[SCSI] libfc: A modular Fibre Channel library

libFC is composed of 4 blocks supported by an exchange manager
and a framing library. The upper 4 layers are fc_lport, fc_disc,
fc_rport and fc_fcp. A LLD that uses libfc could choose to
either use libfc's block, or using the transport template
defined in libfc.h, override one or more blocks with its own
implementation.

The EM (Exchange Manager) manages exhcanges/sequences for all
commands- ELS, CT and FCP.

The framing library frames ELS and CT commands.

The fc_lport block manages the library's representation of the
host's FC enabled ports.

The fc_disc block manages discovery of targets as well as
handling changes that occur in the FC fabric (via. RSCN events).

The fc_rport block manages the library's representation of other
entities in the FC fabric. Currently the library uses this block
for targets, its peer when in point-to-point mode and the
directory server, but can be extended for other entities if
needed.

The fc_fcp block interacts with the scsi-ml and handles all
I/O.

Signed-off-by: Robert Love <robert.w.love@intel.com>
[jejb: added include of delay.h to fix ppc64 compile prob spotted by sfr]
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 938 insertions, 0 deletions

diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
new file mode 100644
index 000000000000..9f2876397dda
--- /dev/null
+++ b/include/scsi/libfc.h
@@ -0,0 +1,938 @@
+/*
+ * Copyright(c) 2007 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Maintained at www.Open-FCoE.org
+ */
+
+#ifndef _LIBFC_H_
+#define _LIBFC_H_
+
+#include <linux/timer.h>
+#include <linux/if.h>
+
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_fc.h>
+
+#include <scsi/fc/fc_fcp.h>
+#include <scsi/fc/fc_ns.h>
+#include <scsi/fc/fc_els.h>
+#include <scsi/fc/fc_gs.h>
+
+#include <scsi/fc_frame.h>
+
+#define LIBFC_DEBUG
+
+#ifdef LIBFC_DEBUG
+/* Log messages */
+#define FC_DBG(fmt, args...)                                            \
+        do {                                                            \
+                printk(KERN_INFO "%s " fmt, __func__, ##args);          \
+        } while (0)
+#else
+#define FC_DBG(fmt, args...)
+#endif
+
+/*
+ * libfc error codes
+ */
+#define FC_NO_ERR       0       /* no error */
+#define FC_EX_TIMEOUT   1       /* Exchange timeout */
+#define FC_EX_CLOSED    2       /* Exchange closed */
+
+/* some helpful macros */
+
+#define ntohll(x) be64_to_cpu(x)
+#define htonll(x) cpu_to_be64(x)
+
+#define ntoh24(p) (((p)[0] << 16) | ((p)[1] << 8) | ((p)[2]))
+
+#define hton24(p, v)    do {                    \
+                p[0] = (((v) >> 16) & 0xFF);    \
+                p[1] = (((v) >> 8) & 0xFF);     \
+                p[2] = ((v) & 0xFF);            \
+        } while (0)
+
+/*
+ * FC HBA status
+ */
+#define FC_PAUSE                    (1 << 1)
+#define FC_LINK_UP                  (1 << 0)
+
+enum fc_lport_state {
+        LPORT_ST_NONE = 0,
+        LPORT_ST_FLOGI,
+        LPORT_ST_DNS,
+        LPORT_ST_RPN_ID,
+        LPORT_ST_RFT_ID,
+        LPORT_ST_SCR,
+        LPORT_ST_READY,
+        LPORT_ST_LOGO,
+        LPORT_ST_RESET
+};
+
+enum fc_disc_event {
+        DISC_EV_NONE = 0,
+        DISC_EV_SUCCESS,
+        DISC_EV_FAILED
+};
+
+enum fc_rport_state {
+        RPORT_ST_NONE = 0,
+        RPORT_ST_INIT,          /* initialized */
+        RPORT_ST_PLOGI,         /* waiting for PLOGI completion */
+        RPORT_ST_PRLI,          /* waiting for PRLI completion */
+        RPORT_ST_RTV,           /* waiting for RTV completion */
+        RPORT_ST_READY,         /* ready for use */
+        RPORT_ST_LOGO,          /* port logout sent */
+};
+
