Commit | Line | Data |
---|---|---|
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 | 115 | sk_wait_event(sk, &timeo, |
d0ac89f6 ED |
116 | READ_ONCE(sk->sk_err) || |
117 | (READ_ONCE(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; | |
249 | for (chunk = 0; chunk < 2; chunk++) { | |
250 | rc = memcpy_from_msg(sndbuf_base + chunk_off, | |
251 | msg, chunk_len); | |
252 | if (rc) { | |
10428dd8 | 253 | smc_sndbuf_sync_sg_for_device(conn); |
e6727f39 UB |
254 | if (send_done) |
255 | return send_done; | |
256 | goto out_err; | |
257 | } | |
258 | send_done += chunk_len; | |
259 | send_remaining -= chunk_len; | |
260 | ||
261 | if (chunk_len_sum == copylen) | |
262 | break; /* either on 1st or 2nd iteration */ | |
263 | /* prepare next (== 2nd) iteration */ | |
264 | chunk_len = copylen - chunk_len; /* remainder */ | |
265 | chunk_len_sum += chunk_len; | |
266 | chunk_off = 0; /* modulo offset in send ring buffer */ | |
267 | } | |
10428dd8 | 268 | smc_sndbuf_sync_sg_for_device(conn); |
e6727f39 | 269 | /* update cursors */ |
69cb7dc0 | 270 | smc_curs_add(conn->sndbuf_desc->len, &prep, copylen); |
bac6de7b | 271 | smc_curs_copy(&conn->tx_curs_prep, &prep, conn); |
e6727f39 UB |
272 | /* increased in send tasklet smc_cdc_tx_handler() */ |
273 | smp_mb__before_atomic(); | |
274 | atomic_sub(copylen, &conn->sndbuf_space); | |
69cb7dc0 | 275 | /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ |
e6727f39 UB |
276 | smp_mb__after_atomic(); |
277 | /* since we just produced more new data into sndbuf, | |
278 | * trigger sndbuf consumer: RDMA write into peer RMBE and CDC | |
279 | */ | |
de8474eb SR |
280 | if ((msg->msg_flags & MSG_OOB) && !send_remaining) |
281 | conn->urg_tx_pend = true; | |
dcd2cf5f DL |
282 | /* If we need to cork, do nothing and wait for the next |
283 | * sendmsg() call or push on tx completion | |
6900de50 | 284 | */ |
dcd2cf5f | 285 | if (!smc_tx_should_cork(smc, msg)) |
6900de50 | 286 | smc_tx_sndbuf_nonempty(conn); |
aff3083f TL |
287 | |
288 | trace_smc_tx_sendmsg(smc, copylen); | |
e6727f39 UB |
289 | } /* while (msg_data_left(msg)) */ |
290 | ||
291 | return send_done; | |
292 | ||
293 | out_err: | |
294 | rc = sk_stream_error(sk, msg->msg_flags, rc); | |
295 | /* make sure we wake any epoll edge trigger waiter */ | |
296 | if (unlikely(rc == -EAGAIN)) | |
297 | sk->sk_write_space(sk); | |
298 | return rc; | |
299 | } | |
300 | ||
be9a16cc TL |
301 | int smc_tx_sendpage(struct smc_sock *smc, struct page *page, int offset, |
302 | size_t size, int flags) | |
303 | { | |
304 | struct msghdr msg = {.msg_flags = flags}; | |
305 | char *kaddr = kmap(page); | |
306 | struct kvec iov; | |
307 | int rc; | |
308 | ||
309 | iov.iov_base = kaddr + offset; | |
310 | iov.iov_len = size; | |
de4eda9d | 311 | iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, size); |
be9a16cc TL |
312 | rc = smc_tx_sendmsg(smc, &msg, size); |
313 | kunmap(page); | |
314 | return rc; | |
315 | } | |
316 | ||
e6727f39 UB |
317 | /***************************** sndbuf consumer *******************************/ |
318 | ||
be244f28 HW |
319 | /* sndbuf consumer: actual data transfer of one target chunk with ISM write */ |
