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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
5f08318f UB |
2 | /* |
3 | * Shared Memory Communications over RDMA (SMC-R) and RoCE | |
4 | * | |
5 | * Connection Data Control (CDC) | |
6 | * handles flow control | |
7 | * | |
8 | * Copyright IBM Corp. 2016 | |
9 | * | |
10 | * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> | |
11 | */ | |
12 | ||
13 | #include <linux/spinlock.h> | |
14 | ||
15 | #include "smc.h" | |
16 | #include "smc_wr.h" | |
17 | #include "smc_cdc.h" | |
e6727f39 | 18 | #include "smc_tx.h" |
952310cc | 19 | #include "smc_rx.h" |
b38d7324 | 20 | #include "smc_close.h" |
5f08318f UB |
21 | |
22 | /********************************** send *************************************/ | |
23 | ||
24 | struct smc_cdc_tx_pend { | |
25 | struct smc_connection *conn; /* socket connection */ | |
26 | union smc_host_cursor cursor; /* tx sndbuf cursor sent */ | |
27 | union smc_host_cursor p_cursor; /* rx RMBE cursor produced */ | |
28 | u16 ctrl_seq; /* conn. tx sequence # */ | |
29 | }; | |
30 | ||
31 | /* handler for send/transmission completion of a CDC msg */ | |
32 | static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd, | |
33 | struct smc_link *link, | |
34 | enum ib_wc_status wc_status) | |
35 | { | |
36 | struct smc_cdc_tx_pend *cdcpend = (struct smc_cdc_tx_pend *)pnd_snd; | |
37 | struct smc_sock *smc; | |
38 | int diff; | |
39 | ||
40 | if (!cdcpend->conn) | |
41 | /* already dismissed */ | |
42 | return; | |
43 | ||
44 | smc = container_of(cdcpend->conn, struct smc_sock, conn); | |
45 | bh_lock_sock(&smc->sk); | |
46 | if (!wc_status) { | |
47 | diff = smc_curs_diff(cdcpend->conn->sndbuf_size, | |
48 | &cdcpend->conn->tx_curs_fin, | |
49 | &cdcpend->cursor); | |
50 | /* sndbuf_space is decreased in smc_sendmsg */ | |
51 | smp_mb__before_atomic(); | |
52 | atomic_add(diff, &cdcpend->conn->sndbuf_space); | |
53 | /* guarantee 0 <= sndbuf_space <= sndbuf_size */ | |
54 | smp_mb__after_atomic(); | |
55 | smc_curs_write(&cdcpend->conn->tx_curs_fin, | |
56 | smc_curs_read(&cdcpend->cursor, cdcpend->conn), | |
57 | cdcpend->conn); | |
58 | } | |
e6727f39 | 59 | smc_tx_sndbuf_nonfull(smc); |
b38d7324 UB |
60 | if (smc->sk.sk_state != SMC_ACTIVE) |
61 | /* wake up smc_close_wait_tx_pends() */ | |
62 | smc->sk.sk_state_change(&smc->sk); | |
5f08318f UB |
63 | bh_unlock_sock(&smc->sk); |
64 | } | |
65 | ||
51957bc5 | 66 | int smc_cdc_get_free_slot(struct smc_connection *conn, |
5f08318f UB |
67 | struct smc_wr_buf **wr_buf, |
68 | struct smc_cdc_tx_pend **pend) | |
69 | { | |
51957bc5 UB |
70 | struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK]; |
71 | ||
5f08318f UB |
72 | return smc_wr_tx_get_free_slot(link, smc_cdc_tx_handler, wr_buf, |
73 | (struct smc_wr_tx_pend_priv **)pend); | |
74 | } | |
75 | ||
76 | static inline void smc_cdc_add_pending_send(struct smc_connection *conn, | |
77 | struct smc_cdc_tx_pend *pend) | |
78 | { | |
79 | BUILD_BUG_ON_MSG( | |
80 | sizeof(struct smc_cdc_msg) > SMC_WR_BUF_SIZE, | |
81 | "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_cdc_msg)"); | |
82 | BUILD_BUG_ON_MSG( | |
83 | offsetof(struct smc_cdc_msg, reserved) > SMC_WR_TX_SIZE, | |
84 | "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 | BUILD_BUG_ON_MSG( | |
86 | sizeof(struct smc_cdc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE, | |
87 | "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_cdc_tx_pend)"); | |
88 | pend->conn = conn; | |
89 | pend->cursor = conn->tx_curs_sent; | |
90 | pend->p_cursor = conn->local_tx_ctrl.prod; | |
91 | pend->ctrl_seq = conn->tx_cdc_seq; | |
92 | } | |
93 | ||
94 | int smc_cdc_msg_send(struct smc_connection *conn, | |
95 | struct smc_wr_buf *wr_buf, | |
96 | struct smc_cdc_tx_pend *pend) | |
97 | { | |
98 | struct smc_link *link; | |
