iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target_stat.h b/drivers/target/iscsi/iscsi_target_stat.h
new file mode 100644
index 0000000..3ff76b4
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_stat.h
@@ -0,0 +1,64 @@
+#ifndef ISCSI_TARGET_STAT_H
+#define ISCSI_TARGET_STAT_H
+
+/*
+ * For struct iscsi_tiqn->tiqn_wwn default groups
+ */
+extern struct config_item_type iscsi_stat_instance_cit;
+extern struct config_item_type iscsi_stat_sess_err_cit;
+extern struct config_item_type iscsi_stat_tgt_attr_cit;
+extern struct config_item_type iscsi_stat_login_cit;
+extern struct config_item_type iscsi_stat_logout_cit;
+
+/*
+ * For struct iscsi_session->se_sess default groups
+ */
+extern struct config_item_type iscsi_stat_sess_cit;
+
+/* iSCSI session error types */
+#define ISCSI_SESS_ERR_UNKNOWN		0
+#define ISCSI_SESS_ERR_DIGEST		1
+#define ISCSI_SESS_ERR_CXN_TIMEOUT	2
+#define ISCSI_SESS_ERR_PDU_FORMAT	3
+
+/* iSCSI session error stats */
+struct iscsi_sess_err_stats {
+	spinlock_t	lock;
+	u32		digest_errors;
+	u32		cxn_timeout_errors;
+	u32		pdu_format_errors;
+	u32		last_sess_failure_type;
+	char		last_sess_fail_rem_name[224];
+} ____cacheline_aligned;
+
+/* iSCSI login failure types (sub oids) */
+#define ISCSI_LOGIN_FAIL_OTHER		2
+#define ISCSI_LOGIN_FAIL_REDIRECT	3
+#define ISCSI_LOGIN_FAIL_AUTHORIZE	4
+#define ISCSI_LOGIN_FAIL_AUTHENTICATE	5
+#define ISCSI_LOGIN_FAIL_NEGOTIATE	6
+
+/* iSCSI login stats */
+struct iscsi_login_stats {
+	spinlock_t	lock;
+	u32		accepts;
+	u32		other_fails;
+	u32		redirects;
+	u32		authorize_fails;
+	u32		authenticate_fails;
+	u32		negotiate_fails;	/* used for notifications */
+	u64		last_fail_time;		/* time stamp (jiffies) */
+	u32		last_fail_type;
+	int		last_intr_fail_ip_family;
+	unsigned char	last_intr_fail_ip_addr[IPV6_ADDRESS_SPACE];
+	char		last_intr_fail_name[224];
+} ____cacheline_aligned;
+
+/* iSCSI logout stats */
+struct iscsi_logout_stats {
+	spinlock_t	lock;
+	u32		normal_logouts;
+	u32		abnormal_logouts;
+} ____cacheline_aligned;
+
+#endif   /*** ISCSI_TARGET_STAT_H ***/