Linux-2.6.12-rc2

[linux-2.6/next.git] / drivers / scsi / scsi_transport_fc.c

/* 
 *  FiberChannel transport specific attributes exported to sysfs.
 *
 *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  ========
 *
 *  Copyright (C) 2004-2005   James Smart, Emulex Corporation
 *    Rewrite for host, target, device, and remote port attributes,
 *    statistics, and service functions...
 *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_fc.h>
#include "scsi_priv.h"

#define FC_PRINTK(x, l, f, a...)        printk(l "scsi(%d:%d:%d:%d): " f, (x)->host->host_no, (x)->channel, (x)->id, (x)->lun , ##a)

/*
 * Redefine so that we can have same named attributes in the
 * sdev/starget/host objects.
 */
#define FC_CLASS_DEVICE_ATTR(_prefix,_name,_mode,_show,_store)          \
struct class_device_attribute class_device_attr_##_prefix##_##_name =   \
        __ATTR(_name,_mode,_show,_store)

#define fc_enum_name_search(title, table_type, table)                   \
static const char *get_fc_##title##_name(enum table_type table_key)     \
{                                                                       \
        int i;                                                          \
        char *name = NULL;                                              \
                                                                        \
        for (i = 0; i < sizeof(table)/sizeof(table[0]); i++) {          \
                if (table[i].value == table_key) {                      \
                        name = table[i].name;                           \
                        break;                                          \
                }                                                       \
        }                                                               \
        return name;                                                    \
}

#define fc_enum_name_match(title, table_type, table)                    \
static int get_fc_##title##_match(const char *table_key,                \
                enum table_type *value)                                 \
{                                                                       \
        int i;                                                          \
                                                                        \
        for (i = 0; i < sizeof(table)/sizeof(table[0]); i++) {          \
                if (strncmp(table_key, table[i].name,                   \
                                table[i].matchlen) == 0) {              \
                        *value = table[i].value;                        \
                        return 0; /* success */                         \
                }                                                       \
        }                                                               \
        return 1; /* failure */                                         \
}


/* Convert fc_port_type values to ascii string name */
static struct {
        enum fc_port_type       value;
        char                    *name;
} fc_port_type_names[] = {
        { FC_PORTTYPE_UNKNOWN,          "Unknown" },
        { FC_PORTTYPE_OTHER,            "Other" },
        { FC_PORTTYPE_NOTPRESENT,       "Not Present" },
        { FC_PORTTYPE_NPORT,    "NPort (fabric via point-to-point)" },
        { FC_PORTTYPE_NLPORT,   "NLPort (fabric via loop)" },
        { FC_PORTTYPE_LPORT,    "LPort (private loop)" },
        { FC_PORTTYPE_PTP,      "Point-To-Point (direct nport connection" },
};
fc_enum_name_search(port_type, fc_port_type, fc_port_type_names)
#define FC_PORTTYPE_MAX_NAMELEN         50


/* Convert fc_port_state values to ascii string name */
static struct {
        enum fc_port_state      value;
        char                    *name;
} fc_port_state_names[] = {
        { FC_PORTSTATE_UNKNOWN,         "Unknown" },
        { FC_PORTSTATE_NOTPRESENT,      "Not Present" },
        { FC_PORTSTATE_ONLINE,          "Online" },
        { FC_PORTSTATE_OFFLINE,         "Offline" },
        { FC_PORTSTATE_BLOCKED,         "Blocked" },
        { FC_PORTSTATE_BYPASSED,        "Bypassed" },
        { FC_PORTSTATE_DIAGNOSTICS,     "Diagnostics" },
        { FC_PORTSTATE_LINKDOWN,        "Linkdown" },
        { FC_PORTSTATE_ERROR,           "Error" },
        { FC_PORTSTATE_LOOPBACK,        "Loopback" },
};
fc_enum_name_search(port_state, fc_port_state, fc_port_state_names)
#define FC_PORTSTATE_MAX_NAMELEN        20


/* Convert fc_tgtid_binding_type values to ascii string name */
static struct {
        enum fc_tgtid_binding_type      value;
        char                            *name;
        int                             matchlen;
} fc_tgtid_binding_type_names[] = {
        { FC_TGTID_BIND_NONE, "none", 4 },
        { FC_TGTID_BIND_BY_WWPN, "wwpn (World Wide Port Name)", 4 },
        { FC_TGTID_BIND_BY_WWNN, "wwnn (World Wide Node Name)", 4 },
        { FC_TGTID_BIND_BY_ID, "port_id (FC Address)", 7 },
};
fc_enum_name_search(tgtid_bind_type, fc_tgtid_binding_type,
                fc_tgtid_binding_type_names)
fc_enum_name_match(tgtid_bind_type, fc_tgtid_binding_type,
                fc_tgtid_binding_type_names)
#define FC_BINDTYPE_MAX_NAMELEN 30


#define fc_bitfield_name_search(title, table)                   \
static ssize_t                                                  \
get_fc_##title##_names(u32 table_key, char *buf)                \
{                                                               \
        char *prefix = "";                                      \
        ssize_t len = 0;                                        \
        int i;                                                  \
                                                                \
        for (i = 0; i < sizeof(table)/sizeof(table[0]); i++) {  \
                if (table[i].value & table_key) {               \
                        len += sprintf(buf + len, "%s%s",       \
                                prefix, table[i].name);         \
                        prefix = ", ";                          \
                }                                               \
        }                                                       \
        len += sprintf(buf + len, "\n");                        \
        return len;                                             \
}


/* Convert FC_COS bit values to ascii string name */
static struct {
        u32                     value;
        char                    *name;
} fc_cos_names[] = {
        { FC_COS_CLASS1,        "Class 1" },
        { FC_COS_CLASS2,        "Class 2" },
        { FC_COS_CLASS3,        "Class 3" },
        { FC_COS_CLASS4,        "Class 4" },
        { FC_COS_CLASS6,        "Class 6" },
};
fc_bitfield_name_search(cos, fc_cos_names)


/* Convert FC_PORTSPEED bit values to ascii string name */
static struct {
        u32                     value;
        char                    *name;
} fc_port_speed_names[] = {
        { FC_PORTSPEED_1GBIT,           "1 Gbit" },
        { FC_PORTSPEED_2GBIT,           "2 Gbit" },
        { FC_PORTSPEED_4GBIT,           "4 Gbit" },
        { FC_PORTSPEED_10GBIT,          "10 Gbit" },
        { FC_PORTSPEED_NOT_NEGOTIATED,  "Not Negotiated" },
};
fc_bitfield_name_search(port_speed, fc_port_speed_names)


static int
show_fc_fc4s (char *buf, u8 *fc4_list)
{
        int i, len=0;

        for (i = 0; i < FC_FC4_LIST_SIZE; i++, fc4_list++)
                len += sprintf(buf + len , "0x%02x ", *fc4_list);
        len += sprintf(buf + len, "\n");
        return len;
}


/* Convert FC_RPORT_ROLE bit values to ascii string name */
static struct {
        u32                     value;
        char                    *name;
} fc_remote_port_role_names[] = {
        { FC_RPORT_ROLE_FCP_TARGET,     "FCP Target" },
        { FC_RPORT_ROLE_FCP_INITIATOR,  "FCP Initiator" },
        { FC_RPORT_ROLE_IP_PORT,        "IP Port" },
};
fc_bitfield_name_search(remote_port_roles, fc_remote_port_role_names)

