net/smc/smc_llc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Link Layer Control (LLC)
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Klaus Wacker <Klaus.Wacker@de.ibm.com>
  10  *              Ursula Braun <ubraun@linux.vnet.ibm.com>
  11  */
  12
  13 #include <net/tcp.h>
  14 #include <rdma/ib_verbs.h>
  15
  16 #include "smc.h"
  17 #include "smc_core.h"
  18 #include "smc_clc.h"
  19 #include "smc_llc.h"
  20
  21 #define SMC_LLC_DATA_LEN                40
  22
  23 struct smc_llc_hdr {
  24         struct smc_wr_rx_hdr common;
  25         u8 length;      /* 44 */
  26 #if defined(__BIG_ENDIAN_BITFIELD)
  27         u8 reserved:4,
  28            add_link_rej_rsn:4;
  29 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  30         u8 add_link_rej_rsn:4,
  31            reserved:4;
  32 #endif
  33         u8 flags;
  34 };
  35
  36 #define SMC_LLC_FLAG_NO_RMBE_EYEC       0x03
  37
  38 struct smc_llc_msg_confirm_link {       /* type 0x01 */
  39         struct smc_llc_hdr hd;
  40         u8 sender_mac[ETH_ALEN];
  41         u8 sender_gid[SMC_GID_SIZE];
  42         u8 sender_qp_num[3];
  43         u8 link_num;
  44         u8 link_uid[SMC_LGR_ID_SIZE];
  45         u8 max_links;
  46         u8 reserved[9];
  47 };
  48
  49 #define SMC_LLC_FLAG_ADD_LNK_REJ        0x40
  50 #define SMC_LLC_REJ_RSN_NO_ALT_PATH     1
  51
  52 #define SMC_LLC_ADD_LNK_MAX_LINKS       2
  53
  54 struct smc_llc_msg_add_link {           /* type 0x02 */
  55         struct smc_llc_hdr hd;
  56         u8 sender_mac[ETH_ALEN];
  57         u8 reserved2[2];
  58         u8 sender_gid[SMC_GID_SIZE];
  59         u8 sender_qp_num[3];
  60         u8 link_num;
  61         u8 flags2;      /* QP mtu */
  62         u8 initial_psn[3];
  63         u8 reserved[8];
  64 };
  65
  66 #define SMC_LLC_FLAG_DEL_LINK_ALL       0x40
  67 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY   0x20
  68
  69 struct smc_llc_msg_del_link {           /* type 0x04 */
  70         struct smc_llc_hdr hd;
  71         u8 link_num;
  72         __be32 reason;
  73         u8 reserved[35];
  74 } __packed;                     /* format defined in RFC7609 */
  75
  76 struct smc_llc_msg_test_link {          /* type 0x07 */
  77         struct smc_llc_hdr hd;
  78         u8 user_data[16];
  79         u8 reserved[24];
  80 };
  81
  82 struct smc_rmb_rtoken {
  83         union {
  84                 u8 num_rkeys;   /* first rtoken byte of CONFIRM LINK msg */
  85                                 /* is actually the num of rtokens, first */
  86                                 /* rtoken is always for the current link */
  87                 u8 link_id;     /* link id of the rtoken */
  88         };
  89         __be32 rmb_key;
  90         __be64 rmb_vaddr;
  91 } __packed;                     /* format defined in RFC7609 */
  92
  93 #define SMC_LLC_RKEYS_PER_MSG   3
  94
  95 struct smc_llc_msg_confirm_rkey {       /* type 0x06 */
  96         struct smc_llc_hdr hd;
  97         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
  98         u8 reserved;
  99 };
 100
 101 struct smc_llc_msg_confirm_rkey_cont {  /* type 0x08 */
 102         struct smc_llc_hdr hd;
 103         u8 num_rkeys;
 104         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
 105 };
 106
 107 #define SMC_LLC_DEL_RKEY_MAX    8
 108 #define SMC_LLC_FLAG_RKEY_NEG   0x20
 109
 110 struct smc_llc_msg_delete_rkey {        /* type 0x09 */
 111         struct smc_llc_hdr hd;
 112         u8 num_rkeys;
 113         u8 err_mask;
 114         u8 reserved[2];
 115         __be32 rkey[8];
 116         u8 reserved2[4];
 117 };
 118
 119 union smc_llc_msg {
 120         struct smc_llc_msg_confirm_link confirm_link;
 121         struct smc_llc_msg_add_link add_link;
 122         struct smc_llc_msg_del_link delete_link;
 123
 124         struct smc_llc_msg_confirm_rkey confirm_rkey;
 125         struct smc_llc_msg_confirm_rkey_cont confirm_rkey_cont;
 126         struct smc_llc_msg_delete_rkey delete_rkey;
 127
 128         struct smc_llc_msg_test_link test_link;
 129         struct {
 130                 struct smc_llc_hdr hdr;
 131                 u8 data[SMC_LLC_DATA_LEN];
 132         } raw;
 133 };
 134
 135 #define SMC_LLC_FLAG_RESP               0x80
 136
 137 /********************************** send *************************************/
 138
