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, struct smc_init_info *ini)
 199 {
 200         struct smc_link_group *lgr;
 201         struct smc_link *lnk;
 202         u8 rndvec[3];
 203         int rc = 0;
 204         int i;
 205
 206         if (ini->is_smcd && ini->vlan_id) {
 207                 if (smc_ism_get_vlan(ini->ism_dev, ini->vlan_id)) {
 208                         rc = SMC_CLC_DECL_ISMVLANERR;
 209                         goto out;
 210                 }
 211         }
 212
 213         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 214         if (!lgr) {
 215                 rc = SMC_CLC_DECL_MEM;
 216                 goto ism_put_vlan;
 217         }
 218         lgr->is_smcd = ini->is_smcd;
 219         lgr->sync_err = 0;
 220         lgr->vlan_id = ini->vlan_id;
 221         rwlock_init(&lgr->sndbufs_lock);
 222         rwlock_init(&lgr->rmbs_lock);
 223         rwlock_init(&lgr->conns_lock);
 224         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 225                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 226                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 227         }
 228         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 229         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 230         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 231         lgr->conns_all = RB_ROOT;
 232         if (ini->is_smcd) {
 233                 /* SMC-D specific settings */
 234                 lgr->peer_gid = ini->ism_gid;
 235                 lgr->smcd = ini->ism_dev;
 236         } else {
 237                 /* SMC-R specific settings */
 238                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 239                 memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
 240                        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 = ini->ib_dev;
 247                 lnk->ibport = ini->ib_port;
 248                 lnk->path_mtu =
 249                         ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
 250                 if (!ini->ib_dev->initialized)
 251                         smc_ib_setup_per_ibdev(ini->ib_dev);
 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                                           ini->vlan_id, lnk->gid,
 257                                           &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 ism_put_vlan:
 293         if (ini->is_smcd && ini->vlan_id)
 294                 smc_ism_put_vlan(ini->ism_dev, ini->vlan_id);
 295 out:
 296         if (rc < 0) {
 297                 if (rc == -ENOMEM)
 298                         rc = SMC_CLC_DECL_MEM;
 299                 else
 300                         rc = SMC_CLC_DECL_INTERR;
 301         }
 302         return rc;
 303 }
 304
 305 static void smc_buf_unuse(struct smc_connection *conn,
 306                           struct smc_link_group *lgr)
 307 {
 308         if (conn->sndbuf_desc)
 309                 conn->sndbuf_desc->used = 0;
 310         if (conn->rmb_desc) {
 311                 if (!conn->rmb_desc->regerr) {
 312                         if (!lgr->is_smcd) {
 313                                 /* unregister rmb with peer */
 314                                 smc_llc_do_delete_rkey(
 315                                                 &lgr->lnk[SMC_SINGLE_LINK],
 316                                                 conn->rmb_desc);
 317                         }
 318                         conn->rmb_desc->used = 0;
 319                 } else {
 320                         /* buf registration failed, reuse not possible */
 321                         write_lock_bh(&lgr->rmbs_lock);
 322                         list_del(&conn->rmb_desc->list);
 323                         write_unlock_bh(&lgr->rmbs_lock);
 324
 325                         smc_buf_free(lgr, true, conn->rmb_desc);
 326                 }
 327         }
 328 }
 329
 330 /* remove a finished connection from its link group */
 331 void smc_conn_free(struct smc_connection *conn)
 332 {
 333         struct smc_link_group *lgr = conn->lgr;
 334
 335         if (!lgr)
 336                 return;
 337         if (lgr->is_smcd) {
 338                 smc_ism_unset_conn(conn);
 339                 tasklet_kill(&conn->rx_tsklet);
 340         } else {
 341                 smc_cdc_tx_dismiss_slots(conn);
 342         }
 343         smc_lgr_unregister_conn(conn);
 344         smc_buf_unuse(conn, lgr);               /* allow buffer reuse */