320 | int smcd_tx_ism_write(struct smc_connection *conn, void *data, size_t len, | |
321 | u32 offset, int signal) | |
322 | { | |
be244f28 HW |
323 | int rc; |
324 | ||
eb481b02 HC |
325 | rc = smc_ism_write(conn->lgr->smcd, conn->peer_token, |
326 | conn->peer_rmbe_idx, signal, conn->tx_off + offset, | |
327 | data, len); | |
be244f28 HW |
328 | if (rc) |
329 | conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; | |
330 | return rc; | |
331 | } | |
332 | ||
e6727f39 UB |
333 | /* sndbuf consumer: actual data transfer of one target chunk with RDMA write */ |
334 | static int smc_tx_rdma_write(struct smc_connection *conn, int peer_rmbe_offset, | |
ad6f317f | 335 | int num_sges, struct ib_rdma_wr *rdma_wr) |
e6727f39 UB |
336 | { |
337 | struct smc_link_group *lgr = conn->lgr; | |
387707fd | 338 | struct smc_link *link = conn->lnk; |
e6727f39 UB |
339 | int rc; |
340 | ||
ad6f317f UB |
341 | rdma_wr->wr.wr_id = smc_wr_tx_get_next_wr_id(link); |
342 | rdma_wr->wr.num_sge = num_sges; | |
343 | rdma_wr->remote_addr = | |
387707fd | 344 | lgr->rtokens[conn->rtoken_idx][link->link_idx].dma_addr + |
e6727f39 | 345 | /* RMBE within RMB */ |
95d8d263 | 346 | conn->tx_off + |
e6727f39 UB |
347 | /* offset within RMBE */ |
348 | peer_rmbe_offset; | |
387707fd | 349 | rdma_wr->rkey = lgr->rtokens[conn->rtoken_idx][link->link_idx].rkey; |
ad6f317f | 350 | rc = ib_post_send(link->roce_qp, &rdma_wr->wr, NULL); |
b2900980 | 351 | if (rc) |
87523930 | 352 | smcr_link_down_cond_sched(link); |
e6727f39 UB |
353 | return rc; |
354 | } | |
355 | ||
356 | /* sndbuf consumer */ | |
357 | static inline void smc_tx_advance_cursors(struct smc_connection *conn, | |
358 | union smc_host_cursor *prod, | |
359 | union smc_host_cursor *sent, | |
360 | size_t len) | |
361 | { | |
362 | smc_curs_add(conn->peer_rmbe_size, prod, len); | |
363 | /* increased in recv tasklet smc_cdc_msg_rcv() */ | |
364 | smp_mb__before_atomic(); | |
365 | /* data in flight reduces usable snd_wnd */ | |
366 | atomic_sub(len, &conn->peer_rmbe_space); | |
367 | /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ | |
368 | smp_mb__after_atomic(); | |
69cb7dc0 | 369 | smc_curs_add(conn->sndbuf_desc->len, sent, len); |
e6727f39 UB |
370 | } |
371 | ||
be244f28 HW |
372 | /* SMC-R helper for smc_tx_rdma_writes() */ |
373 | static int smcr_tx_rdma_writes(struct smc_connection *conn, size_t len, | |
374 | size_t src_off, size_t src_len, | |
ad6f317f UB |
375 | size_t dst_off, size_t dst_len, |
376 | struct smc_rdma_wr *wr_rdma_buf) | |
be244f28 | 377 | { |
387707fd KG |
378 | struct smc_link *link = conn->lnk; |
379 | ||
be244f28 | 380 | dma_addr_t dma_addr = |
387707fd | 381 | sg_dma_address(conn->sndbuf_desc->sgt[link->link_idx].sgl); |
b8d19945 | 382 | u64 virt_addr = (uintptr_t)conn->sndbuf_desc->cpu_addr; |
be244f28 | 383 | int src_len_sum = src_len, dst_len_sum = dst_len; |
be244f28 HW |
384 | int sent_count = src_off; |
385 | int srcchunk, dstchunk; | |
386 | int num_sges; | |
387 | int rc; | |
388 | ||
389 | for (dstchunk = 0; dstchunk < 2; dstchunk++) { | |
793a7df6 GW |
390 | struct ib_rdma_wr *wr = &wr_rdma_buf->wr_tx_rdma[dstchunk]; |
