Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

[mirror_ubuntu-zesty-kernel.git] / drivers / s390 / scsi / zfcp_aux.c

/*
 * This file is part of the zfcp device driver for
 * FCP adapters for IBM System z9 and zSeries.
 *
 * (C) Copyright IBM Corp. 2002, 2006
 *
 * 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, 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * Driver authors:
 *            Martin Peschke (originator of the driver)
 *            Raimund Schroeder
 *            Aron Zeh
 *            Wolfgang Taphorn
 *            Stefan Bader
 *            Heiko Carstens (kernel 2.6 port of the driver)
 *            Andreas Herrmann
 *            Maxim Shchetynin
 *            Volker Sameske
 *            Ralph Wuerthner
 */

#include "zfcp_ext.h"

/* accumulated log level (module parameter) */
static u32 loglevel = ZFCP_LOG_LEVEL_DEFAULTS;
static char *device;
/*********************** FUNCTION PROTOTYPES *********************************/

/* written against the module interface */
static int __init  zfcp_module_init(void);

/* FCP related */
static void zfcp_ns_gid_pn_handler(unsigned long);

/* miscellaneous */
static int zfcp_sg_list_alloc(struct zfcp_sg_list *, size_t);
static void zfcp_sg_list_free(struct zfcp_sg_list *);
static int zfcp_sg_list_copy_from_user(struct zfcp_sg_list *,
                                       void __user *, size_t);
static int zfcp_sg_list_copy_to_user(void __user *,
                                     struct zfcp_sg_list *, size_t);
static long zfcp_cfdc_dev_ioctl(struct file *, unsigned int, unsigned long);

#define ZFCP_CFDC_IOC_MAGIC                     0xDD
#define ZFCP_CFDC_IOC \
        _IOWR(ZFCP_CFDC_IOC_MAGIC, 0, struct zfcp_cfdc_sense_data)


static const struct file_operations zfcp_cfdc_fops = {
        .unlocked_ioctl = zfcp_cfdc_dev_ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl = zfcp_cfdc_dev_ioctl
#endif
};

static struct miscdevice zfcp_cfdc_misc = {
        .minor = ZFCP_CFDC_DEV_MINOR,
        .name = ZFCP_CFDC_DEV_NAME,
        .fops = &zfcp_cfdc_fops
};

/*********************** KERNEL/MODULE PARAMETERS  ***************************/

/* declare driver module init/cleanup functions */
module_init(zfcp_module_init);

MODULE_AUTHOR("IBM Deutschland Entwicklung GmbH - linux390@de.ibm.com");
MODULE_DESCRIPTION
    ("FCP (SCSI over Fibre Channel) HBA driver for IBM System z9 and zSeries");
MODULE_LICENSE("GPL");

module_param(device, charp, 0400);
MODULE_PARM_DESC(device, "specify initial device");

module_param(loglevel, uint, 0400);
MODULE_PARM_DESC(loglevel,
                 "log levels, 8 nibbles: "
                 "FC ERP QDIO CIO Config FSF SCSI Other, "
                 "levels: 0=none 1=normal 2=devel 3=trace");

/****************************************************************/
/************** Functions without logging ***********************/
/****************************************************************/

void
_zfcp_hex_dump(char *addr, int count)
{
        int i;
        for (i = 0; i < count; i++) {
                printk("%02x", addr[i]);
                if ((i % 4) == 3)
                        printk(" ");
                if ((i % 32) == 31)
                        printk("\n");
        }
        if (((i-1) % 32) != 31)
                printk("\n");
}


/****************************************************************/
/****** Functions to handle the request ID hash table    ********/
/****************************************************************/

#define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_FSF

static int zfcp_reqlist_alloc(struct zfcp_adapter *adapter)
{
        int idx;

        adapter->req_list = kcalloc(REQUEST_LIST_SIZE, sizeof(struct list_head),
                                    GFP_KERNEL);
        if (!adapter->req_list)
                return -ENOMEM;

        for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
                INIT_LIST_HEAD(&adapter->req_list[idx]);
        return 0;
}

static void zfcp_reqlist_free(struct zfcp_adapter *adapter)
{
        kfree(adapter->req_list);
}

int zfcp_reqlist_isempty(struct zfcp_adapter *adapter)
{
        unsigned int idx;

        for (idx = 0; idx < REQUEST_LIST_SIZE; idx++)
                if (!list_empty(&adapter->req_list[idx]))
                        return 0;
        return 1;
}

#undef ZFCP_LOG_AREA

/****************************************************************/
/************** Uncategorised Functions *************************/
/****************************************************************/

#define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_OTHER

/**
 * zfcp_device_setup - setup function
 * @str: pointer to parameter string
 *
 * Parse "device=..." parameter string.
 */
static int __init
zfcp_device_setup(char *devstr)
{
        char *tmp, *str;
        size_t len;

        if (!devstr)
                return 0;

        len = strlen(devstr) + 1;
        str = kmalloc(len, GFP_KERNEL);
        if (!str)
                goto err_out;
        memcpy(str, devstr, len);

        tmp = strchr(str, ',');
        if (!tmp)
                goto err_out;
        *tmp++ = '\0';
        strncpy(zfcp_data.init_busid, str, BUS_ID_SIZE);
        zfcp_data.init_busid[BUS_ID_SIZE-1] = '\0';

        zfcp_data.init_wwpn = simple_strtoull(tmp, &tmp, 0);
        if (*tmp++ != ',')
                goto err_out;
        if (*tmp == '\0')
                goto err_out;

        zfcp_data.init_fcp_lun = simple_strtoull(tmp, &tmp, 0);
        if (*tmp != '\0')
                goto err_out;
        kfree(str);
        return 1;

 err_out:
        ZFCP_LOG_NORMAL("Parse error for device parameter string %s\n", str);
        kfree(str);
        return 0;
}

static void __init
zfcp_init_device_configure(void)
{
        struct zfcp_adapter *adapter;
        struct zfcp_port *port;
        struct zfcp_unit *unit;

        down(&zfcp_data.config_sema);
        read_lock_irq(&zfcp_data.config_lock);
        adapter = zfcp_get_adapter_by_busid(zfcp_data.init_busid);
        if (adapter)
                zfcp_adapter_get(adapter);
        read_unlock_irq(&zfcp_data.config_lock);

        if (adapter == NULL)
                goto out_adapter;
        port = zfcp_port_enqueue(adapter, zfcp_data.init_wwpn, 0, 0);
        if (!port)
                goto out_port;
        unit = zfcp_unit_enqueue(port, zfcp_data.init_fcp_lun);
        if (!unit)
                goto out_unit;
        up(&zfcp_data.config_sema);
        ccw_device_set_online(adapter->ccw_device);
        zfcp_erp_wait(adapter);
        down(&zfcp_data.config_sema);
        zfcp_unit_put(unit);
 out_unit:
        zfcp_port_put(port);
 out_port:
        zfcp_adapter_put(adapter);
 out_adapter:
        up(&zfcp_data.config_sema);
        return;
}

static int calc_alignment(int size)
{
        int align = 1;

        if (!size)
                return 0;

        while ((size - align) > 0)
                align <<= 1;

        return align;
}

static int __init
zfcp_module_init(void)
{
        int retval = -ENOMEM;
        int size, align;

        size = sizeof(struct zfcp_fsf_req_qtcb);
        align = calc_alignment(size);
        zfcp_data.fsf_req_qtcb_cache =
                kmem_cache_create("zfcp_fsf", size, align, 0, NULL);
        if (!zfcp_data.fsf_req_qtcb_cache)
                goto out;

        size = sizeof(struct fsf_status_read_buffer);
        align = calc_alignment(size);
        zfcp_data.sr_buffer_cache =
                kmem_cache_create("zfcp_sr", size, align, 0, NULL);
        if (!zfcp_data.sr_buffer_cache)
                goto out_sr_cache;

        size = sizeof(struct zfcp_gid_pn_data);
        align = calc_alignment(size);
        zfcp_data.gid_pn_cache =
                kmem_cache_create("zfcp_gid", size, align, 0, NULL);
        if (!zfcp_data.gid_pn_cache)
                goto out_gid_cache;

        atomic_set(&zfcp_data.loglevel, loglevel);

