1 /* 2 * Shared Memory Communications over RDMA (SMC-R) and RoCE 3 * 4 * Basic Transport Functions exploiting Infiniband API 5 * 6 * Copyright IBM Corp. 2016 7 * 8 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> 9 */ 10 11 #include <linux/socket.h> 12 #include <linux/if_vlan.h> 13 #include <linux/random.h> 14 #include <linux/workqueue.h> 15 #include <net/tcp.h> 16 #include <net/sock.h> 17 #include <rdma/ib_verbs.h> 18 19 #include "smc.h" 20 #include "smc_clc.h" 21 #include "smc_core.h" 22 #include "smc_ib.h" 23 #include "smc_wr.h" 24 #include "smc_llc.h" 25 #include "smc_cdc.h" 26 #include "smc_close.h" 27 28 #define SMC_LGR_NUM_INCR 256 29 #define SMC_LGR_FREE_DELAY_SERV (600 * HZ) 30 #define SMC_LGR_FREE_DELAY_CLNT (SMC_LGR_FREE_DELAY_SERV + 10) 31 32 static u32 smc_lgr_num; /* unique link group number */ 33 34 /* Register connection's alert token in our lookup structure. 35 * To use rbtrees we have to implement our own insert core. 36 * Requires @conns_lock 37 * @smc connection to register 38 * Returns 0 on success, != otherwise. 39 */ 40 static void smc_lgr_add_alert_token(struct smc_connection *conn) 41 { 42 struct rb_node **link, *parent = NULL; 43 u32 token = conn->alert_token_local; 44 45 link = &conn->lgr->conns_all.rb_node; 46 while (*link) { 47 struct smc_connection *cur = rb_entry(*link, 48 struct smc_connection, alert_node); 49 50 parent = *link; 51 if (cur->alert_token_local > token) 52 link = &parent->rb_left; 53 else 54 link = &parent->rb_right; 55 } 56 /* Put the new node there */ 57 rb_link_node(&conn->alert_node, parent, link); 58 rb_insert_color(&conn->alert_node, &conn->lgr->conns_all); 59 } 60 61 /* Register connection in link group by assigning an alert token 62 * registered in a search tree. 63 * Requires @conns_lock 64 * Note that '0' is a reserved value and not assigned. 65 */ 66 static void smc_lgr_register_conn(struct smc_connection *conn) 67 { 68 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 69 static atomic_t nexttoken = ATOMIC_INIT(0); 70 71 /* find a new alert_token_local value not yet used by some connection 72 * in this link group 73 */ 74 sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */ 75 while (!conn->alert_token_local) { 76 conn->alert_token_local = atomic_inc_return(&nexttoken); 77 if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr)) 78 conn->alert_token_local = 0; 79 } 80 smc_lgr_add_alert_token(conn); 81 conn->lgr->conns_num++; 82 } 83 84 /* Unregister connection and reset the alert token of the given connection< 85 */ 86 static void __smc_lgr_unregister_conn(struct smc_connection *conn) 87 { 88 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 89 struct smc_link_group *lgr = conn->lgr; 90 91 rb_erase(&conn->alert_node, &lgr->conns_all); 92 lgr->conns_num--; 93 conn->alert_token_local = 0; 94 conn->lgr = NULL; 95 sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */ 96 } 97 98 /* Unregister connection and trigger lgr freeing if applicable 99 */ 100 static void smc_lgr_unregister_conn(struct smc_connection *conn) 101 { 102 struct smc_link_group *lgr = conn->lgr; 103 int reduced = 0; 104 105 write_lock_bh(&lgr->conns_lock); 106 if (conn->alert_token_local) { 107 reduced = 1; 108 __smc_lgr_unregister_conn(conn); 109 } 110 write_unlock_bh(&lgr->conns_lock); 111 if (!reduced || lgr->conns_num) 112 return; 113 /* client link group creation always follows the server link group 114 * creation. For client use a somewhat higher removal delay time, 115 * otherwise there is a risk of out-of-sync link groups. 