391 | struct ib_sge *sge = wr->wr.sg_list; | |
392 | u64 base_addr = dma_addr; | |
393 | ||
394 | if (dst_len < link->qp_attr.cap.max_inline_data) { | |
b8d19945 | 395 | base_addr = virt_addr; |
793a7df6 GW |
396 | wr->wr.send_flags |= IB_SEND_INLINE; |
397 | } else { | |
398 | wr->wr.send_flags &= ~IB_SEND_INLINE; | |
399 | } | |
ad6f317f | 400 | |
be244f28 HW |
401 | num_sges = 0; |
402 | for (srcchunk = 0; srcchunk < 2; srcchunk++) { | |
b8d19945 WG |
403 | sge[srcchunk].addr = conn->sndbuf_desc->is_vm ? |
404 | (virt_addr + src_off) : (base_addr + src_off); | |
ad6f317f | 405 | sge[srcchunk].length = src_len; |
b8d19945 WG |
406 | if (conn->sndbuf_desc->is_vm) |
407 | sge[srcchunk].lkey = | |
408 | conn->sndbuf_desc->mr[link->link_idx]->lkey; | |
be244f28 HW |
409 | num_sges++; |
410 | ||
411 | src_off += src_len; | |
412 | if (src_off >= conn->sndbuf_desc->len) | |
413 | src_off -= conn->sndbuf_desc->len; | |
414 | /* modulo in send ring */ | |
415 | if (src_len_sum == dst_len) | |
416 | break; /* either on 1st or 2nd iteration */ | |
417 | /* prepare next (== 2nd) iteration */ | |
418 | src_len = dst_len - src_len; /* remainder */ | |
419 | src_len_sum += src_len; | |
420 | } | |
793a7df6 | 421 | rc = smc_tx_rdma_write(conn, dst_off, num_sges, wr); |
be244f28 HW |
422 | if (rc) |
423 | return rc; | |
424 | if (dst_len_sum == len) | |
425 | break; /* either on 1st or 2nd iteration */ | |
426 | /* prepare next (== 2nd) iteration */ | |
427 | dst_off = 0; /* modulo offset in RMBE ring buffer */ | |
428 | dst_len = len - dst_len; /* remainder */ | |
429 | dst_len_sum += dst_len; | |
430 | src_len = min_t(int, dst_len, conn->sndbuf_desc->len - | |
431 | sent_count); | |
432 | src_len_sum = src_len; | |
433 | } | |
434 | return 0; | |
435 | } | |
436 | ||
437 | /* SMC-D helper for smc_tx_rdma_writes() */ | |
438 | static int smcd_tx_rdma_writes(struct smc_connection *conn, size_t len, | |
439 | size_t src_off, size_t src_len, | |
440 | size_t dst_off, size_t dst_len) | |
441 | { | |
442 | int src_len_sum = src_len, dst_len_sum = dst_len; | |
443 | int srcchunk, dstchunk; | |
444 | int rc; | |
445 | ||
446 | for (dstchunk = 0; dstchunk < 2; dstchunk++) { | |
447 | for (srcchunk = 0; srcchunk < 2; srcchunk++) { | |
448 | void *data = conn->sndbuf_desc->cpu_addr + src_off; | |
449 | ||
450 | rc = smcd_tx_ism_write(conn, data, src_len, dst_off + | |
451 | sizeof(struct smcd_cdc_msg), 0); | |
452 | if (rc) | |
453 | return rc; | |
454 | dst_off += src_len; | |
455 | src_off += src_len; | |
456 | if (src_off >= conn->sndbuf_desc->len) | |
457 | src_off -= conn->sndbuf_desc->len; | |
458 | /* modulo in send ring */ | |
459 | if (src_len_sum == dst_len) | |
460 | break; /* either on 1st or 2nd iteration */ | |
461 | /* prepare next (== 2nd) iteration */ | |
462 | src_len = dst_len - src_len; /* remainder */ | |
463 | src_len_sum += src_len; | |
464 | } | |
465 | if (dst_len_sum == len) | |
466 | break; /* either on 1st or 2nd iteration */ | |
467 | /* prepare next (== 2nd) iteration */ | |
468 | dst_off = 0; /* modulo offset in RMBE ring buffer */ | |
469 | dst_len = len - dst_len; /* remainder */ | |
