[SCSI] cxgb3i: Add cxgb3i iSCSI driver.

This patch implements the cxgb3i iscsi connection acceleration for the
open-iscsi initiator.

The cxgb3i driver offers the iscsi PDU based offload:
- digest insertion and verification
- payload direct-placement into host memory buffer.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 951 insertions, 0 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i_iscsi.c b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
new file mode 100644
index 000000000000..d83464b9b3f9
--- /dev/null
+++ b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
@@ -0,0 +1,951 @@
+/* cxgb3i_iscsi.c: Chelsio S3xx iSCSI driver.
+ *
+ * Copyright (c) 2008 Chelsio Communications, Inc.
+ * Copyright (c) 2008 Mike Christie
+ * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
+ *
+ * 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)
+ */
+
+#include <linux/inet.h>
+#include <linux/crypto.h>
+#include <net/tcp.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi.h>
+#include <scsi/iscsi_proto.h>
+#include <scsi/libiscsi.h>
+#include <scsi/scsi_transport_iscsi.h>
+
+#include "cxgb3i.h"
+#include "cxgb3i_pdu.h"
+
+#ifdef __DEBUG_CXGB3I_TAG__
+#define cxgb3i_tag_debug	cxgb3i_log_debug
+#else
+#define cxgb3i_tag_debug(fmt...)
+#endif
+
+#ifdef __DEBUG_CXGB3I_API__
+#define cxgb3i_api_debug	cxgb3i_log_debug
+#else
+#define cxgb3i_api_debug(fmt...)
+#endif
+
+/*
+ * align pdu size to multiple of 512 for better performance
+ */
+#define align_pdu_size(n) do { n = (n) & (~511); } while (0)
+
+static struct scsi_transport_template *cxgb3i_scsi_transport;
+static struct scsi_host_template cxgb3i_host_template;
+static struct iscsi_transport cxgb3i_iscsi_transport;
+static unsigned char sw_tag_idx_bits;
+static unsigned char sw_tag_age_bits;
+
+static LIST_HEAD(cxgb3i_snic_list);
+static DEFINE_RWLOCK(cxgb3i_snic_rwlock);
+
+/**
+ * cxgb3i_adapter_add - init a s3 adapter structure and any h/w settings
+ * @t3dev: t3cdev adapter
+ * return the resulting cxgb3i_adapter struct
+ */
+struct cxgb3i_adapter *cxgb3i_adapter_add(struct t3cdev *t3dev)
+{
+	struct cxgb3i_adapter *snic;
+	struct adapter *adapter = tdev2adap(t3dev);
+	int i;
+
+	snic = kzalloc(sizeof(*snic), GFP_KERNEL);
+	if (!snic) {
+		cxgb3i_api_debug("cxgb3 %s, OOM.\n", t3dev->name);
+		return NULL;
+	}
+	spin_lock_init(&snic->lock);
+
+	snic->tdev = t3dev;
+	snic->pdev = adapter->pdev;
+	snic->tag_format.sw_bits = sw_tag_idx_bits + sw_tag_age_bits;
+
+	if (cxgb3i_adapter_ddp_init(t3dev, &snic->tag_format,
+				    &snic->tx_max_size,
+				    &snic->rx_max_size) < 0)
+		goto free_snic;
+
+	for_each_port(adapter, i) {
+		snic->hba[i] = cxgb3i_hba_host_add(snic, adapter->port[i]);
+		if (!snic->hba[i])
+			goto ulp_cleanup;
+	}
+	snic->hba_cnt = adapter->params.nports;
+
+	/* add to the list */
+	write_lock(&cxgb3i_snic_rwlock);
+	list_add_tail(&snic->list_head, &cxgb3i_snic_list);
+	write_unlock(&cxgb3i_snic_rwlock);
+
+	return snic;
+
+ulp_cleanup:
+	cxgb3i_adapter_ddp_cleanup(t3dev);
+free_snic:
+	kfree(snic);
+	return NULL;
+}
+
+/**
+ * cxgb3i_adapter_remove - release all the resources held and cleanup any
+ *	h/w settings
