[SCSI] libcxgbi: common library for cxgb3i and cxgb4i

[PATCH v5 1/3] libcxgbi: common library for cxgb3i and cxgb4i

From: Karen Xie <kxie@chelsio.com>

Extracts common functions to libcxgbi.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 2610 insertions, 0 deletions

diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c
new file mode 100644
index 000000000000..db9d08a831d0
--- /dev/null
+++ b/drivers/scsi/cxgbi/libcxgbi.c
@@ -0,0 +1,2610 @@
+/*
+ * libcxgbi.c: Chelsio common library for T3/T4 iSCSI driver.
+ *
+ * Copyright (c) 2010 Chelsio Communications, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ *
+ * Written by: Karen Xie (kxie@chelsio.com)
+ * Written by: Rakesh Ranjan (rranjan@chelsio.com)
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/skbuff.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+#include <linux/pci.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_host.h>
+#include <linux/if_vlan.h>
+#include <linux/inet.h>
+#include <net/dst.h>
+#include <net/route.h>
+#include <linux/inetdevice.h>	/* ip_dev_find */
+#include <net/tcp.h>
+
+static unsigned int dbg_level;
+
+#include "libcxgbi.h"
+
+#define DRV_MODULE_NAME		"libcxgbi"
+#define DRV_MODULE_DESC		"Chelsio iSCSI driver library"
+#define DRV_MODULE_VERSION	"0.9.0"
+#define DRV_MODULE_RELDATE	"Jun. 2010"
+
+MODULE_AUTHOR("Chelsio Communications, Inc.");
+MODULE_DESCRIPTION(DRV_MODULE_DESC);
+MODULE_VERSION(DRV_MODULE_VERSION);
+MODULE_LICENSE("GPL");
+
+module_param(dbg_level, uint, 0644);
+MODULE_PARM_DESC(dbg_level, "libiscsi debug level (default=0)");
+
+
+/*
+ * cxgbi device management
+ * maintains a list of the cxgbi devices
+ */
+static LIST_HEAD(cdev_list);
+static DEFINE_MUTEX(cdev_mutex);
+
+int cxgbi_device_portmap_create(struct cxgbi_device *cdev, unsigned int base,
+				unsigned int max_conn)
+{
+	struct cxgbi_ports_map *pmap = &cdev->pmap;
+
+	pmap->port_csk = cxgbi_alloc_big_mem(max_conn *
+					     sizeof(struct cxgbi_sock *),
+					     GFP_KERNEL);
+	if (!pmap->port_csk) {
+		pr_warn("cdev 0x%p, portmap OOM %u.\n", cdev, max_conn);
+		return -ENOMEM;
+	}
+
+	pmap->max_connect = max_conn;
+	pmap->sport_base = base;
+	spin_lock_init(&pmap->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_portmap_create);
+
+void cxgbi_device_portmap_cleanup(struct cxgbi_device *cdev)
+{
+	struct cxgbi_ports_map *pmap = &cdev->pmap;
+	struct cxgbi_sock *csk;
+	int i;
+
+	for (i = 0; i < pmap->max_connect; i++) {
+		if (pmap->port_csk[i]) {
+			csk = pmap->port_csk[i];
+			pmap->port_csk[i] = NULL;
+			log_debug(1 << CXGBI_DBG_SOCK,
+				"csk 0x%p, cdev 0x%p, offload down.\n",
+				csk, cdev);
+			spin_lock_bh(&csk->lock);
+			cxgbi_sock_set_flag(csk, CTPF_OFFLOAD_DOWN);
+			cxgbi_sock_closed(csk);
+			spin_unlock_bh(&csk->lock);
+			cxgbi_sock_put(csk);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_portmap_cleanup);
+
+static inline void cxgbi_device_destroy(struct cxgbi_device *cdev)
+{
+	log_debug(1 << CXGBI_DBG_DEV,
+		"cdev 0x%p, p# %u.\n", cdev, cdev->nports);
+	cxgbi_hbas_remove(cdev);
+	cxgbi_device_portmap_cleanup(cdev);
+	if (cdev->dev_ddp_cleanup)
+		cdev->dev_ddp_cleanup(cdev);
+	else
+		cxgbi_ddp_cleanup(cdev);
+	if (cdev->ddp)
+		cxgbi_ddp_cleanup(cdev);
+	if (cdev->pmap.max_connect)
+		cxgbi_free_big_mem(cdev->pmap.port_csk);
+	kfree(cdev);
+}
+
+struct cxgbi_device *cxgbi_device_register(unsigned int extra,
+					   unsigned int nports)
+{
+	struct cxgbi_device *cdev;
+
+	cdev = kzalloc(sizeof(*cdev) + extra + nports *
+			(sizeof(struct cxgbi_hba *) +
+			 sizeof(struct net_device *)),
+			GFP_KERNEL);
+	if (!cdev) {
+		pr_warn("nport %d, OOM.\n", nports);
+		return NULL;
+	}
+	cdev->ports = (struct net_device **)(cdev + 1);
+	cdev->hbas = (struct cxgbi_hba **)(((char*)cdev->ports) + nports *
+						sizeof(struct net_device *));
+	if (extra)
+		cdev->dd_data = ((char *)cdev->hbas) +
+				nports * sizeof(struct cxgbi_hba *);
+	spin_lock_init(&cdev->pmap.lock);
+
+	mutex_lock(&cdev_mutex);
+	list_add_tail(&cdev->list_head, &cdev_list);
+	mutex_unlock(&cdev_mutex);
+
+	log_debug(1 << CXGBI_DBG_DEV,
+		"cdev 0x%p, p# %u.\n", cdev, nports);
+	return cdev;
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_register);
+
+void cxgbi_device_unregister(struct cxgbi_device *cdev)
+{
+	log_debug(1 << CXGBI_DBG_DEV,
+		"cdev 0x%p, p# %u,%s.\n",
+		cdev, cdev->nports, cdev->nports ? cdev->ports[0]->name : "");
+	mutex_lock(&cdev_mutex);
+	list_del(&cdev->list_head);
+	mutex_unlock(&cdev_mutex);
+	cxgbi_device_destroy(cdev);
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_unregister);
+
+void cxgbi_device_unregister_all(unsigned int flag)
+{
+	struct cxgbi_device *cdev, *tmp;
+
+	mutex_lock(&cdev_mutex);
+	list_for_each_entry_safe(cdev, tmp, &cdev_list, list_head) {
+		if ((cdev->flags & flag) == flag) {
+			log_debug(1 << CXGBI_DBG_DEV,
+				"cdev 0x%p, p# %u,%s.\n",
+				cdev, cdev->nports, cdev->nports ?
+				 cdev->ports[0]->name : "");
+			list_del(&cdev->list_head);
+			cxgbi_device_destroy(cdev);
+		}
+	}
+	mutex_unlock(&cdev_mutex);
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_unregister_all);
+
+struct cxgbi_device *cxgbi_device_find_by_lldev(void *lldev)
+{
+	struct cxgbi_device *cdev, *tmp;
+
+	mutex_lock(&cdev_mutex);
+	list_for_each_entry_safe(cdev, tmp, &cdev_list, list_head) {
+		if (cdev->lldev == lldev) {
+			mutex_unlock(&cdev_mutex);
+			return cdev;
+		}
+	}
+	mutex_unlock(&cdev_mutex);
+	log_debug(1 << CXGBI_DBG_DEV,
+		"lldev 0x%p, NO match found.\n", lldev);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(cxgbi_device_find_by_lldev);
+
+static struct cxgbi_device *cxgbi_device_find_by_netdev(struct net_device *ndev,
+							int *port)
+{
+	struct cxgbi_device *cdev, *tmp;
+	int i;
+
+	if (ndev->priv_flags & IFF_802_1Q_VLAN)
+		ndev = vlan_dev_real_dev(ndev);
+
+	mutex_lock(&cdev_mutex);
+	list_for_each_entry_safe(cdev, tmp, &cdev_list, list_head) {
+		for (i = 0; i < cdev->nports; i++) {
+			if (ndev == cdev->ports[i]) {
+				mutex_unlock(&cdev_mutex);
+				if (port)
+					*port = i;
+				return cdev;
+			}
+		}
+	}
+	mutex_unlock(&cdev_mutex);
+	log_debug(1 << CXGBI_DBG_DEV,
+		"ndev 0x%p, %s, NO match found.\n", ndev, ndev->name);
+	return NULL;
+}
+
+struct cxgbi_hba *cxgbi_hba_find_by_netdev(struct net_device *dev,
+					struct cxgbi_device *cdev)
+{
+	int i;
+
+	if (dev->priv_flags & IFF_802_1Q_VLAN)
+		dev = vlan_dev_real_dev(dev);
+
+	for (i = 0; i < cdev->nports; i++) {
+		if (cdev->hbas[i]->ndev == dev)
+			return cdev->hbas[i];
+	}
+	log_debug(1 << CXGBI_DBG_DEV,
+		"ndev 0x%p, %s, cdev 0x%p, NO match found.\n",
+		dev, dev->name, cdev);
+	return NULL;
+}
+
+void cxgbi_hbas_remove(struct cxgbi_device *cdev)
+{
+	int i;
+	struct cxgbi_hba *chba;
+
+	log_debug(1 << CXGBI_DBG_DEV,
+		"cdev 0x%p, p#%u.\n", cdev, cdev->nports);
+
+	for (i = 0; i < cdev->nports; i++) {
+		chba = cdev->hbas[i];
+		if (chba) {
+			cdev->hbas[i] = NULL;
+			iscsi_host_remove(chba->shost);
+			pci_dev_put(cdev->pdev);
+			iscsi_host_free(chba->shost);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_hbas_remove);
+
+int cxgbi_hbas_add(struct cxgbi_device *cdev, unsigned int max_lun,
+		unsigned int max_id, struct scsi_host_template *sht,
+		struct scsi_transport_template *stt)
+{
+	struct cxgbi_hba *chba;
+	struct Scsi_Host *shost;
+	int i, err;
+
+	log_debug(1 << CXGBI_DBG_DEV, "cdev 0x%p, p#%u.\n", cdev, cdev->nports);
+
+	for (i = 0; i < cdev->nports; i++) {
+		shost = iscsi_host_alloc(sht, sizeof(*chba), 1);
+		if (!shost) {
+			pr_info("0x%p, p%d, %s, host alloc failed.\n",
+				cdev, i, cdev->ports[i]->name);
+			err = -ENOMEM;
+			goto err_out;
+		}
+
+		shost->transportt = stt;
+		shost->max_lun = max_lun;
+		shost->max_id = max_id;
+		shost->max_channel = 0;
+		shost->max_cmd_len = 16;
+
+		chba = iscsi_host_priv(shost);
+		chba->cdev = cdev;
+		chba->ndev = cdev->ports[i];
+		chba->shost = shost;
+
+		log_debug(1 << CXGBI_DBG_DEV,
+			"cdev 0x%p, p#%d %s: chba 0x%p.\n",
+			cdev, i, cdev->ports[i]->name, chba);
+
+		pci_dev_get(cdev->pdev);
+		err = iscsi_host_add(shost, &cdev->pdev->dev);
+		if (err) {
+			pr_info("cdev 0x%p, p#%d %s, host add failed.\n",
+				cdev, i, cdev->ports[i]->name);
+			pci_dev_put(cdev->pdev);
+			scsi_host_put(shost);
+			goto  err_out;
+		}
+
+		cdev->hbas[i] = chba;
+	}
+
+	return 0;
+
+err_out:
+	cxgbi_hbas_remove(cdev);
+	return err;
+}
+EXPORT_SYMBOL_GPL(cxgbi_hbas_add);
+
+/*
+ * iSCSI offload
+ *
+ * - source port management
+ *   To find a free source port in the port allocation map we use a very simple
+ *   rotor scheme to look for the next free port.
+ *
+ *   If a source port has been specified make sure that it doesn't collide with
+ *   our normal source port allocation map.  If it's outside the range of our
+ *   allocation/deallocation scheme just let them use it.
+ *
+ *   If the source port is outside our allocation range, the caller is
+ *   responsible for keeping track of their port usage.
