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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 <[email protected]>
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#include "smc_tracepoint.h"
32
33#define SMC_TX_WORK_DELAY 0
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 */
41static 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 */
67void 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 */
77static 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 READ_ONCE(sk->sk_err) ||
117 (READ_ONCE(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
127static 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/* If we have pending CDC messages, do not send:
135 * Because CQE of this CDC message will happen shortly, it gives
136 * a chance to coalesce future sendmsg() payload in to one RDMA Write,
137 * without need for a timer, and with no latency trade off.
138 * Algorithm here:
139 * 1. First message should never cork
140 * 2. If we have pending Tx CDC messages, wait for the first CDC
141 * message's completion
142 * 3. Don't cork to much data in a single RDMA Write to prevent burst
143 * traffic, total corked message should not exceed sendbuf/2
144 */
145static bool smc_should_autocork(struct smc_sock *smc)
146{
147 struct smc_connection *conn = &smc->conn;
148 int corking_size;
149
150 corking_size = min_t(unsigned int, conn->sndbuf_desc->len >> 1,
151 sock_net(&smc->sk)->smc.sysctl_autocorking_size);
152
153 if (atomic_read(&conn->cdc_pend_tx_wr) == 0 ||
154 smc_tx_prepared_sends(conn) > corking_size)
155 return false;
156 return true;
157}
158
159static bool smc_tx_should_cork(struct smc_sock *smc, struct msghdr *msg)
160{
161 struct smc_connection *conn = &smc->conn;
162
163 if (smc_should_autocork(smc))
164 return true;
165
166 /* for a corked socket defer the RDMA writes if
167 * sndbuf_space is still available. The applications
168 * should known how/when to uncork it.
169 */
170 if ((msg->msg_flags & MSG_MORE ||
171 smc_tx_is_corked(smc)) &&
172 atomic_read(&conn->sndbuf_space))
173 return true;
174
175 return false;
176}
177
178/* sndbuf producer: main API called by socket layer.
179 * called under sock lock.
180 */
181int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len)
182{
183 size_t copylen, send_done = 0, send_remaining = len;
184 size_t chunk_len, chunk_off, chunk_len_sum;
185 struct smc_connection *conn = &smc->conn;
186 union smc_host_cursor prep;
187 struct sock *sk = &smc->sk;
188 char *sndbuf_base;
189 int tx_cnt_prep;
190 int writespace;
191 int rc, chunk;
192
193 /* This should be in poll */
194 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
195
196 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) {
197 rc = -EPIPE;
198 goto out_err;
199 }
200
201 if (sk->sk_state == SMC_INIT)
202 return -ENOTCONN;
203
204 if (len > conn->sndbuf_desc->len)
205 SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk);
206
207 if (len > conn->peer_rmbe_size)
208 SMC_STAT_RMB_TX_PEER_SIZE_SMALL(smc, !conn->lnk);
209
210 if (msg->msg_flags & MSG_OOB)
211 SMC_STAT_INC(smc, urg_data_cnt);
212
213 while (msg_data_left(msg)) {
214 if (smc->sk.sk_shutdown & SEND_SHUTDOWN ||
215 (smc->sk.sk_err == ECONNABORTED) ||
216 conn->killed)
217 return -EPIPE;
218 if (smc_cdc_rxed_any_close(conn))
219 return send_done ?: -ECONNRESET;
220
221 if (msg->msg_flags & MSG_OOB)
222 conn->local_tx_ctrl.prod_flags.urg_data_pending = 1;
223
224 if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) {
225 if (send_done)
226 return send_done;
227 rc = smc_tx_wait(smc, msg->msg_flags);
228 if (rc)
229 goto out_err;
230 continue;
231 }
232
233 /* initialize variables for 1st iteration of subsequent loop */
234 /* could be just 1 byte, even after smc_tx_wait above */
235 writespace = atomic_read(&conn->sndbuf_space);
236 /* not more than what user space asked for */
237 copylen = min_t(size_t, send_remaining, writespace);
238 /* determine start of sndbuf */
239 sndbuf_base = conn->sndbuf_desc->cpu_addr;
240 smc_curs_copy(&prep, &conn->tx_curs_prep, conn);
241 tx_cnt_prep = prep.count;
242 /* determine chunks where to write into sndbuf */
243 /* either unwrapped case, or 1st chunk of wrapped case */
244 chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len -
245 tx_cnt_prep);
246 chunk_len_sum = chunk_len;
247 chunk_off = tx_cnt_prep;
248 for (chunk = 0; chunk < 2; chunk++) {
249 rc = memcpy_from_msg(sndbuf_base + chunk_off,
250 msg, chunk_len);
251 if (rc) {
