smc_core.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  Basic Transport Functions exploiting Infiniband API
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#include <linux/socket.h>
#include <linux/if_vlan.h>
#include <linux/random.h>
#include <linux/workqueue.h>
#include <linux/wait.h>
#include <linux/reboot.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_cache.h>

#include "smc.h"
#include "smc_clc.h"
#include "smc_core.h"
#include "smc_ib.h"
#include "smc_wr.h"
#include "smc_llc.h"
#include "smc_cdc.h"
#include "smc_close.h"
#include "smc_ism.h"

#define SMC_LGR_NUM_INCR		256
#define SMC_LGR_FREE_DELAY_SERV		(600 * HZ)
#define SMC_LGR_FREE_DELAY_CLNT		(SMC_LGR_FREE_DELAY_SERV + 10 * HZ)
#define SMC_LGR_FREE_DELAY_FAST		(8 * HZ)

static struct smc_lgr_list smc_lgr_list = {	/* established link groups */
	.lock = __SPIN_LOCK_UNLOCKED(smc_lgr_list.lock),
	.list = LIST_HEAD_INIT(smc_lgr_list.list),
	.num = 0,
};

static atomic_t lgr_cnt = ATOMIC_INIT(0); /* number of existing link groups */
static DECLARE_WAIT_QUEUE_HEAD(lgrs_deleted);

struct smc_ib_up_work {
	struct work_struct	work;
	struct smc_link_group	*lgr;
	struct smc_ib_device	*smcibdev;
	u8			ibport;
};

static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
			 struct smc_buf_desc *buf_desc);
static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft);

static void smc_link_up_work(struct work_struct *work);
static void smc_link_down_work(struct work_struct *work);

/* return head of link group list and its lock for a given link group */
static inline struct list_head *smc_lgr_list_head(struct smc_link_group *lgr,
						  spinlock_t **lgr_lock)
{
	if (lgr->is_smcd) {
		*lgr_lock = &lgr->smcd->lgr_lock;
		return &lgr->smcd->lgr_list;
	}

	*lgr_lock = &smc_lgr_list.lock;
	return &smc_lgr_list.list;
}

static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
{
	/* client link group creation always follows the server link group
	 * creation. For client use a somewhat higher removal delay time,
	 * otherwise there is a risk of out-of-sync link groups.
	 */
	if (!lgr->freeing && !lgr->freefast) {
		mod_delayed_work(system_wq, &lgr->free_work,
				 (!lgr->is_smcd && lgr->role == SMC_CLNT) ?
						SMC_LGR_FREE_DELAY_CLNT :
						SMC_LGR_FREE_DELAY_SERV);
	}
}

void smc_lgr_schedule_free_work_fast(struct smc_link_group *lgr)
{
	if (!lgr->freeing && !lgr->freefast) {
		lgr->freefast = 1;
		mod_delayed_work(system_wq, &lgr->free_work,
				 SMC_LGR_FREE_DELAY_FAST);
	}
}

/* Register connection's alert token in our lookup structure.
 * To use rbtrees we have to implement our own insert core.
 * Requires @conns_lock
 * @smc		connection to register
 * Returns 0 on success, != otherwise.
 */
static void smc_lgr_add_alert_token(struct smc_connection *conn)
{
	struct rb_node **link, *parent = NULL;
	u32 token = conn->alert_token_local;

	link = &conn->lgr->conns_all.rb_node;
	while (*link) {
		struct smc_connection *cur = rb_entry(*link,
					struct smc_connection, alert_node);

		parent = *link;
		if (cur->alert_token_local > token)
			link = &parent->rb_left;
		else
			link = &parent->rb_right;
	}
	/* Put the new node there */
	rb_link_node(&conn->alert_node, parent, link);
	rb_insert_color(&conn->alert_node, &conn->lgr->conns_all);
}

/* Register connection in link group by assigning an alert token
 * registered in a search tree.
 * Requires @conns_lock
 * Note that '0' is a reserved value and not assigned.
 */
static int smc_lgr_register_conn(struct smc_connection *conn)
{
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	static atomic_t nexttoken = ATOMIC_INIT(0);

