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 <[email protected]>
  10  *              Ursula Braun <[email protected]>
  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, u8 mac[],
 186                               union ib_gid *gid,
 187                               enum smc_llc_reqresp reqresp)
 188 {
 189         struct smc_link_group *lgr = container_of(link, struct smc_link_group,
 190                                                   lnk[SMC_SINGLE_LINK]);
 191         struct smc_llc_msg_confirm_link *confllc;
 192         struct smc_wr_tx_pend_priv *pend;
 193         struct smc_wr_buf *wr_buf;
 194         int rc;
 195
 196         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 197         if (rc)
 198                 return rc;
 199         confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
 200         memset(confllc, 0, sizeof(*confllc));
 201         confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 202         confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
 203         confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 204         if (reqresp == SMC_LLC_RESP)
 205                 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 206         memcpy(confllc->sender_mac, mac, ETH_ALEN);
 207         memcpy(confllc->sender_gid, gid, SMC_GID_SIZE);
 208         hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 209         confllc->link_num = link->link_id;
 210         memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
 211         confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* enforce peer resp. */
 212         /* send llc message */
 213         rc = smc_wr_tx_send(link, pend);
 214         return rc;
 215 }
 216
 217 /* send LLC confirm rkey request */
 218 static int smc_llc_send_confirm_rkey(struct smc_link *link,
 219                                      struct smc_buf_desc *rmb_desc)
 220 {
 221         struct smc_llc_msg_confirm_rkey *rkeyllc;
 222         struct smc_wr_tx_pend_priv *pend;
 223         struct smc_wr_buf *wr_buf;
 224         int rc;
 225
 226         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 227         if (rc)
 228                 return rc;
 229         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 230         memset(rkeyllc, 0, sizeof(*rkeyllc));
 231         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 232         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 233         rkeyllc->rtoken[0].rmb_key =
 234                 htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 235         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 236                 (u64)sg_dma_address(rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 237         /* send llc message */
 238         rc = smc_wr_tx_send(link, pend);
 239         return rc;
 240 }
 241
 242 /* prepare an add link message */
 243 static void smc_llc_prep_add_link(struct smc_llc_msg_add_link *addllc,
 244                                   struct smc_link *link, u8 mac[],
 245                                   union ib_gid *gid,
 246                                   enum smc_llc_reqresp reqresp)
 247 {
 248         memset(addllc, 0, sizeof(*addllc));
 249         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 250         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 251         if (reqresp == SMC_LLC_RESP) {
 252                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 253                 /* always reject more links for now */
 254                 addllc->hd.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 255                 addllc->hd.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 256         }
 257         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 258         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 259 }
 260
 261 /* send ADD LINK request or response */
 262 int smc_llc_send_add_link(struct smc_link *link, u8 mac[],
 263                           union ib_gid *gid,
 264                           enum smc_llc_reqresp reqresp)
 265 {
 266         struct smc_llc_msg_add_link *addllc;
 267         struct smc_wr_tx_pend_priv *pend;
 268         struct smc_wr_buf *wr_buf;
 269         int rc;
 270
 271         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 272         if (rc)
 273                 return rc;
 274         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 275         smc_llc_prep_add_link(addllc, link, mac, gid, reqresp);
 276         /* send llc message */
 277         rc = smc_wr_tx_send(link, pend);
 278         return rc;
 279 }
 280
 281 /* prepare a delete link message */
 282 static void smc_llc_prep_delete_link(struct smc_llc_msg_del_link *delllc,
 283                                      struct smc_link *link,
 284                                      enum smc_llc_reqresp reqresp)
 285 {
 286         memset(delllc, 0, sizeof(*delllc));
 287         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 288         delllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 289         if (reqresp == SMC_LLC_RESP)
 290                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 291         /* DEL_LINK_ALL because only 1 link supported */
 292         delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 293         delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 294         delllc->link_num = link->link_id;
 295 }
 296
 297 /* send DELETE LINK request or response */
 298 int smc_llc_send_delete_link(struct smc_link *link,
 299                              enum smc_llc_reqresp reqresp)
 300 {
 301         struct smc_llc_msg_del_link *delllc;
 302         struct smc_wr_tx_pend_priv *pend;
