net/smc/smc_llc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Link Layer Control (LLC)
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Klaus Wacker <Klaus.Wacker@de.ibm.com>
  10  *              Ursula Braun <ubraun@linux.vnet.ibm.com>
  11  */
  12
  13 #include <net/tcp.h>
  14 #include <rdma/ib_verbs.h>
  15
  16 #include "smc.h"
  17 #include "smc_core.h"
  18 #include "smc_clc.h"
  19 #include "smc_llc.h"
  20
  21 #define SMC_LLC_DATA_LEN                40
  22
  23 struct smc_llc_hdr {
  24         struct smc_wr_rx_hdr common;
  25         u8 length;      /* 44 */
  26 #if defined(__BIG_ENDIAN_BITFIELD)
  27         u8 reserved:4,
  28            add_link_rej_rsn:4;
  29 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  30         u8 add_link_rej_rsn:4,
  31            reserved:4;
  32 #endif
  33         u8 flags;
  34 };
  35
  36 #define SMC_LLC_FLAG_NO_RMBE_EYEC       0x03
  37
  38 struct smc_llc_msg_confirm_link {       /* type 0x01 */
  39         struct smc_llc_hdr hd;
  40         u8 sender_mac[ETH_ALEN];
  41         u8 sender_gid[SMC_GID_SIZE];
  42         u8 sender_qp_num[3];
  43         u8 link_num;
  44         u8 link_uid[SMC_LGR_ID_SIZE];
  45         u8 max_links;
  46         u8 reserved[9];
  47 };
  48
  49 #define SMC_LLC_FLAG_ADD_LNK_REJ        0x40
  50 #define SMC_LLC_REJ_RSN_NO_ALT_PATH     1
  51
  52 #define SMC_LLC_ADD_LNK_MAX_LINKS       2
  53
  54 struct smc_llc_msg_add_link {           /* type 0x02 */
  55         struct smc_llc_hdr hd;
  56         u8 sender_mac[ETH_ALEN];
  57         u8 reserved2[2];
  58         u8 sender_gid[SMC_GID_SIZE];
  59         u8 sender_qp_num[3];
  60         u8 link_num;
  61         u8 flags2;      /* QP mtu */
  62         u8 initial_psn[3];
  63         u8 reserved[8];
  64 };
  65
  66 #define SMC_LLC_FLAG_DEL_LINK_ALL       0x40
  67 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY   0x20
  68
  69 struct smc_llc_msg_del_link {           /* type 0x04 */
  70         struct smc_llc_hdr hd;
  71         u8 link_num;
  72         __be32 reason;
  73         u8 reserved[35];
  74 } __packed;                     /* format defined in RFC7609 */
  75
  76 struct smc_llc_msg_test_link {          /* type 0x07 */
  77         struct smc_llc_hdr hd;
  78         u8 user_data[16];
  79         u8 reserved[24];
  80 };
  81
  82 struct smc_rmb_rtoken {
  83         union {
  84                 u8 num_rkeys;   /* first rtoken byte of CONFIRM LINK msg */
  85                                 /* is actually the num of rtokens, first */
  86                                 /* rtoken is always for the current link */
  87                 u8 link_id;     /* link id of the rtoken */
  88         };
  89         __be32 rmb_key;
  90         __be64 rmb_vaddr;
  91 } __packed;                     /* format defined in RFC7609 */
  92
  93 #define SMC_LLC_RKEYS_PER_MSG   3
  94
  95 struct smc_llc_msg_confirm_rkey {       /* type 0x06 */
  96         struct smc_llc_hdr hd;
  97         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
  98         u8 reserved;
  99 };
 100
 101 struct smc_llc_msg_confirm_rkey_cont {  /* type 0x08 */
 102         struct smc_llc_hdr hd;
 103         u8 num_rkeys;
 104         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
 105 };
 106
 107 #define SMC_LLC_DEL_RKEY_MAX    8
 108 #define SMC_LLC_FLAG_RKEY_NEG   0x20
 109
 110 struct smc_llc_msg_delete_rkey {        /* type 0x09 */
 111         struct smc_llc_hdr hd;
 112         u8 num_rkeys;
 113         u8 err_mask;
 114         u8 reserved[2];
 115         __be32 rkey[8];
 116         u8 reserved2[4];
 117 };
 118
 119 union smc_llc_msg {
 120         struct smc_llc_msg_confirm_link confirm_link;
 121         struct smc_llc_msg_add_link add_link;
 122         struct smc_llc_msg_del_link delete_link;
 123
 124         struct smc_llc_msg_confirm_rkey confirm_rkey;
 125         struct smc_llc_msg_confirm_rkey_cont confirm_rkey_cont;
 126         struct smc_llc_msg_delete_rkey delete_rkey;
 127
 128         struct smc_llc_msg_test_link test_link;
 129         struct {
 130                 struct smc_llc_hdr hdr;
 131                 u8 data[SMC_LLC_DATA_LEN];
 132         } raw;
 133 };
 134
 135 #define SMC_LLC_FLAG_RESP               0x80
 136
 137 /********************************** send *************************************/
 138
 139 struct smc_llc_tx_pend {
 140 };
 141
 142 /* handler for send/transmission completion of an LLC msg */
 143 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
 144                                struct smc_link *link,
 145                                enum ib_wc_status wc_status)
 146 {
