net/smc/smc_llc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Link Layer Control (LLC)
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Klaus Wacker <[email protected]>
  10  *              Ursula Braun <[email protected]>
  11  */
  12
  13 #include <net/tcp.h>
  14 #include <rdma/ib_verbs.h>
  15
  16 #include "smc.h"
  17 #include "smc_core.h"
  18 #include "smc_clc.h"
  19 #include "smc_llc.h"
  20 #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         if (qentry == lgr->delayed_event)
 237                 lgr->delayed_event = NULL;
 238         smc_llc_flow_qentry_set(flow, qentry);
 239         spin_unlock_bh(&lgr->llc_flow_lock);
 240         return true;
 241 }
 242
 243 /* start a new local llc flow, wait till current flow finished */
 244 int smc_llc_flow_initiate(struct smc_link_group *lgr,
 245                           enum smc_llc_flowtype type)
 246 {
 247         enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
 248         int rc;
 249
 250         /* all flows except confirm_rkey and delete_rkey are exclusive,
 251          * confirm/delete rkey flows can run concurrently (local and remote)
 252          */
 253         if (type == SMC_LLC_FLOW_RKEY)
 254                 allowed_remote = SMC_LLC_FLOW_RKEY;
 255 again:
 256         if (list_empty(&lgr->list))
 257                 return -ENODEV;
 258         spin_lock_bh(&lgr->llc_flow_lock);
 259         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 260             (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 261              lgr->llc_flow_rmt.type == allowed_remote)) {
 262                 lgr->llc_flow_lcl.type = type;
 263                 spin_unlock_bh(&lgr->llc_flow_lock);
 264                 return 0;
 265         }
 266         spin_unlock_bh(&lgr->llc_flow_lock);
 267         rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
 268                                 (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 269                                  (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 270                                   lgr->llc_flow_rmt.type == allowed_remote))),
 271                                 SMC_LLC_WAIT_TIME * 10);
 272         if (!rc)
 273                 return -ETIMEDOUT;
 274         goto again;
 275 }
 276
 277 /* finish the current llc flow */
 278 void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
 279 {
 280         spin_lock_bh(&lgr->llc_flow_lock);
 281         memset(flow, 0, sizeof(*flow));
 282         flow->type = SMC_LLC_FLOW_NONE;
 283         spin_unlock_bh(&lgr->llc_flow_lock);
 284         if (!list_empty(&lgr->list) && lgr->delayed_event &&
 285             flow == &lgr->llc_flow_lcl)
 286                 schedule_work(&lgr->llc_event_work);
 287         else
 288                 wake_up(&lgr->llc_flow_waiter);
 289 }
 290
 291 /* lnk is optional and used for early wakeup when link goes down, useful in
 292  * cases where we wait for a response on the link after we sent a request
 293  */
 294 struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
 295                                     struct smc_link *lnk,
 296                                     int time_out, u8 exp_msg)
 297 {
 298         struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
 299         u8 rcv_msg;
 300
 301         wait_event_timeout(lgr->llc_msg_waiter,
 302                            (flow->qentry ||
 303                             (lnk && !smc_link_usable(lnk)) ||
 304                             list_empty(&lgr->list)),
 305                            time_out);
 306         if (!flow->qentry ||
 307             (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
 308                 smc_llc_flow_qentry_del(flow);
 309                 goto out;
 310         }
 311         rcv_msg = flow->qentry->msg.raw.hdr.common.type;
 312         if (exp_msg && rcv_msg != exp_msg) {
 313                 if (exp_msg == SMC_LLC_ADD_LINK &&
 314                     rcv_msg == SMC_LLC_DELETE_LINK) {
 315                         /* flow_start will delay the unexpected msg */
 316                         smc_llc_flow_start(&lgr->llc_flow_lcl,
 317                                            smc_llc_flow_qentry_clr(flow));
 318                         return NULL;
 319                 }
 320                 pr_warn_once("smc: SMC-R lg %*phN dropped unexpected LLC msg: "
 321                              "msg %d exp %d flow %d role %d flags %x\n",
 322                              SMC_LGR_ID_SIZE, &lgr->id, rcv_msg, exp_msg,
 323                              flow->type, lgr->role,
 324                              flow->qentry->msg.raw.hdr.flags);
 325                 smc_llc_flow_qentry_del(flow);
 326         }
 327 out:
 328         return flow->qentry;
 329 }
 330
 331 /********************************** send *************************************/
 332
 333 struct smc_llc_tx_pend {
 334 };
 335
 336 /* handler for send/transmission completion of an LLC msg */
 337 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
 338                                struct smc_link *link,
 339                                enum ib_wc_status wc_status)
 340 {
 341         /* future work: handle wc_status error for recovery and failover */
 342 }
 343
 344 /**
 345  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
 346  * @link: Pointer to SMC link used for sending LLC control message.
 347  * @wr_buf: Out variable returning pointer to work request payload buffer.
 348  * @pend: Out variable returning pointer to private pending WR tracking.
 349  *        It's the context the transmit complete handler will get.
 350  *
 351  * Reserves and pre-fills an entry for a pending work request send/tx.
 352  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
 353  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
 354  *
 355  * Return: 0 on success, otherwise an error value.
