]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - net/smc/smc_tx.c
1 // SPDX-License-Identifier: GPL-2.0
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
7 * Copy user space data into send buffer, if send buffer space available.
9 * Trigger RDMA write into RMBE of peer and send CDC, if RMBE space available.
11 * Copyright IBM Corp. 2016
13 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
16 #include <linux/net.h>
17 #include <linux/rcupdate.h>
18 #include <linux/workqueue.h>
19 #include <linux/sched/signal.h>
27 #include "smc_close.h"
31 #define SMC_TX_WORK_DELAY 0
32 #define SMC_TX_CORK_DELAY (HZ >> 2) /* 250 ms */
34 /***************************** sndbuf producer *******************************/
36 /* callback implementation for sk.sk_write_space()
37 * to wakeup sndbuf producers that blocked with smc_tx_wait().
38 * called under sk_socket lock.
40 static void smc_tx_write_space(struct sock
*sk
)
42 struct socket
*sock
= sk
->sk_socket
;
43 struct smc_sock
*smc
= smc_sk(sk
);
46 /* similar to sk_stream_write_space */
47 if (atomic_read(&smc
->conn
.sndbuf_space
) && sock
) {
48 clear_bit(SOCK_NOSPACE
, &sock
->flags
);
50 wq
= rcu_dereference(sk
->sk_wq
);
51 if (skwq_has_sleeper(wq
))
52 wake_up_interruptible_poll(&wq
->wait
,
53 EPOLLOUT
| EPOLLWRNORM
|
55 if (wq
&& wq
->fasync_list
&& !(sk
->sk_shutdown
& SEND_SHUTDOWN
))
56 sock_wake_async(wq
, SOCK_WAKE_SPACE
, POLL_OUT
);
61 /* Wakeup sndbuf producers that blocked with smc_tx_wait().
62 * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space().
64 void smc_tx_sndbuf_nonfull(struct smc_sock
*smc
)
66 if (smc
->sk
.sk_socket
&&
67 test_bit(SOCK_NOSPACE
, &smc
->sk
.sk_socket
->flags
))
68 smc
->sk
.sk_write_space(&smc
->sk
);
71 /* blocks sndbuf producer until at least one byte of free space available
72 * or urgent Byte was consumed
74 static int smc_tx_wait(struct smc_sock
*smc
, int flags
)
76 DEFINE_WAIT_FUNC(wait
, woken_wake_function
);
77 struct smc_connection
*conn
= &smc
->conn
;
78 struct sock
*sk
= &smc
->sk
;
82 /* similar to sk_stream_wait_memory */
83 timeo
= sock_sndtimeo(sk
, flags
& MSG_DONTWAIT
);
84 add_wait_queue(sk_sleep(sk
), &wait
);
86 sk_set_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
88 (sk
->sk_shutdown
& SEND_SHUTDOWN
) ||
89 conn
->local_tx_ctrl
.conn_state_flags
.peer_done_writing
) {
93 if (smc_cdc_rxed_any_close(conn
)) {
98 /* ensure EPOLLOUT is subsequently generated */
99 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
103 if (signal_pending(current
)) {
104 rc
= sock_intr_errno(timeo
);
107 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
108 if (atomic_read(&conn
->sndbuf_space
) && !conn
->urg_tx_pend
)
109 break; /* at least 1 byte of free & no urgent data */
110 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);
111 sk_wait_event(sk
, &timeo
,
113 (sk
->sk_shutdown
& SEND_SHUTDOWN
) ||
114 smc_cdc_rxed_any_close(conn
) ||
115 (atomic_read(&conn
->sndbuf_space
) &&
119 remove_wait_queue(sk_sleep(sk
), &wait
);
123 static bool smc_tx_is_corked(struct smc_sock
*smc
)
125 struct tcp_sock
*tp
= tcp_sk(smc
->clcsock
->sk
);
127 return (tp
->nonagle
& TCP_NAGLE_CORK
) ? true : false;
130 /* sndbuf producer: main API called by socket layer.
