Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e6727f39 UB |
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> | |
c3edc401 IM |
19 | #include <linux/sched/signal.h> |
20 | ||
e6727f39 | 21 | #include <net/sock.h> |
01d2f7e2 | 22 | #include <net/tcp.h> |
e6727f39 UB |
23 | |
24 | #include "smc.h" | |
25 | #include "smc_wr.h" | |
26 | #include "smc_cdc.h" | |
5bc056d8 | 27 | #include "smc_close.h" |
be244f28 | 28 | #include "smc_ism.h" |
e6727f39 | 29 | #include "smc_tx.h" |
e0e4b8fa | 30 | #include "smc_stats.h" |
aff3083f | 31 | #include "smc_tracepoint.h" |
e6727f39 | 32 | |
16297d14 | 33 | #define SMC_TX_WORK_DELAY 0 |
18e537cd | 34 | |
e6727f39 UB |
35 | /***************************** sndbuf producer *******************************/ |
36 | ||
37 | /* callback implementation for sk.sk_write_space() | |
de8474eb | 38 | * to wakeup sndbuf producers that blocked with smc_tx_wait(). |
e6727f39 UB |
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) { | |
e0e4b8fa | 49 | if (test_bit(SOCK_NOSPACE, &sock->flags)) |
194730a9 | 50 | SMC_STAT_RMB_TX_FULL(smc, !smc->conn.lnk); |
e6727f39 UB |
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, | |
a9a08845 LT |
56 | EPOLLOUT | EPOLLWRNORM | |
57 | EPOLLWRBAND); | |
e6727f39 UB |
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 | ||
de8474eb | 64 | /* Wakeup sndbuf producers that blocked with smc_tx_wait(). |
e6727f39 UB |
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 | ||
de8474eb SR |
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) | |
e6727f39 UB |
78 | { |
79 | DEFINE_WAIT_FUNC(wait, woken_wake_function); | |
80 | struct smc_connection *conn = &smc->conn; | |
81 | struct sock *sk = &smc->sk; | |
e6727f39 UB |
82 | long timeo; |
83 | int rc = 0; | |
84 | ||
85 | /* similar to sk_stream_wait_memory */ | |
86 | timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
e6727f39 UB |
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) || | |
b2900980 | 92 | conn->killed || |
e6727f39 UB |
93 | conn->local_tx_ctrl.conn_state_flags.peer_done_writing) { |
94 | rc = -EPIPE; | |
95 | break; | |
96 | } | |
aa377e68 | 97 | if (smc_cdc_rxed_any_close(conn)) { |
e6727f39 UB |
98 | rc = -ECONNRESET; |
99 | break; | |
100 | } | |
101 | if (!timeo) { | |
4651d180 JB |
102 | /* ensure EPOLLOUT is subsequently generated */ |
103 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
e6727f39 UB |
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); | |
de8474eb SR |
112 | if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) |
113 | break; /* at least 1 byte of free & no urgent data */ | |
e6727f39 | 114 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
e6727f39 UB |
115 | sk_wait_event(sk, &timeo, |
116 | sk->sk_err || | |
117 | (sk->sk_shutdown & SEND_SHUTDOWN) || | |
aa377e68 | 118 | smc_cdc_rxed_any_close(conn) || |
de8474eb SR |
119 | (atomic_read(&conn->sndbuf_space) && |
120 | !conn->urg_tx_pend), | |
e6727f39 | 121 | &wait); |
e6727f39 UB |
122 | } |
123 | remove_wait_queue(sk_sleep(sk), &wait); | |
124 | return rc; | |
125 | } | |
126 | ||
01d2f7e2 UB |
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 | ||
dcd2cf5f DL |
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 | ||
ef739f1d JK |
150 | corking_size = min_t(unsigned int, conn->sndbuf_desc->len >> 1, |
151 | sock_net(&smc->sk)->smc.sysctl_autocorking_size); | |
dcd2cf5f DL |
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 | ||
