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   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
  43struct 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
  49static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
  50static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);
  51
  52static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
  53			 struct smc_buf_desc *buf_desc);
  54static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);
  55
  56static 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 */
  59static 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
  71static void smc_ibdev_cnt_inc(struct smc_link *lnk)
  72{
  73	atomic_inc(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
  74}
  75
  76static void smc_ibdev_cnt_dec(struct smc_link *lnk)
  77{
  78	atomic_dec(&lnk->smcibdev->lnk_cnt_by_port[lnk->ibport - 1]);
  79}
  80
  81static 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 */
 101static 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 */
 123static 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 */
 167static 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 */
 196static 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 */
 211static 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
 224static void smc_lgr_buf_list_add(struct smc_link_group *lgr,
 225				 bool is_rmb,
 226				 struct list_head *buf_list,
 227				 struct smc_buf_desc *buf_desc)
 228{
 229	list_add(&buf_desc->list, buf_list);
 230	if (is_rmb) {
 231		lgr->alloc_rmbs += buf_desc->len;
 232		lgr->alloc_rmbs +=
 233			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
 234	} else {
 235		lgr->alloc_sndbufs += buf_desc->len;
 236	}
 237}
 238
 239static void smc_lgr_buf_list_del(struct smc_link_group *lgr,
 240				 bool is_rmb,
 241				 struct smc_buf_desc *buf_desc)
 242{
 243	list_del(&buf_desc->list);
 244	if (is_rmb) {
 245		lgr->alloc_rmbs -= buf_desc->len;
 246		lgr->alloc_rmbs -=
 247			lgr->is_smcd ? sizeof(struct smcd_cdc_msg) : 0;
 248	} else {
 249		lgr->alloc_sndbufs -= buf_desc->len;
 250	}
 251}
 252
 253int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
 254{
 255	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 256	char hostname[SMC_MAX_HOSTNAME_LEN + 1];
 257	char smc_seid[SMC_MAX_EID_LEN + 1];
 258	struct nlattr *attrs;
 259	u8 *seid = NULL;
 260	u8 *host = NULL;
 261	void *nlh;
 262
 263	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 264			  &smc_gen_nl_family, NLM_F_MULTI,
 265			  SMC_NETLINK_GET_SYS_INFO);
 266	if (!nlh)
 267		goto errmsg;
 268	if (cb_ctx->pos[0])
 269		goto errout;
 270	attrs = nla_nest_start(skb, SMC_GEN_SYS_INFO);
 271	if (!attrs)
 272		goto errout;
 273	if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
 274		goto errattr;
 275	if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
 276		goto errattr;
 277	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
 278		goto errattr;
 279	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
 280		goto errattr;
 281	smc_clc_get_hostname(&host);
 282	if (host) {
 283		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
 284		hostname[SMC_MAX_HOSTNAME_LEN] = 0;
 285		if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
 286			goto errattr;
 287	}
 288	if (smc_ism_is_v2_capable()) {
 289		smc_ism_get_system_eid(&seid);
 290		memcpy(smc_seid, seid, SMC_MAX_EID_LEN);
 291		smc_seid[SMC_MAX_EID_LEN] = 0;
 292		if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
 293			goto errattr;
 294	}
 295	nla_nest_end(skb, attrs);
 296	genlmsg_end(skb, nlh);
 297	cb_ctx->pos[0] = 1;
 298	return skb->len;
 299
 300errattr:
 301	nla_nest_cancel(skb, attrs);
 302errout:
 303	genlmsg_cancel(skb, nlh);
 304errmsg:
 305	return skb->len;
 306}
 307
 308/* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
 309static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
 310				     struct sk_buff *skb,
 311				     struct netlink_callback *cb,
 312				     struct nlattr *v2_attrs)
 313{
 314	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
 315	char smc_eid[SMC_MAX_EID_LEN + 1];
 316
 317	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
 318		goto errv2attr;
 319	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
 320		goto errv2attr;
 321	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
 322		goto errv2attr;
 323	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
 324	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
 325	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
 326		goto errv2attr;
 327	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
 328	smc_eid[SMC_MAX_EID_LEN] = 0;
 329	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
 330		goto errv2attr;
 331
 332	nla_nest_end(skb, v2_attrs);
 333	return 0;
 334
 335errv2attr:
 336	nla_nest_cancel(skb, v2_attrs);
 337	return -EMSGSIZE;
 338}
 339
 340static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
 341				   struct sk_buff *skb,
 342				   struct netlink_callback *cb)
 343{
 344	struct nlattr *v2_attrs;
 345
 346	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
 347	if (!v2_attrs)
 348		goto errattr;
 349	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
 350		goto errv2attr;
 351	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_CONNS, lgr->max_conns))
 352		goto errv2attr;
 353	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_MAX_LINKS, lgr->max_links))
 354		goto errv2attr;
 355
 356	nla_nest_end(skb, v2_attrs);
 357	return 0;
 358
 359errv2attr:
 360	nla_nest_cancel(skb, v2_attrs);
 361errattr:
 362	return -EMSGSIZE;
 363}
 364
 365static int smc_nl_fill_lgr(struct smc_link_group *lgr,
 366			   struct sk_buff *skb,
 367			   struct netlink_callback *cb)
 368{
 369	char smc_target[SMC_MAX_PNETID_LEN + 1];
 370	struct nlattr *attrs, *v2_attrs;
 371
 372	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
 373	if (!attrs)
 374		goto errout;
 375
 376	if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
 377		goto errattr;
 378	if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
 379		goto errattr;
 380	if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
 381		goto errattr;
 382	if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
 383		goto errattr;
 384	if (nla_put_u8(skb, SMC_NLA_LGR_R_BUF_TYPE, lgr->buf_type))
 385		goto errattr;
 386	if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
 387		goto errattr;
 388	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_R_NET_COOKIE,
 389			      lgr->net->net_cookie, SMC_NLA_LGR_R_PAD))
 390		goto errattr;
 391	memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN);
 392	smc_target[SMC_MAX_PNETID_LEN] = 0;
 393	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
 394		goto errattr;
 395	if (nla_put_uint(skb, SMC_NLA_LGR_R_SNDBUF_ALLOC, lgr->alloc_sndbufs))
 396		goto errattr;
 397	if (nla_put_uint(skb, SMC_NLA_LGR_R_RMB_ALLOC, lgr->alloc_rmbs))
 398		goto errattr;
 399	if (lgr->smc_version > SMC_V1) {
 400		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
 401		if (!v2_attrs)
 402			goto errattr;
 403		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
 404			goto errattr;
 405		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
 406			goto errattr;
 407	}
 408
 409	nla_nest_end(skb, attrs);
 410	return 0;
 411errattr:
 412	nla_nest_cancel(skb, attrs);
 413errout:
 414	return -EMSGSIZE;
 415}
 416
 417static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
 418				struct smc_link *link,
 419				struct sk_buff *skb,
 420				struct netlink_callback *cb)
 421{
 422	char smc_ibname[IB_DEVICE_NAME_MAX];
 423	u8 smc_gid_target[41];
 424	struct nlattr *attrs;
 425	u32 link_uid = 0;
 426	void *nlh;
 427
 428	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 429			  &smc_gen_nl_family, NLM_F_MULTI,
 430			  SMC_NETLINK_GET_LINK_SMCR);
 431	if (!nlh)
 432		goto errmsg;
 433
 434	attrs = nla_nest_start(skb, SMC_GEN_LINK_SMCR);
 435	if (!attrs)
 436		goto errout;
 437
 438	if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
 439		goto errattr;
 440	if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
 441		goto errattr;
 442	if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
 443			atomic_read(&link->conn_cnt)))
 444		goto errattr;
 445	if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
 446		goto errattr;
 447	if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
 448		goto errattr;
 449	snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
 450	if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
 451		goto errattr;
 452	memcpy(&link_uid, link->link_uid, sizeof(link_uid));
 453	if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
 454		goto errattr;
 455	memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
 456	if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
 457		goto errattr;
 458	memset(smc_gid_target, 0, sizeof(smc_gid_target));
 459	smc_gid_be16_convert(smc_gid_target, link->gid);
 460	if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
 461		goto errattr;
 462	memset(smc_gid_target, 0, sizeof(smc_gid_target));
 463	smc_gid_be16_convert(smc_gid_target, link->peer_gid);
 464	if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
 465		goto errattr;
 466
 467	nla_nest_end(skb, attrs);
 468	genlmsg_end(skb, nlh);
 469	return 0;
 470errattr:
 471	nla_nest_cancel(skb, attrs);
 472errout:
 473	genlmsg_cancel(skb, nlh);
 474errmsg:
 475	return -EMSGSIZE;
 476}
 477
 478static int smc_nl_handle_lgr(struct smc_link_group *lgr,
 479			     struct sk_buff *skb,
 480			     struct netlink_callback *cb,
 481			     bool list_links)
 482{
 483	void *nlh;
 484	int i;
 485
 486	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 487			  &smc_gen_nl_family, NLM_F_MULTI,
 488			  SMC_NETLINK_GET_LGR_SMCR);
 489	if (!nlh)
 490		goto errmsg;
 491	if (smc_nl_fill_lgr(lgr, skb, cb))