 139 struct smc_llc_tx_pend {
 140 };
 141
 142 /* handler for send/transmission completion of an LLC msg */
 143 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
 144                                struct smc_link *link,
 145                                enum ib_wc_status wc_status)
 146 {
 147         /* future work: handle wc_status error for recovery and failover */
 148 }
 149
 150 /**
 151  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
 152  * @link: Pointer to SMC link used for sending LLC control message.
 153  * @wr_buf: Out variable returning pointer to work request payload buffer.
 154  * @pend: Out variable returning pointer to private pending WR tracking.
 155  *        It's the context the transmit complete handler will get.
 156  *
 157  * Reserves and pre-fills an entry for a pending work request send/tx.
 158  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
 159  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
 160  *
 161  * Return: 0 on success, otherwise an error value.
 162  */
 163 static int smc_llc_add_pending_send(struct smc_link *link,
 164                                     struct smc_wr_buf **wr_buf,
 165                                     struct smc_wr_tx_pend_priv **pend)
 166 {
 167         int rc;
 168
 169         rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, pend);
 170         if (rc < 0)
 171                 return rc;
 172         BUILD_BUG_ON_MSG(
 173                 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
 174                 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
 175         BUILD_BUG_ON_MSG(
 176                 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
 177                 "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
 178         BUILD_BUG_ON_MSG(
 179                 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
 180                 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
 181         return 0;
 182 }
 183
 184 /* high-level API to send LLC confirm link */
 185 int smc_llc_send_confirm_link(struct smc_link *link,
 186                               enum smc_llc_reqresp reqresp)
 187 {
 188         struct smc_link_group *lgr = smc_get_lgr(link);
 189         struct smc_llc_msg_confirm_link *confllc;
 190         struct smc_wr_tx_pend_priv *pend;
 191         struct smc_wr_buf *wr_buf;
 192         int rc;
 193
 194         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 195         if (rc)
 196                 return rc;
 197         confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
 198         memset(confllc, 0, sizeof(*confllc));
 199         confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 200         confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
 201         confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 202         if (reqresp == SMC_LLC_RESP)
 203                 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 204         memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
 205                ETH_ALEN);
 206         memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
 207         hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 208         confllc->link_num = link->link_id;
 209         memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
 210         confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* enforce peer resp. */
 211         /* send llc message */
 212         rc = smc_wr_tx_send(link, pend);
 213         return rc;
 214 }
 215
 216 /* send LLC confirm rkey request */
 217 static int smc_llc_send_confirm_rkey(struct smc_link *link,
 218                                      struct smc_buf_desc *rmb_desc)
 219 {
 220         struct smc_llc_msg_confirm_rkey *rkeyllc;
 221         struct smc_wr_tx_pend_priv *pend;
 222         struct smc_wr_buf *wr_buf;
 223         int rc;
 224
 225         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 226         if (rc)
 227                 return rc;
 228         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 229         memset(rkeyllc, 0, sizeof(*rkeyllc));
 230         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 231         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 232         rkeyllc->rtoken[0].rmb_key =
