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 if (is_vlan_dev(gattr.ndev) && 386 vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id) { 387 lnk->gid = gid; 388 dev_put(gattr.ndev); 389 return 0; 390 } 391 dev_put(gattr.ndev); 392 } 393 } 394 return -ENODEV; 395 } 396 397 /* create a new SMC connection (and a new link group if necessary) */ 398 int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr, 399 struct smc_ib_device *smcibdev, u8 ibport, 400 struct smc_clc_msg_local *lcl, int srv_first_contact) 401 { 402 struct smc_connection *conn = &smc->conn; 403 struct smc_link_group *lgr; 404 unsigned short vlan_id; 405 enum smc_lgr_role role; 406 int local_contact = SMC_FIRST_CONTACT; 407 int rc = 0; 408 409 role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 410 rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id); 411 if (rc) 412 return rc; 413 414 if ((role == SMC_CLNT) && srv_first_contact) 415 /* create new link group as well */ 416 goto create; 417 418 /* determine if an existing link group can be reused */ 419 spin_lock_bh(&smc_lgr_list.lock); 420 list_for_each_entry(lgr, &smc_lgr_list.list, list) { 421 write_lock_bh(&lgr->conns_lock); 422 if (!memcmp(lgr->peer_systemid, lcl->id_for_peer, 423 SMC_SYSTEMID_LEN) && 424 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid, 425 SMC_GID_SIZE) && 426 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac, 427 sizeof(lcl->mac)) && 428 !lgr->sync_err && 429 (lgr->role == role) && 430 (lgr->vlan_id == vlan_id) && 431 ((role == SMC_CLNT) || 432 (lgr->conns_num < SMC_RMBS_PER_LGR_MAX))) { 433 /* link group found */ 434 local_contact = SMC_REUSE_CONTACT; 435 conn->lgr = lgr; 436 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 437 write_unlock_bh(&lgr->conns_lock); 438 break; 439 } 440 write_unlock_bh(&lgr->conns_lock); 441 } 442 spin_unlock_bh(&smc_lgr_list.lock); 443 444 if (role == SMC_CLNT && !srv_first_contact && 445 (local_contact == SMC_FIRST_CONTACT)) { 446 /* Server reuses a link group, but Client wants to start 447 * a new one 448 * send out_of_sync decline, reason synchr. error 449 */ 450 return -ENOLINK; 451 } 452 453 create: 454 if (local_contact == SMC_FIRST_CONTACT) { 455 rc = smc_lgr_create(smc, peer_in_addr, smcibdev, ibport, 456 lcl->id_for_peer, vlan_id); 457 if (rc) 458 goto out; 459 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 460 rc = smc_link_determine_gid(conn->lgr); 461 } 462 conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; 463 conn->local_tx_ctrl.len = sizeof(struct smc_cdc_msg); 464 #ifndef KERNEL_HAS_ATOMIC64 465 spin_lock_init(&conn->acurs_lock); 466 #endif 467 468 out: 469 return rc ? rc : local_contact; 470 } 471 472 /* try to reuse a sndbuf or rmb description slot for a certain 473 * buffer size; if not available, return NULL 474 */ 475 static inline 476 struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr, 477 int compressed_bufsize, 478 rwlock_t *lock, 479 struct list_head *buf_list) 480 { 481 struct smc_buf_desc *buf_slot; 482 483 read_lock_bh(lock); 484 list_for_each_entry(buf_slot, buf_list, list) { 485 if (cmpxchg(&buf_slot->used, 0, 1) == 0) { 486 read_unlock_bh(lock); 487 return buf_slot; 488 } 489 } 490 read_unlock_bh(lock); 491 return NULL; 492 } 493 494 /* one of the conditions for announcing a receiver's current window size is 495 * that it "results in a minimum increase in the window size of 10% of the 496 * receive buffer space" [RFC7609] 497 */ 498 static inline int smc_rmb_wnd_update_limit(int rmbe_size) 499 { 500 return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2); 501 } 502 503 static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr, 504 bool is_rmb, int bufsize) 505 { 506 struct smc_buf_desc *buf_desc; 507 struct smc_link *lnk; 508 int rc; 509 510 /* try to alloc a new buffer */ 511 buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL); 512 if (!buf_desc) 513 return ERR_PTR(-ENOMEM); 514 515 buf_desc->cpu_addr = 516 (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | 517 __GFP_NOMEMALLOC | 518 __GFP_NORETRY | __GFP_ZERO, 519 get_order(bufsize)); 520 if (!buf_desc->cpu_addr) { 521 kfree(buf_desc); 522 return ERR_PTR(-EAGAIN); 523 } 524 buf_desc->order = get_order(bufsize); 525 526 /* build the sg table from the pages */ 527 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 528 rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1, 529 GFP_KERNEL); 530 if (rc) { 531 smc_buf_free(buf_desc, lnk, is_rmb); 532 return ERR_PTR(rc); 533 } 534 sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl, 535 buf_desc->cpu_addr, bufsize); 536 537 /* map sg table to DMA address */ 538 rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, 539 is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 540 /* SMC protocol depends on mapping to one DMA address only */ 541 if (rc != 1) { 542 smc_buf_free(buf_desc, lnk, is_rmb); 543 return ERR_PTR(-EAGAIN); 544 } 545 546 /* create a new memory region for the RMB */ 547 if (is_rmb) { 