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 #include "smc_stats.h" 31 32 #define SMC_TX_WORK_DELAY 0 33 #define SMC_TX_CORK_DELAY (HZ >> 2) /* 250 ms */ 34 35 /***************************** sndbuf producer *******************************/ 36 37 /* callback implementation for sk.sk_write_space() 38 * to wakeup sndbuf producers that blocked with smc_tx_wait(). 39 * called under sk_socket lock. 40 */ 41 static void smc_tx_write_space(struct sock *sk) 42 { 43 struct socket *sock = sk->sk_socket; 44 struct smc_sock *smc = smc_sk(sk); 45 struct socket_wq *wq; 46 47 /* similar to sk_stream_write_space */ 48 if (atomic_read(&smc->conn.sndbuf_space) && sock) { 49 if (test_bit(SOCK_NOSPACE, &sock->flags)) 50 SMC_STAT_RMB_TX_FULL(smc, !smc->conn.lnk); 51 clear_bit(SOCK_NOSPACE, &sock->flags); 52 rcu_read_lock(); 53 wq = rcu_dereference(sk->sk_wq); 54 if (skwq_has_sleeper(wq)) 55 wake_up_interruptible_poll(&wq->wait, 56 EPOLLOUT | EPOLLWRNORM | 57 EPOLLWRBAND); 58 if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN)) 59 sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT); 60 rcu_read_unlock(); 61 } 62 } 63 64 /* Wakeup sndbuf producers that blocked with smc_tx_wait(). 65 * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space(). 66 */ 67 void smc_tx_sndbuf_nonfull(struct smc_sock *smc) 68 { 69 if (smc->sk.sk_socket && 70 test_bit(SOCK_NOSPACE, &smc->sk.sk_socket->flags)) 71 smc->sk.sk_write_space(&smc->sk); 72 } 73 74 /* blocks sndbuf producer until at least one byte of free space available 75 * or urgent Byte was consumed 76 */ 77 static int smc_tx_wait(struct smc_sock *smc, int flags) 78 { 79 DEFINE_WAIT_FUNC(wait, woken_wake_function); 80 struct smc_connection *conn = &smc->conn; 81 struct sock *sk = &smc->sk; 82 long timeo; 83 int rc = 0; 84 85 /* similar to sk_stream_wait_memory */ 86 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); 87 add_wait_queue(sk_sleep(sk), &wait); 88 while (1) { 89 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); 90 if (sk->sk_err || 91 (sk->sk_shutdown & SEND_SHUTDOWN) || 92 conn->killed || 93 conn->local_tx_ctrl.conn_state_flags.peer_done_writing) { 94 rc = -EPIPE; 95 break; 96 } 97 if (smc_cdc_rxed_any_close(conn)) { 98 rc = -ECONNRESET; 99 break; 100 } 101 if (!timeo) { 102 /* ensure EPOLLOUT is subsequently generated */ 103 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 104 rc = -EAGAIN; 105 break; 106 } 107 if (signal_pending(current)) { 108 rc = sock_intr_errno(timeo); 109 break; 110 } 111 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 112 if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) 113 break; /* at least 1 byte of free & no urgent data */ 114 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 115 sk_wait_event(sk, &timeo, 116 sk->sk_err || 117 (sk->sk_shutdown & SEND_SHUTDOWN) || 118 smc_cdc_rxed_any_close(conn) || 119 (atomic_read(&conn->sndbuf_space) && 120 !conn->urg_tx_pend), 121 &wait); 122 } 123 remove_wait_queue(sk_sleep(sk), &wait); 124 return rc; 125 } 126 127 static bool smc_tx_is_corked(struct smc_sock *smc) 128 { 129 struct tcp_sock *tp = tcp_sk(smc->clcsock->sk); 130 131 return (tp->nonagle & TCP_NAGLE_CORK) ? true : false; 132 } 133 134 /* sndbuf producer: main API called by socket layer. 135 * called under sock lock. 136 */ 137 int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) 138 { 139 size_t copylen, send_done = 0, send_remaining = len; 140 size_t chunk_len, chunk_off, chunk_len_sum; 141 struct smc_connection *conn = &smc->conn; 142 union smc_host_cursor prep; 143 struct sock *sk = &smc->sk; 144 char *sndbuf_base; 145 int tx_cnt_prep; 146 int writespace; 147 int rc, chunk; 148 149 /* This should be in poll */ 150 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 151 152 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { 153 rc = -EPIPE; 154 goto out_err; 155 } 156 157 if (len > conn->sndbuf_desc->len) 158 SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); 159 160 if (len > conn->peer_rmbe_size) 161 