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 <linux/wait.h>
  17 #include <linux/reboot.h>
  18 #include <linux/mutex.h>
  19 #include <net/tcp.h>
  20 #include <net/sock.h>
  21 #include <rdma/ib_verbs.h>
  22 #include <rdma/ib_cache.h>
  23
  24 #include "smc.h"
  25 #include "smc_clc.h"
  26 #include "smc_core.h"
  27 #include "smc_ib.h"
  28 #include "smc_wr.h"
  29 #include "smc_llc.h"
  30 #include "smc_cdc.h"
  31 #include "smc_close.h"
  32 #include "smc_ism.h"
  33
  34 #define SMC_LGR_NUM_INCR                256
  35 #define SMC_LGR_FREE_DELAY_SERV         (600 * HZ)
  36 #define SMC_LGR_FREE_DELAY_CLNT         (SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
  37 #define SMC_LGR_FREE_DELAY_FAST         (8 * HZ)
  38
  39 static struct smc_lgr_list smc_lgr_list = {     /* established link groups */
  40         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
  41         .list = LIST_HEAD_INIT(smc_lgr_list.list),
  42         .num = 0,
  43 };
  44
  45 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
  46 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
  47
  48 struct smc_ib_up_work {
  49         struct work_struct      work;
  50         struct smc_link_group   *lgr;
  51         struct smc_ib_device    *smcibdev;
  52         u8                      ibport;
  53 };
  54
  55 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
  56                          struct smc_buf_desc *buf_desc);
  57 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
  58
  59 static void smc_link_up_work(struct work_struct *work);
  60 static void smc_link_down_work(struct work_struct *work);
  61
  62 /* return head of link group list and its lock for a given link group */
  63 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
  64                                                   spinlock_t **lgr_lock)
  65 {
  66         if (lgr->is_smcd) {
  67                 *lgr_lock = &lgr->smcd->lgr_lock;
  68                 return &lgr->smcd->lgr_list;
  69         }
  70
  71         *lgr_lock = &smc_lgr_list.lock;
  72         return &smc_lgr_list.list;
  73 }
  74
  75 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
  76 {
  77         /* client link group creation always follows the server link group
  78          * creation. For client use a somewhat higher removal delay time,
  79          * otherwise there is a risk of out-of-sync link groups.
  80          */
  81         if (!lgr->freeing && !lgr->freefast) {
  82                 mod_delayed_work(system_wq, &lgr->free_work,
  83                                  (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
  84                                                 SMC_LGR_FREE_DELAY_CLNT :
  85                                                 SMC_LGR_FREE_DELAY_SERV);
  86         }
  87 }
  88
  89 void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)
  90 {
  91         if (!lgr->freeing && !lgr->freefast) {
  92                 lgr->freefast = 1;
  93                 mod_delayed_work(system_wq, &lgr->free_work,
  94                                  SMC_LGR_FREE_DELAY_FAST);
  95         }
  96 }
  97
  98 /* Register connection's alert token in our lookup structure.
  99  * To use rbtrees we have to implement our own insert core.
 100  * Requires @conns_lock
 101  * @smc         connection to register
 102  * Returns 0 on success, != otherwise.
 103  */
 104 static void smc_lgr_add_alert_token(struct smc_connection *conn)
 105 {
 106         struct rb_node **link, *parent = NULL;
 107         u32 token = conn->alert_token_local;
 108
 109         link = &conn->lgr->conns_all.rb_node;
 110         while (*link) {
 111                 struct smc_connection *cur = rb_entry(*link,
 112                                         struct smc_connection, alert_node);
 113
 114                 parent = *link;
 115                 if (cur->alert_token_local > token)
 116                         link = &parent->rb_left;
 117                 else
 118                         link = &parent->rb_right;
 119         }
 120         /* Put the new node there */
 121         rb_link_node(&conn->alert_node, parent, link);
 122         rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
 123 }
 124
 125 /* assign an SMC-R link to the connection */
 126 static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
 127 {
 128         enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
 129                                        SMC_LNK_ACTIVE;
 130         int i, j;
 131
 132         /* do link balancing */
 133         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 134                 struct smc_link *lnk = &conn->lgr->lnk[i];
 135
 136                 if (lnk->state != expected || lnk->link_is_asym)
 137                         continue;
 138                 if (conn->lgr->role == SMC_CLNT) {
 139                         conn->lnk = lnk; /* temporary, SMC server assigns link*/
 140                         break;
 141                 }
 142                 if (conn->lgr->conns_num % 2) {
 143                         for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
 144                                 struct smc_link *lnk2;
 145
 146                                 lnk2 = &conn->lgr->lnk[j];
 147                                 if (lnk2->state == expected &&
 148                                     !lnk2->link_is_asym) {
 149                                         conn->lnk = lnk2;
 150                                         break;
 151                                 }
 152                         }
 153                 }
 154                 if (!conn->lnk)
 155                         conn->lnk = lnk;
 156                 break;
 157         }
 158         if (!conn->lnk)
 159                 return SMC_CLC_DECL_NOACTLINK;
 160         return 0;
 161 }
 162
 163 /* Register connection in link group by assigning an alert token
 164  * registered in a search tree.
 165  * Requires @conns_lock
 166  * Note that '0' is a reserved value and not assigned.
 167  */
 168 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
 169 {
 170         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 171         static atomic_t nexttoken = ATOMIC_INIT(0);
 172         int rc;
 173
 174         if (!conn->lgr->is_smcd) {
 175                 rc = smcr_lgr_conn_assign_link(conn, first);
 176                 if (rc)
 177                         return rc;
 178         }
 179         /* find a new alert_token_local value not yet used by some connection
 180          * in this link group
 181          */
 182         sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
 183         while (!conn->alert_token_local) {
 184                 conn->alert_token_local = atomic_inc_return(&nexttoken);
 185                 if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
 186                         conn->alert_token_local = 0;
 187         }
 188         smc_lgr_add_alert_token(conn);
 189         conn->lgr->conns_num++;
 190         return 0;
 191 }
 192
 193 /* Unregister connection and reset the alert token of the given connection<
 194  */
 195 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
 196 {
 197         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 198         struct smc_link_group *lgr = conn->lgr;
 199
 200         rb_erase(&conn->alert_node, &lgr->conns_all);
 201         lgr->conns_num--;
 202         conn->alert_token_local = 0;
 203         sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
 204 }
 205
 206 /* Unregister connection from lgr
 207  */
 208 static void smc_lgr_unregister_conn(struct smc_connection *conn)
 209 {
 210         struct smc_link_group *lgr = conn->lgr;
 211
 212         if (!lgr)
 213                 return;
 214         write_lock_bh(&lgr->conns_lock);
 215         if (conn->alert_token_local) {
 216                 __smc_lgr_unregister_conn(conn);
 217         }
 218         write_unlock_bh(&lgr->conns_lock);
 219         conn->lgr = NULL;
 220 }
 221
 222 void smc_lgr_cleanup_early(struct smc_connection *conn)
 223 {
 224         struct smc_link_group *lgr = conn->lgr;
 225         struct list_head *lgr_list;
 226         spinlock_t *lgr_lock;
 227
 228         if (!lgr)
 229                 return;
 230
 231         smc_conn_free(conn);
 232         lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
 233         spin_lock_bh(lgr_lock);
 234         /* do not use this link group for new connections */
 235         if (!list_empty(lgr_list))
 236                 list_del_init(lgr_list);
 237         spin_unlock_bh(lgr_lock);
 238         smc_lgr_schedule_free_work_fast(lgr);
 239 }
 240
 241 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
 242 {
 243         int i;
 244
 245         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 246                 struct smc_link *lnk = &lgr->lnk[i];
 247
 248                 if (smc_link_usable(lnk))
 249                         lnk->state = SMC_LNK_INACTIVE;
 250         }
 251         wake_up_all(&lgr->llc_msg_waiter);
 252         wake_up_all(&lgr->llc_flow_waiter);
 253 }
 254
 255 static void smc_lgr_free(struct smc_link_group *lgr);
 256
 257 static void smc_lgr_free_work(struct work_struct *work)
 258 {
 259         struct smc_link_group *lgr = container_of(to_delayed_work(work),
 260                                                   struct smc_link_group,
 261                                                   free_work);
 262         spinlock_t *lgr_lock;
 263         bool conns;
 264
