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         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 (link->state == SMC_LNK_ACTIVE && 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 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
 899 {
 900         struct smc_llc_qentry *qentry;
 901
 902         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
 903
 904         mutex_lock(&lgr->llc_conf_mutex);
 905         smc_llc_cli_add_link(qentry->link, qentry);
 906         mutex_unlock(&lgr->llc_conf_mutex);
 907 }
 908
 909 static int smc_llc_active_link_count(struct smc_link_group *lgr)
 910 {
 911         int i, link_count = 0;
 912
 913         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 914                 if (!smc_link_usable(&lgr->lnk[i]))
 915                         continue;
 916                 link_count++;
 917         }
 918         return link_count;
 919 }
 920
 921 /* find the asymmetric link when 3 links are established  */
 922 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
 923 {
 924         int asym_idx = -ENOENT;
 925         int i, j, k;
 926         bool found;
 927
 928         /* determine asymmetric link */
 929         found = false;
 930         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 931                 for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
 932                         if (!smc_link_usable(&lgr->lnk[i]) ||
 933                             !smc_link_usable(&lgr->lnk[j]))
 934                                 continue;
 935                         if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
 936                                     SMC_GID_SIZE)) {
 937                                 found = true;   /* asym_lnk is i or j */
 938                                 break;
 939                         }
 940                 }
 941                 if (found)
 942                         break;
 943         }
 944         if (!found)
 945                 goto out; /* no asymmetric link */
 946         for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
 947                 if (!smc_link_usable(&lgr->lnk[k]))
 948                         continue;
 949                 if (k != i &&
 950                     !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
 951                             SMC_GID_SIZE)) {
 952                         asym_idx = i;
 953                         break;
 954                 }
 955                 if (k != j &&
 956                     !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
 957                             SMC_GID_SIZE)) {
 958                         asym_idx = j;
 959                         break;
 960                 }
 961         }
 962 out:
 963         return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
 964 }
 965
 966 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
 967 {
 968         struct smc_link *lnk_new = NULL, *lnk_asym;
 969         struct smc_llc_qentry *qentry;
 970         int rc;
 971
 972         lnk_asym = smc_llc_find_asym_link(lgr);
 973         if (!lnk_asym)
 974                 return; /* no asymmetric link */
 975         if (!smc_link_downing(&lnk_asym->state))
 976                 return;
 977         lnk_new = smc_switch_conns(lgr, lnk_asym, false);
 978         smc_wr_tx_wait_no_pending_sends(lnk_asym);
 979         if (!lnk_new)
 980                 goto out_free;
 981         /* change flow type from ADD_LINK into DEL_LINK */
 982         lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
 983         rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
 984                                       true, SMC_LLC_DEL_NO_ASYM_NEEDED);
 985         if (rc) {
 986                 smcr_link_down_cond(lnk_new);
 987                 goto out_free;
 988         }
 989         qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
 990                               SMC_LLC_DELETE_LINK);
 991         if (!qentry) {
 992                 smcr_link_down_cond(lnk_new);
 993                 goto out_free;
 994         }
 995         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 996 out_free:
 997         smcr_link_clear(lnk_asym, true);
 998 }
 999
1000 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1001                                      struct smc_link *link_new)
1002 {
1003         struct smc_llc_msg_add_link_cont *addc_llc;
1004         struct smc_link_group *lgr = link->lgr;
1005         u8 max, num_rkeys_send, num_rkeys_recv;
1006         struct smc_llc_qentry *qentry = NULL;
1007         struct smc_buf_desc *buf_pos;
1008         int buf_lst;
1009         int rc = 0;
1010         int i;
1011
1012         mutex_lock(&lgr->rmbs_lock);
1013         num_rkeys_send = lgr->conns_num;
1014         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1015         do {
1016                 smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1017                                       &buf_lst, &buf_pos);
1018                 qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1019                                       SMC_LLC_ADD_LINK_CONT);
1020                 if (!qentry) {
1021                         rc = -ETIMEDOUT;