252 smc_sndbuf_sync_sg_for_device(conn);
253 if (send_done)
254 return send_done;
255 goto out_err;
256 }
257 send_done += chunk_len;
258 send_remaining -= chunk_len;
259
260 if (chunk_len_sum == copylen)
261 break; /* either on 1st or 2nd iteration */
262 /* prepare next (== 2nd) iteration */
263 chunk_len = copylen - chunk_len; /* remainder */
264 chunk_len_sum += chunk_len;
265 chunk_off = 0; /* modulo offset in send ring buffer */
266 }
267 smc_sndbuf_sync_sg_for_device(conn);
268 /* update cursors */
269 smc_curs_add(conn->sndbuf_desc->len, &prep, copylen);
270 smc_curs_copy(&conn->tx_curs_prep, &prep, conn);
271 /* increased in send tasklet smc_cdc_tx_handler() */
272 smp_mb__before_atomic();
273 atomic_sub(copylen, &conn->sndbuf_space);
274 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
275 smp_mb__after_atomic();
276 /* since we just produced more new data into sndbuf,
277 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC
278 */
279 if ((msg->msg_flags & MSG_OOB) && !send_remaining)
280 conn->urg_tx_pend = true;
281 /* If we need to cork, do nothing and wait for the next
282 * sendmsg() call or push on tx completion
283 */
284 if (!smc_tx_should_cork(smc, msg))
285 smc_tx_sndbuf_nonempty(conn);
286
287 trace_smc_tx_sendmsg(smc, copylen);
288 } /* while (msg_data_left(msg)) */
289
290 return send_done;
291
292out_err:
293 rc = sk_stream_error(sk, msg->msg_flags, rc);
294 /* make sure we wake any epoll edge trigger waiter */
295 if (unlikely(rc == -EAGAIN))
296 sk->sk_write_space(sk);
297 return rc;
298}
299
300/***************************** sndbuf consumer *******************************/
301
302/* sndbuf consumer: actual data transfer of one target chunk with ISM write */
303int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len,
304 u32 offset, int signal)
305{
306 int rc;
307
308 rc = smc_ism_write(conn->lgr->smcd, conn->peer_token,
309 conn->peer_rmbe_idx, signal, conn->tx_off + offset,
310 data, len);
311 if (rc)
312 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
313 return rc;
314}
315
316/* sndbuf consumer: actual data transfer of one target chunk with RDMA write */
317static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset,
318 int num_sges, struct ib_rdma_wr *rdma_wr)
319{
320 struct smc_link_group *lgr = conn->lgr;
321 struct smc_link *link = conn->lnk;
322 int rc;
323
324 rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link);
325 rdma_wr->wr.num_sge = num_sges;
326 rdma_wr->remote_addr =
327 lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr +
328 /* RMBE within RMB */
329 conn->tx_off +
330 /* offset within RMBE */
331 peer_rmbe_offset;
332 rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey;
333 rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL);
334 if (rc)
335 smcr_link_down_cond_sched(link);
336 return rc;
337}
338
339/* sndbuf consumer */
340static inline void smc_tx_advance_cursors(struct smc_connection *conn,
341 union smc_host_cursor *prod,
342 union smc_host_cursor *sent,
343 size_t len)
344{
345 smc_curs_add(conn->peer_rmbe_size, prod, len);
346 /* increased in recv tasklet smc_cdc_msg_rcv() */
347 smp_mb__before_atomic();
348 /* data in flight reduces usable snd_wnd */
349 atomic_sub(len, &conn->peer_rmbe_space);
350 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
351 smp_mb__after_atomic();
352 smc_curs_add(conn->sndbuf_desc->len, sent, len);
353}
354
355/* SMC-R helper for smc_tx_rdma_writes() */
356static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len,
357 size_t src_off, size_t src_len,
358 size_t dst_off, size_t dst_len,
359 struct smc_rdma_wr *wr_rdma_buf)
360{
361 struct smc_link *link = conn->lnk;
362
363 dma_addr_t dma_addr =
364 sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl);
365 u64 virt_addr = (uintptr_t)conn->sndbuf_desc->cpu_addr;
366 int src_len_sum = src_len, dst_len_sum = dst_len;
367 int sent_count = src_off;
368 int srcchunk, dstchunk;
369 int num_sges;
370 int rc;
371
372 for (dstchunk = 0; dstchunk < 2; dstchunk++) {
373 struct ib_rdma_wr *wr = &wr_rdma_buf->wr_tx_rdma[dstchunk];
374 struct ib_sge *sge = wr->wr.sg_list;
375 u64 base_addr = dma_addr;
376
377 if (dst_len < link->qp_attr.cap.max_inline_data) {
378 base_addr = virt_addr;
379 wr->wr.send_flags |= IB_SEND_INLINE;
380 } else {
381 wr->wr.send_flags &= ~IB_SEND_INLINE;
382 }
383
384 num_sges = 0;
385 for (srcchunk = 0; srcchunk < 2; srcchunk++) {
386 sge[srcchunk].addr = conn->sndbuf_desc->is_vm ?