	/* find a new alert_token_local value not yet used by some connection
	 * in this link group
	 */
	sock_hold(&smc->sk); /* sock_put in smc_lgr_unregister_conn() */
	while (!conn->alert_token_local) {
		conn->alert_token_local = atomic_inc_return(&nexttoken);
		if (smc_lgr_find_conn(conn->alert_token_local, conn->lgr))
			conn->alert_token_local = 0;
	}
	smc_lgr_add_alert_token(conn);

	/* assign the new connection to a link */
	if (!conn->lgr->is_smcd) {
		struct smc_link *lnk;
		int i;

		/* tbd - link balancing */
		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
			lnk = &conn->lgr->lnk[i];
			if (lnk->state == SMC_LNK_ACTIVATING ||
			    lnk->state == SMC_LNK_ACTIVE)
				conn->lnk = lnk;
		}
		if (!conn->lnk)
			return SMC_CLC_DECL_NOACTLINK;
	}
	conn->lgr->conns_num++;
	return 0;
}

/* Unregister connection and reset the alert token of the given connection<
 */
static void __smc_lgr_unregister_conn(struct smc_connection *conn)
{
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	struct smc_link_group *lgr = conn->lgr;

	rb_erase(&conn->alert_node, &lgr->conns_all);
	lgr->conns_num--;
	conn->alert_token_local = 0;
	sock_put(&smc->sk); /* sock_hold in smc_lgr_register_conn() */
}

/* Unregister connection from lgr
 */
static void smc_lgr_unregister_conn(struct smc_connection *conn)
{
	struct smc_link_group *lgr = conn->lgr;

	if (!lgr)
		return;
	write_lock_bh(&lgr->conns_lock);
	if (conn->alert_token_local) {
		__smc_lgr_unregister_conn(conn);
	}
	write_unlock_bh(&lgr->conns_lock);
	conn->lgr = NULL;
}

void smc_lgr_cleanup_early(struct smc_connection *conn)
{
	struct smc_link_group *lgr = conn->lgr;

	if (!lgr)
		return;

	smc_conn_free(conn);
	smc_lgr_forget(lgr);
	smc_lgr_schedule_free_work_fast(lgr);
}

static void smc_lgr_free(struct smc_link_group *lgr);

static void smc_lgr_free_work(struct work_struct *work)
{
	struct smc_link_group *lgr = container_of(to_delayed_work(work),
						  struct smc_link_group,
						  free_work);
	spinlock_t *lgr_lock;
	bool conns;
	int i;

	smc_lgr_list_head(lgr, &lgr_lock);
	spin_lock_bh(lgr_lock);
	if (lgr->freeing) {
		spin_unlock_bh(lgr_lock);
		return;
	}
	read_lock_bh(&lgr->conns_lock);
	conns = RB_EMPTY_ROOT(&lgr->conns_all);
	read_unlock_bh(&lgr->conns_lock);
	if (!conns) { /* number of lgr connections is no longer zero */
		spin_unlock_bh(lgr_lock);
		return;
	}
	list_del_init(&lgr->list); /* remove from smc_lgr_list */
	lgr->freeing = 1; /* this instance does the freeing, no new schedule */
	spin_unlock_bh(lgr_lock);
	cancel_delayed_work(&lgr->free_work);

	if (lgr->is_smcd && !lgr->terminating)
		smc_ism_signal_shutdown(lgr);
	if (!lgr->is_smcd) {
		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
			struct smc_link *lnk = &lgr->lnk[i];

			if (smc_link_usable(lnk))
				lnk->state = SMC_LNK_INACTIVE;
		}
		wake_up_interruptible_all(&lgr->llc_waiter);
	}
	smc_lgr_free(lgr);
}

static void smc_lgr_terminate_work(struct work_struct *work)
{
	struct smc_link_group *lgr = container_of(work, struct smc_link_group,
						  terminate_work);

	__smc_lgr_terminate(lgr, true);
}

/* return next unique link id for the lgr */
static u8 smcr_next_link_id(struct smc_link_group *lgr)
{
	u8 link_id;
	int i;

	while (1) {
		link_id = ++lgr->next_link_id;
		if (!link_id)	/* skip zero as link_id */
			link_id = ++lgr->next_link_id;
		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
			if (smc_link_usable(&lgr->lnk[i]) &&
			    lgr->lnk[i].link_id == link_id)
				continue;
		}
		break;
	}
	return link_id;
}

int smcr_link_init(struct smc_link_group *lgr, struct smc_link *lnk,
		   u8 link_idx, struct smc_init_info *ini)
{
	u8 rndvec[3];
	int rc;