131 * called under sock lock.
133 int smc_tx_sendmsg(struct smc_sock
*smc
, struct msghdr
*msg
, size_t len
)
135 size_t copylen
, send_done
= 0, send_remaining
= len
;
136 size_t chunk_len
, chunk_off
, chunk_len_sum
;
137 struct smc_connection
*conn
= &smc
->conn
;
138 union smc_host_cursor prep
;
139 struct sock
*sk
= &smc
->sk
;
145 /* This should be in poll */
146 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE
, sk
);
148 if (sk
->sk_err
|| (sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
153 while (msg_data_left(msg
)) {
154 if (sk
->sk_state
== SMC_INIT
)
156 if (smc
->sk
.sk_shutdown
& SEND_SHUTDOWN
||
157 (smc
->sk
.sk_err
== ECONNABORTED
) ||
158 conn
->local_tx_ctrl
.conn_state_flags
.peer_conn_abort
)
160 if (smc_cdc_rxed_any_close(conn
))
161 return send_done
?: -ECONNRESET
;
163 if (msg
->msg_flags
& MSG_OOB
)
164 conn
->local_tx_ctrl
.prod_flags
.urg_data_pending
= 1;
166 if (!atomic_read(&conn
->sndbuf_space
) || conn
->urg_tx_pend
) {
169 rc
= smc_tx_wait(smc
, msg
->msg_flags
);
175 /* initialize variables for 1st iteration of subsequent loop */
176 /* could be just 1 byte, even after smc_tx_wait above */
177 writespace
= atomic_read(&conn
->sndbuf_space
);
178 /* not more than what user space asked for */
179 copylen
= min_t(size_t, send_remaining
, writespace
);
180 /* determine start of sndbuf */
181 sndbuf_base
= conn
->sndbuf_desc
->cpu_addr
;
182 smc_curs_copy(&prep
, &conn
->tx_curs_prep
, conn
);
183 tx_cnt_prep
= prep
.count
;
184 /* determine chunks where to write into sndbuf */
185 /* either unwrapped case, or 1st chunk of wrapped case */
186 chunk_len
= min_t(size_t, copylen
, conn
->sndbuf_desc
->len
-
188 chunk_len_sum
= chunk_len
;
189 chunk_off
= tx_cnt_prep
;
190 smc_sndbuf_sync_sg_for_cpu(conn
);
191 for (chunk
= 0; chunk
< 2; chunk
++) {
192 rc
= memcpy_from_msg(sndbuf_base
+ chunk_off
,
195 smc_sndbuf_sync_sg_for_device(conn
);
200 send_done
+= chunk_len
;
201 send_remaining
-= chunk_len
;
203 if (chunk_len_sum
== copylen
)
204 break; /* either on 1st or 2nd iteration */
205 /* prepare next (== 2nd) iteration */
206 chunk_len
= copylen
- chunk_len
; /* remainder */
207 chunk_len_sum
+= chunk_len
;
208 chunk_off
= 0; /* modulo offset in send ring buffer */
210 smc_sndbuf_sync_sg_for_device(conn
);
212 smc_curs_add(conn
->sndbuf_desc
->len
, &prep
, copylen
);
213 smc_curs_copy(&conn
->tx_curs_prep
, &prep
, conn
);
214 /* increased in send tasklet smc_cdc_tx_handler() */
215 smp_mb__before_atomic();
216 atomic_sub(copylen
, &conn
->sndbuf_space
);
217 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
218 smp_mb__after_atomic();
219 /* since we just produced more new data into sndbuf,
220 * trigger sndbuf consumer: RDMA write into peer RMBE and CDC
222 if ((msg
->msg_flags
& MSG_OOB
) && !send_remaining
)
223 conn
->urg_tx_pend
= true;
224 if ((msg
->msg_flags
& MSG_MORE
|| smc_tx_is_corked(smc
)) &&
225 (atomic_read(&conn
