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