net/smc/smc_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Basic Transport Functions exploiting Infiniband API
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  10  */
  11
  12 #include <linux/socket.h>
  13 #include <linux/if_vlan.h>
  14 #include <linux/random.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/wait.h>
  17 #include <linux/reboot.h>
  18 #include <linux/mutex.h>
  19 #include <linux/list.h>
  20 #include <linux/smc.h>
  21 #include <net/tcp.h>
  22 #include <net/sock.h>
  23 #include <rdma/ib_verbs.h>
  24 #include <rdma/ib_cache.h>
  25
  26 #include "smc.h"
  27 #include "smc_clc.h"
  28 #include "smc_core.h"
  29 #include "smc_ib.h"
  30 #include "smc_wr.h"
  31 #include "smc_llc.h"
  32 #include "smc_cdc.h"
  33 #include "smc_close.h"
  34 #include "smc_ism.h"
  35 #include "smc_netlink.h"
  36 #include "smc_stats.h"
  37 #include "smc_tracepoint.h"
  38
  39 #define SMC_LGR_NUM_INCR                256
  40 #define SMC_LGR_FREE_DELAY_SERV         (600 * HZ)
  41 #define SMC_LGR_FREE_DELAY_CLNT         (SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
  42
  43 struct smc_lgr_list smc_lgr_list = {    /* established link groups */
  44         .lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
  45         .list = LIST_HEAD_INIT(smc_lgr_list.list),
  46         .num = 0,
  47 };
  48
  49 static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
  50 static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
  51
  52 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
  53                          struct smc_buf_desc *buf_desc);
  54 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
  55
  56 static void smc_link_down_work(struct work_struct *work);
  57
  58 /* return head of link group list and its lock for a given link group */
  59 static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
  60                                                   spinlock_t **lgr_lock)
  61 {
  62         if (lgr->is_smcd) {
  63                 *lgr_lock = &lgr->smcd->lgr_lock;
  64                 return &lgr->smcd->lgr_list;
  65         }
  66
  67         *lgr_lock = &smc_lgr_list.lock;
  68         return &smc_lgr_list.list;
  69 }
  70
  71 static void smc_ibdev_cnt_inc(struct smc_link *lnk)
  72 {
  73         atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
  74 }
  75
  76 static void smc_ibdev_cnt_dec(struct smc_link *lnk)
  77 {
  78         atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
  79 }
  80
  81 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
  82 {
  83         /* client link group creation always follows the server link group
  84          * creation. For client use a somewhat higher removal delay time,
  85          * otherwise there is a risk of out-of-sync link groups.
  86          */
  87         if (!lgr->freeing) {
  88                 mod_delayed_work(system_wq, &lgr->free_work,
  89                                  (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
  90                                                 SMC_LGR_FREE_DELAY_CLNT :
  91                                                 SMC_LGR_FREE_DELAY_SERV);
  92         }
  93 }
  94
  95 /* Register connection's alert token in our lookup structure.
  96  * To use rbtrees we have to implement our own insert core.
  97  * Requires @conns_lock
  98  * @smc         connection to register
  99  * Returns 0 on success, != otherwise.
 100  */
 101 static void smc_lgr_add_alert_token(struct smc_connection *conn)
 102 {
 103         struct rb_node **link, *parent = NULL;
 104         u32 token = conn->alert_token_local;
 105
 106         link = &conn->lgr->conns_all.rb_node;
 107         while (*link) {
 108                 struct smc_connection *cur = rb_entry(*link,
 109                                         struct smc_connection, alert_node);
 110
 111                 parent = *link;
 112                 if (cur->alert_token_local > token)
 113                         link = &parent->rb_left;
 114                 else
 115                         link = &parent->rb_right;
 116         }
 117         /* Put the new node there */
 118         rb_link_node(&conn->alert_node, parent, link);
 119         rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
 120 }
 121
 122 /* assign an SMC-R link to the connection */
 123 static int smcr_lgr_conn_assign_link(struct smc_connection *conn, bool first)
 124 {
 125         enum smc_link_state expected = first ? SMC_LNK_ACTIVATING :
 126                                        SMC_LNK_ACTIVE;
 127         int i, j;
 128
 129         /* do link balancing */
 130         conn->lnk = NULL;       /* reset conn->lnk first */
 131         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 132                 struct smc_link *lnk = &conn->lgr->lnk[i];
 133
 134                 if (lnk->state != expected || lnk->link_is_asym)
 135                         continue;
 136                 if (conn->lgr->role == SMC_CLNT) {
 137                         conn->lnk = lnk; /* temporary, SMC server assigns link*/
 138                         break;
 139                 }
 140                 if (conn->lgr->conns_num % 2) {
 141                         for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
 142                                 struct smc_link *lnk2;
 143
 144                                 lnk2 = &conn->lgr->lnk[j];
 145                                 if (lnk2->state == expected &&
 146                                     !lnk2->link_is_asym) {
 147                                         conn->lnk = lnk2;
 148                                         break;
 149                                 }
 150                         }
 151                 }
 152                 if (!conn->lnk)
 153                         conn->lnk = lnk;
 154                 break;
 155         }
 156         if (!conn->lnk)
 157                 return SMC_CLC_DECL_NOACTLINK;
 158         atomic_inc(&conn->lnk->conn_cnt);
 159         return 0;
 160 }
 161
 162 /* Register connection in link group by assigning an alert token
 163  * registered in a search tree.
 164  * Requires @conns_lock
 165  * Note that '0' is a reserved value and not assigned.
 166  */
 167 static int smc_lgr_register_conn(struct smc_connection *conn, bool first)
 168 {
 169         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 170         static atomic_t nexttoken = ATOMIC_INIT(0);
 171         int rc;
 172
 173         if (!conn->lgr->is_smcd) {
 174                 rc = smcr_lgr_conn_assign_link(conn, first);
 175                 if (rc) {
 176                         conn->lgr = NULL;
 177                         return rc;
 178                 }
 179         }
 180         /* find a new alert_token_local value not yet used by some connection
 181          * in this link group
 182          */
 183         sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
 184         while (!conn->alert_token_local) {
 185                 conn->alert_token_local = atomic_inc_return(&nexttoken);
 186                 if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
 187                         conn->alert_token_local = 0;
 188         }
 189         smc_lgr_add_alert_token(conn);
 190         conn->lgr->conns_num++;
 191         return 0;
 192 }
 193
 194 /* Unregister connection and reset the alert token of the given connection<
 195  */
 196 static void __smc_lgr_unregister_conn(struct smc_connection *conn)
 197 {
 198         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 199         struct smc_link_group *lgr = conn->lgr;
 200
 201         rb_erase(&conn->alert_node, &lgr->conns_all);
 202         if (conn->lnk)
 203                 atomic_dec(&conn->lnk->conn_cnt);
 204         lgr->conns_num--;
 205         conn->alert_token_local = 0;
 206         sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
 207 }
 208
 209 /* Unregister connection from lgr
 210  */
 211 static void smc_lgr_unregister_conn(struct smc_connection *conn)
 212 {
 213         struct smc_link_group *lgr = conn->lgr;
 214
 215         if (!smc_conn_lgr_valid(conn))
 216                 return;
 217         write_lock_bh(&lgr->conns_lock);
 218         if (conn->alert_token_local) {
 219                 __smc_lgr_unregister_conn(conn);
 220         }
 221         write_unlock_bh(&lgr->conns_lock);
 222 }
 223
 224 int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
 225 {
 226         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 227         char hostname[SMC_MAX_HOSTNAME_LEN + 1];
 228         char smc_seid[SMC_MAX_EID_LEN + 1];
 229         struct nlattr *attrs;
 230         u8 *seid = NULL;
 231         u8 *host = NULL;
 232         void *nlh;
 233
 234         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 235                           &smc_gen_nl_family, NLM_F_MULTI,
 236                           SMC_NETLINK_GET_SYS_INFO);
 237         if (!nlh)
 238                 goto errmsg;
 239         if (cb_ctx->pos[0])
 240                 goto errout;
 241         attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
 242         if (!attrs)
 243                 goto errout;
 244         if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
 245                 goto errattr;
 246         if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
 247                 goto errattr;
 248         if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
 249                 goto errattr;
 250         if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
 251                 goto errattr;
 252         smc_clc_get_hostname(&host);
 253         if (host) {
 254                 memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
 255                 hostname[SMC_MAX_HOSTNAME_LEN] = 0;
 256                 if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
 257                         goto errattr;
 258         }
 259         if (smc_ism_is_v2_capable()) {
 260                 smc_ism_get_system_eid(&seid);
 261                 memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
 262                 smc_seid[SMC_MAX_EID_LEN] = 0;
 263                 if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
 264                         goto errattr;
 265         }
 266         nla_nest_end(skb, attrs);
 267         genlmsg_end(skb, nlh);
 268         cb_ctx->pos[0] = 1;
 269         return skb->len;
 270
 271 errattr:
 272         nla_nest_cancel(skb, attrs);
 273 errout:
 274         genlmsg_cancel(skb, nlh);
 275 errmsg:
 276         return skb->len;
 277 }
 278
 279 /* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
 280 static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
 281                                      struct sk_buff *skb,
 282                                      struct netlink_callback *cb,
 283                                      struct nlattr *v2_attrs)
 284 {
 285         char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
 286         char smc_eid[SMC_MAX_EID_LEN + 1];
 287
 288         if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
 289                 goto errv2attr;
 290         if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
 291                 goto errv2attr;
 292         if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
 293                 goto errv2attr;
 294         memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
 295         smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
 296         if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
 297                 goto errv2attr;
 298         memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
 299         smc_eid[SMC_MAX_EID_LEN] = 0;
 300         if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
 301                 goto errv2attr;
 302
 303         nla_nest_end(skb, v2_attrs);
 304         return 0;
 305
 306 errv2attr:
 307         nla_nest_cancel(skb, v2_attrs);
 308         return -EMSGSIZE;
 309 }
 310
 311 static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
 312                                    struct sk_buff *skb,
 313                                    struct netlink_callback *cb)
 314 {
 315         struct nlattr *v2_attrs;
 316
 317         v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
 318         if (!v2_attrs)
 319                 goto errattr;
 320         if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
 321                 goto errv2attr;
 322         if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
 323                 goto errv2attr;
 324         if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
 325                 goto errv2attr;
 326
 327         nla_nest_end(skb, v2_attrs);
 328         return 0;
 329
 330 errv2attr:
 331         nla_nest_cancel(skb, v2_attrs);
 332 errattr:
 333         return -EMSGSIZE;
 334 }
 335
 336 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
 337                            struct sk_buff *skb,
 338                            struct netlink_callback *cb)
 339 {
 340         char smc_target[SMC_MAX_PNETID_LEN + 1];
 341         struct nlattr *attrs, *v2_attrs;
 342
 343         attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
 344         if (!attrs)
 345                 goto errout;
 346
 347         if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
 348                 goto errattr;
 349         if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
 350                 goto errattr;
 351         if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
 352                 goto errattr;
 353         if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
 354                 goto errattr;
 355         if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
 356                 goto errattr;
 357         if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
 358                 goto errattr;
 359         if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
 360                               lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
 361                 goto errattr;
 362         memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
 363         smc_target[SMC_MAX_PNETID_LEN] = 0;
 364         if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
 365                 goto errattr;
 366         if (lgr->smc_version > SMC_V1) {
 367                 v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
 368                 if (!v2_attrs)
 369                         goto errattr;
 370                 if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
 371                         goto errattr;
 372                 if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
 373                         goto errattr;
 374         }
 375
 376         nla_nest_end(skb, attrs);
 377         return 0;
 378 errattr:
 379         nla_nest_cancel(skb, attrs);
 380 errout:
 381         return -EMSGSIZE;
 382 }
 383
 384 static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
 385                                 struct smc_link *link,
 386                                 struct sk_buff *skb,
 387                                 struct netlink_callback *cb)
 388 {