 265         smc_lgr_list_head(lgr, &lgr_lock);
 266         spin_lock_bh(lgr_lock);
 267         if (lgr->freeing) {
 268                 spin_unlock_bh(lgr_lock);
 269                 return;
 270         }
 271         read_lock_bh(&lgr->conns_lock);
 272         conns = RB_EMPTY_ROOT(&lgr->conns_all);
 273         read_unlock_bh(&lgr->conns_lock);
 274         if (!conns) { /* number of lgr connections is no longer zero */
 275                 spin_unlock_bh(lgr_lock);
 276                 return;
 277         }
 278         list_del_init(&lgr->list); /* remove from smc_lgr_list */
 279         lgr->freeing = 1; /* this instance does the freeing, no new schedule */
 280         spin_unlock_bh(lgr_lock);
 281         cancel_delayed_work(&lgr->free_work);
 282
 283         if (!lgr->is_smcd && !lgr->terminating)
 284                 smc_llc_send_link_delete_all(lgr, true,
 285                                              SMC_LLC_DEL_PROG_INIT_TERM);
 286         if (lgr->is_smcd && !lgr->terminating)
 287                 smc_ism_signal_shutdown(lgr);
 288         if (!lgr->is_smcd)
 289                 smcr_lgr_link_deactivate_all(lgr);
 290         smc_lgr_free(lgr);
 291 }
 292
 293 static void smc_lgr_terminate_work(struct work_struct *work)
 294 {
 295         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
 296                                                   terminate_work);
 297
 298         __smc_lgr_terminate(lgr, true);
 299 }
 300
 301 /* return next unique link id for the lgr */
 302 static u8 smcr_next_link_id(struct smc_link_group *lgr)
 303 {
 304         u8 link_id;
 305         int i;
 306
 307         while (1) {
 308                 link_id = ++lgr->next_link_id;
 309                 if (!link_id)   /* skip zero as link_id */
 310                         link_id = ++lgr->next_link_id;
 311                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 312                         if (smc_link_usable(&lgr->lnk[i]) &&
 313                             lgr->lnk[i].link_id == link_id)
 314                                 continue;
 315                 }
 316                 break;
 317         }
 318         return link_id;
 319 }
 320
 321 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
 322                    u8 link_idx, struct smc_init_info *ini)
 323 {
 324         u8 rndvec[3];
 325         int rc;
 326
 327         get_device(&ini->ib_dev->ibdev->dev);
 328         atomic_inc(&ini->ib_dev->lnk_cnt);
 329         lnk->state = SMC_LNK_ACTIVATING;
 330         lnk->link_id = smcr_next_link_id(lgr);
 331         lnk->lgr = lgr;
 332         lnk->link_idx = link_idx;
 333         lnk->smcibdev = ini->ib_dev;
 334         lnk->ibport = ini->ib_port;
 335         lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
 336         smc_llc_link_set_uid(lnk);
 337         INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
 338         if (!ini->ib_dev->initialized) {
 339                 rc = (int)smc_ib_setup_per_ibdev(ini->ib_dev);
 340                 if (rc)
 341                         goto out;
 342         }
 343         get_random_bytes(rndvec, sizeof(rndvec));
 344         lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 345                 (rndvec[2] << 16);
 346         rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 347                                   ini->vlan_id, lnk->gid, &lnk->sgid_index);
 348         if (rc)
 349                 goto out;
 350         rc = smc_llc_link_init(lnk);
 351         if (rc)
 352                 goto out;
 353         rc = smc_wr_alloc_link_mem(lnk);
 354         if (rc)
 355                 goto clear_llc_lnk;
 356         rc = smc_ib_create_protection_domain(lnk);
 357         if (rc)
 358                 goto free_link_mem;
 359         rc = smc_ib_create_queue_pair(lnk);
 360         if (rc)
 361                 goto dealloc_pd;
 362         rc = smc_wr_create_link(lnk);
 363         if (rc)
 364                 goto destroy_qp;
 365         return 0;
 366
 367 destroy_qp:
 368         smc_ib_destroy_queue_pair(lnk);
 369 dealloc_pd:
 370         smc_ib_dealloc_protection_domain(lnk);
 371 free_link_mem:
 372         smc_wr_free_link_mem(lnk);
 373 clear_llc_lnk:
 374         smc_llc_link_clear(lnk, false);
 375 out:
 376         put_device(&ini->ib_dev->ibdev->dev);
 377         memset(lnk, 0, sizeof(struct smc_link));
 378         lnk->state = SMC_LNK_UNUSED;
 379         if (!atomic_dec_return(&ini->ib_dev->lnk_cnt))
 380                 wake_up(&ini->ib_dev->lnks_deleted);
 381         return rc;
 382 }
 383
 384 /* create a new SMC link group */
 385 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 386 {
 387         struct smc_link_group *lgr;
 388         struct list_head *lgr_list;
 389         struct smc_link *lnk;
 390         spinlock_t *lgr_lock;
 391         u8 link_idx;
 392         int rc = 0;
 393         int i;
 394
 395         if (ini->is_smcd && ini->vlan_id) {
 396                 if (smc_ism_get_vlan(ini->ism_dev, ini->vlan_id)) {
 397                         rc = SMC_CLC_DECL_ISMVLANERR;
 398                         goto out;
 399                 }
 400         }
 401
 402         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 403         if (!lgr) {
 404                 rc = SMC_CLC_DECL_MEM;
 405                 goto ism_put_vlan;
 406         }
 407         lgr->is_smcd = ini->is_smcd;
 408         lgr->sync_err = 0;
 409         lgr->terminating = 0;
 410         lgr->freefast = 0;
 411         lgr->freeing = 0;
 412         lgr->vlan_id = ini->vlan_id;
 413         mutex_init(&lgr->sndbufs_lock);
 414         mutex_init(&lgr->rmbs_lock);
 415         rwlock_init(&lgr->conns_lock);
 416         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 417                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 418                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 419         }
 420         lgr->next_link_id = 0;
 421         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 422         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 423         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 424         INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
 425         lgr->conns_all = RB_ROOT;
 426         if (ini->is_smcd) {
 427                 /* SMC-D specific settings */
 428                 get_device(&ini->ism_dev->dev);
 429                 lgr->peer_gid = ini->ism_gid;
 430                 lgr->smcd = ini->ism_dev;
 431                 lgr_list = &ini->ism_dev->lgr_list;
 432                 lgr_lock = &lgr->smcd->lgr_lock;
 433                 lgr->peer_shutdown = 0;
 434                 atomic_inc(&ini->ism_dev->lgr_cnt);
 435         } else {
 436                 /* SMC-R specific settings */
 437                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 438                 memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
 439                        SMC_SYSTEMID_LEN);
 440                 memcpy(lgr->pnet_id, ini->ib_dev->pnetid[ini->ib_port - 1],
 441                        SMC_MAX_PNETID_LEN);
 442                 smc_llc_lgr_init(lgr, smc);
 443
 444                 link_idx = SMC_SINGLE_LINK;
 445                 lnk = &lgr->lnk[link_idx];
 446                 rc = smcr_link_init(lgr, lnk, link_idx, ini);
 447                 if (rc)
 448                         goto free_lgr;
 449                 lgr_list = &smc_lgr_list.list;
 450                 lgr_lock = &smc_lgr_list.lock;
 451                 atomic_inc(&lgr_cnt);
 452         }
 453         smc->conn.lgr = lgr;
 454         spin_lock_bh(lgr_lock);
 455         list_add(&lgr->list, lgr_list);
 456         spin_unlock_bh(lgr_lock);
 457         return 0;
 458
 459 free_lgr:
 460         kfree(lgr);
 461 ism_put_vlan:
 462         if (ini->is_smcd && ini->vlan_id)
 463                 smc_ism_put_vlan(ini->ism_dev, ini->vlan_id);
 464 out:
 465         if (rc < 0) {
 466                 if (rc == -ENOMEM)
 467                         rc = SMC_CLC_DECL_MEM;
 468                 else
 469                         rc = SMC_CLC_DECL_INTERR;
 470         }
 471         return rc;
 472 }
 473
 474 static int smc_write_space(struct smc_connection *conn)
 475 {
 476         int buffer_len = conn->peer_rmbe_size;
 477         union smc_host_cursor prod;
 478         union smc_host_cursor cons;
 479         int space;
 480
 481         smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
 482         smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
 483         /* determine rx_buf space */
 484         space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
 485         return space;
 486 }
 487
 488 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
 489                              struct smc_wr_buf *wr_buf)
 490 {
 491         struct smc_connection *conn = &smc->conn;
 492         union smc_host_cursor cons, fin;
 493         int rc = 0;
 494         int diff;
 495
 496         smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
 497         smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
 498         /* set prod cursor to old state, enforce tx_rdma_writes() */
 499         smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
 500         smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
 501
 502         if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
 503                 /* cons cursor advanced more than fin, and prod was set
 504                  * fin above, so now prod is smaller than cons. Fix that.