 345         conn->lgr = NULL;
 346
 347         if (!lgr->conns_num)
 348                 smc_lgr_schedule_free_work(lgr);
 349 }
 350
 351 static void smc_link_clear(struct smc_link *lnk)
 352 {
 353         lnk->peer_qpn = 0;
 354         smc_llc_link_clear(lnk);
 355         smc_ib_modify_qp_reset(lnk);
 356         smc_wr_free_link(lnk);
 357         smc_ib_destroy_queue_pair(lnk);
 358         smc_ib_dealloc_protection_domain(lnk);
 359         smc_wr_free_link_mem(lnk);
 360 }
 361
 362 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
 363                           struct smc_buf_desc *buf_desc)
 364 {
 365         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
 366
 367         if (is_rmb) {
 368                 if (buf_desc->mr_rx[SMC_SINGLE_LINK])
 369                         smc_ib_put_memory_region(
 370                                         buf_desc->mr_rx[SMC_SINGLE_LINK]);
 371                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 372                                     DMA_FROM_DEVICE);
 373         } else {
 374                 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc,
 375                                     DMA_TO_DEVICE);
 376         }
 377         sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]);
 378         if (buf_desc->pages)
 379                 __free_pages(buf_desc->pages, buf_desc->order);
 380         kfree(buf_desc);
 381 }
 382
 383 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
 384                           struct smc_buf_desc *buf_desc)
 385 {
 386         if (is_dmb) {
 387                 /* restore original buf len */
 388                 buf_desc->len += sizeof(struct smcd_cdc_msg);
 389                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
 390         } else {
 391                 kfree(buf_desc->cpu_addr);
 392         }
 393         kfree(buf_desc);
 394 }
 395
 396 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
 397                          struct smc_buf_desc *buf_desc)
 398 {
 399         if (lgr->is_smcd)
 400                 smcd_buf_free(lgr, is_rmb, buf_desc);
 401         else
 402                 smcr_buf_free(lgr, is_rmb, buf_desc);
 403 }
 404
 405 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
 406 {
 407         struct smc_buf_desc *buf_desc, *bf_desc;
 408         struct list_head *buf_list;
 409         int i;
 410
 411         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 412                 if (is_rmb)
 413                         buf_list = &lgr->rmbs[i];
 414                 else
 415                         buf_list = &lgr->sndbufs[i];
 416                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
 417                                          list) {
 418                         list_del(&buf_desc->list);
 419                         smc_buf_free(lgr, is_rmb, buf_desc);
 420                 }
 421         }
 422 }
 423
 424 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
 425 {
 426         /* free send buffers */
 427         __smc_lgr_free_bufs(lgr, false);
 428         /* free rmbs */
 429         __smc_lgr_free_bufs(lgr, true);
 430 }
 431
 432 /* remove a link group */
 433 static void smc_lgr_free(struct smc_link_group *lgr)
 434 {
 435         smc_lgr_free_bufs(lgr);
 436         if (lgr->is_smcd)
 437                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 438         else
 439                 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]);
 440         kfree(lgr);
 441 }
 442
 443 void smc_lgr_forget(struct smc_link_group *lgr)
 444 {
 445         spin_lock_bh(&smc_lgr_list.lock);
 446         /* do not use this link group for new connections */
 447         if (!list_empty(&lgr->list))
 448                 list_del_init(&lgr->list);
 449         spin_unlock_bh(&smc_lgr_list.lock);
 450 }
 451
 452 /* terminate linkgroup abnormally */
 453 static void __smc_lgr_terminate(struct smc_link_group *lgr)
 454 {
 455         struct smc_connection *conn;
 456         struct smc_sock *smc;
 457         struct rb_node *node;
 458
 459         if (lgr->terminating)
 460                 return; /* lgr already terminating */
 461         lgr->terminating = 1;
 462         if (!list_empty(&lgr->list)) /* forget lgr */
 463                 list_del_init(&lgr->list);
 464         if (!lgr->is_smcd)
 465                 smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]);
 466