1022                         goto out;
1023                 }
1024                 addc_llc = &qentry->msg.add_link_cont;
1025                 num_rkeys_recv = addc_llc->num_rkeys;
1026                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1027                 for (i = 0; i < max; i++) {
1028                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1029                                        addc_llc->rt[i].rmb_key,
1030                                        addc_llc->rt[i].rmb_vaddr_new,
1031                                        addc_llc->rt[i].rmb_key_new);
1032                         num_rkeys_recv--;
1033                 }
1034                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1035         } while (num_rkeys_send || num_rkeys_recv);
1036 out:
1037         mutex_unlock(&lgr->rmbs_lock);
1038         return rc;
1039 }
1040
1041 static int smc_llc_srv_conf_link(struct smc_link *link,
1042                                  struct smc_link *link_new,
1043                                  enum smc_lgr_type lgr_new_t)
1044 {
1045         struct smc_link_group *lgr = link->lgr;
1046         struct smc_llc_qentry *qentry = NULL;
1047         int rc;
1048
1049         /* send CONFIRM LINK request over the RoCE fabric */
1050         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1051         if (rc)
1052                 return -ENOLINK;
1053         /* receive CONFIRM LINK response over the RoCE fabric */
1054         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME,
1055                               SMC_LLC_CONFIRM_LINK);
1056         if (!qentry) {
1057                 /* send DELETE LINK */
1058                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1059                                          false, SMC_LLC_DEL_LOST_PATH);
1060                 return -ENOLINK;
1061         }
1062         smc_llc_save_peer_uid(qentry);
1063         smc_llc_link_active(link_new);
1064         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1065             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1066                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1067         else
1068                 smcr_lgr_set_type(lgr, lgr_new_t);
1069         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1070         return 0;
1071 }
1072
1073 int smc_llc_srv_add_link(struct smc_link *link)
1074 {
1075         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1076         struct smc_link_group *lgr = link->lgr;
1077         struct smc_llc_msg_add_link *add_llc;
1078         struct smc_llc_qentry *qentry = NULL;
1079         struct smc_link *link_new;
1080         struct smc_init_info ini;
1081         int lnk_idx, rc = 0;
1082
1083         /* ignore client add link recommendation, start new flow */
1084         ini.vlan_id = lgr->vlan_id;
1085         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
1086         if (!ini.ib_dev) {
1087                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1088                 ini.ib_dev = link->smcibdev;
1089                 ini.ib_port = link->ibport;
1090         }
1091         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1092         if (lnk_idx < 0)
1093                 return 0;
1094
1095         rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, &ini);
1096         if (rc)
1097                 return rc;
1098         link_new = &lgr->lnk[lnk_idx];
1099         rc = smc_llc_send_add_link(link,
1100                                    link_new->smcibdev->mac[ini.ib_port - 1],
1101                                    link_new->gid, link_new, SMC_LLC_REQ);
1102         if (rc)
1103                 goto out_err;
1104         /* receive ADD LINK response over the RoCE fabric */
1105         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1106         if (!qentry) {
1107                 rc = -ETIMEDOUT;
1108                 goto out_err;
1109         }
1110         add_llc = &qentry->msg.add_link;
1111         if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1112                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1113                 rc = -ENOLINK;
1114                 goto out_err;
1115         }
1116         if (lgr->type == SMC_LGR_SINGLE &&
1117             (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1118              !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1119                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1120         }
1121         smc_llc_save_add_link_info(link_new, add_llc);
1122         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1123
1124         rc = smc_ib_ready_link(link_new);
1125         if (rc)
1126                 goto out_err;
1127         rc = smcr_buf_map_lgr(link_new);
1128         if (rc)
1129                 goto out_err;
1130         rc = smcr_buf_reg_lgr(link_new);
1131         if (rc)
1132                 goto out_err;
1133         rc = smc_llc_srv_rkey_exchange(link, link_new);
1134         if (rc)
1135                 goto out_err;
1136         rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1137         if (rc)
1138                 goto out_err;
1139         return 0;