/*
 * Define roles that are specific to port_id. Values are relative to ROLE_MASK.
 */
#define FC_WELLKNOWN_PORTID_MASK        0xfffff0
#define FC_WELLKNOWN_ROLE_MASK          0x00000f
#define FC_FPORT_PORTID                 0x00000e
#define FC_FABCTLR_PORTID               0x00000d
#define FC_DIRSRVR_PORTID               0x00000c
#define FC_TIMESRVR_PORTID              0x00000b
#define FC_MGMTSRVR_PORTID              0x00000a


static void fc_timeout_blocked_rport(void *data);
static void fc_scsi_scan_rport(void *data);
static void fc_rport_terminate(struct fc_rport  *rport);

/*
 * Attribute counts pre object type...
 * Increase these values if you add attributes
 */
#define FC_STARGET_NUM_ATTRS    3
#define FC_RPORT_NUM_ATTRS      9
#define FC_HOST_NUM_ATTRS       15

struct fc_internal {
        struct scsi_transport_template t;
        struct fc_function_template *f;

        /*
         * For attributes : each object has :
         *   An array of the actual attributes structures
         *   An array of null-terminated pointers to the attribute
         *     structures - used for mid-layer interaction.
         *
         * The attribute containers for the starget and host are are
         * part of the midlayer. As the remote port is specific to the
         * fc transport, we must provide the attribute container.
         */
        struct class_device_attribute private_starget_attrs[
                                                        FC_STARGET_NUM_ATTRS];
        struct class_device_attribute *starget_attrs[FC_STARGET_NUM_ATTRS + 1];

        struct class_device_attribute private_host_attrs[FC_HOST_NUM_ATTRS];
        struct class_device_attribute *host_attrs[FC_HOST_NUM_ATTRS + 1];

        struct transport_container rport_attr_cont;
        struct class_device_attribute private_rport_attrs[FC_RPORT_NUM_ATTRS];
        struct class_device_attribute *rport_attrs[FC_RPORT_NUM_ATTRS + 1];
};

#define to_fc_internal(tmpl)    container_of(tmpl, struct fc_internal, t)

static int fc_target_setup(struct device *dev)
{
        struct scsi_target *starget = to_scsi_target(dev);
        struct fc_rport *rport = starget_to_rport(starget);

        /*
         * if parent is remote port, use values from remote port.
         * Otherwise, this host uses the fc_transport, but not the
         * remote port interface. As such, initialize to known non-values.
         */
        if (rport) {
                fc_starget_node_name(starget) = rport->node_name;
                fc_starget_port_name(starget) = rport->port_name;
                fc_starget_port_id(starget) = rport->port_id;
        } else {
                fc_starget_node_name(starget) = -1;
                fc_starget_port_name(starget) = -1;
                fc_starget_port_id(starget) = -1;
        }

        return 0;
}

static DECLARE_TRANSPORT_CLASS(fc_transport_class,
                               "fc_transport",
                               fc_target_setup,
                               NULL,
                               NULL);

static int fc_host_setup(struct device *dev)
{
        struct Scsi_Host *shost = dev_to_shost(dev);

        /* 
         * Set default values easily detected by the midlayer as
         * failure cases.  The scsi lldd is responsible for initializing
         * all transport attributes to valid values per host.
         */
        fc_host_node_name(shost) = -1;
        fc_host_port_name(shost) = -1;
        fc_host_supported_classes(shost) = FC_COS_UNSPECIFIED;
        memset(fc_host_supported_fc4s(shost), 0,
                sizeof(fc_host_supported_fc4s(shost)));
        memset(fc_host_symbolic_name(shost), 0,
                sizeof(fc_host_symbolic_name(shost)));
        fc_host_supported_speeds(shost) = FC_PORTSPEED_UNKNOWN;
        fc_host_maxframe_size(shost) = -1;
        memset(fc_host_serial_number(shost), 0,
                sizeof(fc_host_serial_number(shost)));

        fc_host_port_id(shost) = -1;
        fc_host_port_type(shost) = FC_PORTTYPE_UNKNOWN;
        fc_host_port_state(shost) = FC_PORTSTATE_UNKNOWN;
        memset(fc_host_active_fc4s(shost), 0,
                sizeof(fc_host_active_fc4s(shost)));
        fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN;
        fc_host_fabric_name(shost) = -1;

        fc_host_tgtid_bind_type(shost) = FC_TGTID_BIND_BY_WWPN;

        INIT_LIST_HEAD(&fc_host_rports(shost));
        INIT_LIST_HEAD(&fc_host_rport_bindings(shost));
        fc_host_next_rport_number(shost) = 0;
        fc_host_next_target_id(shost) = 0;

        return 0;
}

static DECLARE_TRANSPORT_CLASS(fc_host_class,
                               "fc_host",
                               fc_host_setup,
                               NULL,
                               NULL);

/*
 * Setup and Remove actions for remote ports are handled
 * in the service functions below.
 */
static DECLARE_TRANSPORT_CLASS(fc_rport_class,
                               "fc_remote_ports",
                               NULL,
                               NULL,
                               NULL);

/*
 * Module Parameters
 */

/*
 * dev_loss_tmo: the default number of seconds that the FC transport
 *   should insulate the loss of a remote port.
 *   The maximum will be capped by the value of SCSI_DEVICE_BLOCK_MAX_TIMEOUT.
 */
static unsigned int fc_dev_loss_tmo = SCSI_DEVICE_BLOCK_MAX_TIMEOUT;

module_param_named(dev_loss_tmo, fc_dev_loss_tmo, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(dev_loss_tmo,
                 "Maximum number of seconds that the FC transport should"
                 " insulate the loss of a remote port. Once this value is"
                 " exceeded, the scsi target is removed. Value should be"
                 " between 1 and SCSI_DEVICE_BLOCK_MAX_TIMEOUT.");


static __init int fc_transport_init(void)
{
        int error = transport_class_register(&fc_host_class);
        if (error)
                return error;
        error = transport_class_register(&fc_rport_class);
        if (error)
                return error;
        return transport_class_register(&fc_transport_class);
}

static void __exit fc_transport_exit(void)
{
        transport_class_unregister(&fc_transport_class);
        transport_class_unregister(&fc_rport_class);
        transport_class_unregister(&fc_host_class);
}

/*
 * FC Remote Port Attribute Management
 */

#define fc_rport_show_function(field, format_string, sz, cast)          \
static ssize_t                                                          \
show_fc_rport_##field (struct class_device *cdev, char *buf)            \
{                                                                       \
        struct fc_rport *rport = transport_class_to_rport(cdev);        \
        struct Scsi_Host *shost = rport_to_shost(rport);                \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
        if (i->f->get_rport_##field)                                    \
                i->f->get_rport_##field(rport);                         \
        return snprintf(buf, sz, format_string, cast rport->field);     \
}

#define fc_rport_store_function(field)                                  \
static ssize_t                                                          \
store_fc_rport_##field(struct class_device *cdev, const char *buf,      \
                           size_t count)                                \
{                                                                       \
        int val;                                                        \
        struct fc_rport *rport = transport_class_to_rport(cdev);        \
        struct Scsi_Host *shost = rport_to_shost(rport);                \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
        val = simple_strtoul(buf, NULL, 0);                             \
        i->f->set_rport_##field(rport, val);                            \
        return count;                                                   \
}

#define fc_rport_rd_attr(field, format_string, sz)                      \
        fc_rport_show_function(field, format_string, sz, )              \
static FC_CLASS_DEVICE_ATTR(rport, field, S_IRUGO,                      \
                         show_fc_rport_##field, NULL)

#define fc_rport_rd_attr_cast(field, format_string, sz, cast)           \
        fc_rport_show_function(field, format_string, sz, (cast))        \
static FC_CLASS_DEVICE_ATTR(rport, field, S_IRUGO,                      \
                          show_fc_rport_##field, NULL)