 467         write_lock_bh(&lgr->conns_lock);
 468         node = rb_first(&lgr->conns_all);
 469         while (node) {
 470                 conn = rb_entry(node, struct smc_connection, alert_node);
 471                 smc = container_of(conn, struct smc_sock, conn);
 472                 sock_hold(&smc->sk); /* sock_put in close work */
 473                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 474                 __smc_lgr_unregister_conn(conn);
 475                 conn->lgr = NULL;
 476                 write_unlock_bh(&lgr->conns_lock);
 477                 if (!schedule_work(&conn->close_work))
 478                         sock_put(&smc->sk);
 479                 write_lock_bh(&lgr->conns_lock);
 480                 node = rb_first(&lgr->conns_all);
 481         }
 482         write_unlock_bh(&lgr->conns_lock);
 483         if (!lgr->is_smcd)
 484                 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait);
 485         smc_lgr_schedule_free_work(lgr);
 486 }
 487
 488 void smc_lgr_terminate(struct smc_link_group *lgr)
 489 {
 490         spin_lock_bh(&smc_lgr_list.lock);
 491         __smc_lgr_terminate(lgr);
 492         spin_unlock_bh(&smc_lgr_list.lock);
 493 }
 494
 495 /* Called when IB port is terminated */
 496 void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 497 {
 498         struct smc_link_group *lgr, *l;
 499
 500         spin_lock_bh(&smc_lgr_list.lock);
 501         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 502                 if (!lgr->is_smcd &&
 503                     lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 504                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 505                         __smc_lgr_terminate(lgr);
 506         }
 507         spin_unlock_bh(&smc_lgr_list.lock);
 508 }
 509
 510 /* Called when SMC-D device is terminated or peer is lost */
 511 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 512 {
 513         struct smc_link_group *lgr, *l;
 514         LIST_HEAD(lgr_free_list);
 515
 516         /* run common cleanup function and build free list */
 517         spin_lock_bh(&smc_lgr_list.lock);
 518         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 519                 if (lgr->is_smcd && lgr->smcd == dev &&
 520                     (!peer_gid || lgr->peer_gid == peer_gid) &&
 521                     (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
 522                         __smc_lgr_terminate(lgr);
 523                         list_move(&lgr->list, &lgr_free_list);
 524                 }
 525         }
 526         spin_unlock_bh(&smc_lgr_list.lock);
 527
 528         /* cancel the regular free workers and actually free lgrs */
 529         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 530                 list_del_init(&lgr->list);
 531                 cancel_delayed_work_sync(&lgr->free_work);
 532                 if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */
 533                         smc_ism_signal_shutdown(lgr);
 534                 smc_lgr_free(lgr);
 535         }
 536 }
 537
 538 /* Determine vlan of internal TCP socket.
 539  * @vlan_id: address to store the determined vlan id into
 540  */
 541 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
 542 {
 543         struct dst_entry *dst = sk_dst_get(clcsock->sk);
 544         struct net_device *ndev;
 545         int i, nest_lvl, rc = 0;
 546
 547         ini->vlan_id = 0;
 548         if (!dst) {
 549                 rc = -ENOTCONN;
 550                 goto out;
 551         }
 552         if (!dst->dev) {
 553                 rc = -ENODEV;
 554                 goto out_rel;
 555         }
 556
 557         ndev = dst->dev;
 558         if (is_vlan_dev(ndev)) {
 559                 ini->vlan_id = vlan_dev_vlan_id(ndev);
 560                 goto out_rel;
 561         }
 562
 563         rtnl_lock();
 564         nest_lvl = dev_get_nest_level(ndev);
 565         for (i = 0; i < nest_lvl; i++) {
 566                 struct list_head *lower = &ndev->adj_list.lower;
 567
 568                 if (list_empty(lower))
 569                         break;
 570                 lower = lower->next;
 571                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
 572                 if (is_vlan_dev(ndev)) {
 573                         ini->vlan_id = vlan_dev_vlan_id(ndev);
 574                         break;
 575                 }
 576         }
 577         rtnl_unlock();
 578
 579 out_rel:
 580         dst_release(dst);
 581 out:
 582         return rc;
 583 }
 584
 585 static bool smcr_lgr_match(struct smc_link_group *lgr,
 586                            struct smc_clc_msg_local *lcl,
 587                            enum smc_lgr_role role, u32 clcqpn)
 588 {
 589         return !memcmp(lgr->peer_systemid, lcl->id_for_peer,
 590                        SMC_SYSTEMID_LEN) &&
 591                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid,
 592                         SMC_GID_SIZE) &&
 593                 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac,
 594                         sizeof(lcl->mac)) &&
 595                 lgr->role == role &&
 596                 (lgr->role == SMC_SERV ||
 597                  lgr->lnk[SMC_SINGLE_LINK].peer_qpn == clcqpn);
 598 }
 599
 600 static bool smcd_lgr_match(struct smc_link_group *lgr,
 601                            struct smcd_dev *smcismdev, u64 peer_gid)
 602 {
 603         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
 604 }
 605
 606 /* create a new SMC connection (and a new link group if necessary) */
 607 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
 608 {
 609         struct smc_connection *conn = &smc->conn;
 610         struct smc_link_group *lgr;
 611         enum smc_lgr_role role;
 612         int rc = 0;
 613
 614         ini->cln_first_contact = SMC_FIRST_CONTACT;
 615         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 616         if (role == SMC_CLNT && ini->srv_first_contact)
 617                 /* create new link group as well */
 618                 goto create;
 619
 620         /* determine if an existing link group can be reused */
 621         spin_lock_bh(&smc_lgr_list.lock);
 622         list_for_each_entry(lgr, &smc_lgr_list.list, list) {
 623                 write_lock_bh(&lgr->conns_lock);
 624                 if ((ini->is_smcd ?
 625                      smcd_lgr_match(lgr, ini->ism_dev, ini->ism_gid) :
 626                      smcr_lgr_match(lgr, ini->ib_lcl, role, ini->ib_clcqpn)) &&
 627                     !lgr->sync_err &&
 628                     lgr->vlan_id == ini->vlan_id &&
 629                     (role == SMC_CLNT ||
 630                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
 631                         /* link group found */
 632                         ini->cln_first_contact = SMC_REUSE_CONTACT;
 633                         conn->lgr = lgr;
 634                         smc_lgr_register_conn(conn); /* add smc conn to lgr */
 635                         if (delayed_work_pending(&lgr->free_work))
 636                                 cancel_delayed_work(&lgr->free_work);
 637                         write_unlock_bh(&lgr->conns_lock);
 638                         break;
 639                 }
 640                 write_unlock_bh(&lgr->conns_lock);
 641         }
 642         spin_unlock_bh(&smc_lgr_list.lock);
 643
 644         if (role == SMC_CLNT && !ini->srv_first_contact &&
 645             ini->cln_first_contact == SMC_FIRST_CONTACT) {
 646                 /* Server reuses a link group, but Client wants to start
 647                  * a new one
 648                  * send out_of_sync decline, reason synchr. error
 649                  */
 650                 return SMC_CLC_DECL_SYNCERR;
 651         }
 652
 653 create:
 654         if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
 655                 rc = smc_lgr_create(smc, ini);
 656                 if (rc)
 657                         goto out;
 658                 lgr = conn->lgr;
 659                 write_lock_bh(&lgr->conns_lock);
 660                 smc_lgr_register_conn(conn); /* add smc conn to lgr */
 661                 write_unlock_bh(&lgr->conns_lock);
 662         }
 663         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
 664         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
 665         conn->urg_state = SMC_URG_READ;
 666         if (ini->is_smcd) {
 667                 conn->rx_off = sizeof(struct smcd_cdc_msg);
 668                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
 669         }
 670 #ifndef KERNEL_HAS_ATOMIC64
 671         spin_lock_init(&conn->acurs_lock);
 672 #endif
 673
 674 out:
 675         return rc;
 676 }
 677
 678 /* convert the RMB size into the compressed notation - minimum 16K.
 679  * In contrast to plain ilog2, this rounds towards the next power of 2,
 680  * so the socket application gets at least its desired sndbuf / rcvbuf size.
