[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, 231 insertions, 0 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i_offload.h b/drivers/scsi/cxgb3i/cxgb3i_offload.h
new file mode 100644
index 000000000000..5b93d629e5c1
--- /dev/null
+++ b/drivers/scsi/cxgb3i/cxgb3i_offload.h
@@ -0,0 +1,231 @@
+/*
+ * cxgb3i_offload.h: Chelsio S3xx iscsi offloaded tcp connection management
+ *
+ * Copyright (C) 2003-2008 Chelsio Communications.  All rights reserved.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the LICENSE file included in this
+ * release for licensing terms and conditions.
+ *
+ * Written by:	Dimitris Michailidis (dm@chelsio.com)
+ *		Karen Xie (kxie@chelsio.com)
+ */
+
+#ifndef _CXGB3I_OFFLOAD_H
+#define _CXGB3I_OFFLOAD_H
+
+#include <linux/skbuff.h>
+#include <net/tcp.h>
+
+#include "common.h"
+#include "adapter.h"
+#include "t3cdev.h"
+#include "cxgb3_offload.h"
+
+#define cxgb3i_log_error(fmt...) printk(KERN_ERR "cxgb3i: ERR! " fmt)
+#define cxgb3i_log_warn(fmt...)	 printk(KERN_WARNING "cxgb3i: WARN! " fmt)
+#define cxgb3i_log_info(fmt...)  printk(KERN_INFO "cxgb3i: " fmt)
+#define cxgb3i_log_debug(fmt, args...) \
+	printk(KERN_INFO "cxgb3i: %s - " fmt, __func__ , ## args)
+
+/**
+ * struct s3_conn - an iscsi tcp connection structure
+ *
+ * @dev:	net device of with connection
+ * @cdev:	adapter t3cdev for net device
+ * @flags:	see c3cn_flags below
+ * @tid:	connection id assigned by the h/w
+ * @qset:	queue set used by connection
+ * @mss_idx:	Maximum Segment Size table index
+ * @l2t:	ARP resolution entry for offload packets
+ * @wr_max:	maximum in-flight writes
+ * @wr_avail:	number of writes available
+ * @wr_unacked:	writes since last request for completion notification
+ * @wr_pending_head: head of pending write queue
+ * @wr_pending_tail: tail of pending write queue
+ * @cpl_close:	skb for cpl_close_req
+ * @cpl_abort_req: skb for cpl_abort_req
+ * @cpl_abort_rpl: skb for cpl_abort_rpl
+ * @lock:	connection status lock
+ * @refcnt:	reference count on connection
+ * @state:	connection state
+ * @saddr:	source ip/port address
+ * @daddr:	destination ip/port address
+ * @dst_cache:	reference to destination route
+ * @receive_queue: received PDUs
+ * @write_queue: un-pushed pending writes
+ * @retry_timer: retry timer for various operations
+ * @err:	connection error status
+ * @callback_lock: lock for opaque user context
+ * @user_data:	opaque user context
+ * @rcv_nxt:	next receive seq. #
+ * @copied_seq:	head of yet unread data
+ * @rcv_wup:	rcv_nxt on last window update sent
+ * @snd_nxt:	next sequence we send
+ * @snd_una:	first byte we want an ack for
+ * @write_seq:	tail+1 of data held in send buffer
+ */
+struct s3_conn {
+	struct net_device *dev;
+	struct t3cdev *cdev;
+	unsigned long flags;
+	int tid;
+	int qset;
+	int mss_idx;
+	struct l2t_entry *l2t;
+	int wr_max;
+	int wr_avail;
+	int wr_unacked;
+	struct sk_buff *wr_pending_head;
+	struct sk_buff *wr_pending_tail;
+	struct sk_buff *cpl_close;
+	struct sk_buff *cpl_abort_req;
+	struct sk_buff *cpl_abort_rpl;
+	spinlock_t lock;
+	atomic_t refcnt;
+	volatile unsigned int state;
+	struct sockaddr_in saddr;
+	struct sockaddr_in daddr;
+	struct dst_entry *dst_cache;
+	struct sk_buff_head receive_queue;
+	struct sk_buff_head write_queue;
+	struct timer_list retry_timer;
+	int err;
+	rwlock_t callback_lock;
+	void *user_data;
+
+	u32 rcv_nxt;
+	u32 copied_seq;
+	u32 rcv_wup;
+	u32 snd_nxt;
+	u32 snd_una;
+	u32 write_seq;
+};
+
+/*
+ * connection state
+ */
+enum conn_states {
+	C3CN_STATE_CONNECTING = 1,
+	C3CN_STATE_ESTABLISHED,
+	C3CN_STATE_ACTIVE_CLOSE,
+	C3CN_STATE_PASSIVE_CLOSE,
+	C3CN_STATE_CLOSE_WAIT_1,
+	C3CN_STATE_CLOSE_WAIT_2,
+	C3CN_STATE_ABORTING,
+	C3CN_STATE_CLOSED,
+};
+
+static inline unsigned int c3cn_is_closing(const struct s3_conn *c3cn)
+{
+	return c3cn->state >= C3CN_STATE_ACTIVE_CLOSE;
+}
+static inline unsigned int c3cn_is_established(const struct s3_conn *c3cn)
+{
+	return c3cn->state == C3CN_STATE_ESTABLISHED;
+}
+
+/*
+ * Connection flags -- many to track some close related events.