 356  */
 357 static int smc_llc_add_pending_send(struct smc_link *link,
 358                                     struct smc_wr_buf **wr_buf,
 359                                     struct smc_wr_tx_pend_priv **pend)
 360 {
 361         int rc;
 362
 363         rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
 364                                      pend);
 365         if (rc < 0)
 366                 return rc;
 367         BUILD_BUG_ON_MSG(
 368                 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
 369                 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
 370         BUILD_BUG_ON_MSG(
 371                 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
 372                 "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()");
 373         BUILD_BUG_ON_MSG(
 374                 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
 375                 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
 376         return 0;
 377 }
 378
 379 /* high-level API to send LLC confirm link */
 380 int smc_llc_send_confirm_link(struct smc_link *link,
 381                               enum smc_llc_reqresp reqresp)
 382 {
 383         struct smc_llc_msg_confirm_link *confllc;
 384         struct smc_wr_tx_pend_priv *pend;
 385         struct smc_wr_buf *wr_buf;
 386         int rc;
 387
 388         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 389         if (rc)
 390                 return rc;
 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         return rc;
 408 }
 409
 410 /* send LLC confirm rkey request */
 411 static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
 412                                      struct smc_buf_desc *rmb_desc)
 413 {
 414         struct smc_llc_msg_confirm_rkey *rkeyllc;
 415         struct smc_wr_tx_pend_priv *pend;
 416         struct smc_wr_buf *wr_buf;
 417         struct smc_link *link;
 418         int i, rc, rtok_ix;
 419
 420         rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
 421         if (rc)
 422                 return rc;
 423         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 424         memset(rkeyllc, 0, sizeof(*rkeyllc));
 425         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 426         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 427
 428         rtok_ix = 1;
 429         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 430                 link = &send_link->lgr->lnk[i];
 431                 if (smc_link_active(link) && link != send_link) {
 432                         rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
 433                         rkeyllc->rtoken[rtok_ix].rmb_key =
 434                                 htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 435                         rkeyllc->rtoken[rtok_ix].rmb_vaddr = cpu_to_be64(
 436                                 (u64)sg_dma_address(
 437                                         rmb_desc->sgt[link->link_idx].sgl));
 438                         rtok_ix++;
 439                 }
 440         }
 441         /* rkey of send_link is in rtoken[0] */
 442         rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
 443         rkeyllc->rtoken[0].rmb_key =
 444                 htonl(rmb_desc->mr_rx[send_link->link_idx]->rkey);
 445         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 446                 (u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl));
 447         /* send llc message */
 448         rc = smc_wr_tx_send(send_link, pend);
 449         return rc;
 450 }
 451
 452 /* send LLC delete rkey request */
 453 static int smc_llc_send_delete_rkey(struct smc_link *link,
 454                                     struct smc_buf_desc *rmb_desc)
 455 {
 456         struct smc_llc_msg_delete_rkey *rkeyllc;
 457         struct smc_wr_tx_pend_priv *pend;
 458         struct smc_wr_buf *wr_buf;
 459         int rc;
 460
 461         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 462         if (rc)
 463                 return rc;
 464         rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
 465         memset(rkeyllc, 0, sizeof(*rkeyllc));
 466         rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
 467         rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
 468         rkeyllc->num_rkeys = 1;
 469         rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 470         /* send llc message */
 471         rc = smc_wr_tx_send(link, pend);
 472         return rc;
 473 }
 474
 475 /* send ADD LINK request or response */
 476 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
 477                           struct smc_link *link_new,
 478                           enum smc_llc_reqresp reqresp)
 479 {
 480         struct smc_llc_msg_add_link *addllc;
 481         struct smc_wr_tx_pend_priv *pend;
 482         struct smc_wr_buf *wr_buf;
 483         int rc;
 484
 485         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 486         if (rc)
 487                 return rc;
 488         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 489
 490         memset(addllc, 0, sizeof(*addllc));
 491         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 492         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 493         if (reqresp == SMC_LLC_RESP)
 494                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 495         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 496         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 497         if (link_new) {
 498                 addllc->link_num = link_new->link_id;
 499                 hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
 500                 hton24(addllc->initial_psn, link_new->psn_initial);
 501                 if (reqresp == SMC_LLC_REQ)
 502                         addllc->qp_mtu = link_new->path_mtu;
 503                 else
 504                         addllc->qp_mtu = min(link_new->path_mtu,
 505                                              link_new->peer_mtu);
 506         }
 507         /* send llc message */
 508         rc = smc_wr_tx_send(link, pend);
 509         return rc;
 510 }
 511
 512 /* send DELETE LINK request or response */
 513 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
 514                              enum smc_llc_reqresp reqresp, bool orderly,
 515                              u32 reason)
 516 {
 517         struct smc_llc_msg_del_link *delllc;
 518         struct smc_wr_tx_pend_priv *pend;
 519         struct smc_wr_buf *wr_buf;
 520         int rc;
 521
 522         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 523         if (rc)
 524                 return rc;
 525         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 526
 527         memset(delllc, 0, sizeof(*delllc));
 528         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 529         delllc->hd.length = sizeof(struct smc_llc_msg_del_link);
 530         if (reqresp == SMC_LLC_RESP)
 531                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 532         if (orderly)
 533                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 534         if (link_del_id)
 535                 delllc->link_num = link_del_id;
 536         else
 537                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 538         delllc->reason = htonl(reason);
 539         /* send llc message */
 540         rc = smc_wr_tx_send(link, pend);
 541         return rc;
 542 }
 543
 544 /* send LLC test link request */
 545 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 546 {
 547         struct smc_llc_msg_test_link *testllc;
 548         struct smc_wr_tx_pend_priv *pend;
 549         struct smc_wr_buf *wr_buf;
 550         int rc;
 551
 552         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 553         if (rc)
 554                 return rc;
 555         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 556         memset(testllc, 0, sizeof(*testllc));
 557         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 558         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 559         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 560         /* send llc message */
 561         rc = smc_wr_tx_send(link, pend);
 562         return rc;
 563 }
 564
 565 /* schedule an llc send on link, may wait for buffers */
 566 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
 567 {
 568         struct smc_wr_tx_pend_priv *pend;
 569         struct smc_wr_buf *wr_buf;
 570         int rc;
 571
 572         if (!smc_link_usable(link))
 573                 return -ENOLINK;
 574         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 575         if (rc)
 576                 return rc;
 577         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 578         return smc_wr_tx_send(link, pend);
 579 }
 580
 581 /* schedule an llc send on link, may wait for buffers,
 582  * and wait for send completion notification.
 583  * @return 0 on success
 584  */
 585 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
 586 {
 587         struct smc_wr_tx_pend_priv *pend;
 588         struct smc_wr_buf *wr_buf;
 589         int rc;
 590
 591         if (!smc_link_usable(link))
 592                 return -ENOLINK;
 593         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 594         if (rc)