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 | msg->msg_flags & MSG_SENDPAGE_NOTLAST) && | |
173 | atomic_read(&conn->sndbuf_space)) | |
174 | return true; | |
175 | ||
176 | return false; | |
177 | } | |
178 | ||
e6727f39 UB |
179 | /* sndbuf producer: main API called by socket layer. |
180 | * called under sock lock. | |
181 | */ | |
182 | int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) | |
183 | { | |
184 | size_t copylen, send_done = 0, send_remaining = len; | |
185 | size_t chunk_len, chunk_off, chunk_len_sum; | |
186 | struct smc_connection *conn = &smc->conn; | |
187 | union smc_host_cursor prep; | |
188 | struct sock *sk = &smc->sk; | |
189 | char *sndbuf_base; | |
190 | int tx_cnt_prep; | |
191 | int writespace; | |
192 | int rc, chunk; | |
193 | ||
194 | /* This should be in poll */ | |
195 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
196 | ||
197 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { | |
198 | rc = -EPIPE; | |
199 | goto out_err; | |
200 | } | |
201 | ||
17081633 GG |
202 | if (sk->sk_state == SMC_INIT) |
203 | return -ENOTCONN; | |
204 | ||
e0e4b8fa | 205 | if (len > conn->sndbuf_desc->len) |
194730a9 | 206 | SMC_STAT_RMB_TX_SIZE_SMALL(smc, !conn->lnk); |
e0e4b8fa GG |
207 | |
208 | if (len > conn->peer_rmbe_size) | |
194730a9 | 209 | SMC_STAT_RMB_TX_PEER_SIZE_SMALL(smc, !conn->lnk); |
e0e4b8fa GG |
210 | |
211 | if (msg->msg_flags & MSG_OOB) | |
194730a9 | 212 | SMC_STAT_INC(smc, urg_data_cnt); |
e0e4b8fa | 213 | |
e6727f39 | 214 | while (msg_data_left(msg)) { |
e6727f39 | 215 | if (smc->sk.sk_shutdown & SEND_SHUTDOWN || |
b38d7324 | 216 | (smc->sk.sk_err == ECONNABORTED) || |
b2900980 | 217 | conn->killed) |
e6727f39 UB |
218 | return -EPIPE; |
219 | if (smc_cdc_rxed_any_close(conn)) | |
220 | return send_done ?: -ECONNRESET; | |
221 | ||
de8474eb SR |
222 | if (msg->msg_flags & MSG_OOB) |
223 | conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; | |
224 | ||
225 | if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { | |
6889b36d KG |
226 | if (send_done) |
227 | return send_done; | |
de8474eb | 228 | rc = smc_tx_wait(smc, msg->msg_flags); |
6889b36d | 229 | if (rc) |
e6727f39 | 230 | goto out_err; |
e6727f39 UB |
231 | continue; |
232 | } | |
233 | ||
234 | /* initialize variables for 1st iteration of subsequent loop */ | |
de8474eb | 235 | /* could be just 1 byte, even after smc_tx_wait above */ |
e6727f39 UB |
236 | writespace = atomic_read(&conn->sndbuf_space); |
237 | /* not more than what user space asked for */ | |
238 | copylen = min_t(size_t, send_remaining, writespace); | |
239 | /* determine start of sndbuf */ | |
240 | sndbuf_base = conn->sndbuf_desc->cpu_addr; | |
bac6de7b | 241 | smc_curs_copy(&prep, &conn->tx_curs_prep, conn); |
e6727f39 UB |
242 | tx_cnt_prep = prep.count; |
243 | /* determine chunks where to write into sndbuf */ | |
244 | /* either unwrapped case, or 1st chunk of wrapped case */ | |
69cb7dc0 HW |
245 | chunk_len = min_t(size_t, copylen, conn->sndbuf_desc->len - |
246 | tx_cnt_prep); | |
e6727f39 UB |
247 | chunk_len_sum = chunk_len; |
248 | chunk_off = tx_cnt_prep; | |
10428dd8 | 249 | smc_sndbuf_sync_sg_for_cpu(conn); |
e6727f39 UB |
250 | for (chunk = 0; chunk < 2; chunk++) { |
251 | rc = memcpy_from_msg(sndbuf_base + chunk_off, | |
252 | msg, chunk_len); | |
253 | if (rc) { | |
10428dd8 | 254 | smc_sndbuf_sync_sg_for_device(conn); |
e6727f39 UB |
255 | if (send_done) |
256 | return send_done; | |
257 | goto out_err; | |
258 | } | |
259 | send_done += chunk_len; | |