 492		goto errout;
 493
 494	genlmsg_end(skb, nlh);
 495	if (!list_links)
 496		goto out;
 497	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 498		if (!smc_link_usable(&lgr->lnk[i]))
 499			continue;
 500		if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
 501			goto errout;
 502	}
 503out:
 504	return 0;
 505
 506errout:
 507	genlmsg_cancel(skb, nlh);
 508errmsg:
 509	return -EMSGSIZE;
 510}
 511
 512static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
 513				 struct sk_buff *skb,
 514				 struct netlink_callback *cb,
 515				 bool list_links)
 516{
 517	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 518	struct smc_link_group *lgr;
 519	int snum = cb_ctx->pos[0];
 520	int num = 0;
 521
 522	spin_lock_bh(&smc_lgr->lock);
 523	list_for_each_entry(lgr, &smc_lgr->list, list) {
 524		if (num < snum)
 525			goto next;
 526		if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
 527			goto errout;
 528next:
 529		num++;
 530	}
 531errout:
 532	spin_unlock_bh(&smc_lgr->lock);
 533	cb_ctx->pos[0] = num;
 534}
 535
 536static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr,
 537				struct sk_buff *skb,
 538				struct netlink_callback *cb)
 539{
 540	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
 541	struct smcd_dev *smcd = lgr->smcd;
 542	struct smcd_gid smcd_gid;
 543	struct nlattr *attrs;
 544	void *nlh;
 545
 546	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 547			  &smc_gen_nl_family, NLM_F_MULTI,
 548			  SMC_NETLINK_GET_LGR_SMCD);
 549	if (!nlh)
 550		goto errmsg;
 551
 552	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCD);
 553	if (!attrs)
 554		goto errout;
 555
 556	if (nla_put_u32(skb, SMC_NLA_LGR_D_ID, *((u32 *)&lgr->id)))
 557		goto errattr;
 558	smcd->ops->get_local_gid(smcd, &smcd_gid);
 559	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_GID,
 560			      smcd_gid.gid, SMC_NLA_LGR_D_PAD))
 561		goto errattr;
 562	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_EXT_GID,
 563			      smcd_gid.gid_ext, SMC_NLA_LGR_D_PAD))
 564		goto errattr;
 565	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_GID, lgr->peer_gid.gid,
 566			      SMC_NLA_LGR_D_PAD))
 567		goto errattr;
 568	if (nla_put_u64_64bit(skb, SMC_NLA_LGR_D_PEER_EXT_GID,
 569			      lgr->peer_gid.gid_ext, SMC_NLA_LGR_D_PAD))
 570		goto errattr;
 571	if (nla_put_u8(skb, SMC_NLA_LGR_D_VLAN_ID, lgr->vlan_id))
 572		goto errattr;
 573	if (nla_put_u32(skb, SMC_NLA_LGR_D_CONNS_NUM, lgr->conns_num))
 574		goto errattr;
 575	if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd)))
 576		goto errattr;
 577	if (nla_put_uint(skb, SMC_NLA_LGR_D_SNDBUF_ALLOC, lgr->alloc_sndbufs))
 578		goto errattr;
 579	if (nla_put_uint(skb, SMC_NLA_LGR_D_DMB_ALLOC, lgr->alloc_rmbs))
 580		goto errattr;
 581	memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN);
 582	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 583	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
 584		goto errattr;
 585	if (lgr->smc_version > SMC_V1) {
 586		struct nlattr *v2_attrs;
 587
 588		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
 589		if (!v2_attrs)
 590			goto errattr;
 591		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
 592			goto errattr;
 593	}
 594	nla_nest_end(skb, attrs);
 595	genlmsg_end(skb, nlh);
 596	return 0;
 597
 598errattr:
 599	nla_nest_cancel(skb, attrs);
 600errout:
 601	genlmsg_cancel(skb, nlh);
 602errmsg:
 603	return -EMSGSIZE;
 604}
 605
 606static int smc_nl_handle_smcd_lgr(struct smcd_dev *dev,
 607				  struct sk_buff *skb,
 608				  struct netlink_callback *cb)
 609{
 610	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 611	struct smc_link_group *lgr;
 612	int snum = cb_ctx->pos[1];
 613	int rc = 0, num = 0;
 614
 615	spin_lock_bh(&dev->lgr_lock);
 616	list_for_each_entry(lgr, &dev->lgr_list, list) {
 617		if (!lgr->is_smcd)
 618			continue;
 619		if (num < snum)
 620			goto next;
 621		rc = smc_nl_fill_smcd_lgr(lgr, skb, cb);
 622		if (rc)
 623			goto errout;
 624next:
 625		num++;
 626	}
 627errout:
 628	spin_unlock_bh(&dev->lgr_lock);
 629	cb_ctx->pos[1] = num;
 630	return rc;
 631}
 632
 633static int smc_nl_fill_smcd_dev(struct smcd_dev_list *dev_list,
 634				struct sk_buff *skb,
 635				struct netlink_callback *cb)
 636{
 637	struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
 638	struct smcd_dev *smcd_dev;
 639	int snum = cb_ctx->pos[0];
 640	int rc = 0, num = 0;
 641
 642	mutex_lock(&dev_list->mutex);
 643	list_for_each_entry(smcd_dev, &dev_list->list, list) {
 644		if (list_empty(&smcd_dev->lgr_list))
 645			continue;
 646		if (num < snum)
 647			goto next;
 648		rc = smc_nl_handle_smcd_lgr(smcd_dev, skb, cb);
 649		if (rc)
 650			goto errout;
 651next:
 652		num++;
 653	}
 654errout:
 655	mutex_unlock(&dev_list->mutex);
 656	cb_ctx->pos[0] = num;
 657	return rc;
 658}
 659
 660int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
 661{
 662	bool list_links = false;
 663
 664	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
 665	return skb->len;
 666}
 667
 668int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
 669{
 670	bool list_links = true;
 671
 672	smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
 673	return skb->len;
 674}
 675
 676int smcd_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
 677{
 678	smc_nl_fill_smcd_dev(&smcd_dev_list, skb, cb);
 679	return skb->len;
 680}
 681
 682void smc_lgr_cleanup_early(struct smc_link_group *lgr)
 683{
 684	spinlock_t *lgr_lock;
 685
 686	if (!lgr)
 687		return;
 688
 689	smc_lgr_list_head(lgr, &lgr_lock);
 690	spin_lock_bh(lgr_lock);
 691	/* do not use this link group for new connections */
 692	if (!list_empty(&lgr->list))
 693		list_del_init(&lgr->list);
 694	spin_unlock_bh(lgr_lock);
 695	__smc_lgr_terminate(lgr, true);
 696}
 697
 698static void smcr_lgr_link_deactivate_all(struct smc_link_group *lgr)
 699{
 700	int i;
 701
 702	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 703		struct smc_link *lnk = &lgr->lnk[i];
 704
 705		if (smc_link_sendable(lnk))
 706			lnk->state = SMC_LNK_INACTIVE;
 707	}
 708	wake_up_all(&lgr->llc_msg_waiter);
 709	wake_up_all(&lgr->llc_flow_waiter);
 710}
 711
 712static void smc_lgr_free(struct smc_link_group *lgr);
 713
 714static void smc_lgr_free_work(struct work_struct *work)
 715{
 716	struct smc_link_group *lgr = container_of(to_delayed_work(work),
 717						  struct smc_link_group,
 718						  free_work);
 719	spinlock_t *lgr_lock;
 720	bool conns;
 721
 722	smc_lgr_list_head(lgr, &lgr_lock);
 723	spin_lock_bh(lgr_lock);
 724	if (lgr->freeing) {
 725		spin_unlock_bh(lgr_lock);
 726		return;
 727	}
 728	read_lock_bh(&lgr->conns_lock);
 729	conns = RB_EMPTY_ROOT(&lgr->conns_all);
 730	read_unlock_bh(&lgr->conns_lock);
 731	if (!conns) { /* number of lgr connections is no longer zero */
 732		spin_unlock_bh(lgr_lock);
 733		return;
 734	}
 735	list_del_init(&lgr->list); /* remove from smc_lgr_list */
 736	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
 737	spin_unlock_bh(lgr_lock);
 738	cancel_delayed_work(&lgr->free_work);
 739
 740	if (!lgr->is_smcd && !lgr->terminating)
 741		smc_llc_send_link_delete_all(lgr, true,
 742					     SMC_LLC_DEL_PROG_INIT_TERM);
 743	if (lgr->is_smcd && !lgr->terminating)
 744		smc_ism_signal_shutdown(lgr);
 745	if (!lgr->is_smcd)
 746		smcr_lgr_link_deactivate_all(lgr);
 747	smc_lgr_free(lgr);
 748}
 749
 750static void smc_lgr_terminate_work(struct work_struct *work)
 751{
 752	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
 753						  terminate_work);
 754
 755	__smc_lgr_terminate(lgr, true);
 756}
 757
 758/* return next unique link id for the lgr */
 759static u8 smcr_next_link_id(struct smc_link_group *lgr)
 760{
 761	u8 link_id;
 762	int i;
 763
 764	while (1) {
 765again:
 766		link_id = ++lgr->next_link_id;
 767		if (!link_id)	/* skip zero as link_id */
 768			link_id = ++lgr->next_link_id;
 769		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 770			if (smc_link_usable(&lgr->lnk[i]) &&
 771			    lgr->lnk[i].link_id == link_id)
 772				goto again;
 773		}
 774		break;
 775	}
 776	return link_id;
 777}
 778
 779static void smcr_copy_dev_info_to_link(struct smc_link *link)
 780{
 781	struct smc_ib_device *smcibdev = link->smcibdev;
 782
 783	snprintf(link->ibname, sizeof(link->ibname), "%s",
 784		 smcibdev->ibdev->name);
 785	link->ndev_ifidx = smcibdev->ndev_ifidx[link->ibport - 1];
 786}
 787
 788int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
 789		   u8 link_idx, struct smc_init_info *ini)
 790{
 791	struct smc_ib_device *smcibdev;
 792	u8 rndvec[3];
 793	int rc;
 794
 795	if (lgr->smc_version == SMC_V2) {
 796		lnk->smcibdev = ini->smcrv2.ib_dev_v2;
 797		lnk->ibport = ini->smcrv2.ib_port_v2;
 798	} else {
 799		lnk->smcibdev = ini->ib_dev;
 800		lnk->ibport = ini->ib_port;
 801	}
 802	get_device(&lnk->smcibdev->ibdev->dev);
 803	atomic_inc(&lnk->smcibdev->lnk_cnt);
 804	refcount_set(&lnk->refcnt, 1); /* link refcnt is set to 1 */
 805	lnk->clearing = 0;
 806	lnk->path_mtu = lnk->smcibdev->pattr[lnk->ibport - 1].active_mtu;
 807	lnk->link_id = smcr_next_link_id(lgr);
 808	lnk->lgr = lgr;
 809	smc_lgr_hold(lgr); /* lgr_put in smcr_link_clear() */
 810	lnk->link_idx = link_idx;
 811	lnk->wr_rx_id_compl = 0;
 812	smc_ibdev_cnt_inc(lnk);
 813	smcr_copy_dev_info_to_link(lnk);
 814	atomic_set(&lnk->conn_cnt, 0);
 815	smc_llc_link_set_uid(lnk);
 816	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
 817	if (!lnk->smcibdev->initialized) {
 818		rc = (int)smc_ib_setup_per_ibdev(lnk->smcibdev);
 819		if (rc)
 820			goto out;
 821	}
 822	get_random_bytes(rndvec, sizeof(rndvec));
 823	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
 824		(rndvec[2] << 16);
 825	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
 826				  ini->vlan_id, lnk->gid, &lnk->sgid_index,
 827				  lgr->smc_version == SMC_V2 ?