116 */ 117 mod_delayed_work(system_wq, &lgr->free_work, 118 lgr->role == SMC_CLNT ? SMC_LGR_FREE_DELAY_CLNT : 119 SMC_LGR_FREE_DELAY_SERV); 120 } 121 122 static void smc_lgr_free_work(struct work_struct *work) 123 { 124 struct smc_link_group *lgr = container_of(to_delayed_work(work), 125 struct smc_link_group, 126 free_work); 127 bool conns; 128 129 spin_lock_bh(&smc_lgr_list.lock); 130 read_lock_bh(&lgr->conns_lock); 131 conns = RB_EMPTY_ROOT(&lgr->conns_all); 132 read_unlock_bh(&lgr->conns_lock); 133 if (!conns) { /* number of lgr connections is no longer zero */ 134 spin_unlock_bh(&smc_lgr_list.lock); 135 return; 136 } 137 list_del_init(&lgr->list); /* remove from smc_lgr_list */ 138 spin_unlock_bh(&smc_lgr_list.lock); 139 smc_lgr_free(lgr); 140 } 141 142 /* create a new SMC link group */ 143 static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr, 144 struct smc_ib_device *smcibdev, u8 ibport, 145 char *peer_systemid, unsigned short vlan_id) 146 { 147 struct smc_link_group *lgr; 148 struct smc_link *lnk; 149 u8 rndvec[3]; 150 int rc = 0; 151 int i; 152 153 lgr = kzalloc(sizeof(*lgr), GFP_KERNEL); 154 if (!lgr) { 155 rc = -ENOMEM; 156 goto out; 157 } 158 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 159 lgr->sync_err = false; 160 lgr->daddr = peer_in_addr; 161 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN); 162 lgr->vlan_id = vlan_id; 163 rwlock_init(&lgr->sndbufs_lock); 164 rwlock_init(&lgr->rmbs_lock); 165 for (i = 0; i < SMC_RMBE_SIZES; i++) { 166 INIT_LIST_HEAD(&lgr->sndbufs[i]); 167 INIT_LIST_HEAD(&lgr->rmbs[i]); 168 } 169 smc_lgr_num += SMC_LGR_NUM_INCR; 170 memcpy(&lgr->id, (u8 *)&smc_lgr_num, SMC_LGR_ID_SIZE); 171 INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work); 172 lgr->conns_all = RB_ROOT; 173 174 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 175 /* initialize link */ 176 lnk->smcibdev = smcibdev; 177 lnk->ibport = ibport; 178 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu; 179 if (!smcibdev->initialized) 180 smc_ib_setup_per_ibdev(smcibdev); 181 get_random_bytes(rndvec, sizeof(rndvec)); 182 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) + (rndvec[2] << 16); 183 rc = smc_wr_alloc_link_mem(lnk); 184 if (rc) 185 goto free_lgr; 186 rc = smc_ib_create_protection_domain(lnk); 187 if (rc) 188 goto free_link_mem; 189 rc = smc_ib_create_queue_pair(lnk); 190 if (rc) 191 goto dealloc_pd; 192 rc = smc_wr_create_link(lnk); 193 if (rc) 194 goto destroy_qp; 195 init_completion(&lnk->llc_confirm); 196 init_completion(&lnk->llc_confirm_resp); 197 198 smc->conn.lgr = lgr; 199 rwlock_init(&lgr->conns_lock); 200 spin_lock_bh(&smc_lgr_list.lock); 201 list_add(&lgr->list, &smc_lgr_list.list); 202 spin_unlock_bh(&smc_lgr_list.lock); 203 return 0; 204 205 destroy_qp: 206 smc_ib_destroy_queue_pair(lnk); 207 dealloc_pd: 208 smc_ib_dealloc_protection_domain(lnk); 209 free_link_mem: 210 smc_wr_free_link_mem(lnk); 211 free_lgr: 212 kfree(lgr); 213 out: 214 return rc; 215 } 216 217 static void smc_buf_unuse(struct smc_connection *conn) 218 { 219 if (conn->sndbuf_desc) { 220 conn->sndbuf_desc->used = 0; 221 conn->sndbuf_size = 0; 222 } 223 if (conn->rmb_desc) { 224 conn->rmb_desc->reused = true; 225 conn->rmb_desc->used = 0; 226 conn->rmbe_size = 0; 227 } 228 } 229 230 /* remove a finished connection from its link group */ 231 void smc_conn_free(struct smc_connection *conn) 232 { 233 struct