260 | send_remaining -= chunk_len; | |
261 | ||
262 | if (chunk_len_sum == copylen) | |
263 | break; /* either on 1st or 2nd iteration */ | |
264 | /* prepare next (== 2nd) iteration */ | |
265 | chunk_len = copylen - chunk_len; /* remainder */ | |
266 | chunk_len_sum += chunk_len; | |
267 | chunk_off = 0; /* modulo offset in send ring buffer */ | |
268 | } | |
10428dd8 | 269 | smc_sndbuf_sync_sg_for_device(conn); |
e6727f39 | 270 | /* update cursors */ |
69cb7dc0 | 271 | smc_curs_add(conn->sndbuf_desc->len, &prep, copylen); |
bac6de7b | 272 | smc_curs_copy(&conn->tx_curs_prep, &prep, conn); |
e6727f39 UB |
273 | /* increased in send tasklet smc_cdc_tx_handler() */ |
274 | smp_mb__before_atomic(); | |
275 | atomic_sub(copylen, &conn->sndbuf_space); | |
69cb7dc0 | 276 | /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ |
e6727f39 UB |
277 | smp_mb__after_atomic(); |
278 | /* since we just produced more new data into sndbuf, | |
279 | * trigger sndbuf consumer: RDMA write into peer RMBE and CDC | |
280 | */ | |
de8474eb SR |
281 | if ((msg->msg_flags & MSG_OOB) && !send_remaining) |
282 | conn->urg_tx_pend = true; | |
dcd2cf5f DL |
283 | /* If we need to cork, do nothing and wait for the next |
284 | * sendmsg() call or push on tx completion | |
6900de50 | 285 | */ |
dcd2cf5f | 286 | if (!smc_tx_should_cork(smc, msg)) |
6900de50 | 287 | smc_tx_sndbuf_nonempty(conn); |
aff3083f TL |
288 | |
289 | trace_smc_tx_sendmsg(smc, copylen); | |
e6727f39 UB |
290 | } /* while (msg_data_left(msg)) */ |
291 | ||
292 | return send_done; | |
293 | ||
294 | out_err: | |
295 | rc = sk_stream_error(sk, msg->msg_flags, rc); | |
296 | /* make sure we wake any epoll edge trigger waiter */ | |
297 | if (unlikely(rc == -EAGAIN)) | |
298 | sk->sk_write_space(sk); | |
299 | return rc; | |
300 | } | |
301 | ||
be9a16cc TL |
302 | int smc_tx_sendpage(struct smc_sock *smc, struct page *page, int offset, |
303 | size_t size, int flags) | |
304 | { | |
305 | struct msghdr msg = {.msg_flags = flags}; | |
306 | char *kaddr = kmap(page); | |
307 | struct kvec iov; | |
308 | int rc; | |
309 | ||
310 | iov.iov_base = kaddr + offset; | |
311 | iov.iov_len = size; | |
312 | iov_iter_kvec(&msg.msg_iter, WRITE, &iov, 1, size); | |
313 | rc = smc_tx_sendmsg(smc, &msg, size); | |
314 | kunmap(page); | |
315 | return rc; | |
316 | } | |
317 | ||
e6727f39 UB |
318 | /***************************** sndbuf consumer *******************************/ |
319 | ||
be244f28 HW |
320 | /* sndbuf consumer: actual data transfer of one target chunk with ISM write */ |
321 | int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len, | |
322 | u32 offset, int signal) | |
323 | { | |
324 | struct smc_ism_position pos; | |
325 | int rc; | |
326 | ||
327 | memset(&pos, 0, sizeof(pos)); | |
328 | pos.token = conn->peer_token; | |
329 | pos.index = conn->peer_rmbe_idx; | |
330 | pos.offset = conn->tx_off + offset; | |
331 | pos.signal = signal; | |
332 | rc = smc_ism_write(conn->lgr->smcd, &pos, data, len); | |
333 | if (rc) | |
334 | conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; | |
335 | return rc; | |
336 | } | |
337 | ||
e6727f39 UB |
338 | /* sndbuf consumer: actual data transfer of one target chunk with RDMA write */ |
339 | static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset, | |
ad6f317f | 340 | int num_sges, struct ib_rdma_wr *rdma_wr) |
e6727f39 UB |
341 | { |
342 | struct smc_link_group *lgr = conn->lgr; | |
387707fd | 343 | struct smc_link *link = conn->lnk; |