->sndbuf_space
) >
226 (conn
->sndbuf_desc
->len
>> 1)))
227 /* for a corked socket defer the RDMA writes if there
228 * is still sufficient sndbuf_space available
230 schedule_delayed_work(&conn
->tx_work
,
233 smc_tx_sndbuf_nonempty(conn
);
234 } /* while (msg_data_left(msg)) */
239 rc
= sk_stream_error(sk
, msg
->msg_flags
, rc
);
240 /* make sure we wake any epoll edge trigger waiter */
241 if (unlikely(rc
== -EAGAIN
))
242 sk
->sk_write_space(sk
);
246 /***************************** sndbuf consumer *******************************/
248 /* sndbuf consumer: actual data transfer of one target chunk with ISM write */
249 int smcd_tx_ism_write(struct smc_connection
*conn
, void *data
, size_t len
,
250 u32 offset
, int signal
)
252 struct smc_ism_position pos
;
255 memset(&pos
, 0, sizeof(pos
));
256 pos
.token
= conn
->peer_token
;
257 pos
.index
= conn
->peer_rmbe_idx
;
258 pos
.offset
= conn
->tx_off
+ offset
;
260 rc
= smc_ism_write(conn
->lgr
->smcd
, &pos
, data
, len
);
262 conn
->local_tx_ctrl
.conn_state_flags
.peer_conn_abort
= 1;
266 /* sndbuf consumer: actual data transfer of one target chunk with RDMA write */
267 static int smc_tx_rdma_write(struct smc_connection
*conn
, int peer_rmbe_offset
,
268 int num_sges
, struct ib_rdma_wr
*rdma_wr
)
270 struct smc_link_group
*lgr
= conn
->lgr
;
271 struct smc_link
*link
;
274 link
= &lgr
->lnk
[SMC_SINGLE_LINK
];
275 rdma_wr
->wr
.wr_id
= smc_wr_tx_get_next_wr_id(link
);
276 rdma_wr
->wr
.num_sge
= num_sges
;
277 rdma_wr
->remote_addr
=
278 lgr
->rtokens
[conn
->rtoken_idx
][SMC_SINGLE_LINK
].dma_addr
+
279 /* RMBE within RMB */
281 /* offset within RMBE */
283 rdma_wr
->rkey
= lgr
->rtokens
[conn
->rtoken_idx
][SMC_SINGLE_LINK
].rkey
;
284 rc
= ib_post_send(link
->roce_qp
, &rdma_wr
->wr
, NULL
);
286 conn
->local_tx_ctrl
.conn_state_flags
.peer_conn_abort
= 1;
287 smc_lgr_terminate(lgr
);
292 /* sndbuf consumer */
293 static inline void smc_tx_advance_cursors(struct smc_connection
*conn
,
294 union smc_host_cursor
*prod
,
295 union smc_host_cursor
*sent
,
298 smc_curs_add(conn
->peer_rmbe_size
, prod
, len
);
299 /* increased in recv tasklet smc_cdc_msg_rcv() */
300 smp_mb__before_atomic();
301 /* data in flight reduces usable snd_wnd */
302 atomic_sub(len
, &conn
->peer_rmbe_space
);
303 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
304 smp_mb__after_atomic();
305 smc_curs_add(conn
->sndbuf_desc
->len
, sent
, len
);
308 /* SMC-R helper for smc_tx_rdma_writes() */
309 static int smcr_tx_rdma_writes(struct smc_connection
*conn
, size_t len
,
310 size_t src_off
, size_t src_len
,
311 size_t dst_off
, size_t dst_len
,
312 struct smc_rdma_wr
*wr_rdma_buf
)
314 dma_addr_t dma_addr
=
315 sg_dma_address(conn
->sndbuf_desc
->sgt
[SMC_SINGLE_LINK
].sgl
);
316 int src_len_sum
= src_len
, dst_len_sum
= dst_len
;
317 int sent_count
= src_off
;
318 int srcchunk
, dstchunk
;
322 for (dstchunk
= 0; dstchunk