+ * @t3dev: t3cdev adapter
+ */
+void cxgb3i_adapter_remove(struct t3cdev *t3dev)
+{
+	int i;
+	struct cxgb3i_adapter *snic;
+
+	/* remove from the list */
+	write_lock(&cxgb3i_snic_rwlock);
+	list_for_each_entry(snic, &cxgb3i_snic_list, list_head) {
+		if (snic->tdev == t3dev) {
+			list_del(&snic->list_head);
+			break;
+		}
+	}
+	write_unlock(&cxgb3i_snic_rwlock);
+
+	if (snic) {
+		for (i = 0; i < snic->hba_cnt; i++) {
+			if (snic->hba[i]) {
+				cxgb3i_hba_host_remove(snic->hba[i]);
+				snic->hba[i] = NULL;
+			}
+		}
+
+		/* release ddp resources */
+		cxgb3i_adapter_ddp_cleanup(snic->tdev);
+		kfree(snic);
+	}
+}
+
+/**
+ * cxgb3i_hba_find_by_netdev - find the cxgb3i_hba structure with a given
+ *	net_device
+ * @t3dev: t3cdev adapter
+ */
+struct cxgb3i_hba *cxgb3i_hba_find_by_netdev(struct net_device *ndev)
+{
+	struct cxgb3i_adapter *snic;
+	int i;
+
+	read_lock(&cxgb3i_snic_rwlock);
+	list_for_each_entry(snic, &cxgb3i_snic_list, list_head) {
+		for (i = 0; i < snic->hba_cnt; i++) {
+			if (snic->hba[i]->ndev == ndev) {
+				read_unlock(&cxgb3i_snic_rwlock);
+				return snic->hba[i];
+			}
+		}
+	}
+	read_unlock(&cxgb3i_snic_rwlock);
+	return NULL;
+}
+
+/**
+ * cxgb3i_hba_host_add - register a new host with scsi/iscsi
+ * @snic: the cxgb3i adapter
+ * @ndev: associated net_device
+ */
+struct cxgb3i_hba *cxgb3i_hba_host_add(struct cxgb3i_adapter *snic,
+				       struct net_device *ndev)
+{
+	struct cxgb3i_hba *hba;
+	struct Scsi_Host *shost;
+	int err;
+
+	shost = iscsi_host_alloc(&cxgb3i_host_template,
+				 sizeof(struct cxgb3i_hba),
+				 CXGB3I_SCSI_QDEPTH_DFLT);
+	if (!shost) {
+		cxgb3i_log_info("iscsi_host_alloc failed.\n");
+		return NULL;
+	}
+
+	shost->transportt = cxgb3i_scsi_transport;
+	shost->max_lun = CXGB3I_MAX_LUN;
+	shost->max_id = CXGB3I_MAX_TARGET;
+	shost->max_channel = 0;
+	shost->max_cmd_len = 16;
+
+	hba = iscsi_host_priv(shost);
+	hba->snic = snic;
+	hba->ndev = ndev;
+	hba->shost = shost;
+
+	pci_dev_get(snic->pdev);
+	err = iscsi_host_add(shost, &snic->pdev->dev);
+	if (err) {
+		cxgb3i_log_info("iscsi_host_add failed.\n");
+		goto pci_dev_put;
+	}
+
+	cxgb3i_api_debug("shost 0x%p, hba 0x%p, no %u.\n",
+			 shost, hba, shost->host_no);
+
+	return hba;
+
+pci_dev_put:
+	pci_dev_put(snic->pdev);
+	scsi_host_put(shost);
+	return NULL;
+}
+
+/**
+ * cxgb3i_hba_host_remove - de-register the host with scsi/iscsi
+ * @hba: the cxgb3i hba
+ */
+void cxgb3i_hba_host_remove(struct cxgb3i_hba *hba)
+{
+	cxgb3i_api_debug("shost 0x%p, hba 0x%p, no %u.\n",
+			 hba->shost, hba, hba->shost->host_no);
+	iscsi_host_remove(hba->shost);
+	pci_dev_put(hba->snic->pdev);
+	iscsi_host_free(hba->shost);
+}
+
+/**
+ * cxgb3i_ep_connect - establish TCP connection to target portal
+ * @dst_addr:		target IP address
+ * @non_blocking:	blocking or non-blocking call
+ *
+ * Initiates a TCP/IP connection to the dst_addr
+ */
+static struct iscsi_endpoint *cxgb3i_ep_connect(struct sockaddr *dst_addr,
+						int non_blocking)
+{
+	struct iscsi_endpoint *ep;
+	struct cxgb3i_endpoint *cep;
+	struct cxgb3i_hba *hba;
+	struct s3_conn *c3cn = NULL;
+	int err = 0;
+
+	c3cn = cxgb3i_c3cn_create();
+	if (!c3cn) {