e6727f39 UB |
344 | int rc; |
345 | ||
ad6f317f UB |
346 | rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link); |
347 | rdma_wr->wr.num_sge = num_sges; | |
348 | rdma_wr->remote_addr = | |
387707fd | 349 | lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr + |
e6727f39 | 350 | /* RMBE within RMB */ |
95d8d263 | 351 | conn->tx_off + |
e6727f39 UB |
352 | /* offset within RMBE */ |
353 | peer_rmbe_offset; | |
387707fd | 354 | rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey; |
ad6f317f | 355 | rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL); |
b2900980 | 356 | if (rc) |
87523930 | 357 | smcr_link_down_cond_sched(link); |
e6727f39 UB |
358 | return rc; |
359 | } | |
360 | ||
361 | /* sndbuf consumer */ | |
362 | static inline void smc_tx_advance_cursors(struct smc_connection *conn, | |
363 | union smc_host_cursor *prod, | |
364 | union smc_host_cursor *sent, | |
365 | size_t len) | |
366 | { | |
367 | smc_curs_add(conn->peer_rmbe_size, prod, len); | |
368 | /* increased in recv tasklet smc_cdc_msg_rcv() */ | |
369 | smp_mb__before_atomic(); | |
370 | /* data in flight reduces usable snd_wnd */ | |
371 | atomic_sub(len, &conn->peer_rmbe_space); | |
372 | /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ | |
373 | smp_mb__after_atomic(); | |
69cb7dc0 | 374 | smc_curs_add(conn->sndbuf_desc->len, sent, len); |
e6727f39 UB |
375 | } |
376 | ||
be244f28 HW |
377 | /* SMC-R helper for smc_tx_rdma_writes() */ |
378 | static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len, | |
379 | size_t src_off, size_t src_len, | |
ad6f317f UB |
380 | size_t dst_off, size_t dst_len, |
381 | struct smc_rdma_wr *wr_rdma_buf) | |
be244f28 | 382 | { |
387707fd KG |
383 | struct smc_link *link = conn->lnk; |
384 | ||
be244f28 | 385 | dma_addr_t dma_addr = |
387707fd | 386 | sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl); |
be244f28 | 387 | int src_len_sum = src_len, dst_len_sum = dst_len; |
be244f28 HW |
388 | int sent_count = src_off; |
389 | int srcchunk, dstchunk; | |
390 | int num_sges; | |
391 | int rc; | |
392 | ||
393 | for (dstchunk = 0; dstchunk < 2; dstchunk++) { | |
ad6f317f UB |
394 | struct ib_sge *sge = |
395 | wr_rdma_buf->wr_tx_rdma[dstchunk].wr.sg_list; | |
396 | ||
be244f28 HW |
397 | num_sges = 0; |
398 | for (srcchunk = 0; srcchunk < 2; srcchunk++) { | |
ad6f317f UB |
399 | sge[srcchunk].addr = dma_addr + src_off; |
400 | sge[srcchunk].length = src_len; | |
be244f28 HW |
401 | num_sges++; |
402 | ||
403 | src_off += src_len; | |
404 | if (src_off >= conn->sndbuf_desc->len) | |
405 | src_off -= conn->sndbuf_desc->len; | |
406 | /* modulo in send ring */ | |
407 | if (src_len_sum == dst_len) | |
408 | break; /* either on 1st or 2nd iteration */ | |
409 | /* prepare next (== 2nd) iteration */ | |
410 | src_len = dst_len - src_len; /* remainder */ | |
411 | src_len_sum += src_len; | |
412 | } | |
ad6f317f UB |
413 | rc = smc_tx_rdma_write(conn, dst_off, num_sges, |
414 | &wr_rdma_buf->wr_tx_rdma[dstchunk]); | |
be244f28 HW |
415 | if (rc) |
416 | return rc; | |
417 | if (dst_len_sum == len) | |
418 | break; /* either on 1st or 2nd iteration */ | |
419 | /* prepare next (== 2nd) iteration */ | |
420 | dst_off = 0; /* modulo offset in RMBE ring buffer */ | |
421 | dst_len = len - dst_len; /* remainder */ | |
422 | dst_len_sum += dst_len; | |
423 | src_len = min_t(int, dst_len, conn->sndbuf_desc->len - | |
424 | sent_count); | |
425 | src_len_sum = src_len; | |
426 | } | |
427 | return 0; | |