470 | dst_len_sum += dst_len; | |
471 | src_len = min_t(int, dst_len, conn->sndbuf_desc->len - src_off); | |
472 | src_len_sum = src_len; | |
473 | } | |
474 | return 0; | |
475 | } | |
476 | ||
e6727f39 UB |
477 | /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit; |
478 | * usable snd_wnd as max transmit | |
479 | */ | |
ad6f317f UB |
480 | static int smc_tx_rdma_writes(struct smc_connection *conn, |
481 | struct smc_rdma_wr *wr_rdma_buf) | |
e6727f39 | 482 | { |
be244f28 | 483 | size_t len, src_len, dst_off, dst_len; /* current chunk values */ |
e6727f39 | 484 | union smc_host_cursor sent, prep, prod, cons; |
de8474eb | 485 | struct smc_cdc_producer_flags *pflags; |
e6727f39 | 486 | int to_send, rmbespace; |
e6727f39 UB |
487 | int rc; |
488 | ||
489 | /* source: sndbuf */ | |
bac6de7b SR |
490 | smc_curs_copy(&sent, &conn->tx_curs_sent, conn); |
491 | smc_curs_copy(&prep, &conn->tx_curs_prep, conn); | |
e6727f39 | 492 | /* cf. wmem_alloc - (snd_max - snd_una) */ |
69cb7dc0 | 493 | to_send = smc_curs_diff(conn->sndbuf_desc->len, &sent, &prep); |
e6727f39 UB |
494 | if (to_send <= 0) |
495 | return 0; | |
496 | ||
497 | /* destination: RMBE */ | |
498 | /* cf. snd_wnd */ | |
499 | rmbespace = atomic_read(&conn->peer_rmbe_space); | |
e0e4b8fa | 500 | if (rmbespace <= 0) { |
194730a9 GG |
501 | struct smc_sock *smc = container_of(conn, struct smc_sock, |
502 | conn); | |
503 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); | |
e6727f39 | 504 | return 0; |
e0e4b8fa | 505 | } |
bac6de7b SR |
506 | smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn); |
507 | smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn); | |
e6727f39 UB |
508 | |
509 | /* if usable snd_wnd closes ask peer to advertise once it opens again */ | |
de8474eb SR |
510 | pflags = &conn->local_tx_ctrl.prod_flags; |
511 | pflags->write_blocked = (to_send >= rmbespace); | |
e6727f39 UB |
512 | /* cf. usable snd_wnd */ |
513 | len = min(to_send, rmbespace); | |
514 | ||
515 | /* initialize variables for first iteration of subsequent nested loop */ | |
e6727f39 UB |
516 | dst_off = prod.count; |
517 | if (prod.wrap == cons.wrap) { | |
518 | /* the filled destination area is unwrapped, | |
519 | * hence the available free destination space is wrapped | |
520 | * and we need 2 destination chunks of sum len; start with 1st | |
521 | * which is limited by what's available in sndbuf | |
522 | */ | |
523 | dst_len = min_t(size_t, | |
524 | conn->peer_rmbe_size - prod.count, len); | |
525 | } else { | |
526 | /* the filled destination area is wrapped, | |
527 | * hence the available free destination space is unwrapped | |
528 | * and we need a single destination chunk of entire len | |
529 | */ | |
530 | dst_len = len; | |
531 | } | |
e6727f39 | 532 | /* dst_len determines the maximum src_len */ |
69cb7dc0 | 533 | if (sent.count + dst_len <= conn->sndbuf_desc->len) { |
e6727f39 UB |
534 | /* unwrapped src case: single chunk of entire dst_len */ |
535 | src_len = dst_len; | |
536 | } else { | |
537 | /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */ | |
69cb7dc0 | 538 | src_len = conn->sndbuf_desc->len - sent.count; |
