/*
 * Copyright(c) 2011 - 2012 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
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/etherdevice.h>
#include <linux/ctype.h>

#include <scsi/fcoe_sysfs.h>
#include <scsi/libfcoe.h>

/*
 * OK to include local libfcoe.h for debug_logging, but cannot include
 * <scsi/libfcoe.h> otherwise non-netdev based fcoe solutions would have
 * have to include more than fcoe_sysfs.h.
 */
#include "libfcoe.h"

static atomic_t ctlr_num;
static atomic_t fcf_num;

/*
 * fcoe_fcf_dev_loss_tmo: the default number of seconds that fcoe sysfs
 * should insulate the loss of a fcf.
 */
static unsigned int fcoe_fcf_dev_loss_tmo = 1800;  /* seconds */

module_param_named(fcf_dev_loss_tmo, fcoe_fcf_dev_loss_tmo,
                   uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(fcf_dev_loss_tmo,
                 "Maximum number of seconds that libfcoe should"
                 " insulate the loss of a fcf. Once this value is"
                 " exceeded, the fcf is removed.");

/*
 * These are used by the fcoe_*_show_function routines, they
 * are intentionally placed in the .c file as they're not intended
 * for use throughout the code.
 */
#define fcoe_ctlr_id(x)                         \
        ((x)->id)
#define fcoe_ctlr_work_q_name(x)                \
        ((x)->work_q_name)
#define fcoe_ctlr_work_q(x)                     \
        ((x)->work_q)
#define fcoe_ctlr_devloss_work_q_name(x)        \
        ((x)->devloss_work_q_name)
#define fcoe_ctlr_devloss_work_q(x)             \
        ((x)->devloss_work_q)
#define fcoe_ctlr_mode(x)                       \
        ((x)->mode)
#define fcoe_ctlr_fcf_dev_loss_tmo(x)           \
        ((x)->fcf_dev_loss_tmo)
#define fcoe_ctlr_link_fail(x)                  \
        ((x)->lesb.lesb_link_fail)
#define fcoe_ctlr_vlink_fail(x)                 \
        ((x)->lesb.lesb_vlink_fail)
#define fcoe_ctlr_miss_fka(x)                   \
        ((x)->lesb.lesb_miss_fka)
#define fcoe_ctlr_symb_err(x)                   \
        ((x)->lesb.lesb_symb_err)
#define fcoe_ctlr_err_block(x)                  \
        ((x)->lesb.lesb_err_block)
#define fcoe_ctlr_fcs_error(x)                  \
        ((x)->lesb.lesb_fcs_error)
#define fcoe_ctlr_enabled(x)                    \
        ((x)->enabled)
#define fcoe_fcf_state(x)                       \
        ((x)->state)
#define fcoe_fcf_fabric_name(x)                 \
        ((x)->fabric_name)
#define fcoe_fcf_switch_name(x)                 \
        ((x)->switch_name)
#define fcoe_fcf_fc_map(x)                      \
        ((x)->fc_map)
#define fcoe_fcf_vfid(x)                        \
        ((x)->vfid)
#define fcoe_fcf_mac(x)                         \
        ((x)->mac)
#define fcoe_fcf_priority(x)                    \
        ((x)->priority)
#define fcoe_fcf_fka_period(x)                  \
        ((x)->fka_period)
#define fcoe_fcf_dev_loss_tmo(x)                \
        ((x)->dev_loss_tmo)
#define fcoe_fcf_selected(x)                    \
        ((x)->selected)
#define fcoe_fcf_vlan_id(x)                     \
        ((x)->vlan_id)

/*
 * dev_loss_tmo attribute
 */
static int fcoe_str_to_dev_loss(const char *buf, unsigned long *val)
{
        int ret;

        ret = kstrtoul(buf, 0, val);
        if (ret)
                return -EINVAL;
        /*
         * Check for overflow; dev_loss_tmo is u32
         */
        if (*val > UINT_MAX)
                return -EINVAL;

        return 0;
}

static int fcoe_fcf_set_dev_loss_tmo(struct fcoe_fcf_device *fcf,
                                     unsigned long val)
{
        if ((fcf->state == FCOE_FCF_STATE_UNKNOWN) ||
            (fcf->state == FCOE_FCF_STATE_DISCONNECTED) ||
            (fcf->state == FCOE_FCF_STATE_DELETED))
                return -EBUSY;
        /*
         * Check for overflow; dev_loss_tmo is u32
         */
        if (val > UINT_MAX)
                return -EINVAL;

        fcoe_fcf_dev_loss_tmo(fcf) = val;
        return 0;
}

#define FCOE_DEVICE_ATTR(_prefix, _name, _mode, _show, _store)  \
struct device_attribute device_attr_fcoe_##_prefix##_##_name =  \
        __ATTR(_name, _mode, _show, _store)

