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 */ 40static 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 */ 64void 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 */ 74static 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 long timeo; 80 int rc = 0; 81 82 /* similar to sk_stream_wait_memory */ 83 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 84 add_wait_queue(sk_sleep(sk), &wait); 85 while (1) { 86 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 87 if (sk->sk_err || 88 (sk->sk_shutdown & SEND_SHUTDOWN) || 89 conn->killed || 90 conn->local_tx_ctrl.conn_state_flags.peer_done_writing) { 91 rc = -EPIPE; 92 break; 93 } 94 if (smc_cdc_rxed_any_close(conn)) { 95 rc = -ECONNRESET; 96 break; 97 } 98 if (!timeo) { 99 /* ensure EPOLLOUT is subsequently generated */ 100 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 101 rc = -EAGAIN; 102 break; 103 } 104 if (signal_pending(current)) { 105 rc = sock_intr_errno(timeo); 106 break; 107 } 108 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 109 if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) 110 break; /* at least 1 byte of free & no urgent data */ 111 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 112 sk_wait_event(sk, &timeo, 113 READ_ONCE(sk->sk_err) || 114 (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) || 115 smc_cdc_rxed_any_close(conn) || 116 (atomic_read(&conn->sndbuf_space) && 117 !conn->urg_tx_pend), 118 &wait); 119 } 120 remove_wait_queue(sk_sleep(sk), &wait); 121 return rc; 122} 123 124static bool smc_tx_is_corked(struct smc_sock *smc) 125{ 126 struct tcp_sock *tp = tcp_sk(smc->clcsock->sk); 127 128 return (tp->nonagle & TCP_NAGLE_CORK) ? true : false; 129} 130 131/* sndbuf producer: main API called by socket layer. 132 * called under sock lock. 133 */ 134int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) 135{ 136 size_t copylen, send_done = 0, send_remaining = len; 137 size_t chunk_len, chunk_off, chunk_len_sum; 138 struct smc_connection *conn = &smc->conn; 139 union smc_host_cursor prep; 140 struct sock *sk = &smc->sk; 141 char *sndbuf_base; 142 int tx_cnt_prep; 143 int writespace; 144 int rc, chunk; 145 146 /* This should be in poll */ 147 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 148 149 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { 150 rc = -EPIPE; 151 goto out_err; 152 } 153 154 while (msg_data_left(msg)) { 155 if (sk->sk_state == SMC_INIT) 156 return -ENOTCONN; 157 if (smc->sk.sk_shutdown & SEND_SHUTDOWN || 158 (smc->sk.sk_err == ECONNABORTED) || 159 conn->killed) 160 return -EPIPE; 161 if (smc_cdc_rxed_any_close(conn)) 162 return send_done ?: -ECONNRESET; 163 164 if (msg->msg_flags & MSG_OOB) 165 conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; 166 167 if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { 168 if (send_done) 169 return send_done; 170 rc = smc_tx_wait(smc, msg->msg_flags); 171 if (rc) 172 goto out_err; 173 continue; 174 } 175 176 /* initialize variables for 1st iteration of subsequent loop */ 177 /* could be just 1 byte, even after smc_tx_wait above */ 178 writespace = atomic_read(&conn->sndbuf_space); 179 /* not more than what user space asked for */ 180 copylen = min_t(size_t, send_remaining, writespace); 181 /* determine start of sndbuf */ 182 sndbuf_base = conn->sndbuf_desc->cpu_addr; 183 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 184 tx_cnt_prep = prep.count; 185 /* determine chunks where to write into sndbuf */ 186 /* either unwrapped case, or 1st chunk of wrapped case */ 187 chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len - 188 tx_cnt_prep); 189 chunk_len_sum = chunk_len; 