/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *                  Horst Hummel <Horst.Hummel@de.ibm.com>
 *                  Carsten Otte <Cotte@de.ibm.com>
 *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999,2001
 *
 * Device mapping and dasd= parameter parsing functions. All devmap
 * functions may not be called from interrupt context. In particular
 * dasd_get_device is a no-no from interrupt context.
 *
 */

#define KMSG_COMPONENT "dasd"

#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <asm/debug.h>
#include <linux/uaccess.h>
#include <asm/ipl.h>

/* This is ugly... */
#define PRINTK_HEADER "dasd_devmap:"
#define DASD_BUS_ID_SIZE 20
#define DASD_MAX_PARAMS 256

#include "dasd_int.h"

struct kmem_cache *dasd_page_cache;
EXPORT_SYMBOL_GPL(dasd_page_cache);

/*
 * dasd_devmap_t is used to store the features and the relation
 * between device number and device index. To find a dasd_devmap_t
 * that corresponds to a device number of a device index each
 * dasd_devmap_t is added to two linked lists, one to search by
 * the device number and one to search by the device index. As
 * soon as big minor numbers are available the device index list
 * can be removed since the device number will then be identical
 * to the device index.
 */
struct dasd_devmap {
        struct list_head list;
        char bus_id[DASD_BUS_ID_SIZE];
        unsigned int devindex;
        unsigned short features;
        struct dasd_device *device;
};

/*
 * Parameter parsing functions for dasd= parameter. The syntax is:
 *   <devno>            : (0x)?[0-9a-fA-F]+
 *   <busid>            : [0-0a-f]\.[0-9a-f]\.(0x)?[0-9a-fA-F]+
 *   <feature>          : ro
 *   <feature_list>     : \(<feature>(:<feature>)*\)
 *   <devno-range>      : <devno>(-<devno>)?<feature_list>?
 *   <busid-range>      : <busid>(-<busid>)?<feature_list>?
 *   <devices>          : <devno-range>|<busid-range>
 *   <dasd_module>      : dasd_diag_mod|dasd_eckd_mod|dasd_fba_mod
 *
 *   <dasd>             : autodetect|probeonly|<devices>(,<devices>)*
 */

int dasd_probeonly =  0;        /* is true, when probeonly mode is active */
int dasd_autodetect = 0;        /* is true, when autodetection is active */
int dasd_nopav = 0;             /* is true, when PAV is disabled */
EXPORT_SYMBOL_GPL(dasd_nopav);
int dasd_nofcx;                 /* disable High Performance Ficon */
EXPORT_SYMBOL_GPL(dasd_nofcx);

/*
 * char *dasd[] is intended to hold the ranges supplied by the dasd= statement
 * it is named 'dasd' to directly be filled by insmod with the comma separated
 * strings when running as a module.
 */
static char *dasd[DASD_MAX_PARAMS];
module_param_array(dasd, charp, NULL, S_IRUGO);

/*
 * Single spinlock to protect devmap and servermap structures and lists.
 */
static DEFINE_SPINLOCK(dasd_devmap_lock);

/*
 * Hash lists for devmap structures.
 */
static struct list_head dasd_hashlists[256];
int dasd_max_devindex;

static struct dasd_devmap *dasd_add_busid(const char *, int);

static inline int
dasd_hash_busid(const char *bus_id)
{
        int hash, i;

        hash = 0;
        for (i = 0; (i < DASD_BUS_ID_SIZE) && *bus_id; i++, bus_id++)
                hash += *bus_id;
        return hash & 0xff;
}

#ifndef MODULE
static int __init dasd_call_setup(char *opt)
{
        static int i __initdata;
        char *tmp;

        while (i < DASD_MAX_PARAMS) {
                tmp = strsep(&opt, ",");
                if (!tmp)
                        break;

                dasd[i++] = tmp;
        }

        return 1;
}

__setup ("dasd=", dasd_call_setup);
#endif  /* #ifndef MODULE */

#define DASD_IPLDEV     "ipldev"

/*
 * Read a device busid/devno from a string.
 */
static int __init dasd_busid(char *str, int *id0, int *id1, int *devno)
{
        unsigned int val;
        char *tok;

        /* Interpret ipldev busid */
        if (strncmp(DASD_IPLDEV, str, strlen(DASD_IPLDEV)) == 0) {
                if (ipl_info.type != IPL_TYPE_CCW) {
                        pr_err("The IPL device is not a CCW device\n");
                        return -EINVAL;
                }
                *id0 = 0;
                *id1 = ipl_info.data.ccw.dev_id.ssid;
                *devno = ipl_info.data.ccw.dev_id.devno;

                return 0;
        }

        /* Old style 0xXXXX or XXXX */
        if (!kstrtouint(str, 16, &val)) {
                *id0 = *id1 = 0;
                if (val > 0xffff)
                        return -EINVAL;
                *devno = val;
                return 0;
        }