#define fcoe_ctlr_show_function(field, format_string, sz, cast) \
static ssize_t show_fcoe_ctlr_device_##field(struct device *dev, \
                                            struct device_attribute *attr, \
                                            char *buf)                  \
{                                                                       \
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);               \
        if (ctlr->f->get_fcoe_ctlr_##field)                             \
                ctlr->f->get_fcoe_ctlr_##field(ctlr);                   \
        return snprintf(buf, sz, format_string,                         \
                        cast fcoe_ctlr_##field(ctlr));                  \
}

#define fcoe_fcf_show_function(field, format_string, sz, cast)  \
static ssize_t show_fcoe_fcf_device_##field(struct device *dev, \
                                           struct device_attribute *attr, \
                                           char *buf)                   \
{                                                                       \
        struct fcoe_fcf_device *fcf = dev_to_fcf(dev);                  \
        struct fcoe_ctlr_device *ctlr = fcoe_fcf_dev_to_ctlr_dev(fcf);  \
        if (ctlr->f->get_fcoe_fcf_##field)                              \
                ctlr->f->get_fcoe_fcf_##field(fcf);                     \
        return snprintf(buf, sz, format_string,                         \
                        cast fcoe_fcf_##field(fcf));                    \
}

#define fcoe_ctlr_private_show_function(field, format_string, sz, cast) \
static ssize_t show_fcoe_ctlr_device_##field(struct device *dev, \
                                            struct device_attribute *attr, \
                                            char *buf)                  \
{                                                                       \
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);               \
        return snprintf(buf, sz, format_string, cast fcoe_ctlr_##field(ctlr)); \
}

#define fcoe_fcf_private_show_function(field, format_string, sz, cast)  \
static ssize_t show_fcoe_fcf_device_##field(struct device *dev, \
                                           struct device_attribute *attr, \
                                           char *buf)                   \
{                                                               \
        struct fcoe_fcf_device *fcf = dev_to_fcf(dev);                  \
        return snprintf(buf, sz, format_string, cast fcoe_fcf_##field(fcf)); \
}

#define fcoe_ctlr_private_rd_attr(field, format_string, sz)             \
        fcoe_ctlr_private_show_function(field, format_string, sz, )     \
        static FCOE_DEVICE_ATTR(ctlr, field, S_IRUGO,                   \
                                show_fcoe_ctlr_device_##field, NULL)

#define fcoe_ctlr_rd_attr(field, format_string, sz)                     \
        fcoe_ctlr_show_function(field, format_string, sz, )             \
        static FCOE_DEVICE_ATTR(ctlr, field, S_IRUGO,                   \
                                show_fcoe_ctlr_device_##field, NULL)

#define fcoe_fcf_rd_attr(field, format_string, sz)                      \
        fcoe_fcf_show_function(field, format_string, sz, )              \
        static FCOE_DEVICE_ATTR(fcf, field, S_IRUGO,                    \
                                show_fcoe_fcf_device_##field, NULL)

#define fcoe_fcf_private_rd_attr(field, format_string, sz)              \
        fcoe_fcf_private_show_function(field, format_string, sz, )      \
        static FCOE_DEVICE_ATTR(fcf, field, S_IRUGO,                    \
                                show_fcoe_fcf_device_##field, NULL)

#define fcoe_ctlr_private_rd_attr_cast(field, format_string, sz, cast)  \
        fcoe_ctlr_private_show_function(field, format_string, sz, (cast)) \
        static FCOE_DEVICE_ATTR(ctlr, field, S_IRUGO,                   \
                                show_fcoe_ctlr_device_##field, NULL)

#define fcoe_fcf_private_rd_attr_cast(field, format_string, sz, cast)   \
        fcoe_fcf_private_show_function(field, format_string, sz, (cast)) \
        static FCOE_DEVICE_ATTR(fcf, field, S_IRUGO,                    \
                                show_fcoe_fcf_device_##field, NULL)