 233                 htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 234         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 235                 (u64)sg_dma_address(rmb_desc->sgt[SMC_SINGLE_LINK].sgl));
 236         /* send llc message */
 237         rc = smc_wr_tx_send(link, pend);
 238         return rc;
 239 }
 240
 241 /* send LLC delete rkey request */
 242 static int smc_llc_send_delete_rkey(struct smc_link *link,
 243                                     struct smc_buf_desc *rmb_desc)
 244 {
 245         struct smc_llc_msg_delete_rkey *rkeyllc;
 246         struct smc_wr_tx_pend_priv *pend;
 247         struct smc_wr_buf *wr_buf;
 248         int rc;
 249
 250         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 251         if (rc)
 252                 return rc;
 253         rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
 254         memset(rkeyllc, 0, sizeof(*rkeyllc));
 255         rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
 256         rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
 257         rkeyllc->num_rkeys = 1;
 258         rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[SMC_SINGLE_LINK]->rkey);
 259         /* send llc message */
 260         rc = smc_wr_tx_send(link, pend);
 261         return rc;
 262 }
 263
 264 /* prepare an add link message */
 265 static void smc_llc_prep_add_link(struct smc_llc_msg_add_link *addllc,
 266                                   struct smc_link *link, u8 mac[], u8 gid[],
 267                                   enum smc_llc_reqresp reqresp)
 268 {
 269         memset(addllc, 0, sizeof(*addllc));
 270         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 271         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 272         if (reqresp == SMC_LLC_RESP) {
 273                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 274                 /* always reject more links for now */
 275                 addllc->hd.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 276                 addllc->hd.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 277         }
 278         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 279         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 280 }
 281
 282 /* send ADD LINK request or response */
 283 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
 284                           enum smc_llc_reqresp reqresp)
 285 {
 286         struct smc_llc_msg_add_link *addllc;
 287         struct smc_wr_tx_pend_priv *pend;
 288         struct smc_wr_buf *wr_buf;
 289         int rc;
 290
 291         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 292         if (rc)
 293                 return rc;
 294         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 295         smc_llc_prep_add_link(addllc, link, mac, gid, reqresp);
 296         /* send llc message */
 297         rc = smc_wr_tx_send(link, pend);
 298         return rc;
 299 }
 300
 301 /* prepare a delete link message */
 302 static void smc_llc_prep_delete_link(struct smc_llc_msg_del_link *delllc,
 303                                      struct smc_link *link,
 304                                      enum smc_llc_reqresp reqresp, bool orderly)
 305 {
 306         memset(delllc, 0, sizeof(*delllc));
 307         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 308         delllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 309         if (reqresp == SMC_LLC_RESP)
 310                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 311         /* DEL_LINK_ALL because only 1 link supported */
 312         delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 313         if (orderly)
 314                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 315         delllc->link_num = link->link_id;
 316 }
 317
 318 /* send DELETE LINK request or response */
 319 int smc_llc_send_delete_link(struct smc_link *link,
 320                              enum smc_llc_reqresp reqresp, bool orderly)
 321 {
 322         struct smc_llc_msg_del_link *delllc;
 323         struct smc_wr_tx_pend_priv *pend;
 324         struct smc_wr_buf *wr_buf;
 325         int rc;
 326
 327         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 328         if (rc)
 329                 return rc;
 330         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 331         smc_llc_prep_delete_link(delllc, link, reqresp, orderly);
 332         /* send llc message */