+		cxgb3i_log_info("ep connect OOM.\n");
+		err = -ENOMEM;
+		goto release_conn;
+	}
+
+	err = cxgb3i_c3cn_connect(c3cn, (struct sockaddr_in *)dst_addr);
+	if (err < 0) {
+		cxgb3i_log_info("ep connect failed.\n");
+		goto release_conn;
+	}
+	hba = cxgb3i_hba_find_by_netdev(c3cn->dst_cache->dev);
+	if (!hba) {
+		err = -ENOSPC;
+		cxgb3i_log_info("NOT going through cxgbi device.\n");
+		goto release_conn;
+	}
+	if (c3cn_is_closing(c3cn)) {
+		err = -ENOSPC;
+		cxgb3i_log_info("ep connect unable to connect.\n");
+		goto release_conn;
+	}
+
+	ep = iscsi_create_endpoint(sizeof(*cep));
+	if (!ep) {
+		err = -ENOMEM;
+		cxgb3i_log_info("iscsi alloc ep, OOM.\n");
+		goto release_conn;
+	}
+	cep = ep->dd_data;
+	cep->c3cn = c3cn;
+	cep->hba = hba;
+
+	cxgb3i_api_debug("ep 0x%p, 0x%p, c3cn 0x%p, hba 0x%p.\n",
+			  ep, cep, c3cn, hba);
+	return ep;
+
+release_conn:
+	cxgb3i_api_debug("conn 0x%p failed, release.\n", c3cn);
+	if (c3cn)
+		cxgb3i_c3cn_release(c3cn);
+	return ERR_PTR(err);
+}
+
+/**
+ * cxgb3i_ep_poll - polls for TCP connection establishement
+ * @ep:		TCP connection (endpoint) handle
+ * @timeout_ms:	timeout value in milli secs
+ *
+ * polls for TCP connect request to complete
+ */
+static int cxgb3i_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)
+{
+	struct cxgb3i_endpoint *cep = ep->dd_data;
+	struct s3_conn *c3cn = cep->c3cn;
+
+	if (!c3cn_is_established(c3cn))
+		return 0;
+	cxgb3i_api_debug("ep 0x%p, c3cn 0x%p established.\n", ep, c3cn);
+	return 1;
+}
+
+/**
+ * cxgb3i_ep_disconnect - teardown TCP connection
+ * @ep:		TCP connection (endpoint) handle
+ *
+ * teardown TCP connection
+ */
+static void cxgb3i_ep_disconnect(struct iscsi_endpoint *ep)
+{
+	struct cxgb3i_endpoint *cep = ep->dd_data;
+	struct cxgb3i_conn *cconn = cep->cconn;
+
+	cxgb3i_api_debug("ep 0x%p, cep 0x%p.\n", ep, cep);
+
+	if (cconn && cconn->conn) {
+		/*
+		 * stop the xmit path so the xmit_pdu function is
+		 * not being called
+		 */
+		iscsi_suspend_tx(cconn->conn);
+
+		write_lock_bh(&cep->c3cn->callback_lock);
+		cep->c3cn->user_data = NULL;
+		cconn->cep = NULL;
+		write_unlock_bh(&cep->c3cn->callback_lock);
+	}
+
+	cxgb3i_api_debug("ep 0x%p, cep 0x%p, release c3cn 0x%p.\n",
+			 ep, cep, cep->c3cn);
+	cxgb3i_c3cn_release(cep->c3cn);
+	iscsi_destroy_endpoint(ep);
+}
+
+/**
+ * cxgb3i_session_create - create a new iscsi session
+ * @cmds_max:		max # of commands
+ * @qdepth:		scsi queue depth
+ * @initial_cmdsn:	initial iscsi CMDSN for this session
+ * @host_no:		pointer to return host no
+ *
+ * Creates a new iSCSI session
+ */
+static struct iscsi_cls_session *
+cxgb3i_session_create(struct iscsi_endpoint *ep, u16 cmds_max, u16 qdepth,
+		      u32 initial_cmdsn, u32 *host_no)
+{
+	struct cxgb3i_endpoint *cep;
+	struct cxgb3i_hba *hba;
+	struct Scsi_Host *shost;
+	struct iscsi_cls_session *cls_session;
+	struct iscsi_session *session;
+
+	if (!ep) {
+		cxgb3i_log_error("%s, missing endpoint.\n", __func__);
+		return NULL;
+	}
+
+	cep = ep->dd_data;
+	hba = cep->hba;
+	shost = hba->shost;
+	cxgb3i_api_debug("ep 0x%p, cep 0x%p, hba 0x%p.\n", ep, cep, hba);
+	BUG_ON(hba != iscsi_host_priv(shost));
+
+	*host_no = shost->host_no;
+
