             (local_contact == SMC_FIRST_CONTACT)) {
 643                 /* Server reuses a link group, but Client wants to start
 644                  * a new one
 645                  * send out_of_sync decline, reason synchr. error
 646                  */
 647                 return -ENOLINK;
 648         }
 649
 650 create:
 651         if (local_contact == SMC_FIRST_CONTACT) {
 652                 rc = smc_lgr_create(smc, is_smcd, smcibdev, ibport,
 653                                     lcl->id_for_peer, vlan_id, smcd, peer_gid);
 654                 if (rc)
 655                         goto out;
 656                 smc_lgr_register_conn(conn); /* add smc conn to lgr */
 657         }
 658         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
 659         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
 660         conn->urg_state = SMC_URG_READ;
 661         if (is_smcd) {
 662                 conn->rx_off = sizeof(struct smcd_cdc_msg);
 663                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
 664         }
 665 #ifndef KERNEL_HAS_ATOMIC64
 666         spin_lock_init(&conn->acurs_lock);
 667 #endif
 668
 669 out:
 670         return rc ? rc : local_contact;
 671 }
 672
 673 /* convert the RMB size into the compressed notation - minimum 16K.
 674  * In contrast to plain ilog2, this rounds towards the next power of 2,
 675  * so the socket application gets at least its desired sndbuf / rcvbuf size.
 676  */
 677 static u8 smc_compress_bufsize(int size)
 678 {
 679         u8 compressed;
 680
 681         if (size <= SMC_BUF_MIN_SIZE)
 682                 return 0;
 683
 684         size = (size - 1) >> 14;
 685         compressed = ilog2(size) + 1;
 686         if (compressed >= SMC_RMBE_SIZES)
 687                 compressed = SMC_RMBE_SIZES - 1;
 688         return compressed;
 689 }
 690
 691 /* convert the RMB size from compressed notation into integer */
 692 int smc_uncompress_bufsize(u8 compressed)
 693 {
 694         u32 size;
 695
 696         size = 0x00000001 << (((int)compressed) + 14);
 697         return (int)size;
 698 }
 699
 700 /* try to reuse a sndbuf or rmb description slot for a certain
 701  * buffer size; if not available, return NULL
 702  */
 703 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
 704                                              rwlock_t *lock,
 705                                              struct list_head *buf_list)
 706 {
 707         struct smc_buf_desc *buf_slot;
 708
 709         read_lock_bh(lock);
 710         list_for_each_entry(buf_slot, buf_list, list) {
 711                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
 712                         read_unlock_bh(lock);
 713                         return buf_slot;
 714                 }
 715         }
 716         read_unlock_bh(lock);
 717         return NULL;
 718 }
 719
 720 /* one of the conditions for announcing a receiver's current window size is
 721  * that it "results in a minimum increase in the window size of 10% of the
 722  * receive buffer space" [RFC7609]
 723  */
 724 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
 725 {
 726         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
 727 }
 728
 729 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
 730                                                 bool is_rmb, int bufsize)
 731 {
 732         struct smc_buf_desc *buf_desc;
 733         struct smc_link *lnk;
 734         int rc;
 735
 736         /* try to alloc a new buffer */
 737         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 738         if (!buf_desc)
 739                 return ERR_PTR(-ENOMEM);
 740
 741         buf_desc->order = get_order(bufsize);
 742         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
 743                                       __GFP_NOMEMALLOC | __GFP_COMP |
 744                                       __GFP_NORETRY | __GFP_ZERO,
 745                                       buf_desc->order);
 746         if (!buf_desc->pages) {
 747                 kfree(buf_desc);
 748                 return ERR_PTR(-EAGAIN);
 749         }
 750         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
 751
 752         /* build the sg table from the pages */
 753         lnk = &lgr->lnk[SMC_SINGLE_LINK];
 754         rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
 755                             GFP_KERNEL);
 756         if (rc) {
 757                 smc_buf_free(lgr, is_rmb, buf_desc);
 758                 return ERR_PTR(rc);
 759         }
 760         sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
 761                    buf_desc->cpu_addr, bufsize);
 762
 763         /* map sg table to DMA address */
 764         rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
 765                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 766         /* SMC protocol depends on mapping to one DMA address only */
 767         if (rc != 1)  {
 768                 smc_buf_free(lgr, is_rmb, buf_desc);
 769                 return ERR_PTR(-EAGAIN);
 770         }
 771
 772         /* create a new memory region for the RMB */
 773         if (is_rmb) {
 774                 rc = smc_ib_get_memory_region(lnk->roce_pd,
 775                                               IB_ACCESS_REMOTE_WRITE |
 776                                               IB_ACCESS_LOCAL_WRITE,
