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>

1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_tq.h b/drivers/target/iscsi/iscsi_target_tq.h
new file mode 100644
index 000000000000..26e6a95ec203
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_tq.h
@@ -0,0 +1,88 @@
+#ifndef ISCSI_THREAD_QUEUE_H
+#define ISCSI_THREAD_QUEUE_H
+
+/*
+ * Defines for thread sets.
+ */
+extern int iscsi_thread_set_force_reinstatement(struct iscsi_conn *);
+extern void iscsi_add_ts_to_inactive_list(struct iscsi_thread_set *);
+extern int iscsi_allocate_thread_sets(u32);
+extern void iscsi_deallocate_thread_sets(void);
+extern void iscsi_activate_thread_set(struct iscsi_conn *, struct iscsi_thread_set *);
+extern struct iscsi_thread_set *iscsi_get_thread_set(void);
+extern void iscsi_set_thread_clear(struct iscsi_conn *, u8);
+extern void iscsi_set_thread_set_signal(struct iscsi_conn *, u8);
+extern int iscsi_release_thread_set(struct iscsi_conn *);
+extern struct iscsi_conn *iscsi_rx_thread_pre_handler(struct iscsi_thread_set *);
+extern struct iscsi_conn *iscsi_tx_thread_pre_handler(struct iscsi_thread_set *);
+extern int iscsi_thread_set_init(void);
+extern void iscsi_thread_set_free(void);
+
+extern int iscsi_target_tx_thread(void *);
+extern int iscsi_target_rx_thread(void *);
+
+#define TARGET_THREAD_SET_COUNT			4
+
+#define ISCSI_RX_THREAD                         1
+#define ISCSI_TX_THREAD                         2
+#define ISCSI_RX_THREAD_NAME			"iscsi_trx"
+#define ISCSI_TX_THREAD_NAME			"iscsi_ttx"
+#define ISCSI_BLOCK_RX_THREAD			0x1
+#define ISCSI_BLOCK_TX_THREAD			0x2
+#define ISCSI_CLEAR_RX_THREAD			0x1
+#define ISCSI_CLEAR_TX_THREAD			0x2
+#define ISCSI_SIGNAL_RX_THREAD			0x1
+#define ISCSI_SIGNAL_TX_THREAD			0x2
+
+/* struct iscsi_thread_set->status */
+#define ISCSI_THREAD_SET_FREE			1
+#define ISCSI_THREAD_SET_ACTIVE			2
+#define ISCSI_THREAD_SET_DIE			3
+#define ISCSI_THREAD_SET_RESET			4
+#define ISCSI_THREAD_SET_DEALLOCATE_THREADS	5
+
+/* By default allow a maximum of 32K iSCSI connections */
+#define ISCSI_TS_BITMAP_BITS			32768
+
+struct iscsi_thread_set {
+	/* flags used for blocking and restarting sets */
+	int	blocked_threads;
+	/* flag for creating threads */
+	int	create_threads;
+	/* flag for delaying readding to inactive list */
+	int	delay_inactive;
+	/* status for thread set */
+	int	status;
+	/* which threads have had signals sent */
+	int	signal_sent;
+	/* flag for which threads exited first */
+	int	thread_clear;
+	/* Active threads in the thread set */
+	int	thread_count;
+	/* Unique thread ID */
+	u32	thread_id;
+	/* pointer to connection if set is active */
+	struct iscsi_conn	*conn;
+	/* used for controlling ts state accesses */
+	spinlock_t	ts_state_lock;
+	/* Used for rx side post startup */
+	struct completion	rx_post_start_comp;
+	/* Used for tx side post startup */
+	struct completion	tx_post_start_comp;
+	/* used for restarting thread queue */
+	struct completion	rx_restart_comp;
+	/* used for restarting thread queue */
+	struct completion	tx_restart_comp;
+	/* used for normal unused blocking */
+	struct completion	rx_start_comp;
+	/* used for normal unused blocking */
+	struct completion	tx_start_comp;
+	/* OS descriptor for rx thread */
+	struct task_struct	*rx_thread;
+	/* OS descriptor for tx thread */
+	struct task_struct	*tx_thread;
+	/* struct iscsi_thread_set in list list head*/
+	struct list_head	ts_list;
+};
+
+#endif   /*** ISCSI_THREAD_QUEUE_H ***/