+	cls_session = iscsi_session_setup(&cxgb3i_iscsi_transport, shost,
+					  cmds_max,
+					  sizeof(struct iscsi_tcp_task),
+					  initial_cmdsn, ISCSI_MAX_TARGET);
+	if (!cls_session)
+		return NULL;
+	session = cls_session->dd_data;
+	if (iscsi_tcp_r2tpool_alloc(session))
+		goto remove_session;
+
+	return cls_session;
+
+remove_session:
+	iscsi_session_teardown(cls_session);
+	return NULL;
+}
+
+/**
+ * cxgb3i_session_destroy - destroys iscsi session
+ * @cls_session:	pointer to iscsi cls session
+ *
+ * Destroys an iSCSI session instance and releases its all resources held
+ */
+static void cxgb3i_session_destroy(struct iscsi_cls_session *cls_session)
+{
+	cxgb3i_api_debug("sess 0x%p.\n", cls_session);
+	iscsi_tcp_r2tpool_free(cls_session->dd_data);
+	iscsi_session_teardown(cls_session);
+}
+
+/**
+ * cxgb3i_conn_max_xmit_dlength -- check the max. xmit pdu segment size,
+ * reduce it to be within the hardware limit if needed
+ * @conn: iscsi connection
+ */
+static inline int cxgb3i_conn_max_xmit_dlength(struct iscsi_conn *conn)
+
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+	unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+				 cconn->hba->snic->tx_max_size -
+				 ISCSI_PDU_NONPAYLOAD_MAX);
+
+	if (conn->max_xmit_dlength)
+		conn->max_xmit_dlength = min_t(unsigned int,
+						conn->max_xmit_dlength, max);
+	else
+		conn->max_xmit_dlength = max;
+	align_pdu_size(conn->max_xmit_dlength);
+	cxgb3i_log_info("conn 0x%p, max xmit %u.\n",
+			 conn, conn->max_xmit_dlength);
+	return 0;
+}
+
+/**
+ * cxgb3i_conn_max_recv_dlength -- check the max. recv pdu segment size against
+ * the hardware limit
+ * @conn: iscsi connection
+ * return 0 if the value is valid, < 0 otherwise.
+ */
+static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+	unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
+				 cconn->hba->snic->rx_max_size -
+				 ISCSI_PDU_NONPAYLOAD_MAX);
+
+	align_pdu_size(max);
+	if (conn->max_recv_dlength) {
+		if (conn->max_recv_dlength > max) {
+			cxgb3i_log_error("MaxRecvDataSegmentLength %u too big."
+					 " Need to be <= %u.\n",
+					 conn->max_recv_dlength, max);
+			return -EINVAL;
+		}
+		conn->max_recv_dlength = min_t(unsigned int,
+						conn->max_recv_dlength, max);
+		align_pdu_size(conn->max_recv_dlength);
+	} else
+		conn->max_recv_dlength = max;
+	cxgb3i_api_debug("conn 0x%p, max recv %u.\n",
+			 conn, conn->max_recv_dlength);
+	return 0;
+}
+
+/**
+ * cxgb3i_conn_create - create iscsi connection instance
+ * @cls_session:	pointer to iscsi cls session
+ * @cid:		iscsi cid
+ *
+ * Creates a new iSCSI connection instance for a given session
+ */
+static struct iscsi_cls_conn *cxgb3i_conn_create(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 cxgb3i_conn *cconn;
+
+	cxgb3i_api_debug("sess 0x%p, cid %u.\n", cls_session, cid);
+
+	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->conn = conn;
+	return cls_conn;
+}
+
+/**
+ * cxgb3i_conn_bind - binds iscsi sess, conn and endpoint together
+ * @cls_session:	pointer to iscsi cls session
+ * @cls_conn:		pointer to iscsi cls conn
+ * @transport_eph:	64-bit EP handle
+ * @is_leading:		leading connection on this session?
