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perf bpf: Move perf_event_output() from stdio.h to bpf.h
[linux/fpc-iii.git] / net / smc / smc_tx.c
blobd8366ed517576ba7f258ad74f0cf91f7fd92d7e0
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_ism.h"
28 #include "smc_tx.h"
29
30 #define SMC_TX_WORK_DELAY HZ
31 #define SMC_TX_CORK_DELAY (HZ >> 2) /* 250 ms */
32
33 /***************************** sndbuf producer *******************************/
34
35 /* callback implementation for sk.sk_write_space()
36 * to wakeup sndbuf producers that blocked with smc_tx_wait().
37 * called under sk_socket lock.
38 */
39 static void smc_tx_write_space(struct sock *sk)
40 {
41 struct socket *sock = sk->sk_socket;
42 struct smc_sock *smc = smc_sk(sk);
43 struct socket_wq *wq;
44
45 /* similar to sk_stream_write_space */
46 if (atomic_read(&smc->conn.sndbuf_space) && sock) {
47 clear_bit(SOCK_NOSPACE, &sock->flags);
48 rcu_read_lock();
49 wq = rcu_dereference(sk->sk_wq);
50 if (skwq_has_sleeper(wq))
51 wake_up_interruptible_poll(&wq->wait,
52 EPOLLOUT | EPOLLWRNORM |
53 EPOLLWRBAND);
54 if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
55 sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT);
56 rcu_read_unlock();
57 }
58 }
59
60 /* Wakeup sndbuf producers that blocked with smc_tx_wait().
61 * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space().
62 */
63 void smc_tx_sndbuf_nonfull(struct smc_sock *smc)
64 {
65 if (smc->sk.sk_socket &&
66 test_bit(SOCK_NOSPACE, &smc->sk.sk_socket->flags))
67 smc->sk.sk_write_space(&smc->sk);
68 }
69
70 /* blocks sndbuf producer until at least one byte of free space available
71 * or urgent Byte was consumed
72 */
73 static int smc_tx_wait(struct smc_sock *smc, int flags)
74 {
75 DEFINE_WAIT_FUNC(wait, woken_wake_function);
76 struct smc_connection *conn = &smc->conn;
77 struct sock *sk = &smc->sk;
78 bool noblock;
79 long timeo;
80 int rc = 0;
81
82 /* similar to sk_stream_wait_memory */
83 timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
84 noblock = timeo ? false : true;
85 add_wait_queue(sk_sleep(sk), &wait);
86 while (1) {
87 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
88 if (sk->sk_err ||
89 (sk->sk_shutdown & SEND_SHUTDOWN) ||
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 if (noblock)
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 sk->sk_err ||
114 (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
124 static 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 */
134 int 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->local_tx_ctrl.conn_state_flags.peer_conn_abort)
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 rc = smc_tx_wait(smc, msg->msg_flags);
169 if (rc) {
170 if (send_done)
171 return send_done;
172 goto out_err;
173 }
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_sge sges[])
271 {
272 struct smc_link_group *lgr = conn->lgr;
273 struct ib_rdma_wr rdma_wr;
274 struct smc_link *link;
275 int rc;
276
277 memset(&rdma_wr, 0, sizeof(rdma_wr));
278 link = &lgr->lnk[SMC_SINGLE_LINK];
279 rdma_wr.wr.wr_id = smc_wr_tx_get_next_wr_id(link);
280 rdma_wr.wr.sg_list = sges;
281 rdma_wr.wr.num_sge = num_sges;
282 rdma_wr.wr.opcode = IB_WR_RDMA_WRITE;
283 rdma_wr.remote_addr =
284 lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].dma_addr +
285 /* RMBE within RMB */
286 conn->tx_off +
287 /* offset within RMBE */
288 peer_rmbe_offset;
289 rdma_wr.rkey = lgr->rtokens[conn->rtoken_idx][SMC_SINGLE_LINK].rkey;
290 rc = ib_post_send(link->roce_qp, &rdma_wr.wr, NULL);
291 if (rc) {
292 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
