1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Shared Memory Communications over RDMA (SMC-R) and RoCE 4 * 5 * Basic Transport Functions exploiting Infiniband API 6 * 7 * Copyright IBM Corp. 2016 8 * 9 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> 10 */ 11 12 #include <linux/socket.h> 13 #include <linux/if_vlan.h> 14 #include <linux/random.h> 15 #include <linux/workqueue.h> 16 #include <net/tcp.h> 17 #include <net/sock.h> 18 #include <rdma/ib_verbs.h> 19 20 #include "smc.h" 21 #include "smc_clc.h" 22 #include "smc_core.h" 23 #include "smc_ib.h" 24 #include "smc_wr.h" 25 #include "smc_llc.h" 26 #include "smc_cdc.h" 27 #include "smc_close.h" 28 29 #define SMC_LGR_NUM_INCR 256 30 #define SMC_LGR_FREE_DELAY_SERV (600 * HZ) 31 #define SMC_LGR_FREE_DELAY_CLNT (SMC_LGR_FREE_DELAY_SERV + 10) 32 33 static u32 smc_lgr_num; /* unique link group number */ 34 35 /* Register connection's alert token in our lookup structure. 36 * To use rbtrees we have to implement our own insert core. 37 * Requires @conns_lock 38 * @smc connection to register 39 * Returns 0 on success, != otherwise. 40 */ 41 static void smc_lgr_add_alert_token(struct smc_connection *conn) 42 { 43 struct rb_node **link, *parent = NULL; 44 u32 token = conn->alert_token_local; 45 46 link = &conn->lgr->conns_all.rb_node; 47 while (*link) { 48 struct smc_connection *cur = rb_entry(*link, 49 struct smc_connection, alert_node); 50 51 parent = *link; 52 if (cur->alert_token_local > token) 53 link = &parent->rb_left; 54 else 55 link = &parent->rb_right; 56 } 57 /* Put the new node there */ 58 rb_link_node(&conn->alert_node, parent, link); 59 rb_insert_color(&conn->alert_node, &conn->lgr->conns_all); 60 } 61 62 /* Register connection in link group by assigning an alert token 63 * registered in a search tree. 64 * Requires @conns_lock 65 * Note that '0' is a reserved value and not assigned. 66 */ 67 static void smc_lgr_register_conn(struct smc_connection *conn) 68 { 69 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 70 static atomic_t nexttoken = ATOMIC_INIT(0); 71 72 /* find a new alert_token_local value not yet used by some connection 73 * in this link group 74 */ 75 sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */ 76 while (!conn->alert_token_local) { 77 conn->alert_token_local = atomic_inc_return(&nexttoken); 78 if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr)) 79 conn->alert_token_local = 0; 80 } 81 smc_lgr_add_alert_token(conn); 82 conn->lgr->conns_num++; 83 } 84 85 /* Unregister connection and reset the alert token of the given connection< 86 */ 87 static void __smc_lgr_unregister_conn(struct smc_connection *conn) 88 { 89 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 90 struct smc_link_group *lgr = conn->lgr; 91 92 rb_erase(&conn->alert_node, &lgr->conns_all); 93 lgr->conns_num--; 94 conn->alert_token_local = 0; 95 conn->lgr = NULL; 96 sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */ 97 } 98 99 /* Unregister connection and trigger lgr freeing if applicable 100 */ 101 static void smc_lgr_unregister_conn(struct smc_connection *conn) 102 { 103 struct smc_link_group *lgr = conn->lgr; 104 int reduced = 0; 105 106 write_lock_bh(&lgr->conns_lock); 107 if (conn->alert_token_local) { 108 reduced = 1; 109 __smc_lgr_unregister_conn(conn); 110 } 111 write_unlock_bh(&lgr->conns_lock); 112 if (!reduced || lgr->conns_num) 113 return; 114 /* client link group creation always follows the server link group 115 * creation. For client use a somewhat higher removal delay time, 116 * otherwise there is a risk of out-of-sync link groups. 