        /* New style x.y.z busid */
        tok = strsep(&str, ".");
        if (kstrtouint(tok, 16, &val) || val > 0xff)
                return -EINVAL;
        *id0 = val;

        tok = strsep(&str, ".");
        if (kstrtouint(tok, 16, &val) || val > 0xff)
                return -EINVAL;
        *id1 = val;

        tok = strsep(&str, ".");
        if (kstrtouint(tok, 16, &val) || val > 0xffff)
                return -EINVAL;
        *devno = val;

        return 0;
}

/*
 * Read colon separated list of dasd features.
 */
static int __init dasd_feature_list(char *str)
{
        int features, len, rc;

        features = 0;
        rc = 0;

        if (!str)
                return DASD_FEATURE_DEFAULT;

        while (1) {
                for (len = 0;
                     str[len] && str[len] != ':' && str[len] != ')'; len++);
                if (len == 2 && !strncmp(str, "ro", 2))
                        features |= DASD_FEATURE_READONLY;
                else if (len == 4 && !strncmp(str, "diag", 4))
                        features |= DASD_FEATURE_USEDIAG;
                else if (len == 3 && !strncmp(str, "raw", 3))
                        features |= DASD_FEATURE_USERAW;
                else if (len == 6 && !strncmp(str, "erplog", 6))
                        features |= DASD_FEATURE_ERPLOG;
                else if (len == 8 && !strncmp(str, "failfast", 8))
                        features |= DASD_FEATURE_FAILFAST;
                else {
                        pr_warn("%*s is not a supported device option\n",
                                len, str);
                        rc = -EINVAL;
                }
                str += len;
                if (*str != ':')
                        break;
                str++;
        }

        return rc ? : features;
}

/*
 * Try to match the first element on the comma separated parse string
 * with one of the known keywords. If a keyword is found, take the approprate
 * action and return a pointer to the residual string. If the first element
 * could not be matched to any keyword then return an error code.
 */
static int __init dasd_parse_keyword(char *keyword)
{
        int length = strlen(keyword);

        if (strncmp("autodetect", keyword, length) == 0) {
                dasd_autodetect = 1;
                pr_info("The autodetection mode has been activated\n");
                return 0;
        }
        if (strncmp("probeonly", keyword, length) == 0) {
                dasd_probeonly = 1;
                pr_info("The probeonly mode has been activated\n");
                return 0;
        }
        if (strncmp("nopav", keyword, length) == 0) {
                if (MACHINE_IS_VM)
                        pr_info("'nopav' is not supported on z/VM\n");
                else {
                        dasd_nopav = 1;
                        pr_info("PAV support has be deactivated\n");
                }
                return 0;
        }
        if (strncmp("nofcx", keyword, length) == 0) {
                dasd_nofcx = 1;
                pr_info("High Performance FICON support has been "
                        "deactivated\n");
                return 0;
        }
        if (strncmp("fixedbuffers", keyword, length) == 0) {
                if (dasd_page_cache)
                        return 0;
                dasd_page_cache =
                        kmem_cache_create("dasd_page_cache", PAGE_SIZE,
                                          PAGE_SIZE, SLAB_CACHE_DMA,
                                          NULL);
                if (!dasd_page_cache)
                        DBF_EVENT(DBF_WARNING, "%s", "Failed to create slab, "
                                "fixed buffer mode disabled.");
                else
                        DBF_EVENT(DBF_INFO, "%s",
                                 "turning on fixed buffer mode");
                return 0;
        }

        return -EINVAL;
}

/*
 * Split a string of a device range into its pieces and return the from, to, and
 * feature parts separately.
 * e.g.:
 * 0.0.1234-0.0.5678(ro:erplog) -> from: 0.0.1234 to: 0.0.5678 features: ro:erplog
 * 0.0.8765(raw) -> from: 0.0.8765 to: null features: raw
 * 0x4321 -> from: 0x4321 to: null features: null
 */
static int __init dasd_evaluate_range_param(char *range, char **from_str,
                                            char **to_str, char **features_str)
{
        int rc = 0;

        /* Do we have a range or a single device? */
        if (strchr(range, '-')) {
                *from_str = strsep(&range, "-");
                *to_str = strsep(&range, "(");
                *features_str = strsep(&range, ")");
        } else {
                *from_str = strsep(&range, "(");
                *features_str = strsep(&range, ")");
        }

        if (*features_str && !range) {
                pr_warn("A closing parenthesis ')' is missing in the dasd= parameter\n");
                rc = -EINVAL;
        }

        return rc;
}

/*
 * Try to interprete the range string as a device number or a range of devices.
 * If the interpretation is successful, create the matching dasd_devmap entries.
 * If interpretation fails or in case of an error, return an error code.
 */
static int __init dasd_parse_range(const char *range)
{
        struct dasd_devmap *devmap;
        int from, from_id0, from_id1;
        int to, to_id0, to_id1;
        int features;
        char bus_id[DASD_BUS_ID_SIZE + 1];
        char *features_str = NULL;
        char *from_str = NULL;
        char *to_str = NULL;
        int rc = 0;
        char *tmp;

        tmp = kstrdup(range, GFP_KERNEL);
        if (!tmp)
                return -ENOMEM;

        if (dasd_evaluate_range_param(tmp, &from_str, &to_str, &features_str)) {
                rc = -EINVAL;
                goto out;
        }

        if (dasd_busid(from_str, &from_id0, &from_id1, &from)) {
                rc = -EINVAL;
                goto out;
        }

        to = from;
        to_id0 = from_id0;
        to_id1 = from_id1;
        if (to_str) {
                if (dasd_busid(to_str, &to_id0, &to_id1, &to)) {
                        rc = -EINVAL;
                        goto out;
                }
                if (from_id0 != to_id0 || from_id1 != to_id1 || from > to) {
                        pr_err("%s is not a valid device range\n", range);
                        rc = -EINVAL;
                        goto out;
                }
        }

        features = dasd_feature_list(features_str);
        if (features < 0) {
                rc = -EINVAL;
                goto out;
        }
        /* each device in dasd= parameter should be set initially online */
        features |= DASD_FEATURE_INITIAL_ONLINE;
        while (from <= to) {
                sprintf(bus_id, "%01x.%01x.%04x", from_id0, from_id1, from++);
                devmap = dasd_add_busid(bus_id, features);
                if (IS_ERR(devmap)) {
                        rc = PTR_ERR(devmap);
                        goto out;
                }
        }