 389         char smc_ibname[IB_DEVICE_NAME_MAX];
 390         u8 smc_gid_target[41];
 391         struct nlattr *attrs;
 392         u32 link_uid = 0;
 393         void *nlh;
 394
 395         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 396                           &smc_gen_nl_family, NLM_F_MULTI,
 397                           SMC_NETLINK_GET_LINK_SMCR);
 398         if (!nlh)
 399                 goto errmsg;
 400
 401         attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
 402         if (!attrs)
 403                 goto errout;
 404
 405         if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
 406                 goto errattr;
 407         if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
 408                 goto errattr;
 409         if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
 410                         atomic_read(&link->conn_cnt)))
 411                 goto errattr;
 412         if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
 413                 goto errattr;
 414         if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
 415                 goto errattr;
 416         snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
 417         if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
 418                 goto errattr;
 419         memcpy(&link_uid, link->link_uid, sizeof(link_uid));
 420         if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
 421                 goto errattr;
 422         memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
 423         if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
 424                 goto errattr;
 425         memset(smc_gid_target, 0, sizeof(smc_gid_target));
 426         smc_gid_be16_convert(smc_gid_target, link->gid);
 427         if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
 428                 goto errattr;
 429         memset(smc_gid_target, 0, sizeof(smc_gid_target));
 430         smc_gid_be16_convert(smc_gid_target, link->peer_gid);
 431         if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
 432                 goto errattr;
 433
 434         nla_nest_end(skb, attrs);
 435         genlmsg_end(skb, nlh);
 436         return 0;
 437 errattr:
 438         nla_nest_cancel(skb, attrs);
 439 errout:
 440         genlmsg_cancel(skb, nlh);
 441 errmsg:
 442         return -EMSGSIZE;
 443 }
 444
 445 static int smc_nl_handle_lgr(struct smc_link_group *lgr,
 446                              struct sk_buff *skb,
 447                              struct netlink_callback *cb,
 448                              bool list_links)
 449 {
 450         void *nlh;
 451         int i;
 452
 453         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 454                           &smc_gen_nl_family, NLM_F_MULTI,
 455                           SMC_NETLINK_GET_LGR_SMCR);
 456         if (!nlh)
 457                 goto errmsg;
 458         if (smc_nl_fill_lgr(lgr, skb, cb))
 459                 goto errout;
 460
 461         genlmsg_end(skb, nlh);
 462         if (!list_links)
 463                 goto out;
 464         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 465                 if (!smc_link_usable(&lgr->lnk[i]))
 466                         continue;
 467                 if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
 468                         goto errout;
 469         }
 470 out:
 471         return 0;
 472
 473 errout:
 474         genlmsg_cancel(skb, nlh);
 475 errmsg:
 476         return -EMSGSIZE;
 477 }
 478
 479 static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
 480                                  struct sk_buff *skb,
 481                                  struct netlink_callback *cb,
 482                                  bool list_links)
 483 {
 484         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 485         struct smc_link_group *lgr;
 486         int snum = cb_ctx->pos[0];
 487         int num = 0;
 488
 489         spin_lock_bh(&smc_lgr->lock);
 490         list_for_each_entry(lgr, &smc_lgr->list, list) {
 491                 if (num < snum)
 492                         goto next;
 493                 if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
 494                         goto errout;
 495 next:
 496                 num++;
 497         }
 498 errout:
 499         spin_unlock_bh(&smc_lgr->lock);
 500         cb_ctx->pos[0] = num;
 501 }
 502
 503 static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
 504                                 struct sk_buff *skb,
 505                                 struct netlink_callback *cb)
 506 {
 507         char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 508         struct smcd_dev *smcd = lgr->smcd;
 509         struct nlattr *attrs;
 510         void *nlh;
 511
 512         nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 513                           &smc_gen_nl_family, NLM_F_MULTI,
 514                           SMC_NETLINK_GET_LGR_SMCD);
 515         if (!nlh)
 516                 goto errmsg;
 517
 518         attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
 519         if (!attrs)
 520                 goto errout;
 521
 522         if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
 523                 goto errattr;
 524         if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
 525                               smcd->ops->get_local_gid(smcd),
 526                                   SMC_NLA_LGR_D_PAD))
 527                 goto errattr;
 528         if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid,
 529                               SMC_NLA_LGR_D_PAD))
 530                 goto errattr;
 531         if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
 532                 goto errattr;
 533         if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
 534                 goto errattr;
 535         if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
 536                 goto errattr;
 537         memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
 538         smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 539         if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
 540                 goto errattr;
 541         if (lgr->smc_version > SMC_V1) {
 542                 struct nlattr *v2_attrs;
 543
 544                 v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
 545                 if (!v2_attrs)
 546                         goto errattr;
 547                 if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
 548                         goto errattr;
 549         }
 550         nla_nest_end(skb, attrs);
 551         genlmsg_end(skb, nlh);
 552         return 0;
 553
 554 errattr:
 555         nla_nest_cancel(skb, attrs);
 556 errout:
 557         genlmsg_cancel(skb, nlh);
 558 errmsg:
 559         return -EMSGSIZE;
 560 }
 561
 562 static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
 563                                   struct sk_buff *skb,
 564                                   struct netlink_callback *cb)
 565 {
 566         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 567         struct smc_link_group *lgr;
 568         int snum = cb_ctx->pos[1];
 569         int rc = 0, num = 0;
 570
 571         spin_lock_bh(&dev->lgr_lock);
 572         list_for_each_entry(lgr, &dev->lgr_list, list) {
 573                 if (!lgr->is_smcd)
 574                         continue;
 575                 if (num < snum)
 576                         goto next;
 577                 rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
 578                 if (rc)
 579                         goto errout;
 580 next:
 581                 num++;
 582         }
 583 errout:
 584         spin_unlock_bh(&dev->lgr_lock);
 585         cb_ctx->pos[1] = num;
 586         return rc;
 587 }
 588
 589 static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
 590                                 struct sk_buff *skb,
 591                                 struct netlink_callback *cb)
 592 {
 593         struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 594         struct smcd_dev *smcd_dev;
 595         int snum = cb_ctx->pos[0];
 596         int rc = 0, num = 0;
 597
 598         mutex_lock(&dev_list->mutex);
 599         list_for_each_entry(smcd_dev, &dev_list->list, list) {
 600                 if (list_empty(&smcd_dev->lgr_list))
 601                         continue;
 602                 if (num < snum)
 603                         goto next;
 604                 rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
 605                 if (rc)
 606                         goto errout;
 607 next:
 608                 num++;
 609         }
 610 errout:
 611         mutex_unlock(&dev_list->mutex);
 612         cb_ctx->pos[0] = num;
 613         return rc;
 614 }
 615
 616 int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
 617 {
 618         bool list_links = false;
 619
 620         smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
 621         return skb->len;
 622 }
 623
 624 int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
 625 {
 626         bool list_links = true;
 627
 628         smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
 629         return skb->len;
 630 }
 631
 632 int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
 633 {
 634         smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
 635         return skb->len;
 636 }
 637
 638 void smc_lgr_cleanup_early(struct smc_link_group *lgr)
 639 {
 640         spinlock_t *lgr_lock;
 641
 642         if (!lgr)
 643                 return;
 644
 645         smc_lgr_list_head(lgr, &lgr_lock);
 646         spin_lock_bh(lgr_lock);
 647         /* do not use this link group for new connections */
 648         if (!list_empty(&lgr->list))
 649                 list_del_init(&lgr->list);
 650         spin_unlock_bh(lgr_lock);
 651         __smc_lgr_terminate(lgr, true);
 652 }
 653
 654 static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
 655 {
 656         int i;
 657
 658         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 659                 struct smc_link *lnk = &lgr->lnk[i];
 660
 661                 if (smc_link_sendable(lnk))
 662                         lnk->state = SMC_LNK_INACTIVE;
 663         }
 664         wake_up_all(&lgr->llc_msg_waiter);
 665         wake_up_all(&lgr->llc_flow_waiter);
 666 }
 667
 668 static void smc_lgr_free(struct smc_link_group *lgr);
 669
 670 static void smc_lgr_free_work(struct work_struct *work)
 671 {
 672         struct smc_link_group *lgr = container_of(to_delayed_work(work),
 673                                                   struct smc_link_group,
 674                                                   free_work);
 675         spinlock_t *lgr_lock;
 676         bool conns;
 677
 678         smc_lgr_list_head(lgr, &lgr_lock);
 679         spin_lock_bh(lgr_lock);
 680         if (lgr->freeing) {
 681                 spin_unlock_bh(lgr_lock);
 682                 return;
 683         }
 684         read_lock_bh(&lgr->conns_lock);
 685         conns = RB_EMPTY_ROOT(&lgr->conns_all);
 686         read_unlock_bh(&lgr->conns_lock);
 687         if (!conns) { /* number of lgr connections is no longer zero */
 688                 spin_unlock_bh(lgr_lock);
 689                 return;
 690         }
 691         list_del_init(&lgr->list); /* remove from smc_lgr_list */
 692         lgr->freeing = 1; /* this instance does the freeing, no new schedule */
 693         spin_unlock_bh(lgr_lock);
 694         cancel_delayed_work(&lgr->free_work);
 695
 696         if (!lgr->is_smcd && !lgr->terminating)
 697                 smc_llc_send_link_delete_all(lgr, true,
 698                                              SMC_LLC_DEL_PROG_INIT_TERM);
 699         if (lgr->is_smcd && !lgr->terminating)
 700                 smc_ism_signal_shutdown(lgr);
 701         if (!lgr->is_smcd)
 702                 smcr_lgr_link_deactivate_all(lgr);
 703         smc_lgr_free(lgr);
 704 }
 705
 706 static void smc_lgr_terminate_work(struct work_struct *work)
 707 {
 708         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
 709                                                   terminate_work);
 710
 711         __smc_lgr_terminate(lgr, true);
 712 }
 713
 714 /* return next unique link id for the lgr */
 715 static u8 smcr_next_link_id(struct smc_link_group *lgr)
 716 {
 717         u8 link_id;
 718         int i;
 719
 720         while (1) {
 721 again:
 722                 link_id = ++lgr->next_link_id;
 723                 if (!link_id)   /* skip zero as link_id */
 724                         link_id = ++lgr->next_link_id;
 725                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 726                         if (smc_link_usable(&lgr->lnk[i]) &&
 727                             lgr->lnk[i].link_id == link_id)
 728                                 goto again;
 729                 }
 730                 break;
 731         }
 732         return link_id;
 733 }
 734
 735 static void smcr_copy_dev_info_to_link(struct smc_link *link)
 736 {
 737         struct smc_ib_device *smcibdev = link->smcibdev;
 738
 739         snprintf(link->ibname, sizeof(link->ibname), "%s",
 740                  smcibdev->ibdev->name);
 741         link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
 742 }
 743
 744 int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
 745                    u8 link_idx, struct smc_init_info *ini)
 746 {
 747         struct smc_ib_device *smcibdev;
 748         u8 rndvec[3];
 749         int rc;
 750
 751         if (lgr->smc_version == SMC_V2) {
 752                 lnk->smcibdev = ini->smcrv2.ib_dev_v2;
 753                 lnk->ibport = ini->smcrv2.ib_port_v2;
 754         } else {
 755                 lnk->smcibdev = ini->ib_dev;
 756                 lnk->ibport = ini->ib_port;
 757         }
 758         get_device(&lnk->smcibdev->ibdev->dev);
 759         atomic_inc(&lnk->smcibdev->lnk_cnt);
 760         refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
 761         lnk->clearing = 0;
 762         lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
 763         lnk->link_id = smcr_next_link_id(lgr);
 764         lnk->lgr = lgr;
 765         smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
 766         lnk->link_idx = link_idx;
 767         lnk->wr_rx_id_compl = 0;
 768         smc_ibdev_cnt_inc(lnk);
 769         smcr_copy_dev_info_to_link(lnk);
 770         atomic_set(&lnk->conn_cnt, 0);
 771         smc_llc_link_set_uid(lnk);
 772         INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
 773         if (!lnk->smcibdev->initialized) {
 774                 rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
 775                 if (rc)
 776                         goto out;
 777         }
 778         get_random_bytes(rndvec, sizeof(rndvec));
 779         lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 780                 (rndvec[2] << 16);
 781         rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 782                                   ini->vlan_id, lnk->gid, &lnk->sgid_index,
 783                                   lgr->smc_version == SMC_V2 ?