        /* initialize adapter list */
        INIT_LIST_HEAD(&zfcp_data.adapter_list_head);

        /* initialize adapters to be removed list head */
        INIT_LIST_HEAD(&zfcp_data.adapter_remove_lh);

        zfcp_data.scsi_transport_template =
                fc_attach_transport(&zfcp_transport_functions);
        if (!zfcp_data.scsi_transport_template)
                goto out_transport;

        retval = misc_register(&zfcp_cfdc_misc);
        if (retval != 0) {
                ZFCP_LOG_INFO("registration of misc device "
                              "zfcp_cfdc failed\n");
                goto out_misc;
        }

        ZFCP_LOG_TRACE("major/minor for zfcp_cfdc: %d/%d\n",
                       ZFCP_CFDC_DEV_MAJOR, zfcp_cfdc_misc.minor);

        /* Initialise proc semaphores */
        sema_init(&zfcp_data.config_sema, 1);

        /* initialise configuration rw lock */
        rwlock_init(&zfcp_data.config_lock);

        /* setup dynamic I/O */
        retval = zfcp_ccw_register();
        if (retval) {
                ZFCP_LOG_NORMAL("registration with common I/O layer failed\n");
                goto out_ccw_register;
        }

        if (zfcp_device_setup(device))
                zfcp_init_device_configure();

        goto out;

 out_ccw_register:
        misc_deregister(&zfcp_cfdc_misc);
 out_misc:
        fc_release_transport(zfcp_data.scsi_transport_template);
 out_transport:
        kmem_cache_destroy(zfcp_data.gid_pn_cache);
 out_gid_cache:
        kmem_cache_destroy(zfcp_data.sr_buffer_cache);
 out_sr_cache:
        kmem_cache_destroy(zfcp_data.fsf_req_qtcb_cache);
 out:
        return retval;
}

/*
 * function:    zfcp_cfdc_dev_ioctl
 *
 * purpose:     Handle control file upload/download transaction via IOCTL
 *              interface
 *
 * returns:     0           - Operation completed successfuly
 *              -ENOTTY     - Unknown IOCTL command
 *              -EINVAL     - Invalid sense data record
 *              -ENXIO      - The FCP adapter is not available
 *              -EOPNOTSUPP - The FCP adapter does not have CFDC support
 *              -ENOMEM     - Insufficient memory
 *              -EFAULT     - User space memory I/O operation fault
 *              -EPERM      - Cannot create or queue FSF request or create SBALs
 *              -ERESTARTSYS- Received signal (is mapped to EAGAIN by VFS)
 */
static long
zfcp_cfdc_dev_ioctl(struct file *file, unsigned int command,
                    unsigned long buffer)
{
        struct zfcp_cfdc_sense_data *sense_data, __user *sense_data_user;
        struct zfcp_adapter *adapter = NULL;
        struct zfcp_fsf_req *fsf_req = NULL;
        struct zfcp_sg_list *sg_list = NULL;
        u32 fsf_command, option;
        char *bus_id = NULL;
        int retval = 0;

        sense_data = kmalloc(sizeof(struct zfcp_cfdc_sense_data), GFP_KERNEL);
        if (sense_data == NULL) {
                retval = -ENOMEM;
                goto out;
        }

        sg_list = kzalloc(sizeof(struct zfcp_sg_list), GFP_KERNEL);
        if (sg_list == NULL) {
                retval = -ENOMEM;
                goto out;
        }

        if (command != ZFCP_CFDC_IOC) {
                ZFCP_LOG_INFO("IOC request code 0x%x invalid\n", command);
                retval = -ENOTTY;
                goto out;
        }

        if ((sense_data_user = (void __user *) buffer) == NULL) {
                ZFCP_LOG_INFO("sense data record is required\n");
                retval = -EINVAL;
                goto out;
        }

        retval = copy_from_user(sense_data, sense_data_user,
                                sizeof(struct zfcp_cfdc_sense_data));
        if (retval) {
                retval = -EFAULT;
                goto out;
        }

        if (sense_data->signature != ZFCP_CFDC_SIGNATURE) {
                ZFCP_LOG_INFO("invalid sense data request signature 0x%08x\n",
                              ZFCP_CFDC_SIGNATURE);
                retval = -EINVAL;
                goto out;
        }

        switch (sense_data->command) {

        case ZFCP_CFDC_CMND_DOWNLOAD_NORMAL:
                fsf_command = FSF_QTCB_DOWNLOAD_CONTROL_FILE;
                option = FSF_CFDC_OPTION_NORMAL_MODE;
                break;

        case ZFCP_CFDC_CMND_DOWNLOAD_FORCE:
                fsf_command = FSF_QTCB_DOWNLOAD_CONTROL_FILE;
                option = FSF_CFDC_OPTION_FORCE;
                break;

        case ZFCP_CFDC_CMND_FULL_ACCESS:
                fsf_command = FSF_QTCB_DOWNLOAD_CONTROL_FILE;
                option = FSF_CFDC_OPTION_FULL_ACCESS;
                break;

        case ZFCP_CFDC_CMND_RESTRICTED_ACCESS:
                fsf_command = FSF_QTCB_DOWNLOAD_CONTROL_FILE;
                option = FSF_CFDC_OPTION_RESTRICTED_ACCESS;
                break;

        case ZFCP_CFDC_CMND_UPLOAD:
                fsf_command = FSF_QTCB_UPLOAD_CONTROL_FILE;
                option = 0;
                break;

        default:
                ZFCP_LOG_INFO("invalid command code 0x%08x\n",
                              sense_data->command);
                retval = -EINVAL;
                goto out;
        }

        bus_id = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
        if (bus_id == NULL) {
                retval = -ENOMEM;
                goto out;
        }
        snprintf(bus_id, BUS_ID_SIZE, "%d.%d.%04x",
                (sense_data->devno >> 24),
                (sense_data->devno >> 16) & 0xFF,
                (sense_data->devno & 0xFFFF));

        read_lock_irq(&zfcp_data.config_lock);
        adapter = zfcp_get_adapter_by_busid(bus_id);
        if (adapter)
                zfcp_adapter_get(adapter);
        read_unlock_irq(&zfcp_data.config_lock);

        kfree(bus_id);

        if (adapter == NULL) {
                ZFCP_LOG_INFO("invalid adapter\n");
                retval = -ENXIO;
                goto out;
        }

        if (sense_data->command & ZFCP_CFDC_WITH_CONTROL_FILE) {
                retval = zfcp_sg_list_alloc(sg_list,
                                            ZFCP_CFDC_MAX_CONTROL_FILE_SIZE);
                if (retval) {
                        retval = -ENOMEM;
                        goto out;
                }
        }

        if ((sense_data->command & ZFCP_CFDC_DOWNLOAD) &&
            (sense_data->command & ZFCP_CFDC_WITH_CONTROL_FILE)) {
                retval = zfcp_sg_list_copy_from_user(
                        sg_list, &sense_data_user->control_file,
                        ZFCP_CFDC_MAX_CONTROL_FILE_SIZE);
                if (retval) {
                        retval = -EFAULT;
                        goto out;
                }
        }

        retval = zfcp_fsf_control_file(adapter, &fsf_req, fsf_command,
                                       option, sg_list);
        if (retval)
                goto out;

        if ((fsf_req->qtcb->prefix.prot_status != FSF_PROT_GOOD) &&
            (fsf_req->qtcb->prefix.prot_status != FSF_PROT_FSF_STATUS_PRESENTED)) {
                retval = -ENXIO;
                goto out;
        }

