ctl_frontend.h

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2003 Silicon Graphics International Corp.
 * Copyright (c) 2014-2017 Alexander Motin <mav@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_frontend.h#2 $
 * $FreeBSD$
 */
/*
 * CAM Target Layer front end registration hooks
 *
 * Author: Ken Merry <ken@FreeBSD.org>
 */
 
#ifndef _CTL_FRONTEND_H_
#define _CTL_FRONTEND_H_
 
#include <cam/ctl/ctl_ioctl.h>
#include <sys/nv.h>
 
typedef enum {
        CTL_PORT_STATUS_NONE            = 0x00,
        CTL_PORT_STATUS_ONLINE          = 0x01,
        CTL_PORT_STATUS_HA_SHARED       = 0x02
} ctl_port_status;
 
typedef int (*fe_init_t)(void);
typedef int (*fe_shutdown_t)(void);
typedef void (*port_func_t)(void *onoff_arg);
typedef int (*port_info_func_t)(void *onoff_arg, struct sbuf *sb);
typedef int (*lun_func_t)(void *arg, int lun_id);
typedef int (*fe_ioctl_t)(struct cdev *dev, u_long cmd, caddr_t addr, int flag,
                          struct thread *td);
 
#define CTL_FRONTEND_DECLARE(name, driver) \
        static int name ## _modevent(module_t mod, int type, void *data) \
        { \
                switch (type) { \
                case MOD_LOAD: \
                        return (ctl_frontend_register( \
                                (struct ctl_frontend *)data)); \
                        break; \
                case MOD_UNLOAD: \
                        return (ctl_frontend_deregister( \
                                (struct ctl_frontend *)data)); \
                        break; \
                default: \
                        return EOPNOTSUPP; \
                } \
                return 0; \
        } \
        static moduledata_t name ## _mod = { \
                #name, \
                name ## _modevent, \
                (void *)&driver \
        }; \
        DECLARE_MODULE(name, name ## _mod, SI_SUB_CONFIGURE, SI_ORDER_FOURTH); \
        MODULE_DEPEND(name, ctl, 1, 1, 1); \
        MODULE_DEPEND(name, cam, 1, 1, 1)
 
struct ctl_wwpn_iid {
        int in_use;
        time_t last_use;
        uint64_t wwpn;
        char *name;
};
 