 784                                                   &ini->smcrv2 : NULL);
 785         if (rc)
 786                 goto out;
 787         rc = smc_llc_link_init(lnk);
 788         if (rc)
 789                 goto out;
 790         rc = smc_wr_alloc_link_mem(lnk);
 791         if (rc)
 792                 goto clear_llc_lnk;
 793         rc = smc_ib_create_protection_domain(lnk);
 794         if (rc)
 795                 goto free_link_mem;
 796         rc = smc_ib_create_queue_pair(lnk);
 797         if (rc)
 798                 goto dealloc_pd;
 799         rc = smc_wr_create_link(lnk);
 800         if (rc)
 801                 goto destroy_qp;
 802         lnk->state = SMC_LNK_ACTIVATING;
 803         return 0;
 804
 805 destroy_qp:
 806         smc_ib_destroy_queue_pair(lnk);
 807 dealloc_pd:
 808         smc_ib_dealloc_protection_domain(lnk);
 809 free_link_mem:
 810         smc_wr_free_link_mem(lnk);
 811 clear_llc_lnk:
 812         smc_llc_link_clear(lnk, false);
 813 out:
 814         smc_ibdev_cnt_dec(lnk);
 815         put_device(&lnk->smcibdev->ibdev->dev);
 816         smcibdev = lnk->smcibdev;
 817         memset(lnk, 0, sizeof(struct smc_link));
 818         lnk->state = SMC_LNK_UNUSED;
 819         if (!atomic_dec_return(&smcibdev->lnk_cnt))
 820                 wake_up(&smcibdev->lnks_deleted);
 821         smc_lgr_put(lgr); /* lgr_hold above */
 822         return rc;
 823 }
 824
 825 /* create a new SMC link group */
 826 static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 827 {
 828         struct smc_link_group *lgr;
 829         struct list_head *lgr_list;
 830         struct smcd_dev *smcd;
 831         struct smc_link *lnk;
 832         spinlock_t *lgr_lock;
 833         u8 link_idx;
 834         int rc = 0;
 835         int i;
 836
 837         if (ini->is_smcd && ini->vlan_id) {
 838                 if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
 839                                      ini->vlan_id)) {
 840                         rc = SMC_CLC_DECL_ISMVLANERR;
 841                         goto out;
 842                 }
 843         }
 844
 845         lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 846         if (!lgr) {
 847                 rc = SMC_CLC_DECL_MEM;
 848                 goto ism_put_vlan;
 849         }
 850         lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
 851                                      SMC_LGR_ID_SIZE, &lgr->id);
 852         if (!lgr->tx_wq) {
 853                 rc = -ENOMEM;
 854                 goto free_lgr;
 855         }
 856         lgr->is_smcd = ini->is_smcd;
 857         lgr->sync_err = 0;
 858         lgr->terminating = 0;
 859         lgr->freeing = 0;
 860         lgr->vlan_id = ini->vlan_id;
 861         refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
 862         init_rwsem(&lgr->sndbufs_lock);
 863         init_rwsem(&lgr->rmbs_lock);
 864         rwlock_init(&lgr->conns_lock);
 865         for (i = 0; i < SMC_RMBE_SIZES; i++) {
 866                 INIT_LIST_HEAD(&lgr->sndbufs[i]);
 867                 INIT_LIST_HEAD(&lgr->rmbs[i]);
 868         }
 869         lgr->next_link_id = 0;
 870         smc_lgr_list.num += SMC_LGR_NUM_INCR;
 871         memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 872         INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 873         INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
 874         lgr->conns_all = RB_ROOT;
 875         if (ini->is_smcd) {
 876                 /* SMC-D specific settings */
 877                 smcd = ini->ism_dev[ini->ism_selected];
 878                 get_device(smcd->ops->get_dev(smcd));
 879                 lgr->peer_gid = ini->ism_peer_gid[ini->ism_selected];
 880                 lgr->smcd = ini->ism_dev[ini->ism_selected];
 881                 lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
 882                 lgr_lock = &lgr->smcd->lgr_lock;
 883                 lgr->smc_version = ini->smcd_version;
 884                 lgr->peer_shutdown = 0;
 885                 atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
 886         } else {
 887                 /* SMC-R specific settings */
 888                 struct smc_ib_device *ibdev;
 889                 int ibport;
 890
 891                 lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 892                 lgr->smc_version = ini->smcr_version;
 893                 memcpy(lgr->peer_systemid, ini->peer_systemid,
 894                        SMC_SYSTEMID_LEN);
 895                 if (lgr->smc_version == SMC_V2) {
 896                         ibdev = ini->smcrv2.ib_dev_v2;
 897                         ibport = ini->smcrv2.ib_port_v2;
 898                         lgr->saddr = ini->smcrv2.saddr;
 899                         lgr->uses_gateway = ini->smcrv2.uses_gateway;
 900                         memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
 901                                ETH_ALEN);
 902                         lgr->max_conns = ini->max_conns;
 903                         lgr->max_links = ini->max_links;
 904                 } else {
 905                         ibdev = ini->ib_dev;
 906                         ibport = ini->ib_port;
 907                         lgr->max_conns = SMC_CONN_PER_LGR_MAX;
 908                         lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
 909                 }
 910                 memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
 911                        SMC_MAX_PNETID_LEN);
 912                 rc = smc_wr_alloc_lgr_mem(lgr);
 913                 if (rc)
 914                         goto free_wq;
 915                 smc_llc_lgr_init(lgr, smc);
 916
 917                 link_idx = SMC_SINGLE_LINK;
 918                 lnk = &lgr->lnk[link_idx];
 919                 rc = smcr_link_init(lgr, lnk, link_idx, ini);
 920                 if (rc) {
 921                         smc_wr_free_lgr_mem(lgr);
 922                         goto free_wq;
 923                 }
 924                 lgr->net = smc_ib_net(lnk->smcibdev);
 925                 lgr_list = &smc_lgr_list.list;
 926                 lgr_lock = &smc_lgr_list.lock;
 927                 lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
 928                 atomic_inc(&lgr_cnt);
 929         }
 930         smc->conn.lgr = lgr;
 931         spin_lock_bh(lgr_lock);
 932         list_add_tail(&lgr->list, lgr_list);
 933         spin_unlock_bh(lgr_lock);
 934         return 0;
 935
 936 free_wq:
 937         destroy_workqueue(lgr->tx_wq);
 938 free_lgr:
 939         kfree(lgr);
 940 ism_put_vlan:
 941         if (ini->is_smcd && ini->vlan_id)
 942                 smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
 943 out:
 944         if (rc < 0) {
 945                 if (rc == -ENOMEM)
 946                         rc = SMC_CLC_DECL_MEM;
 947                 else
 948                         rc = SMC_CLC_DECL_INTERR;
 949         }
 950         return rc;
 951 }
 952
 953 static int smc_write_space(struct smc_connection *conn)
 954 {
 955         int buffer_len = conn->peer_rmbe_size;
 956         union smc_host_cursor prod;
 957         union smc_host_cursor cons;
 958         int space;
 959
 960         smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
 961         smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
 962         /* determine rx_buf space */
 963         space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
 964         return space;
 965 }
 966
 967 static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
 968                              struct smc_wr_buf *wr_buf)
 969 {
 970         struct smc_connection *conn = &smc->conn;
 971         union smc_host_cursor cons, fin;
 972         int rc = 0;
 973         int diff;
 974
 975         smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
 976         smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
 977         /* set prod cursor to old state, enforce tx_rdma_writes() */
 978         smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
 979         smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
 980
 981         if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
 982                 /* cons cursor advanced more than fin, and prod was set
 983                  * fin above, so now prod is smaller than cons. Fix that.