293 smc_lgr_terminate(lgr);
294 }
295 return rc;
296 }
297
298 /* sndbuf consumer */
299 static inline void smc_tx_advance_cursors(struct smc_connection *conn,
300 union smc_host_cursor *prod,
301 union smc_host_cursor *sent,
302 size_t len)
303 {
304 smc_curs_add(conn->peer_rmbe_size, prod, len);
305 /* increased in recv tasklet smc_cdc_msg_rcv() */
306 smp_mb__before_atomic();
307 /* data in flight reduces usable snd_wnd */
308 atomic_sub(len, &conn->peer_rmbe_space);
309 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
310 smp_mb__after_atomic();
311 smc_curs_add(conn->sndbuf_desc->len, sent, len);
312 }
313
314 /* SMC-R helper for smc_tx_rdma_writes() */
315 static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len,
316 size_t src_off, size_t src_len,
317 size_t dst_off, size_t dst_len)
318 {
319 dma_addr_t dma_addr =
320 sg_dma_address(conn->sndbuf_desc->sgt[SMC_SINGLE_LINK].sgl);
321 struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
322 int src_len_sum = src_len, dst_len_sum = dst_len;
323 struct ib_sge sges[SMC_IB_MAX_SEND_SGE];
324 int sent_count = src_off;
325 int srcchunk, dstchunk;
326 int num_sges;
327 int rc;
328
329 for (dstchunk = 0; dstchunk < 2; dstchunk++) {
330 num_sges = 0;
331 for (srcchunk = 0; srcchunk < 2; srcchunk++) {
332 sges[srcchunk].addr = dma_addr + src_off;
333 sges[srcchunk].length = src_len;
334 sges[srcchunk].lkey = link->roce_pd->local_dma_lkey;
335 num_sges++;
336
337 src_off += src_len;
338 if (src_off >= conn->sndbuf_desc->len)
339 src_off -= conn->sndbuf_desc->len;
340 /* modulo in send ring */
341 if (src_len_sum == dst_len)
342 break; /* either on 1st or 2nd iteration */
343 /* prepare next (== 2nd) iteration */
344 src_len = dst_len - src_len; /* remainder */
345 src_len_sum += src_len;
346 }
347 rc = smc_tx_rdma_write(conn, dst_off, num_sges, sges);
348 if (rc)
349 return rc;
350 if (dst_len_sum == len)
351 break; /* either on 1st or 2nd iteration */
352 /* prepare next (== 2nd) iteration */
353 dst_off = 0; /* modulo offset in RMBE ring buffer */
354 dst_len = len - dst_len; /* remainder */
355 dst_len_sum += dst_len;
356 src_len = min_t(int, dst_len, conn->sndbuf_desc->len -
357 sent_count);
358 src_len_sum = src_len;
359 }
360 return 0;
361 }
362
363 /* SMC-D helper for smc_tx_rdma_writes() */
364 static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len,
365 size_t src_off, size_t src_len,
366 size_t dst_off, size_t dst_len)
367 {
368 int src_len_sum = src_len, dst_len_sum = dst_len;
369 int srcchunk, dstchunk;
370 int rc;
371
372 for (dstchunk = 0; dstchunk < 2; dstchunk++) {
373 for (srcchunk = 0; srcchunk < 2; srcchunk++) {
374 void *data = conn->sndbuf_desc->cpu_addr + src_off;
375
376 rc = smcd_tx_ism_write(conn, data, src_len, dst_off +
377 sizeof(struct smcd_cdc_msg), 0);
378 if (rc)
379 return rc;
380 dst_off += src_len;
381 src_off += src_len;
382 if (src_off >= conn->sndbuf_desc->len)
383 src_off -= conn->sndbuf_desc->len;
384 /* modulo in send ring */
385 if (src_len_sum == dst_len)
386 break; /* either on 1st or 2nd iteration */
387 /* prepare next (== 2nd) iteration */
388 src_len = dst_len - src_len; /* remainder */
389 src_len_sum += src_len;
390 }
391 if (dst_len_sum == len)
392 break; /* either on 1st or 2nd iteration */
393 /* prepare next (== 2nd) iteration */
394 dst_off = 0; /* modulo offset in RMBE ring buffer */
395 dst_len = len - dst_len; /* remainder */
396 dst_len_sum += dst_len;
397 src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off);
398 src_len_sum = src_len;
399 }
400 return 0;
401 }
402
403 /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit;
