1 files changed, 772 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
new file mode 100644
index 000000000000..ad1841a96c87
--- /dev/null
+++ b/drivers/s390/block/dasd_devmap.c
@@ -0,0 +1,772 @@
+/*
+ * File...........: linux/drivers/s390/block/dasd_devmap.c
+ * 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>
+ * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 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.
+ *
+ * $Revision: 1.37 $
+ */
+
+#include <linux/config.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+
+#include <asm/debug.h>
+#include <asm/uaccess.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd_devmap:"
+
+#include "dasd_int.h"
+
+kmem_cache_t *dasd_page_cache;
+EXPORT_SYMBOL(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[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 */
+
+/*
+ * 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[256];
+/*
+ * Single spinlock to protect devmap 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(char *, int);
+
+static inline int
+dasd_hash_busid(char *bus_id)
+{
+	int hash, i;
+
+	hash = 0;
+	for (i = 0; (i < BUS_ID_SIZE) && *bus_id; i++, bus_id++)
+		hash += *bus_id;
+	return hash & 0xff;
+}
+
+#ifndef MODULE
+/*
+ * The parameter parsing functions for builtin-drivers are called
+ * before kmalloc works. Store the pointers to the parameters strings
+ * into dasd[] for later processing.
+ */
+static int __init
+dasd_call_setup(char *str)
+{
+	static int count = 0;
+
+	if (count < 256)
+		dasd[count++] = str;
+	return 1;
+}
+
+__setup ("dasd=", dasd_call_setup);
+#endif	/* #ifndef MODULE */
+
+/*
+ * Read a device busid/devno from a string.
+ */
+static inline int
+dasd_busid(char **str, int *id0, int *id1, int *devno)
+{
+	int val, old_style;
+ 
+	/* check for leading '0x' */
+	old_style = 0;
+	if ((*str)[0] == '0' && (*str)[1] == 'x') {
+		*str += 2;
+		old_style = 1;
+	}
+	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
+		return -EINVAL;
+	val = simple_strtoul(*str, str, 16);
+	if (old_style || (*str)[0] != '.') {
+		*id0 = *id1 = 0;
+		if (val < 0 || val > 0xffff)
+			return -EINVAL;
+		*devno = val;
+		return 0;
+	}
+	/* New style x.y.z busid */
+	if (val < 0 || val > 0xff)
+		return -EINVAL;
+	*id0 = val;
+	(*str)++;
+	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
+		return -EINVAL;
+	val = simple_strtoul(*str, str, 16);
+	if (val < 0 || val > 0xff || (*str)++[0] != '.')
+		return -EINVAL;
+	*id1 = val;
+	if (!isxdigit((*str)[0]))	/* We require at least one hex digit */
+		return -EINVAL;
+	val = simple_strtoul(*str, str, 16);
+	if (val < 0 || val > 0xffff)
+		return -EINVAL;
+	*devno = val;
+	return 0;
+}
+
+/*
+ * Read colon separated list of dasd features. Currently there is
+ * only one: "ro" for read-only devices. The default feature set
+ * is empty (value 0).
+ */
+static inline int
+dasd_feature_list(char *str, char **endp)
+{
+	int features, len, rc;
+
+	rc = 0;
+	if (*str != '(') {
+		*endp = str;
+		return DASD_FEATURE_DEFAULT;
+	}
+	str++;
+	features = 0;
+
+	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 {
+			MESSAGE(KERN_WARNING,
+				"unsupported feature: %*s, "
+				"ignoring setting", len, str);
+			rc = -EINVAL;
+		}
+		str += len;
+		if (*str != ':')
+			break;
+		str++;
+	}
+	if (*str != ')') {
+		MESSAGE(KERN_WARNING, "%s",
+			"missing ')' in dasd parameter string\n");
+		rc = -EINVAL;
+	} else
+		str++;
+	*endp = str;
+	if (rc != 0)
+		return rc;
+	return 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 char *
+dasd_parse_keyword( char *parsestring ) {
+
+	char *nextcomma, *residual_str;
+	int length;
+
+	nextcomma = strchr(parsestring,',');
+	if (nextcomma) {
+		length = nextcomma - parsestring;
+		residual_str = nextcomma + 1;
+	} else {
+		length = strlen(parsestring);
+		residual_str = parsestring + length;
+        }
+	if (strncmp ("autodetect", parsestring, length) == 0) {
+		dasd_autodetect = 1;
+		MESSAGE (KERN_INFO, "%s",
+			 "turning to autodetection mode");
+                return residual_str;
+        }
+        if (strncmp ("probeonly", parsestring, length) == 0) {
+		dasd_probeonly = 1;
+		MESSAGE(KERN_INFO, "%s",
+			"turning to probeonly mode");
+                return residual_str;
+        }
+        if (strncmp ("fixedbuffers", parsestring, length) == 0) {
+		if (dasd_page_cache)
+			return residual_str;
+		dasd_page_cache =
+			kmem_cache_create("dasd_page_cache", PAGE_SIZE, 0,
+					  SLAB_CACHE_DMA, NULL, NULL );
+		if (!dasd_page_cache)
+			MESSAGE(KERN_WARNING, "%s", "Failed to create slab, "
+				"fixed buffer mode disabled.");
+		else
+			MESSAGE (KERN_INFO, "%s",
+				 "turning on fixed buffer mode");
+                return residual_str;
+        }
+	return ERR_PTR(-EINVAL);
+}
+
+/*
+ * Try to interprete the first element on the comma separated parse string
+ * as a device number or a range of devices. If the interpretation is
+ * successfull, create the matching dasd_devmap entries and return a pointer
+ * to the residual string.