 505                  */
 506                 diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
 507                 smc_curs_add(conn->sndbuf_desc->len,
 508                              &conn->tx_curs_sent, diff);
 509                 smc_curs_add(conn->sndbuf_desc->len,
 510                              &conn->tx_curs_fin, diff);
 511
 512                 smp_mb__before_atomic();
 513                 atomic_add(diff, &conn->sndbuf_space);
 514                 smp_mb__after_atomic();
 515
 516                 smc_curs_add(conn->peer_rmbe_size,
 517                              &conn->local_tx_ctrl.prod, diff);
 518                 smc_curs_add(conn->peer_rmbe_size,
 519                              &conn->local_tx_ctrl_fin, diff);
 520         }
 521         /* recalculate, value is used by tx_rdma_writes() */
 522         atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
 523
 524         if (smc->sk.sk_state != SMC_INIT &&
 525             smc->sk.sk_state != SMC_CLOSED) {
 526                 rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
 527                 if (!rc) {
 528                         schedule_delayed_work(&conn->tx_work, 0);
 529                         smc->sk.sk_data_ready(&smc->sk);
 530                 }
 531         } else {
 532                 smc_wr_tx_put_slot(conn->lnk,
 533                                    (struct smc_wr_tx_pend_priv *)pend);
 534         }
 535         return rc;
 536 }
 537
 538 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
 539                                   struct smc_link *from_lnk, bool is_dev_err)
 540 {
 541         struct smc_link *to_lnk = NULL;
 542         struct smc_cdc_tx_pend *pend;
 543         struct smc_connection *conn;
 544         struct smc_wr_buf *wr_buf;
 545         struct smc_sock *smc;
 546         struct rb_node *node;
 547         int i, rc = 0;
 548
 549         /* link is inactive, wake up tx waiters */
 550         smc_wr_wakeup_tx_wait(from_lnk);
 551
 552         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 553                 if (lgr->lnk[i].state != SMC_LNK_ACTIVE ||
 554                     i == from_lnk->link_idx)
 555                         continue;
 556                 if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
 557                     from_lnk->ibport == lgr->lnk[i].ibport) {
 558                         continue;
 559                 }
 560                 to_lnk = &lgr->lnk[i];
 561                 break;
 562         }
 563         if (!to_lnk) {
 564                 smc_lgr_terminate_sched(lgr);
 565                 return NULL;
 566         }
 567 again:
 568         read_lock_bh(&lgr->conns_lock);
 569         for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
 570                 conn = rb_entry(node, struct smc_connection, alert_node);
 571                 if (conn->lnk != from_lnk)
 572                         continue;
 573                 smc = container_of(conn, struct smc_sock, conn);
 574                 /* conn->lnk not yet set in SMC_INIT state */
 575                 if (smc->sk.sk_state == SMC_INIT)
 576                         continue;
 577                 if (smc->sk.sk_state == SMC_CLOSED ||
 578                     smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
 579                     smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
 580                     smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
 581                     smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
 582                     smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
 583                     smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
 584                     smc->sk.sk_state == SMC_PEERABORTWAIT ||
 585                     smc->sk.sk_state == SMC_PROCESSABORT) {
 586                         spin_lock_bh(&conn->send_lock);
 587                         conn->lnk = to_lnk;
 588                         spin_unlock_bh(&conn->send_lock);
 589                         continue;
 590                 }
 591                 sock_hold(&smc->sk);
 592                 read_unlock_bh(&lgr->conns_lock);
 593                 /* pre-fetch buffer outside of send_lock, might sleep */
 594                 rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
 595                 if (rc) {
 596                         smcr_link_down_cond_sched(to_lnk);
 597                         return NULL;
 598                 }
 599                 /* avoid race with smcr_tx_sndbuf_nonempty() */
 600                 spin_lock_bh(&conn->send_lock);
 601                 conn->lnk = to_lnk;
 602                 rc = smc_switch_cursor(smc, pend, wr_buf);
 603                 spin_unlock_bh(&conn->send_lock);
 604                 sock_put(&smc->sk);
 605                 if (rc) {
 606                         smcr_link_down_cond_sched(to_lnk);
 607                         return NULL;
 608                 }
 609                 goto again;
 610         }
 611         read_unlock_bh(&lgr->conns_lock);
 612         return to_lnk;
 613 }
 614
 615 static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc,
 616                            struct smc_link_group *lgr)
 617 {
 618         int rc;
 619
 620         if (rmb_desc->is_conf_rkey && !list_empty(&lgr->list)) {
 621                 /* unregister rmb with peer */
 622                 rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
 623                 if (!rc) {
 624                         /* protect against smc_llc_cli_rkey_exchange() */
 625                         mutex_lock(&lgr->llc_conf_mutex);
 626                         smc_llc_do_delete_rkey(lgr, rmb_desc);
 627                         rmb_desc->is_conf_rkey = false;
 628                         mutex_unlock(&lgr->llc_conf_mutex);
 629                         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
 630                 }
 631         }
 632
 633         if (rmb_desc->is_reg_err) {
 634                 /* buf registration failed, reuse not possible */
 635                 mutex_lock(&lgr->rmbs_lock);
 636                 list_del(&rmb_desc->list);
 637                 mutex_unlock(&lgr->rmbs_lock);
 638
 639                 smc_buf_free(lgr, true, rmb_desc);
 640         } else {
 641                 rmb_desc->used = 0;
 642         }
 643 }
 644
 645 static void smc_buf_unuse(struct smc_connection *conn,
 646                           struct smc_link_group *lgr)
 647 {
 648         if (conn->sndbuf_desc)
 649                 conn->sndbuf_desc->used = 0;
 650         if (conn->rmb_desc && lgr->is_smcd)
 651                 conn->rmb_desc->used = 0;
 652         else if (conn->rmb_desc)
 653                 smcr_buf_unuse(conn->rmb_desc, lgr);
 654 }
 655
 656 /* remove a finished connection from its link group */
 657 void smc_conn_free(struct smc_connection *conn)
 658 {
 659         struct smc_link_group *lgr = conn->lgr;
 660
 661         if (!lgr)
 662                 return;
 663         if (lgr->is_smcd) {
 664                 if (!list_empty(&lgr->list))
 665                         smc_ism_unset_conn(conn);
 666                 tasklet_kill(&conn->rx_tsklet);
 667         } else {
 668                 smc_cdc_tx_dismiss_slots(conn);
 669                 if (current_work() != &conn->abort_work)
 670                         cancel_work_sync(&conn->abort_work);
 671         }
 672         if (!list_empty(&lgr->list)) {
 673                 smc_lgr_unregister_conn(conn);
 674                 smc_buf_unuse(conn, lgr); /* allow buffer reuse */
 675         }
 676
 677         if (!lgr->conns_num)
 678                 smc_lgr_schedule_free_work(lgr);
 679 }
 680
 681 /* unregister a link from a buf_desc */
 682 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
 683                                 struct smc_link *lnk)
 684 {
 685         if (is_rmb)
 686                 buf_desc->is_reg_mr[lnk->link_idx] = false;
 687         if (!buf_desc->is_map_ib[lnk->link_idx])
 688                 return;
 689         if (is_rmb) {
 690                 if (buf_desc->mr_rx[lnk->link_idx]) {
 691                         smc_ib_put_memory_region(
 692                                         buf_desc->mr_rx[lnk->link_idx]);
 693                         buf_desc->mr_rx[lnk->link_idx] = NULL;
 694                 }
 695                 smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
 696         } else {
 697                 smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
 698         }
 699         sg_free_table(&buf_desc->sgt[lnk->link_idx]);
 700         buf_desc->is_map_ib[lnk->link_idx] = false;
 701 }
 702
 703 /* unmap all buffers of lgr for a deleted link */
 704 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
 705 {
 706         struct smc_link_group *lgr = lnk->lgr;
 707         struct smc_buf_desc *buf_desc, *bf;
 708         int i;
 709
 710         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 711                 mutex_lock(&lgr->rmbs_lock);
 712                 list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
 713                         smcr_buf_unmap_link(buf_desc, true, lnk);
 714                 mutex_unlock(&lgr->rmbs_lock);
 715                 mutex_lock(&lgr->sndbufs_lock);
 716                 list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
 717                                          list)
 718                         smcr_buf_unmap_link(buf_desc, false, lnk);
 719                 mutex_unlock(&lgr->sndbufs_lock);
 720         }
 721 }
 722
 723 static void smcr_rtoken_clear_link(struct smc_link *lnk)
 724 {
 725         struct smc_link_group *lgr = lnk->lgr;
 726         int i;
 727
 728         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
 729                 lgr->rtokens[i][lnk->link_idx].rkey = 0;
 730                 lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
 731         }
 732 }
 733
 734 /* must be called under lgr->llc_conf_mutex lock */
 735 void smcr_link_clear(struct smc_link *lnk, bool log)
 736 {
 737         struct smc_ib_device *smcibdev;
 738
 739         if (!lnk->lgr || lnk->state == SMC_LNK_UNUSED)
 740                 return;
 741         lnk->peer_qpn = 0;
 742         smc_llc_link_clear(lnk, log);
 743         smcr_buf_unmap_lgr(lnk);
 744         smcr_rtoken_clear_link(lnk);