1140 out_err:
1141         smcr_link_clear(link_new, false);
1142         return rc;
1143 }
1144
1145 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1146 {
1147         struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1148         int rc;
1149
1150         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1151
1152         mutex_lock(&lgr->llc_conf_mutex);
1153         rc = smc_llc_srv_add_link(link);
1154         if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1155                 /* delete any asymmetric link */
1156                 smc_llc_delete_asym_link(lgr);
1157         }
1158         mutex_unlock(&lgr->llc_conf_mutex);
1159 }
1160
1161 /* enqueue a local add_link req to trigger a new add_link flow, only as SERV */
1162 void smc_llc_srv_add_link_local(struct smc_link *link)
1163 {
1164         struct smc_llc_msg_add_link add_llc = {0};
1165
1166         add_llc.hd.length = sizeof(add_llc);
1167         add_llc.hd.common.type = SMC_LLC_ADD_LINK;
1168         /* no dev and port needed, we as server ignore client data anyway */
1169         smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1170 }
1171
1172 /* worker to process an add link message */
1173 static void smc_llc_add_link_work(struct work_struct *work)
1174 {
1175         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1176                                                   llc_add_link_work);
1177
1178         if (list_empty(&lgr->list)) {
1179                 /* link group is terminating */
1180                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1181                 goto out;
1182         }
1183
1184         if (lgr->role == SMC_CLNT)
1185                 smc_llc_process_cli_add_link(lgr);
1186         else
1187                 smc_llc_process_srv_add_link(lgr);
1188 out:
1189         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1190 }
1191
1192 /* enqueue a local del_link msg to trigger a new del_link flow,
1193  * called only for role SMC_SERV
1194  */
1195 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1196 {
1197         struct smc_llc_msg_del_link del_llc = {0};
1198
1199         del_llc.hd.length = sizeof(del_llc);
1200         del_llc.hd.common.type = SMC_LLC_DELETE_LINK;
1201         del_llc.link_num = del_link_id;
1202         del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1203         del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1204         smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1205 }
1206
1207 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1208 {
1209         struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1210         struct smc_llc_msg_del_link *del_llc;
1211         struct smc_llc_qentry *qentry;
1212         int active_links;
1213         int lnk_idx;
1214
1215         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1216         lnk = qentry->link;
1217         del_llc = &qentry->msg.delete_link;
1218
1219         if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1220                 smc_lgr_terminate_sched(lgr);
1221                 goto out;
1222         }
1223         mutex_lock(&lgr->llc_conf_mutex);
1224         /* delete single link */
1225         for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1226                 if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1227                         continue;
1228                 lnk_del = &lgr->lnk[lnk_idx];
1229                 break;
1230         }
1231         del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1232         if (!lnk_del) {
1233                 /* link was not found */
1234                 del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1235                 smc_llc_send_message(lnk, &qentry->msg);
1236                 goto out_unlock;
1237         }
1238         lnk_asym = smc_llc_find_asym_link(lgr);
1239
1240         del_llc->reason = 0;
1241         smc_llc_send_message(lnk, &qentry->msg); /* response */
1242
1243         if (smc_link_downing(&lnk_del->state)) {
1244                 if (smc_switch_conns(lgr, lnk_del, false))
1245                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1246         }
1247         smcr_link_clear(lnk_del, true);
1248
1249         active_links = smc_llc_active_link_count(lgr);
1250         if (lnk_del == lnk_asym) {
1251                 /* expected deletion of asym link, don't change lgr state */
1252         } else if (active_links == 1) {
1253                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1254         } else if (!active_links) {
1255                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1256                 smc_lgr_terminate_sched(lgr);
1257         }
1258 out_unlock:
1259         mutex_unlock(&lgr->llc_conf_mutex);
1260 out:
1261         kfree(qentry);
1262 }
1263
1264 /* try to send a DELETE LINK ALL request on any active link,
1265  * waiting for send completion
1266  */
1267 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1268 {
1269         struct smc_llc_msg_del_link delllc = {0};
1270         int i;
1271
1272         delllc.hd.common.type = SMC_LLC_DELETE_LINK;
1273         delllc.hd.length = sizeof(delllc);
1274         if (ord)