+ * If interpretation fails or in case of an error, return an error code.
+ */
+static char *
+dasd_parse_range( char *parsestring ) {
+
+	struct dasd_devmap *devmap;
+	int from, from_id0, from_id1;
+	int to, to_id0, to_id1;
+	int features, rc;
+	char bus_id[BUS_ID_SIZE+1], *str;
+
+	str = parsestring;
+	rc = dasd_busid(&str, &from_id0, &from_id1, &from);
+	if (rc == 0) {
+		to = from;
+		to_id0 = from_id0;
+		to_id1 = from_id1;
+		if (*str == '-') {
+			str++;
+			rc = dasd_busid(&str, &to_id0, &to_id1, &to);
+		}
+	}
+	if (rc == 0 &&
+	    (from_id0 != to_id0 || from_id1 != to_id1 || from > to))
+		rc = -EINVAL;
+	if (rc) {
+		MESSAGE(KERN_ERR, "Invalid device range %s", parsestring);
+		return ERR_PTR(rc);
+	}
+	features = dasd_feature_list(str, &str);
+	if (features < 0)
+		return ERR_PTR(-EINVAL);
+	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))
+			return (char *)devmap;
+	}
+	if (*str == ',')
+		return str + 1;
+	if (*str == '\0')
+		return str;
+	MESSAGE(KERN_WARNING,
+		"junk at end of dasd parameter string: %s\n", str);
+	return ERR_PTR(-EINVAL);
+}
+
+static inline char *
+dasd_parse_next_element( char *parsestring ) {
+	char * residual_str;
+	residual_str = dasd_parse_keyword(parsestring);
+	if (!IS_ERR(residual_str))
+		return residual_str;
+	residual_str = dasd_parse_range(parsestring);
+	return residual_str;
+}
+
+/*
+ * Parse parameters stored in dasd[]
+ * The 'dasd=...' parameter allows to specify a comma separated list of
+ * keywords and device ranges. When the dasd driver is build into the kernel,
+ * the complete list will be stored as one element of the dasd[] array.
+ * When the dasd driver is build as a module, then the list is broken into
+ * it's elements and each dasd[] entry contains one element.
+ */
+int
+dasd_parse(void)
+{
+	int rc, i;
+	char *parsestring;
+
+	rc = 0;
+	for (i = 0; i < 256; i++) {
+		if (dasd[i] == NULL)
+			break;
+		parsestring = dasd[i];
+		/* loop over the comma separated list in the parsestring */
+		while (*parsestring) {
+			parsestring = dasd_parse_next_element(parsestring);
+			if(IS_ERR(parsestring)) {
+				rc = PTR_ERR(parsestring);
+				break;
+			}
+		}
+		if (rc) {
+			DBF_EVENT(DBF_ALERT, "%s", "invalid range found");
+			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(char *bus_id, int features)
+{
+	struct dasd_devmap *devmap, *new, *tmp;
+	int hash;
+
+	new = (struct dasd_devmap *)
+		kmalloc(sizeof(struct dasd_devmap), GFP_KERNEL);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+	spin_lock(&dasd_devmap_lock);
+	devmap = 0;
+	hash = dasd_hash_busid(bus_id);
+	list_for_each_entry(tmp, &dasd_hashlists[hash], list)
+		if (strncmp(tmp->bus_id, bus_id, 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, BUS_ID_SIZE);
+		new->features = features;
+		new->device = 0;
+		list_add(&new->list, &dasd_hashlists[hash]);
+		devmap = new;
+		new = 0;
+	}
+	spin_unlock(&dasd_devmap_lock);
+	if (new)
+		kfree(new);
+	return devmap;
+}
+
+/*
+ * Find devmap for device with given bus_id.