 681  */
 682 static u8 smc_compress_bufsize(int size)
 683 {
 684         u8 compressed;
 685
 686         if (size <= SMC_BUF_MIN_SIZE)
 687                 return 0;
 688
 689         size = (size - 1) >> 14;
 690         compressed = ilog2(size) + 1;
 691         if (compressed >= SMC_RMBE_SIZES)
 692                 compressed = SMC_RMBE_SIZES - 1;
 693         return compressed;
 694 }
 695
 696 /* convert the RMB size from compressed notation into integer */
 697 int smc_uncompress_bufsize(u8 compressed)
 698 {
 699         u32 size;
 700
 701         size = 0x00000001 << (((int)compressed) + 14);
 702         return (int)size;
 703 }
 704
 705 /* try to reuse a sndbuf or rmb description slot for a certain
 706  * buffer size; if not available, return NULL
 707  */
 708 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
 709                                              rwlock_t *lock,
 710                                              struct list_head *buf_list)
 711 {
 712         struct smc_buf_desc *buf_slot;
 713
 714         read_lock_bh(lock);
 715         list_for_each_entry(buf_slot, buf_list, list) {
 716                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
 717                         read_unlock_bh(lock);
 718                         return buf_slot;
 719                 }
 720         }
 721         read_unlock_bh(lock);
 722         return NULL;
 723 }
 724
 725 /* one of the conditions for announcing a receiver's current window size is
 726  * that it "results in a minimum increase in the window size of 10% of the
 727  * receive buffer space" [RFC7609]
 728  */
 729 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
 730 {
 731         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
 732 }
 733
 734 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
 735                                                 bool is_rmb, int bufsize)
 736 {
 737         struct smc_buf_desc *buf_desc;
 738         struct smc_link *lnk;
 739         int rc;
 740
 741         /* try to alloc a new buffer */
 742         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 743         if (!buf_desc)
 744                 return ERR_PTR(-ENOMEM);
 745
 746         buf_desc->order = get_order(bufsize);
 747         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
 748                                       __GFP_NOMEMALLOC | __GFP_COMP |
 749                                       __GFP_NORETRY | __GFP_ZERO,
 750                                       buf_desc->order);
 751         if (!buf_desc->pages) {
 752                 kfree(buf_desc);
 753                 return ERR_PTR(-EAGAIN);
 754         }
 755         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
 756
 757         /* build the sg table from the pages */
 758         lnk = &lgr->lnk[SMC_SINGLE_LINK];
 759         rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1,
 760                             GFP_KERNEL);
 761         if (rc) {
 762                 smc_buf_free(lgr, is_rmb, buf_desc);
 763                 return ERR_PTR(rc);
 764         }
 765         sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl,
 766                    buf_desc->cpu_addr, bufsize);
 767
 768         /* map sg table to DMA address */
 769         rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc,
 770                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
 771         /* SMC protocol depends on mapping to one DMA address only */
 772         if (rc != 1)  {
 773                 smc_buf_free(lgr, is_rmb, buf_desc);
 774                 return ERR_PTR(-EAGAIN);
 775         }
 776
 777         /* create a new memory region for the RMB */
 778         if (is_rmb) {
 779                 rc = smc_ib_get_memory_region(lnk->roce_pd,
 780                                               IB_ACCESS_REMOTE_WRITE |
 781                                               IB_ACCESS_LOCAL_WRITE,
 782                                               buf_desc);
 783                 if (rc) {
 784                         smc_buf_free(lgr, is_rmb, buf_desc);
 785                         return ERR_PTR(rc);
 786                 }
 787         }
 788
 789         buf_desc->len = bufsize;
 790         return buf_desc;
 791 }
 792
 793 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
 794
 795 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
 796                                                 bool is_dmb, int bufsize)
 797 {
 798         struct smc_buf_desc *buf_desc;
 799         int rc;
 800
 801         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
 802                 return ERR_PTR(-EAGAIN);
 803
 804         /* try to alloc a new DMB */
 805         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
 806         if (!buf_desc)
 807                 return ERR_PTR(-ENOMEM);
 808         if (is_dmb) {
 809                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