	get_device(&ini->ib_dev->ibdev->dev);
	atomic_inc(&ini->ib_dev->lnk_cnt);
	lnk->state = SMC_LNK_ACTIVATING;
	lnk->link_id = smcr_next_link_id(lgr);
	lnk->lgr = lgr;
	lnk->link_idx = link_idx;
	lnk->smcibdev = ini->ib_dev;
	lnk->ibport = ini->ib_port;
	lnk->path_mtu = ini->ib_dev->pattr[ini->ib_port - 1].active_mtu;
	INIT_WORK(&lnk->link_down_wrk, smc_link_down_work);
	if (!ini->ib_dev->initialized) {
		rc = (int)smc_ib_setup_per_ibdev(ini->ib_dev);
		if (rc)
			goto out;
	}
	get_random_bytes(rndvec, sizeof(rndvec));
	lnk->psn_initial = rndvec[0] + (rndvec[1] << 8) +
		(rndvec[2] << 16);
	rc = smc_ib_determine_gid(lnk->smcibdev, lnk->ibport,
				  ini->vlan_id, lnk->gid, &lnk->sgid_index);
	if (rc)
		goto out;
	rc = smc_llc_link_init(lnk);
	if (rc)
		goto out;
	rc = smc_wr_alloc_link_mem(lnk);
	if (rc)
		goto clear_llc_lnk;
	rc = smc_ib_create_protection_domain(lnk);
	if (rc)
		goto free_link_mem;
	rc = smc_ib_create_queue_pair(lnk);
	if (rc)
		goto dealloc_pd;
	rc = smc_wr_create_link(lnk);
	if (rc)
		goto destroy_qp;
	return 0;

destroy_qp:
	smc_ib_destroy_queue_pair(lnk);
dealloc_pd:
	smc_ib_dealloc_protection_domain(lnk);
free_link_mem:
	smc_wr_free_link_mem(lnk);
clear_llc_lnk:
	smc_llc_link_clear(lnk);
out:
	put_device(&ini->ib_dev->ibdev->dev);
	memset(lnk, 0, sizeof(struct smc_link));
	lnk->state = SMC_LNK_UNUSED;
	if (!atomic_dec_return(&ini->ib_dev->lnk_cnt))
		wake_up(&ini->ib_dev->lnks_deleted);
	return rc;
}

/* create a new SMC link group */
static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
{
	struct smc_link_group *lgr;
	struct list_head *lgr_list;
	struct smc_link *lnk;
	spinlock_t *lgr_lock;
	u8 link_idx;
	int rc = 0;
	int i;

	if (ini->is_smcd && ini->vlan_id) {
		if (smc_ism_get_vlan(ini->ism_dev, ini->vlan_id)) {
			rc = SMC_CLC_DECL_ISMVLANERR;
			goto out;
		}
	}

	lgr = kzalloc(sizeof(*lgr), GFP_KERNEL);
	if (!lgr) {
		rc = SMC_CLC_DECL_MEM;
		goto ism_put_vlan;
	}
	lgr->is_smcd = ini->is_smcd;
	lgr->sync_err = 0;
	lgr->terminating = 0;
	lgr->freefast = 0;
	lgr->freeing = 0;
	lgr->vlan_id = ini->vlan_id;
	mutex_init(&lgr->sndbufs_lock);
	mutex_init(&lgr->rmbs_lock);
	rwlock_init(&lgr->conns_lock);
	for (i = 0; i < SMC_RMBE_SIZES; i++) {
		INIT_LIST_HEAD(&lgr->sndbufs[i]);
		INIT_LIST_HEAD(&lgr->rmbs[i]);
	}
	lgr->next_link_id = 0;
	smc_lgr_list.num += SMC_LGR_NUM_INCR;
	memcpy(&lgr->id, (u8 *)&smc_lgr_list.num, SMC_LGR_ID_SIZE);
	INIT_DELAYED_WORK(&lgr->free_work, smc_lgr_free_work);
	INIT_WORK(&lgr->terminate_work, smc_lgr_terminate_work);
	lgr->conns_all = RB_ROOT;
	if (ini->is_smcd) {
		/* SMC-D specific settings */
		get_device(&ini->ism_dev->dev);
		lgr->peer_gid = ini->ism_gid;
		lgr->smcd = ini->ism_dev;
		lgr_list = &ini->ism_dev->lgr_list;
		lgr_lock = &lgr->smcd->lgr_lock;
		lgr->peer_shutdown = 0;
		atomic_inc(&ini->ism_dev->lgr_cnt);
	} else {
		/* SMC-R specific settings */
		lgr->role = smc->listen_smc ? SMC_SERV : SMC_CLNT;
		memcpy(lgr->peer_systemid, ini->ib_lcl->id_for_peer,
		       SMC_SYSTEMID_LEN);
		memcpy(lgr->pnet_id, ini->ib_dev->pnetid[ini->ib_port - 1],
		       SMC_MAX_PNETID_LEN);
		smc_llc_lgr_init(lgr, smc);