+ */
+static int sock_get_port(struct cxgbi_sock *csk)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct cxgbi_ports_map *pmap = &cdev->pmap;
+	unsigned int start;
+	int idx;
+
+	if (!pmap->max_connect) {
+		pr_err("cdev 0x%p, p#%u %s, NO port map.\n",
+			   cdev, csk->port_id, cdev->ports[csk->port_id]->name);
+		return -EADDRNOTAVAIL;
+	}
+
+	if (csk->saddr.sin_port) {
+		pr_err("source port NON-ZERO %u.\n",
+			ntohs(csk->saddr.sin_port));
+		return -EADDRINUSE;
+	}
+
+	spin_lock_bh(&pmap->lock);
+	if (pmap->used >= pmap->max_connect) {
+		spin_unlock_bh(&pmap->lock);
+		pr_info("cdev 0x%p, p#%u %s, ALL ports used.\n",
+			cdev, csk->port_id, cdev->ports[csk->port_id]->name);
+		return -EADDRNOTAVAIL;
+	}
+
+	start = idx = pmap->next;
+	do {
+		if (++idx >= pmap->max_connect)
+			idx = 0;
+		if (!pmap->port_csk[idx]) {
+			pmap->used++;
+			csk->saddr.sin_port =
+				htons(pmap->sport_base + idx);
+			pmap->next = idx;
+			pmap->port_csk[idx] = csk;
+			spin_unlock_bh(&pmap->lock);
+			cxgbi_sock_get(csk);
+			log_debug(1 << CXGBI_DBG_SOCK,
+				"cdev 0x%p, p#%u %s, p %u, %u.\n",
+				cdev, csk->port_id,
+				cdev->ports[csk->port_id]->name,
+				pmap->sport_base + idx, pmap->next);
+			return 0;
+		}
+	} while (idx != start);
+	spin_unlock_bh(&pmap->lock);
+
+	/* should not happen */
+	pr_warn("cdev 0x%p, p#%u %s, next %u?\n",
+		cdev, csk->port_id, cdev->ports[csk->port_id]->name,
+		pmap->next);
+	return -EADDRNOTAVAIL;
+}
+
+static void sock_put_port(struct cxgbi_sock *csk)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct cxgbi_ports_map *pmap = &cdev->pmap;
+
+	if (csk->saddr.sin_port) {
+		int idx = ntohs(csk->saddr.sin_port) - pmap->sport_base;
+
+		csk->saddr.sin_port = 0;
+		if (idx < 0 || idx >= pmap->max_connect) {
+			pr_err("cdev 0x%p, p#%u %s, port %u OOR.\n",
+				cdev, csk->port_id,
+				cdev->ports[csk->port_id]->name,
+				ntohs(csk->saddr.sin_port));
+			return;
+		}
+
+		spin_lock_bh(&pmap->lock);
+		pmap->port_csk[idx] = NULL;
+		pmap->used--;
+		spin_unlock_bh(&pmap->lock);
+
+		log_debug(1 << CXGBI_DBG_SOCK,
+			"cdev 0x%p, p#%u %s, release %u.\n",
+			cdev, csk->port_id, cdev->ports[csk->port_id]->name,
+			pmap->sport_base + idx);
+
+		cxgbi_sock_put(csk);
+	}
+}
+
+/*
+ * iscsi tcp connection
+ */
+void cxgbi_sock_free_cpl_skbs(struct cxgbi_sock *csk)
+{
+	if (csk->cpl_close) {
+		kfree_skb(csk->cpl_close);
+		csk->cpl_close = NULL;
+	}
+	if (csk->cpl_abort_req) {
+		kfree_skb(csk->cpl_abort_req);
+		csk->cpl_abort_req = NULL;
+	}
+	if (csk->cpl_abort_rpl) {
+		kfree_skb(csk->cpl_abort_rpl);
+		csk->cpl_abort_rpl = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_free_cpl_skbs);
+
+static struct cxgbi_sock *cxgbi_sock_create(struct cxgbi_device *cdev)
+{
+	struct cxgbi_sock *csk = kzalloc(sizeof(*csk), GFP_NOIO);
+
+	if (!csk) {
+		pr_info("alloc csk %zu failed.\n", sizeof(*csk));
+		return NULL;
+	}
+
+	if (cdev->csk_alloc_cpls(csk) < 0) {
+		pr_info("csk 0x%p, alloc cpls failed.\n", csk);
+		kfree(csk);
+		return NULL;
+	}
+
+	spin_lock_init(&csk->lock);
+	kref_init(&csk->refcnt);
+	skb_queue_head_init(&csk->receive_queue);
+	skb_queue_head_init(&csk->write_queue);
+	setup_timer(&csk->retry_timer, NULL, (unsigned long)csk);
+	rwlock_init(&csk->callback_lock);
+	csk->cdev = cdev;
+	csk->flags = 0;
+	cxgbi_sock_set_state(csk, CTP_CLOSED);
+
+	log_debug(1 << CXGBI_DBG_SOCK, "cdev 0x%p, new csk 0x%p.\n", cdev, csk);
+
+	return csk;
+}
+
+static struct rtable *find_route_ipv4(__be32 saddr, __be32 daddr,
+					__be16 sport, __be16 dport, u8 tos)
+{
+	struct rtable *rt;
+	struct flowi fl = {
+		.oif = 0,
+		.nl_u = {
+			.ip4_u = {
+				.daddr = daddr,
+				.saddr = saddr,
+				.tos = tos }
+			},
+		.proto = IPPROTO_TCP,
+		.uli_u = {
+			.ports = {
+				.sport = sport,
+				.dport = dport }
+			}
+	};
+
+	if (ip_route_output_flow(&init_net, &rt, &fl, NULL, 0))
+		return NULL;
+
+	return rt;
+}
+
+static struct cxgbi_sock *cxgbi_check_route(struct sockaddr *dst_addr)
+{
+	struct sockaddr_in *daddr = (struct sockaddr_in *)dst_addr;
+	struct dst_entry *dst;
+	struct net_device *ndev;
+	struct cxgbi_device *cdev;
+	struct rtable *rt = NULL;
+	struct cxgbi_sock *csk = NULL;
+	unsigned int mtu = 0;
+	int port = 0xFFFF;
+	int err = 0;
+
+	if (daddr->sin_family != AF_INET) {
+		pr_info("address family 0x%x NOT supported.\n",
+			daddr->sin_family);
+		err = -EAFNOSUPPORT;
+		goto err_out;
+	}
+
+	rt = find_route_ipv4(0, daddr->sin_addr.s_addr, 0, daddr->sin_port, 0);
+	if (!rt) {
+		pr_info("no route to ipv4 0x%x, port %u.\n",
+			daddr->sin_addr.s_addr, daddr->sin_port);
+		err = -ENETUNREACH;
+		goto err_out;
+	}
+	dst = &rt->dst;
+	ndev = dst->neighbour->dev;
+
+	if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
+		pr_info("multi-cast route %pI4, port %u, dev %s.\n",
+			&daddr->sin_addr.s_addr, ntohs(daddr->sin_port),
+			ndev->name);
+		err = -ENETUNREACH;
+		goto rel_rt;
+	}
+
+	if (ndev->flags & IFF_LOOPBACK) {
+		ndev = ip_dev_find(&init_net, daddr->sin_addr.s_addr);
+		mtu = ndev->mtu;
+		pr_info("rt dev %s, loopback -> %s, mtu %u.\n",
+			dst->neighbour->dev->name, ndev->name, mtu);
+	}
+
+	if (ndev->priv_flags & IFF_802_1Q_VLAN) {
+		ndev = vlan_dev_real_dev(ndev);
+		pr_info("rt dev %s, vlan -> %s.\n",
+			dst->neighbour->dev->name, ndev->name);
+	}
+
+	cdev = cxgbi_device_find_by_netdev(ndev, &port);
+	if (!cdev) {
+		pr_info("dst %pI4, %s, NOT cxgbi device.\n",
+			&daddr->sin_addr.s_addr, ndev->name);
+		err = -ENETUNREACH;
+		goto rel_rt;
+	}
+	log_debug(1 << CXGBI_DBG_SOCK,
+		"route to %pI4 :%u, ndev p#%d,%s, cdev 0x%p.\n",
+		&daddr->sin_addr.s_addr, ntohs(daddr->sin_port),
+			   port, ndev->name, cdev);
+
+	csk = cxgbi_sock_create(cdev);
+	if (!csk) {
+		err = -ENOMEM;
+		goto rel_rt;
+	}
+	csk->cdev = cdev;
+	csk->port_id = port;
+	csk->mtu = mtu;
+	csk->dst = dst;
+	csk->daddr.sin_addr.s_addr = daddr->sin_addr.s_addr;
+	csk->daddr.sin_port = daddr->sin_port;
+	if (cdev->hbas[port]->ipv4addr)
+		csk->saddr.sin_addr.s_addr = cdev->hbas[port]->ipv4addr;
+	else
+		csk->saddr.sin_addr.s_addr = rt->rt_src;
+
+	return csk;
+
+rel_rt:
+	ip_rt_put(rt);
+	if (csk)
+		cxgbi_sock_closed(csk);
+err_out:
+	return ERR_PTR(err);
+}
+
+void cxgbi_sock_established(struct cxgbi_sock *csk, unsigned int snd_isn,
+			unsigned int opt)
+{
+	csk->write_seq = csk->snd_nxt = csk->snd_una = snd_isn;
+	dst_confirm(csk->dst);
+	smp_mb();
+	cxgbi_sock_set_state(csk, CTP_ESTABLISHED);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_established);
+
+static void cxgbi_inform_iscsi_conn_closing(struct cxgbi_sock *csk)
+{
+	log_debug(1 << CXGBI_DBG_SOCK,
+		"csk 0x%p, state %u, flags 0x%lx, conn 0x%p.\n",
+		csk, csk->state, csk->flags, csk->user_data);
+
+	if (csk->state != CTP_ESTABLISHED) {
+		read_lock(&csk->callback_lock);
+		if (csk->user_data)
+			iscsi_conn_failure(csk->user_data,
+					ISCSI_ERR_CONN_FAILED);
+		read_unlock(&csk->callback_lock);
+	}
+}
+
+void cxgbi_sock_closed(struct cxgbi_sock *csk)
+{
+	log_debug(1 << CXGBI_DBG_SOCK, "csk 0x%p,%u,0x%lx,%u.\n",
+		csk, (csk)->state, (csk)->flags, (csk)->tid);
+	cxgbi_sock_set_flag(csk, CTPF_ACTIVE_CLOSE_NEEDED);
+	if (csk->state == CTP_ACTIVE_OPEN || csk->state == CTP_CLOSED)
+		return;
+	if (csk->saddr.sin_port)
+		sock_put_port(csk);
+	if (csk->dst)
+		dst_release(csk->dst);
+	csk->cdev->csk_release_offload_resources(csk);
+	cxgbi_sock_set_state(csk, CTP_CLOSED);
+	cxgbi_inform_iscsi_conn_closing(csk);
+	cxgbi_sock_put(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_closed);
+
+static void need_active_close(struct cxgbi_sock *csk)
+{
+	int data_lost;
+	int close_req = 0;
+
+	log_debug(1 << CXGBI_DBG_SOCK, "csk 0x%p,%u,0x%lx,%u.\n",
+		csk, (csk)->state, (csk)->flags, (csk)->tid);
+	spin_lock_bh(&csk->lock);
+	dst_confirm(csk->dst);
+	data_lost = skb_queue_len(&csk->receive_queue);
+	__skb_queue_purge(&csk->receive_queue);
+
+	if (csk->state == CTP_ACTIVE_OPEN)
+		cxgbi_sock_set_flag(csk, CTPF_ACTIVE_CLOSE_NEEDED);
+	else if (csk->state == CTP_ESTABLISHED) {
+		close_req = 1;
+		cxgbi_sock_set_state(csk, CTP_ACTIVE_CLOSE);
+	} else if (csk->state == CTP_PASSIVE_CLOSE) {
+		close_req = 1;
+		cxgbi_sock_set_state(csk, CTP_CLOSE_WAIT_2);
+	}
+
+	if (close_req) {
+		if (data_lost)
+			csk->cdev->csk_send_abort_req(csk);
+		else
+			csk->cdev->csk_send_close_req(csk);
+	}
+
+	spin_unlock_bh(&csk->lock);
+}
+
+void cxgbi_sock_fail_act_open(struct cxgbi_sock *csk, int errno)
+{
+	pr_info("csk 0x%p,%u,%lx, %pI4:%u-%pI4:%u, err %d.\n",
+			csk, csk->state, csk->flags,