 828						  &ini->smcrv2 : NULL);
 829	if (rc)
 830		goto out;
 831	rc = smc_llc_link_init(lnk);
 832	if (rc)
 833		goto out;
 834	rc = smc_wr_alloc_link_mem(lnk);
 835	if (rc)
 836		goto clear_llc_lnk;
 837	rc = smc_ib_create_protection_domain(lnk);
 838	if (rc)
 839		goto free_link_mem;
 840	rc = smc_ib_create_queue_pair(lnk);
 841	if (rc)
 842		goto dealloc_pd;
 843	rc = smc_wr_create_link(lnk);
 844	if (rc)
 845		goto destroy_qp;
 846	lnk->state = SMC_LNK_ACTIVATING;
 847	return 0;
 848
 849destroy_qp:
 850	smc_ib_destroy_queue_pair(lnk);
 851dealloc_pd:
 852	smc_ib_dealloc_protection_domain(lnk);
 853free_link_mem:
 854	smc_wr_free_link_mem(lnk);
 855clear_llc_lnk:
 856	smc_llc_link_clear(lnk, false);
 857out:
 858	smc_ibdev_cnt_dec(lnk);
 859	put_device(&lnk->smcibdev->ibdev->dev);
 860	smcibdev = lnk->smcibdev;
 861	memset(lnk, 0, sizeof(struct smc_link));
 862	lnk->state = SMC_LNK_UNUSED;
 863	if (!atomic_dec_return(&smcibdev->lnk_cnt))
 864		wake_up(&smcibdev->lnks_deleted);
 865	smc_lgr_put(lgr); /* lgr_hold above */
 866	return rc;
 867}
 868
 869/* create a new SMC link group */
 870static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
 871{
 872	struct smc_link_group *lgr;
 873	struct list_head *lgr_list;
 874	struct smcd_dev *smcd;
 875	struct smc_link *lnk;
 876	spinlock_t *lgr_lock;
 877	u8 link_idx;
 878	int rc = 0;
 879	int i;
 880
 881	if (ini->is_smcd && ini->vlan_id) {
 882		if (smc_ism_get_vlan(ini->ism_dev[ini->ism_selected],
 883				     ini->vlan_id)) {
 884			rc = SMC_CLC_DECL_ISMVLANERR;
 885			goto out;
 886		}
 887	}
 888
 889	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
 890	if (!lgr) {
 891		rc = SMC_CLC_DECL_MEM;
 892		goto ism_put_vlan;
 893	}
 894	lgr->tx_wq = alloc_workqueue("smc_tx_wq-%*phN", 0, 0,
 895				     SMC_LGR_ID_SIZE, &lgr->id);
 896	if (!lgr->tx_wq) {
 897		rc = -ENOMEM;
 898		goto free_lgr;
 899	}
 900	lgr->is_smcd = ini->is_smcd;
 901	lgr->sync_err = 0;
 902	lgr->terminating = 0;
 903	lgr->freeing = 0;
 904	lgr->vlan_id = ini->vlan_id;
 905	refcount_set(&lgr->refcnt, 1); /* set lgr refcnt to 1 */
 906	init_rwsem(&lgr->sndbufs_lock);
 907	init_rwsem(&lgr->rmbs_lock);
 908	rwlock_init(&lgr->conns_lock);
 909	for (i = 0; i < SMC_RMBE_SIZES; i++) {
 910		INIT_LIST_HEAD(&lgr->sndbufs[i]);
 911		INIT_LIST_HEAD(&lgr->rmbs[i]);
 912	}
 913	lgr->next_link_id = 0;
 914	smc_lgr_list.num += SMC_LGR_NUM_INCR;
 915	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
 916	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
 917	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
 918	lgr->conns_all = RB_ROOT;
 919	if (ini->is_smcd) {
 920		/* SMC-D specific settings */
 921		smcd = ini->ism_dev[ini->ism_selected];
 922		get_device(smcd->ops->get_dev(smcd));
 923		lgr->peer_gid.gid =
 924			ini->ism_peer_gid[ini->ism_selected].gid;
 925		lgr->peer_gid.gid_ext =
 926			ini->ism_peer_gid[ini->ism_selected].gid_ext;
 927		lgr->smcd = ini->ism_dev[ini->ism_selected];
 928		lgr_list = &ini->ism_dev[ini->ism_selected]->lgr_list;
 929		lgr_lock = &lgr->smcd->lgr_lock;
 930		lgr->smc_version = ini->smcd_version;
 931		lgr->peer_shutdown = 0;
 932		atomic_inc(&ini->ism_dev[ini->ism_selected]->lgr_cnt);
 933	} else {
 934		/* SMC-R specific settings */
 935		struct smc_ib_device *ibdev;
 936		int ibport;
 937
 938		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
 939		lgr->smc_version = ini->smcr_version;
 940		memcpy(lgr->peer_systemid, ini->peer_systemid,
 941		       SMC_SYSTEMID_LEN);
 942		if (lgr->smc_version == SMC_V2) {
 943			ibdev = ini->smcrv2.ib_dev_v2;
 944			ibport = ini->smcrv2.ib_port_v2;
 945			lgr->saddr = ini->smcrv2.saddr;
 946			lgr->uses_gateway = ini->smcrv2.uses_gateway;
 947			memcpy(lgr->nexthop_mac, ini->smcrv2.nexthop_mac,
 948			       ETH_ALEN);
 949			lgr->max_conns = ini->max_conns;
 950			lgr->max_links = ini->max_links;
 951		} else {
 952			ibdev = ini->ib_dev;
 953			ibport = ini->ib_port;
 954			lgr->max_conns = SMC_CONN_PER_LGR_MAX;
 955			lgr->max_links = SMC_LINKS_ADD_LNK_MAX;
 956		}
 957		memcpy(lgr->pnet_id, ibdev->pnetid[ibport - 1],
 958		       SMC_MAX_PNETID_LEN);
 959		rc = smc_wr_alloc_lgr_mem(lgr);
 960		if (rc)
 961			goto free_wq;
 962		smc_llc_lgr_init(lgr, smc);
 963
 964		link_idx = SMC_SINGLE_LINK;
 965		lnk = &lgr->lnk[link_idx];
 966		rc = smcr_link_init(lgr, lnk, link_idx, ini);
 967		if (rc) {
 968			smc_wr_free_lgr_mem(lgr);
 969			goto free_wq;
 970		}
 971		lgr->net = smc_ib_net(lnk->smcibdev);
 972		lgr_list = &smc_lgr_list.list;
 973		lgr_lock = &smc_lgr_list.lock;
 974		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
 975		atomic_inc(&lgr_cnt);
 976	}
 977	smc->conn.lgr = lgr;
 978	spin_lock_bh(lgr_lock);
 979	list_add_tail(&lgr->list, lgr_list);
 980	spin_unlock_bh(lgr_lock);
 981	return 0;
 982
 983free_wq:
 984	destroy_workqueue(lgr->tx_wq);
 985free_lgr:
 986	kfree(lgr);
 987ism_put_vlan:
 988	if (ini->is_smcd && ini->vlan_id)
 989		smc_ism_put_vlan(ini->ism_dev[ini->ism_selected], ini->vlan_id);
 990out:
 991	if (rc < 0) {
 992		if (rc == -ENOMEM)
 993			rc = SMC_CLC_DECL_MEM;
 994		else
 995			rc = SMC_CLC_DECL_INTERR;
 996	}
 997	return rc;
 998}
 999
1000static int smc_write_space(struct smc_connection *conn)
1001{
1002	int buffer_len = conn->peer_rmbe_size;
1003	union smc_host_cursor prod;
1004	union smc_host_cursor cons;
1005	int space;
1006
1007	smc_curs_copy(&prod, &conn->local_tx_ctrl.prod, conn);
1008	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1009	/* determine rx_buf space */
1010	space = buffer_len - smc_curs_diff(buffer_len, &cons, &prod);
1011	return space;
1012}
1013
1014static int smc_switch_cursor(struct smc_sock *smc, struct smc_cdc_tx_pend *pend,
1015			     struct smc_wr_buf *wr_buf)
1016{
1017	struct smc_connection *conn = &smc->conn;
1018	union smc_host_cursor cons, fin;
1019	int rc = 0;
1020	int diff;
1021
1022	smc_curs_copy(&conn->tx_curs_sent, &conn->tx_curs_fin, conn);
1023	smc_curs_copy(&fin, &conn->local_tx_ctrl_fin, conn);
1024	/* set prod cursor to old state, enforce tx_rdma_writes() */
1025	smc_curs_copy(&conn->local_tx_ctrl.prod, &fin, conn);
1026	smc_curs_copy(&cons, &conn->local_rx_ctrl.cons, conn);
1027
1028	if (smc_curs_comp(conn->peer_rmbe_size, &cons, &fin) < 0) {
1029		/* cons cursor advanced more than fin, and prod was set
1030		 * fin above, so now prod is smaller than cons. Fix that.
1031		 */
1032		diff = smc_curs_diff(conn->peer_rmbe_size, &fin, &cons);
1033		smc_curs_add(conn->sndbuf_desc->len,
1034			     &conn->tx_curs_sent, diff);
1035		smc_curs_add(conn->sndbuf_desc->len,
1036			     &conn->tx_curs_fin, diff);
1037
1038		smp_mb__before_atomic();
1039		atomic_add(diff, &conn->sndbuf_space);
1040		smp_mb__after_atomic();
1041
1042		smc_curs_add(conn->peer_rmbe_size,
1043			     &conn->local_tx_ctrl.prod, diff);
1044		smc_curs_add(conn->peer_rmbe_size,
1045			     &conn->local_tx_ctrl_fin, diff);
1046	}
1047	/* recalculate, value is used by tx_rdma_writes() */
1048	atomic_set(&smc->conn.peer_rmbe_space, smc_write_space(conn));
1049
1050	if (smc->sk.sk_state != SMC_INIT &&
1051	    smc->sk.sk_state != SMC_CLOSED) {
1052		rc = smcr_cdc_msg_send_validation(conn, pend, wr_buf);
1053		if (!rc) {
1054			queue_delayed_work(conn->lgr->tx_wq, &conn->tx_work, 0);
1055			smc->sk.sk_data_ready(&smc->sk);
1056		}
1057	} else {
1058		smc_wr_tx_put_slot(conn->lnk,
1059				   (struct smc_wr_tx_pend_priv *)pend);
1060	}
1061	return rc;
1062}
1063
1064void smc_switch_link_and_count(struct smc_connection *conn,
1065			       struct smc_link *to_lnk)
1066{
1067	atomic_dec(&conn->lnk->conn_cnt);
1068	/* link_hold in smc_conn_create() */
1069	smcr_link_put(conn->lnk);
1070	conn->lnk = to_lnk;
1071	atomic_inc(&conn->lnk->conn_cnt);
1072	/* link_put in smc_conn_free() */
1073	smcr_link_hold(conn->lnk);
1074}
1075
1076struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
1077				  struct smc_link *from_lnk, bool is_dev_err)
1078{
1079	struct smc_link *to_lnk = NULL;
1080	struct smc_cdc_tx_pend *pend;
1081	struct smc_connection *conn;
1082	struct smc_wr_buf *wr_buf;
1083	struct smc_sock *smc;
1084	struct rb_node *node;
1085	int i, rc = 0;
1086
1087	/* link is inactive, wake up tx waiters */
1088	smc_wr_wakeup_tx_wait(from_lnk);
1089
1090	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1091		if (!smc_link_active(&lgr->lnk[i]) || i == from_lnk->link_idx)
1092			continue;
1093		if (is_dev_err && from_lnk->smcibdev == lgr->lnk[i].smcibdev &&
1094		    from_lnk->ibport == lgr->lnk[i].ibport) {
1095			continue;
1096		}
1097		to_lnk = &lgr->lnk[i];
1098		break;
1099	}
1100	if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) {
1101		smc_lgr_terminate_sched(lgr);
1102		return NULL;
1103	}
1104again:
1105	read_lock_bh(&lgr->conns_lock);
1106	for (node = rb_first(&lgr->conns_all); node; node = rb_next(node)) {
1107		conn = rb_entry(node, struct smc_connection, alert_node);
1108		if (conn->lnk != from_lnk)
1109			continue;
1110		smc = container_of(conn, struct smc_sock, conn);
1111		/* conn->lnk not yet set in SMC_INIT state */
1112		if (smc->sk.sk_state == SMC_INIT)
1113			continue;
1114		if (smc->sk.sk_state == SMC_CLOSED ||
1115		    smc->sk.sk_state == SMC_PEERCLOSEWAIT1 ||
1116		    smc->sk.sk_state == SMC_PEERCLOSEWAIT2 ||
1117		    smc->sk.sk_state == SMC_APPFINCLOSEWAIT ||
1118		    smc->sk.sk_state == SMC_APPCLOSEWAIT1 ||
1119		    smc->sk.sk_state == SMC_APPCLOSEWAIT2 ||
1120		    smc->sk.sk_state == SMC_PEERFINCLOSEWAIT ||
1121		    smc->sk.sk_state == SMC_PEERABORTWAIT ||
1122		    smc->sk.sk_state == SMC_PROCESSABORT) {
1123			spin_lock_bh(&conn->send_lock);
1124			smc_switch_link_and_count(conn, to_lnk);
1125			spin_unlock_bh(&conn->send_lock);
1126			continue;
1127		}
1128		sock_hold(&smc->sk);
1129		read_unlock_bh(&lgr->conns_lock);
1130		/* pre-fetch buffer outside of send_lock, might sleep */
1131		rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
1132		if (rc)
1133			goto err_out;
1134		/* avoid race with smcr_tx_sndbuf_nonempty() */
1135		spin_lock_bh(&conn->send_lock);
1136		smc_switch_link_and_count(conn, to_lnk);
1137		rc = smc_switch_cursor(smc, pend, wr_buf);
1138		spin_unlock_bh(&conn->send_lock);
1139		sock_put(&smc->sk);
1140		if (rc)
1141			goto err_out;
1142		goto again;
1143	}
1144	read_unlock_bh(&lgr->conns_lock);
1145	smc_wr_tx_link_put(to_lnk);
1146	return to_lnk;
1147
1148err_out:
1149	smcr_link_down_cond_sched(to_lnk);
1150	smc_wr_tx_link_put(to_lnk);
1151	return NULL;
1152}
1153
1154static void smcr_buf_unuse(struct smc_buf_desc *buf_desc, bool is_rmb,
1155			   struct smc_link_group *lgr)
1156{
1157	struct rw_semaphore *lock;	/* lock buffer list */
1158	int rc;
1159
1160	if (is_rmb && buf_desc->is_conf_rkey && !list_empty(&lgr->list)) {
1161		/* unregister rmb with peer */
1162		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
1163		if (!rc) {
1164			/* protect against smc_llc_cli_rkey_exchange() */
1165			down_read(&lgr->llc_conf_mutex);
1166			smc_llc_do_delete_rkey(lgr, buf_desc);
1167			buf_desc->is_conf_rkey = false;
1168			up_read(&lgr->llc_conf_mutex);
1169			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1170		}
1171	}
1172
1173	if (buf_desc->is_reg_err) {
1174		/* buf registration failed, reuse not possible */
1175		lock = is_rmb ? &lgr->rmbs_lock :
1176				&lgr->sndbufs_lock;
1177		down_write(lock);
1178		smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1179		up_write(lock);
1180
1181		smc_buf_free(lgr, is_rmb, buf_desc);
1182	} else {
1183		/* memzero_explicit provides potential memory barrier semantics */
1184		memzero_explicit(buf_desc->cpu_addr, buf_desc->len);
1185		WRITE_ONCE(buf_desc->used, 0);
1186	}
1187}
1188
1189static void smcd_buf_detach(struct smc_connection *conn)
1190{
1191	struct smcd_dev *smcd = conn->lgr->smcd;
1192	u64 peer_token = conn->peer_token;
1193
1194	if (!conn->sndbuf_desc)
1195		return;
1196
1197	smc_ism_detach_dmb(smcd, peer_token);
1198
1199	kfree(conn->sndbuf_desc);
1200	conn->sndbuf_desc = NULL;
1201}
1202
1203static void smc_buf_unuse(struct smc_connection *conn,
1204			  struct smc_link_group *lgr)
1205{
1206	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1207	bool is_smcd = lgr->is_smcd;
1208	int bufsize;
1209
1210	if (conn->sndbuf_desc) {
1211		bufsize = conn->sndbuf_desc->len;
1212		if (!is_smcd && conn->sndbuf_desc->is_vm) {
1213			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
1214		} else {
1215			memzero_explicit(conn->sndbuf_desc->cpu_addr, bufsize);
1216			WRITE_ONCE(conn->sndbuf_desc->used, 0);
1217		}
1218		SMC_STAT_RMB_SIZE(smc, is_smcd, false, false, bufsize);
1219	}
1220	if (conn->rmb_desc) {
1221		bufsize = conn->rmb_desc->len;
1222		if (!is_smcd) {
1223			smcr_buf_unuse(conn->rmb_desc, true, lgr);
1224		} else {
1225			bufsize += sizeof(struct smcd_cdc_msg);
1226			memzero_explicit(conn->rmb_desc->cpu_addr, bufsize);
1227			WRITE_ONCE(conn->rmb_desc->used, 0);
1228		}
1229		SMC_STAT_RMB_SIZE(smc, is_smcd, true, false, bufsize);
1230	}
1231}
1232
1233/* remove a finished connection from its link group */
1234void smc_conn_free(struct smc_connection *conn)
1235{
1236	struct smc_link_group *lgr = conn->lgr;
1237
1238	if (!lgr || conn->freed)
1239		/* Connection has never been registered in a
1240		 * link group, or has already been freed.