+enum fc_rport_trans_state {
+        FC_PORTSTATE_ROGUE,
+        FC_PORTSTATE_REAL,
+};
+
+/**
+ * struct fc_disc_port - temporary discovery port to hold rport identifiers
+ * @lp: Fibre Channel host port instance
+ * @peers: node for list management during discovery and RSCN processing
+ * @ids: identifiers structure to pass to fc_remote_port_add()
+ * @rport_work: work struct for starting the rport state machine
+ */
+struct fc_disc_port {
+        struct fc_lport             *lp;
+        struct list_head            peers;
+        struct fc_rport_identifiers ids;
+        struct work_struct          rport_work;
+};
+
+enum fc_rport_event {
+        RPORT_EV_NONE = 0,
+        RPORT_EV_CREATED,
+        RPORT_EV_FAILED,
+        RPORT_EV_STOP,
+        RPORT_EV_LOGO
+};
+
+struct fc_rport_operations {
+        void (*event_callback)(struct fc_lport *, struct fc_rport *,
+                               enum fc_rport_event);
+};
+
+/**
+ * struct fc_rport_libfc_priv - libfc internal information about a remote port
+ * @local_port: Fibre Channel host port instance
+ * @rp_state: state tracks progress of PLOGI, PRLI, and RTV exchanges
+ * @flags: REC and RETRY supported flags
+ * @max_seq: maximum number of concurrent sequences
+ * @retries: retry count in current state
+ * @e_d_tov: error detect timeout value (in msec)
+ * @r_a_tov: resource allocation timeout value (in msec)
+ * @rp_mutex: mutex protects rport
+ * @retry_work:
+ * @event_callback: Callback for rport READY, FAILED or LOGO
+ */
+struct fc_rport_libfc_priv {
+        struct fc_lport            *local_port;
+        enum fc_rport_state        rp_state;
+        u16                        flags;
+        #define FC_RP_FLAGS_REC_SUPPORTED       (1 << 0)
+        #define FC_RP_FLAGS_RETRY               (1 << 1)
+        u16                        max_seq;
+        unsigned int               retries;
+        unsigned int               e_d_tov;
+        unsigned int               r_a_tov;
+        enum fc_rport_trans_state  trans_state;
+        struct mutex               rp_mutex;
+        struct delayed_work        retry_work;
+        enum fc_rport_event        event;
+        struct fc_rport_operations *ops;
+        struct list_head           peers;
+        struct work_struct         event_work;
+};
+
+#define PRIV_TO_RPORT(x)                                                \
+        (struct fc_rport *)((void *)x - sizeof(struct fc_rport));
+#define RPORT_TO_PRIV(x)                                                \
+        (struct fc_rport_libfc_priv *)((void *)x + sizeof(struct fc_rport));
+
+struct fc_rport *fc_rport_rogue_create(struct fc_disc_port *);
+
+static inline void fc_rport_set_name(struct fc_rport *rport, u64 wwpn, u64 wwnn)
+{
+        rport->node_name = wwnn;
+        rport->port_name = wwpn;
+}
+
+/*
+ * fcoe stats structure
+ */
+struct fcoe_dev_stats {
+        u64             SecondsSinceLastReset;
+        u64             TxFrames;
+        u64             TxWords;
+        u64             RxFrames;
+        u64             RxWords;
+        u64             ErrorFrames;
+        u64             DumpedFrames;
+        u64             LinkFailureCount;
+        u64             LossOfSignalCount;
+        u64             InvalidTxWordCount;
+        u64             InvalidCRCCount;
+        u64             InputRequests;
+        u64             OutputRequests;
+        u64             ControlRequests;
+        u64             InputMegabytes;
+        u64             OutputMegabytes;
+};
+
+/*
+ * els data is used for passing ELS respone specific
+ * data to send ELS response mainly using infomation
+ * in exchange and sequence in EM layer.