		link_idx = SMC_SINGLE_LINK;
		lnk = &lgr->lnk[link_idx];
		rc = smcr_link_init(lgr, lnk, link_idx, ini);
		if (rc)
			goto free_lgr;
		lgr_list = &smc_lgr_list.list;
		lgr_lock = &smc_lgr_list.lock;
		atomic_inc(&lgr_cnt);
	}
	smc->conn.lgr = lgr;
	spin_lock_bh(lgr_lock);
	list_add(&lgr->list, lgr_list);
	spin_unlock_bh(lgr_lock);
	return 0;

free_lgr:
	kfree(lgr);
ism_put_vlan:
	if (ini->is_smcd && ini->vlan_id)
		smc_ism_put_vlan(ini->ism_dev, ini->vlan_id);
out:
	if (rc < 0) {
		if (rc == -ENOMEM)
			rc = SMC_CLC_DECL_MEM;
		else
			rc = SMC_CLC_DECL_INTERR;
	}
	return rc;
}

static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc,
			   struct smc_link_group *lgr)
{
	int rc;

	if (rmb_desc->is_conf_rkey && !list_empty(&lgr->list)) {
		/* unregister rmb with peer */
		rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
		if (!rc) {
			/* protect against smc_llc_cli_rkey_exchange() */
			mutex_lock(&lgr->llc_conf_mutex);
			smc_llc_do_delete_rkey(lgr, rmb_desc);
			rmb_desc->is_conf_rkey = false;
			mutex_unlock(&lgr->llc_conf_mutex);
			smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
		}
	}

	if (rmb_desc->is_reg_err) {
		/* buf registration failed, reuse not possible */
		mutex_lock(&lgr->rmbs_lock);
		list_del(&rmb_desc->list);
		mutex_unlock(&lgr->rmbs_lock);

		smc_buf_free(lgr, true, rmb_desc);
	} else {
		rmb_desc->used = 0;
	}
}

static void smc_buf_unuse(struct smc_connection *conn,
			  struct smc_link_group *lgr)
{
	if (conn->sndbuf_desc)
		conn->sndbuf_desc->used = 0;
	if (conn->rmb_desc && lgr->is_smcd)
		conn->rmb_desc->used = 0;
	else if (conn->rmb_desc)
		smcr_buf_unuse(conn->rmb_desc, lgr);
}

/* remove a finished connection from its link group */
void smc_conn_free(struct smc_connection *conn)
{
	struct smc_link_group *lgr = conn->lgr;

	if (!lgr)
		return;
	if (lgr->is_smcd) {
		if (!list_empty(&lgr->list))
			smc_ism_unset_conn(conn);
		tasklet_kill(&conn->rx_tsklet);
	} else {
		smc_cdc_tx_dismiss_slots(conn);
	}
	if (!list_empty(&lgr->list)) {
		smc_lgr_unregister_conn(conn);
		smc_buf_unuse(conn, lgr); /* allow buffer reuse */
	}

	if (!lgr->conns_num)
		smc_lgr_schedule_free_work(lgr);
}

/* unregister a link from a buf_desc */
static void smcr_buf_unmap_link(struct smc_buf_desc *buf_desc, bool is_rmb,
				struct smc_link *lnk)
{
	if (is_rmb)
		buf_desc->is_reg_mr[lnk->link_idx] = false;
	if (!buf_desc->is_map_ib[lnk->link_idx])
		return;
	if (is_rmb) {
		if (buf_desc->mr_rx[lnk->link_idx]) {
			smc_ib_put_memory_region(
					buf_desc->mr_rx[lnk->link_idx]);
			buf_desc->mr_rx[lnk->link_idx] = NULL;
		}
		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_FROM_DEVICE);
	} else {
		smc_ib_buf_unmap_sg(lnk, buf_desc, DMA_TO_DEVICE);
	}
	sg_free_table(&buf_desc->sgt[lnk->link_idx]);
	buf_desc->is_map_ib[lnk->link_idx] = false;
}