 595                 return rc;
 596         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 597         return smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
 598 }
 599
 600 /********************************* receive ***********************************/
 601
 602 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
 603                                   enum smc_lgr_type lgr_new_t)
 604 {
 605         int i;
 606
 607         if (lgr->type == SMC_LGR_SYMMETRIC ||
 608             (lgr->type != SMC_LGR_SINGLE &&
 609              (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 610               lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
 611                 return -EMLINK;
 612
 613         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 614             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
 615                 for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
 616                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 617                                 return i;
 618         } else {
 619                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
 620                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 621                                 return i;
 622         }
 623         return -EMLINK;
 624 }
 625
 626 /* return first buffer from any of the next buf lists */
 627 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
 628                                                   int *buf_lst)
 629 {
 630         struct smc_buf_desc *buf_pos;
 631
 632         while (*buf_lst < SMC_RMBE_SIZES) {
 633                 buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
 634                                                    struct smc_buf_desc, list);
 635                 if (buf_pos)
 636                         return buf_pos;
 637                 (*buf_lst)++;
 638         }
 639         return NULL;
 640 }
 641
 642 /* return next rmb from buffer lists */
 643 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
 644                                                  int *buf_lst,
 645                                                  struct smc_buf_desc *buf_pos)
 646 {
 647         struct smc_buf_desc *buf_next;
 648
 649         if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
 650                 (*buf_lst)++;
 651                 return _smc_llc_get_next_rmb(lgr, buf_lst);
 652         }
 653         buf_next = list_next_entry(buf_pos, list);
 654         return buf_next;
 655 }
 656
 657 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
 658                                                   int *buf_lst)
 659 {
 660         *buf_lst = 0;
 661         return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
 662 }
 663
 664 /* send one add_link_continue msg */
 665 static int smc_llc_add_link_cont(struct smc_link *link,
 666                                  struct smc_link *link_new, u8 *num_rkeys_todo,
 667                                  int *buf_lst, struct smc_buf_desc **buf_pos)
 668 {
 669         struct smc_llc_msg_add_link_cont *addc_llc;
 670         struct smc_link_group *lgr = link->lgr;
 671         int prim_lnk_idx, lnk_idx, i, rc;
 672         struct smc_wr_tx_pend_priv *pend;
 673         struct smc_wr_buf *wr_buf;
 674         struct smc_buf_desc *rmb;
 675         u8 n;
 676
 677         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 678         if (rc)
 679                 return rc;
 680         addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
 681         memset(addc_llc, 0, sizeof(*addc_llc));
 682
 683         prim_lnk_idx = link->link_idx;
 684         lnk_idx = link_new->link_idx;
 685         addc_llc->link_num = link_new->link_id;
 686         addc_llc->num_rkeys = *num_rkeys_todo;
 687         n = *num_rkeys_todo;
 688         for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
 689                 if (!*buf_pos) {
 690                         addc_llc->num_rkeys = addc_llc->num_rkeys -
 691                                               *num_rkeys_todo;
 692                         *num_rkeys_todo = 0;
 693                         break;
 694                 }
 695                 rmb = *buf_pos;
 696
 697                 addc_llc->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
 698                 addc_llc->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
 699                 addc_llc->rt[i].rmb_vaddr_new =
 700                         cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
 701
 702                 (*num_rkeys_todo)--;
 703                 *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 704                 while (*buf_pos && !(*buf_pos)->used)
 705                         *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 706         }
 707         addc_llc->hd.common.type = SMC_LLC_ADD_LINK_CONT;
 708         addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
 709         if (lgr->role == SMC_CLNT)
 710                 addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
 711         return smc_wr_tx_send(link, pend);
 712 }
 713
 714 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
 715                                      struct smc_link *link_new)
 716 {
 717         struct smc_llc_msg_add_link_cont *addc_llc;
 718         struct smc_link_group *lgr = link->lgr;
 719         u8 max, num_rkeys_send, num_rkeys_recv;
 720         struct smc_llc_qentry *qentry;
 721         struct smc_buf_desc *buf_pos;
 722         int buf_lst;
 723         int rc = 0;
 724         int i;
 725
 726         mutex_lock(&lgr->rmbs_lock);
 727         num_rkeys_send = lgr->conns_num;
 728         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
 729         do {
 730                 qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
 731                                       SMC_LLC_ADD_LINK_CONT);
 732                 if (!qentry) {
 733                         rc = -ETIMEDOUT;
 734                         break;
 735                 }
 736                 addc_llc = &qentry->msg.add_link_cont;
 737                 num_rkeys_recv = addc_llc->num_rkeys;
 738                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
 739                 for (i = 0; i < max; i++) {
 740                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
 741                                        addc_llc->rt[i].rmb_key,
 742                                        addc_llc->rt[i].rmb_vaddr_new,
 743                                        addc_llc->rt[i].rmb_key_new);
 744                         num_rkeys_recv--;
 745                 }
 746                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 747                 rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
 748                                            &buf_lst, &buf_pos);
 749                 if (rc)
 750                         break;
 751         } while (num_rkeys_send || num_rkeys_recv);
 752
 753         mutex_unlock(&lgr->rmbs_lock);
 754         return rc;
 755 }
 756
 757 /* prepare and send an add link reject response */
 758 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
 759 {
 760         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 761         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 762         qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 763         return smc_llc_send_message(qentry->link, &qentry->msg);
 764 }
 765
 766 static int smc_llc_cli_conf_link(struct smc_link *link,
 767                                  struct smc_init_info *ini,
 768                                  struct smc_link *link_new,
 769                                  enum smc_lgr_type lgr_new_t)
 770 {
 771         struct smc_link_group *lgr = link->lgr;
 772         struct smc_llc_qentry *qentry = NULL;
 773         int rc = 0;
 774
 775         /* receive CONFIRM LINK request over RoCE fabric */
 776         qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
 777         if (!qentry) {
 778                 rc = smc_llc_send_delete_link(link, link_new->link_id,
 779                                               SMC_LLC_REQ, false,
 780                                               SMC_LLC_DEL_LOST_PATH);
 781                 return -ENOLINK;
 782         }
 783         if (qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
 784                 /* received DELETE_LINK instead */
 785                 qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 786                 smc_llc_send_message(link, &qentry->msg);
 787                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 788                 return -ENOLINK;
 789         }
 790         smc_llc_save_peer_uid(qentry);
 791         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 792
 793         rc = smc_ib_modify_qp_rts(link_new);
 794         if (rc) {
 795                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 796                                          false, SMC_LLC_DEL_LOST_PATH);
 797                 return -ENOLINK;
 798         }
 799         smc_wr_remember_qp_attr(link_new);
 800
 801         rc = smcr_buf_reg_lgr(link_new);
 802         if (rc) {
 803                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 804                                          false, SMC_LLC_DEL_LOST_PATH);
 805                 return -ENOLINK;