387 (virt_addr + src_off) : (base_addr + src_off);
388 sge[srcchunk].length = src_len;
389 if (conn->sndbuf_desc->is_vm)
390 sge[srcchunk].lkey =
391 conn->sndbuf_desc->mr[link->link_idx]->lkey;
392 num_sges++;
393
394 src_off += src_len;
395 if (src_off >= conn->sndbuf_desc->len)
396 src_off -= conn->sndbuf_desc->len;
397 /* modulo in send ring */
398 if (src_len_sum == dst_len)
399 break; /* either on 1st or 2nd iteration */
400 /* prepare next (== 2nd) iteration */
401 src_len = dst_len - src_len; /* remainder */
402 src_len_sum += src_len;
403 }
404 rc = smc_tx_rdma_write(conn, dst_off, num_sges, wr);
405 if (rc)
406 return rc;
407 if (dst_len_sum == len)
408 break; /* either on 1st or 2nd iteration */
409 /* prepare next (== 2nd) iteration */
410 dst_off = 0; /* modulo offset in RMBE ring buffer */
411 dst_len = len - dst_len; /* remainder */
412 dst_len_sum += dst_len;
413 src_len = min_t(int, dst_len, conn->sndbuf_desc->len -
414 sent_count);
415 src_len_sum = src_len;
416 }
417 return 0;
418}
419
420/* SMC-D helper for smc_tx_rdma_writes() */
421static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len,
422 size_t src_off, size_t src_len,
423 size_t dst_off, size_t dst_len)
424{
425 int src_len_sum = src_len, dst_len_sum = dst_len;
426 int srcchunk, dstchunk;
427 int rc;
428
429 if (conn->sndbuf_desc->is_attached)
430 return 0;
431
432 for (dstchunk = 0; dstchunk < 2; dstchunk++) {
433 for (srcchunk = 0; srcchunk < 2; srcchunk++) {
434 void *data = conn->sndbuf_desc->cpu_addr + src_off;
435
436 rc = smcd_tx_ism_write(conn, data, src_len, dst_off +
437 sizeof(struct smcd_cdc_msg), 0);
438 if (rc)
439 return rc;
440 dst_off += src_len;
441 src_off += src_len;
442 if (src_off >= conn->sndbuf_desc->len)
443 src_off -= conn->sndbuf_desc->len;
444 /* modulo in send ring */
445 if (src_len_sum == dst_len)
446 break; /* either on 1st or 2nd iteration */
447 /* prepare next (== 2nd) iteration */
448 src_len = dst_len - src_len; /* remainder */
449 src_len_sum += src_len;
450 }
451 if (dst_len_sum == len)
452 break; /* either on 1st or 2nd iteration */
453 /* prepare next (== 2nd) iteration */
454 dst_off = 0; /* modulo offset in RMBE ring buffer */
455 dst_len = len - dst_len; /* remainder */
456 dst_len_sum += dst_len;
457 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off);
458 src_len_sum = src_len;
459 }
460 return 0;
461}
462
463/* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit;
464 * usable snd_wnd as max transmit
465 */
466static int smc_tx_rdma_writes(struct smc_connection *conn,
467 struct smc_rdma_wr *wr_rdma_buf)
468{
469 size_t len, src_len, dst_off, dst_len; /* current chunk values */
470 union smc_host_cursor sent, prep, prod, cons;
471 struct smc_cdc_producer_flags *pflags;
472 int to_send, rmbespace;
473 int rc;
474
475 /* source: sndbuf */
476 smc_curs_copy(&sent, &conn->tx_curs_sent, conn);
477 smc_curs_copy(&prep, &conn->tx_curs_prep, conn);
478 /* cf. wmem_alloc - (snd_max - snd_una) */
479 to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep);
480 if (to_send <= 0)
481 return 0;
482
483 /* destination: RMBE */
484 /* cf. snd_wnd */
485 rmbespace = atomic_read(&conn->peer_rmbe_space);
486 if (rmbespace <= 0) {
487 struct smc_sock *smc = container_of(conn, struct smc_sock,
488 conn);
489 SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk);
490 return 0;
491 }
492 smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
493 smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
494
495 /* if usable snd_wnd closes ask peer to advertise once it opens again */
496 pflags = &conn->local_tx_ctrl.prod_flags;
