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 #include "smc_pnet.h"
  21
  22 #define SMC_LLC_DATA_LEN                40
  23
  24 struct smc_llc_hdr {
  25         struct smc_wr_rx_hdr common;
  26         u8 length;      /* 44 */
  27 #if defined(__BIG_ENDIAN_BITFIELD)
  28         u8 reserved:4,
  29            add_link_rej_rsn:4;
  30 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  31         u8 add_link_rej_rsn:4,
  32            reserved:4;
  33 #endif
  34         u8 flags;
  35 };
  36
  37 #define SMC_LLC_FLAG_NO_RMBE_EYEC       0x03
  38
  39 struct smc_llc_msg_confirm_link {       /* type 0x01 */
  40         struct smc_llc_hdr hd;
  41         u8 sender_mac[ETH_ALEN];
  42         u8 sender_gid[SMC_GID_SIZE];
  43         u8 sender_qp_num[3];
  44         u8 link_num;
  45         u8 link_uid[SMC_LGR_ID_SIZE];
  46         u8 max_links;
  47         u8 reserved[9];
  48 };
  49
  50 #define SMC_LLC_FLAG_ADD_LNK_REJ        0x40
  51 #define SMC_LLC_REJ_RSN_NO_ALT_PATH     1
  52
  53 #define SMC_LLC_ADD_LNK_MAX_LINKS       2
  54
  55 struct smc_llc_msg_add_link {           /* type 0x02 */
  56         struct smc_llc_hdr hd;
  57         u8 sender_mac[ETH_ALEN];
  58         u8 reserved2[2];
  59         u8 sender_gid[SMC_GID_SIZE];
  60         u8 sender_qp_num[3];
  61         u8 link_num;
  62 #if defined(__BIG_ENDIAN_BITFIELD)
  63         u8 reserved3 : 4,
  64            qp_mtu   : 4;
  65 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  66         u8 qp_mtu   : 4,
  67            reserved3 : 4;
  68 #endif
  69         u8 initial_psn[3];
  70         u8 reserved[8];
  71 };
  72
  73 struct smc_llc_msg_add_link_cont_rt {
  74         __be32 rmb_key;
  75         __be32 rmb_key_new;
  76         __be64 rmb_vaddr_new;
  77 };
  78
  79 #define SMC_LLC_RKEYS_PER_CONT_MSG      2
  80
  81 struct smc_llc_msg_add_link_cont {      /* type 0x03 */
  82         struct smc_llc_hdr hd;
  83         u8 link_num;
  84         u8 num_rkeys;
  85         u8 reserved2[2];
  86         struct smc_llc_msg_add_link_cont_rt rt[SMC_LLC_RKEYS_PER_CONT_MSG];
  87         u8 reserved[4];
  88 } __packed;                     /* format defined in RFC7609 */
  89
  90 #define SMC_LLC_FLAG_DEL_LINK_ALL       0x40
  91 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY   0x20
  92
  93 struct smc_llc_msg_del_link {           /* type 0x04 */
  94         struct smc_llc_hdr hd;
  95         u8 link_num;
  96         __be32 reason;
  97         u8 reserved[35];
  98 } __packed;                     /* format defined in RFC7609 */
  99
 100 struct smc_llc_msg_test_link {          /* type 0x07 */
 101         struct smc_llc_hdr hd;
 102         u8 user_data[16];
 103         u8 reserved[24];
 104 };
 105
 106 struct smc_rmb_rtoken {
 107         union {
 108                 u8 num_rkeys;   /* first rtoken byte of CONFIRM LINK msg */
 109                                 /* is actually the num of rtokens, first */
 110                                 /* rtoken is always for the current link */
 111                 u8 link_id;     /* link id of the rtoken */
 112         };
 113         __be32 rmb_key;
 114         __be64 rmb_vaddr;
 115 } __packed;                     /* format defined in RFC7609 */
 116
 117 #define SMC_LLC_RKEYS_PER_MSG   3
 118
 119 struct smc_llc_msg_confirm_rkey {       /* type 0x06 */
 120         struct smc_llc_hdr hd;
 121         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
 122         u8 reserved;
 123 };
 124
 125 #define SMC_LLC_DEL_RKEY_MAX    8
 126 #define SMC_LLC_FLAG_RKEY_RETRY 0x10
 127 #define SMC_LLC_FLAG_RKEY_NEG   0x20
 128
 129 struct smc_llc_msg_delete_rkey {        /* type 0x09 */
 130         struct smc_llc_hdr hd;
 131         u8 num_rkeys;
 132         u8 err_mask;
 133         u8 reserved[2];
 134         __be32 rkey[8];
 135         u8 reserved2[4];
 136 };
 137
 138 union smc_llc_msg {
 139         struct smc_llc_msg_confirm_link confirm_link;
 140         struct smc_llc_msg_add_link add_link;
 141         struct smc_llc_msg_add_link_cont add_link_cont;
 142         struct smc_llc_msg_del_link delete_link;
 143
 144         struct smc_llc_msg_confirm_rkey confirm_rkey;
 145         struct smc_llc_msg_delete_rkey delete_rkey;
 146
 147         struct smc_llc_msg_test_link test_link;
 148         struct {
 149                 struct smc_llc_hdr hdr;
 150                 u8 data[SMC_LLC_DATA_LEN];
 151         } raw;
 152 };
 153
 154 #define SMC_LLC_FLAG_RESP               0x80
 155
 156 struct smc_llc_qentry {
 157         struct list_head list;
 158         struct smc_link *link;
 159         union smc_llc_msg msg;
 160 };
 161
 162 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc);
 163
 164 struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow)
 165 {
 166         struct smc_llc_qentry *qentry = flow->qentry;
 167
 168         flow->qentry = NULL;
 169         return qentry;
 170 }
 171
 172 void smc_llc_flow_qentry_del(struct smc_llc_flow *flow)
 173 {
 174         struct smc_llc_qentry *qentry;
 175
 176         if (flow->qentry) {
 177                 qentry = flow->qentry;
 178                 flow->qentry = NULL;
 179                 kfree(qentry);
 180         }
 181 }
 182
 183 static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
 184                                            struct smc_llc_qentry *qentry)
 185 {
 186         flow->qentry = qentry;
 187 }
 188
 189 static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
 190                                   struct smc_llc_qentry *qentry)
 191 {
 192         u8 msg_type = qentry->msg.raw.hdr.common.type;
 193
 194         if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
 195             flow_type != msg_type && !lgr->delayed_event) {
 196                 lgr->delayed_event = qentry;
 197                 return;
 198         }
 199         /* drop parallel or already-in-progress llc requests */
 200         if (flow_type != msg_type)
 201                 pr_warn_once("smc: SMC-R lg %*phN dropped parallel "
 202                              "LLC msg: msg %d flow %d role %d\n",
 203                              SMC_LGR_ID_SIZE, &lgr->id,
 204                              qentry->msg.raw.hdr.common.type,
 205                              flow_type, lgr->role);
 206         kfree(qentry);
 207 }
 208
 209 /* try to start a new llc flow, initiated by an incoming llc msg */
 210 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 211                                struct smc_llc_qentry *qentry)
 212 {
 213         struct smc_link_group *lgr = qentry->link->lgr;
 214
 215         spin_lock_bh(&lgr->llc_flow_lock);
 216         if (flow->type) {
 217                 /* a flow is already active */
 218                 smc_llc_flow_parallel(lgr, flow->type, qentry);
 219                 spin_unlock_bh(&lgr->llc_flow_lock);
 220                 return false;
 221         }
 222         switch (qentry->msg.raw.hdr.common.type) {
 223         case SMC_LLC_ADD_LINK:
 224                 flow->type = SMC_LLC_FLOW_ADD_LINK;
 225                 break;
 226         case SMC_LLC_DELETE_LINK:
 227                 flow->type = SMC_LLC_FLOW_DEL_LINK;
 228                 break;
 229         case SMC_LLC_CONFIRM_RKEY:
 230         case SMC_LLC_DELETE_RKEY:
 231                 flow->type = SMC_LLC_FLOW_RKEY;
 232                 break;
 233         default:
 234                 flow->type = SMC_LLC_FLOW_NONE;
 235         }
 236         smc_llc_flow_qentry_set(flow, qentry);
 237         spin_unlock_bh(&lgr->llc_flow_lock);
 238         return true;
 239 }
 240
 241 /* start a new local llc flow, wait till current flow finished */
 242 int smc_llc_flow_initiate(struct smc_link_group *lgr,
 243                           enum smc_llc_flowtype type)
 244 {
 245         enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
 246         int rc;
 247
 248         /* all flows except confirm_rkey and delete_rkey are exclusive,
 249          * confirm/delete rkey flows can run concurrently (local and remote)
 250          */
 251         if (type == SMC_LLC_FLOW_RKEY)
 252                 allowed_remote = SMC_LLC_FLOW_RKEY;
 253 again:
 254         if (list_empty(&lgr->list))
 255                 return -ENODEV;
 256         spin_lock_bh(&lgr->llc_flow_lock);
 257         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 258             (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 259              lgr->llc_flow_rmt.type == allowed_remote)) {
 260                 lgr->llc_flow_lcl.type = type;
 261                 spin_unlock_bh(&lgr->llc_flow_lock);
 262                 return 0;
 263         }
 264         spin_unlock_bh(&lgr->llc_flow_lock);
 265         rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
 266                                 (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 267                                  (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 268                                   lgr->llc_flow_rmt.type == allowed_remote))),
 269                                 SMC_LLC_WAIT_TIME * 10);
 270         if (!rc)
 271                 return -ETIMEDOUT;
 272         goto again;
 273 }
 274
 275 /* finish the current llc flow */
 276 void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
 277 {
 278         spin_lock_bh(&lgr->llc_flow_lock);
 279         memset(flow, 0, sizeof(*flow));
 280         flow->type = SMC_LLC_FLOW_NONE;
 281         spin_unlock_bh(&lgr->llc_flow_lock);
 282         if (!list_empty(&lgr->list) && lgr->delayed_event &&
 283             flow == &lgr->llc_flow_lcl)
 284                 schedule_work(&lgr->llc_event_work);
 285         else
 286                 wake_up(&lgr->llc_flow_waiter);
 287 }
 288
 289 /* lnk is optional and used for early wakeup when link goes down, useful in
 290  * cases where we wait for a response on the link after we sent a request
 291  */
 292 struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
 293                                     struct smc_link *lnk,
 294                                     int time_out, u8 exp_msg)