        sense_data->fsf_status = fsf_req->qtcb->header.fsf_status;
        memcpy(&sense_data->fsf_status_qual,
               &fsf_req->qtcb->header.fsf_status_qual,
               sizeof(union fsf_status_qual));
        memcpy(&sense_data->payloads, &fsf_req->qtcb->bottom.support.els, 256);

        retval = copy_to_user(sense_data_user, sense_data,
                sizeof(struct zfcp_cfdc_sense_data));
        if (retval) {
                retval = -EFAULT;
                goto out;
        }

        if (sense_data->command & ZFCP_CFDC_UPLOAD) {
                retval = zfcp_sg_list_copy_to_user(
                        &sense_data_user->control_file, sg_list,
                        ZFCP_CFDC_MAX_CONTROL_FILE_SIZE);
                if (retval) {
                        retval = -EFAULT;
                        goto out;
                }
        }

 out:
        if (fsf_req != NULL)
                zfcp_fsf_req_free(fsf_req);

        if ((adapter != NULL) && (retval != -ENXIO))
                zfcp_adapter_put(adapter);

        if (sg_list != NULL) {
                zfcp_sg_list_free(sg_list);
                kfree(sg_list);
        }

        kfree(sense_data);

        return retval;
}


/**
 * zfcp_sg_list_alloc - create a scatter-gather list of the specified size
 * @sg_list: structure describing a scatter gather list
 * @size: size of scatter-gather list
 * Return: 0 on success, else -ENOMEM
 *
 * In sg_list->sg a pointer to the created scatter-gather list is returned,
 * or NULL if we run out of memory. sg_list->count specifies the number of
 * elements of the scatter-gather list. The maximum size of a single element
 * in the scatter-gather list is PAGE_SIZE.
 */
static int
zfcp_sg_list_alloc(struct zfcp_sg_list *sg_list, size_t size)
{
        struct scatterlist *sg;
        unsigned int i;
        int retval = 0;
        void *address;

        BUG_ON(sg_list == NULL);

        sg_list->count = size >> PAGE_SHIFT;
        if (size & ~PAGE_MASK)
                sg_list->count++;
        sg_list->sg = kcalloc(sg_list->count, sizeof(struct scatterlist),
                              GFP_KERNEL);
        if (sg_list->sg == NULL) {
                sg_list->count = 0;
                retval = -ENOMEM;
                goto out;
        }

        for (i = 0, sg = sg_list->sg; i < sg_list->count; i++, sg++) {
                sg->length = min(size, PAGE_SIZE);
                sg->offset = 0;
                address = (void *) get_zeroed_page(GFP_KERNEL);
                if (address == NULL) {
                        sg_list->count = i;
                        zfcp_sg_list_free(sg_list);
                        retval = -ENOMEM;
                        goto out;
                }
                zfcp_address_to_sg(address, sg);
                size -= sg->length;
        }

 out:
        return retval;
}


/**
 * zfcp_sg_list_free - free memory of a scatter-gather list
 * @sg_list: structure describing a scatter-gather list
 *
 * Memory for each element in the scatter-gather list is freed.
 * Finally sg_list->sg is freed itself and sg_list->count is reset.
 */
static void
zfcp_sg_list_free(struct zfcp_sg_list *sg_list)
{
        struct scatterlist *sg;
        unsigned int i;

        BUG_ON(sg_list == NULL);

        for (i = 0, sg = sg_list->sg; i < sg_list->count; i++, sg++)
                free_page((unsigned long) zfcp_sg_to_address(sg));

        sg_list->count = 0;
        kfree(sg_list->sg);
}

/**
 * zfcp_sg_size - determine size of a scatter-gather list
 * @sg: array of (struct scatterlist)
 * @sg_count: elements in array
 * Return: size of entire scatter-gather list
 */
static size_t zfcp_sg_size(struct scatterlist *sg, unsigned int sg_count)
{
        unsigned int i;
        struct scatterlist *p;
        size_t size;

        size = 0;
        for (i = 0, p = sg; i < sg_count; i++, p++) {
                BUG_ON(p == NULL);
                size += p->length;
        }

        return size;
}


/**
 * zfcp_sg_list_copy_from_user -copy data from user space to scatter-gather list
 * @sg_list: structure describing a scatter-gather list
 * @user_buffer: pointer to buffer in user space
 * @size: number of bytes to be copied
 * Return: 0 on success, -EFAULT if copy_from_user fails.
 */
static int
zfcp_sg_list_copy_from_user(struct zfcp_sg_list *sg_list,
                            void __user *user_buffer,
                            size_t size)
{
        struct scatterlist *sg;
        unsigned int length;
        void *zfcp_buffer;
        int retval = 0;

        BUG_ON(sg_list == NULL);

        if (zfcp_sg_size(sg_list->sg, sg_list->count) < size)
                return -EFAULT;

        for (sg = sg_list->sg; size > 0; sg++) {
                length = min((unsigned int)size, sg->length);
                zfcp_buffer = zfcp_sg_to_address(sg);
                if (copy_from_user(zfcp_buffer, user_buffer, length)) {
                        retval = -EFAULT;
                        goto out;
                }
                user_buffer += length;
                size -= length;
        }

 out:
        return retval;
}


/**
 * zfcp_sg_list_copy_to_user - copy data from scatter-gather list to user space
 * @user_buffer: pointer to buffer in user space
 * @sg_list: structure describing a scatter-gather list
 * @size: number of bytes to be copied
 * Return: 0 on success, -EFAULT if copy_to_user fails
 */
static int
zfcp_sg_list_copy_to_user(void __user  *user_buffer,
                          struct zfcp_sg_list *sg_list,
                          size_t size)
{
        struct scatterlist *sg;
        unsigned int length;
        void *zfcp_buffer;
        int retval = 0;

        BUG_ON(sg_list == NULL);

        if (zfcp_sg_size(sg_list->sg, sg_list->count) < size)
                return -EFAULT;

        for (sg = sg_list->sg; size > 0; sg++) {
                length = min((unsigned int) size, sg->length);
                zfcp_buffer = zfcp_sg_to_address(sg);
                if (copy_to_user(user_buffer, zfcp_buffer, length)) {
                        retval = -EFAULT;
                        goto out;
                }
                user_buffer += length;
                size -= length;
        }

 out:
        return retval;
}


#undef ZFCP_LOG_AREA

/****************************************************************/
/****** Functions for configuration/set-up of structures ********/
/****************************************************************/

#define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_CONFIG

/**
 * zfcp_get_unit_by_lun - find unit in unit list of port by FCP LUN
 * @port: pointer to port to search for unit
 * @fcp_lun: FCP LUN to search for
 * Traverse list of all units of a port and return pointer to a unit
 * with the given FCP LUN.
 */
struct zfcp_unit *
zfcp_get_unit_by_lun(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
        struct zfcp_unit *unit;
        int found = 0;

        list_for_each_entry(unit, &port->unit_list_head, list) {
                if ((unit->fcp_lun == fcp_lun) &&
                    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status))
                {
                        found = 1;
                        break;
                }
        }
        return found ? unit : NULL;
}

/**
 * zfcp_get_port_by_wwpn - find port in port list of adapter by wwpn
 * @adapter: pointer to adapter to search for port
 * @wwpn: wwpn to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given wwpn.
 */
struct zfcp_port *
zfcp_get_port_by_wwpn(struct zfcp_adapter *adapter, wwn_t wwpn)
{
        struct zfcp_port *port;
        int found = 0;

        list_for_each_entry(port, &adapter->port_list_head, list) {
                if ((port->wwpn == wwpn) &&
                    !(atomic_read(&port->status) &
                      (ZFCP_STATUS_PORT_NO_WWPN | ZFCP_STATUS_COMMON_REMOVE))) {
                        found = 1;
                        break;
                }
        }
        return found ? port : NULL;
}