1241		 */
1242		return;
1243
1244	conn->freed = 1;
1245	if (!smc_conn_lgr_valid(conn))
1246		/* Connection has already unregistered from
1247		 * link group.
1248		 */
1249		goto lgr_put;
1250
1251	if (lgr->is_smcd) {
1252		if (!list_empty(&lgr->list))
1253			smc_ism_unset_conn(conn);
1254		if (smc_ism_support_dmb_nocopy(lgr->smcd))
1255			smcd_buf_detach(conn);
1256		tasklet_kill(&conn->rx_tsklet);
1257	} else {
1258		smc_cdc_wait_pend_tx_wr(conn);
1259		if (current_work() != &conn->abort_work)
1260			cancel_work_sync(&conn->abort_work);
1261	}
1262	if (!list_empty(&lgr->list)) {
1263		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
1264		smc_lgr_unregister_conn(conn);
1265	}
1266
1267	if (!lgr->conns_num)
1268		smc_lgr_schedule_free_work(lgr);
1269lgr_put:
1270	if (!lgr->is_smcd)
1271		smcr_link_put(conn->lnk); /* link_hold in smc_conn_create() */
1272	smc_lgr_put(lgr); /* lgr_hold in smc_conn_create() */
1273}
1274
1275/* unregister a link from a buf_desc */
1276static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
1277				struct smc_link *lnk)
1278{
1279	if (is_rmb || buf_desc->is_vm)
1280		buf_desc->is_reg_mr[lnk->link_idx] = false;
1281	if (!buf_desc->is_map_ib[lnk->link_idx])
1282		return;
1283
1284	if ((is_rmb || buf_desc->is_vm) &&
1285	    buf_desc->mr[lnk->link_idx]) {
1286		smc_ib_put_memory_region(buf_desc->mr[lnk->link_idx]);
1287		buf_desc->mr[lnk->link_idx] = NULL;
1288	}
1289	if (is_rmb)
1290		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
1291	else
1292		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
1293
1294	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
1295	buf_desc->is_map_ib[lnk->link_idx] = false;
1296}
1297
1298/* unmap all buffers of lgr for a deleted link */
1299static void smcr_buf_unmap_lgr(struct smc_link *lnk)
1300{
1301	struct smc_link_group *lgr = lnk->lgr;
1302	struct smc_buf_desc *buf_desc, *bf;
1303	int i;
1304
1305	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1306		down_write(&lgr->rmbs_lock);
1307		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
1308			smcr_buf_unmap_link(buf_desc, true, lnk);
1309		up_write(&lgr->rmbs_lock);
1310
1311		down_write(&lgr->sndbufs_lock);
1312		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
1313					 list)
1314			smcr_buf_unmap_link(buf_desc, false, lnk);
1315		up_write(&lgr->sndbufs_lock);
1316	}
1317}
1318
1319static void smcr_rtoken_clear_link(struct smc_link *lnk)
1320{
1321	struct smc_link_group *lgr = lnk->lgr;
1322	int i;
1323
1324	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
1325		lgr->rtokens[i][lnk->link_idx].rkey = 0;
1326		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
1327	}
1328}
1329
1330static void __smcr_link_clear(struct smc_link *lnk)
1331{
1332	struct smc_link_group *lgr = lnk->lgr;
1333	struct smc_ib_device *smcibdev;
1334
1335	smc_wr_free_link_mem(lnk);
1336	smc_ibdev_cnt_dec(lnk);
1337	put_device(&lnk->smcibdev->ibdev->dev);
1338	smcibdev = lnk->smcibdev;
1339	memset(lnk, 0, sizeof(struct smc_link));
1340	lnk->state = SMC_LNK_UNUSED;
1341	if (!atomic_dec_return(&smcibdev->lnk_cnt))
1342		wake_up(&smcibdev->lnks_deleted);
1343	smc_lgr_put(lgr); /* lgr_hold in smcr_link_init() */
1344}
1345
1346/* must be called under lgr->llc_conf_mutex lock */
1347void smcr_link_clear(struct smc_link *lnk, bool log)
1348{
1349	if (!lnk->lgr || lnk->clearing ||
1350	    lnk->state == SMC_LNK_UNUSED)
1351		return;
1352	lnk->clearing = 1;
1353	lnk->peer_qpn = 0;
1354	smc_llc_link_clear(lnk, log);
1355	smcr_buf_unmap_lgr(lnk);
1356	smcr_rtoken_clear_link(lnk);
1357	smc_ib_modify_qp_error(lnk);
1358	smc_wr_free_link(lnk);
1359	smc_ib_destroy_queue_pair(lnk);
1360	smc_ib_dealloc_protection_domain(lnk);
1361	smcr_link_put(lnk); /* theoretically last link_put */
1362}
1363
1364void smcr_link_hold(struct smc_link *lnk)
1365{
1366	refcount_inc(&lnk->refcnt);
1367}
1368
1369void smcr_link_put(struct smc_link *lnk)
1370{
1371	if (refcount_dec_and_test(&lnk->refcnt))
1372		__smcr_link_clear(lnk);
1373}
1374
1375static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
1376			  struct smc_buf_desc *buf_desc)
1377{
1378	int i;
1379
1380	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1381		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);
1382
1383	if (!buf_desc->is_vm && buf_desc->pages)
1384		__free_pages(buf_desc->pages, buf_desc->order);
1385	else if (buf_desc->is_vm && buf_desc->cpu_addr)
1386		vfree(buf_desc->cpu_addr);
1387	kfree(buf_desc);
1388}
1389
1390static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
1391			  struct smc_buf_desc *buf_desc)
1392{
1393	if (is_dmb) {
1394		/* restore original buf len */
1395		buf_desc->len += sizeof(struct smcd_cdc_msg);
1396		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
1397	} else {
1398		kfree(buf_desc->cpu_addr);
1399	}
1400	kfree(buf_desc);
1401}
1402
1403static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
1404			 struct smc_buf_desc *buf_desc)
1405{
1406	if (lgr->is_smcd)
1407		smcd_buf_free(lgr, is_rmb, buf_desc);
1408	else
1409		smcr_buf_free(lgr, is_rmb, buf_desc);
1410}
1411
1412static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
1413{
1414	struct smc_buf_desc *buf_desc, *bf_desc;
1415	struct list_head *buf_list;
1416	int i;
1417
1418	for (i = 0; i < SMC_RMBE_SIZES; i++) {
1419		if (is_rmb)
1420			buf_list = &lgr->rmbs[i];
1421		else
1422			buf_list = &lgr->sndbufs[i];
1423		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
1424					 list) {
1425			smc_lgr_buf_list_del(lgr, is_rmb, buf_desc);
1426			smc_buf_free(lgr, is_rmb, buf_desc);
1427		}
1428	}
1429}
1430
1431static void smc_lgr_free_bufs(struct smc_link_group *lgr)
1432{
1433	/* free send buffers */
1434	__smc_lgr_free_bufs(lgr, false);
1435	/* free rmbs */
1436	__smc_lgr_free_bufs(lgr, true);
1437}
1438
1439/* won't be freed until no one accesses to lgr anymore */
1440static void __smc_lgr_free(struct smc_link_group *lgr)
1441{
1442	smc_lgr_free_bufs(lgr);
1443	if (lgr->is_smcd) {
1444		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
1445			wake_up(&lgr->smcd->lgrs_deleted);
1446	} else {
1447		smc_wr_free_lgr_mem(lgr);
1448		if (!atomic_dec_return(&lgr_cnt))
1449			wake_up(&lgrs_deleted);
1450	}
1451	kfree(lgr);
1452}
1453
1454/* remove a link group */
1455static void smc_lgr_free(struct smc_link_group *lgr)
1456{
1457	int i;
1458
1459	if (!lgr->is_smcd) {
1460		down_write(&lgr->llc_conf_mutex);
1461		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1462			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
1463				smcr_link_clear(&lgr->lnk[i], false);
1464		}
1465		up_write(&lgr->llc_conf_mutex);
1466		smc_llc_lgr_clear(lgr);
1467	}
1468
1469	destroy_workqueue(lgr->tx_wq);
1470	if (lgr->is_smcd) {
1471		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
1472		put_device(lgr->smcd->ops->get_dev(lgr->smcd));
1473	}
1474	smc_lgr_put(lgr); /* theoretically last lgr_put */
1475}
1476
1477void smc_lgr_hold(struct smc_link_group *lgr)
1478{
1479	refcount_inc(&lgr->refcnt);
1480}
1481
1482void smc_lgr_put(struct smc_link_group *lgr)
1483{
1484	if (refcount_dec_and_test(&lgr->refcnt))
1485		__smc_lgr_free(lgr);
1486}
1487
1488static void smc_sk_wake_ups(struct smc_sock *smc)
1489{
1490	smc->sk.sk_write_space(&smc->sk);
1491	smc->sk.sk_data_ready(&smc->sk);
1492	smc->sk.sk_state_change(&smc->sk);
1493}
1494
1495/* kill a connection */
1496static void smc_conn_kill(struct smc_connection *conn, bool soft)
1497{
1498	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1499
1500	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
1501		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
1502	else
1503		smc_close_abort(conn);
1504	conn->killed = 1;
1505	smc->sk.sk_err = ECONNABORTED;
1506	smc_sk_wake_ups(smc);
1507	if (conn->lgr->is_smcd) {
1508		smc_ism_unset_conn(conn);
1509		if (smc_ism_support_dmb_nocopy(conn->lgr->smcd))
1510			smcd_buf_detach(conn);
1511		if (soft)
1512			tasklet_kill(&conn->rx_tsklet);
1513		else
1514			tasklet_unlock_wait(&conn->rx_tsklet);
1515	} else {
1516		smc_cdc_wait_pend_tx_wr(conn);
1517	}
1518	smc_lgr_unregister_conn(conn);
1519	smc_close_active_abort(smc);
1520}
1521
1522static void smc_lgr_cleanup(struct smc_link_group *lgr)
1523{
1524	if (lgr->is_smcd) {
1525		smc_ism_signal_shutdown(lgr);
1526	} else {
1527		u32 rsn = lgr->llc_termination_rsn;
1528
1529		if (!rsn)
1530			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
1531		smc_llc_send_link_delete_all(lgr, false, rsn);
1532		smcr_lgr_link_deactivate_all(lgr);
1533	}
1534}
1535
1536/* terminate link group
1537 * @soft: true if link group shutdown can take its time
1538 *	  false if immediate link group shutdown is required
1539 */
1540static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
1541{
1542	struct smc_connection *conn;
1543	struct smc_sock *smc;
1544	struct rb_node *node;
1545
1546	if (lgr->terminating)
1547		return;	/* lgr already terminating */
1548	/* cancel free_work sync, will terminate when lgr->freeing is set */
1549	cancel_delayed_work(&lgr->free_work);
1550	lgr->terminating = 1;
1551
1552	/* kill remaining link group connections */
1553	read_lock_bh(&lgr->conns_lock);
1554	node = rb_first(&lgr->conns_all);
1555	while (node) {
1556		read_unlock_bh(&lgr->conns_lock);
1557		conn = rb_entry(node, struct smc_connection, alert_node);
1558		smc = container_of(conn, struct smc_sock, conn);
1559		sock_hold(&smc->sk); /* sock_put below */
1560		lock_sock(&smc->sk);
1561		smc_conn_kill(conn, soft);
1562		release_sock(&smc->sk);
1563		sock_put(&smc->sk); /* sock_hold above */
1564		read_lock_bh(&lgr->conns_lock);
1565		node = rb_first(&lgr->conns_all);