 333         rc = smc_wr_tx_send(link, pend);
 334         return rc;
 335 }
 336
 337 /* send LLC test link request */
 338 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 339 {
 340         struct smc_llc_msg_test_link *testllc;
 341         struct smc_wr_tx_pend_priv *pend;
 342         struct smc_wr_buf *wr_buf;
 343         int rc;
 344
 345         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 346         if (rc)
 347                 return rc;
 348         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 349         memset(testllc, 0, sizeof(*testllc));
 350         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 351         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 352         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 353         /* send llc message */
 354         rc = smc_wr_tx_send(link, pend);
 355         return rc;
 356 }
 357
 358 struct smc_llc_send_work {
 359         struct work_struct work;
 360         struct smc_link *link;
 361         int llclen;
 362         union smc_llc_msg llcbuf;
 363 };
 364
 365 /* worker that sends a prepared message */
 366 static void smc_llc_send_message_work(struct work_struct *work)
 367 {
 368         struct smc_llc_send_work *llcwrk = container_of(work,
 369                                                 struct smc_llc_send_work, work);
 370         struct smc_wr_tx_pend_priv *pend;
 371         struct smc_wr_buf *wr_buf;
 372         int rc;
 373
 374         if (llcwrk->link->state == SMC_LNK_INACTIVE)
 375                 goto out;
 376         rc = smc_llc_add_pending_send(llcwrk->link, &wr_buf, &pend);
 377         if (rc)
 378                 goto out;
 379         memcpy(wr_buf, &llcwrk->llcbuf, llcwrk->llclen);
 380         smc_wr_tx_send(llcwrk->link, pend);
 381 out:
 382         kfree(llcwrk);
 383 }
 384
 385 /* copy llcbuf and schedule an llc send on link */
 386 static int smc_llc_send_message(struct smc_link *link, void *llcbuf, int llclen)
 387 {
 388         struct smc_llc_send_work *wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
 389
 390         if (!wrk)
 391                 return -ENOMEM;
 392         INIT_WORK(&wrk->work, smc_llc_send_message_work);
 393         wrk->link = link;
 394         wrk->llclen = llclen;
 395         memcpy(&wrk->llcbuf, llcbuf, llclen);
 396         queue_work(link->llc_wq, &wrk->work);
 397         return 0;
 398 }
 399
 400 /********************************* receive ***********************************/
 401
 402 static void smc_llc_rx_confirm_link(struct smc_link *link,
 403                                     struct smc_llc_msg_confirm_link *llc)
 404 {
 405         struct smc_link_group *lgr = smc_get_lgr(link);
 406         int conf_rc;
 407
 408         /* RMBE eyecatchers are not supported */
 409         if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
 410                 conf_rc = 0;
 411         else
 412                 conf_rc = ENOTSUPP;
 413
 414         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 415                 if (lgr->role == SMC_SERV &&
 416                     link->state == SMC_LNK_ACTIVATING) {
 417                         link->llc_confirm_resp_rc = conf_rc;
 418                         complete(&link->llc_confirm_resp);
 419                 }
 420         } else {
 421                 if (lgr->role == SMC_CLNT &&
 422                     link->state == SMC_LNK_ACTIVATING) {
 423                         link->llc_confirm_rc = conf_rc;
 424                         link->link_id = llc->link_num;
 425                         complete(&link->llc_confirm);
 426                 }
 427         }
 428 }
 429
 430 static void smc_llc_rx_add_link(struct smc_link *link,
 431                                 struct smc_llc_msg_add_link *llc)
 432 {
 433         struct smc_link_group *lgr = smc_get_lgr(link);
 434
 435         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 436                 if (link->state == SMC_LNK_ACTIVATING)
 437                         complete(&link->llc_add_resp);
 438         } else {
 439                 if (link->state == SMC_LNK_ACTIVATING) {
 440                         complete(&link->llc_add);
 441                         return;
 442                 }
 443
 444                 if (lgr->role == SMC_SERV) {
 445                         smc_llc_prep_add_link(llc, link,