/**
 * zfcp_get_port_by_did - find port in port list of adapter by d_id
 * @adapter: pointer to adapter to search for port
 * @d_id: d_id to search for
 * Traverse list of all ports of an adapter and return pointer to a port
 * with the given d_id.
 */
struct zfcp_port *
zfcp_get_port_by_did(struct zfcp_adapter *adapter, u32 d_id)
{
        struct zfcp_port *port;
        int found = 0;

        list_for_each_entry(port, &adapter->port_list_head, list) {
                if ((port->d_id == d_id) &&
                    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status))
                {
                        found = 1;
                        break;
                }
        }
        return found ? port : NULL;
}

/**
 * zfcp_get_adapter_by_busid - find adpater in adapter list by bus_id
 * @bus_id: bus_id to search for
 * Traverse list of all adapters and return pointer to an adapter
 * with the given bus_id.
 */
struct zfcp_adapter *
zfcp_get_adapter_by_busid(char *bus_id)
{
        struct zfcp_adapter *adapter;
        int found = 0;

        list_for_each_entry(adapter, &zfcp_data.adapter_list_head, list) {
                if ((strncmp(bus_id, zfcp_get_busid_by_adapter(adapter),
                             BUS_ID_SIZE) == 0) &&
                    !atomic_test_mask(ZFCP_STATUS_COMMON_REMOVE,
                                      &adapter->status)){
                        found = 1;
                        break;
                }
        }
        return found ? adapter : NULL;
}

/**
 * zfcp_unit_enqueue - enqueue unit to unit list of a port.
 * @port: pointer to port where unit is added
 * @fcp_lun: FCP LUN of unit to be enqueued
 * Return: pointer to enqueued unit on success, NULL on error
 * Locks: config_sema must be held to serialize changes to the unit list
 *
 * Sets up some unit internal structures and creates sysfs entry.
 */
struct zfcp_unit *
zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
{
        struct zfcp_unit *unit;

        /*
         * check that there is no unit with this FCP_LUN already in list
         * and enqueue it.
         * Note: Unlike for the adapter and the port, this is an error
         */
        read_lock_irq(&zfcp_data.config_lock);
        unit = zfcp_get_unit_by_lun(port, fcp_lun);
        read_unlock_irq(&zfcp_data.config_lock);
        if (unit)
                return NULL;

        unit = kzalloc(sizeof (struct zfcp_unit), GFP_KERNEL);
        if (!unit)
                return NULL;

        /* initialise reference count stuff */
        atomic_set(&unit->refcount, 0);
        init_waitqueue_head(&unit->remove_wq);

        unit->port = port;
        unit->fcp_lun = fcp_lun;

        /* setup for sysfs registration */
        snprintf(unit->sysfs_device.bus_id, BUS_ID_SIZE, "0x%016llx", fcp_lun);
        unit->sysfs_device.parent = &port->sysfs_device;
        unit->sysfs_device.release = zfcp_sysfs_unit_release;
        dev_set_drvdata(&unit->sysfs_device, unit);

        init_waitqueue_head(&unit->scsi_scan_wq);

        /* mark unit unusable as long as sysfs registration is not complete */
        atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);

        if (device_register(&unit->sysfs_device)) {
                kfree(unit);
                return NULL;
        }

        if (zfcp_sysfs_unit_create_files(&unit->sysfs_device)) {
                device_unregister(&unit->sysfs_device);
                return NULL;
        }

        zfcp_unit_get(unit);
        unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);

        write_lock_irq(&zfcp_data.config_lock);
        list_add_tail(&unit->list, &port->unit_list_head);
        atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
        atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
        write_unlock_irq(&zfcp_data.config_lock);

        port->units++;
        zfcp_port_get(port);

        return unit;
}

void
zfcp_unit_dequeue(struct zfcp_unit *unit)
{
        zfcp_unit_wait(unit);
        write_lock_irq(&zfcp_data.config_lock);
        list_del(&unit->list);
        write_unlock_irq(&zfcp_data.config_lock);
        unit->port->units--;
        zfcp_port_put(unit->port);
        zfcp_sysfs_unit_remove_files(&unit->sysfs_device);
        device_unregister(&unit->sysfs_device);
}

/*
 * Allocates a combined QTCB/fsf_req buffer for erp actions and fcp/SCSI
 * commands.
 * It also genrates fcp-nameserver request/response buffer and unsolicited 
 * status read fsf_req buffers.
 *
 * locks:       must only be called with zfcp_data.config_sema taken
 */
static int
zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
{
        adapter->pool.fsf_req_erp =
                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ERP_NR,
                                         zfcp_data.fsf_req_qtcb_cache);
        if (!adapter->pool.fsf_req_erp)
                return -ENOMEM;

        adapter->pool.fsf_req_scsi =
                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_SCSI_NR,
                                         zfcp_data.fsf_req_qtcb_cache);
        if (!adapter->pool.fsf_req_scsi)
                return -ENOMEM;

        adapter->pool.fsf_req_abort =
                mempool_create_slab_pool(ZFCP_POOL_FSF_REQ_ABORT_NR,
                                         zfcp_data.fsf_req_qtcb_cache);
        if (!adapter->pool.fsf_req_abort)
                return -ENOMEM;

        adapter->pool.fsf_req_status_read =
                mempool_create_kmalloc_pool(ZFCP_POOL_STATUS_READ_NR,
                                            sizeof(struct zfcp_fsf_req));
        if (!adapter->pool.fsf_req_status_read)
                return -ENOMEM;

        adapter->pool.data_status_read =
                mempool_create_slab_pool(ZFCP_POOL_STATUS_READ_NR,
                                         zfcp_data.sr_buffer_cache);
        if (!adapter->pool.data_status_read)
                return -ENOMEM;

        adapter->pool.data_gid_pn =
                mempool_create_slab_pool(ZFCP_POOL_DATA_GID_PN_NR,
                                         zfcp_data.gid_pn_cache);
        if (!adapter->pool.data_gid_pn)
                return -ENOMEM;

        return 0;
}

/**
 * zfcp_free_low_mem_buffers - free memory pools of an adapter
 * @adapter: pointer to zfcp_adapter for which memory pools should be freed
 * locking:  zfcp_data.config_sema must be held
 */
static void
zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
{
        if (adapter->pool.fsf_req_erp)
                mempool_destroy(adapter->pool.fsf_req_erp);
        if (adapter->pool.fsf_req_scsi)
                mempool_destroy(adapter->pool.fsf_req_scsi);
        if (adapter->pool.fsf_req_abort)
                mempool_destroy(adapter->pool.fsf_req_abort);
        if (adapter->pool.fsf_req_status_read)
                mempool_destroy(adapter->pool.fsf_req_status_read);
        if (adapter->pool.data_status_read)
                mempool_destroy(adapter->pool.data_status_read);
        if (adapter->pool.data_gid_pn)
                mempool_destroy(adapter->pool.data_gid_pn);
}

static void zfcp_dummy_release(struct device *dev)
{
        return;
}

/*
 * Enqueues an adapter at the end of the adapter list in the driver data.
 * All adapter internal structures are set up.
 * Proc-fs entries are also created.
 *
 * returns:     0             if a new adapter was successfully enqueued
 *              ZFCP_KNOWN    if an adapter with this devno was already present
 *              -ENOMEM       if alloc failed
 * locks:       config_sema must be held to serialise changes to the adapter list
 */
struct zfcp_adapter *
zfcp_adapter_enqueue(struct ccw_device *ccw_device)
{
        int retval = 0;
        struct zfcp_adapter *adapter;

        /*
         * Note: It is safe to release the list_lock, as any list changes 
         * are protected by the config_sema, which must be held to get here
         */

        /* try to allocate new adapter data structure (zeroed) */
        adapter = kzalloc(sizeof (struct zfcp_adapter), GFP_KERNEL);
        if (!adapter) {
                ZFCP_LOG_INFO("error: allocation of base adapter "
                              "structure failed\n");
                goto out;
        }

        ccw_device->handler = NULL;