 295 {
 296         struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
 297         u8 rcv_msg;
 298
 299         wait_event_timeout(lgr->llc_msg_waiter,
 300                            (flow->qentry ||
 301                             (lnk && !smc_link_usable(lnk)) ||
 302                             list_empty(&lgr->list)),
 303                            time_out);
 304         if (!flow->qentry ||
 305             (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
 306                 smc_llc_flow_qentry_del(flow);
 307                 goto out;
 308         }
 309         rcv_msg = flow->qentry->msg.raw.hdr.common.type;
 310         if (exp_msg && rcv_msg != exp_msg) {
 311                 if (exp_msg == SMC_LLC_ADD_LINK &&
 312                     rcv_msg == SMC_LLC_DELETE_LINK) {
 313                         /* flow_start will delay the unexpected msg */
 314                         smc_llc_flow_start(&lgr->llc_flow_lcl,
 315                                            smc_llc_flow_qentry_clr(flow));
 316                         return NULL;
 317                 }
 318                 pr_warn_once("smc: SMC-R lg %*phN dropped unexpected LLC msg: "
 319                              "msg %d exp %d flow %d role %d flags %x\n",
 320                              SMC_LGR_ID_SIZE, &lgr->id, rcv_msg, exp_msg,
 321                              flow->type, lgr->role,
 322                              flow->qentry->msg.raw.hdr.flags);
 323                 smc_llc_flow_qentry_del(flow);
 324         }
 325 out:
 326         return flow->qentry;
 327 }
 328
 329 /********************************** send *************************************/
 330
 331 struct smc_llc_tx_pend {
 332 };
 333
 334 /* handler for send/transmission completion of an LLC msg */
 335 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
 336                                struct smc_link *link,
 337                                enum ib_wc_status wc_status)
 338 {
 339         /* future work: handle wc_status error for recovery and failover */
 340 }
 341
 342 /**
 343  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
 344  * @link: Pointer to SMC link used for sending LLC control message.
 345  * @wr_buf: Out variable returning pointer to work request payload buffer.
 346  * @pend: Out variable returning pointer to private pending WR tracking.
 347  *        It's the context the transmit complete handler will get.
 348  *
 349  * Reserves and pre-fills an entry for a pending work request send/tx.
 350  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
 351  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
 352  *
 353  * Return: 0 on success, otherwise an error value.
 354  */
 355 static int smc_llc_add_pending_send(struct smc_link *link,
 356                                     struct smc_wr_buf **wr_buf,
 357                                     struct smc_wr_tx_pend_priv **pend)
 358 {
 359         int rc;
 360
 361         rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
 362                                      pend);
 363         if (rc < 0)
 364                 return rc;
 365         BUILD_BUG_ON_MSG(
 366                 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
 367                 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
 368         BUILD_BUG_ON_MSG(
 369                 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
 370                 "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()");
 371         BUILD_BUG_ON_MSG(
 372                 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
 373                 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
 374         return 0;
 375 }
 376
 377 /* high-level API to send LLC confirm link */
 378 int smc_llc_send_confirm_link(struct smc_link *link,
 379                               enum smc_llc_reqresp reqresp)
 380 {
 381         struct smc_llc_msg_confirm_link *confllc;
 382         struct smc_wr_tx_pend_priv *pend;
 383         struct smc_wr_buf *wr_buf;
 384         int rc;
 385
 386         if (!smc_wr_tx_link_hold(link))
 387                 return -ENOLINK;
 388         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 389         if (rc)
 390                 goto put_out;
 391         confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
 392         memset(confllc, 0, sizeof(*confllc));
 393         confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 394         confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
 395         confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 396         if (reqresp == SMC_LLC_RESP)
 397                 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 398         memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
 399                ETH_ALEN);
 400         memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
 401         hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 402         confllc->link_num = link->link_id;
 403         memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
 404         confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
 405         /* send llc message */
 406         rc = smc_wr_tx_send(link, pend);
 407 put_out:
 408         smc_wr_tx_link_put(link);
 409         return rc;
 410 }
 411
 412 /* send LLC confirm rkey request */
 413 static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
 414                                      struct smc_buf_desc *rmb_desc)
 415 {
 416         struct smc_llc_msg_confirm_rkey *rkeyllc;
 417         struct smc_wr_tx_pend_priv *pend;
 418         struct smc_wr_buf *wr_buf;
 419         struct smc_link *link;
 420         int i, rc, rtok_ix;
 421
 422         if (!smc_wr_tx_link_hold(send_link))
 423                 return -ENOLINK;
 424         rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
 425         if (rc)
 426                 goto put_out;
 427         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 428         memset(rkeyllc, 0, sizeof(*rkeyllc));
 429         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 430         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 431
 432         rtok_ix = 1;
 433         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 434                 link = &send_link->lgr->lnk[i];
 435                 if (smc_link_active(link) && link != send_link) {
 436                         rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
 437                         rkeyllc->rtoken[rtok_ix].rmb_key =
 438                                 htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 439                         rkeyllc->rtoken[rtok_ix].rmb_vaddr = cpu_to_be64(
 440                                 (u64)sg_dma_address(
 441                                         rmb_desc->sgt[link->link_idx].sgl));
 442                         rtok_ix++;
 443                 }
 444         }
 445         /* rkey of send_link is in rtoken[0] */
 446         rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
 447         rkeyllc->rtoken[0].rmb_key =
 448                 htonl(rmb_desc->mr_rx[send_link->link_idx]->rkey);
 449         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 450                 (u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl));
 451         /* send llc message */
 452         rc = smc_wr_tx_send(send_link, pend);
 453 put_out:
 454         smc_wr_tx_link_put(send_link);
 455         return rc;
 456 }
 457
 458 /* send LLC delete rkey request */
 459 static int smc_llc_send_delete_rkey(struct smc_link *link,
 460                                     struct smc_buf_desc *rmb_desc)
 461 {
 462         struct smc_llc_msg_delete_rkey *rkeyllc;
 463         struct smc_wr_tx_pend_priv *pend;
 464         struct smc_wr_buf *wr_buf;
 465         int rc;
 466
 467         if (!smc_wr_tx_link_hold(link))
 468                 return -ENOLINK;
 469         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 470         if (rc)
 471                 goto put_out;
 472         rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
 473         memset(rkeyllc, 0, sizeof(*rkeyllc));
 474         rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
 475         rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
 476         rkeyllc->num_rkeys = 1;
 477         rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 478         /* send llc message */
 479         rc = smc_wr_tx_send(link, pend);
 480 put_out:
 481         smc_wr_tx_link_put(link);
 482         return rc;
 483 }
 484
 485 /* send ADD LINK request or response */
 486 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
 487                           struct smc_link *link_new,
 488                           enum smc_llc_reqresp reqresp)
 489 {
 490         struct smc_llc_msg_add_link *addllc;
 491         struct smc_wr_tx_pend_priv *pend;
 492         struct smc_wr_buf *wr_buf;
 493         int rc;
 494
 495         if (!smc_wr_tx_link_hold(link))
 496                 return -ENOLINK;
 497         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 498         if (rc)
 499                 goto put_out;
 500         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 501
 502         memset(addllc, 0, sizeof(*addllc));
 503         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 504         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 505         if (reqresp == SMC_LLC_RESP)
 506                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 507         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 508         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 509         if (link_new) {
 510                 addllc->link_num = link_new->link_id;
 511                 hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
 512                 hton24(addllc->initial_psn, link_new->psn_initial);
 513                 if (reqresp == SMC_LLC_REQ)
 514                         addllc->qp_mtu = link_new->path_mtu;
 515                 else
 516                         addllc->qp_mtu = min(link_new->path_mtu,