 745         smc_ib_modify_qp_reset(lnk);
 746         smc_wr_free_link(lnk);
 747         smc_ib_destroy_queue_pair(lnk);
 748         smc_ib_dealloc_protection_domain(lnk);
 749         smc_wr_free_link_mem(lnk);
 750         put_device(&lnk->smcibdev->ibdev->dev);
 751         smcibdev = lnk->smcibdev;
 752         memset(lnk, 0, sizeof(struct smc_link));
 753         lnk->state = SMC_LNK_UNUSED;
 754         if (!atomic_dec_return(&smcibdev->lnk_cnt))
 755                 wake_up(&smcibdev->lnks_deleted);
 756 }
 757
 758 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
 759                           struct smc_buf_desc *buf_desc)
 760 {
 761         int i;
 762
 763         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
 764                 smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
 765
 766         if (buf_desc->pages)
 767                 __free_pages(buf_desc->pages, buf_desc->order);
 768         kfree(buf_desc);
 769 }
 770
 771 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
 772                           struct smc_buf_desc *buf_desc)
 773 {
 774         if (is_dmb) {
 775                 /* restore original buf len */
 776                 buf_desc->len += sizeof(struct smcd_cdc_msg);
 777                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
 778         } else {
 779                 kfree(buf_desc->cpu_addr);
 780         }
 781         kfree(buf_desc);
 782 }
 783
 784 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
 785                          struct smc_buf_desc *buf_desc)
 786 {
 787         if (lgr->is_smcd)
 788                 smcd_buf_free(lgr, is_rmb, buf_desc);
 789         else
 790                 smcr_buf_free(lgr, is_rmb, buf_desc);
 791 }
 792
 793 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
 794 {
 795         struct smc_buf_desc *buf_desc, *bf_desc;
 796         struct list_head *buf_list;
 797         int i;
 798
 799         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 800                 if (is_rmb)
 801                         buf_list = &lgr->rmbs[i];
 802                 else
 803                         buf_list = &lgr->sndbufs[i];
 804                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
 805                                          list) {
 806                         list_del(&buf_desc->list);
 807                         smc_buf_free(lgr, is_rmb, buf_desc);
 808                 }
 809         }
 810 }
 811
 812 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
 813 {
 814         /* free send buffers */
 815         __smc_lgr_free_bufs(lgr, false);
 816         /* free rmbs */
 817         __smc_lgr_free_bufs(lgr, true);
 818 }
 819
 820 /* remove a link group */
 821 static void smc_lgr_free(struct smc_link_group *lgr)
 822 {
 823         int i;
 824
 825         if (!lgr->is_smcd) {
 826                 mutex_lock(&lgr->llc_conf_mutex);
 827                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 828                         if (lgr->lnk[i].state != SMC_LNK_UNUSED)
 829                                 smcr_link_clear(&lgr->lnk[i], false);
 830                 }
 831                 mutex_unlock(&lgr->llc_conf_mutex);
 832                 smc_llc_lgr_clear(lgr);
 833         }
 834
 835         smc_lgr_free_bufs(lgr);
 836         if (lgr->is_smcd) {
 837                 if (!lgr->terminating) {
 838                         smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 839                         put_device(&lgr->smcd->dev);
 840                 }
 841                 if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
 842                         wake_up(&lgr->smcd->lgrs_deleted);
 843         } else {
 844                 if (!atomic_dec_return(&lgr_cnt))
 845                         wake_up(&lgrs_deleted);
 846         }
 847         kfree(lgr);
 848 }
 849
 850 static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
 851 {
 852         int i;
 853
 854         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 855                 struct smc_buf_desc *buf_desc;
 856
 857                 list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
 858                         buf_desc->len += sizeof(struct smcd_cdc_msg);
 859                         smc_ism_unregister_dmb(lgr->smcd, buf_desc);
 860                 }
 861         }
 862 }
 863
 864 static void smc_sk_wake_ups(struct smc_sock *smc)
 865 {
 866         smc->sk.sk_write_space(&smc->sk);
 867         smc->sk.sk_data_ready(&smc->sk);
 868         smc->sk.sk_state_change(&smc->sk);
 869 }
 870
 871 /* kill a connection */
 872 static void smc_conn_kill(struct smc_connection *conn, bool soft)
 873 {
 874         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 875
 876         if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
 877                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 878         else
 879                 smc_close_abort(conn);
 880         conn->killed = 1;
 881         smc->sk.sk_err = ECONNABORTED;
 882         smc_sk_wake_ups(smc);
 883         if (conn->lgr->is_smcd) {
 884                 smc_ism_unset_conn(conn);
 885                 if (soft)
 886                         tasklet_kill(&conn->rx_tsklet);
 887                 else
 888                         tasklet_unlock_wait(&conn->rx_tsklet);
 889         } else {
 890                 smc_cdc_tx_dismiss_slots(conn);
 891         }
 892         smc_lgr_unregister_conn(conn);
 893         smc_close_active_abort(smc);
 894 }
 895
 896 static void smc_lgr_cleanup(struct smc_link_group *lgr)
 897 {
 898         if (lgr->is_smcd) {
 899                 smc_ism_signal_shutdown(lgr);
 900                 smcd_unregister_all_dmbs(lgr);
 901                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 902                 put_device(&lgr->smcd->dev);
 903         } else {
 904                 u32 rsn = lgr->llc_termination_rsn;
 905
 906                 if (!rsn)
 907                         rsn = SMC_LLC_DEL_PROG_INIT_TERM;
 908                 smc_llc_send_link_delete_all(lgr, false, rsn);
 909                 smcr_lgr_link_deactivate_all(lgr);
 910         }
 911 }
 912
 913 /* terminate link group
 914  * @soft: true if link group shutdown can take its time
 915  *        false if immediate link group shutdown is required
 916  */
 917 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
 918 {
 919         struct smc_connection *conn;
 920         struct smc_sock *smc;
 921         struct rb_node *node;
 922
 923         if (lgr->terminating)
 924                 return; /* lgr already terminating */
 925         /* cancel free_work sync, will terminate when lgr->freeing is set */
 926         cancel_delayed_work_sync(&lgr->free_work);
 927         lgr->terminating = 1;
 928
 929         /* kill remaining link group connections */
 930         read_lock_bh(&lgr->conns_lock);
 931         node = rb_first(&lgr->conns_all);
 932         while (node) {
 933                 read_unlock_bh(&lgr->conns_lock);
 934                 conn = rb_entry(node, struct smc_connection, alert_node);
 935                 smc = container_of(conn, struct smc_sock, conn);
 936                 sock_hold(&smc->sk); /* sock_put below */
 937                 lock_sock(&smc->sk);
 938                 smc_conn_kill(conn, soft);
 939                 release_sock(&smc->sk);
 940                 sock_put(&smc->sk); /* sock_hold above */
 941                 read_lock_bh(&lgr->conns_lock);
 942                 node = rb_first(&lgr->conns_all);
 943         }
 944         read_unlock_bh(&lgr->conns_lock);
 945         smc_lgr_cleanup(lgr);
 946         smc_lgr_free(lgr);
 947 }
 948
 949 /* unlink link group and schedule termination */
 950 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
 951 {
 952         spinlock_t *lgr_lock;
 953
 954         smc_lgr_list_head(lgr, &lgr_lock);
 955         spin_lock_bh(lgr_lock);
 956         if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
 957                 spin_unlock_bh(lgr_lock);
 958                 return; /* lgr already terminating */
 959         }
 960         list_del_init(&lgr->list);
 961         lgr->freeing = 1;
 962         spin_unlock_bh(lgr_lock);
 963         schedule_work(&lgr->terminate_work);
 964 }
 965
 966 /* Called when peer lgr shutdown (regularly or abnormally) is received */
 967 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
 968 {
 969         struct smc_link_group *lgr, *l;
 970         LIST_HEAD(lgr_free_list);
 971
 972         /* run common cleanup function and build free list */
 973         spin_lock_bh(&dev->lgr_lock);
 974         list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
 975                 if ((!peer_gid || lgr->peer_gid == peer_gid) &&
 976                     (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
 977                         if (peer_gid) /* peer triggered termination */
 978                                 lgr->peer_shutdown = 1;
 979                         list_move(&lgr->list, &lgr_free_list);
 980                         lgr->freeing = 1;
 981                 }
 982         }
 983         spin_unlock_bh(&dev->lgr_lock);
 984
 985         /* cancel the regular free workers and actually free lgrs */
 986         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
 987                 list_del_init(&lgr->list);
 988                 schedule_work(&lgr->terminate_work);
 989         }
 990 }
 991
 992 /* Called when an SMCD device is removed or the smc module is unloaded */
 993 void smc_smcd_terminate_all(struct smcd_dev *smcd)
 994 {
 995         struct smc_link_group *lgr, *lg;
 996         LIST_HEAD(lgr_free_list);
 997
 998         spin_lock_bh(&smcd->lgr_lock);
 999         list_splice_init(&smcd->lgr_list, &lgr_free_list);
1000         list_for_each_entry(lgr, &lgr_free_list, list)
1001                 lgr->freeing = 1;
1002         spin_unlock_bh(&smcd->lgr_lock);
1003
1004         list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1005                 list_del_init(&lgr->list);
1006                 __smc_lgr_terminate(lgr, false);
1007         }
1008
1009         if (atomic_read(&smcd->lgr_cnt))
1010                 wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1011 }
1012
1013 /* Called when an SMCR device is removed or the smc module is unloaded.