/* unmap all buffers of lgr for a deleted link */
static void smcr_buf_unmap_lgr(struct smc_link *lnk)
{
	struct smc_link_group *lgr = lnk->lgr;
	struct smc_buf_desc *buf_desc, *bf;
	int i;

	for (i = 0; i < SMC_RMBE_SIZES; i++) {
		mutex_lock(&lgr->rmbs_lock);
		list_for_each_entry_safe(buf_desc, bf, &lgr->rmbs[i], list)
			smcr_buf_unmap_link(buf_desc, true, lnk);
		mutex_unlock(&lgr->rmbs_lock);
		mutex_lock(&lgr->sndbufs_lock);
		list_for_each_entry_safe(buf_desc, bf, &lgr->sndbufs[i],
					 list)
			smcr_buf_unmap_link(buf_desc, false, lnk);
		mutex_unlock(&lgr->sndbufs_lock);
	}
}

static void smcr_rtoken_clear_link(struct smc_link *lnk)
{
	struct smc_link_group *lgr = lnk->lgr;
	int i;

	for (i = 0; i < SMC_RMBS_PER_LGR_MAX; i++) {
		lgr->rtokens[i][lnk->link_idx].rkey = 0;
		lgr->rtokens[i][lnk->link_idx].dma_addr = 0;
	}
}

/* must be called under lgr->llc_conf_mutex lock */
void smcr_link_clear(struct smc_link *lnk)
{
	struct smc_ib_device *smcibdev;

	if (!lnk->lgr || lnk->state == SMC_LNK_UNUSED)
		return;
	lnk->peer_qpn = 0;
	smc_llc_link_clear(lnk);
	smcr_buf_unmap_lgr(lnk);
	smcr_rtoken_clear_link(lnk);
	smc_ib_modify_qp_reset(lnk);
	smc_wr_free_link(lnk);
	smc_ib_destroy_queue_pair(lnk);
	smc_ib_dealloc_protection_domain(lnk);
	smc_wr_free_link_mem(lnk);
	put_device(&lnk->smcibdev->ibdev->dev);
	smcibdev = lnk->smcibdev;
	memset(lnk, 0, sizeof(struct smc_link));
	lnk->state = SMC_LNK_UNUSED;
	if (!atomic_dec_return(&smcibdev->lnk_cnt))
		wake_up(&smcibdev->lnks_deleted);
}

static void smcr_buf_free(struct smc_link_group *lgr, bool is_rmb,
			  struct smc_buf_desc *buf_desc)
{
	int i;

	for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
		smcr_buf_unmap_link(buf_desc, is_rmb, &lgr->lnk[i]);

	if (buf_desc->pages)
		__free_pages(buf_desc->pages, buf_desc->order);
	kfree(buf_desc);
}

static void smcd_buf_free(struct smc_link_group *lgr, bool is_dmb,
			  struct smc_buf_desc *buf_desc)
{
	if (is_dmb) {
		/* restore original buf len */
		buf_desc->len += sizeof(struct smcd_cdc_msg);
		smc_ism_unregister_dmb(lgr->smcd, buf_desc);
	} else {
		kfree(buf_desc->cpu_addr);
	}
	kfree(buf_desc);
}

static void smc_buf_free(struct smc_link_group *lgr, bool is_rmb,
			 struct smc_buf_desc *buf_desc)
{
	if (lgr->is_smcd)
		smcd_buf_free(lgr, is_rmb, buf_desc);
	else
		smcr_buf_free(lgr, is_rmb, buf_desc);
}

static void __smc_lgr_free_bufs(struct smc_link_group *lgr, bool is_rmb)
{
	struct smc_buf_desc *buf_desc, *bf_desc;
	struct list_head *buf_list;
	int i;

	for (i = 0; i < SMC_RMBE_SIZES; i++) {
		if (is_rmb)
			buf_list = &lgr->rmbs[i];
		else
			buf_list = &lgr->sndbufs[i];
		list_for_each_entry_safe(buf_desc, bf_desc, buf_list,
					 list) {
			list_del(&buf_desc->list);
			smc_buf_free(lgr, is_rmb, buf_desc);
		}
	}
}

static void smc_lgr_free_bufs(struct smc_link_group *lgr)
{
	/* free send buffers */
	__smc_lgr_free_bufs(lgr, false);
	/* free rmbs */
	__smc_lgr_free_bufs(lgr, true);
}

