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);
51 smc_tx_sndbuf_nonfull(smc);
52 bh_unlock_sock(&smc->sk);
55 int smc_cdc_get_free_slot(struct smc_connection *conn,
56 struct smc_wr_buf **wr_buf,
57 struct smc_rdma_wr **wr_rdma_buf,
58 struct smc_cdc_tx_pend **pend)
60 struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
63 rc = smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf,
65 (struct smc_wr_tx_pend_priv **)pend);
66 if (!conn->alert_token_local)
67 /* abnormal termination */
72 static inline void smc_cdc_add_pending_send(struct smc_connection *conn,
73 struct smc_cdc_tx_pend *pend)
76 sizeof(struct smc_cdc_msg) > SMC_WR_BUF_SIZE,
77 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_cdc_msg)");
79 offsetofend(struct smc_cdc_msg, reserved) > SMC_WR_TX_SIZE,
80 "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()");
82 sizeof(struct smc_cdc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
83 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_cdc_tx_pend)");
85 pend->cursor = conn->tx_curs_sent;
86 pend->p_cursor = conn->local_tx_ctrl.prod;
87 pend->ctrl_seq = conn->tx_cdc_seq;
90 int smc_cdc_msg_send(struct smc_connection *conn,
91 struct smc_wr_buf *wr_buf,
92 struct smc_cdc_tx_pend *pend)
94 union smc_host_cursor cfed;
95 struct smc_link *link;
98 link = &conn->lgr->lnk[SMC_SINGLE_LINK];
100 smc_cdc_add_pending_send(conn, pend);
103 conn->local_tx_ctrl.seqno = conn->tx_cdc_seq;
104 smc_host_msg_to_cdc((struct smc_cdc_msg *)wr_buf,
105 &conn->local_tx_ctrl, conn);
106 smc_curs_copy(&cfed, &((struct smc_host_cdc_msg *)wr_buf)->cons, conn);
107 rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend);
109 smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn);
114 static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn)
116 struct smc_cdc_tx_pend *pend;
117 struct smc_wr_buf *wr_buf;
120 rc = smc_cdc_get_free_slot(conn, &wr_buf, NULL, &pend);
124 spin_lock_bh(&conn->send_lock);
125 rc = smc_cdc_msg_send(conn, wr_buf, pend);
126 spin_unlock_bh(&conn->send_lock);
130 int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn)
134 if (conn->lgr->is_smcd) {
135 spin_lock_bh(&conn->send_lock);
136 rc = smcd_cdc_msg_send(conn);
137 spin_unlock_bh(&conn->send_lock);
139 rc = smcr_cdc_get_slot_and_msg_send(conn);
145 static bool smc_cdc_tx_filter(struct smc_wr_tx_pend_priv *tx_pend,
148 struct smc_connection *conn = (struct smc_connection *)data;
149 struct smc_cdc_tx_pend *cdc_pend =
150 (struct smc_cdc_tx_pend *)tx_pend;
152 return cdc_pend->conn == conn;
155 static void smc_cdc_tx_dismisser(struct smc_wr_tx_pend_priv *tx_pend)
157 struct smc_cdc_tx_pend *cdc_pend =
158 (struct smc_cdc_tx_pend *)tx_pend;
160 cdc_pend->conn = NULL;
163 void smc_cdc_tx_dismiss_slots(struct smc_connection *conn)
165 struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK];
167 smc_wr_tx_dismiss_slots(link, SMC_CDC_MSG_TYPE,
168 smc_cdc_tx_filter, smc_cdc_tx_dismisser,
169 (unsigned long)conn);
172 /* Send a SMC-D CDC header.
173 * This increments the free space available in our send buffer.
174 * Also update the confirmed receive buffer with what was sent to the peer.