out:
        kfree(tmp);

        return rc;
}

/*
 * Parse parameters stored in dasd[]
 * The 'dasd=...' parameter allows to specify a comma separated list of
 * keywords and device ranges. The parameters in that list will be stored as
 * separate elementes in dasd[].
 */
int __init dasd_parse(void)
{
        int rc, i;
        char *cur;

        rc = 0;
        for (i = 0; i < DASD_MAX_PARAMS; i++) {
                cur = dasd[i];
                if (!cur)
                        break;
                if (*cur == '\0')
                        continue;

                rc = dasd_parse_keyword(cur);
                if (rc)
                        rc = dasd_parse_range(cur);

                if (rc)
                        break;
        }

        return rc;
}

/*
 * Add a devmap for the device specified by busid. It is possible that
 * the devmap already exists (dasd= parameter). The order of the devices
 * added through this function will define the kdevs for the individual
 * devices.
 */
static struct dasd_devmap *
dasd_add_busid(const char *bus_id, int features)
{
        struct dasd_devmap *devmap, *new, *tmp;
        int hash;

        new = kzalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
        if (!new)
                return ERR_PTR(-ENOMEM);
        spin_lock(&dasd_devmap_lock);
        devmap = NULL;
        hash = dasd_hash_busid(bus_id);
        list_for_each_entry(tmp, &dasd_hashlists[hash], list)
                if (strncmp(tmp->bus_id, bus_id, DASD_BUS_ID_SIZE) == 0) {
                        devmap = tmp;
                        break;
                }
        if (!devmap) {
                /* This bus_id is new. */
                new->devindex = dasd_max_devindex++;
                strncpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);
                new->features = features;
                new->device = NULL;
                list_add(&new->list, &dasd_hashlists[hash]);
                devmap = new;
                new = NULL;
        }
        spin_unlock(&dasd_devmap_lock);
        kfree(new);
        return devmap;
}

/*
 * Find devmap for device with given bus_id.
 */
static struct dasd_devmap *
dasd_find_busid(const char *bus_id)
{
        struct dasd_devmap *devmap, *tmp;
        int hash;

        spin_lock(&dasd_devmap_lock);
        devmap = ERR_PTR(-ENODEV);
        hash = dasd_hash_busid(bus_id);
        list_for_each_entry(tmp, &dasd_hashlists[hash], list) {
                if (strncmp(tmp->bus_id, bus_id, DASD_BUS_ID_SIZE) == 0) {
                        devmap = tmp;
                        break;
                }
        }
        spin_unlock(&dasd_devmap_lock);
        return devmap;
}

/*
 * Check if busid has been added to the list of dasd ranges.
 */
int
dasd_busid_known(const char *bus_id)
{
        return IS_ERR(dasd_find_busid(bus_id)) ? -ENOENT : 0;
}

/*
 * Forget all about the device numbers added so far.
 * This may only be called at module unload or system shutdown.
 */
static void
dasd_forget_ranges(void)
{
        struct dasd_devmap *devmap, *n;
        int i;

        spin_lock(&dasd_devmap_lock);
        for (i = 0; i < 256; i++) {
                list_for_each_entry_safe(devmap, n, &dasd_hashlists[i], list) {
                        BUG_ON(devmap->device != NULL);
                        list_del(&devmap->list);
                        kfree(devmap);
                }
        }
        spin_unlock(&dasd_devmap_lock);
}

/*
 * Find the device struct by its device index.
 */
struct dasd_device *
dasd_device_from_devindex(int devindex)
{
        struct dasd_devmap *devmap, *tmp;
        struct dasd_device *device;
        int i;

        spin_lock(&dasd_devmap_lock);
        devmap = NULL;
        for (i = 0; (i < 256) && !devmap; i++)
                list_for_each_entry(tmp, &dasd_hashlists[i], list)
                        if (tmp->devindex == devindex) {
                                /* Found the devmap for the device. */
                                devmap = tmp;
                                break;
                        }
        if (devmap && devmap->device) {
                device = devmap->device;
                dasd_get_device(device);
        } else
                device = ERR_PTR(-ENODEV);
        spin_unlock(&dasd_devmap_lock);
        return device;
}

/*
 * Return devmap for cdev. If no devmap exists yet, create one and
 * connect it to the cdev.
 */
static struct dasd_devmap *
dasd_devmap_from_cdev(struct ccw_device *cdev)
{
        struct dasd_devmap *devmap;

        devmap = dasd_find_busid(dev_name(&cdev->dev));
        if (IS_ERR(devmap))
                devmap = dasd_add_busid(dev_name(&cdev->dev),
                                        DASD_FEATURE_DEFAULT);
        return devmap;
}

/*
 * Create a dasd device structure for cdev.
 */
struct dasd_device *
dasd_create_device(struct ccw_device *cdev)
{
        struct dasd_devmap *devmap;
        struct dasd_device *device;
        unsigned long flags;
        int rc;

        devmap = dasd_devmap_from_cdev(cdev);
        if (IS_ERR(devmap))
                return (void *) devmap;

        device = dasd_alloc_device();
        if (IS_ERR(device))
                return device;
        atomic_set(&device->ref_count, 3);

        spin_lock(&dasd_devmap_lock);
        if (!devmap->device) {
                devmap->device = device;
                device->devindex = devmap->devindex;
                device->features = devmap->features;
                get_device(&cdev->dev);
                device->cdev = cdev;
                rc = 0;
        } else
                /* Someone else was faster. */
                rc = -EBUSY;
        spin_unlock(&dasd_devmap_lock);

        if (rc) {
                dasd_free_device(device);
                return ERR_PTR(rc);
        }