 517                                              link_new->peer_mtu);
 518         }
 519         /* send llc message */
 520         rc = smc_wr_tx_send(link, pend);
 521 put_out:
 522         smc_wr_tx_link_put(link);
 523         return rc;
 524 }
 525
 526 /* send DELETE LINK request or response */
 527 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
 528                              enum smc_llc_reqresp reqresp, bool orderly,
 529                              u32 reason)
 530 {
 531         struct smc_llc_msg_del_link *delllc;
 532         struct smc_wr_tx_pend_priv *pend;
 533         struct smc_wr_buf *wr_buf;
 534         int rc;
 535
 536         if (!smc_wr_tx_link_hold(link))
 537                 return -ENOLINK;
 538         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 539         if (rc)
 540                 goto put_out;
 541         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 542
 543         memset(delllc, 0, sizeof(*delllc));
 544         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 545         delllc->hd.length = sizeof(struct smc_llc_msg_del_link);
 546         if (reqresp == SMC_LLC_RESP)
 547                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 548         if (orderly)
 549                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 550         if (link_del_id)
 551                 delllc->link_num = link_del_id;
 552         else
 553                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 554         delllc->reason = htonl(reason);
 555         /* send llc message */
 556         rc = smc_wr_tx_send(link, pend);
 557 put_out:
 558         smc_wr_tx_link_put(link);
 559         return rc;
 560 }
 561
 562 /* send LLC test link request */
 563 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 564 {
 565         struct smc_llc_msg_test_link *testllc;
 566         struct smc_wr_tx_pend_priv *pend;
 567         struct smc_wr_buf *wr_buf;
 568         int rc;
 569
 570         if (!smc_wr_tx_link_hold(link))
 571                 return -ENOLINK;
 572         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 573         if (rc)
 574                 goto put_out;
 575         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 576         memset(testllc, 0, sizeof(*testllc));
 577         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 578         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 579         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 580         /* send llc message */
 581         rc = smc_wr_tx_send(link, pend);
 582 put_out:
 583         smc_wr_tx_link_put(link);
 584         return rc;
 585 }
 586
 587 /* schedule an llc send on link, may wait for buffers */
 588 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
 589 {
 590         struct smc_wr_tx_pend_priv *pend;
 591         struct smc_wr_buf *wr_buf;
 592         int rc;
 593
 594         if (!smc_wr_tx_link_hold(link))
 595                 return -ENOLINK;
 596         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 597         if (rc)
 598                 goto put_out;
 599         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 600         rc = smc_wr_tx_send(link, pend);
 601 put_out:
 602         smc_wr_tx_link_put(link);
 603         return rc;
 604 }
 605
 606 /* schedule an llc send on link, may wait for buffers,
 607  * and wait for send completion notification.
 608  * @return 0 on success
 609  */
 610 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
 611 {
 612         struct smc_wr_tx_pend_priv *pend;
 613         struct smc_wr_buf *wr_buf;
 614         int rc;
 615
 616         if (!smc_wr_tx_link_hold(link))
 617                 return -ENOLINK;
 618         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 619         if (rc)
 620                 goto put_out;
 621         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 622         rc = smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
 623 put_out:
 624         smc_wr_tx_link_put(link);
 625         return rc;
 626 }
 627
 628 /********************************* receive ***********************************/
 629
 630 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
 631                                   enum smc_lgr_type lgr_new_t)
 632 {
 633         int i;
 634
 635         if (lgr->type == SMC_LGR_SYMMETRIC ||
 636             (lgr->type != SMC_LGR_SINGLE &&
 637              (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 638               lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
 639                 return -EMLINK;
 640
 641         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 642             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
 643                 for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
 644                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 645                                 return i;
 646         } else {
 647                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
 648                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 649                                 return i;
 650         }
 651         return -EMLINK;
 652 }
 653
 654 /* return first buffer from any of the next buf lists */
 655 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
 656                                                   int *buf_lst)
 657 {
 658         struct smc_buf_desc *buf_pos;
 659
 660         while (*buf_lst < SMC_RMBE_SIZES) {
 661                 buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
 662                                                    struct smc_buf_desc, list);
 663                 if (buf_pos)
 664                         return buf_pos;
 665                 (*buf_lst)++;
 666         }
 667         return NULL;
 668 }
 669
 670 /* return next rmb from buffer lists */
 671 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
 672                                                  int *buf_lst,
 673                                                  struct smc_buf_desc *buf_pos)
 674 {
 675         struct smc_buf_desc *buf_next;
 676
 677         if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
 678                 (*buf_lst)++;
 679                 return _smc_llc_get_next_rmb(lgr, buf_lst);
 680         }
 681         buf_next = list_next_entry(buf_pos, list);
 682         return buf_next;
 683 }
 684
 685 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
 686                                                   int *buf_lst)
 687 {
 688         *buf_lst = 0;
 689         return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
 690 }
 691
 692 /* send one add_link_continue msg */
 693 static int smc_llc_add_link_cont(struct smc_link *link,
 694                                  struct smc_link *link_new, u8 *num_rkeys_todo,
 695                                  int *buf_lst, struct smc_buf_desc **buf_pos)
 696 {
 697         struct smc_llc_msg_add_link_cont *addc_llc;
 698         struct smc_link_group *lgr = link->lgr;
 699         int prim_lnk_idx, lnk_idx, i, rc;
 700         struct smc_wr_tx_pend_priv *pend;
 701         struct smc_wr_buf *wr_buf;
 702         struct smc_buf_desc *rmb;
 703         u8 n;
 704
 705         if (!smc_wr_tx_link_hold(link))
 706                 return -ENOLINK;
 707         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 708         if (rc)
 709                 goto put_out;
 710         addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
 711         memset(addc_llc, 0, sizeof(*addc_llc));
 712
 713         prim_lnk_idx = link->link_idx;
 714         lnk_idx = link_new->link_idx;
 715         addc_llc->link_num = link_new->link_id;
 716         addc_llc->num_rkeys = *num_rkeys_todo;
 717         n = *num_rkeys_todo;
 718         for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
 719                 if (!*buf_pos) {
 720                         addc_llc->num_rkeys = addc_llc->num_rkeys -
 721                                               *num_rkeys_todo;
 722                         *num_rkeys_todo = 0;
 723                         break;
 724                 }
 725                 rmb = *buf_pos;
 726
 727                 addc_llc->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
 728                 addc_llc->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
 729                 addc_llc->rt[i].rmb_vaddr_new =
 730                         cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
 731
 732                 (*num_rkeys_todo)--;
 733                 *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 734                 while (*buf_pos && !(*buf_pos)->used)
 735                         *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 736         }
 737         addc_llc->hd.common.type = SMC_LLC_ADD_LINK_CONT;
 738         addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
 739         if (lgr->role == SMC_CLNT)
 740                 addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
 741         rc = smc_wr_tx_send(link, pend);
 742 put_out:
 743         smc_wr_tx_link_put(link);
 744         return rc;
 745 }
 746
 747 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
 748                                      struct smc_link *link_new)
 749 {
 750         struct smc_llc_msg_add_link_cont *addc_llc;
 751         struct smc_link_group *lgr = link->lgr;
 752         u8 max, num_rkeys_send, num_rkeys_recv;
 753         struct smc_llc_qentry *qentry;
 754         struct smc_buf_desc *buf_pos;
 755         int buf_lst;
 756         int rc = 0;
 757         int i;
 758
 759         mutex_lock(&lgr->rmbs_lock);
 760         num_rkeys_send = lgr->conns_num;
 761         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
 762         do {
 763                 qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
 764                                       SMC_LLC_ADD_LINK_CONT);
 765                 if (!qentry) {
 766                         rc = -ETIMEDOUT;
 767                         break;
 768                 }