+ *
+ * Binds together an iSCSI session, an iSCSI connection and a
+ *	TCP connection. This routine returns error code if the TCP
+ *	connection does not belong on the device iSCSI sess/conn is bound
+ */
+
+static int cxgb3i_conn_bind(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 cxgb3i_conn *cconn = tcp_conn->dd_data;
+	struct cxgb3i_adapter *snic;
+	struct iscsi_endpoint *ep;
+	struct cxgb3i_endpoint *cep;
+	struct s3_conn *c3cn;
+	int err;
+
+	ep = iscsi_lookup_endpoint(transport_eph);
+	if (!ep)
+		return -EINVAL;
+
+	/* setup ddp pagesize */
+	cep = ep->dd_data;
+	c3cn = cep->c3cn;
+	snic = cep->hba->snic;
+	err = cxgb3i_setup_conn_host_pagesize(snic->tdev, c3cn->tid, 0);
+	if (err < 0)
+		return err;
+
+	cxgb3i_api_debug("ep 0x%p, cls sess 0x%p, cls conn 0x%p.\n",
+			 ep, cls_session, cls_conn);
+
+	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;
+	cxgb3i_api_debug("session cmds_max 0x%x, bits %u.\n",
+			 conn->session->cmds_max, cconn->task_idx_bits);
+
+	read_lock(&c3cn->callback_lock);
+	c3cn->user_data = conn;
+	cconn->hba = cep->hba;
+	cconn->cep = cep;
+	cep->cconn = cconn;
+	read_unlock(&c3cn->callback_lock);
+
+	cxgb3i_conn_max_xmit_dlength(conn);
+	cxgb3i_conn_max_recv_dlength(conn);
+
+	spin_lock_bh(&conn->session->lock);
+	sprintf(conn->portal_address, NIPQUAD_FMT,
+		NIPQUAD(c3cn->daddr.sin_addr.s_addr));
+	conn->portal_port = ntohs(c3cn->daddr.sin_port);
+	spin_unlock_bh(&conn->session->lock);
+
+	/* init recv engine */
+	iscsi_tcp_hdr_recv_prep(tcp_conn);
+
+	return 0;
+}
+
+/**
+ * cxgb3i_conn_get_param - return iscsi connection parameter to caller
+ * @cls_conn:	pointer to iscsi cls conn
+ * @param:	parameter type identifier
+ * @buf:	buffer pointer
+ *
+ * returns iSCSI connection parameters
+ */
+static int cxgb3i_conn_get_param(struct iscsi_cls_conn *cls_conn,
+				 enum iscsi_param param, char *buf)
+{
+	struct iscsi_conn *conn = cls_conn->dd_data;
+	int len;
+
+	cxgb3i_api_debug("cls_conn 0x%p, param %d.\n", cls_conn, param);
+
+	switch (param) {
+	case ISCSI_PARAM_CONN_PORT:
+		spin_lock_bh(&conn->session->lock);
+		len = sprintf(buf, "%hu\n", conn->portal_port);
+		spin_unlock_bh(&conn->session->lock);
+		break;
+	case ISCSI_PARAM_CONN_ADDRESS:
+		spin_lock_bh(&conn->session->lock);
+		len = sprintf(buf, "%s\n", conn->portal_address);
+		spin_unlock_bh(&conn->session->lock);
+		break;
+	default:
+		return iscsi_conn_get_param(cls_conn, param, buf);
+	}
+
+	return len;
+}
+
+/**
+ * cxgb3i_conn_set_param - set iscsi connection parameter
+ * @cls_conn:	pointer to iscsi cls conn
+ * @param:	parameter type identifier
+ * @buf:	buffer pointer
+ * @buflen:	buffer length
+ *
+ * set iSCSI connection parameters
+ */
+static int cxgb3i_conn_set_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 cxgb3i_conn *cconn = tcp_conn->dd_data;
+	struct cxgb3i_adapter *snic = cconn->hba->snic;
+	struct s3_conn *c3cn = cconn->cep->c3cn;
+	int value, err = 0;
+
+	switch (param) {
+	case ISCSI_PARAM_HDRDGST_EN:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err && conn->hdrdgst_en)