#define fcoe_enum_name_search(title, table_type, table)                 \
static const char *get_fcoe_##title##_name(enum table_type table_key)   \
{                                                                       \
        if (table_key < 0 || table_key >= ARRAY_SIZE(table))            \
                return NULL;                                            \
        return table[table_key];                                        \
}

static char *fip_conn_type_names[] = {
        [ FIP_CONN_TYPE_UNKNOWN ] = "Unknown",
        [ FIP_CONN_TYPE_FABRIC ]  = "Fabric",
        [ FIP_CONN_TYPE_VN2VN ]   = "VN2VN",
};
fcoe_enum_name_search(ctlr_mode, fip_conn_type, fip_conn_type_names)

static enum fip_conn_type fcoe_parse_mode(const char *buf)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(fip_conn_type_names); i++) {
                if (strcasecmp(buf, fip_conn_type_names[i]) == 0)
                        return i;
        }

        return FIP_CONN_TYPE_UNKNOWN;
}

static char *fcf_state_names[] = {
        [ FCOE_FCF_STATE_UNKNOWN ]      = "Unknown",
        [ FCOE_FCF_STATE_DISCONNECTED ] = "Disconnected",
        [ FCOE_FCF_STATE_CONNECTED ]    = "Connected",
};
fcoe_enum_name_search(fcf_state, fcf_state, fcf_state_names)
#define FCOE_FCF_STATE_MAX_NAMELEN 50

static ssize_t show_fcf_state(struct device *dev,
                              struct device_attribute *attr,
                              char *buf)
{
        struct fcoe_fcf_device *fcf = dev_to_fcf(dev);
        const char *name;
        name = get_fcoe_fcf_state_name(fcf->state);
        if (!name)
                return -EINVAL;
        return snprintf(buf, FCOE_FCF_STATE_MAX_NAMELEN, "%s\n", name);
}
static FCOE_DEVICE_ATTR(fcf, state, S_IRUGO, show_fcf_state, NULL);

#define FCOE_MAX_MODENAME_LEN 20
static ssize_t show_ctlr_mode(struct device *dev,
                              struct device_attribute *attr,
                              char *buf)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        const char *name;

        name = get_fcoe_ctlr_mode_name(ctlr->mode);
        if (!name)
                return -EINVAL;
        return snprintf(buf, FCOE_MAX_MODENAME_LEN,
                        "%s\n", name);
}

static ssize_t store_ctlr_mode(struct device *dev,
                               struct device_attribute *attr,
                               const char *buf, size_t count)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        char mode[FCOE_MAX_MODENAME_LEN + 1];

        if (count > FCOE_MAX_MODENAME_LEN)
                return -EINVAL;

        strncpy(mode, buf, count);

        if (mode[count - 1] == '\n')
                mode[count - 1] = '\0';
        else
                mode[count] = '\0';

        switch (ctlr->enabled) {
        case FCOE_CTLR_ENABLED:
                LIBFCOE_SYSFS_DBG(ctlr, "Cannot change mode when enabled.");
                return -EBUSY;
        case FCOE_CTLR_DISABLED:
                if (!ctlr->f->set_fcoe_ctlr_mode) {
                        LIBFCOE_SYSFS_DBG(ctlr,
                                          "Mode change not supported by LLD.");
                        return -ENOTSUPP;
                }

                ctlr->mode = fcoe_parse_mode(mode);
                if (ctlr->mode == FIP_CONN_TYPE_UNKNOWN) {
                        LIBFCOE_SYSFS_DBG(ctlr,
                                          "Unknown mode %s provided.", buf);
                        return -EINVAL;
                }

                ctlr->f->set_fcoe_ctlr_mode(ctlr);
                LIBFCOE_SYSFS_DBG(ctlr, "Mode changed to %s.", buf);

                return count;
        case FCOE_CTLR_UNUSED:
        default:
                LIBFCOE_SYSFS_DBG(ctlr, "Mode change not supported.");
                return -ENOTSUPP;
        };
}

static FCOE_DEVICE_ATTR(ctlr, mode, S_IRUGO | S_IWUSR,
                        show_ctlr_mode, store_ctlr_mode);

static ssize_t store_ctlr_enabled(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        int rc;

        switch (ctlr->enabled) {
        case FCOE_CTLR_ENABLED:
                if (*buf == '1')
                        return count;
                ctlr->enabled = FCOE_CTLR_DISABLED;
                break;
        case FCOE_CTLR_DISABLED:
                if (*buf == '0')
                        return count;
                ctlr->enabled = FCOE_CTLR_ENABLED;
                break;
        case FCOE_CTLR_UNUSED:
                return -ENOTSUPP;
        };

        rc = ctlr->f->set_fcoe_ctlr_enabled(ctlr);
        if (rc)
                return rc;