176 int smcd_cdc_msg_send(struct smc_connection *conn)
178 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
179 union smc_host_cursor curs;
180 struct smcd_cdc_msg cdc;
183 memset(&cdc, 0, sizeof(cdc));
184 cdc.common.type = SMC_CDC_MSG_TYPE;
185 curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.prod.acurs);
186 cdc.prod.wrap = curs.wrap;
187 cdc.prod.count = curs.count;
188 curs.acurs.counter = atomic64_read(&conn->local_tx_ctrl.cons.acurs);
189 cdc.cons.wrap = curs.wrap;
190 cdc.cons.count = curs.count;
191 cdc.cons.prod_flags = conn->local_tx_ctrl.prod_flags;
192 cdc.cons.conn_state_flags = conn->local_tx_ctrl.conn_state_flags;
193 rc = smcd_tx_ism_write(conn, &cdc, sizeof(cdc), 0, 1);
196 smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn);
197 /* Calculate transmitted data and increment free send buffer space */
198 diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin,
199 &conn->tx_curs_sent);
200 /* increased by confirmed number of bytes */
201 smp_mb__before_atomic();
202 atomic_add(diff, &conn->sndbuf_space);
203 /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
204 smp_mb__after_atomic();
205 smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn);
207 smc_tx_sndbuf_nonfull(smc);
211 /********************************* receive ***********************************/
213 static inline bool smc_cdc_before(u16 seq1, u16 seq2)
215 return (s16)(seq1 - seq2) < 0;
218 static void smc_cdc_handle_urg_data_arrival(struct smc_sock *smc,
221 struct smc_connection *conn = &smc->conn;
224 /* new data included urgent business */
225 smc_curs_copy(&conn->urg_curs, &conn->local_rx_ctrl.prod, conn);
226 conn->urg_state = SMC_URG_VALID;
227 if (!sock_flag(&smc->sk, SOCK_URGINLINE))
228 /* we'll skip the urgent byte, so don't account for it */
230 base = (char *)conn->rmb_desc->cpu_addr + conn->rx_off;
231 if (conn->urg_curs.count)
232 conn->urg_rx_byte = *(base + conn->urg_curs.count - 1);
234 conn->urg_rx_byte = *(base + conn->rmb_desc->len - 1);
235 sk_send_sigurg(&smc->sk);
238 static void smc_cdc_msg_recv_action(struct smc_sock *smc,
239 struct smc_cdc_msg *cdc)
241 union smc_host_cursor cons_old, prod_old;
242 struct smc_connection *conn = &smc->conn;
243 int diff_cons, diff_prod;
245 smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn);
246 smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn);
247 smc_cdc_msg_to_host(&conn->local_rx_ctrl, cdc, conn);
249 diff_cons = smc_curs_diff(conn->peer_rmbe_size, &cons_old,
250 &conn->local_rx_ctrl.cons);
252 /* peer_rmbe_space is decreased during data transfer with RDMA
255 smp_mb__before_atomic();
256 atomic_add(diff_cons, &conn->peer_rmbe_space);
257 /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */
258 smp_mb__after_atomic();
261 diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,
262 &conn->local_rx_ctrl.prod);
264 if (conn->local_rx_ctrl.prod_flags.urg_data_present)
265 smc_cdc_handle_urg_data_arrival(smc, &diff_prod);
266 /* bytes_to_rcv is decreased in smc_recvmsg */
267 smp_mb__before_atomic();
268 atomic_add(diff_prod, &conn->bytes_to_rcv);
269 /* guarantee 0 <= bytes_to_rcv <= rmb_desc->len */
270 smp_mb__after_atomic();
271 smc->sk.sk_data_ready(&smc->sk);
273 if (conn->local_rx_ctrl.prod_flags.write_blocked ||
274 conn->local_rx_ctrl.prod_flags.cons_curs_upd_req ||
275 conn->local_rx_ctrl.prod_flags.urg_data_pending) {
276 if (conn->local_rx_ctrl.prod_flags.urg_data_pending)
277 conn->urg_state = SMC_URG_NOTYET;
278 /* force immediate tx of current consumer cursor, but