 303         struct smc_wr_buf *wr_buf;
 304         int rc;
 305
 306         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 307         if (rc)
 308                 return rc;
 309         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 310         smc_llc_prep_delete_link(delllc, link, reqresp);
 311         /* send llc message */
 312         rc = smc_wr_tx_send(link, pend);
 313         return rc;
 314 }
 315
 316 /* send LLC test link request */
 317 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 318 {
 319         struct smc_llc_msg_test_link *testllc;
 320         struct smc_wr_tx_pend_priv *pend;
 321         struct smc_wr_buf *wr_buf;
 322         int rc;
 323
 324         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 325         if (rc)
 326                 return rc;
 327         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 328         memset(testllc, 0, sizeof(*testllc));
 329         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 330         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 331         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 332         /* send llc message */
 333         rc = smc_wr_tx_send(link, pend);
 334         return rc;
 335 }
 336
 337 struct smc_llc_send_work {
 338         struct work_struct work;
 339         struct smc_link *link;
 340         int llclen;
 341         union smc_llc_msg llcbuf;
 342 };
 343
 344 /* worker that sends a prepared message */
 345 static void smc_llc_send_message_work(struct work_struct *work)
 346 {
 347         struct smc_llc_send_work *llcwrk = container_of(work,
 348                                                 struct smc_llc_send_work, work);
 349         struct smc_wr_tx_pend_priv *pend;
 350         struct smc_wr_buf *wr_buf;
 351         int rc;
 352
 353         if (llcwrk->link->state == SMC_LNK_INACTIVE)
 354                 goto out;
 355         rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend);
 356         if (rc)
 357                 goto out;
 358         memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen);
 359         smc_wr_tx_send(llcwrk->link, pend);
 360 out:
 361         kfree(llcwrk);
 362 }
 363
 364 /* copy llcbuf and schedule an llc send on link */
 365 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
 366 {
 367         struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 368
 369         if (!wrk)
 370                 return -ENOMEM;
 371         INIT_WORK(&wrk->work, smc_llc_send_message_work);
 372         wrk->link = link;
 373         wrk->llclen = llclen;
 374         memcpy(&wrk->llcbuf, llcbuf, llclen);
 375         queue_work(link->llc_wq, &wrk->work);
 376         return 0;
 377 }
 378
 379 /********************************* receive ***********************************/
 380
 381 static void smc_llc_rx_confirm_link(struct smc_link *link,
 382                                     struct smc_llc_msg_confirm_link *llc)
 383 {
 384         struct smc_link_group *lgr;
 385         int conf_rc;
 386
 387         lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
 388
 389         /* RMBE eyecatchers are not supported */
 390         if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
 391                 conf_rc = 0;
 392         else
 393                 conf_rc = ENOTSUPP;
 394
 395         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 396                 if (lgr->role == SMC_SERV &&
 397                     link->state == SMC_LNK_ACTIVATING) {
 398                         link->llc_confirm_resp_rc = conf_rc;
 399                         complete(&link->llc_confirm_resp);
 400                 }
 401         } else {
 402                 if (lgr->role == SMC_CLNT &&
 403                     link->state == SMC_LNK_ACTIVATING) {
 404                         link->llc_confirm_rc = conf_rc;
 405                         link->link_id = llc->link_num;
 406                         complete(&link->llc_confirm);
 407                 }
 408         }
 409 }
 410
 411 static void smc_llc_rx_add_link(struct smc_link *link,
 412                                 struct smc_llc_msg_add_link *llc)
 413 {
 414         struct smc_link_group *lgr = container_of(link, struct smc_link_group,
 415                                                   lnk[SMC_SINGLE_LINK]);
 416
 417         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 418                 if (link->state == SMC_LNK_ACTIVATING)
 419                         complete(&link->llc_add_resp);
 420         } else {
 421                 if (link->state == SMC_LNK_ACTIVATING) {
 422                         complete(&link->llc_add);
 423                         return;
 424                 }
 425
 426                 if (lgr->role == SMC_SERV) {
 427                         smc_llc_prep_add_link(llc, link,
 428                                         link->smcibdev->mac[link->ibport - 1],
 429                                         &link->smcibdev->gid[link->ibport - 1],
 430                                         SMC_LLC_REQ);
 431
 432                 } else {
 433                         smc_llc_prep_add_link(llc, link,
 434                                         link->smcibdev->mac[link->ibport - 1],
 435                                         &link->smcibdev->gid[link->ibport - 1],
 436                                         SMC_LLC_RESP);
 437                 }
 438                 smc_llc_send_message(link, llc, sizeof(*llc));
 439         }
 440 }
 441
 442 static void smc_llc_rx_delete_link(struct smc_link *link,
 443                                    struct smc_llc_msg_del_link *llc)
 444 {
 445         struct smc_link_group *lgr = container_of(link, struct smc_link_group,