< 2; dstchunk
++) {
324 wr_rdma_buf
->wr_tx_rdma
[dstchunk
].wr
.sg_list
;
327 for (srcchunk
= 0; srcchunk
< 2; srcchunk
++) {
328 sge
[srcchunk
].addr
= dma_addr
+ src_off
;
329 sge
[srcchunk
].length
= src_len
;
333 if (src_off
>= conn
->sndbuf_desc
->len
)
334 src_off
-= conn
->sndbuf_desc
->len
;
335 /* modulo in send ring */
336 if (src_len_sum
== dst_len
)
337 break; /* either on 1st or 2nd iteration */
338 /* prepare next (== 2nd) iteration */
339 src_len
= dst_len
- src_len
; /* remainder */
340 src_len_sum
+= src_len
;
342 rc
= smc_tx_rdma_write(conn
, dst_off
, num_sges
,
343 &wr_rdma_buf
->wr_tx_rdma
[dstchunk
]);
346 if (dst_len_sum
== len
)
347 break; /* either on 1st or 2nd iteration */
348 /* prepare next (== 2nd) iteration */
349 dst_off
= 0; /* modulo offset in RMBE ring buffer */
350 dst_len
= len
- dst_len
; /* remainder */
351 dst_len_sum
+= dst_len
;
352 src_len
= min_t(int, dst_len
, conn
->sndbuf_desc
->len
-
354 src_len_sum
= src_len
;
359 /* SMC-D helper for smc_tx_rdma_writes() */
360 static int smcd_tx_rdma_writes(struct smc_connection
*conn
, size_t len
,
361 size_t src_off
, size_t src_len
,
362 size_t dst_off
, size_t dst_len
)
364 int src_len_sum
= src_len
, dst_len_sum
= dst_len
;
365 int srcchunk
, dstchunk
;
368 for (dstchunk
= 0; dstchunk
< 2; dstchunk
++) {
369 for (srcchunk
= 0; srcchunk
< 2; srcchunk
++) {
370 void *data
= conn
->sndbuf_desc
->cpu_addr
+ src_off
;
372 rc
= smcd_tx_ism_write(conn
, data
, src_len
, dst_off
+
373 sizeof(struct smcd_cdc_msg
), 0);
378 if (src_off
>= conn
->sndbuf_desc
->len
)
379 src_off
-= conn
->sndbuf_desc
->len
;
380 /* modulo in send ring */
381 if (src_len_sum
== dst_len
)
382 break; /* either on 1st or 2nd iteration */
383 /* prepare next (== 2nd) iteration */
384 src_len
= dst_len
- src_len
; /* remainder */
385 src_len_sum
+= src_len
;
387 if (dst_len_sum
== len
)
388 break; /* either on 1st or 2nd iteration */
389 /* prepare next (== 2nd) iteration */
390 dst_off
= 0; /* modulo offset in RMBE ring buffer */
391 dst_len
= len
- dst_len
; /* remainder */
392 dst_len_sum
+= dst_len
;
393 src_len
= min_t(int, dst_len
, conn
->sndbuf_desc
->len
- src_off
);
394 src_len_sum
= src_len
;
399 /* sndbuf consumer: prepare all necessary (src&dst) chunks of data transmit;
400 * usable snd_wnd as max transmit
402 static int smc_tx_rdma_writes(struct smc_connection
*conn
,
403 struct smc_rdma_wr
*wr_rdma_buf
)
405 size_t len
, src_len
, dst_off
, dst_len
; /* current chunk values */
406 union smc_host_cursor sent
, prep
, prod
, cons
;
407 struct smc_cdc_producer_flags
*pflags
;
408 int to_send
, rmbespace
;
412 smc_curs_copy(&sent
, &conn
->tx_curs_sent
, conn
);
413 smc_curs_copy(&prep
, &conn
->tx_curs_prep
, conn
);
414 /* cf. wmem_alloc - (snd_max - snd_una) */
415 to_send
= smc_curs_diff(conn
->sndbuf_desc
->len
, &sent
, &prep
);
419 /* destination: RMBE */
421 rmbespace
= atomic_read(&conn
->peer_rmbe_space