 806         }
 807
 808         /* send CONFIRM LINK response over RoCE fabric */
 809         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
 810         if (rc) {
 811                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 812                                          false, SMC_LLC_DEL_LOST_PATH);
 813                 return -ENOLINK;
 814         }
 815         smc_llc_link_active(link_new);
 816         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 817             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
 818                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
 819         else
 820                 smcr_lgr_set_type(lgr, lgr_new_t);
 821         return 0;
 822 }
 823
 824 static void smc_llc_save_add_link_info(struct smc_link *link,
 825                                        struct smc_llc_msg_add_link *add_llc)
 826 {
 827         link->peer_qpn = ntoh24(add_llc->sender_qp_num);
 828         memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
 829         memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
 830         link->peer_psn = ntoh24(add_llc->initial_psn);
 831         link->peer_mtu = add_llc->qp_mtu;
 832 }
 833
 834 /* as an SMC client, process an add link request */
 835 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
 836 {
 837         struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
 838         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
 839         struct smc_link_group *lgr = smc_get_lgr(link);
 840         struct smc_link *lnk_new = NULL;
 841         struct smc_init_info ini;
 842         int lnk_idx, rc = 0;
 843
 844         ini.vlan_id = lgr->vlan_id;
 845         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 846         if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
 847             !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN)) {
 848                 if (!ini.ib_dev)
 849                         goto out_reject;
 850                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
 851         }
 852         if (!ini.ib_dev) {
 853                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
 854                 ini.ib_dev = link->smcibdev;
 855                 ini.ib_port = link->ibport;
 856         }
 857         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
 858         if (lnk_idx < 0)
 859                 goto out_reject;
 860         lnk_new = &lgr->lnk[lnk_idx];
 861         rc = smcr_link_init(lgr, lnk_new, lnk_idx, &ini);
 862         if (rc)
 863                 goto out_reject;
 864         smc_llc_save_add_link_info(lnk_new, llc);
 865         lnk_new->link_id = llc->link_num;       /* SMC server assigns link id */
 866         smc_llc_link_set_uid(lnk_new);
 867
 868         rc = smc_ib_ready_link(lnk_new);
 869         if (rc)
 870                 goto out_clear_lnk;
 871
 872         rc = smcr_buf_map_lgr(lnk_new);
 873         if (rc)
 874                 goto out_clear_lnk;
 875
 876         rc = smc_llc_send_add_link(link,
 877                                    lnk_new->smcibdev->mac[ini.ib_port - 1],
 878                                    lnk_new->gid, lnk_new, SMC_LLC_RESP);
 879         if (rc)
 880                 goto out_clear_lnk;
 881         rc = smc_llc_cli_rkey_exchange(link, lnk_new);
 882         if (rc) {
 883                 rc = 0;
 884                 goto out_clear_lnk;
 885         }
 886         rc = smc_llc_cli_conf_link(link, &ini, lnk_new, lgr_new_t);
 887         if (!rc)
 888                 goto out;
 889 out_clear_lnk:
 890         smcr_link_clear(lnk_new, false);
 891 out_reject:
 892         smc_llc_cli_add_link_reject(qentry);
 893 out:
 894         kfree(qentry);
 895         return rc;
 896 }
 897
 898 /* as an SMC client, invite server to start the add_link processing */
 899 static void smc_llc_cli_add_link_invite(struct smc_link *link,
 900                                         struct smc_llc_qentry *qentry)
 901 {
 902         struct smc_link_group *lgr = smc_get_lgr(link);
 903         struct smc_init_info ini;
 904
 905         if (lgr->type == SMC_LGR_SYMMETRIC ||
 906             lgr->type == SMC_LGR_ASYMMETRIC_PEER)
 907                 goto out;
 908
 909         ini.vlan_id = lgr->vlan_id;
 910         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 911         if (!ini.ib_dev)
 912                 goto out;
 913
 914         smc_llc_send_add_link(link, ini.ib_dev->mac[ini.ib_port - 1],
 915                               ini.ib_gid, NULL, SMC_LLC_REQ);
 916 out:
 917         kfree(qentry);
 918 }
 919
 920 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
 921 {
 922         if (llc->raw.hdr.common.type == SMC_LLC_ADD_LINK &&
 923             !llc->add_link.qp_mtu && !llc->add_link.link_num)
 924                 return true;
 925         return false;
 926 }
 927
 928 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
 929 {
 930         struct smc_llc_qentry *qentry;
 931
 932         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
 933
 934         mutex_lock(&lgr->llc_conf_mutex);
 935         if (smc_llc_is_local_add_link(&qentry->msg))
 936                 smc_llc_cli_add_link_invite(qentry->link, qentry);
 937         else
 938                 smc_llc_cli_add_link(qentry->link, qentry);
 939         mutex_unlock(&lgr->llc_conf_mutex);
 940 }
 941
 942 static int smc_llc_active_link_count(struct smc_link_group *lgr)
 943 {
 944         int i, link_count = 0;
 945
 946         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 947                 if (!smc_link_active(&lgr->lnk[i]))
 948                         continue;
 949                 link_count++;
 950         }
 951         return link_count;
 952 }
 953
 954 /* find the asymmetric link when 3 links are established  */
 955 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
 956 {
 957         int asym_idx = -ENOENT;
 958         int i, j, k;
 959         bool found;
 960
 961         /* determine asymmetric link */
 962         found = false;
 963         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 964                 for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
 965                         if (!smc_link_usable(&lgr->lnk[i]) ||
 966                             !smc_link_usable(&lgr->lnk[j]))
 967                                 continue;
 968                         if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
 969                                     SMC_GID_SIZE)) {
 970                                 found = true;   /* asym_lnk is i or j */
 971                                 break;
 972                         }
 973                 }
 974                 if (found)
 975                         break;
 976         }
 977         if (!found)
 978                 goto out; /* no asymmetric link */
 979         for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
 980                 if (!smc_link_usable(&lgr->lnk[k]))
 981                         continue;
 982                 if (k != i &&
 983                     !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
 984                             SMC_GID_SIZE)) {
 985                         asym_idx = i;
 986                         break;
 987                 }
 988                 if (k != j &&
 989                     !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
 990                             SMC_GID_SIZE)) {
 991                         asym_idx = j;
 992                         break;
 993                 }
 994         }
 995 out:
 996         return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
 997 }
 998
 999 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1000 {
1001         struct smc_link *lnk_new = NULL, *lnk_asym;
1002         struct smc_llc_qentry *qentry;
1003         int rc;
1004
1005         lnk_asym = smc_llc_find_asym_link(lgr);
1006         if (!lnk_asym)
1007                 return; /* no asymmetric link */
1008         if (!smc_link_downing(&lnk_asym->state))
1009                 return;
1010         lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1011         smc_wr_tx_wait_no_pending_sends(lnk_asym);
1012         if (!lnk_new)
1013                 goto out_free;
1014         /* change flow type from ADD_LINK into DEL_LINK */
1015         lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1016         rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1017                                       true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1018         if (rc) {
1019                 smcr_link_down_cond(lnk_new);
1020                 goto out_free;
1021         }
1022         qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1023                               SMC_LLC_DELETE_LINK);
1024         if (!qentry) {
1025                 smcr_link_down_cond(lnk_new);
1026                 goto out_free;
1027         }
1028         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1029 out_free:
1030         smcr_link_clear(lnk_asym, true);
1031 }
1032
1033 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1034                                      struct smc_link *link_new)
1035 {
1036         struct smc_llc_msg_add_link_cont *addc_llc;
1037         struct smc_link_group *lgr = link->lgr;
1038         u8 max, num_rkeys_send, num_rkeys_recv;