 810                 if (rc) {
 811                         kfree(buf_desc);
 812                         return ERR_PTR(-EAGAIN);
 813                 }
 814                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
 815                 /* CDC header stored in buf. So, pretend it was smaller */
 816                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
 817         } else {
 818                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
 819                                              __GFP_NOWARN | __GFP_NORETRY |
 820                                              __GFP_NOMEMALLOC);
 821                 if (!buf_desc->cpu_addr) {
 822                         kfree(buf_desc);
 823                         return ERR_PTR(-EAGAIN);
 824                 }
 825                 buf_desc->len = bufsize;
 826         }
 827         return buf_desc;
 828 }
 829
 830 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 831 {
 832         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
 833         struct smc_connection *conn = &smc->conn;
 834         struct smc_link_group *lgr = conn->lgr;
 835         struct list_head *buf_list;
 836         int bufsize, bufsize_short;
 837         int sk_buf_size;
 838         rwlock_t *lock;
 839
 840         if (is_rmb)
 841                 /* use socket recv buffer size (w/o overhead) as start value */
 842                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
 843         else
 844                 /* use socket send buffer size (w/o overhead) as start value */
 845                 sk_buf_size = smc->sk.sk_sndbuf / 2;
 846
 847         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
 848              bufsize_short >= 0; bufsize_short--) {
 849
 850                 if (is_rmb) {
 851                         lock = &lgr->rmbs_lock;
 852                         buf_list = &lgr->rmbs[bufsize_short];
 853                 } else {
 854                         lock = &lgr->sndbufs_lock;
 855                         buf_list = &lgr->sndbufs[bufsize_short];
 856                 }
 857                 bufsize = smc_uncompress_bufsize(bufsize_short);
 858                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
 859                         continue;
 860
 861                 /* check for reusable slot in the link group */
 862                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
 863                 if (buf_desc) {
 864                         memset(buf_desc->cpu_addr, 0, bufsize);
 865                         break; /* found reusable slot */
 866                 }
 867
 868                 if (is_smcd)
 869                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
 870                 else
 871                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
 872
 873                 if (PTR_ERR(buf_desc) == -ENOMEM)
 874                         break;
 875                 if (IS_ERR(buf_desc))
 876                         continue;
 877
 878                 buf_desc->used = 1;
 879                 write_lock_bh(lock);
 880                 list_add(&buf_desc->list, buf_list);
 881                 write_unlock_bh(lock);
 882                 break; /* found */
 883         }
 884
 885         if (IS_ERR(buf_desc))
 886                 return -ENOMEM;
 887
 888         if (is_rmb) {
 889                 conn->rmb_desc = buf_desc;
 890                 conn->rmbe_size_short = bufsize_short;
 891                 smc->sk.sk_rcvbuf = bufsize * 2;
 892                 atomic_set(&conn->bytes_to_rcv, 0);
 893                 conn->rmbe_update_limit =
 894                         smc_rmb_wnd_update_limit(buf_desc->len);
 895                 if (is_smcd)
 896                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
 897         } else {
 898                 conn->sndbuf_desc = buf_desc;
 899                 smc->sk.sk_sndbuf = bufsize * 2;
 900                 atomic_set(&conn->sndbuf_space, bufsize);
 901         }
 902         return 0;
 903 }
 904
 905 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
 906 {
 907         struct smc_link_group *lgr = conn->lgr;
 908
 909         if (!conn->lgr || conn->lgr->is_smcd)
 910                 return;
 911         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 912                                conn->sndbuf_desc, DMA_TO_DEVICE);
 913 }
 914
 915 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
 916 {
 917         struct smc_link_group *lgr = conn->lgr;
 918
 919         if (!conn->lgr || conn->lgr->is_smcd)
 920                 return;
 921         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 922                                   conn->sndbuf_desc, DMA_TO_DEVICE);
 923 }
 924
 925 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
 926 {
 927         struct smc_link_group *lgr = conn->lgr;
 928
 929         if (!conn->lgr || conn->lgr->is_smcd)
 930                 return;