+			err = cxgb3i_setup_conn_digest(snic->tdev, c3cn->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 = cxgb3i_setup_conn_digest(snic->tdev, c3cn->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 = cxgb3i_conn_max_recv_dlength(conn);
+		break;
+	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+		err = iscsi_set_param(cls_conn, param, buf, buflen);
+		if (!err)
+			err = cxgb3i_conn_max_xmit_dlength(conn);
+		break;
+	default:
+		return iscsi_set_param(cls_conn, param, buf, buflen);
+	}
+	return err;
+}
+
+/**
+ * cxgb3i_host_set_param - configure host (adapter) related parameters
+ * @shost:	scsi host pointer
+ * @param:	parameter type identifier
+ * @buf:	buffer pointer
+ */
+static int cxgb3i_host_set_param(struct Scsi_Host *shost,
+				 enum iscsi_host_param param,
+				 char *buf, int buflen)
+{
+	struct cxgb3i_hba *hba = iscsi_host_priv(shost);
+
+	cxgb3i_api_debug("param %d, buf %s.\n", param, buf);
+
+	switch (param) {
+	case ISCSI_HOST_PARAM_IPADDRESS:
+	{
+		__be32 addr = in_aton(buf);
+		cxgb3i_set_private_ipv4addr(hba->ndev, addr);
+		return 0;
+	}
+	case ISCSI_HOST_PARAM_HWADDRESS:
+	case ISCSI_HOST_PARAM_NETDEV_NAME:
+		/* ignore */
+		return 0;
+	default:
+		return iscsi_host_set_param(shost, param, buf, buflen);
+	}
+}
+
+/**
+ * cxgb3i_host_get_param - returns host (adapter) related parameters
+ * @shost:	scsi host pointer
+ * @param:	parameter type identifier
+ * @buf:	buffer pointer
+ */
+static int cxgb3i_host_get_param(struct Scsi_Host *shost,
+				 enum iscsi_host_param param, char *buf)
+{
+	struct cxgb3i_hba *hba = iscsi_host_priv(shost);
+	int len = 0;
+
+	cxgb3i_api_debug("hba %s, param %d.\n", hba->ndev->name, param);
+
+	switch (param) {
+	case ISCSI_HOST_PARAM_HWADDRESS:
+		len = sysfs_format_mac(buf, hba->ndev->dev_addr, 6);
+		break;
+	case ISCSI_HOST_PARAM_NETDEV_NAME:
+		len = sprintf(buf, "%s\n", hba->ndev->name);
+		break;
+	case ISCSI_HOST_PARAM_IPADDRESS:
+	{
+		__be32 addr;
+
+		addr = cxgb3i_get_private_ipv4addr(hba->ndev);
+		len = sprintf(buf, NIPQUAD_FMT, NIPQUAD(addr));
+		break;
+	}
+	default:
+		return iscsi_host_get_param(shost, param, buf);
+	}
+	return len;
+}
+
+/**
+ * cxgb3i_conn_get_stats - returns iSCSI stats
+ * @cls_conn:	pointer to iscsi cls conn
+ * @stats:	pointer to iscsi statistic struct
+ */
+static void cxgb3i_conn_get_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;
+}
+
+/**
+ * cxgb3i_parse_itt - get the idx and age bits from a given tag
+ * @conn:	iscsi connection
+ * @itt:	itt tag
+ * @idx:	task index, filled in by this function
+ * @age:	session age, filled in by this function
+ */
+static void cxgb3i_parse_itt(struct iscsi_conn *conn, itt_t itt,
+			     int *idx, int *age)
+{
+	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+	struct cxgb3i_conn *cconn = tcp_conn->dd_data;
+	struct cxgb3i_adapter *snic = cconn->hba->snic;
+	u32 tag = ntohl((__force u32) itt);
+	u32 sw_bits;
+
+	sw_bits = cxgb3i_tag_nonrsvd_bits(&snic->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;
+
+	cxgb3i_tag_debug("parse tag 0x%x/0x%x, sw 0x%x, itt 0x%x, age 0x%x.\n",
+			 tag, itt, sw_bits, idx ? *idx : 0xFFFFF,
+			 age ? *age : 0xFF);
+}
+
+/**
+ * cxgb3i_reserve_itt - generate tag for a give task
+ * Try to set up ddp for a scsi read task.