1039         struct smc_llc_qentry *qentry = NULL;
1040         struct smc_buf_desc *buf_pos;
1041         int buf_lst;
1042         int rc = 0;
1043         int i;
1044
1045         mutex_lock(&lgr->rmbs_lock);
1046         num_rkeys_send = lgr->conns_num;
1047         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1048         do {
1049                 smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1050                                       &buf_lst, &buf_pos);
1051                 qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1052                                       SMC_LLC_ADD_LINK_CONT);
1053                 if (!qentry) {
1054                         rc = -ETIMEDOUT;
1055                         goto out;
1056                 }
1057                 addc_llc = &qentry->msg.add_link_cont;
1058                 num_rkeys_recv = addc_llc->num_rkeys;
1059                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1060                 for (i = 0; i < max; i++) {
1061                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1062                                        addc_llc->rt[i].rmb_key,
1063                                        addc_llc->rt[i].rmb_vaddr_new,
1064                                        addc_llc->rt[i].rmb_key_new);
1065                         num_rkeys_recv--;
1066                 }
1067                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1068         } while (num_rkeys_send || num_rkeys_recv);
1069 out:
1070         mutex_unlock(&lgr->rmbs_lock);
1071         return rc;
1072 }
1073
1074 static int smc_llc_srv_conf_link(struct smc_link *link,
1075                                  struct smc_link *link_new,
1076                                  enum smc_lgr_type lgr_new_t)
1077 {
1078         struct smc_link_group *lgr = link->lgr;
1079         struct smc_llc_qentry *qentry = NULL;
1080         int rc;
1081
1082         /* send CONFIRM LINK request over the RoCE fabric */
1083         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1084         if (rc)
1085                 return -ENOLINK;
1086         /* receive CONFIRM LINK response over the RoCE fabric */
1087         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1088         if (!qentry ||
1089             qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
1090                 /* send DELETE LINK */
1091                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1092                                          false, SMC_LLC_DEL_LOST_PATH);
1093                 if (qentry)
1094                         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1095                 return -ENOLINK;
1096         }
1097         smc_llc_save_peer_uid(qentry);
1098         smc_llc_link_active(link_new);
1099         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1100             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1101                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1102         else
1103                 smcr_lgr_set_type(lgr, lgr_new_t);
1104         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1105         return 0;
1106 }
1107
1108 int smc_llc_srv_add_link(struct smc_link *link)
1109 {
1110         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1111         struct smc_link_group *lgr = link->lgr;
1112         struct smc_llc_msg_add_link *add_llc;
1113         struct smc_llc_qentry *qentry = NULL;
1114         struct smc_link *link_new;
1115         struct smc_init_info ini;
1116         int lnk_idx, rc = 0;
1117
1118         /* ignore client add link recommendation, start new flow */
1119         ini.vlan_id = lgr->vlan_id;
1120         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
1121         if (!ini.ib_dev) {
1122                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1123                 ini.ib_dev = link->smcibdev;
1124                 ini.ib_port = link->ibport;
1125         }
1126         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1127         if (lnk_idx < 0)
1128                 return 0;
1129
1130         rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, &ini);
1131         if (rc)
1132                 return rc;
1133         link_new = &lgr->lnk[lnk_idx];
1134         rc = smc_llc_send_add_link(link,
1135                                    link_new->smcibdev->mac[ini.ib_port - 1],
1136                                    link_new->gid, link_new, SMC_LLC_REQ);
1137         if (rc)
1138                 goto out_err;
1139         /* receive ADD LINK response over the RoCE fabric */
1140         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1141         if (!qentry) {
1142                 rc = -ETIMEDOUT;
1143                 goto out_err;
1144         }
1145         add_llc = &qentry->msg.add_link;
1146         if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1147                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1148                 rc = -ENOLINK;
1149                 goto out_err;
1150         }
1151         if (lgr->type == SMC_LGR_SINGLE &&
1152             (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1153              !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1154                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1155         }
1156         smc_llc_save_add_link_info(link_new, add_llc);
1157         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1158
1159         rc = smc_ib_ready_link(link_new);
1160         if (rc)
1161                 goto out_err;
1162         rc = smcr_buf_map_lgr(link_new);
1163         if (rc)
1164                 goto out_err;
1165         rc = smcr_buf_reg_lgr(link_new);
1166         if (rc)
1167                 goto out_err;
1168         rc = smc_llc_srv_rkey_exchange(link, link_new);
1169         if (rc)
1170                 goto out_err;
1171         rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1172         if (rc)
1173                 goto out_err;
1174         return 0;
1175 out_err:
1176         smcr_link_clear(link_new, false);
1177         return rc;
1178 }
1179
1180 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1181 {
1182         struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1183         int rc;
1184
1185         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1186
1187         mutex_lock(&lgr->llc_conf_mutex);
1188         rc = smc_llc_srv_add_link(link);
1189         if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1190                 /* delete any asymmetric link */
1191                 smc_llc_delete_asym_link(lgr);
1192         }
1193         mutex_unlock(&lgr->llc_conf_mutex);
1194 }
1195
1196 /* enqueue a local add_link req to trigger a new add_link flow */
1197 void smc_llc_add_link_local(struct smc_link *link)
1198 {
1199         struct smc_llc_msg_add_link add_llc = {0};
1200
1201         add_llc.hd.length = sizeof(add_llc);
1202         add_llc.hd.common.type = SMC_LLC_ADD_LINK;
1203         /* no dev and port needed */
1204         smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1205 }
1206
1207 /* worker to process an add link message */
1208 static void smc_llc_add_link_work(struct work_struct *work)
1209 {
1210         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1211                                                   llc_add_link_work);
1212
1213         if (list_empty(&lgr->list)) {
1214                 /* link group is terminating */
1215                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1216                 goto out;
1217         }
1218
1219         if (lgr->role == SMC_CLNT)
1220                 smc_llc_process_cli_add_link(lgr);
1221         else
1222                 smc_llc_process_srv_add_link(lgr);
1223 out:
1224         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1225 }
1226
1227 /* enqueue a local del_link msg to trigger a new del_link flow,
1228  * called only for role SMC_SERV
1229  */
1230 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1231 {
1232         struct smc_llc_msg_del_link del_llc = {0};
1233
1234         del_llc.hd.length = sizeof(del_llc);
1235         del_llc.hd.common.type = SMC_LLC_DELETE_LINK;
1236         del_llc.link_num = del_link_id;
1237         del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1238         del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1239         smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1240 }
1241
1242 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1243 {
1244         struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1245         struct smc_llc_msg_del_link *del_llc;
1246         struct smc_llc_qentry *qentry;
1247         int active_links;
1248         int lnk_idx;
1249
1250         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1251         lnk = qentry->link;
1252         del_llc = &qentry->msg.delete_link;
1253
1254         if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1255                 smc_lgr_terminate_sched(lgr);
1256                 goto out;
1257         }
1258         mutex_lock(&lgr->llc_conf_mutex);
1259         /* delete single link */
1260         for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1261                 if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1262                         continue;
1263                 lnk_del = &lgr->lnk[lnk_idx];