        /* save ccw_device pointer */
        adapter->ccw_device = ccw_device;

        retval = zfcp_qdio_allocate_queues(adapter);
        if (retval)
                goto queues_alloc_failed;

        retval = zfcp_qdio_allocate(adapter);
        if (retval)
                goto qdio_allocate_failed;

        retval = zfcp_allocate_low_mem_buffers(adapter);
        if (retval) {
                ZFCP_LOG_INFO("error: pool allocation failed\n");
                goto failed_low_mem_buffers;
        }

        /* initialise reference count stuff */
        atomic_set(&adapter->refcount, 0);
        init_waitqueue_head(&adapter->remove_wq);

        /* initialise list of ports */
        INIT_LIST_HEAD(&adapter->port_list_head);

        /* initialise list of ports to be removed */
        INIT_LIST_HEAD(&adapter->port_remove_lh);

        /* initialize list of fsf requests */
        spin_lock_init(&adapter->req_list_lock);
        retval = zfcp_reqlist_alloc(adapter);
        if (retval) {
                ZFCP_LOG_INFO("request list initialization failed\n");
                goto failed_low_mem_buffers;
        }

        /* initialize debug locks */

        spin_lock_init(&adapter->erp_dbf_lock);
        spin_lock_init(&adapter->hba_dbf_lock);
        spin_lock_init(&adapter->san_dbf_lock);
        spin_lock_init(&adapter->scsi_dbf_lock);

        /* initialize error recovery stuff */

        rwlock_init(&adapter->erp_lock);
        sema_init(&adapter->erp_ready_sem, 0);
        INIT_LIST_HEAD(&adapter->erp_ready_head);
        INIT_LIST_HEAD(&adapter->erp_running_head);

        /* initialize abort lock */
        rwlock_init(&adapter->abort_lock);

        /* initialise some erp stuff */
        init_waitqueue_head(&adapter->erp_thread_wqh);
        init_waitqueue_head(&adapter->erp_done_wqh);

        /* initialize lock of associated request queue */
        rwlock_init(&adapter->request_queue.queue_lock);

        /* mark adapter unusable as long as sysfs registration is not complete */
        atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);

        adapter->ccw_device = ccw_device;
        dev_set_drvdata(&ccw_device->dev, adapter);

        if (zfcp_sysfs_adapter_create_files(&ccw_device->dev))
                goto sysfs_failed;

        adapter->generic_services.parent = &adapter->ccw_device->dev;
        adapter->generic_services.release = zfcp_dummy_release;
        snprintf(adapter->generic_services.bus_id, BUS_ID_SIZE,
                 "generic_services");

        if (device_register(&adapter->generic_services))
                goto generic_services_failed;

        /* put allocated adapter at list tail */
        write_lock_irq(&zfcp_data.config_lock);
        atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
        list_add_tail(&adapter->list, &zfcp_data.adapter_list_head);
        write_unlock_irq(&zfcp_data.config_lock);

        zfcp_data.adapters++;

        goto out;

 generic_services_failed:
        zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);
 sysfs_failed:
        dev_set_drvdata(&ccw_device->dev, NULL);
        zfcp_reqlist_free(adapter);
 failed_low_mem_buffers:
        zfcp_free_low_mem_buffers(adapter);
        if (qdio_free(ccw_device) != 0)
                ZFCP_LOG_NORMAL("bug: qdio_free for adapter %s failed\n",
                                zfcp_get_busid_by_adapter(adapter));
 qdio_allocate_failed:
        zfcp_qdio_free_queues(adapter);
 queues_alloc_failed:
        kfree(adapter);
        adapter = NULL;
 out:
        return adapter;
}

/*
 * returns:     0 - struct zfcp_adapter  data structure successfully removed
 *              !0 - struct zfcp_adapter  data structure could not be removed
 *                      (e.g. still used)
 * locks:       adapter list write lock is assumed to be held by caller
 */
void
zfcp_adapter_dequeue(struct zfcp_adapter *adapter)
{
        int retval = 0;
        unsigned long flags;

        zfcp_adapter_scsi_unregister(adapter);
        device_unregister(&adapter->generic_services);
        zfcp_sysfs_adapter_remove_files(&adapter->ccw_device->dev);
        dev_set_drvdata(&adapter->ccw_device->dev, NULL);
        /* sanity check: no pending FSF requests */
        spin_lock_irqsave(&adapter->req_list_lock, flags);
        retval = zfcp_reqlist_isempty(adapter);
        spin_unlock_irqrestore(&adapter->req_list_lock, flags);
        if (!retval) {
                ZFCP_LOG_NORMAL("bug: adapter %s (%p) still in use, "
                                "%i requests outstanding\n",
                                zfcp_get_busid_by_adapter(adapter), adapter,
                                atomic_read(&adapter->reqs_active));
                retval = -EBUSY;
                goto out;
        }

        /* remove specified adapter data structure from list */
        write_lock_irq(&zfcp_data.config_lock);
        list_del(&adapter->list);
        write_unlock_irq(&zfcp_data.config_lock);

        /* decrease number of adapters in list */
        zfcp_data.adapters--;

        ZFCP_LOG_TRACE("adapter %s (%p) removed from list, "
                       "%i adapters still in list\n",
                       zfcp_get_busid_by_adapter(adapter),
                       adapter, zfcp_data.adapters);

        retval = qdio_free(adapter->ccw_device);
        if (retval)
                ZFCP_LOG_NORMAL("bug: qdio_free for adapter %s failed\n",
                                zfcp_get_busid_by_adapter(adapter));

        zfcp_free_low_mem_buffers(adapter);
        /* free memory of adapter data structure and queues */
        zfcp_qdio_free_queues(adapter);
        zfcp_reqlist_free(adapter);
        kfree(adapter->fc_stats);
        kfree(adapter->stats_reset_data);
        ZFCP_LOG_TRACE("freeing adapter structure\n");
        kfree(adapter);
 out:
        return;
}

/**
 * zfcp_port_enqueue - enqueue port to port list of adapter
 * @adapter: adapter where remote port is added
 * @wwpn: WWPN of the remote port to be enqueued
 * @status: initial status for the port
 * @d_id: destination id of the remote port to be enqueued
 * Return: pointer to enqueued port on success, NULL on error
 * Locks: config_sema must be held to serialize changes to the port list
 *
 * All port internal structures are set up and the sysfs entry is generated.
 * d_id is used to enqueue ports with a well known address like the Directory
 * Service for nameserver lookup.
 */
struct zfcp_port *
zfcp_port_enqueue(struct zfcp_adapter *adapter, wwn_t wwpn, u32 status,
                  u32 d_id)
{
        struct zfcp_port *port;
        int check_wwpn;

        check_wwpn = !(status & ZFCP_STATUS_PORT_NO_WWPN);
        /*
         * check that there is no port with this WWPN already in list
         */
        if (check_wwpn) {
                read_lock_irq(&zfcp_data.config_lock);
                port = zfcp_get_port_by_wwpn(adapter, wwpn);
                read_unlock_irq(&zfcp_data.config_lock);
                if (port)
                        return NULL;
        }

        port = kzalloc(sizeof (struct zfcp_port), GFP_KERNEL);
        if (!port)
                return NULL;

        /* initialise reference count stuff */
        atomic_set(&port->refcount, 0);
        init_waitqueue_head(&port->remove_wq);

        INIT_LIST_HEAD(&port->unit_list_head);
        INIT_LIST_HEAD(&port->unit_remove_lh);

        port->adapter = adapter;

        if (check_wwpn)
                port->wwpn = wwpn;

        atomic_set_mask(status, &port->status);