+ * @task: iscsi task
+ * @hdr_itt: tag, filled in by this function
+ */
+int cxgb3i_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 cxgb3i_conn *cconn = tcp_conn->dd_data;
+	struct cxgb3i_adapter *snic = cconn->hba->snic;
+	struct cxgb3i_tag_format *tformat = &snic->tag_format;
+	u32 sw_tag = (sess->age << cconn->task_idx_bits) | task->itt;
+	u32 tag;
+	int err = -EINVAL;
+
+	if (sc &&
+	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_FROM_DEVICE) &&
+	    cxgb3i_sw_tag_usable(tformat, sw_tag)) {
+		struct s3_conn *c3cn = cconn->cep->c3cn;
+		struct cxgb3i_gather_list *gl;
+
+		gl = cxgb3i_ddp_make_gl(scsi_in(sc)->length,
+					scsi_in(sc)->table.sgl,
+					scsi_in(sc)->table.nents,
+					snic->pdev,
+					GFP_ATOMIC);
+		if (gl) {
+			tag = sw_tag;
+			err = cxgb3i_ddp_tag_reserve(snic->tdev, c3cn->tid,
+						     tformat, &tag,
+						     gl, GFP_ATOMIC);
+			if (err < 0)
+				cxgb3i_ddp_release_gl(gl, snic->pdev);
+		}
+	}
+
+	if (err < 0)
+		tag = cxgb3i_set_non_ddp_tag(tformat, sw_tag);
+	/* the itt need to sent in big-endian order */
+	*hdr_itt = (__force itt_t)htonl(tag);
+
+	cxgb3i_tag_debug("new tag 0x%x/0x%x (itt 0x%x, age 0x%x).\n",
+			 tag, *hdr_itt, task->itt, sess->age);
+	return 0;
+}
+
+/**
+ * cxgb3i_release_itt - release the tag for a given task
+ * if the tag is a ddp tag, release the ddp setup
+ * @task:	iscsi task
+ * @hdr_itt:	tag
+ */
+void cxgb3i_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 cxgb3i_conn *cconn = tcp_conn->dd_data;
+	struct cxgb3i_adapter *snic = cconn->hba->snic;
+	struct cxgb3i_tag_format *tformat = &snic->tag_format;
+	u32 tag = ntohl((__force u32)hdr_itt);
+
+	cxgb3i_tag_debug("release tag 0x%x.\n", tag);
+
+	if (sc &&
+	    (scsi_bidi_cmnd(sc) || sc->sc_data_direction == DMA_FROM_DEVICE) &&
+	    cxgb3i_is_ddp_tag(tformat, tag))
+		cxgb3i_ddp_tag_release(snic->tdev, tag);
+}
+
+/**
+ * cxgb3i_host_template -- Scsi_Host_Template structure
+ *	used when registering with the scsi mid layer
+ */
+static struct scsi_host_template cxgb3i_host_template = {
+	.module			= THIS_MODULE,
+	.name			= "Chelsio S3xx iSCSI Initiator",
+	.proc_name		= "cxgb3i",
+	.queuecommand		= iscsi_queuecommand,
+	.change_queue_depth	= iscsi_change_queue_depth,
+	.can_queue		= 128 * (ISCSI_DEF_XMIT_CMDS_MAX - 1),
+	.sg_tablesize		= SG_ALL,
+	.max_sectors		= 0xFFFF,
+	.cmd_per_lun		= ISCSI_DEF_CMD_PER_LUN,
+	.eh_abort_handler	= iscsi_eh_abort,
+	.eh_device_reset_handler = iscsi_eh_device_reset,
+	.eh_target_reset_handler = iscsi_eh_target_reset,
+	.use_clustering		= DISABLE_CLUSTERING,
+	.this_id		= -1,
+};
+
+static struct iscsi_transport cxgb3i_iscsi_transport = {
+	.owner			= THIS_MODULE,
+	.name			= "cxgb3i",
+	.caps			= CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST
+				| CAP_DATADGST | CAP_DIGEST_OFFLOAD |