 984                  */
 985                 diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
 986                 smc_curs_add(conn->sndbuf_desc->len,
 987                              &conn->tx_curs_sent, diff);
 988                 smc_curs_add(conn->sndbuf_desc->len,
 989                              &conn->tx_curs_fin, diff);
 990
 991                 smp_mb__before_atomic();
 992                 atomic_add(diff, &conn->sndbuf_space);
 993                 smp_mb__after_atomic();
 994
 995                 smc_curs_add(conn->peer_rmbe_size,
 996                              &conn->local_tx_ctrl.prod, diff);
 997                 smc_curs_add(conn->peer_rmbe_size,
 998                              &conn->local_tx_ctrl_fin, diff);
 999         }
1000         /* recalculate, value is used by tx_rdma_writes() */
1001         atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
1002
1003         if (smc->sk.sk_state != SMC_INIT &&
1004             smc->sk.sk_state != SMC_CLOSED) {
1005                 rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
1006                 if (!rc) {
1007                         queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
1008                         smc->sk.sk_data_ready(&smc->sk);
1009                 }
1010         } else {
1011                 smc_wr_tx_put_slot(conn->lnk,
1012                                    (struct smc_wr_tx_pend_priv *)pend);
1013         }
1014         return rc;
1015 }
1016
1017 void smc_switch_link_and_count(struct smc_connection *conn,
1018                                struct smc_link *to_lnk)
1019 {
1020         atomic_dec(&conn->lnk->conn_cnt);
1021         /* link_hold in smc_conn_create() */
1022         smcr_link_put(conn->lnk);
1023         conn->lnk = to_lnk;
1024         atomic_inc(&conn->lnk->conn_cnt);
1025         /* link_put in smc_conn_free() */
1026         smcr_link_hold(conn->lnk);
1027 }
1028
1029 struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1030                                   struct smc_link *from_lnk, bool is_dev_err)
1031 {
1032         struct smc_link *to_lnk = NULL;
1033         struct smc_cdc_tx_pend *pend;
1034         struct smc_connection *conn;
1035         struct smc_wr_buf *wr_buf;
1036         struct smc_sock *smc;
1037         struct rb_node *node;
1038         int i, rc = 0;
1039
1040         /* link is inactive, wake up tx waiters */
1041         smc_wr_wakeup_tx_wait(from_lnk);
1042
1043         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1044                 if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1045                         continue;
1046                 if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1047                     from_lnk->ibport == lgr->lnk[i].ibport) {
1048                         continue;
1049                 }
1050                 to_lnk = &lgr->lnk[i];
1051                 break;
1052         }
1053         if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1054                 smc_lgr_terminate_sched(lgr);
1055                 return NULL;
1056         }
1057 again:
1058         read_lock_bh(&lgr->conns_lock);
1059         for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1060                 conn = rb_entry(node, struct smc_connection, alert_node);
1061                 if (conn->lnk != from_lnk)
1062                         continue;
1063                 smc = container_of(conn, struct smc_sock, conn);
1064                 /* conn->lnk not yet set in SMC_INIT state */
1065                 if (smc->sk.sk_state == SMC_INIT)
1066                         continue;
1067                 if (smc->sk.sk_state == SMC_CLOSED ||
1068                     smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1069                     smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1070                     smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1071                     smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1072                     smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1073                     smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1074                     smc->sk.sk_state == SMC_PEERABORTWAIT ||
1075                     smc->sk.sk_state == SMC_PROCESSABORT) {
1076                         spin_lock_bh(&conn->send_lock);
1077                         smc_switch_link_and_count(conn, to_lnk);
1078                         spin_unlock_bh(&conn->send_lock);
1079                         continue;
1080                 }
1081                 sock_hold(&smc->sk);
1082                 read_unlock_bh(&lgr->conns_lock);
1083                 /* pre-fetch buffer outside of send_lock, might sleep */
1084                 rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1085                 if (rc)
1086                         goto err_out;
1087                 /* avoid race with smcr_tx_sndbuf_nonempty() */
1088                 spin_lock_bh(&conn->send_lock);
1089                 smc_switch_link_and_count(conn, to_lnk);
1090                 rc = smc_switch_cursor(smc, pend, wr_buf);
1091                 spin_unlock_bh(&conn->send_lock);
1092                 sock_put(&smc->sk);
1093                 if (rc)
1094                         goto err_out;
1095                 goto again;
1096         }
1097         read_unlock_bh(&lgr->conns_lock);
1098         smc_wr_tx_link_put(to_lnk);
1099         return to_lnk;
1100
1101 err_out:
1102         smcr_link_down_cond_sched(to_lnk);
1103         smc_wr_tx_link_put(to_lnk);
1104         return NULL;
1105 }
1106
1107 static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1108                            struct smc_link_group *lgr)
1109 {
1110         struct rw_semaphore *lock;      /* lock buffer list */
1111         int rc;
1112
1113         if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1114                 /* unregister rmb with peer */
1115                 rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1116                 if (!rc) {
1117                         /* protect against smc_llc_cli_rkey_exchange() */
1118                         down_read(&lgr->llc_conf_mutex);
1119                         smc_llc_do_delete_rkey(lgr, buf_desc);
1120                         buf_desc->is_conf_rkey = false;
1121                         up_read(&lgr->llc_conf_mutex);
1122                         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1123                 }
1124         }
1125
1126         if (buf_desc->is_reg_err) {
1127                 /* buf registration failed, reuse not possible */
1128                 lock = is_rmb ? &lgr->rmbs_lock :
1129                                 &lgr->sndbufs_lock;
1130                 down_write(lock);
1131                 list_del(&buf_desc->list);
1132                 up_write(lock);
1133
1134                 smc_buf_free(lgr, is_rmb, buf_desc);
1135         } else {
1136                 /* memzero_explicit provides potential memory barrier semantics */
1137                 memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
1138                 WRITE_ONCE(buf_desc->used, 0);
1139         }
1140 }
1141
1142 static void smc_buf_unuse(struct smc_connection *conn,
1143                           struct smc_link_group *lgr)
1144 {
1145         if (conn->sndbuf_desc) {
1146                 if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) {
1147                         smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1148                 } else {
1149                         memzero_explicit(conn->sndbuf_desc->cpu_addr, conn->sndbuf_desc->len);
1150                         WRITE_ONCE(conn->sndbuf_desc->used, 0);
1151                 }
1152         }
1153         if (conn->rmb_desc) {
1154                 if (!lgr->is_smcd) {
1155                         smcr_buf_unuse(conn->rmb_desc, true, lgr);
1156                 } else {
1157                         memzero_explicit(conn->rmb_desc->cpu_addr,
1158                                          conn->rmb_desc->len + sizeof(struct smcd_cdc_msg));
1159                         WRITE_ONCE(conn->rmb_desc->used, 0);
1160                 }
1161         }
1162 }
1163
1164 /* remove a finished connection from its link group */
1165 void smc_conn_free(struct smc_connection *conn)
1166 {
1167         struct smc_link_group *lgr = conn->lgr;
1168
1169         if (!lgr || conn->freed)
1170                 /* Connection has never been registered in a
1171                  * link group, or has already been freed.
1172                  */
1173                 return;
1174
1175         conn->freed = 1;
1176         if (!smc_conn_lgr_valid(conn))
1177                 /* Connection has already unregistered from
1178                  * link group.
1179                  */
1180                 goto lgr_put;
1181
1182         if (lgr->is_smcd) {
1183                 if (!list_empty(&lgr->list))
1184                         smc_ism_unset_conn(conn);
1185                 tasklet_kill(&conn->rx_tsklet);
1186         } else {
1187                 smc_cdc_wait_pend_tx_wr(conn);
1188                 if (current_work() != &conn->abort_work)
1189                         cancel_work_sync(&conn->abort_work);
1190         }
1191         if (!list_empty(&lgr->list)) {
1192                 smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1193                 smc_lgr_unregister_conn(conn);
1194         }
1195
1196         if (!lgr->conns_num)
1197                 smc_lgr_schedule_free_work(lgr);
1198 lgr_put:
1199         if (!lgr->is_smcd)
1200                 smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1201         smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1202 }
1203
1204 /* unregister a link from a buf_desc */
1205 static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1206                                 struct smc_link *lnk)
1207 {
1208         if (is_rmb || buf_desc->is_vm)
1209                 buf_desc->is_reg_mr[lnk->link_idx] = false;
1210         if (!buf_desc->is_map_ib[lnk->link_idx])
1211                 return;
1212
1213         if ((is_rmb || buf_desc->is_vm) &&
1214             buf_desc->mr[lnk->link_idx]) {
1215                 smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1216                 buf_desc->mr[lnk->link_idx] = NULL;
1217         }
1218         if (is_rmb)
1219                 smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1220         else
1221                 smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1222
1223         sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1224         buf_desc->is_map_ib[lnk->link_idx] = false;
1225 }
1226
1227 /* unmap all buffers of lgr for a deleted link */
1228 static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1229 {
1230         struct smc_link_group *lgr = lnk->lgr;
1231         struct smc_buf_desc *buf_desc, *bf;
1232         int i;
1233
1234         for (i = 0; i < SMC_RMBE_SIZES; i++) {
1235                 down_write(&lgr->rmbs_lock);
1236                 list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1237                         smcr_buf_unmap_link(buf_desc, true, lnk);
1238                 up_write(&lgr->rmbs_lock);
1239
1240                 down_write(&lgr->sndbufs_lock);
1241                 list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1242                                          list)
1243                         smcr_buf_unmap_link(buf_desc, false, lnk);
1244                 up_write(&lgr->sndbufs_lock);
1245         }
1246 }
1247
1248 static void smcr_rtoken_clear_link(struct smc_link *lnk)
1249 {
1250         struct smc_link_group *lgr = lnk->lgr;
1251         int i;
1252
1253         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1254                 lgr->rtokens[i][lnk->link_idx].rkey = 0;