190 chunk_off = tx_cnt_prep; 191 smc_sndbuf_sync_sg_for_cpu(conn); 192 for (chunk = 0; chunk < 2; chunk++) { 193 rc = memcpy_from_msg(sndbuf_base + chunk_off, 194 msg, chunk_len); 195 if (rc) { 196 smc_sndbuf_sync_sg_for_device(conn); 197 if (send_done) 198 return send_done; 199 goto out_err; 200 } 201 send_done += chunk_len; 202 send_remaining -= chunk_len; 203 204 if (chunk_len_sum == copylen) 205 break; /* either on 1st or 2nd iteration */ 206 /* prepare next (== 2nd) iteration */ 207 chunk_len = copylen - chunk_len; /* remainder */ 208 chunk_len_sum += chunk_len; 209 chunk_off = 0; /* modulo offset in send ring buffer */ 210 } 211 smc_sndbuf_sync_sg_for_device(conn); 212 /* update cursors */ 213 smc_curs_add(conn->sndbuf_desc->len, &prep, copylen); 214 smc_curs_copy(&conn->tx_curs_prep, &prep, conn); 215 /* increased in send tasklet smc_cdc_tx_handler() */ 216 smp_mb__before_atomic(); 217 atomic_sub(copylen, &conn->sndbuf_space); 218 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ 219 smp_mb__after_atomic(); 220 /* since we just produced more new data into sndbuf, 221 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC 222 */ 223 if ((msg->msg_flags & MSG_OOB) && !send_remaining) 224 conn->urg_tx_pend = true; 225 if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) && 226 (atomic_read(&conn->sndbuf_space) > 227 (conn->sndbuf_desc->len >> 1))) 228 /* for a corked socket defer the RDMA writes if there 229 * is still sufficient sndbuf_space available 230 */ 231 queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 232 SMC_TX_CORK_DELAY); 233 else 234 smc_tx_sndbuf_nonempty(conn); 235 } /* while (msg_data_left(msg)) */ 236 237 return send_done; 238 239out_err: 240 rc = sk_stream_error(sk, msg->msg_flags, rc); 241 /* make sure we wake any epoll edge trigger waiter */ 242 if (unlikely(rc == -EAGAIN)) 243 sk->sk_write_space(sk); 244 return rc; 245} 246 247/***************************** sndbuf consumer *******************************/ 248 249/* sndbuf consumer: actual data transfer of one target chunk with ISM write */ 250int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len, 251 u32 offset, int signal) 252{ 253 struct smc_ism_position pos; 254 int rc; 255 256 memset(&pos, 0, sizeof(pos)); 257 pos.token = conn->peer_token; 258 pos.index = conn->peer_rmbe_idx; 259 pos.offset = conn->tx_off + offset; 260 pos.signal = signal; 261 rc = smc_ism_write(conn->lgr->smcd, &pos, data, len); 262 if (rc) 263 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; 264 return rc; 265} 266 267/* sndbuf consumer: actual data transfer of one target chunk with RDMA write */ 268static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset, 269 int num_sges, struct ib_rdma_wr *rdma_wr) 270{ 271 struct smc_link_group *lgr = conn->lgr; 272 struct smc_link *link = conn->lnk; 273 int rc; 274 275 rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link); 276 rdma_wr->wr.num_sge = num_sges; 277 rdma_wr->remote_addr = 278 lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr + 279 /* RMBE within RMB */ 280 conn->tx_off + 281 /* offset within RMBE */ 282 peer_rmbe_offset; 283 rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey; 284 rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL); 285 if (rc) 286 smcr_link_down_cond_sched(link); 287 return rc; 288} 289 290/* sndbuf consumer */ 291static inline void smc_tx_advance_cursors(struct smc_connection *conn, 292 union smc_host_cursor *prod, 293 union smc_host_cursor *sent, 294 size_t len) 295{ 296 smc_curs_add(conn->peer_rmbe_size, prod, len); 297 /* increased in recv tasklet smc_cdc_msg_rcv() */ 298 smp_mb__before_atomic(); 299 /* data in flight reduces usable snd_wnd */ 300 atomic_sub(len, &conn->peer_rmbe_space); 301 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ 302 smp_mb__after_atomic(); 303 smc_curs_add(conn->sndbuf_desc->len, sent, len); 304} 305 306/* SMC-R helper for smc_tx_rdma_writes() */ 307static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len, 308 size_t src_off, size_t src_len, 309 size_t dst_off, size_t dst_len, 310 struct smc_rdma_wr *wr_rdma_buf) 311{ 312 struct smc_link *link = conn->lnk; 313 314 dma_addr_t dma_addr = 315 sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl); 316 int src_len_sum = src_len, dst_len_sum = dst_len; 317 int sent_count = src_off; 318 int srcchunk, dstchunk; 319 int num_sges; 320 int rc; 321 322 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 323 struct ib_sge *sge = 324 wr_rdma_buf->wr_tx_rdma[dstchunk].wr.sg_list; 325 326 num_sges = 0; 327 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 328 sge[srcchunk].addr = dma_addr + src_off; 329 sge[srcchunk].length = src_len; 330 num_sges++; 331 332 src_off += src_len; 333 if (src_off >= conn->sndbuf_desc->len) 334 src_off -= conn->sndbuf_desc->len; 335 /* modulo in send ring */ 336 if (src_len_sum == dst_len) 337 break; /* either on 1st or 2nd iteration */ 338 /* prepare next (== 2nd) iteration */ 339 src_len = dst_len - src_len; /* remainder */ 340 src_len_sum += src_len; 341 } 342 rc = smc_tx_rdma_write(conn, dst_off, num_sges, 343 &wr_rdma_buf->wr_tx_rdma[dstchunk]); 344 if (rc) 345 return rc; 346 if (dst_len_sum == len) 347 break; /* either on 1st or 2nd iteration */ 348 /* prepare next (== 2nd) iteration */ 349 dst_off = 0; /* modulo offset in RMBE ring buffer */ 350 dst_len = len - dst_len; /* remainder */ 351 dst_len_sum += dst_len; 352 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - 353 sent_count); 354 src_len_sum = src_len; 355 } 356 return 0; 357} 358 359/* SMC-D helper for smc_tx_rdma_writes() */ 360static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, 361 size_t src_off, size_t src_len, 362 size_t dst_off, size_t dst_len) 363{ 364 int src_len_sum = src_len, dst_len_sum = dst_len; 365 int srcchunk, dstchunk; 366 int rc; 367 368 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 369 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 370 void *data = conn->sndbuf_desc->cpu_addr + src_off; 371 372 rc = smcd_tx_ism_write(conn, data, src_len, dst_off + 373 sizeof(struct smcd_cdc_msg), 0); 374 if (rc) 375 return rc; 376 dst_off += src_len; 377 src_off += src_len; 378 if (src_off >= conn->sndbuf_desc->len) 379 src_off -= conn->sndbuf_desc->len; 380 /* modulo in send ring */ 381 if (src_len_sum == dst_len) 382 break; /* either on 1st or 2nd iteration */ 383 /* prepare next (== 2nd) iteration */ 384 src_len = dst_len - src_len; /* remainder */ 385 src_len_sum += src_len; 386 } 387 if (dst_len_sum == len) 388 break; /* either on 1st or 2nd iteration */ 389 /* prepare next (== 2nd) iteration */ 390 dst_off = 0; /* modulo offset in RMBE ring buffer */ 391 dst_len = len - dst_len; /* remainder */ 392 dst_len_sum += dst_len; 393 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); 394 src_len_sum = src_len; 395 } 396 return 0; 397} 398 399/* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; 400 * usable snd_wnd as max transmit 401 */ 402static int smc_tx_rdma_writes(struct smc_connection *conn, 403 struct smc_rdma_wr *wr_rdma_buf) 404{ 405 size_t len, src_len, dst_off, dst_len; /* current chunk values */ 406 union smc_host_cursor sent, prep, prod, cons; 407 struct smc_cdc_producer_flags *pflags; 408 int to_send, rmbespace; 409 int rc; 410 411 /* source: sndbuf */ 412 smc_curs_copy(&sent, &conn->tx_curs_sent, conn); 413 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 414 /* cf. wmem_alloc - (snd_max - snd_una) */ 415 to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep); 416 if (to_send <= 0) 417 return 0; 418 419 /* destination: RMBE */ 420 /* cf. snd_wnd */ 421 rmbespace = atomic_read(&conn->peer_rmbe_space); 422 if (rmbespace <= 0) 423 return 0; 424 smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn); 425 smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn); 426 427 /* if usable snd_wnd closes ask peer to advertise once it opens again */ 428 pflags = &conn->local_tx_ctrl.prod_flags; 429 pflags->write_blocked = (to_send >= rmbespace); 430 /* cf. usable snd_wnd */ 431 len = min(to_send, rmbespace); 432 433 /* initialize variables for first iteration of subsequent nested loop */ 434 dst_off = prod.count; 435 if (prod.wrap == cons.wrap) { 436 /* the filled destination area is unwrapped, 437 * hence the available free destination space is wrapped 438 * and we need 2 destination chunks of sum len; start with 1st 439 * which is limited by what's available in sndbuf 440 */ 441 dst_len = min_t(size_t, 442 conn->peer_rmbe_size - prod.count, len); 443 } else { 444 /* the filled destination area is wrapped, 445 * hence the available free destination space is unwrapped 446 * and we need a single destination chunk of entire len 447 */ 448 dst_len = len; 449 } 450 /* dst_len determines the maximum src_len */ 451 if (sent.count + dst_len <= conn->sndbuf_desc->len) { 452 /* unwrapped src case: single chunk of entire dst_len */ 453 src_len = dst_len; 454 } else { 455 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ 456 src_len = conn->sndbuf_desc->len - sent.count; 457 } 458 459 if (conn->lgr->is_smcd) 460 rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len, 461 dst_off, dst_len); 462 else 463 rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len, 464 dst_off, dst_len, wr_rdma_buf); 465 if (rc) 466 return rc; 467 468 if (conn->urg_tx_pend && len == to_send) 469 pflags->urg_data_present = 1; 470 smc_tx_advance_cursors(conn, &prod, &sent, len); 471 /* update connection's cursors with advanced local cursors */ 472 smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn); 473 /* dst: peer RMBE */ 474 smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */ 475 476 return 0; 477} 478 479/* Wakeup sndbuf consumers from any context (IRQ or process) 480 * since there is more data to transmit; usable snd_wnd as max transmit 481 */ 482static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) 483{ 484 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 485 struct smc_link *link = conn->lnk; 486 struct smc_rdma_wr *wr_rdma_buf; 487 struct smc_cdc_tx_pend *pend; 488 struct smc_wr_buf *wr_buf; 489 int rc; 490 491 if (!link || !smc_wr_tx_link_hold(link)) 492 return -ENOLINK; 493 rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend); 494 if (rc < 0) { 495 smc_wr_tx_link_put(link); 496 if (rc == -EBUSY) { 497 struct smc_sock *smc = 498 container_of(conn, struct smc_sock, conn); 499 500 if (smc->sk.sk_err == ECONNABORTED) 501 return sock_error(&smc->sk); 502 if (conn->killed) 503 return -EPIPE; 504 rc = 0; 505 mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 506 SMC_TX_WORK_DELAY); 507 } 508 return rc; 509 } 510 511 spin_lock_bh(&conn->send_lock); 512 if (link != conn->lnk) { 513 /* link of connection changed, tx_work will restart */ 514 smc_wr_tx_put_slot(link, 515 (struct smc_wr_tx_pend_priv *)pend); 516 rc = -ENOLINK; 517 goto out_unlock; 518 } 519 if (!pflags->urg_data_present) { 520 rc = smc_tx_rdma_writes(conn, wr_rdma_buf); 