+ */
+static struct dasd_devmap *
+dasd_find_busid(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, 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(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) {
+			if (devmap->device != NULL)
+				BUG();
+			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 = 0;
+	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(cdev->dev.bus_id);
+	if (IS_ERR(devmap))
+		devmap = dasd_add_busid(cdev->dev.bus_id,
+					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;
+	int rc;
+
+	devmap = dasd_devmap_from_cdev(cdev);
+	if (IS_ERR(devmap))
+		return (void *) devmap;
+	cdev->dev.driver_data = devmap;
+
+	device = dasd_alloc_device();
+	if (IS_ERR(device))
+		return device;
+	atomic_set(&device->ref_count, 2);
+
+	spin_lock(&dasd_devmap_lock);
+	if (!devmap->device) {
+		devmap->device = device;
+		device->devindex = devmap->devindex;
+		if (devmap->features & DASD_FEATURE_READONLY)
+			set_bit(DASD_FLAG_RO, &device->flags);
+		else
+			clear_bit(DASD_FLAG_RO, &device->flags);
+		if (devmap->features & DASD_FEATURE_USEDIAG)
+			set_bit(DASD_FLAG_USE_DIAG, &device->flags);
+		else
+			clear_bit(DASD_FLAG_USE_DIAG, &device->flags);
+		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);
+	}
+	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;
+
+	/* First remove device pointer from devmap. */
+	devmap = dasd_find_busid(device->cdev->dev.bus_id);
+	if (IS_ERR(devmap))
+		BUG();
+	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);
+
+	/* Drop ref_count by 2, one for the devmap reference and
+	 * one for the passed reference. */
+	atomic_sub(2, &device->ref_count);
+
+	/* Wait for reference counter to drop to zero. */
+	wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0);
+
+	/* Disconnect dasd_device structure from ccw_device structure. */
+	cdev = device->cdev;
+	device->cdev = NULL;
+
+	/* Disconnect dasd_devmap structure from ccw_device structure. */
+	cdev->dev.driver_data = 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);
+}
+
+/*
+ * Return dasd_device structure associated with cdev.
+ */
+struct dasd_device *
+dasd_device_from_cdev(struct ccw_device *cdev)
+{
+	struct dasd_devmap *devmap;
+	struct dasd_device *device;
+
+	device = ERR_PTR(-ENODEV);
+	spin_lock(&dasd_devmap_lock);
+	devmap = cdev->dev.driver_data;
+	if (devmap && devmap->device) {
+		device = devmap->device;
+		dasd_get_device(device);
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return device;
+}
+
+/*
+ * SECTION: files in sysfs
+ */
+
+/*
+ * readonly controls the readonly status of a dasd
+ */
+static ssize_t
+dasd_ro_show(struct device *dev, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int ro_flag;
+
+	devmap = dasd_find_busid(dev->bus_id);
+	if (!IS_ERR(devmap))
+		ro_flag = (devmap->features & DASD_FEATURE_READONLY) != 0;
+	else
+		ro_flag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_READONLY) != 0;
+	return snprintf(buf, PAGE_SIZE, ro_flag ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_ro_store(struct device *dev, const char *buf, size_t count)
+{
+	struct dasd_devmap *devmap;
+	int ro_flag;
+
+	devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+	ro_flag = buf[0] == '1';
+	spin_lock(&dasd_devmap_lock);
+	if (ro_flag)
+		devmap->features |= DASD_FEATURE_READONLY;
+	else
+		devmap->features &= ~DASD_FEATURE_READONLY;
+	if (devmap->device) {
+		if (devmap->device->gdp)
+			set_disk_ro(devmap->device->gdp, ro_flag);
+		if (ro_flag)
+			set_bit(DASD_FLAG_RO, &devmap->device->flags);
+		else
+			clear_bit(DASD_FLAG_RO, &devmap->device->flags);
+	}
+	spin_unlock(&dasd_devmap_lock);
+	return count;
+}
+
+static DEVICE_ATTR(readonly, 0644, dasd_ro_show, dasd_ro_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, char *buf)
+{
+	struct dasd_devmap *devmap;
+	int use_diag;
+
+	devmap = dasd_find_busid(dev->bus_id);
+	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, const char *buf, size_t count)
+{
+	struct dasd_devmap *devmap;
+	ssize_t rc;
+	int use_diag;
+
+	devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(devmap))
+		return PTR_ERR(devmap);
+	use_diag = buf[0] == '1';
+	spin_lock(&dasd_devmap_lock);
+	/* Changing diag discipline flag is only allowed in offline state. */
+	rc = count;
+	if (!devmap->device) {
+		if (use_diag)
+			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);
+
+static ssize_t
+dasd_discipline_show(struct device *dev, char *buf)
+{
+	struct dasd_devmap *devmap;
+	char *dname;
+
+	spin_lock(&dasd_devmap_lock);
+	dname = "none";
+	devmap = dev->driver_data;
+	if (devmap && devmap->device && devmap->device->discipline)
+		dname = devmap->device->discipline->name;
+	spin_unlock(&dasd_devmap_lock);
+	return snprintf(buf, PAGE_SIZE, "%s\n", dname);
+}
+
+static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL);
+
+static struct attribute * dasd_attrs[] = {
+	&dev_attr_readonly.attr,
+	&dev_attr_discipline.attr,
+	&dev_attr_use_diag.attr,
+	NULL,
+};
+
+static struct attribute_group dasd_attr_group = {
+	.attrs = dasd_attrs,
+};
+
+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();
+}