1264                 break;
1265         }
1266         del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1267         if (!lnk_del) {
1268                 /* link was not found */
1269                 del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1270                 smc_llc_send_message(lnk, &qentry->msg);
1271                 goto out_unlock;
1272         }
1273         lnk_asym = smc_llc_find_asym_link(lgr);
1274
1275         del_llc->reason = 0;
1276         smc_llc_send_message(lnk, &qentry->msg); /* response */
1277
1278         if (smc_link_downing(&lnk_del->state)) {
1279                 if (smc_switch_conns(lgr, lnk_del, false))
1280                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1281         }
1282         smcr_link_clear(lnk_del, true);
1283
1284         active_links = smc_llc_active_link_count(lgr);
1285         if (lnk_del == lnk_asym) {
1286                 /* expected deletion of asym link, don't change lgr state */
1287         } else if (active_links == 1) {
1288                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1289         } else if (!active_links) {
1290                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1291                 smc_lgr_terminate_sched(lgr);
1292         }
1293 out_unlock:
1294         mutex_unlock(&lgr->llc_conf_mutex);
1295 out:
1296         kfree(qentry);
1297 }
1298
1299 /* try to send a DELETE LINK ALL request on any active link,
1300  * waiting for send completion
1301  */
1302 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1303 {
1304         struct smc_llc_msg_del_link delllc = {0};
1305         int i;
1306
1307         delllc.hd.common.type = SMC_LLC_DELETE_LINK;
1308         delllc.hd.length = sizeof(delllc);
1309         if (ord)
1310                 delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1311         delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1312         delllc.reason = htonl(rsn);
1313
1314         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1315                 if (!smc_link_usable(&lgr->lnk[i]))
1316                         continue;
1317                 if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1318                         break;
1319         }
1320 }
1321
1322 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1323 {
1324         struct smc_llc_msg_del_link *del_llc;
1325         struct smc_link *lnk, *lnk_del;
1326         struct smc_llc_qentry *qentry;
1327         int active_links;
1328         int i;
1329
1330         mutex_lock(&lgr->llc_conf_mutex);
1331         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1332         lnk = qentry->link;
1333         del_llc = &qentry->msg.delete_link;
1334
1335         if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1336                 /* delete entire lgr */
1337                 smc_llc_send_link_delete_all(lgr, true, ntohl(
1338                                               qentry->msg.delete_link.reason));
1339                 smc_lgr_terminate_sched(lgr);
1340                 goto out;
1341         }
1342         /* delete single link */
1343         lnk_del = NULL;
1344         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1345                 if (lgr->lnk[i].link_id == del_llc->link_num) {
1346                         lnk_del = &lgr->lnk[i];
1347                         break;
1348                 }
1349         }
1350         if (!lnk_del)
1351                 goto out; /* asymmetric link already deleted */
1352
1353         if (smc_link_downing(&lnk_del->state)) {
1354                 if (smc_switch_conns(lgr, lnk_del, false))
1355                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1356         }
1357         if (!list_empty(&lgr->list)) {
1358                 /* qentry is either a request from peer (send it back to
1359                  * initiate the DELETE_LINK processing), or a locally
1360                  * enqueued DELETE_LINK request (forward it)
1361                  */
1362                 if (!smc_llc_send_message(lnk, &qentry->msg)) {
1363                         struct smc_llc_qentry *qentry2;
1364
1365                         qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1366                                                SMC_LLC_DELETE_LINK);
1367                         if (qentry2)
1368                                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1369                 }
1370         }
1371         smcr_link_clear(lnk_del, true);
1372
1373         active_links = smc_llc_active_link_count(lgr);
1374         if (active_links == 1) {
1375                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1376         } else if (!active_links) {
1377                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1378                 smc_lgr_terminate_sched(lgr);
1379         }
1380
1381         if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1382                 /* trigger setup of asymm alt link */
1383                 smc_llc_add_link_local(lnk);
1384         }
1385 out:
1386         mutex_unlock(&lgr->llc_conf_mutex);
1387         kfree(qentry);
1388 }
1389
1390 static void smc_llc_delete_link_work(struct work_struct *work)
1391 {
1392         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1393                                                   llc_del_link_work);
1394
1395         if (list_empty(&lgr->list)) {
1396                 /* link group is terminating */
1397                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1398                 goto out;
1399         }
1400
1401         if (lgr->role == SMC_CLNT)
1402                 smc_llc_process_cli_delete_link(lgr);
1403         else
1404                 smc_llc_process_srv_delete_link(lgr);
1405 out:
1406         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1407 }
1408
1409 /* process a confirm_rkey request from peer, remote flow */
1410 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1411 {
1412         struct smc_llc_msg_confirm_rkey *llc;
1413         struct smc_llc_qentry *qentry;
1414         struct smc_link *link;
1415         int num_entries;
1416         int rk_idx;
1417         int i;
1418
1419         qentry = lgr->llc_flow_rmt.qentry;
1420         llc = &qentry->msg.confirm_rkey;
1421         link = qentry->link;
1422
1423         num_entries = llc->rtoken[0].num_rkeys;
1424         /* first rkey entry is for receiving link */
1425         rk_idx = smc_rtoken_add(link,
1426                                 llc->rtoken[0].rmb_vaddr,
1427                                 llc->rtoken[0].rmb_key);
1428         if (rk_idx < 0)
1429                 goto out_err;
1430
1431         for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1432                 smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1433                                 llc->rtoken[i].rmb_vaddr,
1434                                 llc->rtoken[i].rmb_key);
1435         /* max links is 3 so there is no need to support conf_rkey_cont msgs */
1436         goto out;
1437 out_err:
1438         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1439         llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1440 out:
1441         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1442         smc_llc_send_message(link, &qentry->msg);
1443         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1444 }
1445
1446 /* process a delete_rkey request from peer, remote flow */
1447 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1448 {
1449         struct smc_llc_msg_delete_rkey *llc;
1450         struct smc_llc_qentry *qentry;
1451         struct smc_link *link;
1452         u8 err_mask = 0;
1453         int i, max;
1454
1455         qentry = lgr->llc_flow_rmt.qentry;
1456         llc = &qentry->msg.delete_rkey;
1457         link = qentry->link;
1458
1459         max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1460         for (i = 0; i < max; i++) {
1461                 if (smc_rtoken_delete(link, llc->rkey[i]))
1462                         err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1463         }
1464         if (err_mask) {
1465                 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1466                 llc->err_mask = err_mask;
1467         }
1468         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1469         smc_llc_send_message(link, &qentry->msg);
1470         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1471 }
1472
1473 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1474 {
1475         pr_warn_ratelimited("smc: SMC-R lg %*phN LLC protocol violation: "
1476                             "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id, type);
1477         smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1478         smc_lgr_terminate_sched(lgr);
1479 }
1480
1481 /* flush the llc event queue */
1482 static void smc_llc_event_flush(struct smc_link_group *lgr)
1483 {
1484         struct smc_llc_qentry *qentry, *q;
1485
1486         spin_lock_bh(&lgr->llc_event_q_lock);
1487         list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1488                 list_del_init(&qentry->list);
1489                 kfree(qentry);
1490         }
1491         spin_unlock_bh(&lgr->llc_event_q_lock);
1492 }
1493
1494 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1495 {