117 */ 118 mod_delayed_work(system_wq, &lgr->free_work, 119 lgr->role == SMC_CLNT ? SMC_LGR_FREE_DELAY_CLNT : 120 SMC_LGR_FREE_DELAY_SERV); 121 } 122 123 static void smc_lgr_free_work(struct work_struct *work) 124 { 125 struct smc_link_group *lgr = container_of(to_delayed_work(work), 126 struct smc_link_group, 127 free_work); 128 bool conns; 129 130 spin_lock_bh(&smc_lgr_list.lock); 131 read_lock_bh(&lgr->conns_lock); 132 conns = RB_EMPTY_ROOT(&lgr->conns_all); 133 read_unlock_bh(&lgr->conns_lock); 134 if (!conns) { /* number of lgr connections is no longer zero */ 135 spin_unlock_bh(&smc_lgr_list.lock); 136 return; 137 } 138 list_del_init(&lgr->list); /* remove from smc_lgr_list */ 139 spin_unlock_bh(&smc_lgr_list.lock); 140 smc_lgr_free(lgr); 141 } 142 143 /* create a new SMC link group */ 144 static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr, 145 struct smc_ib_device *smcibdev, u8 ibport, 146 char *peer_systemid, unsigned short vlan_id) 147 { 148 struct smc_link_group *lgr; 149 struct smc_link *lnk; 150 u8 rndvec[3]; 151 int rc = 0; 152 int i; 153 154 lgr = kzalloc(sizeof(*lgr), GFP_KERNEL); 155 if (!lgr) { 156 rc = -ENOMEM; 157 goto out; 158 } 159 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 160 lgr->sync_err = false; 161 lgr->daddr = peer_in_addr; 162 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN); 163 lgr->vlan_id = vlan_id; 164 rwlock_init(&lgr->sndbufs_lock); 165 rwlock_init(&lgr->rmbs_lock); 166 for (i = 0; i < SMC_RMBE_SIZES; i++) { 167 INIT_LIST_HEAD(&lgr->sndbufs[i]); 168 INIT_LIST_HEAD(&lgr->rmbs[i]); 169 } 170 smc_lgr_num += SMC_LGR_NUM_INCR; 171 memcpy(&lgr->id, (u8 *)&smc_lgr_num, SMC_LGR_ID_SIZE); 172 INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work); 173 lgr->conns_all = RB_ROOT; 174 175 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 176 /* initialize link */ 177 lnk->smcibdev = smcibdev; 178 lnk->ibport = ibport; 179 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu; 180 if (!smcibdev->initialized) 181 smc_ib_setup_per_ibdev(smcibdev); 182 get_random_bytes(rndvec, sizeof(rndvec)); 183 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) + (rndvec[2] << 16); 184 rc = smc_wr_alloc_link_mem(lnk); 185 if (rc) 186 goto free_lgr; 187 rc = smc_ib_create_protection_domain(lnk); 188 if (rc) 189 goto free_link_mem; 190 rc = smc_ib_create_queue_pair(lnk); 191 if (rc) 192 goto dealloc_pd; 193 rc = smc_wr_create_link(lnk); 194 if (rc) 195 goto destroy_qp; 196 init_completion(&lnk->llc_confirm); 197 init_completion(&lnk->llc_confirm_resp); 198 199 smc->conn.lgr = lgr; 200 rwlock_init(&lgr->conns_lock); 201 spin_lock_bh(&smc_lgr_list.lock); 202 list_add(&lgr->list, &smc_lgr_list.list); 203 spin_unlock_bh(&smc_lgr_list.lock); 204 return 0; 205 206 destroy_qp: 207 smc_ib_destroy_queue_pair(lnk); 208 dealloc_pd: 209 smc_ib_dealloc_protection_domain(lnk); 210 free_link_mem: 211 smc_wr_free_link_mem(lnk); 212 free_lgr: 213 kfree(lgr); 214 out: 215 return rc; 216 } 217 218 static void smc_buf_unuse(struct smc_connection *conn) 219 { 220 if (conn->sndbuf_desc) { 221 conn->sndbuf_desc->used = 0; 222 conn->sndbuf_size = 0; 223 } 224 if (conn->rmb_desc) { 225 conn->rmb_desc->reused = true; 226 conn->rmb_desc->used = 0; 227 conn->rmbe_size = 0; 228 } 229 } 230 231 /* remove a finished connection from its link group */ 232 void