404 * usable snd_wnd as max transmit
405 */
406 static int smc_tx_rdma_writes(struct smc_connection *conn)
407 {
408 size_t len, src_len, dst_off, dst_len; /* current chunk values */
409 union smc_host_cursor sent, prep, prod, cons;
410 struct smc_cdc_producer_flags *pflags;
411 int to_send, rmbespace;
412 int rc;
413
414 /* source: sndbuf */
415 smc_curs_copy(&sent, &conn->tx_curs_sent, conn);
416 smc_curs_copy(&prep, &conn->tx_curs_prep, conn);
417 /* cf. wmem_alloc - (snd_max - snd_una) */
418 to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep);
419 if (to_send <= 0)
420 return 0;
421
422 /* destination: RMBE */
423 /* cf. snd_wnd */
424 rmbespace = atomic_read(&conn->peer_rmbe_space);
425 if (rmbespace <= 0)
426 return 0;
427 smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
428 smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
429
430 /* if usable snd_wnd closes ask peer to advertise once it opens again */
431 pflags = &conn->local_tx_ctrl.prod_flags;
432 pflags->write_blocked = (to_send >= rmbespace);
433 /* cf. usable snd_wnd */
434 len = min(to_send, rmbespace);
435
436 /* initialize variables for first iteration of subsequent nested loop */
437 dst_off = prod.count;
438 if (prod.wrap == cons.wrap) {
439 /* the filled destination area is unwrapped,
440 * hence the available free destination space is wrapped
441 * and we need 2 destination chunks of sum len; start with 1st
442 * which is limited by what's available in sndbuf
443 */
444 dst_len = min_t(size_t,
445 conn->peer_rmbe_size - prod.count, len);
446 } else {
447 /* the filled destination area is wrapped,
448 * hence the available free destination space is unwrapped
449 * and we need a single destination chunk of entire len
450 */
451 dst_len = len;
452 }
453 /* dst_len determines the maximum src_len */
454 if (sent.count + dst_len <= conn->sndbuf_desc->len) {
455 /* unwrapped src case: single chunk of entire dst_len */
456 src_len = dst_len;
457 } else {
458 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */
459 src_len = conn->sndbuf_desc->len - sent.count;
460 }
461
462 if (conn->lgr->is_smcd)
463 rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len,
464 dst_off, dst_len);
465 else
466 rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len,
467 dst_off, dst_len);
468 if (rc)
469 return rc;
470
471 if (conn->urg_tx_pend && len == to_send)
472 pflags->urg_data_present = 1;
473 smc_tx_advance_cursors(conn, &prod, &sent, len);
474 /* update connection's cursors with advanced local cursors */
475 smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn);
476 /* dst: peer RMBE */
477 smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */
478
479 return 0;
480 }
481
482 /* Wakeup sndbuf consumers from any context (IRQ or process)
483 * since there is more data to transmit; usable snd_wnd as max transmit
484 */
485 static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn)
486 {
487 struct smc_cdc_producer_flags *pflags;
488 struct smc_cdc_tx_pend *pend;
489 struct smc_wr_buf *wr_buf;
490 int rc;
491
492 spin_lock_bh(&conn->send_lock);
493 rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend);
494 if (rc < 0) {
495 if (rc == -EBUSY) {
496 struct smc_sock *smc =
497 container_of(conn, struct smc_sock, conn);
498
499 if (smc->sk.sk_err == ECONNABORTED) {
500 rc = sock_error(&smc->sk);
501 goto out_unlock;
502 }
503 rc = 0;
504 if (conn->alert_token_local) /* connection healthy */
505 mod_delayed_work(system_wq, &conn->tx_work,
506 SMC_TX_WORK_DELAY);
507 }
508 goto out_unlock;
509 }
510
511 if (!conn->local_tx_ctrl.prod_flags.urg_data_present) {