 769                 addc_llc = &qentry->msg.add_link_cont;
 770                 num_rkeys_recv = addc_llc->num_rkeys;
 771                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
 772                 for (i = 0; i < max; i++) {
 773                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
 774                                        addc_llc->rt[i].rmb_key,
 775                                        addc_llc->rt[i].rmb_vaddr_new,
 776                                        addc_llc->rt[i].rmb_key_new);
 777                         num_rkeys_recv--;
 778                 }
 779                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 780                 rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
 781                                            &buf_lst, &buf_pos);
 782                 if (rc)
 783                         break;
 784         } while (num_rkeys_send || num_rkeys_recv);
 785
 786         mutex_unlock(&lgr->rmbs_lock);
 787         return rc;
 788 }
 789
 790 /* prepare and send an add link reject response */
 791 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
 792 {
 793         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 794         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 795         qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 796         return smc_llc_send_message(qentry->link, &qentry->msg);
 797 }
 798
 799 static int smc_llc_cli_conf_link(struct smc_link *link,
 800                                  struct smc_init_info *ini,
 801                                  struct smc_link *link_new,
 802                                  enum smc_lgr_type lgr_new_t)
 803 {
 804         struct smc_link_group *lgr = link->lgr;
 805         struct smc_llc_qentry *qentry = NULL;
 806         int rc = 0;
 807
 808         /* receive CONFIRM LINK request over RoCE fabric */
 809         qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
 810         if (!qentry) {
 811                 rc = smc_llc_send_delete_link(link, link_new->link_id,
 812                                               SMC_LLC_REQ, false,
 813                                               SMC_LLC_DEL_LOST_PATH);
 814                 return -ENOLINK;
 815         }
 816         if (qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
 817                 /* received DELETE_LINK instead */
 818                 qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 819                 smc_llc_send_message(link, &qentry->msg);
 820                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 821                 return -ENOLINK;
 822         }
 823         smc_llc_save_peer_uid(qentry);
 824         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 825
 826         rc = smc_ib_modify_qp_rts(link_new);
 827         if (rc) {
 828                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 829                                          false, SMC_LLC_DEL_LOST_PATH);
 830                 return -ENOLINK;
 831         }
 832         smc_wr_remember_qp_attr(link_new);
 833
 834         rc = smcr_buf_reg_lgr(link_new);
 835         if (rc) {
 836                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 837                                          false, SMC_LLC_DEL_LOST_PATH);
 838                 return -ENOLINK;
 839         }
 840
 841         /* send CONFIRM LINK response over RoCE fabric */
 842         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
 843         if (rc) {
 844                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 845                                          false, SMC_LLC_DEL_LOST_PATH);
 846                 return -ENOLINK;
 847         }
 848         smc_llc_link_active(link_new);
 849         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 850             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
 851                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
 852         else
 853                 smcr_lgr_set_type(lgr, lgr_new_t);
 854         return 0;
 855 }
 856
 857 static void smc_llc_save_add_link_info(struct smc_link *link,
 858                                        struct smc_llc_msg_add_link *add_llc)
 859 {
 860         link->peer_qpn = ntoh24(add_llc->sender_qp_num);
 861         memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
 862         memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
 863         link->peer_psn = ntoh24(add_llc->initial_psn);
 864         link->peer_mtu = add_llc->qp_mtu;
 865 }
 866
 867 /* as an SMC client, process an add link request */
 868 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
 869 {
 870         struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
 871         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
 872         struct smc_link_group *lgr = smc_get_lgr(link);
 873         struct smc_link *lnk_new = NULL;
 874         struct smc_init_info ini;
 875         int lnk_idx, rc = 0;
 876
 877         if (!llc->qp_mtu)
 878                 goto out_reject;
 879
 880         ini.vlan_id = lgr->vlan_id;
 881         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 882         if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
 883             !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN)) {
 884                 if (!ini.ib_dev)
 885                         goto out_reject;
 886                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
 887         }
 888         if (!ini.ib_dev) {
 889                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
 890                 ini.ib_dev = link->smcibdev;
 891                 ini.ib_port = link->ibport;
 892         }
 893         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
 894         if (lnk_idx < 0)
 895                 goto out_reject;
 896         lnk_new = &lgr->lnk[lnk_idx];
 897         rc = smcr_link_init(lgr, lnk_new, lnk_idx, &ini);
 898         if (rc)
 899                 goto out_reject;
 900         smc_llc_save_add_link_info(lnk_new, llc);
 901         lnk_new->link_id = llc->link_num;       /* SMC server assigns link id */
 902         smc_llc_link_set_uid(lnk_new);
 903
 904         rc = smc_ib_ready_link(lnk_new);
 905         if (rc)
 906                 goto out_clear_lnk;
 907
 908         rc = smcr_buf_map_lgr(lnk_new);
 909         if (rc)
 910                 goto out_clear_lnk;
 911
 912         rc = smc_llc_send_add_link(link,
 913                                    lnk_new->smcibdev->mac[ini.ib_port - 1],
 914                                    lnk_new->gid, lnk_new, SMC_LLC_RESP);
 915         if (rc)
 916                 goto out_clear_lnk;
 917         rc = smc_llc_cli_rkey_exchange(link, lnk_new);
 918         if (rc) {
 919                 rc = 0;
 920                 goto out_clear_lnk;
 921         }
 922         rc = smc_llc_cli_conf_link(link, &ini, lnk_new, lgr_new_t);
 923         if (!rc)
 924                 goto out;
 925 out_clear_lnk:
 926         lnk_new->state = SMC_LNK_INACTIVE;
 927         smcr_link_clear(lnk_new, false);
 928 out_reject:
 929         smc_llc_cli_add_link_reject(qentry);
 930 out:
 931         kfree(qentry);
 932         return rc;
 933 }
 934
 935 /* as an SMC client, invite server to start the add_link processing */
 936 static void smc_llc_cli_add_link_invite(struct smc_link *link,
 937                                         struct smc_llc_qentry *qentry)
 938 {
 939         struct smc_link_group *lgr = smc_get_lgr(link);
 940         struct smc_init_info ini;
 941
 942         if (lgr->type == SMC_LGR_SYMMETRIC ||
 943             lgr->type == SMC_LGR_ASYMMETRIC_PEER)
 944                 goto out;
 945
 946         ini.vlan_id = lgr->vlan_id;
 947         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 948         if (!ini.ib_dev)
 949                 goto out;
 950
 951         smc_llc_send_add_link(link, ini.ib_dev->mac[ini.ib_port - 1],
 952                               ini.ib_gid, NULL, SMC_LLC_REQ);
 953 out:
 954         kfree(qentry);
 955 }
 956
 957 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
 958 {
 959         int i;
 960
 961         for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
 962                 if (llc->raw.data[i])
 963                         return false;
 964         return true;
 965 }
 966
 967 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
 968 {
 969         if (llc->raw.hdr.common.type == SMC_LLC_ADD_LINK &&
 970             smc_llc_is_empty_llc_message(llc))
 971                 return true;
 972         return false;
 973 }
 974
 975 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
 976 {
 977         struct smc_llc_qentry *qentry;
 978
 979         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
 980
 981         mutex_lock(&lgr->llc_conf_mutex);
 982         if (smc_llc_is_local_add_link(&qentry->msg))
 983                 smc_llc_cli_add_link_invite(qentry->link, qentry);
 984         else
 985                 smc_llc_cli_add_link(qentry->link, qentry);
 986         mutex_unlock(&lgr->llc_conf_mutex);
 987 }
 988
 989 static int smc_llc_active_link_count(struct smc_link_group *lgr)
 990 {
 991         int i, link_count = 0;
 992
 993         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 994                 if (!smc_link_active(&lgr->lnk[i]))
 995                         continue;
 996                 link_count++;
 997         }
 998         return link_count;
 999 }
1000
1001 /* find the asymmetric link when 3 links are established  */
1002 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
1003 {
1004         int asym_idx = -ENOENT;
1005         int i, j, k;
1006         bool found;
1007
1008         /* determine asymmetric link */
1009         found = false;
1010         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1011                 for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
1012                         if (!smc_link_usable(&lgr->lnk[i]) ||
1013                             !smc_link_usable(&lgr->lnk[j]))