428 | } | |
429 | ||
430 | /* SMC-D helper for smc_tx_rdma_writes() */ | |
431 | static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, | |
432 | size_t src_off, size_t src_len, | |
433 | size_t dst_off, size_t dst_len) | |
434 | { | |
435 | int src_len_sum = src_len, dst_len_sum = dst_len; | |
436 | int srcchunk, dstchunk; | |
437 | int rc; | |
438 | ||
439 | for (dstchunk = 0; dstchunk < 2; dstchunk++) { | |
440 | for (srcchunk = 0; srcchunk < 2; srcchunk++) { | |
441 | void *data = conn->sndbuf_desc->cpu_addr + src_off; | |
442 | ||
443 | rc = smcd_tx_ism_write(conn, data, src_len, dst_off + | |
444 | sizeof(struct smcd_cdc_msg), 0); | |
445 | if (rc) | |
446 | return rc; | |
447 | dst_off += src_len; | |
448 | src_off += src_len; | |
449 | if (src_off >= conn->sndbuf_desc->len) | |
450 | src_off -= conn->sndbuf_desc->len; | |
451 | /* modulo in send ring */ | |
452 | if (src_len_sum == dst_len) | |
453 | break; /* either on 1st or 2nd iteration */ | |
454 | /* prepare next (== 2nd) iteration */ | |
455 | src_len = dst_len - src_len; /* remainder */ | |
456 | src_len_sum += src_len; | |
457 | } | |
458 | if (dst_len_sum == len) | |
459 | break; /* either on 1st or 2nd iteration */ | |
460 | /* prepare next (== 2nd) iteration */ | |
461 | dst_off = 0; /* modulo offset in RMBE ring buffer */ | |
462 | dst_len = len - dst_len; /* remainder */ | |
463 | dst_len_sum += dst_len; | |
464 | src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); | |
465 | src_len_sum = src_len; | |
466 | } | |
467 | return 0; | |
468 | } | |
469 | ||
e6727f39 UB |
470 | /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; |
471 | * usable snd_wnd as max transmit | |
472 | */ | |
ad6f317f UB |
473 | static int smc_tx_rdma_writes(struct smc_connection *conn, |
474 | struct smc_rdma_wr *wr_rdma_buf) | |
e6727f39 | 475 | { |
be244f28 | 476 | size_t len, src_len, dst_off, dst_len; /* current chunk values */ |
e6727f39 | 477 | union smc_host_cursor sent, prep, prod, cons; |
de8474eb | 478 | struct smc_cdc_producer_flags *pflags; |
e6727f39 | 479 | int to_send, rmbespace; |
e6727f39 UB |
480 | int rc; |
481 | ||
482 | /* source: sndbuf */ | |
bac6de7b SR |
483 | smc_curs_copy(&sent, &conn->tx_curs_sent, conn); |
484 | smc_curs_copy(&prep, &conn->tx_curs_prep, conn); | |
e6727f39 | 485 | /* cf. wmem_alloc - (snd_max - snd_una) */ |
69cb7dc0 | 486 | to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep); |
e6727f39 UB |
487 | if (to_send <= 0) |
488 | return 0; | |
489 | ||
490 | /* destination: RMBE */ | |
491 | /* cf. snd_wnd */ | |
492 | rmbespace = atomic_read(&conn->peer_rmbe_space); | |
e0e4b8fa | 493 | if (rmbespace <= 0) { |
194730a9 GG |
494 | struct smc_sock *smc = container_of(conn, struct smc_sock, |
495 | conn); | |
496 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); | |
e6727f39 | 497 | return 0; |
e0e4b8fa | 498 | } |
bac6de7b SR |
499 | smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn); |
500 | smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn); | |
e6727f39 UB |
501 | |
502 | /* if usable snd_wnd closes ask peer to advertise once it opens again */ | |
de8474eb SR |
503 | pflags = &conn->local_tx_ctrl.prod_flags; |
504 | pflags->write_blocked = (to_send >= rmbespace); | |
e6727f39 UB |
505 | /* cf. usable snd_wnd */ |
506 | len = min(to_send, rmbespace); | |
507 | ||
508 | /* initialize variables for first iteration of subsequent nested loop */ | |
e6727f39 UB |
509 | dst_off = prod.count; |