+			&csk->saddr.sin_addr.s_addr, csk->saddr.sin_port,
+			&csk->daddr.sin_addr.s_addr, csk->daddr.sin_port,
+			errno);
+
+	cxgbi_sock_set_state(csk, CTP_CONNECTING);
+	csk->err = errno;
+	cxgbi_sock_closed(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_fail_act_open);
+
+void cxgbi_sock_act_open_req_arp_failure(void *handle, struct sk_buff *skb)
+{
+	struct cxgbi_sock *csk = (struct cxgbi_sock *)skb->sk;
+
+	log_debug(1 << CXGBI_DBG_SOCK, "csk 0x%p,%u,0x%lx,%u.\n",
+		csk, (csk)->state, (csk)->flags, (csk)->tid);
+	cxgbi_sock_get(csk);
+	spin_lock_bh(&csk->lock);
+	if (csk->state == CTP_ACTIVE_OPEN)
+		cxgbi_sock_fail_act_open(csk, -EHOSTUNREACH);
+	spin_unlock_bh(&csk->lock);
+	cxgbi_sock_put(csk);
+	__kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_act_open_req_arp_failure);
+
+void cxgbi_sock_rcv_abort_rpl(struct cxgbi_sock *csk)
+{
+	cxgbi_sock_get(csk);
+	spin_lock_bh(&csk->lock);
+	if (cxgbi_sock_flag(csk, CTPF_ABORT_RPL_PENDING)) {
+		if (!cxgbi_sock_flag(csk, CTPF_ABORT_RPL_RCVD))
+			cxgbi_sock_set_flag(csk, CTPF_ABORT_RPL_RCVD);
+		else {
+			cxgbi_sock_clear_flag(csk, CTPF_ABORT_RPL_RCVD);
+			cxgbi_sock_clear_flag(csk, CTPF_ABORT_RPL_PENDING);
+			if (cxgbi_sock_flag(csk, CTPF_ABORT_REQ_RCVD))
+				pr_err("csk 0x%p,%u,0x%lx,%u,ABT_RPL_RSS.\n",
+					csk, csk->state, csk->flags, csk->tid);
+			cxgbi_sock_closed(csk);
+		}
+	}
+	spin_unlock_bh(&csk->lock);
+	cxgbi_sock_put(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_rcv_abort_rpl);
+
+void cxgbi_sock_rcv_peer_close(struct cxgbi_sock *csk)
+{
+	log_debug(1 << CXGBI_DBG_SOCK, "csk 0x%p,%u,0x%lx,%u.\n",
+		csk, (csk)->state, (csk)->flags, (csk)->tid);
+	cxgbi_sock_get(csk);
+	spin_lock_bh(&csk->lock);
+
+	if (cxgbi_sock_flag(csk, CTPF_ABORT_RPL_PENDING))
+		goto done;
+
+	switch (csk->state) {
+	case CTP_ESTABLISHED:
+		cxgbi_sock_set_state(csk, CTP_PASSIVE_CLOSE);
+		break;
+	case CTP_ACTIVE_CLOSE:
+		cxgbi_sock_set_state(csk, CTP_CLOSE_WAIT_2);
+		break;
+	case CTP_CLOSE_WAIT_1:
+		cxgbi_sock_closed(csk);
+		break;
+	case CTP_ABORTING:
+		break;
+	default:
+		pr_err("csk 0x%p,%u,0x%lx,%u, bad state.\n",
+			csk, csk->state, csk->flags, csk->tid);
+	}
+	cxgbi_inform_iscsi_conn_closing(csk);
+done:
+	spin_unlock_bh(&csk->lock);
+	cxgbi_sock_put(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_rcv_peer_close);
+
+void cxgbi_sock_rcv_close_conn_rpl(struct cxgbi_sock *csk, u32 snd_nxt)
+{
+	log_debug(1 << CXGBI_DBG_SOCK, "csk 0x%p,%u,0x%lx,%u.\n",
+		csk, (csk)->state, (csk)->flags, (csk)->tid);
+	cxgbi_sock_get(csk);
+	spin_lock_bh(&csk->lock);
+
+	csk->snd_una = snd_nxt - 1;
+	if (cxgbi_sock_flag(csk, CTPF_ABORT_RPL_PENDING))
+		goto done;
+
+	switch (csk->state) {
+	case CTP_ACTIVE_CLOSE:
+		cxgbi_sock_set_state(csk, CTP_CLOSE_WAIT_1);
+		break;
+	case CTP_CLOSE_WAIT_1:
+	case CTP_CLOSE_WAIT_2:
+		cxgbi_sock_closed(csk);
+		break;
+	case CTP_ABORTING:
+		break;
+	default:
+		pr_err("csk 0x%p,%u,0x%lx,%u, bad state.\n",
+			csk, csk->state, csk->flags, csk->tid);
+	}
+done:
+	spin_unlock_bh(&csk->lock);
+	cxgbi_sock_put(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_rcv_close_conn_rpl);
+
+void cxgbi_sock_rcv_wr_ack(struct cxgbi_sock *csk, unsigned int credits,
+			   unsigned int snd_una, int seq_chk)
+{
+	log_debug(1 << CXGBI_DBG_TOE | 1 << CXGBI_DBG_SOCK,
+			"csk 0x%p,%u,0x%lx,%u, cr %u,%u+%u, snd_una %u,%d.\n",
+			csk, csk->state, csk->flags, csk->tid, credits,
+			csk->wr_cred, csk->wr_una_cred, snd_una, seq_chk);
+
+	spin_lock_bh(&csk->lock);
+
+	csk->wr_cred += credits;
+	if (csk->wr_una_cred > csk->wr_max_cred - csk->wr_cred)
+		csk->wr_una_cred = csk->wr_max_cred - csk->wr_cred;
+
+	while (credits) {
+		struct sk_buff *p = cxgbi_sock_peek_wr(csk);
+
+		if (unlikely(!p)) {
+			pr_err("csk 0x%p,%u,0x%lx,%u, cr %u,%u+%u, empty.\n",
+				csk, csk->state, csk->flags, csk->tid, credits,
+				csk->wr_cred, csk->wr_una_cred);
+			break;
+		}
+
+		if (unlikely(credits < p->csum)) {
+			pr_warn("csk 0x%p,%u,0x%lx,%u, cr %u,%u+%u, < %u.\n",
+				csk, csk->state, csk->flags, csk->tid,
+				credits, csk->wr_cred, csk->wr_una_cred,
+				p->csum);
+			p->csum -= credits;
+			break;
+		} else {
+			cxgbi_sock_dequeue_wr(csk);
+			credits -= p->csum;
+			kfree_skb(p);
+		}
+	}
+
+	cxgbi_sock_check_wr_invariants(csk);
+
+	if (seq_chk) {
+		if (unlikely(before(snd_una, csk->snd_una))) {
+			pr_warn("csk 0x%p,%u,0x%lx,%u, snd_una %u/%u.",
+				csk, csk->state, csk->flags, csk->tid, snd_una,
+				csk->snd_una);
+			goto done;
+		}
+
+		if (csk->snd_una != snd_una) {
+			csk->snd_una = snd_una;
+			dst_confirm(csk->dst);
+		}
+	}
+
+	if (skb_queue_len(&csk->write_queue)) {
+		if (csk->cdev->csk_push_tx_frames(csk, 0))
+			cxgbi_conn_tx_open(csk);
+	} else
+		cxgbi_conn_tx_open(csk);
+done:
+	spin_unlock_bh(&csk->lock);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_rcv_wr_ack);
+
+static unsigned int cxgbi_sock_find_best_mtu(struct cxgbi_sock *csk,
+					     unsigned short mtu)
+{
+	int i = 0;
+
+	while (i < csk->cdev->nmtus - 1 && csk->cdev->mtus[i + 1] <= mtu)
+		++i;
+
+	return i;
+}
+
+unsigned int cxgbi_sock_select_mss(struct cxgbi_sock *csk, unsigned int pmtu)
+{
+	unsigned int idx;
+	struct dst_entry *dst = csk->dst;
+
+	csk->advmss = dst_metric(dst, RTAX_ADVMSS);
+
+	if (csk->advmss > pmtu - 40)
+		csk->advmss = pmtu - 40;
+	if (csk->advmss < csk->cdev->mtus[0] - 40)
+		csk->advmss = csk->cdev->mtus[0] - 40;
+	idx = cxgbi_sock_find_best_mtu(csk, csk->advmss + 40);
+
+	return idx;
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_select_mss);
+
+void cxgbi_sock_skb_entail(struct cxgbi_sock *csk, struct sk_buff *skb)
+{
+	cxgbi_skcb_tcp_seq(skb) = csk->write_seq;
+	__skb_queue_tail(&csk->write_queue, skb);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_skb_entail);
+
+void cxgbi_sock_purge_wr_queue(struct cxgbi_sock *csk)
+{
+	struct sk_buff *skb;
+
+	while ((skb = cxgbi_sock_dequeue_wr(csk)) != NULL)
+		kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_purge_wr_queue);
+
+void cxgbi_sock_check_wr_invariants(const struct cxgbi_sock *csk)
+{
+	int pending = cxgbi_sock_count_pending_wrs(csk);
+
+	if (unlikely(csk->wr_cred + pending != csk->wr_max_cred))
+		pr_err("csk 0x%p, tid %u, credit %u + %u != %u.\n",
+			csk, csk->tid, csk->wr_cred, pending, csk->wr_max_cred);
+}
+EXPORT_SYMBOL_GPL(cxgbi_sock_check_wr_invariants);
+
+static int cxgbi_sock_send_pdus(struct cxgbi_sock *csk, struct sk_buff *skb)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct sk_buff *next;
+	int err, copied = 0;
+
+	spin_lock_bh(&csk->lock);
+
+	if (csk->state != CTP_ESTABLISHED) {
+		log_debug(1 << CXGBI_DBG_PDU_TX,
+			"csk 0x%p,%u,0x%lx,%u, EAGAIN.\n",
+			csk, csk->state, csk->flags, csk->tid);
+		err = -EAGAIN;
+		goto out_err;
+	}
+
+	if (csk->err) {
+		log_debug(1 << CXGBI_DBG_PDU_TX,
+			"csk 0x%p,%u,0x%lx,%u, EPIPE %d.\n",
+			csk, csk->state, csk->flags, csk->tid, csk->err);
+		err = -EPIPE;
+		goto out_err;
+	}
+
+	if (csk->write_seq - csk->snd_una >= cdev->snd_win) {
+		log_debug(1 << CXGBI_DBG_PDU_TX,
+			"csk 0x%p,%u,0x%lx,%u, FULL %u-%u >= %u.\n",
+			csk, csk->state, csk->flags, csk->tid, csk->write_seq,
+			csk->snd_una, cdev->snd_win);
+		err = -ENOBUFS;
+		goto out_err;
+	}
+
+	while (skb) {
+		int frags = skb_shinfo(skb)->nr_frags +
+				(skb->len != skb->data_len);
+
+		if (unlikely(skb_headroom(skb) < cdev->skb_tx_rsvd)) {
+			pr_err("csk 0x%p, skb head %u < %u.\n",
+				csk, skb_headroom(skb), cdev->skb_tx_rsvd);
+			err = -EINVAL;
+			goto out_err;
+		}
+
+		if (frags >= SKB_WR_LIST_SIZE) {
+			pr_err("csk 0x%p, frags %d, %u,%u >%u.\n",
+				csk, skb_shinfo(skb)->nr_frags, skb->len,
+				skb->data_len, (uint)(SKB_WR_LIST_SIZE));
+			err = -EINVAL;
+			goto out_err;
+		}
+
+		next = skb->next;
+		skb->next = NULL;
+		cxgbi_skcb_set_flag(skb, SKCBF_TX_NEED_HDR);
+		cxgbi_sock_skb_entail(csk, skb);
+		copied += skb->len;
+		csk->write_seq += skb->len +
+				cxgbi_ulp_extra_len(cxgbi_skcb_ulp_mode(skb));
+		skb = next;
+	}
+done:
+	if (likely(skb_queue_len(&csk->write_queue)))
+		cdev->csk_push_tx_frames(csk, 1);
+	spin_unlock_bh(&csk->lock);
+	return copied;
+
+out_err:
+	if (copied == 0 && err == -EPIPE)
+		copied = csk->err ? csk->err : -EPIPE;
+	else
+		copied = err;
+	goto done;
+}
+
+/*
+ * Direct Data Placement -
+ * Directly place the iSCSI Data-In or Data-Out PDU's payload into pre-posted
+ * final destination host-memory buffers based on the Initiator Task Tag (ITT)
+ * in Data-In or Target Task Tag (TTT) in Data-Out PDUs.