e6727f39 | 539 | } |
be244f28 HW |
540 | |
541 | if (conn->lgr->is_smcd) | |
542 | rc = smcd_tx_rdma_writes(conn, len, sent.count, src_len, | |
543 | dst_off, dst_len); | |
544 | else | |
545 | rc = smcr_tx_rdma_writes(conn, len, sent.count, src_len, | |
ad6f317f | 546 | dst_off, dst_len, wr_rdma_buf); |
be244f28 HW |
547 | if (rc) |
548 | return rc; | |
e6727f39 | 549 | |
de8474eb SR |
550 | if (conn->urg_tx_pend && len == to_send) |
551 | pflags->urg_data_present = 1; | |
e6727f39 UB |
552 | smc_tx_advance_cursors(conn, &prod, &sent, len); |
553 | /* update connection's cursors with advanced local cursors */ | |
bac6de7b | 554 | smc_curs_copy(&conn->local_tx_ctrl.prod, &prod, conn); |
e6727f39 | 555 | /* dst: peer RMBE */ |
bac6de7b | 556 | smc_curs_copy(&conn->tx_curs_sent, &sent, conn);/* src: local sndbuf */ |
e6727f39 UB |
557 | |
558 | return 0; | |
559 | } | |
560 | ||
561 | /* Wakeup sndbuf consumers from any context (IRQ or process) | |
562 | * since there is more data to transmit; usable snd_wnd as max transmit | |
563 | */ | |
95f7f3e7 | 564 | static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) |
e6727f39 | 565 | { |
cecc7a31 | 566 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; |
c6f02ebe | 567 | struct smc_link *link = conn->lnk; |
ad6f317f | 568 | struct smc_rdma_wr *wr_rdma_buf; |
e6727f39 UB |
569 | struct smc_cdc_tx_pend *pend; |
570 | struct smc_wr_buf *wr_buf; | |
571 | int rc; | |
572 | ||
95f7f3e7 KG |
573 | if (!link || !smc_wr_tx_link_hold(link)) |
574 | return -ENOLINK; | |
c6f02ebe | 575 | rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend); |
e6727f39 | 576 | if (rc < 0) { |
95f7f3e7 | 577 | smc_wr_tx_link_put(link); |
e6727f39 | 578 | if (rc == -EBUSY) { |
b38d7324 UB |
579 | struct smc_sock *smc = |
580 | container_of(conn, struct smc_sock, conn); | |
581 | ||
33f3fcc2 KG |
582 | if (smc->sk.sk_err == ECONNABORTED) |
583 | return sock_error(&smc->sk); | |
b2900980 UB |
584 | if (conn->killed) |
585 | return -EPIPE; | |
e6727f39 | 586 | rc = 0; |
22ef473d | 587 | mod_delayed_work(conn->lgr->tx_wq, &conn->tx_work, |
b2900980 | 588 | SMC_TX_WORK_DELAY); |
e6727f39 | 589 | } |
33f3fcc2 | 590 | return rc; |
e6727f39 UB |
591 | } |
592 | ||
33f3fcc2 | 593 | spin_lock_bh(&conn->send_lock); |
c6f02ebe KG |
594 | if (link != conn->lnk) { |
595 | /* link of connection changed, tx_work will restart */ | |
596 | smc_wr_tx_put_slot(link, | |
597 | (struct smc_wr_tx_pend_priv *)pend); | |
598 | rc = -ENOLINK; | |
599 | goto out_unlock; | |
600 | } | |
cecc7a31 | 601 | if (!pflags->urg_data_present) { |
ad6f317f | 602 | rc = smc_tx_rdma_writes(conn, wr_rdma_buf); |
de8474eb | 603 | if (rc) { |
c6f02ebe | 604 | smc_wr_tx_put_slot(link, |
de8474eb SR |
605 | (struct smc_wr_tx_pend_priv *)pend); |
606 | goto out_unlock; | |
607 | } | |
e6727f39 UB |
608 | } |
609 | ||
610 | rc = smc_cdc_msg_send(conn, wr_buf, pend); | |
de8474eb SR |
611 | if (!rc && pflags->urg_data_present) { |
612 | pflags->urg_data_pending = 0; | |
613 | pflags->urg_data_present = 0; | |
614 | } | |
e6727f39 UB |
615 | |
616 | out_unlock: | |
617 | spin_unlock_bh(&conn->send_lock); | |