1255                 lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1256         }
1257 }
1258
1259 static void __smcr_link_clear(struct smc_link *lnk)
1260 {
1261         struct smc_link_group *lgr = lnk->lgr;
1262         struct smc_ib_device *smcibdev;
1263
1264         smc_wr_free_link_mem(lnk);
1265         smc_ibdev_cnt_dec(lnk);
1266         put_device(&lnk->smcibdev->ibdev->dev);
1267         smcibdev = lnk->smcibdev;
1268         memset(lnk, 0, sizeof(struct smc_link));
1269         lnk->state = SMC_LNK_UNUSED;
1270         if (!atomic_dec_return(&smcibdev->lnk_cnt))
1271                 wake_up(&smcibdev->lnks_deleted);
1272         smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1273 }
1274
1275 /* must be called under lgr->llc_conf_mutex lock */
1276 void smcr_link_clear(struct smc_link *lnk, bool log)
1277 {
1278         if (!lnk->lgr || lnk->clearing ||
1279             lnk->state == SMC_LNK_UNUSED)
1280                 return;
1281         lnk->clearing = 1;
1282         lnk->peer_qpn = 0;
1283         smc_llc_link_clear(lnk, log);
1284         smcr_buf_unmap_lgr(lnk);
1285         smcr_rtoken_clear_link(lnk);
1286         smc_ib_modify_qp_error(lnk);
1287         smc_wr_free_link(lnk);
1288         smc_ib_destroy_queue_pair(lnk);
1289         smc_ib_dealloc_protection_domain(lnk);
1290         smcr_link_put(lnk); /* theoretically last link_put */
1291 }
1292
1293 void smcr_link_hold(struct smc_link *lnk)
1294 {
1295         refcount_inc(&lnk->refcnt);
1296 }
1297
1298 void smcr_link_put(struct smc_link *lnk)
1299 {
1300         if (refcount_dec_and_test(&lnk->refcnt))
1301                 __smcr_link_clear(lnk);
1302 }
1303
1304 static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1305                           struct smc_buf_desc *buf_desc)
1306 {
1307         int i;
1308
1309         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1310                 smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1311
1312         if (!buf_desc->is_vm && buf_desc->pages)
1313                 __free_pages(buf_desc->pages, buf_desc->order);
1314         else if (buf_desc->is_vm && buf_desc->cpu_addr)
1315                 vfree(buf_desc->cpu_addr);
1316         kfree(buf_desc);
1317 }
1318
1319 static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1320                           struct smc_buf_desc *buf_desc)
1321 {
1322         if (is_dmb) {
1323                 /* restore original buf len */
1324                 buf_desc->len += sizeof(struct smcd_cdc_msg);
1325                 smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1326         } else {
1327                 kfree(buf_desc->cpu_addr);
1328         }
1329         kfree(buf_desc);
1330 }
1331
1332 static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1333                          struct smc_buf_desc *buf_desc)
1334 {
1335         if (lgr->is_smcd)
1336                 smcd_buf_free(lgr, is_rmb, buf_desc);
1337         else
1338                 smcr_buf_free(lgr, is_rmb, buf_desc);
1339 }
1340
1341 static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1342 {
1343         struct smc_buf_desc *buf_desc, *bf_desc;
1344         struct list_head *buf_list;
1345         int i;
1346
1347         for (i = 0; i < SMC_RMBE_SIZES; i++) {
1348                 if (is_rmb)
1349                         buf_list = &lgr->rmbs[i];
1350                 else
1351                         buf_list = &lgr->sndbufs[i];
1352                 list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1353                                          list) {
1354                         list_del(&buf_desc->list);
1355                         smc_buf_free(lgr, is_rmb, buf_desc);
1356                 }
1357         }
1358 }
1359
1360 static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1361 {
1362         /* free send buffers */
1363         __smc_lgr_free_bufs(lgr, false);
1364         /* free rmbs */
1365         __smc_lgr_free_bufs(lgr, true);
1366 }
1367
1368 /* won't be freed until no one accesses to lgr anymore */
1369 static void __smc_lgr_free(struct smc_link_group *lgr)
1370 {
1371         smc_lgr_free_bufs(lgr);
1372         if (lgr->is_smcd) {
1373                 if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1374                         wake_up(&lgr->smcd->lgrs_deleted);
1375         } else {
1376                 smc_wr_free_lgr_mem(lgr);
1377                 if (!atomic_dec_return(&lgr_cnt))
1378                         wake_up(&lgrs_deleted);
1379         }
1380         kfree(lgr);
1381 }
1382
1383 /* remove a link group */
1384 static void smc_lgr_free(struct smc_link_group *lgr)
1385 {
1386         int i;
1387
1388         if (!lgr->is_smcd) {
1389                 down_write(&lgr->llc_conf_mutex);
1390                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1391                         if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1392                                 smcr_link_clear(&lgr->lnk[i], false);
1393                 }
1394                 up_write(&lgr->llc_conf_mutex);
1395                 smc_llc_lgr_clear(lgr);
1396         }
1397
1398         destroy_workqueue(lgr->tx_wq);
1399         if (lgr->is_smcd) {
1400                 smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1401                 put_device(lgr->smcd->ops->get_dev(lgr->smcd));
1402         }
1403         smc_lgr_put(lgr); /* theoretically last lgr_put */
1404 }
1405
1406 void smc_lgr_hold(struct smc_link_group *lgr)
1407 {
1408         refcount_inc(&lgr->refcnt);
1409 }
1410
1411 void smc_lgr_put(struct smc_link_group *lgr)
1412 {
1413         if (refcount_dec_and_test(&lgr->refcnt))
1414                 __smc_lgr_free(lgr);
1415 }
1416
1417 static void smc_sk_wake_ups(struct smc_sock *smc)
1418 {
1419         smc->sk.sk_write_space(&smc->sk);
1420         smc->sk.sk_data_ready(&smc->sk);
1421         smc->sk.sk_state_change(&smc->sk);
1422 }
1423
1424 /* kill a connection */
1425 static void smc_conn_kill(struct smc_connection *conn, bool soft)
1426 {
1427         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1428
1429         if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1430                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1431         else
1432                 smc_close_abort(conn);
1433         conn->killed = 1;
1434         smc->sk.sk_err = ECONNABORTED;
1435         smc_sk_wake_ups(smc);
1436         if (conn->lgr->is_smcd) {
1437                 smc_ism_unset_conn(conn);
1438                 if (soft)
1439                         tasklet_kill(&conn->rx_tsklet);
1440                 else
1441                         tasklet_unlock_wait(&conn->rx_tsklet);
1442         } else {
1443                 smc_cdc_wait_pend_tx_wr(conn);
1444         }
1445         smc_lgr_unregister_conn(conn);
1446         smc_close_active_abort(smc);
1447 }
1448
1449 static void smc_lgr_cleanup(struct smc_link_group *lgr)
1450 {
1451         if (lgr->is_smcd) {
1452                 smc_ism_signal_shutdown(lgr);
1453         } else {
1454                 u32 rsn = lgr->llc_termination_rsn;
1455
1456                 if (!rsn)
1457                         rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1458                 smc_llc_send_link_delete_all(lgr, false, rsn);
1459                 smcr_lgr_link_deactivate_all(lgr);
1460         }
1461 }
1462
1463 /* terminate link group
1464  * @soft: true if link group shutdown can take its time
1465  *        false if immediate link group shutdown is required
1466  */
1467 static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1468 {
1469         struct smc_connection *conn;
1470         struct smc_sock *smc;
1471         struct rb_node *node;
1472
1473         if (lgr->terminating)
1474                 return; /* lgr already terminating */
1475         /* cancel free_work sync, will terminate when lgr->freeing is set */
1476         cancel_delayed_work(&lgr->free_work);
1477         lgr->terminating = 1;
1478
1479         /* kill remaining link group connections */
1480         read_lock_bh(&lgr->conns_lock);
1481         node = rb_first(&lgr->conns_all);
1482         while (node) {
1483                 read_unlock_bh(&lgr->conns_lock);
1484                 conn = rb_entry(node, struct smc_connection, alert_node);
1485                 smc = container_of(conn, struct smc_sock, conn);
1486                 sock_hold(&smc->sk); /* sock_put below */
1487                 lock_sock(&smc->sk);
1488                 smc_conn_kill(conn, soft);
1489                 release_sock(&smc->sk);
1490                 sock_put(&smc->sk); /* sock_hold above */
1491                 read_lock_bh(&lgr->conns_lock);
1492                 node = rb_first(&lgr->conns_all);
1493         }
1494         read_unlock_bh(&lgr->conns_lock);
1495         smc_lgr_cleanup(lgr);
1496         smc_lgr_free(lgr);
1497 }
1498
1499 /* unlink link group and schedule termination */
1500 void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1501 {
1502         spinlock_t *lgr_lock;
1503
1504         smc_lgr_list_head(lgr, &lgr_lock);
1505         spin_lock_bh(lgr_lock);
1506         if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1507                 spin_unlock_bh(lgr_lock);
1508                 return; /* lgr already terminating */
1509         }
1510         list_del_init(&lgr->list);
1511         lgr->freeing = 1;
1512         spin_unlock_bh(lgr_lock);
1513         schedule_work(&lgr->terminate_work);
1514 }
1515
1516 /* Called when peer lgr shutdown (regularly or abnormally) is received */
1517 void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
1518 {
1519         struct smc_link_group *lgr, *l;
1520         LIST_HEAD(lgr_free_list);
1521
1522         /* run common cleanup function and build free list */
1523         spin_lock_bh(&dev->lgr_lock);
1524         list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1525                 if ((!peer_gid || lgr->peer_gid == peer_gid) &&
1526                     (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1527                         if (peer_gid) /* peer triggered termination */
1528                                 lgr->peer_shutdown = 1;
1529                         list_move(&lgr->list, &lgr_free_list);
1530                         lgr->freeing = 1;
1531                 }
1532         }
1533         spin_unlock_bh(&dev->lgr_lock);
1534
1535         /* cancel the regular free workers and actually free lgrs */
1536         list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1537                 list_del_init(&lgr->list);
1538                 schedule_work(&lgr->terminate_work);
1539         }
1540 }
1541
1542 /* Called when an SMCD device is removed or the smc module is unloaded */
1543 void smc_smcd_terminate_all(struct smcd_dev *smcd)
1544 {
1545         struct smc_link_group *lgr, *lg;
1546         LIST_HEAD(lgr_free_list);
1547
1548         spin_lock_bh(&smcd->lgr_lock);
1549         list_splice_init(&smcd->lgr_list, &lgr_free_list);
1550         list_for_each_entry(lgr, &lgr_free_list, list)
1551                 lgr->freeing = 1;
1552         spin_unlock_bh(&smcd->lgr_lock);
1553
1554         list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1555                 list_del_init(&lgr->list);
1556                 __smc_lgr_terminate(lgr, false);
1557         }
1558
1559         if (atomic_read(&smcd->lgr_cnt))
1560                 wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1561 }
1562
1563 /* Called when an SMCR device is removed or the smc module is unloaded.
1564  * If smcibdev is given, all SMCR link groups using this device are terminated.
1565  * If smcibdev is NULL, all SMCR link groups are terminated.