+ * The host memory address is programmed into h/w in the format of pagepod
+ * entries.
+ * The location of the pagepod entry is encoded into ddp tag which is used as
+ * the base for ITT/TTT.
+ */
+
+static unsigned char ddp_page_order[DDP_PGIDX_MAX] = {0, 1, 2, 4};
+static unsigned char ddp_page_shift[DDP_PGIDX_MAX] = {12, 13, 14, 16};
+static unsigned char page_idx = DDP_PGIDX_MAX;
+
+static unsigned char sw_tag_idx_bits;
+static unsigned char sw_tag_age_bits;
+
+/*
+ * Direct-Data Placement page size adjustment
+ */
+static int ddp_adjust_page_table(void)
+{
+	int i;
+	unsigned int base_order, order;
+
+	if (PAGE_SIZE < (1UL << ddp_page_shift[0])) {
+		pr_info("PAGE_SIZE 0x%lx too small, min 0x%lx\n",
+			PAGE_SIZE, 1UL << ddp_page_shift[0]);
+		return -EINVAL;
+	}
+
+	base_order = get_order(1UL << ddp_page_shift[0]);
+	order = get_order(1UL << PAGE_SHIFT);
+
+	for (i = 0; i < DDP_PGIDX_MAX; i++) {
+		/* first is the kernel page size, then just doubling */
+		ddp_page_order[i] = order - base_order + i;
+		ddp_page_shift[i] = PAGE_SHIFT + i;
+	}
+	return 0;
+}
+
+static int ddp_find_page_index(unsigned long pgsz)
+{
+	int i;
+
+	for (i = 0; i < DDP_PGIDX_MAX; i++) {
+		if (pgsz == (1UL << ddp_page_shift[i]))
+			return i;
+	}
+	pr_info("ddp page size %lu not supported.\n", pgsz);
+	return DDP_PGIDX_MAX;
+}
+
+static void ddp_setup_host_page_size(void)
+{
+	if (page_idx == DDP_PGIDX_MAX) {
+		page_idx = ddp_find_page_index(PAGE_SIZE);
+
+		if (page_idx == DDP_PGIDX_MAX) {
+			pr_info("system PAGE %lu, update hw.\n", PAGE_SIZE);
+			if (ddp_adjust_page_table() < 0) {
+				pr_info("PAGE %lu, disable ddp.\n", PAGE_SIZE);
+				return;
+			}
+			page_idx = ddp_find_page_index(PAGE_SIZE);
+		}
+		pr_info("system PAGE %lu, ddp idx %u.\n", PAGE_SIZE, page_idx);
+	}
+}
+
+void cxgbi_ddp_page_size_factor(int *pgsz_factor)
+{
+	int i;
+
+	for (i = 0; i < DDP_PGIDX_MAX; i++)
+		pgsz_factor[i] = ddp_page_order[i];
+}
+EXPORT_SYMBOL_GPL(cxgbi_ddp_page_size_factor);
+
+/*
+ * DDP setup & teardown
+ */
+
+void cxgbi_ddp_ppod_set(struct cxgbi_pagepod *ppod,
+			struct cxgbi_pagepod_hdr *hdr,
+			struct cxgbi_gather_list *gl, unsigned int gidx)
+{
+	int i;
+
+	memcpy(ppod, hdr, sizeof(*hdr));
+	for (i = 0; i < (PPOD_PAGES_MAX + 1); i++, gidx++) {
+		ppod->addr[i] = gidx < gl->nelem ?
+				cpu_to_be64(gl->phys_addr[gidx]) : 0ULL;
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_ddp_ppod_set);
+
+void cxgbi_ddp_ppod_clear(struct cxgbi_pagepod *ppod)
+{
+	memset(ppod, 0, sizeof(*ppod));
+}
+EXPORT_SYMBOL_GPL(cxgbi_ddp_ppod_clear);
+
+static inline int ddp_find_unused_entries(struct cxgbi_ddp_info *ddp,
+					unsigned int start, unsigned int max,
+					unsigned int count,
+					struct cxgbi_gather_list *gl)
+{
+	unsigned int i, j, k;
+
+	/*  not enough entries */
+	if ((max - start) < count) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"NOT enough entries %u+%u < %u.\n", start, count, max);
+		return -EBUSY;
+	}
+
+	max -= count;
+	spin_lock(&ddp->map_lock);
+	for (i = start; i < max;) {
+		for (j = 0, k = i; j < count; j++, k++) {
+			if (ddp->gl_map[k])
+				break;
+		}
+		if (j == count) {
+			for (j = 0, k = i; j < count; j++, k++)
+				ddp->gl_map[k] = gl;
+			spin_unlock(&ddp->map_lock);
+			return i;
+		}
+		i += j + 1;
+	}
+	spin_unlock(&ddp->map_lock);
+	log_debug(1 << CXGBI_DBG_DDP,
+		"NO suitable entries %u available.\n", count);
+	return -EBUSY;
+}
+
+static inline void ddp_unmark_entries(struct cxgbi_ddp_info *ddp,
+						int start, int count)
+{
+	spin_lock(&ddp->map_lock);
+	memset(&ddp->gl_map[start], 0,
+		count * sizeof(struct cxgbi_gather_list *));
+	spin_unlock(&ddp->map_lock);
+}
+
+static inline void ddp_gl_unmap(struct pci_dev *pdev,
+					struct cxgbi_gather_list *gl)
+{
+	int i;
+
+	for (i = 0; i < gl->nelem; i++)
+		dma_unmap_page(&pdev->dev, gl->phys_addr[i], PAGE_SIZE,
+				PCI_DMA_FROMDEVICE);
+}
+
+static inline int ddp_gl_map(struct pci_dev *pdev,
+				    struct cxgbi_gather_list *gl)
+{
+	int i;
+
+	for (i = 0; i < gl->nelem; i++) {
+		gl->phys_addr[i] = dma_map_page(&pdev->dev, gl->pages[i], 0,
+						PAGE_SIZE,
+						PCI_DMA_FROMDEVICE);
+		if (unlikely(dma_mapping_error(&pdev->dev, gl->phys_addr[i]))) {
+			log_debug(1 << CXGBI_DBG_DDP,
+				"page %d 0x%p, 0x%p dma mapping err.\n",
+				i, gl->pages[i], pdev);
+			goto unmap;
+		}
+	}
+	return i;
+unmap:
+	if (i) {
+		unsigned int nelem = gl->nelem;
+
+		gl->nelem = i;
+		ddp_gl_unmap(pdev, gl);
+		gl->nelem = nelem;
+	}
+	return -EINVAL;
+}
+
+static void ddp_release_gl(struct cxgbi_gather_list *gl,
+				  struct pci_dev *pdev)
+{
+	ddp_gl_unmap(pdev, gl);
+	kfree(gl);
+}
+
+static struct cxgbi_gather_list *ddp_make_gl(unsigned int xferlen,
+						    struct scatterlist *sgl,
+						    unsigned int sgcnt,
+						    struct pci_dev *pdev,
+						    gfp_t gfp)
+{
+	struct cxgbi_gather_list *gl;
+	struct scatterlist *sg = sgl;
+	struct page *sgpage = sg_page(sg);
+	unsigned int sglen = sg->length;
+	unsigned int sgoffset = sg->offset;
+	unsigned int npages = (xferlen + sgoffset + PAGE_SIZE - 1) >>
+				PAGE_SHIFT;
+	int i = 1, j = 0;
+
+	if (xferlen < DDP_THRESHOLD) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"xfer %u < threshold %u, no ddp.\n",
+			xferlen, DDP_THRESHOLD);
+		return NULL;
+	}
+
+	gl = kzalloc(sizeof(struct cxgbi_gather_list) +
+		     npages * (sizeof(dma_addr_t) +
+		     sizeof(struct page *)), gfp);
+	if (!gl) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"xfer %u, %u pages, OOM.\n", xferlen, npages);
+		return NULL;
+	}
+
+	 log_debug(1 << CXGBI_DBG_DDP,
+		"xfer %u, sgl %u, gl max %u.\n", xferlen, sgcnt, npages);
+
+	gl->pages = (struct page **)&gl->phys_addr[npages];
+	gl->nelem = npages;
+	gl->length = xferlen;
+	gl->offset = sgoffset;
+	gl->pages[0] = sgpage;
+
+	for (i = 1, sg = sg_next(sgl), j = 0; i < sgcnt;
+		i++, sg = sg_next(sg)) {
+		struct page *page = sg_page(sg);
+
+		if (sgpage == page && sg->offset == sgoffset + sglen)
+			sglen += sg->length;
+		else {
+			/*  make sure the sgl is fit for ddp:
+			 *  each has the same page size, and
+			 *  all of the middle pages are used completely
+			 */
+			if ((j && sgoffset) || ((i != sgcnt - 1) &&
+			    ((sglen + sgoffset) & ~PAGE_MASK))) {
+				log_debug(1 << CXGBI_DBG_DDP,
+					"page %d/%u, %u + %u.\n",
+					i, sgcnt, sgoffset, sglen);
+				goto error_out;
+			}
+
+			j++;
+			if (j == gl->nelem || sg->offset) {
+				log_debug(1 << CXGBI_DBG_DDP,
+					"page %d/%u, offset %u.\n",
+					j, gl->nelem, sg->offset);
+				goto error_out;
+			}
+			gl->pages[j] = page;
+			sglen = sg->length;
+			sgoffset = sg->offset;
+			sgpage = page;
+		}
+	}
+	gl->nelem = ++j;
+
+	if (ddp_gl_map(pdev, gl) < 0)
+		goto error_out;
+
+	return gl;
+
+error_out:
+	kfree(gl);
+	return NULL;
+}
+
+static void ddp_tag_release(struct cxgbi_hba *chba, u32 tag)
+{
+	struct cxgbi_device *cdev = chba->cdev;
+	struct cxgbi_ddp_info *ddp = cdev->ddp;
+	u32 idx;
+
+	idx = (tag >> PPOD_IDX_SHIFT) & ddp->idx_mask;
+	if (idx < ddp->nppods) {
+		struct cxgbi_gather_list *gl = ddp->gl_map[idx];
+		unsigned int npods;
+
+		if (!gl || !gl->nelem) {
+			pr_warn("tag 0x%x, idx %u, gl 0x%p, %u.\n",
+				tag, idx, gl, gl ? gl->nelem : 0);
+			return;
+		}
+		npods = (gl->nelem + PPOD_PAGES_MAX - 1) >> PPOD_PAGES_SHIFT;
+		log_debug(1 << CXGBI_DBG_DDP,
+			"tag 0x%x, release idx %u, npods %u.\n",
+			tag, idx, npods);
+		cdev->csk_ddp_clear(chba, tag, idx, npods);
+		ddp_unmark_entries(ddp, idx, npods);
+		ddp_release_gl(gl, ddp->pdev);
+	} else
+		pr_warn("tag 0x%x, idx %u > max %u.\n", tag, idx, ddp->nppods);
+}
+
+static int ddp_tag_reserve(struct cxgbi_sock *csk, unsigned int tid,
+			   u32 sw_tag, u32 *tagp, struct cxgbi_gather_list *gl,
+			   gfp_t gfp)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct cxgbi_ddp_info *ddp = cdev->ddp;
+	struct cxgbi_tag_format *tformat = &cdev->tag_format;
+	struct cxgbi_pagepod_hdr hdr;
+	unsigned int npods;
+	int idx = -1;
+	int err = -ENOMEM;
+	u32 tag;
+
+	npods = (gl->nelem + PPOD_PAGES_MAX - 1) >> PPOD_PAGES_SHIFT;
+	if (ddp->idx_last == ddp->nppods)
+		idx = ddp_find_unused_entries(ddp, 0, ddp->nppods,
+							npods, gl);
+	else {
+		idx = ddp_find_unused_entries(ddp, ddp->idx_last + 1,
+							ddp->nppods, npods,
+							gl);
+		if (idx < 0 && ddp->idx_last >= npods) {
+			idx = ddp_find_unused_entries(ddp, 0,
+				min(ddp->idx_last + npods, ddp->nppods),
+							npods, gl);
+		}
+	}
+	if (idx < 0) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"xferlen %u, gl %u, npods %u NO DDP.\n",
+			gl->length, gl->nelem, npods);
+		return idx;
+	}
+
+	if (cdev->csk_ddp_alloc_gl_skb) {