        /* setup for sysfs registration */
        if (status & ZFCP_STATUS_PORT_WKA) {
                switch (d_id) {
                case ZFCP_DID_DIRECTORY_SERVICE:
                        snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
                                 "directory");
                        break;
                case ZFCP_DID_MANAGEMENT_SERVICE:
                        snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
                                 "management");
                        break;
                case ZFCP_DID_KEY_DISTRIBUTION_SERVICE:
                        snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
                                 "key_distribution");
                        break;
                case ZFCP_DID_ALIAS_SERVICE:
                        snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
                                 "alias");
                        break;
                case ZFCP_DID_TIME_SERVICE:
                        snprintf(port->sysfs_device.bus_id, BUS_ID_SIZE,
                                 "time");
                        break;
                default:
                        kfree(port);
                        return NULL;
                }
                port->d_id = d_id;
                port->sysfs_device.parent = &adapter->generic_services;
        } else {
                snprintf(port->sysfs_device.bus_id,
                         BUS_ID_SIZE, "0x%016llx", wwpn);
                port->sysfs_device.parent = &adapter->ccw_device->dev;
        }
        port->sysfs_device.release = zfcp_sysfs_port_release;
        dev_set_drvdata(&port->sysfs_device, port);

        /* mark port unusable as long as sysfs registration is not complete */
        atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);

        if (device_register(&port->sysfs_device)) {
                kfree(port);
                return NULL;
        }

        if (zfcp_sysfs_port_create_files(&port->sysfs_device, status)) {
                device_unregister(&port->sysfs_device);
                return NULL;
        }

        zfcp_port_get(port);

        write_lock_irq(&zfcp_data.config_lock);
        list_add_tail(&port->list, &adapter->port_list_head);
        atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
        atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &port->status);
        if (d_id == ZFCP_DID_DIRECTORY_SERVICE)
                if (!adapter->nameserver_port)
                        adapter->nameserver_port = port;
        adapter->ports++;
        write_unlock_irq(&zfcp_data.config_lock);

        zfcp_adapter_get(adapter);

        return port;
}

void
zfcp_port_dequeue(struct zfcp_port *port)
{
        zfcp_port_wait(port);
        write_lock_irq(&zfcp_data.config_lock);
        list_del(&port->list);
        port->adapter->ports--;
        write_unlock_irq(&zfcp_data.config_lock);
        if (port->rport)
                fc_remote_port_delete(port->rport);
        port->rport = NULL;
        zfcp_adapter_put(port->adapter);
        zfcp_sysfs_port_remove_files(&port->sysfs_device,
                                     atomic_read(&port->status));
        device_unregister(&port->sysfs_device);
}

/* Enqueues a nameserver port */
int
zfcp_nameserver_enqueue(struct zfcp_adapter *adapter)
{
        struct zfcp_port *port;

        port = zfcp_port_enqueue(adapter, 0, ZFCP_STATUS_PORT_WKA,
                                 ZFCP_DID_DIRECTORY_SERVICE);
        if (!port) {
                ZFCP_LOG_INFO("error: enqueue of nameserver port for "
                              "adapter %s failed\n",
                              zfcp_get_busid_by_adapter(adapter));
                return -ENXIO;
        }
        zfcp_port_put(port);

        return 0;
}

#undef ZFCP_LOG_AREA

/****************************************************************/
/******* Fibre Channel Standard related Functions  **************/
/****************************************************************/

#define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_FC

static void
zfcp_fsf_incoming_els_rscn(struct zfcp_adapter *adapter,
                           struct fsf_status_read_buffer *status_buffer)
{
        struct fcp_rscn_head *fcp_rscn_head;
        struct fcp_rscn_element *fcp_rscn_element;
        struct zfcp_port *port;
        u16 i;
        u16 no_entries;
        u32 range_mask;
        unsigned long flags;

        fcp_rscn_head = (struct fcp_rscn_head *) status_buffer->payload;
        fcp_rscn_element = (struct fcp_rscn_element *) status_buffer->payload;

        /* see FC-FS */
        no_entries = (fcp_rscn_head->payload_len / 4);

        for (i = 1; i < no_entries; i++) {
                /* skip head and start with 1st element */
                fcp_rscn_element++;
                switch (fcp_rscn_element->addr_format) {
                case ZFCP_PORT_ADDRESS:
                        range_mask = ZFCP_PORTS_RANGE_PORT;
                        break;
                case ZFCP_AREA_ADDRESS:
                        range_mask = ZFCP_PORTS_RANGE_AREA;
                        break;
                case ZFCP_DOMAIN_ADDRESS:
                        range_mask = ZFCP_PORTS_RANGE_DOMAIN;
                        break;
                case ZFCP_FABRIC_ADDRESS:
                        range_mask = ZFCP_PORTS_RANGE_FABRIC;
                        break;
                default:
                        ZFCP_LOG_INFO("incoming RSCN with unknown "
                                      "address format\n");
                        continue;
                }
                read_lock_irqsave(&zfcp_data.config_lock, flags);
                list_for_each_entry(port, &adapter->port_list_head, list) {
                        if (atomic_test_mask
                            (ZFCP_STATUS_PORT_WKA, &port->status))
                                continue;
                        /* Do we know this port? If not skip it. */
                        if (!atomic_test_mask
                            (ZFCP_STATUS_PORT_DID_DID, &port->status)) {
                                ZFCP_LOG_INFO("incoming RSCN, trying to open "
                                              "port 0x%016Lx\n", port->wwpn);
                                zfcp_erp_port_reopen(port,
                                                     ZFCP_STATUS_COMMON_ERP_FAILED);
                                continue;
                        }

                        /*
                         * FIXME: race: d_id might being invalidated
                         * (...DID_DID reset)
                         */
                        if ((port->d_id & range_mask)
                            == (fcp_rscn_element->nport_did & range_mask)) {
                                ZFCP_LOG_TRACE("reopen did 0x%08x\n",
                                               fcp_rscn_element->nport_did);
                                /*
                                 * Unfortunately, an RSCN does not specify the
                                 * type of change a target underwent. We assume
                                 * that it makes sense to reopen the link.
                                 * FIXME: Shall we try to find out more about
                                 * the target and link state before closing it?
                                 * How to accomplish this? (nameserver?)
                                 * Where would such code be put in?
                                 * (inside or outside erp)
                                 */
                                ZFCP_LOG_INFO("incoming RSCN, trying to open "
                                              "port 0x%016Lx\n", port->wwpn);
                                zfcp_test_link(port);
                        }
                }
                read_unlock_irqrestore(&zfcp_data.config_lock, flags);
        }
}

static void
zfcp_fsf_incoming_els_plogi(struct zfcp_adapter *adapter,
                            struct fsf_status_read_buffer *status_buffer)
{
        struct fsf_plogi *els_plogi;
        struct zfcp_port *port;
        unsigned long flags;

        els_plogi = (struct fsf_plogi *) status_buffer->payload;
        read_lock_irqsave(&zfcp_data.config_lock, flags);
        list_for_each_entry(port, &adapter->port_list_head, list) {
                if (port->wwpn == (*(wwn_t *) &els_plogi->serv_param.wwpn))
                        break;
        }
        read_unlock_irqrestore(&zfcp_data.config_lock, flags);

        if (!port || (port->wwpn != (*(wwn_t *) &els_plogi->serv_param.wwpn))) {
                ZFCP_LOG_DEBUG("ignored incoming PLOGI for nonexisting port "
                               "with d_id 0x%06x on adapter %s\n",
                               status_buffer->d_id,
                               zfcp_get_busid_by_adapter(adapter));
        } else {
                zfcp_erp_port_forced_reopen(port, 0);
        }
}

static void
zfcp_fsf_incoming_els_logo(struct zfcp_adapter *adapter,
                           struct fsf_status_read_buffer *status_buffer)
{
        struct fcp_logo *els_logo = (struct fcp_logo *) status_buffer->payload;
        struct zfcp_port *port;
        unsigned long flags;

        read_lock_irqsave(&zfcp_data.config_lock, flags);
        list_for_each_entry(port, &adapter->port_list_head, list) {
                if (port->wwpn == els_logo->nport_wwpn)
                        break;
        }
        read_unlock_irqrestore(&zfcp_data.config_lock, flags);

        if (!port || (port->wwpn != els_logo->nport_wwpn)) {
                ZFCP_LOG_DEBUG("ignored incoming LOGO for nonexisting port "
                               "with d_id 0x%06x on adapter %s\n",
                               status_buffer->d_id,
                               zfcp_get_busid_by_adapter(adapter));
        } else {
                zfcp_erp_port_forced_reopen(port, 0);
        }
}

static void
zfcp_fsf_incoming_els_unknown(struct zfcp_adapter *adapter,
                              struct fsf_status_read_buffer *status_buffer)
{
        ZFCP_LOG_NORMAL("warning: unknown incoming ELS 0x%08x "
                        "for adapter %s\n", *(u32 *) (status_buffer->payload),
                        zfcp_get_busid_by_adapter(adapter));

