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 if (list_empty(&lgr->list)) 132 goto free; 133 read_lock_bh(&lgr->conns_lock); 134 conns = RB_EMPTY_ROOT(&lgr->conns_all); 135 read_unlock_bh(&lgr->conns_lock); 136 if (!conns) { /* number of lgr connections is no longer zero */ 137 spin_unlock_bh(&smc_lgr_list.lock); 138 return; 139 } 140 list_del_init(&lgr->list); /* remove from smc_lgr_list */ 141 free: 142 spin_unlock_bh(&smc_lgr_list.lock); 143 smc_lgr_free(lgr); 144 } 145 146 /* create a new SMC link group */ 147 static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr, 148 struct smc_ib_device *smcibdev, u8 ibport, 149 char *peer_systemid, unsigned short vlan_id) 150 { 151 struct smc_link_group *lgr; 152 struct smc_link *lnk; 153 u8 rndvec[3]; 154 int rc = 0; 155 int i; 156 157 lgr = kzalloc(sizeof(*lgr), GFP_KERNEL); 158 if (!lgr) { 159 rc = -ENOMEM; 160 goto out; 161 } 162 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 163 lgr->sync_err = false; 164 lgr->daddr = peer_in_addr; 165 memcpy(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN); 166 lgr->vlan_id = vlan_id; 167 rwlock_init(&lgr->sndbufs_lock); 168 rwlock_init(&lgr->rmbs_lock); 169 for (i = 0; i < SMC_RMBE_SIZES; i++) { 170 INIT_LIST_HEAD(&lgr->sndbufs[i]); 171 INIT_LIST_HEAD(&lgr->rmbs[i]); 172 } 173 smc_lgr_num += SMC_LGR_NUM_INCR; 174 memcpy(&lgr->id, (u8 *)&smc_lgr_num, SMC_LGR_ID_SIZE); 175 INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work); 176 lgr->conns_all = RB_ROOT; 177 178 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 179 /* initialize link */ 180 lnk->smcibdev = smcibdev; 181 lnk->ibport = ibport; 182 lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu; 183 if (!smcibdev->initialized) 184 smc_ib_setup_per_ibdev(smcibdev); 185 get_random_bytes(rndvec, sizeof(rndvec)); 186 lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) + (rndvec[2] << 16); 187 rc = smc_wr_alloc_link_mem(lnk); 188 if (rc) 189 goto free_lgr; 190 rc = smc_ib_create_protection_domain(lnk); 191 if (rc) 192 goto free_link_mem; 193 rc = smc_ib_create_queue_pair(lnk); 194 if (rc) 195 goto dealloc_pd; 196 rc = smc_wr_create_link(lnk); 197 if (rc) 198 goto destroy_qp; 199 init_completion(&lnk->llc_confirm); 200 init_completion(&lnk->llc_confirm_resp); 201 202 smc->conn.lgr = lgr; 203 rwlock_init(&lgr->conns_lock); 204 spin_lock_bh(&smc_lgr_list.lock); 205 list_add(&lgr->list, &smc_lgr_list.list); 206 spin_unlock_bh(&smc_lgr_list.lock); 207 return 0; 208 209 destroy_qp: 210 smc_ib_destroy_queue_pair(lnk); 211 dealloc_pd: 212 smc_ib_dealloc_protection_domain(lnk); 213 free_link_mem: 214 smc_wr_free_link_mem(lnk); 215 free_lgr: 216 kfree(lgr); 217 out: 218 return rc; 219 } 220 221 static void smc_buf_unuse(struct smc_connection *conn) 222 { 223 if (conn->sndbuf_desc) { 224 conn->sndbuf_desc->used = 0; 225 conn->sndbuf_size = 0; 226 } 227 if (conn->rmb_desc) { 228 conn->rmb_desc->reused = true; 229 conn->rmb_desc->used = 0; 230 conn->rmbe_size = 0; 231 } 232 } 233 234 /* remove a finished connection from its link group */ 235 void smc_conn_free(struct smc_connection *conn) 236 { 237 if (!conn->lgr) 238 return; 239 smc_cdc_tx_dismiss_slots(conn); 240 smc_lgr_unregister_conn(conn); 241 smc_buf_unuse(conn); 242 } 243 244 static void smc_link_clear(struct smc_link *lnk) 245 { 246 lnk->peer_qpn = 0; 247 smc_ib_modify_qp_reset(lnk); 248 smc_wr_free_link(lnk); 249 smc_ib_destroy_queue_pair(lnk); 