 446                                                   lnk[SMC_SINGLE_LINK]);
 447
 448         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 449                 if (lgr->role == SMC_SERV)
 450                         smc_lgr_terminate(lgr);
 451         } else {
 452                 if (lgr->role == SMC_SERV) {
 453                         smc_lgr_forget(lgr);
 454                         smc_llc_prep_delete_link(llc, link, SMC_LLC_REQ);
 455                         smc_llc_send_message(link, llc, sizeof(*llc));
 456                 } else {
 457                         smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP);
 458                         smc_llc_send_message(link, llc, sizeof(*llc));
 459                         smc_lgr_terminate(lgr);
 460                 }
 461         }
 462 }
 463
 464 static void smc_llc_rx_test_link(struct smc_link *link,
 465                                  struct smc_llc_msg_test_link *llc)
 466 {
 467         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 468                 if (link->state == SMC_LNK_ACTIVE)
 469                         complete(&link->llc_testlink_resp);
 470         } else {
 471                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 472                 smc_llc_send_message(link, llc, sizeof(*llc));
 473         }
 474 }
 475
 476 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
 477                                     struct smc_llc_msg_confirm_rkey *llc)
 478 {
 479         struct smc_link_group *lgr;
 480         int rc;
 481
 482         lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
 483
 484         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 485                 link->llc_confirm_rkey_rc = llc->hd.flags &
 486                                             SMC_LLC_FLAG_RKEY_NEG;
 487                 complete(&link->llc_confirm_rkey);
 488         } else {
 489                 rc = smc_rtoken_add(lgr,
 490                                     llc->rtoken[0].rmb_vaddr,
 491                                     llc->rtoken[0].rmb_key);
 492
 493                 /* ignore rtokens for other links, we have only one link */
 494
 495                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 496                 if (rc < 0)
 497                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 498                 smc_llc_send_message(link, llc, sizeof(*llc));
 499         }
 500 }
 501
 502 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
 503                                       struct smc_llc_msg_confirm_rkey_cont *llc)
 504 {
 505         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 506                 /* unused as long as we don't send this type of msg */
 507         } else {
 508                 /* ignore rtokens for other links, we have only one link */
 509                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 510                 smc_llc_send_message(link, llc, sizeof(*llc));
 511         }
 512 }
 513
 514 static void smc_llc_rx_delete_rkey(struct smc_link *link,
 515                                    struct smc_llc_msg_delete_rkey *llc)
 516 {
 517         struct smc_link_group *lgr;
 518         u8 err_mask = 0;
 519         int i, max;
 520
 521         lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
 522
 523         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 524                 /* unused as long as we don't send this type of msg */
 525         } else {
 526                 max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
 527                 for (i = 0; i < max; i++) {
 528                         if (smc_rtoken_delete(lgr, llc->rkey[i]))
 529                                 err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
 530                 }
 531
 532                 if (err_mask) {
 533                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 534                         llc->err_mask = err_mask;
 535                 }
 536
 537                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 538                 smc_llc_send_message(link, llc, sizeof(*llc));
 539         }
 540 }
 541
 542 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
 543 {
 544         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
 545         union smc_llc_msg *llc = buf;
 546
 547         if (wc->byte_len < sizeof(*llc))
 548                 return; /* short message */
 549         if (llc->raw.hdr.length != sizeof(*llc))
 550                 return; /* invalid message */
 551         if (link->state == SMC_LNK_INACTIVE)
 552                 return; /* link not active, drop msg */
 553
 554         switch (llc->raw.hdr.common.type) {
 555         case SMC_LLC_TEST_LINK:
 556                 smc_llc_rx_test_link(link, &llc->test_link);
 557                 break;
 558         case SMC_LLC_CONFIRM_LINK:
 559                 smc_llc_rx_confirm_link(link, &llc->confirm_link);
 560                 break;
 561         case SMC_LLC_ADD_LINK:
 562                 smc_llc_rx_add_link(link, &llc->add_link);
 563                 break;
 564         case SMC_LLC_DELETE_LINK:
 565                 smc_llc_rx_delete_link(link, &llc->delete_link);
 566                 break;
 567         case SMC_LLC_CONFIRM_RKEY:
 568                 smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
 569                 break;
 570         case SMC_LLC_CONFIRM_RKEY_CONT:
 571                 smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
 572                 break;
 573         case SMC_LLC_DELETE_RKEY:
 574                 smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