1014                                 continue;
1015                         if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
1016                                     SMC_GID_SIZE)) {
1017                                 found = true;   /* asym_lnk is i or j */
1018                                 break;
1019                         }
1020                 }
1021                 if (found)
1022                         break;
1023         }
1024         if (!found)
1025                 goto out; /* no asymmetric link */
1026         for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
1027                 if (!smc_link_usable(&lgr->lnk[k]))
1028                         continue;
1029                 if (k != i &&
1030                     !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
1031                             SMC_GID_SIZE)) {
1032                         asym_idx = i;
1033                         break;
1034                 }
1035                 if (k != j &&
1036                     !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1037                             SMC_GID_SIZE)) {
1038                         asym_idx = j;
1039                         break;
1040                 }
1041         }
1042 out:
1043         return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1044 }
1045
1046 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1047 {
1048         struct smc_link *lnk_new = NULL, *lnk_asym;
1049         struct smc_llc_qentry *qentry;
1050         int rc;
1051
1052         lnk_asym = smc_llc_find_asym_link(lgr);
1053         if (!lnk_asym)
1054                 return; /* no asymmetric link */
1055         if (!smc_link_downing(&lnk_asym->state))
1056                 return;
1057         lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1058         smc_wr_tx_wait_no_pending_sends(lnk_asym);
1059         if (!lnk_new)
1060                 goto out_free;
1061         /* change flow type from ADD_LINK into DEL_LINK */
1062         lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1063         rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1064                                       true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1065         if (rc) {
1066                 smcr_link_down_cond(lnk_new);
1067                 goto out_free;
1068         }
1069         qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1070                               SMC_LLC_DELETE_LINK);
1071         if (!qentry) {
1072                 smcr_link_down_cond(lnk_new);
1073                 goto out_free;
1074         }
1075         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1076 out_free:
1077         smcr_link_clear(lnk_asym, true);
1078 }
1079
1080 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1081                                      struct smc_link *link_new)
1082 {
1083         struct smc_llc_msg_add_link_cont *addc_llc;
1084         struct smc_link_group *lgr = link->lgr;
1085         u8 max, num_rkeys_send, num_rkeys_recv;
1086         struct smc_llc_qentry *qentry = NULL;
1087         struct smc_buf_desc *buf_pos;
1088         int buf_lst;
1089         int rc = 0;
1090         int i;
1091
1092         mutex_lock(&lgr->rmbs_lock);
1093         num_rkeys_send = lgr->conns_num;
1094         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1095         do {
1096                 smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1097                                       &buf_lst, &buf_pos);
1098                 qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1099                                       SMC_LLC_ADD_LINK_CONT);
1100                 if (!qentry) {
1101                         rc = -ETIMEDOUT;
1102                         goto out;
1103                 }
1104                 addc_llc = &qentry->msg.add_link_cont;
1105                 num_rkeys_recv = addc_llc->num_rkeys;
1106                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1107                 for (i = 0; i < max; i++) {
1108                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1109                                        addc_llc->rt[i].rmb_key,
1110                                        addc_llc->rt[i].rmb_vaddr_new,
1111                                        addc_llc->rt[i].rmb_key_new);
1112                         num_rkeys_recv--;
1113                 }
1114                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1115         } while (num_rkeys_send || num_rkeys_recv);
1116 out:
1117         mutex_unlock(&lgr->rmbs_lock);
1118         return rc;
1119 }
1120
1121 static int smc_llc_srv_conf_link(struct smc_link *link,
1122                                  struct smc_link *link_new,
1123                                  enum smc_lgr_type lgr_new_t)
1124 {
1125         struct smc_link_group *lgr = link->lgr;
1126         struct smc_llc_qentry *qentry = NULL;
1127         int rc;
1128
1129         /* send CONFIRM LINK request over the RoCE fabric */
1130         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1131         if (rc)
1132                 return -ENOLINK;
1133         /* receive CONFIRM LINK response over the RoCE fabric */
1134         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1135         if (!qentry ||
1136             qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
1137                 /* send DELETE LINK */
1138                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1139                                          false, SMC_LLC_DEL_LOST_PATH);
1140                 if (qentry)
1141                         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1142                 return -ENOLINK;
1143         }
1144         smc_llc_save_peer_uid(qentry);
1145         smc_llc_link_active(link_new);
1146         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1147             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1148                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1149         else
1150                 smcr_lgr_set_type(lgr, lgr_new_t);
1151         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1152         return 0;
1153 }
1154
1155 int smc_llc_srv_add_link(struct smc_link *link)
1156 {
1157         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1158         struct smc_link_group *lgr = link->lgr;
1159         struct smc_llc_msg_add_link *add_llc;
1160         struct smc_llc_qentry *qentry = NULL;
1161         struct smc_link *link_new;
1162         struct smc_init_info ini;
1163         int lnk_idx, rc = 0;
1164
1165         /* ignore client add link recommendation, start new flow */
1166         ini.vlan_id = lgr->vlan_id;
1167         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
1168         if (!ini.ib_dev) {
1169                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1170                 ini.ib_dev = link->smcibdev;
1171                 ini.ib_port = link->ibport;
1172         }
1173         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1174         if (lnk_idx < 0)
1175                 return 0;
1176
1177         rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, &ini);
1178         if (rc)
1179                 return rc;
1180         link_new = &lgr->lnk[lnk_idx];
1181         rc = smc_llc_send_add_link(link,
1182                                    link_new->smcibdev->mac[ini.ib_port - 1],
1183                                    link_new->gid, link_new, SMC_LLC_REQ);
1184         if (rc)
1185                 goto out_err;
1186         /* receive ADD LINK response over the RoCE fabric */
1187         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1188         if (!qentry) {
1189                 rc = -ETIMEDOUT;
1190                 goto out_err;
1191         }
1192         add_llc = &qentry->msg.add_link;
1193         if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1194                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1195                 rc = -ENOLINK;
1196                 goto out_err;
1197         }
1198         if (lgr->type == SMC_LGR_SINGLE &&
1199             (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1200              !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1201                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1202         }
1203         smc_llc_save_add_link_info(link_new, add_llc);
1204         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1205
1206         rc = smc_ib_ready_link(link_new);
1207         if (rc)
1208                 goto out_err;
1209         rc = smcr_buf_map_lgr(link_new);
1210         if (rc)
1211                 goto out_err;
1212         rc = smcr_buf_reg_lgr(link_new);
1213         if (rc)
1214                 goto out_err;
1215         rc = smc_llc_srv_rkey_exchange(link, link_new);
1216         if (rc)
1217                 goto out_err;
1218         rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1219         if (rc)
1220                 goto out_err;
1221         return 0;
1222 out_err:
1223         link_new->state = SMC_LNK_INACTIVE;
1224         smcr_link_clear(link_new, false);
1225         return rc;
1226 }
1227
1228 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1229 {
1230         struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1231         int rc;
1232
1233         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1234
1235         mutex_lock(&lgr->llc_conf_mutex);
1236         rc = smc_llc_srv_add_link(link);
1237         if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1238                 /* delete any asymmetric link */
1239                 smc_llc_delete_asym_link(lgr);
1240         }
1241         mutex_unlock(&lgr->llc_conf_mutex);
1242 }
1243
1244 /* enqueue a local add_link req to trigger a new add_link flow */
1245 void smc_llc_add_link_local(struct smc_link *link)
1246 {
1247         struct smc_llc_msg_add_link add_llc = {};
1248
1249         add_llc.hd.length = sizeof(add_llc);
1250         add_llc.hd.common.type = SMC_LLC_ADD_LINK;
1251         /* no dev and port needed */