+		err = cdev->csk_ddp_alloc_gl_skb(ddp, idx, npods, gfp);
+		if (err < 0)
+			goto unmark_entries;
+	}
+
+	tag = cxgbi_ddp_tag_base(tformat, sw_tag);
+	tag |= idx << PPOD_IDX_SHIFT;
+
+	hdr.rsvd = 0;
+	hdr.vld_tid = htonl(PPOD_VALID_FLAG | PPOD_TID(tid));
+	hdr.pgsz_tag_clr = htonl(tag & ddp->rsvd_tag_mask);
+	hdr.max_offset = htonl(gl->length);
+	hdr.page_offset = htonl(gl->offset);
+
+	err = cdev->csk_ddp_set(csk, &hdr, idx, npods, gl);
+	if (err < 0) {
+		if (cdev->csk_ddp_free_gl_skb)
+			cdev->csk_ddp_free_gl_skb(ddp, idx, npods);
+		goto unmark_entries;
+	}
+
+	ddp->idx_last = idx;
+	log_debug(1 << CXGBI_DBG_DDP,
+		"xfer %u, gl %u,%u, tid 0x%x, tag 0x%x->0x%x(%u,%u).\n",
+		gl->length, gl->nelem, gl->offset, tid, sw_tag, tag, idx,
+		npods);
+	*tagp = tag;
+	return 0;
+
+unmark_entries:
+	ddp_unmark_entries(ddp, idx, npods);
+	return err;
+}
+
+int cxgbi_ddp_reserve(struct cxgbi_sock *csk, unsigned int *tagp,
+			unsigned int sw_tag, unsigned int xferlen,
+			struct scatterlist *sgl, unsigned int sgcnt, gfp_t gfp)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct cxgbi_tag_format *tformat = &cdev->tag_format;
+	struct cxgbi_gather_list *gl;
+	int err;
+
+	if (page_idx >= DDP_PGIDX_MAX || !cdev->ddp ||
+	    xferlen < DDP_THRESHOLD) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"pgidx %u, xfer %u, NO ddp.\n", page_idx, xferlen);
+		return -EINVAL;
+	}
+
+	if (!cxgbi_sw_tag_usable(tformat, sw_tag)) {
+		log_debug(1 << CXGBI_DBG_DDP,
+			"sw_tag 0x%x NOT usable.\n", sw_tag);
+		return -EINVAL;
+	}
+
+	gl = ddp_make_gl(xferlen, sgl, sgcnt, cdev->pdev, gfp);
+	if (!gl)
+		return -ENOMEM;
+
+	err = ddp_tag_reserve(csk, csk->tid, sw_tag, tagp, gl, gfp);
+	if (err < 0)
+		ddp_release_gl(gl, cdev->pdev);
+
+	return err;
+}
+
+static void ddp_destroy(struct kref *kref)
+{
+	struct cxgbi_ddp_info *ddp = container_of(kref,
+						struct cxgbi_ddp_info,
+						refcnt);
+	struct cxgbi_device *cdev = ddp->cdev;
+	int i = 0;
+
+	pr_info("kref 0, destroy ddp 0x%p, cdev 0x%p.\n", ddp, cdev);
+
+	while (i < ddp->nppods) {
+		struct cxgbi_gather_list *gl = ddp->gl_map[i];
+
+		if (gl) {
+			int npods = (gl->nelem + PPOD_PAGES_MAX - 1)
+					>> PPOD_PAGES_SHIFT;
+			pr_info("cdev 0x%p, ddp %d + %d.\n", cdev, i, npods);
+			kfree(gl);
+			if (cdev->csk_ddp_free_gl_skb)
+				cdev->csk_ddp_free_gl_skb(ddp, i, npods);
+			i += npods;
+		} else
+			i++;
+	}
+	cxgbi_free_big_mem(ddp);
+}
+
+int cxgbi_ddp_cleanup(struct cxgbi_device *cdev)
+{
+	struct cxgbi_ddp_info *ddp = cdev->ddp;
+
+	log_debug(1 << CXGBI_DBG_DDP,
+		"cdev 0x%p, release ddp 0x%p.\n", cdev, ddp);
+	cdev->ddp = NULL;
+	if (ddp)
+		return kref_put(&ddp->refcnt, ddp_destroy);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_ddp_cleanup);
+
+int cxgbi_ddp_init(struct cxgbi_device *cdev,
+		   unsigned int llimit, unsigned int ulimit,
+		   unsigned int max_txsz, unsigned int max_rxsz)
+{
+	struct cxgbi_ddp_info *ddp;
+	unsigned int ppmax, bits;
+
+	ppmax = (ulimit - llimit + 1) >> PPOD_SIZE_SHIFT;
+	bits = __ilog2_u32(ppmax) + 1;
+	if (bits > PPOD_IDX_MAX_SIZE)
+		bits = PPOD_IDX_MAX_SIZE;
+	ppmax = (1 << (bits - 1)) - 1;
+
+	ddp = cxgbi_alloc_big_mem(sizeof(struct cxgbi_ddp_info) +
+				ppmax * (sizeof(struct cxgbi_gather_list *) +
+					 sizeof(struct sk_buff *)),
+				GFP_KERNEL);
+	if (!ddp) {
+		pr_warn("cdev 0x%p, ddp ppmax %u OOM.\n", cdev, ppmax);
+		return -ENOMEM;
+	}
+	ddp->gl_map = (struct cxgbi_gather_list **)(ddp + 1);
+	ddp->gl_skb = (struct sk_buff **)(((char *)ddp->gl_map) +
+				ppmax * sizeof(struct cxgbi_gather_list *));
+	cdev->ddp = ddp;
+
+	spin_lock_init(&ddp->map_lock);
+	kref_init(&ddp->refcnt);
+
+	ddp->cdev = cdev;
+	ddp->pdev = cdev->pdev;
+	ddp->llimit = llimit;
+	ddp->ulimit = ulimit;
+	ddp->max_txsz = min_t(unsigned int, max_txsz, ULP2_MAX_PKT_SIZE);
+	ddp->max_rxsz = min_t(unsigned int, max_rxsz, ULP2_MAX_PKT_SIZE);
+	ddp->nppods = ppmax;
+	ddp->idx_last = ppmax;
+	ddp->idx_bits = bits;
+	ddp->idx_mask = (1 << bits) - 1;
+	ddp->rsvd_tag_mask = (1 << (bits + PPOD_IDX_SHIFT)) - 1;
+
+	cdev->tag_format.sw_bits = sw_tag_idx_bits + sw_tag_age_bits;
+	cdev->tag_format.rsvd_bits = ddp->idx_bits;
+	cdev->tag_format.rsvd_shift = PPOD_IDX_SHIFT;
+	cdev->tag_format.rsvd_mask = (1 << cdev->tag_format.rsvd_bits) - 1;
+
+	pr_info("%s tag format, sw %u, rsvd %u,%u, mask 0x%x.\n",
+		cdev->ports[0]->name, cdev->tag_format.sw_bits,
+		cdev->tag_format.rsvd_bits, cdev->tag_format.rsvd_shift,
+		cdev->tag_format.rsvd_mask);
+
+	cdev->tx_max_size = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+				ddp->max_txsz - ISCSI_PDU_NONPAYLOAD_LEN);
+	cdev->rx_max_size = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+				ddp->max_rxsz - ISCSI_PDU_NONPAYLOAD_LEN);
+
+	log_debug(1 << CXGBI_DBG_DDP,
+		"%s max payload size: %u/%u, %u/%u.\n",
+		cdev->ports[0]->name, cdev->tx_max_size, ddp->max_txsz,
+		cdev->rx_max_size, ddp->max_rxsz);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_ddp_init);
+
+/*
+ * APIs interacting with open-iscsi libraries
+ */
+
+static unsigned char padding[4];
+
+static void task_release_itt(struct iscsi_task *task, itt_t hdr_itt)
+{
+	struct scsi_cmnd *sc = task->sc;
+	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_hba *chba = cconn->chba;
+	struct cxgbi_tag_format *tformat = &chba->cdev->tag_format;
+	u32 tag = ntohl((__force u32)hdr_itt);
+
+	log_debug(1 << CXGBI_DBG_DDP,
+		   "cdev 0x%p, release tag 0x%x.\n", chba->cdev, tag);
+	if (sc &&
+	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_FROM_DEVICE) &&
+	    cxgbi_is_ddp_tag(tformat, tag))
+		ddp_tag_release(chba, tag);
+}
+
+static int task_reserve_itt(struct iscsi_task *task, itt_t *hdr_itt)
+{
+	struct scsi_cmnd *sc = task->sc;
+	struct iscsi_conn *conn = task->conn;
+	struct iscsi_session *sess = conn->session;
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_hba *chba = cconn->chba;
+	struct cxgbi_tag_format *tformat = &chba->cdev->tag_format;
+	u32 sw_tag = (sess->age << cconn->task_idx_bits) | task->itt;
+	u32 tag = 0;
+	int err = -EINVAL;
+
+	if (sc &&
+	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_FROM_DEVICE)) {
+		err = cxgbi_ddp_reserve(cconn->cep->csk, &tag, sw_tag,
+					scsi_in(sc)->length,
+					scsi_in(sc)->table.sgl,
+					scsi_in(sc)->table.nents,
+					GFP_ATOMIC);
+		if (err < 0)
+			log_debug(1 << CXGBI_DBG_DDP,
+				"csk 0x%p, R task 0x%p, %u,%u, no ddp.\n",
+				cconn->cep->csk, task, scsi_in(sc)->length,
+				scsi_in(sc)->table.nents);
+	}
+
+	if (err < 0)
+		tag = cxgbi_set_non_ddp_tag(tformat, sw_tag);
+	/*  the itt need to sent in big-endian order */
+	*hdr_itt = (__force itt_t)htonl(tag);
+
+	log_debug(1 << CXGBI_DBG_DDP,
+		"cdev 0x%p, task 0x%p, 0x%x(0x%x,0x%x)->0x%x/0x%x.\n",
+		chba->cdev, task, sw_tag, task->itt, sess->age, tag, *hdr_itt);
+	return 0;
+}
+
+void cxgbi_parse_pdu_itt(struct iscsi_conn *conn, itt_t itt, int *idx, int *age)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_device *cdev = cconn->chba->cdev;
+	u32 tag = ntohl((__force u32) itt);
+	u32 sw_bits;
+
+	sw_bits = cxgbi_tag_nonrsvd_bits(&cdev->tag_format, tag);
+	if (idx)
+		*idx = sw_bits & ((1 << cconn->task_idx_bits) - 1);
+	if (age)
+		*age = (sw_bits >> cconn->task_idx_bits) & ISCSI_AGE_MASK;
+
+	log_debug(1 << CXGBI_DBG_DDP,
+		"cdev 0x%p, tag 0x%x/0x%x, -> 0x%x(0x%x,0x%x).\n",
+		cdev, tag, itt, sw_bits, idx ? *idx : 0xFFFFF,
+		age ? *age : 0xFF);
+}
+EXPORT_SYMBOL_GPL(cxgbi_parse_pdu_itt);
+
+void cxgbi_conn_tx_open(struct cxgbi_sock *csk)
+{
+	struct iscsi_conn *conn = csk->user_data;
+
+	if (conn) {
+		log_debug(1 << CXGBI_DBG_SOCK,
+			"csk 0x%p, cid %d.\n", csk, conn->id);
+		iscsi_conn_queue_work(conn);
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_conn_tx_open);
+
+/*
+ * pdu receive, interact with libiscsi_tcp
+ */
+static inline int read_pdu_skb(struct iscsi_conn *conn,
+			       struct sk_buff *skb,
+			       unsigned int offset,
+			       int offloaded)
+{
+	int status = 0;
+	int bytes_read;
+
+	bytes_read = iscsi_tcp_recv_skb(conn, skb, offset, offloaded, &status);
+	switch (status) {
+	case ISCSI_TCP_CONN_ERR:
+		pr_info("skb 0x%p, off %u, %d, TCP_ERR.\n",
+			  skb, offset, offloaded);
+		return -EIO;
+	case ISCSI_TCP_SUSPENDED:
+		log_debug(1 << CXGBI_DBG_PDU_RX,
+			"skb 0x%p, off %u, %d, TCP_SUSPEND, rc %d.\n",
+			skb, offset, offloaded, bytes_read);
+		/* no transfer - just have caller flush queue */
+		return bytes_read;
+	case ISCSI_TCP_SKB_DONE:
+		pr_info("skb 0x%p, off %u, %d, TCP_SKB_DONE.\n",
+			skb, offset, offloaded);
+		/*
+		 * pdus should always fit in the skb and we should get
+		 * segment done notifcation.