1014  * If smcibdev is given, all SMCR link groups using this device are terminated.
1015  * If smcibdev is NULL, all SMCR link groups are terminated.
1016  */
1017 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1018 {
1019         struct smc_link_group *lgr, *lg;
1020         LIST_HEAD(lgr_free_list);
1021         int i;
1022
1023         spin_lock_bh(&smc_lgr_list.lock);
1024         if (!smcibdev) {
1025                 list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1026                 list_for_each_entry(lgr, &lgr_free_list, list)
1027                         lgr->freeing = 1;
1028         } else {
1029                 list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1030                         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1031                                 if (lgr->lnk[i].smcibdev == smcibdev)
1032                                         smcr_link_down_cond_sched(&lgr->lnk[i]);
1033                         }
1034                 }
1035         }
1036         spin_unlock_bh(&smc_lgr_list.lock);
1037
1038         list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1039                 list_del_init(&lgr->list);
1040                 smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1041                 __smc_lgr_terminate(lgr, false);
1042         }
1043
1044         if (smcibdev) {
1045                 if (atomic_read(&smcibdev->lnk_cnt))
1046                         wait_event(smcibdev->lnks_deleted,
1047                                    !atomic_read(&smcibdev->lnk_cnt));
1048         } else {
1049                 if (atomic_read(&lgr_cnt))
1050                         wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1051         }
1052 }
1053
1054 /* set new lgr type and clear all asymmetric link tagging */
1055 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1056 {
1057         char *lgr_type = "";
1058         int i;
1059
1060         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1061                 if (smc_link_usable(&lgr->lnk[i]))
1062                         lgr->lnk[i].link_is_asym = false;
1063         if (lgr->type == new_type)
1064                 return;
1065         lgr->type = new_type;
1066
1067         switch (lgr->type) {
1068         case SMC_LGR_NONE:
1069                 lgr_type = "NONE";
1070                 break;
1071         case SMC_LGR_SINGLE:
1072                 lgr_type = "SINGLE";
1073                 break;
1074         case SMC_LGR_SYMMETRIC:
1075                 lgr_type = "SYMMETRIC";
1076                 break;
1077         case SMC_LGR_ASYMMETRIC_PEER:
1078                 lgr_type = "ASYMMETRIC_PEER";
1079                 break;
1080         case SMC_LGR_ASYMMETRIC_LOCAL:
1081                 lgr_type = "ASYMMETRIC_LOCAL";
1082                 break;
1083         }
1084         pr_warn_ratelimited("smc: SMC-R lg %*phN state changed: "
1085                             "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1086                             lgr_type, lgr->pnet_id);
1087 }
1088
1089 /* set new lgr type and tag a link as asymmetric */
1090 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1091                             enum smc_lgr_type new_type, int asym_lnk_idx)
1092 {
1093         smcr_lgr_set_type(lgr, new_type);
1094         lgr->lnk[asym_lnk_idx].link_is_asym = true;
1095 }
1096
1097 /* abort connection, abort_work scheduled from tasklet context */
1098 static void smc_conn_abort_work(struct work_struct *work)
1099 {
1100         struct smc_connection *conn = container_of(work,
1101                                                    struct smc_connection,
1102                                                    abort_work);
1103         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1104
1105         smc_conn_kill(conn, true);
1106         sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1107 }
1108
1109 /* link is up - establish alternate link if applicable */
1110 static void smcr_link_up(struct smc_link_group *lgr,
1111                          struct smc_ib_device *smcibdev, u8 ibport)
1112 {
1113         struct smc_link *link = NULL;
1114
1115         if (list_empty(&lgr->list) ||
1116             lgr->type == SMC_LGR_SYMMETRIC ||
1117             lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1118                 return;
1119
1120         if (lgr->role == SMC_SERV) {
1121                 /* trigger local add link processing */
1122                 link = smc_llc_usable_link(lgr);
1123                 if (!link)
1124                         return;
1125                 smc_llc_srv_add_link_local(link);
1126         } else {
1127                 /* invite server to start add link processing */
1128                 u8 gid[SMC_GID_SIZE];
1129
1130                 if (smc_ib_determine_gid(smcibdev, ibport, lgr->vlan_id, gid,
1131                                          NULL))
1132                         return;
1133                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1134                         /* some other llc task is ongoing */
1135                         wait_event_timeout(lgr->llc_flow_waiter,
1136                                 (list_empty(&lgr->list) ||
1137                                  lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1138                                 SMC_LLC_WAIT_TIME);
1139                 }
1140                 /* lgr or device no longer active? */
1141                 if (!list_empty(&lgr->list) &&
1142                     smc_ib_port_active(smcibdev, ibport))
1143                         link = smc_llc_usable_link(lgr);
1144                 if (link)
1145                         smc_llc_send_add_link(link, smcibdev->mac[ibport - 1],
1146                                               gid, NULL, SMC_LLC_REQ);
1147                 wake_up(&lgr->llc_flow_waiter); /* wake up next waiter */
1148         }
1149 }
1150
1151 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1152 {
1153         struct smc_ib_up_work *ib_work;
1154         struct smc_link_group *lgr, *n;
1155
1156         list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1157                 if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1158                             SMC_MAX_PNETID_LEN) ||
1159                     lgr->type == SMC_LGR_SYMMETRIC ||
1160                     lgr->type == SMC_LGR_ASYMMETRIC_PEER)
1161                         continue;
1162                 ib_work = kmalloc(sizeof(*ib_work), GFP_KERNEL);
1163                 if (!ib_work)
1164                         continue;
1165                 INIT_WORK(&ib_work->work, smc_link_up_work);
1166                 ib_work->lgr = lgr;
1167                 ib_work->smcibdev = smcibdev;
1168                 ib_work->ibport = ibport;
1169                 schedule_work(&ib_work->work);
1170         }
1171 }
1172
1173 /* link is down - switch connections to alternate link,
1174  * must be called under lgr->llc_conf_mutex lock
1175  */
1176 static void smcr_link_down(struct smc_link *lnk)
1177 {
1178         struct smc_link_group *lgr = lnk->lgr;
1179         struct smc_link *to_lnk;
1180         int del_link_id;
1181
1182         if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1183                 return;
1184
1185         smc_ib_modify_qp_reset(lnk);
1186         to_lnk = smc_switch_conns(lgr, lnk, true);
1187         if (!to_lnk) { /* no backup link available */
1188                 smcr_link_clear(lnk, true);
1189                 return;
1190         }
1191         smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1192         del_link_id = lnk->link_id;
1193
1194         if (lgr->role == SMC_SERV) {
1195                 /* trigger local delete link processing */
1196                 smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1197         } else {
1198                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1199                         /* another llc task is ongoing */
1200                         mutex_unlock(&lgr->llc_conf_mutex);
1201                         wait_event_timeout(lgr->llc_flow_waiter,
1202                                 (list_empty(&lgr->list) ||
1203                                  lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1204                                 SMC_LLC_WAIT_TIME);
1205                         mutex_lock(&lgr->llc_conf_mutex);
1206                 }
1207                 if (!list_empty(&lgr->list)) {
1208                         smc_llc_send_delete_link(to_lnk, del_link_id,
1209                                                  SMC_LLC_REQ, true,
1210                                                  SMC_LLC_DEL_LOST_PATH);
1211                         smcr_link_clear(lnk, true);
1212                 }
1213                 wake_up(&lgr->llc_flow_waiter); /* wake up next waiter */
1214         }
1215 }
1216
1217 /* must be called under lgr->llc_conf_mutex lock */
1218 void smcr_link_down_cond(struct smc_link *lnk)
1219 {
1220         if (smc_link_downing(&lnk->state))
1221                 smcr_link_down(lnk);
1222 }
1223
1224 /* will get the lgr->llc_conf_mutex lock */
1225 void smcr_link_down_cond_sched(struct smc_link *lnk)
1226 {
1227         if (smc_link_downing(&lnk->state))
1228                 schedule_work(&lnk->link_down_wrk);
1229 }
1230
1231 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1232 {
1233         struct smc_link_group *lgr, *n;
1234         int i;
1235
1236         list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1237                 if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1238                             SMC_MAX_PNETID_LEN))
1239                         continue; /* lgr is not affected */
1240                 if (list_empty(&lgr->list))
1241                         continue;
1242                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1243                         struct smc_link *lnk = &lgr->lnk[i];
1244
1245                         if (smc_link_usable(lnk) &&
1246                             lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1247                                 smcr_link_down_cond_sched(lnk);
1248                 }
1249         }
1250 }
1251
1252 static void smc_link_up_work(struct work_struct *work)
1253 {
1254         struct smc_ib_up_work *ib_work = container_of(work,
1255                                                       struct smc_ib_up_work,
1256                                                       work);
1257         struct smc_link_group *lgr = ib_work->lgr;
1258
1259         if (list_empty(&lgr->list))
1260                 goto out;
1261         smcr_link_up(lgr, ib_work->smcibdev, ib_work->ibport);
1262 out:
1263         kfree(ib_work);
1264 }
1265
1266 static void smc_link_down_work(struct work_struct *work)
1267 {
1268         struct smc_link *link = container_of(work, struct smc_link,
1269                                              link_down_wrk);
1270         struct smc_link_group *lgr = link->lgr;
1271
1272         if (list_empty(&lgr->list))
1273                 return;
1274         wake_up_all(&lgr->llc_msg_waiter);
1275         mutex_lock(&lgr->llc_conf_mutex);
1276         smcr_link_down(link);
1277         mutex_unlock(&lgr->llc_conf_mutex);
1278 }
1279
1280 /* Determine vlan of internal TCP socket.