#define fc_rport_rw_attr(field, format_string, sz)                      \
        fc_rport_show_function(field, format_string, sz, )              \
        fc_rport_store_function(field)                                  \
static FC_CLASS_DEVICE_ATTR(rport, field, S_IRUGO | S_IWUSR,            \
                        show_fc_rport_##field,                          \
                        store_fc_rport_##field)


#define fc_private_rport_show_function(field, format_string, sz, cast)  \
static ssize_t                                                          \
show_fc_rport_##field (struct class_device *cdev, char *buf)            \
{                                                                       \
        struct fc_rport *rport = transport_class_to_rport(cdev);        \
        return snprintf(buf, sz, format_string, cast rport->field);     \
}

#define fc_private_rport_rd_attr(field, format_string, sz)              \
        fc_private_rport_show_function(field, format_string, sz, )      \
static FC_CLASS_DEVICE_ATTR(rport, field, S_IRUGO,                      \
                         show_fc_rport_##field, NULL)

#define fc_private_rport_rd_attr_cast(field, format_string, sz, cast)   \
        fc_private_rport_show_function(field, format_string, sz, (cast)) \
static FC_CLASS_DEVICE_ATTR(rport, field, S_IRUGO,                      \
                          show_fc_rport_##field, NULL)


#define fc_private_rport_rd_enum_attr(title, maxlen)                    \
static ssize_t                                                          \
show_fc_rport_##title (struct class_device *cdev, char *buf)            \
{                                                                       \
        struct fc_rport *rport = transport_class_to_rport(cdev);        \
        const char *name;                                               \
        name = get_fc_##title##_name(rport->title);                     \
        if (!name)                                                      \
                return -EINVAL;                                         \
        return snprintf(buf, maxlen, "%s\n", name);                     \
}                                                                       \
static FC_CLASS_DEVICE_ATTR(rport, title, S_IRUGO,                      \
                        show_fc_rport_##title, NULL)


#define SETUP_RPORT_ATTRIBUTE_RD(field)                                 \
        i->private_rport_attrs[count] = class_device_attr_rport_##field; \
        i->private_rport_attrs[count].attr.mode = S_IRUGO;              \
        i->private_rport_attrs[count].store = NULL;                     \
        i->rport_attrs[count] = &i->private_rport_attrs[count];         \
        if (i->f->show_rport_##field)                                   \
                count++

#define SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(field)                         \
        i->private_rport_attrs[count] = class_device_attr_rport_##field; \
        i->private_rport_attrs[count].attr.mode = S_IRUGO;              \
        i->private_rport_attrs[count].store = NULL;                     \
        i->rport_attrs[count] = &i->private_rport_attrs[count];         \
        count++

#define SETUP_RPORT_ATTRIBUTE_RW(field)                                 \
        i->private_rport_attrs[count] = class_device_attr_rport_##field; \
        if (!i->f->set_rport_##field) {                                 \
                i->private_rport_attrs[count].attr.mode = S_IRUGO;      \
                i->private_rport_attrs[count].store = NULL;             \
        }                                                               \
        i->rport_attrs[count] = &i->private_rport_attrs[count];         \
        if (i->f->show_rport_##field)                                   \
                count++


/* The FC Transport Remote Port Attributes: */

/* Fixed Remote Port Attributes */

fc_private_rport_rd_attr(maxframe_size, "%u bytes\n", 20);

static ssize_t
show_fc_rport_supported_classes (struct class_device *cdev, char *buf)
{
        struct fc_rport *rport = transport_class_to_rport(cdev);
        if (rport->supported_classes == FC_COS_UNSPECIFIED)
                return snprintf(buf, 20, "unspecified\n");
        return get_fc_cos_names(rport->supported_classes, buf);
}
static FC_CLASS_DEVICE_ATTR(rport, supported_classes, S_IRUGO,
                show_fc_rport_supported_classes, NULL);

/* Dynamic Remote Port Attributes */

fc_rport_rw_attr(dev_loss_tmo, "%d\n", 20);


/* Private Remote Port Attributes */

fc_private_rport_rd_attr_cast(node_name, "0x%llx\n", 20, unsigned long long);
fc_private_rport_rd_attr_cast(port_name, "0x%llx\n", 20, unsigned long long);
fc_private_rport_rd_attr(port_id, "0x%06x\n", 20);

static ssize_t
show_fc_rport_roles (struct class_device *cdev, char *buf)
{
        struct fc_rport *rport = transport_class_to_rport(cdev);

        /* identify any roles that are port_id specific */
        if ((rport->port_id != -1) &&
            (rport->port_id & FC_WELLKNOWN_PORTID_MASK) ==
                                        FC_WELLKNOWN_PORTID_MASK) {
                switch (rport->port_id & FC_WELLKNOWN_ROLE_MASK) {
                case FC_FPORT_PORTID:
                        return snprintf(buf, 30, "Fabric Port\n");
                case FC_FABCTLR_PORTID:
                        return snprintf(buf, 30, "Fabric Controller\n");
                case FC_DIRSRVR_PORTID:
                        return snprintf(buf, 30, "Directory Server\n");
                case FC_TIMESRVR_PORTID:
                        return snprintf(buf, 30, "Time Server\n");
                case FC_MGMTSRVR_PORTID:
                        return snprintf(buf, 30, "Management Server\n");
                default:
                        return snprintf(buf, 30, "Unknown Fabric Entity\n");
                }
        } else {
                if (rport->roles == FC_RPORT_ROLE_UNKNOWN)
                        return snprintf(buf, 20, "unknown\n");
                return get_fc_remote_port_roles_names(rport->roles, buf);
        }
}
static FC_CLASS_DEVICE_ATTR(rport, roles, S_IRUGO,
                show_fc_rport_roles, NULL);

fc_private_rport_rd_enum_attr(port_state, FC_PORTSTATE_MAX_NAMELEN);
fc_private_rport_rd_attr(scsi_target_id, "%d\n", 20);



/*
 * FC SCSI Target Attribute Management
 */

/*
 * Note: in the target show function we recognize when the remote
 *  port is in the heirarchy and do not allow the driver to get
 *  involved in sysfs functions. The driver only gets involved if
 *  it's the "old" style that doesn't use rports.
 */
#define fc_starget_show_function(field, format_string, sz, cast)        \
static ssize_t                                                          \
show_fc_starget_##field (struct class_device *cdev, char *buf)          \
{                                                                       \
        struct scsi_target *starget = transport_class_to_starget(cdev); \
        struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
        struct fc_rport *rport = starget_to_rport(starget);             \
        if (rport)                                                      \
                fc_starget_##field(starget) = rport->field;             \
        else if (i->f->get_starget_##field)                             \
                i->f->get_starget_##field(starget);                     \
        return snprintf(buf, sz, format_string,                         \
                cast fc_starget_##field(starget));                      \
}

#define fc_starget_rd_attr(field, format_string, sz)                    \
        fc_starget_show_function(field, format_string, sz, )            \
static FC_CLASS_DEVICE_ATTR(starget, field, S_IRUGO,                    \
                         show_fc_starget_##field, NULL)

#define fc_starget_rd_attr_cast(field, format_string, sz, cast)         \
        fc_starget_show_function(field, format_string, sz, (cast))      \
static FC_CLASS_DEVICE_ATTR(starget, field, S_IRUGO,                    \
                          show_fc_starget_##field, NULL)

#define SETUP_STARGET_ATTRIBUTE_RD(field)                               \
        i->private_starget_attrs[count] = class_device_attr_starget_##field; \
        i->private_starget_attrs[count].attr.mode = S_IRUGO;            \
        i->private_starget_attrs[count].store = NULL;                   \
        i->starget_attrs[count] = &i->private_starget_attrs[count];     \
        if (i->f->show_starget_##field)                                 \
                count++