);
424 smc_curs_copy(&prod
, &conn
->local_tx_ctrl
.prod
, conn
);
425 smc_curs_copy(&cons
, &conn
->local_rx_ctrl
.cons
, conn
);
427 /* if usable snd_wnd closes ask peer to advertise once it opens again */
428 pflags
= &conn
->local_tx_ctrl
.prod_flags
;
429 pflags
->write_blocked
= (to_send
>= rmbespace
);
430 /* cf. usable snd_wnd */
431 len
= min(to_send
, rmbespace
);
433 /* initialize variables for first iteration of subsequent nested loop */
434 dst_off
= prod
.count
;
435 if (prod
.wrap
== cons
.wrap
) {
436 /* the filled destination area is unwrapped,
437 * hence the available free destination space is wrapped
438 * and we need 2 destination chunks of sum len; start with 1st
439 * which is limited by what's available in sndbuf
441 dst_len
= min_t(size_t,
442 conn
->peer_rmbe_size
- prod
.count
, len
);
444 /* the filled destination area is wrapped,
445 * hence the available free destination space is unwrapped
446 * and we need a single destination chunk of entire len
450 /* dst_len determines the maximum src_len */
451 if (sent
.count
+ dst_len
<= conn
->sndbuf_desc
->len
) {
452 /* unwrapped src case: single chunk of entire dst_len */
455 /* wrapped src case: 2 chunks of sum dst_len; start with 1st: */
456 src_len
= conn
->sndbuf_desc
->len
- sent
.count
;
459 if (conn
->lgr
->is_smcd
)
460 rc
= smcd_tx_rdma_writes(conn
, len
, sent
.count
, src_len
,
463 rc
= smcr_tx_rdma_writes(conn
, len
, sent
.count
, src_len
,
464 dst_off
, dst_len
, wr_rdma_buf
);
468 if (conn
->urg_tx_pend
&& len
== to_send
)
469 pflags
->urg_data_present
= 1;
470 smc_tx_advance_cursors(conn
, &prod
, &sent
, len
);
471 /* update connection's cursors with advanced local cursors */
472 smc_curs_copy(&conn
->local_tx_ctrl
.prod
, &prod
, conn
);
474 smc_curs_copy(&conn
->tx_curs_sent
, &sent
, conn
);/* src: local sndbuf */
479 /* Wakeup sndbuf consumers from any context (IRQ or process)
480 * since there is more data to transmit; usable snd_wnd as max transmit
482 static int smcr_tx_sndbuf_nonempty(struct smc_connection
*conn
)
484 struct smc_cdc_producer_flags
*pflags
= &conn
->local_tx_ctrl
.prod_flags
;
485 struct smc_rdma_wr
*wr_rdma_buf
;
486 struct smc_cdc_tx_pend
*pend
;
487 struct smc_wr_buf
*wr_buf
;
490 rc
= smc_cdc_get_free_slot(conn
, &wr_buf
, &wr_rdma_buf
, &pend
);
493 struct smc_sock
*smc
=
494 container_of(conn
, struct smc_sock
, conn
);
496 if (smc
->sk
.sk_err
== ECONNABORTED
)
497 return sock_error(&smc
->sk
);
499 if (conn
->alert_token_local
) /* connection healthy */
500 mod_delayed_work(system_wq
, &conn
->tx_work
,
506 spin_lock_bh(&conn
->send_lock
);
507 if (!pflags
->urg_data_present
) {
508 rc
= smc_tx_rdma_writes(conn
, wr_rdma_buf
);
510 smc_wr_tx_put_slot(&conn
->lgr
->lnk
[SMC_SINGLE_LINK
],
511 (struct smc_wr_tx_pend_priv
*)pend
);
516 rc
= smc_cdc_msg_send(conn
, wr_buf
, pend
);
517 if (!rc
&& pflags
->urg_data_present
) {
518 pflags