        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
        dev_set_drvdata(&cdev->dev, device);
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);

        return device;
}

/*
 * Wait queue for dasd_delete_device waits.
 */
static DECLARE_WAIT_QUEUE_HEAD(dasd_delete_wq);

/*
 * Remove a dasd device structure. The passed referenced
 * is destroyed.
 */
void
dasd_delete_device(struct dasd_device *device)
{
        struct ccw_device *cdev;
        struct dasd_devmap *devmap;
        unsigned long flags;

        /* First remove device pointer from devmap. */
        devmap = dasd_find_busid(dev_name(&device->cdev->dev));
        BUG_ON(IS_ERR(devmap));
        spin_lock(&dasd_devmap_lock);
        if (devmap->device != device) {
                spin_unlock(&dasd_devmap_lock);
                dasd_put_device(device);
                return;
        }
        devmap->device = NULL;
        spin_unlock(&dasd_devmap_lock);

        /* Disconnect dasd_device structure from ccw_device structure. */
        spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
        dev_set_drvdata(&device->cdev->dev, NULL);
        spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

        /*
         * Drop ref_count by 3, one for the devmap reference, one for
         * the cdev reference and one for the passed reference.
         */
        atomic_sub(3, &device->ref_count);

        /* Wait for reference counter to drop to zero. */
        wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);

        dasd_generic_free_discipline(device);
        /* Disconnect dasd_device structure from ccw_device structure. */
        cdev = device->cdev;
        device->cdev = NULL;

        /* Put ccw_device structure. */
        put_device(&cdev->dev);

        /* Now the device structure can be freed. */
        dasd_free_device(device);
}

/*
 * Reference counter dropped to zero. Wake up waiter
 * in dasd_delete_device.
 */
void
dasd_put_device_wake(struct dasd_device *device)
{
        wake_up(&dasd_delete_wq);
}
EXPORT_SYMBOL_GPL(dasd_put_device_wake);

/*
 * Return dasd_device structure associated with cdev.
 * This function needs to be called with the ccw device
 * lock held. It can be used from interrupt context.
 */
struct dasd_device *
dasd_device_from_cdev_locked(struct ccw_device *cdev)
{
        struct dasd_device *device = dev_get_drvdata(&cdev->dev);

        if (!device)
                return ERR_PTR(-ENODEV);
        dasd_get_device(device);
        return device;
}

/*
 * Return dasd_device structure associated with cdev.
 */
struct dasd_device *
dasd_device_from_cdev(struct ccw_device *cdev)
{
        struct dasd_device *device;
        unsigned long flags;

        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
        device = dasd_device_from_cdev_locked(cdev);
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
        return device;
}

void dasd_add_link_to_gendisk(struct gendisk *gdp, struct dasd_device *device)
{
        struct dasd_devmap *devmap;

        devmap = dasd_find_busid(dev_name(&device->cdev->dev));
        if (IS_ERR(devmap))
                return;
        spin_lock(&dasd_devmap_lock);
        gdp->private_data = devmap;
        spin_unlock(&dasd_devmap_lock);
}

struct dasd_device *dasd_device_from_gendisk(struct gendisk *gdp)
{
        struct dasd_device *device;
        struct dasd_devmap *devmap;

        if (!gdp->private_data)
                return NULL;
        device = NULL;
        spin_lock(&dasd_devmap_lock);
        devmap = gdp->private_data;
        if (devmap && devmap->device) {
                device = devmap->device;
                dasd_get_device(device);
        }
        spin_unlock(&dasd_devmap_lock);
        return device;
}

/*
 * SECTION: files in sysfs
 */

/*
 * failfast controls the behaviour, if no path is available
 */
static ssize_t dasd_ff_show(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        struct dasd_devmap *devmap;
        int ff_flag;

        devmap = dasd_find_busid(dev_name(dev));
        if (!IS_ERR(devmap))
                ff_flag = (devmap->features & DASD_FEATURE_FAILFAST) != 0;
        else
                ff_flag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_FAILFAST) != 0;
        return snprintf(buf, PAGE_SIZE, ff_flag ? "1\n" : "0\n");
}

static ssize_t dasd_ff_store(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
{
        unsigned int val;
        int rc;

        if (kstrtouint(buf, 0, &val) || val > 1)
                return -EINVAL;

        rc = dasd_set_feature(to_ccwdev(dev), DASD_FEATURE_FAILFAST, val);

        return rc ? : count;
}

static DEVICE_ATTR(failfast, 0644, dasd_ff_show, dasd_ff_store);

/*
 * readonly controls the readonly status of a dasd
 */
static ssize_t
dasd_ro_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_devmap *devmap;
        struct dasd_device *device;
        int ro_flag = 0;

        devmap = dasd_find_busid(dev_name(dev));
        if (IS_ERR(devmap))
                goto out;

        ro_flag = !!(devmap->features & DASD_FEATURE_READONLY);

        spin_lock(&dasd_devmap_lock);
        device = devmap->device;
        if (device)
                ro_flag |= test_bit(DASD_FLAG_DEVICE_RO, &device->flags);
        spin_unlock(&dasd_devmap_lock);

out:
        return snprintf(buf, PAGE_SIZE, ro_flag ? "1\n" : "0\n");
}

static ssize_t
dasd_ro_store(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
{
        struct ccw_device *cdev = to_ccwdev(dev);
        struct dasd_device *device;
        unsigned long flags;
        unsigned int val;
        int rc;

        if (kstrtouint(buf, 0, &val) || val > 1)
                return -EINVAL;

        rc = dasd_set_feature(cdev, DASD_FEATURE_READONLY, val);
        if (rc)
                return rc;

        device = dasd_device_from_cdev(cdev);
        if (IS_ERR(device))
                return count;