#define SETUP_STARGET_ATTRIBUTE_RW(field)                               \
        i->private_starget_attrs[count] = class_device_attr_starget_##field; \
        if (!i->f->set_starget_##field) {                               \
                i->private_starget_attrs[count].attr.mode = S_IRUGO;    \
                i->private_starget_attrs[count].store = NULL;           \
        }                                                               \
        i->starget_attrs[count] = &i->private_starget_attrs[count];     \
        if (i->f->show_starget_##field)                                 \
                count++

/* The FC Transport SCSI Target Attributes: */
fc_starget_rd_attr_cast(node_name, "0x%llx\n", 20, unsigned long long);
fc_starget_rd_attr_cast(port_name, "0x%llx\n", 20, unsigned long long);
fc_starget_rd_attr(port_id, "0x%06x\n", 20);


/*
 * Host Attribute Management
 */

#define fc_host_show_function(field, format_string, sz, cast)           \
static ssize_t                                                          \
show_fc_host_##field (struct class_device *cdev, char *buf)             \
{                                                                       \
        struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
        if (i->f->get_host_##field)                                     \
                i->f->get_host_##field(shost);                          \
        return snprintf(buf, sz, format_string, cast fc_host_##field(shost)); \
}

#define fc_host_store_function(field)                                   \
static ssize_t                                                          \
store_fc_host_##field(struct class_device *cdev, const char *buf,       \
                           size_t count)                                \
{                                                                       \
        int val;                                                        \
        struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
                                                                        \
        val = simple_strtoul(buf, NULL, 0);                             \
        i->f->set_host_##field(shost, val);                             \
        return count;                                                   \
}

#define fc_host_rd_attr(field, format_string, sz)                       \
        fc_host_show_function(field, format_string, sz, )               \
static FC_CLASS_DEVICE_ATTR(host, field, S_IRUGO,                       \
                         show_fc_host_##field, NULL)

#define fc_host_rd_attr_cast(field, format_string, sz, cast)            \
        fc_host_show_function(field, format_string, sz, (cast))         \
static FC_CLASS_DEVICE_ATTR(host, field, S_IRUGO,                       \
                          show_fc_host_##field, NULL)

#define fc_host_rw_attr(field, format_string, sz)                       \
        fc_host_show_function(field, format_string, sz, )               \
        fc_host_store_function(field)                                   \
static FC_CLASS_DEVICE_ATTR(host, field, S_IRUGO | S_IWUSR,             \
                        show_fc_host_##field,                           \
                        store_fc_host_##field)

#define fc_host_rd_enum_attr(title, maxlen)                             \
static ssize_t                                                          \
show_fc_host_##title (struct class_device *cdev, char *buf)             \
{                                                                       \
        struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
        struct fc_internal *i = to_fc_internal(shost->transportt);      \
        const char *name;                                               \
        if (i->f->get_host_##title)                                     \
                i->f->get_host_##title(shost);                          \
        name = get_fc_##title##_name(fc_host_##title(shost));           \
        if (!name)                                                      \
                return -EINVAL;                                         \
        return snprintf(buf, maxlen, "%s\n", name);                     \
}                                                                       \
static FC_CLASS_DEVICE_ATTR(host, title, S_IRUGO, show_fc_host_##title, NULL)

#define SETUP_HOST_ATTRIBUTE_RD(field)                                  \
        i->private_host_attrs[count] = class_device_attr_host_##field;  \
        i->private_host_attrs[count].attr.mode = S_IRUGO;               \
        i->private_host_attrs[count].store = NULL;                      \
        i->host_attrs[count] = &i->private_host_attrs[count];           \
        if (i->f->show_host_##field)                                    \
                count++

#define SETUP_HOST_ATTRIBUTE_RW(field)                                  \
        i->private_host_attrs[count] = class_device_attr_host_##field;  \
        if (!i->f->set_host_##field) {                                  \
                i->private_host_attrs[count].attr.mode = S_IRUGO;       \
                i->private_host_attrs[count].store = NULL;              \
        }                                                               \
        i->host_attrs[count] = &i->private_host_attrs[count];           \
        if (i->f->show_host_##field)                                    \
                count++


#define fc_private_host_show_function(field, format_string, sz, cast)   \
static ssize_t                                                          \
show_fc_host_##field (struct class_device *cdev, char *buf)             \
{                                                                       \
        struct Scsi_Host *shost = transport_class_to_shost(cdev);       \
        return snprintf(buf, sz, format_string, cast fc_host_##field(shost)); \
}

#define fc_private_host_rd_attr(field, format_string, sz)               \
        fc_private_host_show_function(field, format_string, sz, )       \
static FC_CLASS_DEVICE_ATTR(host, field, S_IRUGO,                       \
                         show_fc_host_##field, NULL)

#define fc_private_host_rd_attr_cast(field, format_string, sz, cast)    \
        fc_private_host_show_function(field, format_string, sz, (cast)) \
static FC_CLASS_DEVICE_ATTR(host, field, S_IRUGO,                       \
                          show_fc_host_##field, NULL)

#define SETUP_PRIVATE_HOST_ATTRIBUTE_RD(field)                  \
        i->private_host_attrs[count] = class_device_attr_host_##field;  \
        i->private_host_attrs[count].attr.mode = S_IRUGO;               \
        i->private_host_attrs[count].store = NULL;                      \
        i->host_attrs[count] = &i->private_host_attrs[count];           \
        count++

#define SETUP_PRIVATE_HOST_ATTRIBUTE_RW(field)                  \
        i->private_host_attrs[count] = class_device_attr_host_##field;  \
        i->host_attrs[count] = &i->private_host_attrs[count];           \
        count++


/* Fixed Host Attributes */

static ssize_t
show_fc_host_supported_classes (struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);

        if (fc_host_supported_classes(shost) == FC_COS_UNSPECIFIED)
                return snprintf(buf, 20, "unspecified\n");

        return get_fc_cos_names(fc_host_supported_classes(shost), buf);
}
static FC_CLASS_DEVICE_ATTR(host, supported_classes, S_IRUGO,
                show_fc_host_supported_classes, NULL);

static ssize_t
show_fc_host_supported_fc4s (struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        return (ssize_t)show_fc_fc4s(buf, fc_host_supported_fc4s(shost));
}
static FC_CLASS_DEVICE_ATTR(host, supported_fc4s, S_IRUGO,
                show_fc_host_supported_fc4s, NULL);

static ssize_t
show_fc_host_supported_speeds (struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);

        if (fc_host_supported_speeds(shost) == FC_PORTSPEED_UNKNOWN)
                return snprintf(buf, 20, "unknown\n");

        return get_fc_port_speed_names(fc_host_supported_speeds(shost), buf);
}
static FC_CLASS_DEVICE_ATTR(host, supported_speeds, S_IRUGO,
                show_fc_host_supported_speeds, NULL);


fc_private_host_rd_attr_cast(node_name, "0x%llx\n", 20, unsigned long long);
fc_private_host_rd_attr_cast(port_name, "0x%llx\n", 20, unsigned long long);
fc_private_host_rd_attr(symbolic_name, "%s\n", (FC_SYMBOLIC_NAME_SIZE +1));
fc_private_host_rd_attr(maxframe_size, "%u bytes\n", 20);
fc_private_host_rd_attr(serial_number, "%s\n", (FC_SERIAL_NUMBER_SIZE +1));