 777                                               buf_desc);
 778                 if (rc) {
 779                         smc_buf_free(lgr, is_rmb, buf_desc);
 780                         return ERR_PTR(rc);
 781                 }
 782         }
 783
 784         buf_desc->len = bufsize;
 785         return buf_desc;
 786 }
 787
 788 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
 789
 790 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
 791                                                 bool is_dmb, int bufsize)
 792 {
 793         struct smc_buf_desc *buf_desc;
 794         int rc;
 795
 796         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
 797                 return ERR_PTR(-EAGAIN);
 798
 799         /* try to alloc a new DMB */
 800         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 801         if (!buf_desc)
 802                 return ERR_PTR(-ENOMEM);
 803         if (is_dmb) {
 804                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
 805                 if (rc) {
 806                         kfree(buf_desc);
 807                         return ERR_PTR(-EAGAIN);
 808                 }
 809                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
 810                 /* CDC header stored in buf. So, pretend it was smaller */
 811                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
 812         } else {
 813                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
 814                                              __GFP_NOWARN | __GFP_NORETRY |
 815                                              __GFP_NOMEMALLOC);
 816                 if (!buf_desc->cpu_addr) {
 817                         kfree(buf_desc);
 818                         return ERR_PTR(-EAGAIN);
 819                 }
 820                 buf_desc->len = bufsize;
 821         }
 822         return buf_desc;
 823 }
 824
 825 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 826 {
 827         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
 828         struct smc_connection *conn = &smc->conn;
 829         struct smc_link_group *lgr = conn->lgr;
 830         struct list_head *buf_list;
 831         int bufsize, bufsize_short;
 832         int sk_buf_size;
 833         rwlock_t *lock;
 834
 835         if (is_rmb)
 836                 /* use socket recv buffer size (w/o overhead) as start value */
 837                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
 838         else
 839                 /* use socket send buffer size (w/o overhead) as start value */
 840                 sk_buf_size = smc->sk.sk_sndbuf / 2;
 841
 842         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
 843              bufsize_short >= 0; bufsize_short--) {
 844
 845                 if (is_rmb) {
 846                         lock = &lgr->rmbs_lock;
 847                         buf_list = &lgr->rmbs[bufsize_short];
 848                 } else {
 849                         lock = &lgr->sndbufs_lock;
 850                         buf_list = &lgr->sndbufs[bufsize_short];
 851                 }
 852                 bufsize = smc_uncompress_bufsize(bufsize_short);
 853                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
 854                         continue;
 855
 856                 /* check for reusable slot in the link group */
 857                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
 858                 if (buf_desc) {
 859                         memset(buf_desc->cpu_addr, 0, bufsize);
 860                         break; /* found reusable slot */
 861                 }
 862
 863                 if (is_smcd)
 864                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
 865                 else
 866                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
 867
 868                 if (PTR_ERR(buf_desc) == -ENOMEM)
 869                         break;
 870                 if (IS_ERR(buf_desc))
 871                         continue;
 872
 873                 buf_desc->used = 1;
 874                 write_lock_bh(lock);
 875                 list_add(&buf_desc->list, buf_list);
 876                 write_unlock_bh(lock);
 877                 break; /* found */
 878         }
 879
 880         if (IS_ERR(buf_desc))
 881                 return -ENOMEM;
 882
 883         if (is_rmb) {
 884                 conn->rmb_desc = buf_desc;
 885                 conn->rmbe_size_short = bufsize_short;
 886                 smc->sk.sk_rcvbuf = bufsize * 2;
 887                 atomic_set(&conn->bytes_to_rcv, 0);
 888                 conn->rmbe_update_limit =
 889                         smc_rmb_wnd_update_limit(buf_desc->len);
 890                 if (is_smcd)
 891                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
 892         } else {
 893                 conn->sndbuf_desc = buf_desc;
 894                 smc->sk.sk_sndbuf = bufsize * 2;
 895                 atomic_set(&conn->sndbuf_space, bufsize);
 896         }
 897         return 0;
 898 }
 899
 900 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
 901 {
 902         struct smc_link_group *lgr = conn->lgr;
 903
 904         if (!conn->lgr || conn->lgr->is_smcd)
 905                 return;
 906         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 907                                conn->sndbuf_desc, DMA_TO_DEVICE);
 908 }
 909