->urg_data_pending
= 0;
519 pflags
->urg_data_present
= 0;
523 spin_unlock_bh(&conn
->send_lock
);
527 static int smcd_tx_sndbuf_nonempty(struct smc_connection
*conn
)
529 struct smc_cdc_producer_flags
*pflags
= &conn
->local_tx_ctrl
.prod_flags
;
532 spin_lock_bh(&conn
->send_lock
);
533 if (!pflags
->urg_data_present
)
534 rc
= smc_tx_rdma_writes(conn
, NULL
);
536 rc
= smcd_cdc_msg_send(conn
);
538 if (!rc
&& pflags
->urg_data_present
) {
539 pflags
->urg_data_pending
= 0;
540 pflags
->urg_data_present
= 0;
542 spin_unlock_bh(&conn
->send_lock
);
546 int smc_tx_sndbuf_nonempty(struct smc_connection
*conn
)
550 if (conn
->lgr
->is_smcd
)
551 rc
= smcd_tx_sndbuf_nonempty(conn
);
553 rc
= smcr_tx_sndbuf_nonempty(conn
);
556 /* trigger socket release if connection is closing */
557 struct smc_sock
*smc
= container_of(conn
, struct smc_sock
,
559 smc_close_wake_tx_prepared(smc
);
564 /* Wakeup sndbuf consumers from process context
565 * since there is more data to transmit
567 void smc_tx_work(struct work_struct
*work
)
569 struct smc_connection
*conn
= container_of(to_delayed_work(work
),
570 struct smc_connection
,
572 struct smc_sock
*smc
= container_of(conn
, struct smc_sock
, conn
);
576 if (smc
->sk
.sk_err
||
577 !conn
->alert_token_local
||
578 conn
->local_rx_ctrl
.conn_state_flags
.peer_conn_abort
)
581 rc
= smc_tx_sndbuf_nonempty(conn
);
582 if (!rc
&& conn
->local_rx_ctrl
.prod_flags
.write_blocked
&&
583 !atomic_read(&conn
->bytes_to_rcv
))
584 conn
->local_rx_ctrl
.prod_flags
.write_blocked
= 0;
587 release_sock(&smc
->sk
);
590 void smc_tx_consumer_update(struct smc_connection
*conn
, bool force
)
592 union smc_host_cursor cfed
, cons
, prod
;
593 int sender_free
= conn
->rmb_desc
->len
;
596 smc_curs_copy(&cons
, &conn
->local_tx_ctrl
.cons
, conn
);
597 smc_curs_copy(&cfed
, &conn
->rx_curs_confirmed
, conn
);
598 to_confirm
= smc_curs_diff(conn
->rmb_desc
->len
, &cfed
, &cons
);
599 if (to_confirm
> conn
->rmbe_update_limit
) {
600 smc_curs_copy(&prod
, &conn
->local_rx_ctrl
.prod
, conn
);
601 sender_free
= conn
->rmb_desc
->len
-
602 smc_curs_diff_large(conn
->rmb_desc
->len
,
606 if (conn
->local_rx_ctrl
.prod_flags
.cons_curs_upd_req
||
608 ((to_confirm
> conn
->rmbe_update_limit
) &&
609 ((sender_free
<= (conn
->rmb_desc
->len
/ 2)) ||
610 conn
->local_rx_ctrl
.prod_flags
.write_blocked
))) {
611 if ((smc_cdc_get_slot_and_msg_send(conn
) < 0) &&
612 conn
->alert_token_local
) { /* connection healthy */
613 schedule_delayed_work(&conn
->tx_work
,
618 if (conn
->local_rx_ctrl
.prod_flags
.write_blocked
&&
619 !atomic_read(&conn
->bytes_to_rcv
))
620 conn
->local_rx_ctrl
.prod_flags
.write_blocked
= 0;
623 /***************************** send initialize *******************************/
625 /* Initialize send properties on connection establishment. NB: not __init! */
626 void smc_tx_init(struct smc_sock
*smc
)
628 smc
->sk
.sk_write_space
= smc_tx_write_space
;