1496         union smc_llc_msg *llc = &qentry->msg;
1497         struct smc_link *link = qentry->link;
1498         struct smc_link_group *lgr = link->lgr;
1499
1500         if (!smc_link_usable(link))
1501                 goto out;
1502
1503         switch (llc->raw.hdr.common.type) {
1504         case SMC_LLC_TEST_LINK:
1505                 llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1506                 smc_llc_send_message(link, llc);
1507                 break;
1508         case SMC_LLC_ADD_LINK:
1509                 if (list_empty(&lgr->list))
1510                         goto out;       /* lgr is terminating */
1511                 if (lgr->role == SMC_CLNT) {
1512                         if (smc_llc_is_local_add_link(llc)) {
1513                                 if (lgr->llc_flow_lcl.type ==
1514                                     SMC_LLC_FLOW_ADD_LINK)
1515                                         break;  /* add_link in progress */
1516                                 if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1517                                                        qentry)) {
1518                                         schedule_work(&lgr->llc_add_link_work);
1519                                 }
1520                                 return;
1521                         }
1522                         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1523                             !lgr->llc_flow_lcl.qentry) {
1524                                 /* a flow is waiting for this message */
1525                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1526                                                         qentry);
1527                                 wake_up(&lgr->llc_msg_waiter);
1528                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1529                                                       qentry)) {
1530                                 schedule_work(&lgr->llc_add_link_work);
1531                         }
1532                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1533                         /* as smc server, handle client suggestion */
1534                         schedule_work(&lgr->llc_add_link_work);
1535                 }
1536                 return;
1537         case SMC_LLC_CONFIRM_LINK:
1538         case SMC_LLC_ADD_LINK_CONT:
1539                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1540                         /* a flow is waiting for this message */
1541                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1542                         wake_up(&lgr->llc_msg_waiter);
1543                         return;
1544                 }
1545                 break;
1546         case SMC_LLC_DELETE_LINK:
1547                 if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1548                     !lgr->llc_flow_lcl.qentry) {
1549                         /* DEL LINK REQ during ADD LINK SEQ */
1550                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1551                         wake_up(&lgr->llc_msg_waiter);
1552                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1553                         schedule_work(&lgr->llc_del_link_work);
1554                 }
1555                 return;
1556         case SMC_LLC_CONFIRM_RKEY:
1557                 /* new request from remote, assign to remote flow */
1558                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1559                         /* process here, does not wait for more llc msgs */
1560                         smc_llc_rmt_conf_rkey(lgr);
1561                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1562                 }
1563                 return;
1564         case SMC_LLC_CONFIRM_RKEY_CONT:
1565                 /* not used because max links is 3, and 3 rkeys fit into
1566                  * one CONFIRM_RKEY message
1567                  */
1568                 break;
1569         case SMC_LLC_DELETE_RKEY:
1570                 /* new request from remote, assign to remote flow */
1571                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1572                         /* process here, does not wait for more llc msgs */
1573                         smc_llc_rmt_delete_rkey(lgr);
1574                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1575                 }
1576                 return;
1577         default:
1578                 smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1579                 break;
1580         }
1581 out:
1582         kfree(qentry);
1583 }
1584
1585 /* worker to process llc messages on the event queue */
1586 static void smc_llc_event_work(struct work_struct *work)
1587 {
1588         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1589                                                   llc_event_work);
1590         struct smc_llc_qentry *qentry;
1591
1592         if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1593                 if (smc_link_usable(lgr->delayed_event->link)) {
1594                         smc_llc_event_handler(lgr->delayed_event);
1595                 } else {
1596                         qentry = lgr->delayed_event;
1597                         lgr->delayed_event = NULL;
1598                         kfree(qentry);
1599                 }
1600         }
1601
1602 again:
1603         spin_lock_bh(&lgr->llc_event_q_lock);
1604         if (!list_empty(&lgr->llc_event_q)) {
1605                 qentry = list_first_entry(&lgr->llc_event_q,
1606                                           struct smc_llc_qentry, list);
1607                 list_del_init(&qentry->list);
1608                 spin_unlock_bh(&lgr->llc_event_q_lock);
1609                 smc_llc_event_handler(qentry);
1610                 goto again;
1611         }
1612         spin_unlock_bh(&lgr->llc_event_q_lock);
1613 }
1614
1615 /* process llc responses in tasklet context */
1616 static void smc_llc_rx_response(struct smc_link *link,
1617                                 struct smc_llc_qentry *qentry)
1618 {
1619         enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
1620         struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
1621         u8 llc_type = qentry->msg.raw.hdr.common.type;
1622
1623         switch (llc_type) {
1624         case SMC_LLC_TEST_LINK:
1625                 if (smc_link_active(link))
1626                         complete(&link->llc_testlink_resp);
1627                 break;
1628         case SMC_LLC_ADD_LINK:
1629         case SMC_LLC_ADD_LINK_CONT:
1630         case SMC_LLC_CONFIRM_LINK:
1631                 if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
1632                         break;  /* drop out-of-flow response */
1633                 goto assign;
1634         case SMC_LLC_DELETE_LINK:
1635                 if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
1636                         break;  /* drop out-of-flow response */
1637                 goto assign;
1638         case SMC_LLC_CONFIRM_RKEY:
1639         case SMC_LLC_DELETE_RKEY:
1640                 if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
1641                         break;  /* drop out-of-flow response */
1642                 goto assign;
1643         case SMC_LLC_CONFIRM_RKEY_CONT:
1644                 /* not used because max links is 3 */
1645                 break;
1646         default:
1647                 smc_llc_protocol_violation(link->lgr, llc_type);
1648                 break;
1649         }
1650         kfree(qentry);
1651         return;
1652 assign:
1653         /* assign responses to the local flow, we requested them */
1654         smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
1655         wake_up(&link->lgr->llc_msg_waiter);
1656 }
1657
1658 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
1659 {
1660         struct smc_link_group *lgr = link->lgr;
1661         struct smc_llc_qentry *qentry;
1662         unsigned long flags;
1663
1664         qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
1665         if (!qentry)
1666                 return;
1667         qentry->link = link;
1668         INIT_LIST_HEAD(&qentry->list);
1669         memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
1670
1671         /* process responses immediately */
1672         if (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) {
1673                 smc_llc_rx_response(link, qentry);
1674                 return;
1675         }
1676
1677         /* add requests to event queue */
1678         spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
1679         list_add_tail(&qentry->list, &lgr->llc_event_q);
1680         spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
1681         schedule_work(&lgr->llc_event_work);
1682 }
1683
1684 /* copy received msg and add it to the event queue */
1685 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
1686 {
1687         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
1688         union smc_llc_msg *llc = buf;
1689
1690         if (wc->byte_len < sizeof(*llc))
1691                 return; /* short message */
1692         if (llc->raw.hdr.length != sizeof(*llc))
1693                 return; /* invalid message */
1694
1695         smc_llc_enqueue(link, llc);
1696 }
1697
1698 /***************************** worker, utils *********************************/
1699