 147         /* future work: handle wc_status error for recovery and failover */
 148 }
 149
 150 /**
 151  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
 152  * @link: Pointer to SMC link used for sending LLC control message.
 153  * @wr_buf: Out variable returning pointer to work request payload buffer.
 154  * @pend: Out variable returning pointer to private pending WR tracking.
 155  *        It's the context the transmit complete handler will get.
 156  *
 157  * Reserves and pre-fills an entry for a pending work request send/tx.
 158  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
 159  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
 160  *
 161  * Return: 0 on success, otherwise an error value.
 162  */
 163 static int smc_llc_add_pending_send(struct smc_link *link,
 164                                     struct smc_wr_buf **wr_buf,
 165                                     struct smc_wr_tx_pend_priv **pend)
 166 {
 167         int rc;
 168
 169         rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, pend);
 170         if (rc < 0)
 171                 return rc;
 172         BUILD_BUG_ON_MSG(
 173                 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
 174                 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
 175         BUILD_BUG_ON_MSG(
 176                 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
 177                 "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()");
 178         BUILD_BUG_ON_MSG(
 179                 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
 180                 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
 181         return 0;
 182 }
 183
 184 /* high-level API to send LLC confirm link */
 185 int smc_llc_send_confirm_link(struct smc_link *link,
 186                               enum smc_llc_reqresp reqresp)
 187 {
 188         struct smc_link_group *lgr = smc_get_lgr(link);
 189         struct smc_llc_msg_confirm_link *confllc;
 190         struct smc_wr_tx_pend_priv *pend;
 191         struct smc_wr_buf *wr_buf;
 192         int rc;
 193
 194         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 195         if (rc)
 196                 return rc;
 197         confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
 198         memset(confllc, 0, sizeof(*confllc));
 199         confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 200         confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
 201         confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 202         if (reqresp == SMC_LLC_RESP)
 203                 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 204         memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
 205                ETH_ALEN);
 206         memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
 207         hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 208         confllc->link_num = link->link_id;
 209         memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
 210         confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* enforce peer resp. */
 211         /* send llc message */
 212         rc = smc_wr_tx_send(link, pend);
 213         return rc;
 214 }
 215
 216 /* send LLC confirm rkey request */
 217 static int smc_llc_send_confirm_rkey(struct smc_link *link,
 218                                      struct smc_buf_desc *rmb_desc)
 219 {
 220         struct smc_llc_msg_confirm_rkey *rkeyllc;
 221         struct smc_wr_tx_pend_priv *pend;
 222         struct smc_wr_buf *wr_buf;
 223         int rc;
 224
 225         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 226         if (rc)
 227                 return rc;
 228         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 229         memset(rkeyllc, 0, sizeof(*rkeyllc));
 230         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 231         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 232         rkeyllc->rtoken[0].rmb_key =
 233                 htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 234         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 235                 (u64)sg_dma_address(rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 236         /* send llc message */
 237         rc = smc_wr_tx_send(link, pend);
 238         return rc;
 239 }
 240
 241 /* prepare an add link message */
 242 static void smc_llc_prep_add_link(struct smc_llc_msg_add_link *addllc,
 243                                   struct smc_link *link, u8 mac[], u8 gid[],
 244                                   enum smc_llc_reqresp reqresp)
 245 {
 246         memset(addllc, 0, sizeof(*addllc));