 446                                         link->smcibdev->mac[link->ibport - 1],
 447                                         link->gid, SMC_LLC_REQ);
 448
 449                 } else {
 450                         smc_llc_prep_add_link(llc, link,
 451                                         link->smcibdev->mac[link->ibport - 1],
 452                                         link->gid, SMC_LLC_RESP);
 453                 }
 454                 smc_llc_send_message(link, llc, sizeof(*llc));
 455         }
 456 }
 457
 458 static void smc_llc_rx_delete_link(struct smc_link *link,
 459                                    struct smc_llc_msg_del_link *llc)
 460 {
 461         struct smc_link_group *lgr = smc_get_lgr(link);
 462
 463         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 464                 if (lgr->role == SMC_SERV)
 465                         smc_lgr_schedule_free_work_fast(lgr);
 466         } else {
 467                 smc_lgr_forget(lgr);
 468                 smc_llc_link_deleting(link);
 469                 if (lgr->role == SMC_SERV) {
 470                         /* client asks to delete this link, send request */
 471                         smc_llc_prep_delete_link(llc, link, SMC_LLC_REQ, true);
 472                 } else {
 473                         /* server requests to delete this link, send response */
 474                         smc_llc_prep_delete_link(llc, link, SMC_LLC_RESP, true);
 475                 }
 476                 smc_llc_send_message(link, llc, sizeof(*llc));
 477                 smc_lgr_schedule_free_work_fast(lgr);
 478         }
 479 }
 480
 481 static void smc_llc_rx_test_link(struct smc_link *link,
 482                                  struct smc_llc_msg_test_link *llc)
 483 {
 484         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 485                 if (link->state == SMC_LNK_ACTIVE)
 486                         complete(&link->llc_testlink_resp);
 487         } else {
 488                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 489                 smc_llc_send_message(link, llc, sizeof(*llc));
 490         }
 491 }
 492
 493 static void smc_llc_rx_confirm_rkey(struct smc_link *link,
 494                                     struct smc_llc_msg_confirm_rkey *llc)
 495 {
 496         int rc;
 497
 498         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 499                 link->llc_confirm_rkey_rc = llc->hd.flags &
 500                                             SMC_LLC_FLAG_RKEY_NEG;
 501                 complete(&link->llc_confirm_rkey);
 502         } else {
 503                 rc = smc_rtoken_add(smc_get_lgr(link),
 504                                     llc->rtoken[0].rmb_vaddr,
 505                                     llc->rtoken[0].rmb_key);
 506
 507                 /* ignore rtokens for other links, we have only one link */
 508
 509                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 510                 if (rc < 0)
 511                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 512                 smc_llc_send_message(link, llc, sizeof(*llc));
 513         }
 514 }
 515
 516 static void smc_llc_rx_confirm_rkey_cont(struct smc_link *link,
 517                                       struct smc_llc_msg_confirm_rkey_cont *llc)
 518 {
 519         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 520                 /* unused as long as we don't send this type of msg */
 521         } else {
 522                 /* ignore rtokens for other links, we have only one link */
 523                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 524                 smc_llc_send_message(link, llc, sizeof(*llc));
 525         }
 526 }
 527
 528 static void smc_llc_rx_delete_rkey(struct smc_link *link,
 529                                    struct smc_llc_msg_delete_rkey *llc)
 530 {
 531         u8 err_mask = 0;
 532         int i, max;
 533
 534         if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
 535                 link->llc_delete_rkey_rc = llc->hd.flags &
 536                                             SMC_LLC_FLAG_RKEY_NEG;
 537                 complete(&link->llc_delete_rkey);
 538         } else {
 539                 max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
 540                 for (i = 0; i < max; i++) {
 541                         if (smc_rtoken_delete(smc_get_lgr(link), llc->rkey[i]))