95f7f3e7 | 618 | smc_wr_tx_link_put(link); |
8f3d65c1 KG |
619 | return rc; |
620 | } | |
621 | ||
be244f28 HW |
622 | static int smcd_tx_sndbuf_nonempty(struct smc_connection *conn) |
623 | { | |
624 | struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; | |
625 | int rc = 0; | |
626 | ||
627 | spin_lock_bh(&conn->send_lock); | |
628 | if (!pflags->urg_data_present) | |
ad6f317f | 629 | rc = smc_tx_rdma_writes(conn, NULL); |
be244f28 HW |
630 | if (!rc) |
631 | rc = smcd_cdc_msg_send(conn); | |
632 | ||
633 | if (!rc && pflags->urg_data_present) { | |
634 | pflags->urg_data_pending = 0; | |
635 | pflags->urg_data_present = 0; | |
636 | } | |
637 | spin_unlock_bh(&conn->send_lock); | |
638 | return rc; | |
639 | } | |
640 | ||
dcd2cf5f | 641 | static int __smc_tx_sndbuf_nonempty(struct smc_connection *conn) |
be244f28 | 642 | { |
dcd2cf5f DL |
643 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
644 | int rc = 0; | |
645 | ||
646 | /* No data in the send queue */ | |
647 | if (unlikely(smc_tx_prepared_sends(conn) <= 0)) | |
648 | goto out; | |
649 | ||
650 | /* Peer don't have RMBE space */ | |
651 | if (unlikely(atomic_read(&conn->peer_rmbe_space) <= 0)) { | |
652 | SMC_STAT_RMB_TX_PEER_FULL(smc, !conn->lnk); | |
653 | goto out; | |
654 | } | |
be244f28 | 655 | |
b2900980 | 656 | if (conn->killed || |
dcd2cf5f DL |
657 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { |
658 | rc = -EPIPE; /* connection being aborted */ | |
659 | goto out; | |
660 | } | |
be244f28 HW |
661 | if (conn->lgr->is_smcd) |
662 | rc = smcd_tx_sndbuf_nonempty(conn); | |
663 | else | |
664 | rc = smcr_tx_sndbuf_nonempty(conn); | |
665 | ||
5bc056d8 KG |
666 | if (!rc) { |
667 | /* trigger socket release if connection is closing */ | |
5bc056d8 KG |
668 | smc_close_wake_tx_prepared(smc); |
669 | } | |
dcd2cf5f DL |
670 | |
671 | out: | |
672 | return rc; | |
673 | } | |
674 | ||
675 | int smc_tx_sndbuf_nonempty(struct smc_connection *conn) | |
676 | { | |
677 | int rc; | |
678 | ||
679 | /* This make sure only one can send simultaneously to prevent wasting | |
680 | * of CPU and CDC slot. | |
681 | * Record whether someone has tried to push while we are pushing. | |
682 | */ | |
683 | if (atomic_inc_return(&conn->tx_pushing) > 1) | |
684 | return 0; | |
685 | ||
686 | again: | |
687 | atomic_set(&conn->tx_pushing, 1); | |
688 | smp_wmb(); /* Make sure tx_pushing is 1 before real send */ | |
689 | rc = __smc_tx_sndbuf_nonempty(conn); | |
690 | ||
691 | /* We need to check whether someone else have added some data into | |
692 | * the send queue and tried to push but failed after the atomic_set() | |
693 | * when we are pushing. | |
694 | * If so, we need to push again to prevent those data hang in the send | |
695 | * queue. | |
696 | */ | |
697 | if (unlikely(!atomic_dec_and_test(&conn->tx_pushing))) | |
698 | goto again; | |
699 | ||
be244f28 HW |
700 | return rc; |
701 | } | |
702 | ||
2e13bde1 TL |
703 | /* Wakeup sndbuf consumers from process context |
704 | * since there is more data to transmit. The caller | |
705 | * must hold sock lock. | |
706 | */ | |
ea785a1a | 707 | void smc_tx_pending(struct smc_connection *conn) |