99 | int rc; | |
100 | ||
101 | link = &conn->lgr->lnk[SMC_SINGLE_LINK]; | |
102 | ||
103 | smc_cdc_add_pending_send(conn, pend); | |
104 | ||
105 | conn->tx_cdc_seq++; | |
106 | conn->local_tx_ctrl.seqno = conn->tx_cdc_seq; | |
107 | smc_host_msg_to_cdc((struct smc_cdc_msg *)wr_buf, | |
108 | &conn->local_tx_ctrl, conn); | |
109 | rc = smc_wr_tx_send(link, (struct smc_wr_tx_pend_priv *)pend); | |
110 | if (!rc) | |
111 | smc_curs_write(&conn->rx_curs_confirmed, | |
112 | smc_curs_read(&conn->local_tx_ctrl.cons, conn), | |
113 | conn); | |
114 | ||
115 | return rc; | |
116 | } | |
117 | ||
118 | int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn) | |
119 | { | |
120 | struct smc_cdc_tx_pend *pend; | |
121 | struct smc_wr_buf *wr_buf; | |
122 | int rc; | |
123 | ||
51957bc5 | 124 | rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend); |
5f08318f UB |
125 | if (rc) |
126 | return rc; | |
127 | ||
128 | return smc_cdc_msg_send(conn, wr_buf, pend); | |
129 | } | |
130 | ||
131 | static bool smc_cdc_tx_filter(struct smc_wr_tx_pend_priv *tx_pend, | |
132 | unsigned long data) | |
133 | { | |
134 | struct smc_connection *conn = (struct smc_connection *)data; | |
135 | struct smc_cdc_tx_pend *cdc_pend = | |
136 | (struct smc_cdc_tx_pend *)tx_pend; | |
137 | ||
138 | return cdc_pend->conn == conn; | |
139 | } | |
140 | ||
141 | static void smc_cdc_tx_dismisser(struct smc_wr_tx_pend_priv *tx_pend) | |
142 | { | |
143 | struct smc_cdc_tx_pend *cdc_pend = | |
144 | (struct smc_cdc_tx_pend *)tx_pend; | |
145 | ||
146 | cdc_pend->conn = NULL; | |
147 | } | |
148 | ||
149 | void smc_cdc_tx_dismiss_slots(struct smc_connection *conn) | |
150 | { | |
151 | struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK]; | |
152 | ||
153 | smc_wr_tx_dismiss_slots(link, SMC_CDC_MSG_TYPE, | |
154 | smc_cdc_tx_filter, smc_cdc_tx_dismisser, | |
155 | (unsigned long)conn); | |
156 | } | |
157 | ||
b38d7324 UB |
158 | bool smc_cdc_tx_has_pending(struct smc_connection *conn) |
159 | { | |
160 | struct smc_link *link = &conn->lgr->lnk[SMC_SINGLE_LINK]; | |
161 | ||
162 | return smc_wr_tx_has_pending(link, SMC_CDC_MSG_TYPE, | |
163 | smc_cdc_tx_filter, (unsigned long)conn); | |
164 | } | |
165 | ||
5f08318f UB |
166 | /********************************* receive ***********************************/ |
167 | ||
168 | static inline bool smc_cdc_before(u16 seq1, u16 seq2) | |
169 | { | |
170 | return (s16)(seq1 - seq2) < 0; | |
171 | } | |
172 | ||
173 | static void smc_cdc_msg_recv_action(struct smc_sock *smc, | |
174 | struct smc_link *link, | |
175 | struct smc_cdc_msg *cdc) | |
176 | { | |
177 | union smc_host_cursor cons_old, prod_old; | |
178 | struct smc_connection *conn = &smc->conn; | |
179 | int diff_cons, diff_prod; | |
180 | ||
181 | if (!cdc->prod_flags.failover_validation) { | |
182 | if (smc_cdc_before(ntohs(cdc->seqno), | |
183 | conn->local_rx_ctrl.seqno)) | |
184 | /* received seqno is old */ | |
185 | return; | |
186 | } | |
187 | smc_curs_write(&prod_old, | |
188 | smc_curs_read(&conn->local_rx_ctrl.prod, conn), | |
189 | conn); | |
190 | smc_curs_write(&cons_old, | |
191 | smc_curs_read(&conn->local_rx_ctrl.cons, conn), | |
192 | conn); | |
193 | smc_cdc_msg_to_host(&conn->local_rx_ctrl, cdc, conn); | |
194 | ||
195 | diff_cons = smc_curs_diff(conn->peer_rmbe_size, &cons_old, | |
196 | &conn->local_rx_ctrl.cons); | |
197 | if (diff_cons) { | |
198 | /* peer_rmbe_space is decreased during data transfer with RDMA | |
199 | * write | |
200 | */ | |
201 | smp_mb__before_atomic(); | |
202 | atomic_add(diff_cons, &conn->peer_rmbe_space); | |
203 | /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ | |
204 | smp_mb__after_atomic(); | |
205 | } | |
206 | ||
207 | diff_prod = smc_curs_diff(conn->rmbe_size, &prod_old, | |
208 | &conn->local_rx_ctrl.prod); | |