+		 */
+		iscsi_conn_printk(KERN_ERR, conn, "Invalid pdu or skb.");
+		return -EFAULT;
+	case ISCSI_TCP_SEGMENT_DONE:
+		log_debug(1 << CXGBI_DBG_PDU_RX,
+			"skb 0x%p, off %u, %d, TCP_SEG_DONE, rc %d.\n",
+			skb, offset, offloaded, bytes_read);
+		return bytes_read;
+	default:
+		pr_info("skb 0x%p, off %u, %d, invalid status %d.\n",
+			skb, offset, offloaded, status);
+		return -EINVAL;
+	}
+}
+
+static int skb_read_pdu_bhs(struct iscsi_conn *conn, struct sk_buff *skb)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+
+	log_debug(1 << CXGBI_DBG_PDU_RX,
+		"conn 0x%p, skb 0x%p, len %u, flag 0x%lx.\n",
+		conn, skb, skb->len, cxgbi_skcb_flags(skb));
+
+	if (!iscsi_tcp_recv_segment_is_hdr(tcp_conn)) {
+		pr_info("conn 0x%p, skb 0x%p, not hdr.\n", conn, skb);
+		iscsi_conn_failure(conn, ISCSI_ERR_PROTO);
+		return -EIO;
+	}
+
+	if (conn->hdrdgst_en &&
+	    cxgbi_skcb_test_flag(skb, SKCBF_RX_HCRC_ERR)) {
+		pr_info("conn 0x%p, skb 0x%p, hcrc.\n", conn, skb);
+		iscsi_conn_failure(conn, ISCSI_ERR_HDR_DGST);
+		return -EIO;
+	}
+
+	return read_pdu_skb(conn, skb, 0, 0);
+}
+
+static int skb_read_pdu_data(struct iscsi_conn *conn, struct sk_buff *lskb,
+			     struct sk_buff *skb, unsigned int offset)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	bool offloaded = 0;
+	int opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
+
+	log_debug(1 << CXGBI_DBG_PDU_RX,
+		"conn 0x%p, skb 0x%p, len %u, flag 0x%lx.\n",
+		conn, skb, skb->len, cxgbi_skcb_flags(skb));
+
+	if (conn->datadgst_en &&
+	    cxgbi_skcb_test_flag(lskb, SKCBF_RX_DCRC_ERR)) {
+		pr_info("conn 0x%p, skb 0x%p, dcrc 0x%lx.\n",
+			conn, lskb, cxgbi_skcb_flags(lskb));
+		iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
+		return -EIO;
+	}
+
+	if (iscsi_tcp_recv_segment_is_hdr(tcp_conn))
+		return 0;
+
+	/* coalesced, add header digest length */
+	if (lskb == skb && conn->hdrdgst_en)
+		offset += ISCSI_DIGEST_SIZE;
+
+	if (cxgbi_skcb_test_flag(lskb, SKCBF_RX_DATA_DDPD))
+		offloaded = 1;
+
+	if (opcode == ISCSI_OP_SCSI_DATA_IN)
+		log_debug(1 << CXGBI_DBG_PDU_RX,
+			"skb 0x%p, op 0x%x, itt 0x%x, %u %s ddp'ed.\n",
+			skb, opcode, ntohl(tcp_conn->in.hdr->itt),
+			tcp_conn->in.datalen, offloaded ? "is" : "not");
+
+	return read_pdu_skb(conn, skb, offset, offloaded);
+}
+
+static void csk_return_rx_credits(struct cxgbi_sock *csk, int copied)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	int must_send;
+	u32 credits;
+
+	log_debug(1 << CXGBI_DBG_PDU_RX,
+		"csk 0x%p,%u,0x%lu,%u, seq %u, wup %u, thre %u, %u.\n",
+		csk, csk->state, csk->flags, csk->tid, csk->copied_seq,
+		csk->rcv_wup, cdev->rx_credit_thres,
+		cdev->rcv_win);
+
+	if (csk->state != CTP_ESTABLISHED)
+		return;
+
+	credits = csk->copied_seq - csk->rcv_wup;
+	if (unlikely(!credits))
+		return;
+	if (unlikely(cdev->rx_credit_thres == 0))
+		return;
+
+	must_send = credits + 16384 >= cdev->rcv_win;
+	if (must_send || credits >= cdev->rx_credit_thres)
+		csk->rcv_wup += cdev->csk_send_rx_credits(csk, credits);
+}
+
+void cxgbi_conn_pdu_ready(struct cxgbi_sock *csk)
+{
+	struct cxgbi_device *cdev = csk->cdev;
+	struct iscsi_conn *conn = csk->user_data;
+	struct sk_buff *skb;
+	unsigned int read = 0;
+	int err = 0;
+
+	log_debug(1 << CXGBI_DBG_PDU_RX,
+		"csk 0x%p, conn 0x%p.\n", csk, conn);
+
+	if (unlikely(!conn || conn->suspend_rx)) {
+		log_debug(1 << CXGBI_DBG_PDU_RX,
+			"csk 0x%p, conn 0x%p, id %d, suspend_rx %lu!\n",
+			csk, conn, conn ? conn->id : 0xFF,
+			conn ? conn->suspend_rx : 0xFF);
+		read_unlock(&csk->callback_lock);
+		return;
+	}
+
+	while (!err) {
+		read_lock(&csk->callback_lock);
+		skb = skb_peek(&csk->receive_queue);
+		if (!skb ||
+		    !(cxgbi_skcb_test_flag(skb, SKCBF_RX_STATUS))) {
+			if (skb)
+				log_debug(1 << CXGBI_DBG_PDU_RX,
+					"skb 0x%p, NOT ready 0x%lx.\n",
+					skb, cxgbi_skcb_flags(skb));
+			read_unlock(&csk->callback_lock);
+			break;
+		}
+		__skb_unlink(skb, &csk->receive_queue);
+		read_unlock(&csk->callback_lock);
+
+		read += cxgbi_skcb_rx_pdulen(skb);
+		log_debug(1 << CXGBI_DBG_PDU_RX,
+			"csk 0x%p, skb 0x%p,%u,f 0x%lx, pdu len %u.\n",
+			csk, skb, skb->len, cxgbi_skcb_flags(skb),
+			cxgbi_skcb_rx_pdulen(skb));
+
+		if (cxgbi_skcb_test_flag(skb, SKCBF_RX_COALESCED)) {
+			err = skb_read_pdu_bhs(conn, skb);
+			if (err < 0)
+				break;
+			err = skb_read_pdu_data(conn, skb, skb,
+						err + cdev->skb_rx_extra);
+		} else {
+			err = skb_read_pdu_bhs(conn, skb);
+			if (err < 0)
+				break;
+			if (cxgbi_skcb_test_flag(skb, SKCBF_RX_DATA)) {
+				struct sk_buff *dskb;
+
+				read_lock(&csk->callback_lock);
+				dskb = skb_peek(&csk->receive_queue);
+				if (!dskb) {
+					read_unlock(&csk->callback_lock);
+					pr_err("csk 0x%p, NO data.\n", csk);
+					err = -EAGAIN;
+					break;
+				}
+				__skb_unlink(dskb, &csk->receive_queue);
+				read_unlock(&csk->callback_lock);
+
+				err = skb_read_pdu_data(conn, skb, dskb, 0);
+				__kfree_skb(dskb);
+			} else
+				err = skb_read_pdu_data(conn, skb, skb, 0);
+		}
+		if (err < 0)
+			break;
+
+		__kfree_skb(skb);
+	}
+
+	log_debug(1 << CXGBI_DBG_PDU_RX, "csk 0x%p, read %u.\n", csk, read);
+	if (read) {
+		csk->copied_seq += read;
+		csk_return_rx_credits(csk, read);
+		conn->rxdata_octets += read;
+	}
+
+	if (err < 0) {
+		pr_info("csk 0x%p, 0x%p, rx failed %d.\n", csk, conn, err);
+		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_conn_pdu_ready);
+
+static int sgl_seek_offset(struct scatterlist *sgl, unsigned int sgcnt,
+				unsigned int offset, unsigned int *off,
+				struct scatterlist **sgp)
+{
+	int i;
+	struct scatterlist *sg;
+
+	for_each_sg(sgl, sg, sgcnt, i) {
+		if (offset < sg->length) {
+			*off = offset;
+			*sgp = sg;
+			return 0;
+		}
+		offset -= sg->length;
+	}
+	return -EFAULT;
+}
+
+static int sgl_read_to_frags(struct scatterlist *sg, unsigned int sgoffset,
+				unsigned int dlen, skb_frag_t *frags,
+				int frag_max)
+{
+	unsigned int datalen = dlen;
+	unsigned int sglen = sg->length - sgoffset;
+	struct page *page = sg_page(sg);
+	int i;
+
+	i = 0;
+	do {
+		unsigned int copy;
+
+		if (!sglen) {
+			sg = sg_next(sg);
+			if (!sg) {
+				pr_warn("sg %d NULL, len %u/%u.\n",
+					i, datalen, dlen);
+				return -EINVAL;
+			}
+			sgoffset = 0;
+			sglen = sg->length;
+			page = sg_page(sg);
+
+		}
+		copy = min(datalen, sglen);
+		if (i && page == frags[i - 1].page &&
+		    sgoffset + sg->offset ==
+			frags[i - 1].page_offset + frags[i - 1].size) {
+			frags[i - 1].size += copy;
+		} else {
+			if (i >= frag_max) {
+				pr_warn("too many pages %u, dlen %u.\n",
+					frag_max, dlen);
+				return -EINVAL;
+			}
+
+			frags[i].page = page;
+			frags[i].page_offset = sg->offset + sgoffset;
+			frags[i].size = copy;
+			i++;
+		}
+		datalen -= copy;
+		sgoffset += copy;
+		sglen -= copy;
+	} while (datalen);
+
+	return i;
+}
+
+int cxgbi_conn_alloc_pdu(struct iscsi_task *task, u8 opcode)
+{
+	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_device *cdev = cconn->chba->cdev;
+	struct iscsi_conn *conn = task->conn;
+	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct cxgbi_task_data *tdata = task->dd_data + sizeof(*tcp_task);
+	struct scsi_cmnd *sc = task->sc;
+	int headroom = SKB_TX_ISCSI_PDU_HEADER_MAX;
+
+	tcp_task->dd_data = tdata;
+	task->hdr = NULL;
+
+	if (SKB_MAX_HEAD(cdev->skb_tx_rsvd) > (512 * MAX_SKB_FRAGS) &&
+	    (opcode == ISCSI_OP_SCSI_DATA_OUT ||
+	     (opcode == ISCSI_OP_SCSI_CMD &&
+	      (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_TO_DEVICE))))
+		/* data could goes into skb head */
+		headroom += min_t(unsigned int,
+				SKB_MAX_HEAD(cdev->skb_tx_rsvd),
+				conn->max_xmit_dlength);
+
+	tdata->skb = alloc_skb(cdev->skb_tx_rsvd + headroom, GFP_ATOMIC);
+	if (!tdata->skb) {
+		pr_warn("alloc skb %u+%u, opcode 0x%x failed.\n",
+			cdev->skb_tx_rsvd, headroom, opcode);
+		return -ENOMEM;
+	}
+
+	skb_reserve(tdata->skb, cdev->skb_tx_rsvd);
+	task->hdr = (struct iscsi_hdr *)tdata->skb->data;
+	task->hdr_max = SKB_TX_ISCSI_PDU_HEADER_MAX; /* BHS + AHS */
+
+	/* data_out uses scsi_cmd's itt */
+	if (opcode != ISCSI_OP_SCSI_DATA_OUT)
+		task_reserve_itt(task, &task->hdr->itt);
+
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX,
+		"task 0x%p, op 0x%x, skb 0x%p,%u+%u/%u, itt 0x%x.\n",
+		task, opcode, tdata->skb, cdev->skb_tx_rsvd, headroom,
+		conn->max_xmit_dlength, ntohl(task->hdr->itt));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_conn_alloc_pdu);
+
+static inline void tx_skb_setmode(struct sk_buff *skb, int hcrc, int dcrc)
+{
+	u8 submode = 0;
+
+	if (hcrc)
+		submode |= 1;
+	if (dcrc)
+		submode |= 2;
+	cxgbi_skcb_ulp_mode(skb) = (ULP2_MODE_ISCSI << 4) | submode;
+}
+
+int cxgbi_conn_init_pdu(struct iscsi_task *task, unsigned int offset,
+			      unsigned int count)
+{
+	struct iscsi_conn *conn = task->conn;
+	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct cxgbi_task_data *tdata = tcp_task->dd_data;
+	struct sk_buff *skb = tdata->skb;
+	unsigned int datalen = count;
+	int i, padlen = iscsi_padding(count);
+	struct page *pg;
+
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX,
+		"task 0x%p,0x%p, skb 0x%p, 0x%x,0x%x,0x%x, %u+%u.\n",
+		task, task->sc, skb, (*skb->data) & ISCSI_OPCODE_MASK,