 542                                 err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
 543                 }
 544
 545                 if (err_mask) {
 546                         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
 547                         llc->err_mask = err_mask;
 548                 }
 549
 550                 llc->hd.flags |= SMC_LLC_FLAG_RESP;
 551                 smc_llc_send_message(link, llc, sizeof(*llc));
 552         }
 553 }
 554
 555 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
 556 {
 557         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
 558         union smc_llc_msg *llc = buf;
 559
 560         if (wc->byte_len < sizeof(*llc))
 561                 return; /* short message */
 562         if (llc->raw.hdr.length != sizeof(*llc))
 563                 return; /* invalid message */
 564         if (link->state == SMC_LNK_INACTIVE)
 565                 return; /* link not active, drop msg */
 566
 567         switch (llc->raw.hdr.common.type) {
 568         case SMC_LLC_TEST_LINK:
 569                 smc_llc_rx_test_link(link, &llc->test_link);
 570                 break;
 571         case SMC_LLC_CONFIRM_LINK:
 572                 smc_llc_rx_confirm_link(link, &llc->confirm_link);
 573                 break;
 574         case SMC_LLC_ADD_LINK:
 575                 smc_llc_rx_add_link(link, &llc->add_link);
 576                 break;
 577         case SMC_LLC_DELETE_LINK:
 578                 smc_llc_rx_delete_link(link, &llc->delete_link);
 579                 break;
 580         case SMC_LLC_CONFIRM_RKEY:
 581                 smc_llc_rx_confirm_rkey(link, &llc->confirm_rkey);
 582                 break;
 583         case SMC_LLC_CONFIRM_RKEY_CONT:
 584                 smc_llc_rx_confirm_rkey_cont(link, &llc->confirm_rkey_cont);
 585                 break;
 586         case SMC_LLC_DELETE_RKEY:
 587                 smc_llc_rx_delete_rkey(link, &llc->delete_rkey);
 588                 break;
 589         }
 590 }
 591
 592 /***************************** worker, utils *********************************/
 593
 594 static void smc_llc_testlink_work(struct work_struct *work)
 595 {
 596         struct smc_link *link = container_of(to_delayed_work(work),
 597                                              struct smc_link, llc_testlink_wrk);
 598         unsigned long next_interval;
 599         unsigned long expire_time;
 600         u8 user_data[16] = { 0 };
 601         int rc;
 602
 603         if (link->state != SMC_LNK_ACTIVE)
 604                 return;         /* don't reschedule worker */
 605         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
 606         if (time_is_after_jiffies(expire_time)) {
 607                 next_interval = expire_time - jiffies;
 608                 goto out;
 609         }
 610         reinit_completion(&link->llc_testlink_resp);
 611         smc_llc_send_test_link(link, user_data);
 612         /* receive TEST LINK response over RoCE fabric */
 613         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
 614                                                        SMC_LLC_WAIT_TIME);
 615         if (rc <= 0) {
 616                 smc_lgr_terminate(smc_get_lgr(link));
 617                 return;
 618         }
 619         next_interval = link->llc_testlink_time;
 620 out:
 621         queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 622                            next_interval);
 623 }
 624
 625 int smc_llc_link_init(struct smc_link *link)
 626 {
 627         struct smc_link_group *lgr = smc_get_lgr(link);
 628         link->llc_wq = alloc_ordered_workqueue("llc_wq-%x:%x)", WQ_MEM_RECLAIM,
 629                                                *((u32 *)lgr->id),
 630                                                link->link_id);
 631         if (!link->llc_wq)
 632                 return -ENOMEM;
 633         init_completion(&link->llc_confirm);
 634         init_completion(&link->llc_confirm_resp);
 635         init_completion(&link->llc_add);
 636         init_completion(&link->llc_add_resp);
 637         init_completion(&link->llc_confirm_rkey);
 638         init_completion(&link->llc_delete_rkey);
 639         mutex_init(&link->llc_delete_rkey_mutex);
 640         init_completion(&link->llc_testlink_resp);
 641         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