}

void
zfcp_fsf_incoming_els(struct zfcp_fsf_req *fsf_req)
{
        struct fsf_status_read_buffer *status_buffer;
        u32 els_type;
        struct zfcp_adapter *adapter;

        status_buffer = (struct fsf_status_read_buffer *) fsf_req->data;
        els_type = *(u32 *) (status_buffer->payload);
        adapter = fsf_req->adapter;

        zfcp_san_dbf_event_incoming_els(fsf_req);
        if (els_type == LS_PLOGI)
                zfcp_fsf_incoming_els_plogi(adapter, status_buffer);
        else if (els_type == LS_LOGO)
                zfcp_fsf_incoming_els_logo(adapter, status_buffer);
        else if ((els_type & 0xffff0000) == LS_RSCN)
                /* we are only concerned with the command, not the length */
                zfcp_fsf_incoming_els_rscn(adapter, status_buffer);
        else
                zfcp_fsf_incoming_els_unknown(adapter, status_buffer);
}


/**
 * zfcp_gid_pn_buffers_alloc - allocate buffers for GID_PN nameserver request
 * @gid_pn: pointer to return pointer to struct zfcp_gid_pn_data
 * @pool: pointer to mempool_t if non-null memory pool is used for allocation
 */
static int
zfcp_gid_pn_buffers_alloc(struct zfcp_gid_pn_data **gid_pn, mempool_t *pool)
{
        struct zfcp_gid_pn_data *data;

        if (pool != NULL) {
                data = mempool_alloc(pool, GFP_ATOMIC);
                if (likely(data != NULL)) {
                        data->ct.pool = pool;
                }
        } else {
                data = kmalloc(sizeof(struct zfcp_gid_pn_data), GFP_ATOMIC);
        }

        if (NULL == data)
                return -ENOMEM;

        memset(data, 0, sizeof(*data));
        data->ct.req = &data->req;
        data->ct.resp = &data->resp;
        data->ct.req_count = data->ct.resp_count = 1;
        zfcp_address_to_sg(&data->ct_iu_req, &data->req);
        zfcp_address_to_sg(&data->ct_iu_resp, &data->resp);
        data->req.length = sizeof(struct ct_iu_gid_pn_req);
        data->resp.length = sizeof(struct ct_iu_gid_pn_resp);

        *gid_pn = data;
        return 0;
}

/**
 * zfcp_gid_pn_buffers_free - free buffers for GID_PN nameserver request
 * @gid_pn: pointer to struct zfcp_gid_pn_data which has to be freed
 */
static void zfcp_gid_pn_buffers_free(struct zfcp_gid_pn_data *gid_pn)
{
        if (gid_pn->ct.pool)
                mempool_free(gid_pn, gid_pn->ct.pool);
        else
                kfree(gid_pn);
}

/**
 * zfcp_ns_gid_pn_request - initiate GID_PN nameserver request
 * @erp_action: pointer to zfcp_erp_action where GID_PN request is needed
 */
int
zfcp_ns_gid_pn_request(struct zfcp_erp_action *erp_action)
{
        int ret;
        struct ct_iu_gid_pn_req *ct_iu_req;
        struct zfcp_gid_pn_data *gid_pn;
        struct zfcp_adapter *adapter = erp_action->adapter;

        ret = zfcp_gid_pn_buffers_alloc(&gid_pn, adapter->pool.data_gid_pn);
        if (ret < 0) {
                ZFCP_LOG_INFO("error: buffer allocation for gid_pn nameserver "
                              "request failed for adapter %s\n",
                              zfcp_get_busid_by_adapter(adapter));
                goto out;
        }

        /* setup nameserver request */
        ct_iu_req = zfcp_sg_to_address(gid_pn->ct.req);
        ct_iu_req->header.revision = ZFCP_CT_REVISION;
        ct_iu_req->header.gs_type = ZFCP_CT_DIRECTORY_SERVICE;
        ct_iu_req->header.gs_subtype = ZFCP_CT_NAME_SERVER;
        ct_iu_req->header.options = ZFCP_CT_SYNCHRONOUS;
        ct_iu_req->header.cmd_rsp_code = ZFCP_CT_GID_PN;
        ct_iu_req->header.max_res_size = ZFCP_CT_MAX_SIZE;
        ct_iu_req->wwpn = erp_action->port->wwpn;

        /* setup parameters for send generic command */
        gid_pn->ct.port = adapter->nameserver_port;
        gid_pn->ct.handler = zfcp_ns_gid_pn_handler;
        gid_pn->ct.handler_data = (unsigned long) gid_pn;
        gid_pn->ct.timeout = ZFCP_NS_GID_PN_TIMEOUT;
        gid_pn->port = erp_action->port;

        ret = zfcp_fsf_send_ct(&gid_pn->ct, adapter->pool.fsf_req_erp,
                               erp_action);
        if (ret) {
                ZFCP_LOG_INFO("error: initiation of gid_pn nameserver request "
                              "failed for adapter %s\n",
                              zfcp_get_busid_by_adapter(adapter));

                zfcp_gid_pn_buffers_free(gid_pn);
        }

 out:
        return ret;
}

/**
 * zfcp_ns_gid_pn_handler - handler for GID_PN nameserver request
 * @data: unsigned long, contains pointer to struct zfcp_gid_pn_data
 */
static void zfcp_ns_gid_pn_handler(unsigned long data)
{
        struct zfcp_port *port;
        struct zfcp_send_ct *ct;
        struct ct_iu_gid_pn_req *ct_iu_req;
        struct ct_iu_gid_pn_resp *ct_iu_resp;
        struct zfcp_gid_pn_data *gid_pn;


        gid_pn = (struct zfcp_gid_pn_data *) data;
        port = gid_pn->port;
        ct = &gid_pn->ct;
        ct_iu_req = zfcp_sg_to_address(ct->req);
        ct_iu_resp = zfcp_sg_to_address(ct->resp);

        if (ct->status != 0)
                goto failed;

        if (zfcp_check_ct_response(&ct_iu_resp->header)) {
                /* FIXME: do we need some specific erp entry points */
                atomic_set_mask(ZFCP_STATUS_PORT_INVALID_WWPN, &port->status);
                goto failed;
        }
        /* paranoia */
        if (ct_iu_req->wwpn != port->wwpn) {
                ZFCP_LOG_NORMAL("bug: wwpn 0x%016Lx returned by nameserver "
                                "lookup does not match expected wwpn 0x%016Lx "
                                "for adapter %s\n", ct_iu_req->wwpn, port->wwpn,
                                zfcp_get_busid_by_port(port));
                goto mismatch;
        }

        /* looks like a valid d_id */
        port->d_id = ct_iu_resp->d_id & ZFCP_DID_MASK;
        atomic_set_mask(ZFCP_STATUS_PORT_DID_DID, &port->status);
        ZFCP_LOG_DEBUG("adapter %s:  wwpn=0x%016Lx ---> d_id=0x%06x\n",
                       zfcp_get_busid_by_port(port), port->wwpn, port->d_id);
        goto out;

 mismatch:
        ZFCP_LOG_DEBUG("CT IUs do not match:\n");
        ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_DEBUG, (char *) ct_iu_req,
                      sizeof(struct ct_iu_gid_pn_req));
        ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_DEBUG, (char *) ct_iu_resp,
                      sizeof(struct ct_iu_gid_pn_resp));

 failed:
        ZFCP_LOG_NORMAL("warning: failed gid_pn nameserver request for wwpn "
                        "0x%016Lx for adapter %s\n",
                        port->wwpn, zfcp_get_busid_by_port(port));
 out:
        zfcp_gid_pn_buffers_free(gid_pn);
        return;
}

