1 // SPDX-License-Identifier: GPL-2.0
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
5 * Connection Data Control (CDC)
8 * Copyright IBM Corp. 2016
10 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
13 #include <linux/spinlock.h>
20 #include "smc_close.h"
22 /********************************** send *************************************/
24 /* handler for send/transmission completion of a CDC msg */
25 static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd,
26 struct smc_link *link,
27 enum ib_wc_status wc_status)
29 struct smc_cdc_tx_pend *cdcpend = (struct smc_cdc_tx_pend *)pnd_snd;
30 struct smc_connection *conn = cdcpend->conn;
35 /* already dismissed */
38 smc = container_of(conn, struct smc_sock, conn);
39 bh_lock_sock(&smc->sk);
41 diff = smc_curs_diff(cdcpend->conn->sndbuf_desc->len,
42 &cdcpend->conn->tx_curs_fin,
44 /* sndbuf_space is decreased in smc_sendmsg */
45 smp_mb__before_atomic();
46 atomic_add(diff, &cdcpend->conn->sndbuf_space);
47 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
48 smp_mb__after_atomic();
49 smc_curs_copy(&conn->tx_curs_fin, &cdcpend->cursor, conn);
50 smc_curs_copy(&conn->local_tx_ctrl_fin, &cdcpend->p_cursor,
52 conn->tx_cdc_seq_fin = cdcpend->ctrl_seq;
54 smc_tx_sndbuf_nonfull(smc);
55 bh_unlock_sock(&smc->sk);
58 int smc_cdc_get_free_slot(struct smc_connection *conn,
59 struct smc_link *link,
60 struct smc_wr_buf **wr_buf,
61 struct smc_rdma_wr **wr_rdma_buf,
62 struct smc_cdc_tx_pend **pend)
66 rc = smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf,
68 (struct smc_wr_tx_pend_priv **)pend);
70 /* abnormal termination */
75 static inline void smc_cdc_add_pending_send(struct smc_connection *conn,
76 struct smc_cdc_tx_pend *pend)
79 sizeof(struct smc_cdc_msg) > SMC_WR_BUF_SIZE,
80 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_cdc_msg)");
82 offsetofend(struct smc_cdc_msg, reserved) > SMC_WR_TX_SIZE,
83 "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_cdc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
85 sizeof(struct smc_cdc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
86 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_cdc_tx_pend)");
88 pend->cursor = conn->tx_curs_sent;
89 pend->p_cursor = conn->local_tx_ctrl.prod;
90 pend->ctrl_seq = conn->tx_cdc_seq;
93 int smc_cdc_msg_send(struct smc_connection *conn,
94 struct smc_wr_buf *wr_buf,
95 struct smc_cdc_tx_pend *pend)
97 struct smc_link *link = conn->lnk;
98 union smc_host_cursor cfed;
101 smc_cdc_add_pending_send(conn, pend);
104 conn->local_tx_ctrl.seqno = conn->tx_cdc_seq;
105 smc_host_msg_to_cdc((struct smc_cdc_msg *)wr_buf, conn, &cfed);
106 rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
108 smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn);
109 conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
112 conn->local_tx_ctrl.seqno = conn->tx_cdc_seq;
118 /* send a validation msg indicating the move of a conn to an other QP link */
119 int smcr_cdc_msg_send_validation(struct smc_connection *conn,
120 struct smc_cdc_tx_pend *pend,
121 struct smc_wr_buf *wr_buf)
123 struct smc_host_cdc_msg *local = &conn->local_tx_ctrl;
124 struct smc_link *link = conn->lnk;
125 struct smc_cdc_msg *peer;
128 peer = (struct smc_cdc_msg *)wr_buf;
129 peer->common.type = local->common.type;
130 peer->len = local->len;
131 peer->seqno = htons(conn->tx_cdc_seq_fin); /* seqno last compl. tx */
132 peer->token = htonl(local->token);
133 peer->prod_flags.failover_validation = 1;
135 rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
139 static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn)
141 struct smc_cdc_tx_pend *pend;
142 struct smc_wr_buf *wr_buf;
143 struct smc_link *link;
149 rc = smc_cdc_get_free_slot(conn, link, &wr_buf, NULL, &pend);
153 spin_lock_bh(&conn->send_lock);
154 if (link != conn->lnk) {
155 /* link of connection changed, try again one time*/
156 spin_unlock_bh(&conn->send_lock);
157 smc_wr_tx_put_slot(link,
158 (struct smc_wr_tx_pend_priv *)pend);
164 rc = smc_cdc_msg_send(conn, wr_buf, pend);
165 spin_unlock_bh(&conn->send_lock);
169 int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn)
173 if (!conn->lgr || (conn->lgr->is_smcd && conn->lgr->peer_shutdown))
176 if (conn->lgr->is_smcd) {
177 spin_lock_bh(&conn->send_lock);
178 rc = smcd_cdc_msg_send(conn);
179 spin_unlock_bh(&conn->send_lock);
181 rc = smcr_cdc_get_slot_and_msg_send(conn);
187 static bool smc_cdc_tx_filter(struct smc_wr_tx_pend_priv *tx_pend,
190 struct smc_connection *conn = (struct smc_connection *)data;
191 struct smc_cdc_tx_pend *cdc_pend =
192 (struct smc_cdc_tx_pend *)tx_pend;
194 return cdc_pend->conn == conn;
197 static void smc_cdc_tx_dismisser(struct smc_wr_tx_pend_priv *tx_pend)
199 struct smc_cdc_tx_pend *cdc_pend =
200 (struct smc_cdc_tx_pend *)tx_pend;
202 cdc_pend->conn = NULL;
205 void smc_cdc_tx_dismiss_slots(struct smc_connection *conn)
207 struct smc_link *link = conn->lnk;
209 smc_wr_tx_dismiss_slots(link, SMC_CDC_MSG_TYPE,
210 smc_cdc_tx_filter, smc_cdc_tx_dismisser,
211 (unsigned long)conn);
214 /* Send a SMC-D CDC header.