/*
 * The ctl_frontend structure is the registration mechanism between a FETD
 * (Front End Target Driver) and the CTL layer.  Here is a description of
 * the fields:
 *
 * port_type:             This field tells CTL what kind of front end it is
 *                        dealing with.  This field serves two purposes.
 *                        The first is to let CTL know whether the frontend
 *                        in question is inside the main CTL module (i.e.
 *                        the ioctl front end), and therefore its module
 *                        reference count shouldn't be incremented.  The
 *                        CTL ioctl front end should continue to use the
 *                        CTL_PORT_IOCTL argument as long as it is part of
 *                        the main CTL module.  The second is to let CTL
 *                        know what kind of front end it is dealing with, so
 *                        it can return the proper inquiry data for that
 *                        particular port.
 *
 * num_requested_ctl_io:  This is the number of ctl_io structures that the
 *                        front end needs for its pool.  This should
 *                        generally be the maximum number of outstanding
 *                        transactions that the FETD can handle.  The CTL
 *                        layer will add a few to this to account for
 *                        ctl_io buffers queued for pending sense data.
 *                        (Pending sense only gets queued if the FETD
 *                        doesn't support autosense.  e.g. non-packetized
 *                        parallel SCSI doesn't support autosense.)
 *
 * port_name:             A string describing the FETD.  e.g. "LSI 1030T U320"
 *                        or whatever you want to use to describe the driver.
 *
 * physical_port:         This is the physical port number of this
 *                        particular port within the driver/hardware.  This
 *                        number is hardware/driver specific.
 * virtual_port:          This is the virtual port number of this
 *                        particular port.  This is for things like NP-IV.
 * 
 * port_online():         This function is called, with onoff_arg as its
 *                        argument, by the CTL layer when it wants the FETD
 *                        to start responding to selections on the specified
 *                        target ID.
 *
 * port_offline():        This function is called, with onoff_arg as its
 *                        argument, by the CTL layer when it wants the FETD
 *                        to stop responding to selection on the specified
 *                        target ID.
 *
 * onoff_arg:             This is supplied as an argument to port_online()
 *                        and port_offline().  This is specified by the
 *                        FETD.
 *
 * lun_enable():          This function is called, with targ_lun_arg, a target
 *                        ID and a LUN ID as its arguments, by CTL when it
 *                        wants the FETD to enable a particular LUN.  If the
 *                        FETD doesn't really know about LUNs, it should
 *                        just ignore this call and return 0.  If the FETD
 *                        cannot enable the requested LUN for some reason, the
 *                        FETD should return non-zero status.
 *
 * lun_disable():         This function is called, with targ_lun_arg, a target
 *                        ID and LUN ID as its arguments, by CTL when it
 *                        wants the FETD to disable a particular LUN.  If the
 *                        FETD doesn't really know about LUNs, it should just
 *                        ignore this call and return 0.  If the FETD cannot
 *                        disable the requested LUN for some reason, the
 *                        FETD should return non-zero status.
 *
 * targ_lun_arg:          This is supplied as an argument to the targ/lun
 *                        enable/disable() functions.  This is specified by
 *                        the FETD.
 *
 * fe_datamove():         This function is called one or more times per I/O
 *                        by the CTL layer to tell the FETD to initiate a
 *                        DMA to or from the data buffer(s) specified by
 *                        the passed-in ctl_io structure.
 *
 * fe_done():             This function is called by the CTL layer when a
 *                        particular SCSI I/O or task management command has
 *                        completed.  For SCSI I/O requests (CTL_IO_SCSI),
 *                        sense data is always supplied if the status is
 *                        CTL_SCSI_ERROR and the SCSI status byte is
 *                        SCSI_STATUS_CHECK_COND.  If the FETD doesn't
 *                        support autosense, the sense should be queued
 *                        back to the CTL layer via ctl_queue_sense().
 *
 * fe_dump():             This function, if it exists, is called by CTL
 *                        to request a dump of any debugging information or
 *                        state to the console.
 *
 * targ_port:             The CTL layer assigns a "port number" to every
 *                        FETD.  This port number should be passed back in
 *                        in the header of every ctl_io that is queued to
 *                        the CTL layer.  This enables us to determine
 *                        which bus the command came in on.
 *
 * ctl_pool_ref:          Memory pool reference used by the FETD in calls to
 *                        ctl_alloc_io().
 *
 * max_initiators:        Maximum number of initiators that the FETD is
 *                        allowed to have.  Initiators should be numbered
 *                        from 0 to max_initiators - 1.  This value will
 *                        typically be 16, and thus not a problem for
 *                        parallel SCSI.  This may present issues for Fibre
 *                        Channel.
 *
 * wwnn                   World Wide Node Name to be used by the FETD.
 *                        Note that this is set *after* registration.  It
 *                        will be set prior to the online function getting
 *                        called.
 *
 * wwpn                   World Wide Port Name to be used by the FETD.
 *                        Note that this is set *after* registration.  It
 *                        will be set prior to the online function getting
 *                        called.
 *
 * status:                Used by CTL to keep track of per-FETD state.
 *
 * links:                 Linked list pointers, used by CTL.  The FETD
 *                        shouldn't touch this field.
 */
struct ctl_port {
        struct ctl_softc *ctl_softc;
        struct ctl_frontend *frontend;
        ctl_port_type   port_type;              /* passed to CTL */
        int             num_requested_ctl_io;   /* passed to CTL */
        char            *port_name;             /* passed to CTL */
        int             physical_port;          /* passed to CTL */
        int             virtual_port;           /* passed to CTL */
        port_func_t     port_online;            /* passed to CTL */
        port_func_t     port_offline;           /* passed to CTL */
        port_info_func_t port_info;             /* passed to CTL */
        void            *onoff_arg;             /* passed to CTL */
        lun_func_t      lun_enable;             /* passed to CTL */
        lun_func_t      lun_disable;            /* passed to CTL */
        int             lun_map_size;           /* passed to CTL */
        uint32_t        *lun_map;               /* passed to CTL */
        void            *targ_lun_arg;          /* passed to CTL */
        void            (*fe_datamove)(union ctl_io *io); /* passed to CTL */
        void            (*fe_done)(union ctl_io *io); /* passed to CTL */
        int32_t         targ_port;              /* passed back to FETD */
        void            *ctl_pool_ref;          /* passed back to FETD */
        uint32_t        max_initiators;         /* passed back to FETD */
        struct ctl_wwpn_iid *wwpn_iid;          /* used by CTL */
        uint64_t        wwnn;                   /* set by CTL before online */
        uint64_t        wwpn;                   /* set by CTL before online */
        ctl_port_status status;                 /* used by CTL */
        nvlist_t        *options;               /* passed to CTL */
        struct ctl_devid *port_devid;           /* passed to CTL */
        struct ctl_devid *target_devid;         /* passed to CTL */
        struct ctl_devid *init_devid;           /* passed to CTL */
        struct ctl_io_stats stats;              /* used by CTL */
        struct mtx      port_lock;              /* used by CTL */
        STAILQ_ENTRY(ctl_port) fe_links;        /* used by CTL */
        STAILQ_ENTRY(ctl_port) links;           /* used by CTL */
};
 