smc_conn_free(struct smc_connection *conn) 233 { 234 struct smc_link_group *lgr = conn->lgr; 235 236 if (!lgr) 237 return; 238 smc_cdc_tx_dismiss_slots(conn); 239 smc_lgr_unregister_conn(conn); 240 smc_buf_unuse(conn); 241 } 242 243 static void smc_link_clear(struct smc_link *lnk) 244 { 245 lnk->peer_qpn = 0; 246 smc_ib_modify_qp_reset(lnk); 247 smc_wr_free_link(lnk); 248 smc_ib_destroy_queue_pair(lnk); 249 smc_ib_dealloc_protection_domain(lnk); 250 smc_wr_free_link_mem(lnk); 251 } 252 253 static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk, 254 bool is_rmb) 255 { 256 if (is_rmb) { 257 if (buf_desc->mr_rx[SMC_SINGLE_LINK]) 258 smc_ib_put_memory_region( 259 buf_desc->mr_rx[SMC_SINGLE_LINK]); 260 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 261 DMA_FROM_DEVICE); 262 } else { 263 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 264 DMA_TO_DEVICE); 265 } 266 sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]); 267 if (buf_desc->cpu_addr) 268 free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order); 269 kfree(buf_desc); 270 } 271 272 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb) 273 { 274 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 275 struct smc_buf_desc *buf_desc, *bf_desc; 276 struct list_head *buf_list; 277 int i; 278 279 for (i = 0; i < SMC_RMBE_SIZES; i++) { 280 if (is_rmb) 281 buf_list = &lgr->rmbs[i]; 282 else 283 buf_list = &lgr->sndbufs[i]; 284 list_for_each_entry_safe(buf_desc, bf_desc, buf_list, 285 list) { 286 list_del(&buf_desc->list); 287 smc_buf_free(buf_desc, lnk, is_rmb); 288 } 289 } 290 } 291 292 static void smc_lgr_free_bufs(struct smc_link_group *lgr) 293 { 294 /* free send buffers */ 295 __smc_lgr_free_bufs(lgr, false); 296 /* free rmbs */ 297 __smc_lgr_free_bufs(lgr, true); 298 } 299 300 /* remove a link group */ 301 void smc_lgr_free(struct smc_link_group *lgr) 302 { 303 smc_lgr_free_bufs(lgr); 304 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]); 305 kfree(lgr); 306 } 307 308 /* terminate linkgroup abnormally */ 309 void smc_lgr_terminate(struct smc_link_group *lgr) 310 { 311 struct smc_connection *conn; 312 struct smc_sock *smc; 313 struct rb_node *node; 314 315 spin_lock_bh(&smc_lgr_list.lock); 316 if (list_empty(&lgr->list)) { 317 /* termination already triggered */ 318 spin_unlock_bh(&smc_lgr_list.lock); 319 return; 320 } 321 /* do not use this link group for new connections */ 322 list_del_init(&lgr->list); 323 spin_unlock_bh(&smc_lgr_list.lock); 324 325 write_lock_bh(&lgr->conns_lock); 326 node = rb_first(&lgr->conns_all); 327 while (node) { 328 conn = rb_entry(node, struct smc_connection, alert_node); 329 smc = container_of(conn, struct smc_sock, conn); 330 sock_hold(&smc->sk); 331 __smc_lgr_unregister_conn(conn); 332 schedule_work(&conn->close_work); 333 sock_put(&smc->sk); 334 node = rb_first(&lgr->conns_all); 335 } 336 write_unlock_bh(&lgr->conns_lock); 337 } 338 339 /* Determine vlan of internal TCP socket. 