250 smc_ib_dealloc_protection_domain(lnk); 251 smc_wr_free_link_mem(lnk); 252 } 253 254 static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk, 255 bool is_rmb) 256 { 257 if (is_rmb) { 258 if (buf_desc->mr_rx[SMC_SINGLE_LINK]) 259 smc_ib_put_memory_region( 260 buf_desc->mr_rx[SMC_SINGLE_LINK]); 261 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 262 DMA_FROM_DEVICE); 263 } else { 264 smc_ib_buf_unmap_sg(lnk->smcibdev, buf_desc, 265 DMA_TO_DEVICE); 266 } 267 sg_free_table(&buf_desc->sgt[SMC_SINGLE_LINK]); 268 if (buf_desc->cpu_addr) 269 free_pages((unsigned long)buf_desc->cpu_addr, buf_desc->order); 270 kfree(buf_desc); 271 } 272 273 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb) 274 { 275 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 276 struct smc_buf_desc *buf_desc, *bf_desc; 277 struct list_head *buf_list; 278 int i; 279 280 for (i = 0; i < SMC_RMBE_SIZES; i++) { 281 if (is_rmb) 282 buf_list = &lgr->rmbs[i]; 283 else 284 buf_list = &lgr->sndbufs[i]; 285 list_for_each_entry_safe(buf_desc, bf_desc, buf_list, 286 list) { 287 list_del(&buf_desc->list); 288 smc_buf_free(buf_desc, lnk, is_rmb); 289 } 290 } 291 } 292 293 static void smc_lgr_free_bufs(struct smc_link_group *lgr) 294 { 295 /* free send buffers */ 296 __smc_lgr_free_bufs(lgr, false); 297 /* free rmbs */ 298 __smc_lgr_free_bufs(lgr, true); 299 } 300 301 /* remove a link group */ 302 void smc_lgr_free(struct smc_link_group *lgr) 303 { 304 smc_lgr_free_bufs(lgr); 305 smc_link_clear(&lgr->lnk[SMC_SINGLE_LINK]); 306 kfree(lgr); 307 } 308 309 /* terminate linkgroup abnormally */ 310 void smc_lgr_terminate(struct smc_link_group *lgr) 311 { 312 struct smc_connection *conn; 313 struct smc_sock *smc; 314 struct rb_node *node; 315 316 spin_lock_bh(&smc_lgr_list.lock); 317 if (list_empty(&lgr->list)) { 318 /* termination already triggered */ 319 spin_unlock_bh(&smc_lgr_list.lock); 320 return; 321 } 322 /* do not use this link group for new connections */ 323 list_del_init(&lgr->list); 324 spin_unlock_bh(&smc_lgr_list.lock); 325 326 write_lock_bh(&lgr->conns_lock); 327 node = rb_first(&lgr->conns_all); 328 while (node) { 329 conn = rb_entry(node, struct smc_connection, alert_node); 330 smc = container_of(conn, struct smc_sock, conn); 331 sock_hold(&smc->sk); /* sock_put in close work */ 332 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; 333 __smc_lgr_unregister_conn(conn); 334 write_unlock_bh(&lgr->conns_lock); 335 if (!schedule_work(&conn->close_work)) 336 sock_put(&smc->sk); 337 write_lock_bh(&lgr->conns_lock); 338 node = rb_first(&lgr->conns_all); 339 } 340 write_unlock_bh(&lgr->conns_lock); 341 wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait); 342 } 343 344 /* Determine vlan of internal TCP socket. 345 * @vlan_id: address to store the determined vlan id into 346 */ 347 static int smc_vlan_by_tcpsk(struct socket *clcsock, unsigned short *vlan_id) 348 { 349 struct dst_entry *dst = sk_dst_get(clcsock->sk); 350 int rc = 0; 351 352 *vlan_id = 0; 353 if (!dst) { 354 rc = -ENOTCONN; 355 goto out; 356 } 357 if (!dst->dev) { 358 rc = -ENODEV; 359 goto out_rel; 360 } 361 362 if (is_vlan_dev(dst->dev)) 363 *vlan_id = vlan_dev_vlan_id(dst->dev); 364 365 out_rel: 366 dst_release(dst); 367 out: 368 return rc; 369 } 370 371 /* determine the link gid matching the vlan id of the link group */ 372 static int smc_link_determine_gid(struct smc_link_group *lgr) 373 { 374 struct smc_link *lnk = &lgr->lnk[SMC_SINGLE_LINK]; 375 struct ib_gid_attr gattr; 376 union ib_gid gid; 377 int i; 378 379 if (!lgr->vlan_id) { 380 lnk->gid = lnk->smcibdev->gid[lnk->ibport - 1]; 381 return 0; 382 } 383 384 for (i = 0; i < lnk->smcibdev->pattr[lnk->ibport - 1].gid_tbl_len; 385 i++) { 386 if (ib_query_gid(lnk->smcibdev->ibdev, lnk->ibport, i, &gid, 387 &gattr)) 388 continue; 389 if (gattr.ndev) { 390 if (is_vlan_dev(gattr.ndev) && 391 vlan_dev_vlan_id(gattr.ndev) == lgr->vlan_id) { 392 lnk->gid = gid; 393 dev_put(gattr.ndev); 394 return 0; 395 } 396 dev_put(gattr.ndev); 397 } 398 } 399 return -ENODEV; 400 } 401 402 /* create a new SMC connection (and a new link group if necessary) */ 403 int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr, 404 struct smc_ib_device *smcibdev, u8 ibport, 405 struct smc_clc_msg_local *lcl, int srv_first_contact) 406 { 407 struct smc_connection *conn = &smc->conn; 408 struct smc_link_group *lgr; 409 unsigned short vlan_id; 410 enum smc_lgr_role role; 411 int local_contact = SMC_FIRST_CONTACT; 412 int rc = 0; 413 414 role = smc->listen_smc ? SMC_SERV : SMC_CLNT; 415 rc = smc_vlan_by_tcpsk(smc->clcsock, &vlan_id); 416 if (rc) 417 return rc; 418 419 if ((role == SMC_CLNT) && srv_first_contact) 420 /* create new link group as well */ 421 goto create; 422 423 /* determine if an existing link group can be reused */ 424 spin_lock_bh(&smc_lgr_list.lock); 425 list_for_each_entry(lgr, &smc_lgr_list.list, list) { 426 write_lock_bh(&lgr->conns_lock); 427 if (!memcmp(lgr->peer_systemid, lcl->id_for_peer, 428 SMC_SYSTEMID_LEN) && 429 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_gid, &lcl->gid, 430 SMC_GID_SIZE) && 431 !memcmp(lgr->lnk[SMC_SINGLE_LINK].peer_mac, lcl->mac, 432 sizeof(lcl->mac)) && 433 !lgr->sync_err && 434 (lgr->role == role) && 435 (lgr->vlan_id == vlan_id) && 436 ((role == SMC_CLNT) || 437 (lgr->conns_num < SMC_RMBS_PER_LGR_MAX))) { 438 /* link group found */ 439 local_contact = SMC_REUSE_CONTACT; 440 conn->lgr = lgr; 441 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 442 write_unlock_bh(&lgr->conns_lock); 443 break; 444 } 445 write_unlock_bh(&lgr->conns_lock); 446 } 447 spin_unlock_bh(&smc_lgr_list.lock); 448 449 if (role == SMC_CLNT && !srv_first_contact && 450 (local_contact == SMC_FIRST_CONTACT)) { 451 /* Server reuses a link group, but Client wants to start 452 * a new one 453 * send out_of_sync decline, reason synchr. error 454 */ 455 return -ENOLINK; 456 } 457 458 create: 459 if (local_contact == SMC_FIRST_CONTACT) { 460 rc = smc_lgr_create(smc, peer_in_addr, smcibdev, ibport, 461 lcl->id_for_peer, vlan_id); 462 if (rc) 463 goto out; 464 smc_lgr_register_conn(conn); /* add smc conn to lgr */ 465 rc = smc_link_determine_gid(conn->lgr); 466 } 467 conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE; 468 conn->local_tx_ctrl.len = sizeof(struct smc_cdc_msg); 469 #ifndef KERNEL_HAS_ATOMIC64 470 spin_lock_init(&conn->acurs_lock); 471 #endif 472 473 out: 474 return rc ? rc : local_contact; 475 } 476 477 /* try to reuse a sndbuf or rmb description slot for a certain 478 * buffer size; if not available, return NULL 479 */ 480 static inline 481 struct smc_buf_desc *smc_buf_get_slot(struct smc_link_group *lgr, 482 int compressed_bufsize, 483 rwlock_t *lock, 484 struct list_head *buf_list) 485 { 486 struct smc_buf_desc *buf_slot; 487 488 read_lock_bh(lock); 489 list_for_each_entry(buf_slot, buf_list, list) { 490 if (cmpxchg(&buf_slot->used, 0, 1) == 0) { 491 read_unlock_bh(lock); 492 return buf_slot; 493 } 494 } 495 read_unlock_bh(lock); 496 return NULL; 497 } 498 499 /* one of the conditions for announcing a receiver's current window size is 500 * that it "results in a minimum increase in the window size of 10% of the 501 * receive buffer space" [RFC7609] 502 */ 503 static inline int smc_rmb_wnd_update_limit(int rmbe_size) 504 { 505 return min_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2); 506 } 507 508 static struct smc_buf_desc *smc_new_buf_create(struct smc_link_group *lgr, 509 bool is_rmb, int bufsize) 510 { 511 struct smc_buf_desc *buf_desc; 512 struct smc_link *lnk; 513 int rc; 514 515 /* try to alloc a new buffer */ 516 buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL); 517 if (!buf_desc) 518 return ERR_PTR(-ENOMEM); 519 520 buf_desc->cpu_addr = 521 (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | 522 __GFP_NOMEMALLOC | 523 __GFP_NORETRY | __GFP_ZERO, 524 get_order(bufsize)); 525 if (!buf_desc->cpu_addr) { 526 kfree(buf_desc); 527 return ERR_PTR(-EAGAIN); 528 } 529 buf_desc->order = get_order(bufsize); 530 531 /* build the sg table from the pages */ 532 lnk = &lgr->lnk[SMC_SINGLE_LINK]; 533 rc = sg_alloc_table(&buf_desc->sgt[SMC_SINGLE_LINK], 1, 534 GFP_KERNEL); 535 if (rc) { 536 smc_buf_free(buf_desc, lnk, is_rmb); 537 return ERR_PTR(rc); 538 } 539 sg_set_buf(buf_desc->sgt[SMC_SINGLE_LINK].sgl, 540 buf_desc->cpu_addr, bufsize); 541 542 /* map sg table to DMA address */ 543 rc = smc_ib_buf_map_sg(lnk->smcibdev, buf_desc, 544 is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 545 /* SMC protocol depends on mapping to one DMA address only */ 546 if (rc != 1) { 547 smc_buf_free(buf_desc, lnk, is_rmb); 548 return ERR_PTR(-EAGAIN); 549 } 550 551 /* create a new memory region for the RMB */ 552 if (is_rmb) { 553 rc = smc_ib_get_memory_region(lnk->roce_pd, 554 IB_ACCESS_REMOTE_WRITE | 555 IB_ACCESS_LOCAL_WRITE, 556 buf_desc); 557 if (rc) { 558 smc_buf_free(buf_desc, lnk, is_rmb); 559 return ERR_PTR(rc); 560 } 561 } 562 563 return buf_desc; 564 } 565 566 static int __smc_buf_create(struct smc_sock *smc, bool is_rmb) 567 { 568 struct smc_connection *conn = &smc->conn; 569 struct smc_link_group *lgr = conn->lgr; 570 struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM); 571 struct list_head *buf_list; 572 int bufsize, bufsize_short; 573 int sk_buf_size; 574 rwlock_t *lock; 575 576 if (is_rmb) 577 /* use socket recv buffer size (w/o overhead) as start value */ 578 sk_buf_size = smc->sk.sk_rcvbuf / 2; 579 else 580 /* use socket send buffer size (w/o overhead) as start value */ 581 sk_buf_size = smc->sk.sk_sndbuf / 2; 582 583 for (bufsize_short = smc_compress_bufsize(sk_buf_size); 584 bufsize_short >= 0; bufsize_short--) { 585 586 if (is_rmb) { 587 lock = &lgr->rmbs_lock; 588 buf_list = &lgr->rmbs[bufsize_short]; 589 } else { 590 lock = &lgr->sndbufs_lock; 591 buf_list = &lgr->sndbufs[bufsize_short]; 592 } 593 bufsize = smc_uncompress_bufsize(bufsize_short); 594 if ((1 << get_order(bufsize)) > SG_MAX_SINGLE_ALLOC) 595 continue; 596 597 /* check for reusable slot in the link group */ 598 buf_desc = smc_buf_get_slot(lgr, bufsize_short, lock, buf_list); 599 if (buf_desc) { 600 memset(buf_desc->cpu_addr, 0, bufsize); 601 break; /* found reusable slot */ 602 } 603 604 buf_desc = smc_new_buf_create(lgr, is_rmb, bufsize); 605 if (PTR_ERR(buf_desc) == -ENOMEM) 