 247         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 248         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 249         if (reqresp == SMC_LLC_RESP) {
 250                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 251                 /* always reject more links for now */
 252                 addllc->hd.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 253                 addllc->hd.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 254         }
 255         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 256         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 257 }
 258
 259 /* send ADD LINK request or response */
 260 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
 261                           enum smc_llc_reqresp reqresp)
 262 {
 263         struct smc_llc_msg_add_link *addllc;
 264         struct smc_wr_tx_pend_priv *pend;
 265         struct smc_wr_buf *wr_buf;
 266         int rc;
 267
 268         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 269         if (rc)
 270                 return rc;
 271         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 272         smc_llc_prep_add_link(addllc, link, mac, gid, reqresp);
 273         /* send llc message */
 274         rc = smc_wr_tx_send(link, pend);
 275         return rc;
 276 }
 277
 278 /* prepare a delete link message */
 279 static void smc_llc_prep_delete_link(struct smc_llc_msg_del_link *delllc,
 280                                      struct smc_link *link,
 281                                      enum smc_llc_reqresp reqresp)
 282 {
 283         memset(delllc, 0, sizeof(*delllc));
 284         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 285         delllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 286         if (reqresp == SMC_LLC_RESP)
 287                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 288         /* DEL_LINK_ALL because only 1 link supported */
 289         delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 290         delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 291         delllc->link_num = link->link_id;
 292 }
 293
 294 /* send DELETE LINK request or response */
 295 int smc_llc_send_delete_link(struct smc_link *link,
 296                              enum smc_llc_reqresp reqresp)
 297 {
 298         struct smc_llc_msg_del_link *delllc;
 299         struct smc_wr_tx_pend_priv *pend;
 300         struct smc_wr_buf *wr_buf;
 301         int rc;
 302
 303         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 304         if (rc)
 305                 return rc;
 306         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 307         smc_llc_prep_delete_link(delllc, link, reqresp);
 308         /* send llc message */
 309         rc = smc_wr_tx_send(link, pend);
 310         return rc;
 311 }
 312
 313 /* send LLC test link request */
 314 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 315 {
 316         struct smc_llc_msg_test_link *testllc;
 317         struct smc_wr_tx_pend_priv *pend;
 318         struct smc_wr_buf *wr_buf;
 319         int rc;
 320
 321         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 322         if (rc)
 323                 return rc;
 324         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 325         memset(testllc, 0, sizeof(*testllc));
 326         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 327         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 328         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 329         /* send llc message */
 330         rc = smc_wr_tx_send(link, pend);
 331         return rc;
 332 }
 333
 334 struct smc_llc_send_work {
 335         struct work_struct work;
 336         struct smc_link *link;
 337         int llclen;
 338         union smc_llc_msg llcbuf;
 339 };
 340
 341 /* worker that sends a prepared message */
 342 static void smc_llc_send_message_work(struct work_struct *work)
 343 {
 344         struct smc_llc_send_work *llcwrk = container_of(work,
 345                                                 struct smc_llc_send_work, work);
 346         struct smc_wr_tx_pend_priv *pend;
 347         struct smc_wr_buf *wr_buf;
 348         int rc;
 349
 350         if (llcwrk->link->state == SMC_LNK_INACTIVE)
 351                 goto out;
 352         rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend);
 353         if (rc)
 354                 goto out;
 355         memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen);
 356         smc_wr_tx_send(llcwrk->link, pend);
 357 out:
 358         kfree(llcwrk);
 359 }
 360
 361 /* copy llcbuf and schedule an llc send on link */