smc_link_group *lgr = conn->lgr; 234 235 if (!lgr) 236 return; 237 smc_cdc_tx_dismiss_slots(conn); 238 smc_lgr_unregister_conn(conn); 239 smc_buf_unuse(conn); 240 } 241 242 static void smc_link_clear(struct smc_link *lnk) 243 { 244 lnk->peer_qpn = 0; 245 smc_ib_modify_qp_reset(lnk); 246 smc_wr_free_link(lnk); 247 smc_ib_destroy_queue_pair(lnk); 248 smc_ib_dealloc_protection_domain(lnk); 249 smc_wr_free_link_mem(lnk); 250 } 251 252 static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk, 253 bool is_rmb) 254 { 255 if (is_rmb) { 256 if (buf_desc->mr_rx[SMC_SINGLE_LINK]) 257 smc_ib_put_memory_region( 258 buf_desc->mr_rx[SMC_SINGLE_LINK]); 259 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 260 DMA_FROM_DEVICE); 261 } else { 262 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 263 DMA_TO_DEVICE); 264 } 265 sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]); 266 if (buf_desc->cpu_addr) 267 free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order); 268 kfree(buf_desc); 269 } 270 271 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb) 272 { 273 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 274 struct smc_buf_desc *buf_desc, *bf_desc; 275 struct list_head *buf_list; 276 int i; 277 278 for (i = 0; i < SMC_RMBE_SIZES; i++) { 279 if (is_rmb) 280 buf_list = &lgr->rmbs[i]; 281 else 282 buf_list = &lgr->sndbufs[i]; 283 list_for_each_entry_safe(buf_desc, bf_desc, buf_list, 284 list) { 285 list_del(&buf_desc->list); 286 smc_buf_free(buf_desc, lnk, is_rmb); 287 } 288 } 289 } 290 291 static void smc_lgr_free_bufs(struct smc_link_group *lgr) 292 { 293 /* free send buffers */ 294 __smc_lgr_free_bufs(lgr, false); 295 /* free rmbs */ 296 __smc_lgr_free_bufs(lgr, true); 297 } 298 299 /* remove a link group */ 300 void smc_lgr_free(struct smc_link_group *lgr) 301 { 302 smc_lgr_free_bufs(lgr); 303 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]); 304 kfree(lgr); 305 } 306 307 /* terminate linkgroup abnormally */ 308 void smc_lgr_terminate(struct smc_link_group *lgr) 309 { 310 struct smc_connection *conn; 311 struct smc_sock *smc; 312 struct rb_node *node; 313 314 spin_lock_bh(&smc_lgr_list.lock); 315 if (list_empty(&lgr->list)) { 316 /* termination already triggered */ 317 spin_unlock_bh(&smc_lgr_list.lock); 318 return; 319 } 320 /* do not use this link group for new connections */ 321 list_del_init(&lgr->list); 322 spin_unlock_bh(&smc_lgr_list.lock); 323 324 write_lock_bh(&lgr->conns_lock); 325 node = rb_first(&lgr->conns_all); 326 while (node) { 327 conn = rb_entry(node, struct smc_connection, alert_node); 328 smc = container_of(conn, struct smc_sock, conn); 329 sock_hold(&smc->sk); 330 __smc_lgr_unregister_conn(conn); 331 schedule_work(&conn->close_work); 332 sock_put(&smc->sk); 333 node = rb_first(&lgr->conns_all); 334 } 335 write_unlock_bh(&lgr->conns_lock); 336 } 337 338 /* Determine vlan of internal TCP socket. 339 * @vlan_id: address to store the determined vlan id into 340 */ 341 static int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id) 342 { 343 struct dst_entry *dst = sk_dst_get(clcsock->sk); 344 int rc = 0; 345 346 *vlan_id = 0; 347 if (!dst) { 348 rc = -ENOTCONN; 349 goto out; 350 } 351 if (!dst->dev) { 352 rc = -ENODEV; 353 goto out_rel; 354 } 355 356 if (is_vlan_dev(dst->dev)) 357 *vlan_id = vlan_dev_vlan_id(dst->dev); 358 359 out_rel: 360 dst_release(dst); 361 out: 362 return rc; 363 } 364 365 /* determine the link gid matching the vlan id of the link group */ 366 static int smc_link_determine_gid(struct smc_link_group *lgr) 367 { 368 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 369 struct ib_gid_attr gattr; 370 union ib_gid gid; 371 int i; 372 373 if (!lgr->vlan_id) { 374 lnk->gid = lnk->smcibdev->gid[lnk->ibport - 1]; 375 return 0; 376 } 377 378 for (i = 0; i < lnk->smcibdev->pattr[lnk->ibport - 1].gid_tbl_len; 379 i++) { 380 if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid, 381 &gattr)) 382 continue; 383 if (gattr.ndev) { 384 if (is_vlan_dev(gattr.ndev) && 385 vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id) { 386 lnk->gid = gid; 387 dev_put(gattr.ndev); 388 return 0; 389 } 390 dev_put(gattr.ndev); 391 } 392 } 393 return -ENODEV; 394 } 395 396 /* create a new SMC connection (and a new link group if necessary) */ 397 int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr, 398 struct smc_ib_device *smcibdev, u8 ibport, 399 struct smc_clc_msg_local *lcl, int srv_first_contact) 400 { 401 struct smc_connection *conn = &smc->conn; 402 struct smc_link_group *lgr; 403 unsigned short vlan_id; 404 enum smc_lgr_role role; 405 int local_contact = SMC_FIRST_CONTACT; 406 int rc = 0; 407 408 role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 409 rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id); 410 if (rc) 411 return rc; 412 413 if ((role == SMC_CLNT) && srv_first_contact) 414 /* create new link group as well */ 415 goto create; 416 417 /* determine if an existing link group can be reused */ 418 spin_lock_bh(&smc_lgr_list.lock); 419 list_for_each_entry(lgr, &smc_lgr_list.list, list) { 420 write_lock_bh(&lgr->conns_lock); 421 if (!memcmp(lgr->peer_systemid, lcl->id_for_peer, 422 SMC_SYSTEMID_LEN) && 423 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid, 424 SMC_GID_SIZE) && 425 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac, 426 sizeof(lcl->mac)) && 427 !lgr->sync_err && 428 (lgr->role == role) && 429 (lgr->vlan_id == vlan_id) && 430 ((role == SMC_CLNT) || 431 (lgr->conns_num < SMC_RMBS_PER_LGR_MAX))) { 432 /* link group found */ 433 local_contact = SMC_REUSE_CONTACT; 434 conn->lgr = lgr; 435 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 436 write_unlock_bh(&lgr->conns_lock); 437 break; 438 } 439 write_unlock_bh(&lgr->conns_lock); 440 } 441 spin_unlock_bh(&smc_lgr_list.lock); 442 443 if (role == SMC_CLNT && !srv_first_contact && 444 (local_contact == SMC_FIRST_CONTACT)) { 445 /* Server reuses a link group, but Client wants to start 446 * a new one 447 * send out_of_sync decline, reason synchr. error 448 */ 449 return -ENOLINK; 450 } 451 452 create: 453 if (local_contact == SMC_FIRST_CONTACT) { 454 rc = smc_lgr_create(smc, peer_in_addr, smcibdev, ibport, 455 lcl->id_for_peer, vlan_id); 456 if (rc) 457 goto out; 458 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 459 rc = smc_link_determine_gid(conn->lgr); 460 } 461 conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; 462 conn->local_tx_ctrl.len = sizeof(struct smc_cdc_msg); 463 #ifndef KERNEL_HAS_ATOMIC64 464 spin_lock_init(&conn->acurs_lock); 465 #endif 466 467 out: 468 return rc ? rc : local_contact; 469 } 470 471 /* try to reuse a sndbuf or rmb description slot for a certain 472 * buffer size; if not available, return NULL 473 */ 474 static inline 475 struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr, 476 int compressed_bufsize, 477 rwlock_t *lock, 478 struct list_head *buf_list) 479 { 480 struct smc_buf_desc *buf_slot; 481 482 