e6727f39 | 708 | { |
e6727f39 | 709 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); |
90cacb2e | 710 | int rc; |
e6727f39 | 711 | |
b2900980 | 712 | if (smc->sk.sk_err) |
ea785a1a | 713 | return; |
1a0a04c7 | 714 | |
90cacb2e UB |
715 | rc = smc_tx_sndbuf_nonempty(conn); |
716 | if (!rc && conn->local_rx_ctrl.prod_flags.write_blocked && | |
717 | !atomic_read(&conn->bytes_to_rcv)) | |
718 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; | |
ea785a1a TL |
719 | } |
720 | ||
721 | /* Wakeup sndbuf consumers from process context | |
2e13bde1 TL |
722 | * since there is more data to transmit in locked |
723 | * sock. | |
ea785a1a TL |
724 | */ |
725 | void smc_tx_work(struct work_struct *work) | |
726 | { | |
727 | struct smc_connection *conn = container_of(to_delayed_work(work), | |
728 | struct smc_connection, | |
729 | tx_work); | |
730 | struct smc_sock *smc = container_of(conn, struct smc_sock, conn); | |
1a0a04c7 | 731 | |
ea785a1a TL |
732 | lock_sock(&smc->sk); |
733 | smc_tx_pending(conn); | |
e6727f39 UB |
734 | release_sock(&smc->sk); |
735 | } | |
736 | ||
de8474eb | 737 | void smc_tx_consumer_update(struct smc_connection *conn, bool force) |
952310cc | 738 | { |
99be51f1 UB |
739 | union smc_host_cursor cfed, cons, prod; |
740 | int sender_free = conn->rmb_desc->len; | |
6b5771aa | 741 | int to_confirm; |
952310cc | 742 | |
bac6de7b SR |
743 | smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn); |
744 | smc_curs_copy(&cfed, &conn->rx_curs_confirmed, conn); | |
69cb7dc0 | 745 | to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); |
99be51f1 | 746 | if (to_confirm > conn->rmbe_update_limit) { |
bac6de7b | 747 | smc_curs_copy(&prod, &conn->local_rx_ctrl.prod, conn); |
99be51f1 | 748 | sender_free = conn->rmb_desc->len - |
b8649efa UB |
749 | smc_curs_diff_large(conn->rmb_desc->len, |
750 | &cfed, &prod); | |
99be51f1 | 751 | } |
952310cc UB |
752 | |
753 | if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || | |
de8474eb | 754 | force || |
952310cc | 755 | ((to_confirm > conn->rmbe_update_limit) && |
99be51f1 | 756 | ((sender_free <= (conn->rmb_desc->len / 2)) || |
952310cc | 757 | conn->local_rx_ctrl.prod_flags.write_blocked))) { |
b2900980 UB |
758 | if (conn->killed || |
759 | conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) | |
760 | return; | |
1a0a04c7 | 761 | if ((smc_cdc_get_slot_and_msg_send(conn) < 0) && |
b2900980 | 762 | !conn->killed) { |
22ef473d KG |
763 | queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, |
764 | SMC_TX_WORK_DELAY); | |
952310cc UB |
765 | return; |
766 | } | |
952310cc UB |
767 | } |
768 | if (conn->local_rx_ctrl.prod_flags.write_blocked && | |
769 | !atomic_read(&conn->bytes_to_rcv)) | |
770 | conn->local_rx_ctrl.prod_flags.write_blocked = 0; | |
771 | } | |
772 | ||
e6727f39 UB |
773 | /***************************** send initialize *******************************/ |
774 | ||
775 | /* Initialize send properties on connection establishment. NB: not __init! */ | |
776 | void smc_tx_init(struct smc_sock *smc) | |
777 | { | |
778 | smc->sk.sk_write_space = smc_tx_write_space; | |
e6727f39 | 779 | } |