497 pflags->write_blocked = (to_send >= rmbespace);
498 /* cf. usable snd_wnd */
499 len = min(to_send, rmbespace);
500
501 /* initialize variables for first iteration of subsequent nested loop */
502 dst_off = prod.count;
503 if (prod.wrap == cons.wrap) {
504 /* the filled destination area is unwrapped,
505 * hence the available free destination space is wrapped
506 * and we need 2 destination chunks of sum len; start with 1st
507 * which is limited by what's available in sndbuf
508 */
509 dst_len = min_t(size_t,
510 conn->peer_rmbe_size - prod.count, len);
511 } else {
512 /* the filled destination area is wrapped,
513 * hence the available free destination space is unwrapped
514 * and we need a single destination chunk of entire len
515 */
516 dst_len = len;
517 }
518 /* dst_len determines the maximum src_len */
519 if (sent.count + dst_len <= conn->sndbuf_desc->len) {
520 /* unwrapped src case: single chunk of entire dst_len */
521 src_len = dst_len;
522 } else {
523 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */
524 src_len = conn->sndbuf_desc->len - sent.count;
525 }
526
527 if (conn->lgr->is_smcd)
528 rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len,
529 dst_off, dst_len);
530 else
531 rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len,
532 dst_off, dst_len, wr_rdma_buf);
533 if (rc)
534 return rc;
535
536 if (conn->urg_tx_pend && len == to_send)
537 pflags->urg_data_present = 1;
538 smc_tx_advance_cursors(conn, &prod, &sent, len);
539 /* update connection's cursors with advanced local cursors */
540 smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn);
541 /* dst: peer RMBE */
542 smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */
543
544 return 0;
545}
546
547/* Wakeup sndbuf consumers from any context (IRQ or process)
548 * since there is more data to transmit; usable snd_wnd as max transmit
549 */
550static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn)
551{
552 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags;
553 struct smc_link *link = conn->lnk;
554 struct smc_rdma_wr *wr_rdma_buf;
555 struct smc_cdc_tx_pend *pend;
556 struct smc_wr_buf *wr_buf;
557 int rc;
558
559 if (!link || !smc_wr_tx_link_hold(link))
560 return -ENOLINK;
561 rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend);
562 if (rc < 0) {
563 smc_wr_tx_link_put(link);
564 if (rc == -EBUSY) {
565 struct smc_sock *smc =
566 container_of(conn, struct smc_sock, conn);
567
568 if (smc->sk.sk_err == ECONNABORTED)
569 return sock_error(&smc->sk);
570 if (conn->killed)
571 return -EPIPE;
572 rc = 0;
573 mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work,
574 SMC_TX_WORK_DELAY);
575 }
576 return rc;
577 }
578
579 spin_lock_bh(&conn->send_lock);
580 if (link != conn->lnk) {
581 /* link of connection changed, tx_work will restart */
582 smc_wr_tx_put_slot(link,
583 (struct smc_wr_tx_pend_priv *)pend);
584 rc = -ENOLINK;
585 goto out_unlock;
586 }
587 if (!pflags->urg_data_present) {
588 rc = smc_tx_rdma_writes(conn, wr_rdma_buf);
589 if (rc) {
590 smc_wr_tx_put_slot(link,
591 (struct smc_wr_tx_pend_priv *)pend);
592 goto out_unlock;
593 }
594 }
595
596 rc = smc_cdc_msg_send(conn, wr_buf, pend);
597 if (!rc && pflags->urg_data_present) {
598 pflags->urg_data_pending = 0;
599 pflags->urg_data_present = 0;
600 }
601
602out_unlock:
603 spin_unlock_bh(&conn->send_lock);
604 smc_wr_tx_link_put(link);
605 return rc;
606}
607
608static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn)
609{
610 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags;
611 int rc = 0;
612
613 spin_lock_bh(&conn->send_lock);
614 if (!pflags->urg_data_present)