read_lock_bh(lock); 483 list_for_each_entry(buf_slot, buf_list, list) { 484 if (cmpxchg(&buf_slot->used, 0, 1) == 0) { 485 read_unlock_bh(lock); 486 return buf_slot; 487 } 488 } 489 read_unlock_bh(lock); 490 return NULL; 491 } 492 493 /* one of the conditions for announcing a receiver's current window size is 494 * that it "results in a minimum increase in the window size of 10% of the 495 * receive buffer space" [RFC7609] 496 */ 497 static inline int smc_rmb_wnd_update_limit(int rmbe_size) 498 { 499 return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2); 500 } 501 502 static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr, 503 bool is_rmb, int bufsize) 504 { 505 struct smc_buf_desc *buf_desc; 506 struct smc_link *lnk; 507 int rc; 508 509 /* try to alloc a new buffer */ 510 buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL); 511 if (!buf_desc) 512 return ERR_PTR(-ENOMEM); 513 514 buf_desc->cpu_addr = 515 (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | 516 __GFP_NOMEMALLOC | 517 __GFP_NORETRY | __GFP_ZERO, 518 get_order(bufsize)); 519 if (!buf_desc->cpu_addr) { 520 kfree(buf_desc); 521 return ERR_PTR(-EAGAIN); 522 } 523 buf_desc->order = get_order(bufsize); 524 525 /* build the sg table from the pages */ 526 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 527 rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1, 528 GFP_KERNEL); 529 if (rc) { 530 smc_buf_free(buf_desc, lnk, is_rmb); 531 return ERR_PTR(rc); 532 } 533 sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl, 534 buf_desc->cpu_addr, bufsize); 535 536 /* map sg table to DMA address */ 537 rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, 538 is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 539 /* SMC protocol depends on mapping to one DMA address only */ 540 if (rc != 1) { 541 smc_buf_free(buf_desc, lnk, is_rmb); 542 return ERR_PTR(-EAGAIN); 543 } 544 545 /* create a new memory region for the RMB */ 546 if (is_rmb) { 547 rc = smc_ib_get_memory_region(lnk->roce_pd, 548 IB_ACCESS_REMOTE_WRITE | 549 IB_ACCESS_LOCAL_WRITE, 550 buf_desc); 551 if (rc) { 552 smc_buf_free(buf_desc, lnk, is_rmb); 553 return ERR_PTR(rc); 554 } 555 } 556 557 return buf_desc; 558 } 559 560 static int __smc_buf_create(struct smc_sock *smc, bool is_rmb) 561 { 562 struct smc_connection *conn = &smc->conn; 563 struct smc_link_group *lgr = conn->lgr; 564 struct smc_buf_desc *buf_desc = NULL; 565 struct list_head *buf_list; 566 int bufsize, bufsize_short; 567 int sk_buf_size; 568 rwlock_t *lock; 569 570 if (is_rmb) 571 /* use socket recv buffer size (w/o overhead) as start value */ 572 sk_buf_size = smc->sk.sk_rcvbuf / 2; 573 else 574 /* use socket send buffer size (w/o overhead) as start value */ 575 sk_buf_size = smc->sk.sk_sndbuf / 2; 576 577 for (bufsize_short = smc_compress_bufsize(smc->sk.sk_sndbuf / 2); 578 bufsize_short >= 0; bufsize_short--) { 579 580 if (is_rmb) { 581 lock = &lgr->rmbs_lock; 582 buf_list = &lgr->rmbs[bufsize_short]; 583 } else { 584 lock = &lgr->sndbufs_lock; 585 buf_list = &lgr->sndbufs[bufsize_short]; 586 } 587 bufsize = smc_uncompress_bufsize(bufsize_short); 588 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC) 589 continue; 590 591 /* check for reusable slot in the link group */ 592 buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list); 593 if (buf_desc) { 594 memset(buf_desc->cpu_addr, 0, bufsize); 595 break; /* found reusable slot */ 596 } 597 598 buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize); 