 642         return 0;
 643 }
 644
 645 void smc_llc_link_active(struct smc_link *link, int testlink_time)
 646 {
 647         link->state = SMC_LNK_ACTIVE;
 648         if (testlink_time) {
 649                 link->llc_testlink_time = testlink_time * HZ;
 650                 queue_delayed_work(link->llc_wq, &link->llc_testlink_wrk,
 651                                    link->llc_testlink_time);
 652         }
 653 }
 654
 655 void smc_llc_link_deleting(struct smc_link *link)
 656 {
 657         link->state = SMC_LNK_DELETING;
 658 }
 659
 660 /* called in tasklet context */
 661 void smc_llc_link_inactive(struct smc_link *link)
 662 {
 663         link->state = SMC_LNK_INACTIVE;
 664         cancel_delayed_work(&link->llc_testlink_wrk);
 665 }
 666
 667 /* called in worker context */
 668 void smc_llc_link_clear(struct smc_link *link)
 669 {
 670         flush_workqueue(link->llc_wq);
 671         destroy_workqueue(link->llc_wq);
 672 }
 673
 674 /* register a new rtoken at the remote peer */
 675 int smc_llc_do_confirm_rkey(struct smc_link *link,
 676                             struct smc_buf_desc *rmb_desc)
 677 {
 678         int rc;
 679
 680         /* protected by mutex smc_create_lgr_pending */
 681         reinit_completion(&link->llc_confirm_rkey);
 682         rc = smc_llc_send_confirm_rkey(link, rmb_desc);
 683         if (rc)
 684                 return rc;
 685         /* receive CONFIRM RKEY response from server over RoCE fabric */
 686         rc = wait_for_completion_interruptible_timeout(&link->llc_confirm_rkey,
 687                                                        SMC_LLC_WAIT_TIME);
 688         if (rc <= 0 || link->llc_confirm_rkey_rc)
 689                 return -EFAULT;
 690         return 0;
 691 }
 692
 693 /* unregister an rtoken at the remote peer */
 694 int smc_llc_do_delete_rkey(struct smc_link *link,
 695                            struct smc_buf_desc *rmb_desc)
 696 {
 697         int rc;
 698
 699         mutex_lock(&link->llc_delete_rkey_mutex);
 700         reinit_completion(&link->llc_delete_rkey);
 701         rc = smc_llc_send_delete_rkey(link, rmb_desc);
 702         if (rc)
 703                 goto out;
 704         /* receive DELETE RKEY response from server over RoCE fabric */
 705         rc = wait_for_completion_interruptible_timeout(&link->llc_delete_rkey,
 706                                                        SMC_LLC_WAIT_TIME);
 707         if (rc <= 0 || link->llc_delete_rkey_rc)
 708                 rc = -EFAULT;
 709         else
 710                 rc = 0;
 711 out:
 712         mutex_unlock(&link->llc_delete_rkey_mutex);
 713         return rc;
 714 }
 715
 716 /***************************** init, exit, misc ******************************/
 717
 718 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
 719         {
 720                 .handler        = smc_llc_rx_handler,
 721                 .type           = SMC_LLC_CONFIRM_LINK
 722         },
 723         {
 724                 .handler        = smc_llc_rx_handler,
 725                 .type           = SMC_LLC_TEST_LINK
 726         },
 727         {
 728                 .handler        = smc_llc_rx_handler,
 729                 .type           = SMC_LLC_ADD_LINK
 730         },
 731         {
 732                 .handler        = smc_llc_rx_handler,
 733                 .type           = SMC_LLC_DELETE_LINK
 734         },
 735         {
 736                 .handler        = smc_llc_rx_handler,
 737                 .type           = SMC_LLC_CONFIRM_RKEY
 738         },
 739         {
 740                 .handler        = smc_llc_rx_handler,
 741                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
 742         },
 743         {
 744                 .handler        = smc_llc_rx_handler,
 745                 .type           = SMC_LLC_DELETE_RKEY
 746         },
 747         {
 748                 .handler        = NULL,
 749         }
 750 };
 751
 752 int __init smc_llc_init(void)
 753 {
 754         struct smc_wr_rx_handler *handler;
 755         int rc = 0;
 756
 757         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
 758                 INIT_HLIST_NODE(&handler->list);
 759                 rc = smc_wr_rx_register_handler(handler);
 760                 if (rc)
 761                         break;
 762         }
 763         return rc;
 764 }