/* Dynamic Host Attributes */

static ssize_t
show_fc_host_active_fc4s (struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        struct fc_internal *i = to_fc_internal(shost->transportt);

        if (i->f->get_host_active_fc4s)
                i->f->get_host_active_fc4s(shost);

        return (ssize_t)show_fc_fc4s(buf, fc_host_active_fc4s(shost));
}
static FC_CLASS_DEVICE_ATTR(host, active_fc4s, S_IRUGO,
                show_fc_host_active_fc4s, NULL);

static ssize_t
show_fc_host_speed (struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        struct fc_internal *i = to_fc_internal(shost->transportt);

        if (i->f->get_host_speed)
                i->f->get_host_speed(shost);

        if (fc_host_speed(shost) == FC_PORTSPEED_UNKNOWN)
                return snprintf(buf, 20, "unknown\n");

        return get_fc_port_speed_names(fc_host_speed(shost), buf);
}
static FC_CLASS_DEVICE_ATTR(host, speed, S_IRUGO,
                show_fc_host_speed, NULL);


fc_host_rd_attr(port_id, "0x%06x\n", 20);
fc_host_rd_enum_attr(port_type, FC_PORTTYPE_MAX_NAMELEN);
fc_host_rd_enum_attr(port_state, FC_PORTSTATE_MAX_NAMELEN);
fc_host_rd_attr_cast(fabric_name, "0x%llx\n", 20, unsigned long long);


/* Private Host Attributes */

static ssize_t
show_fc_private_host_tgtid_bind_type(struct class_device *cdev, char *buf)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        const char *name;

        name = get_fc_tgtid_bind_type_name(fc_host_tgtid_bind_type(shost));
        if (!name)
                return -EINVAL;
        return snprintf(buf, FC_BINDTYPE_MAX_NAMELEN, "%s\n", name);
}

static ssize_t
store_fc_private_host_tgtid_bind_type(struct class_device *cdev,
        const char *buf, size_t count)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        struct fc_rport *rport, *next_rport;
        enum fc_tgtid_binding_type val;
        unsigned long flags;

        if (get_fc_tgtid_bind_type_match(buf, &val))
                return -EINVAL;

        /* if changing bind type, purge all unused consistent bindings */
        if (val != fc_host_tgtid_bind_type(shost)) {
                spin_lock_irqsave(shost->host_lock, flags);
                list_for_each_entry_safe(rport, next_rport,
                                &fc_host_rport_bindings(shost), peers)
                        fc_rport_terminate(rport);
                spin_unlock_irqrestore(shost->host_lock, flags);
        }

        fc_host_tgtid_bind_type(shost) = val;
        return count;
}

static FC_CLASS_DEVICE_ATTR(host, tgtid_bind_type, S_IRUGO | S_IWUSR,
                        show_fc_private_host_tgtid_bind_type,
                        store_fc_private_host_tgtid_bind_type);

/*
 * Host Statistics Management
 */

/* Show a given an attribute in the statistics group */
static ssize_t
fc_stat_show(const struct class_device *cdev, char *buf, unsigned long offset)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        struct fc_internal *i = to_fc_internal(shost->transportt);
        struct fc_host_statistics *stats;
        ssize_t ret = -ENOENT;

        if (offset > sizeof(struct fc_host_statistics) ||
            offset % sizeof(u64) != 0)
                WARN_ON(1);

        if (i->f->get_fc_host_stats) {
                stats = (i->f->get_fc_host_stats)(shost);
                if (stats)
                        ret = snprintf(buf, 20, "0x%llx\n",
                              (unsigned long long)*(u64 *)(((u8 *) stats) + offset));
        }
        return ret;
}


/* generate a read-only statistics attribute */
#define fc_host_statistic(name)                                         \
static ssize_t show_fcstat_##name(struct class_device *cd, char *buf)   \
{                                                                       \
        return fc_stat_show(cd, buf,                                    \
                            offsetof(struct fc_host_statistics, name)); \
}                                                                       \
static FC_CLASS_DEVICE_ATTR(host, name, S_IRUGO, show_fcstat_##name, NULL)

fc_host_statistic(seconds_since_last_reset);
fc_host_statistic(tx_frames);
fc_host_statistic(tx_words);
fc_host_statistic(rx_frames);
fc_host_statistic(rx_words);
fc_host_statistic(lip_count);
fc_host_statistic(nos_count);
fc_host_statistic(error_frames);
fc_host_statistic(dumped_frames);
fc_host_statistic(link_failure_count);
fc_host_statistic(loss_of_sync_count);
fc_host_statistic(loss_of_signal_count);
fc_host_statistic(prim_seq_protocol_err_count);
fc_host_statistic(invalid_tx_word_count);
fc_host_statistic(invalid_crc_count);
fc_host_statistic(fcp_input_requests);
fc_host_statistic(fcp_output_requests);
fc_host_statistic(fcp_control_requests);
fc_host_statistic(fcp_input_megabytes);
fc_host_statistic(fcp_output_megabytes);

static ssize_t
fc_reset_statistics(struct class_device *cdev, const char *buf,
                           size_t count)
{
        struct Scsi_Host *shost = transport_class_to_shost(cdev);
        struct fc_internal *i = to_fc_internal(shost->transportt);

        /* ignore any data value written to the attribute */
        if (i->f->reset_fc_host_stats) {
                i->f->reset_fc_host_stats(shost);
                return count;
        }

        return -ENOENT;
}
static FC_CLASS_DEVICE_ATTR(host, reset_statistics, S_IWUSR, NULL,
                                fc_reset_statistics);


static struct attribute *fc_statistics_attrs[] = {
        &class_device_attr_host_seconds_since_last_reset.attr,
        &class_device_attr_host_tx_frames.attr,
        &class_device_attr_host_tx_words.attr,
        &class_device_attr_host_rx_frames.attr,
        &class_device_attr_host_rx_words.attr,
        &class_device_attr_host_lip_count.attr,
        &class_device_attr_host_nos_count.attr,
        &class_device_attr_host_error_frames.attr,
        &class_device_attr_host_dumped_frames.attr,
        &class_device_attr_host_link_failure_count.attr,
        &class_device_attr_host_loss_of_sync_count.attr,
        &class_device_attr_host_loss_of_signal_count.attr,
        &class_device_attr_host_prim_seq_protocol_err_count.attr,
        &class_device_attr_host_invalid_tx_word_count.attr,
        &class_device_attr_host_invalid_crc_count.attr,
        &class_device_attr_host_fcp_input_requests.attr,
        &class_device_attr_host_fcp_output_requests.attr,
        &class_device_attr_host_fcp_control_requests.attr,
        &class_device_attr_host_fcp_input_megabytes.attr,
        &class_device_attr_host_fcp_output_megabytes.attr,
        &class_device_attr_host_reset_statistics.attr,
        NULL
};

static struct attribute_group fc_statistics_group = {
        .name = "statistics",
        .attrs = fc_statistics_attrs,
};

static int fc_host_match(struct attribute_container *cont,
                          struct device *dev)
{
        struct Scsi_Host *shost;
        struct fc_internal *i;

        if (!scsi_is_host_device(dev))
                return 0;

        shost = dev_to_shost(dev);
        if (!shost->transportt  || shost->transportt->host_attrs.ac.class
            != &fc_host_class.class)
                return 0;

        i = to_fc_internal(shost->transportt);

        return &i->t.host_attrs.ac == cont;
}

static int fc_target_match(struct attribute_container *cont,
                            struct device *dev)
{
        struct Scsi_Host *shost;
        struct fc_internal *i;

        if (!scsi_is_target_device(dev))
                return 0;

