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 | #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 | */ |
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(v: &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, addr: &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(sk_wq: wq, how: 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, noblock: flags & MSG_DONTWAIT); |
87 | add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &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, addr: &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(v: &conn->sndbuf_space) && !conn->urg_tx_pend) |
113 | break; /* at least 1 byte of free & no urgent data */ |
114 | set_bit(SOCK_NOSPACE, addr: &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(wq_head: sk_sleep(sk), wq_entry: &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 | /* 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 | */ |
145 | static 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(v: &conn->cdc_pend_tx_wr) == 0 || |
154 | smc_tx_prepared_sends(conn) > corking_size) |
155 | return false; |
156 | return true; |
157 | } |
158 | |
159 | static 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(v: &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 | */ |
181 | int 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(v: &conn->sndbuf_space) || conn->urg_tx_pend) { |
225 | if (send_done) |
226 | return send_done; |
227 | rc = smc_tx_wait(smc, flags: 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(v: &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(tgt: &prep, src: &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(data: sndbuf_base + chunk_off, |
250 | msg, len: 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(size: conn->sndbuf_desc->len, curs: &prep, value: copylen); |
270 | smc_curs_copy(tgt: &conn->tx_curs_prep, src: &prep, conn); |
271 | /* increased in send tasklet smc_cdc_tx_handler() */ |
272 | smp_mb__before_atomic(); |
273 | atomic_sub(i: copylen, v: &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, len: copylen); |
288 | } /* while (msg_data_left(msg)) */ |
289 | |
290 | return send_done; |
291 | |
292 | out_err: |
293 | rc = sk_stream_error(sk, flags: msg->msg_flags, err: 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 */ |
303 | int 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(smcd: conn->lgr->smcd, dmb_tok: conn->peer_token, |
309 | idx: conn->peer_rmbe_idx, sf: signal, offset: 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 */ |
317 | static 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(qp: link->roce_qp, send_wr: &rdma_wr->wr, NULL); |
334 | if (rc) |
335 | smcr_link_down_cond_sched(lnk: link); |
336 | return rc; |
337 | } |
338 | |
339 | /* sndbuf consumer */ |
340 | static 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(size: conn->peer_rmbe_size, curs: prod, value: 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(i: len, v: &conn->peer_rmbe_space); |
350 | /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ |
351 | smp_mb__after_atomic(); |
352 | smc_curs_add(size: conn->sndbuf_desc->len, curs: sent, value: len); |
353 | } |
354 | |
355 | /* SMC-R helper for smc_tx_rdma_writes() */ |
356 | static 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, peer_rmbe_offset: dst_off, num_sges, rdma_wr: 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() */ |
421 | static 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 | for (dstchunk = 0; dstchunk < 2; dstchunk++) { |
430 | for (srcchunk = 0; srcchunk < 2; srcchunk++) { |
431 | void *data = conn->sndbuf_desc->cpu_addr + src_off; |
432 | |
433 | rc = smcd_tx_ism_write(conn, data, len: src_len, offset: dst_off + |
434 | sizeof(struct smcd_cdc_msg), signal: 0); |
435 | if (rc) |
436 | return rc; |
437 | dst_off += src_len; |
438 | src_off += src_len; |