340 * @vlan_id: address to store the determined vlan id into 341 */ 342 static int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id) 343 { 344 struct dst_entry *dst = sk_dst_get(clcsock->sk); 345 int rc = 0; 346 347 *vlan_id = 0; 348 if (!dst) { 349 rc = -ENOTCONN; 350 goto out; 351 } 352 if (!dst->dev) { 353 rc = -ENODEV; 354 goto out_rel; 355 } 356 357 if (is_vlan_dev(dst->dev)) 358 *vlan_id = vlan_dev_vlan_id(dst->dev); 359 360 out_rel: 361 dst_release(dst); 362 out: 363 return rc; 364 } 365 366 /* determine the link gid matching the vlan id of the link group */ 367 static int smc_link_determine_gid(struct smc_link_group *lgr) 368 { 369 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 370 struct ib_gid_attr gattr; 371 union ib_gid gid; 372 int i; 373 374 if (!lgr->vlan_id) { 375 lnk->gid = lnk->smcibdev->gid[lnk->ibport - 1]; 376 return 0; 377 } 378 379 for (i = 0; i < lnk->smcibdev->pattr[lnk->ibport - 1].gid_tbl_len; 380 i++) { 381 if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid, 382 &gattr)) 383 continue; 384 if (gattr.ndev && 385 (vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id)) { 386 lnk->gid = gid; 387 return 0; 388 } 389 } 390 return -ENODEV; 391 } 392 393 /* create a new SMC connection (and a new link group if necessary) */ 394 int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr, 395 struct smc_ib_device *smcibdev, u8 ibport, 396 struct smc_clc_msg_local *lcl, int srv_first_contact) 397 { 398 struct smc_connection *conn = &smc->conn; 399 struct smc_link_group *lgr; 400 unsigned short vlan_id; 401 enum smc_lgr_role role; 402 int local_contact = SMC_FIRST_CONTACT; 403 int rc = 0; 404 405 role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 406 rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id); 407 if (rc) 408 return rc; 409 410 if ((role == SMC_CLNT) && srv_first_contact) 411 /* create new link group as well */ 412 goto create; 413 414 /* determine if an existing link group can be reused */ 415 spin_lock_bh(&smc_lgr_list.lock); 416 list_for_each_entry(lgr, &smc_lgr_list.list, list) { 417 write_lock_bh(&lgr->conns_lock); 418 if (!memcmp(lgr->peer_systemid, lcl->id_for_peer, 419 SMC_SYSTEMID_LEN) && 420 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid, 421 SMC_GID_SIZE) && 422 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac, 423 sizeof(lcl->mac)) && 424 !lgr->sync_err && 425 (lgr->role == role) && 426 (lgr->vlan_id == vlan_id) && 427 ((role == SMC_CLNT) || 428 (lgr->conns_num < SMC_RMBS_PER_LGR_MAX))) { 429 /* link group found */ 430 local_contact = SMC_REUSE_CONTACT; 431 conn->lgr = lgr; 432 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 433 write_unlock_bh(&lgr->conns_lock); 434 break; 435 } 436 write_unlock_bh(&lgr->conns_lock); 437 } 438 spin_unlock_bh(&smc_lgr_list.lock); 439 440 if (role == SMC_CLNT && !srv_first_contact && 441 (local_contact == SMC_FIRST_CONTACT)) { 442 /* Server reuses a link group, but Client wants to start 443 * a new one 444 * send out_of_sync decline, reason synchr. error 445 */ 446 return -ENOLINK; 447 } 448 449 create: 450 if (local_contact == SMC_FIRST_CONTACT) { 451 rc = smc_lgr_create(smc, peer_in_addr, smcibdev, ibport, 452 lcl->id_for_peer, vlan_id); 453 if (rc) 454 goto out; 455 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 456 rc = smc_link_determine_gid(conn->lgr); 457 } 458 conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; 459 conn->local_tx_ctrl.len = sizeof(struct smc_cdc_msg); 460 #ifndef KERNEL_HAS_ATOMIC64 461 spin_lock_init(&conn->acurs_lock); 462 #endif 463 464 out: 465 return rc ? rc : local_contact; 466 } 467 468 /* try to reuse a sndbuf or rmb description slot for a certain 469 * buffer size; if not available, return NULL 470 */ 471 static inline 472 struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr, 473 int compressed_bufsize, 474 rwlock_t *lock, 475 struct list_head *buf_list) 476 { 477 struct smc_buf_desc *buf_slot; 478 479 read_lock_bh(lock); 