        shost = dev_to_shost(dev->parent);
        if (!shost->transportt  || shost->transportt->host_attrs.ac.class
            != &fc_host_class.class)
                return 0;

        i = to_fc_internal(shost->transportt);

        return &i->t.target_attrs.ac == cont;
}

static void fc_rport_dev_release(struct device *dev)
{
        struct fc_rport *rport = dev_to_rport(dev);
        put_device(dev->parent);
        kfree(rport);
}

int scsi_is_fc_rport(const struct device *dev)
{
        return dev->release == fc_rport_dev_release;
}
EXPORT_SYMBOL(scsi_is_fc_rport);

static int fc_rport_match(struct attribute_container *cont,
                            struct device *dev)
{
        struct Scsi_Host *shost;
        struct fc_internal *i;

        if (!scsi_is_fc_rport(dev))
                return 0;

        shost = dev_to_shost(dev->parent);
        if (!shost->transportt  || shost->transportt->host_attrs.ac.class
            != &fc_host_class.class)
                return 0;

        i = to_fc_internal(shost->transportt);

        return &i->rport_attr_cont.ac == cont;
}

struct scsi_transport_template *
fc_attach_transport(struct fc_function_template *ft)
{
        struct fc_internal *i = kmalloc(sizeof(struct fc_internal),
                                        GFP_KERNEL);
        int count;

        if (unlikely(!i))
                return NULL;

        memset(i, 0, sizeof(struct fc_internal));

        i->t.target_attrs.ac.attrs = &i->starget_attrs[0];
        i->t.target_attrs.ac.class = &fc_transport_class.class;
        i->t.target_attrs.ac.match = fc_target_match;
        i->t.target_size = sizeof(struct fc_starget_attrs);
        transport_container_register(&i->t.target_attrs);

        i->t.host_attrs.ac.attrs = &i->host_attrs[0];
        i->t.host_attrs.ac.class = &fc_host_class.class;
        i->t.host_attrs.ac.match = fc_host_match;
        i->t.host_size = sizeof(struct fc_host_attrs);
        if (ft->get_fc_host_stats)
                i->t.host_attrs.statistics = &fc_statistics_group;
        transport_container_register(&i->t.host_attrs);

        i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
        i->rport_attr_cont.ac.class = &fc_rport_class.class;
        i->rport_attr_cont.ac.match = fc_rport_match;
        transport_container_register(&i->rport_attr_cont);

        i->f = ft;

        /* Transport uses the shost workq for scsi scanning */
        i->t.create_work_queue = 1;
        
        /*
         * Setup SCSI Target Attributes.
         */
        count = 0;
        SETUP_STARGET_ATTRIBUTE_RD(node_name);
        SETUP_STARGET_ATTRIBUTE_RD(port_name);
        SETUP_STARGET_ATTRIBUTE_RD(port_id);

        BUG_ON(count > FC_STARGET_NUM_ATTRS);

        i->starget_attrs[count] = NULL;


        /*
         * Setup SCSI Host Attributes.
         */
        count=0;
        SETUP_HOST_ATTRIBUTE_RD(node_name);
        SETUP_HOST_ATTRIBUTE_RD(port_name);
        SETUP_HOST_ATTRIBUTE_RD(supported_classes);
        SETUP_HOST_ATTRIBUTE_RD(supported_fc4s);
        SETUP_HOST_ATTRIBUTE_RD(symbolic_name);
        SETUP_HOST_ATTRIBUTE_RD(supported_speeds);
        SETUP_HOST_ATTRIBUTE_RD(maxframe_size);
        SETUP_HOST_ATTRIBUTE_RD(serial_number);

        SETUP_HOST_ATTRIBUTE_RD(port_id);
        SETUP_HOST_ATTRIBUTE_RD(port_type);
        SETUP_HOST_ATTRIBUTE_RD(port_state);
        SETUP_HOST_ATTRIBUTE_RD(active_fc4s);
        SETUP_HOST_ATTRIBUTE_RD(speed);
        SETUP_HOST_ATTRIBUTE_RD(fabric_name);

        /* Transport-managed attributes */
        SETUP_PRIVATE_HOST_ATTRIBUTE_RW(tgtid_bind_type);

        BUG_ON(count > FC_HOST_NUM_ATTRS);

        i->host_attrs[count] = NULL;

        /*
         * Setup Remote Port Attributes.
         */
        count=0;
        SETUP_RPORT_ATTRIBUTE_RD(maxframe_size);
        SETUP_RPORT_ATTRIBUTE_RD(supported_classes);
        SETUP_RPORT_ATTRIBUTE_RW(dev_loss_tmo);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(node_name);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(port_name);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(port_id);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(roles);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(port_state);
        SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(scsi_target_id);

        BUG_ON(count > FC_RPORT_NUM_ATTRS);

        i->rport_attrs[count] = NULL;

        return &i->t;
}
EXPORT_SYMBOL(fc_attach_transport);

void fc_release_transport(struct scsi_transport_template *t)
{
        struct fc_internal *i = to_fc_internal(t);

        transport_container_unregister(&i->t.target_attrs);
        transport_container_unregister(&i->t.host_attrs);
        transport_container_unregister(&i->rport_attr_cont);

        kfree(i);
}
EXPORT_SYMBOL(fc_release_transport);


/**
 * fc_remove_host - called to terminate any fc_transport-related elements
 *                  for a scsi host.
 * @rport:      remote port to be unblocked.
 *
 * This routine is expected to be called immediately preceeding the
 * a driver's call to scsi_remove_host().
 *
 * WARNING: A driver utilizing the fc_transport, which fails to call
 *   this routine prior to scsi_remote_host(), will leave dangling
 *   objects in /sys/class/fc_remote_ports. Access to any of these
 *   objects can result in a system crash !!!
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
void
fc_remove_host(struct Scsi_Host *shost)
{
        struct fc_rport *rport, *next_rport;

        /* Remove any remote ports */
        list_for_each_entry_safe(rport, next_rport,
                        &fc_host_rports(shost), peers)
                fc_rport_terminate(rport);
        list_for_each_entry_safe(rport, next_rport,
                        &fc_host_rport_bindings(shost), peers)
                fc_rport_terminate(rport);
}
EXPORT_SYMBOL(fc_remove_host);

/**
 * fc_rport_create - allocates and creates a remote FC port.
 * @shost:      scsi host the remote port is connected to.
 * @channel:    Channel on shost port connected to.
 * @ids:        The world wide names, fc address, and FC4 port
 *              roles for the remote port.
 *
 * Allocates and creates the remoter port structure, including the
 * class and sysfs creation.
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
struct fc_rport *
fc_rport_create(struct Scsi_Host *shost, int channel,
        struct fc_rport_identifiers  *ids)
{
        struct fc_host_attrs *fc_host =
                        (struct fc_host_attrs *)shost->shost_data;
        struct fc_internal *fci = to_fc_internal(shost->transportt);
        struct fc_rport *rport;
        struct device *dev;
        unsigned long flags;
        int error;
        size_t size;

        size = (sizeof(struct fc_rport) + fci->f->dd_fcrport_size);
        rport = kmalloc(size, GFP_KERNEL);
        if (unlikely(!rport)) {
                printk(KERN_ERR "%s: allocation failure\n", __FUNCTION__);
                return NULL;
        }
        memset(rport, 0, size);

        rport->maxframe_size = -1;
        rport->supported_classes = FC_COS_UNSPECIFIED;
        rport->dev_loss_tmo = fc_dev_loss_tmo;
        memcpy(&rport->node_name, &ids->node_name, sizeof(rport->node_name));
        memcpy(&rport->port_name, &ids->port_name, sizeof(rport->port_name));
        rport->port_id = ids->port_id;
        rport->roles = ids->roles;
        rport->port_state = FC_PORTSTATE_ONLINE;
        if (fci->f->dd_fcrport_size)
                rport->dd_data = &rport[1];
        rport->channel = channel;