599 if (PTR_ERR(buf_desc) == -ENOMEM) 600 break; 601 if (IS_ERR(buf_desc)) 602 continue; 603 604 buf_desc->used = 1; 605 write_lock_bh(lock); 606 list_add(&buf_desc->list, buf_list); 607 write_unlock_bh(lock); 608 break; /* found */ 609 } 610 611 if (IS_ERR(buf_desc)) 612 return -ENOMEM; 613 614 if (is_rmb) { 615 conn->rmb_desc = buf_desc; 616 conn->rmbe_size = bufsize; 617 conn->rmbe_size_short = bufsize_short; 618 smc->sk.sk_rcvbuf = bufsize * 2; 619 atomic_set(&conn->bytes_to_rcv, 0); 620 conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize); 621 } else { 622 conn->sndbuf_desc = buf_desc; 623 conn->sndbuf_size = bufsize; 624 smc->sk.sk_sndbuf = bufsize * 2; 625 atomic_set(&conn->sndbuf_space, bufsize); 626 } 627 return 0; 628 } 629 630 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn) 631 { 632 struct smc_link_group *lgr = conn->lgr; 633 634 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 635 conn->sndbuf_desc, DMA_TO_DEVICE); 636 } 637 638 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn) 639 { 640 struct smc_link_group *lgr = conn->lgr; 641 642 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 643 conn->sndbuf_desc, DMA_TO_DEVICE); 644 } 645 646 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn) 647 { 648 struct smc_link_group *lgr = conn->lgr; 649 650 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 651 conn->rmb_desc, DMA_FROM_DEVICE); 652 } 653 654 void smc_rmb_sync_sg_for_device(struct smc_connection *conn) 655 { 656 struct smc_link_group *lgr = conn->lgr; 657 658 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 659 conn->rmb_desc, DMA_FROM_DEVICE); 660 } 661 662 /* create the send and receive buffer for an SMC socket; 663 * receive buffers are called RMBs; 664 * (even though the SMC protocol allows more than one RMB-element per RMB, 665 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an 666 * extra RMB for every connection in a link group 667 */ 668 int smc_buf_create(struct smc_sock *smc) 669 { 670 int rc; 671 672 /* create send buffer */ 673 rc = __smc_buf_create(smc, false); 674 if (rc) 675 return rc; 676 /* create rmb */ 677 rc = __smc_buf_create(smc, true); 678 if (rc) 679 smc_buf_free(smc->conn.sndbuf_desc, 680 &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false); 681 return rc; 682 } 683 684 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr) 685 { 686 int i; 687 688 for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) { 689 if (!test_and_set_bit(i, lgr->rtokens_used_mask)) 690 return i; 691 } 692 return -ENOSPC; 693 } 694 695 /* save rkey and dma_addr received from peer during clc handshake */ 696 int smc_rmb_rtoken_handling(struct smc_connection *conn, 697 struct smc_clc_msg_accept_confirm *clc) 698 { 699 u64 dma_addr = be64_to_cpu(clc->rmb_dma_addr); 700 struct smc_link_group *lgr = conn->lgr; 701 u32 rkey = ntohl(clc->rmb_rkey); 702 int i; 703 704 for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { 705 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) && 706 (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) && 707 test_bit(i, lgr->rtokens_used_mask)) { 708 conn->rtoken_idx = i; 709 return 0; 710 } 711 } 712 conn->rtoken_idx = smc_rmb_reserve_rtoken_idx(lgr); 713 if (conn->rtoken_idx < 0) 714 return conn->rtoken_idx; 715 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey = rkey; 716 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr = dma_addr; 717 return 0; 718 } 719