SMC_STAT_RMB_TX_PEER_SIZE_SMALL(smc, !conn->lnk); 162 163 if (msg->msg_flags & MSG_OOB) 164 SMC_STAT_INC(smc, urg_data_cnt); 165 166 while (msg_data_left(msg)) { 167 if (sk->sk_state == SMC_INIT) 168 return -ENOTCONN; 169 if (smc->sk.sk_shutdown & SEND_SHUTDOWN || 170 (smc->sk.sk_err == ECONNABORTED) || 171 conn->killed) 172 return -EPIPE; 173 if (smc_cdc_rxed_any_close(conn)) 174 return send_done ?: -ECONNRESET; 175 176 if (msg->msg_flags & MSG_OOB) 177 conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; 178 179 if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { 180 if (send_done) 181 return send_done; 182 rc = smc_tx_wait(smc, msg->msg_flags); 183 if (rc) 184 goto out_err; 185 continue; 186 } 187 188 /* initialize variables for 1st iteration of subsequent loop */ 189 /* could be just 1 byte, even after smc_tx_wait above */ 190 writespace = atomic_read(&conn->sndbuf_space); 191 /* not more than what user space asked for */ 192 copylen = min_t(size_t, send_remaining, writespace); 193 /* determine start of sndbuf */ 194 sndbuf_base = conn->sndbuf_desc->cpu_addr; 195 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 196 tx_cnt_prep = prep.count; 197 /* determine chunks where to write into sndbuf */ 198 /* either unwrapped case, or 1st chunk of wrapped case */ 199 chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len - 200 tx_cnt_prep); 201 chunk_len_sum = chunk_len; 202 chunk_off = tx_cnt_prep; 203 smc_sndbuf_sync_sg_for_cpu(conn); 204 for (chunk = 0; chunk < 2; chunk++) { 205 rc = memcpy_from_msg(sndbuf_base + chunk_off, 206 msg, chunk_len); 207 if (rc) { 208 smc_sndbuf_sync_sg_for_device(conn); 209 if (send_done) 210 return send_done; 211 goto out_err; 212 } 213 send_done += chunk_len; 214 send_remaining -= chunk_len; 215 216 if (chunk_len_sum == copylen) 217 break; /* either on 1st or 2nd iteration */ 218 /* prepare next (== 2nd) iteration */ 219 chunk_len = copylen - chunk_len; /* remainder */ 220 chunk_len_sum += chunk_len; 221 chunk_off = 0; /* modulo offset in send ring buffer */ 222 } 223 smc_sndbuf_sync_sg_for_device(conn); 224 /* update cursors */ 225 smc_curs_add(conn->sndbuf_desc->len, &prep, copylen); 226 smc_curs_copy(&conn->tx_curs_prep, &prep, conn); 227 /* increased in send tasklet smc_cdc_tx_handler() */ 228 smp_mb__before_atomic(); 229 atomic_sub(copylen, &conn->sndbuf_space); 230 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ 231 smp_mb__after_atomic(); 232 /* since we just produced more new data into sndbuf, 233 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC 234 */ 235 if ((msg->msg_flags & MSG_OOB) && !send_remaining) 236 conn->urg_tx_pend = true; 237 if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) && 238 (atomic_read(&conn->sndbuf_space) > 239 (conn->sndbuf_desc->len >> 1))) 240 /* for a corked socket defer the RDMA writes if there 241 * is still sufficient sndbuf_space available 242 */ 243 queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 244 SMC_TX_CORK_DELAY); 245 else 246 smc_tx_sndbuf_nonempty(conn); 247 } /* while (msg_data_left(msg)) */ 248 249 return send_done; 250 251 out_err: 252 rc = sk_stream_error(sk, msg->msg_flags, rc); 253 /* make sure we wake any epoll edge trigger waiter */ 254 if (unlikely(rc == -EAGAIN)) 255 sk->sk_write_space(sk); 256 return rc; 257 } 258 259 /***************************** sndbuf consumer *******************************/ 260 261 /* sndbuf consumer: actual data transfer of one target chunk with ISM write */ 262 int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len, 263 u32 offset, int signal) 264 { 265 struct smc_ism_position pos; 266 int rc; 267 268 memset(&pos, 0, sizeof(pos)); 269 pos.token = conn->peer_token; 270 pos.index = conn->peer_rmbe_idx; 271 pos.offset = conn->tx_off + offset; 272 pos.signal = signal; 273 rc = smc_ism_write(conn->lgr->smcd, &pos, data, len); 274 if (rc) 275 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; 276 return rc; 277 } 278 279 /* sndbuf consumer: actual data transfer of one target chunk