439 | if (src_off >= conn->sndbuf_desc->len) |
440 | src_off -= conn->sndbuf_desc->len; |
441 | /* modulo in send ring */ |
442 | if (src_len_sum == dst_len) |
443 | break; /* either on 1st or 2nd iteration */ |
444 | /* prepare next (== 2nd) iteration */ |
445 | src_len = dst_len - src_len; /* remainder */ |
446 | src_len_sum += src_len; |
447 | } |
448 | if (dst_len_sum == len) |
449 | break; /* either on 1st or 2nd iteration */ |
450 | /* prepare next (== 2nd) iteration */ |
451 | dst_off = 0; /* modulo offset in RMBE ring buffer */ |
452 | dst_len = len - dst_len; /* remainder */ |
453 | dst_len_sum += dst_len; |
454 | src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); |
455 | src_len_sum = src_len; |
456 | } |
457 | return 0; |
458 | } |
459 | |
460 | /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; |
461 | * usable snd_wnd as max transmit |
462 | */ |
463 | static int smc_tx_rdma_writes(struct smc_connection *conn, |
464 | struct smc_rdma_wr *wr_rdma_buf) |
465 | { |
466 | size_t len, src_len, dst_off, dst_len; /* current chunk values */ |
467 | union smc_host_cursor sent, prep, prod, cons; |
468 | struct smc_cdc_producer_flags *pflags; |
469 | int to_send, rmbespace; |
470 | int rc; |
471 | |
472 | /* source: sndbuf */ |
473 | smc_curs_copy(tgt: &sent, src: &conn->tx_curs_sent, conn); |
474 | smc_curs_copy(tgt: &prep, src: &conn->tx_curs_prep, conn); |
475 | /* cf. wmem_alloc - (snd_max - snd_una) */ |
476 | to_send = smc_curs_diff(size: conn->sndbuf_desc->len, old: &sent, new: &prep); |
477 | if (to_send <= 0) |
478 | return 0; |
479 | |
480 | /* destination: RMBE */ |
481 | /* cf. snd_wnd */ |
482 | rmbespace = atomic_read(v: &conn->peer_rmbe_space); |
483 | if (rmbespace <= 0) { |
484 | struct smc_sock *smc = container_of(conn, struct smc_sock, |
485 | conn); |
486 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); |
487 | return 0; |
488 | } |
489 | smc_curs_copy(tgt: &prod, src: &conn->local_tx_ctrl.prod, conn); |
490 | smc_curs_copy(tgt: &cons, src: &conn->local_rx_ctrl.cons, conn); |
491 | |
492 | /* if usable snd_wnd closes ask peer to advertise once it opens again */ |
493 | pflags = &conn->local_tx_ctrl.prod_flags; |
494 | pflags->write_blocked = (to_send >= rmbespace); |
495 | /* cf. usable snd_wnd */ |
496 | len = min(to_send, rmbespace); |
497 | |
498 | /* initialize variables for first iteration of subsequent nested loop */ |
499 | dst_off = prod.count; |
500 | if (prod.wrap == cons.wrap) { |
501 | /* the filled destination area is unwrapped, |
502 | * hence the available free destination space is wrapped |
503 | * and we need 2 destination chunks of sum len; start with 1st |
504 | * which is limited by what's available in sndbuf |
505 | */ |
506 | dst_len = min_t(size_t, |
507 | conn->peer_rmbe_size - prod.count, len); |
508 | } else { |
509 | /* the filled destination area is wrapped, |
510 | * hence the available free destination space is unwrapped |
511 | * and we need a single destination chunk of entire len |
512 | */ |
513 | dst_len = len; |
514 | } |
515 | /* dst_len determines the maximum src_len */ |
516 | if (sent.count + dst_len <= conn->sndbuf_desc->len) { |
517 | /* unwrapped src case: single chunk of entire dst_len */ |
518 | src_len = dst_len; |
519 | } else { |
520 | /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ |
521 | src_len = conn->sndbuf_desc->len - sent.count; |
522 | } |
523 | |
524 | if (conn->lgr->is_smcd) |
525 | rc = smcd_tx_rdma_writes(conn, len, src_off: sent.count, src_len, |
526 | dst_off, dst_len); |
527 | else |
528 | rc = smcr_tx_rdma_writes(conn, len, src_off: sent.count, src_len, |
529 | dst_off, dst_len, wr_rdma_buf); |
530 | if (rc) |
531 | return rc; |
532 | |
533 | if (conn->urg_tx_pend && len == to_send) |
534 | pflags->urg_data_present = 1; |
535 | smc_tx_advance_cursors(conn, prod: &prod, sent: &sent, len); |