/* remove a link group */
static void smc_lgr_free(struct smc_link_group *lgr)
{
	int i;

	smc_lgr_free_bufs(lgr);
	if (lgr->is_smcd) {
		if (!lgr->terminating) {
			smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
			put_device(&lgr->smcd->dev);
		}
		if (!atomic_dec_return(&lgr->smcd->lgr_cnt))
			wake_up(&lgr->smcd->lgrs_deleted);
	} else {
		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
			if (lgr->lnk[i].state != SMC_LNK_UNUSED)
				smcr_link_clear(&lgr->lnk[i]);
		}
		smc_llc_lgr_clear(lgr);
		if (!atomic_dec_return(&lgr_cnt))
			wake_up(&lgrs_deleted);
	}
	kfree(lgr);
}

void smc_lgr_forget(struct smc_link_group *lgr)
{
	struct list_head *lgr_list;
	spinlock_t *lgr_lock;

	lgr_list = smc_lgr_list_head(lgr, &lgr_lock);
	spin_lock_bh(lgr_lock);
	/* do not use this link group for new connections */
	if (!list_empty(lgr_list))
		list_del_init(lgr_list);
	spin_unlock_bh(lgr_lock);
}

static void smcd_unregister_all_dmbs(struct smc_link_group *lgr)
{
	int i;

	for (i = 0; i < SMC_RMBE_SIZES; i++) {
		struct smc_buf_desc *buf_desc;

		list_for_each_entry(buf_desc, &lgr->rmbs[i], list) {
			buf_desc->len += sizeof(struct smcd_cdc_msg);
			smc_ism_unregister_dmb(lgr->smcd, buf_desc);
		}
	}
}

static void smc_sk_wake_ups(struct smc_sock *smc)
{
	smc->sk.sk_write_space(&smc->sk);
	smc->sk.sk_data_ready(&smc->sk);
	smc->sk.sk_state_change(&smc->sk);
}

/* kill a connection */
static void smc_conn_kill(struct smc_connection *conn, bool soft)
{
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);

	if (conn->lgr->is_smcd && conn->lgr->peer_shutdown)
		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
	else
		smc_close_abort(conn);
	conn->killed = 1;
	smc->sk.sk_err = ECONNABORTED;
	smc_sk_wake_ups(smc);
	if (conn->lgr->is_smcd) {
		smc_ism_unset_conn(conn);
		if (soft)
			tasklet_kill(&conn->rx_tsklet);
		else
			tasklet_unlock_wait(&conn->rx_tsklet);
	} else {
		smc_cdc_tx_dismiss_slots(conn);
	}
	smc_lgr_unregister_conn(conn);
	smc_close_active_abort(smc);
}

static void smc_lgr_cleanup(struct smc_link_group *lgr)
{
	int i;

	if (lgr->is_smcd) {
		smc_ism_signal_shutdown(lgr);
		smcd_unregister_all_dmbs(lgr);
		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
		put_device(&lgr->smcd->dev);
	} else {
		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
			struct smc_link *lnk = &lgr->lnk[i];

			if (smc_link_usable(lnk))
				lnk->state = SMC_LNK_INACTIVE;
		}
		wake_up_interruptible_all(&lgr->llc_waiter);
	}
}

/* terminate link group
 * @soft: true if link group shutdown can take its time
 *	  false if immediate link group shutdown is required
 */
static void __smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
{
	struct smc_connection *conn;
	struct smc_sock *smc;
	struct rb_node *node;

	if (lgr->terminating)
		return;	/* lgr already terminating */
	if (!soft)
		cancel_delayed_work_sync(&lgr->free_work);
	lgr->terminating = 1;