1700 static void smc_llc_testlink_work(struct work_struct *work)
1701 {
1702         struct smc_link *link = container_of(to_delayed_work(work),
1703                                              struct smc_link, llc_testlink_wrk);
1704         unsigned long next_interval;
1705         unsigned long expire_time;
1706         u8 user_data[16] = { 0 };
1707         int rc;
1708
1709         if (!smc_link_active(link))
1710                 return;         /* don't reschedule worker */
1711         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
1712         if (time_is_after_jiffies(expire_time)) {
1713                 next_interval = expire_time - jiffies;
1714                 goto out;
1715         }
1716         reinit_completion(&link->llc_testlink_resp);
1717         smc_llc_send_test_link(link, user_data);
1718         /* receive TEST LINK response over RoCE fabric */
1719         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
1720                                                        SMC_LLC_WAIT_TIME);
1721         if (!smc_link_active(link))
1722                 return;         /* link state changed */
1723         if (rc <= 0) {
1724                 smcr_link_down_cond_sched(link);
1725                 return;
1726         }
1727         next_interval = link->llc_testlink_time;
1728 out:
1729         schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
1730 }
1731
1732 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
1733 {
1734         struct net *net = sock_net(smc->clcsock->sk);
1735
1736         INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
1737         INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
1738         INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
1739         INIT_LIST_HEAD(&lgr->llc_event_q);
1740         spin_lock_init(&lgr->llc_event_q_lock);
1741         spin_lock_init(&lgr->llc_flow_lock);
1742         init_waitqueue_head(&lgr->llc_flow_waiter);
1743         init_waitqueue_head(&lgr->llc_msg_waiter);
1744         mutex_init(&lgr->llc_conf_mutex);
1745         lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
1746 }
1747
1748 /* called after lgr was removed from lgr_list */
1749 void smc_llc_lgr_clear(struct smc_link_group *lgr)
1750 {
1751         smc_llc_event_flush(lgr);
1752         wake_up_all(&lgr->llc_flow_waiter);
1753         wake_up_all(&lgr->llc_msg_waiter);
1754         cancel_work_sync(&lgr->llc_event_work);
1755         cancel_work_sync(&lgr->llc_add_link_work);
1756         cancel_work_sync(&lgr->llc_del_link_work);
1757         if (lgr->delayed_event) {
1758                 kfree(lgr->delayed_event);
1759                 lgr->delayed_event = NULL;
1760         }
1761 }
1762
1763 int smc_llc_link_init(struct smc_link *link)
1764 {
1765         init_completion(&link->llc_testlink_resp);
1766         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
1767         return 0;
1768 }
1769
1770 void smc_llc_link_active(struct smc_link *link)
1771 {
1772         pr_warn_ratelimited("smc: SMC-R lg %*phN link added: id %*phN, "
1773                             "peerid %*phN, ibdev %s, ibport %d\n",
1774                             SMC_LGR_ID_SIZE, &link->lgr->id,
1775                             SMC_LGR_ID_SIZE, &link->link_uid,
1776                             SMC_LGR_ID_SIZE, &link->peer_link_uid,
1777                             link->smcibdev->ibdev->name, link->ibport);
1778         link->state = SMC_LNK_ACTIVE;
1779         if (link->lgr->llc_testlink_time) {
1780                 link->llc_testlink_time = link->lgr->llc_testlink_time * HZ;
1781                 schedule_delayed_work(&link->llc_testlink_wrk,
1782                                       link->llc_testlink_time);
1783         }
1784 }
1785
1786 /* called in worker context */
1787 void smc_llc_link_clear(struct smc_link *link, bool log)
1788 {
1789         if (log)
1790                 pr_warn_ratelimited("smc: SMC-R lg %*phN link removed: id %*phN"
1791                                     ", peerid %*phN, ibdev %s, ibport %d\n",
1792                                     SMC_LGR_ID_SIZE, &link->lgr->id,
1793                                     SMC_LGR_ID_SIZE, &link->link_uid,
1794                                     SMC_LGR_ID_SIZE, &link->peer_link_uid,
1795                                     link->smcibdev->ibdev->name, link->ibport);
1796         complete(&link->llc_testlink_resp);
1797         cancel_delayed_work_sync(&link->llc_testlink_wrk);
1798         smc_wr_wakeup_reg_wait(link);
1799         smc_wr_wakeup_tx_wait(link);
1800 }
1801
1802 /* register a new rtoken at the remote peer (for all links) */
1803 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
1804                             struct smc_buf_desc *rmb_desc)
1805 {
1806         struct smc_link_group *lgr = send_link->lgr;
1807         struct smc_llc_qentry *qentry = NULL;
1808         int rc = 0;
1809
1810         rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
1811         if (rc)
1812                 goto out;
1813         /* receive CONFIRM RKEY response from server over RoCE fabric */
1814         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1815                               SMC_LLC_CONFIRM_RKEY);
1816         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1817                 rc = -EFAULT;
1818 out:
1819         if (qentry)
1820                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1821         return rc;
1822 }
1823
1824 /* unregister an rtoken at the remote peer */
1825 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
1826                            struct smc_buf_desc *rmb_desc)
1827 {
1828         struct smc_llc_qentry *qentry = NULL;
1829         struct smc_link *send_link;
1830         int rc = 0;
1831
1832         send_link = smc_llc_usable_link(lgr);
1833         if (!send_link)
1834                 return -ENOLINK;
1835
1836         /* protected by llc_flow control */
1837         rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
1838         if (rc)
1839                 goto out;
1840         /* receive DELETE RKEY response from server over RoCE fabric */
1841         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1842                               SMC_LLC_DELETE_RKEY);
1843         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1844                 rc = -EFAULT;
1845 out:
1846         if (qentry)
1847                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1848         return rc;
1849 }
1850
1851 void smc_llc_link_set_uid(struct smc_link *link)
1852 {
1853         __be32 link_uid;
1854
1855         link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
1856         memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
1857 }
1858
1859 /* save peers link user id, used for debug purposes */
1860 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
1861 {
1862         memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
1863                SMC_LGR_ID_SIZE);
1864 }
1865
1866 /* evaluate confirm link request or response */
1867 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
1868                            enum smc_llc_reqresp type)
1869 {
1870         if (type == SMC_LLC_REQ) {      /* SMC server assigns link_id */
1871                 qentry->link->link_id = qentry->msg.confirm_link.link_num;
1872                 smc_llc_link_set_uid(qentry->link);
1873         }
1874         if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
1875                 return -ENOTSUPP;
1876         return 0;
1877 }
1878
1879 /***************************** init, exit, misc ******************************/
1880
1881 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
1882         {
1883                 .handler        = smc_llc_rx_handler,
1884                 .type           = SMC_LLC_CONFIRM_LINK
1885         },
1886         {
1887                 .handler        = smc_llc_rx_handler,
1888                 .type           = SMC_LLC_TEST_LINK
1889         },
1890         {
1891                 .handler        = smc_llc_rx_handler,
1892                 .type           = SMC_LLC_ADD_LINK
1893         },
1894         {
1895                 .handler        = smc_llc_rx_handler,
1896                 .type           = SMC_LLC_ADD_LINK_CONT
1897         },
1898         {
1899                 .handler        = smc_llc_rx_handler,
1900                 .type           = SMC_LLC_DELETE_LINK
1901         },
1902         {
1903                 .handler        = smc_llc_rx_handler,
1904                 .type           = SMC_LLC_CONFIRM_RKEY
1905         },
1906         {
1907                 .handler        = smc_llc_rx_handler,
1908                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
1909         },
1910         {
1911                 .handler        = smc_llc_rx_handler,
1912                 .type           = SMC_LLC_DELETE_RKEY
1913         },
1914         {
1915                 .handler        = NULL,
1916         }
1917 };
1918
1919 int __init smc_llc_init(void)
1920 {
1921         struct smc_wr_rx_handler *handler;
1922         int rc = 0;
1923
1924         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
1925                 INIT_HLIST_NODE(&handler->list);
1926                 rc = smc_wr_rx_register_handler(handler);
1927                 if (rc)
1928                         break;
1929         }
1930         return rc;
1931 }