+ */
+struct fc_seq_els_data {
+        struct fc_frame *fp;
+        enum fc_els_rjt_reason reason;
+        enum fc_els_rjt_explan explan;
+};
+
+/*
+ * FCP request structure, one for each scsi cmd request
+ */
+struct fc_fcp_pkt {
+        /*
+         * housekeeping stuff
+         */
+        struct fc_lport *lp;    /* handle to hba struct */
+        u16             state;          /* scsi_pkt state state */
+        u16             tgt_flags;      /* target flags  */
+        atomic_t        ref_cnt;        /* fcp pkt ref count */
+        spinlock_t      scsi_pkt_lock;  /* Must be taken before the host lock
+                                         * if both are held at the same time */
+        /*
+         * SCSI I/O related stuff
+         */
+        struct scsi_cmnd *cmd;          /* scsi command pointer. set/clear
+                                         * under host lock */
+        struct list_head list;          /* tracks queued commands. access under
+                                         * host lock */
+        /*
+         * timeout related stuff
+         */
+        struct timer_list timer;        /* command timer */
+        struct completion tm_done;
+        int     wait_for_comp;
+        unsigned long   start_time;     /* start jiffie */
+        unsigned long   end_time;       /* end jiffie */
+        unsigned long   last_pkt_time;   /* jiffies of last frame received */
+
+        /*
+         * scsi cmd and data transfer information
+         */
+        u32             data_len;
+        /*
+         * transport related veriables
+         */
+        struct fcp_cmnd cdb_cmd;
+        size_t          xfer_len;
+        u32             xfer_contig_end; /* offset of end of contiguous xfer */
+        u16             max_payload;    /* max payload size in bytes */
+
+        /*
+         * scsi/fcp return status
+         */
+        u32             io_status;      /* SCSI result upper 24 bits */
+        u8              cdb_status;
+        u8              status_code;    /* FCP I/O status */
+        /* bit 3 Underrun bit 2: overrun */
+        u8              scsi_comp_flags;
+        u32             req_flags;      /* bit 0: read bit:1 write */
+        u32             scsi_resid;     /* residule length */
+
+        struct fc_rport *rport;         /* remote port pointer */
+        struct fc_seq   *seq_ptr;       /* current sequence pointer */
+        /*
+         * Error Processing
+         */
+        u8              recov_retry;    /* count of recovery retries */
+        struct fc_seq   *recov_seq;     /* sequence for REC or SRR */
+};
+
+/*
+ * Structure and function definitions for managing Fibre Channel Exchanges
+ * and Sequences
+ *
+ * fc_exch holds state for one exchange and links to its active sequence.
+ *
+ * fc_seq holds the state for an individual sequence.
+ */
+
+struct fc_exch_mgr;
+
+/*
+ * Sequence.
+ */
+struct fc_seq {
+        u8      id;             /* seq ID */
+        u16     ssb_stat;       /* status flags for sequence status block */
+        u16     cnt;            /* frames sent so far on sequence */
+        u32     rec_data;       /* FC-4 value for REC */
+};
+
+#define FC_EX_DONE              (1 << 0) /* ep is completed */
+#define FC_EX_RST_CLEANUP       (1 << 1) /* reset is forcing completion */
+
+/*
+ * Exchange.
+ *
+ * Locking notes: The ex_lock protects following items:
+ *      state, esb_stat, f_ctl, seq.ssb_stat
+ *      seq_id
+ *      sequence allocation
+ */
+struct fc_exch {
+        struct fc_exch_mgr *em;         /* exchange manager */
+        u32             state;          /* internal driver state */
+        u16             xid;            /* our exchange ID */
+        struct list_head        ex_list;        /* free or busy list linkage */
+        spinlock_t      ex_lock;        /* lock covering exchange state */
+        atomic_t        ex_refcnt;      /* reference counter */
+        struct delayed_work timeout_work; /* timer for upper level protocols */
+        struct fc_lport *lp;            /* fc device instance */
+        u16             oxid;           /* originator's exchange ID */
+        u16             rxid;           /* responder's exchange ID */
+        u32             oid;            /* originator's FCID */
+        u32             sid;            /* source FCID */
+        u32             did;            /* destination FCID */
+        u32             esb_stat;       /* exchange status for ESB */
+        u32             r_a_tov;        /* r_a_tov from rport (msec) */
+        u8              seq_id;         /* next sequence ID to use */
+        u32             f_ctl;          /* F_CTL flags for sequences */
+        u8              fh_type;        /* frame type */
+        enum fc_class   class;          /* class of service */
+        struct fc_seq   seq;            /* single sequence */
+        /*
+         * Handler for responses to this current exchange.