with RDMA write */ 280 static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset, 281 int num_sges, struct ib_rdma_wr *rdma_wr) 282 { 283 struct smc_link_group *lgr = conn->lgr; 284 struct smc_link *link = conn->lnk; 285 int rc; 286 287 rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link); 288 rdma_wr->wr.num_sge = num_sges; 289 rdma_wr->remote_addr = 290 lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr + 291 /* RMBE within RMB */ 292 conn->tx_off + 293 /* offset within RMBE */ 294 peer_rmbe_offset; 295 rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey; 296 rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL); 297 if (rc) 298 smcr_link_down_cond_sched(link); 299 return rc; 300 } 301 302 /* sndbuf consumer */ 303 static inline void smc_tx_advance_cursors(struct smc_connection *conn, 304 union smc_host_cursor *prod, 305 union smc_host_cursor *sent, 306 size_t len) 307 { 308 smc_curs_add(conn->peer_rmbe_size, prod, len); 309 /* increased in recv tasklet smc_cdc_msg_rcv() */ 310 smp_mb__before_atomic(); 311 /* data in flight reduces usable snd_wnd */ 312 atomic_sub(len, &conn->peer_rmbe_space); 313 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ 314 smp_mb__after_atomic(); 315 smc_curs_add(conn->sndbuf_desc->len, sent, len); 316 } 317 318 /* SMC-R helper for smc_tx_rdma_writes() */ 319 static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len, 320 size_t src_off, size_t src_len, 321 size_t dst_off, size_t dst_len, 322 struct smc_rdma_wr *wr_rdma_buf) 323 { 324 struct smc_link *link = conn->lnk; 325 326 dma_addr_t dma_addr = 327 sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl); 328 int src_len_sum = src_len, dst_len_sum = dst_len; 329 int sent_count = src_off; 330 int srcchunk, dstchunk; 331 int num_sges; 332 int rc; 333 334 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 335 struct ib_sge *sge = 336 wr_rdma_buf->wr_tx_rdma[dstchunk].wr.sg_list; 337 338 num_sges = 0; 339 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 340 sge[srcchunk].addr = dma_addr + src_off; 341 sge[srcchunk].length = src_len; 342 num_sges++; 343 344 src_off += src_len; 345 if (src_off >= conn->sndbuf_desc->len) 346 src_off -= conn->sndbuf_desc->len; 347 /* modulo in send ring */ 348 if (src_len_sum == dst_len) 349 break; /* either on 1st or 2nd iteration */ 350 /* prepare next (== 2nd) iteration */ 351 src_len = dst_len - src_len; /* remainder */ 352 src_len_sum += src_len; 353 } 354 rc = smc_tx_rdma_write(conn, dst_off, num_sges, 355 &wr_rdma_buf->wr_tx_rdma[dstchunk]); 356 if (rc) 357 return rc; 358 if (dst_len_sum == len) 359 break; /* either on 1st or 2nd iteration */ 360 /* prepare next (== 2nd) iteration */ 361 dst_off = 0; /* modulo offset in RMBE ring buffer */ 362 dst_len = len - dst_len; /* remainder */ 363 dst_len_sum += dst_len; 364 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - 365 sent_count); 366 src_len_sum = src_len; 367 } 368 return 0; 369 } 370 371 /* SMC-D helper for smc_tx_rdma_writes() */ 372 static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, 373 size_t src_off, size_t src_len, 374 size_t dst_off, size_t dst_len) 375 { 376 int src_len_sum = src_len, dst_len_sum = dst_len; 377 int srcchunk, dstchunk; 378 int rc; 379 380 for (dstchunk = 0; dstchunk < 2; dstchunk++) { 381 for (srcchunk = 0; srcchunk < 2; srcchunk++) { 382 void *data = conn->sndbuf_desc->cpu_addr + src_off; 383 384 rc = smcd_tx_ism_write(conn, data, src_len, dst_off + 385 sizeof(struct smcd_cdc_msg), 0); 386 if (rc) 387 return rc; 388 dst_off += src_len; 389 src_off += src_len; 390 if (src_off >= conn->sndbuf_desc->len) 391 src_off -= conn->sndbuf_desc->len; 392 /* modulo in send ring */ 393 if (src_len_sum == dst_len) 394 break; /* either on 1st or 2nd iteration */ 395 /* prepare next (== 2nd) iteration */ 396 src_len = dst_len - src_len; /* remainder */ 397 src_len_sum += src_len; 398 } 399 if (dst_len_sum == len) 400 break; /* either on 1st or 2nd iteration */ 401 /* prepare next (== 2nd) iteration */ 402 