        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
        val = val || test_bit(DASD_FLAG_DEVICE_RO, &device->flags);

        if (!device->block || !device->block->gdp ||
            test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
                spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
                goto out;
        }
        /* Increase open_count to avoid losing the block device */
        atomic_inc(&device->block->open_count);
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);

        set_disk_ro(device->block->gdp, val);
        atomic_dec(&device->block->open_count);

out:
        dasd_put_device(device);

        return count;
}

static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_store);
/*
 * erplog controls the logging of ERP related data
 * (e.g. failing channel programs).
 */
static ssize_t
dasd_erplog_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_devmap *devmap;
        int erplog;

        devmap = dasd_find_busid(dev_name(dev));
        if (!IS_ERR(devmap))
                erplog = (devmap->features & DASD_FEATURE_ERPLOG) != 0;
        else
                erplog = (DASD_FEATURE_DEFAULT & DASD_FEATURE_ERPLOG) != 0;
        return snprintf(buf, PAGE_SIZE, erplog ? "1\n" : "0\n");
}

static ssize_t
dasd_erplog_store(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
{
        unsigned int val;
        int rc;

        if (kstrtouint(buf, 0, &val) || val > 1)
                return -EINVAL;

        rc = dasd_set_feature(to_ccwdev(dev), DASD_FEATURE_ERPLOG, val);

        return rc ? : count;
}

static DEVICE_ATTR(erplog, 0644, dasd_erplog_show, dasd_erplog_store);

/*
 * use_diag controls whether the driver should use diag rather than ssch
 * to talk to the device
 */
static ssize_t
dasd_use_diag_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_devmap *devmap;
        int use_diag;

        devmap = dasd_find_busid(dev_name(dev));
        if (!IS_ERR(devmap))
                use_diag = (devmap->features & DASD_FEATURE_USEDIAG) != 0;
        else
                use_diag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USEDIAG) != 0;
        return sprintf(buf, use_diag ? "1\n" : "0\n");
}

static ssize_t
dasd_use_diag_store(struct device *dev, struct device_attribute *attr,
                    const char *buf, size_t count)
{
        struct dasd_devmap *devmap;
        unsigned int val;
        ssize_t rc;

        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);

        if (kstrtouint(buf, 0, &val) || val > 1)
                return -EINVAL;

        spin_lock(&dasd_devmap_lock);
        /* Changing diag discipline flag is only allowed in offline state. */
        rc = count;
        if (!devmap->device && !(devmap->features & DASD_FEATURE_USERAW)) {
                if (val)
                        devmap->features |= DASD_FEATURE_USEDIAG;
                else
                        devmap->features &= ~DASD_FEATURE_USEDIAG;
        } else
                rc = -EPERM;
        spin_unlock(&dasd_devmap_lock);
        return rc;
}

static DEVICE_ATTR(use_diag, 0644, dasd_use_diag_show, dasd_use_diag_store);

/*
 * use_raw controls whether the driver should give access to raw eckd data or
 * operate in standard mode
 */
static ssize_t
dasd_use_raw_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_devmap *devmap;
        int use_raw;

        devmap = dasd_find_busid(dev_name(dev));
        if (!IS_ERR(devmap))
                use_raw = (devmap->features & DASD_FEATURE_USERAW) != 0;
        else
                use_raw = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USERAW) != 0;
        return sprintf(buf, use_raw ? "1\n" : "0\n");
}

static ssize_t
dasd_use_raw_store(struct device *dev, struct device_attribute *attr,
                    const char *buf, size_t count)
{
        struct dasd_devmap *devmap;
        ssize_t rc;
        unsigned long val;

        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);

        if ((kstrtoul(buf, 10, &val) != 0) || val > 1)
                return -EINVAL;

        spin_lock(&dasd_devmap_lock);
        /* Changing diag discipline flag is only allowed in offline state. */
        rc = count;
        if (!devmap->device && !(devmap->features & DASD_FEATURE_USEDIAG)) {
                if (val)
                        devmap->features |= DASD_FEATURE_USERAW;
                else
                        devmap->features &= ~DASD_FEATURE_USERAW;
        } else
                rc = -EPERM;
        spin_unlock(&dasd_devmap_lock);
        return rc;
}

static DEVICE_ATTR(raw_track_access, 0644, dasd_use_raw_show,
                   dasd_use_raw_store);

static ssize_t
dasd_safe_offline_store(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t count)
{
        struct ccw_device *cdev = to_ccwdev(dev);
        struct dasd_device *device;
        unsigned long flags;
        int rc;

        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
        device = dasd_device_from_cdev_locked(cdev);
        if (IS_ERR(device)) {
                rc = PTR_ERR(device);
                spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
                goto out;
        }

        if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
            test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
                /* Already doing offline processing */
                dasd_put_device(device);
                spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
                rc = -EBUSY;
                goto out;
        }

        set_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags);
        dasd_put_device(device);
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);

        rc = ccw_device_set_offline(cdev);

out:
        return rc ? rc : count;
}

static DEVICE_ATTR(safe_offline, 0200, NULL, dasd_safe_offline_store);

static ssize_t
dasd_access_show(struct device *dev, struct device_attribute *attr,
                 char *buf)
{
        struct ccw_device *cdev = to_ccwdev(dev);
        struct dasd_device *device;
        int count;

        device = dasd_device_from_cdev(cdev);
        if (IS_ERR(device))
                return PTR_ERR(device);

        if (!device->discipline)
                count = -ENODEV;
        else if (!device->discipline->host_access_count)
                count = -EOPNOTSUPP;