+         */
+        void            (*resp)(struct fc_seq *, struct fc_frame *, void *);
+        void            (*destructor)(struct fc_seq *, void *);
+        /*
+         * arg is passed as void pointer to exchange
+         * resp and destructor handlers
+         */
+        void            *arg;
+};
+#define fc_seq_exch(sp) container_of(sp, struct fc_exch, seq)
+
+struct libfc_function_template {
+
+        /**
+         * Mandatory Fields
+         *
+         * These handlers must be implemented by the LLD.
+         */
+
+        /*
+         * Interface to send a FC frame
+         */
+        int (*frame_send)(struct fc_lport *lp, struct fc_frame *fp);
+
+        /**
+         * Optional Fields
+         *
+         * The LLD may choose to implement any of the following handlers.
+         * If LLD doesn't specify hander and leaves its pointer NULL then
+         * the default libfc function will be used for that handler.
+         */
+
+        /**
+         * ELS/CT interfaces
+         */
+
+        /*
+         * elsct_send - sends ELS/CT frame
+         */
+        struct fc_seq *(*elsct_send)(struct fc_lport *lport,
+                                     struct fc_rport *rport,
+                                     struct fc_frame *fp,
+                                     unsigned int op,
+                                     void (*resp)(struct fc_seq *,
+                                             struct fc_frame *fp,
+                                             void *arg),
+                                     void *arg, u32 timer_msec);
+        /**
+         * Exhance Manager interfaces
+         */
+
+        /*
+         * Send the FC frame payload using a new exchange and sequence.
+         *
+         * The frame pointer with some of the header's fields must be
+         * filled before calling exch_seq_send(), those fields are,
+         *
+         * - routing control
+         * - FC port did
+         * - FC port sid
+         * - FC header type
+         * - frame control
+         * - parameter or relative offset
+         *
+         * The exchange response handler is set in this routine to resp()
+         * function pointer. It can be called in two scenarios: if a timeout
+         * occurs or if a response frame is received for the exchange. The
+         * fc_frame pointer in response handler will also indicate timeout
+         * as error using IS_ERR related macros.
+         *
+         * The exchange destructor handler is also set in this routine.
+         * The destructor handler is invoked by EM layer when exchange
+         * is about to free, this can be used by caller to free its
+         * resources along with exchange free.
+         *
+         * The arg is passed back to resp and destructor handler.
+         *
+         * The timeout value (in msec) for an exchange is set if non zero
+         * timer_msec argument is specified. The timer is canceled when
+         * it fires or when the exchange is done. The exchange timeout handler
+         * is registered by EM layer.
+         */
+        struct fc_seq *(*exch_seq_send)(struct fc_lport *lp,
+                                        struct fc_frame *fp,
+                                        void (*resp)(struct fc_seq *sp,
+                                                     struct fc_frame *fp,
+                                                     void *arg),
+                                        void (*destructor)(struct fc_seq *sp,
+                                                           void *arg),
+                                        void *arg, unsigned int timer_msec);
+
+        /*
+         * send a frame using existing sequence and exchange.
+         */
+        int (*seq_send)(struct fc_lport *lp, struct fc_seq *sp,
+                        struct fc_frame *fp);
+
+        /*
+         * Send ELS response using mainly infomation
+         * in exchange and sequence in EM layer.