606 break; 607 if (IS_ERR(buf_desc)) 608 continue; 609 610 buf_desc->used = 1; 611 write_lock_bh(lock); 612 list_add(&buf_desc->list, buf_list); 613 write_unlock_bh(lock); 614 break; /* found */ 615 } 616 617 if (IS_ERR(buf_desc)) 618 return -ENOMEM; 619 620 if (is_rmb) { 621 conn->rmb_desc = buf_desc; 622 conn->rmbe_size = bufsize; 623 conn->rmbe_size_short = bufsize_short; 624 smc->sk.sk_rcvbuf = bufsize * 2; 625 atomic_set(&conn->bytes_to_rcv, 0); 626 conn->rmbe_update_limit = smc_rmb_wnd_update_limit(bufsize); 627 } else { 628 conn->sndbuf_desc = buf_desc; 629 conn->sndbuf_size = bufsize; 630 smc->sk.sk_sndbuf = bufsize * 2; 631 atomic_set(&conn->sndbuf_space, bufsize); 632 } 633 return 0; 634 } 635 636 void smc_sndbuf_sync_sg_for_cpu(struct smc_connection *conn) 637 { 638 struct smc_link_group *lgr = conn->lgr; 639 640 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 641 conn->sndbuf_desc, DMA_TO_DEVICE); 642 } 643 644 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn) 645 { 646 struct smc_link_group *lgr = conn->lgr; 647 648 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 649 conn->sndbuf_desc, DMA_TO_DEVICE); 650 } 651 652 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn) 653 { 654 struct smc_link_group *lgr = conn->lgr; 655 656 smc_ib_sync_sg_for_cpu(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 657 conn->rmb_desc, DMA_FROM_DEVICE); 658 } 659 660 void smc_rmb_sync_sg_for_device(struct smc_connection *conn) 661 { 662 struct smc_link_group *lgr = conn->lgr; 663 664 smc_ib_sync_sg_for_device(lgr->lnk[SMC_SINGLE_LINK].smcibdev, 665 conn->rmb_desc, DMA_FROM_DEVICE); 666 } 667 668 /* create the send and receive buffer for an SMC socket; 669 * receive buffers are called RMBs; 670 * (even though the SMC protocol allows more than one RMB-element per RMB, 671 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an 672 * extra RMB for every connection in a link group 673 */ 674 int smc_buf_create(struct smc_sock *smc) 675 { 676 int rc; 677 678 /* create send buffer */ 679 rc = __smc_buf_create(smc, false); 680 if (rc) 681 return rc; 682 /* create rmb */ 683 rc = __smc_buf_create(smc, true); 684 if (rc) 685 smc_buf_free(smc->conn.sndbuf_desc, 686 &smc->conn.lgr->lnk[SMC_SINGLE_LINK], false); 687 return rc; 688 } 689 690 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr) 691 { 692 int i; 693 694 for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) { 695 if (!test_and_set_bit(i, lgr->rtokens_used_mask)) 696 return i; 697 } 698 return -ENOSPC; 699 } 700 701 /* save rkey and dma_addr received from peer during clc handshake */ 702 int smc_rmb_rtoken_handling(struct smc_connection *conn, 703 struct smc_clc_msg_accept_confirm *clc) 704 { 705 u64 dma_addr = be64_to_cpu(clc->rmb_dma_addr); 706 struct smc_link_group *lgr = conn->lgr; 707 u32 rkey = ntohl(clc->rmb_rkey); 708 int i; 709 710 for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) { 711 if ((lgr->rtokens[i][SMC_SINGLE_LINK].rkey == rkey) && 712 (lgr->rtokens[i][SMC_SINGLE_LINK].dma_addr == dma_addr) && 713 test_bit(i, lgr->rtokens_used_mask)) { 714 conn->rtoken_idx = i; 715 return 0; 716 } 717 } 718 conn->rtoken_idx = smc_rmb_reserve_rtoken_idx(lgr); 719 if (conn->rtoken_idx < 0) 720 return conn->rtoken_idx; 721 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey = rkey; 722 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr = dma_addr; 723 return 0; 724 } 725