510 | if (prod.wrap == cons.wrap) { | |
511 | /* the filled destination area is unwrapped, | |
512 | * hence the available free destination space is wrapped | |
513 | * and we need 2 destination chunks of sum len; start with 1st | |
514 | * which is limited by what's available in sndbuf | |
515 | */ | |
516 | dst_len = min_t(size_t, | |
517 | conn->peer_rmbe_size - prod.count, len); | |
518 | } else { | |
519 | /* the filled destination area is wrapped, | |
520 | * hence the available free destination space is unwrapped | |
521 | * and we need a single destination chunk of entire len | |
522 | */ | |
523 | dst_len = len; | |
524 | } | |
e6727f39 | 525 | /* dst_len determines the maximum src_len */ |
69cb7dc0 | 526 | if (sent.count + dst_len <= conn->sndbuf_desc->len) { |
e6727f39 UB |
527 | /* unwrapped src case: single chunk of entire dst_len */ |
528 | src_len = dst_len; | |
529 | } else { | |
530 | /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ | |
69cb7dc0 | 531 | src_len = conn->sndbuf_desc->len - sent.count; |
e6727f39 | 532 | } |
be244f28 HW |
533 | |
534 | if (conn->lgr->is_smcd) | |
535 | rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len, | |
536 | dst_off, dst_len); | |
537 | else | |
538 | rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len, | |
ad6f317f | 539 | dst_off, dst_len, wr_rdma_buf); |
be244f28 HW |
540 | if (rc) |
541 | return rc; | |
e6727f39 | 542 | |
de8474eb SR |
543 | if (conn->urg_tx_pend && len == to_send) |
544 | pflags->urg_data_present = 1; | |
e6727f39 UB |
545 | smc_tx_advance_cursors(conn, &prod, &sent, len); |
546 | /* update connection's cursors with advanced local cursors */ | |
bac6de7b | 547 | smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn); |
e6727f39 | 548 | /* dst: peer RMBE */ |
bac6de7b | 549 | smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */ |
e6727f39 UB |
550 | |
551 | return 0; | |
552 | } | |
553 | ||
554 | /* Wakeup sndbuf consumers from any context (IRQ or process) | |
555 | * since there is more data to transmit; usable snd_wnd as max transmit | |
556 | */ | |
95f7f3e7 | 557 | static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) |
e6727f39 | 558 | { |
cecc7a31 | 559 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; |
c6f02ebe | 560 | struct smc_link *link = conn->lnk; |
ad6f317f | 561 | struct smc_rdma_wr *wr_rdma_buf; |
e6727f39 UB |
562 | struct smc_cdc_tx_pend *pend; |
563 | struct smc_wr_buf *wr_buf; | |
564 | int rc; | |
565 | ||
95f7f3e7 KG |
566 | if (!link || !smc_wr_tx_link_hold(link)) |
567 | return -ENOLINK; | |
c6f02ebe | 568 | rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend); |
e6727f39 | 569 | if (rc < 0) { |
95f7f3e7 | 570 | smc_wr_tx_link_put(link); |
e6727f39 | 571 | if (rc == -EBUSY) { |
b38d7324 UB |
572 | struct smc_sock *smc = |
573 | container_of(conn, struct smc_sock, conn); | |
574 | ||
33f3fcc2 KG |
575 | if (smc->sk.sk_err == ECONNABORTED) |
576 | return sock_error(&smc->sk); | |
b2900980 UB |
577 | if (conn->killed) |
578 | return -EPIPE; | |
e6727f39 | 579 | rc = 0; |
22ef473d | 580 | mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work, |
b2900980 | 581 | SMC_TX_WORK_DELAY); |
e6727f39 | 582 | } |
33f3fcc2 | 583 | return rc; |
e6727f39 UB |
584 | } |
585 | ||
33f3fcc2 | 586 | spin_lock_bh(&conn->send_lock); |
c6f02ebe KG |
587 | if (link != conn->lnk) { |
588 | /* link of connection changed, tx_work will restart */ | |
589 | smc_wr_tx_put_slot(link, | |
590 | (struct smc_wr_tx_pend_priv *)pend); | |