        INIT_WORK(&rport->dev_loss_work, fc_timeout_blocked_rport, rport);
        INIT_WORK(&rport->scan_work, fc_scsi_scan_rport, rport);

        spin_lock_irqsave(shost->host_lock, flags);

        rport->number = fc_host->next_rport_number++;
        if (rport->roles & FC_RPORT_ROLE_FCP_TARGET)
                rport->scsi_target_id = fc_host->next_target_id++;
        else
                rport->scsi_target_id = -1;
        list_add_tail(&rport->peers, &fc_host_rports(shost));
        get_device(&shost->shost_gendev);

        spin_unlock_irqrestore(shost->host_lock, flags);

        dev = &rport->dev;
        device_initialize(dev);
        dev->parent = get_device(&shost->shost_gendev);
        dev->release = fc_rport_dev_release;
        sprintf(dev->bus_id, "rport-%d:%d-%d",
                shost->host_no, channel, rport->number);
        transport_setup_device(dev);

        error = device_add(dev);
        if (error) {
                printk(KERN_ERR "FC Remote Port device_add failed\n");
                goto delete_rport;
        }
        transport_add_device(dev);
        transport_configure_device(dev);

        if (rport->roles & FC_RPORT_ROLE_FCP_TARGET)
                /* initiate a scan of the target */
                scsi_queue_work(shost, &rport->scan_work);

        return rport;

delete_rport:
        transport_destroy_device(dev);
        put_device(dev->parent);
        spin_lock_irqsave(shost->host_lock, flags);
        list_del(&rport->peers);
        put_device(&shost->shost_gendev);
        spin_unlock_irqrestore(shost->host_lock, flags);
        put_device(dev->parent);
        kfree(rport);
        return NULL;
}

/**
 * fc_remote_port_add - notifies the fc transport of the existence
 *              of a remote FC port.
 * @shost:      scsi host the remote port is connected to.
 * @channel:    Channel on shost port connected to.
 * @ids:        The world wide names, fc address, and FC4 port
 *              roles for the remote port.
 *
 * The LLDD calls this routine to notify the transport of the existence
 * of a remote port. The LLDD provides the unique identifiers (wwpn,wwn)
 * of the port, it's FC address (port_id), and the FC4 roles that are
 * active for the port.
 *
 * For ports that are FCP targets (aka scsi targets), the FC transport
 * maintains consistent target id bindings on behalf of the LLDD.
 * A consistent target id binding is an assignment of a target id to
 * a remote port identifier, which persists while the scsi host is
 * attached. The remote port can disappear, then later reappear, and
 * it's target id assignment remains the same. This allows for shifts
 * in FC addressing (if binding by wwpn or wwnn) with no apparent
 * changes to the scsi subsystem which is based on scsi host number and
 * target id values.  Bindings are only valid during the attachment of
 * the scsi host. If the host detaches, then later re-attaches, target
 * id bindings may change.
 *
 * This routine is responsible for returning a remote port structure.
 * The routine will search the list of remote ports it maintains
 * internally on behalf of consistent target id mappings. If found, the
 * remote port structure will be reused. Otherwise, a new remote port
 * structure will be allocated.
 *
 * Whenever a remote port is allocated, a new fc_remote_port class
 * device is created.
 *
 * Should not be called from interrupt context.
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
struct fc_rport *
fc_remote_port_add(struct Scsi_Host *shost, int channel,
        struct fc_rport_identifiers  *ids)
{
        struct fc_rport *rport;
        unsigned long flags;
        int match = 0;

        if (likely((ids->roles & FC_RPORT_ROLE_FCP_TARGET) &&
                (fc_host_tgtid_bind_type(shost) != FC_TGTID_BIND_NONE))) {

                /* search for a matching consistent binding */

                spin_lock_irqsave(shost->host_lock, flags);

                list_for_each_entry(rport, &fc_host_rport_bindings(shost),
                                        peers) {
                        if (rport->channel != channel)
                                continue;

                        switch (fc_host_tgtid_bind_type(shost)) {
                        case FC_TGTID_BIND_BY_WWPN:
                                if (rport->port_name == ids->port_name)
                                        match = 1;
                                break;
                        case FC_TGTID_BIND_BY_WWNN:
                                if (rport->node_name == ids->node_name)
                                        match = 1;
                                break;
                        case FC_TGTID_BIND_BY_ID:
                                if (rport->port_id == ids->port_id)
                                        match = 1;
                                break;
                        case FC_TGTID_BIND_NONE: /* to keep compiler happy */
                                break;
                        }

                        if (match) {
                                list_move_tail(&rport->peers,
                                        &fc_host_rports(shost));
                                break;
                        }
                }

                spin_unlock_irqrestore(shost->host_lock, flags);

                if (match) {
                        memcpy(&rport->node_name, &ids->node_name,
                                sizeof(rport->node_name));
                        memcpy(&rport->port_name, &ids->port_name,
                                sizeof(rport->port_name));
                        rport->port_id = ids->port_id;
                        rport->roles = ids->roles;
                        rport->port_state = FC_PORTSTATE_ONLINE;

                        if (rport->roles & FC_RPORT_ROLE_FCP_TARGET)
                                /* initiate a scan of the target */
                                scsi_queue_work(shost, &rport->scan_work);

                        return rport;
                }
        }

        /* No consistent binding found - create new remote port entry */
        rport = fc_rport_create(shost, channel, ids);

        return rport;
}
EXPORT_SYMBOL(fc_remote_port_add);

/*
 * fc_rport_tgt_remove - Removes the scsi target on the remote port
 * @rport:      The remote port to be operated on
 */
static void
fc_rport_tgt_remove(struct fc_rport *rport)
{
        struct Scsi_Host *shost = rport_to_shost(rport);

        scsi_target_unblock(&rport->dev);

        /* Stop anything on the workq */
        if (!cancel_delayed_work(&rport->dev_loss_work))
                flush_scheduled_work();
        scsi_flush_work(shost);

        scsi_remove_target(&rport->dev);
}

/*
 * fc_rport_terminate - this routine tears down and deallocates a remote port.
 * @rport:      The remote port to be terminated
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 */
static void
fc_rport_terminate(struct fc_rport  *rport)
{
        struct Scsi_Host *shost = rport_to_shost(rport);
        struct device *dev = &rport->dev;
        unsigned long flags;

        fc_rport_tgt_remove(rport);

        transport_remove_device(dev);
        device_del(dev);
        transport_destroy_device(dev);
        spin_lock_irqsave(shost->host_lock, flags);
        list_del(&rport->peers);
        spin_unlock_irqrestore(shost->host_lock, flags);
        put_device(&shost->shost_gendev);
}

/**
 * fc_remote_port_delete - notifies the fc transport that a remote
 *              port is no longer in existence.
 * @rport:      The remote port that no longer exists
 *
 * The LLDD calls this routine to notify the transport that a remote
 * port is no longer part of the topology. Note: Although a port
 * may no longer be part of the topology, it may persist in the remote
 * ports displayed by the fc_host. This is done so that target id
 * mappings (managed via the remote port structures), are always visible
 * as long as the mapping is valid, regardless of port state,
 *
 * If the remote port is not an FCP Target, it will be fully torn down
 * and deallocated, including the fc_remote_port class device.
 *
 * If the remote port is an FCP Target, the port structure will be
 * marked as Not Present, but will remain as long as there is a valid
 * SCSI target id mapping associated with the port structure. Validity
 * is determined by the binding type. If binding by wwpn, then the port
 * structure is always valid and will not be deallocated until the host
 * is removed.  If binding by wwnn, then the port structure is valid
 * until another port with the same node name is found in the topology.
 * If binding by port id (fc address), then the port structure is valid
 * valid until another port with the same address is identified.
 *
 * Called from interrupt or normal process context.
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
void
fc_remote_port_delete(struct fc_rport  *rport)
{
        struct Scsi_Host *shost = rport_to_shost(rport);
        unsigned long flags;