        return count;
}

static char *ctlr_enabled_state_names[] = {
        [ FCOE_CTLR_ENABLED ]  = "1",
        [ FCOE_CTLR_DISABLED ] = "0",
};
fcoe_enum_name_search(ctlr_enabled_state, ctlr_enabled_state,
                      ctlr_enabled_state_names)
#define FCOE_CTLR_ENABLED_MAX_NAMELEN 50

static ssize_t show_ctlr_enabled_state(struct device *dev,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        const char *name;

        name = get_fcoe_ctlr_enabled_state_name(ctlr->enabled);
        if (!name)
                return -EINVAL;
        return snprintf(buf, FCOE_CTLR_ENABLED_MAX_NAMELEN,
                        "%s\n", name);
}

static FCOE_DEVICE_ATTR(ctlr, enabled, S_IRUGO | S_IWUSR,
                        show_ctlr_enabled_state,
                        store_ctlr_enabled);

static ssize_t
store_private_fcoe_ctlr_fcf_dev_loss_tmo(struct device *dev,
                                         struct device_attribute *attr,
                                         const char *buf, size_t count)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        struct fcoe_fcf_device *fcf;
        unsigned long val;
        int rc;

        rc = fcoe_str_to_dev_loss(buf, &val);
        if (rc)
                return rc;

        fcoe_ctlr_fcf_dev_loss_tmo(ctlr) = val;
        mutex_lock(&ctlr->lock);
        list_for_each_entry(fcf, &ctlr->fcfs, peers)
                fcoe_fcf_set_dev_loss_tmo(fcf, val);
        mutex_unlock(&ctlr->lock);
        return count;
}
fcoe_ctlr_private_show_function(fcf_dev_loss_tmo, "%d\n", 20, );
static FCOE_DEVICE_ATTR(ctlr, fcf_dev_loss_tmo, S_IRUGO | S_IWUSR,
                        show_fcoe_ctlr_device_fcf_dev_loss_tmo,
                        store_private_fcoe_ctlr_fcf_dev_loss_tmo);

/* Link Error Status Block (LESB) */
fcoe_ctlr_rd_attr(link_fail, "%u\n", 20);
fcoe_ctlr_rd_attr(vlink_fail, "%u\n", 20);
fcoe_ctlr_rd_attr(miss_fka, "%u\n", 20);
fcoe_ctlr_rd_attr(symb_err, "%u\n", 20);
fcoe_ctlr_rd_attr(err_block, "%u\n", 20);
fcoe_ctlr_rd_attr(fcs_error, "%u\n", 20);

fcoe_fcf_private_rd_attr_cast(fabric_name, "0x%llx\n", 20, unsigned long long);
fcoe_fcf_private_rd_attr_cast(switch_name, "0x%llx\n", 20, unsigned long long);
fcoe_fcf_private_rd_attr(priority, "%u\n", 20);
fcoe_fcf_private_rd_attr(fc_map, "0x%x\n", 20);
fcoe_fcf_private_rd_attr(vfid, "%u\n", 20);
fcoe_fcf_private_rd_attr(mac, "%pM\n", 20);
fcoe_fcf_private_rd_attr(fka_period, "%u\n", 20);
fcoe_fcf_rd_attr(selected, "%u\n", 20);
fcoe_fcf_rd_attr(vlan_id, "%u\n", 20);

fcoe_fcf_private_show_function(dev_loss_tmo, "%d\n", 20, )
static ssize_t
store_fcoe_fcf_dev_loss_tmo(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t count)
{
        struct fcoe_fcf_device *fcf = dev_to_fcf(dev);
        unsigned long val;
        int rc;

        rc = fcoe_str_to_dev_loss(buf, &val);
        if (rc)
                return rc;

        rc = fcoe_fcf_set_dev_loss_tmo(fcf, val);
        if (rc)
                return rc;
        return count;
}
static FCOE_DEVICE_ATTR(fcf, dev_loss_tmo, S_IRUGO | S_IWUSR,
                        show_fcoe_fcf_device_dev_loss_tmo,
                        store_fcoe_fcf_dev_loss_tmo);

static struct attribute *fcoe_ctlr_lesb_attrs[] = {
        &device_attr_fcoe_ctlr_link_fail.attr,
        &device_attr_fcoe_ctlr_vlink_fail.attr,
        &device_attr_fcoe_ctlr_miss_fka.attr,
        &device_attr_fcoe_ctlr_symb_err.attr,
        &device_attr_fcoe_ctlr_err_block.attr,
        &device_attr_fcoe_ctlr_fcs_error.attr,
        NULL,
};