1275                 delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1276         delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1277         delllc.reason = htonl(rsn);
1278
1279         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1280                 if (!smc_link_usable(&lgr->lnk[i]))
1281                         continue;
1282                 if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1283                         break;
1284         }
1285 }
1286
1287 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1288 {
1289         struct smc_llc_msg_del_link *del_llc;
1290         struct smc_link *lnk, *lnk_del;
1291         struct smc_llc_qentry *qentry;
1292         int active_links;
1293         int i;
1294
1295         mutex_lock(&lgr->llc_conf_mutex);
1296         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1297         lnk = qentry->link;
1298         del_llc = &qentry->msg.delete_link;
1299
1300         if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1301                 /* delete entire lgr */
1302                 smc_llc_send_link_delete_all(lgr, true, ntohl(
1303                                               qentry->msg.delete_link.reason));
1304                 smc_lgr_terminate_sched(lgr);
1305                 goto out;
1306         }
1307         /* delete single link */
1308         lnk_del = NULL;
1309         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1310                 if (lgr->lnk[i].link_id == del_llc->link_num) {
1311                         lnk_del = &lgr->lnk[i];
1312                         break;
1313                 }
1314         }
1315         if (!lnk_del)
1316                 goto out; /* asymmetric link already deleted */
1317
1318         if (smc_link_downing(&lnk_del->state)) {
1319                 if (smc_switch_conns(lgr, lnk_del, false))
1320                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1321         }
1322         if (!list_empty(&lgr->list)) {
1323                 /* qentry is either a request from peer (send it back to
1324                  * initiate the DELETE_LINK processing), or a locally
1325                  * enqueued DELETE_LINK request (forward it)
1326                  */
1327                 if (!smc_llc_send_message(lnk, &qentry->msg)) {
1328                         struct smc_llc_qentry *qentry2;
1329
1330                         qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1331                                                SMC_LLC_DELETE_LINK);
1332                         if (qentry2)
1333                                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1334                 }
1335         }
1336         smcr_link_clear(lnk_del, true);
1337
1338         active_links = smc_llc_active_link_count(lgr);
1339         if (active_links == 1) {
1340                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1341         } else if (!active_links) {
1342                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1343                 smc_lgr_terminate_sched(lgr);
1344         }
1345
1346         if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1347                 /* trigger setup of asymm alt link */
1348                 smc_llc_srv_add_link_local(lnk);
1349         }
1350 out:
1351         mutex_unlock(&lgr->llc_conf_mutex);
1352         kfree(qentry);
1353 }
1354
1355 static void smc_llc_delete_link_work(struct work_struct *work)
1356 {
1357         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1358                                                   llc_del_link_work);
1359
1360         if (list_empty(&lgr->list)) {
1361                 /* link group is terminating */
1362                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1363                 goto out;
1364         }
1365
1366         if (lgr->role == SMC_CLNT)
1367                 smc_llc_process_cli_delete_link(lgr);
1368         else
1369                 smc_llc_process_srv_delete_link(lgr);
1370 out:
1371         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1372 }
1373
1374 /* process a confirm_rkey request from peer, remote flow */
1375 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1376 {
1377         struct smc_llc_msg_confirm_rkey *llc;
1378         struct smc_llc_qentry *qentry;
1379         struct smc_link *link;
1380         int num_entries;
1381         int rk_idx;
1382         int i;
1383
1384         qentry = lgr->llc_flow_rmt.qentry;
1385         llc = &qentry->msg.confirm_rkey;
1386         link = qentry->link;
1387
1388         num_entries = llc->rtoken[0].num_rkeys;
1389         /* first rkey entry is for receiving link */
1390         rk_idx = smc_rtoken_add(link,
1391                                 llc->rtoken[0].rmb_vaddr,
1392                                 llc->rtoken[0].rmb_key);
1393         if (rk_idx < 0)
1394                 goto out_err;
1395
1396         for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1397                 smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1398                                 llc->rtoken[i].rmb_vaddr,
1399                                 llc->rtoken[i].rmb_key);