512 rc = smc_tx_rdma_writes(conn);
513 if (rc) {
514 smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK],
515 (struct smc_wr_tx_pend_priv *)pend);
516 goto out_unlock;
517 }
518 }
519
520 rc = smc_cdc_msg_send(conn, wr_buf, pend);
521 pflags = &conn->local_tx_ctrl.prod_flags;
522 if (!rc && pflags->urg_data_present) {
523 pflags->urg_data_pending = 0;
524 pflags->urg_data_present = 0;
525 }
526
527 out_unlock:
528 spin_unlock_bh(&conn->send_lock);
529 return rc;
530 }
531
532 static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn)
533 {
534 struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags;
535 int rc = 0;
536
537 spin_lock_bh(&conn->send_lock);
538 if (!pflags->urg_data_present)
539 rc = smc_tx_rdma_writes(conn);
540 if (!rc)
541 rc = smcd_cdc_msg_send(conn);
542
543 if (!rc && pflags->urg_data_present) {
544 pflags->urg_data_pending = 0;
545 pflags->urg_data_present = 0;
546 }
547 spin_unlock_bh(&conn->send_lock);
548 return rc;
549 }
550
551 int smc_tx_sndbuf_nonempty(struct smc_connection *conn)
552 {
553 int rc;
554
555 if (conn->lgr->is_smcd)
556 rc = smcd_tx_sndbuf_nonempty(conn);
557 else
558 rc = smcr_tx_sndbuf_nonempty(conn);
559
560 return rc;
561 }
562
563 /* Wakeup sndbuf consumers from process context
564 * since there is more data to transmit
565 */
566 void smc_tx_work(struct work_struct *work)
567 {
568 struct smc_connection *conn = container_of(to_delayed_work(work),
569 struct smc_connection,
570 tx_work);
571 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
572 int rc;
573
574 lock_sock(&smc->sk);
575 if (smc->sk.sk_err ||
576 !conn->alert_token_local ||
577 conn->local_rx_ctrl.conn_state_flags.peer_conn_abort)
578 goto out;
579
580 rc = smc_tx_sndbuf_nonempty(conn);
581 if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked &&
582 !atomic_read(&conn->bytes_to_rcv))
583 conn->local_rx_ctrl.prod_flags.write_blocked = 0;
584
585 out:
586 release_sock(&smc->sk);
587 }
588
589 void smc_tx_consumer_update(struct smc_connection *conn, bool force)
590 {
591 union smc_host_cursor cfed, cons, prod;
592 int sender_free = conn->rmb_desc->len;
593 int to_confirm;
594
595 smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
596 smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn);
597 to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons);
598 if (to_confirm > conn->rmbe_update_limit) {
599 smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn);
600 sender_free = conn->rmb_desc->len -
601 smc_curs_diff(conn->rmb_desc->len, &prod, &cfed);
602 }
603
604 if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
605 force ||
606 ((to_confirm > conn->rmbe_update_limit) &&
607 ((sender_free <= (conn->rmb_desc->len / 2)) ||
608 conn->local_rx_ctrl.prod_flags.write_blocked))) {
609 if ((smc_cdc_get_slot_and_msg_send(conn) < 0) &&
610 conn->alert_token_local) { /* connection healthy */
611 schedule_delayed_work(&conn->tx_work,
612 SMC_TX_WORK_DELAY);
613 return;
614 }
615 smc_curs_copy(&conn->rx_curs_confirmed,
616 &conn->local_tx_ctrl.cons, conn);
617 conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
618 }
619 if (conn->local_rx_ctrl.prod_flags.write_blocked &&
620 !atomic_read(&conn->bytes_to_rcv))
621 conn->local_rx_ctrl.prod_flags.write_blocked = 0;
622 }
623
624 /***************************** send initialize *******************************/
625
626 /* Initialize send properties on connection establishment. NB: not __init! */
627 void smc_tx_init(struct smc_sock *smc)
628 {
629 smc->sk.sk_write_space = smc_tx_write_space;
630 }
Linux with added FPC-III support