1566	}
1567	read_unlock_bh(&lgr->conns_lock);
1568	smc_lgr_cleanup(lgr);
1569	smc_lgr_free(lgr);
1570}
1571
1572/* unlink link group and schedule termination */
1573void smc_lgr_terminate_sched(struct smc_link_group *lgr)
1574{
1575	spinlock_t *lgr_lock;
1576
1577	smc_lgr_list_head(lgr, &lgr_lock);
1578	spin_lock_bh(lgr_lock);
1579	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
1580		spin_unlock_bh(lgr_lock);
1581		return;	/* lgr already terminating */
1582	}
1583	list_del_init(&lgr->list);
1584	lgr->freeing = 1;
1585	spin_unlock_bh(lgr_lock);
1586	schedule_work(&lgr->terminate_work);
1587}
1588
1589/* Called when peer lgr shutdown (regularly or abnormally) is received */
1590void smc_smcd_terminate(struct smcd_dev *dev, struct smcd_gid *peer_gid,
1591			unsigned short vlan)
1592{
1593	struct smc_link_group *lgr, *l;
1594	LIST_HEAD(lgr_free_list);
1595
1596	/* run common cleanup function and build free list */
1597	spin_lock_bh(&dev->lgr_lock);
1598	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
1599		if ((!peer_gid->gid ||
1600		     (lgr->peer_gid.gid == peer_gid->gid &&
1601		      !smc_ism_is_emulated(dev) ? 1 :
1602		      lgr->peer_gid.gid_ext == peer_gid->gid_ext)) &&
1603		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
1604			if (peer_gid->gid) /* peer triggered termination */
1605				lgr->peer_shutdown = 1;
1606			list_move(&lgr->list, &lgr_free_list);
1607			lgr->freeing = 1;
1608		}
1609	}
1610	spin_unlock_bh(&dev->lgr_lock);
1611
1612	/* cancel the regular free workers and actually free lgrs */
1613	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
1614		list_del_init(&lgr->list);
1615		schedule_work(&lgr->terminate_work);
1616	}
1617}
1618
1619/* Called when an SMCD device is removed or the smc module is unloaded */
1620void smc_smcd_terminate_all(struct smcd_dev *smcd)
1621{
1622	struct smc_link_group *lgr, *lg;
1623	LIST_HEAD(lgr_free_list);
1624
1625	spin_lock_bh(&smcd->lgr_lock);
1626	list_splice_init(&smcd->lgr_list, &lgr_free_list);
1627	list_for_each_entry(lgr, &lgr_free_list, list)
1628		lgr->freeing = 1;
1629	spin_unlock_bh(&smcd->lgr_lock);
1630
1631	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1632		list_del_init(&lgr->list);
1633		__smc_lgr_terminate(lgr, false);
1634	}
1635
1636	if (atomic_read(&smcd->lgr_cnt))
1637		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
1638}
1639
1640/* Called when an SMCR device is removed or the smc module is unloaded.
1641 * If smcibdev is given, all SMCR link groups using this device are terminated.
1642 * If smcibdev is NULL, all SMCR link groups are terminated.
1643 */
1644void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
1645{
1646	struct smc_link_group *lgr, *lg;
1647	LIST_HEAD(lgr_free_list);
1648	int i;
1649
1650	spin_lock_bh(&smc_lgr_list.lock);
1651	if (!smcibdev) {
1652		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
1653		list_for_each_entry(lgr, &lgr_free_list, list)
1654			lgr->freeing = 1;
1655	} else {
1656		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
1657			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1658				if (lgr->lnk[i].smcibdev == smcibdev)
1659					smcr_link_down_cond_sched(&lgr->lnk[i]);
1660			}
1661		}
1662	}
1663	spin_unlock_bh(&smc_lgr_list.lock);
1664
1665	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
1666		list_del_init(&lgr->list);
1667		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
1668		__smc_lgr_terminate(lgr, false);
1669	}
1670
1671	if (smcibdev) {
1672		if (atomic_read(&smcibdev->lnk_cnt))
1673			wait_event(smcibdev->lnks_deleted,
1674				   !atomic_read(&smcibdev->lnk_cnt));
1675	} else {
1676		if (atomic_read(&lgr_cnt))
1677			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
1678	}
1679}
1680
1681/* set new lgr type and clear all asymmetric link tagging */
1682void smcr_lgr_set_type(struct smc_link_group *lgr, enum smc_lgr_type new_type)
1683{
1684	char *lgr_type = "";
1685	int i;
1686
1687	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
1688		if (smc_link_usable(&lgr->lnk[i]))
1689			lgr->lnk[i].link_is_asym = false;
1690	if (lgr->type == new_type)
1691		return;
1692	lgr->type = new_type;
1693
1694	switch (lgr->type) {
1695	case SMC_LGR_NONE:
1696		lgr_type = "NONE";
1697		break;
1698	case SMC_LGR_SINGLE:
1699		lgr_type = "SINGLE";
1700		break;
1701	case SMC_LGR_SYMMETRIC:
1702		lgr_type = "SYMMETRIC";
1703		break;
1704	case SMC_LGR_ASYMMETRIC_PEER:
1705		lgr_type = "ASYMMETRIC_PEER";
1706		break;
1707	case SMC_LGR_ASYMMETRIC_LOCAL:
1708		lgr_type = "ASYMMETRIC_LOCAL";
1709		break;
1710	}
1711	pr_warn_ratelimited("smc: SMC-R lg %*phN net %llu state changed: "
1712			    "%s, pnetid %.16s\n", SMC_LGR_ID_SIZE, &lgr->id,
1713			    lgr->net->net_cookie, lgr_type, lgr->pnet_id);
1714}
1715
1716/* set new lgr type and tag a link as asymmetric */
1717void smcr_lgr_set_type_asym(struct smc_link_group *lgr,
1718			    enum smc_lgr_type new_type, int asym_lnk_idx)
1719{
1720	smcr_lgr_set_type(lgr, new_type);
1721	lgr->lnk[asym_lnk_idx].link_is_asym = true;
1722}
1723
1724/* abort connection, abort_work scheduled from tasklet context */
1725static void smc_conn_abort_work(struct work_struct *work)
1726{
1727	struct smc_connection *conn = container_of(work,
1728						   struct smc_connection,
1729						   abort_work);
1730	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
1731
1732	lock_sock(&smc->sk);
1733	smc_conn_kill(conn, true);
1734	release_sock(&smc->sk);
1735	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
1736}
1737
1738void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
1739{
1740	struct smc_link_group *lgr, *n;
1741
1742	spin_lock_bh(&smc_lgr_list.lock);
1743	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1744		struct smc_link *link;
1745
1746		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1747			    SMC_MAX_PNETID_LEN) ||
1748		    lgr->type == SMC_LGR_SYMMETRIC ||
1749		    lgr->type == SMC_LGR_ASYMMETRIC_PEER ||
1750		    !rdma_dev_access_netns(smcibdev->ibdev, lgr->net))
1751			continue;
1752
1753		if (lgr->type == SMC_LGR_SINGLE && lgr->max_links <= 1)
1754			continue;
1755
1756		/* trigger local add link processing */
1757		link = smc_llc_usable_link(lgr);
1758		if (link)
1759			smc_llc_add_link_local(link);
1760	}
1761	spin_unlock_bh(&smc_lgr_list.lock);
1762}
1763
1764/* link is down - switch connections to alternate link,
1765 * must be called under lgr->llc_conf_mutex lock
1766 */
1767static void smcr_link_down(struct smc_link *lnk)
1768{
1769	struct smc_link_group *lgr = lnk->lgr;
1770	struct smc_link *to_lnk;
1771	int del_link_id;
1772
1773	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
1774		return;
1775
1776	to_lnk = smc_switch_conns(lgr, lnk, true);
1777	if (!to_lnk) { /* no backup link available */
1778		smcr_link_clear(lnk, true);
1779		return;
1780	}
1781	smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1782	del_link_id = lnk->link_id;
1783
1784	if (lgr->role == SMC_SERV) {
1785		/* trigger local delete link processing */
1786		smc_llc_srv_delete_link_local(to_lnk, del_link_id);
1787	} else {
1788		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1789			/* another llc task is ongoing */
1790			up_write(&lgr->llc_conf_mutex);
1791			wait_event_timeout(lgr->llc_flow_waiter,
1792				(list_empty(&lgr->list) ||
1793				 lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
1794				SMC_LLC_WAIT_TIME);
1795			down_write(&lgr->llc_conf_mutex);
1796		}
1797		if (!list_empty(&lgr->list)) {
1798			smc_llc_send_delete_link(to_lnk, del_link_id,
1799						 SMC_LLC_REQ, true,
1800						 SMC_LLC_DEL_LOST_PATH);
1801			smcr_link_clear(lnk, true);
1802		}
1803		wake_up(&lgr->llc_flow_waiter);	/* wake up next waiter */
1804	}
1805}
1806
1807/* must be called under lgr->llc_conf_mutex lock */
1808void smcr_link_down_cond(struct smc_link *lnk)
1809{
1810	if (smc_link_downing(&lnk->state)) {
1811		trace_smcr_link_down(lnk, __builtin_return_address(0));
1812		smcr_link_down(lnk);
1813	}
1814}
1815
1816/* will get the lgr->llc_conf_mutex lock */
1817void smcr_link_down_cond_sched(struct smc_link *lnk)
1818{
1819	if (smc_link_downing(&lnk->state)) {
1820		trace_smcr_link_down(lnk, __builtin_return_address(0));
1821		smcr_link_hold(lnk); /* smcr_link_put in link_down_wrk */
1822		if (!schedule_work(&lnk->link_down_wrk))
1823			smcr_link_put(lnk);
1824	}
1825}
1826
1827void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
1828{
1829	struct smc_link_group *lgr, *n;
1830	int i;
1831
1832	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
1833		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
1834			    SMC_MAX_PNETID_LEN))
1835			continue; /* lgr is not affected */
1836		if (list_empty(&lgr->list))
1837			continue;
1838		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1839			struct smc_link *lnk = &lgr->lnk[i];
1840
1841			if (smc_link_usable(lnk) &&
1842			    lnk->smcibdev == smcibdev && lnk->ibport == ibport)
1843				smcr_link_down_cond_sched(lnk);
1844		}
1845	}
1846}
1847
1848static void smc_link_down_work(struct work_struct *work)
1849{
1850	struct smc_link *link = container_of(work, struct smc_link,
1851					     link_down_wrk);
1852	struct smc_link_group *lgr = link->lgr;
1853
1854	if (list_empty(&lgr->list))
1855		goto out;
1856	wake_up_all(&lgr->llc_msg_waiter);
1857	down_write(&lgr->llc_conf_mutex);
1858	smcr_link_down(link);
1859	up_write(&lgr->llc_conf_mutex);
1860
1861out:
1862	smcr_link_put(link); /* smcr_link_hold by schedulers of link_down_work */
1863}
1864
1865static int smc_vlan_by_tcpsk_walk(struct net_device *lower_dev,
1866				  struct netdev_nested_priv *priv)
1867{