dst_off = 0; /* modulo offset in RMBE ring buffer */ 403 dst_len = len - dst_len; /* remainder */ 404 dst_len_sum += dst_len; 405 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); 406 src_len_sum = src_len; 407 } 408 return 0; 409 } 410 411 /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; 412 * usable snd_wnd as max transmit 413 */ 414 static int smc_tx_rdma_writes(struct smc_connection *conn, 415 struct smc_rdma_wr *wr_rdma_buf) 416 { 417 size_t len, src_len, dst_off, dst_len; /* current chunk values */ 418 union smc_host_cursor sent, prep, prod, cons; 419 struct smc_cdc_producer_flags *pflags; 420 int to_send, rmbespace; 421 int rc; 422 423 /* source: sndbuf */ 424 smc_curs_copy(&sent, &conn->tx_curs_sent, conn); 425 smc_curs_copy(&prep, &conn->tx_curs_prep, conn); 426 /* cf. wmem_alloc - (snd_max - snd_una) */ 427 to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep); 428 if (to_send <= 0) 429 return 0; 430 431 /* destination: RMBE */ 432 /* cf. snd_wnd */ 433 rmbespace = atomic_read(&conn->peer_rmbe_space); 434 if (rmbespace <= 0) { 435 struct smc_sock *smc = container_of(conn, struct smc_sock, 436 conn); 437 SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); 438 return 0; 439 } 440 smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn); 441 smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn); 442 443 /* if usable snd_wnd closes ask peer to advertise once it opens again */ 444 pflags = &conn->local_tx_ctrl.prod_flags; 445 pflags->write_blocked = (to_send >= rmbespace); 446 /* cf. usable snd_wnd */ 447 len = min(to_send, rmbespace); 448 449 /* initialize variables for first iteration of subsequent nested loop */ 450 dst_off = prod.count; 451 if (prod.wrap == cons.wrap) { 452 /* the filled destination area is unwrapped, 453 * hence the available free destination space is wrapped 454 * and we need 2 destination chunks of sum len; start with 1st 455 * which is limited by what's available in sndbuf 456 */ 457 dst_len = min_t(size_t, 458 conn->peer_rmbe_size - prod.count, len); 459 } else { 460 /* the filled destination area is wrapped, 461 * hence the available free destination space is unwrapped 462 * and we need a single destination chunk of entire len 463 */ 464 dst_len = len; 465 } 466 /* dst_len determines the maximum src_len */ 467 if (sent.count + dst_len <= conn->sndbuf_desc->len) { 468 /* unwrapped src case: single chunk of entire dst_len */ 469 src_len = dst_len; 470 } else { 471 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ 472 src_len = conn->sndbuf_desc->len - sent.count; 473 } 474 475 if (conn->lgr->is_smcd) 476 rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len, 477 dst_off, dst_len); 478 else 479 rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len, 480 dst_off, dst_len, wr_rdma_buf); 481 if (rc) 482 return rc; 483 484 if (conn->urg_tx_pend && len == to_send) 485 pflags->urg_data_present = 1; 486 smc_tx_advance_cursors(conn, &prod, &sent, len); 487 /* update connection's cursors with advanced local cursors */ 488 smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn); 489 /* dst: peer RMBE */ 490 smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */ 491 492 return 0; 493 } 494 495 /* Wakeup sndbuf consumers from any context (IRQ or process) 496 * since there is more data to transmit; usable snd_wnd as max transmit 497 */ 498 static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) 499 { 500 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 501 struct smc_link *link = conn->lnk; 502 struct smc_rdma_wr *wr_rdma_buf; 503 struct smc_cdc_tx_pend *pend; 504 struct smc_wr_buf *wr_buf; 505 int rc; 506 507 rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend); 508 if (rc < 0) { 509 if (rc == -EBUSY) { 510 struct smc_sock *smc = 511 container_of(conn, struct smc_sock, conn); 512 513 if (smc->sk.sk_err == ECONNABORTED) 514 return sock_error(&smc->sk); 515 if (conn->killed) 516 return -EPIPE; 517 rc = 0; 518 mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 