static struct attribute_group fcoe_ctlr_lesb_attr_group = {
        .name = "lesb",
        .attrs = fcoe_ctlr_lesb_attrs,
};

static struct attribute *fcoe_ctlr_attrs[] = {
        &device_attr_fcoe_ctlr_fcf_dev_loss_tmo.attr,
        &device_attr_fcoe_ctlr_enabled.attr,
        &device_attr_fcoe_ctlr_mode.attr,
        NULL,
};

static struct attribute_group fcoe_ctlr_attr_group = {
        .attrs = fcoe_ctlr_attrs,
};

static const struct attribute_group *fcoe_ctlr_attr_groups[] = {
        &fcoe_ctlr_attr_group,
        &fcoe_ctlr_lesb_attr_group,
        NULL,
};

static struct attribute *fcoe_fcf_attrs[] = {
        &device_attr_fcoe_fcf_fabric_name.attr,
        &device_attr_fcoe_fcf_switch_name.attr,
        &device_attr_fcoe_fcf_dev_loss_tmo.attr,
        &device_attr_fcoe_fcf_fc_map.attr,
        &device_attr_fcoe_fcf_vfid.attr,
        &device_attr_fcoe_fcf_mac.attr,
        &device_attr_fcoe_fcf_priority.attr,
        &device_attr_fcoe_fcf_fka_period.attr,
        &device_attr_fcoe_fcf_state.attr,
        &device_attr_fcoe_fcf_selected.attr,
        &device_attr_fcoe_fcf_vlan_id.attr,
        NULL
};

static struct attribute_group fcoe_fcf_attr_group = {
        .attrs = fcoe_fcf_attrs,
};

static const struct attribute_group *fcoe_fcf_attr_groups[] = {
        &fcoe_fcf_attr_group,
        NULL,
};

struct bus_type fcoe_bus_type;

static int fcoe_bus_match(struct device *dev,
                          struct device_driver *drv)
{
        if (dev->bus == &fcoe_bus_type)
                return 1;
        return 0;
}

/**
 * fcoe_ctlr_device_release() - Release the FIP ctlr memory
 * @dev: Pointer to the FIP ctlr's embedded device
 *
 * Called when the last FIP ctlr reference is released.
 */
static void fcoe_ctlr_device_release(struct device *dev)
{
        struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
        kfree(ctlr);
}

/**
 * fcoe_fcf_device_release() - Release the FIP fcf memory
 * @dev: Pointer to the fcf's embedded device
 *
 * Called when the last FIP fcf reference is released.
 */
static void fcoe_fcf_device_release(struct device *dev)
{
        struct fcoe_fcf_device *fcf = dev_to_fcf(dev);
        kfree(fcf);
}

struct device_type fcoe_ctlr_device_type = {
        .name = "fcoe_ctlr",
        .groups = fcoe_ctlr_attr_groups,
        .release = fcoe_ctlr_device_release,
};

struct device_type fcoe_fcf_device_type = {
        .name = "fcoe_fcf",
        .groups = fcoe_fcf_attr_groups,
        .release = fcoe_fcf_device_release,
};

struct bus_attribute fcoe_bus_attr_group[] = {
        __ATTR(ctlr_create, S_IWUSR, NULL, fcoe_ctlr_create_store),
        __ATTR(ctlr_destroy, S_IWUSR, NULL, fcoe_ctlr_destroy_store),
        __ATTR_NULL
};

struct bus_type fcoe_bus_type = {
        .name = "fcoe",
        .match = &fcoe_bus_match,
        .bus_attrs = fcoe_bus_attr_group,
};

/**
 * fcoe_ctlr_device_flush_work() - Flush a FIP ctlr's workqueue
 * @ctlr: Pointer to the FIP ctlr whose workqueue is to be flushed
 */
void fcoe_ctlr_device_flush_work(struct fcoe_ctlr_device *ctlr)
{
        if (!fcoe_ctlr_work_q(ctlr)) {
                printk(KERN_ERR
                       "ERROR: FIP Ctlr '%d' attempted to flush work, "
                       "when no workqueue created.\n", ctlr->id);
                dump_stack();
                return;
        }