536 | /* update connection's cursors with advanced local cursors */ |
537 | smc_curs_copy(tgt: &conn->local_tx_ctrl.prod, src: &prod, conn); |
538 | /* dst: peer RMBE */ |
539 | smc_curs_copy(tgt: &conn->tx_curs_sent, src: &sent, conn);/* src: local sndbuf */ |
540 | |
541 | return 0; |
542 | } |
543 | |
544 | /* Wakeup sndbuf consumers from any context (IRQ or process) |
545 | * since there is more data to transmit; usable snd_wnd as max transmit |
546 | */ |
547 | static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) |
548 | { |
549 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; |
550 | struct smc_link *link = conn->lnk; |
551 | struct smc_rdma_wr *wr_rdma_buf; |
552 | struct smc_cdc_tx_pend *pend; |
553 | struct smc_wr_buf *wr_buf; |
554 | int rc; |
555 | |
556 | if (!link || !smc_wr_tx_link_hold(link)) |
557 | return -ENOLINK; |
558 | rc = smc_cdc_get_free_slot(conn, link, wr_buf: &wr_buf, wr_rdma_buf: &wr_rdma_buf, pend: &pend); |
559 | if (rc < 0) { |
560 | smc_wr_tx_link_put(link); |
561 | if (rc == -EBUSY) { |
562 | struct smc_sock *smc = |
563 | container_of(conn, struct smc_sock, conn); |
564 | |
565 | if (smc->sk.sk_err == ECONNABORTED) |
566 | return sock_error(sk: &smc->sk); |
567 | if (conn->killed) |
568 | return -EPIPE; |
569 | rc = 0; |
570 | mod_delayed_work(wq: conn->lgr->tx_wq, dwork: &conn->tx_work, |
571 | SMC_TX_WORK_DELAY); |
572 | } |
573 | return rc; |
574 | } |
575 | |
576 | spin_lock_bh(lock: &conn->send_lock); |
577 | if (link != conn->lnk) { |
578 | /* link of connection changed, tx_work will restart */ |
579 | smc_wr_tx_put_slot(link, |
580 | wr_pend_priv: (struct smc_wr_tx_pend_priv *)pend); |
581 | rc = -ENOLINK; |
582 | goto out_unlock; |
583 | } |
584 | if (!pflags->urg_data_present) { |
585 | rc = smc_tx_rdma_writes(conn, wr_rdma_buf); |
586 | if (rc) { |
587 | smc_wr_tx_put_slot(link, |
588 | wr_pend_priv: (struct smc_wr_tx_pend_priv *)pend); |
589 | goto out_unlock; |
590 | } |
591 | } |
592 | |
593 | rc = smc_cdc_msg_send(conn, wr_buf, pend); |
594 | if (!rc && pflags->urg_data_present) { |
595 | pflags->urg_data_pending = 0; |
596 | pflags->urg_data_present = 0; |
597 | } |
598 | |
599 | out_unlock: |
600 | spin_unlock_bh(lock: &conn->send_lock); |
601 | smc_wr_tx_link_put(link); |
602 | return rc; |
603 | } |
604 | |
605 | static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) |
606 | { |
607 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; |
608 | int rc = 0; |
609 | |
610 | spin_lock_bh(lock: &conn->send_lock); |
611 | if (!pflags->urg_data_present) |
612 | rc = smc_tx_rdma_writes(conn, NULL); |
613 | if (!rc) |
614 | rc = smcd_cdc_msg_send(conn); |
615 | |
616 | if (!rc && pflags->urg_data_present) { |
617 | pflags->urg_data_pending = 0; |
618 | pflags->urg_data_present = 0; |
619 | } |
620 | spin_unlock_bh(lock: &conn->send_lock); |
621 | return rc; |
622 | } |
623 | |
624 | static int __smc_tx_sndbuf_nonempty(struct smc_connection *conn) |
625 | { |
626 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
627 | int rc = 0; |
628 | |
629 | /* No data in the send queue */ |
630 | if (unlikely(smc_tx_prepared_sends(conn) <= 0)) |
631 | goto out; |
632 | |
633 | /* Peer don't have RMBE space */ |
634 | if (unlikely(atomic_read(&conn->peer_rmbe_space) <= 0)) { |
635 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); |
636 | goto out; |
637 | } |
638 | |
639 | if (conn->killed || |
640 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { |
641 | rc = -EPIPE; /* connection being aborted */ |
642 | goto out; |
643 | } |
644 | if (conn->lgr->is_smcd) |
645 | rc = smcd_tx_sndbuf_nonempty(conn); |
646 | else |
647 | rc = smcr_tx_sndbuf_nonempty(conn); |
648 | |
649 | if (!rc) { |
650 | /* trigger socket release if connection is closing */ |
651 | smc_close_wake_tx_prepared(smc); |
652 | } |
653 | |
654 | out: |
655 | return rc; |
656 | } |