519 SMC_TX_WORK_DELAY); 520 } 521 return rc; 522 } 523 524 spin_lock_bh(&conn->send_lock); 525 if (link != conn->lnk) { 526 /* link of connection changed, tx_work will restart */ 527 smc_wr_tx_put_slot(link, 528 (struct smc_wr_tx_pend_priv *)pend); 529 rc = -ENOLINK; 530 goto out_unlock; 531 } 532 if (!pflags->urg_data_present) { 533 rc = smc_tx_rdma_writes(conn, wr_rdma_buf); 534 if (rc) { 535 smc_wr_tx_put_slot(link, 536 (struct smc_wr_tx_pend_priv *)pend); 537 goto out_unlock; 538 } 539 } 540 541 rc = smc_cdc_msg_send(conn, wr_buf, pend); 542 if (!rc && pflags->urg_data_present) { 543 pflags->urg_data_pending = 0; 544 pflags->urg_data_present = 0; 545 } 546 547 out_unlock: 548 spin_unlock_bh(&conn->send_lock); 549 return rc; 550 } 551 552 static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) 553 { 554 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; 555 int rc = 0; 556 557 spin_lock_bh(&conn->send_lock); 558 if (!pflags->urg_data_present) 559 rc = smc_tx_rdma_writes(conn, NULL); 560 if (!rc) 561 rc = smcd_cdc_msg_send(conn); 562 563 if (!rc && pflags->urg_data_present) { 564 pflags->urg_data_pending = 0; 565 pflags->urg_data_present = 0; 566 } 567 spin_unlock_bh(&conn->send_lock); 568 return rc; 569 } 570 571 int smc_tx_sndbuf_nonempty(struct smc_connection *conn) 572 { 573 int rc; 574 575 if (conn->killed || 576 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) 577 return -EPIPE; /* connection being aborted */ 578 if (conn->lgr->is_smcd) 579 rc = smcd_tx_sndbuf_nonempty(conn); 580 else 581 rc = smcr_tx_sndbuf_nonempty(conn); 582 583 if (!rc) { 584 /* trigger socket release if connection is closing */ 585 struct smc_sock *smc = container_of(conn, struct smc_sock, 586 conn); 587 smc_close_wake_tx_prepared(smc); 588 } 589 return rc; 590 } 591 592 /* Wakeup sndbuf consumers from process context 593 * since there is more data to transmit 594 */ 595 void smc_tx_work(struct work_struct *work) 596 { 597 struct smc_connection *conn = container_of(to_delayed_work(work), 598 struct smc_connection, 599 tx_work); 600 struct smc_sock *smc = container_of(conn, struct smc_sock, conn); 601 int rc; 602 603 lock_sock(&smc->sk); 604 if (smc->sk.sk_err) 605 goto out; 606 607 rc = smc_tx_sndbuf_nonempty(conn); 608 if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && 609 !atomic_read(&conn->bytes_to_rcv)) 610 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 611 612 out: 613 release_sock(&smc->sk); 614 } 615 616 void smc_tx_consumer_update(struct smc_connection *conn, bool force) 617 { 618 union smc_host_cursor cfed, cons, prod; 619 int sender_free = conn->rmb_desc->len; 620 int to_confirm; 621 622 smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn); 623 smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn); 624 to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); 625 if (to_confirm > conn->rmbe_update_limit) { 626 smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); 627 sender_free = conn->rmb_desc->len - 628 smc_curs_diff_large(conn->rmb_desc->len, 629 &cfed, &prod); 630 } 631 632 if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || 633 force || 634 ((to_confirm > conn->rmbe_update_limit) && 635 ((sender_free <= (conn->rmb_desc->len / 2)) || 636 conn->local_rx_ctrl.prod_flags.write_blocked))) { 637 if (conn->killed || 638 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) 639 return; 640 if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && 641 !conn->killed) { 642 queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 643 SMC_TX_WORK_DELAY); 644 return; 645 } 646 } 647 if (conn->local_rx_ctrl.prod_flags.write_blocked && 648 !atomic_read(&conn->bytes_to_rcv)) 649 conn->local_rx_ctrl.prod_flags.write_blocked = 0; 650 } 651 652 /***************************** send initialize *******************************/ 653 654 /* Initialize send properties on connection establishment. NB: not __init! */ 655 void smc_tx_init(struct smc_sock *smc) 656 { 657 smc->sk.sk_write_space = smc_tx_write_space; 658 } 659