1566  */
1567 void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1568 {
1569         struct smc_link_group *lgr, *lg;
1570         LIST_HEAD(lgr_free_list);
1571         int i;
1572
1573         spin_lock_bh(&smc_lgr_list.lock);
1574         if (!smcibdev) {
1575                 list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1576                 list_for_each_entry(lgr, &lgr_free_list, list)
1577                         lgr->freeing = 1;
1578         } else {
1579                 list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1580                         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1581                                 if (lgr->lnk[i].smcibdev == smcibdev)
1582                                         smcr_link_down_cond_sched(&lgr->lnk[i]);
1583                         }
1584                 }
1585         }
1586         spin_unlock_bh(&smc_lgr_list.lock);
1587
1588         list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1589                 list_del_init(&lgr->list);
1590                 smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1591                 __smc_lgr_terminate(lgr, false);
1592         }
1593
1594         if (smcibdev) {
1595                 if (atomic_read(&smcibdev->lnk_cnt))
1596                         wait_event(smcibdev->lnks_deleted,
1597                                    !atomic_read(&smcibdev->lnk_cnt));
1598         } else {
1599                 if (atomic_read(&lgr_cnt))
1600                         wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1601         }
1602 }
1603
1604 /* set new lgr type and clear all asymmetric link tagging */
1605 void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1606 {
1607         char *lgr_type = "";
1608         int i;
1609
1610         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1611                 if (smc_link_usable(&lgr->lnk[i]))
1612                         lgr->lnk[i].link_is_asym = false;
1613         if (lgr->type == new_type)
1614                 return;
1615         lgr->type = new_type;
1616
1617         switch (lgr->type) {
1618         case SMC_LGR_NONE:
1619                 lgr_type = "NONE";
1620                 break;
1621         case SMC_LGR_SINGLE:
1622                 lgr_type = "SINGLE";
1623                 break;
1624         case SMC_LGR_SYMMETRIC:
1625                 lgr_type = "SYMMETRIC";
1626                 break;
1627         case SMC_LGR_ASYMMETRIC_PEER:
1628                 lgr_type = "ASYMMETRIC_PEER";
1629                 break;
1630         case SMC_LGR_ASYMMETRIC_LOCAL:
1631                 lgr_type = "ASYMMETRIC_LOCAL";
1632                 break;
1633         }
1634         pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1635                             "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1636                             lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1637 }
1638
1639 /* set new lgr type and tag a link as asymmetric */
1640 void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1641                             enum smc_lgr_type new_type, int asym_lnk_idx)
1642 {
1643         smcr_lgr_set_type(lgr, new_type);
1644         lgr->lnk[asym_lnk_idx].link_is_asym = true;
1645 }
1646
1647 /* abort connection, abort_work scheduled from tasklet context */
1648 static void smc_conn_abort_work(struct work_struct *work)
1649 {
1650         struct smc_connection *conn = container_of(work,
1651                                                    struct smc_connection,
1652                                                    abort_work);
1653         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1654
1655         lock_sock(&smc->sk);
1656         smc_conn_kill(conn, true);
1657         release_sock(&smc->sk);
1658         sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1659 }
1660
1661 void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1662 {
1663         struct smc_link_group *lgr, *n;
1664
1665         spin_lock_bh(&smc_lgr_list.lock);
1666         list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1667                 struct smc_link *link;
1668
1669                 if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1670                             SMC_MAX_PNETID_LEN) ||
1671                     lgr->type == SMC_LGR_SYMMETRIC ||
1672                     lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1673                     !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1674                         continue;
1675
1676                 if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1677                         continue;
1678
1679                 /* trigger local add link processing */
1680                 link = smc_llc_usable_link(lgr);
1681                 if (link)
1682                         smc_llc_add_link_local(link);
1683         }
1684         spin_unlock_bh(&smc_lgr_list.lock);
1685 }
1686
1687 /* link is down - switch connections to alternate link,
1688  * must be called under lgr->llc_conf_mutex lock
1689  */
1690 static void smcr_link_down(struct smc_link *lnk)
1691 {
1692         struct smc_link_group *lgr = lnk->lgr;
1693         struct smc_link *to_lnk;
1694         int del_link_id;
1695
1696         if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1697                 return;
1698
1699         to_lnk = smc_switch_conns(lgr, lnk, true);
1700         if (!to_lnk) { /* no backup link available */
1701                 smcr_link_clear(lnk, true);
1702                 return;
1703         }
1704         smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1705         del_link_id = lnk->link_id;
1706
1707         if (lgr->role == SMC_SERV) {
1708                 /* trigger local delete link processing */
1709                 smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1710         } else {
1711                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1712                         /* another llc task is ongoing */
1713                         up_write(&lgr->llc_conf_mutex);
1714                         wait_event_timeout(lgr->llc_flow_waiter,
1715                                 (list_empty(&lgr->list) ||
1716                                  lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1717                                 SMC_LLC_WAIT_TIME);
1718                         down_write(&lgr->llc_conf_mutex);
1719                 }
1720                 if (!list_empty(&lgr->list)) {
1721                         smc_llc_send_delete_link(to_lnk, del_link_id,
1722                                                  SMC_LLC_REQ, true,
1723                                                  SMC_LLC_DEL_LOST_PATH);
1724                         smcr_link_clear(lnk, true);
1725                 }
1726                 wake_up(&lgr->llc_flow_waiter); /* wake up next waiter */
1727         }
1728 }
1729
1730 /* must be called under lgr->llc_conf_mutex lock */
1731 void smcr_link_down_cond(struct smc_link *lnk)
1732 {
1733         if (smc_link_downing(&lnk->state)) {
1734                 trace_smcr_link_down(lnk, __builtin_return_address(0));
1735                 smcr_link_down(lnk);
1736         }
1737 }
1738
1739 /* will get the lgr->llc_conf_mutex lock */
1740 void smcr_link_down_cond_sched(struct smc_link *lnk)
1741 {
1742         if (smc_link_downing(&lnk->state)) {
1743                 trace_smcr_link_down(lnk, __builtin_return_address(0));
1744                 schedule_work(&lnk->link_down_wrk);
1745         }
1746 }
1747
1748 void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1749 {
1750         struct smc_link_group *lgr, *n;
1751         int i;
1752
1753         list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1754                 if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1755                             SMC_MAX_PNETID_LEN))
1756                         continue; /* lgr is not affected */
1757                 if (list_empty(&lgr->list))
1758                         continue;
1759                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1760                         struct smc_link *lnk = &lgr->lnk[i];
1761
1762                         if (smc_link_usable(lnk) &&
1763                             lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1764                                 smcr_link_down_cond_sched(lnk);
1765                 }
1766         }
1767 }
1768
1769 static void smc_link_down_work(struct work_struct *work)
1770 {
1771         struct smc_link *link = container_of(work, struct smc_link,
1772                                              link_down_wrk);
1773         struct smc_link_group *lgr = link->lgr;
1774
1775         if (list_empty(&lgr->list))
1776                 return;
1777         wake_up_all(&lgr->llc_msg_waiter);
1778         down_write(&lgr->llc_conf_mutex);
1779         smcr_link_down(link);
1780         up_write(&lgr->llc_conf_mutex);
1781 }
1782
1783 static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1784                                   struct netdev_nested_priv *priv)
1785 {
1786         unsigned short *vlan_id = (unsigned short *)priv->data;
1787
1788         if (is_vlan_dev(lower_dev)) {
1789                 *vlan_id = vlan_dev_vlan_id(lower_dev);
1790                 return 1;
1791         }
1792
1793         return 0;
1794 }
1795
1796 /* Determine vlan of internal TCP socket. */
1797 int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1798 {
1799         struct dst_entry *dst = sk_dst_get(clcsock->sk);
1800         struct netdev_nested_priv priv;
1801         struct net_device *ndev;
1802         int rc = 0;
1803
1804         ini->vlan_id = 0;
1805         if (!dst) {
1806                 rc = -ENOTCONN;
1807                 goto out;
1808         }
1809         if (!dst->dev) {
1810                 rc = -ENODEV;
1811                 goto out_rel;
1812         }
1813
1814         ndev = dst->dev;
1815         if (is_vlan_dev(ndev)) {
1816                 ini->vlan_id = vlan_dev_vlan_id(ndev);
1817                 goto out_rel;
1818         }
1819
1820         priv.data = (void *)&ini->vlan_id;
1821         rtnl_lock();
1822         netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
1823         rtnl_unlock();
1824
1825 out_rel:
1826         dst_release(dst);
1827 out:
1828         return rc;
1829 }
1830
1831 static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1832                            u8 peer_systemid[],
1833                            u8 peer_gid[],
1834                            u8 peer_mac_v1[],
1835                            enum smc_lgr_role role, u32 clcqpn,
1836                            struct net *net)
1837 {
1838         struct smc_link *lnk;
1839         int i;
1840
1841         if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1842             lgr->role != role)
1843                 return false;
1844
1845         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1846                 lnk = &lgr->lnk[i];
1847
1848                 if (!smc_link_active(lnk))
1849                         continue;
1850                 /* use verbs API to check netns, instead of lgr->net */
1851                 if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1852                         return false;
1853                 if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1854                     !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1855                     (smcr_version == SMC_V2 ||
1856                      !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1857                         return true;
1858         }
1859         return false;
1860 }
1861
1862 static bool smcd_lgr_match(struct smc_link_group *lgr,
1863                            struct smcd_dev *smcismdev, u64 peer_gid)
1864 {
1865         return lgr->peer_gid == peer_gid && lgr->smcd == smcismdev;
1866 }
1867
1868 /* create a new SMC connection (and a new link group if necessary) */
1869 int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1870 {
1871         struct smc_connection *conn = &smc->conn;
1872         struct net *net = sock_net(&smc->sk);
1873         struct list_head *lgr_list;
1874         struct smc_link_group *lgr;
1875         enum smc_lgr_role role;
1876         spinlock_t *lgr_lock;
1877         int rc = 0;
1878
1879         lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1880                                   &smc_lgr_list.list;
1881         lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1882                                   &smc_lgr_list.lock;
1883         ini->first_contact_local = 1;
1884         role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1885         if (role == SMC_CLNT && ini->first_contact_peer)
1886                 /* create new link group as well */
1887                 goto create;
1888
1889         /* determine if an existing link group can be reused */
1890         spin_lock_bh(lgr_lock);
1891         list_for_each_entry(lgr, lgr_list, list) {
1892                 write_lock_bh(&lgr->conns_lock);
1893                 if ((ini->is_smcd ?
1894                      smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1895                                     ini->ism_peer_gid[ini->ism_selected]) :
1896                      smcr_lgr_match(lgr, ini->smcr_version,
1897                                     ini->peer_systemid,
1898                                     ini->peer_gid, ini->peer_mac, role,
1899                                     ini->ib_clcqpn, net)) &&
1900                     !lgr->sync_err &&
1901                     (ini->smcd_version == SMC_V2 ||
1902                      lgr->vlan_id == ini->vlan_id) &&
1903                     (role == SMC_CLNT || ini->is_smcd ||
1904                     (lgr->conns_num < lgr->max_conns &&
1905                       !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
1906                         /* link group found */
1907                         ini->first_contact_local = 0;
1908                         conn->lgr = lgr;
1909                         rc = smc_lgr_register_conn(conn, false);
1910                         write_unlock_bh(&lgr->conns_lock);
1911                         if (!rc && delayed_work_pending(&lgr->free_work))
1912                                 cancel_delayed_work(&lgr->free_work);
1913                         break;
1914                 }
1915                 write_unlock_bh(&lgr->conns_lock);
1916         }
1917         spin_unlock_bh(lgr_lock);
1918         if (rc)
1919                 return rc;
1920
1921         if (role == SMC_CLNT && !ini->first_contact_peer &&
1922             ini->first_contact_local) {
1923                 /* Server reuses a link group, but Client wants to start
1924                  * a new one
1925                  * send out_of_sync decline, reason synchr. error
1926                  */
1927                 return SMC_CLC_DECL_SYNCERR;
1928         }
1929
1930 create:
1931         if (ini->first_contact_local) {
1932                 rc = smc_lgr_create(smc, ini);
1933                 if (rc)
1934                         goto out;
1935                 lgr = conn->lgr;
1936                 write_lock_bh(&lgr->conns_lock);
1937                 rc = smc_lgr_register_conn(conn, true);
1938                 write_unlock_bh(&lgr->conns_lock);
1939                 if (rc) {
1940                         smc_lgr_cleanup_early(lgr);
1941                         goto out;
1942                 }
1943         }
1944         smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
1945         if (!conn->lgr->is_smcd)
1946                 smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
1947         conn->freed = 0;
1948         conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
1949         conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
1950         conn->urg_state = SMC_URG_READ;
1951         init_waitqueue_head(&conn->cdc_pend_tx_wq);
1952         INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
1953         if (ini->is_smcd) {
1954                 conn->rx_off = sizeof(struct smcd_cdc_msg);
1955                 smcd_cdc_rx_init(conn); /* init tasklet for this conn */
1956         } else {
1957                 conn->rx_off = 0;
1958         }
1959 #ifndef KERNEL_HAS_ATOMIC64
1960         spin_lock_init(&conn->acurs_lock);
1961 #endif
1962
1963 out:
1964         return rc;
1965 }
1966
1967 #define SMCD_DMBE_SIZES         6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
1968 #define SMCR_RMBE_SIZES         5 /* 0 -> 16KB, 1 -> 32KB, .. 5 -> 512KB */
1969
1970 /* convert the RMB size into the compressed notation (minimum 16K, see
1971  * SMCD/R_DMBE_SIZES.