        flush_workqueue(fcoe_ctlr_work_q(ctlr));
}

/**
 * fcoe_ctlr_device_queue_work() - Schedule work for a FIP ctlr's workqueue
 * @ctlr: Pointer to the FIP ctlr who owns the devloss workqueue
 * @work:   Work to queue for execution
 *
 * Return value:
 *      1 on success / 0 already queued / < 0 for error
 */
int fcoe_ctlr_device_queue_work(struct fcoe_ctlr_device *ctlr,
                               struct work_struct *work)
{
        if (unlikely(!fcoe_ctlr_work_q(ctlr))) {
                printk(KERN_ERR
                       "ERROR: FIP Ctlr '%d' attempted to queue work, "
                       "when no workqueue created.\n", ctlr->id);
                dump_stack();

                return -EINVAL;
        }

        return queue_work(fcoe_ctlr_work_q(ctlr), work);
}

/**
 * fcoe_ctlr_device_flush_devloss() - Flush a FIP ctlr's devloss workqueue
 * @ctlr: Pointer to FIP ctlr whose workqueue is to be flushed
 */
void fcoe_ctlr_device_flush_devloss(struct fcoe_ctlr_device *ctlr)
{
        if (!fcoe_ctlr_devloss_work_q(ctlr)) {
                printk(KERN_ERR
                       "ERROR: FIP Ctlr '%d' attempted to flush work, "
                       "when no workqueue created.\n", ctlr->id);
                dump_stack();
                return;
        }

        flush_workqueue(fcoe_ctlr_devloss_work_q(ctlr));
}

/**
 * fcoe_ctlr_device_queue_devloss_work() - Schedule work for a FIP ctlr's devloss workqueue
 * @ctlr: Pointer to the FIP ctlr who owns the devloss workqueue
 * @work:   Work to queue for execution
 * @delay:  jiffies to delay the work queuing
 *
 * Return value:
 *      1 on success / 0 already queued / < 0 for error
 */
int fcoe_ctlr_device_queue_devloss_work(struct fcoe_ctlr_device *ctlr,
                                       struct delayed_work *work,
                                       unsigned long delay)
{
        if (unlikely(!fcoe_ctlr_devloss_work_q(ctlr))) {
                printk(KERN_ERR
                       "ERROR: FIP Ctlr '%d' attempted to queue work, "
                       "when no workqueue created.\n", ctlr->id);
                dump_stack();

                return -EINVAL;
        }

        return queue_delayed_work(fcoe_ctlr_devloss_work_q(ctlr), work, delay);
}

static int fcoe_fcf_device_match(struct fcoe_fcf_device *new,
                                 struct fcoe_fcf_device *old)
{
        if (new->switch_name == old->switch_name &&
            new->fabric_name == old->fabric_name &&
            new->fc_map == old->fc_map &&
            compare_ether_addr(new->mac, old->mac) == 0)
                return 1;
        return 0;
}

/**
 * fcoe_ctlr_device_add() - Add a FIP ctlr to sysfs
 * @parent:    The parent device to which the fcoe_ctlr instance
 *             should be attached
 * @f:         The LLD's FCoE sysfs function template pointer
 * @priv_size: Size to be allocated with the fcoe_ctlr_device for the LLD
 *
 * This routine allocates a FIP ctlr object with some additional memory
 * for the LLD. The FIP ctlr is initialized, added to sysfs and then
 * attributes are added to it.
 */
struct fcoe_ctlr_device *fcoe_ctlr_device_add(struct device *parent,
                                    struct fcoe_sysfs_function_template *f,
                                    int priv_size)
{
        struct fcoe_ctlr_device *ctlr;
        int error = 0;

        ctlr = kzalloc(sizeof(struct fcoe_ctlr_device) + priv_size,
                       GFP_KERNEL);
        if (!ctlr)
                goto out;

        ctlr->id = atomic_inc_return(&ctlr_num) - 1;
        ctlr->f = f;
        ctlr->mode = FIP_CONN_TYPE_FABRIC;
        INIT_LIST_HEAD(&ctlr->fcfs);
        mutex_init(&ctlr->lock);
        ctlr->dev.parent = parent;
        ctlr->dev.bus = &fcoe_bus_type;
        ctlr->dev.type = &fcoe_ctlr_device_type;

        ctlr->fcf_dev_loss_tmo = fcoe_fcf_dev_loss_tmo;

        snprintf(ctlr->work_q_name, sizeof(ctlr->work_q_name),
                 "ctlr_wq_%d", ctlr->id);
        ctlr->work_q = create_singlethread_workqueue(
                ctlr->work_q_name);
        if (!ctlr->work_q)
                goto out_del;