657 | |
658 | int smc_tx_sndbuf_nonempty(struct smc_connection *conn) |
659 | { |
660 | int rc; |
661 | |
662 | /* This make sure only one can send simultaneously to prevent wasting |
663 | * of CPU and CDC slot. |
664 | * Record whether someone has tried to push while we are pushing. |
665 | */ |
666 | if (atomic_inc_return(v: &conn->tx_pushing) > 1) |
667 | return 0; |
668 | |
669 | again: |
670 | atomic_set(v: &conn->tx_pushing, i: 1); |
671 | smp_wmb(); /* Make sure tx_pushing is 1 before real send */ |
672 | rc = __smc_tx_sndbuf_nonempty(conn); |
673 | |
674 | /* We need to check whether someone else have added some data into |
675 | * the send queue and tried to push but failed after the atomic_set() |
676 | * when we are pushing. |
677 | * If so, we need to push again to prevent those data hang in the send |
678 | * queue. |
679 | */ |
680 | if (unlikely(!atomic_dec_and_test(&conn->tx_pushing))) |
681 | goto again; |
682 | |
683 | return rc; |
684 | } |
685 | |
686 | /* Wakeup sndbuf consumers from process context |
687 | * since there is more data to transmit. The caller |
688 | * must hold sock lock. |
689 | */ |
690 | void smc_tx_pending(struct smc_connection *conn) |
691 | { |
692 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
693 | int rc; |
694 | |
695 | if (smc->sk.sk_err) |
696 | return; |
697 | |
698 | rc = smc_tx_sndbuf_nonempty(conn); |
699 | if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && |
700 | !atomic_read(v: &conn->bytes_to_rcv)) |
701 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; |
702 | } |
703 | |
704 | /* Wakeup sndbuf consumers from process context |
705 | * since there is more data to transmit in locked |
706 | * sock. |
707 | */ |
708 | void smc_tx_work(struct work_struct *work) |
709 | { |
710 | struct smc_connection *conn = container_of(to_delayed_work(work), |
711 | struct smc_connection, |
712 | tx_work); |
713 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
714 | |
715 | lock_sock(sk: &smc->sk); |
716 | smc_tx_pending(conn); |
717 | release_sock(sk: &smc->sk); |
718 | } |
719 | |
720 | void smc_tx_consumer_update(struct smc_connection *conn, bool force) |
721 | { |
722 | union smc_host_cursor cfed, cons, prod; |
723 | int sender_free = conn->rmb_desc->len; |
724 | int to_confirm; |
725 | |
726 | smc_curs_copy(tgt: &cons, src: &conn->local_tx_ctrl.cons, conn); |
727 | smc_curs_copy(tgt: &cfed, src: &conn->rx_curs_confirmed, conn); |
728 | to_confirm = smc_curs_diff(size: conn->rmb_desc->len, old: &cfed, new: &cons); |
729 | if (to_confirm > conn->rmbe_update_limit) { |
730 | smc_curs_copy(tgt: &prod, src: &conn->local_rx_ctrl.prod, conn); |
731 | sender_free = conn->rmb_desc->len - |
732 | smc_curs_diff_large(size: conn->rmb_desc->len, |
733 | old: &cfed, new: &prod); |
734 | } |
735 | |
736 | if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || |
737 | force || |
738 | ((to_confirm > conn->rmbe_update_limit) && |
739 | ((sender_free <= (conn->rmb_desc->len / 2)) || |
740 | conn->local_rx_ctrl.prod_flags.write_blocked))) { |
741 | if (conn->killed || |
742 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) |
743 | return; |
744 | if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && |
745 | !conn->killed) { |
746 | queue_delayed_work(wq: conn->lgr->tx_wq, dwork: &conn->tx_work, |
747 | SMC_TX_WORK_DELAY); |
748 | return; |
749 | } |
750 | } |
751 | if (conn->local_rx_ctrl.prod_flags.write_blocked && |
752 | !atomic_read(v: &conn->bytes_to_rcv)) |
753 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; |
754 | } |
755 | |
756 | /***************************** send initialize *******************************/ |
757 | |
758 | /* Initialize send properties on connection establishment. NB: not __init! */ |
759 | void smc_tx_init(struct smc_sock *smc) |
760 | { |
761 | smc->sk.sk_write_space = smc_tx_write_space; |
762 | } |
763 | |