1252         smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1253 }
1254
1255 /* worker to process an add link message */
1256 static void smc_llc_add_link_work(struct work_struct *work)
1257 {
1258         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1259                                                   llc_add_link_work);
1260
1261         if (list_empty(&lgr->list)) {
1262                 /* link group is terminating */
1263                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1264                 goto out;
1265         }
1266
1267         if (lgr->role == SMC_CLNT)
1268                 smc_llc_process_cli_add_link(lgr);
1269         else
1270                 smc_llc_process_srv_add_link(lgr);
1271 out:
1272         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1273 }
1274
1275 /* enqueue a local del_link msg to trigger a new del_link flow,
1276  * called only for role SMC_SERV
1277  */
1278 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1279 {
1280         struct smc_llc_msg_del_link del_llc = {};
1281
1282         del_llc.hd.length = sizeof(del_llc);
1283         del_llc.hd.common.type = SMC_LLC_DELETE_LINK;
1284         del_llc.link_num = del_link_id;
1285         del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1286         del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1287         smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1288 }
1289
1290 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1291 {
1292         struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1293         struct smc_llc_msg_del_link *del_llc;
1294         struct smc_llc_qentry *qentry;
1295         int active_links;
1296         int lnk_idx;
1297
1298         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1299         lnk = qentry->link;
1300         del_llc = &qentry->msg.delete_link;
1301
1302         if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1303                 smc_lgr_terminate_sched(lgr);
1304                 goto out;
1305         }
1306         mutex_lock(&lgr->llc_conf_mutex);
1307         /* delete single link */
1308         for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1309                 if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1310                         continue;
1311                 lnk_del = &lgr->lnk[lnk_idx];
1312                 break;
1313         }
1314         del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1315         if (!lnk_del) {
1316                 /* link was not found */
1317                 del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1318                 smc_llc_send_message(lnk, &qentry->msg);
1319                 goto out_unlock;
1320         }
1321         lnk_asym = smc_llc_find_asym_link(lgr);
1322
1323         del_llc->reason = 0;
1324         smc_llc_send_message(lnk, &qentry->msg); /* response */
1325
1326         if (smc_link_downing(&lnk_del->state))
1327                 smc_switch_conns(lgr, lnk_del, false);
1328         smcr_link_clear(lnk_del, true);
1329
1330         active_links = smc_llc_active_link_count(lgr);
1331         if (lnk_del == lnk_asym) {
1332                 /* expected deletion of asym link, don't change lgr state */
1333         } else if (active_links == 1) {
1334                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1335         } else if (!active_links) {
1336                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1337                 smc_lgr_terminate_sched(lgr);
1338         }
1339 out_unlock:
1340         mutex_unlock(&lgr->llc_conf_mutex);
1341 out:
1342         kfree(qentry);
1343 }
1344
1345 /* try to send a DELETE LINK ALL request on any active link,
1346  * waiting for send completion
1347  */
1348 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1349 {
1350         struct smc_llc_msg_del_link delllc = {};
1351         int i;
1352
1353         delllc.hd.common.type = SMC_LLC_DELETE_LINK;
1354         delllc.hd.length = sizeof(delllc);
1355         if (ord)
1356                 delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1357         delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1358         delllc.reason = htonl(rsn);
1359
1360         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1361                 if (!smc_link_sendable(&lgr->lnk[i]))
1362                         continue;
1363                 if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1364                         break;
1365         }
1366 }
1367
1368 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1369 {
1370         struct smc_llc_msg_del_link *del_llc;
1371         struct smc_link *lnk, *lnk_del;
1372         struct smc_llc_qentry *qentry;
1373         int active_links;
1374         int i;
1375
1376         mutex_lock(&lgr->llc_conf_mutex);
1377         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1378         lnk = qentry->link;
1379         del_llc = &qentry->msg.delete_link;
1380
1381         if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1382                 /* delete entire lgr */
1383                 smc_llc_send_link_delete_all(lgr, true, ntohl(
1384                                               qentry->msg.delete_link.reason));
1385                 smc_lgr_terminate_sched(lgr);
1386                 goto out;
1387         }
1388         /* delete single link */
1389         lnk_del = NULL;
1390         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1391                 if (lgr->lnk[i].link_id == del_llc->link_num) {
1392                         lnk_del = &lgr->lnk[i];
1393                         break;
1394                 }
1395         }
1396         if (!lnk_del)
1397                 goto out; /* asymmetric link already deleted */
1398
1399         if (smc_link_downing(&lnk_del->state)) {
1400                 if (smc_switch_conns(lgr, lnk_del, false))
1401                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1402         }
1403         if (!list_empty(&lgr->list)) {
1404                 /* qentry is either a request from peer (send it back to
1405                  * initiate the DELETE_LINK processing), or a locally
1406                  * enqueued DELETE_LINK request (forward it)
1407                  */
1408                 if (!smc_llc_send_message(lnk, &qentry->msg)) {
1409                         struct smc_llc_qentry *qentry2;
1410
1411                         qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1412                                                SMC_LLC_DELETE_LINK);
1413                         if (qentry2)
1414                                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1415                 }
1416         }
1417         smcr_link_clear(lnk_del, true);
1418
1419         active_links = smc_llc_active_link_count(lgr);
1420         if (active_links == 1) {
1421                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1422         } else if (!active_links) {
1423                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1424                 smc_lgr_terminate_sched(lgr);
1425         }
1426
1427         if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1428                 /* trigger setup of asymm alt link */
1429                 smc_llc_add_link_local(lnk);
1430         }
1431 out:
1432         mutex_unlock(&lgr->llc_conf_mutex);
1433         kfree(qentry);
1434 }
1435
1436 static void smc_llc_delete_link_work(struct work_struct *work)
1437 {
1438         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1439                                                   llc_del_link_work);
1440
1441         if (list_empty(&lgr->list)) {
1442                 /* link group is terminating */
1443                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1444                 goto out;
1445         }
1446
1447         if (lgr->role == SMC_CLNT)
1448                 smc_llc_process_cli_delete_link(lgr);
1449         else
1450                 smc_llc_process_srv_delete_link(lgr);
1451 out:
1452         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1453 }
1454
1455 /* process a confirm_rkey request from peer, remote flow */
1456 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1457 {
1458         struct smc_llc_msg_confirm_rkey *llc;
1459         struct smc_llc_qentry *qentry;
1460         struct smc_link *link;
1461         int num_entries;
1462         int rk_idx;
1463         int i;
1464
1465         qentry = lgr->llc_flow_rmt.qentry;
1466         llc = &qentry->msg.confirm_rkey;
1467         link = qentry->link;
1468
1469         num_entries = llc->rtoken[0].num_rkeys;
1470         /* first rkey entry is for receiving link */
1471         rk_idx = smc_rtoken_add(link,
1472                                 llc->rtoken[0].rmb_vaddr,
1473                                 llc->rtoken[0].rmb_key);
1474         if (rk_idx < 0)
1475                 goto out_err;
1476
1477         for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1478                 smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1479                                 llc->rtoken[i].rmb_vaddr,
1480                                 llc->rtoken[i].rmb_key);
1481         /* max links is 3 so there is no need to support conf_rkey_cont msgs */
1482         goto out;
1483 out_err:
1484         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1485         llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1486 out:
1487         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1488         smc_llc_send_message(link, &qentry->msg);
1489         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1490 }
1491
1492 /* process a delete_rkey request from peer, remote flow */
1493 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1494 {
1495         struct smc_llc_msg_delete_rkey *llc;
1496         struct smc_llc_qentry *qentry;
1497         struct smc_link *link;
1498         u8 err_mask = 0;
1499         int i, max;
1500
1501         qentry = lgr->llc_flow_rmt.qentry;
1502         llc = &qentry->msg.delete_rkey;
