1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Shared Memory Communications over RDMA (SMC-R) and RoCE 4 * 5 * Manage send buffer. 6 * Producer: 7 * Copy user space data into send buffer, if send buffer space available. 8 * Consumer: 9 * Trigger RDMA write into RMBE of peer and send CDC, if RMBE space available. 10 * 11 * Copyright IBM Corp. 2016 12 * 13 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> 14 */ 15 16 #include <linux/net.h> 17 #include <linux/rcupdate.h> 18 #include <linux/workqueue.h> 19 #include <linux/sched/signal.h> 20 21 #include <net/sock.h> 22 #include <net/tcp.h> 23 24 #include "smc.h" 25 #include "smc_wr.h" 26 #include "smc_cdc.h" 27 #include "smc_close.h" 28 #include "smc_ism.h" 29 #include "smc_tx.h" 30 31 #define SMC_TX_WORK_DELAY 0 32 #define SMC_TX_CORK_DELAY (HZ >> 2) /* 250 ms */ 33 34 /***************************** sndbuf producer *******************************/ 35 36 /* callback implementation for sk.sk_write_space() 37 * to wakeup sndbuf producers that blocked with smc_tx_wait(). 38 * called under sk_socket lock. 39 */ 40 static void smc_tx_write_space(struct sock *sk) 41 { 42 struct socket *sock = sk->sk_socket; 43 struct smc_sock *smc = smc_sk(sk); 44 struct socket_wq *wq; 45 46 /* similar to sk_stream_write_space */ 47 if (atomic_read(&smc->conn.sndbuf_space) && sock) { 48 clear_bit(SOCK_NOSPACE, &sock->flags); 49 rcu_read_lock(); 50 wq = rcu_dereference(sk->sk_wq); 51 if (skwq_has_sleeper(wq)) 52 wake_up_interruptible_poll(&wq->wait, 53 EPOLLOUT | EPOLLWRNORM | 54 EPOLLWRBAND); 55 if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN)) 56 sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT); 57 rcu_read_unlock(); 58 } 59 } 60 61 /* Wakeup sndbuf producers that blocked with smc_tx_wait(). 62 * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space(). 63 */ 64 void smc_tx_sndbuf_nonfull(struct smc_sock *smc) 65 { 66 if (smc->sk.sk_socket && 67 test_bit(SOCK_NOSPACE, &smc->sk.sk_socket->flags)) 68 smc->sk.sk_write_space(&smc->sk); 69 } 70 71 /* blocks sndbuf producer until at least one byte of free space available 72 * or urgent Byte was consumed 73 */ 74 static int smc_tx_wait(struct smc_sock *smc, int flags) 75 { 76 DEFINE_WAIT_FUNC(wait, woken_wake_function); 77 struct smc_connection *conn = &smc->conn; 78 struct sock *sk = &smc->sk; 79 bool noblock; 80 long timeo; 81 int rc = 0; 82 83 /* similar to sk_stream_wait_memory */ 84 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 85 noblock = timeo ? false : true; 86 add_wait_queue(sk_sleep(sk), &wait); 87 while (1) { 88 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 89 if (sk->sk_err || 90 (sk->sk_shutdown & SEND_SHUTDOWN) || 91 conn->local_tx_ctrl.conn_state_flags.peer_done_writing) { 92 rc = -EPIPE; 93 break; 94 } 95 if (smc_cdc_rxed_any_close(conn)) { 96 rc = -ECONNRESET; 97 break; 98 } 99 if (!timeo) { 100 if (noblock) 101 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 102 rc = -EAGAIN; 103 break; 104 } 105 if (signal_pending(current)) { 106 rc = sock_intr_errno(timeo); 107 break; 108 } 109 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 110 if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) 111 break; /* at least 1 byte of free & no urgent data */ 112 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 113 sk_wait_event(sk, &timeo, 114 sk->sk_err || 115 (sk->sk_shutdown & SEND_SHUTDOWN) || 116 smc_cdc_rxed_any_close(conn) || 117 (atomic_read(&conn->sndbuf_space) && 118 !conn->urg_tx_pend), 119 &wait); 120 } 121 remove_wait_queue(sk_sleep(sk), &wait); 122 return rc; 123 } 124 125 static bool smc_tx_is_corked(struct smc_sock *smc) 126 { 127 struct tcp_sock *tp = tcp_sk(smc->clcsock->sk); 128 129 return (tp->nonagle & TCP_NAGLE_CORK) ? true : false; 130 } 131 132 /* sndbuf producer: main API called by socket layer. 