615 rc = smc_tx_rdma_writes(conn, NULL);
616 if (!rc)
617 rc = smcd_cdc_msg_send(conn);
618
619 if (!rc && pflags->urg_data_present) {
620 pflags->urg_data_pending = 0;
621 pflags->urg_data_present = 0;
622 }
623 spin_unlock_bh(&conn->send_lock);
624 return rc;
625}
626
627int smc_tx_sndbuf_nonempty(struct smc_connection *conn)
628{
629 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
630 int rc = 0;
631
632 /* No data in the send queue */
633 if (unlikely(smc_tx_prepared_sends(conn) <= 0))
634 goto out;
635
636 /* Peer don't have RMBE space */
637 if (unlikely(atomic_read(&conn->peer_rmbe_space) <= 0)) {
638 SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk);
639 goto out;
640 }
641
642 if (conn->killed ||
643 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
644 rc = -EPIPE; /* connection being aborted */
645 goto out;
646 }
647 if (conn->lgr->is_smcd)
648 rc = smcd_tx_sndbuf_nonempty(conn);
649 else
650 rc = smcr_tx_sndbuf_nonempty(conn);
651
652 if (!rc) {
653 /* trigger socket release if connection is closing */
654 smc_close_wake_tx_prepared(smc);
655 }
656
657out:
658 return rc;
659}
660
661/* Wakeup sndbuf consumers from process context
662 * since there is more data to transmit. The caller
663 * must hold sock lock.
664 */
665void smc_tx_pending(struct smc_connection *conn)
666{
667 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
668 int rc;
669
670 if (smc->sk.sk_err)
671 return;
672
673 rc = smc_tx_sndbuf_nonempty(conn);
674 if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked &&
675 !atomic_read(&conn->bytes_to_rcv))
676 conn->local_rx_ctrl.prod_flags.write_blocked = 0;
677}
678
679/* Wakeup sndbuf consumers from process context
680 * since there is more data to transmit in locked
681 * sock.
682 */
683void smc_tx_work(struct work_struct *work)
684{
685 struct smc_connection *conn = container_of(to_delayed_work(work),
686 struct smc_connection,
687 tx_work);
688 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
689
690 lock_sock(&smc->sk);
691 smc_tx_pending(conn);
692 release_sock(&smc->sk);
693}
694
695void smc_tx_consumer_update(struct smc_connection *conn, bool force)
696{
697 union smc_host_cursor cfed, cons, prod;
698 int sender_free = conn->rmb_desc->len;
699 int to_confirm;
700
701 smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
702 smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn);
703 to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons);
704 if (to_confirm > conn->rmbe_update_limit) {
705 smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn);
706 sender_free = conn->rmb_desc->len -
707 smc_curs_diff_large(conn->rmb_desc->len,
708 &cfed, &prod);
709 }
710
711 if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
712 force ||
713 ((to_confirm > conn->rmbe_update_limit) &&
714 ((sender_free <= (conn->rmb_desc->len / 2)) ||
715 conn->local_rx_ctrl.prod_flags.write_blocked))) {
716 if (conn->killed ||
717 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort)
718 return;
719 if ((smc_cdc_get_slot_and_msg_send(conn) < 0) &&
720 !conn->killed) {
721 queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work,
722 SMC_TX_WORK_DELAY);
723 return;
724 }
725 }
726 if (conn->local_rx_ctrl.prod_flags.write_blocked &&
727 !atomic_read(&conn->bytes_to_rcv))
728 conn->local_rx_ctrl.prod_flags.write_blocked = 0;
729}
730
731/***************************** send initialize *******************************/
732
733/* Initialize send properties on connection establishment. NB: not __init! */
734void smc_tx_init(struct smc_sock *smc)
735{
736 smc->sk.sk_write_space = smc_tx_write_space;
737}