279 * under send_lock to guarantee arrival in seqno-order
281 if (smc->sk.sk_state != SMC_INIT)
282 smc_tx_sndbuf_nonempty(conn);
286 /* piggy backed tx info */
287 /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
288 if (diff_cons && smc_tx_prepared_sends(conn)) {
289 smc_tx_sndbuf_nonempty(conn);
290 /* trigger socket release if connection closed */
291 smc_close_wake_tx_prepared(smc);
293 if (diff_cons && conn->urg_tx_pend &&
294 atomic_read(&conn->peer_rmbe_space) == conn->peer_rmbe_size) {
295 /* urg data confirmed by peer, indicate we're ready for more */
296 conn->urg_tx_pend = false;
297 smc->sk.sk_write_space(&smc->sk);
300 if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
301 smc->sk.sk_err = ECONNRESET;
302 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
304 if (smc_cdc_rxed_any_close_or_senddone(conn)) {
305 smc->sk.sk_shutdown |= RCV_SHUTDOWN;
306 if (smc->clcsock && smc->clcsock->sk)
307 smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
308 sock_set_flag(&smc->sk, SOCK_DONE);
309 sock_hold(&smc->sk); /* sock_put in close_work */
310 if (!schedule_work(&conn->close_work))
315 /* called under tasklet context */
316 static void smc_cdc_msg_recv(struct smc_sock *smc, struct smc_cdc_msg *cdc)
319 bh_lock_sock(&smc->sk);
320 smc_cdc_msg_recv_action(smc, cdc);
321 bh_unlock_sock(&smc->sk);
322 sock_put(&smc->sk); /* no free sk in softirq-context */
325 /* Schedule a tasklet for this connection. Triggered from the ISM device IRQ
326 * handler to indicate update in the DMBE.
331 static void smcd_cdc_rx_tsklet(unsigned long data)
333 struct smc_connection *conn = (struct smc_connection *)data;
334 struct smcd_cdc_msg *data_cdc;
335 struct smcd_cdc_msg cdc;
336 struct smc_sock *smc;
341 data_cdc = (struct smcd_cdc_msg *)conn->rmb_desc->cpu_addr;
342 smcd_curs_copy(&cdc.prod, &data_cdc->prod, conn);
343 smcd_curs_copy(&cdc.cons, &data_cdc->cons, conn);
344 smc = container_of(conn, struct smc_sock, conn);
345 smc_cdc_msg_recv(smc, (struct smc_cdc_msg *)&cdc);
348 /* Initialize receive tasklet. Called from ISM device IRQ handler to start
351 void smcd_cdc_rx_init(struct smc_connection *conn)
353 tasklet_init(&conn->rx_tsklet, smcd_cdc_rx_tsklet, (unsigned long)conn);
356 /***************************** init, exit, misc ******************************/
358 static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf)
360 struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
361 struct smc_cdc_msg *cdc = buf;
362 struct smc_connection *conn;
363 struct smc_link_group *lgr;
364 struct smc_sock *smc;
366 if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved))
367 return; /* short message */
368 if (cdc->len != SMC_WR_TX_SIZE)
369 return; /* invalid message */
371 /* lookup connection */
372 lgr = smc_get_lgr(link);
373 read_lock_bh(&lgr->conns_lock);
374 conn = smc_lgr_find_conn(ntohl(cdc->token), lgr);
375 read_unlock_bh(&lgr->conns_lock);
378 smc = container_of(conn, struct smc_sock, conn);
380 if (!cdc->prod_flags.failover_validation) {
381 if (smc_cdc_before(ntohs(cdc->seqno),
382 conn->local_rx_ctrl.seqno))
383 /* received seqno is old */
386 smc_cdc_msg_recv(smc, cdc);
389 static struct smc_wr_rx_handler smc_cdc_rx_handlers[] = {
391 .handler = smc_cdc_rx_handler,
392 .type = SMC_CDC_MSG_TYPE
399 int __init smc_cdc_init(void)
401 struct smc_wr_rx_handler *handler;
404 for (handler = smc_cdc_rx_handlers; handler->handler; handler++) {
405 INIT_HLIST_NODE(&handler->list);
406 rc = smc_wr_rx_register_handler(handler);