+         */
+        void (*seq_els_rsp_send)(struct fc_seq *sp, enum fc_els_cmd els_cmd,
+                                 struct fc_seq_els_data *els_data);
+
+        /*
+         * Abort an exchange and sequence. Generally called because of a
+         * exchange timeout or an abort from the upper layer.
+         *
+         * A timer_msec can be specified for abort timeout, if non-zero
+         * timer_msec value is specified then exchange resp handler
+         * will be called with timeout error if no response to abort.
+         */
+        int (*seq_exch_abort)(const struct fc_seq *req_sp,
+                              unsigned int timer_msec);
+
+        /*
+         * Indicate that an exchange/sequence tuple is complete and the memory
+         * allocated for the related objects may be freed.
+         */
+        void (*exch_done)(struct fc_seq *sp);
+
+        /*
+         * Assigns a EM and a free XID for an new exchange and then
+         * allocates a new exchange and sequence pair.
+         * The fp can be used to determine free XID.
+         */
+        struct fc_exch *(*exch_get)(struct fc_lport *lp, struct fc_frame *fp);
+
+        /*
+         * Release previously assigned XID by exch_get API.
+         * The LLD may implement this if XID is assigned by LLD
+         * in exch_get().
+         */
+        void (*exch_put)(struct fc_lport *lp, struct fc_exch_mgr *mp,
+                         u16 ex_id);
+
+        /*
+         * Start a new sequence on the same exchange/sequence tuple.
+         */
+        struct fc_seq *(*seq_start_next)(struct fc_seq *sp);
+
+        /*
+         * Reset an exchange manager, completing all sequences and exchanges.
+         * If s_id is non-zero, reset only exchanges originating from that FID.
+         * If d_id is non-zero, reset only exchanges sending to that FID.
+         */
+        void (*exch_mgr_reset)(struct fc_exch_mgr *,
+                               u32 s_id, u32 d_id);
+
+        void (*rport_flush_queue)(void);
+        /**
+         * Local Port interfaces
+         */
+
+        /*
+         * Receive a frame to a local port.
+         */
+        void (*lport_recv)(struct fc_lport *lp, struct fc_seq *sp,
+                           struct fc_frame *fp);
+
+        int (*lport_reset)(struct fc_lport *);
+
+        /**
+         * Remote Port interfaces
+         */
+
+        /*
+         * Initiates the RP state machine. It is called from the LP module.
+         * This function will issue the following commands to the N_Port
+         * identified by the FC ID provided.
+         *
+         * - PLOGI
+         * - PRLI
+         * - RTV
+         */
+        int (*rport_login)(struct fc_rport *rport);
+
+        /*
+         * Logoff, and remove the rport from the transport if
+         * it had been added. This will send a LOGO to the target.
+         */
+        int (*rport_logoff)(struct fc_rport *rport);
+
+        /*
+         * Recieve a request from a remote port.
+         */
+        void (*rport_recv_req)(struct fc_seq *, struct fc_frame *,
+                               struct fc_rport *);
+
+        struct fc_rport *(*rport_lookup)(const struct fc_lport *, u32);
+
+        /**
+         * FCP interfaces
+         */
+
+        /*
+         * Send a fcp cmd from fsp pkt.
+         * Called with the SCSI host lock unlocked and irqs disabled.
+         *
+         * The resp handler is called when FCP_RSP received.
+         *
+         */
+        int (*fcp_cmd_send)(struct fc_lport *lp, struct fc_fcp_pkt *fsp,
+                            void (*resp)(struct fc_seq *, struct fc_frame *fp,
+                                         void *arg));
+
+        /*
+         * Used at least durring linkdown and reset
+         */
+        void (*fcp_cleanup)(struct fc_lport *lp);
+
+        /*
+         * Abort all I/O on a local port
+         */
+        void (*fcp_abort_io)(struct fc_lport *lp);
+
+        /**
+         * Discovery interfaces
+         */
+
+        void (*disc_recv_req)(struct fc_seq *,
+                              struct fc_frame *, struct fc_lport *);
+
+        /*
+         * Start discovery for a local port.
