1 // SPDX-License-Identifier: GPL-2.0
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
5 * Link Layer Control (LLC)
7 * For now, we only support the necessary "confirm link" functionality
8 * which happens for the first RoCE link after successful CLC handshake.
10 * Copyright IBM Corp. 2016
12 * Author(s): Klaus Wacker <Klaus.Wacker@de.ibm.com>
13 * Ursula Braun <ubraun@linux.vnet.ibm.com>
17 #include <rdma/ib_verbs.h>
24 #define SMC_LLC_DATA_LEN 40
27 struct smc_wr_rx_hdr common;
33 #define SMC_LLC_FLAG_NO_RMBE_EYEC 0x03
35 struct smc_llc_msg_confirm_link { /* type 0x01 */
36 struct smc_llc_hdr hd;
37 u8 sender_mac[ETH_ALEN];
38 u8 sender_gid[SMC_GID_SIZE];
41 u8 link_uid[SMC_LGR_ID_SIZE];
46 struct smc_llc_msg_test_link { /* type 0x07 */
47 struct smc_llc_hdr hd;
52 struct smc_rmb_rtoken {
54 u8 num_rkeys; /* first rtoken byte of CONFIRM LINK msg */
55 /* is actually the num of rtokens, first */
56 /* rtoken is always for the current link */
57 u8 link_id; /* link id of the rtoken */
61 } __packed; /* format defined in RFC7609 */
63 #define SMC_LLC_RKEYS_PER_MSG 3
65 struct smc_llc_msg_confirm_rkey { /* type 0x06 */
66 struct smc_llc_hdr hd;
67 struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
71 struct smc_llc_msg_confirm_rkey_cont { /* type 0x08 */
72 struct smc_llc_hdr hd;
74 struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
77 #define SMC_LLC_DEL_RKEY_MAX 8
78 #define SMC_LLC_FLAG_RKEY_NEG 0x20
80 struct smc_llc_msg_delete_rkey { /* type 0x09 */
81 struct smc_llc_hdr hd;
90 struct smc_llc_msg_confirm_link confirm_link;
92 struct smc_llc_msg_confirm_rkey confirm_rkey;
93 struct smc_llc_msg_confirm_rkey_cont confirm_rkey_cont;
94 struct smc_llc_msg_delete_rkey delete_rkey;
96 struct smc_llc_msg_test_link test_link;
98 struct smc_llc_hdr hdr;
99 u8 data[SMC_LLC_DATA_LEN];
103 #define SMC_LLC_FLAG_RESP 0x80
105 /********************************** send *************************************/
107 struct smc_llc_tx_pend {
110 /* handler for send/transmission completion of an LLC msg */
111 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
112 struct smc_link *link,
113 enum ib_wc_status wc_status)
115 /* future work: handle wc_status error for recovery and failover */
119 * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
120 * @link: Pointer to SMC link used for sending LLC control message.
121 * @wr_buf: Out variable returning pointer to work request payload buffer.
122 * @pend: Out variable returning pointer to private pending WR tracking.
123 * It's the context the transmit complete handler will get.
125 * Reserves and pre-fills an entry for a pending work request send/tx.
126 * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
127 * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
129 * Return: 0 on success, otherwise an error value.
131 static int smc_llc_add_pending_send(struct smc_link *link,
132 struct smc_wr_buf **wr_buf,
133 struct smc_wr_tx_pend_priv **pend)
137 rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, pend);
141 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
142 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
144 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
145 "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_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()");
147 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
148 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
152 /* high-level API to send LLC confirm link */
153 int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[],
155 enum smc_llc_reqresp reqresp)
157 struct smc_link_group *lgr = container_of(link, struct smc_link_group,
158 lnk[SMC_SINGLE_LINK]);
159 struct smc_llc_msg_confirm_link *confllc;
160 struct smc_wr_tx_pend_priv *pend;
161 struct smc_wr_buf *wr_buf;
164 rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
167 confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
168 memset(confllc, 0, sizeof(*confllc));
169 confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
170 confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
171 confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
172 if (reqresp == SMC_LLC_RESP)
173 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
174 memcpy(confllc->sender_mac, mac, ETH_ALEN);
175 memcpy(confllc->sender_gid, gid, SMC_GID_SIZE);
176 hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
177 /* confllc->link_num = SMC_SINGLE_LINK; already done by memset above */
178 memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
179 confllc->max_links = SMC_LINKS_PER_LGR_MAX;
180 /* send llc message */
181 rc = smc_wr_tx_send(link, pend);
185 /* send LLC test link request or response */
186 int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16],
187 enum smc_llc_reqresp reqresp)
189 struct smc_llc_msg_test_link *testllc;
190 struct smc_wr_tx_pend_priv *pend;
191 struct smc_wr_buf *wr_buf;