 362 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
 363 {
 364         struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 365
 366         if (!wrk)
 367                 return -ENOMEM;
 368         INIT_WORK(&wrk->work, smc_llc_send_message_work);
 369         wrk->link = link;
 370         wrk->llclen = llclen;
 371         memcpy(&wrk->llcbuf, llcbuf, llclen);
 372         queue_work(link->llc_wq, &wrk->work);
 373         return 0;
 374 }
 375
 376 /********************************* receive ***********************************/
 377
 378 static void smc_llc_rx_confirm_link(struct smc_link *link,
 379                                     struct smc_llc_msg_confirm_link *llc)
 380 {
 381         struct smc_link_group *lgr = smc_get_lgr(link);
 382         int conf_rc;
 383
 384         /* RMBE eyecatchers are not supported */
 385         if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
 386                 conf_rc = 0;
 387         else
 388                 conf_rc = ENOTSUPP;
 389
 390         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 391                 if (lgr->role == SMC_SERV &&
 392                     link->state == SMC_LNK_ACTIVATING) {
 393                         link->llc_confirm_resp_rc = conf_rc;
 394                         complete(&link->llc_confirm_resp);
 395                 }
 396         } else {
 397                 if (lgr->role == SMC_CLNT &&
 398                     link->state == SMC_LNK_ACTIVATING) {
 399                         link->llc_confirm_rc = conf_rc;
 400                         link->link_id = llc->link_num;
 401                         complete(&link->llc_confirm);
 402                 }
 403         }
 404 }
 405
 406 static void smc_llc_rx_add_link(struct smc_link *link,
 407                                 struct smc_llc_msg_add_link *llc)
 408 {
 409         struct smc_link_group *lgr = smc_get_lgr(link);
 410
 411         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 412                 if (link->state == SMC_LNK_ACTIVATING)
 413                         complete(&link->llc_add_resp);
 414         } else {
 415                 if (link->state == SMC_LNK_ACTIVATING) {
 416                         complete(&link->llc_add);
 417                         return;
 418                 }
 419
 420                 if (lgr->role == SMC_SERV) {
 421                         smc_llc_prep_add_link(llc, link,
 422                                         link->smcibdev->mac[link->ibport - 1],
 423                                         link->gid, SMC_LLC_REQ);
 424
 425                 } else {
 426                         smc_llc_prep_add_link(llc, link,
 427                                         link->smcibdev->mac[link->ibport - 1],
 428                                         link->gid, SMC_LLC_RESP);
 429                 }
 430                 smc_llc_send_message(link, llc, sizeof(*llc));
 431         }
 432 }
 433
 434 static void smc_llc_rx_delete_link(struct smc_link *link,
 435                                    struct smc_llc_msg_del_link *llc)
 436 {
 437         struct smc_link_group *lgr = smc_get_lgr(link);
 438
 439         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 440                 if (lgr->role == SMC_SERV)
 441                         smc_lgr_terminate(lgr);
 442         } else {
 443                 if (lgr->role == SMC_SERV) {
 444                         smc_lgr_forget(lgr);
 445                         smc_llc_prep_delete_link(llc, link, SMC_LLC_REQ);
 446                         smc_llc_send_message(link, llc, sizeof(*llc));
 447                 } else {
 448                         smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP);
 449                         smc_llc_send_message(link, llc, sizeof(*llc));
 450                         smc_lgr_terminate(lgr);
 451                 }
 452         }
 453 }
 454
 455 static void smc_llc_rx_test_link(struct smc_link *link,
 456                                  struct smc_llc_msg_test_link *llc)
 457 {
 458         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 459                 if (link->state == SMC_LNK_ACTIVE)
 460                         complete(&link->llc_testlink_resp);
 461         } else {
 462                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 463                 smc_llc_send_message(link, llc, sizeof(*llc));
 464         }
 465 }
 466
 467 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
 468                                     struct smc_llc_msg_confirm_rkey *llc)
 469 {
 470         int rc;
 471
 472         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 473                 link->llc_confirm_rkey_rc = llc->hd.flags &