        else
                count = device->discipline->host_access_count(device);

        dasd_put_device(device);
        if (count < 0)
                return count;

        return sprintf(buf, "%d\n", count);
}

static DEVICE_ATTR(host_access_count, 0444, dasd_access_show, NULL);

static ssize_t
dasd_discipline_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
{
        struct dasd_device *device;
        ssize_t len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                goto out;
        else if (!device->discipline) {
                dasd_put_device(device);
                goto out;
        } else {
                len = snprintf(buf, PAGE_SIZE, "%s\n",
                               device->discipline->name);
                dasd_put_device(device);
                return len;
        }
out:
        len = snprintf(buf, PAGE_SIZE, "none\n");
        return len;
}

static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);

static ssize_t
dasd_device_status_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
{
        struct dasd_device *device;
        ssize_t len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (!IS_ERR(device)) {
                switch (device->state) {
                case DASD_STATE_NEW:
                        len = snprintf(buf, PAGE_SIZE, "new\n");
                        break;
                case DASD_STATE_KNOWN:
                        len = snprintf(buf, PAGE_SIZE, "detected\n");
                        break;
                case DASD_STATE_BASIC:
                        len = snprintf(buf, PAGE_SIZE, "basic\n");
                        break;
                case DASD_STATE_UNFMT:
                        len = snprintf(buf, PAGE_SIZE, "unformatted\n");
                        break;
                case DASD_STATE_READY:
                        len = snprintf(buf, PAGE_SIZE, "ready\n");
                        break;
                case DASD_STATE_ONLINE:
                        len = snprintf(buf, PAGE_SIZE, "online\n");
                        break;
                default:
                        len = snprintf(buf, PAGE_SIZE, "no stat\n");
                        break;
                }
                dasd_put_device(device);
        } else
                len = snprintf(buf, PAGE_SIZE, "unknown\n");
        return len;
}

static DEVICE_ATTR(status, 0444, dasd_device_status_show, NULL);

static ssize_t dasd_alias_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        struct dasd_uid uid;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return sprintf(buf, "0\n");

        if (device->discipline && device->discipline->get_uid &&
            !device->discipline->get_uid(device, &uid)) {
                if (uid.type == UA_BASE_PAV_ALIAS ||
                    uid.type == UA_HYPER_PAV_ALIAS) {
                        dasd_put_device(device);
                        return sprintf(buf, "1\n");
                }
        }
        dasd_put_device(device);

        return sprintf(buf, "0\n");
}

static DEVICE_ATTR(alias, 0444, dasd_alias_show, NULL);

static ssize_t dasd_vendor_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        struct dasd_uid uid;
        char *vendor;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        vendor = "";
        if (IS_ERR(device))
                return snprintf(buf, PAGE_SIZE, "%s\n", vendor);

        if (device->discipline && device->discipline->get_uid &&
            !device->discipline->get_uid(device, &uid))
                        vendor = uid.vendor;

        dasd_put_device(device);

        return snprintf(buf, PAGE_SIZE, "%s\n", vendor);
}

static DEVICE_ATTR(vendor, 0444, dasd_vendor_show, NULL);

#define UID_STRLEN ( /* vendor */ 3 + 1 + /* serial    */ 14 + 1 +\
                     /* SSID   */ 4 + 1 + /* unit addr */ 2 + 1 +\
                     /* vduit */ 32 + 1)

static ssize_t
dasd_uid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        struct dasd_uid uid;
        char uid_string[UID_STRLEN];
        char ua_string[3];

        device = dasd_device_from_cdev(to_ccwdev(dev));
        uid_string[0] = 0;
        if (IS_ERR(device))
                return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);

        if (device->discipline && device->discipline->get_uid &&
            !device->discipline->get_uid(device, &uid)) {
                switch (uid.type) {
                case UA_BASE_DEVICE:
                        snprintf(ua_string, sizeof(ua_string), "%02x",
                                 uid.real_unit_addr);
                        break;
                case UA_BASE_PAV_ALIAS:
                        snprintf(ua_string, sizeof(ua_string), "%02x",
                                 uid.base_unit_addr);
                        break;
                case UA_HYPER_PAV_ALIAS:
                        snprintf(ua_string, sizeof(ua_string), "xx");
                        break;
                default:
                        /* should not happen, treat like base device */
                        snprintf(ua_string, sizeof(ua_string), "%02x",
                                 uid.real_unit_addr);
                        break;
                }

                if (strlen(uid.vduit) > 0)
                        snprintf(uid_string, sizeof(uid_string),
                                 "%s.%s.%04x.%s.%s",
                                 uid.vendor, uid.serial, uid.ssid, ua_string,
                                 uid.vduit);
                else
                        snprintf(uid_string, sizeof(uid_string),
                                 "%s.%s.%04x.%s",
                                 uid.vendor, uid.serial, uid.ssid, ua_string);
        }
        dasd_put_device(device);

        return snprintf(buf, PAGE_SIZE, "%s\n", uid_string);
}
static DEVICE_ATTR(uid, 0444, dasd_uid_show, NULL);

/*
 * extended error-reporting
 */
static ssize_t
dasd_eer_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_devmap *devmap;
        int eer_flag;

        devmap = dasd_find_busid(dev_name(dev));
        if (!IS_ERR(devmap) && devmap->device)
                eer_flag = dasd_eer_enabled(devmap->device);
        else
                eer_flag = 0;
        return snprintf(buf, PAGE_SIZE, eer_flag ? "1\n" : "0\n");
}

static ssize_t
dasd_eer_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned int val;
        int rc = 0;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return PTR_ERR(device);

        if (kstrtouint(buf, 0, &val) || val > 1)
                return -EINVAL;

        if (val)
                rc = dasd_eer_enable(device);
        else
                dasd_eer_disable(device);

        dasd_put_device(device);

        return rc ? : count;
}

static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);