struct ctl_frontend {
        char            name[CTL_DRIVER_NAME_LEN];      /* passed to CTL */
        fe_init_t       init;                   /* passed to CTL */
        fe_ioctl_t      ioctl;                  /* passed to CTL */
        void            (*fe_dump)(void);       /* passed to CTL */
        fe_shutdown_t   shutdown;               /* passed to CTL */
        STAILQ_HEAD(, ctl_port) port_list;      /* used by CTL */
        STAILQ_ENTRY(ctl_frontend) links;       /* used by CTL */
};
 
/*
 * This may block until resources are allocated.  Called at FETD module load
 * time. Returns 0 for success, non-zero for failure.
 */
int ctl_frontend_register(struct ctl_frontend *fe);
 
/*
 * Called at FETD module unload time.
 * Returns 0 for success, non-zero for failure.
 */
int ctl_frontend_deregister(struct ctl_frontend *fe);
 
/*
 * Find the frontend by its name. Returns NULL if not found.
 */
struct ctl_frontend * ctl_frontend_find(char *frontend_name);
 
/*
 * This may block until resources are allocated.  Called at FETD module load
 * time. Returns 0 for success, non-zero for failure.
 */
int ctl_port_register(struct ctl_port *port);
 
/*
 * Called at FETD module unload time.
 * Returns 0 for success, non-zero for failure.
 */
int ctl_port_deregister(struct ctl_port *port);
 
/*
 * Called to set the WWNN and WWPN for a particular frontend.
 */
void ctl_port_set_wwns(struct ctl_port *port, int wwnn_valid,
                           uint64_t wwnn, int wwpn_valid, uint64_t wwpn);
 
/*
 * Called to bring a particular frontend online.
 */
void ctl_port_online(struct ctl_port *fe);
 
/*
 * Called to take a particular frontend offline.
 */
void ctl_port_offline(struct ctl_port *fe);
 
/*
 * This routine queues I/O and task management requests from the FETD to the
 * CTL layer.  Returns immediately.  Returns 0 for success, non-zero for
 * failure.
 */
int ctl_queue(union ctl_io *io);
 
/*
 * This routine starts execution of I/O and task management requests from
 * the FETD to the CTL layer.  May sleep.  Returns 0 for success, non-zero
 * for failure.
 */
int ctl_run(union ctl_io *io);
 
/*
 * This routine is used if the front end interface doesn't support
 * autosense (e.g. non-packetized parallel SCSI).  This will queue the
 * scsiio structure back to a per-lun pending sense queue.  This MUST be
 * called BEFORE any request sense can get queued to the CTL layer -- I
 * need it in the queue in order to service the request.  The scsiio
 * structure passed in here will be freed by the CTL layer when sense is
 * retrieved by the initiator.  Returns 0 for success, non-zero for failure.
 */
int ctl_queue_sense(union ctl_io *io);
 
/*
 * This routine adds an initiator to CTL's port database.
 * The iid field should be the same as the iid passed in the nexus of each
 * ctl_io from this initiator.
 * The WWPN should be the FC WWPN, if available.
 */
int ctl_add_initiator(struct ctl_port *port, int iid, uint64_t wwpn, char *name);
 
/*
 * This routine will remove an initiator from CTL's port database.
 * The iid field should be the same as the iid passed in the nexus of each
 * ctl_io from this initiator.
 */
int ctl_remove_initiator(struct ctl_port *port, int iid);
 
#endif  /* _CTL_FRONTEND_H_ */