	/* kill remaining link group connections */
	read_lock_bh(&lgr->conns_lock);
	node = rb_first(&lgr->conns_all);
	while (node) {
		read_unlock_bh(&lgr->conns_lock);
		conn = rb_entry(node, struct smc_connection, alert_node);
		smc = container_of(conn, struct smc_sock, conn);
		sock_hold(&smc->sk); /* sock_put below */
		lock_sock(&smc->sk);
		smc_conn_kill(conn, soft);
		release_sock(&smc->sk);
		sock_put(&smc->sk); /* sock_hold above */
		read_lock_bh(&lgr->conns_lock);
		node = rb_first(&lgr->conns_all);
	}
	read_unlock_bh(&lgr->conns_lock);
	smc_lgr_cleanup(lgr);
	if (soft)
		smc_lgr_schedule_free_work_fast(lgr);
	else
		smc_lgr_free(lgr);
}

/* unlink link group and schedule termination */
void smc_lgr_terminate_sched(struct smc_link_group *lgr)
{
	spinlock_t *lgr_lock;

	smc_lgr_list_head(lgr, &lgr_lock);
	spin_lock_bh(lgr_lock);
	if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
		spin_unlock_bh(lgr_lock);
		return;	/* lgr already terminating */
	}
	list_del_init(&lgr->list);
	spin_unlock_bh(lgr_lock);
	schedule_work(&lgr->terminate_work);
}

/* Called when peer lgr shutdown (regularly or abnormally) is received */
void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan)
{
	struct smc_link_group *lgr, *l;
	LIST_HEAD(lgr_free_list);

	/* run common cleanup function and build free list */
	spin_lock_bh(&dev->lgr_lock);
	list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) {
		if ((!peer_gid || lgr->peer_gid == peer_gid) &&
		    (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) {
			if (peer_gid) /* peer triggered termination */
				lgr->peer_shutdown = 1;
			list_move(&lgr->list, &lgr_free_list);
		}
	}
	spin_unlock_bh(&dev->lgr_lock);

	/* cancel the regular free workers and actually free lgrs */
	list_for_each_entry_safe(lgr, l, &lgr_free_list, list) {
		list_del_init(&lgr->list);
		schedule_work(&lgr->terminate_work);
	}
}

/* Called when an SMCD device is removed or the smc module is unloaded */
void smc_smcd_terminate_all(struct smcd_dev *smcd)
{
	struct smc_link_group *lgr, *lg;
	LIST_HEAD(lgr_free_list);

	spin_lock_bh(&smcd->lgr_lock);
	list_splice_init(&smcd->lgr_list, &lgr_free_list);
	list_for_each_entry(lgr, &lgr_free_list, list)
		lgr->freeing = 1;
	spin_unlock_bh(&smcd->lgr_lock);

	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
		list_del_init(&lgr->list);
		__smc_lgr_terminate(lgr, false);
	}

	if (atomic_read(&smcd->lgr_cnt))
		wait_event(smcd->lgrs_deleted, !atomic_read(&smcd->lgr_cnt));
}

/* Called when an SMCR device is removed or the smc module is unloaded.
 * If smcibdev is given, all SMCR link groups using this device are terminated.
 * If smcibdev is NULL, all SMCR link groups are terminated.
 */
void smc_smcr_terminate_all(struct smc_ib_device *smcibdev)
{
	struct smc_link_group *lgr, *lg;
	LIST_HEAD(lgr_free_list);
	int i;

	spin_lock_bh(&smc_lgr_list.lock);
	if (!smcibdev) {
		list_splice_init(&smc_lgr_list.list, &lgr_free_list);
		list_for_each_entry(lgr, &lgr_free_list, list)
			lgr->freeing = 1;
	} else {
		list_for_each_entry_safe(lgr, lg, &smc_lgr_list.list, list) {
			for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
				if (lgr->lnk[i].smcibdev == smcibdev)
					smcr_link_down_cond_sched(&lgr->lnk[i]);
			}
		}
	}
	spin_unlock_bh(&smc_lgr_list.lock);

	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
		list_del_init(&lgr->list);
		__smc_lgr_terminate(lgr, false);
	}

	if (smcibdev) {
		if (atomic_read(&smcibdev->lnk_cnt))
			wait_event(smcibdev->lnks_deleted,
				   !atomic_read(&smcibdev->lnk_cnt));
	} else {
		if (atomic_read(&lgr_cnt))
			wait_event(lgrs_deleted, !atomic_read(&lgr_cnt));
	}
}