+         */
+        void (*disc_start)(void (*disc_callback)(struct fc_lport *,
+                                                 enum fc_disc_event),
+                           struct fc_lport *);
+
+        /*
+         * Stop discovery for a given lport. This will remove
+         * all discovered rports
+         */
+        void (*disc_stop) (struct fc_lport *);
+
+        /*
+         * Stop discovery for a given lport. This will block
+         * until all discovered rports are deleted from the
+         * FC transport class
+         */
+        void (*disc_stop_final) (struct fc_lport *);
+};
+
+/* information used by the discovery layer */
+struct fc_disc {
+        unsigned char           retry_count;
+        unsigned char           delay;
+        unsigned char           pending;
+        unsigned char           requested;
+        unsigned short          seq_count;
+        unsigned char           buf_len;
+        enum fc_disc_event      event;
+
+        void (*disc_callback)(struct fc_lport *,
+                              enum fc_disc_event);
+
+        struct list_head         rports;
+        struct fc_lport         *lport;
+        struct mutex            disc_mutex;
+        struct fc_gpn_ft_resp   partial_buf;    /* partial name buffer */
+        struct delayed_work     disc_work;
+};
+
+struct fc_lport {
+        struct list_head list;
+
+        /* Associations */
+        struct Scsi_Host        *host;
+        struct fc_exch_mgr      *emp;
+        struct fc_rport         *dns_rp;
+        struct fc_rport         *ptp_rp;
+        void                    *scsi_priv;
+        struct fc_disc          disc;
+
+        /* Operational Information */
+        struct libfc_function_template tt;
+        u16                     link_status;
+        enum fc_lport_state     state;
+        unsigned long           boot_time;
+
+        struct fc_host_statistics host_stats;
+        struct fcoe_dev_stats   *dev_stats[NR_CPUS];
+        u64                     wwpn;
+        u64                     wwnn;
+        u8                      retry_count;
+
+        /* Capabilities */
+        u32                     sg_supp:1;      /* scatter gather supported */
+        u32                     seq_offload:1;  /* seq offload supported */
+        u32                     crc_offload:1;  /* crc offload supported */
+        u32                     lro_enabled:1;  /* large receive offload */
+        u32                     mfs;            /* max FC payload size */
+        unsigned int            service_params;
+        unsigned int            e_d_tov;
+        unsigned int            r_a_tov;
+        u8                      max_retry_count;
+        u16                     link_speed;
+        u16                     link_supported_speeds;
+        u16                     lro_xid;        /* max xid for fcoe lro */
+        struct fc_ns_fts        fcts;           /* FC-4 type masks */
+        struct fc_els_rnid_gen  rnid_gen;       /* RNID information */
+
+        /* Semaphores */
+        struct mutex lp_mutex;
+
+        /* Miscellaneous */
+        struct delayed_work     retry_work;
+        struct delayed_work     disc_work;
+};
+
+/**
+ * FC_LPORT HELPER FUNCTIONS
+ *****************************/
+static inline void *lport_priv(const struct fc_lport *lp)
+{
+        return (void *)(lp + 1);
+}
+
+static inline int fc_lport_test_ready(struct fc_lport *lp)
+{
+        return lp->state == LPORT_ST_READY;
+}
+
+static inline void fc_set_wwnn(struct fc_lport *lp, u64 wwnn)
+{
+        lp->wwnn = wwnn;
+}
+
+static inline void fc_set_wwpn(struct fc_lport *lp, u64 wwnn)
+{
+        lp->wwpn = wwnn;
+}
+
+static inline void fc_lport_state_enter(struct fc_lport *lp,
+                                        enum fc_lport_state state)
+{
+        if (state != lp->state)
+                lp->retry_count = 0;
+        lp->state = state;
+}
+
+
+/**
+ * LOCAL PORT LAYER
+ *****************************/
+int fc_lport_init(struct fc_lport *lp);
+
+/*
+ * Destroy the specified local port by finding and freeing all
+ * fc_rports associated with it and then by freeing the fc_lport
+ * itself.