209 | if (diff_prod) { | |
210 | /* bytes_to_rcv is decreased in smc_recvmsg */ | |
211 | smp_mb__before_atomic(); | |
212 | atomic_add(diff_prod, &conn->bytes_to_rcv); | |
213 | /* guarantee 0 <= bytes_to_rcv <= rmbe_size */ | |
214 | smp_mb__after_atomic(); | |
952310cc | 215 | smc->sk.sk_data_ready(&smc->sk); |
5f08318f UB |
216 | } |
217 | ||
b38d7324 | 218 | if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) { |
5f08318f | 219 | smc->sk.sk_err = ECONNRESET; |
b38d7324 UB |
220 | conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; |
221 | } | |
46c28dbd UB |
222 | if (smc_cdc_rxed_any_close_or_senddone(conn)) { |
223 | smc->sk.sk_shutdown |= RCV_SHUTDOWN; | |
224 | if (smc->clcsock && smc->clcsock->sk) | |
225 | smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN; | |
226 | sock_set_flag(&smc->sk, SOCK_DONE); | |
227 | schedule_work(&conn->close_work); | |
228 | } | |
5f08318f UB |
229 | |
230 | /* piggy backed tx info */ | |
e6727f39 | 231 | /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */ |
b38d7324 | 232 | if (diff_cons && smc_tx_prepared_sends(conn)) { |
e6727f39 | 233 | smc_tx_sndbuf_nonempty(conn); |
b38d7324 UB |
234 | /* trigger socket release if connection closed */ |
235 | smc_close_wake_tx_prepared(smc); | |
236 | } | |
5f08318f | 237 | |
5f08318f UB |
238 | /* socket connected but not accepted */ |
239 | if (!smc->sk.sk_socket) | |
240 | return; | |
241 | ||
242 | /* data available */ | |
952310cc UB |
243 | if ((conn->local_rx_ctrl.prod_flags.write_blocked) || |
244 | (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req)) | |
245 | smc_tx_consumer_update(conn); | |
5f08318f UB |
246 | } |
247 | ||
248 | /* called under tasklet context */ | |
249 | static inline void smc_cdc_msg_recv(struct smc_cdc_msg *cdc, | |
250 | struct smc_link *link, u64 wr_id) | |
251 | { | |
252 | struct smc_link_group *lgr = container_of(link, struct smc_link_group, | |
253 | lnk[SMC_SINGLE_LINK]); | |
254 | struct smc_connection *connection; | |
255 | struct smc_sock *smc; | |
256 | ||
257 | /* lookup connection */ | |
258 | read_lock_bh(&lgr->conns_lock); | |
259 | connection = smc_lgr_find_conn(ntohl(cdc->token), lgr); | |
260 | if (!connection) { | |
261 | read_unlock_bh(&lgr->conns_lock); | |
262 | return; | |
263 | } | |
264 | smc = container_of(connection, struct smc_sock, conn); | |
265 | sock_hold(&smc->sk); | |
266 | read_unlock_bh(&lgr->conns_lock); | |
267 | bh_lock_sock(&smc->sk); | |
268 | smc_cdc_msg_recv_action(smc, link, cdc); | |
269 | bh_unlock_sock(&smc->sk); | |
270 | sock_put(&smc->sk); /* no free sk in softirq-context */ | |
271 | } | |
272 | ||
273 | /***************************** init, exit, misc ******************************/ | |
274 | ||
275 | static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf) | |
276 | { | |
277 | struct smc_link *link = (struct smc_link *)wc->qp->qp_context; | |
278 | struct smc_cdc_msg *cdc = buf; | |
279 | ||
280 | if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved)) | |
281 | return; /* short message */ | |
282 | if (cdc->len != sizeof(*cdc)) | |
283 | return; /* invalid message */ | |
284 | smc_cdc_msg_recv(cdc, link, wc->wr_id); | |
285 | } | |
286 | ||
287 | static struct smc_wr_rx_handler smc_cdc_rx_handlers[] = { | |
288 | { | |
289 | .handler = smc_cdc_rx_handler, | |
290 | .type = SMC_CDC_MSG_TYPE | |
291 | }, | |
292 | { | |
293 | .handler = NULL, | |
294 | } | |
295 | }; | |
296 | ||
297 | int __init smc_cdc_init(void) | |
298 | { | |
299 | struct smc_wr_rx_handler *handler; | |
300 | int rc = 0; | |
301 | ||
302 | for (handler = smc_cdc_rx_handlers; handler->handler; handler++) { | |
303 | INIT_HLIST_NODE(&handler->list); | |
304 | rc = smc_wr_rx_register_handler(handler); | |
305 | if (rc) | |
306 | break; | |
307 | } | |
308 | return rc; | |
309 | } |