591 | rc = -ENOLINK; | |
592 | goto out_unlock; | |
593 | } | |
cecc7a31 | 594 | if (!pflags->urg_data_present) { |
ad6f317f | 595 | rc = smc_tx_rdma_writes(conn, wr_rdma_buf); |
de8474eb | 596 | if (rc) { |
c6f02ebe | 597 | smc_wr_tx_put_slot(link, |
de8474eb SR |
598 | (struct smc_wr_tx_pend_priv *)pend); |
599 | goto out_unlock; | |
600 | } | |
e6727f39 UB |
601 | } |
602 | ||
603 | rc = smc_cdc_msg_send(conn, wr_buf, pend); | |
de8474eb SR |
604 | if (!rc && pflags->urg_data_present) { |
605 | pflags->urg_data_pending = 0; | |
606 | pflags->urg_data_present = 0; | |
607 | } | |
e6727f39 UB |
608 | |
609 | out_unlock: | |
610 | spin_unlock_bh(&conn->send_lock); | |
95f7f3e7 | 611 | smc_wr_tx_link_put(link); |
8f3d65c1 KG |
612 | return rc; |
613 | } | |
614 | ||
be244f28 HW |
615 | static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) |
616 | { | |
617 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; | |
618 | int rc = 0; | |
619 | ||
620 | spin_lock_bh(&conn->send_lock); | |
621 | if (!pflags->urg_data_present) | |
ad6f317f | 622 | rc = smc_tx_rdma_writes(conn, NULL); |
be244f28 HW |
623 | if (!rc) |
624 | rc = smcd_cdc_msg_send(conn); | |
625 | ||
626 | if (!rc && pflags->urg_data_present) { | |
627 | pflags->urg_data_pending = 0; | |
628 | pflags->urg_data_present = 0; | |
629 | } | |
630 | spin_unlock_bh(&conn->send_lock); | |
631 | return rc; | |
632 | } | |
633 | ||
dcd2cf5f | 634 | static int __smc_tx_sndbuf_nonempty(struct smc_connection *conn) |
be244f28 | 635 | { |
dcd2cf5f DL |
636 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
637 | int rc = 0; | |
638 | ||
639 | /* No data in the send queue */ | |
640 | if (unlikely(smc_tx_prepared_sends(conn) <= 0)) | |
641 | goto out; | |
642 | ||
643 | /* Peer don't have RMBE space */ | |
644 | if (unlikely(atomic_read(&conn->peer_rmbe_space) <= 0)) { | |
645 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); | |
646 | goto out; | |
647 | } | |
be244f28 | 648 | |
b2900980 | 649 | if (conn->killed || |
dcd2cf5f DL |
650 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { |
651 | rc = -EPIPE; /* connection being aborted */ | |
652 | goto out; | |
653 | } | |
be244f28 HW |
654 | if (conn->lgr->is_smcd) |
655 | rc = smcd_tx_sndbuf_nonempty(conn); | |
656 | else | |
657 | rc = smcr_tx_sndbuf_nonempty(conn); | |
658 | ||
5bc056d8 KG |
659 | if (!rc) { |
660 | /* trigger socket release if connection is closing */ | |
5bc056d8 KG |
661 | smc_close_wake_tx_prepared(smc); |
662 | } | |
dcd2cf5f DL |
663 | |
664 | out: | |
665 | return rc; | |
666 | } | |
667 | ||
668 | int smc_tx_sndbuf_nonempty(struct smc_connection *conn) | |
669 | { | |
670 | int rc; | |
671 | ||
672 | /* This make sure only one can send simultaneously to prevent wasting | |
673 | * of CPU and CDC slot. | |
674 | * Record whether someone has tried to push while we are pushing. | |
675 | */ | |
676 | if (atomic_inc_return(&conn->tx_pushing) > 1) | |
677 | return 0; | |
678 | ||
679 | again: | |
680 | atomic_set(&conn->tx_pushing, 1); | |
681 | smp_wmb(); /* Make sure tx_pushing is 1 before real send */ | |
682 | rc = __smc_tx_sndbuf_nonempty(conn); | |
683 | ||
684 | /* We need to check whether someone else have added some data into | |
685 | * the send queue and tried to push but failed after the atomic_set() | |
686 | * when we are pushing. | |
687 | * If so, we need to push again to prevent those data hang in the send | |
688 | * queue. | |
689 | */ | |
690 | if (unlikely(!atomic_dec_and_test(&conn->tx_pushing))) | |