1503         link = qentry->link;
1504
1505         max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1506         for (i = 0; i < max; i++) {
1507                 if (smc_rtoken_delete(link, llc->rkey[i]))
1508                         err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1509         }
1510         if (err_mask) {
1511                 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1512                 llc->err_mask = err_mask;
1513         }
1514         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1515         smc_llc_send_message(link, &qentry->msg);
1516         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1517 }
1518
1519 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1520 {
1521         pr_warn_ratelimited("smc: SMC-R lg %*phN LLC protocol violation: "
1522                             "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id, type);
1523         smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1524         smc_lgr_terminate_sched(lgr);
1525 }
1526
1527 /* flush the llc event queue */
1528 static void smc_llc_event_flush(struct smc_link_group *lgr)
1529 {
1530         struct smc_llc_qentry *qentry, *q;
1531
1532         spin_lock_bh(&lgr->llc_event_q_lock);
1533         list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1534                 list_del_init(&qentry->list);
1535                 kfree(qentry);
1536         }
1537         spin_unlock_bh(&lgr->llc_event_q_lock);
1538 }
1539
1540 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1541 {
1542         union smc_llc_msg *llc = &qentry->msg;
1543         struct smc_link *link = qentry->link;
1544         struct smc_link_group *lgr = link->lgr;
1545
1546         if (!smc_link_usable(link))
1547                 goto out;
1548
1549         switch (llc->raw.hdr.common.type) {
1550         case SMC_LLC_TEST_LINK:
1551                 llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1552                 smc_llc_send_message(link, llc);
1553                 break;
1554         case SMC_LLC_ADD_LINK:
1555                 if (list_empty(&lgr->list))
1556                         goto out;       /* lgr is terminating */
1557                 if (lgr->role == SMC_CLNT) {
1558                         if (smc_llc_is_local_add_link(llc)) {
1559                                 if (lgr->llc_flow_lcl.type ==
1560                                     SMC_LLC_FLOW_ADD_LINK)
1561                                         break;  /* add_link in progress */
1562                                 if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1563                                                        qentry)) {
1564                                         schedule_work(&lgr->llc_add_link_work);
1565                                 }
1566                                 return;
1567                         }
1568                         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1569                             !lgr->llc_flow_lcl.qentry) {
1570                                 /* a flow is waiting for this message */
1571                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1572                                                         qentry);
1573                                 wake_up(&lgr->llc_msg_waiter);
1574                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1575                                                       qentry)) {
1576                                 schedule_work(&lgr->llc_add_link_work);
1577                         }
1578                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1579                         /* as smc server, handle client suggestion */
1580                         schedule_work(&lgr->llc_add_link_work);
1581                 }
1582                 return;
1583         case SMC_LLC_CONFIRM_LINK:
1584         case SMC_LLC_ADD_LINK_CONT:
1585                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1586                         /* a flow is waiting for this message */
1587                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1588                         wake_up(&lgr->llc_msg_waiter);
1589                         return;
1590                 }
1591                 break;
1592         case SMC_LLC_DELETE_LINK:
1593                 if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1594                     !lgr->llc_flow_lcl.qentry) {
1595                         /* DEL LINK REQ during ADD LINK SEQ */
1596                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1597                         wake_up(&lgr->llc_msg_waiter);
1598                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1599                         schedule_work(&lgr->llc_del_link_work);
1600                 }
1601                 return;
1602         case SMC_LLC_CONFIRM_RKEY:
1603                 /* new request from remote, assign to remote flow */
1604                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1605                         /* process here, does not wait for more llc msgs */
1606                         smc_llc_rmt_conf_rkey(lgr);
1607                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1608                 }
1609                 return;
1610         case SMC_LLC_CONFIRM_RKEY_CONT:
1611                 /* not used because max links is 3, and 3 rkeys fit into
1612                  * one CONFIRM_RKEY message
1613                  */
1614                 break;
1615         case SMC_LLC_DELETE_RKEY:
1616                 /* new request from remote, assign to remote flow */
1617                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1618                         /* process here, does not wait for more llc msgs */
1619                         smc_llc_rmt_delete_rkey(lgr);
1620                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1621                 }
1622                 return;
1623         default:
1624                 smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1625                 break;
1626         }
1627 out:
1628         kfree(qentry);
1629 }
1630
1631 /* worker to process llc messages on the event queue */
1632 static void smc_llc_event_work(struct work_struct *work)
1633 {
1634         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1635                                                   llc_event_work);
1636         struct smc_llc_qentry *qentry;
1637
1638         if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1639                 qentry = lgr->delayed_event;
1640                 lgr->delayed_event = NULL;
1641                 if (smc_link_usable(qentry->link))
1642                         smc_llc_event_handler(qentry);
1643                 else
1644                         kfree(qentry);
1645         }
1646
1647 again:
1648         spin_lock_bh(&lgr->llc_event_q_lock);
1649         if (!list_empty(&lgr->llc_event_q)) {
1650                 qentry = list_first_entry(&lgr->llc_event_q,
1651                                           struct smc_llc_qentry, list);
1652                 list_del_init(&qentry->list);
1653                 spin_unlock_bh(&lgr->llc_event_q_lock);
1654                 smc_llc_event_handler(qentry);
1655                 goto again;
1656         }
1657         spin_unlock_bh(&lgr->llc_event_q_lock);
1658 }
1659
1660 /* process llc responses in tasklet context */
1661 static void smc_llc_rx_response(struct smc_link *link,
1662                                 struct smc_llc_qentry *qentry)
1663 {
1664         enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
1665         struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
1666         u8 llc_type = qentry->msg.raw.hdr.common.type;
1667
1668         switch (llc_type) {
1669         case SMC_LLC_TEST_LINK:
1670                 if (smc_link_active(link))
1671                         complete(&link->llc_testlink_resp);
1672                 break;
1673         case SMC_LLC_ADD_LINK:
1674         case SMC_LLC_ADD_LINK_CONT:
1675         case SMC_LLC_CONFIRM_LINK:
1676                 if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
1677                         break;  /* drop out-of-flow response */
1678                 goto assign;
1679         case SMC_LLC_DELETE_LINK:
1680                 if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
1681                         break;  /* drop out-of-flow response */
1682                 goto assign;
1683         case SMC_LLC_CONFIRM_RKEY:
1684         case SMC_LLC_DELETE_RKEY:
1685                 if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
1686                         break;  /* drop out-of-flow response */
1687                 goto assign;
1688         case SMC_LLC_CONFIRM_RKEY_CONT:
1689                 /* not used because max links is 3 */
1690                 break;
1691         default:
1692                 smc_llc_protocol_violation(link->lgr, llc_type);
1693                 break;
1694         }
1695         kfree(qentry);
1696         return;
1697 assign:
1698         /* assign responses to the local flow, we requested them */
1699         smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
1700         wake_up(&link->lgr->llc_msg_waiter);
1701 }
1702
1703 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
1704 {
1705         struct smc_link_group *lgr = link->lgr;
1706         struct smc_llc_qentry *qentry;
1707         unsigned long flags;
1708
1709         qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
1710         if (!qentry)
1711                 return;
1712         qentry->link = link;
1713         INIT_LIST_HEAD(&qentry->list);
1714         memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
1715
1716         /* process responses immediately */
1717         if (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) {
1718                 smc_llc_rx_response(link, qentry);
1719                 return;
1720         }
1721
1722         /* add requests to event queue */
1723         spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