1400         /* max links is 3 so there is no need to support conf_rkey_cont msgs */
1401         goto out;
1402 out_err:
1403         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1404         llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1405 out:
1406         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1407         smc_llc_send_message(link, &qentry->msg);
1408         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1409 }
1410
1411 /* process a delete_rkey request from peer, remote flow */
1412 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1413 {
1414         struct smc_llc_msg_delete_rkey *llc;
1415         struct smc_llc_qentry *qentry;
1416         struct smc_link *link;
1417         u8 err_mask = 0;
1418         int i, max;
1419
1420         qentry = lgr->llc_flow_rmt.qentry;
1421         llc = &qentry->msg.delete_rkey;
1422         link = qentry->link;
1423
1424         max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1425         for (i = 0; i < max; i++) {
1426                 if (smc_rtoken_delete(link, llc->rkey[i]))
1427                         err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1428         }
1429         if (err_mask) {
1430                 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1431                 llc->err_mask = err_mask;
1432         }
1433         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1434         smc_llc_send_message(link, &qentry->msg);
1435         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1436 }
1437
1438 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1439 {
1440         pr_warn_ratelimited("smc: SMC-R lg %*phN LLC protocol violation: "
1441                             "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id, type);
1442         smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1443         smc_lgr_terminate_sched(lgr);
1444 }
1445
1446 /* flush the llc event queue */
1447 static void smc_llc_event_flush(struct smc_link_group *lgr)
1448 {
1449         struct smc_llc_qentry *qentry, *q;
1450
1451         spin_lock_bh(&lgr->llc_event_q_lock);
1452         list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1453                 list_del_init(&qentry->list);
1454                 kfree(qentry);
1455         }
1456         spin_unlock_bh(&lgr->llc_event_q_lock);
1457 }
1458
1459 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1460 {
1461         union smc_llc_msg *llc = &qentry->msg;
1462         struct smc_link *link = qentry->link;
1463         struct smc_link_group *lgr = link->lgr;
1464
1465         if (!smc_link_usable(link))
1466                 goto out;
1467
1468         switch (llc->raw.hdr.common.type) {
1469         case SMC_LLC_TEST_LINK:
1470                 llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1471                 smc_llc_send_message(link, llc);
1472                 break;
1473         case SMC_LLC_ADD_LINK:
1474                 if (list_empty(&lgr->list))
1475                         goto out;       /* lgr is terminating */
1476                 if (lgr->role == SMC_CLNT) {
1477                         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK) {
1478                                 /* a flow is waiting for this message */
1479                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1480                                                         qentry);
1481                                 wake_up(&lgr->llc_msg_waiter);
1482                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1483                                                       qentry)) {
1484                                 schedule_work(&lgr->llc_add_link_work);
1485                         }
1486                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1487                         /* as smc server, handle client suggestion */
1488                         schedule_work(&lgr->llc_add_link_work);
1489                 }
1490                 return;
1491         case SMC_LLC_CONFIRM_LINK:
1492         case SMC_LLC_ADD_LINK_CONT:
1493                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1494                         /* a flow is waiting for this message */
1495                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1496                         wake_up(&lgr->llc_msg_waiter);
1497                         return;
1498                 }
1499                 break;
1500         case SMC_LLC_DELETE_LINK:
1501                 if (lgr->role == SMC_CLNT) {
1502                         /* server requests to delete this link, send response */
1503                         if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1504                                 /* DEL LINK REQ during ADD LINK SEQ */
1505                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1506                                                         qentry);
1507                                 wake_up(&lgr->llc_msg_waiter);
1508                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1509                                                       qentry)) {
1510                                 schedule_work(&lgr->llc_del_link_work);
1511                         }