+ */
+int fc_lport_destroy(struct fc_lport *lp);
+
+/*
+ * Logout the specified local port from the fabric
+ */
+int fc_fabric_logoff(struct fc_lport *lp);
+
+/*
+ * Initiate the LP state machine. This handler will use fc_host_attr
+ * to store the FLOGI service parameters, so fc_host_attr must be
+ * initialized before calling this handler.
+ */
+int fc_fabric_login(struct fc_lport *lp);
+
+/*
+ * The link is up for the given local port.
+ */
+void fc_linkup(struct fc_lport *);
+
+/*
+ * Link is down for the given local port.
+ */
+void fc_linkdown(struct fc_lport *);
+
+/*
+ * Pause and unpause traffic.
+ */
+void fc_pause(struct fc_lport *);
+void fc_unpause(struct fc_lport *);
+
+/*
+ * Configure the local port.
+ */
+int fc_lport_config(struct fc_lport *);
+
+/*
+ * Reset the local port.
+ */
+int fc_lport_reset(struct fc_lport *);
+
+/*
+ * Set the mfs or reset
+ */
+int fc_set_mfs(struct fc_lport *lp, u32 mfs);
+
+
+/**
+ * REMOTE PORT LAYER
+ *****************************/
+int fc_rport_init(struct fc_lport *lp);
+void fc_rport_terminate_io(struct fc_rport *rp);
+
+/**
+ * DISCOVERY LAYER
+ *****************************/
+int fc_disc_init(struct fc_lport *lp);
+
+
+/**
+ * SCSI LAYER
+ *****************************/
+/*
+ * Initialize the SCSI block of libfc
+ */
+int fc_fcp_init(struct fc_lport *);
+
+/*
+ * This section provides an API which allows direct interaction
+ * with the SCSI-ml. Each of these functions satisfies a function
+ * pointer defined in Scsi_Host and therefore is always called
+ * directly from the SCSI-ml.
+ */
+int fc_queuecommand(struct scsi_cmnd *sc_cmd,
+                    void (*done)(struct scsi_cmnd *));
+
+/*
+ * complete processing of a fcp packet
+ *
+ * This function may sleep if a fsp timer is pending.
+ * The host lock must not be held by caller.
+ */
+void fc_fcp_complete(struct fc_fcp_pkt *fsp);
+
+/*
+ * Send an ABTS frame to the target device. The sc_cmd argument
+ * is a pointer to the SCSI command to be aborted.
+ */
+int fc_eh_abort(struct scsi_cmnd *sc_cmd);
+
+/*
+ * Reset a LUN by sending send the tm cmd to the target.
+ */
+int fc_eh_device_reset(struct scsi_cmnd *sc_cmd);
+
+/*
+ * Reset the host adapter.
+ */
+int fc_eh_host_reset(struct scsi_cmnd *sc_cmd);
+
+/*
+ * Check rport status.
+ */
+int fc_slave_alloc(struct scsi_device *sdev);
+
+/*
+ * Adjust the queue depth.
+ */
+int fc_change_queue_depth(struct scsi_device *sdev, int qdepth);
+
+/*
+ * Change the tag type.
+ */
+int fc_change_queue_type(struct scsi_device *sdev, int tag_type);
+
+/*
+ * Free memory pools used by the FCP layer.
+ */
+void fc_fcp_destroy(struct fc_lport *);
+
+/**
+ * ELS/CT interface
+ *****************************/
+/*
+ * Initializes ELS/CT interface
+ */
+int fc_elsct_init(struct fc_lport *lp);
+
+
+/**
+ * EXCHANGE MANAGER LAYER
+ *****************************/
+/*
+ * Initializes Exchange Manager related
+ * function pointers in struct libfc_function_template.
+ */
+int fc_exch_init(struct fc_lport *lp);
+
+/*
+ * Allocates an Exchange Manager (EM).
+ *
+ * The EM manages exchanges for their allocation and
+ * free, also allows exchange lookup for received
+ * frame.
+ *
+ * The class is used for initializing FC class of
+ * allocated exchange from EM.