1868	unsigned short *vlan_id = (unsigned short *)priv->data;
1869
1870	if (is_vlan_dev(lower_dev)) {
1871		*vlan_id = vlan_dev_vlan_id(lower_dev);
1872		return 1;
1873	}
1874
1875	return 0;
1876}
1877
1878/* Determine vlan of internal TCP socket. */
1879int smc_vlan_by_tcpsk(struct socket *clcsock, struct smc_init_info *ini)
1880{
1881	struct dst_entry *dst = sk_dst_get(clcsock->sk);
1882	struct netdev_nested_priv priv;
1883	struct net_device *ndev;
1884	int rc = 0;
1885
1886	ini->vlan_id = 0;
1887	if (!dst) {
1888		rc = -ENOTCONN;
1889		goto out;
1890	}
1891	if (!dst->dev) {
1892		rc = -ENODEV;
1893		goto out_rel;
1894	}
1895
1896	ndev = dst->dev;
1897	if (is_vlan_dev(ndev)) {
1898		ini->vlan_id = vlan_dev_vlan_id(ndev);
1899		goto out_rel;
1900	}
1901
1902	priv.data = (void *)&ini->vlan_id;
1903	rtnl_lock();
1904	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
1905	rtnl_unlock();
1906
1907out_rel:
1908	dst_release(dst);
1909out:
1910	return rc;
1911}
1912
1913static bool smcr_lgr_match(struct smc_link_group *lgr, u8 smcr_version,
1914			   u8 peer_systemid[],
1915			   u8 peer_gid[],
1916			   u8 peer_mac_v1[],
1917			   enum smc_lgr_role role, u32 clcqpn,
1918			   struct net *net)
1919{
1920	struct smc_link *lnk;
1921	int i;
1922
1923	if (memcmp(lgr->peer_systemid, peer_systemid, SMC_SYSTEMID_LEN) ||
1924	    lgr->role != role)
1925		return false;
1926
1927	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1928		lnk = &lgr->lnk[i];
1929
1930		if (!smc_link_active(lnk))
1931			continue;
1932		/* use verbs API to check netns, instead of lgr->net */
1933		if (!rdma_dev_access_netns(lnk->smcibdev->ibdev, net))
1934			return false;
1935		if ((lgr->role == SMC_SERV || lnk->peer_qpn == clcqpn) &&
1936		    !memcmp(lnk->peer_gid, peer_gid, SMC_GID_SIZE) &&
1937		    (smcr_version == SMC_V2 ||
1938		     !memcmp(lnk->peer_mac, peer_mac_v1, ETH_ALEN)))
1939			return true;
1940	}
1941	return false;
1942}
1943
1944static bool smcd_lgr_match(struct smc_link_group *lgr,
1945			   struct smcd_dev *smcismdev,
1946			   struct smcd_gid *peer_gid)
1947{
1948	if (lgr->peer_gid.gid != peer_gid->gid ||
1949	    lgr->smcd != smcismdev)
1950		return false;
1951
1952	if (smc_ism_is_emulated(smcismdev) &&
1953	    lgr->peer_gid.gid_ext != peer_gid->gid_ext)
1954		return false;
1955
1956	return true;
1957}
1958
1959/* create a new SMC connection (and a new link group if necessary) */
1960int smc_conn_create(struct smc_sock *smc, struct smc_init_info *ini)
1961{
1962	struct smc_connection *conn = &smc->conn;
1963	struct net *net = sock_net(&smc->sk);
1964	struct list_head *lgr_list;
1965	struct smc_link_group *lgr;
1966	enum smc_lgr_role role;
1967	spinlock_t *lgr_lock;
1968	int rc = 0;
1969
1970	lgr_list = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_list :
1971				  &smc_lgr_list.list;
1972	lgr_lock = ini->is_smcd ? &ini->ism_dev[ini->ism_selected]->lgr_lock :
1973				  &smc_lgr_list.lock;
1974	ini->first_contact_local = 1;
1975	role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
1976	if (role == SMC_CLNT && ini->first_contact_peer)
1977		/* create new link group as well */
1978		goto create;
1979
1980	/* determine if an existing link group can be reused */
1981	spin_lock_bh(lgr_lock);
1982	list_for_each_entry(lgr, lgr_list, list) {
1983		write_lock_bh(&lgr->conns_lock);
1984		if ((ini->is_smcd ?
1985		     smcd_lgr_match(lgr, ini->ism_dev[ini->ism_selected],
1986				    &ini->ism_peer_gid[ini->ism_selected]) :
1987		     smcr_lgr_match(lgr, ini->smcr_version,
1988				    ini->peer_systemid,
1989				    ini->peer_gid, ini->peer_mac, role,
1990				    ini->ib_clcqpn, net)) &&
1991		    !lgr->sync_err &&
1992		    (ini->smcd_version == SMC_V2 ||
1993		     lgr->vlan_id == ini->vlan_id) &&
1994		    (role == SMC_CLNT || ini->is_smcd ||
1995		    (lgr->conns_num < lgr->max_conns &&
1996		      !bitmap_full(lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX)))) {
1997			/* link group found */
1998			ini->first_contact_local = 0;
1999			conn->lgr = lgr;
2000			rc = smc_lgr_register_conn(conn, false);
2001			write_unlock_bh(&lgr->conns_lock);
2002			if (!rc && delayed_work_pending(&lgr->free_work))
2003				cancel_delayed_work(&lgr->free_work);
2004			break;
2005		}
2006		write_unlock_bh(&lgr->conns_lock);
2007	}
2008	spin_unlock_bh(lgr_lock);
2009	if (rc)
2010		return rc;
2011
2012	if (role == SMC_CLNT && !ini->first_contact_peer &&
2013	    ini->first_contact_local) {
2014		/* Server reuses a link group, but Client wants to start
2015		 * a new one
2016		 * send out_of_sync decline, reason synchr. error
2017		 */
2018		return SMC_CLC_DECL_SYNCERR;
2019	}
2020
2021create:
2022	if (ini->first_contact_local) {
2023		rc = smc_lgr_create(smc, ini);
2024		if (rc)
2025			goto out;
2026		lgr = conn->lgr;
2027		write_lock_bh(&lgr->conns_lock);
2028		rc = smc_lgr_register_conn(conn, true);
2029		write_unlock_bh(&lgr->conns_lock);
2030		if (rc) {
2031			smc_lgr_cleanup_early(lgr);
2032			goto out;
2033		}
2034	}
2035	smc_lgr_hold(conn->lgr); /* lgr_put in smc_conn_free() */
2036	if (!conn->lgr->is_smcd)
2037		smcr_link_hold(conn->lnk); /* link_put in smc_conn_free() */
2038	conn->freed = 0;
2039	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
2040	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
2041	conn->urg_state = SMC_URG_READ;
2042	init_waitqueue_head(&conn->cdc_pend_tx_wq);
2043	INIT_WORK(&smc->conn.abort_work, smc_conn_abort_work);
2044	if (ini->is_smcd) {
2045		conn->rx_off = sizeof(struct smcd_cdc_msg);
2046		smcd_cdc_rx_init(conn); /* init tasklet for this conn */
2047	} else {
2048		conn->rx_off = 0;
2049	}
2050#ifndef KERNEL_HAS_ATOMIC64
2051	spin_lock_init(&conn->acurs_lock);
2052#endif
2053
2054out:
2055	return rc;
2056}
2057
2058#define SMCD_DMBE_SIZES		6 /* 0 -> 16KB, 1 -> 32KB, .. 6 -> 1MB */
2059#define SMCR_RMBE_SIZES		15 /* 0 -> 16KB, 1 -> 32KB, .. 15 -> 512MB */
2060
2061/* convert the RMB size into the compressed notation (minimum 16K, see
2062 * SMCD/R_DMBE_SIZES.
2063 * In contrast to plain ilog2, this rounds towards the next power of 2,
2064 * so the socket application gets at least its desired sndbuf / rcvbuf size.
2065 */
2066static u8 smc_compress_bufsize(int size, bool is_smcd, bool is_rmb)
2067{
2068	u8 compressed;
2069
2070	if (size <= SMC_BUF_MIN_SIZE)
2071		return 0;
2072
2073	size = (size - 1) >> 14;  /* convert to 16K multiple */
2074	compressed = min_t(u8, ilog2(size) + 1,
2075			   is_smcd ? SMCD_DMBE_SIZES : SMCR_RMBE_SIZES);
2076
2077#ifdef CONFIG_ARCH_NO_SG_CHAIN
2078	if (!is_smcd && is_rmb)
2079		/* RMBs are backed by & limited to max size of scatterlists */
2080		compressed = min_t(u8, compressed, ilog2((SG_MAX_SINGLE_ALLOC * PAGE_SIZE) >> 14));
2081#endif
2082
2083	return compressed;
2084}
2085
2086/* convert the RMB size from compressed notation into integer */
2087int smc_uncompress_bufsize(u8 compressed)
2088{
2089	u32 size;
2090
2091	size = 0x00000001 << (((int)compressed) + 14);
2092	return (int)size;
2093}
2094
2095/* try to reuse a sndbuf or rmb description slot for a certain
2096 * buffer size; if not available, return NULL
2097 */
2098static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
2099					     struct rw_semaphore *lock,
2100					     struct list_head *buf_list)
2101{
2102	struct smc_buf_desc *buf_slot;
2103
2104	down_read(lock);
2105	list_for_each_entry(buf_slot, buf_list, list) {
2106		if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
2107			up_read(lock);
2108			return buf_slot;
2109		}
2110	}
2111	up_read(lock);
2112	return NULL;
2113}
2114
2115/* one of the conditions for announcing a receiver's current window size is
2116 * that it "results in a minimum increase in the window size of 10% of the
2117 * receive buffer space" [RFC7609]
2118 */
2119static inline int smc_rmb_wnd_update_limit(int rmbe_size)
2120{
2121	return max_t(int, rmbe_size / 10, SOCK_MIN_SNDBUF / 2);
2122}
2123
2124/* map an buf to a link */
2125static int smcr_buf_map_link(struct smc_buf_desc *buf_desc, bool is_rmb,
2126			     struct smc_link *lnk)
2127{
2128	int rc, i, nents, offset, buf_size, size, access_flags;
2129	struct scatterlist *sg;
2130	void *buf;
2131
2132	if (buf_desc->is_map_ib[lnk->link_idx])
2133		return 0;
2134
2135	if (buf_desc->is_vm) {
2136		buf = buf_desc->cpu_addr;
2137		buf_size = buf_desc->len;
2138		offset = offset_in_page(buf_desc->cpu_addr);
2139		nents = PAGE_ALIGN(buf_size + offset) / PAGE_SIZE;
2140	} else {
2141		nents = 1;
2142	}
2143
2144	rc = sg_alloc_table(&buf_desc->sgt[lnk->link_idx], nents, GFP_KERNEL);
2145	if (rc)
2146		return rc;
2147
2148	if (buf_desc->is_vm) {
2149		/* virtually contiguous buffer */
2150		for_each_sg(buf_desc->sgt[lnk->link_idx].sgl, sg, nents, i) {
2151			size = min_t(int, PAGE_SIZE - offset, buf_size);
2152			sg_set_page(sg, vmalloc_to_page(buf), size, offset);
2153			buf += size / sizeof(*buf);
2154			buf_size -= size;
2155			offset = 0;
2156		}
2157	} else {
2158		/* physically contiguous buffer */
2159		sg_set_buf(buf_desc->sgt[lnk->link_idx].sgl,
2160			   buf_desc->cpu_addr, buf_desc->len);
2161	}
2162
2163	/* map sg table to DMA address */
2164	rc = smc_ib_buf_map_sg(lnk, buf_desc,
2165			       is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2166	/* SMC protocol depends on mapping to one DMA address only */
2167	if (rc != nents) {
2168		rc = -EAGAIN;
2169		goto free_table;
2170	}
2171
2172	buf_desc->is_dma_need_sync |=
2173		smc_ib_is_sg_need_sync(lnk, buf_desc) << lnk->link_idx;
2174
2175	if (is_rmb || buf_desc->is_vm) {
2176		/* create a new memory region for the RMB or vzalloced sndbuf */
2177		access_flags = is_rmb ?