        /* If no scsi target id mapping or consistent binding type, delete it */
        if ((rport->scsi_target_id == -1) ||
            (fc_host_tgtid_bind_type(shost) == FC_TGTID_BIND_NONE)) {
                fc_rport_terminate(rport);
                return;
        }

        fc_rport_tgt_remove(rport);

        spin_lock_irqsave(shost->host_lock, flags);
        list_move_tail(&rport->peers, &fc_host_rport_bindings(shost));
        spin_unlock_irqrestore(shost->host_lock, flags);

        /*
         * Note: We do not remove or clear the hostdata area. This allows
         *   host-specific target data to persist along with the
         *   scsi_target_id. It's up to the host to manage it's hostdata area.
         */

        /*
         * Reinitialize port attributes that may change if the port comes back.
         */
        rport->maxframe_size = -1;
        rport->supported_classes = FC_COS_UNSPECIFIED;
        rport->roles = FC_RPORT_ROLE_UNKNOWN;
        rport->port_state = FC_PORTSTATE_NOTPRESENT;

        /* remove the identifiers that aren't used in the consisting binding */
        switch (fc_host_tgtid_bind_type(shost)) {
        case FC_TGTID_BIND_BY_WWPN:
                rport->node_name = -1;
                rport->port_id = -1;
                break;
        case FC_TGTID_BIND_BY_WWNN:
                rport->port_name = -1;
                rport->port_id = -1;
                break;
        case FC_TGTID_BIND_BY_ID:
                rport->node_name = -1;
                rport->port_name = -1;
                break;
        case FC_TGTID_BIND_NONE:        /* to keep compiler happy */
                break;
        }
}
EXPORT_SYMBOL(fc_remote_port_delete);

/**
 * fc_remote_port_rolechg - notifies the fc transport that the roles
 *              on a remote may have changed.
 * @rport:      The remote port that changed.
 *
 * The LLDD calls this routine to notify the transport that the roles
 * on a remote port may have changed. The largest effect of this is
 * if a port now becomes a FCP Target, it must be allocated a
 * scsi target id.  If the port is no longer a FCP target, any
 * scsi target id value assigned to it will persist in case the
 * role changes back to include FCP Target. No changes in the scsi
 * midlayer will be invoked if the role changes (in the expectation
 * that the role will be resumed. If it doesn't normal error processing
 * will take place).
 *
 * Should not be called from interrupt context.
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
void
fc_remote_port_rolechg(struct fc_rport  *rport, u32 roles)
{
        struct Scsi_Host *shost = rport_to_shost(rport);
        struct fc_host_attrs *fc_host =
                        (struct fc_host_attrs *)shost->shost_data;
        unsigned long flags;
        int create = 0;

        rport->roles = roles;

        spin_lock_irqsave(shost->host_lock, flags);
        if ((rport->scsi_target_id == -1) &&
            (rport->roles & FC_RPORT_ROLE_FCP_TARGET)) {
                rport->scsi_target_id = fc_host->next_target_id++;
                create = 1;
        }
        spin_unlock_irqrestore(shost->host_lock, flags);

        if (create)
                /* initiate a scan of the target */
                scsi_queue_work(shost, &rport->scan_work);
}
EXPORT_SYMBOL(fc_remote_port_rolechg);

/**
 * fc_timeout_blocked_rport - Timeout handler for blocked remote port
 *                       that fails to return in the alloted time.
 * @data:       scsi target that failed to reappear in the alloted time.
 **/
static void
fc_timeout_blocked_rport(void  *data)
{
        struct fc_rport *rport = (struct fc_rport *)data;

        rport->port_state = FC_PORTSTATE_OFFLINE;

        dev_printk(KERN_ERR, &rport->dev,
                "blocked FC remote port time out: removing target\n");

        /*
         * As this only occurs if the remote port (scsi target)
         * went away and didn't come back - we'll remove
         * all attached scsi devices.
         */
        scsi_target_unblock(&rport->dev);
        scsi_remove_target(&rport->dev);
}

/**
 * fc_remote_port_block - temporarily block any scsi traffic to a remote port.
 * @rport:      remote port to be blocked.
 *
 * scsi lldd's with a FC transport call this routine to temporarily stop
 * all scsi traffic to a remote port. If the port is not a SCSI target,
 * no action is taken. If the port is a SCSI target, all attached devices
 * are placed into a SDEV_BLOCK state and a timer is started. The timer is
 * represents the maximum amount of time the port may be blocked. If the
 * timer expires, the port is considered non-existent and the attached
 * scsi devices will be removed.
 *
 * Called from interrupt or normal process context.
 *
 * Returns zero if successful or error if not
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 *
 *      The timeout and timer types are extracted from the fc transport 
 *      attributes from the caller's rport pointer.
 **/
int
fc_remote_port_block(struct fc_rport *rport)
{
        int timeout = rport->dev_loss_tmo;
        struct work_struct *work = &rport->dev_loss_work;

        if (timeout < 0 || timeout > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
                return -EINVAL;

        scsi_target_block(&rport->dev);

        /* cap the length the devices can be blocked */
        schedule_delayed_work(work, timeout * HZ);

        rport->port_state = FC_PORTSTATE_BLOCKED;
        return 0;
}
EXPORT_SYMBOL(fc_remote_port_block);

/**
 * fc_remote_port_unblock - restart any blocked scsi traffic to a remote port.
 * @rport:      remote port to be unblocked.
 *
 * scsi lld's with a FC transport call this routine to restart IO to all
 * devices associated with the caller's scsi target following a fc_target_block
 * request.  Called from interrupt or normal process context.
 *
 * Notes:
 *      This routine assumes no locks are held on entry.
 **/
 void
fc_remote_port_unblock(struct fc_rport *rport)
{
        struct work_struct *work = &rport->dev_loss_work;
        struct Scsi_Host *shost = rport_to_shost(rport);

        /*
         * Stop the target timer first. Take no action on the del_timer
         * failure as the state machine state change will validate the
         * transaction.
         */
        if (!cancel_delayed_work(work))
                flush_scheduled_work();

        if (rport->port_state == FC_PORTSTATE_OFFLINE)
                /*
                 * initiate a scan of the target as the target has
                 * been torn down.
                 */
                scsi_queue_work(shost, &rport->scan_work);
        else
                scsi_target_unblock(&rport->dev);

        rport->port_state = FC_PORTSTATE_ONLINE;
}
EXPORT_SYMBOL(fc_remote_port_unblock);

/**
 * fc_scsi_scan_rport - called to perform a scsi scan on a remote port.
 * @data:       remote port to be scanned.
 **/
static void
fc_scsi_scan_rport(void *data)
{
        struct fc_rport *rport = (struct fc_rport *)data;

        scsi_scan_target(&rport->dev, rport->channel, rport->scsi_target_id,
                        SCAN_WILD_CARD, 1);
}


MODULE_AUTHOR("Martin Hicks");
MODULE_DESCRIPTION("FC Transport Attributes");
MODULE_LICENSE("GPL");

module_init(fc_transport_init);
module_exit(fc_transport_exit);