1512                 } else {
1513                         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1514                             !lgr->llc_flow_lcl.qentry) {
1515                                 /* DEL LINK REQ during ADD LINK SEQ */
1516                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1517                                                         qentry);
1518                                 wake_up(&lgr->llc_msg_waiter);
1519                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1520                                                       qentry)) {
1521                                 schedule_work(&lgr->llc_del_link_work);
1522                         }
1523                 }
1524                 return;
1525         case SMC_LLC_CONFIRM_RKEY:
1526                 /* new request from remote, assign to remote flow */
1527                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1528                         /* process here, does not wait for more llc msgs */
1529                         smc_llc_rmt_conf_rkey(lgr);
1530                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1531                 }
1532                 return;
1533         case SMC_LLC_CONFIRM_RKEY_CONT:
1534                 /* not used because max links is 3, and 3 rkeys fit into
1535                  * one CONFIRM_RKEY message
1536                  */
1537                 break;
1538         case SMC_LLC_DELETE_RKEY:
1539                 /* new request from remote, assign to remote flow */
1540                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1541                         /* process here, does not wait for more llc msgs */
1542                         smc_llc_rmt_delete_rkey(lgr);
1543                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1544                 }
1545                 return;
1546         default:
1547                 smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1548                 break;
1549         }
1550 out:
1551         kfree(qentry);
1552 }
1553
1554 /* worker to process llc messages on the event queue */
1555 static void smc_llc_event_work(struct work_struct *work)
1556 {
1557         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1558                                                   llc_event_work);
1559         struct smc_llc_qentry *qentry;
1560
1561         if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1562                 if (smc_link_usable(lgr->delayed_event->link)) {
1563                         smc_llc_event_handler(lgr->delayed_event);
1564                 } else {
1565                         qentry = lgr->delayed_event;
1566                         lgr->delayed_event = NULL;
1567                         kfree(qentry);
1568                 }
1569         }
1570
1571 again:
1572         spin_lock_bh(&lgr->llc_event_q_lock);
1573         if (!list_empty(&lgr->llc_event_q)) {
1574                 qentry = list_first_entry(&lgr->llc_event_q,
1575                                           struct smc_llc_qentry, list);
1576                 list_del_init(&qentry->list);
1577                 spin_unlock_bh(&lgr->llc_event_q_lock);
1578                 smc_llc_event_handler(qentry);
1579                 goto again;
1580         }
1581         spin_unlock_bh(&lgr->llc_event_q_lock);
1582 }
1583
1584 /* process llc responses in tasklet context */
1585 static void smc_llc_rx_response(struct smc_link *link,
1586                                 struct smc_llc_qentry *qentry)
1587 {
1588         u8 llc_type = qentry->msg.raw.hdr.common.type;
1589
1590         switch (llc_type) {
1591         case SMC_LLC_TEST_LINK:
1592                 if (link->state == SMC_LNK_ACTIVE)
1593                         complete(&link->llc_testlink_resp);
1594                 break;
1595         case SMC_LLC_ADD_LINK:
1596         case SMC_LLC_DELETE_LINK:
1597         case SMC_LLC_CONFIRM_LINK:
1598         case SMC_LLC_ADD_LINK_CONT:
1599         case SMC_LLC_CONFIRM_RKEY:
1600         case SMC_LLC_DELETE_RKEY:
1601                 /* assign responses to the local flow, we requested them */
1602                 smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
1603                 wake_up(&link->lgr->llc_msg_waiter);
1604                 return;
1605         case SMC_LLC_CONFIRM_RKEY_CONT:
1606                 /* not used because max links is 3 */
1607                 break;
1608         default:
1609                 smc_llc_protocol_violation(link->lgr, llc_type);
1610                 break;
1611         }
1612         kfree(qentry);
1613 }
1614
1615 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
1616 {
1617         struct smc_link_group *lgr = link->lgr;
1618         struct smc_llc_qentry *qentry;
1619         unsigned long flags;
1620
1621         qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
1622         if (!qentry)
1623                 return;
1624         qentry->link = link;
1625         INIT_LIST_HEAD(&qentry->list);
1626         memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
1627
1628         /* process responses immediately */
1629         if (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) {