2178			       IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2179			       IB_ACCESS_LOCAL_WRITE;
2180
2181		rc = smc_ib_get_memory_region(lnk->roce_pd, access_flags,
2182					      buf_desc, lnk->link_idx);
2183		if (rc)
2184			goto buf_unmap;
2185		smc_ib_sync_sg_for_device(lnk, buf_desc,
2186					  is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2187	}
2188	buf_desc->is_map_ib[lnk->link_idx] = true;
2189	return 0;
2190
2191buf_unmap:
2192	smc_ib_buf_unmap_sg(lnk, buf_desc,
2193			    is_rmb ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
2194free_table:
2195	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
2196	return rc;
2197}
2198
2199/* register a new buf on IB device, rmb or vzalloced sndbuf
2200 * must be called under lgr->llc_conf_mutex lock
2201 */
2202int smcr_link_reg_buf(struct smc_link *link, struct smc_buf_desc *buf_desc)
2203{
2204	if (list_empty(&link->lgr->list))
2205		return -ENOLINK;
2206	if (!buf_desc->is_reg_mr[link->link_idx]) {
2207		/* register memory region for new buf */
2208		if (buf_desc->is_vm)
2209			buf_desc->mr[link->link_idx]->iova =
2210				(uintptr_t)buf_desc->cpu_addr;
2211		if (smc_wr_reg_send(link, buf_desc->mr[link->link_idx])) {
2212			buf_desc->is_reg_err = true;
2213			return -EFAULT;
2214		}
2215		buf_desc->is_reg_mr[link->link_idx] = true;
2216	}
2217	return 0;
2218}
2219
2220static int _smcr_buf_map_lgr(struct smc_link *lnk, struct rw_semaphore *lock,
2221			     struct list_head *lst, bool is_rmb)
2222{
2223	struct smc_buf_desc *buf_desc, *bf;
2224	int rc = 0;
2225
2226	down_write(lock);
2227	list_for_each_entry_safe(buf_desc, bf, lst, list) {
2228		if (!buf_desc->used)
2229			continue;
2230		rc = smcr_buf_map_link(buf_desc, is_rmb, lnk);
2231		if (rc)
2232			goto out;
2233	}
2234out:
2235	up_write(lock);
2236	return rc;
2237}
2238
2239/* map all used buffers of lgr for a new link */
2240int smcr_buf_map_lgr(struct smc_link *lnk)
2241{
2242	struct smc_link_group *lgr = lnk->lgr;
2243	int i, rc = 0;
2244
2245	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2246		rc = _smcr_buf_map_lgr(lnk, &lgr->rmbs_lock,
2247				       &lgr->rmbs[i], true);
2248		if (rc)
2249			return rc;
2250		rc = _smcr_buf_map_lgr(lnk, &lgr->sndbufs_lock,
2251				       &lgr->sndbufs[i], false);
2252		if (rc)
2253			return rc;
2254	}
2255	return 0;
2256}
2257
2258/* register all used buffers of lgr for a new link,
2259 * must be called under lgr->llc_conf_mutex lock
2260 */
2261int smcr_buf_reg_lgr(struct smc_link *lnk)
2262{
2263	struct smc_link_group *lgr = lnk->lgr;
2264	struct smc_buf_desc *buf_desc, *bf;
2265	int i, rc = 0;
2266
2267	/* reg all RMBs for a new link */
2268	down_write(&lgr->rmbs_lock);
2269	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2270		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list) {
2271			if (!buf_desc->used)
2272				continue;
2273			rc = smcr_link_reg_buf(lnk, buf_desc);
2274			if (rc) {
2275				up_write(&lgr->rmbs_lock);
2276				return rc;
2277			}
2278		}
2279	}
2280	up_write(&lgr->rmbs_lock);
2281
2282	if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2283		return rc;
2284
2285	/* reg all vzalloced sndbufs for a new link */
2286	down_write(&lgr->sndbufs_lock);
2287	for (i = 0; i < SMC_RMBE_SIZES; i++) {
2288		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i], list) {
2289			if (!buf_desc->used || !buf_desc->is_vm)
2290				continue;
2291			rc = smcr_link_reg_buf(lnk, buf_desc);
2292			if (rc) {
2293				up_write(&lgr->sndbufs_lock);
2294				return rc;
2295			}
2296		}
2297	}
2298	up_write(&lgr->sndbufs_lock);
2299	return rc;
2300}
2301
2302static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr,
2303						int bufsize)
2304{
2305	struct smc_buf_desc *buf_desc;
2306
2307	/* try to alloc a new buffer */
2308	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2309	if (!buf_desc)
2310		return ERR_PTR(-ENOMEM);
2311
2312	switch (lgr->buf_type) {
2313	case SMCR_PHYS_CONT_BUFS:
2314	case SMCR_MIXED_BUFS:
2315		buf_desc->order = get_order(bufsize);
2316		buf_desc->pages = alloc_pages(GFP_KERNEL | __GFP_NOWARN |
2317					      __GFP_NOMEMALLOC | __GFP_COMP |
2318					      __GFP_NORETRY | __GFP_ZERO,
2319					      buf_desc->order);
2320		if (buf_desc->pages) {
2321			buf_desc->cpu_addr =
2322				(void *)page_address(buf_desc->pages);
2323			buf_desc->len = bufsize;
2324			buf_desc->is_vm = false;
2325			break;
2326		}
2327		if (lgr->buf_type == SMCR_PHYS_CONT_BUFS)
2328			goto out;
2329		fallthrough;	// try virtually contiguous buf
2330	case SMCR_VIRT_CONT_BUFS:
2331		buf_desc->order = get_order(bufsize);
2332		buf_desc->cpu_addr = vzalloc(PAGE_SIZE << buf_desc->order);
2333		if (!buf_desc->cpu_addr)
2334			goto out;
2335		buf_desc->pages = NULL;
2336		buf_desc->len = bufsize;
2337		buf_desc->is_vm = true;
2338		break;
2339	}
2340	return buf_desc;
2341
2342out:
2343	kfree(buf_desc);
2344	return ERR_PTR(-EAGAIN);
2345}
2346
2347/* map buf_desc on all usable links,
2348 * unused buffers stay mapped as long as the link is up
2349 */
2350static int smcr_buf_map_usable_links(struct smc_link_group *lgr,
2351				     struct smc_buf_desc *buf_desc, bool is_rmb)
2352{
2353	int i, rc = 0, cnt = 0;
2354
2355	/* protect against parallel link reconfiguration */
2356	down_read(&lgr->llc_conf_mutex);
2357	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2358		struct smc_link *lnk = &lgr->lnk[i];
2359
2360		if (!smc_link_usable(lnk))
2361			continue;
2362		if (smcr_buf_map_link(buf_desc, is_rmb, lnk)) {
2363			rc = -ENOMEM;
2364			goto out;
2365		}
2366		cnt++;
2367	}
2368out:
2369	up_read(&lgr->llc_conf_mutex);
2370	if (!rc && !cnt)
2371		rc = -EINVAL;
2372	return rc;
2373}
2374
2375static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
2376						bool is_dmb, int bufsize)
2377{
2378	struct smc_buf_desc *buf_desc;
2379	int rc;
2380
2381	/* try to alloc a new DMB */
2382	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2383	if (!buf_desc)
2384		return ERR_PTR(-ENOMEM);
2385	if (is_dmb) {
2386		rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
2387		if (rc) {
2388			kfree(buf_desc);
2389			if (rc == -ENOMEM)
2390				return ERR_PTR(-EAGAIN);
2391			if (rc == -ENOSPC)
2392				return ERR_PTR(-ENOSPC);
2393			return ERR_PTR(-EIO);
2394		}
2395		buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
2396		/* CDC header stored in buf. So, pretend it was smaller */
2397		buf_desc->len = bufsize - sizeof(struct smcd_cdc_msg);
2398	} else {
2399		buf_desc->cpu_addr = kzalloc(bufsize, GFP_KERNEL |
2400					     __GFP_NOWARN | __GFP_NORETRY |
2401					     __GFP_NOMEMALLOC);
2402		if (!buf_desc->cpu_addr) {
2403			kfree(buf_desc);
2404			return ERR_PTR(-EAGAIN);
2405		}
2406		buf_desc->len = bufsize;
2407	}
2408	return buf_desc;
2409}
2410
2411static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
2412{
2413	struct smc_buf_desc *buf_desc = ERR_PTR(-ENOMEM);
2414	struct smc_connection *conn = &smc->conn;
2415	struct smc_link_group *lgr = conn->lgr;
2416	struct list_head *buf_list;
2417	int bufsize, bufsize_comp;
2418	struct rw_semaphore *lock;	/* lock buffer list */
2419	bool is_dgraded = false;
2420
2421	if (is_rmb)
2422		/* use socket recv buffer size (w/o overhead) as start value */
2423		bufsize = smc->sk.sk_rcvbuf / 2;
2424	else
2425		/* use socket send buffer size (w/o overhead) as start value */
2426		bufsize = smc->sk.sk_sndbuf / 2;
2427
2428	for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb);
2429	     bufsize_comp >= 0; bufsize_comp--) {
2430		if (is_rmb) {
2431			lock = &lgr->rmbs_lock;
2432			buf_list = &lgr->rmbs[bufsize_comp];
2433		} else {
2434			lock = &lgr->sndbufs_lock;
2435			buf_list = &lgr->sndbufs[bufsize_comp];
2436		}
2437		bufsize = smc_uncompress_bufsize(bufsize_comp);
2438
2439		/* check for reusable slot in the link group */
2440		buf_desc = smc_buf_get_slot(bufsize_comp, lock, buf_list);
2441		if (buf_desc) {
2442			buf_desc->is_dma_need_sync = 0;
2443			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2444			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
2445			break; /* found reusable slot */
2446		}
2447
2448		if (is_smcd)
2449			buf_desc = smcd_new_buf_create(lgr, is_rmb, bufsize);
2450		else
2451			buf_desc = smcr_new_buf_create(lgr, bufsize);
2452
2453		if (PTR_ERR(buf_desc) == -ENOMEM)
2454			break;
2455		if (IS_ERR(buf_desc)) {
2456			if (!is_dgraded) {
2457				is_dgraded = true;
2458				SMC_STAT_RMB_DOWNGRADED(smc, is_smcd, is_rmb);
2459			}
2460			continue;
2461		}
2462
2463		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
2464		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
2465		buf_desc->used = 1;
2466		down_write(lock);
2467		smc_lgr_buf_list_add(lgr, is_rmb, buf_list, buf_desc);
2468		up_write(lock);
2469		break; /* found */
2470	}
2471