 910 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
 911 {
 912         struct smc_link_group *lgr = conn->lgr;
 913
 914         if (!conn->lgr || conn->lgr->is_smcd)
 915                 return;
 916         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 917                                   conn->sndbuf_desc, DMA_TO_DEVICE);
 918 }
 919
 920 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
 921 {
 922         struct smc_link_group *lgr = conn->lgr;
 923
 924         if (!conn->lgr || conn->lgr->is_smcd)
 925                 return;
 926         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 927                                conn->rmb_desc, DMA_FROM_DEVICE);
 928 }
 929
 930 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
 931 {
 932         struct smc_link_group *lgr = conn->lgr;
 933
 934         if (!conn->lgr || conn->lgr->is_smcd)
 935                 return;
 936         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 937                                   conn->rmb_desc, DMA_FROM_DEVICE);
 938 }
 939
 940 /* create the send and receive buffer for an SMC socket;
 941  * receive buffers are called RMBs;
 942  * (even though the SMC protocol allows more than one RMB-element per RMB,
 943  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
 944  * extra RMB for every connection in a link group
 945  */
 946 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
 947 {
 948         int rc;
 949
 950         /* create send buffer */
 951         rc = __smc_buf_create(smc, is_smcd, false);
 952         if (rc)
 953                 return rc;
 954         /* create rmb */
 955         rc = __smc_buf_create(smc, is_smcd, true);
 956         if (rc)
 957                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
 958         return rc;
 959 }
 960
 961 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
 962 {
 963         int i;
 964
 965         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
 966                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
 967                         return i;
 968         }
 969         return -ENOSPC;
 970 }
 971
 972 /* add a new rtoken from peer */
 973 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
 974 {
 975         u64 dma_addr = be64_to_cpu(nw_vaddr);
 976         u32 rkey = ntohl(nw_rkey);
 977         int i;
 978
 979         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 980                 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
 981                     (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
 982                     test_bit(i, lgr->rtokens_used_mask)) {
 983                         /* already in list */
 984                         return i;
 985                 }
 986         }
 987         i = smc_rmb_reserve_rtoken_idx(lgr);
 988         if (i < 0)
 989                 return i;
 990         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
 991         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
 992         return i;
 993 }
 994
 995 /* delete an rtoken */
 996 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
 997 {
 998         u32 rkey = ntohl(nw_rkey);
 999         int i;
1000
1001         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1002                 if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
1003                     test_bit(i, lgr->rtokens_used_mask)) {
1004                         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
1005                         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
1006
1007                         clear_bit(i, lgr->rtokens_used_mask);
1008                         return 0;
1009                 }
1010         }
1011         return -ENOENT;
1012 }
1013
1014 /* save rkey and dma_addr received from peer during clc handshake */
1015 int smc_rmb_rtoken_handling(struct smc_connection *conn,
1016                             struct smc_clc_msg_accept_confirm *clc)
1017 {
1018         conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1019                                           clc->rmb_rkey);
1020         if (conn->rtoken_idx < 0)
1021                 return conn->rtoken_idx;
1022         return 0;
1023 }
1024
1025 /* Called (from smc_exit) when module is removed */
1026 void smc_core_exit(void)
1027 {
1028         struct smc_link_group *lgr, *lg;
1029         LIST_HEAD(lgr_freeing_list);
1030
1031         spin_lock_bh(&smc_lgr_list.lock);
1032         if (!list_empty(&smc_lgr_list.list))
1033                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1034         spin_unlock_bh(&smc_lgr_list.lock);
1035         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1036                 list_del_init(&lgr->list);
1037                 if (!lgr->is_smcd) {
1038                         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
1039
1040                         if (lnk->state == SMC_LNK_ACTIVE)
1041                                 smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
1042                                                          false);
1043                         smc_llc_link_inactive(lnk);
1044                 }
1045                 cancel_delayed_work_sync(&lgr->free_work);
1046                 if (lgr->is_smcd)
1047                         smc_ism_signal_shutdown(lgr);
1048                 smc_lgr_free(lgr); /* free link group */
1049         }
1050 }