133 * called under sock lock. 134 */ 135 int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) 136 { 137 size_t copylen, send_done = 0, send_remaining = len; 138 size_t chunk_len, chunk_off, chunk_len_sum; 139 struct smc_connection *conn = &smc->conn; 140 union smc_host_cursor prep; 141 struct sock *sk = &smc->sk; 142 char *sndbuf_base; 143 int tx_cnt_prep; 144 int writespace; 145 int rc, chunk; 146 147 /* This should be in poll */ 148 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 149 150 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { 151 rc = -EPIPE; 152 goto out_err; 153 } 154 155 while (msg_data_left(msg)) { 156 if (sk->sk_state == SMC_INIT) 157 return -ENOTCONN; 158 if (smc->sk.sk_shutdown & SEND_SHUTDOWN || 159 (smc->sk.sk_err == ECONNABORTED) || 160 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort) 161 return -EPIPE; 162 if (smc_cdc_rxed_any_close(conn)) 163 return send_done ?: -ECONNRESET; 164 165 if (msg->msg_flags & MSG_OOB) 166 conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; 167 168 if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { 169 if (send_done) 170 return send_done; 171 rc = smc_tx_wait(smc, msg->msg_flags); 172 if (rc) 173 goto out_err; 174 continue; 175 } 176 177 /* initialize variables for 1st iteration of subsequent loop */ 178 /* could be just 1 byte, even after smc_tx_wait above */ 179 writespace = atomic_read(&conn->sndbuf_space); 180 /* not more than what user space asked for */ 181 copylen = min_t(size_t, send_remaining, writespace); 182 /* determine start of sndbuf */ 183 sndbuf_base = conn->sndbuf_desc->cpu_addr; 184 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 185 tx_cnt_prep = prep.count; 186 /* determine chunks where to write into sndbuf */ 187 /* either unwrapped case, or 1st chunk of wrapped case */ 188 chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len - 189 tx_cnt_prep); 190 chunk_len_sum = chunk_len; 191 chunk_off = tx_cnt_prep; 192 smc_sndbuf_sync_sg_for_cpu(conn); 193 for (chunk = 0; chunk < 2; chunk++) { 194 rc = memcpy_from_msg(sndbuf_base + chunk_off, 195 msg, chunk_len); 196 if (rc) { 197 smc_sndbuf_sync_sg_for_device(conn); 198 if (send_done) 199 return send_done; 200 goto out_err; 201 } 202 send_done += chunk_len; 203 send_remaining -= chunk_len; 204 205 if (chunk_len_sum == copylen) 206 break; /* either on 1st or 2nd iteration */ 207 /* prepare next (== 2nd) iteration */ 208 chunk_len = copylen - chunk_len; /* remainder */ 209 chunk_len_sum += chunk_len; 210 chunk_off = 0; /* modulo offset in send ring buffer */ 211 } 212 smc_sndbuf_sync_sg_for_device(conn); 213 /* update cursors */ 214 smc_curs_add(conn->sndbuf_desc->len, &prep, copylen); 215 smc_curs_copy(&conn->tx_curs_prep, &prep, conn); 216 /* increased in send tasklet smc_cdc_tx_handler() */ 217 smp_mb__before_atomic(); 218 atomic_sub(copylen, &conn->sndbuf_space); 219 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ 220 smp_mb__after_atomic(); 221 /* since we just produced more new data into sndbuf, 222 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC 223 */ 224 if ((msg->msg_flags & MSG_OOB) && !send_remaining) 225 conn->urg_tx_pend = true; 226 if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) && 227 (atomic_read(&conn->sndbuf_space) > 228 (conn->sndbuf_desc->len >> 1))) 229 /* for a corked socket defer the RDMA writes if there 230 * is still sufficient sndbuf_space available 231 */ 232 schedule_delayed_work(&conn->tx_work, 233 SMC_TX_CORK_DELAY); 234 else 235 smc_tx_sndbuf_nonempty(conn); 236 } /* while (msg_data_left(msg)) */ 237 238 return send_done; 239 240 out_err: 241 rc = sk_stream_error(sk, msg->msg_flags, rc); 242 /* make sure we wake any epoll edge trigger waiter */ 243 if (unlikely(rc == -EAGAIN)) 244 sk->sk_write_space(sk); 245 return rc; 246 } 247 248 /***************************** sndbuf consumer *******************************/ 249 250 /* sndbuf consumer: actual data transfer of one target chunk with ISM write */ 251 int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len, 252 u32 offset, int signal) 253 { 254 struct smc_ism_position pos; 255 int rc; 256 257 memset(&pos, 0, sizeof(pos)); 