 474                                             SMC_LLC_FLAG_RKEY_NEG;
 475                 complete(&link->llc_confirm_rkey);
 476         } else {
 477                 rc = smc_rtoken_add(smc_get_lgr(link),
 478                                     llc->rtoken[0].rmb_vaddr,
 479                                     llc->rtoken[0].rmb_key);
 480
 481                 /* ignore rtokens for other links, we have only one link */
 482
 483                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 484                 if (rc < 0)
 485                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 486                 smc_llc_send_message(link, llc, sizeof(*llc));
 487         }
 488 }
 489
 490 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
 491                                       struct smc_llc_msg_confirm_rkey_cont *llc)
 492 {
 493         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 494                 /* unused as long as we don't send this type of msg */
 495         } else {
 496                 /* ignore rtokens for other links, we have only one link */
 497                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 498                 smc_llc_send_message(link, llc, sizeof(*llc));
 499         }
 500 }
 501
 502 static void smc_llc_rx_delete_rkey(struct smc_link *link,
 503                                    struct smc_llc_msg_delete_rkey *llc)
 504 {
 505         u8 err_mask = 0;
 506         int i, max;
 507
 508         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 509                 /* unused as long as we don't send this type of msg */
 510         } else {
 511                 max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
 512                 for (i = 0; i < max; i++) {
 513                         if (smc_rtoken_delete(smc_get_lgr(link), llc->rkey[i]))
 514                                 err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
 515                 }
 516
 517                 if (err_mask) {
 518                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 519                         llc->err_mask = err_mask;
 520                 }
 521
 522                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 523                 smc_llc_send_message(link, llc, sizeof(*llc));
 524         }
 525 }
 526
 527 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
 528 {
 529         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
 530         union smc_llc_msg *llc = buf;
 531
 532         if (wc->byte_len < sizeof(*llc))
 533                 return; /* short message */
 534         if (llc->raw.hdr.length != sizeof(*llc))
 535                 return; /* invalid message */
 536         if (link->state == SMC_LNK_INACTIVE)
 537                 return; /* link not active, drop msg */
 538
 539         switch (llc->raw.hdr.common.type) {
 540         case SMC_LLC_TEST_LINK:
 541                 smc_llc_rx_test_link(link, &llc->test_link);
 542                 break;
 543         case SMC_LLC_CONFIRM_LINK:
 544                 smc_llc_rx_confirm_link(link, &llc->confirm_link);
 545                 break;
 546         case SMC_LLC_ADD_LINK:
 547                 smc_llc_rx_add_link(link, &llc->add_link);
 548                 break;
 549         case SMC_LLC_DELETE_LINK:
 550                 smc_llc_rx_delete_link(link, &llc->delete_link);
 551                 break;
 552         case SMC_LLC_CONFIRM_RKEY:
 553                 smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
 554                 break;
 555         case SMC_LLC_CONFIRM_RKEY_CONT:
 556                 smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
 557                 break;
 558         case SMC_LLC_DELETE_RKEY:
 559                 smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
 560                 break;
 561         }
 562 }
 563
 564 /***************************** worker, utils *********************************/
 565
 566 static void smc_llc_testlink_work(struct work_struct *work)
 567 {
 568         struct smc_link *link = container_of(to_delayed_work(work),
 569                                              struct smc_link, llc_testlink_wrk);
 570         unsigned long next_interval;
 571         unsigned long expire_time;
 572         u8 user_data[16] = { 0 };
 573         int rc;
 574
 575         if (link->state != SMC_LNK_ACTIVE)
 576                 return;         /* don't reschedule worker */
 577         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
 578         if (time_is_after_jiffies(expire_time)) {
 579                 next_interval = expire_time - jiffies;