        snprintf(ctlr->devloss_work_q_name,
                 sizeof(ctlr->devloss_work_q_name),
                 "ctlr_dl_wq_%d", ctlr->id);
        ctlr->devloss_work_q = create_singlethread_workqueue(
                ctlr->devloss_work_q_name);
        if (!ctlr->devloss_work_q)
                goto out_del_q;

        dev_set_name(&ctlr->dev, "ctlr_%d", ctlr->id);
        error = device_register(&ctlr->dev);
        if (error)
                goto out_del_q2;

        return ctlr;

out_del_q2:
        destroy_workqueue(ctlr->devloss_work_q);
        ctlr->devloss_work_q = NULL;
out_del_q:
        destroy_workqueue(ctlr->work_q);
        ctlr->work_q = NULL;
out_del:
        kfree(ctlr);
out:
        return NULL;
}
EXPORT_SYMBOL_GPL(fcoe_ctlr_device_add);

/**
 * fcoe_ctlr_device_delete() - Delete a FIP ctlr and its subtree from sysfs
 * @ctlr: A pointer to the ctlr to be deleted
 *
 * Deletes a FIP ctlr and any fcfs attached
 * to it. Deleting fcfs will cause their childen
 * to be deleted as well.
 *
 * The ctlr is detached from sysfs and it's resources
 * are freed (work q), but the memory is not freed
 * until its last reference is released.
 *
 * This routine expects no locks to be held before
 * calling.
 *
 * TODO: Currently there are no callbacks to clean up LLD data
 * for a fcoe_fcf_device. LLDs must keep this in mind as they need
 * to clean up each of their LLD data for all fcoe_fcf_device before
 * calling fcoe_ctlr_device_delete.
 */
void fcoe_ctlr_device_delete(struct fcoe_ctlr_device *ctlr)
{
        struct fcoe_fcf_device *fcf, *next;
        /* Remove any attached fcfs */
        mutex_lock(&ctlr->lock);
        list_for_each_entry_safe(fcf, next,
                                 &ctlr->fcfs, peers) {
                list_del(&fcf->peers);
                fcf->state = FCOE_FCF_STATE_DELETED;
                fcoe_ctlr_device_queue_work(ctlr, &fcf->delete_work);
        }
        mutex_unlock(&ctlr->lock);

        fcoe_ctlr_device_flush_work(ctlr);

        destroy_workqueue(ctlr->devloss_work_q);
        ctlr->devloss_work_q = NULL;
        destroy_workqueue(ctlr->work_q);
        ctlr->work_q = NULL;

        device_unregister(&ctlr->dev);
}
EXPORT_SYMBOL_GPL(fcoe_ctlr_device_delete);

/**
 * fcoe_fcf_device_final_delete() - Final delete routine
 * @work: The FIP fcf's embedded work struct
 *
 * It is expected that the fcf has been removed from
 * the FIP ctlr's list before calling this routine.
 */
static void fcoe_fcf_device_final_delete(struct work_struct *work)
{
        struct fcoe_fcf_device *fcf =
                container_of(work, struct fcoe_fcf_device, delete_work);
        struct fcoe_ctlr_device *ctlr = fcoe_fcf_dev_to_ctlr_dev(fcf);

        /*
         * Cancel any outstanding timers. These should really exist
         * only when rmmod'ing the LLDD and we're asking for
         * immediate termination of the rports
         */
        if (!cancel_delayed_work(&fcf->dev_loss_work))
                fcoe_ctlr_device_flush_devloss(ctlr);

        device_unregister(&fcf->dev);
}

/**
 * fip_timeout_deleted_fcf() - Delete a fcf when the devloss timer fires
 * @work: The FIP fcf's embedded work struct
 *
 * Removes the fcf from the FIP ctlr's list of fcfs and
 * queues the final deletion.
 */
static void fip_timeout_deleted_fcf(struct work_struct *work)
{
        struct fcoe_fcf_device *fcf =
                container_of(work, struct fcoe_fcf_device, dev_loss_work.work);
        struct fcoe_ctlr_device *ctlr = fcoe_fcf_dev_to_ctlr_dev(fcf);

        mutex_lock(&ctlr->lock);