480 list_for_each_entry(buf_slot, buf_list, list) { 481 if (cmpxchg(&buf_slot->used, 0, 1) == 0) { 482 read_unlock_bh(lock); 483 return buf_slot; 484 } 485 } 486 read_unlock_bh(lock); 487 return NULL; 488 } 489 490 /* one of the conditions for announcing a receiver's current window size is 491 * that it "results in a minimum increase in the window size of 10% of the 492 * receive buffer space" [RFC7609] 493 */ 494 static inline int smc_rmb_wnd_update_limit(int rmbe_size) 495 { 496 return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2); 497 } 498 499 static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr, 500 bool is_rmb, int bufsize) 501 { 502 struct smc_buf_desc *buf_desc; 503 struct smc_link *lnk; 504 int rc; 505 506 /* try to alloc a new buffer */ 507 buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL); 508 if (!buf_desc) 509 return ERR_PTR(-ENOMEM); 510 511 buf_desc->cpu_addr = 512 (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | 513 __GFP_NOMEMALLOC | 514 __GFP_NORETRY | __GFP_ZERO, 515 get_order(bufsize)); 516 if (!buf_desc->cpu_addr) { 517 kfree(buf_desc); 518 return ERR_PTR(-EAGAIN); 519 } 520 buf_desc->order = get_order(bufsize); 521 522 /* build the sg table from the pages */ 523 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 524 rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1, 525 GFP_KERNEL); 526 if (rc) { 527 smc_buf_free(buf_desc, lnk, is_rmb); 528 return ERR_PTR(rc); 529 } 530 sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl, 531 buf_desc->cpu_addr, bufsize); 532 533 /* map sg table to DMA address */ 534 rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, 535 is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 536 /* SMC protocol depends on mapping to one DMA address only */ 537 if (rc != 1) { 538 smc_buf_free(buf_desc, lnk, is_rmb); 539 return ERR_PTR(-EAGAIN); 540 } 541 542 /* create a new memory region for the RMB */ 543 if (is_rmb) { 544 rc = smc_ib_get_memory_region(lnk->roce_pd, 545 IB_ACCESS_REMOTE_WRITE | 546 IB_ACCESS_LOCAL_WRITE, 547 buf_desc); 548 if (rc) { 549 smc_buf_free(buf_desc, lnk, is_rmb); 550 return ERR_PTR(rc); 551 } 552 } 553 554 return buf_desc; 555 } 556 557 static int __smc_buf_create(struct smc_sock *smc, bool is_rmb) 558 { 559 struct smc_connection *conn = &smc->conn; 560 struct smc_link_group *lgr = conn->lgr; 561 struct smc_buf_desc *buf_desc = NULL; 562 struct list_head *buf_list; 563 int bufsize, bufsize_short; 564 int sk_buf_size; 565 rwlock_t *lock; 566 567 if (is_rmb) 568 /* use socket recv buffer size (w/o overhead) as start value */ 569 sk_buf_size = smc->sk.sk_rcvbuf / 2; 570 else 571 /* use socket send buffer size (w/o overhead) as start value */ 572 sk_buf_size = smc->sk.sk_sndbuf / 2; 573 574 for (bufsize_short = smc_compress_bufsize(smc->sk.sk_sndbuf / 2); 575 bufsize_short >= 0; bufsize_short--) { 576 577 if (is_rmb) { 578 lock = &lgr->rmbs_lock; 579 buf_list = &lgr->rmbs[bufsize_short]; 580 } else { 581 lock = &lgr->sndbufs_lock; 582 buf_list = &lgr->sndbufs[bufsize_short]; 583 } 584 bufsize = smc_uncompress_bufsize(bufsize_short); 585 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC) 586 continue; 587 588 /* check for reusable slot in the link group */ 589 buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list); 590 if (buf_desc) { 591 memset(buf_desc->cpu_addr, 0, bufsize); 592 break; /* found reusable slot */ 593 } 594 595 buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize); 