 931         smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 932                                conn->rmb_desc, DMA_FROM_DEVICE);
 933 }
 934
 935 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
 936 {
 937         struct smc_link_group *lgr = conn->lgr;
 938
 939         if (!conn->lgr || conn->lgr->is_smcd)
 940                 return;
 941         smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev,
 942                                   conn->rmb_desc, DMA_FROM_DEVICE);
 943 }
 944
 945 /* create the send and receive buffer for an SMC socket;
 946  * receive buffers are called RMBs;
 947  * (even though the SMC protocol allows more than one RMB-element per RMB,
 948  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
 949  * extra RMB for every connection in a link group
 950  */
 951 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
 952 {
 953         int rc;
 954
 955         /* create send buffer */
 956         rc = __smc_buf_create(smc, is_smcd, false);
 957         if (rc)
 958                 return rc;
 959         /* create rmb */
 960         rc = __smc_buf_create(smc, is_smcd, true);
 961         if (rc)
 962                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
 963         return rc;
 964 }
 965
 966 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
 967 {
 968         int i;
 969
 970         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
 971                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
 972                         return i;
 973         }
 974         return -ENOSPC;
 975 }
 976
 977 /* add a new rtoken from peer */
 978 int smc_rtoken_add(struct smc_link_group *lgr, __be64 nw_vaddr, __be32 nw_rkey)
 979 {
 980         u64 dma_addr = be64_to_cpu(nw_vaddr);
 981         u32 rkey = ntohl(nw_rkey);
 982         int i;
 983
 984         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 985                 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) &&
 986                     (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) &&
 987                     test_bit(i, lgr->rtokens_used_mask)) {
 988                         /* already in list */
 989                         return i;
 990                 }
 991         }
 992         i = smc_rmb_reserve_rtoken_idx(lgr);
 993         if (i < 0)
 994                 return i;
 995         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = rkey;
 996         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = dma_addr;
 997         return i;
 998 }
 999
1000 /* delete an rtoken */
1001 int smc_rtoken_delete(struct smc_link_group *lgr, __be32 nw_rkey)
1002 {
1003         u32 rkey = ntohl(nw_rkey);
1004         int i;
1005
1006         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1007                 if (lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey &&
1008                     test_bit(i, lgr->rtokens_used_mask)) {
1009                         lgr->rtokens[i][SMC_SINGLE_LINK].rkey = 0;
1010                         lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr = 0;
1011
1012                         clear_bit(i, lgr->rtokens_used_mask);
1013                         return 0;
1014                 }
1015         }
1016         return -ENOENT;
1017 }
1018
1019 /* save rkey and dma_addr received from peer during clc handshake */
1020 int smc_rmb_rtoken_handling(struct smc_connection *conn,
1021                             struct smc_clc_msg_accept_confirm *clc)
1022 {
1023         conn->rtoken_idx = smc_rtoken_add(conn->lgr, clc->rmb_dma_addr,
1024                                           clc->rmb_rkey);
1025         if (conn->rtoken_idx < 0)
1026                 return conn->rtoken_idx;
1027         return 0;
1028 }
1029
1030 /* Called (from smc_exit) when module is removed */
1031 void smc_core_exit(void)
1032 {
1033         struct smc_link_group *lgr, *lg;
1034         LIST_HEAD(lgr_freeing_list);
1035
1036         spin_lock_bh(&smc_lgr_list.lock);
1037         if (!list_empty(&smc_lgr_list.list))
1038                 list_splice_init(&smc_lgr_list.list, &lgr_freeing_list);
1039         spin_unlock_bh(&smc_lgr_list.lock);
1040         list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
1041                 list_del_init(&lgr->list);
1042                 if (!lgr->is_smcd) {
1043                         struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK];
1044
1045                         if (lnk->state == SMC_LNK_ACTIVE)
1046                                 smc_llc_send_delete_link(lnk, SMC_LLC_REQ,
1047                                                          false);
1048                         smc_llc_link_inactive(lnk);
1049                 }
1050                 cancel_delayed_work_sync(&lgr->free_work);
1051                 if (lgr->is_smcd)
1052                         smc_ism_signal_shutdown(lgr);
1053                 smc_lgr_free(lgr); /* free link group */
1054         }
1055 }