194 rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
197 testllc = (struct smc_llc_msg_test_link *)wr_buf;
198 memset(testllc, 0, sizeof(*testllc));
199 testllc->hd.common.type = SMC_LLC_TEST_LINK;
200 testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
201 if (reqresp == SMC_LLC_RESP)
202 testllc->hd.flags |= SMC_LLC_FLAG_RESP;
203 memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
204 /* send llc message */
205 rc = smc_wr_tx_send(link, pend);
209 /* send a prepared message */
210 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
212 struct smc_wr_tx_pend_priv *pend;
213 struct smc_wr_buf *wr_buf;
216 rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
219 memcpy(wr_buf, llcbuf, llclen);
220 /* send llc message */
221 rc = smc_wr_tx_send(link, pend);
225 /********************************* receive ***********************************/
227 static void smc_llc_rx_confirm_link(struct smc_link *link,
228 struct smc_llc_msg_confirm_link *llc)
230 struct smc_link_group *lgr;
233 lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
235 /* RMBE eyecatchers are not supported */
236 if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
241 if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
242 if (lgr->role == SMC_SERV) {
243 link->llc_confirm_resp_rc = conf_rc;
244 complete(&link->llc_confirm_resp);
247 if (lgr->role == SMC_CLNT) {
248 link->llc_confirm_rc = conf_rc;
249 link->link_id = llc->link_num;
250 complete(&link->llc_confirm);
255 static void smc_llc_rx_test_link(struct smc_link *link,
256 struct smc_llc_msg_test_link *llc)
258 if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
259 /* unused as long as we don't send this type of msg */
261 smc_llc_send_test_link(link, llc->user_data, SMC_LLC_RESP);
265 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
266 struct smc_llc_msg_confirm_rkey *llc)
268 struct smc_link_group *lgr;
271 lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
273 if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
274 /* unused as long as we don't send this type of msg */
276 rc = smc_rtoken_add(lgr,
277 llc->rtoken[0].rmb_vaddr,
278 llc->rtoken[0].rmb_key);
280 /* ignore rtokens for other links, we have only one link */
282 llc->hd.flags |= SMC_LLC_FLAG_RESP;
284 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
285 smc_llc_send_message(link, (void *)llc, sizeof(*llc));
289 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
290 struct smc_llc_msg_confirm_rkey_cont *llc)
292 if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
293 /* unused as long as we don't send this type of msg */
295 /* ignore rtokens for other links, we have only one link */
296 llc->hd.flags |= SMC_LLC_FLAG_RESP;
297 smc_llc_send_message(link, (void *)llc, sizeof(*llc));
301 static void smc_llc_rx_delete_rkey(struct smc_link *link,
302 struct smc_llc_msg_delete_rkey *llc)
304 struct smc_link_group *lgr;
308 lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
310 if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
311 /* unused as long as we don't send this type of msg */
313 max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
314 for (i = 0; i < max; i++) {
315 if (smc_rtoken_delete(lgr, llc->rkey[i]))
316 err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
320 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
321 llc->err_mask = err_mask;
324 llc->hd.flags |= SMC_LLC_FLAG_RESP;
325 smc_llc_send_message(link, (void *)llc, sizeof(*llc));
329 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
331 struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
332 union smc_llc_msg *llc = buf;
334 if (wc->byte_len < sizeof(*llc))
335 return; /* short message */
336 if (llc->raw.hdr.length != sizeof(*llc))
337 return; /* invalid message */
339 switch (llc->raw.hdr.common.type) {
340 case SMC_LLC_TEST_LINK:
341 smc_llc_rx_test_link(link, &llc->test_link);
343 case SMC_LLC_CONFIRM_LINK:
344 smc_llc_rx_confirm_link(link, &llc->confirm_link);
346 case SMC_LLC_CONFIRM_RKEY:
347 smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
349 case SMC_LLC_CONFIRM_RKEY_CONT:
350 smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
352 case SMC_LLC_DELETE_RKEY:
353 smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
358 /***************************** init, exit, misc ******************************/
360 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
362 .handler = smc_llc_rx_handler,
363 .type = SMC_LLC_CONFIRM_LINK
366 .handler = smc_llc_rx_handler,
367 .type = SMC_LLC_TEST_LINK
370 .handler = smc_llc_rx_handler,
371 .type = SMC_LLC_CONFIRM_RKEY
374 .handler = smc_llc_rx_handler,
375 .type = SMC_LLC_CONFIRM_RKEY_CONT
378 .handler = smc_llc_rx_handler,
379 .type = SMC_LLC_DELETE_RKEY
386 int __init smc_llc_init(void)
388 struct smc_wr_rx_handler *handler;
391 for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
392 INIT_HLIST_NODE(&handler->list);
393 rc = smc_wr_rx_register_handler(handler);