521 if (rc) { 522 smc_wr_tx_put_slot(link, 523 (struct smc_wr_tx_pend_priv *)pend); 524 goto out_unlock; 525 } 526 } 527 528 rc = smc_cdc_msg_send(conn, wr_buf, pend); 529 if (!rc && pflags->urg_data_present) { 530 pflags->urg_data_pending = 0; 531 pflags->urg_data_present = 0; 532 } 533 534out_unlock: 535 spin_unlock_bh(&conn->send_lock); 536 smc_wr_tx_link_put(link); 537 return rc; 538} 539 540static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) 541{ 542 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 543 int rc = 0; 544 545 spin_lock_bh(&conn->send_lock); 546 if (!pflags->urg_data_present) 547 rc = smc_tx_rdma_writes(conn, NULL); 548 if (!rc) 549 rc = smcd_cdc_msg_send(conn); 550 551 if (!rc && pflags->urg_data_present) { 552 pflags->urg_data_pending = 0; 553 pflags->urg_data_present = 0; 554 } 555 spin_unlock_bh(&conn->send_lock); 556 return rc; 557} 558 559int smc_tx_sndbuf_nonempty(struct smc_connection *conn) 560{ 561 int rc; 562 563 if (conn->killed || 564 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) 565 return -EPIPE; /* connection being aborted */ 566 if (conn->lgr->is_smcd) 567 rc = smcd_tx_sndbuf_nonempty(conn); 568 else 569 rc = smcr_tx_sndbuf_nonempty(conn); 570 571 if (!rc) { 572 /* trigger socket release if connection is closing */ 573 struct smc_sock *smc = container_of(conn, struct smc_sock, 574 conn); 575 smc_close_wake_tx_prepared(smc); 576 } 577 return rc; 578} 579 580/* Wakeup sndbuf consumers from process context 581 * since there is more data to transmit 582 */ 583void smc_tx_work(struct work_struct *work) 584{ 585 struct smc_connection *conn = container_of(to_delayed_work(work), 586 struct smc_connection, 587 tx_work); 588 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 589 int rc; 590 591 lock_sock(&smc->sk); 592 if (smc->sk.sk_err) 593 goto out; 594 595 rc = smc_tx_sndbuf_nonempty(conn); 596 if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && 597 !atomic_read(&conn->bytes_to_rcv)) 598 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 599 600out: 601 release_sock(&smc->sk); 602} 603 604void smc_tx_consumer_update(struct smc_connection *conn, bool force) 605{ 606 union smc_host_cursor cfed, cons, prod; 607 int sender_free = conn->rmb_desc->len; 608 int to_confirm; 609 610 smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn); 611 smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn); 612 to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); 613 if (to_confirm > conn->rmbe_update_limit) { 614 smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); 615 sender_free = conn->rmb_desc->len - 616 smc_curs_diff_large(conn->rmb_desc->len, 617 &cfed, &prod); 618 } 619 620 if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || 621 force || 622 ((to_confirm > conn->rmbe_update_limit) && 623 ((sender_free <= (conn->rmb_desc->len / 2)) || 624 conn->local_rx_ctrl.prod_flags.write_blocked))) { 625 if (conn->killed || 626 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) 627 return; 628 if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && 629 !conn->killed) { 630 queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 631 SMC_TX_WORK_DELAY); 632 return; 633 } 634 } 635 if (conn->local_rx_ctrl.prod_flags.write_blocked && 636 !atomic_read(&conn->bytes_to_rcv)) 637 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 638} 639 640/***************************** send initialize *******************************/ 641 642/* Initialize send properties on connection establishment. NB: not __init! */ 643void smc_tx_init(struct smc_sock *smc) 644{ 645 smc->sk.sk_write_space = smc_tx_write_space; 646} 647