        /*
         * If the fcf is deleted or reconnected before the timer
         * fires the devloss queue will be flushed, but the state will
         * either be CONNECTED or DELETED. If that is the case we
         * cancel deleting the fcf.
         */
        if (fcf->state != FCOE_FCF_STATE_DISCONNECTED)
                goto out;

        dev_printk(KERN_ERR, &fcf->dev,
                   "FIP fcf connection time out: removing fcf\n");

        list_del(&fcf->peers);
        fcf->state = FCOE_FCF_STATE_DELETED;
        fcoe_ctlr_device_queue_work(ctlr, &fcf->delete_work);

out:
        mutex_unlock(&ctlr->lock);
}

/**
 * fcoe_fcf_device_delete() - Delete a FIP fcf
 * @fcf: Pointer to the fcf which is to be deleted
 *
 * Queues the FIP fcf on the devloss workqueue
 *
 * Expects the ctlr_attrs mutex to be held for fcf
 * state change.
 */
void fcoe_fcf_device_delete(struct fcoe_fcf_device *fcf)
{
        struct fcoe_ctlr_device *ctlr = fcoe_fcf_dev_to_ctlr_dev(fcf);
        int timeout = fcf->dev_loss_tmo;

        if (fcf->state != FCOE_FCF_STATE_CONNECTED)
                return;

        fcf->state = FCOE_FCF_STATE_DISCONNECTED;

        /*
         * FCF will only be re-connected by the LLD calling
         * fcoe_fcf_device_add, and it should be setting up
         * priv then.
         */
        fcf->priv = NULL;

        fcoe_ctlr_device_queue_devloss_work(ctlr, &fcf->dev_loss_work,
                                           timeout * HZ);
}
EXPORT_SYMBOL_GPL(fcoe_fcf_device_delete);

/**
 * fcoe_fcf_device_add() - Add a FCoE sysfs fcoe_fcf_device to the system
 * @ctlr:    The fcoe_ctlr_device that will be the fcoe_fcf_device parent
 * @new_fcf: A temporary FCF used for lookups on the current list of fcfs
 *
 * Expects to be called with the ctlr->lock held
 */
struct fcoe_fcf_device *fcoe_fcf_device_add(struct fcoe_ctlr_device *ctlr,
                                            struct fcoe_fcf_device *new_fcf)
{
        struct fcoe_fcf_device *fcf;
        int error = 0;

        list_for_each_entry(fcf, &ctlr->fcfs, peers) {
                if (fcoe_fcf_device_match(new_fcf, fcf)) {
                        if (fcf->state == FCOE_FCF_STATE_CONNECTED)
                                return fcf;

                        fcf->state = FCOE_FCF_STATE_CONNECTED;

                        if (!cancel_delayed_work(&fcf->dev_loss_work))
                                fcoe_ctlr_device_flush_devloss(ctlr);

                        return fcf;
                }
        }

        fcf = kzalloc(sizeof(struct fcoe_fcf_device), GFP_ATOMIC);
        if (unlikely(!fcf))
                goto out;

        INIT_WORK(&fcf->delete_work, fcoe_fcf_device_final_delete);
        INIT_DELAYED_WORK(&fcf->dev_loss_work, fip_timeout_deleted_fcf);

        fcf->dev.parent = &ctlr->dev;
        fcf->dev.bus = &fcoe_bus_type;
        fcf->dev.type = &fcoe_fcf_device_type;
        fcf->id = atomic_inc_return(&fcf_num) - 1;
        fcf->state = FCOE_FCF_STATE_UNKNOWN;

        fcf->dev_loss_tmo = ctlr->fcf_dev_loss_tmo;

        dev_set_name(&fcf->dev, "fcf_%d", fcf->id);

        fcf->fabric_name = new_fcf->fabric_name;
        fcf->switch_name = new_fcf->switch_name;
        fcf->fc_map = new_fcf->fc_map;
        fcf->vfid = new_fcf->vfid;
        memcpy(fcf->mac, new_fcf->mac, ETH_ALEN);
        fcf->priority = new_fcf->priority;
        fcf->fka_period = new_fcf->fka_period;
        fcf->selected = new_fcf->selected;

        error = device_register(&fcf->dev);
        if (error)
                goto out_del;

        fcf->state = FCOE_FCF_STATE_CONNECTED;
        list_add_tail(&fcf->peers, &ctlr->fcfs);

        return fcf;

out_del:
        kfree(fcf);
out:
        return NULL;
}
EXPORT_SYMBOL_GPL(fcoe_fcf_device_add);

int __init fcoe_sysfs_setup(void)
{
        int error;

        atomic_set(&ctlr_num, 0);
        atomic_set(&fcf_num, 0);

        error = bus_register(&fcoe_bus_type);
        if (error)
                return error;

        return 0;
}

void __exit fcoe_sysfs_teardown(void)
{
        bus_unregister(&fcoe_bus_type);
}