1281  * @vlan_id: address to store the determined vlan id into
1282  */
1283 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1284 {
1285         struct dst_entry *dst = sk_dst_get(clcsock->sk);
1286         struct net_device *ndev;
1287         int i, nest_lvl, rc = 0;
1288
1289         ini->vlan_id = 0;
1290         if (!dst) {
1291                 rc = -ENOTCONN;
1292                 goto out;
1293         }
1294         if (!dst->dev) {
1295                 rc = -ENODEV;
1296                 goto out_rel;
1297         }
1298
1299         ndev = dst->dev;
1300         if (is_vlan_dev(ndev)) {
1301                 ini->vlan_id = vlan_dev_vlan_id(ndev);
1302                 goto out_rel;
1303         }
1304
1305         rtnl_lock();
1306         nest_lvl = ndev->lower_level;
1307         for (i = 0; i < nest_lvl; i++) {
1308                 struct list_head *lower = &ndev->adj_list.lower;
1309
1310                 if (list_empty(lower))
1311                         break;
1312                 lower = lower->next;
1313                 ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);
1314                 if (is_vlan_dev(ndev)) {
1315                         ini->vlan_id = vlan_dev_vlan_id(ndev);
1316                         break;
1317                 }
1318         }
1319         rtnl_unlock();
1320
1321 out_rel:
1322         dst_release(dst);
1323 out:
1324         return rc;
1325 }
1326
1327 static bool smcr_lgr_match(struct smc_link_group *lgr,
1328                            struct smc_clc_msg_local *lcl,
1329                            enum smc_lgr_role role, u32 clcqpn)
1330 {
1331         int i;
1332
1333         if (memcmp(lgr->peer_systemid, lcl->id_for_peer, SMC_SYSTEMID_LEN) ||
1334             lgr->role != role)
1335                 return false;
1336
1337         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1338                 if (lgr->lnk[i].state != SMC_LNK_ACTIVE)
1339                         continue;
1340                 if ((lgr->role == SMC_SERV || lgr->lnk[i].peer_qpn == clcqpn) &&
1341                     !memcmp(lgr->lnk[i].peer_gid, &lcl->gid, SMC_GID_SIZE) &&
1342                     !memcmp(lgr->lnk[i].peer_mac, lcl->mac, sizeof(lcl->mac)))
1343                         return true;
1344         }
1345         return false;
1346 }
1347
1348 static bool smcd_lgr_match(struct smc_link_group *lgr,
1349                            struct smcd_dev *smcismdev, u64 peer_gid)
1350 {
1351         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
1352 }
1353
1354 /* create a new SMC connection (and a new link group if necessary) */
1355 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1356 {
1357         struct smc_connection *conn = &smc->conn;
1358         struct list_head *lgr_list;
1359         struct smc_link_group *lgr;
1360         enum smc_lgr_role role;
1361         spinlock_t *lgr_lock;
1362         int rc = 0;
1363
1364         lgr_list = ini->is_smcd ? &ini->ism_dev->lgr_list : &smc_lgr_list.list;
1365         lgr_lock = ini->is_smcd ? &ini->ism_dev->lgr_lock : &smc_lgr_list.lock;
1366         ini->cln_first_contact = SMC_FIRST_CONTACT;
1367         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1368         if (role == SMC_CLNT && ini->srv_first_contact)
1369                 /* create new link group as well */
1370                 goto create;
1371
1372         /* determine if an existing link group can be reused */
1373         spin_lock_bh(lgr_lock);
1374         list_for_each_entry(lgr, lgr_list, list) {
1375                 write_lock_bh(&lgr->conns_lock);
1376                 if ((ini->is_smcd ?
1377                      smcd_lgr_match(lgr, ini->ism_dev, ini->ism_gid) :
1378                      smcr_lgr_match(lgr, ini->ib_lcl, role, ini->ib_clcqpn)) &&
1379                     !lgr->sync_err &&
1380                     lgr->vlan_id == ini->vlan_id &&
1381                     (role == SMC_CLNT ||
1382                      lgr->conns_num < SMC_RMBS_PER_LGR_MAX)) {
1383                         /* link group found */
1384                         ini->cln_first_contact = SMC_REUSE_CONTACT;
1385                         conn->lgr = lgr;
1386                         rc = smc_lgr_register_conn(conn, false);
1387                         write_unlock_bh(&lgr->conns_lock);
1388                         if (!rc && delayed_work_pending(&lgr->free_work))
1389                                 cancel_delayed_work(&lgr->free_work);
1390                         break;
1391                 }
1392                 write_unlock_bh(&lgr->conns_lock);
1393         }
1394         spin_unlock_bh(lgr_lock);
1395         if (rc)
1396                 return rc;
1397
1398         if (role == SMC_CLNT && !ini->srv_first_contact &&
1399             ini->cln_first_contact == SMC_FIRST_CONTACT) {
1400                 /* Server reuses a link group, but Client wants to start
1401                  * a new one
1402                  * send out_of_sync decline, reason synchr. error
1403                  */
1404                 return SMC_CLC_DECL_SYNCERR;
1405         }
1406
1407 create:
1408         if (ini->cln_first_contact == SMC_FIRST_CONTACT) {
1409                 rc = smc_lgr_create(smc, ini);
1410                 if (rc)
1411                         goto out;
1412                 lgr = conn->lgr;
1413                 write_lock_bh(&lgr->conns_lock);
1414                 rc = smc_lgr_register_conn(conn, true);
1415                 write_unlock_bh(&lgr->conns_lock);
1416                 if (rc)
1417                         goto out;
1418         }
1419         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
1420         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
1421         conn->urg_state = SMC_URG_READ;
1422         INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
1423         if (ini->is_smcd) {
1424                 conn->rx_off = sizeof(struct smcd_cdc_msg);
1425                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
1426         }
1427 #ifndef KERNEL_HAS_ATOMIC64
1428         spin_lock_init(&conn->acurs_lock);
1429 #endif
1430
1431 out:
1432         return rc;
1433 }
1434
1435 /* convert the RMB size into the compressed notation - minimum 16K.
1436  * In contrast to plain ilog2, this rounds towards the next power of 2,
1437  * so the socket application gets at least its desired sndbuf / rcvbuf size.