215 * This increments the free space available in our send buffer.
216 * Also update the confirmed receive buffer with what was sent to the peer.
218 int smcd_cdc_msg_send(struct smc_connection *conn)
220 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
221 union smc_host_cursor curs;
222 struct smcd_cdc_msg cdc;
225 memset(&cdc, 0, sizeof(cdc));
226 cdc.common.type = SMC_CDC_MSG_TYPE;
227 curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.prod.acurs);
228 cdc.prod.wrap = curs.wrap;
229 cdc.prod.count = curs.count;
230 curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.cons.acurs);
231 cdc.cons.wrap = curs.wrap;
232 cdc.cons.count = curs.count;
233 cdc.cons.prod_flags = conn->local_tx_ctrl.prod_flags;
234 cdc.cons.conn_state_flags = conn->local_tx_ctrl.conn_state_flags;
235 rc = smcd_tx_ism_write(conn, &cdc, sizeof(cdc), 0, 1);
238 smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn);
239 conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
240 /* Calculate transmitted data and increment free send buffer space */
241 diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin,
242 &conn->tx_curs_sent);
243 /* increased by confirmed number of bytes */
244 smp_mb__before_atomic();
245 atomic_add(diff, &conn->sndbuf_space);
246 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
247 smp_mb__after_atomic();
248 smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn);
250 smc_tx_sndbuf_nonfull(smc);
254 /********************************* receive ***********************************/
256 static inline bool smc_cdc_before(u16 seq1, u16 seq2)
258 return (s16)(seq1 - seq2) < 0;
261 static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc,
264 struct smc_connection *conn = &smc->conn;
267 /* new data included urgent business */
268 smc_curs_copy(&conn->urg_curs, &conn->local_rx_ctrl.prod, conn);
269 conn->urg_state = SMC_URG_VALID;
270 if (!sock_flag(&smc->sk, SOCK_URGINLINE))
271 /* we'll skip the urgent byte, so don't account for it */
273 base = (char *)conn->rmb_desc->cpu_addr + conn->rx_off;
274 if (conn->urg_curs.count)
275 conn->urg_rx_byte = *(base + conn->urg_curs.count - 1);
277 conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1);
278 sk_send_sigurg(&smc->sk);
281 static void smc_cdc_msg_validate(struct smc_sock *smc, struct smc_cdc_msg *cdc,
282 struct smc_link *link)
284 struct smc_connection *conn = &smc->conn;
285 u16 recv_seq = ntohs(cdc->seqno);
288 /* check that seqnum was seen before */
289 diff = conn->local_rx_ctrl.seqno - recv_seq;
290 if (diff < 0) { /* diff larger than 0x7fff */
291 /* drop connection */
292 conn->out_of_sync = 1; /* prevent any further receives */
293 spin_lock_bh(&conn->send_lock);
294 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
296 spin_unlock_bh(&conn->send_lock);
297 sock_hold(&smc->sk); /* sock_put in abort_work */
298 if (!schedule_work(&conn->abort_work))
303 static void smc_cdc_msg_recv_action(struct smc_sock *smc,
304 struct smc_cdc_msg *cdc)
306 union smc_host_cursor cons_old, prod_old;
307 struct smc_connection *conn = &smc->conn;
308 int diff_cons, diff_prod;
310 smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn);
311 smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn);
312 smc_cdc_msg_to_host(&conn->local_rx_ctrl, cdc, conn);
314 diff_cons = smc_curs_diff(conn->peer_rmbe_size, &cons_old,
315 &conn->local_rx_ctrl.cons);
317 /* peer_rmbe_space is decreased during data transfer with RDMA
320 smp_mb__before_atomic();
321 atomic_add(diff_cons, &conn->peer_rmbe_space);
322 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
323 smp_mb__after_atomic();
326 diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
327 &conn->local_rx_ctrl.prod);
329 if (conn->local_rx_ctrl.prod_flags.urg_data_present)
330 smc_cdc_handle_urg_data_arrival(smc, &diff_prod);
331 /* bytes_to_rcv is decreased in smc_recvmsg */