/*
 * expiration time for default requests
 */
static ssize_t
dasd_expires_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        int len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_expires);
        dasd_put_device(device);
        return len;
}

static ssize_t
dasd_expires_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned long val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;

        if ((kstrtoul(buf, 10, &val) != 0) ||
            (val > DASD_EXPIRES_MAX) || val == 0) {
                dasd_put_device(device);
                return -EINVAL;
        }

        if (val)
                device->default_expires = val;

        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(expires, 0644, dasd_expires_show, dasd_expires_store);

static ssize_t
dasd_retries_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        int len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->default_retries);
        dasd_put_device(device);
        return len;
}

static ssize_t
dasd_retries_store(struct device *dev, struct device_attribute *attr,
                   const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned long val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;

        if ((kstrtoul(buf, 10, &val) != 0) ||
            (val > DASD_RETRIES_MAX)) {
                dasd_put_device(device);
                return -EINVAL;
        }

        if (val)
                device->default_retries = val;

        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(retries, 0644, dasd_retries_show, dasd_retries_store);

static ssize_t
dasd_timeout_show(struct device *dev, struct device_attribute *attr,
                  char *buf)
{
        struct dasd_device *device;
        int len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->blk_timeout);
        dasd_put_device(device);
        return len;
}

static ssize_t
dasd_timeout_store(struct device *dev, struct device_attribute *attr,
                   const char *buf, size_t count)
{
        struct dasd_device *device;
        struct request_queue *q;
        unsigned long val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device) || !device->block)
                return -ENODEV;

        if ((kstrtoul(buf, 10, &val) != 0) ||
            val > UINT_MAX / HZ) {
                dasd_put_device(device);
                return -EINVAL;
        }
        q = device->block->request_queue;
        if (!q) {
                dasd_put_device(device);
                return -ENODEV;
        }

        device->blk_timeout = val;

        blk_queue_rq_timeout(q, device->blk_timeout * HZ);

        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(timeout, 0644,
                   dasd_timeout_show, dasd_timeout_store);


static ssize_t
dasd_path_reset_store(struct device *dev, struct device_attribute *attr,
                      const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned int val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;

        if ((kstrtouint(buf, 16, &val) != 0) || val > 0xff)
                val = 0;

        if (device->discipline && device->discipline->reset_path)
                device->discipline->reset_path(device, (__u8) val);

        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(path_reset, 0200, NULL, dasd_path_reset_store);

static ssize_t dasd_hpf_show(struct device *dev, struct device_attribute *attr,
                             char *buf)
{
        struct dasd_device *device;
        int hpf;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        if (!device->discipline || !device->discipline->hpf_enabled) {
                dasd_put_device(device);
                return snprintf(buf, PAGE_SIZE, "%d\n", dasd_nofcx);
        }
        hpf = device->discipline->hpf_enabled(device);
        dasd_put_device(device);
        return snprintf(buf, PAGE_SIZE, "%d\n", hpf);
}

static DEVICE_ATTR(hpf, 0444, dasd_hpf_show, NULL);

static ssize_t dasd_reservation_policy_show(struct device *dev,
                                            struct device_attribute *attr,
                                            char *buf)
{
        struct dasd_devmap *devmap;
        int rc = 0;

        devmap = dasd_find_busid(dev_name(dev));
        if (IS_ERR(devmap)) {
                rc = snprintf(buf, PAGE_SIZE, "ignore\n");
        } else {
                spin_lock(&dasd_devmap_lock);
                if (devmap->features & DASD_FEATURE_FAILONSLCK)
                        rc = snprintf(buf, PAGE_SIZE, "fail\n");
                else
                        rc = snprintf(buf, PAGE_SIZE, "ignore\n");
                spin_unlock(&dasd_devmap_lock);
        }
        return rc;
}

static ssize_t dasd_reservation_policy_store(struct device *dev,
                                             struct device_attribute *attr,
                                             const char *buf, size_t count)
{
        struct ccw_device *cdev = to_ccwdev(dev);
        int rc;

        if (sysfs_streq("ignore", buf))
                rc = dasd_set_feature(cdev, DASD_FEATURE_FAILONSLCK, 0);
        else if (sysfs_streq("fail", buf))
                rc = dasd_set_feature(cdev, DASD_FEATURE_FAILONSLCK, 1);
        else
                rc = -EINVAL;

        return rc ? : count;
}

static DEVICE_ATTR(reservation_policy, 0644,
                   dasd_reservation_policy_show, dasd_reservation_policy_store);

static ssize_t dasd_reservation_state_show(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct dasd_device *device;
        int rc = 0;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return snprintf(buf, PAGE_SIZE, "none\n");

        if (test_bit(DASD_FLAG_IS_RESERVED, &device->flags))
                rc = snprintf(buf, PAGE_SIZE, "reserved\n");
        else if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags))
                rc = snprintf(buf, PAGE_SIZE, "lost\n");
        else
                rc = snprintf(buf, PAGE_SIZE, "none\n");
        dasd_put_device(device);
        return rc;
}

static ssize_t dasd_reservation_state_store(struct device *dev,
                                            struct device_attribute *attr,
                                            const char *buf, size_t count)
{
        struct dasd_device *device;
        int rc = 0;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        if (sysfs_streq("reset", buf))
                clear_bit(DASD_FLAG_LOCK_STOLEN, &device->flags);
        else
                rc = -EINVAL;
        dasd_put_device(device);