+				CAP_PADDING_OFFLOAD,
+	.param_mask		= ISCSI_MAX_RECV_DLENGTH |
+				ISCSI_MAX_XMIT_DLENGTH |
+				ISCSI_HDRDGST_EN |
+				ISCSI_DATADGST_EN |
+				ISCSI_INITIAL_R2T_EN |
+				ISCSI_MAX_R2T |
+				ISCSI_IMM_DATA_EN |
+				ISCSI_FIRST_BURST |
+				ISCSI_MAX_BURST |
+				ISCSI_PDU_INORDER_EN |
+				ISCSI_DATASEQ_INORDER_EN |
+				ISCSI_ERL |
+				ISCSI_CONN_PORT |
+				ISCSI_CONN_ADDRESS |
+				ISCSI_EXP_STATSN |
+				ISCSI_PERSISTENT_PORT |
+				ISCSI_PERSISTENT_ADDRESS |
+				ISCSI_TARGET_NAME | ISCSI_TPGT |
+				ISCSI_USERNAME | ISCSI_PASSWORD |
+				ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN |
+				ISCSI_FAST_ABORT | ISCSI_ABORT_TMO |
+				ISCSI_LU_RESET_TMO |
+				ISCSI_PING_TMO | ISCSI_RECV_TMO |
+				ISCSI_IFACE_NAME | ISCSI_INITIATOR_NAME,
+	.host_param_mask	= ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS |
+			ISCSI_HOST_INITIATOR_NAME | ISCSI_HOST_NETDEV_NAME,
+	.get_host_param		= cxgb3i_host_get_param,
+	.set_host_param		= cxgb3i_host_set_param,
+	/* session management */
+	.create_session		= cxgb3i_session_create,
+	.destroy_session	= cxgb3i_session_destroy,
+	.get_session_param	= iscsi_session_get_param,
+	/* connection management */
+	.create_conn		= cxgb3i_conn_create,
+	.bind_conn		= cxgb3i_conn_bind,
+	.destroy_conn		= iscsi_tcp_conn_teardown,
+	.start_conn		= iscsi_conn_start,
+	.stop_conn		= iscsi_conn_stop,
+	.get_conn_param		= cxgb3i_conn_get_param,
+	.set_param		= cxgb3i_conn_set_param,
+	.get_stats		= cxgb3i_conn_get_stats,
+	/* pdu xmit req. from user space */
+	.send_pdu		= iscsi_conn_send_pdu,
+	/* task */
+	.init_task		= iscsi_tcp_task_init,
+	.xmit_task		= iscsi_tcp_task_xmit,
+	.cleanup_task		= cxgb3i_conn_cleanup_task,
+
+	/* pdu */
+	.alloc_pdu		= cxgb3i_conn_alloc_pdu,
+	.init_pdu		= cxgb3i_conn_init_pdu,
+	.xmit_pdu		= cxgb3i_conn_xmit_pdu,
+	.parse_pdu_itt		= cxgb3i_parse_itt,
+
+	/* TCP connect/disconnect */
+	.ep_connect		= cxgb3i_ep_connect,
+	.ep_poll		= cxgb3i_ep_poll,
+	.ep_disconnect		= cxgb3i_ep_disconnect,
+	/* Error recovery timeout call */
+	.session_recovery_timedout = iscsi_session_recovery_timedout,
+};
+
+int cxgb3i_iscsi_init(void)
+{
+	sw_tag_idx_bits = (__ilog2_u32(ISCSI_ITT_MASK)) + 1;
+	sw_tag_age_bits = (__ilog2_u32(ISCSI_AGE_MASK)) + 1;
+	cxgb3i_log_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);
+
+	cxgb3i_scsi_transport =
+	    iscsi_register_transport(&cxgb3i_iscsi_transport);
+	if (!cxgb3i_scsi_transport) {
+		cxgb3i_log_error("Could not register cxgb3i transport.\n");
+		return -ENODEV;
+	}
+	cxgb3i_api_debug("cxgb3i transport 0x%p.\n", cxgb3i_scsi_transport);
+	return 0;
+}
+
+void cxgb3i_iscsi_cleanup(void)
+{
+	if (cxgb3i_scsi_transport) {
+		cxgb3i_api_debug("cxgb3i transport 0x%p.\n",
+				 cxgb3i_scsi_transport);
+		iscsi_unregister_transport(&cxgb3i_iscsi_transport);
+	}
+}