691 | goto again; | |
692 | ||
be244f28 HW |
693 | return rc; |
694 | } | |
695 | ||
2e13bde1 TL |
696 | /* Wakeup sndbuf consumers from process context |
697 | * since there is more data to transmit. The caller | |
698 | * must hold sock lock. | |
699 | */ | |
ea785a1a | 700 | void smc_tx_pending(struct smc_connection *conn) |
e6727f39 | 701 | { |
e6727f39 | 702 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
90cacb2e | 703 | int rc; |
e6727f39 | 704 | |
b2900980 | 705 | if (smc->sk.sk_err) |
ea785a1a | 706 | return; |
1a0a04c7 | 707 | |
90cacb2e UB |
708 | rc = smc_tx_sndbuf_nonempty(conn); |
709 | if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && | |
710 | !atomic_read(&conn->bytes_to_rcv)) | |
711 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; | |
ea785a1a TL |
712 | } |
713 | ||
714 | /* Wakeup sndbuf consumers from process context | |
2e13bde1 TL |
715 | * since there is more data to transmit in locked |
716 | * sock. | |
ea785a1a TL |
717 | */ |
718 | void smc_tx_work(struct work_struct *work) | |
719 | { | |
720 | struct smc_connection *conn = container_of(to_delayed_work(work), | |
721 | struct smc_connection, | |
722 | tx_work); | |
723 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); | |
1a0a04c7 | 724 | |
ea785a1a TL |
725 | lock_sock(&smc->sk); |
726 | smc_tx_pending(conn); | |
e6727f39 UB |
727 | release_sock(&smc->sk); |
728 | } | |
729 | ||
de8474eb | 730 | void smc_tx_consumer_update(struct smc_connection *conn, bool force) |
952310cc | 731 | { |
99be51f1 UB |
732 | union smc_host_cursor cfed, cons, prod; |
733 | int sender_free = conn->rmb_desc->len; | |
6b5771aa | 734 | int to_confirm; |
952310cc | 735 | |
bac6de7b SR |
736 | smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn); |
737 | smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn); | |
69cb7dc0 | 738 | to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); |
99be51f1 | 739 | if (to_confirm > conn->rmbe_update_limit) { |
bac6de7b | 740 | smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); |
99be51f1 | 741 | sender_free = conn->rmb_desc->len - |
b8649efa UB |
742 | smc_curs_diff_large(conn->rmb_desc->len, |
743 | &cfed, &prod); | |
99be51f1 | 744 | } |
952310cc UB |
745 | |
746 | if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || | |
de8474eb | 747 | force || |
952310cc | 748 | ((to_confirm > conn->rmbe_update_limit) && |
99be51f1 | 749 | ((sender_free <= (conn->rmb_desc->len / 2)) || |
952310cc | 750 | conn->local_rx_ctrl.prod_flags.write_blocked))) { |
b2900980 UB |
751 | if (conn->killed || |
752 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) | |
753 | return; | |
1a0a04c7 | 754 | if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && |
b2900980 | 755 | !conn->killed) { |
22ef473d KG |
756 | queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, |
757 | SMC_TX_WORK_DELAY); | |
952310cc UB |
758 | return; |
759 | } | |
952310cc UB |
760 | } |
761 | if (conn->local_rx_ctrl.prod_flags.write_blocked && | |
762 | !atomic_read(&conn->bytes_to_rcv)) | |
763 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; | |
764 | } | |
765 | ||
e6727f39 UB |
766 | /***************************** send initialize *******************************/ |
767 | ||
768 | /* Initialize send properties on connection establishment. NB: not __init! */ | |
769 | void smc_tx_init(struct smc_sock *smc) | |
770 | { | |
771 | smc->sk.sk_write_space = smc_tx_write_space; | |
e6727f39 | 772 | } |