1972  * In contrast to plain ilog2, this rounds towards the next power of 2,
1973  * so the socket application gets at least its desired sndbuf / rcvbuf size.
1974  */
1975 static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
1976 {
1977         const unsigned int max_scat = SG_MAX_SINGLE_ALLOC * PAGE_SIZE;
1978         u8 compressed;
1979
1980         if (size <= SMC_BUF_MIN_SIZE)
1981                 return 0;
1982
1983         size = (size - 1) >> 14;  /* convert to 16K multiple */
1984         compressed = min_t(u8, ilog2(size) + 1,
1985                            is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
1986
1987         if (!is_smcd && is_rmb)
1988                 /* RMBs are backed by & limited to max size of scatterlists */
1989                 compressed = min_t(u8, compressed, ilog2(max_scat >> 14));
1990
1991         return compressed;
1992 }
1993
1994 /* convert the RMB size from compressed notation into integer */
1995 int smc_uncompress_bufsize(u8 compressed)
1996 {
1997         u32 size;
1998
1999         size = 0x00000001 << (((int)compressed) + 14);
2000         return (int)size;
2001 }
2002
2003 /* try to reuse a sndbuf or rmb description slot for a certain
2004  * buffer size; if not available, return NULL
2005  */
2006 static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
2007                                              struct rw_semaphore *lock,
2008                                              struct list_head *buf_list)
2009 {
2010         struct smc_buf_desc *buf_slot;
2011
2012         down_read(lock);
2013         list_for_each_entry(buf_slot, buf_list, list) {
2014                 if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
2015                         up_read(lock);
2016                         return buf_slot;
2017                 }
2018         }
2019         up_read(lock);
2020         return NULL;
2021 }
2022
2023 /* one of the conditions for announcing a receiver's current window size is
2024  * that it "results in a minimum increase in the window size of 10% of the
2025  * receive buffer space" [RFC7609]
2026  */
2027 static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2028 {
2029         return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2030 }
2031
2032 /* map an buf to a link */
2033 static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2034                              struct smc_link *lnk)
2035 {
2036         int rc, i, nents, offset, buf_size, size, access_flags;
2037         struct scatterlist *sg;
2038         void *buf;
2039
2040         if (buf_desc->is_map_ib[lnk->link_idx])
2041                 return 0;
2042
2043         if (buf_desc->is_vm) {
2044                 buf = buf_desc->cpu_addr;
2045                 buf_size = buf_desc->len;
2046                 offset = offset_in_page(buf_desc->cpu_addr);
2047                 nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2048         } else {
2049                 nents = 1;
2050         }
2051
2052         rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2053         if (rc)
2054                 return rc;
2055
2056         if (buf_desc->is_vm) {
2057                 /* virtually contiguous buffer */
2058                 for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2059                         size = min_t(int, PAGE_SIZE - offset, buf_size);
2060                         sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2061                         buf += size / sizeof(*buf);
2062                         buf_size -= size;
2063                         offset = 0;
2064                 }
2065         } else {
2066                 /* physically contiguous buffer */
2067                 sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2068                            buf_desc->cpu_addr, buf_desc->len);
2069         }
2070
2071         /* map sg table to DMA address */
2072         rc = smc_ib_buf_map_sg(lnk, buf_desc,
2073                                is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2074         /* SMC protocol depends on mapping to one DMA address only */
2075         if (rc != nents) {
2076                 rc = -EAGAIN;
2077                 goto free_table;
2078         }
2079
2080         buf_desc->is_dma_need_sync |=
2081                 smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2082
2083         if (is_rmb || buf_desc->is_vm) {
2084                 /* create a new memory region for the RMB or vzalloced sndbuf */
2085                 access_flags = is_rmb ?
2086                                IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2087                                IB_ACCESS_LOCAL_WRITE;
2088
2089                 rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2090                                               buf_desc, lnk->link_idx);
2091                 if (rc)
2092                         goto buf_unmap;
2093                 smc_ib_sync_sg_for_device(lnk, buf_desc,
2094                                           is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2095         }
2096         buf_desc->is_map_ib[lnk->link_idx] = true;
2097         return 0;
2098
2099 buf_unmap:
2100         smc_ib_buf_unmap_sg(lnk, buf_desc,
2101                             is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2102 free_table:
2103         sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2104         return rc;
2105 }
2106
2107 /* register a new buf on IB device, rmb or vzalloced sndbuf
2108  * must be called under lgr->llc_conf_mutex lock
2109  */
2110 int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2111 {
2112         if (list_empty(&link->lgr->list))
2113                 return -ENOLINK;
2114         if (!buf_desc->is_reg_mr[link->link_idx]) {
2115                 /* register memory region for new buf */
2116                 if (buf_desc->is_vm)
2117                         buf_desc->mr[link->link_idx]->iova =
2118                                 (uintptr_t)buf_desc->cpu_addr;
2119                 if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2120                         buf_desc->is_reg_err = true;
2121                         return -EFAULT;
2122                 }
2123                 buf_desc->is_reg_mr[link->link_idx] = true;
2124         }
2125         return 0;
2126 }
2127
2128 static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
2129                              struct list_head *lst, bool is_rmb)
2130 {
2131         struct smc_buf_desc *buf_desc, *bf;
2132         int rc = 0;
2133
2134         down_write(lock);
2135         list_for_each_entry_safe(buf_desc, bf, lst, list) {
2136                 if (!buf_desc->used)
2137                         continue;
2138                 rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2139                 if (rc)
2140                         goto out;
2141         }
2142 out:
2143         up_write(lock);
2144         return rc;
2145 }
2146
2147 /* map all used buffers of lgr for a new link */
2148 int smcr_buf_map_lgr(struct smc_link *lnk)
2149 {
2150         struct smc_link_group *lgr = lnk->lgr;
2151         int i, rc = 0;
2152
2153         for (i = 0; i < SMC_RMBE_SIZES; i++) {
2154                 rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2155                                        &lgr->rmbs[i], true);
2156                 if (rc)
2157                         return rc;
2158                 rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2159                                        &lgr->sndbufs[i], false);
2160                 if (rc)
2161                         return rc;
2162         }
2163         return 0;
2164 }
2165
2166 /* register all used buffers of lgr for a new link,
2167  * must be called under lgr->llc_conf_mutex lock
2168  */
2169 int smcr_buf_reg_lgr(struct smc_link *lnk)
2170 {
2171         struct smc_link_group *lgr = lnk->lgr;
2172         struct smc_buf_desc *buf_desc, *bf;
2173         int i, rc = 0;
2174
2175         /* reg all RMBs for a new link */
2176         down_write(&lgr->rmbs_lock);
2177         for (i = 0; i < SMC_RMBE_SIZES; i++) {
2178                 list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2179                         if (!buf_desc->used)
2180                                 continue;
2181                         rc = smcr_link_reg_buf(lnk, buf_desc);
2182                         if (rc) {
2183                                 up_write(&lgr->rmbs_lock);
2184                                 return rc;
2185                         }
2186                 }
2187         }
2188         up_write(&lgr->rmbs_lock);
2189
2190         if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2191                 return rc;
2192
2193         /* reg all vzalloced sndbufs for a new link */
2194         down_write(&lgr->sndbufs_lock);
2195         for (i = 0; i < SMC_RMBE_SIZES; i++) {
2196                 list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2197                         if (!buf_desc->used || !buf_desc->is_vm)
2198                                 continue;
2199                         rc = smcr_link_reg_buf(lnk, buf_desc);
2200                         if (rc) {
2201                                 up_write(&lgr->sndbufs_lock);
2202                                 return rc;
2203                         }
2204                 }
2205         }
2206         up_write(&lgr->sndbufs_lock);
2207         return rc;
2208 }
2209
2210 static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2211                                                 bool is_rmb, int bufsize)
2212 {
2213         struct smc_buf_desc *buf_desc;
2214
2215         /* try to alloc a new buffer */
2216         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2217         if (!buf_desc)
2218                 return ERR_PTR(-ENOMEM);
2219
2220         switch (lgr->buf_type) {
2221         case SMCR_PHYS_CONT_BUFS:
2222         case SMCR_MIXED_BUFS:
2223                 buf_desc->order = get_order(bufsize);
2224                 buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2225                                               __GFP_NOMEMALLOC | __GFP_COMP |
2226                                               __GFP_NORETRY | __GFP_ZERO,
2227                                               buf_desc->order);
2228                 if (buf_desc->pages) {
2229                         buf_desc->cpu_addr =
2230                                 (void *)page_address(buf_desc->pages);
2231                         buf_desc->len = bufsize;
2232                         buf_desc->is_vm = false;
2233                         break;
2234                 }
2235                 if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2236                         goto out;
2237                 fallthrough;    // try virtually continguous buf
2238         case SMCR_VIRT_CONT_BUFS:
2239                 buf_desc->order = get_order(bufsize);
2240                 buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2241                 if (!buf_desc->cpu_addr)
2242                         goto out;
2243                 buf_desc->pages = NULL;
2244                 buf_desc->len = bufsize;
2245                 buf_desc->is_vm = true;
2246                 break;
2247         }
2248         return buf_desc;
2249
2250 out:
2251         kfree(buf_desc);
2252         return ERR_PTR(-EAGAIN);
2253 }
2254
2255 /* map buf_desc on all usable links,
2256  * unused buffers stay mapped as long as the link is up
2257  */
2258 static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2259                                      struct smc_buf_desc *buf_desc, bool is_rmb)
2260 {
2261         int i, rc = 0, cnt = 0;
2262
2263         /* protect against parallel link reconfiguration */
2264         down_read(&lgr->llc_conf_mutex);
2265         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2266                 struct smc_link *lnk = &lgr->lnk[i];
2267
2268                 if (!smc_link_usable(lnk))
2269                         continue;
2270                 if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2271                         rc = -ENOMEM;
2272                         goto out;
2273                 }
2274                 cnt++;
2275         }
2276 out:
2277         up_read(&lgr->llc_conf_mutex);
2278         if (!rc && !cnt)
2279                 rc = -EINVAL;
2280         return rc;
2281 }
2282
2283 static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2284                                                 bool is_dmb, int bufsize)
2285 {
2286         struct smc_buf_desc *buf_desc;
2287         int rc;
2288
2289         /* try to alloc a new DMB */
2290         buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2291         if (!buf_desc)
2292                 return ERR_PTR(-ENOMEM);
2293         if (is_dmb) {
2294                 rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2295                 if (rc) {
2296                         kfree(buf_desc);
2297                         if (rc == -ENOMEM)
2298                                 return ERR_PTR(-EAGAIN);