        if (rc)
                return rc;
        else
                return count;
}

static DEVICE_ATTR(last_known_reservation_state, 0644,
                   dasd_reservation_state_show, dasd_reservation_state_store);

static ssize_t dasd_pm_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        u8 opm, nppm, cablepm, cuirpm, hpfpm, ifccpm;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return sprintf(buf, "0\n");

        opm = dasd_path_get_opm(device);
        nppm = dasd_path_get_nppm(device);
        cablepm = dasd_path_get_cablepm(device);
        cuirpm = dasd_path_get_cuirpm(device);
        hpfpm = dasd_path_get_hpfpm(device);
        ifccpm = dasd_path_get_ifccpm(device);
        dasd_put_device(device);

        return sprintf(buf, "%02x %02x %02x %02x %02x %02x\n", opm, nppm,
                       cablepm, cuirpm, hpfpm, ifccpm);
}

static DEVICE_ATTR(path_masks, 0444, dasd_pm_show, NULL);

/*
 * threshold value for IFCC/CCC errors
 */
static ssize_t
dasd_path_threshold_show(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        int len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->path_thrhld);
        dasd_put_device(device);
        return len;
}

static ssize_t
dasd_path_threshold_store(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned long flags;
        unsigned long val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;

        if (kstrtoul(buf, 10, &val) != 0 || val > DASD_THRHLD_MAX) {
                dasd_put_device(device);
                return -EINVAL;
        }
        spin_lock_irqsave(get_ccwdev_lock(to_ccwdev(dev)), flags);
        device->path_thrhld = val;
        spin_unlock_irqrestore(get_ccwdev_lock(to_ccwdev(dev)), flags);
        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(path_threshold, 0644, dasd_path_threshold_show,
                   dasd_path_threshold_store);
/*
 * interval for IFCC/CCC checks
 * meaning time with no IFCC/CCC error before the error counter
 * gets reset
 */
static ssize_t
dasd_path_interval_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        struct dasd_device *device;
        int len;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;
        len = snprintf(buf, PAGE_SIZE, "%lu\n", device->path_interval);
        dasd_put_device(device);
        return len;
}

static ssize_t
dasd_path_interval_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
{
        struct dasd_device *device;
        unsigned long flags;
        unsigned long val;

        device = dasd_device_from_cdev(to_ccwdev(dev));
        if (IS_ERR(device))
                return -ENODEV;

        if ((kstrtoul(buf, 10, &val) != 0) ||
            (val > DASD_INTERVAL_MAX) || val == 0) {
                dasd_put_device(device);
                return -EINVAL;
        }
        spin_lock_irqsave(get_ccwdev_lock(to_ccwdev(dev)), flags);
        if (val)
                device->path_interval = val;
        spin_unlock_irqrestore(get_ccwdev_lock(to_ccwdev(dev)), flags);
        dasd_put_device(device);
        return count;
}

static DEVICE_ATTR(path_interval, 0644, dasd_path_interval_show,
                   dasd_path_interval_store);


static struct attribute * dasd_attrs[] = {
        &dev_attr_readonly.attr,
        &dev_attr_discipline.attr,
        &dev_attr_status.attr,
        &dev_attr_alias.attr,
        &dev_attr_vendor.attr,
        &dev_attr_uid.attr,
        &dev_attr_use_diag.attr,
        &dev_attr_raw_track_access.attr,
        &dev_attr_eer_enabled.attr,
        &dev_attr_erplog.attr,
        &dev_attr_failfast.attr,
        &dev_attr_expires.attr,
        &dev_attr_retries.attr,
        &dev_attr_timeout.attr,
        &dev_attr_reservation_policy.attr,
        &dev_attr_last_known_reservation_state.attr,
        &dev_attr_safe_offline.attr,
        &dev_attr_host_access_count.attr,
        &dev_attr_path_masks.attr,
        &dev_attr_path_threshold.attr,
        &dev_attr_path_interval.attr,
        &dev_attr_path_reset.attr,
        &dev_attr_hpf.attr,
        NULL,
};

static const struct attribute_group dasd_attr_group = {
        .attrs = dasd_attrs,
};

/*
 * Return value of the specified feature.
 */
int
dasd_get_feature(struct ccw_device *cdev, int feature)
{
        struct dasd_devmap *devmap;

        devmap = dasd_find_busid(dev_name(&cdev->dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);

        return ((devmap->features & feature) != 0);
}

/*
 * Set / reset given feature.
 * Flag indicates whether to set (!=0) or the reset (=0) the feature.
 */
int
dasd_set_feature(struct ccw_device *cdev, int feature, int flag)
{
        struct dasd_devmap *devmap;

        devmap = dasd_devmap_from_cdev(cdev);
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);

        spin_lock(&dasd_devmap_lock);
        if (flag)
                devmap->features |= feature;
        else
                devmap->features &= ~feature;
        if (devmap->device)
                devmap->device->features = devmap->features;
        spin_unlock(&dasd_devmap_lock);
        return 0;
}
EXPORT_SYMBOL(dasd_set_feature);


int
dasd_add_sysfs_files(struct ccw_device *cdev)
{
        return sysfs_create_group(&cdev->dev.kobj, &dasd_attr_group);
}

void
dasd_remove_sysfs_files(struct ccw_device *cdev)
{
        sysfs_remove_group(&cdev->dev.kobj, &dasd_attr_group);
}


int
dasd_devmap_init(void)
{
        int i;

        /* Initialize devmap structures. */
        dasd_max_devindex = 0;
        for (i = 0; i < 256; i++)
                INIT_LIST_HEAD(&dasd_hashlists[i]);
        return 0;
}

void
dasd_devmap_exit(void)
{
        dasd_forget_ranges();
}