+		ntohl(task->cmdsn), ntohl(task->hdr->itt), offset, count);
+
+	skb_put(skb, task->hdr_len);
+	tx_skb_setmode(skb, conn->hdrdgst_en, datalen ? conn->datadgst_en : 0);
+	if (!count)
+		return 0;
+
+	if (task->sc) {
+		struct scsi_data_buffer *sdb = scsi_out(task->sc);
+		struct scatterlist *sg = NULL;
+		int err;
+
+		tdata->offset = offset;
+		tdata->count = count;
+		err = sgl_seek_offset(
+					sdb->table.sgl, sdb->table.nents,
+					tdata->offset, &tdata->sgoffset, &sg);
+		if (err < 0) {
+			pr_warn("tpdu, sgl %u, bad offset %u/%u.\n",
+				sdb->table.nents, tdata->offset, sdb->length);
+			return err;
+		}
+		err = sgl_read_to_frags(sg, tdata->sgoffset, tdata->count,
+					tdata->frags, MAX_PDU_FRAGS);
+		if (err < 0) {
+			pr_warn("tpdu, sgl %u, bad offset %u + %u.\n",
+				sdb->table.nents, tdata->offset, tdata->count);
+			return err;
+		}
+		tdata->nr_frags = err;
+
+		if (tdata->nr_frags > MAX_SKB_FRAGS ||
+		    (padlen && tdata->nr_frags == MAX_SKB_FRAGS)) {
+			char *dst = skb->data + task->hdr_len;
+			skb_frag_t *frag = tdata->frags;
+
+			/* data fits in the skb's headroom */
+			for (i = 0; i < tdata->nr_frags; i++, frag++) {
+				char *src = kmap_atomic(frag->page,
+							KM_SOFTIRQ0);
+
+				memcpy(dst, src+frag->page_offset, frag->size);
+				dst += frag->size;
+				kunmap_atomic(src, KM_SOFTIRQ0);
+			}
+			if (padlen) {
+				memset(dst, 0, padlen);
+				padlen = 0;
+			}
+			skb_put(skb, count + padlen);
+		} else {
+			/* data fit into frag_list */
+			for (i = 0; i < tdata->nr_frags; i++)
+				get_page(tdata->frags[i].page);
+
+			memcpy(skb_shinfo(skb)->frags, tdata->frags,
+				sizeof(skb_frag_t) * tdata->nr_frags);
+			skb_shinfo(skb)->nr_frags = tdata->nr_frags;
+			skb->len += count;
+			skb->data_len += count;
+			skb->truesize += count;
+		}
+
+	} else {
+		pg = virt_to_page(task->data);
+
+		get_page(pg);
+		skb_fill_page_desc(skb, 0, pg, offset_in_page(task->data),
+					count);
+		skb->len += count;
+		skb->data_len += count;
+		skb->truesize += count;
+	}
+
+	if (padlen) {
+		i = skb_shinfo(skb)->nr_frags;
+		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
+				virt_to_page(padding), offset_in_page(padding),
+				padlen);
+
+		skb->data_len += padlen;
+		skb->truesize += padlen;
+		skb->len += padlen;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_conn_init_pdu);
+
+int cxgbi_conn_xmit_pdu(struct iscsi_task *task)
+{
+	struct iscsi_tcp_conn *tcp_conn = task->conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct iscsi_tcp_task *tcp_task = task->dd_data;
+	struct cxgbi_task_data *tdata = tcp_task->dd_data;
+	struct sk_buff *skb = tdata->skb;
+	unsigned int datalen;
+	int err;
+
+	if (!skb) {
+		log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX,
+			"task 0x%p, skb NULL.\n", task);
+		return 0;
+	}
+
+	datalen = skb->data_len;
+	tdata->skb = NULL;
+	err = cxgbi_sock_send_pdus(cconn->cep->csk, skb);
+	if (err > 0) {
+		int pdulen = err;
+
+		log_debug(1 << CXGBI_DBG_PDU_TX,
+			"task 0x%p,0x%p, skb 0x%p, len %u/%u, rv %d.\n",
+			task, task->sc, skb, skb->len, skb->data_len, err);
+
+		if (task->conn->hdrdgst_en)
+			pdulen += ISCSI_DIGEST_SIZE;
+
+		if (datalen && task->conn->datadgst_en)
+			pdulen += ISCSI_DIGEST_SIZE;
+
+		task->conn->txdata_octets += pdulen;
+		return 0;
+	}
+
+	if (err == -EAGAIN || err == -ENOBUFS) {
+		log_debug(1 << CXGBI_DBG_PDU_TX,
+			"task 0x%p, skb 0x%p, len %u/%u, %d EAGAIN.\n",
+			task, skb, skb->len, skb->data_len, err);
+		/* reset skb to send when we are called again */
+		tdata->skb = skb;
+		return err;
+	}
+
+	kfree_skb(skb);
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX,
+		"itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n",
+		task->itt, skb, skb->len, skb->data_len, err);
+	iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err);
+	iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED);
+	return err;
+}
+EXPORT_SYMBOL_GPL(cxgbi_conn_xmit_pdu);
+
+void cxgbi_cleanup_task(struct iscsi_task *task)
+{
+	struct cxgbi_task_data *tdata = task->dd_data +
+				sizeof(struct iscsi_tcp_task);
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"task 0x%p, skb 0x%p, itt 0x%x.\n",
+		task, tdata->skb, task->hdr_itt);
+
+	/*  never reached the xmit task callout */
+	if (tdata->skb)
+		__kfree_skb(tdata->skb);
+	memset(tdata, 0, sizeof(*tdata));
+
+	task_release_itt(task, task->hdr_itt);
+	iscsi_tcp_cleanup_task(task);
+}
+EXPORT_SYMBOL_GPL(cxgbi_cleanup_task);
+
+void cxgbi_get_conn_stats(struct iscsi_cls_conn *cls_conn,
+				struct iscsi_stats *stats)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+
+	stats->txdata_octets = conn->txdata_octets;
+	stats->rxdata_octets = conn->rxdata_octets;
+	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
+	stats->dataout_pdus = conn->dataout_pdus_cnt;
+	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
+	stats->datain_pdus = conn->datain_pdus_cnt;
+	stats->r2t_pdus = conn->r2t_pdus_cnt;
+	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
+	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
+	stats->digest_err = 0;
+	stats->timeout_err = 0;
+	stats->custom_length = 1;
+	strcpy(stats->custom[0].desc, "eh_abort_cnt");
+	stats->custom[0].value = conn->eh_abort_cnt;
+}
+EXPORT_SYMBOL_GPL(cxgbi_get_conn_stats);
+
+static int cxgbi_conn_max_xmit_dlength(struct iscsi_conn *conn)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_device *cdev = cconn->chba->cdev;
+	unsigned int headroom = SKB_MAX_HEAD(cdev->skb_tx_rsvd);
+	unsigned int max_def = 512 * MAX_SKB_FRAGS;
+	unsigned int max = max(max_def, headroom);
+
+	max = min(cconn->chba->cdev->tx_max_size, max);
+	if (conn->max_xmit_dlength)
+		conn->max_xmit_dlength = min(conn->max_xmit_dlength, max);
+	else
+		conn->max_xmit_dlength = max;
+	cxgbi_align_pdu_size(conn->max_xmit_dlength);
+
+	return 0;
+}
+
+static int cxgbi_conn_max_recv_dlength(struct iscsi_conn *conn)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	unsigned int max = cconn->chba->cdev->rx_max_size;
+
+	cxgbi_align_pdu_size(max);
+
+	if (conn->max_recv_dlength) {
+		if (conn->max_recv_dlength > max) {
+			pr_err("MaxRecvDataSegmentLength %u > %u.\n",
+				conn->max_recv_dlength, max);
+			return -EINVAL;
+		}
+		conn->max_recv_dlength = min(conn->max_recv_dlength, max);
+		cxgbi_align_pdu_size(conn->max_recv_dlength);
+	} else
+		conn->max_recv_dlength = max;
+
+	return 0;
+}
+
+int cxgbi_set_conn_param(struct iscsi_cls_conn *cls_conn,
+			enum iscsi_param param, char *buf, int buflen)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iscsi_session *session = conn->session;
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct cxgbi_sock *csk = cconn->cep->csk;
+	int value, err = 0;
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"cls_conn 0x%p, param %d, buf(%d) %s.\n",
+		cls_conn, param, buflen, buf);
+
+	switch (param) {
+	case ISCSI_PARAM_HDRDGST_EN:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err && conn->hdrdgst_en)
+			err = csk->cdev->csk_ddp_setup_digest(csk, csk->tid,
+							conn->hdrdgst_en,
+							conn->datadgst_en, 0);
+		break;
+	case ISCSI_PARAM_DATADGST_EN:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err && conn->datadgst_en)
+			err = csk->cdev->csk_ddp_setup_digest(csk, csk->tid,
+							conn->hdrdgst_en,
+							conn->datadgst_en, 0);
+		break;
+	case ISCSI_PARAM_MAX_R2T:
+		sscanf(buf, "%d", &value);
+		if (value <= 0 || !is_power_of_2(value))
+			return -EINVAL;
+		if (session->max_r2t == value)
+			break;
+		iscsi_tcp_r2tpool_free(session);
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err && iscsi_tcp_r2tpool_alloc(session))
+			return -ENOMEM;
+	case ISCSI_PARAM_MAX_RECV_DLENGTH:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err)
+			err = cxgbi_conn_max_recv_dlength(conn);
+		break;
+	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err)
+			err = cxgbi_conn_max_xmit_dlength(conn);
+		break;
+	default:
+		return iscsi_set_param(cls_conn, param, buf, buflen);
+	}
+	return err;
+}
+EXPORT_SYMBOL_GPL(cxgbi_set_conn_param);
+
+int cxgbi_get_conn_param(struct iscsi_cls_conn *cls_conn,
+			enum iscsi_param param, char *buf)
+{
+	struct iscsi_conn *iconn = cls_conn->dd_data;
+	int len;
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"cls_conn 0x%p, param %d.\n", cls_conn, param);
+
+	switch (param) {
+	case ISCSI_PARAM_CONN_PORT:
+		spin_lock_bh(&iconn->session->lock);
+		len = sprintf(buf, "%hu\n", iconn->portal_port);
+		spin_unlock_bh(&iconn->session->lock);
+		break;
+	case ISCSI_PARAM_CONN_ADDRESS:
+		spin_lock_bh(&iconn->session->lock);
+		len = sprintf(buf, "%s\n", iconn->portal_address);
+		spin_unlock_bh(&iconn->session->lock);
+		break;
+	default:
+		return iscsi_conn_get_param(cls_conn, param, buf);
+	}
+	return len;
+}
+EXPORT_SYMBOL_GPL(cxgbi_get_conn_param);
+
+struct iscsi_cls_conn *
+cxgbi_create_conn(struct iscsi_cls_session *cls_session, u32 cid)
+{
+	struct iscsi_cls_conn *cls_conn;
+	struct iscsi_conn *conn;
+	struct iscsi_tcp_conn *tcp_conn;
+	struct cxgbi_conn *cconn;
+
+	cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*cconn), cid);
+	if (!cls_conn)
+		return NULL;
+
+	conn = cls_conn->dd_data;
+	tcp_conn = conn->dd_data;
+	cconn = tcp_conn->dd_data;
+	cconn->iconn = conn;