1438  */
1439 static u8 smc_compress_bufsize(int size)
1440 {
1441         u8 compressed;
1442
1443         if (size <= SMC_BUF_MIN_SIZE)
1444                 return 0;
1445
1446         size = (size - 1) >> 14;
1447         compressed = ilog2(size) + 1;
1448         if (compressed >= SMC_RMBE_SIZES)
1449                 compressed = SMC_RMBE_SIZES - 1;
1450         return compressed;
1451 }
1452
1453 /* convert the RMB size from compressed notation into integer */
1454 int smc_uncompress_bufsize(u8 compressed)
1455 {
1456         u32 size;
1457
1458         size = 0x00000001 << (((int)compressed) + 14);
1459         return (int)size;
1460 }
1461
1462 /* try to reuse a sndbuf or rmb description slot for a certain
1463  * buffer size; if not available, return NULL
1464  */
1465 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
1466                                              struct mutex *lock,
1467                                              struct list_head *buf_list)
1468 {
1469         struct smc_buf_desc *buf_slot;
1470
1471         mutex_lock(lock);
1472         list_for_each_entry(buf_slot, buf_list, list) {
1473                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
1474                         mutex_unlock(lock);
1475                         return buf_slot;
1476                 }
1477         }
1478         mutex_unlock(lock);
1479         return NULL;
1480 }
1481
1482 /* one of the conditions for announcing a receiver's current window size is
1483  * that it "results in a minimum increase in the window size of 10% of the
1484  * receive buffer space" [RFC7609]
1485  */
1486 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
1487 {
1488         return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
1489 }
1490
1491 /* map an rmb buf to a link */
1492 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1493                              struct smc_link *lnk)
1494 {
1495         int rc;
1496
1497         if (buf_desc->is_map_ib[lnk->link_idx])
1498                 return 0;
1499
1500         rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], 1, GFP_KERNEL);
1501         if (rc)
1502                 return rc;
1503         sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
1504                    buf_desc->cpu_addr, buf_desc->len);
1505
1506         /* map sg table to DMA address */
1507         rc = smc_ib_buf_map_sg(lnk, buf_desc,
1508                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1509         /* SMC protocol depends on mapping to one DMA address only */
1510         if (rc != 1) {
1511                 rc = -EAGAIN;
1512                 goto free_table;
1513         }
1514
1515         /* create a new memory region for the RMB */
1516         if (is_rmb) {
1517                 rc = smc_ib_get_memory_region(lnk->roce_pd,
1518                                               IB_ACCESS_REMOTE_WRITE |
1519                                               IB_ACCESS_LOCAL_WRITE,
1520                                               buf_desc, lnk->link_idx);
1521                 if (rc)
1522                         goto buf_unmap;
1523                 smc_ib_sync_sg_for_device(lnk, buf_desc, DMA_FROM_DEVICE);
1524         }
1525         buf_desc->is_map_ib[lnk->link_idx] = true;
1526         return 0;
1527
1528 buf_unmap:
1529         smc_ib_buf_unmap_sg(lnk, buf_desc,
1530                             is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1531 free_table:
1532         sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1533         return rc;
1534 }
1535
1536 /* register a new rmb on IB device,
1537  * must be called under lgr->llc_conf_mutex lock
1538  */
1539 int smcr_link_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc)
1540 {
1541         if (list_empty(&link->lgr->list))
1542                 return -ENOLINK;
1543         if (!rmb_desc->is_reg_mr[link->link_idx]) {
1544                 /* register memory region for new rmb */
1545                 if (smc_wr_reg_send(link, rmb_desc->mr_rx[link->link_idx])) {
1546                         rmb_desc->is_reg_err = true;
1547                         return -EFAULT;
1548                 }
1549                 rmb_desc->is_reg_mr[link->link_idx] = true;
1550         }
1551         return 0;
1552 }
1553
1554 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct mutex *lock,
1555                              struct list_head *lst, bool is_rmb)
1556 {
1557         struct smc_buf_desc *buf_desc, *bf;
1558         int rc = 0;
1559
1560         mutex_lock(lock);
1561         list_for_each_entry_safe(buf_desc, bf, lst, list) {
1562                 if (!buf_desc->used)
1563                         continue;
1564                 rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
1565                 if (rc)
1566                         goto out;
1567         }
1568 out:
1569         mutex_unlock(lock);
1570         return rc;
1571 }
1572
1573 /* map all used buffers of lgr for a new link */
1574 int smcr_buf_map_lgr(struct smc_link *lnk)
1575 {
1576         struct smc_link_group *lgr = lnk->lgr;
1577         int i, rc = 0;
1578
1579         for (i = 0; i < SMC_RMBE_SIZES; i++) {
1580                 rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
1581                                        &lgr->rmbs[i], true);
1582                 if (rc)
1583                         return rc;
1584                 rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
1585                                        &lgr->sndbufs[i], false);
1586                 if (rc)
1587                         return rc;
1588         }
1589         return 0;
1590 }
1591
1592 /* register all used buffers of lgr for a new link,
1593  * must be called under lgr->llc_conf_mutex lock
1594  */
1595 int smcr_buf_reg_lgr(struct smc_link *lnk)
1596 {
1597         struct smc_link_group *lgr = lnk->lgr;
1598         struct smc_buf_desc *buf_desc, *bf;
1599         int i, rc = 0;
1600
1601         mutex_lock(&lgr->rmbs_lock);
1602         for (i = 0; i < SMC_RMBE_SIZES; i++) {
1603                 list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
1604                         if (!buf_desc->used)
1605                                 continue;
1606                         rc = smcr_link_reg_rmb(lnk, buf_desc);
1607                         if (rc)
1608                                 goto out;
1609                 }
1610         }
1611 out:
1612         mutex_unlock(&lgr->rmbs_lock);
1613         return rc;
1614 }
1615
1616 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
1617                                                 bool is_rmb, int bufsize)
1618 {
1619         struct smc_buf_desc *buf_desc;
1620
1621         /* try to alloc a new buffer */
1622         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
1623         if (!buf_desc)
1624                 return ERR_PTR(-ENOMEM);
1625
1626         buf_desc->order = get_order(bufsize);
1627         buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
1628                                       __GFP_NOMEMALLOC | __GFP_COMP |
1629                                       __GFP_NORETRY | __GFP_ZERO,
1630                                       buf_desc->order);
1631         if (!buf_desc->pages) {
1632                 kfree(buf_desc);
1633                 return ERR_PTR(-EAGAIN);
1634         }
1635         buf_desc->cpu_addr = (void *)page_address(buf_desc->pages);
1636         buf_desc->len = bufsize;
1637         return buf_desc;
1638 }
1639
1640 /* map buf_desc on all usable links,
1641  * unused buffers stay mapped as long as the link is up
1642  */
1643 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
1644                                      struct smc_buf_desc *buf_desc, bool is_rmb)
1645 {
1646         int i, rc = 0;
1647
1648         /* protect against parallel link reconfiguration */
1649         mutex_lock(&lgr->llc_conf_mutex);
1650         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1651                 struct smc_link *lnk = &lgr->lnk[i];
1652
1653                 if (!smc_link_usable(lnk))
1654                         continue;
1655                 if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
1656                         rc = -ENOMEM;
1657                         goto out;
1658                 }
1659         }
1660 out:
1661         mutex_unlock(&lgr->llc_conf_mutex);
1662         return rc;
1663 }
1664
1665 #define SMCD_DMBE_SIZES         7 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1666
1667 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
1668                                                 bool is_dmb, int bufsize)
1669 {
1670         struct smc_buf_desc *buf_desc;
1671         int rc;
1672
1673         if (smc_compress_bufsize(bufsize) > SMCD_DMBE_SIZES)
1674                 return ERR_PTR(-EAGAIN);
1675
1676         /* try to alloc a new DMB */
1677         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
1678         if (!buf_desc)
1679                 return ERR_PTR(-ENOMEM);
1680         if (is_dmb) {
1681                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
1682                 if (rc) {
1683                         kfree(buf_desc);
1684                         return ERR_PTR(-EAGAIN);
1685                 }
1686                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
1687                 /* CDC header stored in buf. So, pretend it was smaller */
1688                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
1689         } else {
1690                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
1691                                              __GFP_NOWARN | __GFP_NORETRY |
1692                                              __GFP_NOMEMALLOC);
1693                 if (!buf_desc->cpu_addr) {
1694                         kfree(buf_desc);
1695                         return ERR_PTR(-EAGAIN);
1696                 }
1697                 buf_desc->len = bufsize;
1698         }
1699         return buf_desc;
1700 }
1701
1702 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
1703 {
1704         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
1705         struct smc_connection *conn = &smc->conn;
1706         struct smc_link_group *lgr = conn->lgr;
1707         struct list_head *buf_list;
1708         int bufsize, bufsize_short;
1709         struct mutex *lock;     /* lock buffer list */
1710         int sk_buf_size;
1711
1712         if (is_rmb)
1713                 /* use socket recv buffer size (w/o overhead) as start value */
1714                 sk_buf_size = smc->sk.sk_rcvbuf / 2;
1715         else
1716                 /* use socket send buffer size (w/o overhead) as start value */
1717                 sk_buf_size = smc->sk.sk_sndbuf / 2;
1718
1719         for (bufsize_short = smc_compress_bufsize(sk_buf_size);
1720              bufsize_short >= 0; bufsize_short--) {
1721
1722                 if (is_rmb) {
1723                         lock = &lgr->rmbs_lock;