258 pos.token = conn->peer_token; 259 pos.index = conn->peer_rmbe_idx; 260 pos.offset = conn->tx_off + offset; 261 pos.signal = signal; 262 rc = smc_ism_write(conn->lgr->smcd, &pos, data, len); 263 if (rc) 264 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; 265 return rc; 266 } 267 268 /* sndbuf consumer: actual data transfer of one target chunk with RDMA write */ 269 static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset, 270 int num_sges, struct ib_rdma_wr *rdma_wr) 271 { 272 struct smc_link_group *lgr = conn->lgr; 273 struct smc_link *link; 274 int rc; 275 276 link = &lgr->lnk[SMC_SINGLE_LINK]; 277 rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link); 278 rdma_wr->wr.num_sge = num_sges; 279 rdma_wr->remote_addr = 280 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr + 281 /* RMBE within RMB */ 282 conn->tx_off + 283 /* offset within RMBE */ 284 peer_rmbe_offset; 285 rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey; 286 rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL); 287 if (rc) { 288 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; 289 smc_lgr_terminate(lgr); 290 } 291 return rc; 292 } 293 294 /* sndbuf consumer */ 295 static inline void smc_tx_advance_cursors(struct smc_connection *conn, 296 union smc_host_cursor *prod, 297 union smc_host_cursor *sent, 298 size_t len) 299 { 300 smc_curs_add(conn->peer_rmbe_size, prod, len); 301 /* increased in recv tasklet smc_cdc_msg_rcv() */ 302 smp_mb__before_atomic(); 303 /* data in flight reduces usable snd_wnd */ 304 atomic_sub(len, &conn->peer_rmbe_space); 305 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ 306 smp_mb__after_atomic(); 307 smc_curs_add(conn->sndbuf_desc->len, sent, len); 308 } 309 310 /* SMC-R helper for smc_tx_rdma_writes() */ 311 static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len, 312 size_t src_off, size_t src_len, 313 size_t dst_off, size_t dst_len, 314 struct smc_rdma_wr *wr_rdma_buf) 315 { 316 dma_addr_t dma_addr = 317 sg_dma_address(conn->sndbuf_desc->sgt[SMC_SINGLE_LINK].sgl); 318 int src_len_sum = src_len, dst_len_sum = dst_len; 319 int sent_count = src_off; 320 int srcchunk, dstchunk; 321 int num_sges; 322 int rc; 323 324 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 325 struct ib_sge *sge = 326 wr_rdma_buf->wr_tx_rdma[dstchunk].wr.sg_list; 327 328 num_sges = 0; 329 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 330 sge[srcchunk].addr = dma_addr + src_off; 331 sge[srcchunk].length = src_len; 332 num_sges++; 333 334 src_off += src_len; 335 if (src_off >= conn->sndbuf_desc->len) 336 src_off -= conn->sndbuf_desc->len; 337 /* modulo in send ring */ 338 if (src_len_sum == dst_len) 339 break; /* either on 1st or 2nd iteration */ 340 /* prepare next (== 2nd) iteration */ 341 src_len = dst_len - src_len; /* remainder */ 342 src_len_sum += src_len; 343 } 344 rc = smc_tx_rdma_write(conn, dst_off, num_sges, 345 &wr_rdma_buf->wr_tx_rdma[dstchunk]); 346 if (rc) 347 return rc; 348 if (dst_len_sum == len) 349 break; /* either on 1st or 2nd iteration */ 350 /* prepare next (== 2nd) iteration */ 351 dst_off = 0; /* modulo offset in RMBE ring buffer */ 352 dst_len = len - dst_len; /* remainder */ 353 dst_len_sum += dst_len; 354 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - 355 sent_count); 356 src_len_sum = src_len; 357 } 358 return 0; 359 } 360 361 /* SMC-D helper for smc_tx_rdma_writes() */ 362 static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, 363 size_t src_off, size_t src_len, 364 size_t dst_off, size_t dst_len) 365 { 366 int src_len_sum = src_len, dst_len_sum = dst_len; 367 int srcchunk, dstchunk; 368 int rc; 369 370 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 371 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 372 void *data = conn->sndbuf_desc->cpu_addr + src_off; 373 374 rc = smcd_tx_ism_write(conn, data, src_len, dst_off + 375 sizeof(struct smcd_cdc_msg), 0); 376 if (rc) 377 return rc; 378 dst_off += src_len; 379 src_off += src_len; 380 if (src_off >= conn->sndbuf_desc->len) 381 src_off -= conn->sndbuf_desc->len; 382 /* modulo in send ring */ 383 if (src_len_sum == dst_len) 384 break; /* either on 1st or 2nd iteration */ 385 /* prepare next (== 2nd) iteration */ 386 src_len = dst_len - src_len; /* remainder */ 387 src_len_sum += src_len; 388 } 389 if (dst_len_sum == len) 390 break; /* either on 1st or 2nd iteration */ 391 /* prepare next (== 2nd) iteration */ 392 dst_off = 0; /* modulo offset in RMBE ring buffer */ 393 dst_len = len - dst_len; /* remainder */ 394 dst_len_sum += dst_len; 395 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); 396 src_len_sum = src_len; 397 } 398 return 0; 399 } 400 401 /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; 402 * usable snd_wnd as max transmit 403 */ 404 static int smc_tx_rdma_writes(struct smc_connection *conn, 405 struct smc_rdma_wr *wr_rdma_buf) 406 { 407 size_t len, src_len, dst_off, dst_len; /* current chunk values */ 408 union smc_host_cursor sent, prep, prod, cons; 409 struct smc_cdc_producer_flags *pflags; 410 int to_send, rmbespace; 411 int rc; 412 413 /* source: sndbuf */ 414 smc_curs_copy(&sent, &conn->tx_curs_sent, conn); 415 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 416 /* cf. wmem_alloc - (snd_max - snd_una) */ 417 to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep); 418 if (to_send <= 0) 419 return 0; 420 421 /* destination: RMBE */ 422 /* cf. snd_wnd */ 423 rmbespace = atomic_read(&conn->peer_rmbe_space); 424 if (rmbespace <= 0) 425 return 0; 426 smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn); 427 smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn); 428 429 /* if usable snd_wnd closes ask peer to advertise once it opens again */ 430 pflags = &conn->local_tx_ctrl.prod_flags; 431 pflags->write_blocked = (to_send >= rmbespace); 432 /* cf. usable snd_wnd */ 433 len = min(to_send, rmbespace); 434 435 /* initialize variables for first iteration of subsequent nested loop */ 436 dst_off = prod.count; 437 if (prod.wrap == cons.wrap) { 438 /* the filled destination area is unwrapped, 439 * hence the available free destination space is wrapped 440 * and we need 2 destination chunks of sum len; start with 1st 441 * which is limited by what's available in sndbuf 442 */ 443 dst_len = min_t(size_t, 444 conn->peer_rmbe_size - prod.count, len); 445 } else { 446 /* the filled destination area is wrapped, 447 * hence the available free destination space is unwrapped 448 * and we need a single destination chunk of entire len 449 */ 450 dst_len = len; 451 } 452 /* dst_len determines the maximum src_len */ 453 if (sent.count + dst_len <= conn->sndbuf_desc->len) { 454 /* unwrapped src case: single chunk of entire dst_len */ 455 src_len = dst_len; 456 } else { 457 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ 458 src_len = conn->sndbuf_desc->len - sent.count; 459 } 460 461 if (conn->lgr->is_smcd) 462 rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len, 463 dst_off, dst_len); 464 else 465 rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len, 466 dst_off, dst_len, wr_rdma_buf); 467 if (rc) 468 return rc; 469 470 if (conn->urg_tx_pend && len == to_send) 471 pflags->urg_data_present = 1; 472 smc_tx_advance_cursors(conn, &prod, &sent, len); 473 /* update connection's cursors with advanced local cursors */ 474 smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn); 475 /* dst: peer RMBE */ 476 smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */ 477 478 return 0; 479 } 480 481 /* Wakeup sndbuf consumers from any context (IRQ or process) 482 * since there is more data to transmit; usable snd_wnd as max transmit 483 */ 484 static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) 485 { 486 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 487 struct smc_rdma_wr *wr_rdma_buf; 488 struct smc_cdc_tx_pend *pend; 489 struct smc_wr_buf *wr_buf; 490 int rc; 491 492 rc = smc_cdc_get_free_slot(conn, &wr_buf, &wr_rdma_buf, &pend); 493 if (rc < 0) { 494 if (rc == -EBUSY) { 495 struct smc_sock *smc = 496 container_of(conn, struct smc_sock, conn); 497 498 if (smc->sk.sk_err == ECONNABORTED) 499 return sock_error(&smc->sk); 500 rc = 0; 501 if (conn->alert_token_local) /* connection healthy */ 502 mod_delayed_work(system_wq, &conn->tx_work, 503 SMC_TX_WORK_DELAY); 504 } 505 return rc; 506 } 507 508 spin_lock_bh(&conn->send_lock); 509 if (!pflags->urg_data_present) { 510 rc = smc_tx_rdma_writes(conn, wr_rdma_buf); 511 if (rc) { 512 smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], 513 (struct smc_wr_tx_pend_priv *)pend); 514 goto out_unlock; 515 } 516 } 517 518 rc = smc_cdc_msg_send(conn, wr_buf, pend); 519 if (!rc && pflags->urg_data_present) { 520 pflags->urg_data_pending = 0; 521 pflags->urg_data_present = 0; 522 } 523 524 out_unlock: 525 spin_unlock_bh(&conn->send_lock); 526 return rc; 527 } 528 529 static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) 530 { 531 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 532 int rc = 0; 533 534 spin_lock_bh(&conn->send_lock); 535 if (!pflags->urg_data_present) 536 rc = smc_tx_rdma_writes(conn, NULL); 537 if (!rc) 538 rc = smcd_cdc_msg_send(conn); 539 540 if (!rc && pflags->urg_data_present) { 541 pflags->urg_data_pending = 0; 542 pflags->urg_data_present = 0; 543 } 544 spin_unlock_bh(&conn->send_lock); 545 return rc; 546 } 547 548 int smc_tx_sndbuf_nonempty(struct smc_connection *conn) 549 { 550 int rc; 551 552 if (conn->lgr->is_smcd) 553 rc = smcd_tx_sndbuf_nonempty(conn); 554 else 555 rc = smcr_tx_sndbuf_nonempty(conn); 556 557 if (!rc) { 558 /* trigger socket release if connection is closing */ 559 struct smc_sock *smc = container_of(conn, struct smc_sock, 560 conn); 561 smc_close_wake_tx_prepared(smc); 562 } 563 return rc; 564 } 565 566 /* Wakeup sndbuf consumers from process context 567 * since there is more data to transmit 568 */ 569 void smc_tx_work(struct work_struct *work) 570 { 571 struct smc_connection *conn = container_of(to_delayed_work(work), 572 struct smc_connection, 573 tx_work); 574 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 575 int rc; 576 577 lock_sock(&smc->sk); 578 if (smc->sk.sk_err || 579 !conn->alert_token_local || 580 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) 581 goto out; 582 583 rc = smc_tx_sndbuf_nonempty(conn); 584 if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && 585 !atomic_read(&conn->bytes_to_rcv)) 586 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 587 588 out: 589 release_sock(&smc->sk); 590 } 591 592 void smc_tx_consumer_update(struct smc_connection *conn, bool force) 593 { 594 union smc_host_cursor cfed, cons, prod; 595 int sender_free = conn->rmb_desc->len; 596 int to_confirm; 597 598 smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn); 599 smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn); 600 to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); 601 if (to_confirm > conn->rmbe_update_limit) { 602 smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); 603 sender_free = conn->rmb_desc->len - 604 smc_curs_diff_large(conn->rmb_desc->len, 605 &cfed, &prod); 606 } 607 608 if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || 609 force || 610 ((to_confirm > conn->rmbe_update_limit) && 611 ((sender_free <= (conn->rmb_desc->len / 2)) || 612 conn->local_rx_ctrl.prod_flags.write_blocked))) { 613 if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && 614 conn->alert_token_local) { /* connection healthy */ 615 schedule_delayed_work(&conn->tx_work, 616 SMC_TX_WORK_DELAY); 617 return; 618 } 619 } 620 if (conn->local_rx_ctrl.prod_flags.write_blocked && 621 !atomic_read(&conn->bytes_to_rcv)) 622 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 623 } 624 625 /***************************** send initialize *******************************/ 626 627 /* Initialize send properties on connection establishment. NB: not __init! */ 628 void smc_tx_init(struct smc_sock *smc) 629 { 630 smc->sk.sk_write_space = smc_tx_write_space; 631 } 632