 580                 goto out;
 581         }
 582         reinit_completion(&link->llc_testlink_resp);
 583         smc_llc_send_test_link(link, user_data);
 584         /* receive TEST LINK response over RoCE fabric */
 585         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
 586                                                        SMC_LLC_WAIT_TIME);
 587         if (rc <= 0) {
 588                 smc_lgr_terminate(smc_get_lgr(link));
 589                 return;
 590         }
 591         next_interval = link->llc_testlink_time;
 592 out:
 593         queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 594                            next_interval);
 595 }
 596
 597 int smc_llc_link_init(struct smc_link *link)
 598 {
 599         struct smc_link_group *lgr = smc_get_lgr(link);
 600         link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM,
 601                                                *((u32 *)lgr->id),
 602                                                link->link_id);
 603         if (!link->llc_wq)
 604                 return -ENOMEM;
 605         init_completion(&link->llc_confirm);
 606         init_completion(&link->llc_confirm_resp);
 607         init_completion(&link->llc_add);
 608         init_completion(&link->llc_add_resp);
 609         init_completion(&link->llc_confirm_rkey);
 610         init_completion(&link->llc_testlink_resp);
 611         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
 612         return 0;
 613 }
 614
 615 void smc_llc_link_active(struct smc_link *link, int testlink_time)
 616 {
 617         link->state = SMC_LNK_ACTIVE;
 618         if (testlink_time) {
 619                 link->llc_testlink_time = testlink_time * HZ;
 620                 queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 621                                    link->llc_testlink_time);
 622         }
 623 }
 624
 625 /* called in tasklet context */
 626 void smc_llc_link_inactive(struct smc_link *link)
 627 {
 628         link->state = SMC_LNK_INACTIVE;
 629         cancel_delayed_work(&link->llc_testlink_wrk);
 630 }
 631
 632 /* called in worker context */
 633 void smc_llc_link_clear(struct smc_link *link)
 634 {
 635         flush_workqueue(link->llc_wq);
 636         destroy_workqueue(link->llc_wq);
 637 }
 638
 639 /* register a new rtoken at the remote peer */
 640 int smc_llc_do_confirm_rkey(struct smc_link *link,
 641                             struct smc_buf_desc *rmb_desc)
 642 {
 643         int rc;
 644
 645         reinit_completion(&link->llc_confirm_rkey);
 646         smc_llc_send_confirm_rkey(link, rmb_desc);
 647         /* receive CONFIRM RKEY response from server over RoCE fabric */
 648         rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
 649                                                        SMC_LLC_WAIT_TIME);
 650         if (rc <= 0 || link->llc_confirm_rkey_rc)
 651                 return -EFAULT;
 652         return 0;
 653 }
 654
 655 /***************************** init, exit, misc ******************************/
 656
 657 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
 658         {
 659                 .handler        = smc_llc_rx_handler,
 660                 .type           = SMC_LLC_CONFIRM_LINK
 661         },
 662         {
 663                 .handler        = smc_llc_rx_handler,
 664                 .type           = SMC_LLC_TEST_LINK
 665         },
 666         {
 667                 .handler        = smc_llc_rx_handler,
 668                 .type           = SMC_LLC_ADD_LINK
 669         },
 670         {
 671                 .handler        = smc_llc_rx_handler,
 672                 .type           = SMC_LLC_DELETE_LINK
 673         },
 674         {
 675                 .handler        = smc_llc_rx_handler,
 676                 .type           = SMC_LLC_CONFIRM_RKEY
 677         },
 678         {
 679                 .handler        = smc_llc_rx_handler,
 680                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
 681         },
 682         {
 683                 .handler        = smc_llc_rx_handler,
 684                 .type           = SMC_LLC_DELETE_RKEY
 685         },
 686         {
 687                 .handler        = NULL,
 688         }
 689 };
 690
 691 int __init smc_llc_init(void)
 692 {
 693         struct smc_wr_rx_handler *handler;
 694         int rc = 0;
 695
 696         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
 697                 INIT_HLIST_NODE(&handler->list);
 698                 rc = smc_wr_rx_register_handler(handler);
 699                 if (rc)
 700                         break;
 701         }
 702         return rc;
 703 }