/* link is up - establish alternate link if applicable */
static void smcr_link_up(struct smc_link_group *lgr,
			 struct smc_ib_device *smcibdev, u8 ibport)
{
	struct smc_link *link = NULL;

	if (list_empty(&lgr->list) ||
	    lgr->type == SMC_LGR_SYMMETRIC ||
	    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
		return;

	if (lgr->role == SMC_SERV) {
		/* trigger local add link processing */
		link = smc_llc_usable_link(lgr);
		if (!link)
			return;
		/* tbd: call smc_llc_srv_add_link_local(link); */
	} else {
		/* invite server to start add link processing */
		u8 gid[SMC_GID_SIZE];

		if (smc_ib_determine_gid(smcibdev, ibport, lgr->vlan_id, gid,
					 NULL))
			return;
		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
			/* some other llc task is ongoing */
			wait_event_interruptible_timeout(lgr->llc_waiter,
				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
				SMC_LLC_WAIT_TIME);
		}
		if (list_empty(&lgr->list) ||
		    !smc_ib_port_active(smcibdev, ibport))
			return; /* lgr or device no longer active */
		link = smc_llc_usable_link(lgr);
		if (!link)
			return;
		smc_llc_send_add_link(link, smcibdev->mac[ibport - 1], gid,
				      NULL, SMC_LLC_REQ);
	}
}

void smcr_port_add(struct smc_ib_device *smcibdev, u8 ibport)
{
	struct smc_ib_up_work *ib_work;
	struct smc_link_group *lgr, *n;

	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
			    SMC_MAX_PNETID_LEN) ||
		    lgr->type == SMC_LGR_SYMMETRIC ||
		    lgr->type == SMC_LGR_ASYMMETRIC_PEER)
			continue;
		ib_work = kmalloc(sizeof(*ib_work), GFP_KERNEL);
		if (!ib_work)
			continue;
		INIT_WORK(&ib_work->work, smc_link_up_work);
		ib_work->lgr = lgr;
		ib_work->smcibdev = smcibdev;
		ib_work->ibport = ibport;
		schedule_work(&ib_work->work);
	}
}

/* link is down - switch connections to alternate link,
 * must be called under lgr->llc_conf_mutex lock
 */
static void smcr_link_down(struct smc_link *lnk)
{
	struct smc_link_group *lgr = lnk->lgr;
	struct smc_link *to_lnk;
	int del_link_id;

	if (!lgr || lnk->state == SMC_LNK_UNUSED || list_empty(&lgr->list))
		return;

	smc_ib_modify_qp_reset(lnk);
	to_lnk = NULL;
	/* tbd: call to_lnk = smc_switch_conns(lgr, lnk, true); */
	if (!to_lnk) { /* no backup link available */
		smcr_link_clear(lnk);
		return;
	}
	lgr->type = SMC_LGR_SINGLE;
	del_link_id = lnk->link_id;

	if (lgr->role == SMC_SERV) {
		/* trigger local delete link processing */
	} else {
		if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
			/* another llc task is ongoing */
			mutex_unlock(&lgr->llc_conf_mutex);
			wait_event_interruptible_timeout(lgr->llc_waiter,
				(lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE),
				SMC_LLC_WAIT_TIME);
			mutex_lock(&lgr->llc_conf_mutex);
		}
		smc_llc_send_delete_link(to_lnk, del_link_id, SMC_LLC_REQ, true,
					 SMC_LLC_DEL_LOST_PATH);
	}
}

/* must be called under lgr->llc_conf_mutex lock */
void smcr_link_down_cond(struct smc_link *lnk)
{
	if (smc_link_downing(&lnk->state))
		smcr_link_down(lnk);
}

/* will get the lgr->llc_conf_mutex lock */
void smcr_link_down_cond_sched(struct smc_link *lnk)
{
	if (smc_link_downing(&lnk->state))
		schedule_work(&lnk->link_down_wrk);
}

void smcr_port_err(struct smc_ib_device *smcibdev, u8 ibport)
{
	struct smc_link_group *lgr, *n;
	int i;

	list_for_each_entry_safe(lgr, n, &smc_lgr_list.list, list) {
		if (strncmp(smcibdev->pnetid[ibport - 1], lgr->pnet_id,
			    SMC_MAX_PNETID_LEN))
			continue; /* lgr is not affected */
		if (list_empty(&lgr->list))