 575                 break;
 576         }
 577 }
 578
 579 /***************************** worker, utils *********************************/
 580
 581 static void smc_llc_testlink_work(struct work_struct *work)
 582 {
 583         struct smc_link *link = container_of(to_delayed_work(work),
 584                                              struct smc_link, llc_testlink_wrk);
 585         unsigned long next_interval;
 586         struct smc_link_group *lgr;
 587         unsigned long expire_time;
 588         u8 user_data[16] = { 0 };
 589         int rc;
 590
 591         lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
 592         if (link->state != SMC_LNK_ACTIVE)
 593                 return;         /* don't reschedule worker */
 594         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
 595         if (time_is_after_jiffies(expire_time)) {
 596                 next_interval = expire_time - jiffies;
 597                 goto out;
 598         }
 599         reinit_completion(&link->llc_testlink_resp);
 600         smc_llc_send_test_link(link, user_data);
 601         /* receive TEST LINK response over RoCE fabric */
 602         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
 603                                                        SMC_LLC_WAIT_TIME);
 604         if (rc <= 0) {
 605                 smc_lgr_terminate(lgr);
 606                 return;
 607         }
 608         next_interval = link->llc_testlink_time;
 609 out:
 610         queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 611                            next_interval);
 612 }
 613
 614 int smc_llc_link_init(struct smc_link *link)
 615 {
 616         struct smc_link_group *lgr = container_of(link, struct smc_link_group,
 617                                                   lnk[SMC_SINGLE_LINK]);
 618         link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM,
 619                                                *((u32 *)lgr->id),
 620                                                link->link_id);
 621         if (!link->llc_wq)
 622                 return -ENOMEM;
 623         init_completion(&link->llc_confirm);
 624         init_completion(&link->llc_confirm_resp);
 625         init_completion(&link->llc_add);
 626         init_completion(&link->llc_add_resp);
 627         init_completion(&link->llc_confirm_rkey);
 628         init_completion(&link->llc_testlink_resp);
 629         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
 630         return 0;
 631 }
 632
 633 void smc_llc_link_active(struct smc_link *link, int testlink_time)
 634 {
 635         link->state = SMC_LNK_ACTIVE;
 636         if (testlink_time) {
 637                 link->llc_testlink_time = testlink_time * HZ;
 638                 queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 639                                    link->llc_testlink_time);
 640         }
 641 }
 642
 643 /* called in tasklet context */
 644 void smc_llc_link_inactive(struct smc_link *link)
 645 {
 646         link->state = SMC_LNK_INACTIVE;
 647         cancel_delayed_work(&link->llc_testlink_wrk);
 648 }
 649
 650 /* called in worker context */
 651 void smc_llc_link_clear(struct smc_link *link)
 652 {
 653         flush_workqueue(link->llc_wq);
 654         destroy_workqueue(link->llc_wq);
 655 }
 656
 657 /* register a new rtoken at the remote peer */
 658 int smc_llc_do_confirm_rkey(struct smc_link *link,
 659                             struct smc_buf_desc *rmb_desc)
 660 {
 661         int rc;
 662
 663         reinit_completion(&link->llc_confirm_rkey);
 664         smc_llc_send_confirm_rkey(link, rmb_desc);
 665         /* receive CONFIRM RKEY response from server over RoCE fabric */
 666         rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
 667                                                        SMC_LLC_WAIT_TIME);
 668         if (rc <= 0 || link->llc_confirm_rkey_rc)
 669                 return -EFAULT;
 670         return 0;
 671 }
 672
 673 /***************************** init, exit, misc ******************************/
 674
 675 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
 676         {
 677                 .handler        = smc_llc_rx_handler,
 678                 .type           = SMC_LLC_CONFIRM_LINK
 679         },
 680         {
 681                 .handler        = smc_llc_rx_handler,
 682                 .type           = SMC_LLC_TEST_LINK
 683         },
 684         {
 685                 .handler        = smc_llc_rx_handler,
 686                 .type           = SMC_LLC_ADD_LINK
 687         },
 688         {
 689                 .handler        = smc_llc_rx_handler,
 690                 .type           = SMC_LLC_DELETE_LINK
 691         },
 692         {
 693                 .handler        = smc_llc_rx_handler,
 694                 .type           = SMC_LLC_CONFIRM_RKEY
 695         },
 696         {
 697                 .handler        = smc_llc_rx_handler,
 698                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
 699         },
 700         {
 701                 .handler        = smc_llc_rx_handler,
 702                 .type           = SMC_LLC_DELETE_RKEY
 703         },
 704         {
 705                 .handler        = NULL,
 706         }
 707 };
 708
 709 int __init smc_llc_init(void)
 710 {
 711         struct smc_wr_rx_handler *handler;
 712         int rc = 0;
 713
 714         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
 715                 INIT_HLIST_NODE(&handler->list);
 716                 rc = smc_wr_rx_register_handler(handler);
 717                 if (rc)
 718                         break;
 719         }
 720         return rc;
 721 }