332 smp_mb__before_atomic();
333 atomic_add(diff_prod, &conn->bytes_to_rcv);
334 /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
335 smp_mb__after_atomic();
336 smc->sk.sk_data_ready(&smc->sk);
338 if (conn->local_rx_ctrl.prod_flags.write_blocked)
339 smc->sk.sk_data_ready(&smc->sk);
340 if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
341 conn->urg_state = SMC_URG_NOTYET;
344 /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
345 if ((diff_cons && smc_tx_prepared_sends(conn)) ||
346 conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
347 conn->local_rx_ctrl.prod_flags.urg_data_pending)
348 smc_tx_sndbuf_nonempty(conn);
350 if (diff_cons && conn->urg_tx_pend &&
351 atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
352 /* urg data confirmed by peer, indicate we're ready for more */
353 conn->urg_tx_pend = false;
354 smc->sk.sk_write_space(&smc->sk);
357 if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
358 smc->sk.sk_err = ECONNRESET;
359 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
361 if (smc_cdc_rxed_any_close_or_senddone(conn)) {
362 smc->sk.sk_shutdown |= RCV_SHUTDOWN;
363 if (smc->clcsock && smc->clcsock->sk)
364 smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
365 sock_set_flag(&smc->sk, SOCK_DONE);
366 sock_hold(&smc->sk); /* sock_put in close_work */
367 if (!schedule_work(&conn->close_work))
372 /* called under tasklet context */
373 static void smc_cdc_msg_recv(struct smc_sock *smc, struct smc_cdc_msg *cdc)
376 bh_lock_sock(&smc->sk);
377 smc_cdc_msg_recv_action(smc, cdc);
378 bh_unlock_sock(&smc->sk);
379 sock_put(&smc->sk); /* no free sk in softirq-context */
382 /* Schedule a tasklet for this connection. Triggered from the ISM device IRQ
383 * handler to indicate update in the DMBE.
388 static void smcd_cdc_rx_tsklet(unsigned long data)
390 struct smc_connection *conn = (struct smc_connection *)data;
391 struct smcd_cdc_msg *data_cdc;
392 struct smcd_cdc_msg cdc;
393 struct smc_sock *smc;
395 if (!conn || conn->killed)
398 data_cdc = (struct smcd_cdc_msg *)conn->rmb_desc->cpu_addr;
399 smcd_curs_copy(&cdc.prod, &data_cdc->prod, conn);
400 smcd_curs_copy(&cdc.cons, &data_cdc->cons, conn);
401 smc = container_of(conn, struct smc_sock, conn);
402 smc_cdc_msg_recv(smc, (struct smc_cdc_msg *)&cdc);
405 /* Initialize receive tasklet. Called from ISM device IRQ handler to start
408 void smcd_cdc_rx_init(struct smc_connection *conn)
410 tasklet_init(&conn->rx_tsklet, smcd_cdc_rx_tsklet, (unsigned long)conn);
413 /***************************** init, exit, misc ******************************/
415 static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf)
417 struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
418 struct smc_cdc_msg *cdc = buf;
419 struct smc_connection *conn;
420 struct smc_link_group *lgr;
421 struct smc_sock *smc;
423 if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved))
424 return; /* short message */
425 if (cdc->len != SMC_WR_TX_SIZE)
426 return; /* invalid message */
428 /* lookup connection */
429 lgr = smc_get_lgr(link);
430 read_lock_bh(&lgr->conns_lock);
431 conn = smc_lgr_find_conn(ntohl(cdc->token), lgr);
432 read_unlock_bh(&lgr->conns_lock);
433 if (!conn || conn->out_of_sync)
435 smc = container_of(conn, struct smc_sock, conn);
437 if (cdc->prod_flags.failover_validation) {
438 smc_cdc_msg_validate(smc, cdc, link);
441 if (smc_cdc_before(ntohs(cdc->seqno),
442 conn->local_rx_ctrl.seqno))
443 /* received seqno is old */
446 smc_cdc_msg_recv(smc, cdc);
449 static struct smc_wr_rx_handler smc_cdc_rx_handlers[] = {
451 .handler = smc_cdc_rx_handler,
452 .type = SMC_CDC_MSG_TYPE
459 int __init smc_cdc_init(void)
461 struct smc_wr_rx_handler *handler;
464 for (handler = smc_cdc_rx_handlers; handler->handler; handler++) {
465 INIT_HLIST_NODE(&handler->list);
466 rc = smc_wr_rx_register_handler(handler);