1630                 smc_llc_rx_response(link, qentry);
1631                 return;
1632         }
1633
1634         /* add requests to event queue */
1635         spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
1636         list_add_tail(&qentry->list, &lgr->llc_event_q);
1637         spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
1638         schedule_work(&lgr->llc_event_work);
1639 }
1640
1641 /* copy received msg and add it to the event queue */
1642 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
1643 {
1644         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
1645         union smc_llc_msg *llc = buf;
1646
1647         if (wc->byte_len < sizeof(*llc))
1648                 return; /* short message */
1649         if (llc->raw.hdr.length != sizeof(*llc))
1650                 return; /* invalid message */
1651
1652         smc_llc_enqueue(link, llc);
1653 }
1654
1655 /***************************** worker, utils *********************************/
1656
1657 static void smc_llc_testlink_work(struct work_struct *work)
1658 {
1659         struct smc_link *link = container_of(to_delayed_work(work),
1660                                              struct smc_link, llc_testlink_wrk);
1661         unsigned long next_interval;
1662         unsigned long expire_time;
1663         u8 user_data[16] = { 0 };
1664         int rc;
1665
1666         if (link->state != SMC_LNK_ACTIVE)
1667                 return;         /* don't reschedule worker */
1668         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
1669         if (time_is_after_jiffies(expire_time)) {
1670                 next_interval = expire_time - jiffies;
1671                 goto out;
1672         }
1673         reinit_completion(&link->llc_testlink_resp);
1674         smc_llc_send_test_link(link, user_data);
1675         /* receive TEST LINK response over RoCE fabric */
1676         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
1677                                                        SMC_LLC_WAIT_TIME);
1678         if (link->state != SMC_LNK_ACTIVE)
1679                 return;         /* link state changed */
1680         if (rc <= 0) {
1681                 smcr_link_down_cond_sched(link);
1682                 return;
1683         }
1684         next_interval = link->llc_testlink_time;
1685 out:
1686         schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
1687 }
1688
1689 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
1690 {
1691         struct net *net = sock_net(smc->clcsock->sk);
1692
1693         INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
1694         INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
1695         INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
1696         INIT_LIST_HEAD(&lgr->llc_event_q);
1697         spin_lock_init(&lgr->llc_event_q_lock);
1698         spin_lock_init(&lgr->llc_flow_lock);
1699         init_waitqueue_head(&lgr->llc_flow_waiter);
1700         init_waitqueue_head(&lgr->llc_msg_waiter);
1701         mutex_init(&lgr->llc_conf_mutex);
1702         lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
1703 }
1704
1705 /* called after lgr was removed from lgr_list */
1706 void smc_llc_lgr_clear(struct smc_link_group *lgr)
1707 {
1708         smc_llc_event_flush(lgr);
1709         wake_up_all(&lgr->llc_flow_waiter);
1710         wake_up_all(&lgr->llc_msg_waiter);
1711         cancel_work_sync(&lgr->llc_event_work);
1712         cancel_work_sync(&lgr->llc_add_link_work);
1713         cancel_work_sync(&lgr->llc_del_link_work);
1714         if (lgr->delayed_event) {
1715                 kfree(lgr->delayed_event);
1716                 lgr->delayed_event = NULL;
1717         }
1718 }
1719
1720 int smc_llc_link_init(struct smc_link *link)
1721 {
1722         init_completion(&link->llc_testlink_resp);
1723         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
1724         return 0;
1725 }
1726
1727 void smc_llc_link_active(struct smc_link *link)
1728 {
1729         pr_warn_ratelimited("smc: SMC-R lg %*phN link added: id %*phN, "
1730                             "peerid %*phN, ibdev %s, ibport %d\n",
1731                             SMC_LGR_ID_SIZE, &link->lgr->id,
1732                             SMC_LGR_ID_SIZE, &link->link_uid,
1733                             SMC_LGR_ID_SIZE, &link->peer_link_uid,
1734                             link->smcibdev->ibdev->name, link->ibport);
1735         link->state = SMC_LNK_ACTIVE;
1736         if (link->lgr->llc_testlink_time) {
1737                 link->llc_testlink_time = link->lgr->llc_testlink_time * HZ;
1738                 schedule_delayed_work(&link->llc_testlink_wrk,
1739                                       link->llc_testlink_time);
1740         }
1741 }
1742
1743 /* called in worker context */
1744 void smc_llc_link_clear(struct smc_link *link, bool log)
1745 {
1746         if (log)
1747                 pr_warn_ratelimited("smc: SMC-R lg %*phN link removed: id %*phN"
1748                                     ", peerid %*phN, ibdev %s, ibport %d\n",
1749                                     SMC_LGR_ID_SIZE, &link->lgr->id,
1750                                     SMC_LGR_ID_SIZE, &link->link_uid,