1724                         buf_list = &lgr->rmbs[bufsize_short];
1725                 } else {
1726                         lock = &lgr->sndbufs_lock;
1727                         buf_list = &lgr->sndbufs[bufsize_short];
1728                 }
1729                 bufsize = smc_uncompress_bufsize(bufsize_short);
1730                 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC)
1731                         continue;
1732
1733                 /* check for reusable slot in the link group */
1734                 buf_desc = smc_buf_get_slot(bufsize_short, lock, buf_list);
1735                 if (buf_desc) {
1736                         memset(buf_desc->cpu_addr, 0, bufsize);
1737                         break; /* found reusable slot */
1738                 }
1739
1740                 if (is_smcd)
1741                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
1742                 else
1743                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
1744
1745                 if (PTR_ERR(buf_desc) == -ENOMEM)
1746                         break;
1747                 if (IS_ERR(buf_desc))
1748                         continue;
1749
1750                 buf_desc->used = 1;
1751                 mutex_lock(lock);
1752                 list_add(&buf_desc->list, buf_list);
1753                 mutex_unlock(lock);
1754                 break; /* found */
1755         }
1756
1757         if (IS_ERR(buf_desc))
1758                 return -ENOMEM;
1759
1760         if (!is_smcd) {
1761                 if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
1762                         smcr_buf_unuse(buf_desc, lgr);
1763                         return -ENOMEM;
1764                 }
1765         }
1766
1767         if (is_rmb) {
1768                 conn->rmb_desc = buf_desc;
1769                 conn->rmbe_size_short = bufsize_short;
1770                 smc->sk.sk_rcvbuf = bufsize * 2;
1771                 atomic_set(&conn->bytes_to_rcv, 0);
1772                 conn->rmbe_update_limit =
1773                         smc_rmb_wnd_update_limit(buf_desc->len);
1774                 if (is_smcd)
1775                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
1776         } else {
1777                 conn->sndbuf_desc = buf_desc;
1778                 smc->sk.sk_sndbuf = bufsize * 2;
1779                 atomic_set(&conn->sndbuf_space, bufsize);
1780         }
1781         return 0;
1782 }
1783
1784 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn)
1785 {
1786         if (!conn->lgr || conn->lgr->is_smcd || !smc_link_usable(conn->lnk))
1787                 return;
1788         smc_ib_sync_sg_for_cpu(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
1789 }
1790
1791 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
1792 {
1793         if (!conn->lgr || conn->lgr->is_smcd || !smc_link_usable(conn->lnk))
1794                 return;
1795         smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
1796 }
1797
1798 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
1799 {
1800         int i;
1801
1802         if (!conn->lgr || conn->lgr->is_smcd)
1803                 return;
1804         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1805                 if (!smc_link_usable(&conn->lgr->lnk[i]))
1806                         continue;
1807                 smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
1808                                        DMA_FROM_DEVICE);
1809         }
1810 }
1811
1812 void smc_rmb_sync_sg_for_device(struct smc_connection *conn)
1813 {
1814         int i;
1815
1816         if (!conn->lgr || conn->lgr->is_smcd)
1817                 return;
1818         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1819                 if (!smc_link_usable(&conn->lgr->lnk[i]))
1820                         continue;
1821                 smc_ib_sync_sg_for_device(&conn->lgr->lnk[i], conn->rmb_desc,
1822                                           DMA_FROM_DEVICE);
1823         }
1824 }
1825
1826 /* create the send and receive buffer for an SMC socket;
1827  * receive buffers are called RMBs;
1828  * (even though the SMC protocol allows more than one RMB-element per RMB,
1829  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
1830  * extra RMB for every connection in a link group
1831  */
1832 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
1833 {
1834         int rc;
1835
1836         /* create send buffer */
1837         rc = __smc_buf_create(smc, is_smcd, false);
1838         if (rc)
1839                 return rc;
1840         /* create rmb */
1841         rc = __smc_buf_create(smc, is_smcd, true);
1842         if (rc)
1843                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
1844         return rc;
1845 }
1846
1847 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
1848 {
1849         int i;
1850
1851         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
1852                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
1853                         return i;
1854         }
1855         return -ENOSPC;
1856 }
1857
1858 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
1859                                    u32 rkey)
1860 {
1861         int i;
1862
1863         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1864                 if (test_bit(i, lgr->rtokens_used_mask) &&
1865                     lgr->rtokens[i][lnk_idx].rkey == rkey)
1866                         return i;
1867         }
1868         return -ENOENT;
1869 }
1870
1871 /* set rtoken for a new link to an existing rmb */
1872 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
1873                     __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
1874 {
1875         int rtok_idx;
1876
1877         rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
1878         if (rtok_idx == -ENOENT)
1879                 return;
1880         lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
1881         lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
1882 }
1883
1884 /* set rtoken for a new link whose link_id is given */
1885 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
1886                      __be64 nw_vaddr, __be32 nw_rkey)
1887 {
1888         u64 dma_addr = be64_to_cpu(nw_vaddr);
1889         u32 rkey = ntohl(nw_rkey);
1890         bool found = false;
1891         int link_idx;
1892
1893         for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
1894                 if (lgr->lnk[link_idx].link_id == link_id) {
1895                         found = true;
1896                         break;
1897                 }
1898         }
1899         if (!found)
1900                 return;
1901         lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
1902         lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
1903 }
1904
1905 /* add a new rtoken from peer */
1906 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
1907 {
1908         struct smc_link_group *lgr = smc_get_lgr(lnk);
1909         u64 dma_addr = be64_to_cpu(nw_vaddr);
1910         u32 rkey = ntohl(nw_rkey);
1911         int i;
1912
1913         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1914                 if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
1915                     lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
1916                     test_bit(i, lgr->rtokens_used_mask)) {
1917                         /* already in list */
1918                         return i;
1919                 }
1920         }
1921         i = smc_rmb_reserve_rtoken_idx(lgr);
1922         if (i < 0)
1923                 return i;
1924         lgr->rtokens[i][lnk->link_idx].rkey = rkey;
1925         lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
1926         return i;
1927 }
1928
1929 /* delete an rtoken from all links */
1930 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
1931 {
1932         struct smc_link_group *lgr = smc_get_lgr(lnk);
1933         u32 rkey = ntohl(nw_rkey);
1934         int i, j;
1935
1936         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1937                 if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
1938                     test_bit(i, lgr->rtokens_used_mask)) {
1939                         for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
1940                                 lgr->rtokens[i][j].rkey = 0;
1941                                 lgr->rtokens[i][j].dma_addr = 0;
1942                         }
1943                         clear_bit(i, lgr->rtokens_used_mask);
1944                         return 0;
1945                 }
1946         }
1947         return -ENOENT;
1948 }
1949
1950 /* save rkey and dma_addr received from peer during clc handshake */
1951 int smc_rmb_rtoken_handling(struct smc_connection *conn,
1952                             struct smc_link *lnk,
1953                             struct smc_clc_msg_accept_confirm *clc)
1954 {
1955         conn->rtoken_idx = smc_rtoken_add(lnk, clc->rmb_dma_addr,
1956                                           clc->rmb_rkey);
1957         if (conn->rtoken_idx < 0)
1958                 return conn->rtoken_idx;
1959         return 0;
1960 }
1961
1962 static void smc_core_going_away(void)
1963 {
1964         struct smc_ib_device *smcibdev;
1965         struct smcd_dev *smcd;
1966
1967         mutex_lock(&smc_ib_devices.mutex);
1968         list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
1969                 int i;
1970
1971                 for (i = 0; i < SMC_MAX_PORTS; i++)
1972                         set_bit(i, smcibdev->ports_going_away);
1973         }
1974         mutex_unlock(&smc_ib_devices.mutex);
1975
1976         mutex_lock(&smcd_dev_list.mutex);
1977         list_for_each_entry(smcd, &smcd_dev_list.list, list) {
1978                 smcd->going_away = 1;
1979         }
1980         mutex_unlock(&smcd_dev_list.mutex);
1981 }
1982
1983 /* Clean up all SMC link groups */
1984 static void smc_lgrs_shutdown(void)
1985 {
1986         struct smcd_dev *smcd;
1987
1988         smc_core_going_away();
1989
1990         smc_smcr_terminate_all(NULL);
1991
1992         mutex_lock(&smcd_dev_list.mutex);
1993         list_for_each_entry(smcd, &smcd_dev_list.list, list)
1994                 smc_smcd_terminate_all(smcd);
1995         mutex_unlock(&smcd_dev_list.mutex);
1996 }
1997
1998 static int smc_core_reboot_event(struct notifier_block *this,
1999                                  unsigned long event, void *ptr)
2000 {
2001         smc_lgrs_shutdown();
2002         smc_ib_unregister_client();
2003         return 0;
2004 }
2005
2006 static struct notifier_block smc_reboot_notifier = {
2007         .notifier_call = smc_core_reboot_event,
2008 };
2009
2010 int __init smc_core_init(void)
2011 {
2012         return register_reboot_notifier(&smc_reboot_notifier);
2013 }
2014
2015 /* Called (from smc_exit) when module is removed */
2016 void smc_core_exit(void)
2017 {
2018         unregister_reboot_notifier(&smc_reboot_notifier);
2019         smc_lgrs_shutdown();
2020 }