+ *
+ * The min_xid and max_xid will limit new
+ * exchange ID (XID) within this range for
+ * a new exchange.
+ * The LLD may choose to have multiple EMs,
+ * e.g. one EM instance per CPU receive thread in LLD.
+ * The LLD can use exch_get() of struct libfc_function_template
+ * to specify XID for a new exchange within
+ * a specified EM instance.
+ *
+ * The em_idx to uniquely identify an EM instance.
+ */
+struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lp,
+                                      enum fc_class class,
+                                      u16 min_xid,
+                                      u16 max_xid);
+
+/*
+ * Free an exchange manager.
+ */
+void fc_exch_mgr_free(struct fc_exch_mgr *mp);
+
+/*
+ * Receive a frame on specified local port and exchange manager.
+ */
+void fc_exch_recv(struct fc_lport *lp, struct fc_exch_mgr *mp,
+                  struct fc_frame *fp);
+
+/*
+ * This function is for exch_seq_send function pointer in
+ * struct libfc_function_template, see comment block on
+ * exch_seq_send for description of this function.
+ */
+struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
+                                struct fc_frame *fp,
+                                void (*resp)(struct fc_seq *sp,
+                                             struct fc_frame *fp,
+                                             void *arg),
+                                void (*destructor)(struct fc_seq *sp,
+                                                   void *arg),
+                                void *arg, u32 timer_msec);
+
+/*
+ * send a frame using existing sequence and exchange.
+ */
+int fc_seq_send(struct fc_lport *lp, struct fc_seq *sp, struct fc_frame *fp);
+
+/*
+ * Send ELS response using mainly infomation
+ * in exchange and sequence in EM layer.
+ */
+void fc_seq_els_rsp_send(struct fc_seq *sp, enum fc_els_cmd els_cmd,
+                         struct fc_seq_els_data *els_data);
+
+/*
+ * This function is for seq_exch_abort function pointer in
+ * struct libfc_function_template, see comment block on
+ * seq_exch_abort for description of this function.
+ */
+int fc_seq_exch_abort(const struct fc_seq *req_sp, unsigned int timer_msec);
+
+/*
+ * Indicate that an exchange/sequence tuple is complete and the memory
+ * allocated for the related objects may be freed.
+ */
+void fc_exch_done(struct fc_seq *sp);
+
+/*
+ * Assigns a EM and XID for a frame and then allocates
+ * a new exchange and sequence pair.
+ * The fp can be used to determine free XID.
+ */
+struct fc_exch *fc_exch_get(struct fc_lport *lp, struct fc_frame *fp);
+
+/*
+ * Allocate a new exchange and sequence pair.
+ * if ex_id is zero then next free exchange id
+ * from specified exchange manger mp will be assigned.
+ */
+struct fc_exch *fc_exch_alloc(struct fc_exch_mgr *mp,
+                              struct fc_frame *fp, u16 ex_id);
+/*
+ * Start a new sequence on the same exchange as the supplied sequence.
+ */
+struct fc_seq *fc_seq_start_next(struct fc_seq *sp);
+
+/*
+ * Reset an exchange manager, completing all sequences and exchanges.
+ * If s_id is non-zero, reset only exchanges originating from that FID.
+ * If d_id is non-zero, reset only exchanges sending to that FID.
+ */
+void fc_exch_mgr_reset(struct fc_exch_mgr *, u32 s_id, u32 d_id);
+
+/*
+ * Functions for fc_functions_template
+ */
+void fc_get_host_speed(struct Scsi_Host *shost);
+void fc_get_host_port_type(struct Scsi_Host *shost);
+void fc_get_host_port_state(struct Scsi_Host *shost);
+void fc_set_rport_loss_tmo(struct fc_rport *rport, u32 timeout);
+struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *);
+
+/*
+ * module setup functions.
+ */
+int fc_setup_exch_mgr(void);
+void fc_destroy_exch_mgr(void);
+int fc_setup_rport(void);
+void fc_destroy_rport(void);
+
+#endif /* _LIBFC_H_ */