1751                                     SMC_LGR_ID_SIZE, &link->peer_link_uid,
1752                                     link->smcibdev->ibdev->name, link->ibport);
1753         complete(&link->llc_testlink_resp);
1754         cancel_delayed_work_sync(&link->llc_testlink_wrk);
1755         smc_wr_wakeup_reg_wait(link);
1756         smc_wr_wakeup_tx_wait(link);
1757 }
1758
1759 /* register a new rtoken at the remote peer (for all links) */
1760 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
1761                             struct smc_buf_desc *rmb_desc)
1762 {
1763         struct smc_link_group *lgr = send_link->lgr;
1764         struct smc_llc_qentry *qentry = NULL;
1765         int rc = 0;
1766
1767         rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
1768         if (rc)
1769                 goto out;
1770         /* receive CONFIRM RKEY response from server over RoCE fabric */
1771         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1772                               SMC_LLC_CONFIRM_RKEY);
1773         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1774                 rc = -EFAULT;
1775 out:
1776         if (qentry)
1777                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1778         return rc;
1779 }
1780
1781 /* unregister an rtoken at the remote peer */
1782 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
1783                            struct smc_buf_desc *rmb_desc)
1784 {
1785         struct smc_llc_qentry *qentry = NULL;
1786         struct smc_link *send_link;
1787         int rc = 0;
1788
1789         send_link = smc_llc_usable_link(lgr);
1790         if (!send_link)
1791                 return -ENOLINK;
1792
1793         /* protected by llc_flow control */
1794         rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
1795         if (rc)
1796                 goto out;
1797         /* receive DELETE RKEY response from server over RoCE fabric */
1798         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1799                               SMC_LLC_DELETE_RKEY);
1800         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1801                 rc = -EFAULT;
1802 out:
1803         if (qentry)
1804                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1805         return rc;
1806 }
1807
1808 void smc_llc_link_set_uid(struct smc_link *link)
1809 {
1810         __be32 link_uid;
1811
1812         link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
1813         memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
1814 }
1815
1816 /* save peers link user id, used for debug purposes */
1817 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
1818 {
1819         memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
1820                SMC_LGR_ID_SIZE);
1821 }
1822
1823 /* evaluate confirm link request or response */
1824 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
1825                            enum smc_llc_reqresp type)
1826 {
1827         if (type == SMC_LLC_REQ) {      /* SMC server assigns link_id */
1828                 qentry->link->link_id = qentry->msg.confirm_link.link_num;
1829                 smc_llc_link_set_uid(qentry->link);
1830         }
1831         if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
1832                 return -ENOTSUPP;
1833         return 0;
1834 }
1835
1836 /***************************** init, exit, misc ******************************/
1837
1838 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
1839         {
1840                 .handler        = smc_llc_rx_handler,
1841                 .type           = SMC_LLC_CONFIRM_LINK
1842         },
1843         {
1844                 .handler        = smc_llc_rx_handler,
1845                 .type           = SMC_LLC_TEST_LINK
1846         },
1847         {
1848                 .handler        = smc_llc_rx_handler,
1849                 .type           = SMC_LLC_ADD_LINK
1850         },
1851         {
1852                 .handler        = smc_llc_rx_handler,
1853                 .type           = SMC_LLC_ADD_LINK_CONT
1854         },
1855         {
1856                 .handler        = smc_llc_rx_handler,
1857                 .type           = SMC_LLC_DELETE_LINK
1858         },
1859         {
1860                 .handler        = smc_llc_rx_handler,
1861                 .type           = SMC_LLC_CONFIRM_RKEY
1862         },
1863         {
1864                 .handler        = smc_llc_rx_handler,
1865                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
1866         },
1867         {
1868                 .handler        = smc_llc_rx_handler,
1869                 .type           = SMC_LLC_DELETE_RKEY
1870         },
1871         {
1872                 .handler        = NULL,
1873         }
1874 };
1875
1876 int __init smc_llc_init(void)
1877 {
1878         struct smc_wr_rx_handler *handler;
1879         int rc = 0;
1880
1881         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
1882                 INIT_HLIST_NODE(&handler->list);
1883                 rc = smc_wr_rx_register_handler(handler);
1884                 if (rc)
1885                         break;
1886         }
1887         return rc;
1888 }