+ */
+enum c3cn_flags {
+	C3CN_ABORT_RPL_RCVD,	/* received one ABORT_RPL_RSS message */
+	C3CN_ABORT_REQ_RCVD,	/* received one ABORT_REQ_RSS message */
+	C3CN_ABORT_RPL_PENDING,	/* expecting an abort reply */
+	C3CN_TX_DATA_SENT,	/* already sent a TX_DATA WR */
+	C3CN_ACTIVE_CLOSE_NEEDED,	/* need to be closed */
+};
+
+/**
+ * cxgb3i_sdev_data - Per adapter data.
+ * Linked off of each Ethernet device port on the adapter.
+ * Also available via the t3cdev structure since we have pointers to our port
+ * net_device's there ...
+ *
+ * @list:	list head to link elements
+ * @cdev:	t3cdev adapter
+ * @client:	CPL client pointer
+ * @ports:	array of adapter ports
+ * @sport_map_next: next index into the port map
+ * @sport_map:	source port map
+ */
+struct cxgb3i_sdev_data {
+	struct list_head list;
+	struct t3cdev *cdev;
+	struct cxgb3_client *client;
+	struct adap_ports ports;
+	unsigned int sport_map_next;
+	unsigned long sport_map[0];
+};
+#define NDEV2CDATA(ndev) (*(struct cxgb3i_sdev_data **)&(ndev)->ec_ptr)
+#define CXGB3_SDEV_DATA(cdev) NDEV2CDATA((cdev)->lldev)
+
+void cxgb3i_sdev_cleanup(void);
+int cxgb3i_sdev_init(cxgb3_cpl_handler_func *);
+void cxgb3i_sdev_add(struct t3cdev *, struct cxgb3_client *);
+void cxgb3i_sdev_remove(struct t3cdev *);
+
+struct s3_conn *cxgb3i_c3cn_create(void);
+int cxgb3i_c3cn_connect(struct s3_conn *, struct sockaddr_in *);
+void cxgb3i_c3cn_rx_credits(struct s3_conn *, int);
+int cxgb3i_c3cn_send_pdus(struct s3_conn *, struct sk_buff *);
+void cxgb3i_c3cn_release(struct s3_conn *);
+
+/**
+ * cxgb3_skb_cb - control block for received pdu state and ULP mode management.
+ *
+ * @flag:	see C3CB_FLAG_* below
+ * @ulp_mode:	ULP mode/submode of sk_buff
+ * @seq:	tcp sequence number
+ * @ddigest:	pdu data digest
+ * @pdulen:	recovered pdu length
+ * @ulp_data:	scratch area for ULP
+ */
+struct cxgb3_skb_cb {
+	__u8 flags;
+	__u8 ulp_mode;
+	__u32 seq;
+	__u32 ddigest;
+	__u32 pdulen;
+	__u8 ulp_data[16];
+};
+
+#define CXGB3_SKB_CB(skb)	((struct cxgb3_skb_cb *)&((skb)->cb[0]))
+
+#define skb_ulp_mode(skb)	(CXGB3_SKB_CB(skb)->ulp_mode)
+#define skb_ulp_ddigest(skb)	(CXGB3_SKB_CB(skb)->ddigest)
+#define skb_ulp_pdulen(skb)	(CXGB3_SKB_CB(skb)->pdulen)
+#define skb_ulp_data(skb)	(CXGB3_SKB_CB(skb)->ulp_data)
+
+enum c3cb_flags {
+	C3CB_FLAG_NEED_HDR = 1 << 0,	/* packet needs a TX_DATA_WR header */
+	C3CB_FLAG_NO_APPEND = 1 << 1,	/* don't grow this skb */
+	C3CB_FLAG_COMPL = 1 << 2,	/* request WR completion */
+};
+
+/**
+ * sge_opaque_hdr -
+ * Opaque version of structure the SGE stores at skb->head of TX_DATA packets
+ * and for which we must reserve space.
+ */
+struct sge_opaque_hdr {
+	void *dev;
+	dma_addr_t addr[MAX_SKB_FRAGS + 1];
+};
+
+/* for TX: a skb must have a headroom of at least TX_HEADER_LEN bytes */
+#define TX_HEADER_LEN \
+		(sizeof(struct tx_data_wr) + sizeof(struct sge_opaque_hdr))
+
+/*
+ * get and set private ip for iscsi traffic
+ */
+#define cxgb3i_get_private_ipv4addr(ndev) \
+	(((struct port_info *)(netdev_priv(ndev)))->iscsi_ipv4addr)
+#define cxgb3i_set_private_ipv4addr(ndev, addr) \
+	(((struct port_info *)(netdev_priv(ndev)))->iscsi_ipv4addr) = addr
+
+/* max. connections per adapter */
+#define CXGB3I_MAX_CONN		16384
+#endif /* _CXGB3_OFFLOAD_H */