1724         list_add_tail(&qentry->list, &lgr->llc_event_q);
1725         spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
1726         queue_work(system_highpri_wq, &lgr->llc_event_work);
1727 }
1728
1729 /* copy received msg and add it to the event queue */
1730 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
1731 {
1732         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
1733         union smc_llc_msg *llc = buf;
1734
1735         if (wc->byte_len < sizeof(*llc))
1736                 return; /* short message */
1737         if (llc->raw.hdr.length != sizeof(*llc))
1738                 return; /* invalid message */
1739
1740         smc_llc_enqueue(link, llc);
1741 }
1742
1743 /***************************** worker, utils *********************************/
1744
1745 static void smc_llc_testlink_work(struct work_struct *work)
1746 {
1747         struct smc_link *link = container_of(to_delayed_work(work),
1748                                              struct smc_link, llc_testlink_wrk);
1749         unsigned long next_interval;
1750         unsigned long expire_time;
1751         u8 user_data[16] = { 0 };
1752         int rc;
1753
1754         if (!smc_link_active(link))
1755                 return;         /* don't reschedule worker */
1756         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
1757         if (time_is_after_jiffies(expire_time)) {
1758                 next_interval = expire_time - jiffies;
1759                 goto out;
1760         }
1761         reinit_completion(&link->llc_testlink_resp);
1762         smc_llc_send_test_link(link, user_data);
1763         /* receive TEST LINK response over RoCE fabric */
1764         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
1765                                                        SMC_LLC_WAIT_TIME);
1766         if (!smc_link_active(link))
1767                 return;         /* link state changed */
1768         if (rc <= 0) {
1769                 smcr_link_down_cond_sched(link);
1770                 return;
1771         }
1772         next_interval = link->llc_testlink_time;
1773 out:
1774         schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
1775 }
1776
1777 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
1778 {
1779         struct net *net = sock_net(smc->clcsock->sk);
1780
1781         INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
1782         INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
1783         INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
1784         INIT_LIST_HEAD(&lgr->llc_event_q);
1785         spin_lock_init(&lgr->llc_event_q_lock);
1786         spin_lock_init(&lgr->llc_flow_lock);
1787         init_waitqueue_head(&lgr->llc_flow_waiter);
1788         init_waitqueue_head(&lgr->llc_msg_waiter);
1789         mutex_init(&lgr->llc_conf_mutex);
1790         lgr->llc_testlink_time = READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time);
1791 }
1792
1793 /* called after lgr was removed from lgr_list */
1794 void smc_llc_lgr_clear(struct smc_link_group *lgr)
1795 {
1796         smc_llc_event_flush(lgr);
1797         wake_up_all(&lgr->llc_flow_waiter);
1798         wake_up_all(&lgr->llc_msg_waiter);
1799         cancel_work_sync(&lgr->llc_event_work);
1800         cancel_work_sync(&lgr->llc_add_link_work);
1801         cancel_work_sync(&lgr->llc_del_link_work);
1802         if (lgr->delayed_event) {
1803                 kfree(lgr->delayed_event);
1804                 lgr->delayed_event = NULL;
1805         }
1806 }
1807
1808 int smc_llc_link_init(struct smc_link *link)
1809 {
1810         init_completion(&link->llc_testlink_resp);
1811         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
1812         return 0;
1813 }
1814
1815 void smc_llc_link_active(struct smc_link *link)
1816 {
1817         pr_warn_ratelimited("smc: SMC-R lg %*phN link added: id %*phN, "
1818                             "peerid %*phN, ibdev %s, ibport %d\n",
1819                             SMC_LGR_ID_SIZE, &link->lgr->id,
1820                             SMC_LGR_ID_SIZE, &link->link_uid,
1821                             SMC_LGR_ID_SIZE, &link->peer_link_uid,
1822                             link->smcibdev->ibdev->name, link->ibport);
1823         link->state = SMC_LNK_ACTIVE;
1824         if (link->lgr->llc_testlink_time) {
1825                 link->llc_testlink_time = link->lgr->llc_testlink_time;
1826                 schedule_delayed_work(&link->llc_testlink_wrk,
1827                                       link->llc_testlink_time);
1828         }
1829 }
1830
1831 /* called in worker context */
1832 void smc_llc_link_clear(struct smc_link *link, bool log)
1833 {
1834         if (log)
1835                 pr_warn_ratelimited("smc: SMC-R lg %*phN link removed: id %*phN"
1836                                     ", peerid %*phN, ibdev %s, ibport %d\n",
1837                                     SMC_LGR_ID_SIZE, &link->lgr->id,
1838                                     SMC_LGR_ID_SIZE, &link->link_uid,
1839                                     SMC_LGR_ID_SIZE, &link->peer_link_uid,
1840                                     link->smcibdev->ibdev->name, link->ibport);
1841         complete(&link->llc_testlink_resp);
1842         cancel_delayed_work_sync(&link->llc_testlink_wrk);
1843 }
1844
1845 /* register a new rtoken at the remote peer (for all links) */
1846 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
1847                             struct smc_buf_desc *rmb_desc)
1848 {
1849         struct smc_link_group *lgr = send_link->lgr;
1850         struct smc_llc_qentry *qentry = NULL;
1851         int rc = 0;
1852
1853         rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
1854         if (rc)
1855                 goto out;
1856         /* receive CONFIRM RKEY response from server over RoCE fabric */
1857         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1858                               SMC_LLC_CONFIRM_RKEY);
1859         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1860                 rc = -EFAULT;
1861 out:
1862         if (qentry)
1863                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1864         return rc;
1865 }
1866
1867 /* unregister an rtoken at the remote peer */
1868 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
1869                            struct smc_buf_desc *rmb_desc)
1870 {
1871         struct smc_llc_qentry *qentry = NULL;
1872         struct smc_link *send_link;
1873         int rc = 0;
1874
1875         send_link = smc_llc_usable_link(lgr);
1876         if (!send_link)
1877                 return -ENOLINK;
1878
1879         /* protected by llc_flow control */
1880         rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
1881         if (rc)
1882                 goto out;
1883         /* receive DELETE RKEY response from server over RoCE fabric */
1884         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1885                               SMC_LLC_DELETE_RKEY);
1886         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1887                 rc = -EFAULT;
1888 out:
1889         if (qentry)
1890                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1891         return rc;
1892 }
1893
1894 void smc_llc_link_set_uid(struct smc_link *link)
1895 {
1896         __be32 link_uid;
1897
1898         link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
1899         memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
1900 }
1901
1902 /* save peers link user id, used for debug purposes */
1903 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
1904 {
1905         memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
1906                SMC_LGR_ID_SIZE);
1907 }
1908
1909 /* evaluate confirm link request or response */
1910 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
1911                            enum smc_llc_reqresp type)
1912 {
1913         if (type == SMC_LLC_REQ) {      /* SMC server assigns link_id */
1914                 qentry->link->link_id = qentry->msg.confirm_link.link_num;
1915                 smc_llc_link_set_uid(qentry->link);
1916         }
1917         if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
1918                 return -ENOTSUPP;
1919         return 0;
1920 }
1921
1922 /***************************** init, exit, misc ******************************/
1923
1924 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
1925         {
1926                 .handler        = smc_llc_rx_handler,
1927                 .type           = SMC_LLC_CONFIRM_LINK
1928         },
1929         {
1930                 .handler        = smc_llc_rx_handler,
1931                 .type           = SMC_LLC_TEST_LINK
1932         },
1933         {
1934                 .handler        = smc_llc_rx_handler,
1935                 .type           = SMC_LLC_ADD_LINK
1936         },
1937         {
1938                 .handler        = smc_llc_rx_handler,
1939                 .type           = SMC_LLC_ADD_LINK_CONT
1940         },
1941         {
1942                 .handler        = smc_llc_rx_handler,
1943                 .type           = SMC_LLC_DELETE_LINK
1944         },
1945         {
1946                 .handler        = smc_llc_rx_handler,
1947                 .type           = SMC_LLC_CONFIRM_RKEY
1948         },
1949         {
1950                 .handler        = smc_llc_rx_handler,
1951                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
1952         },
1953         {
1954                 .handler        = smc_llc_rx_handler,
1955                 .type           = SMC_LLC_DELETE_RKEY
1956         },
1957         {
1958                 .handler        = NULL,
1959         }
1960 };
1961
1962 int __init smc_llc_init(void)
1963 {
1964         struct smc_wr_rx_handler *handler;
1965         int rc = 0;
1966
1967         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
1968                 INIT_HLIST_NODE(&handler->list);
1969                 rc = smc_wr_rx_register_handler(handler);
1970                 if (rc)
1971                         break;
1972         }
1973         return rc;
1974 }