596 if (PTR_ERR(buf_desc) == -ENOMEM) 597 break; 598 if (IS_ERR(buf_desc)) 599 continue; 600 601 buf_desc->used = 1; 602 write_lock_bh(lock); 603 list_add(&buf_desc->list, buf_list); 604 write_unlock_bh(lock); 605 break; /* found */ 606 } 607 608 if (IS_ERR(buf_desc)) 609 return -ENOMEM; 610 611 if (is_rmb) { 612 conn->rmb_desc = buf_desc; 613 conn->rmbe_size = bufsize; 614 conn->rmbe_size_short = bufsize_short; 615 smc->sk.sk_rcvbuf = bufsize * 2; 616 atomic_set(&conn->bytes_to_rcv, 0); 617 conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize); 618 } else { 619 conn->sndbuf_desc = buf_desc; 620 conn->sndbuf_size = bufsize; 621 smc->sk.sk_sndbuf = bufsize * 2; 622 atomic_set(&conn->sndbuf_space, bufsize); 623 } 624 return 0; 625 } 626 627 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn) 628 { 629 struct smc_link_group *lgr = conn->lgr; 630 631 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 632 conn->sndbuf_desc, DMA_TO_DEVICE); 633 } 634 635 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn) 636 { 637 struct smc_link_group *lgr = conn->lgr; 638 639 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 640 conn->sndbuf_desc, DMA_TO_DEVICE); 641 } 642 643 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn) 644 { 645 struct smc_link_group *lgr = conn->lgr; 646 647 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 648 conn->rmb_desc, DMA_FROM_DEVICE); 649 } 650 651 void smc_rmb_sync_sg_for_device(struct smc_connection *conn) 652 { 653 struct smc_link_group *lgr = conn->lgr; 654 655 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 656 conn->rmb_desc, DMA_FROM_DEVICE); 657 } 658 659 /* create the send and receive buffer for an SMC socket; 660 * receive buffers are called RMBs; 661 * (even though the SMC protocol allows more than one RMB-element per RMB, 662 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an 663 * extra RMB for every connection in a link group 664 */ 665 int smc_buf_create(struct smc_sock *smc) 666 { 667 int rc; 668 669 /* create send buffer */ 670 rc = __smc_buf_create(smc, false); 671 if (rc) 672 return rc; 673 /* create rmb */ 674 rc = __smc_buf_create(smc, true); 675 if (rc) 676 smc_buf_free(smc->conn.sndbuf_desc, 677 &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false); 678 return rc; 679 } 680 681 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr) 682 { 683 int i; 684 685 for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) { 686 if (!test_and_set_bit(i, lgr->rtokens_used_mask)) 687 return i; 688 } 689 return -ENOSPC; 690 } 691 692 /* save rkey and dma_addr received from peer during clc handshake */ 693 int smc_rmb_rtoken_handling(struct smc_connection *conn, 694 struct smc_clc_msg_accept_confirm *clc) 695 { 696 u64 dma_addr = be64_to_cpu(clc->rmb_dma_addr); 697 struct smc_link_group *lgr = conn->lgr; 698 u32 rkey = ntohl(clc->rmb_rkey); 699 int i; 700 701 for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { 702 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) && 703 (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) && 704 test_bit(i, lgr->rtokens_used_mask)) { 705 conn->rtoken_idx = i; 706 return 0; 707 } 708 } 709 conn->rtoken_idx = smc_rmb_reserve_rtoken_idx(lgr); 710 if (conn->rtoken_idx < 0) 711 return conn->rtoken_idx; 712 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey = rkey; 713 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr = dma_addr; 714 return 0; 715 } 716