548 rc = smc_ib_get_memory_region(lnk->roce_pd, 549 IB_ACCESS_REMOTE_WRITE | 550 IB_ACCESS_LOCAL_WRITE, 551 buf_desc); 552 if (rc) { 553 smc_buf_free(buf_desc, lnk, is_rmb); 554 return ERR_PTR(rc); 555 } 556 } 557 558 return buf_desc; 559 } 560 561 static int __smc_buf_create(struct smc_sock *smc, bool is_rmb) 562 { 563 struct smc_connection *conn = &smc->conn; 564 struct smc_link_group *lgr = conn->lgr; 565 struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM); 566 struct list_head *buf_list; 567 int bufsize, bufsize_short; 568 int sk_buf_size; 569 rwlock_t *lock; 570 571 if (is_rmb) 572 /* use socket recv buffer size (w/o overhead) as start value */ 573 sk_buf_size = smc->sk.sk_rcvbuf / 2; 574 else 575 /* use socket send buffer size (w/o overhead) as start value */ 576 sk_buf_size = smc->sk.sk_sndbuf / 2; 577 578 for (bufsize_short = smc_compress_bufsize(sk_buf_size); 579 bufsize_short >= 0; bufsize_short--) { 580 581 if (is_rmb) { 582 lock = &lgr->rmbs_lock; 583 buf_list = &lgr->rmbs[bufsize_short]; 584 } else { 585 lock = &lgr->sndbufs_lock; 586 buf_list = &lgr->sndbufs[bufsize_short]; 587 } 588 bufsize = smc_uncompress_bufsize(bufsize_short); 589 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC) 590 continue; 591 592 /* check for reusable slot in the link group */ 593 buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list); 594 if (buf_desc) { 595 memset(buf_desc->cpu_addr, 0, bufsize); 596 break; /* found reusable slot */ 597 } 598 599 buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize); 600 if (PTR_ERR(buf_desc) == -ENOMEM) 601 break; 602 if (IS_ERR(buf_desc)) 603 continue; 604 605 buf_desc->used = 1; 606 write_lock_bh(lock); 607 list_add(&buf_desc->list, buf_list); 608 write_unlock_bh(lock); 609 break; /* found */ 610 } 611 612 if (IS_ERR(buf_desc)) 613 return -ENOMEM; 614 615 if (is_rmb) { 616 conn->rmb_desc = buf_desc; 617 conn->rmbe_size = bufsize; 618 conn->rmbe_size_short = bufsize_short; 619 smc->sk.sk_rcvbuf = bufsize * 2; 620 atomic_set(&conn->bytes_to_rcv, 0); 621 conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize); 622 } else { 623 conn->sndbuf_desc = buf_desc; 624 conn->sndbuf_size = bufsize; 625 smc->sk.sk_sndbuf = bufsize * 2; 626 atomic_set(&conn->sndbuf_space, bufsize); 627 } 628 return 0; 629 } 630 631 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn) 632 { 633 struct smc_link_group *lgr = conn->lgr; 634 635 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 636 conn->sndbuf_desc, DMA_TO_DEVICE); 637 } 638 639 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn) 640 { 641 struct smc_link_group *lgr = conn->lgr; 642 643 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 644 conn->sndbuf_desc, DMA_TO_DEVICE); 645 } 646 647 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn) 648 { 649 struct smc_link_group *lgr = conn->lgr; 650 651 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 652 conn->rmb_desc, DMA_FROM_DEVICE); 653 } 654 655 void smc_rmb_sync_sg_for_device(struct smc_connection *conn) 656 { 657 struct smc_link_group *lgr = conn->lgr; 658 659 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 660 conn->rmb_desc, DMA_FROM_DEVICE); 661 } 662 663 /* create the send and receive buffer for an SMC socket; 664 * receive buffers are called RMBs; 665 * (even though the SMC protocol allows more than one RMB-element per RMB, 666 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an 667 * extra RMB for every connection in a link group 668 */ 669 int smc_buf_create(struct smc_sock *smc) 670 { 671 int rc; 672 673 /* create send buffer */ 674 rc = __smc_buf_create(smc, false); 675 if (rc) 676 return rc; 677 /* create rmb */ 678 rc = __smc_buf_create(smc, true); 679 if (rc) 680 smc_buf_free(smc->conn.sndbuf_desc, 681 &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false); 682 return rc; 683 } 684 685 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr) 686 { 687 int i; 688 689 for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) { 690 if (!test_and_set_bit(i, lgr->rtokens_used_mask)) 691 return i; 692 } 693 return -ENOSPC; 694 } 695 696 /* save rkey and dma_addr received from peer during clc handshake */ 697 int smc_rmb_rtoken_handling(struct smc_connection *conn, 698 struct smc_clc_msg_accept_confirm *clc) 699 { 700 u64 dma_addr = be64_to_cpu(clc->rmb_dma_addr); 701 struct smc_link_group *lgr = conn->lgr; 702 u32 rkey = ntohl(clc->rmb_rkey); 703 int i; 704 705 for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { 706 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) && 707 (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) && 708 test_bit(i, lgr->rtokens_used_mask)) { 709 conn->rtoken_idx = i; 710 return 0; 711 } 712 } 713 conn->rtoken_idx = smc_rmb_reserve_rtoken_idx(lgr); 714 if (conn->rtoken_idx < 0) 715 return conn->rtoken_idx; 716 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey = rkey; 717 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr = dma_addr; 718 return 0; 719 } 720