2299                         if (rc == -ENOSPC)
2300                                 return ERR_PTR(-ENOSPC);
2301                         return ERR_PTR(-EIO);
2302                 }
2303                 buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2304                 /* CDC header stored in buf. So, pretend it was smaller */
2305                 buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2306         } else {
2307                 buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2308                                              __GFP_NOWARN | __GFP_NORETRY |
2309                                              __GFP_NOMEMALLOC);
2310                 if (!buf_desc->cpu_addr) {
2311                         kfree(buf_desc);
2312                         return ERR_PTR(-EAGAIN);
2313                 }
2314                 buf_desc->len = bufsize;
2315         }
2316         return buf_desc;
2317 }
2318
2319 static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2320 {
2321         struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2322         struct smc_connection *conn = &smc->conn;
2323         struct smc_link_group *lgr = conn->lgr;
2324         struct list_head *buf_list;
2325         int bufsize, bufsize_comp;
2326         struct rw_semaphore *lock;      /* lock buffer list */
2327         bool is_dgraded = false;
2328
2329         if (is_rmb)
2330                 /* use socket recv buffer size (w/o overhead) as start value */
2331                 bufsize = smc->sk.sk_rcvbuf / 2;
2332         else
2333                 /* use socket send buffer size (w/o overhead) as start value */
2334                 bufsize = smc->sk.sk_sndbuf / 2;
2335
2336         for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb);
2337              bufsize_comp >= 0; bufsize_comp--) {
2338                 if (is_rmb) {
2339                         lock = &lgr->rmbs_lock;
2340                         buf_list = &lgr->rmbs[bufsize_comp];
2341                 } else {
2342                         lock = &lgr->sndbufs_lock;
2343                         buf_list = &lgr->sndbufs[bufsize_comp];
2344                 }
2345                 bufsize = smc_uncompress_bufsize(bufsize_comp);
2346
2347                 /* check for reusable slot in the link group */
2348                 buf_desc = smc_buf_get_slot(bufsize_comp, lock, buf_list);
2349                 if (buf_desc) {
2350                         buf_desc->is_dma_need_sync = 0;
2351                         SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2352                         SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2353                         break; /* found reusable slot */
2354                 }
2355
2356                 if (is_smcd)
2357                         buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2358                 else
2359                         buf_desc = smcr_new_buf_create(lgr, is_rmb, bufsize);
2360
2361                 if (PTR_ERR(buf_desc) == -ENOMEM)
2362                         break;
2363                 if (IS_ERR(buf_desc)) {
2364                         if (!is_dgraded) {
2365                                 is_dgraded = true;
2366                                 SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2367                         }
2368                         continue;
2369                 }
2370
2371                 SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2372                 SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
2373                 buf_desc->used = 1;
2374                 down_write(lock);
2375                 list_add(&buf_desc->list, buf_list);
2376                 up_write(lock);
2377                 break; /* found */
2378         }
2379
2380         if (IS_ERR(buf_desc))
2381                 return PTR_ERR(buf_desc);
2382
2383         if (!is_smcd) {
2384                 if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2385                         smcr_buf_unuse(buf_desc, is_rmb, lgr);
2386                         return -ENOMEM;
2387                 }
2388         }
2389
2390         if (is_rmb) {
2391                 conn->rmb_desc = buf_desc;
2392                 conn->rmbe_size_comp = bufsize_comp;
2393                 smc->sk.sk_rcvbuf = bufsize * 2;
2394                 atomic_set(&conn->bytes_to_rcv, 0);
2395                 conn->rmbe_update_limit =
2396                         smc_rmb_wnd_update_limit(buf_desc->len);
2397                 if (is_smcd)
2398                         smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2399         } else {
2400                 conn->sndbuf_desc = buf_desc;
2401                 smc->sk.sk_sndbuf = bufsize * 2;
2402                 atomic_set(&conn->sndbuf_space, bufsize);
2403         }
2404         return 0;
2405 }
2406
2407 void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2408 {
2409         if (!conn->sndbuf_desc->is_dma_need_sync)
2410                 return;
2411         if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2412             !smc_link_active(conn->lnk))
2413                 return;
2414         smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2415 }
2416
2417 void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2418 {
2419         int i;
2420
2421         if (!conn->rmb_desc->is_dma_need_sync)
2422                 return;
2423         if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2424                 return;
2425         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2426                 if (!smc_link_active(&conn->lgr->lnk[i]))
2427                         continue;
2428                 smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2429                                        DMA_FROM_DEVICE);
2430         }
2431 }
2432
2433 /* create the send and receive buffer for an SMC socket;
2434  * receive buffers are called RMBs;
2435  * (even though the SMC protocol allows more than one RMB-element per RMB,
2436  * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2437  * extra RMB for every connection in a link group
2438  */
2439 int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2440 {
2441         int rc;
2442
2443         /* create send buffer */
2444         rc = __smc_buf_create(smc, is_smcd, false);
2445         if (rc)
2446                 return rc;
2447         /* create rmb */
2448         rc = __smc_buf_create(smc, is_smcd, true);
2449         if (rc) {
2450                 down_write(&smc->conn.lgr->sndbufs_lock);
2451                 list_del(&smc->conn.sndbuf_desc->list);
2452                 up_write(&smc->conn.lgr->sndbufs_lock);
2453                 smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2454                 smc->conn.sndbuf_desc = NULL;
2455         }
2456         return rc;
2457 }
2458
2459 static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2460 {
2461         int i;
2462
2463         for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2464                 if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2465                         return i;
2466         }
2467         return -ENOSPC;
2468 }
2469
2470 static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2471                                    u32 rkey)
2472 {
2473         int i;
2474
2475         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2476                 if (test_bit(i, lgr->rtokens_used_mask) &&
2477                     lgr->rtokens[i][lnk_idx].rkey == rkey)
2478                         return i;
2479         }
2480         return -ENOENT;
2481 }
2482
2483 /* set rtoken for a new link to an existing rmb */
2484 void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2485                     __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2486 {
2487         int rtok_idx;
2488
2489         rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2490         if (rtok_idx == -ENOENT)
2491                 return;
2492         lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2493         lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2494 }
2495
2496 /* set rtoken for a new link whose link_id is given */
2497 void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2498                      __be64 nw_vaddr, __be32 nw_rkey)
2499 {
2500         u64 dma_addr = be64_to_cpu(nw_vaddr);
2501         u32 rkey = ntohl(nw_rkey);
2502         bool found = false;
2503         int link_idx;
2504
2505         for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2506                 if (lgr->lnk[link_idx].link_id == link_id) {
2507                         found = true;
2508                         break;
2509                 }
2510         }
2511         if (!found)
2512                 return;
2513         lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2514         lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2515 }
2516
2517 /* add a new rtoken from peer */
2518 int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2519 {
2520         struct smc_link_group *lgr = smc_get_lgr(lnk);
2521         u64 dma_addr = be64_to_cpu(nw_vaddr);
2522         u32 rkey = ntohl(nw_rkey);
2523         int i;
2524
2525         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2526                 if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2527                     lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2528                     test_bit(i, lgr->rtokens_used_mask)) {
2529                         /* already in list */
2530                         return i;
2531                 }
2532         }
2533         i = smc_rmb_reserve_rtoken_idx(lgr);
2534         if (i < 0)
2535                 return i;
2536         lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2537         lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2538         return i;
2539 }
2540
2541 /* delete an rtoken from all links */
2542 int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2543 {
2544         struct smc_link_group *lgr = smc_get_lgr(lnk);
2545         u32 rkey = ntohl(nw_rkey);
2546         int i, j;
2547
2548         for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2549                 if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2550                     test_bit(i, lgr->rtokens_used_mask)) {
2551                         for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2552                                 lgr->rtokens[i][j].rkey = 0;
2553                                 lgr->rtokens[i][j].dma_addr = 0;
2554                         }
2555                         clear_bit(i, lgr->rtokens_used_mask);
2556                         return 0;
2557                 }
2558         }
2559         return -ENOENT;
2560 }
2561
2562 /* save rkey and dma_addr received from peer during clc handshake */
2563 int smc_rmb_rtoken_handling(struct smc_connection *conn,
2564                             struct smc_link *lnk,
2565                             struct smc_clc_msg_accept_confirm *clc)
2566 {
2567         conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2568                                           clc->r0.rmb_rkey);
2569         if (conn->rtoken_idx < 0)
2570                 return conn->rtoken_idx;
2571         return 0;
2572 }
2573
2574 static void smc_core_going_away(void)
2575 {
2576         struct smc_ib_device *smcibdev;
2577         struct smcd_dev *smcd;
2578
2579         mutex_lock(&smc_ib_devices.mutex);
2580         list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2581                 int i;
2582
2583                 for (i = 0; i < SMC_MAX_PORTS; i++)
2584                         set_bit(i, smcibdev->ports_going_away);
2585         }
2586         mutex_unlock(&smc_ib_devices.mutex);
2587
2588         mutex_lock(&smcd_dev_list.mutex);
2589         list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2590                 smcd->going_away = 1;
2591         }
2592         mutex_unlock(&smcd_dev_list.mutex);
2593 }
2594
2595 /* Clean up all SMC link groups */
2596 static void smc_lgrs_shutdown(void)
2597 {
2598         struct smcd_dev *smcd;
2599
2600         smc_core_going_away();
2601
2602         smc_smcr_terminate_all(NULL);
2603
2604         mutex_lock(&smcd_dev_list.mutex);
2605         list_for_each_entry(smcd, &smcd_dev_list.list, list)
2606                 smc_smcd_terminate_all(smcd);
2607         mutex_unlock(&smcd_dev_list.mutex);
2608 }
2609
2610 static int smc_core_reboot_event(struct notifier_block *this,
2611                                  unsigned long event, void *ptr)
2612 {
2613         smc_lgrs_shutdown();
2614         smc_ib_unregister_client();
2615         smc_ism_exit();
2616         return 0;
2617 }
2618
2619 static struct notifier_block smc_reboot_notifier = {
2620         .notifier_call = smc_core_reboot_event,
2621 };
2622
2623 int __init smc_core_init(void)
2624 {
2625         return register_reboot_notifier(&smc_reboot_notifier);
2626 }
2627
2628 /* Called (from smc_exit) when module is removed */
2629 void smc_core_exit(void)
2630 {
2631         unregister_reboot_notifier(&smc_reboot_notifier);
2632         smc_lgrs_shutdown();
2633 }