/* reject CT_IU reason codes acc. to FC-GS-4 */
static const struct zfcp_rc_entry zfcp_ct_rc[] = {
        {0x01, "invalid command code"},
        {0x02, "invalid version level"},
        {0x03, "logical error"},
        {0x04, "invalid CT_IU size"},
        {0x05, "logical busy"},
        {0x07, "protocol error"},
        {0x09, "unable to perform command request"},
        {0x0b, "command not supported"},
        {0x0d, "server not available"},
        {0x0e, "session could not be established"},
        {0xff, "vendor specific error"},
        {0, NULL},
};

/* LS_RJT reason codes acc. to FC-FS */
static const struct zfcp_rc_entry zfcp_ls_rjt_rc[] = {
        {0x01, "invalid LS_Command code"},
        {0x03, "logical error"},
        {0x05, "logical busy"},
        {0x07, "protocol error"},
        {0x09, "unable to perform command request"},
        {0x0b, "command not supported"},
        {0x0e, "command already in progress"},
        {0xff, "vendor specific error"},
        {0, NULL},
};

/* reject reason codes according to FC-PH/FC-FS */
static const struct zfcp_rc_entry zfcp_p_rjt_rc[] = {
        {0x01, "invalid D_ID"},
        {0x02, "invalid S_ID"},
        {0x03, "Nx_Port not available, temporary"},
        {0x04, "Nx_Port not available, permament"},
        {0x05, "class not supported"},
        {0x06, "delimiter usage error"},
        {0x07, "TYPE not supported"},
        {0x08, "invalid Link_Control"},
        {0x09, "invalid R_CTL field"},
        {0x0a, "invalid F_CTL field"},
        {0x0b, "invalid OX_ID"},
        {0x0c, "invalid RX_ID"},
        {0x0d, "invalid SEQ_ID"},
        {0x0e, "invalid DF_CTL"},
        {0x0f, "invalid SEQ_CNT"},
        {0x10, "invalid parameter field"},
        {0x11, "exchange error"},
        {0x12, "protocol error"},
        {0x13, "incorrect length"},
        {0x14, "unsupported ACK"},
        {0x15, "class of service not supported by entity at FFFFFE"},
        {0x16, "login required"},
        {0x17, "excessive sequences attempted"},
        {0x18, "unable to establish exchange"},
        {0x1a, "fabric path not available"},
        {0x1b, "invalid VC_ID (class 4)"},
        {0x1c, "invalid CS_CTL field"},
        {0x1d, "insufficient resources for VC (class 4)"},
        {0x1f, "invalid class of service"},
        {0x20, "preemption request rejected"},
        {0x21, "preemption not enabled"},
        {0x22, "multicast error"},
        {0x23, "multicast error terminate"},
        {0x24, "process login required"},
        {0xff, "vendor specific reject"},
        {0, NULL},
};

/**
 * zfcp_rc_description - return description for given reaon code
 * @code: reason code
 * @rc_table: table of reason codes and descriptions
 */
static const char *
zfcp_rc_description(u8 code, const struct zfcp_rc_entry *rc_table)
{
        const char *descr = "unknown reason code";

        do {
                if (code == rc_table->code) {
                        descr = rc_table->description;
                        break;
                }
                rc_table++;
        } while (rc_table->code && rc_table->description);

        return descr;
}

/**
 * zfcp_check_ct_response - evaluate reason code for CT_IU
 * @rjt: response payload to an CT_IU request
 * Return: 0 for accept CT_IU, 1 for reject CT_IU or invlid response code
 */
int
zfcp_check_ct_response(struct ct_hdr *rjt)
{
        if (rjt->cmd_rsp_code == ZFCP_CT_ACCEPT)
                return 0;

        if (rjt->cmd_rsp_code != ZFCP_CT_REJECT) {
                ZFCP_LOG_NORMAL("error: invalid Generic Service command/"
                                "response code (0x%04hx)\n",
                                rjt->cmd_rsp_code);
                return 1;
        }

        ZFCP_LOG_INFO("Generic Service command rejected\n");
        ZFCP_LOG_INFO("%s (0x%02x, 0x%02x, 0x%02x)\n",
                      zfcp_rc_description(rjt->reason_code, zfcp_ct_rc),
                      (u32) rjt->reason_code, (u32) rjt->reason_code_expl,
                      (u32) rjt->vendor_unique);

        return 1;
}

/**
 * zfcp_print_els_rjt - print reject parameter and description for ELS reject
 * @rjt_par: reject parameter acc. to FC-PH/FC-FS
 * @rc_table: table of reason codes and descriptions
 */
static void
zfcp_print_els_rjt(struct zfcp_ls_rjt_par *rjt_par,
                   const struct zfcp_rc_entry *rc_table)
{
        ZFCP_LOG_INFO("%s (%02x %02x %02x %02x)\n",
                      zfcp_rc_description(rjt_par->reason_code, rc_table),
                      (u32) rjt_par->action, (u32) rjt_par->reason_code,
                      (u32) rjt_par->reason_expl, (u32) rjt_par->vendor_unique);
}

/**
 * zfcp_fsf_handle_els_rjt - evaluate status qualifier/reason code on ELS reject
 * @sq: status qualifier word
 * @rjt_par: reject parameter as described in FC-PH and FC-FS
 * Return: -EROMTEIO for LS_RJT, -EREMCHG for invalid D_ID, -EIO else
 */
int
zfcp_handle_els_rjt(u32 sq, struct zfcp_ls_rjt_par *rjt_par)
{
        int ret = -EIO;

        if (sq == FSF_IOSTAT_NPORT_RJT) {
                ZFCP_LOG_INFO("ELS rejected (P_RJT)\n");
                zfcp_print_els_rjt(rjt_par, zfcp_p_rjt_rc);
                /* invalid d_id */
                if (rjt_par->reason_code == 0x01)
                        ret = -EREMCHG;
        } else if (sq == FSF_IOSTAT_FABRIC_RJT) {
                ZFCP_LOG_INFO("ELS rejected (F_RJT)\n");
                zfcp_print_els_rjt(rjt_par, zfcp_p_rjt_rc);
                /* invalid d_id */
                if (rjt_par->reason_code == 0x01)
                        ret = -EREMCHG;
        } else if (sq == FSF_IOSTAT_LS_RJT) {
                ZFCP_LOG_INFO("ELS rejected (LS_RJT)\n");
                zfcp_print_els_rjt(rjt_par, zfcp_ls_rjt_rc);
                ret = -EREMOTEIO;
        } else
                ZFCP_LOG_INFO("unexpected SQ: 0x%02x\n", sq);

        return ret;
}

/**
 * zfcp_plogi_evaluate - evaluate PLOGI playload and copy important fields
 * into zfcp_port structure
 * @port: zfcp_port structure
 * @plogi: plogi payload
 */
void
zfcp_plogi_evaluate(struct zfcp_port *port, struct fsf_plogi *plogi)
{
        port->maxframe_size = plogi->serv_param.common_serv_param[7] |
                ((plogi->serv_param.common_serv_param[6] & 0x0F) << 8);
        if (plogi->serv_param.class1_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS1;
        if (plogi->serv_param.class2_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS2;
        if (plogi->serv_param.class3_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS3;
        if (plogi->serv_param.class4_serv_param[0] & 0x80)
                port->supported_classes |= FC_COS_CLASS4;
}

#undef ZFCP_LOG_AREA