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"cid %u(0x%x), cls 0x%p,0x%p, conn 0x%p,0x%p,0x%p.\n",
+		cid, cid, cls_session, cls_conn, conn, tcp_conn, cconn);
+
+	return cls_conn;
+}
+EXPORT_SYMBOL_GPL(cxgbi_create_conn);
+
+int cxgbi_bind_conn(struct iscsi_cls_session *cls_session,
+				struct iscsi_cls_conn *cls_conn,
+				u64 transport_eph, int is_leading)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgbi_conn *cconn = tcp_conn->dd_data;
+	struct iscsi_endpoint *ep;
+	struct cxgbi_endpoint *cep;
+	struct cxgbi_sock *csk;
+	int err;
+
+	ep = iscsi_lookup_endpoint(transport_eph);
+	if (!ep)
+		return -EINVAL;
+
+	/*  setup ddp pagesize */
+	cep = ep->dd_data;
+	csk = cep->csk;
+	err = csk->cdev->csk_ddp_setup_pgidx(csk, csk->tid, page_idx, 0);
+	if (err < 0)
+		return err;
+
+	err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
+	if (err)
+		return -EINVAL;
+
+	/*  calculate the tag idx bits needed for this conn based on cmds_max */
+	cconn->task_idx_bits = (__ilog2_u32(conn->session->cmds_max - 1)) + 1;
+
+	write_lock(&csk->callback_lock);
+	csk->user_data = conn;
+	cconn->chba = cep->chba;
+	cconn->cep = cep;
+	cep->cconn = cconn;
+	write_unlock(&csk->callback_lock);
+
+	cxgbi_conn_max_xmit_dlength(conn);
+	cxgbi_conn_max_recv_dlength(conn);
+
+	spin_lock_bh(&conn->session->lock);
+	sprintf(conn->portal_address, "%pI4", &csk->daddr.sin_addr.s_addr);
+	conn->portal_port = ntohs(csk->daddr.sin_port);
+	spin_unlock_bh(&conn->session->lock);
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"cls 0x%p,0x%p, ep 0x%p, cconn 0x%p, csk 0x%p.\n",
+		cls_session, cls_conn, ep, cconn, csk);
+	/*  init recv engine */
+	iscsi_tcp_hdr_recv_prep(tcp_conn);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_bind_conn);
+
+struct iscsi_cls_session *cxgbi_create_session(struct iscsi_endpoint *ep,
+						u16 cmds_max, u16 qdepth,
+						u32 initial_cmdsn)
+{
+	struct cxgbi_endpoint *cep;
+	struct cxgbi_hba *chba;
+	struct Scsi_Host *shost;
+	struct iscsi_cls_session *cls_session;
+	struct iscsi_session *session;
+
+	if (!ep) {
+		pr_err("missing endpoint.\n");
+		return NULL;
+	}
+
+	cep = ep->dd_data;
+	chba = cep->chba;
+	shost = chba->shost;
+
+	BUG_ON(chba != iscsi_host_priv(shost));
+
+	cls_session = iscsi_session_setup(chba->cdev->itp, shost,
+					cmds_max, 0,
+					sizeof(struct iscsi_tcp_task) +
+					sizeof(struct cxgbi_task_data),
+					initial_cmdsn, ISCSI_MAX_TARGET);
+	if (!cls_session)
+		return NULL;
+
+	session = cls_session->dd_data;
+	if (iscsi_tcp_r2tpool_alloc(session))
+		goto remove_session;
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"ep 0x%p, cls sess 0x%p.\n", ep, cls_session);
+	return cls_session;
+
+remove_session:
+	iscsi_session_teardown(cls_session);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(cxgbi_create_session);
+
+void cxgbi_destroy_session(struct iscsi_cls_session *cls_session)
+{
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"cls sess 0x%p.\n", cls_session);
+
+	iscsi_tcp_r2tpool_free(cls_session->dd_data);
+	iscsi_session_teardown(cls_session);
+}
+EXPORT_SYMBOL_GPL(cxgbi_destroy_session);
+
+int cxgbi_set_host_param(struct Scsi_Host *shost, enum iscsi_host_param param,
+			char *buf, int buflen)
+{
+	struct cxgbi_hba *chba = iscsi_host_priv(shost);
+
+	if (!chba->ndev) {
+		shost_printk(KERN_ERR, shost, "Could not get host param. "
+				"netdev for host not set.\n");
+		return -ENODEV;
+	}
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"shost 0x%p, hba 0x%p,%s, param %d, buf(%d) %s.\n",
+		shost, chba, chba->ndev->name, param, buflen, buf);
+
+	switch (param) {
+	case ISCSI_HOST_PARAM_IPADDRESS:
+	{
+		__be32 addr = in_aton(buf);
+		log_debug(1 << CXGBI_DBG_ISCSI,
+			"hba %s, req. ipv4 %pI4.\n", chba->ndev->name, &addr);
+		cxgbi_set_iscsi_ipv4(chba, addr);
+		return 0;
+	}
+	case ISCSI_HOST_PARAM_HWADDRESS:
+	case ISCSI_HOST_PARAM_NETDEV_NAME:
+		return 0;
+	default:
+		return iscsi_host_set_param(shost, param, buf, buflen);
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_set_host_param);
+
+int cxgbi_get_host_param(struct Scsi_Host *shost, enum iscsi_host_param param,
+			char *buf)
+{
+	struct cxgbi_hba *chba = iscsi_host_priv(shost);
+	int len = 0;
+
+	if (!chba->ndev) {
+		shost_printk(KERN_ERR, shost, "Could not get host param. "
+				"netdev for host not set.\n");
+		return -ENODEV;
+	}
+
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"shost 0x%p, hba 0x%p,%s, param %d.\n",
+		shost, chba, chba->ndev->name, param);
+
+	switch (param) {
+	case ISCSI_HOST_PARAM_HWADDRESS:
+		len = sysfs_format_mac(buf, chba->ndev->dev_addr, 6);
+		break;
+	case ISCSI_HOST_PARAM_NETDEV_NAME:
+		len = sprintf(buf, "%s\n", chba->ndev->name);
+		break;
+	case ISCSI_HOST_PARAM_IPADDRESS:
+	{
+		__be32 addr;
+
+		addr = cxgbi_get_iscsi_ipv4(chba);
+		len = sprintf(buf, "%pI4", &addr);
+		log_debug(1 << CXGBI_DBG_ISCSI,
+			"hba %s, ipv4 %pI4.\n", chba->ndev->name, &addr);
+		break;
+	}
+	default:
+		return iscsi_host_get_param(shost, param, buf);
+	}
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(cxgbi_get_host_param);
+
+struct iscsi_endpoint *cxgbi_ep_connect(struct Scsi_Host *shost,
+					struct sockaddr *dst_addr,
+					int non_blocking)
+{
+	struct iscsi_endpoint *ep;
+	struct cxgbi_endpoint *cep;
+	struct cxgbi_hba *hba = NULL;
+	struct cxgbi_sock *csk;
+	int err = -EINVAL;
+
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_SOCK,
+		"shost 0x%p, non_blocking %d, dst_addr 0x%p.\n",
+		shost, non_blocking, dst_addr);
+
+	if (shost) {
+		hba = iscsi_host_priv(shost);
+		if (!hba) {
+			pr_info("shost 0x%p, priv NULL.\n", shost);
+			goto err_out;
+		}
+	}
+
+	csk = cxgbi_check_route(dst_addr);
+	if (IS_ERR(csk))
+		return (struct iscsi_endpoint *)csk;
+	cxgbi_sock_get(csk);
+
+	if (!hba)
+		hba = csk->cdev->hbas[csk->port_id];
+	else if (hba != csk->cdev->hbas[csk->port_id]) {
+		pr_info("Could not connect through requested host %u"
+			"hba 0x%p != 0x%p (%u).\n",
+			shost->host_no, hba,
+			csk->cdev->hbas[csk->port_id], csk->port_id);
+		err = -ENOSPC;
+		goto release_conn;
+	}
+
+	err = sock_get_port(csk);
+	if (err)
+		goto release_conn;
+
+	cxgbi_sock_set_state(csk, CTP_CONNECTING);
+	err = csk->cdev->csk_init_act_open(csk);
+	if (err)
+		goto release_conn;
+
+	if (cxgbi_sock_is_closing(csk)) {
+		err = -ENOSPC;
+		pr_info("csk 0x%p is closing.\n", csk);
+		goto release_conn;
+	}
+
+	ep = iscsi_create_endpoint(sizeof(*cep));
+	if (!ep) {
+		err = -ENOMEM;
+		pr_info("iscsi alloc ep, OOM.\n");
+		goto release_conn;
+	}
+
+	cep = ep->dd_data;
+	cep->csk = csk;
+	cep->chba = hba;
+
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_SOCK,
+		"ep 0x%p, cep 0x%p, csk 0x%p, hba 0x%p,%s.\n",
+		ep, cep, csk, hba, hba->ndev->name);
+	return ep;
+
+release_conn:
+	cxgbi_sock_put(csk);
+	cxgbi_sock_closed(csk);
+err_out:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(cxgbi_ep_connect);
+
+int cxgbi_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
+{
+	struct cxgbi_endpoint *cep = ep->dd_data;
+	struct cxgbi_sock *csk = cep->csk;
+
+	if (!cxgbi_sock_is_established(csk))
+		return 0;
+	return 1;
+}
+EXPORT_SYMBOL_GPL(cxgbi_ep_poll);
+
+void cxgbi_ep_disconnect(struct iscsi_endpoint *ep)
+{
+	struct cxgbi_endpoint *cep = ep->dd_data;
+	struct cxgbi_conn *cconn = cep->cconn;
+	struct cxgbi_sock *csk = cep->csk;
+
+	log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_SOCK,
+		"ep 0x%p, cep 0x%p, cconn 0x%p, csk 0x%p,%u,0x%lx.\n",
+		ep, cep, cconn, csk, csk->state, csk->flags);
+
+	if (cconn && cconn->iconn) {
+		iscsi_suspend_tx(cconn->iconn);
+		write_lock_bh(&csk->callback_lock);
+		cep->csk->user_data = NULL;
+		cconn->cep = NULL;
+		write_unlock_bh(&csk->callback_lock);
+	}
+	iscsi_destroy_endpoint(ep);
+
+	if (likely(csk->state >= CTP_ESTABLISHED))
+		need_active_close(csk);
+	else
+		cxgbi_sock_closed(csk);
+
+	cxgbi_sock_put(csk);
+}
+EXPORT_SYMBOL_GPL(cxgbi_ep_disconnect);
+
+int cxgbi_iscsi_init(struct iscsi_transport *itp,
+			struct scsi_transport_template **stt)
+{
+	*stt = iscsi_register_transport(itp);
+	if (*stt == NULL) {
+		pr_err("unable to register %s transport 0x%p.\n",
+			itp->name, itp);
+		return -ENODEV;
+	}
+	log_debug(1 << CXGBI_DBG_ISCSI,
+		"%s, registered iscsi transport 0x%p.\n",
+		itp->name, stt);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxgbi_iscsi_init);
+
+void cxgbi_iscsi_cleanup(struct iscsi_transport *itp,
+			struct scsi_transport_template **stt)
+{
+	if (*stt) {
+		log_debug(1 << CXGBI_DBG_ISCSI,
+			"de-register transport 0x%p, %s, stt 0x%p.\n",
+			itp, itp->name, *stt);
+		*stt = NULL;
+		iscsi_unregister_transport(itp);
+	}
+}
+EXPORT_SYMBOL_GPL(cxgbi_iscsi_cleanup);
+
+static int __init libcxgbi_init_module(void)
+{
+	sw_tag_idx_bits = (__ilog2_u32(ISCSI_ITT_MASK)) + 1;
+	sw_tag_age_bits = (__ilog2_u32(ISCSI_AGE_MASK)) + 1;
+
+	pr_info("tag itt 0x%x, %u bits, age 0x%x, %u bits.\n",
+		ISCSI_ITT_MASK, sw_tag_idx_bits,
+		ISCSI_AGE_MASK, sw_tag_age_bits);
+
+	ddp_setup_host_page_size();
+	return 0;
+}
+
+static void __exit libcxgbi_exit_module(void)
+{
+	cxgbi_device_unregister_all(0xFF);
+	return;
+}
+
+module_init(libcxgbi_init_module);
+module_exit(libcxgbi_exit_module);