2472	if (IS_ERR(buf_desc))
2473		return PTR_ERR(buf_desc);
2474
2475	if (!is_smcd) {
2476		if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {
2477			smcr_buf_unuse(buf_desc, is_rmb, lgr);
2478			return -ENOMEM;
2479		}
2480	}
2481
2482	if (is_rmb) {
2483		conn->rmb_desc = buf_desc;
2484		conn->rmbe_size_comp = bufsize_comp;
2485		smc->sk.sk_rcvbuf = bufsize * 2;
2486		atomic_set(&conn->bytes_to_rcv, 0);
2487		conn->rmbe_update_limit =
2488			smc_rmb_wnd_update_limit(buf_desc->len);
2489		if (is_smcd)
2490			smc_ism_set_conn(conn); /* map RMB/smcd_dev to conn */
2491	} else {
2492		conn->sndbuf_desc = buf_desc;
2493		smc->sk.sk_sndbuf = bufsize * 2;
2494		atomic_set(&conn->sndbuf_space, bufsize);
2495	}
2496	return 0;
2497}
2498
2499void smc_sndbuf_sync_sg_for_device(struct smc_connection *conn)
2500{
2501	if (!conn->sndbuf_desc->is_dma_need_sync)
2502		return;
2503	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd ||
2504	    !smc_link_active(conn->lnk))
2505		return;
2506	smc_ib_sync_sg_for_device(conn->lnk, conn->sndbuf_desc, DMA_TO_DEVICE);
2507}
2508
2509void smc_rmb_sync_sg_for_cpu(struct smc_connection *conn)
2510{
2511	int i;
2512
2513	if (!conn->rmb_desc->is_dma_need_sync)
2514		return;
2515	if (!smc_conn_lgr_valid(conn) || conn->lgr->is_smcd)
2516		return;
2517	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
2518		if (!smc_link_active(&conn->lgr->lnk[i]))
2519			continue;
2520		smc_ib_sync_sg_for_cpu(&conn->lgr->lnk[i], conn->rmb_desc,
2521				       DMA_FROM_DEVICE);
2522	}
2523}
2524
2525/* create the send and receive buffer for an SMC socket;
2526 * receive buffers are called RMBs;
2527 * (even though the SMC protocol allows more than one RMB-element per RMB,
2528 * the Linux implementation uses just one RMB-element per RMB, i.e. uses an
2529 * extra RMB for every connection in a link group
2530 */
2531int smc_buf_create(struct smc_sock *smc, bool is_smcd)
2532{
2533	int rc;
2534
2535	/* create send buffer */
2536	if (is_smcd &&
2537	    smc_ism_support_dmb_nocopy(smc->conn.lgr->smcd))
2538		goto create_rmb;
2539
2540	rc = __smc_buf_create(smc, is_smcd, false);
2541	if (rc)
2542		return rc;
2543
2544create_rmb:
2545	/* create rmb */
2546	rc = __smc_buf_create(smc, is_smcd, true);
2547	if (rc && smc->conn.sndbuf_desc) {
2548		down_write(&smc->conn.lgr->sndbufs_lock);
2549		smc_lgr_buf_list_del(smc->conn.lgr, false,
2550				     smc->conn.sndbuf_desc);
2551		up_write(&smc->conn.lgr->sndbufs_lock);
2552		smc_buf_free(smc->conn.lgr, false, smc->conn.sndbuf_desc);
2553		smc->conn.sndbuf_desc = NULL;
2554	}
2555	return rc;
2556}
2557
2558int smcd_buf_attach(struct smc_sock *smc)
2559{
2560	struct smc_connection *conn = &smc->conn;
2561	struct smcd_dev *smcd = conn->lgr->smcd;
2562	u64 peer_token = conn->peer_token;
2563	struct smc_buf_desc *buf_desc;
2564	int rc;
2565
2566	buf_desc = kzalloc(sizeof(*buf_desc), GFP_KERNEL);
2567	if (!buf_desc)
2568		return -ENOMEM;
2569
2570	/* The ghost sndbuf_desc describes the same memory region as
2571	 * peer RMB. Its lifecycle is consistent with the connection's
2572	 * and it will be freed with the connections instead of the
2573	 * link group.
2574	 */
2575	rc = smc_ism_attach_dmb(smcd, peer_token, buf_desc);
2576	if (rc)
2577		goto free;
2578
2579	smc->sk.sk_sndbuf = buf_desc->len;
2580	buf_desc->cpu_addr =
2581		(u8 *)buf_desc->cpu_addr + sizeof(struct smcd_cdc_msg);
2582	buf_desc->len -= sizeof(struct smcd_cdc_msg);
2583	conn->sndbuf_desc = buf_desc;
2584	conn->sndbuf_desc->used = 1;
2585	atomic_set(&conn->sndbuf_space, conn->sndbuf_desc->len);
2586	return 0;
2587
2588free:
2589	kfree(buf_desc);
2590	return rc;
2591}
2592
2593static inline int smc_rmb_reserve_rtoken_idx(struct smc_link_group *lgr)
2594{
2595	int i;
2596
2597	for_each_clear_bit(i, lgr->rtokens_used_mask, SMC_RMBS_PER_LGR_MAX) {
2598		if (!test_and_set_bit(i, lgr->rtokens_used_mask))
2599			return i;
2600	}
2601	return -ENOSPC;
2602}
2603
2604static int smc_rtoken_find_by_link(struct smc_link_group *lgr, int lnk_idx,
2605				   u32 rkey)
2606{
2607	int i;
2608
2609	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2610		if (test_bit(i, lgr->rtokens_used_mask) &&
2611		    lgr->rtokens[i][lnk_idx].rkey == rkey)
2612			return i;
2613	}
2614	return -ENOENT;
2615}
2616
2617/* set rtoken for a new link to an existing rmb */
2618void smc_rtoken_set(struct smc_link_group *lgr, int link_idx, int link_idx_new,
2619		    __be32 nw_rkey_known, __be64 nw_vaddr, __be32 nw_rkey)
2620{
2621	int rtok_idx;
2622
2623	rtok_idx = smc_rtoken_find_by_link(lgr, link_idx, ntohl(nw_rkey_known));
2624	if (rtok_idx == -ENOENT)
2625		return;
2626	lgr->rtokens[rtok_idx][link_idx_new].rkey = ntohl(nw_rkey);
2627	lgr->rtokens[rtok_idx][link_idx_new].dma_addr = be64_to_cpu(nw_vaddr);
2628}
2629
2630/* set rtoken for a new link whose link_id is given */
2631void smc_rtoken_set2(struct smc_link_group *lgr, int rtok_idx, int link_id,
2632		     __be64 nw_vaddr, __be32 nw_rkey)
2633{
2634	u64 dma_addr = be64_to_cpu(nw_vaddr);
2635	u32 rkey = ntohl(nw_rkey);
2636	bool found = false;
2637	int link_idx;
2638
2639	for (link_idx = 0; link_idx < SMC_LINKS_PER_LGR_MAX; link_idx++) {
2640		if (lgr->lnk[link_idx].link_id == link_id) {
2641			found = true;
2642			break;
2643		}
2644	}
2645	if (!found)
2646		return;
2647	lgr->rtokens[rtok_idx][link_idx].rkey = rkey;
2648	lgr->rtokens[rtok_idx][link_idx].dma_addr = dma_addr;
2649}
2650
2651/* add a new rtoken from peer */
2652int smc_rtoken_add(struct smc_link *lnk, __be64 nw_vaddr, __be32 nw_rkey)
2653{
2654	struct smc_link_group *lgr = smc_get_lgr(lnk);
2655	u64 dma_addr = be64_to_cpu(nw_vaddr);
2656	u32 rkey = ntohl(nw_rkey);
2657	int i;
2658
2659	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2660		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2661		    lgr->rtokens[i][lnk->link_idx].dma_addr == dma_addr &&
2662		    test_bit(i, lgr->rtokens_used_mask)) {
2663			/* already in list */
2664			return i;
2665		}
2666	}
2667	i = smc_rmb_reserve_rtoken_idx(lgr);
2668	if (i < 0)
2669		return i;
2670	lgr->rtokens[i][lnk->link_idx].rkey = rkey;
2671	lgr->rtokens[i][lnk->link_idx].dma_addr = dma_addr;
2672	return i;
2673}
2674
2675/* delete an rtoken from all links */
2676int smc_rtoken_delete(struct smc_link *lnk, __be32 nw_rkey)
2677{
2678	struct smc_link_group *lgr = smc_get_lgr(lnk);
2679	u32 rkey = ntohl(nw_rkey);
2680	int i, j;
2681
2682	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
2683		if (lgr->rtokens[i][lnk->link_idx].rkey == rkey &&
2684		    test_bit(i, lgr->rtokens_used_mask)) {
2685			for (j = 0; j < SMC_LINKS_PER_LGR_MAX; j++) {
2686				lgr->rtokens[i][j].rkey = 0;
2687				lgr->rtokens[i][j].dma_addr = 0;
2688			}
2689			clear_bit(i, lgr->rtokens_used_mask);
2690			return 0;
2691		}
2692	}
2693	return -ENOENT;
2694}
2695
2696/* save rkey and dma_addr received from peer during clc handshake */
2697int smc_rmb_rtoken_handling(struct smc_connection *conn,
2698			    struct smc_link *lnk,
2699			    struct smc_clc_msg_accept_confirm *clc)
2700{
2701	conn->rtoken_idx = smc_rtoken_add(lnk, clc->r0.rmb_dma_addr,
2702					  clc->r0.rmb_rkey);
2703	if (conn->rtoken_idx < 0)
2704		return conn->rtoken_idx;
2705	return 0;
2706}
2707
2708static void smc_core_going_away(void)
2709{
2710	struct smc_ib_device *smcibdev;
2711	struct smcd_dev *smcd;
2712
2713	mutex_lock(&smc_ib_devices.mutex);
2714	list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
2715		int i;
2716
2717		for (i = 0; i < SMC_MAX_PORTS; i++)
2718			set_bit(i, smcibdev->ports_going_away);
2719	}
2720	mutex_unlock(&smc_ib_devices.mutex);
2721
2722	mutex_lock(&smcd_dev_list.mutex);
2723	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
2724		smcd->going_away = 1;
2725	}
2726	mutex_unlock(&smcd_dev_list.mutex);
2727}
2728
2729/* Clean up all SMC link groups */
2730static void smc_lgrs_shutdown(void)
2731{
2732	struct smcd_dev *smcd;
2733
2734	smc_core_going_away();
2735
2736	smc_smcr_terminate_all(NULL);
2737
2738	mutex_lock(&smcd_dev_list.mutex);
2739	list_for_each_entry(smcd, &smcd_dev_list.list, list)
2740		smc_smcd_terminate_all(smcd);
2741	mutex_unlock(&smcd_dev_list.mutex);
2742}
2743
2744static int smc_core_reboot_event(struct notifier_block *this,
2745				 unsigned long event, void *ptr)
2746{
2747	smc_lgrs_shutdown();
2748	smc_ib_unregister_client();
2749	smc_ism_exit();
2750	return 0;
2751}
2752
2753static struct notifier_block smc_reboot_notifier = {
2754	.notifier_call = smc_core_reboot_event,
2755};
2756
2757int __init smc_core_init(void)
2758{
2759	return register_reboot_notifier(&smc_reboot_notifier);
2760}
2761
2762/* Called (from smc_exit) when module is removed */
2763void smc_core_exit(void)
2764{
2765	unregister_reboot_notifier(&smc_reboot_notifier);
2766	smc_lgrs_shutdown();
2767}